82 results on '"Baer LA"'
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2. Effects of severe burn and muscle disuse on total corticosterone excretion and overall muscle wasting in rats.
- Author
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Baer LA, Wade CE, Getchell S, Silliman DT, Walters TJ, Wolf SE, and Wu X
- Published
- 2008
3. The impact of muscle disuse on muscle atrophy after severe burn in rats.
- Author
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Wu X, Baer LA, Walters TJ, Wade CE, Silliman DT, and Wolf SE
- Published
- 2008
4. Metabolic trade-offs in Neonatal sepsis triggered by TLR4 and TLR1/2 ligands result in unique dysfunctions in neural breathing circuits.
- Author
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Joana Alves M, Browe BM, Carolina Rodrigues Dias A, Torres JM, Zaza G, Bangudi S, Blackburn J, Wang W, de Araujo Fernandes-Junior S, Fadda P, Toland A, Baer LA, Stanford KI, Czeisler C, Garcia AJ 3rd, and Javier Otero J
- Subjects
- Animals, Mice, Lipopeptides pharmacology, Respiration drug effects, Mice, Inbred C57BL, Neurons metabolism, Astrocytes metabolism, Male, Ligands, Microglia metabolism, Female, Inflammation metabolism, Toll-Like Receptor 4 metabolism, Lipopolysaccharides pharmacology, Toll-Like Receptor 2 metabolism, Animals, Newborn, Neonatal Sepsis metabolism, Brain Stem metabolism, Toll-Like Receptor 1 metabolism
- Abstract
Neonatal sepsis remains one of the leading causes of mortality in newborns. Several brainstem-regulated physiological processes undergo disruption during neonatal sepsis. Mechanistic knowledge gaps exist at the interplay between metabolism and immune activation to brainstem neural circuits and pertinent physiological functions in neonates. To delineate this association, we induced systemic inflammation either by TLR4 (LPS) or TLR1/2 (PAM3CSK4) ligand administration in postnatal day 5 mice (PD5). Our findings show that LPS and PAM3CSK4 evoke substantial changes in respiration and metabolism. Physiological trade-offs led to hypometabolic-hypothermic responses due to LPS, but not PAM3CSK4, whereas to both TLR ligands blunted respiratory chemoreflexes. Neuroinflammatory pathways modulation in brainstem showed more robust effects in LPS than PAM3CSK4. Brainstem neurons, microglia, and astrocyte gene expression analyses showed unique responses to TLR ligands. PAM3CSK4 did not significantly modulate gene expression changes in GLAST-1 positive brainstem astrocytes. PD5 pups receiving PAM3CSK4 failed to maintain a prolonged metabolic state repression, which correlated to enhanced gasping latency and impaired autoresuscitation during anoxic chemoreflex challenges. In contrast, LPS administered pups showed no significant changes in anoxic chemoreflex. Electrophysiological studies from brainstem slices prepared from pups exposed to either TLR4 or PAM3CSK4 showed compromised transmission between preBötzinger complex and Hypoglossal as an exclusive response to the TLR1/2 ligand. Spatial gene expression analysis demonstrated a region-specific modulation of PAM3CSK4 within the raphe nucleus relative to other anatomical sites evaluated. Our findings suggest that metabolic changes due to inflammation might be a crucial tolerance mechanism for neonatal sepsis preserving neural control of breathing., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
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5. UCP1-dependent brown adipose activation accelerates cardiac metabolic remodeling and reduces initial hypertrophic and fibrotic responses to pathological stress.
- Author
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Challa AA, Vidal P, Maurya SK, Maurya CK, Baer LA, Wang Y, James NM, Pardeshi PJ, Fasano M, Carley AN, Stanford KI, and Lewandowski ED
- Subjects
- Animals, Mice, Male, Carnitine O-Palmitoyltransferase metabolism, Carnitine O-Palmitoyltransferase genetics, Mice, Inbred C57BL, Cardiomegaly metabolism, Cardiomegaly pathology, Myocardium metabolism, Myocardium pathology, Stress, Physiological, Ventricular Remodeling physiology, Mice, Knockout, Cold Temperature, Adipose Tissue, Brown metabolism, Uncoupling Protein 1 metabolism, Fibrosis metabolism
- Abstract
Brown adipose tissue (BAT) is correlated to cardiovascular health in rodents and humans, but the physiological role of BAT in the initial cardiac remodeling at the onset of stress is unknown. Activation of BAT via 48 h cold (16°C) in mice following transverse aortic constriction (TAC) reduced cardiac gene expression for LCFA uptake and oxidation in male mice and accelerated the onset of cardiac metabolic remodeling, with an early isoform shift of carnitine palmitoyltransferase 1 (CPT1) toward increased CPT1a, reduced entry of long chain fatty acid (LCFA) into oxidative metabolism (0.59 ± 0.02 vs. 0.72 ± 0.02 in RT TAC hearts, p < .05) and increased carbohydrate oxidation with altered glucose transporter content. BAT activation with TAC reduced early hypertrophic expression of β-MHC by 61% versus RT-TAC and reduced pro-fibrotic TGF-β1 and COL3α1 expression. While cardiac natriuretic peptide expression was yet to increase at only 3 days TAC, Nppa and Nppb expression were elevated in Cold TAC versus RT TAC hearts 2.7- and 2.4-fold, respectively. Eliminating BAT thermogenic activation with UCP1 KO mice eliminated differences between Cold TAC and RT TAC hearts, confirming effects of BAT activation rather than autonomous cardiac responses to cold. Female responses to BAT activation were blunted, with limited UCP1 changes with cold, partly due to already activated BAT in females at RT compared to thermoneutrality. These data reveal a previously unknown physiological mechanism of UCP1-dependent BAT activation in attenuating early cardiac hypertrophic and profibrotic signaling and accelerating remodeled metabolic activity in the heart at the onset of cardiac stress., (© 2024 The Author(s). The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.)
- Published
- 2024
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6. Maternal exercise preserves offspring cardiovascular health via oxidative regulation of the ryanodine receptor.
- Author
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Pinckard KM, Félix-Soriano E, Hamilton S, Terentyeva R, Baer LA, Wright KR, Nassal D, Esteves JV, Abay E, Shettigar VK, Ziolo MT, Hund TJ, Wold LE, Terentyev D, and Stanford KI
- Subjects
- Pregnancy, Mice, Female, Animals, Obesity metabolism, Diet, High-Fat adverse effects, Oxidative Stress, Ryanodine Receptor Calcium Release Channel metabolism, Calcium metabolism
- Abstract
Objective: The intrauterine environment during pregnancy is a critical factor in the development of obesity, diabetes, and cardiovascular disease in offspring. Maternal exercise prevents the detrimental effects of a maternal high fat diet on the metabolic health in adult offspring, but the effects of maternal exercise on offspring cardiovascular health have not been thoroughly investigated., Methods: To determine the effects of maternal exercise on offspring cardiovascular health, female mice were fed a chow (C; 21% kcal from fat) or high-fat (H; 60% kcal from fat) diet and further subdivided into sedentary (CS, HS) or wheel exercised (CW, HW) prior to pregnancy and throughout gestation. Offspring were maintained in a sedentary state and chow-fed throughout 52 weeks of age and subjected to serial echocardiography and cardiomyocyte isolation for functional and mechanistic studies., Results: High-fat fed sedentary dams (HS) produced female offspring with reduced ejection fraction (EF) compared to offspring from chow-fed dams (CS), but EF was preserved in offspring from high-fat fed exercised dams (HW) throughout 52 weeks of age. Cardiomyocytes from HW female offspring had increased kinetics, calcium cycling, and respiration compared to CS and HS offspring. HS offspring had increased oxidation of the RyR2 in cardiomyocytes coupled with increased baseline sarcomere length, resulting in RyR2 overactivity, which was negated in female HW offspring., Conclusions: These data suggest a role for maternal exercise to protect against the detrimental effects of a maternal high-fat diet on female offspring cardiac health. Maternal exercise improved female offspring cardiomyocyte contraction, calcium cycling, respiration, RyR2 oxidation, and RyR2 activity. These data present an important, translatable role for maternal exercise to preserve cardiac health of female offspring and provide insight on mechanisms to prevent the transmission of cardiovascular diseases to subsequent generations., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2024 The Author(s). Published by Elsevier GmbH.. All rights reserved.)
- Published
- 2024
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7. Chronic exercise improves hepatic acylcarnitine handling.
- Author
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Hernández-Saavedra D, Hinkley JM, Baer LA, Pinckard KM, Vidal P, Nirengi S, Brennan AM, Chen EY, Narain NR, Bussberg V, Tolstikov VV, Kiebish MA, Markunas C, Ilkayeva O, Goodpaster BH, Newgard CB, Goodyear LJ, Coen PM, and Stanford KI
- Abstract
Exercise mediates tissue metabolic function through direct and indirect adaptations to acylcarnitine (AC) metabolism, but the exact mechanisms are unclear. We found that circulating medium-chain acylcarnitines (AC) (C12-C16) are lower in active/endurance trained human subjects compared to sedentary controls, and this is correlated with elevated cardiorespiratory fitness and reduced adiposity. In mice, exercise reduced serum AC and increased liver AC, and this was accompanied by a marked increase in expression of genes involved in hepatic AC metabolism and mitochondrial β-oxidation. Primary hepatocytes from high-fat fed, exercise trained mice had increased basal respiration compared to hepatocytes from high-fat fed sedentary mice, which may be attributed to increased Ca
2+ cycling and lipid uptake into mitochondria. The addition of specific medium- and long-chain AC to sedentary hepatocytes increased mitochondrial respiration, mirroring the exercise phenotype. These data indicate that AC redistribution is an exercise-induced mechanism to improve hepatic function and metabolism., Competing Interests: P.M.C. is a consultant for Astellas/Mitobridge, Incorporate. K.I.S. is a consultant for Lygenesis., (© 2024 The Author(s).)- Published
- 2024
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8. Transplantation of committed pre-adipocytes from brown adipose tissue improves whole-body glucose homeostasis.
- Author
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Dewal RS, Yang FT, Baer LA, Vidal P, Hernandez-Saavedra D, Seculov NP, Ghosh A, Noé F, Togliatti O, Hughes L, DeBari MK, West MD, Soroko R, Sternberg H, Malik NN, Puchulu-Campanella E, Wang H, Yan P, Wolfrum C, Abbott RD, and Stanford KI
- Abstract
Obesity and its co-morbidities including type 2 diabetes are increasing at epidemic rates in the U.S. and worldwide. Brown adipose tissue (BAT) is a potential therapeutic to combat obesity and type 2 diabetes. Increasing BAT mass by transplantation improves metabolic health in rodents, but its clinical translation remains a challenge. Here, we investigated if transplantation of 2-4 million differentiated brown pre-adipocytes from mouse BAT stromal fraction (SVF) or human pluripotent stem cells (hPSCs) could improve metabolic health. Transplantation of differentiated brown pre-adipocytes, termed "committed pre-adipocytes" from BAT SVF from mice or derived from hPSCs improves glucose homeostasis and insulin sensitivity in recipient mice under conditions of diet-induced obesity, and this improvement is mediated through the collaborative actions of the liver transcriptome, tissue AKT signaling, and FGF21. These data demonstrate that transplantation of a small number of brown adipocytes has significant long-term translational and therapeutic potential to improve glucose metabolism., Competing Interests: M.D.W., R.S., H.S., and N.N.M. are employed by AgeX Therapeutics., (© 2024 The Author(s).)
- Published
- 2024
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9. Hepatic protein kinase Cbeta deficiency mitigates late-onset obesity.
- Author
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Shu Y, Gumma N, Hassan F, Branch DA, Baer LA, Ostrowski MC, Stanford KI, Baskin KK, and Mehta KD
- Subjects
- Animals, Mice, Adipose Tissue, Brown metabolism, Adipose Tissue, White metabolism, Diet, High-Fat adverse effects, Energy Metabolism genetics, Mice, Inbred C57BL, Oxidation-Reduction, Gene Expression Regulation, Enzymologic, Aging, Signal Transduction, Liver metabolism, Liver pathology, Obesity genetics, Obesity metabolism, Obesity pathology, Protein Kinase C beta deficiency, Protein Kinase C beta genetics, Protein Kinase C beta metabolism
- Abstract
Although aging is associated with progressive adiposity and a decline in liver function, the underlying molecular mechanisms and metabolic interplay are incompletely understood. Here, we demonstrate that aging induces hepatic protein kinase Cbeta (PKCβ) expression, while hepatocyte PKCβ deficiency (PKCβ
Hep-/- ) in mice significantly attenuates obesity in aged mice fed a high-fat diet. Compared with control PKCβfl/fl mice, PKCβHep-/- mice showed elevated energy expenditure with augmentation of oxygen consumption and carbon dioxide production which was dependent on β3-adrenergic receptor signaling, thereby favoring negative energy balance. This effect was accompanied by induction of thermogenic genes in brown adipose tissue (BAT) and increased BAT respiratory capacity, as well as a shift to oxidative muscle fiber type with an improved mitochondrial function, thereby enhancing oxidative capacity of thermogenic tissues. Furthermore, in PKCβHep-/- mice, we determined that PKCβ overexpression in the liver mitigated elevated expression of thermogenic genes in BAT. In conclusion, our study thus establishes hepatocyte PKCβ induction as a critical component of pathophysiological energy metabolism by promoting progressive hepatic and extrahepatic metabolic derangements in energy homeostasis, contributing to late-onset obesity. These findings have potential implications for augmenting thermogenesis as a means of combating aging-induced obesity., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2023
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10. Exercise training after myocardial infarction increases survival but does not prevent adverse left ventricle remodeling and dysfunction in high-fat diet fed mice.
- Author
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Peres Valgas Da Silva C, Shettigar VK, Baer LA, Abay E, Pinckard KM, Vinales J, Sturgill SL, Vidal P, Ziolo MT, and Stanford KI
- Subjects
- Animals, Male, Mice, Diet, High-Fat adverse effects, Fibrosis, Mice, Inbred C57BL, Obesity, Ventricular Remodeling, Myocardial Infarction metabolism, Physical Conditioning, Animal
- Abstract
Aims: Aerobic exercise is an important component of rehabilitation after cardiovascular injuries including myocardial infarction (MI). In human studies, the beneficial effects of exercise after an MI are blunted in patients who are obese or glucose intolerant. Here, we investigated the effects of exercise on MI-induced cardiac dysfunction and remodeling in mice chronically fed a high-fat diet (HFD)., Main Methods: C57Bl/6 male mice were fed either a standard (Chow; 21% kcal/fat) or HFD (60% kcal/fat) for 36 weeks. After 24 weeks of diet, the HFD mice were randomly subjected to an MI (MI) or a sham surgery (Sham). Following the MI or sham surgery, a subset of mice were subjected to treadmill exercise., Key Findings: HFD resulted in obesity and glucose intolerance, and this was not altered by exercise or MI. MI resulted in decreased ejection fraction, increased left ventricle mass, increased end systolic and diastolic diameters, increased cardiac fibrosis, and increased expression of genes involved in cardiac hypertrophy and heart failure in the MI-Sed and MI-Exe mice. Exercise prevented HFD-induced cardiac fibrosis in Sham mice (Sham-Exe) but not in MI-Exe mice. Exercise did, however, reduce post-MI mortality., Significance: These data indicate that exercise significantly increased survival after MI in a model of diet-induced obesity independent of effects on cardiac function. These data have important translational ramifications because they demonstrate that environmental interventions, including diet, need to be carefully evaluated and taken into consideration to support the effects of exercise in the cardiac rehabilitation of patients who are obese., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2022
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11. Maternal Exercise and Paternal Exercise Induce Distinct Metabolite Signatures in Offspring Tissues.
- Author
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Hernández-Saavedra D, Markunas C, Takahashi H, Baer LA, Harris JE, Hirshman MF, Ilkayeva O, Newgard CB, Stanford KI, and Goodyear LJ
- Subjects
- Animals, Fatty Acids, Female, Glucose metabolism, Liver metabolism, Male, Diet, High-Fat adverse effects, Physical Conditioning, Animal physiology
- Abstract
That maternal and paternal exercise improve the metabolic health of adult offspring is well established. Tissue and serum metabolites play a fundamental role in the health of an organism, but how parental exercise affects offspring tissue and serum metabolites has not yet been investigated. Here, male and female breeders were fed a high-fat diet and housed with or without running wheels before breeding (males) and before and during gestation (females). Offspring were sedentary and chow fed, with parents as follows: sedentary (Sed), maternal exercise (MatEx), paternal exercise (PatEx), or maternal+paternal exercise (Mat+PatEx). Adult offspring from all parental exercise groups had similar improvement in glucose tolerance and hepatic glucose production. Targeted metabolomics was performed in offspring serum, liver, and triceps muscle. Offspring from MatEx, PatEx, and Mat+PatEx each had a unique tissue metabolite signature, but Mat+PatEx offspring had an additive phenotype relative to MatEx or PatEx alone in a subset of liver and muscle metabolites. Tissue metabolites consistently indicated that the metabolites altered with parental exercise contribute to enhanced fatty acid oxidation. These data identify distinct tissue-specific adaptations and mechanisms for parental exercise-induced improvement in offspring metabolic health. Further mining of this data set could aid the development of novel therapeutic targets to combat metabolic diseases., (© 2022 by the American Diabetes Association.)
- Published
- 2022
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12. Interferon gamma mediates the reduction of adipose tissue regulatory T cells in human obesity.
- Author
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Bradley D, Smith AJ, Blaszczak A, Shantaram D, Bergin SM, Jalilvand A, Wright V, Wyne KL, Dewal RS, Baer LA, Wright KR, Stanford KI, Needleman B, Brethauer S, Noria S, Renton D, Joseph JJ, Lovett-Racke A, Liu J, and Hsueh WA
- Subjects
- Adipose Tissue metabolism, Animals, Humans, Interferon-gamma metabolism, Mice, Mice, Inbred C57BL, Mice, Obese, Obesity metabolism, Programmed Cell Death 1 Receptor metabolism, T-Lymphocytes, Regulatory metabolism, Insulin Resistance
- Abstract
Decreased adipose tissue regulatory T cells contribute to insulin resistance in obese mice, however, little is known about the mechanisms regulating adipose tissue regulatory T cells numbers in humans. Here we obtain adipose tissue from obese and lean volunteers. Regulatory T cell abundance is lower in obese vs. lean visceral and subcutaneous adipose tissue and associates with reduced insulin sensitivity and altered adipocyte metabolic gene expression. Regulatory T cells numbers decline following high-fat diet induction in lean volunteers. We see alteration in major histocompatibility complex II pathway in adipocytes from obese patients and after high fat ingestion, which increases T helper 1 cell numbers and decreases regulatory T cell differentiation. We also observe increased expression of inhibitory co-receptors including programmed cell death protein 1 and OX40 in visceral adipose tissue regulatory T cells from patients with obesity. In human obesity, these global effects of interferon gamma to reduce regulatory T cells and diminish their function appear to instigate adipose inflammation and suppress adipocyte metabolism, leading to insulin resistance., (© 2022. The Author(s).)
- Published
- 2022
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13. Differential Responses to Sigma-1 or Sigma-2 Receptor Ablation in Adiposity, Fat Oxidation, and Sexual Dimorphism.
- Author
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Li J, Félix-Soriano E, Wright KR, Shen H, Baer LA, Stanford KI, and Guo LW
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- Adiposity, Animals, Carbon Dioxide pharmacology, Diet, High-Fat, Female, Glucose pharmacology, Male, Mice, Mice, Inbred C57BL, Obesity genetics, Receptors, sigma genetics, Sex Characteristics, Sigma-1 Receptor, COVID-19, Insulins metabolism, Receptors, sigma metabolism
- Abstract
Obesity is increasing at epidemic rates across the US and worldwide, as are its co-morbidities, including type-2 diabetes and cardiovascular disease. Thus, targeted interventions to reduce the prevalence of obesity are of the utmost importance. The sigma-1 receptor (S1R) and sigma-2 receptor (S2R; encoded by Tmem97 ) belong to the same class of drug-binding sites, yet they are genetically distinct. There are multiple ongoing clinical trials focused on sigma receptors, targeting diseases ranging from Alzheimer's disease through chronic pain to COVID-19. However, little is known regarding their gene-specific role in obesity. In this study, we measured body composition, used a comprehensive laboratory-animal monitoring system, and determined the glucose and insulin tolerance in mice fed a high-fat diet. Compared to Sigmar1+/+ mice of the same sex, the male and female Sigmar1-/- mice had lower fat mass (17% and 12% lower, respectively), and elevated lean mass (16% and 10% higher, respectively), but S1R ablation had no effect on their metabolism. The male Tmem97-/- mice exhibited 7% lower fat mass, 8% higher lean mass, increased volumes of O
2 and CO2 , a decreased respiratory exchange ratio indicating elevated fatty-acid oxidation, and improved insulin tolerance, compared to the male Tmem97+/+ mice. There were no changes in any of these parameters in the female Tmem97-/- mice. Together, these data indicate that the S1R ablation in male and female mice or the S2R ablation in male mice protects against diet-induced adiposity, and that S2R ablation, but not S1R deletion, improves insulin tolerance and enhances fatty-acid oxidation in male mice. Further mechanistic investigations may lead to translational strategies to target differential S1R/S2R regulations and sexual dimorphism for precision treatments of obesity.- Published
- 2022
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14. Distinct Effects of High-Fat and High-Phosphate Diet on Glucose Metabolism and the Response to Voluntary Exercise in Male Mice.
- Author
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Vidal P, Baer LA, Félix-Soriano E, Yang FT, Branch DA, Baskin KK, and Stanford KI
- Subjects
- Animals, Diet, High-Fat adverse effects, Glucose metabolism, Male, Mice, Mice, Inbred C57BL, Phosphates, Physical Conditioning, Animal physiology
- Abstract
The prevalence of metabolic diseases is rapidly increasing and a principal contributor to this is diet, including increased consumption of energy-rich foods and foods with added phosphates. Exercise is an effective therapeutic approach to combat metabolic disease. While exercise is effective to combat the detrimental effects of a high-fat diet on metabolic health, the effects of exercise on a high-phosphate diet have not been thoroughly investigated. Here, we investigated the effects of a high-fat or high-phosphate diet in the presence or absence of voluntary exercise on metabolic function in male mice. To do this, mice were fed a low-fat, normal-phosphate diet (LFPD), a high-phosphate diet (HPD) or a high-fat diet (HFD) for 6 weeks and then subdivided into either sedentary or exercised (housed with running wheels) for an additional 8 weeks. An HFD severely impaired metabolic function in mice, increasing total fat mass and worsening whole-body glucose tolerance, while HPD did not induce any notable effects on glucose metabolism. Exercise reverted most of the detrimental metabolic adaptations induced by HFD, decreasing total fat mass and restoring whole-body glucose tolerance and insulin sensitivity. Interestingly, voluntary exercise had a similar effect on LFPD and HPD mice. These data suggest that a high-phosphate diet does not significantly impair glucose metabolism in sedentary or voluntary exercised conditions.
- Published
- 2022
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15. Brown adipose tissue prevents glucose intolerance and cardiac remodeling in high-fat-fed mice after a mild myocardial infarction.
- Author
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Peres Valgas da Silva C, Shettigar VK, Baer LA, Abay E, Madaris KL, Mehling MR, Hernandez-Saavedra D, Pinckard KM, Seculov NP, Ziolo MT, and Stanford KI
- Subjects
- Adipose Tissue, Brown physiopathology, Animals, Diet, High-Fat methods, Diet, High-Fat statistics & numerical data, Disease Models, Animal, Glucose Intolerance metabolism, Glucose Intolerance physiopathology, Mice, Mice, Inbred C57BL growth & development, Mice, Inbred C57BL metabolism, Myocardial Infarction physiopathology, Polymerase Chain Reaction methods, Polymerase Chain Reaction statistics & numerical data, Adipose Tissue, Brown metabolism, Glucose Intolerance prevention & control, Myocardial Infarction complications, Ventricular Remodeling physiology
- Abstract
Background: Obesity increases the risk of developing impaired glucose tolerance (IGT) and type 2 diabetes (T2D) after myocardial infarction (MI). Brown adipose tissue (BAT) is important to combat obesity and T2D, and increasing BAT mass by transplantation improves glucose metabolism and cardiac function. The objective of this study was to determine if BAT had a protective effect on glucose tolerance and cardiac function in high-fat diet (HFD) fed mice subjected to a mild MI., Methods: Male C57BL/6 mice were fed a HFD for eight weeks and then divided into Sham (Sham-operated) and +BAT (mice receiving 0.1 g BAT into their visceral cavity). Sixteen weeks post-transplantation, mice were further subdivided into ±MI (Sham; Sham-MI; +BAT; +BAT-MI) and maintained on a HFD. Cardiac (echocardiography) and metabolic function (glucose and insulin tolerance tests, body composition and exercise tolerance) were assessed throughout 22 weeks post-MI. Quantitative PCR (qPCR) was performed to determine the expression of genes related to metabolic function of perigonadal adipose tissue (pgWAT), subcutaneous white adipose tissue (scWAT), liver, heart, tibialis anterior skeletal muscle (TA); and BAT., Results: +BAT prevented the increase in left ventricle mass (LVM) and exercise intolerance in response to MI. Similar to what is observed in humans, Sham-MI mice developed IGT post-MI, but this was negated in +BAT-MI mice. IGT was independent of changes in body composition. Genes involved in inflammation, insulin resistance, and metabolism were significantly altered in pgWAT, scWAT, and liver in Sham-MI mice compared to all other groups., Conclusions: BAT transplantation prevents IGT, the increase in LVM, and exercise intolerance following MI. MI alters the expression of several metabolic-related genes in WAT and liver in Sham-MI mice, suggesting that these tissues may contribute to the impaired metabolic response. Increasing BAT may be an important intervention to prevent the development of IGT or T2D and cardiac remodeling in obese patients post-MI., (© 2021. The Author(s).)
- Published
- 2022
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16. Metabolic shifts modulate lung injury caused by infection with H1N1 influenza A virus.
- Author
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Nolan KE, Baer LA, Karekar P, Nelson AM, Stanford KI, Doolittle LM, Rosas LE, Hickman-Davis JM, Singh H, and Davis IC
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- Animals, Female, Lung chemistry, Lung virology, Lung Injury prevention & control, Male, Mice, Mice, Inbred C57BL, Pyruvate Dehydrogenase Acetyl-Transferring Kinase antagonists & inhibitors, Tyrosine analogs & derivatives, Tyrosine analysis, Tyrosine metabolism, Virus Replication, Epithelial Cells metabolism, Glycolysis, Influenza A Virus, H1N1 Subtype pathogenicity, Lung metabolism, Lung Injury virology
- Abstract
Influenza A virus (IAV) infection alters lung epithelial cell metabolism in vitro by promoting a glycolytic shift. We hypothesized that this shift benefits the virus rather than the host and that inhibition of glycolysis would improve infection outcomes. A/WSN/33 IAV-inoculated C57BL/6 mice were treated daily from 1 day post-inoculation (d.p.i.) with 2-deoxy-d-glucose (2-DG) to inhibit glycolysis and with the pyruvate dehydrogenase kinase (PDK) inhibitor dichloroacetate (DCA) to promote flux through the TCA cycle. To block OXPHOS, mice were treated every other day from 1 d.p.i. with the Complex I inhibitor rotenone (ROT). 2-DG significantly decreased nocturnal activity, reduced respiratory exchange ratios, worsened hypoxemia, exacerbated lung dysfunction, and increased humoral inflammation at 6 d.p.i. DCA and ROT treatment normalized oxygenation and airway resistance and attenuated IAV-induced pulmonary edema, histopathology, and nitrotyrosine formation. None of the treatments altered viral replication. These data suggest that a shift to glycolysis is host-protective in influenza., (Copyright © 2021 Elsevier Inc. All rights reserved.)
- Published
- 2021
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17. Phospho-ablation of cardiac sodium channel Na v 1.5 mitigates susceptibility to atrial fibrillation and improves glucose homeostasis under conditions of diet-induced obesity.
- Author
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Dewal RS, Greer-Short A, Lane C, Nirengi S, Manzano PA, Hernández-Saavedra D, Wright KR, Nassal D, Baer LA, Mohler PJ, Hund TJ, and Stanford KI
- Subjects
- Animals, Diet, High-Fat adverse effects, Gene Knock-In Techniques, Glucose metabolism, Homeostasis, Male, Mexiletine pharmacology, Mice, Mice, Inbred C57BL, NAV1.5 Voltage-Gated Sodium Channel genetics, Phosphorylation, Atrial Fibrillation prevention & control, Calcium-Calmodulin-Dependent Protein Kinase Type 2 metabolism, NAV1.5 Voltage-Gated Sodium Channel metabolism, Obesity physiopathology
- Abstract
Background: Atrial fibrillation (AF) is the most common sustained arrhythmia, with growing evidence identifying obesity as an important risk factor for the development of AF. Although defective atrial myocyte excitability due to stress-induced remodeling of ion channels is commonly observed in the setting of AF, little is known about the mechanistic link between obesity and AF. Recent studies have identified increased cardiac late sodium current (I
Na,L ) downstream of calmodulin-dependent kinase II (CaMKII) activation as an important driver of AF susceptibility., Methods: Here, we investigated a possible role for CaMKII-dependent INa,L in obesity-induced AF using wild-type (WT) and whole-body knock-in mice that ablates phosphorylation of the Nav 1.5 sodium channel and prevents augmentation of the late sodium current (S571A; SA mice)., Results: A high-fat diet (HFD) increased susceptibility to arrhythmias in WT mice, while SA mice were protected from this effect. Unexpectedly, SA mice had improved glucose homeostasis and decreased body weight compared to WT mice. However, SA mice also had reduced food consumption compared to WT mice. Controlling for food consumption through pair feeding of WT and SA mice abrogated differences in weight gain and AF inducibility, but not atrial fibrosis, premature atrial contractions or metabolic capacity., Conclusions: These data demonstrate a novel role for CaMKII-dependent regulation of Nav 1.5 in mediating susceptibility to arrhythmias and whole-body metabolism under conditions of diet-induced obesity.- Published
- 2021
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18. A Novel Endocrine Role for the BAT-Released Lipokine 12,13-diHOME to Mediate Cardiac Function.
- Author
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Pinckard KM, Shettigar VK, Wright KR, Abay E, Baer LA, Vidal P, Dewal RS, Das D, Duarte-Sanmiguel S, Hernández-Saavedra D, Arts PJ, Lehnig AC, Bussberg V, Narain NR, Kiebish MA, Yi F, Sparks LM, Goodpaster BH, Smith SR, Pratley RE, Lewandowski ED, Raman SV, Wold LE, Gallego-Perez D, Coen PM, Ziolo MT, and Stanford KI
- Subjects
- Aged, Animals, Cells, Cultured, Cohort Studies, Female, Humans, Male, Mice, Mice, Inbred C57BL, Middle Aged, Oleic Acids administration & dosage, Physical Conditioning, Animal methods, Physical Conditioning, Animal physiology, Adipose Tissue, Brown metabolism, Adipose Tissue, Brown transplantation, Heart Failure metabolism, Heart Failure therapy, Lipidomics methods, Oleic Acids metabolism
- Abstract
Background: Brown adipose tissue (BAT) is an important tissue for thermogenesis, making it a potential target to decrease the risks of obesity, type 2 diabetes, and cardiovascular disease, and recent studies have also identified BAT as an endocrine organ. Although BAT has been implicated to be protective in cardiovascular disease, to this point there are no studies that identify a direct role for BAT to mediate cardiac function., Methods: To determine the role of BAT on cardiac function, we utilized a model of BAT transplantation. We then performed lipidomics and identified an increase in the lipokine 12,13-dihydroxy-9Z-octadecenoic acid (12,13-diHOME). We utilized a mouse model with sustained overexpression of 12,13-diHOME and investigated the role of 12,13-diHOME in a nitric oxide synthase type 1 deficient (NOS1
-/- ) mouse and in isolated cardiomyocytes to determine effects on function and respiration. We also investigated 12,13-diHOME in a cohort of human patients with heart disease., Results: Here, we determined that transplantation of BAT (+BAT) improves cardiac function via the release of the lipokine 12,13-diHOME. Sustained overexpression of 12,13-diHOME using tissue nanotransfection negated the deleterious effects of a high-fat diet on cardiac function and remodeling, and acute injection of 12,13-diHOME increased cardiac hemodynamics via direct effects on the cardiomyocyte. Furthermore, incubation of cardiomyocytes with 12,13-diHOME increased mitochondrial respiration. The effects of 12,13-diHOME were absent in NOS1-/- mice and cardiomyocytes. We also provide the first evidence that 12,13-diHOME is decreased in human patients with heart disease., Conclusions: Our results identify an endocrine role for BAT to enhance cardiac function that is mediated by regulation of calcium cycling via 12,13-diHOME and NOS1.- Published
- 2021
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19. Neonatal apneic phenotype in a murine congenital central hypoventilation syndrome model is induced through non-cell autonomous developmental mechanisms.
- Author
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Alzate-Correa D, Mei-Ling Liu J, Jones M, Silva TM, Alves MJ, Burke E, Zuñiga J, Kaya B, Zaza G, Aslan MT, Blackburn J, Shimada MY, Fernandes-Junior SA, Baer LA, Stanford KI, Kempton A, Smith S, Szujewski CC, Silbaugh A, Viemari JC, Takakura AC, Garcia AJ 3rd, Moreira TS, Czeisler CM, and Otero JJ
- Subjects
- Animals, Animals, Newborn, Apnea etiology, Disease Models, Animal, Hypoventilation complications, Hypoventilation physiopathology, Mice, Phenotype, Sleep Apnea, Central complications, Apnea physiopathology, Homeodomain Proteins metabolism, Hypoventilation congenital, Motor Neurons metabolism, Neurogenesis physiology, Sleep Apnea, Central physiopathology, Transcription Factors metabolism
- Abstract
Congenital central hypoventilation syndrome (CCHS) represents a rare genetic disorder usually caused by mutations in the homeodomain transcription factor PHOX2B. Some CCHS patients suffer mainly from deficiencies in CO
2 and/or O2 respiratory chemoreflex, whereas other patients present with full apnea shortly after birth. Our goal was to identify the neuropathological mechanisms of apneic presentations in CCHS. In the developing murine neuroepithelium, Phox2b is expressed in three discrete progenitor domains across the dorsal-ventral axis, with different domains responsible for producing unique autonomic or visceral motor neurons. Restricting the expression of mutant Phox2b to the ventral visceral motor neuron domain induces marked newborn apnea together with a significant loss of visceral motor neurons, RTN ablation, and preBötzinger complex dysfunction. This finding suggests that the observed apnea develops through non-cell autonomous developmental mechanisms. Mutant Phox2b expression in dorsal rhombencephalic neurons did not generate significant respiratory dysfunction, but did result in subtle metabolic thermoregulatory deficiencies. We confirm the expression of a novel murine Phox2b splice variant which shares exons 1 and 2 with the more widely studied Phox2b splice variant, but which differs in exon 3 where most CCHS mutations occur. We also show that mutant Phox2b expression in the visceral motor neuron progenitor domain increases cell proliferation at the expense of visceral motor neuron development. We propose that visceral motor neurons may function as organizers of brainstem respiratory neuron development, and that disruptions in their development result in secondary/non-cell autonomous maldevelopment of key brainstem respiratory neurons., (© 2020 International Society of Neuropathology.)- Published
- 2021
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20. Exercise-induced 3'-sialyllactose in breast milk is a critical mediator to improve metabolic health and cardiac function in mouse offspring.
- Author
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Harris JE, Pinckard KM, Wright KR, Baer LA, Arts PJ, Abay E, Shettigar VK, Lehnig AC, Robertson B, Madaris K, Canova TJ, Sims C, Goodyear LJ, Andres A, Ziolo MT, Bode L, and Stanford KI
- Subjects
- Adult, Animals, Body Composition, Diet, High-Fat adverse effects, Exercise physiology, Female, Gene Expression Regulation genetics, Humans, Mice, Mice, Inbred C57BL, Mice, Knockout, Milk, Human chemistry, Myocardium metabolism, Oligosaccharides analysis, Oligosaccharides chemistry, Oligosaccharides genetics, Health Status, Heart physiology, Milk chemistry, Oligosaccharides metabolism, Physical Conditioning, Animal physiology
- Abstract
Poor maternal environments, such as under- or overnutrition, can increase the risk for the development of obesity, type 2 diabetes and cardiovascular disease in offspring
1-9 . Recent studies in animal models have shown that maternal exercise before and during pregnancy abolishes the age-related development of impaired glucose metabolism10-15 , decreased cardiovascular function16 and increased adiposity11,15 ; however, the underlying mechanisms for maternal exercise to improve offspring's health have not been identified. In the present study, we identify an exercise-induced increase in the oligosaccharide 3'-sialyllactose (3'-SL) in milk in humans and mice, and show that the beneficial effects of maternal exercise on mouse offspring's metabolic health and cardiac function are mediated by 3'-SL. In global 3'-SL knockout mice (3'-SL-/- ), maternal exercise training failed to improve offspring metabolic health or cardiac function in mice. There was no beneficial effect of maternal exercise on wild-type offspring who consumed milk from exercise-trained 3'-SL-/- dams, whereas supplementing 3'-SL during lactation to wild-type mice improved metabolic health and cardiac function in offspring during adulthood. Importantly, supplementation of 3'-SL negated the detrimental effects of a high-fat diet on body composition and metabolism. The present study reveals a critical role for the oligosaccharide 3'-SL in milk to mediate the effects of maternal exercise on offspring's health. 3'-SL supplementation is a potential therapeutic approach to combat the development of obesity, type 2 diabetes and cardiovascular disease.- Published
- 2020
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21. Amino acid-based compound activates atypical PKC and leptin receptor pathways to improve glycemia and anxiety like behavior in diabetic mice.
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Lee A, Sun Y, Lin T, Song NJ, Mason ML, Leung JH, Kowdley D, Wall J, Brunetti A, Fitzgerald J, Baer LA, Stanford KI, Ortega-Anaya J, Gomes-Dias L, Needleman B, Noria S, Weil Z, Blakeslee JJ, Jiménez-Flores R, Parquette JR, and Ziouzenkova O
- Subjects
- Amino Acids, Animals, Anxiety, Insulin, Mice, Mice, Inbred C57BL, Receptors, Leptin, Blood Glucose, Diabetes Mellitus, Experimental drug therapy
- Abstract
Differences in glucose uptake in peripheral and neural tissues account for the reduced efficacy of insulin in nervous tissues. Herein, we report the design of short peptides, referred as amino acid compounds (AAC) with and without a modified side chain moiety. At nanomolar concentrations, a candidate therapeutic molecule, AAC2, containing a 7-(diethylamino) coumarin-3-carboxamide side-chain improved glucose control in human peripheral adipocytes and the endothelial brain barrier cells by activation of insulin-insensitive glucose transporter 1 (GLUT1). AAC2 interacted specifically with the leptin receptor (LepR) and activated atypical protein kinase C zeta (PKCς) to increase glucose uptake. The effects induced by AAC2 were absent in leptin receptor-deficient predipocytes and in Lepr
db mice. In contrast, AAC2 established glycemic control altering food intake in leptin-deficient Lepob mice. Therefore, AAC2 activated the LepR and acted in a cytokine-like manner distinct from leptin. In a monogenic Ins2Akita mouse model for the phenotypes associated with type 1 diabetes, AAC2 rescued systemic glucose uptake in these mice without an increase in insulin levels and adiposity, as seen in insulin-treated Ins2Akita mice. In contrast to insulin, AAC2 treatment increased brain mass and reduced anxiety-related behavior in Ins2Akita mice. Our data suggests that the unique mechanism of action for AAC2, activating LepR/PKCς/GLUT1 axis, offers an effective strategy to broaden glycemic control for the prevention of diabetic complications of the nervous system and, possibly, other insulin insensitive or resistant tissues., Competing Interests: Declaration of competing interest The authors declare no competing financial interests., (Copyright © 2020 Elsevier Ltd. All rights reserved.)- Published
- 2020
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22. Exercise does not ameliorate cardiac dysfunction in obese mice exposed to fine particulate matter.
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Grimmer JA, Tanwar V, Youtz DJ, Adelstein JM, Baine SH, Carnes CA, Baer LA, Stanford KI, and Wold LE
- Subjects
- Air Pollutants, Animals, Cardiovascular Diseases etiology, Cardiovascular Diseases metabolism, Heart Diseases etiology, Male, Mice, Mice, Inbred C57BL, Mice, Obese, Myocytes, Cardiac, Particle Size, Physical Conditioning, Animal physiology, Heart Diseases metabolism, Obesity metabolism, Particulate Matter adverse effects
- Abstract
Background: Studies have demonstrated that exposure to fine particulate matter (PM
2.5 ) is linked to cardiovascular disease (CVD), which is exacerbated in patients with pre-existing conditions such as obesity. In the present study, we examined cardiac function of obese mice exposed to PM2.5 and determined if mild exercise affected cardiac function., Methods: Obese mice (ob/ob) (leptin deficient, C57BL/6J background) were exposed to either filtered air (FA) or PM2.5 at an average concentration of 32 μg/m3 for 6 h/day, 5 days/week for 9 months. Following exposure, mice were divided into four groups: (1) FA sedentary, (2) FA treadmill exercise, (3) PM2.5 sedentary, and (4) PM2.5 treadmill exercise and all mice were analyzed after 8 weeks of exercise training., Results: Echocardiography showed increased left ventricular end systolic (LVESd) and diastolic (LVEDd) diameters in PM2.5 sedentary mice compared to FA sedentary mice. There was increased expression of ICAM1, VCAM and CRP markers in sedentary PM2.5 mice compared to FA mice. Both FA and PM2.5 exercised mice showed decreased posterior wall thickness in systole compared to FA sedentary mice, coupled with altered expression of inflammatory markers following exercise., Conclusion: Obese mice exposed to PM2.5 for 9 months showed cardiac dysfunction, which was not improved following mild exercise training., (Copyright © 2019 Elsevier Inc. All rights reserved.)- Published
- 2019
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23. Insulin and exercise improved muscle function in rats with severe burns and hindlimb unloading.
- Author
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Song J, Baer LA, Threlkeld MRS, Geng C, Wade CE, and Wolf SE
- Subjects
- 3-Phosphoinositide-Dependent Protein Kinases genetics, 3-Phosphoinositide-Dependent Protein Kinases metabolism, Animals, Burns drug therapy, Elongation Factor 2 Kinase genetics, Elongation Factor 2 Kinase metabolism, Glycogen Synthase Kinase 3 beta genetics, Glycogen Synthase Kinase 3 beta metabolism, Hindlimb Suspension methods, Insulin administration & dosage, Male, Muscle Contraction, Muscle Proteins genetics, Muscle Proteins metabolism, Muscle, Skeletal physiopathology, Rats, Rats, Sprague-Dawley, TOR Serine-Threonine Kinases genetics, TOR Serine-Threonine Kinases metabolism, Tripartite Motif Proteins genetics, Tripartite Motif Proteins metabolism, Ubiquitin-Protein Ligases genetics, Ubiquitin-Protein Ligases metabolism, Burns therapy, Insulin therapeutic use, Muscle, Skeletal metabolism, Physical Conditioning, Animal methods
- Abstract
Prior work established that exercise alleviates muscle function loss in a clinically relevant rodent model mimicking the clinical sequelae of severely burned patients. On the basis of these data, we posit that pharmacologic treatment with insulin combined with exercise further mitigates loss of muscle function following severe burn with immobilization. Twenty-four Sprague-Dawley rats were assessed and trained to complete a climbing exercise. All rats followed a standardized protocol to mimic severe burn patients (40% total body surface area scald burn); all rats were immediately placed into a hindlimb unloading apparatus to simulate bedrest. The rats were then randomly assigned to four treatment groups: saline vehicle injection without exercise (VEH/NEX), insulin (5 U/kg) injection without exercise (INS/NEX), saline vehicle with daily exercise (VEH/EX), and insulin with daily exercise (INS/EX). The animals were assessed for 14 days following injury. The groups were compared for multiple variables. Isometric tetanic (Po) and twitch (Pt) forces were significantly elevated in the plantaris and soleus muscles of the INS/EX rats (P < 0.05). Genomic analysis revealed mechanistic causes with specific candidate changes. Molecular analysis of INS/EX rats revealed Akt phosphorylated by PDPK1 was increased with this treatment, and it further activated downstream signals mTOR, eEF2, and GSK3-β (P < 0.05). Furthermore, muscle RING-finger protein-1 (MuRF-1), an E3 ubiquitin ligase, was reduced in the INS/EX group (P < 0.05). Insulin and resistance exercise have a positive combined effect on the muscle function recovery in this clinically relevant rodent model of severe burn. Both treatments altered signaling pathways of increasing protein synthesis and decreasing protein degradation., (© 2019 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.)
- Published
- 2019
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24. Absences of Endothelial Microvesicle Changes in the Presence of the Endotheliopathy of Trauma.
- Author
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Wade CE, Matijevic N, Wang YW, Rodriguez EG, Lopez E, Ostrowski SR, Cardenas JC, Baer LA, Chen TA, Tomasek JS, Henriksen HH, Stensballe J, Cotton BA, Holcomb JB, and Johansson PI
- Subjects
- Adult, Biomarkers blood, Female, Humans, Injury Severity Score, Male, Middle Aged, Apoptosis, Blood Coagulation Disorders blood, Blood Coagulation Disorders etiology, Blood Coagulation Disorders pathology, Endothelial Cells metabolism, Endothelial Cells pathology, Glycocalyx metabolism, Glycocalyx pathology, Wounds and Injuries blood, Wounds and Injuries complications, Wounds and Injuries pathology
- Abstract
Introduction: Severe trauma is accompanied by endothelial glycocalyx disruption, which drives coagulopathy, increasing transfusion requirements and death. This syndrome has been termed endotheliopathy of trauma (EOT). Some have suggested EOT results from endothelial cellular damage and apoptosis. Endothelial microvesicles (EMVs) represent cellular damage. We hypothesized that EOT is associated with endothelial damage and apoptosis resulting in an increase in circulating EMVs., Methods: Prospective, observational study enrolling severely injured patients. Twelve patients with EOT, based on elevated Syndecan-1 levels, were matched with 12 patients with lower levels, based on Injury Severity Score (ISS), abbreviated injury scale profile, and age. Thrombelastography and plasma levels of biomarkers indicative of cellular damage were measured from blood samples collected on admission. EMVs were determined by flow cytometry using varied monoclonal antibodies associated with endothelial cells. Significance was set at P < 0.05., Results: Admission physiology and ISS (29 vs. 28) were similar between groups. Patients with EOT had higher Syndecan-1, 230 (158, 293) vs. 19 (14, 25) ng/mL, epinephrine, and soluble thrombomodulin levels. Based on thrombelastography, EOT had reductions in clot initiation, amplification, propagation and strength, and a greater frequency of transfusion, 92% vs. 33%. There were no differences in EMVs irrespective of the antibody used. Plasma norepinephrine, sE-selectin, sVE-cadherin, and histone-complexed DNA fragments levels were similar., Conclusion: In trauma patients presenting with EOT, endothelial cellular damage or apoptosis does not seem to occur based on the absence of an increase in EMVs and other biomarkers. Thus, this suggests endothelial glycocalyx disruption is the underlying primary cause of EOT.
- Published
- 2019
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25. Exercise Training Induces Depot-Specific Adaptations to White and Brown Adipose Tissue.
- Author
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Lehnig AC, Dewal RS, Baer LA, Kitching KM, Munoz VR, Arts PJ, Sindeldecker DA, May FJ, Lauritzen HPMM, Goodyear LJ, and Stanford KI
- Abstract
Exercise affects whole-body metabolism through adaptations to various tissues, including adipose tissue (AT). Recent studies investigated exercise-induced adaptations to AT, focusing on inguinal white adipose tissue (WAT), perigonadal WAT, and interscapular brown adipose tissue (iBAT). Although these AT depots play important roles in metabolism, they account for only ∼50% of the AT mass in a mouse. Here, we investigated the effects of 3 weeks of exercise training on all 14 AT depots. Exercise induced depot-specific effects in genes involved in mitochondrial activity, glucose metabolism, and fatty acid uptake and oxidation in each adipose tissue (AT) depot. These data demonstrate that exercise training results in unique responses in each AT depot; identifying the depot-specific adaptations to AT in response to exercise is essential to determine how AT contributes to the overall beneficial effect of exercise., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
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26. Preconception Exposure to Fine Particulate Matter Leads to Cardiac Dysfunction in Adult Male Offspring.
- Author
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Tanwar V, Adelstein JM, Grimmer JA, Youtz DJ, Katapadi A, Sugar BP, Falvo MJ, Baer LA, Stanford KI, and Wold LE
- Subjects
- Animals, Calcium Signaling drug effects, Epigenesis, Genetic drug effects, Female, Gene Expression Regulation, Developmental drug effects, Inflammation Mediators metabolism, Male, Mice, Myocardial Contraction drug effects, Myocytes, Cardiac drug effects, Myocytes, Cardiac metabolism, Oxidative Stress drug effects, Particle Size, Preconception Injuries genetics, Preconception Injuries metabolism, Preconception Injuries physiopathology, Risk Assessment, Risk Factors, Sex Factors, Stroke Volume drug effects, Ventricular Dysfunction, Left genetics, Ventricular Dysfunction, Left metabolism, Ventricular Dysfunction, Left physiopathology, Ventricular Function, Left genetics, Inhalation Exposure adverse effects, Maternal Exposure adverse effects, Particulate Matter toxicity, Paternal Exposure adverse effects, Preconception Injuries chemically induced, Ventricular Dysfunction, Left chemically induced, Ventricular Function, Left drug effects
- Abstract
Background Particulate matter (particles < 2.5 μm [ PM
2.5 ]) exposure during the in utero and postnatal developmental periods causes cardiac dysfunction during adulthood. Here, we investigated the potential priming effects of preconception exposure of PM2.5 on cardiac function in adult offspring. Methods and Results Male and female friend leukemia virus b (FVB) mice were exposed to either filtered air ( FA ) or PM2.5 at an average concentration of 38.58 μg/m3 for 6 hours/day, 5 days/week for 3 months. Mice were then crossbred into 2 groups: (1) FAmale × FAfemale (both parents were exposed to FA preconception) and, (2) PM2.5male × PM2.5female (both parents were exposed to PM2.5 preconception). Male offspring were divided: (1) preconception FA (offspring born to FA exposed parents) and, (2) preconception PM2.5 (offspring born to PM2.5 exposed parents) and analyzed at 3 months of age. Echocardiography identified increased left ventricular end systolic volume and reduced posterior wall thickness, reduced %fractional shortening and %ejection fraction in preconception PM2.5 offspring. Cardiomyocytes isolated from preconception PM2.5 offspring showed reduced %peak shortening, -dL/dT, TPS 90 and slower calcium reuptake (tau). Gene and protein expression revealed modifications in markers of inflammation ( IL -6, IL -15, TNF α, NF қB, CRP , CD 26E, CD 26P, intercellular adhesion molecule 1, and monocyte chemoattractant protein-1) profibrosis (collagen type III alpha 1 chain), oxidative stress ( NOS 2), antioxidants (Nrf2, SOD , catalase), Ca2+ regulatory proteins ( SERCA 2a, p- PLN , NCX ), and epigenetic regulators (Dnmt1, Dnmt3a, Dnmt3b, Sirt1, and Sirt2) in preconception PM2.5 offspring. Conclusions Preconception exposure to PM2.5 results in global cardiac dysfunction in adult offspring, suggesting that abnormalities during development are not limited to the prenatal or postnatal periods but can also be determined before conception.- Published
- 2018
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27. βIV-Spectrin regulates STAT3 targeting to tune cardiac response to pressure overload.
- Author
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Unudurthi SD, Nassal D, Greer-Short A, Patel N, Howard T, Xu X, Onal B, Satroplus T, Hong D, Lane C, Dalic A, Koenig SN, Lehnig AC, Baer LA, Musa H, Stanford KI, Smith S, Mohler PJ, and Hund TJ
- Subjects
- Animals, Calcium-Calmodulin-Dependent Protein Kinase Type 2 genetics, Calcium-Calmodulin-Dependent Protein Kinase Type 2 metabolism, Cardiomegaly genetics, Cardiomegaly pathology, Fibrosis, Heart Failure genetics, Heart Failure pathology, Mice, Mice, Transgenic, Phosphorylation, STAT3 Transcription Factor genetics, Spectrin genetics, Cardiomegaly metabolism, Heart Failure metabolism, STAT3 Transcription Factor metabolism, Signal Transduction, Spectrin metabolism
- Abstract
Heart failure (HF) remains a major source of morbidity and mortality in the US. The multifunctional Ca2+/calmodulin-dependent kinase II (CaMKII) has emerged as a critical regulator of cardiac hypertrophy and failure, although the mechanisms remain unclear. Previous studies have established that the cytoskeletal protein βIV-spectrin coordinates local CaMKII signaling. Here, we sought to determine the role of a spectrin-CaMKII complex in maladaptive remodeling in HF. Chronic pressure overload (6 weeks of transaortic constriction [TAC]) induced a decrease in cardiac function in WT mice but not in animals expressing truncated βIV-spectrin lacking spectrin-CaMKII interaction (qv3J mice). Underlying the observed differences in function was an unexpected differential regulation of STAT3-related genes in qv3J TAC hearts. In vitro experiments demonstrated that βIV-spectrin serves as a target for CaMKII phosphorylation, which regulates its stability. Cardiac-specific βIV-spectrin-KO (βIV-cKO) mice showed STAT3 dysregulation, fibrosis, and decreased cardiac function at baseline, similar to what was observed with TAC in WT mice. STAT3 inhibition restored normal cardiac structure and function in βIV-cKO and WT TAC hearts. Our studies identify a spectrin-based complex essential for regulation of the cardiac response to chronic pressure overload. We anticipate that strategies targeting the new spectrin-based "statosome" will be effective at suppressing maladaptive remodeling in response to chronic stress.
- Published
- 2018
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28. Paternal Exercise Improves Glucose Metabolism in Adult Offspring.
- Author
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Stanford KI, Rasmussen M, Baer LA, Lehnig AC, Rowland LA, White JD, So K, De Sousa-Coelho AL, Hirshman MF, Patti ME, Rando OJ, and Goodyear LJ
- Subjects
- Adiposity physiology, Animals, Diet, High-Fat, Female, Male, Mice, Nuclear Proteins physiology, Obesity metabolism, Pregnancy, Sex Factors, Blood Glucose metabolism, Carbohydrate Metabolism physiology, Muscle, Skeletal metabolism, Paternal Behavior physiology, Physical Conditioning, Animal physiology, Prenatal Exposure Delayed Effects metabolism
- Abstract
Poor paternal diet has emerged as a risk factor for metabolic disease in offspring, and alterations in sperm may be a major mechanism mediating these detrimental effects of diet. Although exercise in the general population is known to improve health, the effects of paternal exercise on sperm and offspring metabolic health are largely unknown. Here, we studied 7-week-old C57BL/6 male mice fed a chow or high-fat diet and housed either in static cages (sedentary) or cages with attached running wheels (exercise trained). After 3 weeks, one cohort of males was sacrificed and cauda sperm obtained, while the other cohort was bred with chow-fed sedentary C57BL/6 females. Offspring were chow fed, sedentary, and studied during the first year of life. We found that high-fat feeding of sires impairs glucose tolerance and increases the percentage of fat mass in both male and female offspring at 52 weeks of age. Strikingly, paternal exercise suppresses the effects of paternal high-fat diet on offspring, reversing the observed impairment in glucose tolerance, percentage of fat mass, and glucose uptake in skeletal muscles of the offspring. These changes in offspring phenotype are accompanied by changes in sperm physiology, as, for example, high-fat feeding results in decreased sperm motility, an effect normalized in males subject to exercise training. Deep sequencing of sperm reveals pronounced effects of exercise training on multiple classes of small RNAs, as multiple changes to the sperm RNA payload observed in animals consuming a high-fat diet are suppressed by exercise training. Thus, voluntary exercise training of male mice results in pronounced improvements in the metabolic health of adult male and female offspring. We provide the first in-depth analysis of small RNAs in sperm from exercise-trained males, revealing a marked change in the levels of multiple small RNAs with the potential to alter phenotypes in the next generation., (© 2018 by the American Diabetes Association.)
- Published
- 2018
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29. Early Identification of the Patient with Endotheliopathy of Trauma by Arrival Serum Albumin.
- Author
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Gonzalez Rodriguez E, Cardenas JC, Lopez E, Cotton BA, Tomasek JS, Ostrowski SR, Baer LA, Stensballe J, Holcomb JB, Johansson PI, and Wade CE
- Subjects
- Adult, Edema blood, Edema diagnosis, Edema therapy, Female, Glycocalyx metabolism, Hemorrhage blood, Hemorrhage diagnosis, Hemorrhage therapy, Humans, Male, Middle Aged, Prospective Studies, Shock blood, Shock diagnosis, Shock therapy, Syndecan-1 blood, Thrombomodulin blood, Wounds and Injuries blood, Serum Albumin metabolism, Wounds and Injuries diagnosis, Wounds and Injuries therapy
- Abstract
Objective: Traumatic endotheliopathy (EoT) is associated with glycocalyx breakdown and capillary leak resulting in the extravasation of proteins. We hypothesized that lower serum albumin levels are associated with EoT, poor outcomes, and can be used for early EoT screening in trauma patients., Methods: We enrolled severely injured trauma patients with serum albumin levels available on admission. Syndecan-1 and soluble thrombomodulin were quantified from plasma by ELISA. Demographic and clinical data were obtained. We evaluated the association of serum albumin and EoT+ (syndecan-1 level ≥40 ng/mL), followed by dichotomization by serum albumin level, and subgroup comparisons., Results: Of the 258 patients enrolled 92 (36.0%) were EoT+ (syndecan-1 ≥ 40 ng/mL). Median albumin levels in the EoT+ group were 3.4 g/dL, and 3.8 g/dL in EoT- patients, P < 0.05. In a multifactorial analysis, lower albumin levels were inversely associated with the likelihood of EoT+. With receiver characteristic curve analysis, we determined a cutoff albumin level < 3.6 g/dL for EoT+ prediction (area under the curve 0.70; 95% CI: 0.63, 0.77). After dichotomizing by albumin <3.6 or ≥3.6 g/dL, 51.5% of patients had low albumin. Low albumin patients were more likely to have EoT+, as well as higher soluble thrombomodulin (both P < 0.05). Furthermore, they required more frequently blood transfusions, had fewer hospital-free days and higher mortality rate than those with normal albumin., Conclusions: EoT is a syndrome associated with leakage of albumin from the intravascular compartment, which re-emphasizes that arrival albumin may be a novel and timely approach to the identification of patients needing endothelial rescue therapy.
- Published
- 2018
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30. 12,13-diHOME: An Exercise-Induced Lipokine that Increases Skeletal Muscle Fatty Acid Uptake.
- Author
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Stanford KI, Lynes MD, Takahashi H, Baer LA, Arts PJ, May FJ, Lehnig AC, Middelbeek RJW, Richard JJ, So K, Chen EY, Gao F, Narain NR, Distefano G, Shettigar VK, Hirshman MF, Ziolo MT, Kiebish MA, Tseng YH, Coen PM, and Goodyear LJ
- Published
- 2018
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31. Maternal Exercise Improves the Metabolic Health of Adult Offspring.
- Author
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Harris JE, Baer LA, and Stanford KI
- Subjects
- Adult, Adult Children, Animals, Female, Humans, Pregnancy, Exercise physiology, Maternal Health, Physical Conditioning, Animal physiology, Prenatal Exposure Delayed Effects metabolism
- Abstract
The intrauterine environment can modulate the course of development and confer an enduring effect on offspring health. The effects of maternal diet to impair offspring metabolic health are well established, but the effects of maternal exercise on offspring metabolic health have been less defined. Because physical exercise is a treatment for obesity and type 2 diabetes (T2D), maternal exercise is an appealing intervention to positively influence the intrauterine environment and improve the metabolic health of offspring. Recent research has provided insights into the effects of maternal exercise on the metabolic health of adult offspring, which is the focus of this review., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2018
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32. Corrigendum: The cold-induced lipokine 12,13-diHOME promotes fatty acid transport into brown adipose tissue.
- Author
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Lynes MD, Leiria LO, Lundh M, Bartelt A, Shamsi F, Huang TL, Takahashi H, Hirshman MF, Schlein C, Lee A, Baer LA, May FJ, Gao F, Narain NR, Chen EY, Kiebish MA, Cypess AM, Blüher M, Goodyear LJ, Hotamisligil GS, Stanford KI, and Tseng YH
- Abstract
This corrects the article DOI: 10.1038/nm.4297.
- Published
- 2017
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33. Stress-responsive HILPDA is necessary for thermoregulation during fasting.
- Author
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VandeKopple MJ, Wu J, Baer LA, Bal NC, Maurya SK, Kalyanasundaram A, Periasamy M, Stanford KI, Giaccia AJ, Denko NC, and Papandreou I
- Subjects
- Adipocytes metabolism, Animals, DNA-Binding Proteins genetics, Female, Mice, Mice, Knockout, Stress, Physiological, Triglycerides metabolism, Body Temperature Regulation, DNA-Binding Proteins metabolism, Fasting physiology
- Abstract
Hypoxia-inducible lipid droplet-associated protein (HILPDA) has been shown to localize to lipid droplets in nutrient-responsive cell types such as hepatocytes and adipocytes. However, its role in the control of whole-body homeostasis is not known. We sought to measure cell-intrinsic and systemic stress responses in a mouse strain harboring whole-body Hilpda deficiency. We generated a genetically engineered mouse model of whole-body HILPDA deficiency by replacing the coding Hilpda exon with luciferase. We subjected the knockout animals to environmental stresses and measured whole-animal metabolic and behavioral parameters. Brown adipocyte precursors were isolated and differentiated in vitro to quantify the impact of HILPDA ablation in lipid storage and mobilization in these cells. HILPDA-knockout animals are viable and fertile, but show reduced ambulatory activity and oxygen consumption at regular housing conditions. Acclimatization at thermoneutral conditions abolished the phenotypic differences observed at 22°C. When fasted, HILPDA KO mice are unable to maintain body temperature and become hypothermic at 22°C, without apparent abnormalities in blood chemistry parameters or tissue triglyceride content. HILPDA expression was upregulated during adipocyte differentiation and activation in vitro ; however, it was not required for lipid droplet formation in brown adipocytes. We conclude that HILPDA is necessary for efficient fuel utilization suggesting a homeostatic role for Hilpda in sub-optimal environments., (© 2017 Society for Endocrinology.)
- Published
- 2017
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34. Syndecan-1: A Quantitative Marker for the Endotheliopathy of Trauma.
- Author
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Gonzalez Rodriguez E, Ostrowski SR, Cardenas JC, Baer LA, Tomasek JS, Henriksen HH, Stensballe J, Cotton BA, Holcomb JB, Johansson PI, and Wade CE
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Biomarkers blood, Enzyme-Linked Immunosorbent Assay, Female, Humans, Injury Severity Score, Logistic Models, Male, Middle Aged, Multivariate Analysis, Prospective Studies, ROC Curve, Sensitivity and Specificity, Vascular Diseases blood, Vascular Diseases etiology, Wounds and Injuries blood, Young Adult, Endothelium, Vascular physiopathology, Syndecan-1 blood, Vascular Diseases diagnosis, Wounds and Injuries physiopathology
- Abstract
Background: Endothelial glycocalyx breakdown elicits syndecan-1 shedding and endotheliopathy of trauma (EoT). We hypothesized that a cutoff syndecan-1 level can identify patients with endothelial dysfunction who would have poorer outcomes., Study Design: We conducted a prospective observational study. Trauma patients with the highest level of activation admitted from July 2011 through September 2013 were eligible. We recorded demographics, injury type/severity (Injury Severity Score), physiology and outcomes data, and quantified syndecan-1 and soluble thrombomodulin from plasma with ELISAs. With receiver operating characteristic curve analysis, we defined EoT+ as the syndecan-1 cutoff level that maximized the sum of sensitivity and specificity (Youden index) in predicting 24-hour in-hospital mortality. We stratified by this cutoff and compared both groups. Factors associated with 30-day in-hospital mortality were assessed with multivariable logistic regression (adjusted odds ratios and 95% CIs reported)., Results: From receiver operating characteristic curve analysis (area under the curve = 0.71; 95% CI 0.58 to 0.84), we defined EoT+ as syndecan-1 level ≥40 ng/mL (sensitivity = 0.62, specificity = 0.73). Of the 410 patients evaluated, 34% (n = 138) were EoT+ patients, who presented with higher Injury Severity Scores (p < 0.001) and blunt trauma frequency (p = 0.016) than EoT- patients. Although EoT+ patients had lower systolic blood pressure (median 119 vs 128 mmHg; p < 0.001), base excess and hemoglobin were similar between groups. The proportion of transfused (EoT+ 71.7% vs EoT- 36.4%; p < 0.001) and deceased EoT+ patients (EoT+ 24.6% vs EoT- 12.1%; p < 0.001) was higher. EoT+ was significantly associated with 30-day in-hospital mortality (adjusted odds ratio = 2.23; 95% CI 1.22 to 4.04)., Conclusions: A syndecan-1 level ≥40 ng/mL identified patients with significantly worse outcomes, despite admission physiology similar to those without the condition., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
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35. Impact of blood products on platelet function in patients with traumatic injuries: a translational study.
- Author
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Henriksen HH, Grand AG, Viggers S, Baer LA, Solbeck S, Cotton BA, Matijevic N, Ostrowski SR, Stensballe J, Fox EE, Chen TA, Holcomb JB, Johansson PI, Cardenas JC, and Wade CE
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Blood Component Transfusion methods, Female, Humans, Male, Middle Aged, Platelet Count, Platelet Function Tests, Prospective Studies, Wounds and Injuries physiopathology, Wounds and Injuries therapy, Young Adult, Blood Component Transfusion adverse effects, Blood Platelets physiology, Wounds and Injuries blood
- Abstract
Background: Reductions in platelet (PLT) count and function are associated with poor outcomes in trauma patients. We proposed to determine if patients expected to receive blood products have a decrease in PLT function higher than expected based on the reduction in PLT count, and if the reduction in function could be associated with the donor plasma/supernatant received., Methods: PLT count and function were measured on admission to the emergency department and intensive care unit in severely injured patients expected to receive a transfusion. PLT function was measured by Multiplate aggregometry in response to five agonists. Function was corrected for alterations in count. In vitro studies were conducted in the blood of normal subjects to assess the effect of dilutions with AB donor plasma on PLT function., Results: Forty-six patients were enrolled, with 87% requiring a transfusion. Median Injury Severity Score was 23 (13, 29) and mortality 15%. PLT count and function were decreased from emergency department to intensive care unit admission by 25% and 58%, respectively. Decreases in function persisted after adjustment for count. Patients requiring large volumes of blood products had reductions in function that were disproportionately greater. Reductions in PLT function were greatest after transfusion of PLTs. In in vitro studies with a 30% dilution by autologous plasma caused a relational reduction in function, whereas allogenic plasma resulted in greater decreases that were highly variable between donors., Conclusions: Within hours of injury a decrease in both PLT count and function occurs, that is aggravated with the administration of blood products, with transfusion of PLTs showing the greatest effect. The effect on PLT function of allogenic transfused plasma appears to be highly donor related., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2017
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36. Identification and characterization of a supraclavicular brown adipose tissue in mice.
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Mo Q, Salley J, Roshan T, Baer LA, May FJ, Jaehnig EJ, Lehnig AC, Guo X, Tong Q, Nuotio-Antar AM, Shamsi F, Tseng YH, Stanford KI, and Chen MH
- Abstract
A fundamental challenge to our understanding of brown adipose tissue (BAT) is the lack of an animal model that faithfully represents human BAT. Such a model is essential for direct assessment of the function and therapeutic potential of BAT depots in humans. In human adults, most of the thermoactive BAT depots are located in the supraclavicular region of the neck, while mouse studies focus on depots located in the interscapular region of the torso. We recently discovered BAT depots that are located in a region analogous to that of human supraclavicular BAT (scBAT). Here, we report that the mouse scBAT depot has morphological characteristics of classical BAT, possesses the potential for high thermogenic activity, and expresses a gene signature that is similar to that of human scBAT. Taken together, our studies reveal a mouse BAT depot that represents human BAT and provides a unique tool for developing new translatable approaches for utilizing human scBAT.
- Published
- 2017
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37. The cold-induced lipokine 12,13-diHOME promotes fatty acid transport into brown adipose tissue.
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Lynes MD, Leiria LO, Lundh M, Bartelt A, Shamsi F, Huang TL, Takahashi H, Hirshman MF, Schlein C, Lee A, Baer LA, May FJ, Gao F, Narain NR, Chen EY, Kiebish MA, Cypess AM, Blüher M, Goodyear LJ, Hotamisligil GS, Stanford KI, and Tseng YH
- Subjects
- Adipose Tissue, Brown drug effects, Animals, Biological Transport drug effects, CD36 Antigens drug effects, CD36 Antigens metabolism, Cell Membrane drug effects, Cell Membrane metabolism, Energy Metabolism drug effects, Fatty Acid Transport Proteins drug effects, Fatty Acid Transport Proteins metabolism, Female, Fluorodeoxyglucose F18, Humans, Male, Mice, Oleic Acids biosynthesis, Oleic Acids pharmacology, Overweight metabolism, Positron Emission Tomography Computed Tomography, RNA, Messenger metabolism, Radiopharmaceuticals, Triglycerides metabolism, Adipose Tissue, Brown metabolism, Cold Temperature, Fatty Acids metabolism, Insulin Resistance, Obesity metabolism, Oleic Acids metabolism, Thermogenesis
- Abstract
Brown adipose tissue (BAT) and beige adipose tissue combust fuels for heat production in adult humans, and so constitute an appealing target for the treatment of metabolic disorders such as obesity, diabetes and hyperlipidemia. Cold exposure can enhance energy expenditure by activating BAT, and it has been shown to improve nutrient metabolism. These therapies, however, are time consuming and uncomfortable, demonstrating the need for pharmacological interventions. Recently, lipids have been identified that are released from tissues and act locally or systemically to promote insulin sensitivity and glucose tolerance; as a class, these lipids are referred to as 'lipokines'. Because BAT is a specialized metabolic tissue that takes up and burns lipids and is linked to systemic metabolic homeostasis, we hypothesized that there might be thermogenic lipokines that activate BAT in response to cold. Here we show that the lipid 12,13-dihydroxy-9Z-octadecenoic acid (12,13-diHOME) is a stimulator of BAT activity, and that its levels are negatively correlated with body-mass index and insulin sensitivity. Using a global lipidomic analysis, we found that 12,13-diHOME was increased in the circulation of humans and mice exposed to cold. Furthermore, we found that the enzymes that produce 12,13-diHOME were uniquely induced in BAT by cold stimulation. The injection of 12,13-diHOME acutely activated BAT fuel uptake and enhanced cold tolerance, which resulted in decreased levels of serum triglycerides. Mechanistically, 12,13-diHOME increased fatty acid (FA) uptake into brown adipocytes by promoting the translocation of the FA transporters FATP1 and CD36 to the cell membrane. These data suggest that 12,13-diHOME, or a functional analog, could be developed as a treatment for metabolic disorders.
- Published
- 2017
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38. Traumatic Endotheliopathy: A Prospective Observational Study of 424 Severely Injured Patients.
- Author
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Johansson PI, Henriksen HH, Stensballe J, Gybel-Brask M, Cardenas JC, Baer LA, Cotton BA, Holcomb JB, Wade CE, and Ostrowski SR
- Subjects
- Adult, Biomarkers blood, Cohort Studies, Endothelium, Vascular metabolism, Epinephrine blood, Female, Humans, Injury Severity Score, Linear Models, Male, Middle Aged, Multivariate Analysis, Norepinephrine blood, Predictive Value of Tests, Prognosis, Proportional Hazards Models, Prospective Studies, Survival Analysis, Thrombomodulin blood, Trauma Centers, Wounds and Injuries mortality, Wounds and Injuries therapy, Catecholamines blood, E-Selectin blood, Endothelium, Vascular pathology, Syndecan-1 blood, Wounds and Injuries blood, Wounds and Injuries diagnosis
- Abstract
Objective: Investigate and confirm the association between sympathoadrenal activation, endotheliopathy and poor outcome in trauma patients., Background: The association between sympathoadrenal activation, endotheliopathy, and poor outcome in trauma has only been demonstrated in smaller patient cohorts and animal models but needs confirmation in a large independent patient cohort., Methods: Prospective observational study of 424 trauma patients admitted to a level 1 Trauma Center. Admission plasma levels of catecholamines (adrenaline, noradrenaline) and biomarkers reflecting endothelial damage (syndecan-1, thrombomodulin, and sE-selectin) were measured and demography, injury type and severity, physiology, treatment, and mortality up till 28 days were recorded., Results: Patients had a median ISS of 17 with 72% suffering from blunt injury. Adrenaline and noradrenaline correlated with syndecan-1 (r = 0.38, P < 0.001 and r = 0.23, P < 0.001, respectively) but adrenaline was the only independent predictor of syndecan-1 by multiple linear regression adjusted for age, injury severity score, Glascow Coma Scale, systolic blood pressure, base excess, platelet count, hemoglobin, prehospital plasma, and prehospital fluids (100 pg/mL higher adrenaline predicted 2.75 ng/mL higher syndecan-1, P < 0.001). By Cox analyses adjusted for age, sex, injury severity score, Glascow Coma Scale, base excess, platelet count and hemoglobin, adrenaline, and syndecan-1 were the only independent predictors of both <24-hours, 7-day and 28-day mortality (all P < 0.05). Furthermore, noradrenaline was an independent predictor of <24-hours mortality and thrombomodulin was an independent predictor of 7-day and 28-day mortality (all P < 0.05)., Conclusions: We confirmed that sympathoadrenal activation was strongly and independently associated with endothelial glycocalyx and cell damage (ie, endotheliopathy) and furthermore that sympathoadrenal activation and endotheliopathy were independent predictors of mortality in trauma patients., Competing Interests: The authors declare no conflicts of interest.
- Published
- 2017
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39. Lipidomic Adaptations in White and Brown Adipose Tissue in Response to Exercise Demonstrate Molecular Species-Specific Remodeling.
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May FJ, Baer LA, Lehnig AC, So K, Chen EY, Gao F, Narain NR, Gushchina L, Rose A, Doseff AI, Kiebish MA, Goodyear LJ, and Stanford KI
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- Animals, Lipid Metabolism physiology, Male, Mice, Mice, Inbred C57BL, Phosphatidic Acids metabolism, Phosphatidylcholines metabolism, Phosphatidylethanolamines metabolism, Phosphatidylserines metabolism, Phospholipids metabolism, Triglycerides metabolism, Adaptation, Physiological physiology, Adipose Tissue, Brown metabolism, Adipose Tissue, White metabolism, Physical Conditioning, Animal physiology
- Abstract
Exercise improves whole-body metabolic health through adaptations to various tissues, including adipose tissue, but the effects of exercise training on the lipidome of white adipose tissue (WAT) and brown adipose tissue (BAT) are unknown. Here, we utilize MS/MS
ALL shotgun lipidomics to determine the molecular signatures of exercise-induced adaptations to subcutaneous WAT (scWAT) and BAT. Three weeks of exercise training decrease specific molecular species of phosphatidic acid (PA), phosphatidylcholines (PC), phosphatidylethanolamines (PE), and phosphatidylserines (PS) in scWAT and increase specific molecular species of PC and PE in BAT. Exercise also decreases most triacylglycerols (TAGs) in scWAT and BAT. In summary, exercise-induced changes to the scWAT and BAT lipidome are highly specific to certain molecular lipid species, indicating that changes in tissue lipid content reflect selective remodeling in scWAT and BAT of both phospholipids and glycerol lipids in response to exercise training, thus providing a comprehensive resource for future studies of lipid metabolism pathways., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2017
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40. Sympathoadrenal activation and endotheliopathy are drivers of hypocoagulability and hyperfibrinolysis in trauma: A prospective observational study of 404 severely injured patients.
- Author
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Ostrowski SR, Henriksen HH, Stensballe J, Gybel-Brask M, Cardenas JC, Baer LA, Cotton BA, Holcomb JB, Wade CE, and Johansson PI
- Subjects
- Adult, Biomarkers blood, Blood Coagulation Disorders mortality, Female, Hospital Mortality, Humans, Injury Severity Score, Male, Middle Aged, Prognosis, Prospective Studies, Thrombelastography, Trauma Centers, Wounds, Nonpenetrating mortality, Adrenal Glands innervation, Blood Coagulation Disorders etiology, Endothelium, Vascular pathology, Fibrinolysis physiology, Sympathetic Nervous System physiopathology, Wounds, Nonpenetrating blood, Wounds, Nonpenetrating complications
- Abstract
Background: One third of severely injured patients present with a laboratory-based diagnosis of coagulopathy. This study investigated clinical and biomarker profile of patients with rapid thrombelastography (rTEG) coagulopathy, hypothesizing that sympathoadrenal activation and endothelial damage were drivers of this condition., Methods: Prospective observational study of 404 trauma patients admitted to a Level 1 US Trauma Center. Patients with admission rTEG and plasma measurements of catecholamines (adrenaline, noradrenaline) and biomarkers reflecting endothelial activation/damage (syndecan-1, thrombomodulin, sE-selectin, sVE-cadherin, nucleosomes) were included. Demography, injury type/severity, physiology, treatment, and inhospital mortality were recorded., Results: Patients had a median Injury Severity Score (ISS) of 17, 73% from blunt injury. One third (35%) of the patients had rTEG coagulopathy, which was associated with higher plasma adrenaline, syndecan-1, and nucleosomes (all <0.05), higher transfusion requirements and higher early (<24 hours, 9.3% vs. 2.5%) and late (28 days, 23.8% vs. 13.4%) mortality. By adjusted linear regression analyses, high plasma adrenaline, sVE-cadherin, and syndecan-1 (reflecting sympathoadrenal activation and endothelial cell junction and glycocalyx damage) along with male sex, high ISS, low platelet count and prehospital red blood cell transfusion were independently associated with hypocoagulable rTEG, whereas prehospital plasma and sE-selectin (reflecting endothelial activation) were independently associated with more hypercoagulable rTEG., Conclusion: In this cohort of severely injured trauma patients, rTEG coagulopathy was associated with sympathoadrenal activation, endotheliopathy, and excess mortality. High adrenaline and biomarkers reflecting endothelial cell junction and glycocalyx damage were independently associated with hypocoagulability and hyperfibrinolysis. These findings support that sympathoadrenal activation and endotheliopathy contribute to trauma-induced coagulopathy and warrants further studies of endothelial repair management., Level of Evidence: Prognostic, Level III.
- Published
- 2017
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41. Exercise Altered the Skeletal Muscle MicroRNAs and Gene Expression Profiles in Burn Rats With Hindlimb Unloading.
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Song J, Saeman MR, Baer LA, Cai AR, Wade CE, and Wolf SE
- Subjects
- Animals, Hindlimb, Male, Rats, Rats, Sprague-Dawley, Weight-Bearing, Burns metabolism, Hindlimb Suspension, MicroRNAs metabolism, Muscle, Skeletal metabolism, Physical Conditioning, Animal, Transcriptome
- Abstract
This study investigated microRNA and target gene profiles under different conditions of burn, bed rest, and exercise training. Male Sprague-Dawley rats (n = 48) were assigned to sham ambulatory, sham hindlimb unloading, burn ambulatory, or burn plus hindlimb unloading groups. Rats received a 40% TBSA scald burn or sham treatments and were ambulatory or hindlimb unloaded. Rats were further assigned to exercise or no exercise. Plantaris tissues were harvested on day 14 and pooled to analyze for microRNA and gene expression profiles. Compared with the sham ambulatory-no exercise group, 73, 79, and 80 microRNAs were altered 2-fold in the burn ambulatory, sham hindlimb unloading, and burn hindlimb unloading groups, all with no exercise, respectively. More than 70% of microRNAs were upregulated in response to burn and hindlimb unloading, whereas 60% microRNA of the profile decreased in hindlimb unloaded burn rats with exercise training. MiR-182 was the most affected in rat muscle. Gene ontology biological process and pathway analysis showed that the oxidative stress pathway was most stimulated in the hindlimb unloaded burn rats; while in response to exercise training, all genes in related pathways such as hypermetabolic, inflammation, and blood coagulation were alleviated. MicroRNAs and transcript gene profiles were altered in burn and hindlimb unloading groups, with additive effects on hindlimb unloaded burn rats. The altered genes' signal pathways were associated with muscle mass loss and function impairment. Muscle improvement with exercise training was observed in gene levels with microRNA alterations as well., Competing Interests: The authors have no financial or other interests construed as a conflict of interest.
- Published
- 2017
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42. Thematic accuracy assessment of the 2011 National Land Cover Database (NLCD).
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Wickham J, Stehman SV, Gass L, Dewitz JA, Sorenson DG, Granneman BJ, Poss RV, and Baer LA
- Abstract
Accuracy assessment is a standard protocol of National Land Cover Database (NLCD) mapping. Here we report agreement statistics between map and reference labels for NLCD 2011, which includes land cover for ca. 2001, ca. 2006, and ca. 2011. The two main objectives were assessment of agreement between map and reference labels for the three, single-date NLCD land cover products at Level II and Level I of the classification hierarchy, and agreement for 17 land cover change reporting themes based on Level I classes (e.g., forest loss; forest gain; forest, no change) for three change periods (2001-2006, 2006-2011, and 2001-2011). The single-date overall accuracies were 82%, 83%, and 83% at Level II and 88%, 89%, and 89% at Level I for 2011, 2006, and 2001, respectively. Many class-specific user's accuracies met or exceeded a previously established nominal accuracy benchmark of 85%. Overall accuracies for 2006 and 2001 land cover components of NLCD 2011 were approximately 4% higher (at Level II and Level I) than the overall accuracies for the same components of NLCD 2006. The high Level I overall, user's, and producer's accuracies for the single-date eras in NLCD 2011 did not translate into high class-specific user's and producer's accuracies for many of the 17 change reporting themes. User's accuracies were high for the no change reporting themes, commonly exceeding 85%, but were typically much lower for the reporting themes that represented change. Only forest loss, forest gain, and urban gain had user's accuracies that exceeded 70%. Lower user's accuracies for the other change reporting themes may be attributable to the difficulty in determining the context of grass (e.g., open urban, grassland, agriculture) and between the components of the forest-shrubland-grassland gradient at either the mapping phase, reference label assignment phase, or both. NLCD 2011 user's accuracies for forest loss, forest gain, and urban gain compare favorably with results from other land cover change accuracy assessments.
- Published
- 2017
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43. Pre-hospital transfusion of plasma in hemorrhaging trauma patients independently improves hemostatic competence and acidosis.
- Author
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Henriksen HH, Rahbar E, Baer LA, Holcomb JB, Cotton BA, Steinmetz J, Ostrowski SR, Stensballe J, Johansson PI, and Wade CE
- Subjects
- Acidosis etiology, Adult, Female, Follow-Up Studies, Hemorrhage etiology, Humans, Male, Middle Aged, Prospective Studies, Young Adult, Acidosis therapy, Blood Component Transfusion methods, Emergency Medical Services methods, Hemorrhage therapy, Hemostasis physiology, Plasma, Trauma Centers, Wounds and Injuries complications
- Abstract
Background: The early use of blood products has been associated with improved patient outcomes following severe hemorrhage or traumatic injury. We aimed to investigate the influence of pre-hospital blood products (i.e. plasma and/or RBCs) on admission hemostatic properties and patient outcomes. We hypothesized that pre-hospital plasma would improve hemostatic function as evaluated by rapid thrombelastography (rTEG)., Methods: We conducted a prospective observational study recruiting 257 trauma patients admitted to a Level I trauma center having received either blood products pre-hospital or in-hospital within 6 hours of admission. Clinical data on patient demographics, blood biochemistry, injury severity score and mortality were collected. Admission rTEG was conducted to characterize the coagulation profile and hemostatic function., Results: 75 patients received pre-hospital plasma and/or RBCs (PH group; nearly half received both RBCs and plasma) whereas 182 patients only received in-hospital blood products (RBCs, Plasma and Platelets) within 6 hours of admission (IH group). PH patients had lower Glasgow coma scale (GCS) scores, more penetrating injuries, lower systolic blood pressures, lower hemoglobin levels, lower platelet counts and greater acidosis upon ED admission than the IH group (all p < 0.05). Despite differences in type of injury and admission vitals indicating that the PH group had more signs of bleeding than the IH group, there were no significant differences in in-hospital mortality (PH 26.7% vs. IH 20.9% p = 0.31). When comparing rTEG variables between PH patients transfused with 0, 1 or 2 units of plasma, more pre-hospital plasma transfusion was tendency towards improved rTEG variables. When adjusting for pre-hospital RBC, pre-hospital plasma was associated with significantly higher rTEG MA (p = 0.012) at hospital admission., Discussion: After adjusting for pre-hospital RBCs, pre-hospital plasma transfusion was independently associated with increased rTEG MA, as well as arrival indices of shock and hemodynamic instability. Besides more severe injury and worse clinical presentation, the group that received pre-hospital transfusion had early and late mortality similar to patients not transfused pre-hospital., Conclusions: These data suggest that early administration of plasma can provide significant hemostatic and potential survival benefit to severely hemorrhaging trauma patients.
- Published
- 2016
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44. Upon admission coagulation and platelet function in patients with thermal and electrical injuries.
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Wade CE, Baer LA, Cardenas JC, Folkerson LE, Nutall-Aurora K, Cotton BA, Matijevic N, Holcomb JB, Cross JM, and Huzar T
- Subjects
- Adult, Blood Coagulation Tests, Burns blood, Burns complications, Burns, Electric complications, Case-Control Studies, Electric Injuries complications, Female, Humans, Male, Middle Aged, Platelet Adhesiveness, Platelet Aggregation, Platelet Function Tests, Prospective Studies, Thrombelastography, Thrombin, Thrombophilia complications, Wounds and Injuries blood, Wounds and Injuries complications, Young Adult, Burns, Electric blood, Electric Injuries blood, Thrombophilia blood
- Abstract
Rational: There has been increased focus on hemostatic potential and function in the initial assessment of the patient with traumatic injuries, that not been extensively studied in patients with burns. We proposed to determine the hemostatic potential of patients with burns upon admission to the emergency department and contrasted their condition with that of healthy controls and patients with other traumatic injuries. In addition we assessed differences due to thermal versus electrical injury and evaluated the effect of burn size., Methods: This is a patient based prospective observational study conducted with delayed consented. Subjects at the highest level of trauma activation upon admission to the ED had a blood sample collected for research purposes and were subsequently consented. Hemostatic potential was measured by rapid thromelastography (r-TEG
® ), thrombin generation by calibrated automated thrombogram (CAT) and platelet function by Multiplate® using five activators. Burn subjects were compared to subjects with other traumatic injuries and controls. Within the burn subjects additional analysis compared mechanism (thermal vs. electrical) and burn size. Values are medians (IQR)., Results: Two hundred and eighty two trauma patients (with burns n=40, 14%) and 27 controls were enrolled. Upon admission, compared to controls, subjects with burns or trauma were hyper-coagulable based on r-TEG and CAT, with increased rates of clot formation and thrombin generation. There were no differences in burns compared to other traumatic injuries. The presence of hyper-coagulation did not appear to be related to the type of burn or the percentage of total body surface area involved. Employing previous defined cut points for R-TEG driven therapeutic interventions burn patients had similar rates of hyper- and hypo-coagulation noted in patients with traumatic injuries., Conclusion: Upon admission patients with burns are in a hyper-coagulable state similar to that of other trauma patients. Employing demonstrated cut points of hemostatic potential in trauma patients associated with increased risk of poor outcomes demonstrated the incidence in burn patients to be similar, suggesting that these values could be used in the early assessment of the patient with burns to guide treatment interventions., (Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.)- Published
- 2016
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45. PLASMA RESUSCITATION PROMOTES COAGULATION HOMEOSTASIS FOLLOWING SHOCK-INDUCED HYPERCOAGULABILITY.
- Author
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Cardenas JC, Cap AP, Swartz MD, Huby Mdel P, Baer LA, Matijevic N, Cotton BA, Holcomb JB, and Wade CE
- Subjects
- Animals, Blood Coagulation physiology, Fluid Therapy, Homeostasis, Humans, Prospective Studies, Rats, Rats, Sprague-Dawley, Shock, Hemorrhagic physiopathology, Shock, Hemorrhagic therapy
- Abstract
Background: Increased thrombin generation in injured patients possibly contributes to early consumption of coagulation factors, exacerbating hemorrhage. Identifying optimal resuscitation products for restoring plasma homeostasis following injury is important for improving management of these patients., Objectives: To determine the effects of crystalloid versus plasma resuscitation on thrombin generation in a rat model of trauma and hemorrhagic shock (HS)., Patients/methods: Rats were subjected to trauma and HS followed by resuscitation with Lactated Ringer's solution (LR) or fresh frozen plasma (FFP). Blood was collected at baseline, decompensation, and 3-h post-resuscitation. Thrombin generation was measured by calibrated automated thrombogram and antithrombin III (AT) by ELISA. In a prospective observational study, admission blood samples were collected on highest-level activation trauma patients and diluted with LR or FFP for thrombin generation analysis., Results: Resuscitation with LR resulted in persistent hypercoagulability; however, FFP resuscitation reversed this hypercoagulability to baseline thrombin generation or below. Plasma AT levels decreased following HS and remained low in rats receiving LR, but were corrected in rats receiving FFP. Similarly, in trauma patient plasma LR increased thrombin generation while FFP reduced it. However, results with AT-deficient plasma dilution were similar to LR. In patients with admission hypocoagulability, FFP slightly increased thrombin generation., Conclusions: HS in rats is associated with increased thrombin generation and resuscitation with FFP, not LR, reverses hypercoagulability. Dilution of trauma patient plasma with LR or FFP yielded similar results; however, the modulatory effects of FFP were attenuated when AT was absent. Importantly, FFP reduced thrombin generation in hypercoagulable patient plasma, but slightly increased thrombin generation in hypocoagulable patient plasma. Thus, FFP restores hemostatic balance following trauma and HS which is, in part, by delivering AT.
- Published
- 2016
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46. Effects of exercise on soleus in severe burn and muscle disuse atrophy.
- Author
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Saeman MR, DeSpain K, Liu MM, Carlson BA, Song J, Baer LA, Wade CE, and Wolf SE
- Subjects
- Animals, Burns physiopathology, Hindlimb physiopathology, Male, Rats, Rats, Sprague-Dawley, Burns complications, Muscle, Skeletal physiopathology, Muscular Disorders, Atrophic etiology, Physical Conditioning, Animal
- Abstract
Background: Muscle loss is a sequela of severe burn and critical illness with bed rest contributing significantly to atrophy. We hypothesize that exercise will mitigate muscle loss after burn with bed rest., Materials and Methods: Male rats were assigned to sham ambulatory (S/A), burn ambulatory (B/A), sham hindlimb unloading (S/H), or burn hindlimb unloading (B/H). Rats received a 40% scald burn or sham and were ambulatory or placed in hindlimb unloading, a model of bed rest. Half from each group performed twice daily resistance climbing. Hindlimb isometric forces were measured on day 14., Results: Soleus mass and muscle function were not affected by burn alone. Mass was significantly lower in hindlimb unloading (79 versus 139 mg, P < 0.001) and no exercise (103 versus 115 mg, P < 0.01). Exercise significantly increased soleus mass in B/H (86 versus 77 mg, P < 0.01). Hindlimb unloading significantly decreased muscle force in the twitch (12 versus 31 g, P < 0.001), tetanic (55 versus 148 g, P < 0.001), and specific tetanic measurements (12 versus 22 N/cm(2), P < 0.001). Effects of exercise on force depended on other factors. In B/H, exercise significantly increased twitch (14 versus 8 g, P < 0.05) and specific tetanic force (14 versus 7 N/cm(2), P < 0.01). Fatigue index was lower in ambulatory (55%) and exercise (52%) versus hindlimb (69%, P = 0.03) and no exercise (73%, P = 0.002)., Conclusions: Hindlimb unloading is a significant factor in muscle atrophy. Exercise increased the soleus muscle mass, twitch, and specific force in this model. However, the fatigue index decreased with exercise in all groups. This suggests exercise contributes to functional muscle change in this model of disuse and critical illness., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
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47. Measuring thrombin generation as a tool for predicting hemostatic potential and transfusion requirements following trauma.
- Author
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Cardenas JC, Rahbar E, Pommerening MJ, Baer LA, Matijevic N, Cotton BA, Holcomb JB, and Wade CE
- Subjects
- Adult, Blood Coagulation, Blood Coagulation Tests, Case-Control Studies, Female, Humans, Injury Severity Score, Male, Middle Aged, Wounds and Injuries mortality, Wounds and Injuries therapy, Blood Transfusion methods, Blood Transfusion mortality, Hemostasis, Thrombin analysis, Wounds and Injuries blood
- Abstract
Background: Thrombin is the central coagulation protease that activates clotting proteins, triggers platelet aggregation, and converts fibrinogen to fibrin. Relationships between thrombin generation (TG) and clinical outcomes have not been defined following trauma. We hypothesize that TG is predictive of transfusion requirements and patient outcomes., Methods: Plasma was collected from 406 highest-level activation trauma patients upon admission and 29 healthy donors. Standard coagulation tests were performed, and TG was measured by calibrated automated thrombogram. Mann-Whitney U-tests were used to compare healthy versus trauma patients, and subgroup analyses were used to compare hypocoagulable versus nonhypocoagulable patients. Hypocoagulability was determined by area under the receiver operating characteristic curve analysis and was defined as peak TG of less than 250 nM. Multiple logistic regressions were used to assess the ability of TG to predict massive transfusion and mortality., Results: The median (interquartile range) age was 39 years (28-52 years), with an Injury Severity Score (ISS) of 17 (9-26). The trauma patients had greater TG (peak, 316.2 nM [270.1-355.5 nM]) compared with the healthy controls (124.6 nM [91.1-156.2 nM]), p < 0.001. The overall rate of hypocoagulability was 17%. The patients with peak TG of less than 250 nM were more severely injured (ISS, 25 [13-30] vs. 16 [9-25], p = 0.003); required more transfusions of red blood cells (p = 0.02), plasma (p = 0.003), and platelets (p = 0.006); had fewer hospital-free days (p = 0.001); and had increased mortality (10% vs. 3% at 24 hours, p = 0.006, and 29% vs. 11% at 30 days, p = 0.0004). Peak TG of less than 250 nM was predictive of massive transfusion (odds ratio, 4.18; p = 0.01) and 30-day mortality (odds ratio, 2.78; p = 0.02). Finally, peak TG was inversely correlated with standard coagulation tests., Conclusion: While the physiologic response to injury is to upregulate plasma procoagulant activity, the patients with reduced TG required more transfusions and had poorer outcomes. Measuring TG may provide an exquisitely sensitive tool for detecting disturbances in the enzymatic phases of coagulation in critically injured patients., Level of Evidence: Prognostic/epidemiologic study, level III.
- Published
- 2014
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48. Insulin effects on glucose tolerance, hypermetabolic response, and circadian-metabolic protein expression in a rat burn and disuse model.
- Author
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Pidcoke HF, Baer LA, Wu X, Wolf SE, Aden JK, and Wade CE
- Subjects
- Animals, Biomarkers blood, Blood Glucose metabolism, Burns metabolism, Burns pathology, Burns physiopathology, Caspase 3 metabolism, Disease Models, Animal, Drug Administration Schedule, Forkhead Transcription Factors metabolism, Injections, Subcutaneous, Insulin Receptor Substrate Proteins metabolism, Male, Muscle, Skeletal drug effects, Muscle, Skeletal metabolism, Muscle, Skeletal pathology, Muscular Atrophy drug therapy, Muscular Atrophy metabolism, Muscular Atrophy pathology, Nerve Tissue Proteins metabolism, Period Circadian Proteins metabolism, Phosphorylation, Proto-Oncogene Proteins c-akt metabolism, Rats, Rats, Sprague-Dawley, Time Factors, Weight Loss drug effects, Blood Glucose drug effects, Burns drug therapy, Circadian Rhythm, Circadian Rhythm Signaling Peptides and Proteins metabolism, Energy Metabolism drug effects, Hypoglycemic Agents administration & dosage, Insulin administration & dosage
- Abstract
Insulin controls hyperglycemia after severe burns, and its use opposes the hypermetabolic response. The underlying molecular mechanisms are poorly understood, and previous research in this area has been limited because of the inadequacy of animal models to mimic the physiological effects seen in humans with burns. Using a recently published rat model that combines both burn and disuse components, we compare the effects of insulin treatment vs. vehicle on glucose tolerance, hypermetabolic response, muscle loss, and circadian-metabolic protein expression after burns. Male Sprague-Dawley rats were assigned to three groups: cage controls (n = 6); vehicle-treated burn and hindlimb unloading (VBH; n = 11), and insulin-treated burn and hindlimb unloading (IBH; n = 9). With the exception of cage controls, rats underwent a 40% total body surface area burn with hindlimb unloading, then IBH rats received 12 days of subcutaneous insulin injections (5 units·kg(-1)·day(-1)), and VBH rats received an equivalent dose of vehicle. Glucose tolerance testing was performed on day 14, after which blood and tissues were collected for analysis. Body mass loss was attenuated by insulin treatment (VBH = 265 ± 17 g vs. IBH = 283 ± 14 g, P = 0.016), and glucose clearance capacity was increased. Soleus and gastrocnemius muscle loss was decreased in the IBH group. Insulin receptor substrate-1, AKT, FOXO-1, caspase-3, and PER1 phosphorylation was altered by injury and disuse, with levels restored by insulin treatment in almost all cases. Insulin treatment after burn and during disuse attenuated the hypermetabolic response, increased glucose clearance, and normalized circadian-metabolic protein expression patterns. Therapies aimed at targeting downstream effectors may provide the beneficial effects of insulin without hypoglycemic risk.
- Published
- 2014
- Full Text
- View/download PDF
49. Establishment of methods for performing thrombelastography and calibrated automated thrombography in rats.
- Author
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Huby Mdel P, Cardenas JC, Baer LA, Pawelczyk NS, Salsbury JR, Wang YW, Matijevic N, Holcomb JB, and Wade CE
- Subjects
- Animals, Blood Coagulation Tests methods, Blood Specimen Collection standards, Cardiac Catheterization methods, Femoral Artery, Hemostasis physiology, Humans, Male, Punctures methods, Rats, Sprague-Dawley, Reference Values, Reproducibility of Results, Thrombin biosynthesis, Blood Specimen Collection methods, Disease Models, Animal, Shock, Hemorrhagic blood, Thrombelastography methods
- Abstract
Rodent models of hemorrhagic shock are paramount to our understanding of the pathophysiology of this disease, the effects on coagulation and in exploring the utility of resuscitative methods for managing patients in shock. These models usually require serial blood sampling during experimentation. The lack of standardized practices for these experimental models has resulted in technical variability, discordance in the literature, and incomparable results on blood coagulation analysis between researchers, hindering substantial progress in the field of hemorrhagic shock. The aim of this study was to define the effects of cardiac puncture versus arterial catheterization on coagulation in a rat model to provide data supporting standardization of one practice over another. Blood was collected from anesthetized rats via cardiac puncture or femoral artery catheterization and hemostatic potential analyzed by thrombelastography and calibrated automated thrombography. Our data show that blood collected via cardiac puncture demonstrated hypercoagulability as indicated by faster rates of clot formation and thrombin generation, increased overall clot strength, and a greater thrombin-generating capacity when compared with blood collected via femoral artery catheter. We conclude that blood collection methods have a profound effect on hemostatic potential, and standardization of these practices is necessary to define the effects of shock on coagulation in rodents.
- Published
- 2014
- Full Text
- View/download PDF
50. Elevated tissue plasminogen activator and reduced plasminogen activator inhibitor promote hyperfibrinolysis in trauma patients.
- Author
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Cardenas JC, Matijevic N, Baer LA, Holcomb JB, Cotton BA, and Wade CE
- Subjects
- Adult, Cohort Studies, Female, Humans, Male, Middle Aged, Prospective Studies, Severity of Illness Index, Texas, Fibrinogen analysis, Fibrinolysin analysis, Fibrinolysis physiology, Plasminogen Activator Inhibitor 1 blood, Tissue Plasminogen Activator blood, Wounds and Injuries blood, alpha-2-Antiplasmin analysis
- Abstract
Severe hyperfibrinolysis after trauma is a poorly understood phenomenon associated with profound shock, serious anatomic injuries, increased transfusions, and high mortality rates. Molecular mechanisms driving hyperfibrinolysis in trauma have not been completely delineated. The authors aimed to determine the relationship between severe hyperfibrinolysis and outcomes in trauma patients and characterize the role of the plasminogen activator (PA) system in this condition. A prospective observational study was performed in 163 adult level I trauma patients admitted between April and August 2012. Blood was collected on admission, and fibrinolysis was determined by plasmin-α2 antiplasmin (PAP) levels. Tissue-derived and urokinase PA (tPA and uPA, respectively), PA inhibitor (PAI-1), fibrinogen, and antithrombin levels were also measured. Patient demographics, vital signs, laboratory values, mechanisms and severity of injuries, transfusions, and outcomes were collected at admission or from patient records. Moderate fibrinolysis was defined as PAP level 1,500 to 20,000 μg/L and severe hyperfibrinolysis as PAP level more than 20,000 μg/L. Severe hyperfibrinolysis was observed in 10% of patients and associated with increased injury severity, greater transfusions, fewer ventilator and hospital-free days, and higher mortality. Plasmin-α2 antiplasmin level was directly correlated with tPA level and inversely correlated with PAI-1 level. Patients with both elevated tPA and reduced PAI-1 were more severely injured, received more transfusions, and experienced fewer ventilator and hospital-free days. In conclusion, Severe hyperfibrinolysis is observed in a small percentage of trauma patients and is associated with severe injuries, greater transfusions, and worse outcomes. This condition is mediated, in part, by excessive upregulation of profibrinolytic tPA in the absence of concomitant increases in antifibrinolytic PAI-1.
- Published
- 2014
- Full Text
- View/download PDF
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