26 results on '"Tzu Wen Liu"'
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2. Physical Activity Differentially Affects the Cecal Microbiota of Ovariectomized Female Rats Selectively Bred for High and Low Aerobic Capacity.
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Tzu-Wen Liu, Young-Min Park, Hannah D Holscher, Jaume Padilla, Rebecca J Scroggins, Rebecca Welly, Steven L Britton, Lauren G Koch, Victoria J Vieira-Potter, and Kelly S Swanson
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Medicine ,Science - Abstract
The gut microbiota is considered a relevant factor in obesity and associated metabolic diseases, for which postmenopausal women are particularly at risk. Increasing physical activity has been recognized as an efficacious approach to prevent or treat obesity, yet the impact of physical activity on the microbiota remains under-investigated. We examined the impacts of voluntary exercise on host metabolism and gut microbiota in ovariectomized (OVX) high capacity (HCR) and low capacity running (LCR) rats. HCR and LCR rats (age = 27 wk) were OVX and fed a high-fat diet (45% kcal fat) ad libitum and housed in cages equipped with (exercise, EX) or without (sedentary, SED) running wheels for 11 wk (n = 7-8/group). We hypothesized that increased physical activity would hinder weight gain, increase metabolic health and shift the microbiota of LCR rats, resulting in populations more similar to that of HCR rats. Animals were compared for characteristic metabolic parameters including body composition, lipid profile and energy expenditure; whereas cecal digesta were collected for DNA extraction. 16S rRNA gene-based amplicon Illumina MiSeq sequencing was performed, followed by analysis using QIIME 1.8.0 to assess cecal microbiota. Voluntary exercise decreased body and fat mass, and normalized fasting NEFA concentrations of LCR rats, despite only running one-third the distance of HCR rats. Exercise, however, increased food intake, weight gain and fat mass of HCR rats. Exercise clustered the gut microbial community of LCR rats, which separated them from the other groups. Assessments of specific taxa revealed significant (p
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- 2015
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3. Effects of ketogenic diet on cognitive functions of mice fed high-fat-high-cholesterol diet
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Dai-Ting Lin, Ning-Juo Kao, Tzu-Wen Liu Cross, Wei-Ju Lee, and Shyh-Hsiang Lin
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Male ,Nutrition and Dietetics ,Endocrinology, Diabetes and Metabolism ,Clinical Biochemistry ,Diet, High-Fat ,Biochemistry ,Mice, Inbred C57BL ,Mice ,Cholesterol ,Cognition ,Animals ,Diet, Ketogenic ,Molecular Biology ,Triglycerides - Abstract
Long-term dietary intake of elevated levels of refined sugars, fats and cholesterols is among the factors causing cognitive impairment. Ketone bodies can be used as an alternative energy source when glucose is not available. The study investigated the effects of a ketogenic diet (medium chain triglyceride, MCT) on cognitive performance after a long-term consumption of a high-fat-high-cholesterol diet using a mice model. Seventy eight-week-old male C57BL/6 mice were fed an HFHC diet for 16 weeks to establish a model of an HFHC dietary pattern, before receiving intervention diets containing MCT diet or with Metformin for another 8 weeks in the second part of the experiment. Spatial learning, memory performance, and cortical and hippocampal protein expression levels were assessed. After consuming the HFHC diet for 16 weeks and subsequently receiving the MCT diet for 8 weeks, results showed that the mice fed a MCT diet had significantly better spatial learning and memory performance, lower expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), tumor necrosis factor-α (TNF-α), glial fibrillary acidic protein (GFAP), amyloid protein precursor (APP) and phosphate tau, and higher expression of brain-derived neurotrophic factor (BDNF) than the mice fed the HFHC diet. Long-term consumption of an HFHC diet caused a decline in cognitive functions and increased the risk factors for neurodegeneration, such as BBB permeability, neuropathy and inflammation. An MCT diet can be considered as an option for slowing down the early stage of neurodegeneration in mice.
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- 2022
4. Efficient Targeting of Adipose Tissue Macrophages in Obesity with Polysaccharide Nanocarriers
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Matthew A. Wallig, Erik R. Nelson, Liang Ma, Iwona T. Dobrucki, Andrew M. Smith, Lawrence W. Dobrucki, Kelly S. Swanson, and Tzu Wen Liu
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0301 basic medicine ,Adipose tissue macrophages ,General Physics and Astronomy ,Adipose tissue ,Type 2 diabetes ,Systemic inflammation ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,Drug Delivery Systems ,Polysaccharides ,medicine ,Animals ,Macrophage ,General Materials Science ,Obesity ,Inflammation ,business.industry ,Macrophages ,General Engineering ,Cancer ,medicine.disease ,030104 developmental biology ,Dextran ,Adipose Tissue ,Diabetes Mellitus, Type 2 ,chemistry ,Immunology ,Cancer research ,Nanocarriers ,medicine.symptom ,business - Abstract
Obesity leads to an increased risk for type 2 diabetes, heart disease, stroke, and cancer. The causal link between obesity and these pathologies has recently been identified as chronic low-grade systemic inflammation initiated by pro-inflammatory macrophages in visceral adipose tissue. Current medications based on small-molecule drugs yield significant off-target side effects with long-term use, and therefore there is a major need for targeted therapies. Here we report that nanoscale polysaccharides based on biocompatible glucose polymers can efficiently target adipose macrophages in obese mice. We synthesized a series of dextran conjugates with tunable size linked to contrast agents for positron emission tomography, fluorophores for optical microscopy, and anti-inflammatory drugs for therapeutic modulation of macrophage phenotype. We observed that larger conjugates efficiently distribute to visceral adipose tissue and selectively associate with macrophages after regional peritoneal administration. Up to 63% of the injected dose remained in visceral adipose tissue 24 h after administration, resulting in2-fold higher local concentration compared to liver, the dominant site of uptake for most nanomedicines. Furthermore, a single-dose treatment of anti-inflammatory conjugates significantly reduced pro-inflammatory markers in adipose tissue of obese mice. Importantly, all components of these therapeutic agents are approved for clinical use. This work provides a promising nanomaterials-based delivery strategy to inhibit critical factors leading to obesity comorbidities and demonstrates a unique transport mechanism for drug delivery to visceral tissues. This approach may be further applied for high-efficiency targeting of other inflammatory diseases of visceral organs.
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- 2016
5. Changes in fatty acids profiles after three weeks of high-fat diet feeding in obesity-prone rats
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Tzu-Wen Liu
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- 2018
6. High-Fat Diet Alters Serum Fatty Acid Profiles in Obesity Prone Rats: Implications for In Vitro Studies
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Timothy D. Heden, John P. Thyfault, Kevin L. Fritsche, Victoria J. Vieira-Potter, E. Matthew Morris, and Tzu Wen Liu
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Male ,medicine.medical_specialty ,Clinical chemistry ,Linoleic acid ,In Vitro Techniques ,Biology ,Diet, High-Fat ,Biochemistry ,Article ,Diglycerides ,Rats, Sprague-Dawley ,chemistry.chemical_compound ,In vivo ,Internal medicine ,medicine ,Animals ,Obesity ,Phospholipids ,Triglycerides ,chemistry.chemical_classification ,Fatty Acids ,Organic Chemistry ,food and beverages ,Fatty acid ,Cell Biology ,Rats ,Disease Models, Animal ,Endocrinology ,Liver ,chemistry ,Lipotoxicity ,lipids (amino acids, peptides, and proteins) ,Arachidonic acid ,Polyunsaturated fatty acid ,Lipidology - Abstract
High-fat diets (HFD) are commonly used in rodents to induce obesity, increase serum fatty acids, and induce lipotoxicity in various organs. In-vitro studies commonly utilize individual free fatty acids (FFA) to study lipid exposure in an effort to model what is occurring in-vivo, however, these approaches are not physiological as tissues are exposed to multiple fatty acids in-vivo. Here we characterize circulating lipids in obese-prone rats fed a HFD in both fasted and fed states with the goal of developing physiologically relevant fatty acid mixtures for subsequent in-vitro studies. Rats were fed a HFD (60% kcal fat) or a control diet (10% kcal fat) for 3 weeks; liver tissue, and both portal and systemic blood was collected. Fatty acid profiles and absolute concentrations of triglycerides (TAG) and FFA in the serum and TAG, diacylglycerol (DAG), and phospholipids (PL) in the liver were measured. Surprisingly, both systemic and portal serum TAG were ~40% lower in HFD-fed compared to controls. Overall, compared to the control diet, HFD feeding consistently induced an increase in the proportion of circulating polyunsaturated fatty acids (PUFA) with a concomitant decline in monounsaturated fatty acids (MUFA), and saturated fatty acids (SFA) in both serum TAG and FFA. The elevations of PUFA were mostly attributed to increases in n-6 PUFA, linoleic acid and arachidonic acid. In conclusion, fatty acid mixtures enriched with linoleic and arachidonic acid in addition to SFA and MUFA should be utilized for in-vitro studies attempting to model lipid exposures that occur during in-vivo HFD condition.
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- 2015
7. Intrinsic aerobic capacity impacts susceptibility to acute high-fat diet-induced hepatic steatosis
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E. Matthew Morris, Justin A. Fletcher, Tzu Wen Liu, Paul S. MacLean, R. Scott Rector, Matthew R. Jackman, Stephen Britton, Jordan L. Lopez, John P. Thyfault, Grace M. Meers, Jamal A. Ibdah, Monica L. Kearney, Ginger C. Johnson, and Lauren G. Koch
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Male ,medicine.medical_specialty ,Physiology ,Endocrinology, Diabetes and Metabolism ,Biology ,Diet, High-Fat ,Lipid oxidation ,Physical Conditioning, Animal ,Physiology (medical) ,Internal medicine ,medicine ,Animals ,Resting energy expenditure ,Beta oxidation ,Cells, Cultured ,Aerobic capacity ,Exercise Tolerance ,Fatty liver ,Rats, Inbred Strains ,Articles ,medicine.disease ,Dietary Fats ,Rats ,Fatty Liver ,Respiratory quotient ,Endocrinology ,Physical Fitness ,Disease Susceptibility ,Steatosis ,medicine.symptom ,Energy Metabolism ,human activities ,Weight gain - Abstract
Aerobic capacity/fitness significantly impacts susceptibility for fatty liver and diabetes, but the mechanisms remain unknown. Herein, we utilized rats selectively bred for high (HCR) and low (LCR) intrinsic aerobic capacity to examine the mechanisms by which aerobic capacity impacts metabolic vulnerability for fatty liver following a 3-day high-fat diet (HFD). Indirect calorimetry assessment of energy metabolism combined with radiolabeled dietary food was employed to examine systemic metabolism in combination with ex vivo measurements of hepatic lipid oxidation. The LCR, but not HCR, displayed increased hepatic lipid accumulation in response to the HFD despite both groups increasing energy intake. However, LCR rats had a greater increase in energy intake and demonstrated greater daily weight gain and percent body fat due to HFD compared with HCR. Additionally, total energy expenditure was higher in the larger LCR. However, controlling for the difference in body weight, the LCR has lower resting energy expenditure compared with HCR. Importantly, respiratory quotient was significantly higher during the HFD in the LCR compared with HCR, suggesting reduced whole body lipid utilization in the LCR. This was confirmed by the observed lower whole body dietary fatty acid oxidation in LCR compared with HCR. Furthermore, LCR liver homogenate and isolated mitochondria showed lower complete fatty acid oxidation compared with HCR. We conclude that rats bred for low intrinsic aerobic capacity show greater susceptibility for dietary-induced hepatic steatosis, which is associated with a lower energy expenditure and reduced whole body and hepatic mitochondrial lipid oxidation.
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- 2014
8. Genome-Wide Association Mapping Combined with Reverse Genetics Identifies New Effectors of Low Water Potential-Induced Proline Accumulation in Arabidopsis
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Tzu Wen Liu, M. Nagaraj Kumar, Paul E. Verslues, Thomas E. Juenger, and Jesse R. Lasky
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Genetics ,biology ,Physiology ,Effector ,Genome-wide association study ,Single-nucleotide polymorphism ,Plant Science ,biology.organism_classification ,Genetic analysis ,Reverse genetics ,Arabidopsis ,Arabidopsis thaliana ,Gene - Abstract
Arabidopsis (Arabidopsis thaliana) exhibits natural genetic variation in drought response, including varying levels of proline (Pro) accumulation under low water potential. As Pro accumulation is potentially important for stress tolerance and cellular redox control, we conducted a genome-wide association (GWAS) study of low water potential-induced Pro accumulation using a panel of natural accessions and publicly available single-nucleotide polymorphism (SNP) data sets. Candidate genomic regions were prioritized for subsequent study using metrics considering both the strength and spatial clustering of the association signal. These analyses found many candidate regions likely containing gene(s) influencing Pro accumulation. Reverse genetic analysis of several candidates identified new Pro effector genes, including thioredoxins and several genes encoding Universal Stress Protein A domain proteins. These new Pro effector genes further link Pro accumulation to cellular redox and energy status. Additional new Pro effector genes found include the mitochondrial protease LON1, ribosomal protein RPL24A, protein phosphatase 2A subunit A3, a MADS box protein, and a nucleoside triphosphate hydrolase. Several of these new Pro effector genes were from regions with multiple SNPs, each having moderate association with Pro accumulation. This pattern supports the use of summary approaches that incorporate clusters of SNP associations in addition to consideration of individual SNP probability values. Further GWAS-guided reverse genetics promises to find additional effectors of Pro accumulation. The combination of GWAS and reverse genetics to efficiently identify new effector genes may be especially applicable for traits difficult to analyze by other genetic screening methods.
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- 2013
9. COMPARISON OF DIET VS. EXERCISE ON METABOLIC FUNCTION & GUT MICROBIOTA IN OBESE RATS
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Terese M. Zidon, Victoria J. Vieira-Potter, Joe L. Rowles, Jaume Padilla, Tzu Wen Liu, Kelly S. Swanson, Rebecca J. Welly, T. Nicholas Smith, and Young-Min Park
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0301 basic medicine ,Male ,medicine.medical_specialty ,Adipose tissue ,Physical Therapy, Sports Therapy and Rehabilitation ,Inflammation ,Gut flora ,Diet, High-Fat ,Article ,03 medical and health sciences ,0302 clinical medicine ,Insulin resistance ,Internal medicine ,Physical Conditioning, Animal ,Brown adipose tissue ,medicine ,Animals ,Orthopedics and Sports Medicine ,Obesity ,Adiposity ,Metabolic function ,biology ,business.industry ,Lipid metabolism ,medicine.disease ,biology.organism_classification ,Lipid Metabolism ,Lipids ,Gastrointestinal Microbiome ,Rats ,030104 developmental biology ,medicine.anatomical_structure ,Endocrinology ,Adipose Tissue ,medicine.symptom ,Insulin Resistance ,business ,Energy Metabolism ,030217 neurology & neurosurgery - Abstract
Cardiometabolic impairments that begin early in life are particularly critical, because they often predict metabolic dysfunction in adulthood. Obesity, high-fat diet (HFD), and inactivity are all associated with adipose tissue (AT) inflammation and insulin resistance (IR), major predictors of metabolic dysfunction. Recent evidence has also associated the gut microbiome with cardiometabolic health.The objective of this study is to compare equal energy deficits induced by exercise and caloric reduction on cardiometabolic disease risk parameters including AT inflammation, IR, and gut microbiota changes during HFD consumption.Obesity-prone rats fed HFD were exercise trained (Ex, n = 10) or weight matched to Ex via caloric reduction although kept sedentary (WM, n = 10), and compared with ad libitum HFD-fed (Sed, n = 10) rats for IR, systemic energetics and spontaneous physical activity (SPA), adiposity, and fasting metabolic parameters. Visceral, subcutaneous, periaortic, and brown AT (BAT), liver, aorta, and cecal digesta were examined.Despite identical reductions in adiposity, Ex, but not WM, improved IR, increased SPA by approximately 26% (P0.05 compared with WM and Sed), and reduced LDL cholesterol (P0.05 compared with Sed). WM and Ex both reduced inflammatory markers in all AT depots and aorta, whereas only Ex increased indicators of mitochondrial function in BAT. Ex significantly increased the relative abundance of cecal Streptococcaceae and decreased S24-7 and one undefined genus in Rikenellaceae; WM induced similar changes but did not reach statistical significance.Both Ex and WM reduced AT inflammation across depots, whereas Ex caused more robust changes to gut microbial communities, improved IR, increased fat oxidation, increased SPA, and increased indices of BAT mitochondrial function. Our findings add to the growing body of literature indicating that there are weight-loss-independent metabolic benefits of exercise.
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- 2016
10. Performance of a 270,000 CMD integrated membrane system for water supply in Taiwan
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Benson Liao, Chao-Chang Chang, Chia-Yuan Chang, and Tzu-Wen Liu
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Waste management ,business.industry ,Environmental engineering ,Water supply ,Ocean Engineering ,Pollution ,Tap water ,Environmental science ,Water treatment ,Nanofiltration ,Turbidity ,business ,Reverse osmosis ,Subsurface flow ,Groundwater ,Water Science and Technology - Abstract
This paper presents an integrated membrane system (IMS) designed, installed by KINTECH Technology Co. Ltd. and its long term performance at Kaotan Water Treatment Plant (KTWTP). The IMS installed at KTWTP is the first membrane system as well as the first IMS for tap water production in Taiwan. The raw waters from Kaoping River, local subsurface flow and groundwater were pumped into KTWTP for the tap water supply of Kaohsiung area. Turbidity of water in the Kaoping River during the typhoon usually increases abruptly up to 5,000–10,000 NTU, greatly surpassing the upper limit of 1,500 NTU for conventional purification to be effective. In addition, field data also showed that the levels of ammonia-nitrogen, total hardness, total dissolved solid and certain inorganic constituents in local groundwater are too high to be effectively removed by conventional system. The KTWTP was established by Taiwan Water Corporation (TWC) in 1972 and initially operated on conventional process. To meet increasingly stringent dri...
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- 2011
11. Nondigestible Fructans Alter Gastrointestinal Barrier Function, Gene Expression, Histomorphology, and the Microbiota Profiles of Diet-Induced Obese C57BL/6J Mice
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Katherine R. Kerr, Kimberly D. Cephas, Kelly S. Swanson, Kelly A. Tappenden, Heather F. Mangian, Hannah D. Holscher, and Tzu Wen Liu
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0301 basic medicine ,Dietary Fiber ,Male ,Monocarboxylic Acid Transporters ,medicine.medical_specialty ,Inulin ,Medicine (miscellaneous) ,Gene Expression ,Mice, Obese ,Oligosaccharides ,Gut flora ,Diet, High-Fat ,Weight Gain ,Intestinal absorption ,Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,Feces ,Intestinal mucosa ,Internal medicine ,Occludin ,medicine ,Animals ,Intestine, Large ,Obesity ,RNA, Messenger ,Intestinal Mucosa ,Cellulose ,Inflammation ,Nutrition and Dietetics ,biology ,Bacteria ,Symporters ,Fructooligosaccharide ,Akkermansia ,biology.organism_classification ,Fructans ,Gastrointestinal Microbiome ,Mice, Inbred C57BL ,030104 developmental biology ,Endocrinology ,chemistry ,Intestinal Absorption ,medicine.symptom ,Weight gain ,Diet-induced obese - Abstract
BACKGROUND Obesity is associated with compromised intestinal barrier function and shifts in gastrointestinal microbiota that may contribute to inflammation. Fiber provides benefits, but impacts of fiber type are not understood. OBJECTIVE We aimed to determine the impact of cellulose compared with fructans on the fecal microbiota and gastrointestinal physiology in obese mice. METHODS Eighteen-wk-old male diet-induced obese C57BL/6J mice (n = 6/group; 40.5 g) were fed high-fat diets (45% kcal fat) containing 5% cellulose (control), 10% cellulose, 10% short-chain fructooligosaccharides (scFOS), or 10% inulin for 4 wk. Cecal and colon tissues were collected to assess barrier function, histomorphology, and gene expression. Fecal DNA extracts were subjected to 16S ribosomal RNA amplicon-based Illumina MiSeq sequencing to assess microbiota. RESULTS Body weight gain was greater (P < 0.05) in scFOS-fed than in 10% cellulose-fed mice. Both groups of fructan-fed mice had greater (P < 0.05) cecal crypt depth (scFOS: 141 μm; inulin: 145 μm) than both groups of cellulose-fed mice (5% and 10%: 109 μm). Inulin-fed mice had greater (P < 0.05) cecal transmural resistance (101 Ω × cm(2)) than 5% cellulose-fed controls (45 Ω × cm(2)). Inulin-fed mice had lower (P < 0.05) colonic mRNA abundance of Ocln (0.41) and Mct1 (0.35) than those fed 10% cellulose (Ocln: 1.28; Mct1: 0.90). Fructan and cellulose groups had different UniFrac distances of fecal microbiota (P < 0.05) and α diversity, which demonstrated lower (P < 0.01) species richness in fructan-fed mice. Mice fed scFOS had greater (P < 0.05) Actinobacteria (15.9%) and Verrucomicrobia (Akkermansia) (17.0%) than 5% controls (Actinobacteria: 0.07%; Akkermansia: 0.08%). Relative abundance of Akkermansia was positively correlated (r = 0.56, P < 0.01) with cecal crypt depth. CONCLUSIONS Fructans markedly shifted gut microbiota and improved intestinal physiology in obese mice, but the mechanisms by which they affect gut integrity and inflammation in the obese are still unknown.
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- 2015
12. Prebiotics Impact Fecal Microbiota and Gut Physiology in Diet‐Induced Obese Mice
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Kimberly D. Cephas, Katherine R. Kerr, Heather Mangian, Kelly S. Swanson, Tzu Wen Liu, Kelly A. Tappenden, and Hannah D. Holscher
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Inulin ,Crypt ,Physiology ,Biology ,Gut flora ,biology.organism_classification ,Biochemistry ,chemistry.chemical_compound ,Cecum ,Fructan ,medicine.anatomical_structure ,chemistry ,Genetics ,medicine ,Molecular Biology ,Diet-induced obese ,Barrier function ,Feces ,Biotechnology - Abstract
Obesity is associated with compromised intestinal barrier function and shifts in microbiota that may contribute to inflammation. Previous research suggests benefits of supplemental fiber, but the impacts of fermentable vs. non-fermentable fibers are not well understood. OBJECTIVE: To determine the impact of cellulose vs. fructan (short-chain fructooligosaccharides [scFOS] or inulin) supplementation on fecal microbiota and gut physiology in obese mice. METHODS: 18-wk old C57BL/6J mice (n=6/group) were fed high-fat diets (45% kcal fat) containing 5% cellulose, 10% cellulose, 10% scFOS or 10% inulin for 4-wk. Cecum and distal colon were collected to assess barrier function, histomorphology and gene expression. Fecal DNA was extracted, followed by 16S rRNA amplicon Illumina MiSeq sequencing and analysis with QIIME 1.8.0. RESULTS: Both fructans increased (p
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- 2015
13. Effects of travel on the equine cecal microbiota
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E. B. Venable, Tzu Wen Liu, Stephanie D. Bland, Kelly S. Swanson, and H.H. Holscher
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0403 veterinary science ,040301 veterinary sciences ,Equine ,business.industry ,0402 animal and dairy science ,Medicine ,04 agricultural and veterinary sciences ,business ,040201 dairy & animal science - Published
- 2017
14. Abstract B31: Sulfidogenic bacteria are an important diet-driven exposure promoting colorectal cancer in African Americans
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Xavier Llor, Timothy J. Carroll, Rosa M. Xicola, Barbara Jung, Tzu-Wen Liu, H. Rex Gaskins, Carol L. Braunschweig, Nathan A. Ellis, Lisa Tussing-Humphreys, Ece Mutlu, Patricia G. Wolf, Karin Vermillion, and Cemal Yazici
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Epidemiology ,Colorectal cancer ,Incidence (epidemiology) ,Cancer ,Environmental exposure ,Butyrate ,Reductase ,Biology ,medicine.disease ,biology.organism_classification ,Microbiology ,Oncology ,medicine ,Biomarker (medicine) ,Bacteria - Abstract
Objectives. Colorectal cancer (CRC) incidence is higher in post-industrial cultures, and the incidences varies among different populations. In the US, there is a higher incidence of CRC in African Americans (AAs) compared to non-Hispanic whites (NHWs). Recent evidence links consumption of a diet high in animal protein and fat as an environmental risk factor for the development of CRC. The intestinal microbiota is postulated to modulate the effects of diet in promoting or preventing CRC development. Hydrogen sulfide, which is produced by normal members of the colonic microenvironment (sulfidogenic bacteria), triggers pro-inflammatory and hyper-proliferative pathways, and it is genotoxic. We hypothesized that the production of hydrogen sulfide by sulfidogenic bacteria is a key environmental carcinogen contributing to CRC risk. Design. The abundance of sulfidogenic bacteria via quantitative PCR (qPCR) was compared in non-involved colonic mucosa of 97 AA and 56 NHW CRC patients and in 100 AA and 76 NHW healthy controls. In addition, we performed 16S rDNA sequencing in 61 AA cases and 94 AA controls. Additionally, we tested correlations among race, dietary intake, disease status, and sulfidogenic bacterial abundance. Results. Overall, the functional gene for hydrogen sulfide production in sulfate-reducing bacteria, dissimilatory sulfate reductase (dsrA), was more abundant in AAs than in NHWs, in both cases and controls. In addition, AA CRC cases exhibited a significantly higher abundance of Bilophila wadsworthia-specific dsrA. Linear discriminant analysis of 16S rDNA sequencing results revealed several taxa that differed between AA cases and controls, including the known butyrate producer Faecalibacterium that was more abundant in AA controls, and the sulfidogenic Pyramidobacter that was more abundant in AA CRC cases. Importantly, we found that dietary intake of protein and fat was higher in AAs compared to NHWs, and these dietary components correlated with a higher abundance of sulfidogenic bacteria. Conclusion. There were significant differences in sulfidogenic bacterial abundance between AAs and NHWs, in both cases and controls, and implicate sulfidogenic bacteria as an important diet-driven environmental exposure that contributes to the increased risk of CRC in AAs. Replication studies are needed to test that effectiveness of using B. wadsworthia as a biomarker for increased CRC risk. Citation Format: Cemal Yazici, Patricia G. Wolf, Tzu-Wen Liu, Karin Vermillion, Timothy Carroll, Ece Mutlu, Lisa Tussing-Humphreys, Carol Braunschweig, Rosa M. Xicola, Barbara Jung, Xavier Llor, Nathan A. Ellis, H. Rex Gaskins. Sulfidogenic bacteria are an important diet-driven exposure promoting colorectal cancer in African Americans. [abstract]. In: Proceedings of the Ninth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2016 Sep 25-28; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(2 Suppl):Abstract nr B31.
- Published
- 2017
15. Differential effects of low-fat and high-fat diets on fed-state hepatic triacylglycerol secretion, hepatic fatty acid profiles, and DGAT-1 protein expression in obese-prone Sprague-Dawley rats
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Young-Min Park, Monica L. Kearney, E. Matthew Morris, Tzu Wen Liu, Jill A. Kanaley, John P. Thyfault, and Timothy D. Heden
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Male ,medicine.medical_specialty ,Very low-density lipoprotein ,Physiology ,Endocrinology, Diabetes and Metabolism ,Biology ,Diet, High-Fat ,Protein expression ,Article ,Rats, Sprague-Dawley ,Physiology (medical) ,Internal medicine ,medicine ,Sprague dawley rats ,Animals ,Secretion ,Diacylglycerol O-Acyltransferase ,Obesity ,Diet, Fat-Restricted ,Triglycerides ,chemistry.chemical_classification ,Nutrition and Dietetics ,Fatty Acids ,Fatty acid ,Lipid metabolism ,High fat diet ,General Medicine ,medicine.disease ,Rats ,Endocrinology ,chemistry ,Liver - Abstract
The purpose of this study was to compare the effects of short-term low-fat (LF) and high-fat (HF) diets on fed-state hepatic triacylglycerol (TAG) secretion, the content of proteins involved in TAG assembly and secretion, fatty acid oxidation (FAO), and the fatty acid profile of stored TAG. Using selectively bred obese-prone Sprague–Dawley rats, we directly measured fed-state hepatic TAG secretion, using Tyloxapol (a lipoprotein lipase inhibitor) and a standardized oral mixed meal (45% carbohydrate, 40% fat, 15% protein) bolus in animals fed a HF or LF diet for 2 weeks, after which the rats were maintained on their respective diet for 1 week (washout) prior to the liver being excised to measure protein content, FAO, and TAG fatty acid profiles. Hepatic DGAT-1 protein expression was ∼27% lower in HF- than in LF-fed animals (p < 0.05); the protein expression of all other molecules was similar in the 2 diets. The fed-state hepatic TAG secretion rate was ∼39% lower (p < 0.05) in HF- (4.62 ± 0.18 mmol·h−1) than in LF- (7.60 ± 0.57 mmol·h−1) fed animals. Hepatic TAG content was ∼2-fold higher (p < 0.05) in HF- (1.07 ± 0.15 nmol·g−1tissue) than in LF- (0.50 ± 0.16 nmol·g−1tissue) fed animals. In addition, the fatty acid profile of liver TAG in HF-fed animals closely resembled the diet, whereas in LF-fed animals, the fatty acid profile consisted of mostly de novo synthesized fatty acids. FAO was not altered by diet. LF and HF diets differentially alter fed-state hepatic TAG secretion, hepatic fatty acid profiles, and DGAT-1 protein expression.
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- 2014
16. High‐fat diet alters serum fatty acid profiles in obesity prone rats: implications for in‐vitro studies
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E. Matthew Morris, Tzu Wen Liu, John P. Thyfault, Abiezer Blandon, Timothy D. Heden, and Kevin L. Fritsche
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chemistry.chemical_classification ,medicine.medical_specialty ,Fatty acid ,High fat diet ,Biochemistry ,In vitro ,Endocrinology ,chemistry ,Internal medicine ,Obesity prone ,Genetics ,medicine ,Molecular Biology ,Biotechnology - Published
- 2013
17. Abstract # 1854 Cohort differences in learning and memory in response to fiber feeding in genetically identical C57Bl/6J mice: A relationship to the gut microbiota?
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Keith W. Kelley, Brandt D. Pence, Pul Park, Tzu Wen Liu, Rodney W. Johnson, Jennifer L. Rytych, J.A. Woods, Jacob M. Allen, Tushar K. Bhattacharya, George C. Fahey, Justin S. Rhodes, Yi Sun, and Kelly S. Swanson
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Probe trial ,biology ,Endocrine and Autonomic Systems ,business.industry ,Immunology ,Morris water navigation task ,Physiology ,Gut flora ,C57bl 6j ,biology.organism_classification ,Biotechnology ,Behavioral Neuroscience ,UniFrac ,Cohort ,Microbiome ,Distal colon ,business - Abstract
Introduction Recent data indicates that environmental conditions early in life can alter behavioral outcomes and responses to dietary interventions in model experiments. The gut microbiota may mediate such differences. Methods Two cohorts, C1 ( n = 20) and C2 ( n = 20), of C57Bl/6J mice were randomized to a 5% pectin ( n = 20) or cellulose diet ( n = 20) for 16 weeks. Thereafter, learning and memory tests were conducted and distal colon contents were analyzed by 16S rRNA sequencing to measure compositional changes in the microbiota. Results In C1, pectin-fed mice displayed a higher percentage of time in target quadrant at the 24-h probe trial of the Morris Water Maze (MWM) versus cellulose-fed mice (p = 0.01). In C2, however, no effect of pectin was observed at the 24-h probe of MWM (p = 0.88). In both cohorts, UniFrac distance revealed a significant shift in the community structure of the microbiota by pectin feeding ( p p p Conclusions Cohort differences in the microbiome may play a pivotal role in host behavior after a dietary intervention.
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- 2016
18. 0821 Effects of meal size and frequency on the equine cecal microbiota
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Kelly S. Swanson, Tzu Wen Liu, S. S. Bland, Hannah D. Holscher, and E. B. Venable
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Meal ,Genetics ,Animal Science and Zoology ,General Medicine ,Food science ,Biology ,Food Science - Published
- 2016
19. Intron-mediated alternative splicing of Arabidopsis P5CS1 and its association with natural variation in proline and climate adaptation
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Ravi Kesari, Tzu Wen Liu, Wen-Dar Lin, Joji Grace Villamor, Thomas E. Juenger, Jesse R. Lasky, Ying Jiun C. Chen, David L. Des Marais, and Paul E. Verslues
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Proline ,Climate ,Population ,Blotting, Western ,Quantitative Trait Loci ,Adaptation, Biological ,Arabidopsis ,Exon ,Allele ,Cloning, Molecular ,education ,Transversion ,DNA Primers ,Genetics ,education.field_of_study ,Multidisciplinary ,biology ,Ornithine-Oxo-Acid Transaminase ,Reverse Transcriptase Polymerase Chain Reaction ,Alternative splicing ,Intron ,Computational Biology ,Biological Sciences ,biology.organism_classification ,Plants, Genetically Modified ,Introns ,Alternative Splicing ,Genetics, Population ,Haplotypes - Abstract
Drought-induced proline accumulation is widely observed in plants but its regulation and adaptive value are not as well understood. Proline accumulation of the Arabidopsis accession Shakdara (Sha) was threefold less than that of Landsberg erecta (L er ) and quantitative trait loci mapping identified a reduced function allele of the proline synthesis enzyme Δ 1 -pyrroline-5-carboxylate synthetase1 ( P5CS1 ) as a basis for the lower proline of Sha. Sha P5CS1 had additional TA repeats in intron 2 and a G-to-T transversion in intron 3 that were sufficient to promote alternative splicing and production of a nonfunctional transcript lacking exon 3 (exon 3-skip P5CS1 ). In Sha, and additional accessions with the same intron polymorphisms, the nonfunctional exon 3-skip P5CS1 splice variant constituted as much as half of the total P5CS1 transcript. In a larger panel of Arabidopsis accessions, low water potential-induced proline accumulation varied by 10-fold and variable production of exon 3-skip P5CS1 among accessions was an important, but not the sole, factor underlying variation in proline accumulation. Population genetic analyses suggest that P5CS1 may have evolved under positive selection, and more extensive correlation of exon 3-skip P5CS1 production than proline abundance with climate conditions of natural accessions also suggest a role of P5CS1 in local adaptation to the environment. These data identify a unique source of alternative splicing in plants, demonstrate a role of exon 3-skip P5CS1 in natural variation of proline metabolism, and suggest an association of P5CS1 and its alternative splicing with environmental adaptation.
- Published
- 2012
20. A Comparison of Inflammatory and Oxidative Stress Markers in Adipose Tissue from Weight-Matched Obese Male and Female Mice
- Author
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Kelly L. Stromsdorfer, R. Taylor Pickering, James W. Perfield, Karen Nickelson, Tzu Wen Liu, Laura C Ortinau, and Aileen F. Keating
- Subjects
Male ,medicine.medical_specialty ,lcsh:Internal medicine ,Intra-Abdominal Fat ,Article Subject ,lcsh:Specialties of internal medicine ,medicine.drug_class ,Endocrinology, Diabetes and Metabolism ,Adipose tissue ,Mice, Obese ,lcsh:Medicine ,Inflammation ,Biology ,lcsh:Diseases of the endocrine glands. Clinical endocrinology ,chemistry.chemical_compound ,Mice ,Sex Factors ,lcsh:RC581-951 ,Internal medicine ,Adipocyte ,medicine ,Animals ,Obesity ,RNA, Messenger ,lcsh:RC31-1245 ,Glucose tolerance test ,lcsh:RC648-665 ,Adiponectin ,medicine.diagnostic_test ,lcsh:R ,General Medicine ,Glucose Tolerance Test ,medicine.disease ,Mice, Inbred C57BL ,Disease Models, Animal ,Oxidative Stress ,Endocrinology ,chemistry ,Adipose Tissue ,Estrogen ,Female ,medicine.symptom ,Research Article - Abstract
Expansion of intra-abdominal adipose tissue and the accompanying inflammatory response has been put forward as a unifying link between obesity and the development of chronic diseases. However, an apparent sexual dimorphism exists between obesity and chronic disease risk due to differences in the distribution and abundance of adipose tissue. A range of experimental protocols have been employed to demonstrate the role of estrogen in regulating health benefits; however, most studies are confounded by significant differences in body weight and adiposity. Therefore, the purpose of this study was to compare weight-matched obese male and female mice to determine if the sex-dependent health benefits remain when body weight is similar. The development of obesity in female mice receiving a high-fat diet was delayed; however, subsequent comparisons of weight-matched obese mice revealed greater adiposity in obese female mice. Despite excess adiposity and enlarged adipocyte size, obese females remained more glucose tolerant than weight-matched male mice, and this benefit was associated with increased expression of adiponectin and reductions in immune cell infiltration and oxidative stress in adipose tissue. Therefore, the protective benefits of estrogen persist in the obese state and appear to improve the metabolic phenotype of adipose tissue and the individual.
- Published
- 2012
21. Physical Activity Differentially Affects the Cecal Microbiota of Ovariectomized Female Rats Selectively Bred for High and Low Aerobic Capacity
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Rebecca J. Welly, Lauren G. Koch, Jaume Padilla, Tzu Wen Liu, Rebecca J. Scroggins, Steven L. Britton, Kelly S. Swanson, Hannah D. Holscher, Victoria J. Vieira-Potter, and Young-Min Park
- Subjects
medicine.medical_specialty ,Ovariectomy ,Firmicutes ,lcsh:Medicine ,Motor Activity ,Biology ,Gut flora ,Cyanobacteria ,Cecum ,NEFA ,Physical Conditioning, Animal ,RNA, Ribosomal, 16S ,Internal medicine ,Proteobacteria ,medicine ,Animals ,Humans ,Obesity ,lcsh:Science ,computer.programming_language ,2. Zero hunger ,Multidisciplinary ,medicine.diagnostic_test ,sed ,Microbiota ,Ovary ,lcsh:R ,medicine.disease ,biology.organism_classification ,Aerobiosis ,Rats ,Endocrinology ,medicine.anatomical_structure ,Biochemistry ,Ovariectomized rat ,Female ,lcsh:Q ,medicine.symptom ,Lipid profile ,human activities ,Weight gain ,computer ,Research Article - Abstract
The gut microbiota is considered a relevant factor in obesity and associated metabolic diseases, for which postmenopausal women are particularly at risk. Increasing physical activity has been recognized as an efficacious approach to prevent or treat obesity, yet the impact of physical activity on the microbiota remains under-investigated. We examined the impacts of voluntary exercise on host metabolism and gut microbiota in ovariectomized (OVX) high capacity (HCR) and low capacity running (LCR) rats. HCR and LCR rats (age = 27 wk) were OVX and fed a high-fat diet (45% kcal fat) ad libitum and housed in cages equipped with (exercise, EX) or without (sedentary, SED) running wheels for 11 wk (n = 7-8/group). We hypothesized that increased physical activity would hinder weight gain, increase metabolic health and shift the microbiota of LCR rats, resulting in populations more similar to that of HCR rats. Animals were compared for characteristic metabolic parameters including body composition, lipid profile and energy expenditure; whereas cecal digesta were collected for DNA extraction. 16S rRNA gene-based amplicon Illumina MiSeq sequencing was performed, followed by analysis using QIIME 1.8.0 to assess cecal microbiota. Voluntary exercise decreased body and fat mass, and normalized fasting NEFA concentrations of LCR rats, despite only running one-third the distance of HCR rats. Exercise, however, increased food intake, weight gain and fat mass of HCR rats. Exercise clustered the gut microbial community of LCR rats, which separated them from the other groups. Assessments of specific taxa revealed significant (p
- Published
- 2015
22. Comparison of Diet versus Exercise on Metabolic Function and Gut Microbiota in Obese Rats.
- Author
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WELLY, REBECCA J., TZU-WEN LIU, ZIDON, TERESE M., ROWLES III, JOE L., YOUNG-MIN PARK, SMITH, T. NICHOLAS, SWANSON, KELLY S., PADILLA, JAUME, and VIEIRA-POTTER, VICTORIA J.
- Subjects
- *
OBESITY treatment , *ADIPOSE tissues , *ANIMAL experimentation , *BIOTIC communities , *COMPARATIVE studies , *DIET , *EXERCISE , *INFLAMMATION , *INGESTION , *INSULIN resistance , *PROBABILITY theory , *RATS , *STOMACH , *WEIGHT loss , *PHYSICAL activity , *DESCRIPTIVE statistics - Abstract
Cardiometabolic impairments that begin early in life are particularly critical, because they often predict metabolic dysfunction in adulthood. Obesity, high-fat diet (HFD), and inactivity are all associated with adipose tissue (AT) inflammation and insulin resistance (IR), major predictors of metabolic dysfunction. Recent evidence has also associated the gut microbiome with cardiometabolic health. Purpose: The objective of this study is to compare equal energy deficits induced by exercise and caloric reduction on cardiometabolic disease risk parameters including AT inflammation, IR, and gut microbiota changes during HFD consumption. Methods: Obesity-prone rats fed HFD were exercise trained (Ex, n = 10) or weight matched to Ex via caloric reduction although kept sedentary (WM, n = 10), and compared with ad libitum HFD-fed (Sed, n = 10) rats for IR, systemic energetics and spontaneous physical activity (SPA), adiposity, and fasting metabolic parameters. Visceral, subcutaneous, periaortic, and brown AT (BAT), liver, aorta, and cecal digesta were examined. Results: Despite identical reductions in adiposity, Ex, but not WM, improved IR, increased SPA by approximately 26% (P < 0.05 compared with WM and Sed), and reduced LDL cholesterol (P < 0.05 compared with Sed). WM and Ex both reduced inflammatory markers in all AT depots and aorta, whereas only Ex increased indicators of mitochondrial function in BAT. Ex significantly increased the relative abundance of cecal Streptococcaceae and decreased S24-7 and one undefined genus in Rikenellaceae; WM induced similar changes but did not reach statistical significance. Conclusions: Both Ex and WM reduced AT inflammation across depots, whereas Ex caused more robust changes to gut microbial communities, improved IR, increased fat oxidation, increased SPA, and increased indices of BAT mitochondrial function. Our findings add to the growing body of literature indicating that there are weight-loss-independent metabolic benefits of exercise [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
23. Nondigestible Fructans Alter Gastrointestinal Barrier Function, Gene Expression, Histomorphology, and the Microbiota Profiles of Diet-Induced Obese C57BL/6J Mice.
- Author
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Tzu-Wen Liu, Cephas, Kimberly D., Holscher, Hannah D., Kerr, Katherine R., Mangian, Heather F., Tappenden, Kelly A., Swanson, Kelly S., and Liu, Tzu-Wen
- Subjects
- *
FRUCTANS , *GASTROINTESTINAL system physiology , *GENE expression in mammals , *DIET in disease , *OBESITY in animals , *LABORATORY mice , *INULIN , *MICROBIOLOGY , *FECES , *PROTEIN metabolism , *RNA metabolism , *OBESITY complications , *ANIMAL experimentation , *BACTERIA , *CELLULOSE , *COMPARATIVE studies , *DIET , *DIETARY fiber , *GENE expression , *GLUCANS , *INFLAMMATION , *INTESTINAL absorption , *INTESTINAL mucosa , *LARGE intestine , *OLIGOSACCHARIDES , *RESEARCH methodology , *MEDICAL cooperation , *MEMBRANE proteins , *MICE , *OBESITY , *POLYSACCHARIDES , *PROTEINS , *RESEARCH , *WEIGHT gain , *EVALUATION research , *ION transport (Biology) , *THERAPEUTICS - Abstract
Background: Obesity is associated with compromised intestinal barrier function and shifts in gastrointestinal microbiota that may contribute to inflammation. Fiber provides benefits, but impacts of fiber type are not understood.Objective: We aimed to determine the impact of cellulose compared with fructans on the fecal microbiota and gastrointestinal physiology in obese mice.Methods: Eighteen-wk-old male diet-induced obese C57BL/6J mice (n = 6/group; 40.5 g) were fed high-fat diets (45% kcal fat) containing 5% cellulose (control), 10% cellulose, 10% short-chain fructooligosaccharides (scFOS), or 10% inulin for 4 wk. Cecal and colon tissues were collected to assess barrier function, histomorphology, and gene expression. Fecal DNA extracts were subjected to 16S ribosomal RNA amplicon-based Illumina MiSeq sequencing to assess microbiota.Results: Body weight gain was greater (P < 0.05) in scFOS-fed than in 10% cellulose-fed mice. Both groups of fructan-fed mice had greater (P < 0.05) cecal crypt depth (scFOS: 141 μm; inulin: 145 μm) than both groups of cellulose-fed mice (5% and 10%: 109 μm). Inulin-fed mice had greater (P < 0.05) cecal transmural resistance (101 Ω × cm(2)) than 5% cellulose-fed controls (45 Ω × cm(2)). Inulin-fed mice had lower (P < 0.05) colonic mRNA abundance of Ocln (0.41) and Mct1 (0.35) than those fed 10% cellulose (Ocln: 1.28; Mct1: 0.90). Fructan and cellulose groups had different UniFrac distances of fecal microbiota (P < 0.05) and α diversity, which demonstrated lower (P < 0.01) species richness in fructan-fed mice. Mice fed scFOS had greater (P < 0.05) Actinobacteria (15.9%) and Verrucomicrobia (Akkermansia) (17.0%) than 5% controls (Actinobacteria: 0.07%; Akkermansia: 0.08%). Relative abundance of Akkermansia was positively correlated (r = 0.56, P < 0.01) with cecal crypt depth.Conclusions: Fructans markedly shifted gut microbiota and improved intestinal physiology in obese mice, but the mechanisms by which they affect gut integrity and inflammation in the obese are still unknown. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
24. Intrinsic aerobic capacity impacts susceptibility to acute high-fat diet-induced hepatic steatosis.
- Author
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Morris, E. Matthew, Jackman, Matthew R., Johnson, Ginger C., Tzu-Wen Liu, Lopez, Jordan L., Kearney, Monica L., Fletcher, Justin A., Meers, Grace M. E., Koch, Lauren G., Britton, Stephen L., Scott Rector, R., Ibdah, Jamal A., MacLean, Paul S., and Thyfault, John P.
- Subjects
FATTY degeneration ,DISEASE susceptibility ,FATTY liver ,DIABETES ,AEROBIC capacity ,CARDIOPULMONARY fitness measurement - Abstract
Aerobic capacity/ fitness significantly impacts susceptibility for fatty liver and diabetes, but the mechanisms remain unknown. Herein, we utilized rats selectively bred for high (HCR) and low (LCR) intrinsic aerobic capacity to examine the mechanisms by which aerobic capacity impacts metabolic vulnerability for fatty liver following a 3-day high-fat diet (HFD). Indirect calorimetry assessment of energy metabolism combined with radiolabeled dietary food was employed to examine systemic metabolism in combination with ex vivo measurements of hepatic lipid oxidation. The LCR, but not HCR, displayed increased hepatic lipid accumulation in response to the HFD despite both groups increasing energy intake. However, LCR rats had a greater increase in energy intake and demonstrated greater daily weight gain and percent body fat due to HFD compared with HCR. Additionally, total energy expenditure was higher in the larger LCR. However, controlling for the difference in body weight, the LCR has lower resting energy expenditure compared with HCR. Importantly, respiratory quotient was significantly higher during the HFD in the LCR compared with HCR, suggesting reduced whole body lipid utilization in the LCR. This was confirmed by the observed lower whole body dietary fatty acid oxidation in LCR compared with HCR. Furthermore, LCR liver homogenate and isolated mitochondria showed lower complete fatty acid oxidation compared with HCR. We conclude that rats bred for low intrinsic aerobic capacity show greater susceptibility for dietary-induced hepatic steatosis, which is associated with a lower energy expenditure and reduced whole body and hepatic mitochondrial lipid oxidation. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
25. Genome-Wide Association Mapping Combined with Reverse Genetics Identifies New Effectors of Low Water Potential-Induced Proline Accumulation in Arabidopsis.
- Author
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Verslues, Paul E., Lasky, Jesse R., Juenger, Thomas E., Tzu-Wen Liu, and Kumar, M. Nagaraj
- Subjects
GENOMICS ,MOLECULAR genetics ,REVERSE genetics ,GENETICS ,ARABIDOPSIS - Abstract
Arabidopsis (Arabidopsis thaliana) exhibits natural genetic variation in drought response, including varying levels of proline (Pro) accumulation under low water potential. As Pro accumulation is potentially important for stress tolerance and cellular redox control, we conducted a genome-wide association (GWAS) study of low water potential-induced Pro accumulation using a panel of natural accessions and publicly available single-nucleotide polymorphism (SNP) data sets. Candidate genomic regions were prioritized for subsequent study using metrics considering both the strength and spatial clustering of the association signal. These analyses found many candidate regions likely containing gene(s) influencing Pro accumulation. Reverse genetic analysis of several candidates identified new Pro effector genes, including thioredoxins and several genes encoding Universal Stress Protein A domain proteins. These new Pro effector genes further link Pro accumulation to cellular redox and energy status. Additional new Pro effector genes found include the mitochondrial protease LON1, ribosomal protein RPL24A, protein phosphatase 2A subunit A3, a MADS box protein, and a nucleoside triphosphate hydrolase. Several of these new Pro effector genes were from regions with multiple SNPs, each having moderate association with Pro accumulation. This pattern supports the use of summary approaches that incorporate clusters of SNP associations in addition to consideration of individual SNP probability values. Further GWAS-guided reverse genetics promises to find additional effectors of Pro accumulation. The combination of GWAS and reverse genetics to efficiently identify new effector genes may be especially applicable for traits difficult to analyze by other genetic screening methods. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
26. A Comparison of Inflammatory and Oxidative Stress Markers in Adipose Tissue from Weight-Matched Obese Male and Female Mice.
- Author
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Nickelson, Karen J., Stromsdorfer, Kelly L., Pickering, R. Taylor, Tzu-Wen Liu, Ortinau, Laura C., Keating, Aileen F., and Perfield II, James W.
- Subjects
ADIPOSE tissues ,CHRONIC diseases ,OBESITY ,DIMORPHISM (Biology) ,BODY weight - Abstract
Expansion of intra-abdominal adipose tissue and the accompanying inflammatory response has been put forward as a unifying link between obesity and the development of chronic diseases. However, an apparent sexual dimorphism exists between obesity and chronic disease risk due to differences in the distribution and abundance of adipose tissue. A range of experimental protocols have been employed to demonstrate the role of estrogen in regulating health benefits; however, most studies are confounded by significant differences in body weight and adiposity. Therefore, the purpose of this study was to compare weight-matched obese male and female mice to determine if the sex-dependent health benefits remain when body weight is similar. The development of obesity in female mice receiving a high-fat diet was delayed; however, subsequent comparisons of weight-matched obese mice revealed greater adiposity in obese female mice. Despite excess adiposity and enlarged adipocyte size, obese females remained more glucose tolerant than weight-matched male mice, and this benefit was associated with increased expression of adiponectin and reductions in immune cell infiltration and oxidative stress in adipose tissue. Therefore, the protective benefits of estrogen persist in the obese state and appear to improve the metabolic phenotype of adipose tissue and the individual. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
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