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OBJECTIVES: Adipose tissue has been associated with knee osteoarthritis (KOA) pathogenesis, but the longitudinal changes in adipose tissue with KOA progression have not been carefully evaluated. This study aimed to determine if longitudinal changes of systemic and local adipose tissue is associated with radiographic progression of KOA. METHODS: This case-control study used data from the Osteoarthritis Initiative (OAI) and included 315 cases (all the right knees with a minimum of Kellgren-Lawrence score (KL) of 0 and an increase of ≥ 1 KL from baseline to 48 months) and 315 controls matched by age, sex, race, and baseline KL. Cross sectional area of IPFP (IPFP CSA) and subcutaneous adipose tissue around the distal thigh (SCATthigh) were measured using MRI images at baseline and 24 months. Conditional logistic regression models were fitted to estimate associations of obesity markers, IPFP CSA, and SCATthigh with radiographic KOA progression. Mediation analysis was used to assess whether IPFP CSA or SCATthigh mediates the relationships between baseline BMI and radiographic KOA progression. RESULTS: 24-month changes of IPFP CSA (ΔIPFP CSA) and SCATthigh (ΔSCATthigh) were significantly greater in cases compared to controls, whereas Δ BMI and Δ abdominal circumference were similar in both groups during follow-up. Adjusted ORs for radiographic KOA progression were 9.299, 95% CI (5.357-16.141) per 1 SD increase of Δ IPFP CSA and 1.646, 95% CI (1.288-2.103) per 1 SD increase of Δ SCATthigh. ΔIPFP CSA mediated the association between baseline BMI and radiographic KOA progression (87%). CONCLUSIONS: Subjects with radiographic progression of KOA, had significant increases in IPFP CSA and subcutaneous adipose tissue while BMI and abdominal circumference remained stable. Additional studies are needed to confirm these associations.

Healthy adipose tissue is essential for normal physiology. There are 2 broad types of adipose tissue depots: brown adipose tissue (BAT), which contains adipocytes poised to burn energy through thermogenesis, and white adipose tissue (WAT), which contains adipocytes that store lipids. However, within those types of adipose, adipocytes possess depot and cell-specific properties that have important implications. For example, the subcutaneous and visceral WAT confers divergent risk for metabolic disease. Further, within a depot, different adipocytes can have distinct properties; subcutaneous WAT can contain adipocytes with either white or brown-like (beige) adipocyte properties. However, the pathways that regulate and maintain this cell and depot-specificity are incompletely understood. Here, we found that the transcription factor KLF15 is required for maintaining white adipocyte properties selectively within the subcutaneous WAT. We revealed that deletion of Klf15 is sufficient to induce beige adipocyte properties and that KLF15s direct regulation of Adrb1 is a critical molecular mechanism for this process. We uncovered that this activity is cell autonomous but has systemic implications in mouse models and is conserved in primary human adipose cells. Our results elucidate a pathway for depot-specific maintenance of white adipocyte properties that could enable the development of therapies for obesity and associated diseases.

Subcutaneous white adipose tissue (scWAT) is a dynamic storage and secretory organ that regulates systemic homeostasis, yet the impact of endurance exercise training (ExT) and sex on its molecular landscape is not fully established. Utilizing an integrative multi-omics approach, and leveraging data generated by the Molecular Transducers of Physical Activity Consortium (MoTrPAC), we show profound sexual dimorphism in the scWAT of sedentary rats and in the dynamic response of this tissue to ExT. Specifically, the scWAT of sedentary females displays -omic signatures related to insulin signaling and adipogenesis, whereas the scWAT of sedentary males is enriched in terms related to aerobic metabolism. These sex-specific -omic signatures are preserved or amplified with ExT. Integration of multi-omic analyses with phenotypic measures identifies molecular hubs predicted to drive sexually distinct responses to training. Overall, this study underscores the powerful impact of sex on adipose tissue biology and provides a rich resource to investigate the scWAT response to ExT.

BackgroundObesity influences the development of osteoarthritis via low-grade inflammation. Progression of local inflammation (= synovitis) increased with weight gain in overweight and obese women compared to stable weight. Synovitis could be associated with subcutaneous fat (SCF) around the knee. Purpose of the study was to investigate the effect of weight loss on synovitis progression and to assess whether SCF around the knee mediates the relationship between weight loss and synovitis progression.MethodsWe included 234 overweight and obese participants (body mass index [BMI] ≥ 25 kg/m2) from the Osteoarthritis Initiative (OAI) with > 10% weight loss (n = 117) or stable overweight (

ObjectiveTo assess (i) the impact of changes in body weight on changes in joint-adjacent subcutaneous fat (SCF) and cartilage thickness over 4 years and (ii) the relation between changes in joint-adjacent SCF and knee cartilage thickness.DesignIndividuals from the Osteoarthritis Initiative (total=399) with > 10% weight gain (n=100) and > 10% weight loss (n=100) over 4 years were compared to a matched control cohort with less than 3% change in weight (n=199). 3.0T Magnetic Resonance Imaging (MRI) of the right knee was performed at baseline and after 4 years to quantify joint-adjacent SCF and cartilage thickness. Linear regression models were used to evaluate the associations between the (i) weight change group and 4-year changes in both knee SCF and cartilage thickness, and (ii) 4-year changes in knee SCF and in cartilage thickness. Analyses were adjusted for age, sex, baseline body mass index (BMI), tibial diameter (and weight change group in analysis (ii)).ResultsIndividuals who lost weight over 4-years had significantly less joint-adjacent SCF (beta range, medial/lateral joint sides: 2.2-4.2 mm, p

BACKGROUND: Adipocytes are crucial regulators of cardiovascular health. However, not much is known about gene expression profiles of adipocytes residing in nonfat cardiovascular tissues, their genetic regulation, and contribution to coronary artery disease. Here, we investigated whether and how the gene expression profiles of adipocytes in the subcutaneous adipose tissue differ from adipocytes residing in the heart. METHODS: We used single-nucleus RNA-sequencing data sets of subcutaneous adipose tissue and heart and performed in-depth analysis of tissue-resident adipocytes and their cell-cell interactions. RESULTS: We first discovered tissue-specific features of tissue-resident adipocytes, identified functional pathways involved in their tissue specificity, and found genes with cell type-specific expression enrichment in tissue-resident adipocytes. By following up these results, we discovered the propanoate metabolism pathway as a novel distinct characteristic of the heart-resident adipocytes and found a significant enrichment of coronary artery disease genome-wide association study risk variants among the right atrium-specific adipocyte marker genes. Our cell-cell communication analysis identified 22 specific heart adipocyte-associated ligand-receptor pairs and signaling pathways, including THBS (thrombospondin) and EPHA (ephrin type-A), further supporting the distinct tissue-resident role of heart adipocytes. Our results also suggest chamber-level coordination of heart adipocyte expression profiles as we observed a consistently larger number of adipocyte-associated ligand-receptor interactions and functional pathways in the atriums than ventricles. CONCLUSIONS: Overall, we introduce a new function and genetic link to coronary artery disease for the previously unexplored heart-resident adipocytes.

Aims/hypothesisSouth Asians have a two- to fivefold higher risk of developing type 2 diabetes than those of white European descent. Greater central adiposity and storage of fat in deeper or ectopic depots are potential contributing mechanisms. We collated existing and new data on the amount of subcutaneous (SAT), visceral (VAT) and liver fat in adults of South Asian and white European descent to provide a robust assessment of potential ethnic differences in these factors.MethodsWe performed a systematic review of the Embase and PubMed databases from inception to August 2021. Unpublished imaging data were also included. The weighted standardised mean difference (SMD) for each adiposity measure was estimated using random-effects models. The quality of the studies was assessed using the ROBINS-E tool for risk of bias and overall certainty of the evidence was assessed using the GRADE approach. The study was pre-registered with the OSF Registries ( https://osf.io/w5bf9 ).ResultsWe summarised imaging data on SAT, VAT and liver fat from eight published and three previously unpublished datasets, including a total of 1156 South Asian and 2891 white European men, and 697 South Asian and 2271 white European women. Despite South Asian men having a mean BMI approximately 0.5-0.7 kg/m2 lower than white European men (depending on the comparison), nine studies showed 0.34 SMD (95% CI 0.12, 0.55; I2=83%) more SAT and seven studies showed 0.56 SMD (95% CI 0.14, 0.98; I2=93%) more liver fat, but nine studies had similar VAT (-0.03 SMD; 95% CI -0.24, 0.19; I2=85%) compared with their white European counterparts. South Asian women had an approximately 0.9 kg/m2 lower BMI but 0.31 SMD (95% CI 0.14, 0.48; I2=53%) more liver fat than their white European counterparts in five studies. Subcutaneous fat levels (0.03 SMD; 95% CI -0.17, 0.23; I2=72%) and VAT levels (0.04 SMD; 95% CI -0.16, 0.24; I2=71%) did not differ significantly between ethnic groups in eight studies of women.Conclusions/interpretationSouth Asian men and women appear to store more ectopic fat in the liver compared with their white European counterparts with similar BMI levels. Given the emerging understanding of the importance of liver fat in diabetes pathogenesis, these findings help explain the greater diabetes risks in South Asians.FundingThere was no primary direct funding for undertaking the systematic review and meta-analysis.

ObjectivesTraditional fat contouring is now regularly performed using numerous office- based less invasive techniques. However, some limitations of these minimally invasive techniques include high cost or limited selectivity with performing localized contouring and reduction of fat. These shortcomings may potentially be addressed by electrochemical lipolysis (ECLL), a novel approach that involves the insertion of electrodes into tissue followed by application of a direct current (DC) electrical potential. This results in the hydrolysis of tissue water creating active species that lead to fat necrosis and apoptosis. ECLL can be accomplished using a simple voltage-driven system (V-ECLL) or a potential-driven feedback cell (P-ECLL) both leading to water electrolysis and the creation of acid and base in situ. The aim of this study is to determine the long-lasting effects of targeted ECLL in a Yucatan pig model.MethodsA 5-year-old Yucatan pig was treated with both V-ECLL and P-ECLL in the subcutaneous fat layer using 80:20 platinum:iridium needle electrodes along an 8 cm length. Dosimetry parameters included 5 V V-ECLL for 5, 10, and 20 minutes, and -1.5 V P-ECLL, -2.5 V P-ECLL, -3.5 V P-ECLL for 5 minutes. The pig was assessed for changes in fat reduction over 3 months with digital photography and ultrasound. After euthanasia, tissue sections were harvested and gross pathology and histology were examined.ResultsV-ECLL and P-ECLL treatments led to visible fat reduction (12.1%-27.7% and 9.4%-40.8%, respectively) and contour changes across several parameters. An increased reduction of the superficial fat layer occurred with increased dosimetry parameters with an average charge transfer of 12.5, 24.3, and 47.5 C transferred for 5 V V-ECLL for 5, 10, and 20 minutes, respectively, and 2.0, 11.5, and 24.0 C for -1.5 V P-ECLL, -2.5 V P-ECLL, -3.5 V P-ECLL for 5 minutes, respectively. These dose-dependent changes were also evidenced by digital photography, gross pathology, ultrasound imaging, and histology.ConclusionsECLL results in selective damage and long-lasting changes to the adipose layer in vivo. These changes are dose-dependent, thus allowing for more precise contouring of target areas. P-ECLL has greater efficiency and control of total charge transfer compared to V-ECLL, suggesting that a low-voltage potentiostat treatment can result in fat apoptosis equivalent to a high-voltage DC system.

Background and aimsAccumulation of visceral adipose tissue is associated with hepatic inflammation and fibrosis, suggestive of its metabolic and inflammatory properties. We aimed to examine the histologic findings of visceral and subcutaneous adipose tissue and to associate these findings with clinical and radiologic characteristics in patients with cirrhosis.MethodsIncluded were 55 adults with cirrhosis who underwent liver transplantation from 3/2017-12/2018 and had an abdominal computed tomography (CT) scan within 6 months prior to transplant. Visceral-to-subcutaneous adipose tissue ratio (VSR) was calculated using visceral (VATI) and subcutaneous adipose tissue index (SATI) quantified by CT at the L3-vertebral level and normalized for height (cm2/m2). VAT (greater omentum), SAT (abdominal wall), and skeletal muscle (rectus abdominis) biopsies were collected at transplant.ResultsMajority of patients had VAT inflammation (71%); only one patient (2%) had SAT inflammation. Patients with VAT inflammation had similar median VATI (42 vs 41 cm2/m2), lower median SATI (64 vs 97 cm2/m2), and higher median VSR (0.63 vs 0.37, p = 0.002) than patients without inflammation. In univariable logistic regression, VSR was associated with VAT inflammation (OR 1.47, 95%CI 1.11-1.96); this association remained significant even after adjusting for age, sex, BMI, HCC, or MELD-Na on bivariable analyses.ConclusionIn patients with cirrhosis undergoing liver transplantation, histologic VAT inflammation was common, but SAT inflammation was not. Increased VSR was independently associated with VAT inflammation. Given the emerging data demonstrating the prognostic value of VSR, our findings support the value of CT-quantified VSR as a prognostic marker for adverse outcomes in the liver transplant setting.

BackgroundHigher levels of intra-abdominal adipose tissue (IAAT) comprising visceral adipose tissue (VAT), intermuscular adipose tissue (IMAT), and liver fat are posited drivers of obesity-related chronic disease risk. Fast food is hypothesized to contribute to IAAT patterns.ObjectivesWe quantified levels of abdominal subcutaneous adipose tissue (SAT), IAAT, and odds of metabolic-associated fatty liver disease (MAFLD) in middle age according to average fast-food intake over the preceding 25 y.MethodsWe analyzed data from the Coronary Artery Risk Development in Young Adults (CARDIA) study. Participants underwent 6 clinical exams and measurements over 25 y with computed tomography-measured VAT, SAT, and IMAT (n = 3156), plus MAFLD defined by liver attenuation (≤40 Hounsfield units) and 1 metabolic abnormality at year 25 (2010, n = 3001, n cases = 302). We estimated means of VAT, SAT, IMAT, and liver attenuation at the year 25 exam according to categories of average fast-food intake over the previous 25 y adjusted for sociodemographic and lifestyle factors and logistic regression to estimate the odds ratio of MAFLD at year 25.ResultsWith higher average fast-food intake over 25 y (categorized as follows: never-1×/mo, >1×-3×/mo, 1-

IntroductionVisceral adipose tissue (VAT) is a hypothesized driver of chronic disease. Dual-energy X-ray absorptiometry (DXA) potentially offers a lower cost and more available alternative compared to gold-standard magnetic resonance imaging (MRI) for quantification of abdominal fat sub-compartments, VAT and subcutaneous adipose tissue (SAT). We sought to validate VAT and SAT area (cm2) from historical DXA scans against MRI.MethodologyParticipants (n = 69) from the Women's Health Initiative (WHI) completed a 3 T MRI scan and a whole body DXA scan (Hologic QDR2000 or QDR4500; 2004-2005). A subset of 43 participants were scanned on both DXA devices. DXA-derived VAT and SAT at the 4th lumbar vertebrae (5 cm wide) were analyzed using APEX software (v4.0, Hologic, Inc., Marlborough, MA). MRI VAT and SAT areas for the corresponding DXA region of interest were quantified using sliceOmatic software (v5.0, Tomovision, Magog, Canada). Pearson correlations between MRI and DXA-derived VAT and SAT were computed, and a Bland-Altman analysis was performed.ResultsParticipants were primarily non-Hispanic white (86%) with a mean age of 70.51 ± 5.79 years and a mean BMI of 27.33 ± 5.40 kg/m2. Correlations between MRI and DXA measured VAT and SAT were 0.90 and 0.92, respectively (p ≤ 0.001). Bland-Altman plots showed that DXA-VAT slightly overestimated VAT on the QDR4500 (-3.31 cm2); this bias was greater in the smaller subset measured on the older DXA model (QDR2000; -30.71 cm2). The overestimation of DXA-SAT was large (-85.16 to -118.66 cm2), but differences were relatively uniform for the QDR4500.ConclusionsNew software applied to historic Hologic DXA scans provide estimates of VAT and SAT that are well-correlated with criterion MRI among postmenopausal women.

ObjectiveGiven the importance of body fat distribution in chronic disease development, feasible methods to assess body fat are essential. This study compared dual-energy x-ray absorptiometry (DXA) in measuring visceral and subcutaneous adipose tissue (VAT and SAT) with magnetic resonance imaging (MRI).MethodsVAT and SAT were assessed using similar DXA and MRI protocols among 1,795 elderly participants of the Adiposity Phenotype Study (APS) and 309 children/adolescents in Shape Up! Kids (SKids). Spearman correlations, Bland-Altman plots, and coefficients of determination (R2 ) assessed agreement between DXA and MRI measures.ResultsDXA overestimated SAT values in APS (315 vs. 229 cm2 ) and SKids (212 vs. 161 cm2 ), whereas DXA underestimated VAT measures (141 vs. 167 cm2 ) in adults only. The correlations between DXA and MRI values were stronger for SAT than VAT (APS: r = 0.92 vs. 0.88; SKids: 0.90 vs. 0.74). Bland-Altman plots confirmed better agreement for SAT than VAT despite differences by sex, ethnicity, and weight status with respective R2 values for SAT and VAT of 0.88 and 0.84 (APS) and 0.81 and 0.69 (SKids).ConclusionThese findings indicate that SAT by DXA reflects MRI measures in children and older adults, whereas agreement for VAT is weaker for individuals with low VAT levels.

OBJECTIVE: To investigate the role of adipocyte Pcpe2 (procollagen C-endopeptidase enhancer 2) in SR-BI (scavenger receptor class BI)-mediated HDL-C (high-density lipoprotein cholesterol) uptake and contributions to adipose lipid storage. APPROACH AND RESULTS: Pcpe2, a glycoprotein devoid of intrinsic proteolytic activity, is believed to participate in extracellular protein-protein interactions, supporting SR-BI- mediated HDL-C uptake. In published studies, Pcpe2 deficiency increased the development of atherosclerosis by reducing SR-BI-mediated HDL-C catabolism, but the biological impact of this deficiency on adipocyte SR-BI-mediated HDL-C uptake is unknown. Differentiated cells from Ldlr-/-/Pcpe2-/- (Pcpe2-/-) mouse adipose tissue showed elevated SR-BI protein levels, but significantly reduced HDL-C uptake compared to Ldlr-/- (control) adipose tissue. SR-BI-mediated HDL-C uptake was restored by preincubation of cells with exogenous Pcpe2. In diet-fed mice lacking Pcpe2, significant reductions in visceral, subcutaneous, and brown adipose tissue mass were observed, despite elevations in plasma triglyceride and cholesterol concentrations. Significant positive correlations exist between adipose mass and Pcpe2 expression in both mice and humans. CONCLUSIONS: Overall, these findings reveal a novel and unexpected function for Pcpe2 in modulating SR-BI expression and function as it relates to adipose tissue expansion and cholesterol balance in both mice and humans.

Adipose tissue mass and adiposity change throughout the lifespan. During aging, while visceral adipose tissue (VAT) tends to increase, peripheral subcutaneous adipose tissue (SAT) decreases significantly. Unlike VAT, which is linked to metabolic diseases, including type 2 diabetes, SAT has beneficial effects. However, the molecular details behind the aging-associated loss of SAT remain unclear. Here, by comparing scRNA-seq of total stromal vascular cells of SAT from young and aging mice, we identify an aging-dependent regulatory cell (ARC) population that emerges only in SAT of aged mice and humans. ARCs express adipose progenitor markers but lack adipogenic capacity; they secrete high levels of pro-inflammatory chemokines, including Ccl6, to inhibit proliferation and differentiation of neighboring adipose precursors. We also found Pu.1 to be a driving factor for ARC development. We identify an ARC population and its capacity to inhibit differentiation of neighboring adipose precursors, correlating with aging-associated loss of SAT.

White adipose tissue (WAT) is an essential regulator of energy storage and systemic metabolic homeostasis. Regulatory networks consisting of immune and structural cells are necessary to maintain WAT metabolism, which can become impaired during obesity in mammals. Using single-cell transcriptomics and flow cytometry, we unveil a large-scale comprehensive cellular census of the stromal vascular fraction of healthy lean and obese human WAT. We report new subsets and developmental trajectories of adipose-resident innate lymphoid cells, dendritic cells and monocyte-derived macrophage populations that accumulate in obese WAT. Analysis of cell-cell ligand-receptor interactions and obesity-enriched signaling pathways revealed a switch from immunoregulatory mechanisms in lean WAT to inflammatory networks in obese WAT. These results provide a detailed and unbiased cellular landscape of homeostatic and inflammatory circuits in healthy human WAT.

PurposeIncreasing measures of adiposity have been correlated with poor oncologic outcomes and a lack of response to anti-angiogenic therapies. Limited data exists on the impact of subcutaneous fat density (SFD) and visceral fat density (VFD) on oncologic outcomes. This ancillary analysis of GOG-218, evaluates whether imaging markers of adiposity were predictive biomarkers for bevacizumab (bev) use in epithelial ovarian cancer (EOC).Patients and methodsThere were 1249 patients (67%) from GOG-218 with imaging measurements. SFD and VFD were calculated utilizing Hounsfield units (HU). Proportional hazards models were used to assess the association between SFD and VFD with overall survival (OS).ResultsIncreased SFD and VFD showed an increased HR for death (HR per 1-SD increase 1.12, 95% CI:1.05-1.19 p = 0.0009 and 1.13, 95% CI: 1.05-1.20 p = 0.0006 respectively). In the predictive analysis for response to bev, high VFD showed an increased hazard for death in the placebo group (HR per 1-SD increase 1.22, 95% CI: 1.09-1.37; p = 0.025). However, in the bev group there was no effect seen (HR per 1-SD increase: 1.01, 95% CI: 0.90-1.14) Median OS was 45 vs 47 months in the VFD low groups and 36 vs 42 months in the VFD high groups on placebo versus bev, respectively.ConclusionHigh VFD and SFD have a negative prognostic impact on patients with EOC. High VFD appears to be a predictive marker of bev response and patients with high VFD may be more likely to benefit from initial treatment with bev.

White adipose tissue (WAT) is an essential regulator of energy storage and systemic metabolic homeostasis. Regulatory networks consisting of immune and structural cells are necessary to maintain WAT metabolism, which can become impaired during obesity in mammals. Using single-cell transcriptomics and flow cytometry, we unveil a large-scale comprehensive cellular census of the stromal vascular fraction of healthy lean and obese human WAT. We report new subsets and developmental trajectories of adipose-resident innate lymphoid cells, dendritic cells and monocyte-derived macrophage populations that accumulate in obese WAT. Analysis of cell-cell ligand-receptor interactions and obesity-enriched signaling pathways revealed a switch from immunoregulatory mechanisms in lean WAT to inflammatory networks in obese WAT. These results provide a detailed and unbiased cellular landscape of homeostatic and inflammatory circuits in healthy human WAT.

BackgroundAdipose tissue (AT) alterations are common in people living with human immunodeficiency virus (PLWH). Decreases in AT density suggest disrupted adipocyte function/hypertrophy. We assessed changes in AT density after antiretroviral therapy (ART) initiation and associations with immunometabolic parameters.MethodsIn a prospective randomized clinical trial of ART initiation, L4-L5 abdominal CT scans measured subcutaneous AT (SAT) and visceral AT (VAT) area and density in treatment-naive PLWH randomized to tenofovir-emtricitabine plus ritonavir-boosted atazanavir, ritonavir-boosted darunavir, or raltegravir. Linear regression models compared week 0 and week 96 levels, and 96-week changes, in SAT and VAT density (in Hounsfield units [HU]). Spearman correlations assessed relationships between AT density and immunometabolic parameters.ResultsOf the 228 participants, 89% were male and 44% were white non-Hispanic. Median age was 36 years, baseline HIV-1 RNA was 4.6 log10 copies/mL, and CD4+ T-cell count was 344 cells/μL. Over 96 weeks, SAT and VAT HU decreased significantly in all arms. Less dense week 96 SAT and VAT density correlated with higher high-density lipoprotein (HDL) cholesterol and adiponectin (r = 0.19-0.30) levels and lower interleukin 6, non-HDL cholesterol, triglyceride, leptin, and homeostatic model assessment of insulin resistance (r = -0.23 to -0.68) levels at week 96 after adjusting for baseline CD4+ T-cell count, HIV-1 RNA, and baseline AT area.ConclusionsFollowing virologic suppression, lower SAT and VAT density was associated with greater plasma measures of systemic inflammation, lipid disturbances, and insulin resistance independent of AT area, suggesting that changes in AT density with ART may lead to adverse health outcomes independent of AT quantity.Clinical trials registrationNCT00851799.

While it has been hypothesized that brown adipocytes responsible for mammalian thermogenesis are absent in birds, the existence of beige fat has yet to be studied directly. The present study tests the hypothesis that beige fat emerges in birds as a mechanism of physiological adaptation to cold environments. Subcutaneous neck adipose tissue from cold-acclimated or triiodothyronine (T3)-treated chickens exhibited increases in the expression of avian uncoupling protein (avUCP, an ortholog of mammalian UCP2 and UCP3) gene and some known mammalian beige adipocyte-specific markers. Morphological characteristics of white adipose tissues of treated chickens showed increased numbers of both small and larger clusters of multilocular fat cells within the tissues. Increases in protein levels of avUCP and mitochondrial marker protein, voltage-dependent anion channel, and immunohistochemical analysis for subcutaneous neck fat revealed the presence of potentially thermogenic mitochondria-rich cells. This is the first evidence that the capacity for thermogenesis may be acquired by differentiating adipose tissue into beige-like fat for maintaining temperature homeostasis in the subcutaneous fat 'neck warmer' in chickens exposed to a cold environment.

Background and objectivesA previous pre-clinical study on electromagnetic muscle stimulation (EMMS) suggested that fat cell apoptosis occurs following treatment in a porcine model. While EMMS can induce changes in muscle, the effect on fat tissue is not established. This clinical study sought to assess adipose tissue response to EMMS in comparison to cryolipolysis treatment.Study design/materials and methodsStudy subjects were recruited prior to abdominoplasty to receive body contouring treatments and subsequently to obtain tissue for histological analysis. Non-invasive abdominal treatments were delivered using a commercially available (n = 6) or prototype (n = 3) EMMS system or a cryolipolysis system (n = 2). Subjects received a single EMMS treatment (100% intensity for 30 minutes) or a single cryolipolysis treatment (-11°C for 35 minutes) to the abdomen. Superficial and deep (i.e., adjacent to muscle layer) subcutaneous adipose tissue was harvested at set timepoints post-treatment. The presence or absence of an inflammatory response was evaluated using standard hematoxylin and eosin (H&E) staining. As adipocytes that are destined to become apoptotic cannot be distinguished by traditional H&E staining during the early phases of injury, irreversible fat cell injury was assessed using perilipin immunofluorescence.ResultsFollowing H&E histological analysis at 3, 10, 11, and 17 days post-treatment, no EMMS-treated samples showed an inflammatory response in either the superficial or deep subcutaneous adipose tissue. For the cryolipolysis-treated adipose tissue, however, the H&E staining revealed a marked inflammatory response with an influx of neutrophils, lymphocytes, and macrophages at timepoints consistent with previous histological studies. Further, loss of perilipin staining provided clear visual evidence of irreversible fat cell injury in the cryolipolysis-treated adipose tissue. In contrast, the electromagnetic muscle stimulation-treated samples showed persistence of perilipin staining of adipose tissue indicating that all fat cells were viable.ConclusionThis study failed to demonstrate either fat cell injury or inflammatory response following EMMS treatment. While electromagnetic muscle stimulation may non-invasively induce muscle changes, this clinical study found no evidence of an impact injurious or otherwise on subcutaneous fat. © 2020 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC.

BackgroundGiven the central role of skeletal muscles in glucose homeostasis, deposition of adipose depots beneath the fascia of muscles (versus subcutaneous adipose tissue [SAT]) may precede insulin resistance and type 2 diabetes (T2D) incidence. This study was aimed to investigate the associations between computed tomography (CT)-derived biomarkers for adipose tissue and T2D incidence in normoglycemic adults.Methods and findingsThis study was a population-based multiethnic retrospective cohort of 1,744 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) with normoglycemia (baseline fasting plasma glucose [FPG] less than 100 mg/dL) from 6 United States of America communities. Participants were followed from April 2010 and January 2012 to December 2017, for a median of 7 years. The intermuscular adipose tissue (IMAT) and SAT areas were measured in baseline chest CT exams and were corrected by height squared (SAT and IMAT indices) using a predefined measurement protocol. T2D incidence, as the main outcome, was based on follow-up FPG, review of hospital records, or self-reported physician diagnoses. Participants' mean age was 69 ± 9 years at baseline, and 977 (56.0%) were women. Over a median of 7 years, 103 (5.9%) participants were diagnosed with T2D, and 147 (8.4%) participants died. The IMAT index (hazard ratio [HR]: 1.27 [95% confidence interval [CI]: 1.15-1.41] per 1-standard deviation [SD] increment) and the SAT index (HR: 1.43 [95% CI: 1.16-1.77] per 1-SD increment) at baseline were associated with T2D incidence over the follow-up. The associations of the IMAT and SAT indices with T2D incidence were attenuated after adjustment for body mass index (BMI) and waist circumference, with HRs of 1.23 (95% CI: 1.09-1.38) and 1.29 (95% CI: 0.96-1.74) per 1-SD increment, respectively. The limitations of this study include unmeasured residual confounders and one-time measurement of adipose tissue biomarkers.ConclusionsIn this study, we observed an association between IMAT at baseline and T2D incidence over the follow-up. This study suggests the potential role of intermuscular adipose depots in the pathophysiology of T2D.Trial registrationClinicalTrials.gov NCT00005487.

BackgroundNormal-weight polycystic ovary syndrome (PCOS) women exhibit adipose resistance in vivo accompanied by enhanced subcutaneous (SC) abdominal adipose stem cell (ASC) development to adipocytes with accelerated lipid accumulation per cell in vitro. The present study examines chromatin accessibility, RNA expression and fatty acid (FA) synthesis during SC abdominal ASC differentiation into adipocytes in vitro of normal-weight PCOS versus age- and body mass index-matched normoandrogenic ovulatory (control) women to study epigenetic/genetic characteristics as well as functional alterations of PCOS and control ASCs during adipogenesis.ResultsSC abdominal ASCs from PCOS women versus controls exhibited dynamic chromatin accessibility during adipogenesis, from significantly less chromatin accessibility at day 0 to greater chromatin accessibility by day 12, with enrichment of binding motifs for transcription factors (TFs) of the AP-1 subfamily at days 0, 3, and 12. In PCOS versus control cells, expression of genes governing adipocyte differentiation (PPARγ, CEBPα, AGPAT2) and function (ADIPOQ, FABP4, LPL, PLIN1, SLC2A4) was increased two-sixfold at days 3, 7, and 12, while that involving Wnt signaling (FZD1, SFRP1, and WNT10B) was decreased. Differential gene expression in PCOS cells at these time points involved triacylglycerol synthesis, lipid oxidation, free fatty acid beta-oxidation, and oxidative phosphorylation of the TCA cycle, with TGFB1 as a significant upstream regulator. There was a broad correspondence between increased chromatin accessibility and increased RNA expression of those 12 genes involved in adipocyte differentiation and function, Wnt signaling, as well as genes involved in the triacylglycerol synthesis functional group at day 12 of adipogenesis. Total content and de novo synthesis of myristic (C14:0), palmitic (C16:0), palmitoleic (C16:1), and oleic (C18:1) acid increased from day 7 to day 12 in all cells, with total content and de novo synthesis of FAs significantly greater in PCOS than controls cells at day 12.ConclusionsIn normal-weight PCOS women, dynamic chromatin remodeling of SC abdominal ASCs during adipogenesis may enhance adipogenic gene expression as a programmed mechanism to promote greater fat storage.

Obesity is a major public health burden worldwide and is characterized by chronic low-grade inflammation driven by the cooperation of the innate immune system and dysregulated metabolism in adipose tissue and other metabolic organs. Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) is a central regulator of inflammatory cell function that coordinates inflammation, apoptosis and necroptosis in response to inflammatory stimuli. Here we show that genetic polymorphisms near the human RIPK1 locus associate with increased RIPK1 gene expression and obesity. We show that one of these single nucleotide polymorphisms is within a binding site for E4BP4 and increases RIPK1 promoter activity and RIPK1 gene expression in adipose tissue. Therapeutic silencing of RIPK1 in vivo in a mouse model of diet-induced obesity dramatically reduces fat mass, total body weight and improves insulin sensitivity, while simultaneously reducing macrophage and promoting invariant natural killer T cell accumulation in adipose tissue. These findings demonstrate that RIPK1 is genetically associated with obesity, and reducing RIPK1 expression is a potential therapeutic approach to target obesity and related diseases.

Background/objectivesQuantile-dependent expressivity occurs when a gene's phenotypic expression depends upon whether the trait (e.g., BMI) is high or low relative to its distribution. We have previously shown that the obesity effects of a genetic risk score (GRSBMI) increased significantly with increasing quantiles of BMI. However, BMI is an inexact adiposity measure and GRSBMI explains

ObjectiveOsteoarthritis (OA) and pain are both made more severe by low-grade inflammation. This study was undertaken to examine whether visceral fat, a major source of inflammatory cytokines and adipokines, is associated with an increased risk of knee OA or musculoskeletal pain.MethodsSubjects in the Multicenter Osteoarthritis Study cohort, who were age 50-79 years and had or were at high risk of knee OA, underwent whole-body dual x-ray absorptiometry (DXA) at baseline. At baseline, 30 months, and 60 months radiographs and magnetic resonance images (MRIs) of the knees were obtained, and patients were asked to score the severity of their knee pain and to identify sites of joint pain using a body homunculus. Baseline DXA scans were used to measure total body fat and visceral and subcutaneous fat in the torso. The association of fat depot size with structural outcomes (incident radiographic OA and cartilage loss and synovitis on MRI) and with pain outcomes (worsening knee pain, number of painful joints, and widespread pain) was assessed. Regression analyses were adjusted for age, sex, race, education level, smoking status, physical activity, body mass index (BMI), and depressive symptoms.ResultsOf the 2,961 participants at baseline, 60.7% were women. The mean age was 62.5 years and mean BMI was 30.5 kg/m2 . After adjustment for covariates, no fat measures were associated with any structural outcomes. However, total and visceral, but not subcutaneous, fat were positively associated with worsening knee pain (P = 0.0005 for total fat and P = 0.007 for visceral fat) and widespread pain (P = 0.001 for total fat and P = 0.02 for visceral fat), and the amount of visceral fat was associated with the number of painful joints (P = 0.07).ConclusionOur findings indicate that visceral fat is associated with an increased risk of musculoskeletal and widespread pain.

Importance: Body fat contouring procedures have increasingly grown in popularity over the years. As such, there is a need for inexpensive, minimally invasive, and simple fat reduction/contouring technique. Objective: To examine the acid-base and histological changes in ex vivo human adipose tissue after electrochemolipolysis (ECL). Design, Setting, and Participants: Panniculus tissue specimens obtained after abdominoplasty procedures were tumesced with normal saline. Two platinum needle electrodes were inserted into each sample and connected to a DC power supply. Voltage (3-6 V) was varied and applied for 5 min. Specimens were sectioned through a sagittal midline across both electrode insertion sites and immediately stained with pH-sensitive dye. A numerical algorithm was used to calculate the area of the dye color change for each dosimetry pair. Samples were also evaluated utilizing light microscopy (hematoxylin and eosin). An ex vivo human adipose tissue model was used for evaluating the effects of ECL. Results: Acidic and basic pH was appreciated surrounding the anode and cathode insertion sites, respectively. The effect was spatially localized and dose dependent. Statistical analysis of these data showed no significant difference between the mean area of the pH disturbance generated at the anode compared with the cathode at 3 V for 5 min (6.04 mm2 vs. 2.95 mm2, p = 0.40, 95% CI -4.8 to 11). A significantly greater area of pH disruption was generated at the cathode versus the anode in groups 4 V for 5 min (14.7 mm2 vs. 5.00 mm2, p = 0.032, 95% CI 0.93-19), 5 V for 5 min (15.5 mm2 vs. 6.72 mm2, p = 0.019, 95% CI 1.6-16), and 6 V for 5 min (22.5 mm2 vs. 10.0 mm2, p = 0.047, 95% CI 0.22-25). Acute structural changes in adipocytes were observed in all specimens. Vascular damage with adjacent adipocyte necrosis was prominent at the cathode site in group 6 V for 5 min. Conclusions and Relevance: ECL at the studied dosimetry parameters induced acid and base changes in human adipose tissue, suggesting its potential use in nonsurgical fat reduction as an ultralow cost alternative to current lipolytic devices and pharmaceuticals. Level of Evidence: NA.

Importance: Body fat contouring procedures have increasingly grown in popularity over the years. As such, there is a need for inexpensive, minimally invasive, and simple fat reduction/contouring technique. Objective: To examine the acid-base and histological changes in ex vivo human adipose tissue after electrochemolipolysis (ECL). Design, Setting, and Participants: Panniculus tissue specimens obtained after abdominoplasty procedures were tumesced with normal saline. Two platinum needle electrodes were inserted into each sample and connected to a DC power supply. Voltage (3-6 V) was varied and applied for 5 min. Specimens were sectioned through a sagittal midline across both electrode insertion sites and immediately stained with pH-sensitive dye. A numerical algorithm was used to calculate the area of the dye color change for each dosimetry pair. Samples were also evaluated utilizing light microscopy (hematoxylin and eosin). An ex vivo human adipose tissue model was used for evaluating the effects of ECL. Results: Acidic and basic pH was appreciated surrounding the anode and cathode insertion sites, respectively. The effect was spatially localized and dose dependent. Statistical analysis of these data showed no significant difference between the mean area of the pH disturbance generated at the anode compared with the cathode at 3 V for 5 min (6.04 mm2 vs. 2.95 mm2, p = 0.40, 95% CI -4.8 to 11). A significantly greater area of pH disruption was generated at the cathode versus the anode in groups 4 V for 5 min (14.7 mm2 vs. 5.00 mm2, p = 0.032, 95% CI 0.93-19), 5 V for 5 min (15.5 mm2 vs. 6.72 mm2, p = 0.019, 95% CI 1.6-16), and 6 V for 5 min (22.5 mm2 vs. 10.0 mm2, p = 0.047, 95% CI 0.22-25). Acute structural changes in adipocytes were observed in all specimens. Vascular damage with adjacent adipocyte necrosis was prominent at the cathode site in group 6 V for 5 min. Conclusions and Relevance: ECL at the studied dosimetry parameters induced acid and base changes in human adipose tissue, suggesting its potential use in nonsurgical fat reduction as an ultralow cost alternative to current lipolytic devices and pharmaceuticals. Level of Evidence: NA.

PurposeDirect myelin imaging can improve the characterization of myelin-related diseases such as multiple sclerosis. In this study, we explore a novel method to directly image myelin using inversion recovery-prepared hybrid encoding (IR-HE) UTE MRI.MethodsThe IR-HE sequence uses an adiabatic inversion pulse to suppress the long T2 white matter signal, followed by 3D dual-echo HE utilizing both single point imaging and radial frequency encoding, for which the subtraction image between 2 echoes reveals the myelin signal with high contrast. To reduce scan time, it is common to obtain multiple spokes per IR. Here, we invented a novel method to improve the HE, adapted for the multi-spoke IR imaging-termed interleaved HE-for which single point imaging encoding is interleaved between radial frequency encodings near nulling point to allow more efficient IR-signal suppression. To evaluate the proposed approach, a computer simulation, myelin phantom experiment, an ex vivo experiment with a cadaveric multiple sclerosis brain, and an in vivo experiment with 8 healthy volunteers and 13 multiple sclerosis patients were performed.ResultsThe computer simulation showed that IR-interleaved HE allows for improved contrast of myelin signal with reduced imaging artifacts. The myelin phantom experiment showed IR-interleaved HE allows direct imaging of myelin lipid with excellent suppression of water signal. In the ex vivo and in vivo experiments, the proposed method demonstrated highly specific imaging of myelin in white matter of the brain.ConclusionIR-interleaved HE allows for time-efficient, high-contrast direct myelin imaging and can detect demyelinated lesions in multiple sclerosis patients.

Genetic variation in the FAM13A (Family with Sequence Similarity 13 Member A) locus has been associated with several glycemic and metabolic traits in genome-wide association studies (GWAS). Here, we demonstrate that in humans, FAM13A alleles are associated with increased FAM13A expression in subcutaneous adipose tissue (SAT) and an insulin resistance-related phenotype (e.g. higher waist-to-hip ratio and fasting insulin levels, but lower body fat). In human adipocyte models, knockdown of FAM13A in preadipocytes accelerates adipocyte differentiation. In mice, Fam13a knockout (KO) have a lower visceral to subcutaneous fat (VAT/SAT) ratio after high-fat diet challenge, in comparison to their wild-type counterparts. Subcutaneous adipocytes in KO mice show a size distribution shift toward an increased number of smaller adipocytes, along with an improved adipogenic potential. Our results indicate that GWAS-associated variants within the FAM13A locus alter adipose FAM13A expression, which in turn, regulates adipocyte differentiation and contribute to changes in body fat distribution.

Proper storage of excessive dietary fat into subcutaneous adipose tissue (SAT) prevents ectopic lipid deposition-induced insulin resistance, yet the underlying mechanism remains unclear. Here, we identify angiopoietin-2 (Angpt2)-integrin α5β1 signaling as an inducer of fat uptake specifically in SAT. Adipocyte-specific deletion of Angpt2 markedly reduced fatty acid uptake and storage in SAT, leading to ectopic lipid accumulation in glucose-consuming organs including skeletal muscle and liver and to systemic insulin resistance. Mechanistically, Angpt2 activated integrin α5β1 signaling in the endothelium and triggered fatty acid transport via CD36 and FATP3 into SAT. Genetic or pharmacological inhibition of the endothelial integrin α5β1 recapitulated adipocyte-specific Angpt2 knockout phenotypes. Our findings demonstrate the critical roles of Angpt2-integrin α5β1 signaling in SAT endothelium in regulating whole-body fat distribution for metabolic health and highlight adipocyte-endothelial crosstalk as a potential target for prevention of ectopic lipid deposition-induced lipotoxicity and insulin resistance.

It has been suggested that beige fat thermogenesis is tightly controlled by epigenetic regulators that sense environmental cues such as temperature. Here, we report that subcutaneous adipose expression of the DNA demethylase TET1 is suppressed by cold and other stimulators of beige adipocyte thermogenesis. TET1 acts as an autonomous repressor of key thermogenic genes, including Ucp1 and Ppargc1a, in beige adipocytes. Adipose-selective Tet1 knockout mice generated by using Fabp4-Cre improves cold tolerance and increases energy expenditure and protects against diet-induced obesity and insulin resistance. Moreover, the suppressive role of TET1 in the thermogenic gene regulation of beige adipocytes is largely DNA demethylase-independent. Rather, TET1 coordinates with HDAC1 to mediate the epigenetic changes to suppress thermogenic gene transcription. Taken together, TET1 is a potent beige-selective epigenetic breaker of the thermogenic gene program. Our findings may lead to a therapeutic strategy to increase energy expenditure in obesity and related metabolic disorders.

Integration of genome-wide association study (GWAS) signals with expression quantitative trait loci (eQTL) studies enables identification of candidate genes. However, evaluating whether nearby signals may share causal variants, termed colocalization, is affected by the presence of allelic heterogeneity, different variants at the same locus impacting the same phenotype. We previously identified eQTL in subcutaneous adipose tissue from 770 participants in the Metabolic Syndrome in Men (METSIM) study and detected 15 eQTL signals that colocalized with GWAS signals for waist-hip ratio adjusted for body mass index (WHRadjBMI) from the Genetic Investigation of Anthropometric Traits consortium. Here, we reevaluated evidence of colocalization using two approaches, conditional analysis and the Bayesian test COLOC, and show that providing COLOC with approximate conditional summary statistics at multi-signal GWAS loci can reconcile disagreements in colocalization classification between the two tests. Next, we performed conditional analysis on the METSIM subcutaneous adipose tissue data to identify conditionally distinct or secondary eQTL signals. We used the two approaches to test for colocalization with WHRadjBMI GWAS signals and evaluated the differences in colocalization classification between the two tests. Through these analyses, we identified four GWAS signals colocalized with secondary eQTL signals for FAM13A, SSR3, GRB14 and FMO1. Thus, at loci with multiple eQTL and/or GWAS signals, analyzing each signal independently enabled additional candidate genes to be identified.

Frailty is a state of decreased physiologic reserve associated with poor outcomes before and after lung transplantation. Obesity, particularly central obesity characterized by excess proinflammatory visceral adipose tissue (VAT), is associated with incident frailty in middle-aged and older adults. The association between VAT and frailty in advanced lung disease, however, is unknown. In two, nonoverlapping multicenter cohorts of adults listed for lung transplantation, we measured VAT area on bioelectrical impedance assay (BIA) in one cohort and cross-sectional VAT and subcutaneous adipose tissue (SAT) areas on abdominal computed tomography (CT) in the other. We identified a nonlinear relationship between greater VAT by BIA and frailty. In fully adjusted piecewise regression models, every 20 cm2 increase in VAT area was associated with 50% increased odds of frailty in subjects with high VAT (95% CI 1.2-1.9, P

ObjectivesAdipose tissue (AT) density measurement may provide information about AT quality among people living with HIV. We assessed AT density and evaluated relationships between AT density and immunometabolic biomarker concentrations in men with HIV.DesignCross-sectional analysis of men enrolled in the Multicenter AIDS Cohort Study.MethodsAbdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) density (Hounsfield units, HU; less negative = more dense) were quantified from computed tomography (CT) scans. Multivariate linear regression models described relationships between abdominal AT density and circulating biomarker concentrations.ResultsHIV+ men had denser SAT (-95 vs -98 HU HIV-, P < 0.001), whereas VAT density was equivalent by HIV serostatus men (382 HIV-, 462 HIV+). Historical thymidine analog nucleoside reverse transcriptase inhibitor (tNRTI) use was associated with denser SAT but not VAT. In adjusted models, a 1 s.d. greater SAT or VAT density was associated with higher levels of adiponectin, leptin, HOMA-IR and triglyceride:HDL cholesterol ratio and lower hs-CRP concentrations in HIV- men. Conversely, in HIV+ men, each s.d. greater SAT density was not associated with metabolic parameter improvements and was significantly (P < 0.05) associated with higher systemic inflammation. Trends toward higher inflammatory biomarker concentrations per 1 s.d. greater VAT density were also observed among HIV+ men.ConclusionsAmong men living with HIV, greater SAT density was associated with greater systemic inflammation independent of SAT area. AT density measurement provides additional insight into AT density beyond measurement of AT quantity alone, and may have implications for metabolic disease risk.

ObjectivesAdipose tissue (AT) density measurement may provide information about AT quality among people living with HIV. We assessed AT density and evaluated relationships between AT density and immunometabolic biomarker concentrations in men with HIV.DesignCross-sectional analysis of men enrolled in the Multicenter AIDS Cohort Study.MethodsAbdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) density (Hounsfield units, HU; less negative = more dense) were quantified from computed tomography (CT) scans. Multivariate linear regression models described relationships between abdominal AT density and circulating biomarker concentrations.ResultsHIV+ men had denser SAT (-95 vs -98 HU HIV-, P < 0.001), whereas VAT density was equivalent by HIV serostatus men (382 HIV-, 462 HIV+). Historical thymidine analog nucleoside reverse transcriptase inhibitor (tNRTI) use was associated with denser SAT but not VAT. In adjusted models, a 1 s.d. greater SAT or VAT density was associated with higher levels of adiponectin, leptin, HOMA-IR and triglyceride:HDL cholesterol ratio and lower hs-CRP concentrations in HIV- men. Conversely, in HIV+ men, each s.d. greater SAT density was not associated with metabolic parameter improvements and was significantly (P < 0.05) associated with higher systemic inflammation. Trends toward higher inflammatory biomarker concentrations per 1 s.d. greater VAT density were also observed among HIV+ men.ConclusionsAmong men living with HIV, greater SAT density was associated with greater systemic inflammation independent of SAT area. AT density measurement provides additional insight into AT density beyond measurement of AT quantity alone, and may have implications for metabolic disease risk.

ObjectivePrevious studies of breast cancer survival have not considered specific depots of adipose tissue such as subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT).MethodsThis study assessed these relationships among 3,235 women with stage II and III breast cancer diagnosed between 2005 and 2013 at Kaiser Permanente Northern California and between 2000 and 2012 at Dana Farber Cancer Institute. SAT and VAT areas (in centimeters squared) were calculated from routine computed tomography scans within 6 (median: 1.2) months of diagnosis, covariates were collected from electronic health records, and vital status was assessed by death records. Hazard ratios (HRs) and 95% CIs were estimated using Cox regression.ResultsSAT and VAT ranged from 19.0 to 891 cm2 and from 0.484 to 454 cm2 , respectively. SAT was related to increased risk of death (127-cm2 increase; HR [95% CI]: 1.13 [1.02-1.26]), but no relationship was found with VAT (78.18-cm2 increase; HR [95% CI]: 1.02 [0.91-1.14]). An association with VAT was noted among women with stage II cancer (stage II: HR: 1.17 [95% CI: 0.99-1.39]; stage III: HR: 0.90 [95% CI: 0.76-1.07]; P interaction

ObjectivePrevious studies of breast cancer survival have not considered specific depots of adipose tissue such as subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT).MethodsThis study assessed these relationships among 3,235 women with stage II and III breast cancer diagnosed between 2005 and 2013 at Kaiser Permanente Northern California and between 2000 and 2012 at Dana Farber Cancer Institute. SAT and VAT areas (in centimeters squared) were calculated from routine computed tomography scans within 6 (median: 1.2) months of diagnosis, covariates were collected from electronic health records, and vital status was assessed by death records. Hazard ratios (HRs) and 95% CIs were estimated using Cox regression.ResultsSAT and VAT ranged from 19.0 to 891 cm2 and from 0.484 to 454 cm2 , respectively. SAT was related to increased risk of death (127-cm2 increase; HR [95% CI]: 1.13 [1.02-1.26]), but no relationship was found with VAT (78.18-cm2 increase; HR [95% CI]: 1.02 [0.91-1.14]). An association with VAT was noted among women with stage II cancer (stage II: HR: 1.17 [95% CI: 0.99-1.39]; stage III: HR: 0.90 [95% CI: 0.76-1.07]; P interaction

Non-surgical fat reduction procedures have gained in popularity over the past few years and remain in great demand. The process results in accumulation of breakdown products, lipid droplets, that are slowly absorbed over a period of months. This paper outlines the physiological process whereby lipid droplets are absorbed through a process of autophagy (lipophagy) involving a repackaging of these droplets to smaller sizes so that macrophages can then cope with digestion of these very large particles. Furthermore, a fat compartment is described within the dermis surrounding the tail of the hair follicle, which is attracting much attention due to its unique phenotype, function, and connection to the deeper subcutaneous fat compartment. This provides an entry route for direct signaling to the subcutaneous fat. Related to these novel concepts, peptides can be designed in liposomal delivery systems to target lipid droplet breakdown via the hair follicle entry route. This concept is elucidated in this paper.J Drugs Dermatol. 2019;18(4):375-380.

Dermal fibroblasts (dFBs) resist infection by locally differentiating into adipocytes and producing cathelicidin antimicrobial peptide in response to Staphylococcus aureus (S. aureus). Here, we show that neonatal skin was enriched with adipogenic dFBs and immature dermal fat that highly expressed cathelicidin. The pool of adipogenic and antimicrobial dFBs declined after birth, leading to an age-dependent loss of dermal fat and a decrease in adipogenesis and cathelidicin production in response to infection. Transforming growth factor beta (TGF-β), which acted on uncommitted embryonic and adult dFBs and inhibited their adipogenic and antimicrobial function, was identified as a key upstream regulator of this process. Furthermore, inhibition of the TGF-β receptor restored the adipogenic and antimicrobial function of dFBs in culture and increased resistance of adult mice to S. aureus infection. These results provide insight into changes that occur in the skin innate immune system between the perinatal and adult periods of life.

Chronic inflammation accompanies obesity and limits subcutaneous white adipose tissue (WAT) expandability, accelerating the development of insulin resistance and type 2 diabetes mellitus. MicroRNAs (miRNAs) influence expression of many metabolic genes in fat cells, but physiological roles in WAT remain poorly characterized. Here, we report that expression of the miRNA miR-30a in subcutaneous WAT corresponds with insulin sensitivity in obese mice and humans. To examine the hypothesis that restoration of miR-30a expression in WAT improves insulin sensitivity, we injected adenovirus (Adv) expressing miR-30a into the subcutaneous fat pad of diabetic mice. Exogenous miR-30a expression in the subcutaneous WAT depot of obese mice coupled improved insulin sensitivity and increased energy expenditure with decreased ectopic fat deposition in the liver and reduced WAT inflammation. High-throughput proteomic profiling and RNA-Seq suggested that miR-30a targets the transcription factor STAT1 to limit the actions of the proinflammatory cytokine interferon-γ (IFN-γ) that would otherwise restrict WAT expansion and decrease insulin sensitivity. We further demonstrated that miR-30a opposes the actions of IFN-γ, suggesting an important role for miR-30a in defending adipocytes against proinflammatory cytokines that reduce peripheral insulin sensitivity. Together, our data identify a critical molecular signaling axis, elements of which are involved in uncoupling obesity from metabolic dysfunction.

ObjectiveTo examine whether abnormal subcutaneous (SC) abdominal adipose stem cell (ASC) development to adipocytes in polycystic ovary syndrome (PCOS) correlates with hyperandrogenism.DesignProspective cohort study.SettingAcademic medical center.Patient(s)Eight normal-weight women with PCOS and eight normoandrogenic ovulatory (control) women matched for age and body mass index.Intervention(s)Circulating hormone and metabolic measurements, intravenous glucose tolerance testing, total body dual-energy X-ray absorptiometry, and SC abdominal fat biopsy.Main outcome measure(s)In vitro ASC commitment to preadipocytes (ZFP423 protein expression, day 0.5), preadipocyte differentiation to adipocytes (PPARγ gene expression, day 3) and adipocyte lipid content (Oil-Red-O fluorescence, day 12) comparisons correlated with clinical outcomes.Result(s)In women with PCOS, SC abdominal ASCs compared with those of control women showed exaggerated commitment to preadipocytes and had greater lipid content in newly formed adipocytes after in vitro maturation. In all women combined, ZFP423 protein expression negatively correlated with fasting plasma glucose levels whereas the lipid content of newly formed adipocytes positively correlated with both PPARγ gene expression and serum free testosterone levels.Conclusion(s)In normal-weight women with PCOS compared with the control group, exaggerated SC abdominal ASC commitment to preadipocytes and enhanced adipocyte lipid content during maturation in vitro negatively and positively correlate with circulating fasting glucose and androgen levels, respectively, as a possible mechanism to maintain glucose-insulin homeostasis when fat accretion is accelerated.

Chronic inflammation accompanies obesity and limits subcutaneous white adipose tissue (WAT) expandability, accelerating the development of insulin resistance and type 2 diabetes mellitus. MicroRNAs (miRNAs) influence expression of many metabolic genes in fat cells, but physiological roles in WAT remain poorly characterized. Here, we report that expression of the miRNA miR-30a in subcutaneous WAT corresponds with insulin sensitivity in obese mice and humans. To examine the hypothesis that restoration of miR-30a expression in WAT improves insulin sensitivity, we injected adenovirus (Adv) expressing miR-30a into the subcutaneous fat pad of diabetic mice. Exogenous miR-30a expression in the subcutaneous WAT depot of obese mice coupled improved insulin sensitivity and increased energy expenditure with decreased ectopic fat deposition in the liver and reduced WAT inflammation. High-throughput proteomic profiling and RNA-Seq suggested that miR-30a targets the transcription factor STAT1 to limit the actions of the proinflammatory cytokine interferon-γ (IFN-γ) that would otherwise restrict WAT expansion and decrease insulin sensitivity. We further demonstrated that miR-30a opposes the actions of IFN-γ, suggesting an important role for miR-30a in defending adipocytes against proinflammatory cytokines that reduce peripheral insulin sensitivity. Together, our data identify a critical molecular signaling axis, elements of which are involved in uncoupling obesity from metabolic dysfunction.

PurposeSkeletal muscle is the largest regulator of glucose metabolism, but few population-based studies have examined the associations between muscle and inflammation. We studied the relationships between abdominal muscle area and density with selected adiposity-associated inflammatory mediators.MethodsNearly 2000 subjects underwent computed tomography of the abdomen and had venous fasting blood drawn concomitantly. The computed tomography scans were interrogated for visceral and subcutaneous fat, as well as abdominal lean muscle areas and densities. We then categorized the muscle into locomotion (psoas) and stabilization (rectus, obliques, and paraspinal) groups. Blood samples were assayed for interleukin-6 (IL-6), resistin, C-reactive protein, and TNF-α.ResultsThe mean age was 64.7 yr, and 49% were female. Forty percent were white, 26% Hispanic/Latino American, 21% African American, and 13% Chinese American. The mean body mass index was 28.0 kg·m, and 30% were obese (body mass index, >30 kg·m). Using multivariable linear regression models that included adjustment for abdominal muscle area, a 1-SD increment in the mean densities for total, stabilization, and locomotive abdominal muscle were each significantly associated with lower levels of IL-6 (β = -15%, -15%, and -9%, P < 0.01 for all) and resistin (β = -0.11, -0.11, and -0.07 ng·mL, P < 0.02 for all), but not C-reactive protein or TNF-α. Conversely, muscle area was not independently associated with any of the inflammatory mediators studied.ConclusionsHigher densities of several muscle groups in the abdomen are significantly associated with lower IL-6 and resistin levels, independent of the muscle area in these groups. Techniques that enhance muscle density may reduce levels of adiposity-associated inflammatory mediators.

AimsIncreased epicardial adipose tissue (EAT), pericardial adipose tissue (PAT), periaortic adipose tissue (PaAT), and subcutaneous adipose tissue (SAT) are mediators of metabolic risk, and are associated with the severity of coronary artery calcium (CAC). Aged garlic extract (AGE) has been shown to reduce the progression of coronary atherosclerosis. This study evaluates the effect of AGE with supplements (AGE+S) on EAT, PAT, SAT, and PaAT.MethodsSixty asymptomatic participants participated in a randomized trial evaluating the effect of AGE+S versus placebo on coronary atherosclerosis progression, and underwent CAC at baseline and after 12 months of treatment. EAT, PAT, PaAT, and SAT volumes were measured on CAC scans. PAT was calculated as: intrathoracic adipose tissue-EAT. SAT was defined as the volume of fat depot anterior to the sternum and posterior to the vertebra. PaAT was defined as fat depot around the descending aorta.ResultsAt 1 year, the increase in EAT, PAT, PaAT, and SAT was significantly lower in the AGE+S as compared with the placebo group (P

AimsIncreased epicardial adipose tissue (EAT), pericardial adipose tissue (PAT), periaortic adipose tissue (PaAT), and subcutaneous adipose tissue (SAT) are mediators of metabolic risk, and are associated with the severity of coronary artery calcium (CAC). Aged garlic extract (AGE) has been shown to reduce the progression of coronary atherosclerosis. This study evaluates the effect of AGE with supplements (AGE+S) on EAT, PAT, SAT, and PaAT.MethodsSixty asymptomatic participants participated in a randomized trial evaluating the effect of AGE+S versus placebo on coronary atherosclerosis progression, and underwent CAC at baseline and after 12 months of treatment. EAT, PAT, PaAT, and SAT volumes were measured on CAC scans. PAT was calculated as: intrathoracic adipose tissue-EAT. SAT was defined as the volume of fat depot anterior to the sternum and posterior to the vertebra. PaAT was defined as fat depot around the descending aorta.ResultsAt 1 year, the increase in EAT, PAT, PaAT, and SAT was significantly lower in the AGE+S as compared with the placebo group (P

BackgroundComputed tomography (CT)-based fat and muscle measures are associated with outcome in large populations. We tested if muscle and fat characteristics are associated with long-term outcomes after TAVR.MethodsWe included 403 clinical CTs performed prior to TAVR at our center between 2008 and 2016, measuring area (cm2) and density (Hounsfield units, HU) of both psoas muscles (PM), subcutaneous adipose (SAT), and visceral adipose tissue (VAT). Area measures were indexed to height, log-transformed and both area and density were standardized for analysis. We assessed the association of each measure with all-cause mortality (adjusted for age, sex, body mass index (BMI), and the Society of Thoracic Surgeons (STS) risk score.ResultsOf the 403 individuals (83 ± 8 years; 52% female), 167 (41.4%) died during a median follow-up of 458 days (interquartile range IQR 297-840). Fat measures were feasible and rapid. Fat area was available in 242 (60%) patients with an adequate field of view. Individuals with the lowest PM area, SAT area or VAT area exhibited the highest hazard of mortality. In addition, greater SAT density was associated with a higher mortality hazard (adjusted HR per standard deviation increase in density = 1.35, 95%CI 1.10-1.67, P = 0.005).ConclusionRapid CT-based tissue characterization is feasible in patients referred for TAVR. Decreased PM area and increased SAT density are associated with long-term mortality after TAVR, even after accounting for age, sex, BMI, and STS score. Further studies are necessary to interrogate sex-specific relationships between CT tissue metrics and mortality and whether CT measures are incremental to well-established frailty metrics.

BackgroundData on associations between abdominal fat depot mass and subclinical atherosclerosis are limited, especially in women with HIV.MethodsWe assessed cross-sectional associations of dual X-ray absorptiometry scan-derived estimates of visceral adipose tissue (VAT) and abdominal subcutaneous adipose tissue (SAT) with 3 measures of subclinical carotid artery atherosclerosis-carotid artery stiffness (Young's modulus of elasticity), presence of carotid artery lesions, and carotid artery intima-media thickness-in a subsample of participants in the Women's Interagency HIV Study. Statistical models adjusted for demographic variables, HIV serostatus, behavioral variables, and cardiovascular risk factors.ResultsThere were 244 women with and 99 without HIV infection (median age 42, 62% black). VAT mass (but not SAT) was associated with greater carotid artery stiffness in a fully adjusted linear regression model, including adjustment for SAT (β = 11.3 log 10·N·m per kg VAT, 95% confidence interval: 1.0 to 21.7). Greater SAT mass was associated with lower odds of having a carotid artery lesion in a fully adjusted model, including adjustment for VAT [adjusted odds ratio, 0.49 per kg of SAT (0.25 to 0.94)]. Neither VAT nor SAT was associated with carotid artery intima-media thickness. The VAT/SAT ratio was not statistically associated with any of the outcomes after covariate adjustment.ConclusionsIn our cross-sectional study of women, the majority of whom had HIV, greater VAT mass was associated with increased carotid artery stiffness, whereas greater SAT mass was associated with a reduced odds of prevalent carotid artery lesions.

PURPOSE:Obesity is a leading modifiable contributor to breast cancer mortality due to its association with increased recurrence and decreased overall survival rate. Obesity stimulates cancer progression through chronic, low-grade inflammation in white adipose tissue, leading to accumulation of adipose tissue macrophages (ATMs), in particular, the pro-inflammatory M1 phenotype macrophage. Exercise has been shown to reduce M1 ATMs and increase the more anti-inflammatory M2 ATMs in obese adults. The purpose of this study was to determine whether a 16-week exercise intervention would positively alter ATM phenotype in obese postmenopausal breast cancer survivors. METHODS:Twenty obese postmenopausal breast cancer survivors were randomized to a 16-week aerobic and resistance exercise (EX) intervention or delayed intervention control (CON). The EX group participated in 16 weeks of supervised exercise sessions 3 times/week. Participants provided fasting blood, dual-energy X-ray absorptiometry (DXA), and superficial subcutaneous abdominal adipose tissue biopsies at baseline and following the 16-week study period. RESULTS:EX participants experienced significant improvements in body composition, cardiometabolic biomarkers, and systemic inflammation (all p