Adipose Tissue mRNA Expression Research Articles

IL-6 gene expression in adipose tissue of postmenopausal women and its association with metabolic risk factors

Adipose tissue secretes various kinds of adipokines that controls the glucose and lipid metabolism in humans. The abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) both are associated with metabolic syndrome and insulin resistance. IL-6 is one of the adipokines, which promotes insulin resistance and dyslipidemia in humans. The association of adipokines with metabolic syndrome at protein levels are well documented. However, their association at gene expression level are lacking. The present study was design to investigate IL-6 mRNA expression in adipose tissues (VAT and SAT) and its correlation with metabolic risk factors and insulin resistance (HOMA) in post menopausal women. A total of 108 Asian North Indian post menopausal women, 54 without metabolic syndrome (controls) and 54 with metabolic syndrome (cases) were recruited and evaluated. Overnight fasting blood samples were collected at admission and abdominal visceral and subcutaneous adipose tissues were collected during open abdomen surgery. The results showed significantly (p < 0.05 or p < 0.01 or p < 0.001) higher mean SBP, glucose, insulin, HOMA, TG, VLDL and serum IL-6 while significantly (p < 0.001) lower HDL and estrogen in cases as compared to controls. In cases, the relative mean SAT IL-6 expression was also significantly (p < 0.05) higher as compared to VAT. Further, in cases, the VAT IL-6 expression showed significant (p < 0.05 or p < 0.001) and negative correlation with WC, WHR, glucose, HOMA, TC, LDL and estrogen while SAT IL-6 expression also showed significant (p < 0.05 or p < 0.01 or p < 0.001) and negative correlation with WC, WHR and estrogen. The Cox regression analysis found VAT IL-6 mRNA expression the significant (p < 0.05 or p < 0.01) an independent predictor of WC, HOMA, TC, LDL and estrogen while SAT IL-6 mRNA expression the significant (p < 0.01) an independent predictor of TG and VLDL. The study concluded that IL-6 expressions of both visceral and subcutaneous tissues may be associated with metabolic risk factors in postmenopausal Asian North Indian women.

Serum vaspin levels and vaspin mRNA expression in subcutaneous adipose tissue in women with gestational diabetes mellitus

ObjectiveTo compare serum vaspin level and mRNA and protein levels of vaspin in adipose tissue in women with gestational diabetes mellitus (GDM) and normal glucose tolerance (NGR), along with the correlation between serum vaspin level with fasting insulin (FINS), homeostasis model assessment of insulin resistance (HOMA-IR) and birth-weight. Study designThirty-seven women with GDM and 36 with NGR were enrolled. Total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), fasting plasma glucose (FPG), FINS and vaspin levels were measured. The mRNA and protein levels were detected using RT-PCR and Western blot. Pearson correlation analysis (PCA) was performed to reveal the correlation between serum vaspin level and FINS, HOMA-IR. Spearman correlation analysis (SCA) was conducted to examine the association between serum vaspin level and birth-weight. ResultsHDL-C level in GDM was lower than NGR group (P<0.05), and there were no statistical differences in TC, TG, LDL-C, FPG, FINS and HOMA-IR between the two groups. Serum vaspin level, mRNA and protein expression levels of vaspin in GDM were higher than NGR group (P<0.05). Serum vaspin level was not significantly correlated with FINS and HOMA-IR, but had a positive correlation with birth-weight (P=0.023). ConclusionSerum vaspin level cannot serve as an independent predictor of IR. The increased serum vaspin level and increased vaspin mRNA and protein expression in adipose tissues in GDM women indicate that vaspin may be involved in the pathogenesis of GDM, but its exact mechanism needs further study.

Twist 1 regulates the expression of PPARγ during hormone-induced 3T3-L1 preadipocyte differentiation: a possible role in obesity and associated diseases.

BackgroundTwist 1 is highly expressed in adipose tissue and has been associated with obesity and related disorders. However, the molecular function of Twist 1 in adipose tissue is unclear. Twist 1 has been implicated in cell lineage determination and differentiation. Therefore, we investigated both the role of Twist 1 in adipocyte precursor mobilization and the relationship of Twist 1 with other molecular determinants of adipocyte differentiation.MethodsWe examined Twist 1 mRNA and protein expression in subcutaneous adipose tissues from diet-induced obese C57/BL6 mice and Wistar rats and in obese patients undergoing liposuction or adipose transplant surgeries. Twist 1 expression was measured on days 0, 2, 4, 8, and 12 of 3T3-L1 differentiation in vitro. The role of Twist 1 in adipogenesis was explored using retroviral interference of Twist 1 expression. Adipokine secretion was evaluated using a RayBio® Biotin Label-based Adipokine Array.ResultsTwist 1 mRNA and protein levels were reduced in diet-induced obese mice and rats and in obese humans. Twist 1 was upregulated during 3T3-L1 preadipocyte differentiation in vitro, beginning from the fourth day of differentiation induction. Retroviral interference of Twist 1 expression did not significantly impair lipid formation; however, retroviral interference induced PPARγ mRNA and protein expression on day 4 of differentiation induction. Adipokine array analyses revealed increased secretion of CXCR4 (19.55-fold), VEGFR1 (92.13-fold), L-21 R (63.55-fold), and IL-12 R beta 1 (59.66-fold) and decreased secretion of VEGFR3 (0.01-fold), TSLP R (0.071-fold), MIP-1 gamma (0.069-fold), TNF RI/TNFRSF1A (0.09-fold), and MFG-E8 (0.06-fold).ConclusionsTwist 1 is a regulator of adipocyte gene expression although it is not likely to regulate differentiation. We identified PPARγ as a potential target of Twist 1 and found variation in the secretion of multiple adipokines, which might indicate a prospective mechanism linking Twist 1 expression with obesity or associated diseases.

Increased body weight induced by perinatal exposure to bisphenol A was associated with down-regulation zinc-alpha2-glycoprotein expression in offspring female rats

We reported that perinatal exposure to bisphenol A (BPA) resulted in obesity in offspring female rats, and down-regulated zinc-alpha2-glycoprotein (ZAG) mRNA expression in subcutaneous adipose tissue maybe was associated with increased body weight in previous study. Considering that the mechanism of ZAG actions has not been clear, and ZAG gene expression levels are different with adipose tissues, we investigate the levels of ZAG mRNA and protein expression in visceral (perigonadal and perirenal) adipose tissue, and the mechanism of ZAG increasing body weight in BPA exposed rats. Pregnant rats were exposed to BPA in water at levels of either 1 μg/mL(low dose of BPA, LBPA) or 10 μg/mL (high dose of BPA, HBPA) from gestation day 6 to the end of lactation. ZAG mRNA and protein expression from visceral adipose tissue of offspring female rats on postnatal day 50 (PND50) were measured. The levels of fatty acid synthase (FAS) and hormone-sensitive lipase (HSL) gene expression, and peroxisome proliferator-activated receptors-γ (PPARγ) mRNA and protein in visceral adipose tissue were also determined. There was large size of adipocytes in perigonadal adipose tissues in BPA treated offspring female rats. Perinatal exposure to BPA could decrease the levels of ZAG and PPARγ mRNA and protein expression in visceral adipose tissues, and increase FAS gene expression, but decrease HSL gene expression. These findings indicated that BPA exposure during early development results in large size of adipocytes, which was associated with down-regulated ZAG gene. Low expression of ZAG gene increased lipogenesis and decreased lipolysis, which was associated with down-regulated PPARγ gene induced by BPA.

Adipose tissue mRNA expression of WHR-associated genes correlates with fat distribution

Background: Body fat distribution (FD) is one of the main predictors of obesity associated complications.

Improved glucose tolerance with restored expression of glucose transporter 4 in C57BL/6 mice after a long period of high-fat diet feeding

This study examined the effects of long-term consumption of a high-fat diet (HFD) on glucose metabolism in C57BL/6 mice. A total of 95 male 6-week-old mice were divided into normal diet (ND) and HFD groups until 16, 26, 36, 47, or 77 weeks of age. Plasma and blood glucose and insulin levels and area under the glucose curve (AUCglucose) during an intraperitoneal glucose tolerance test were measured. Quantitative real-time PCR was performed to determine the mRNA expression levels of glucose transporter 4 (GLUT4) in adipose tissue. AUCglucose levels in HFD mice at 16, 26, and 36 weeks were significantly higher than those in ND mice (p < 0.001) and significantly reduced in HFD mice at 47 and 77 weeks. Nonfasting plasma glucose concentrations in both groups were significantly decreased at 47 and 77 weeks (p ≤ 0.05). Insulin levels in HFD mice at 47 and 77 weeks were 12.5% lower than those at 36 weeks. Relative GLUT4 mRNA expression in adipose tissue of HFD mice was significantly decreased at 26 and 36 weeks and increased at 47 and 77 weeks. These data suggest that the glucose tolerance was impaired by relatively short-term high-fat feeding and significantly improved by very long periods of high-fat feeding with restored GLUT4 expression in adipose tissue in HFD mice. The differential effects of short- and long-term HFD on glucose metabolism must be considered for recharacterizing the diet-induced obesity and clarify the pathogenesis of metabolic disorders in this animal model.

Serum Concentrations and Subcutaneous Adipose Tissue mRNA Expression of Omentin in Morbid Obesity and Type 2 Diabetes Mellitus: the Effect of Very-Low-Calorie Diet, Physical Activity and Laparoscopic Sleeve Gastrectomy

Omentin is a novel adipokine with insulin-sensitizing effects expressed predominantly in visceral fat. We investigated serum omentin levels and its mRNA expression in subcutaneous adipose tissue (SCAT) of 11 women with type 2 diabetes mellitus (T2DM), 37 obese non-diabetic women (OB) and 26 healthy lean women (C) before and after various weight loss interventions: 2-week very-low-calorie diet (VLCD), 3-month regular exercise and laparoscopic sleeve gastrectomy (LSG). At baseline, both T2DM and OB groups had decreased serum omentin concentrations compared with C group while omentin mRNA expression in SCAT did not significantly differ among the groups. Neither VLCD nor exercise significantly affected serum omentin concentrations and its mRNA expression in SCAT of OB or T2DM group. LSG significantly increased serum omentin levels in OB group. In contrast, omentin mRNA expression in SCAT was significantly reduced after LSG. Baseline fasting serum omentin levels in a combined group of the studied subjects (C, OB, T2DM) negatively correlated with BMI, CRP, insulin, LDL-cholesterol, triglycerides and leptin and were positively related to HDL-cholesterol. Reduced circulating omentin levels could play a role in the etiopathogenesis of obesity and T2DM. The increase in circulating omentin levels and the decrease in omentin mRNA expression in SCAT of obese women after LSG might contribute to surgery-induced metabolic improvements and sustained reduction of body weight.

Reducing the dietary omega-6:omega-3 utilizing α-linolenic acid; not a sufficient therapy for attenuating high-fat-diet-induced obesity development nor related detrimental metabolic and adipose tissue inflammatory outcomes.

AimsTo examine the effect of manipulating the omega-6:omega-3 (1∶1, 5∶1, 10∶1, and 20∶1) utilizing only α-linolenic and linoleic acid within a clinically-relevant high-fat diet (HFD) composed of up to seven sources of fat and designed to be similar to the standard American diet (MUFA∶PUFA of 2∶1, 12% and 40% of calories from saturated and total fat, respectively) on body composition, macrophage polarization, inflammation, and metabolic dysfunction in mice.MethodsDiets were administered for 20 weeks. Body composition and metabolism (HOMA index and lipid profile) were examined monthly. GC-MS was utilized to determine the eicosapentaenoic acid (EPA):arachidonic acid (AA) and the docosahexaenoic acid (DHA):AA in AT phospholipids. Adipose tissue (AT) mRNA expression of chemokines (MCP-1, Fetuin-A, CXCL14), marker genes for M1 and M2 macrophages (CD11c and CD206, respectively) and inflammatory markers (TNF-α, IL-6, IL-1β, TLR-2, TLR-4, IL-10, GPR120) were measured along with activation of NFκB, JNK, and STAT-3. Macrophage infiltration into AT was examined using F4/80 immunohistochemistry.ResultsAny therapeutic benefit produced by reducing the omega-6:omega-3 was evident only when comparing the 1∶1 to 20∶1 HFD; the 1∶1 HFD resulted in a lower TC:HDL-C and decreased AT CXCL14 gene expression and AT macrophage infiltration, which was linked to a higher EPA:AA and DHA:AA in AT phospholipids. However, despite these effects, and independent of the omega-6:omega-3, all HFDs, in general, led to similar levels of adiposity, insulin resistance, and AT inflammation.ConclusionReducing the omega-6:omega-3 using α-linolenic acid is not an effective therapy for attenuating obesity and type II diabetes mellitus development.

Gene expression in subcutaneous adipose tissue differs in women with polycystic ovary syndrome and controls matched pair-wise for age, body weight, and body mass index

Adipose tissue dysfunction may be a central factor in the pathogenesis of insulin resistance in women with polycystic ovary syndrome (PCOS). Gene expression in subcutaneous adipose tissue in PCOS and its relation to metabolic and endocrine features of the syndrome have been fragmentarily investigated. The aim was to assess in subcutaneous adipose tissue the expression of genes potentially associated with adipose tissue dysfunction and to explore their relation to features of the syndrome. Twenty-one women with PCOS (body mass index [BMI] 18.2–33.4 kg/m2) and 21 controls (BMI 19.2–31.7 kg/m2) were matched pair-wise for age, body weight, and BMI. Tissue biopsies were obtained to measure mRNA expression of 44 genes (TaqMan Low Density Array). Differential expression levels were correlated with BMI, glucose infusion rate (GIR), sex hormone binding globulin (SHBG), and sex steroids. In PCOS, expression of adiponectin receptor 2 (ADIPOR2), LPL, and twist-related protein 1 (TWIST1) was decreased, while expression of chemokine (C-C motif) ligand 2 (CCL2) and heme oxygenase (decycling 1) (HMOX1) was increased. TWIST1 and HMOX1, both novel adipokines, correlated with BMI and GIR. After BMI adjustment, LPL and ADIPOR2 expression correlated with plasma estradiol, and CCL2 expression correlated with GIR, in all women. We conclude that adipose tissue mRNA expression differed in PCOS women and controls and that two novel adipokines, TWIST1 and HMOX1, together with adiponectin, LPL, and CCL2, and their downstream pathways merit further investigation.

Effect of Sleeve Gastrectomy on Osteopontin Circulating Levels and Expression in Adipose Tissue and Liver in Rats

Sleeve gastrectomy (SG) constitutes an effective procedure for the treatment of morbid obesity. The aim of the present study was to establish in rats the effects of surgically induced weight loss on circulating concentrations and mRNA expression in adipose tissue and liver of osteopontin (OPN), a proinflammatory protein involved in the development of obesity. Eighty male diet-induced obese Wistar rats were subjected to surgical interventions [sham operation (SH), SG, or pair-fed to the amount of food eaten by SG animals] and dietary interventions [fed ad libitum with a normal chow diet (ND) or a high-fat diet (HFD)]. Body, epididymal adipose tissue (EWAT), and liver weights were determined. Circulating OPN concentrations and the transcript levels of Spp1 (OPN) in EWAT and liver were analyzed. Rats undergoing SG showed decreased body weight (P < 0.001) and fat mass (P < 0.001) and greater excess weight loss (P < 0.001). The HFD significantly decreased serum OPN levels (P < 0.001). However, SG did not change serum OPN concentrations. OPN expression was dramatically increased in animals fed HFD (P < 0.001) in EWAT, but was unaffected by SG. The expression of OPN in the liver was not affected by HFD or SG. Circulating OPN levels decreased with HFD feeding remaining unaltered after SG. The expression of Spp1 in EWAT and liver was not modified by SG. The global improvement of metabolism after SG appears not to involve changes in serum OPN concentrations as well as in EWAT and liver expression in rats.

Perinatal BPA Exposure Induces Hyperglycemia, Oxidative Stress and Decreased Adiponectin Production in Later Life of Male Rat Offspring

The main object of the present study was to explore the effect of perinatal bisphenol A (BPA) exposure on glucose metabolism in early and later life of male rat offspring, and to establish the potential mechanism of BPA-induced dysglycemia. Pregnant rats were treated with either vehicle or BPA by drinking water at concentrations of 1 and 10 µg/mL BPA from gestation day 6 through the end of lactation. We measured the levels of fasting serum glucose, insulin, adiponectin and parameters of oxidative stress on postnatal day (PND) 50 and PND100 in male offspring, and adiponectin mRNA and protein expression in adipose tissue were also examined. Our results showed that perinatal exposure to 1 or 10 µg/mL BPA induced hyperglycemia with insulin resistance on PND100, but only 10 µg/mL BPA exposure had similar effects as early as PND50. In addition, increased oxidative stress and decreased adiponectin production were also observed in BPA exposed male offspring. Our findings indicated that perinatal exposure to BPA resulted in abnormal glucose metabolism in later life of male offspring, with an earlier and more exacerbated effect at higher doses. Down-regulated expression of adiponectin gene and increased oxidative stress induced by BPA may be associated with insulin resistance.

Extensive changes in the transcriptional profile of human adipose tissue including genes involved in oxidative phosphorylation after a 6‐month exercise intervention

Adipose tissue has an important function in total energy homeostasis, and its dysregulation may contribute to lifestyle-related diseases such as type 2 diabetes, cancer and cardiovascular diseases. The aim of this study was to investigate genome-wide mRNA expression in adipose tissue in healthy men before and after an exercise intervention to identify genes or pathways that mediate the beneficial effect of regular exercise. We also investigated the difference in adipose tissue mRNA expression between individuals with or without a family history of type 2 diabetes. The 6-month supervised exercise intervention was conducted in 47 healthy men (age 37.8 ± 4.3 years, BMI 28.5 ± 3.6 kg m(-2) ) with a previous low level of physical activity. RNA was analysed using GeneChip Human Gene 1.0 ST arrays (Affymetrix) before and after the exercise. We identified 2,560 significant transcripts differentially expressed before vs. after exercise with a false discovery rate (FDR) < 0.1%, including genes encoding the respiratory chain, histone subunits, small nucleolar RNAs and ribosomal proteins. Additionally, pathways enriched in response to exercise include the ribosome, oxidative phosphorylation, proteasome and many metabolic pathways, whereas the WNT and MAPK signalling pathways were down-regulated (FDR < 5%) after exercise. There were no significant differences in mRNA expression between individuals with or without a family history of type 2 diabetes. Exercise increased the expression of genes involved in oxidative phosphorylation, which is the opposite of what has been seen in adipose tissue from elderly or obese individuals with low physical fitness, and our study thereby demonstrates a mechanism for the beneficial effect of exercise.

Environmentally relevant levels of Bisphenol A may accelerate the development of type II diabetes mellitus in adolescent Otsuka Long Evans Tokushima Fatty rats

Environmental chemicals may contribute to the development of obesity and metabolic disorders such as diabetes. Bisphenol A (BPA) is one of the environmental chemicals that are widely used in daily life. This study was performed to investigate whether low dose BPA exposure can influence the occurrence of type II diabetes mellitus. Four weeks old Otsuka Long Evans Tokushima Fatty (OLETF) rats were randomly assigned to three groups of five animals and each group was given different concentrations of corn oil with BPA (0, 0.001, and 0.1 mg/kg/day). BPA 0.1 mg/kg/ day produced impairment of glucose tolerance, and induced higher insulin (p=0.028) and malondialdehyde levels (p=0.009) in serum than control group. Serum insulin levels in BPA 0.001 mg/kg/day treated group showed significantly higher than the control group (p=0.016). BPA tended to induce down-regulation of PPARγ mRNA and protein expression in white adipose tissue than control. In conclusion, low dose BPA exposed OLETF rats in adolescent period could accelerate the development of diabetes mellitus in younger adult period.

Effect of rate of weight gain of steers during the stocker phase. III. Gene expression of adipose tissues and skeletal muscle in growing–finishing beef cattle1

The objective of this study was to determine the impact of stocker production systems differing in growth rate on differential adipogenic and lipogenic gene expression of intramuscular (IM), subcutaneous (SC), and perirenal (PR) adipose tissues. Angus steers were assigned to 4 stocker cattle production systems in 2 consecutive years: 1) cottonseed meal-based supplement while grazing dormant native range (CON), 2) ground corn/soybean meal-based supplement while grazing dormant native range (CORN), 3) grazing wheat pasture at a high stocking rate for a low rate of BW gain (LGWP), and 4) grazing wheat pasture at a low stocking rate for a high rate of BW gain (HGWP). Steers were harvested during the stocker phase at similar age (different carcass weight) in Exp. 1 (3 steers/treatment) or at similar carcass weight in Exp. 2 (4 steers/treatment). Adipose tissues were analyzed for mRNA expression of adipogenic (peroxisome proliferator activated receptor γ [PPARγ], sterol regulatory element binding factor 1 [SREBF1], CAATT/enhancer binding protein β, and delta-like homolog 1) and lipogenic (glycerol-3-phosphate dehydrogenase [GPDH], fatty acid synthase [FASN], and diacylglycerol acyltransferase 2 [DGAT2]) genes. Multivariate analysis was used to evaluate the expression of adipogenic or lipogenic genes collectively. There was not a treatment × adipose tissue interaction (F-test, P > 0.15) when steers were harvested at similar age, but a treatment × adipose tissue interaction (F-test, P < 0.05) was evident when steers were harvested at similar carcass weight. At similar carcass weight, treatment had no effect (P > 0.10) on the canonical variate of adipogenic or lipogenic mRNA expression in IM adipose tissue, but faster rates of gain of LGWP and HGWP steers increased (P < 0.10) the canonical variate of adipogenic and lipogenic mRNA expression in SC and PR adipose tissue compared with CON and CORN steers. Strong positive correlations (P < 0.05) of PPARγ, SREBF1, GPDH, FASN, and DGAT2 mRNA expression with the canonical variate indicate that these genes strongly influenced differences between treatments and adipose tissues. These results suggest that contrary to our hypothesis rate of gain has little influence on differentiation and lipid synthesis of IM adipose tissue at similar carcass weight but faster rates of gain increase differentiation and lipid synthesis of SC and PR adipose tissue even at similar carcass weight.

The Influence of an Obesogenic Diet on Oxysterol Metabolism in C57BL/6J Mice

Our current understanding of oxysterol metabolism during different disease states such as obesity and dyslipidemia is limited. Therefore, the aim of this study was to determine the effect of diet-induced obesity on the tissue distribution of various oxysterols and the mRNA expression of key enzymes involved in oxysterol metabolism. To induce obesity, male C57BL/6J mice were fed a high fat-cholesterol diet for 24 weeks. Following diet-induced obesity, plasma levels of 4β-hydroxycholesterol, 5,6α-epoxycholesterol, 5,6β-epoxycholesterol, 7α-hydroxycholesterol, 7β-hydroxycholesterol, and 27-hydroxycholesterol were significantly (P < 0.05) increased. In the liver and adipose tissue of the obese mice, 4β-hydroxycholesterol was significantly (P < 0.05) increased, whereas 27-hydroxycholesterol was increased only in the adipose tissue. No significant changes in either hepatic or adipose tissue mRNA expression were observed for oxysterol synthesizing enzymes 4β-hydroxylase, 27-hydroxylase, or 7α-hydroxylase. Hepatic mRNA expression of SULT2B1b, a key enzyme involved in oxysterol detoxification, was significantly (P < 0.05) elevated in the obese mice. Interestingly, the appearance of the large HDL1 lipoprotein was observed with increased oxysterol synthesis during obesity. In diet-induced obese mice, dietary intake and endogenous enzymatic synthesis of oxysterols could not account for the increased oxysterol levels, suggesting that nonenzymatic cholesterol oxidation pathways may be responsible for the changes in oxysterol metabolism.

Soluble CD163 Is Associated With CD163 mRNA Expression in Adipose Tissue and With Insulin Sensitivity in Steady-State Condition but Not in Response to Calorie Restriction

Soluble CD163 (sCD163) was suggested as a biomarker of insulin sensitivity and CD163 mRNA expression representing macrophage content in adipose tissue (AT). The aim of this study was to investigate, in cross-sectional and prospective design, the relationship between sCD163 circulating levels and CD163 mRNA expression in adipose tissue and insulin sensitivity assessed by euglycemic-hyperinsulinemic clamp. Two cohorts of subjects were examined in the study. Cohort 1 included 42 women with a wide range of body mass index (17-48 kg/m(2)); cohort 2 included 27 obese women who followed a dietary intervention consisting of 1 month of a very low-calorie diet and 5 months of a weight-stabilization period. Serum levels of CD163 and mRNA expression of CD163 and CD68 in sc and visceral (visc) AT were determined, and insulin sensitivity [expressed as glucose disposal rate (GDR)] was measured in cohort 1. In cohort 2, serum levels of CD163, mRNA expressions of CD163, CD68, and CD163-shedding factors [TNF-α-converting enzyme (TACE) and tissue inhibitor of metalloproteinase (TIMP3)] in sc AT were examined and GDR was measured before and during dietary intervention. In cohort 1, circulating sCD163 correlated with CD163 mRNA levels in both sc and visc AT. sCD163 and CD163 mRNA expression in both fat depots correlated with GDR. In cohort 2, the diet-induced changes of sCD163 levels did not correlate with those of CD163, CD68, TACE, and TIMP3 mRNA levels. Although the pattern of the diet-induced change of sCD163 paralleled that of GDR, there was no correlation between the changes of these two variables. sCD163 correlates with CD163 mRNA expression in sc and visc AT and with whole-body insulin sensitivity in the steady-state condition. These associations are not observed with respect to the diet-induced changes during a weight-reducing hypocaloric diet.

Expression of genes related to prostaglandin synthesis or signaling in human subcutaneous and omental adipose tissue: depot differences and modulation by adipogenesis.

Objectives. (1) To examine depot-specific PGE2 and PGF2α release and mRNA expression of enzymes or receptors involved in PG synthesis or signaling in human adipose tissues; (2) to identify changes in expression of these transcripts through preadipocyte differentiation; and (3) to examine associations between adipose tissue mRNA expression of these transcripts and adiposity measurements. Methods. Fat samples were obtained surgically in women. PGE2 and PGF2α release by preadipocytes and adipose tissue explants was measured. Expression levels of mRNA coding for enzymes or receptors involved in PG synthesis or signaling were measured by RT-PCR. Results. Cultured preadipocytes and explants from omental fat released more PGE2 and PGF2α than those from the subcutaneous depot and the corresponding transcripts showed consistent depot differences. Following preadipocyte differentiation, expression of PLA2G16 and PTGER3 mRNA was significantly increased whereas COX-1, COX-2, PTGIS, and PTGES mRNA abundance were decreased in both compartments (P ≤ 0.01 for all). Transcripts that were stimulated during adipogenesis were those that correlated best with adiposity measurements. Conclusion. Cells from the omental fat compartment release more PGE2 and PGF2α than those from the subcutaneous depot. Obesity modulates expression of PG-synthesizing enzymes and PG receptors which likely occurs through adipogenesis-induced changes in expression of these transcripts.

TNF-α Gene Expression in Subcutaneous Adipose Tissue Associated with HOMA in Asian Indian Postmenopausal Women

The present study determines the fat depot-specific expression of leptin and TNF-α and its association with biochemical parameters in postmenopausal women. A total of 108 postmenopausal women were recruited prospectively; 54 were with metabolic syndrome (cases) and 54 were without metabolic syndrome (controls). Leptin and TNF-α mRNA expression in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were done by Real Time-RT PCR. In cases, the mean (±SD) serum estrogen was significantly lower (41.33±24.90 vs. 23.95±14.45, p<0.001) while leptin (12.85±4.51 vs. 10.34±3.89, p=0.002) and TNF-α (13.81±7.13 vs. 8.00±4.38, p<0.001) were significantly higher as compared to controls. Further, the mean relative VAT mRNA expression of both leptin (0.33±0.29 vs. 0.05±0.09, p<0.001) and TNF-α (0.32±0.31 vs. 0.13±0.09, p<0.001) and expression of SAT leptin (4.91±4.01 vs. 0.50±0.92, p<0.001) also lowered significantly in cases as compared to controls. Further, the relative VAT expression of both leptin (r=-0.32, p<0.001) and TNF-α (r=-0.23, p<0.01) showed significant and negative correlation with glucose; expression of SAT leptin showed significant and positive correlation with HDL (r=0.20, p<0.05) and serum estrogen (r=0.30, p<0.01) while negative correlation with glucose (r=-0.26, p<0.01) and serum TNF-α (r=-0.29, p<0.01); and expression of SAT TNF-α showed significant and positive correlation with insulin (r=0.21, p<0.05) and HOMA (r=0.20, p<0.05). In conclusion, the VAT and SAT leptin mRNA expressions may have a modulatory role in metabolic syndrome.

Effect of Exercise on DNA Methylation and Metabolism in Human Adipose Tissue and Skeletal Muscle

in total glucose homeostasis as reduced insulin sensitivity in fat cells results in increased hydrolysis of triglycerides, which may further increase whole-body insulin resistance. Additionally, adipose tissue is an endocrine organ and its capacity to secrete adipokines changes in response to environmental stimuli, such as exercise. Future exercise intervention studies should aim to investigate a combination of tissues involved in human metabolism, including skeletal muscle, adipose tissue and blood. We recently described the genome-wide pattern of DNA methylation in human subcutaneous adipose tissue of 23 healthy men before and after a 6-month exercise intervention [4]. In total, 485,577 individual CpG sites were investigated, broadly covering all human genes and different genomic regions, and the results can be seen as reference for the human methylome in adipose tissue. These results were also related to mRNA expression and, for a third of the genes with changes in DNA methylation greater than 5%, we also detected altered mRNA levels. Interestingly, we found a total of 17,975 individual CpG sites in or near 7663 genes with altered levels of DNA methylation after the exercise intervention. The absolute difference in DNA methylation before versus after exercise ranges from 0.2 to 10.9%, corresponding with increased or decreased DNA methylation by 6–38%. More specifically, we detected 18 obesity and 21 Type 2 diabetes candidate genes; for example, TCF7L2 and KCNQ1, with one or more CpG sites altered in response to exercise. To further study the effect of DNA methylation on adipocyte metabolism, we silenced two genes that displayed both increased DNA methylation and decreased mRNA expression in adipose tissue in response to exercise. Silencing of Hdac4 and Ncor2, Exercise is a physiological stressor with the ability to regulate whole-body energy balance and glucose homeostasis. Regular exercise is important for maintaining physical fitness and has many beneficial effects on the immune system and mental health, as well as the potential to prevent or treat metabolic diseases including obesity, cardiovascular diseases and Type 2 diabetes. Epigenetics has been suggested as a link between the ever-changing environment and the genome, with the potential to alter gene expression [1]. The complex epigenetic mechanisms that modulate gene expression include DNA methylation and histone modifications. Epigenetics, therefore, has the potential to contribute to phenotypic variation; however, to what extent is currently hard to tell and is likely to differ between cell types and individuals. Hence, it is also likely that the effect of physical exercise on gene expression and physiological parameters could partly be mediated by epigenetic factors. Studies investigating the effect of exercise on DNA methylation in human tissues are starting to emerge. However, as the epigenome differs between cell types [2], the number of methylomes to analyze is numerous. Most studies so far have focused on epigenetic changes in human skeletal muscle in response to exercise, and both acute and long-term interventions. The rationale for these studies is to find a mechanism for the finding that exercise alters mRNA and protein levels of genes involved in mitochondrial function and fuel utilization in skeletal muscle [3]. Less attention has been paid to the role of exercise on epigenetic changes in adipose tissue, and surprisingly also on the transcriptomic changes likely to occur in adipose tissue in response to exercise. Although adipose tissue only accounts for a small proportion of glucose clearance, it is important

Abstract 18676: Anti-miR33 Therapy Induces PGC1a Expression to Regulate Immunometabolic Pathways in Atherosclerosis and Obesity

Atherosclerosis and obesity are epidemic causes of morbidity and mortality, and immunometabolic mechanisms are at the intersection of both diseases. Recently, microRNA 33 (miR33) was identified as a novel and critical regulator of lipid metabolism and a therapeutic target for reducing atherosclerosis. However, the exact mechanism(s) by which anti-miR33 exerts these beneficial effects are unclear. Comprehensive microarray profiling of mRNA from atherosclerotic plaque macrophages of anti-miR33 treated mice identified PPARγ coactivator 1α (PGC1α) as a novel miR33 target gene that is markedly de-repressed. PGC1α is a key regulator of mitochondrial function and energy metabolism, and promoting its activity improves metabolic syndrome (e.g. insulin resistance, obesity, inflammation). Here, we determine if anti-miR33 therapy upregulates PGC1α and affects energy metabolism in atherosclerosis. Results: miR33 overexpression reduced the 3’UTR activity of PGC1α by 40% (p≤0.05), confirming it was a direct and specific target of miR33. Transfection of macrophages with either miR33 mimics or anti-miR33 in vitro resulted in a decrease or increase of Pgc1α mRNA and protein respectively. Using the Seahorse XF Flux Analyzer, we showed that anti-miR33 treatment boosted maximal mitochondrial oxygen consumption rate, confirming that anti-miR33 impacts positively on mitochondrial respiration. Anti-miR33 treated macrophages also increased the expression of known functional mitochondrial genes (e.g. Slc25a25, Nrf1, Bid and Mtch2), implying miR33 controls several genes in the mitochondrial metabolic pathway. Inhibition of miR33 in vivo in Ldlr-/- mice upregulated Pgc1α mRNA expression in adipose tissue, liver and macrophages. Adipose tissue from anti-miR33 treated obese mice also showed upregulation of so-called “browning” genes (e.g. Ucp-1, Elovl3) that contribute to increased energy utilization of white adipose tissue, possibly improving whole-body metabolism. Conclusion: Anti-miR33 therapy specifically targets PGC1α in macrophages and adipose tissue and improves mitochondrial function, all of which can positively regulate inflammatory and energy utilization processes in cardiometabolic diseases (eg. atherosclerosis and obesity).