Adipose Tissue mRNA Research Articles

The deubiquitinating enzyme USP19 modulates adipogenesis and potentiates high-fat-diet-induced obesity and glucose intolerance in mice.

Elucidating the molecular mechanisms of fat accumulation and its metabolic consequences is crucial to understanding and treating obesity, an epidemic disease. We have previously observed that Usp19 deubiquitinating enzyme-null mice (Usp19-/-) have significantly lower fat mass than wild-type (WT) mice. Thus, this study aimed to provide further understanding of the role of ubiquitin-specific peptidase 19 (USP19) in fat development, obesity and diabetes. In this study, the metabolic phenotypes of WT and Usp19-/- mice were compared. The stromal vascular fractions (SVFs) of inguinal fat pads from WT and Usp19-/- mice were isolated and cells were differentiated into adipocytes in culture to assess their adipogenic capacity. Mice were fed a high-fat diet (HFD) for 18weeks. Body composition, glucose metabolism and metabolic variables were assessed. In addition, following insulin injection, signalling activity was analysed in the muscle, liver and adipose tissue. Finally, the correlation between the expression of Usp19 mRNA and adipocyte function genes in human adipose tissue was analysed. Upon adipogenic differentiation, SVF cells from Usp19-/- failed to accumulate lipid and upregulate adipogenic genes, unlike cells from WT mice. Usp19-/- mice were also found to have smaller fat pads throughout the lifespan and a higher percentage of lean mass, compared with WT mice. When fed an HFD, Usp19-/- mice were more glucose tolerant, pyruvate tolerant and insulin sensitive than WT mice. Moreover, HFD-fed Usp19-/- mice had enhanced insulin signalling in the muscle and the liver, but not in adipose tissue. Finally, USP19 mRNA expression in human adipose tissue was positively correlated with the expression of important adipocyte genes in abdominal fat depots, but not subcutaneous fat depots. USP19 is an important regulator of fat development. Its inactivation in mice exerts effects on multiple tissues, which may protect against the negative metabolic effects of high-fat feeding. These findings suggest that inhibition of USP19 could have therapeutic potential to protect from the deleterious consequences of obesity and diabetes.

Voluntary Corn Oil Ingestion Increases Energy Expenditure and Interscapular UCP1 Expression Through the Sympathetic Nerve in C57BL/6 Mice.

Previously, it has been found that corn oil ingestion activates both the gustatory system and brain reward system, stimulating motivation for eating. In the present study, the effect of voluntary corn oil ingestion on body weight gain and energy metabolism in mice is investigated. Voluntary corn oil ingestion with normal chow feeding does not lead to higher body weight than that of only the chow-fed control group. Mice that ingested corn oil have a higher total caloric intake and energy expenditure than did mice in the control group. Further, voluntary corn oil ingestion significantly upregulates Ucp1 mRNA and protein in interscapular brown adipose tissue (IBAT). Finally, the sympathetic nerve connected to IBAT was surgically transacted, then the body weight is measured for 8 weeks. IBAT sympathetic nerve transection surgery does not affect the body weight gain and food intake; however, when mice ingested corn oil, it induces significant body weight gain without changing the total caloric intake. IBAT sympathetic nerve transection surgery significantly suppresses UCP1 upregulation by corn oil ingestion. The present data suggest that corn oil ingestion activates IBAT through the sympathetic nerve, upregulating UCP1 expression and increasing energy expenditure.

PO-044 Effects of one-time high intensity intermittent training on the expression of UCP1 mRNA in adipose tissue of obese rats

Objective To observe the effect of one-time high-intensity intermittent training (HIIT) on the white fat browning in obese rats.
 Methods 12 obese male rats at the age of 19-week were randomly divided into control group (OC group, n=6) and HIIT group (n=6). OC group doesn’t do exercise, and HIIT group finish the once high-intensity intermittent training ( ①Warm up: 70%VO2max, 7min; ②High intensity exercise: 90%VO2max, 3min+ 50%VO2max, 3min, 6 times; ③Convalescence: 70%VO2max, 7min.). The maximal oxygen uptake (VO2max) of HIIT group was tested before training, and the exercise intensity was determined according to the average VO2max. The subcutaneous and testicle white adipose tissue (WAT) and brown adipose tissue (BAT) of the scapula were taken immediately after exercise. The expression of UCP1 mRNA in the WAT and BAT using the fluorescent quantitative PCR.
 Results Compared with the OC group, the expression of BAT UCP1 mRNA , in the HIIT group was increased, but there was no significant difference (1.40±0.50 vs 1.03±0.27, P>0.05). In both OC and HIIT group, the expression of UCP1 mRNA of the subcutaneous and testicle WAT were too low to test. The results showed that one-time HIIT exercise had no effect on the expression of UCP1 mRNA in WAT.
 Conclusions The effects of One-time HIIT on the expression of UCP1 mRNA in adipose tissue of obese rats are still not definite.

Adipose Tissue Responses to Breaking Sitting in Men and Women with Central Adiposity.

Breaking prolonged sitting reduces postprandial glucose and insulin concentrations and influences skeletal muscle molecular signaling pathways, but it is unknown whether breaking sitting also affects adipose tissue. Eleven central overweight participants (seven men and four postmenopausal women) 50 ± 5 yr old (mean ± SD) completed two mixed-meal feeding trials (prolonged sitting vs breaking sitting) in a randomized, counterbalanced design. The breaking sitting intervention comprised walking for 2 min every 20 min over 5.5 h. Blood samples were collected at regular intervals to examine metabolic biomarkers and adipokine concentrations. Adipose tissue samples were collected at baseline and at 5.5 h to examine changes in mRNA expression and secretion of selected adipokines ex vivo. Postprandial glycemia and insulinemia were attenuated by approximately 50% and 40% in breaking sitting compared with prolonged sitting (iAUC: 359 ± 117 vs 697 ± 218 mmol per 330 min·L, P = 0.001, and 202 ± 71 vs 346 ± 150 nmol per 330 min·L, P = 0.001, respectively). Despite these pronounced and sustained differences in postprandial glucose and insulin concentrations, adipose tissue mRNA expression for various genes (interleukin 6, leptin, adiponectin, pyruvate dehydrogenase kinase isozyme 4, insulin receptor substrates 1 and 2, phosphoinositide 3-kinase, and RAC-alpha serine/threonine-protein kinase) and ex vivo adipose tissue secretion of interleukin 6, leptin, and adiponectin were not different between trials. This study demonstrates that breaking sitting with short bouts of physical activity has very pronounced effects on systemic postprandial glucose and insulin concentrations, but this does not translate into corresponding effects within adipose tissue.

Serum and Adipose Tissue mRNA Levels of ATF3 and FNDC5/Irisin in Colorectal Cancer Patients With or Without Obesity.

Objectives: To explore the activating transcription factor 3 (ATF3) and fibronectin type III domain-containing protein 5 (FNDC5)/irisin protein levels in serum and mRNA levels in subcutaneous and visceral white adipose tissue (sWAT and vWAT) in normal-weight (NW) and overweight/obese (OW/OB) patients with colorectal cancer (CRC).Methods: 76 CRC patients and 40 healthy controls were recruited. Serum ATF3 and irisin levels were detected by using ELISA kits, and the mRNA expression levels in sWAT and vWAT were measured by performing RT-qPCR.Results: The serum ATF3 levels were greater by 37.2%, whereas the irisin levels were lower by 23.3% in NW+CRC patients compared with those in healthy controls. CRC was independently associated with both ATF3 and irisin levels. The probability of CRC greater by 22.3-fold in individuals with high ATF3 levels compared with those with low ATF3 levels, whereas the risk of CRC in subjects with high irisin levels was lower by 78.0% compared to the risk in those with low irisin levels after adjustment for age, gender, BMI, and other biochemical parameters. Serum ATF3 and irisin could differentiate CRC patients from controls with receiver operating characteristic (ROC) curve areas of 0.745 (95% CI, 0.655–0.823) and 0.656 (95% CI, 0.561–0.743), respectively. The combination of ATF3 and irisin exhibited improved diagnosis value accuracy with ROC curve areas of 0.796 (95% CI, 0.710–0.866) as well as 72.6% sensitivity and 80.0% specificity.Conclusion: Increased ATF3 and reduced irisin levels were observed in sera from CRC patients. Individuals with high ATF3 and low irisin levels were more likely to have CRC. ATF3 and irisin represent potential diagnostic biomarkers for CRC patients.

Effects of maternal obesity on maternal and fetal plasma concentrations of adiponectin and expression of adiponectin and its receptor genes in cotyledonary and adipose tissues at mid- and late-gestation in sheep

Adiponectin potentially influences fetal weight by altering insulin signaling and trans-placental amino acid and glucose transporters. The objective of this study was to determine how maternal obesity influences maternal and fetal plasma concentrations of adiponectin, expression of fetal adiponectin, its receptors, and adipogenic genes at mid- and late-gestation. Blood samples and tissues were collected from obese and control multiparous pregnant ewes at day 75 or 135 of gestation. Although day of gestation or maternal obesity did not influence (P > 0.6) maternal plasma concentrations of adiponectin, fetal weight was increased (P < 0.001) and adiponectin tended to decrease (P = 0.10) at mid-gestation in fetuses from obese ewes. Differences were not apparent at late-gestation (P > 0.70). Relative abundance of adiponectin (P = 0.01), AdipoR2 (P = 0.04) and PPARγ (P = 0.01) mRNA was less at mid-gestation in fetal adipose tissue from obese mothers. By late gestation, maternal obesity tended to associated with a decrease in relative abundance of adiponectin (P = 0.09) and SREBF1 (P = 0.10) mRNA in fetal adipose tissue. Maternal obesity did not influence (P ≥ 0.20) the relative abundance of adiponectin, AdipoR1 and AdipoR2 mRNA in cotyledonary tissue at mid or late- gestation. In conclusion, maternal obesity in sheep influences relative abundance of fetal adipose tissue mRNA for adiponectin and adipogenic, as well as plasma concentrations of total adiponectin. Although adiposity in pregnant ewes did not influence maternal adiponectin, maternal obesity potentially influenced fetal adipogenesis by altering the abundance of adiponectin, PPARγ and SREBF1 mRNA in fetal adipose tissue.

Sulfuretin Prevents Obesity and Metabolic Diseases in Diet Induced Obese Mice.

The global obesity epidemic and associated metabolic diseases require alternative biological targets for new therapeutic strategies. In this study, we show that a phytochemical sulfuretin suppressed adipocyte differentiation of preadipocytes and administration of sulfuretin to high fat diet-fed obese mice prevented obesity and increased insulin sensitivity. These effects were associated with a suppressed expression of inflammatory markers, induced expression of adiponectin, and increased levels of phosphorylated ERK and AKT. To elucidate the molecular mechanism of sulfuretin in adipocytes, we performed microarray analysis and identified activating transcription factor 3 (Atf3) as a sulfuretin-responsive gene. Sulfuretin elevated Atf3 mRNA and protein levels in white adipose tissue and adipocytes. Consistently, deficiency of Atf3 promoted lipid accumulation and the expression of adipocyte markers. Sulfuretin’s but not resveratrol’s anti-adipogenic effects were diminished in Atf3 deficient cells, indicating that Atf3 is an essential factor in the effects of sulfuretin. These results highlight the usefulness of sulfuretin as a new anti-obesity intervention for the prevention of obesity and its associated metabolic diseases.

Food Overconsumption in Healthy Adults Triggers Early and Sustained Increases in Serum Branched-Chain Amino Acids and Changes in Cysteine Linked to Fat Gain

Plasma concentrations of branched-chain amino acids (BCAAs) and the sulfur-containing amino acid cysteine are associated with obesity and insulin resistance. BCAAs predict future diabetes. We investigated amino acid changes during food overconsumption. Forty healthy men and women with a body mass index (mean±SEM) of 25.6±0.6 were overfed by 1250 kcal/d for 28 d, increasing consumption of all macronutrients. Insulin sensitivity and body composition were assessed at baseline (day 0) and day 28. Fasting serum amino acids were measured at days 0, 3, and 28. Linear mixed-effects models evaluated the effect of time in the total group and separately in those with low and high body fat gain (below compared with at or above median fat gain, 1.95 kg). At days 0 and 28, insulin-induced suppression of serum amino acids during a hyperinsulinemic-euglycemic clamp test and, in a subset (n=20), adipose tissue mRNA expression of selected amino acid metabolizing enzymes were assessed. Weight increased by 2.8 kg. High fat gainers gained 2.6 kg fat mass compared with 1.1 kg in low fat gainers. Valine and isoleucine increased at day 3 (+17% and +22%, respectively; P≤0.002) and remained elevated at day 28, despite a decline in valine (P=0.019) from day 3 values. Methionine, cystathionine, and taurine were unaffected. Serum total cysteine (tCys) transiently increased at day 3 (+11%; P=0.022) only in high fat gainers (P-interaction=0.043), in whom the cysteine catabolic enzyme cysteine dioxygenase (CDO1) was induced (+26%; P=0.025) in adipose tissue (P-interaction=0.045). Overconsumption did not alter adipose tissue mRNA expression of the BCAA-metabolizing enzymes branched-chain keto acid dehydrogenase E1α polypeptide (BCKDHA) or branched-chain amino transferase 1 (BCAT1). In the total population at day 0, insulin infusion decreased all serum amino acids (-11% to -47%; P<0.01), except for homocysteine and tCys, which were unchanged, and glutathione, which was increased by 54%. At day 28, insulin increased tCys (+8%), and the insulin-induced suppression of taurine and phenylalanine observed at day 0, but not that of BCAAs, was significantly impaired. These findings highlight the role of nutrient oversupply in increasing fasting BCAA concentrations in healthy adults. The link between cysteine availability, CDO1 expression, and fat gain deserves investigation. This trial was registered at www.clinicaltrials.gov as NCT00562393.

Neudesin, a Novel Regulator of Energy Metabolism in Obesity and Type 2 Diabetes Mellitus—The Effect of Acute Fasting and Endoscopic Duodenal-Jejunal Bypass Liner Implantation

Neudesin has recently been identified as a negative regulator of energy expenditure in experimental animals; however, its role in humans remains unexplored. The aim of our study was to assess the effects of obesity and type 2 diabetes mellitus along with selected interventions including acute fasting and endoscopic duodenal-jejunal by-pass liner implantation (DJBL) on its serum levels and adipose tissue mRNA expression. Fifteen obese T2DM subjects undergoing DJBL implantation, 15 subjects with functional hypoglycemia subjected to 72-hour fasting (Fast) and 12 healthy controls (C) were included in the study. Samples were taken at baseline and 6 and 10 months after DJBL and after 78 hours of fasting and 2 hours after realimentation, respectively. Serum neudesin was measured using ELISA kit (Neudesin Human ELISA, Biovendor, CR). qRT PCR was used to detect mRNA expression of neudesin in white adipose tissue (WAT). Baseline serum neudesin levels were comparable between all groups (1.77 ± 0.86 vs. 1.74 ± 0.54 vs. 1.88 ± 0.70 ng/ml, n.s. for DJBL vs. Fast vs. C). Along with reduction in body weight (BMI 42.8 ± 6.53 vs. 36.6 ± 4.91 kg/m2, p=0.038) and improvement of HbA1c (73.5 ± 17.2 vs. 50.0 ± 12.6 mmol/mol, p=0.001) DJBL increased serum neudesin at 6 and 10 months after procedure (1.77 ± 0.86 vs. 2.28 ± 1.27 vs. 2.13 ± 1.02 ng/ml, p=0.001 for baseline vs. 6 vs. 10 months), while having no effect on neudesin mRNA expression in WAT. In contrast, acute fasting decreased serum neudesin during the whole period (1.74 ± 0.54 vs. 1.46 ± 0.48 ng/ml, p=0.001 for baseline vs. 72 hours) with no impact of subsequent realimentation (1.37 ± 0.44 ng/ml, n.s. 2 h postprandially).To conclude, serum neudesin levels are regulated differently during acute fasting and chronic weight reduction induced by DJBL. Further studies are needed to assess its potential in the treatment of obesity and T2DM. Disclosure H. Kratochvilova: None. Z. Lacinová: None. J. Klouckova: None. P. Kaválková: None. A. Cinkajzlova: None. P. Trachta: None. J. Krizova: None. M. Benes: None. Z. Vlasakova: None. T. Pelikanova: None. M. Mraz: None. M. Haluzik: None.

Effects of vitamin D-induced chronic renal disease on quality and cryopreservation of spermatozoa from the endangered Iberian lynx

Adiponectin potentially influences fetal weight by altering insulin signaling and trans-placental amino acid and glucose transporters. The objective of this study was to determine how maternal obesity influences maternal and fetal plasma concentrations of adiponectin, expression of fetal adiponectin, its receptors, and adipogenic genes at mid- and late-gestation. Blood samples and tissues were collected from obese and control multiparous pregnant ewes at day 75 or 135 of gestation. Although day of gestation or maternal obesity did not influence (P > 0.6) maternal plasma concentrations of adiponectin, fetal weight was increased (P < 0.001) and adiponectin tended to decrease (P = 0.10) at mid-gestation in fetuses from obese ewes. Differences were not apparent at late-gestation (P > 0.70). Relative abundance of adiponectin (P = 0.01), AdipoR2 (P = 0.04) and PPARγ (P = 0.01) mRNA was less at mid-gestation in fetal adipose tissue from obese mothers. By late gestation, maternal obesity tended to associated with a decrease in relative abundance of adiponectin (P = 0.09) and SREBF1 (P = 0.10) mRNA in fetal adipose tissue. Maternal obesity did not influence (P ≥ 0.20) the relative abundance of adiponectin, AdipoR1 and AdipoR2 mRNA in cotyledonary tissue at mid or late- gestation. In conclusion, maternal obesity in sheep influences relative abundance of fetal adipose tissue mRNA for adiponectin and adipogenic, as well as plasma concentrations of total adiponectin. Although adiposity in pregnant ewes did not influence maternal adiponectin, maternal obesity potentially influenced fetal adipogenesis by altering the abundance of adiponectin, PPARγ and SREBF1 mRNA in fetal adipose tissue.

Dietary sucrose regulates the expression of the Cd36 gene in hepatic tissue of rats with obesity and Non Alcoholic Fatty Liver Disease (NAFLD).

To evaluate the mRNA expression levels of Cd36 in adipose and hepatic tissues, in rats with NAFLD after the consumption of sucrose for 10 and 20 weeks. Twenty Wistar rats, all nearly 21 days old were divided into two experimental groups (NAFLD-10 and NAFLD-20), that received a standard diet (2014 Teklad Global) plus 30% sucrose in their drinking water for 10 and 20 weeks and the control groups (C Groups). Variables such as body weight, food intakes, and serum parameters were measured. Adipose and hepatic tissues were extirpated; some tissue was preserved in formalin and some at -70 °C until analysis. Histological analysis was carried out, and the Cd36 mRNA expression levels were determined. The rats in the NAFLD-10 and NAFLD-20 groups showed a significative increase in abdominal fat, triglycerides, free fatty acids, insulin, AST, ALT, uric acid and HOMA index; as well as changes in the cellular dynamics in adipose tissue, (adipocytes hypertrophic: >1500 µm2) with respect to the control groups (P<0.05). The histological analysis showed development of mild portal hepatitis in rats of the NAFLD-10 group and grade 1 hepatic steatosis with mild portal inflammation in rats of the NAFLD-20 group. Finally, Cd36 mRNA expression levels were significantly increased in hepatic tissue after 10 (1.5-fold) and 20 (3.5-fold) weeks of sucrose ingestion (P<0.05). mRNA expression is a molecular mechanism involved in the development of NAFLD associated with obesity in rats consuming sucrose. However, there was increased Cd36 mRNA expression only in hepatic tissue while in hypertrophic adipose tissue mRNA levels remained unchanged.

Disruption of tumor necrosis factor alpha receptor 1 signaling accelerates NAFLD progression in mice upon a high-fat diet

Obesity is accompanied by a low-grade inflammation state, characterized by increased proinflammatory cytokines levels such as tumor necrosis factor alpha (TNFα) and interleukin-1 beta (IL-1β). In this regard, there exists a lack of studies in hepatic tissue about the role of TNFα receptor 1 (TNFR1) in the context of obesity and insulin resistance during the progression of nonalcoholic fatty liver disease (NAFLD). The aim of this work was to evaluate the effects of high-caloric feeding (HFD) (40% fat, for 16 weeks) on liver inflammation-induced apoptosis, insulin resistance, hepatic lipid accumulation and its progression toward nonalcoholic steatohepatitis (NASH) in TNFR1 knock-out and wild-type mice. Mechanisms involved in HFD-derived IL-1β release and impairment of insulin signaling are still unknown, so we determined whether IL-1β affects liver insulin sensitivity and apoptosis through TNFα receptor 1 (TNFR1)-dependent pathways. We showed that knocking out TNFR1 induces an enhanced IL-1β plasmatic release upon HFD feed. This was correlated with higher hepatic and epididymal white adipose tissue mRNA levels. In vivo and in vitro assays confirmed an impairment in hepatic insulin signaling, in part due to IL-1β-induced decrease of AKT activation and diminution of IRS1 levels, followed by an increase in inflammation, macrophage (resident and recruited) accumulation, hepatocyte apoptotic process and finally hepatic damage. In addition, TNFR1 KO mice displayed higher levels of pro-fibrogenic markers. TNFR1 signaling disruption upon an HFD leads to an accelerated progression from simple steatosis to a more severe phenotype with many NASH features, pointing out a key role of TNFR1 in NAFLD progression.

Circulating and Adipose Tissue mRNA Levels of Zinc-α2-Glycoprotein, Leptin, High-Molecular-Weight Adiponectin, and Tumor Necrosis Factor-Alpha in Colorectal Cancer Patients With or Without Obesity.

To explore zinc-α2-glycoprotein (ZAG), leptin, high-molecular-weight adiponectin (HMW-ADPN), and tumor necrosis factor-alpha (TNF-α) levels in serum and subcutaneous and visceral white adipose tissue (sWAT and vWAT) among normal weight (NW) and overweight/obese (OW/OB) patients with colorectal cancer (CRC). A total of 76 Chinese CRC patients (42 NW + CRC, 34 OW/OB + CRC) and 40 healthy controls were recruited. Serum levels of the adipokines of interest were measured by an enzyme-linked immunosorbent assay method, and their mRNA levels in sWAT and vWAT were determined by reverse transcription quantitative PCR methods. Serum ZAG levels in the NW + CRC group were significantly increased by 11.7% compared with the healthy controls. Serum leptin levels in the OW/OB + CRC group were found to be increased by 57.7%, while HMW-ADPN levels were decreased by 23.5% when compared with the NW + CRC group of CRC patients. Additionally, ZAG mRNA levels in sWAT were significantly reduced by 78.8% in OB + CRC in comparison with NW + CRC patients. ZAG mRNA levels were negatively associated with body mass index (BMI) in sWAT but positively correlated with BMI in vWAT. TNF-α mRNA levels in vWAT of OB + CRC patients were significantly increased by 2.8-fold when compared with NW + CRC patients. In particular, CRC was independently associated with serum ZAG levels. The risk of CRC in participants with high tertile serum ZAG levels was 5.84-fold higher than in those with low tertile ZAG levels after adjusting for age, gender, and other confounders [odds ratio (OR) = 6.84, 95% confidence interval (CI) 1.70-27.54, P = 0.03]. The CRC risk in participants with high tertile leptin levels was only 10.7% of those with low tertile leptin levels (OR = 0.11, 95% CI 0.01-0.89, P = 0.04). The area under the receiver operating characteristic (ROC) curve of ZAG was 0.66 (95% CI 0.54-0.77, P < 0.05). At the cutoff value of 1.42 µg/mL serum ZAG, the sensitivity and specificity for differentiating patients with CRC from controls were 62.2 and 69.2%, respectively. Serum ZAG levels were significantly increased in CRC patients. Subjects with higher circulating ZAG and lower leptin levels were more likely to have CRC than those with lower ZAG and higher leptin levels. Serum ZAG might be a potential diagnostic biomarker for CRC in the Chinese population.

Effect of exercise on adiponectin in aged obese rats

To explore effects of exercise on the expression of adiponectin mRNA and protein in visceral adipose tissue, plasma adiponectin concentration, and insulin resistance of aged obese rats. Male SD rats age to 21 days old were fed with high-fat diet (fat percentage was 36.3% to 40.0%) for three stages of adolescence, maturity and old age to establish elderly obesity rats model. When the rats aged to 60 weeks old, natural growing elderly rats were randomly divided into control group (C) and aged exercise group (AE), n=6; elderly obesity rats were randomly divided into obesity control group (OC) and obesity exercise group (OE), n=6. The treadmill grade was 0°, the exercise speed and time were 15 m/min×15 min, 4 groups each time, between consecutive groups the rats had 5 minutes rest, the rats were exercised for 60 minutes every day, five days a week, continuous exercise for 8 weeks. Then, the expressions of adiponectin mRNA and protein in visceral adipose tissue were determined. The concentrations of blood glucose, plasma adiponectin and insulin were measured. Insulin resistance was calculated. Comparison with control group, the expressions of adiponectin mRNA and protein were obviously decreased, the concentration of blood glucose and insulin resistance were significantly increased in obesity control group, while the expressions of adiponectin mRNA and protein were obviously increased. Comparison with obesity control group, the expressions of adiponectin mRNA and protein, the concentration of plasma adiponectin were obviously increased, the concentration of blood glucose and insulin resistance were significantly decreased in obesity exercise group. Adiponectin mRNA and protein expression in visceral adipose tissue is decreased and accompanied by high blood glucose and insulin resistance in elderly obesity rats. Exercise can increase the adiponectin mRNA and protein expression in visceral adipose tissue, elevate levels of plasma adiponectin, and decrease the level of blood glucose and insulin resistance in elderly obesity rats.

Epigenetic Regulations of Genes Related to Lipid Metabolism by MicroRNA in Mice Fed High Fat Diet

BackgroundHigh fat diet impacts lipid metabolism by altering the transportation, oxidation, and storage of fatty acids. Lipoprotein lipase (LPL) plays a critical role in lipid metabolism by catalyzing triglyceride hydrolysis and lipoprotein uptake in multiple tissues. Previous study reported that miR‐29b negatively regulated LPL expression in mammary epithelial cells transfected with miR‐29b mimics. The present study investigated changes in LPL expression and epigenetic mechanisms by miR‐29 family in different tissues in mice fed a high fat diet.MethodFive‐week old male CBA mice were fed with either a control diet (Con group, 10% kcal from diet) or a high fat diet (HF group, 45% kcal from diet) ad libitum for 11 weeks.ResultsLPL mRNA was increased in adipose, muscle and colon in response to high fat diet. However, LPL mRNA expression decreased in the liver by high fat diet as well as hepatic lipase (HL). The results also showed the highest expression level of LPL mRNA in adipose tissue, followed by muscle, colon, and liver. Cpt1a mRNA, an important gene related to beta oxidation, was increased in adipose, muscle, colon, and liver in the HF group. Moreover, Cpt1a mRNA expression was the highest in liver followed by adipose, muscle, and colon. Meanwhile, high fat diet reduced the expression of miR‐29a, a predicted suppressor of LPL from miR‐29 family, in adipose tissue.ConclusionThe present results indicated that the triglyceride hydrolysis could be activated by high fat diet in other tissues than the liver and fatty acid transportation could be induced in mitochondria. Overall, LPL and Cpt1a mRNA changed differently in multiple tissue in response to high fat diet and is potentially post‐transcriptionally regulated by microRNA.Support or Funding InformationSource of research support (in a separate textbox): Campus Research Board of University of Illinois at Urbana‐Champaign and the USDA Cooperative State Research, Education and Extension Service, Hatch project numbers # ILLU‐698‐923 and ILLU‐698‐379This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Mechanisms Linking the Adipocyte Renin Angiotensin System, Inflammation and Endoplasmic Reticulum (ER) Stress

One of the critical pathways involved in obesity is the Renin angiotensin system (RAS) which is classically known to regulate blood pressure and fluid balance. Components of RAS are expressed in adipose tissue; however, mechanisms governing RAS‐obesity interactions are not well identified. Both ER stress and inflammation are increased in adipose tissue and we proposed that it is through ER stress and inflammatory pathways, that RAS contributes to obesity and regulates adipocyte function. This hypothesis was tested using male wild type C57BL/6 mice (Wt) and transgenic mice (Agt‐Tg) overexpressing angiotensinogen (Agt) via P2 promoter in the adipose tissue. Mice were fed a low fat (LF) or a high fat (HF) diet with or without RAS inhibition (captopril, an angiotensin converting enzyme inhibitor). Furthermore, for mechanistic analyses, we used mouse and human adipocytes treated with various inhibitors of RAS (Telmisartan, P‐186), inflammation (11‐7082), and ER stress (PBA).Markers of ER stress such as BiP (Binding immunoglobulin protein), ATF4 (activating transcription factor 4), XBP1 (X‐box binding protein 1) and CHOP (CCAAT/‐enhancer‐binding protein homologous protein) were significantly higher in Agt‐Tg mice compared to Wt mice. Moreover, adipose tissue mRNA and serum levels for pro‐inflammatory markers MCP‐1 (Monocyte Chemoattractant Protein‐1), and IL‐6 (interleukin‐6) were also significantly higher in Agt‐Tg compared to Wt mice. By contrast, anti‐inflammatory cytokine IL‐10 was significantly lower in Agt‐Tg mice compared to Wt mice. Captoril‐treated Agt‐Tg mice demonstrated a significantly lower expression of both ER stress and pro‐inflammatory markers indicating the importance of RAS in these metabolic pathways. To gain further insight into direct mechanisms by which RAS induces obesity, in vitro experiments were conducted. Inhibitors of angiotensin type 1 and type 2 receptors (Agtr) were used to determine the pathway through which RAS induces ER stress and inflammation. Inhibition of Agtr1 receptor significantly reduced RAS effect in both mouse and human adipocytes. As anticipated PBA and 11‐7082 reduced RAS‐induced ER stress and inflammation in vitro further confirming the involvement of RAS. In agreement with these findings, captopril and telmisartan prevented angiotensin‐II (Ang II) induced expression of ER stress, and pro inflammatory markers in both cell types. Further studies are ongoing in cultured adipocytes to dissect molecular mechanisms linking RAS to ER stress and inflammation in obesity.In conclusion, overexpression of RAS in adipose tissue and adipocytes increases inflammation and ER stress. These effects are mediated by Agtr1 receptors. These pathways could be used as potential targets to reduce RAS induced obesity and related metabolic diseases.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Central irisin administration suppresses thyroid hormone production but increases energy consumption in rats

Irisin, which is secreted from the skeletal muscle in response to physical exercise and defined as a thermogenic peptide, may play an important role in energy metabolism. Thyroid hormones, which are one of the other influential factors on the metabolic status, increase heat production and are the main regulators of energy metabolism. This study was conducted to determine the possible effects of irisin administration on thyroid hormones.Forty adult male Wistar albino rats were used in the study. The rats were equally divided into 4 groups (n = 10). The brain infusion kit was implanted in the groups, and irisin (or solvent as control) was centrally administered to the rats via osmotic mini pumps for 7 days. During the experiment, food consumption, body weights, and body temperatures of the animals were recorded.Food intake was significantly increased in the groups treated with irisin (p < 0.05), but their body weights were not changed. Hypothalamic TRH gene expression, serum TSH, fT3, and fT4 levels were significantly lower in the groups treated with irisin as compared to the naive and control groups (p < 0.05). In addition, irisin increased UCP1 mRNA expression in white and brown adipose tissue and UCP3 mRNA expression in muscle tissue in rats and also raised their body temperature (p < 0.05).Consequently, although central irisin administration has inhibitory effects on the hypothalamic-pituitary-thyroid axis, it seems to be an important agent in the regulation of food intake and energy metabolism.

Myeloid-specific deletion of Zfp36 protects against insulin resistance and fatty liver in diet-induced obese mice.

Obesity is associated with adipose tissue inflammation that contributes to insulin resistance. Zinc finger protein 36 (Zfp36) is an mRNA-binding protein that reduces inflammation by binding to cytokine transcripts and promoting their degradation. We hypothesized that myeloid-specific deficiency of Zfp36 would lead to increased adipose tissue inflammation and reduced insulin sensitivity in diet-induced obese mice. As expected, wild-type (Control) mice became obese and diabetic on a high-fat diet, and obese mice with myeloid-specific loss of Zfp36 [knockout (KO)] demonstrated increased adipose tissue and liver cytokine mRNA expression compared with Control mice. Unexpectedly, in glucose tolerance testing and hyperinsulinemic-euglycemic clamp studies, myeloid Zfp36 KO mice demonstrated improved insulin sensitivity compared with Control mice. Obese KO and Control mice had similar macrophage infiltration of the adipose depots and similar peripheral cytokine levels, but lean and obese KO mice demonstrated increased Kupffer cell (KC; the hepatic macrophage)-expressed Mac2 compared with lean Control mice. Insulin resistance in obese Control mice was associated with enhanced Zfp36 expression in KCs. Compared with Control mice, KO mice demonstrated increased hepatic mRNA expression of a multitude of classical (M1) inflammatory cytokines/chemokines, and this M1-inflammatory hepatic milieu was associated with enhanced nuclear localization of IKKβ and the p65 subunit of NF-κB. Our data confirm the important role of innate immune cells in regulating hepatic insulin sensitivity and lipid metabolism, challenge-prevailing models in which M1 inflammatory responses predict insulin resistance, and indicate that myeloid-expressed Zfp36 modulates the response to insulin in mice.

Whole-Body but Not Hepatic Knockdown of Chemerin by Antisense Oligonucleotide Decreases Blood Pressure in Rats.

Chemerin is an inflammatory adipokine positively associated with hypertension and obesity. The majority of chemerin derives from the liver and adipose tissue, however, their individual contributions to blood pressure are unknown. We began studying chemerin in the normal rat using antisense oligonucleotides (ASO) with whole-body activity (Gen 2.5 chemerin ASO) or liver-restricted activity (GalNAc chemerin ASO). We hypothesized that in normotensive male Sprague-Dawley rats, circulating chemerin is predominately liver-derived and regulates blood pressure. A dosing study of the Gen 2.5 chemerin ASO (with a scrambled control ASO) supported 25 mg/kg as the appropriate dose. GalNAc chemerin ASO was also assessed and used at 10 mg/kg. Radiotelemetry monitored mean arterial pressure (MAP) for a 1-week baseline and weekly subcutaneous ASO injections for 4 weeks. Two days after the final injection, animals were euthanized for tissue reverse transcription-polymerase chain reaction and chemerin Western analysis. Gen 2.5 chemerin ASO treatments reduced chemerin mRNA and protein in liver, retroperitoneal fat (RP), and mesenteric perivascular adipose tissue (mPVAT), as well as reducing protein in plasma. GalNAc chemerin ASO treatments reduced chemerin mRNA and protein in liver and chemerin protein in plasma but had no effect on expression in RP fat or mPVAT. Gen 2.5 chemerin ASO treatment reduced MAP compared with control ASO but was unchanged in animals receiving the GalNAc chemerin ASO. Although circulating chemerin is liver-derived, it does not play a major role in blood pressure regulation. Local effects of chemerin from fat may explain this discrepancy and support chemerin's association with hypertension and obesity.

CDH13 abundance interferes with adipocyte differentiation and is a novel biomarker for adipose tissue health.

CDH13, an atypical member of the cadherin superfamily, has been identified in adipocyte secretomes of lean mouse models. CDH13 abundance differs in mouse models according to their susceptibility to develop metabolic disorders, but the role of CDH13 in adipose tissue is unknown. Secreted CDH13 protein levels and mRNA levels in visceral adipose tissue were determined in lean and obese mouse models. In vitro studies were performed in 3T3-L1 adipocytes to determine the role of CDH13 in adipocyte differentiation. The pathophysiological impact of visceral adipose tissue CDH13 mRNA and circulating CDH13 levels were determined in humans (normal-weight men n = 37, obese men n = 109 including n = 51 type 2 diabetes patients) and in obese patients (n = 14) pre- and post-metabolic surgery. This study shows that in visceral adipose tissue CDH13 protein secretion and mRNA levels were decreased in obese mouse models. Mechanistically, CDH13 affects lipid metabolism during adipogenesis but not in mature adipocytes. CDH13 knockdown during adipogenesis reduced fatty acid uptake and lipid content in developing adipocytes. Furthermore, CDH13 depletion during adipogenesis lowered the induction of PPARγ and C/EBPα expression. These observations are of pathophysiological impact since visceral adipose tissue CDH13 mRNA and circulating CDH13 levels were decreased in obese men compared to normal-weight controls. Weight loss induced by bariatric surgery restored circulating CDH13 to levels found in normal-weight controls. CDH13 levels in adipose tissue and the circulation are affected by obesity in mouse models and humans and are restored by weight loss in humans. CDH13 interferes with the differentiation potential of adipocytes and therefore is a marker for plasticity of fat tissue that might reflect the health status of adipose tissue.