Adipose Tissue mRNA Expression Research Articles

Muscle metabolome and adipose tissue mRNA expression of lipid metabolism-related genes in over-conditioned dairy cows differing in serum-metabotype

Over-conditioned dairy cows, classified by body condition score (BCS) and backfat thickness (BFT) are less able to metabolically adapt to the rapidly increasing milk yield after parturition. Based on serum metabolome and cluster analyses, high BCS cows (HBCS) could be classified into metabotypes that are more similar to normal (NBCS) cows, i.e., HBCS predicted normal (HBCS-PN) than the HBCS predicted high (HBCS-PH) cows—similar to the concept of obese but metabolically healthy humans. Our objective was to compare muscle metabolome and mRNA abundance of genes related to lipogenesis and lipolysis in adipose tissue between HBCS-PH (n = 13), HBCS-PN (n = 6), and NBCS-PN (n = 15). Tail-head subcutaneous fat was biopsied on d −49, 3, 21, and 84 relative to parturition. Potential differences in the oxidative capacity of skeletal muscle were assessed by targeted metabolomics in M. semitendinosus from d 21. Besides characteristic changes with time, differences in the mRNA abundance were limited to lipogenesis-related genes on d −49 (HBCS-PH > HBCS-PN). The HBCS-PH had more than two-fold higher muscle concentrations of short (C2, C4-OH, C6-OH) and long-chain acylcarnitines (C16, C18, and C18:1) than HBCS-PN, indicating a greater oxidative capacity for fatty acids (and utilization of ketones) in muscle of HBCS-PN than HBCS-PH cows.

Spinal Cord Injury Reduces Serum Levels of Fibroblast Growth Factor-21 and Impairs Its Signaling Pathways in Liver and Adipose Tissue in Mice.

Spinal cord injury (SCI) results in dysregulation of carbohydrate and lipid metabolism; the underlying cellular and physiological mechanisms remain unclear. Fibroblast growth factor 21 (FGF21) is a circulating protein primarily secreted by the liver that lowers blood glucose levels, corrects abnormal lipid profiles, and mitigates non-alcoholic fatty liver disease. FGF21 acts via activating FGF receptor 1 and ß-klotho in adipose tissue and stimulating release of adiponectin from adipose tissue which in turn signals in the liver and skeletal muscle. We examined FGF21/adiponectin signaling after spinal cord transection in mice fed a high fat diet (HFD) or a standard mouse chow. Tissues were collected at 84 days after spinal cord transection or a sham SCI surgery. SCI reduced serum FGF21 levels and hepatic FGF21 expression, as well as β-klotho and FGF receptor-1 (FGFR1) mRNA expression in adipose tissue. SCI also reduced serum levels and adipose tissue mRNA expression of adiponectin and leptin, two major adipokines. In addition, SCI suppressed hepatic type 2 adiponectin receptor (AdipoR2) mRNA expression and PPARα activation in the liver. Post-SCI mice fed a HFD had further suppression of serum FGF21 levels and hepatic FGF21 expression. Elevated serum free fatty acid (FFA) levels after HFD feeding were observed in post-SCI mice but not in sham-mice, suggesting defective FFA uptake after SCI. Moreover, after SCI several genes that are implicated in insulin’s action had reduced expression in tissues of interest. These findings suggest that downregulated FGF21/adiponectin signaling and impaired responsiveness of adipose tissues to FGF21 may, at least in part, contribute to the overall picture of metabolic dysfunction after SCI.

NLRP3 and 4 mRNA Expression in Epicardial Adipose Tissue Is Associated to Inflammosome Components Driven by Adipose Tissue Macrophages in Cardiovascular Disease Patients

Visceral obesity is characterized by low grade chronic inflammation especially driven by activated adipose tissue macrophages (ATMs) infiltration in response to danger-associated molecular patterns (DAMPs) including necrotic adipocytes and pro-inflammatory fat mediators. Among pattern recognition receptors (PPRs), nucleotide-binding and oligomerization domain (NOD)-like receptors (NLRs) gained attention as part of inflammasomes of adipose tissue which can promote insuline resistance and amplify inflammation through ATMs activation in fat tissue. Nod-like receptor protein 3 and 4 inflammasomes have been extensively studied in adipose tissue but is unclear their role in a peculiar visceral fat depot known as epicardial adipose tissue (EAT) contiguous to the myocardium and directly involved in cardiac inflammation and outcomes. In this study we evaluated NLR 3 and 4 protein (NLRP3 and 4) expression in EAT and their association to local inflammosomes and ATMs activation in overweight cardiovascular disease (CVDs) patients. We enrolled at IRCCS Policlinico San Donato 33 CVDs patients who underwent to open heart surgery and their EAT thickness, anthropometric and biochemical data were measured. Blood, plasma and EAT biopsies were collected for molecular and proteomic assays. All patients given their informed consent according to the Basic Principles of the Declaration of Helsinki and their extension. Our data shown that NLRP3 and 4 mRNA were expressed in EAT of overweight CVDs patients. NLRP4 mRNA expression increased during fat mass gain, indeed its expression correlates with EAT measurement (r=0.53, p=0.02), body mass index (0.41, p=0.01), weight (r=0.35, p=0.04) and waist (r=0.36, p=0.03). Notably both NLRP3 and 4 mRNA expression in EAT correlate with the major inflammasome genes associated to ATMs activation including ITGAX encoding for CD11c (isoform 3 r=0.38, p=0.02; isoform 4 r=-0.46, p=0.006), MRC1 encoding for CD206 (isoform 3 r=0.68, p=0.0001; isoform 4 r=-0.48, p=0.004), CCL2 encoding for MCP1(isoform 3 r=0.39, p=0.02; isoform 4 not statistically significant). Interesting the two isoforms shown a direct association to TNF-α expression in EAT (p<0.001 for both NLRPs), suggesting their implication in ATMs activation and the promotion of local inflammation in this visceral depot. In conclusion our results demonstrated that NLRP3 and 4 were expressed in EAT of overweight CVD patients and NLRP4 expression increases during fat mass increase. Moreover, both NLRPs isoforms are associated to the local activation ATMs inflammasomes which could be potentially implicated to cardiovascular outcomes in overweight CVDs population.

Relationship Between Serum Adipocyte Fatty Acid Binding Protein and Atherosclerosis in Type 2 Diabetes Patients

Background: Atherosclerosis as a complication of diabetes, is considered to be a chronic inflammatory disease, developing over years and proceeding through many steps. Adiposity fatty acid–binding protein (A-FABP) is highly expressed in mature adipocytes and plays a central regulatory role in energy metabolism and inflammation. A-FABP mRNA expression in adipose tissues predicted coronary artery disease in homozygous subjects. A-FABP may also play a role in the development of atherosclerotic diseases in humans. Objective: To detect the relationship between serum A-FABP level and carotid intima-media thickness (IMT) as indicator of atherosclerosis in patients with type 2 diabetes mellitus. Patients and methods: 124 patients with type 2 diabetes (T2D), were divided into two groups: Group 1: 62 patients with T2D ≤ 5 years duration, and Group 2: 62 patients with T2D > 5 years duration. They were subjected to full history taking, clinical examination, and laboratory investigations in the form of CBC, LFT, KFT, HBA1c, fasting and postprandial blood sugar, A-FABP serum level, and carotid Doppler. Results: Serum level A-FABP and carotid IMT was significantly higher in long standing diabetes group compared to short standing diabetes group.A-FABP cutoff was proven to have a high sensitivity 94.4%, specificity 100.0%, positive predictive value of 100.0%, negative predictive value of 97.7% and overall accuracy of 98.3% regarding the prediction of atherosclerosis. Conclusions: A-FABP serum level have a high sensitivity, specificity, predictive value and overall accuracy regarding atherosclerosis, and should be recommended as a part of routine surveillance for atherosclerosis in patients with type 2 diabetes.

Therapeutic effect of oxyberberine on obese non-alcoholic fatty liver disease rats

BackgroundBerberine (BBR) has been widely used to treat non-alcoholic fatty liver disease (NAFLD). The metabolites of BBR were believed to contribute significantly to its pharmacological effects. Oxyberberine (OBB), a gut microbiota-mediated oxidative metabolite of BBR, has been firstly identified in our recent work. PurposeHere, we aimed to comparatively investigate the anti-NAFLD properties of OBB and BBR. MethodsThe anti-NAFLD effect was evaluated in high-fat diet-induced obese NAFLD rats with biochemical/ELISA tests and histological staining. The related gene and protein expressions were detected by qRT-PCR and Western blotting respectively. Molecular docking and dynamic simulation were also performed to provide further insight. ResultsResults indicated OBB remarkably and dose-dependently attenuated the clinical manifestations of NAFLD, which (100 mg/kg) achieved similar therapeutic effect to metformin (300 mg/kg) and was superior to BBR of the same dose. OBB significantly inhibited aberrant phosphorylation of IRS-1 and up-regulated the downstream protein expression and phosphorylation (PI3K, p-Akt/Akt and p-GSK-3β/GSK-3β) to improve hepatic insulin signal transduction. Meanwhile, OBB treatment remarkably alleviated inflammation via down-regulating the mRNA expression of MCP-1, Cd68, Nos2, Cd11c, while enhancing Arg1 mRNA expression in white adipose tissue. Moreover, OBB exhibited closer affinity with AMPK in silicon and superior hyperphosphorylation of AMPK in vivo, leading to increased ACC mRNA expression in liver and UCP-1 protein expression in adipose tissue. ConclusionTaken together, compared with BBR, OBB was more capable of maintaining lipid homeostasis between liver and WAT via attenuating hepatic insulin pathway and adipocyte inflammation, which was associated with its property of superior AMPK activator.

N-3 PUFAs protect against adiposity and fatty liver by promoting browning in postnatally overfed male rats: a role for NRG4

Early-life nutrition plays an important role in regulating adult metabolism. This study evaluated the effects of early nutrition during the suckling and postweaning periods on expression of the adipocytokine Neuregulin 4 (Nrg4) and its relationship with nonalcoholic fatty liver disease (NAFLD) in adulthood. In vivo, male rats were adjusted to litter sizes of three (small litter, SL) or ten (normal litter, NL) on postnatal day 3. Pups were fed control chow (NL and SL groups) or a high-fat diet (NL-HF and SL-HF groups), and SL pups specifically were fed a fish oil diet rich in n-3 polyunsaturated fatty acids (n-3 PUFAs) (SL-FO group), from postnatal weeks 3 to 13. The results demonstrated that postnatal overnutrition increased weight, hepatic de novo lipogenesis (DNL) gene expression and NAFLD and decreased body temperature and Nrg4, Ucp1 and Pgc1a mRNA expression in adipose tissues in SL, SL-HF and NL-HF rats compared to NL rats in adulthood. The opposite trends were observed in SL-FO rats. Moreover, in vitro, recombinant NRG4 protein reduced lipid accumulation by inhibiting DNL gene expression in fatty HepG2 cells stimulated with sodium oleate. In HPAs, eicosapentaenoic acid (EPA) treatment elevated NRG4 production and caused adipocyte browning, and these effects were abrogated by PPARG antagonism. In conclusion, a postweaning n-3 PUFA diet enhanced Nrg4 expression in adipose tissues, associated with attenuation of NAFLD induced by SL rearing. Additionally, external NRG4 reduced lipogenesis in steatotic hepatocytes. Thus, white adipose tissue browning induced by n-3 PUFAs may promote NRG4 production through the PPARG pathway.

Treatment of Primary Aldosteronism Increases Plasma Epoxyeicosatrienoic Acids.

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Fatty Acid Synthase Correlates With Prognosis-Related Abdominal Adipose Distribution and Metabolic Disorders of Clear Cell Renal Cell Carcinoma.

Purpose: Lipid metabolism reprogramming is a major pathway in tumor evolution. This study investigated fatty acid synthase (FASN) mRNA expression in anthropometric adipose tissue and elucidated the prognostic value and potential mechanism of clear cell renal cell carcinoma (ccRCC).Materials and Methods: Transcription profiles were obtained from 533 ccRCC samples in The Cancer Genome Atlas (TCGA) cohorts. Real-time quantitative PCR (RT-qPCR) and immunohistochemistry were performed to detect FASN expression in 380 paired ccRCC and normal tissues from the Fudan University Shanghai Cancer Center (FUSCC). Visceral adipose tissue (VAT) and subcutaneous adipose tissue were at the level of the umbilicus as measured by magnetic resonance imaging (MRI). Non-targeted metabolomics and in vitro experiments were used to reveal the biological functions of FASN.Results: Increased FASN expression was significantly relevant to advanced T, N, and American Joint Committee on Cancer (AJCC) stages (p < 0.01) and significantly correlated to poor progression-free survival (PFS) and overall survival (OS) of 913 ccRCC patients in FUSCC and TCGA cohorts. Pearson's correlation coefficient indicated that FASN amplification was positively correlated to VAT% (r = 0.772, p < 0.001), which significantly correlated to poor PFS (HR = 2.066, p = 0.028) and OS (HR = 2.773, p = 0.023) in the FUSCC cohort. Transient inhibition or overexpression of FASN significantly regulated A498 and 786O cell proliferation and migration by regulating epithelial–mesenchymal transition. Inhibition of FASN led to a higher apoptotic rate and decreased lipid droplet formation compared with normal control in ccRCC cells. Non-targeted metabolomics showed that decreased de novo lipogenesis might be required to sustain an elevation of glycolytic activity in 786O cells by regulating galactinol, dl-lactate, N-acetylaspartylglutamate, and sucrose, thereby participating in carcinogenesis and progression of ccRCC.Conclusion: This study demonstrated that FASN expression is positively related to aggressive cell proliferation, migration, apoptosis, and lipid droplet formation and regulates metabolic disorders of the ccRCC microenvironment. Additionally, elevated FASN mRNA expression is significantly correlated to the abdominal obesity distribution, especially VAT%, which is a significant predictor of a poor prognosis for ccRCC patients.

Duration and degree of diet-induced metabolic acidosis prepartum alter tissue responses to insulin in dairy cows

The objective of this experiment was to determine the effects of altering the dietary cation-anion difference (DCAD) fed for the last 21 or 42 d of gestation on glucose metabolism and tissue insulin responsiveness. Ninety parous Holstein cows at 232 d of gestation were assigned randomly to dietary treatments with 2 levels of DCAD (-70 or -180 mEq/kg) fed for 2 durations (short: the last 21 d of gestation; long: the last 42 d of gestation). For the short treatments, a diet with +110 mEq/kg was fed from 232 to 254 d of gestation. Intravenous glucose tolerance tests (IVGTT) were performed at either 250 or 270 d of gestation by infusing 0.25 g of dextrose/kg of body weight within 1 min. The following day, cows underwent an insulin challenge (IC) and received 0.1 IU of insulin/kg of body weight intravenously. Blood was sampled at min -15, -5, and 0 to establish a baseline and from 5 to 180 min relative to infusions; plasma concentrations of glucose, insulin, and fatty acids were determined, and the respective areas under the curves (AUC) were calculated. Liver was sampled after the IVGTT, and adipose tissue was sampled after the IVGTT and IC for quantification of mRNA expression and protein abundance. Reducing the DCAD altered acid-base balance compatible with a compensated metabolic acidosis. At 250 d, reducing the DCAD increased the AUC for glucose and reduced that of insulin following the IVGTT, whereas during the IC, clearance rate decreased and time to half-life of insulin increased with reducing DCAD, resulting in a tendency to a larger AUC for fatty acids. At 270 d, quantitative insulin sensitivity check index and the revised quantitative insulin sensitivity check index were smaller in cows fed the acidogenic diets for the last 42 d of gestation compared with the last 21 d of gestation, thereby suggesting reduced insulin sensitivity. In addition, cows fed for the long duration tended to have greater AUC for glucose but smaller AUC for insulin following an IVGTT than those fed for the short duration, thereby suggesting reduced insulin release and glucose disposal. Treatments did not affect hepatic mRNA expression of G6PC, PCK1, PCK2, and PC or adipose tissue mRNA expression of ATGL, ACC, B2AR, HSL, and PLIN1. On the other hand, for proteins, reducing the DCAD linearly reduced abundance of rabbit anti-mouse protein kinase B (AKT) and tended to reduce rabbit anti-human phosphorylated (Ser-9) glycogen synthase kinase-3 β (pGSK) and the pGSK:rabbit anti-human glycogen synthase kinase-3 β (GSK) ratio in hepatic tissue, whereas a linear increase in rabbit anti-human hormone-sensitive lipase (HSL) and rabbit anti-mouse phosphorylated (Ser-660) hormone-sensitive lipase (pHSL) in adipose tissue was observed after the IVGTT at 250 d. Moreover, reducing the DCAD resulted in a linear reduction of AKT and tended to reduce rabbit anti-human acetyl-CoA carboxylase (ACC) but increased pHSL linearly in adipose tissue after an IC at 250 d. Cows fed acidogenic diets for a short duration tended to have less pHSL in adipose tissue than those fed for a long duration after an IVGTT at 270 d. Associations were observed between blood pH and mRNA and protein abundance in hepatic and adipose tissues. Diet-induced metabolic acidosis altered insulin release and insulin signaling, resulting in a shift in adipose tissue metabolism that would favor lipolysis over lipogenesis.

The association of dietary and plasma fatty acid composition with FTO gene expression in human visceral and subcutaneous adipose tissues.

The human obesity susceptibility gene, FTO, associates with body mass and obesity in humans through regulation of energy expenditure and intake. We aimed to determine how fatty acids in plasma and in diet associate with FTO gene expression in subcutaneous and visceral adipose tissues. In this study, 97 participants aged ≥ 18years were selected from patients admitted to the hospital for abdominal surgeries. Habitual dietary intake of participants was collected using a valid and reliable food frequency questionnaire (FFQ), from which the intake of fatty acids was quantified. Plasma fatty acids were assessed by gas-liquid chromatography. The mRNA expression of the FTO gene in visceral and subcutaneous adipose tissues obtained by biopsy was measured by Real-Time Quantitative Reverse Transcription PCR. Standardized β-coefficients were calculated by multivariable linear regression. After adjusting for age, homeostasis model insulin resistance index (HOMA-IR), and body mass index, total fatty acid intake was significantly associated with FTO gene expression in visceral (STZβ = 0.208, P = 0.037) and subcutaneous (STZβ = 0.236, P = 0.020) adipose tissues. Dietary intake of monounsaturated fatty acid (MUFA) and polyunsaturated fatty acids (PUFA) had positive significant associations with the expression of FTO in visceral (STZβ = 0.227, P = 0.023; STZβ = 0.346, P < 0.001, respectively) and subcutaneous (STZβ = 0.227, P = 0.026; STZβ = 0.274, P = 0.006, respectively) adipose tissues. There were no associations between plasma fatty acids and FTO mRNA expression in either subcutaneous or visceral adipose tissues. The weak association of dietary total fatty acids, MUFA, and PUFA with FTO gene expression in both adipose tissues may highlight the importance of dietary fatty acids composition along with total fat intake in relation to FTO gene expression.

Effect of high-fat diet and exercise on asprosin and CTRP6 expression in subcutaneous and retroperitoneal adipose tissues in rats during mid-gestation

To study the effects of high-fat (HF) diet and exercise on the expressions of asprosin and CTRP6 in adipose tissues in different regions of rats during mid-gestation. Pregnant SD rats were fed on a standard chow diet or a high-fat (60% fat content) diet for 14 days starting on gestation day (GD) 1. Starting from GD3, the rats fed either on normal or high-fat diet in the exercise groups (CH-RW and HF-RW groups) were allowed access to the running wheels for voluntary running, and those in sedentary groups (CH-SD and HF-SD groups) remained sedentary. At the end of the 14 days, adipose tissues were sampled from different regions of the rats for detecting the mRNA and protein expressions of asprosin and CTRP6 using RT-qPCR and Western blotting. The mRNA expression of asprosin in retroperitoneal adipose tissues was significantly higher in HF-RW group than in the other 3 groups (P < 0.0001). Asprosin mRNA expression in subcutaneous adipose tissues was significantly higher in HF-SD group than in CH-SD group (P=0.0234) and comparable between HF-RW and CH-SD groups (P=0.0494). CTRP6 mRNA expression in retroperitoneal adipose tissues was also significantly higher in HF-RW group than in the other groups (P < 0.0001), and CTRP6 protein expression was signficiantly higher in HF-RW group than in CH-RW and HF-SD groups (P < 0.05). In subcutaneous adipose tissues, CTRP6 mRNA expression was significantly higher in CH-RW group than in HF-SD and HF-RW groups (P < 0.05). The protein expression level of CTRP6 in subcutaneous adipose tissues showed a significant negative correlation with blood glucose (r=-0.6038, P=0.0172), while its expression in retroperitoneal adipose tissues was positively correlated with blood glucose (r=0.5305, P= 0.0285); the mRNA expression levels of asprosin and CTRP6 were significantly lower in subcutaneous than in retroperitoneal adipose tissues (P < 0.0001). High-fat diet and exercise during mid-gedtation can affect the expression levels of asprosin and CTRP6 in adipose tissues of rats in a site-specific manner.

DNA methylation of CpG sites in the chicken KLF7 promoter and Exon 2 in association with mRNA expression in abdominal adipose tissue and blood metabolic indicators

BackgroundOur previous study found that chicken KLF7 was an important regulator in formation of adipose tissue. In the present study, we analyzed the association for DNA methylation in chicken KLF7 with its transcripts of abdominal adipose tissue and blood metabolic indicators.ResultsThe KLF7 transcripts of the adipose tissue of Chinese yellow broilers were associated with age (F = 6.67, P = 0.0035). In addition, the KLF7 transcripts were negatively correlated with blood glucose levels (r = − 0.61841, P = 0.0140). The DNA methylation levels of 26 CpG loci in the chicken KLF7 promoter and Exon 2 were studied by Sequenom MassArray. A total of 22 valid datasets were obtained. None of them was significantly different in relation to age (P > 0.05). However, the DNA methylation levels in the promoter were lower than those in Exon 2 (T = 40.74, P < 0.01). Correlation analysis showed that the DNA methylation levels of PCpG6 and E2CpG9 were significantly correlated with KLF7 transcripts and blood high-density lipoprotein levels, respectively, and many CpG loci were correlated with each other (P < 0.05). The methylation data were subjected to principal component analysis and factor analysis. The six principal components (z1–z6) were extracted and named Factors 1–6, respectively. Factor analysis showed that Factor 1 had a higher load on the loci in the promoter, and Factors 2–6 loaded highly on quite different loci in Exon 2. Correlation analysis showed that only z1 was significantly correlated to KLF7 transcripts (P < 0.05). In addition, an established regression equation between z1 and KLF7 transcripts was built, and the contribution of z1 to the variation on KLF7 transcripts was 34.29%.ConclusionsIn conclusion, the KLF7 transcripts of chicken abdominal adipose tissue might be inhibited by DNA methylation in the promoter, and it might be related to the DNA methylation level of PCpG6.

Cardiotrophin-1 contributes to metabolic adaptations through the regulation of lipid metabolism and to the fasting-induced fatty acid mobilization.

It is becoming clear that several human pathologies are caused by altered metabolic adaptations. During liver development, there are physiological changes, from the predominant utilization of glucose (fetal life) to the use of lipids (postnatal life). Fasting is another physiological stress that elicits well-known metabolic adjustments. We have reported the metabolic properties of cardiotrophin-1 (CT-1), a member of the interleukin-6 family of cytokines. Here, we aimed at analyzing the role of CT-1 in response to these metabolic changes. We used different in vivo models. Furthermore, a differential study was carried out with wild-type and CT-1 null mice in fed (ad libitum) and food-restricted conditions. We demonstrated that Ct-1 is a metabolic gene induced in the liver via PPARα in response to lipids in mice (neonates- and food-restricted adults). We found that Ct-1 mRNA expression in white adipose tissue directly involved PPARα and PPARγ. Finally, the physiological role of CT-1 in fasting is confirmed by the impaired food restriction-induced adipose tissue lipid mobilization in CT-1 null mice. Our findings support a previously unrecognized physiological role of CT-1 in metabolic adaptations, through the regulation of lipid metabolism and contributes to fasting-induced free fatty acid mobilization.

Nano Chromium Picolinate Improves Gene Expression Associated with Insulin Signaling in Porcine Skeletal Muscle and Adipose Tissue

Simple SummaryDietary chromium has been shown to reduce fat deposition and improve insulin action whereas dietary fat can increase fat deposition and cause insulin resistance. This study found that dietary nanoparticles of chromium picolinate, an organic form of chromium, caused changes in the genes involved in insulin action in both muscle and fat tissue that indicated improved insulin action. Conversely, a moderate increase in dietary fat caused changes consistent with increased fat deposition and reduced insulin action. In conclusion, nanoparticles of chromium picolinate offer a means of supplementing pigs diets to improve growth performance and carcass composition.The aim of this study was to investigate the interactive effects of dietary nano chromium picolinate (nCrPic) and dietary fat on genes involved in insulin signaling in skeletal muscle and subcutaneous adipose tissue of pigs. Forty-eight gilts were stratified on body weight into four blocks of four pens of three pigs and then within each block each pen was randomly allocated to four treatment groups in a 2 × 2 factorial design. The respective factors were dietary fat (22 or 57 g/kg) and dietary nCrPic (0 or 400 ppb nCrPic) fed for six weeks. Skeletal muscle samples were collected from the Longissimus thoracis and subcutaneous adipose tissue collected from above this muscle. Dietary nCrPic increased adiponectin, uncoupling protein 3 (UCP3) and serine/threonine protein kinase (AKT) mRNA expression, whereas dietary fat decreased adiponectin and increased leptin, tumor necrosis factor-α (TNF-α), peroxisome proliferator-activated receptors γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα) mRNA expression in adipose tissue. In skeletal muscle, dietary nCrPic increased phosphatidylinositol 3 kinase (PI3K), AKT, UCP3 and interleukin-15 (IL-15), as well as decreased suppressor of cytokine signaling 3 (SOCS3) mRNA expression. The improvement in insulin signaling and muscle mass and the reduction in carcass fatness by dietary nCrPic may be via decreased SOCS3 and increased UCP3 and IL-15 in skeletal muscle and increased adiponectin in subcutaneous adipose tissue.

Exacerbated obesogenic response in female mice exposed to early life stress is linked to fat depot-specific upregulation of leptin protein expression.

Early life stress (ELS) is an independent risk factor for increased BMI and cardiometabolic disease risk later in life. We have previously shown that a mouse model of ELS, maternal separation and early weaning (MSEW), exacerbates high-fat diet (HF)-induced obesity only in adult female mice. Therefore, the aim of this study was to investigate 1) whether the short- and long-term effects of HF on leptin expression are influenced by MSEW in a sex-specific manner and 2) the potential epigenetic mechanisms underlying the MSEW-induced changes in leptin expression. After 1 wk of HF, both MSEW male and female mice displayed increased fat mass compared with controls (P < 0.05). However, only MSEW female mice showed elevated leptin mRNA expression in gonadal white adipose tissue (gWAT; P < 0.05). After 12 wk of HF, fat mass remained increased only in female mice (P < 0.05). Moreover, plasma leptin and both leptin mRNA and protein expression in gWAT were augmented in MSEW female mice compered to controls (P < 0.05), but not in MSEW male mice. This association was not present in subcutaneous WAT. Furthermore, among 16 CpG sites in the leptin promoter, we identified three hypomethylated sites in tissue from HF-fed MSEW female mice compared with controls (3, 15, and 16, P < 0.05). These hypomethylated sites showed greater binding of key adipogenic factors such as PPARγ (P < 0.05). Taken together, our study reveals that MSEW superimposed to HF increases leptin protein expression in a sex- and fat depot-specific fashion. Our data suggest that the mechanism by which MSEW increases leptin expression could be epigenetic.

Oxytocin reduces adipose tissue inflammation in obese mice

BackgroundObesity and adipose tissue expansion is characterized by a chronic state of systemic inflammation that contributes to disease. The neuropeptide, oxytocin, working through its receptor has been shown to attenuate inflammation in sepsis, wound healing, and cardiovascular disease. The current study examined the effects of chronic oxytocin infusions on adipose tissue inflammation in a murine model of obesity, the leptin receptor-deficient (db/db) mouse.MethodsThe effect of obesity on oxytocin receptor protein and mRNA expression in adipose tissue was evaluated by Western blotting and real-time polymerase chain reaction. Mice were implanted with osmotic minipumps filled with oxytocin or vehicle for 8 weeks. At study endpoint adipose tissue inflammation was assessed by measurement of cytokine and adipokine mRNA tissue levels, adipocyte size and macrophage infiltration via histopathology, and plasma levels of adiponectin and serum amyloid A as markers of systemic inflammation.ResultsThe expression of adipose tissue oxytocin receptor was increased in obese db/db mice compared to lean controls. In adipose tissue oxytocin infusion reduced adipocyte size, macrophage infiltration, IL-6 and TNFα mRNA expression, and increased the expression of the anti-inflammatory adipokine, adiponectin. In plasma, oxytocin infusion reduced the level of serum amyloid A, a marker of systemic inflammation, and increased circulating adiponectin.ConclusionsIn an animal model of obesity and diabetes chronic oxytocin treatment led to a reduction in visceral adipose tissue inflammation and plasma markers of systemic inflammation, which may play a role in disease progression.

Relationship between interleukin-1β gene expression in epicardial adipose tissue and coronary atherosclerosis based on computed tomographic analysis

BackgroundAnti-inflammatory therapy targeting interleukin (IL)-1β reduced cardiovascular events in a randomized trial. We evaluated the relationship between IL-1β mRNA expression in epicardial adipose tissue (EAT) and clinically-assessed coronary atherosclerosis on computed tomography (CT). MethodsWe studied 45 patients before cardiac surgery (coronary artery bypass grafting [CABG], n ​= ​18; non-CABG, n ​= ​27). EAT volume, the coronary calcium score (CCS), and the presence of non- and/or partially-calcified coronary plaques (NCPs) and high-risk coronary plaques (HRPs; minimum CT density <30 Hounsfield units and vascular remodeling index >1.1) on CT angiography were assessed. EAT samples were obtained during cardiac surgery. IL-1β mRNA expression in EAT was measured using quantitative real-time PCR and normalized to that of β-actin in each patient. ResultsThere was no difference in IL-1β mRNA levels between patients who were scheduled for CABG and non-CABG surgery or among subgroups based on the CCS. However, patients with NCPs (median [interquartile range], 4.1[2.0-11.6]E-4 versus 1.8[0.6-4.5]E-4, p ​= ​0.024) and HRP (7.6[3.0-20.4]E-4 versus 1.9[0.7-4.3]E-4, p ​= ​0.0023) had higher IL-1β mRNA levels than those without these plaques. On multivariate analysis adjusted for age, sex, coronary risk factors, statin therapy, CCS, and EAT volume, the presence of HRPs was significantly correlated with elevated IL-1β mRNA levels in EAT (β ​= ​0.39, p ​= ​0.047). ConclusionOur data suggest a contribution of EAT to coronary atherosclerosis through molecular behavior, such as IL-1β gene expression, which may be a new therapeutic target.

Expression of clock gene Dbp in omental and mesenteric adipose tissue in patients with type 2 diabetes.

IntroductionWe previously reported in ob/ob mice, one of animal models of human type 2 diabetes mellitus (DM2), that (i) acetylation of histone H3 lysine 9 (H3K9) at the promoter region of clock gene Dbp and DBP mRNA expression are reduced in epididymal adipose tissue, (ii) binding of DBP to the promoter region of peroxisome proliferator-activated receptor (Ppar)-γ and mRNA expression of PPAR-γ1sv were decreased in preadipocytes and (iii) adiponectin secretion was decreased, leading to the impaired insulin sensitivity.Research design and methodsThe present study was undertaken to evaluate whether such the changes in visceral adipose tissue were detected in patients with DM2. We obtained omental and mesenteric adipose tissue during surgery of lymph node dissection for gastric and colorectal cancers, and investigated these variables in adipose tissue (omental from gastric cancer; 13 non-DM, 12 DM2: mesenteric from colorectal cancer; 12 non-DM, 11 DM2).ResultsAcetylation of histone H3K9 at the promoter region of Dbp and DBP mRNA expression in omental, but not in mesenteric adipose tissue were significantly lower in DM2 than in patients without DM. PPAR-γ mRNA expression in omental adipose tissue was also lower in patients with DM2, but not in mesenteric adipose tissue.ConclusionsThe changes in DBP-PPAR-γ axis observed in mice with diabetes were also detected in patients with DM2. Because adiponectin secretion is reported to be enhanced through the PPAR-γ-related mechanism, this study supports the hypothesis that omental adipose tissue is involved in the mechanism of DM2.

Modulation of Leptin and Leptin Receptor Expression in Mice Acutely Infected with Neospora caninum

Neospora caninum is an apicomplexan parasite that in cattle assumes particular importance, as it is responsible for abortions reported worldwide. Leptin is an adipokine mainly secreted by adipocytes, which beside its role in maintaining metabolic homeostasis also has important effects in both innate and adaptive immunity. In previous work, we showed that mice chronically infected with N. caninum had elevated serum leptin levels. Here, we sought to assess whether acute infection with N. caninum infection influenced the production of this adipokine as well as leptin receptor mRNA levels. Our results show that acute infection with N. caninum led to decreased leptin serum levels and mRNA expression in adipose tissue. A decrease in leptin receptor transcript variant 1 mRNA (long isoform) and leptin receptor transcript variant 3 mRNA (one of the short isoforms) expression was also observed. An increase in the number of cells staining positive for leptin in the liver of infected mice was observed, although this increase was less marked in Interleukin (IL)-12/IL-23 p40-deficient mice. Overall, our results show that N. caninum infection also influences leptin production during acute infection.

Relationship between perirenal adipose tissue neuropeptide Y and insulin resistance in nutritional transition model

To observe the changes of neuropeptide Y(NPY) expression in perirenal adipose tissue and its relationship with insulin resistance in the nutritional transition models of refeeding after calorie restriction. SPF Male SD rats, aged 8 weeks, were randomly divided into normal chow group and refeeding with normal chow after calorie restriction for 4 weeks group. NPY gene expression in perirenal adipose tissue were detected by real-time quantitative PCR at the end of 4 and 12 weeks, along with fasting plasma glucose, fasting serum lisulin, free fatty acids and average glucose infusion rate(GIR_(60-120)) of hyperinsulinemic-euglycemic clamp test for 60-120 minutes. NPY gene mRNA expression in perirenal adipose tissue was detected by real-time quantitative PCR. And the relationship between NPY gene expression and insulin resistance was detected by Spearman correlation analysis. The expression level of NPY gene in perirenal adipose tissue in caloric restriction for 4 weeks group was significantly increased by calorie restriction(P&lt;0. 01). After refeeding, the expression level of NPY gene in refeeding with normal group was still slightly increased, which was significantly higher than that in normal group at the end of the experiment(P&lt;0. 01). The levels of fasting plasma glucose and fasting insulin in caloric restriction for 4 weeks group decreased slightly, GIR_(60-120) increased slightly, but there were no statistical differences compared with normal group(P&gt;0. 05), but free fatty acid levels increased significantly(P&lt;0. 01). After refeeding, the levels of fasting insulin, free fatty acid in refeeding with normal group increased significantly, GIR_(60-120) decreased evidently(P&lt;0. 01), but the changes of fasting blood glucose were not obvious. The result of stepwise regression showed that the expression level of NPY gene in perirenal adipose tissue was closely related to GIR_(60-120) and fasting insulin, with R values of-0. 816 and 0. 789 respectively(R~2=0. 892, P&lt;0. 01). The result of correlation analysis showed that in the 4-week group, the mRNA expression level of NPY gene in perirenal adipose tissue was closely related to GIR_( 60-120)、fasting insulin and free fatty acid, with R values of-0. 765, 0. 716 and 0. 657 respectively(P&lt;0. 01). In the 12 week group, the mRNA expression level of NPY gene in perirenal adipose tissue was closely related to GIR_(60-120), fasting insulin and free fatty acid, with R values of-0. 853, 0. 622 and 0. 608 respectively(P&lt;0. 01). The mRNA expression of NPY gene in perirenal adipose tissue was closely related to indicators of insulin resistance. It is an important factor affecting insulin sensitivity.