Effects of concurrent training on irisin and fibronectin type-III domain containing 5 (FNDC5) expression in visceral adipose tissue in type-2 diabetic rats

Author(s):  
Ahmad Abdi ◽  
Javad Mehrabani ◽  
Michael Nordvall ◽  
Alexei Wong ◽  
Abbas Fallah ◽  
...  
2010 ◽  
Vol 24 (5) ◽  
pp. 1107-1107
Author(s):  
Joan Vendrell ◽  
Elsa Maymó-Masip ◽  
Francisco Tinahones ◽  
Antonio García-España ◽  
Ana Megia ◽  
...  

abstract Context: Adipose tissue hypoxia and endoplasmic reticulum (ER) stress may link the presence of chronic inflammation and macrophage infiltration in severely obese subjects. We previously reported the up-regulation of TNF-like weak inducer of apoptosis (TWEAK)/fibroblast growth factor-inducible 14 (Fn14) axis in adipose tissue of severely obese type 2 diabetic subjects. Objectives: The objective of the study was to examine TWEAK and Fn14 adipose tissue expression in obesity, severe obesity, and type 2 diabetes in relation to hypoxia and ER stress. Design: In the obesity study, 19 lean, 28 overweight, and 15 obese nondiabetic subjects were studied. In the severe obesity study, 23 severely obese and 35 control subjects were studied. In the type 2 diabetes study, 11 type 2 diabetic and 36 control subjects were studied. The expression levels of the following genes were analyzed in paired samples of sc and visceral adipose tissue: Fn14, TWEAK, VISFATIN, HYOU1, FIAF, HIF-1a, VEGF, GLUT-1, GRP78, and XBP-1. The effect of hypoxia, inflammation, and ER stress on the expression of TWEAK and Fn14 was examined in human adipocyte and macrophage cell lines. Results: Up-regulation of TWEAK/Fn14 and hypoxia and ER stress surrogate gene expression was observed in sc and visceral adipose tissue only in our severely obese cohort. Hypoxia modulates TWEAK or Fn14 expression in neither adipocytes nor macrophages. On the contrary, inflammation up-regulated TWEAK in macrophages and Fn14 expression in adipocytes. Moreover, TWEAK had a proinflammatory effect in adipocytes mediated by the nuclear factor-κB and ERK but not JNK signaling pathways. Conclusions: Our data suggest that TWEAK acts as a pro-inflammatory cytokine in the adipose tissue and that inflammation, but not hypoxia, may be behind its up-regulation in severe obesity.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Lenore R Rengel ◽  
Brittaney Obi ◽  
Jon Gould ◽  
Matthew Goldblatt ◽  
Andrew Kastenmeier ◽  
...  

Introduction: Peripheral adiposity is associated with better metabolic health and higher plasma adiponectin (ADPN) levels. Since ADPN is secreted mainly by adipose tissue (AT), it is intriguing that higher visceral adipose tissue (VAT) is associated with lower ADPN levels and poor metabolic health. Hypothesis: We hypothesized that various AT depots differ in their ability to secrete ADPN. Methods: Paired AT samples (VAT and subcutaneous adipose tissue (SAT)) were collected from 19 subjects (10 women, 15 obese) undergoing elective abdominal surgery. The samples were cultured and the supernatant was collected after 24 hours. ADPN levels released into the supernatant from VAT and SAT were measured using multiplex methods. Subjects were defined as obese or non-obese (NO) based on BMI > or ≤ 30kg/m2 respectively. Obese subjects were further classified as metabolically unhealthy obese (MUO) or metabolically healthy obese (MHO) based on presence or absence of type 2 diabetes mellitus, hypertension, or cardiovascular disease at the time of surgery. Results: Mean ADPN secretion levels from SAT and VAT were similar in NO subjects (17.3 ± 3.4 vs. 9.8 ± 13.0 ng/mL/mg, p=0.5) whereas the mean ADPN secretion was lower from VAT among obese subjects (15.9 ± 0.8 vs. 4.5 ± 0.2 ng/mL/mg, p=0.0002). ADPN secretion decreased from VAT (r=-0.16) and increased from SAT (r=0.33) with increased BMI (Fig.1). When MHO and MUO were compared, ADPN secretion from VAT in MHO was reduced only slightly (16.1 ± 8.2 vs. 4.0 ± 2.0 ng/mL/mg, p=0.07) whereas ADPN secretion was significantly reduced in MUO (15.9 ± 5.3 vs. 4.7 ± 4.6 ng/mL/mg, p=0.003). Conclusions: Reduced ADPN secretion from VAT in subjects with increasing BMI may explain lower circulating ADPN levels in obese individuals. Higher ADPN production from SAT and the relatively preserved secretion of ADPN from VAT may explain metabolic health in some obese individuals. Futures studies will help identify factors that control ADPN secretion from AT.


Author(s):  
Helen Sievert ◽  
Christin Krause ◽  
Cathleen Geißler ◽  
Martina Grohs ◽  
Alexander T. El-Gammal ◽  
...  

Abstract Objective The risk to develop type 2 diabetes increases with the amount of visceral adiposity presumably due to increased lipolysis and subsequent lipid accumulation in visceral organs. However, data describing the molecular regulation of these pathways in humans are rare. We tested if genes of the lipogenic and lipolytic pathways are associated with glucose intolerance independently of obesity in visceral adipose tissue (VAT) of obese subjects. Moreover, we studied DNA methylation of FASN (fatty acid synthase), that catalyses the synthesis of long-chain fatty acids, in VAT of the same subjects and whether it is associated with metabolic traits. Subjects and methods Visceral adipose tissue biopsies and blood samples were taken from 93 severely obese subjects undergoing bariatric surgery. Subjects were grouped in low HbA1c (L-HbA1c, HbA1c<6.5 %) and high HbA1c (H-HbA1c, HbA1c≥6.5 %) groups and expression of genes from the lipogenic and lipolytic pathways was analysed by TaqMan qPCR. DNA methylation of FASN was quantified by bisulfite-pyrosequencing. Results FASN expression was downregulated in visceral fat from subjects with high HbA1c (p = 0.00009). Expression of other lipogenetic (SCD, ELOVL6) or lipolytic genes (ADRB3, PNPLA2) and FABP4 was not changed. DNA methylation of FASN was increased at a regulatory ChoRE recognition site in the H-HbA1c-subgroup and correlated negatively with FASN mRNA (r = − 0.302, p = 0.0034) and positively with HbA1c (r = 0.296, p = 0.0040) and blood glucose (r = 0.363, p = 0.0005). Conclusions Epigenetic downregulation of FASN in visceral adipose tissue of obese subjects might contribute to limited de novo lipogenesis of important insulin sensitizing fatty acids and could thereby contribute to glucose intolerance and the development of type 2 diabetes independently of obesity.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nicholas J. Carruthers ◽  
Clarissa Strieder-Barboza ◽  
Joseph A. Caruso ◽  
Carmen G. Flesher ◽  
Nicki A. Baker ◽  
...  

AbstractDysfunctional visceral adipose tissue (VAT) in obesity is associated with type 2 diabetes (DM) but underlying mechanisms remain unclear. Our objective in this discovery analysis was to identify genes and proteins regulated by DM to elucidate aberrant cellular metabolic and signaling mediators. We performed label-free proteomics and RNA-sequencing analysis of VAT from female bariatric surgery subjects with DM and without DM (NDM). We quantified 1965 protein groups, 23 proteins, and 372 genes that were differently abundant in DM vs. NDM VAT. Proteins downregulated in DM were related to fatty acid synthesis and mitochondrial function (fatty acid synthase, FASN; dihydrolipoyl dehydrogenase, mitochondrial, E3 component, DLD; succinate dehydrogenase-α, SDHA) while proteins upregulated in DM were associated with innate immunity and transcriptional regulation (vitronectin, VTN; endothelial protein C receptor, EPCR; signal transducer and activator of transcription 5B, STAT5B). Transcriptome indicated defects in innate inflammation, lipid metabolism, and extracellular matrix (ECM) function, and components of complement classical and alternative cascades. The VAT proteome and transcriptome shared 13 biological processes impacted by DM, related to complement activation, cell proliferation and migration, ECM organization, lipid metabolism, and gluconeogenesis. Our data revealed a marked effect of DM in downregulating FASN. We also demonstrate enrichment of complement factor B (CFB), coagulation factor XIII A chain (F13A1), thrombospondin 1 (THBS1), and integrins at mRNA and protein levels, albeit with lower q-values and lack of Western blot or PCR confirmation. Our findings suggest putative mechanisms of VAT dysfunction in DM.


PLoS ONE ◽  
2012 ◽  
Vol 7 (10) ◽  
pp. e48155 ◽  
Author(s):  
Nuria Barbarroja ◽  
Chary Lopez-Pedrera ◽  
Lourdes Garrido-Sanchez ◽  
Maria Dolores Mayas ◽  
Wilfredo Oliva-Olivera ◽  
...  

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