scholarly journals Visceral Adipose Tissue of Prediabetic and Diabetic Females Shares a Set of Similarly Upregulated microRNAs Functionally Annotated to Inflammation, Oxidative Stress and Insulin Signaling

Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 101
Author(s):  
Justyna Strycharz ◽  
Adam Wróblewski ◽  
Andrzej Zieleniak ◽  
Ewa Świderska ◽  
Tomasz Matyjas ◽  
...  

Hypertrophic and hypoxic visceral adipose tissue (VAT) secretes proinflammatory cytokines promoting insulin resistance (IR), prediabetes and type 2 diabetes (T2DM) microRNAs (miRNAs) are markers of metabolic disorders regulating genes critical for e.g., inflammation, glucose metabolism, and antioxidant defense, with raising diagnostic value. The aim of the current study was to evaluate whether hyperglycemia is able to affect the expression of selected miRNAs in VAT of prediabetic (IFG) and diabetic (T2DM) patients vs. normoglycemic (NG) subjects using qPCR. Statistical analyses suggested that miRNAs expression could be sex-dependent. Thus, we determined 15 miRNAs as differentially expressed (DE) among NG, T2DM, IFG females (miR-10a-5p, let-7d-5p, miR-532-5p, miR-127-3p, miR-125b-5p, let-7a-5p, let-7e-5p, miR-199a-3p, miR-365a-3p, miR-99a-5p, miR-100-5p, miR-342-3p, miR-146b-5p, miR-204-5p, miR-409-3p). Majority of significantly changed miRNAs was similarly upregulated in VAT of female T2DM and IFG patients in comparison to NG subjects, positively correlated with FPG and HbA1c, yet, uncorrelated with WHR/BMI. Enrichment analyses indicated involvement of 11 top DE miRNAs in oxidative stress, inflammation and insulin signaling. Those miRNAs expression changes could be possibly associated with low-grade chronic inflammation and oxidative stress in VAT of hyperglycemic subjects.

Antioxidants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 892
Author(s):  
Zaida Abad-Jiménez ◽  
Sandra López-Domènech ◽  
Rubén Díaz-Rúa ◽  
Francesca Iannantuoni ◽  
Segundo Ángel Gómez-Abril ◽  
...  

Obesity is a low-grade inflammatory condition affecting a range of individuals, from metabolically healthy obese (MHO) subjects to type 2 diabetes (T2D) patients. Metformin has been shown to display anti-inflammatory properties, though the underlying molecular mechanisms are unclear. To study whether the effects of metformin are mediated by changes in the inflammasome complex and autophagy in visceral adipose tissue (VAT) of obese patients, a biopsy of VAT was obtained from a total of 68 obese patients undergoing gastric bypass surgery. The patients were clustered into two groups: MHO patients and T2D patients treated with metformin. Patients treated with metformin showed decreased levels of all analyzed serum pro-inflammatory markers (TNFα, IL6, IL1β and MCP1) and a downwards trend in IL18 levels associated with a lower production of oxidative stress markers in leukocytes (mitochondrial ROS and myeloperoxidase (MPO)). A reduction in protein levels of MCP1, NFκB, NLRP3, ASC, ATG5, Beclin1 and CHOP and an increase in p62 were also observed in the VAT of the diabetic group. This downregulation of both the NLRP3 inflammasome and autophagy in VAT may be associated with the improved inflammatory profile and leukocyte homeostasis seen in obese T2D patients treated with metformin with respect to MHO subjects and endorses the cardiometabolic protective effect of this drug.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Yahya M. Naguib ◽  
Rehab M. Samaka ◽  
Mohamed S. Rizk ◽  
Omnia Ameen ◽  
Shaimaa M. Motawea

Abstract Background The prevalence of hypertension and obesity has increased significantly in recent decades. Hypertension and obesity often coexist, and both are associated with increased cardiovascular mortality. Obese hypertensive patients usually require special anti-hypertensive treatment strategy due to the increased risk of treatment resistance. Molecules that can target both obesity and hypertension underlying pathologies should get more attention. Herein, we evaluated the therapeutic effects of telmisartan, with special interest in visceral adipose tissue dysfunction, in obesity-related hypertension rat model. Methods Thirty male Wistar rats weighing 150–200 g were equally divided into: 1—Control group (fed normal laboratory diet for 24 weeks), 2—Diet-induced obesity group (DIO, fed high fat diet for 24 weeks), and 3—Diet-induced obesity treated with telmisartan group (DIO + Tel, fed high fat diet and received telmisartan for 24 weeks). At the end of the study, anthropometrical parameters were evaluated. Systolic blood pressure and heart rate were measured. Blood samples were collected for the measurement of serum lipids, adipokines, cardiac, renal, inflammatory, and oxidative stress biomarkers. Kidneys were removed and used for histopathological studies, and visceral adipose tissue was utilized for histopathological, immunohistochemical and RT-PCR studies. Results High fat diet resulted in obesity-related changes in anthropometrical parameters, elevation of blood pressure, increase in heart rate, higher serum levels of cardiac, inflammatory and kidney function biomarkers, with altered serum lipids, adipokines and oxidative stress markers. Morphological changes (H&E and PAS-stained sections) were noticed in kidneys and visceral adipose tissue. Immunohistochemistry and RT-PCR studies confirmed adipose tissue dysfunction and over-expression of inflammatory and oxidative stress proteins. Telmisartan countered obesity-induced alterations in cardiovascular, renal, and adipose tissue functions. Conclusion Adipose tissue dysfunction could be the core pathophysiology of obesity-related hypertension. Besides its anti-hypertensive effect, telmisartan had profound actions on visceral adipose tissue structure and function. Attention should be given to polymodal molecules targeting adipose tissue-related disorders.


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.


2020 ◽  
Author(s):  
Ada Admin ◽  
Julia Braune ◽  
Andreas Lindhorst ◽  
Janine Fröba ◽  
Constance Hobusch ◽  
...  

Obesity is associated with a chronic low-grade inflammation in visceral adipose tissue (AT) characterized by an increasing number of adipose tissue macrophages (ATMs) and linked to type 2 diabetes. AT inflammation is histologically indicated by the formation of so-called crown-like structures (CLS), as accumulation of ATMs around dying adipocytes, and the occurrence of multi-nucleated giant cells (MGCs). However to date, the function of MGCs in obesity is unknown. Hence, the aim of this study was to characterize MGCs in AT and unravel the function of these cells. <p>We demonstrate that MGCs occur in obese patients and after 24 weeks of high fat diet (HFD) in mice, accompanying signs of AT inflammation and then represent ~3% of ATMs in mice. Mechanistically, we found evidence that adipocyte death triggers MGC formation. Most importantly, MGCs in obese AT have a higher capacity to phagocytose oversized particles, such as adipocytes, as shown by live-imaging of AT, 45 µm bead uptake <i>ex vivo</i> and a higher lipid content <i>in vivo</i>. Finally, we show that IL-4 treatment is sufficient to increase the number of MGCs in AT, whereas other factors maybe more important for endogenous MGC formation <i>in vivo</i>.</p>


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.


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