scholarly journals Blimp-1 in adipose resident Tregs controls adipocyte beiging and obesity

2019 ◽  
Author(s):  
Lisa Y. Beppu ◽  
Xiaoyao Qu ◽  
Giovanni J. Marrero ◽  
Allen N. Fooks ◽  
Adolfo B. Frias ◽  
...  

ABSTRACTCrosstalk between the immune system and adipocytes is critical for maintaining tissue homeostasis and regulating chronic systemic inflammation during diet-induced obesity (DIO). How visceral adipose tissue resident regulatory T cells (aTregs) signal to adipocytes in the visceral adipose tissue (VAT) is not understood. Here we show that Treg-specific ablation of the transcriptional regulator Blimp-1 resulted in increased insulin sensitivity, decreased body weight and increased Ucp-1 in adipocytes in high fat diet (HFD)-fed mice. Mechanistically, we demonstrate that Blimp-1 drives IL-10 production in Tregs, thus suppressing beiging and energy expenditure in adipocytes. Moreover, IL-10 mRNA expression positively correlated with increasing body weight in humans. These findings reveal a surprising relationship between aTregs and adipocytes in promoting insulin resistance during excessive caloric intake, placing Blimp-1-regulated IL-10 expression by aTregs at a critical juncture in the development of obesity and its associated comorbidities in mice and humans.SUMMARYHere we show that ablation of Blimp-1 in adipose tissue resident Tregs (aTregs) leads to decreased IL-10 production, resulting in increased Ucp-1 expression and beiging by adipocytes and protection from diet-induced obesity and insulin resistance.

2021 ◽  
pp. 1-24
Author(s):  
L. Irasema Chávaro-Ortiz ◽  
Brenda D. Tapia-Vargas ◽  
Mariel Rico-Hidalgo ◽  
Ruth Gutiérrez-Aguilar ◽  
María E. Frigolet

Abstract Obesity is defined as increased adiposity, which leads to metabolic disease. The growth of adipose tissue depends on its capacity to expand, through hyperplasia or hypertrophy, in order to buffer energy surplus. Also, during the establishment of obesity, adipose tissue expansion reflects adipose lipid metabolism (lipogenesis and/or lipolysis). It is well known that dietary factors can modify lipid metabolism promoting or preventing the development of metabolic abnormalities that concur with obesity. Trans-palmitoleic acid (TP), a biomarker of dairy consumption, has been associated with reduced adiposity in clinical studies. Thus, we aimed to evaluate the effect of TP over adiposity and lipid metabolism-related genes in a rodent model of diet-induced obesity (DIO). To fulfil this aim, we fed C57BL/6 mice with a Control or a High Fat diet, added with or without TP (3g/kg diet), during 11 weeks. Body weight and food intake were monitored, fat pads were weighted, histology of visceral adipose tissue was analysed, and lipid metabolism-related gene expression was explored by qPCR. Results show that TP consumption prevented weight gain induced by high fat diet, reduced visceral adipose tissue weight, and adipocyte size, while increasing the expression of lipolytic molecules. In conclusion, we show for the first time that TP influences adipose tissue metabolism, specifically lipolysis, resulting in decreased adiposity and reduced adipocyte size in a DIO mice model.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A41-A42
Author(s):  
Osvaldo Rivera-Gonzalez ◽  
Erin Taylor ◽  
Joshua S Speed

Abstract Endothelin-1 (ET-1) is elevated in patients with obesity; however, its contribution to the pathophysiology related to obesity is not fully understood. Obesity is associated with dyslipidemia and insulin resistance, which may in part be mediated by inflammation and alterations to immune cell subsets within the adipose tissue. ET-1 promotes inflammation via the ET-1 type A (ETA) receptor, and blockade of ETA receptors improves dyslipidemia in patients with chronic kidney disease. We hypothesized that ET-1 causes dyslipidemia and inflammation within the adipose tissue of obese mice. To test this hypothesis, C57BL/6J mice were fed either normal diet (NMD) or high fat diet (HFD) for 8 weeks followed by 2 weeks of treatment with either vehicle or atrasentan (ETA receptor antagonist, 10mg/kg/day). HFD mice had significantly higher fat mass than NMD mice, with no significant effect of treatment with atrasentan. HFD mice had significantly higher circulating non-esterified free fatty acids, an effect that was ameliorated in mice treated with atrasentran (1.03±0.07 vs 0.58±0.02 mEq/L, p<0.05). Atrasentan-treated mice had significantly attenuated increase in liver triglycerides compared to non-treated HFD mice (3.8±0.7 vs 7.5±1.3mg/dL respectively, p<0.05). Mice treated with atrasentan had significantly improved glucose tolerance (10150±1031 vs 6563±975 AUC, p<0.05) and insulin tolerance (-2796±386 vs -9825±319 AUC, p<0.05) compared to non-treated insulin-resistant HFD mice. Plasma adiponectin, an insulin sensitizing adipokine that is inversely associated with adiposity and insulin resistance, was significantly increased in atrasentan-treated mice compared to non-treated HFD (4.8±0.1326 vs 6.5±0.3 µg/ml, p<0.05), with no differences in plasma insulin levels. Gene expression analysis of visceral fat showed improved expression of genes negatively associated with insulin resistance that were downregulated in non-treated HFD mice vs. NMD (IRS-1, PPAR-gamma, GLUT4, and adiponectin). Flow cytometric analyses of visceral adipose tissue indicated that HFD mice had a significantly higher number of both CD4+ and CD8+ T cells compared to NMD mice, which was attenuated by treatment with atrasentan. Further, eosinophils, which are important in maintaining adipose tissue health and reducing inflammation, were significantly decreased in HFD mice compared to NMD. Atrasentan treatment abolished the decrease in eosinophils. Taken together, these data indicate that ETA receptor blockade improves peripheral glucose homeostasis, dyslipidemia, and liver triglyceride levels, and also attenuates the proinflammatory immune profile in visceral adipose tissue. These data suggest a potential use for ETA receptor blockers in the treatment of obesity-associated dyslipidemia and insulin resistance.


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.


2016 ◽  
Vol 17 (3) ◽  
pp. 231-240 ◽  
Author(s):  
Ilija Jeftic ◽  
Marina Miletic-Kovacevic ◽  
Nemanja Jovicic ◽  
Jelena Pantic ◽  
Nebojsa Arsenijevic ◽  
...  

Abstract Obesity and type 2 diabetes mellitus (T2DM) constitute major health problems worldwide. Increased visceral adiposity enhances the risk of insulin resistance and type 2 diabetes. The mechanisms involved in obesity-associated chronic inflammation in metabolic tissues (metaflammation) that lead to insulin resistance and dysregulated glucose metabolism are incompletely defined. Galectin-3 (Gal-3), a β-galactoside-binding lectin, modulates immune/inflammatory responses and specifically binds to metabolic danger molecules. To dissect the role of Gal-3 in obesity and diabetes, Gal-3-deficient (LGALS3-/-) and wild-type (WT) C57Bl/6 male mice were placed on a high-fat diet (HFD, 60% kcal fat) or a standard chow diet (10% kcal fat) for 6 months and metabolic, histological and immunophenotypical analyses of the visceral adipose tissue were performed. HFD-fed LGALS3-/- mice had higher body weights and more body weight gain, visceral adipose tissue (VAT), hyperglycaemia, hyperinsulinemia, insulin resistance and hyperlipidemia than diet-matched WT mice. Compared to WT mice, the enlarged VAT in obese LGALS3-/- mice contained larger adipocytes. Additionally, we demonstrate enhanced inflammation in the VAT of LGALS3-/- mice compared with diet-matched WT mice. The VAT of LGALS3-/- mice fed a HFD contained more numerous dendritic cells and proinflammatory F4/80+CD11c+CD11b+ and F4/80high macrophages. In contrast to WT mice, the numbers of CXCR3+ and CD8+ T cells were increased in the VAT of Gal-3-deficient mice after 6 months of high-fat feeding. We provide evidence that Gal-3 ablation results in enhanced HFD-induced adiposity, inflammation in the adipose tissue, insulin resistance and hyperglycaemia. Thus, Gal-3 represents an important regulator of obesity-associated immunometabolic alterations.


Endocrinology ◽  
2009 ◽  
Vol 150 (5) ◽  
pp. 2109-2117 ◽  
Author(s):  
Elodie Riant ◽  
Aurélie Waget ◽  
Haude Cogo ◽  
Jean-François Arnal ◽  
Rémy Burcelin ◽  
...  

Although corroborating data indicate that estrogens influence glucose metabolism through the activation of the estrogen receptor α (ERα), it has not been established whether this pathway could represent an effective therapeutic target to fight against metabolic disturbances induced by a high-fat diet (HFD). To this end, we first evaluated the influence of chronic 17β-estradiol (E2) administration in wild-type ovariectomized mice submitted to either a normal chow diet or a HFD. Whereas only a modest effect was observed in normal chow diet-fed mice, E2 administration exerted a protective effect against HFD-induced glucose intolerance, and this beneficial action was abolished in ERα-deficient mice. Furthermore, E2 treatment reduced HFD-induced insulin resistance by 50% during hyperinsulinemic euglycemic clamp studies and improved insulin signaling (Akt phosphorylation) in insulin-stimulated skeletal muscles. Unexpectedly, we found that E2 treatment enhanced cytokine (IL-6, TNF-α) and plasminogen activator inhibitor-1 mRNA expression induced by HFD in the liver and visceral adipose tissue. Interestingly, although the proinflammatory effect of E2 was abolished in visceral adipose tissue from chimeric mice grafted with bone marrow cells from ERα-deficient mice, the beneficial effect of the hormone on glucose tolerance was not altered, suggesting that the metabolic and inflammatory effects of estrogens can be dissociated. Eventually comparison of sham-operated with ovariectomized HFD-fed mice demonstrated that endogenous estrogens levels are sufficient to exert a full protective effect against insulin resistance and glucose intolerance. In conclusion, the regulation of the ERα pathway could represent an effective strategy to reduce the impact of high-fat diet-induced type 2 diabetes.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Rieko Takanabe ◽  
Koh Ono ◽  
Tomohide Takaya ◽  
Takahiro Horie ◽  
Hiromichi Wada ◽  
...  

Obesity is the result of an expansion and increase in the number of individual adipocytes. Since changes in gene expression during adipocyte differentiation and hypertrophy are closely associated with insulin resistance and cardiovascular diseases, further insight into the molecular basis of obesity is needed to better understand obesity-associated diseases. MicroRNAs (miRNAs) are approximately 17–24nt single stranded RNA, that post-transcriptionally regulate gene expression. MiRNAs control cell growth, differentiation and metabolism, and may be also involved in pathogenesis and pathophysiology of diseases. It has been proposed that miR-143 plays a role in the differentiation of preadipocytes into mature adipocytes in culture. However, regulated expression of miR-143 in the adult adipose tissue during the development of obesity in vivo is unknown. To solve this problem, C57BL/6 mice were fed with either high-fat diet (HFD) or normal chow (NC). Eight weeks later, severe insulin resistance was observed in mice on HFD. Body weight increased by 35% and the mesenteric fat weight increased by 3.3-fold in HFD mice compared with NC mice. We measured expression levels of miR-143 in the mesenteric fat tissue by real-time PCR and normalized with those of 5S ribosomal RNA. Expression of miR-143 in the mesenteric fat was significantly up-regulated (3.3-fold, p<0.05) in HFD mice compared to NC mice. MiR-143 expression levels were positively correlated with body weight (R=0.577, p=0.0011) and the mesenteric fat weight (R=0.608, p=0.0005). We also measured expression levels in the mesenteric fat of PPARγ and AP2, whose expression are deeply involved in the development of obesity, insulin resistant and arteriosclerosis. The expression levels of miR-143 were closely correlated with those of PPARγ (R=0.600, p=0.0040) and AP2 (R=0.630, p=0.0022). These findings provide the first evidence for up-regulated expression of miR-143 in the mesenteric fat of HFD-induced obese mice, which might contribute to regulated expression of genes involved in the pathophysiology of obesity.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Jun Muratsu ◽  
Yoshiaki Taniyama ◽  
Fumihiro Sanada ◽  
Atsuyuki Morishima ◽  
Katsuhiko Sakaguchi ◽  
...  

Abstract Background and Aims Obesity and its associated chronic inflammation in adipose tissue initiate insulin resistance, which is related to several pathologies including hypertension and atherosclerosis. Previous reports demonstrated that circulating hepatocyte growth factor (HGF) level was associated with obesity and type 2 diabetes. However, its precise role in obesity and related-pathology is unclear. Method In this experiment, cardiac-specific over-expression of human HGF in mice (HGF-Tg mice) which showed 4-5 times higher serum HGF levels than wild-type mice were used. We chose cardiac specific HGF overexpression, as other strain of HGF transgenic mice such as liver and kidney specific HGF overexpression mice develop cancer and cystic diseases, which are rare in the heart. In the present study, using HGF-Tg mice and anti-HGF neutralizing antibody (HGF-Ab), we explored the role of HGF in obese and insulin resistance induced by high fat diet (HFD) for 14 weeks (200 or 400ug/week). Results With normal chow diet (ND), there were no significant changes in body weight between WT and HGF-Tg mice. While body weight in wild-type mice fed with HFD for 14 weeks was significantly increased accompanied with insulin resistance, HGF-Tg mice prevented body weight gain and insulin resistance. Insulin resistance in obesity arises from the combination of altered functions of insulin target cells (e.g., liver, skeletal muscle, and adipose tissue) and the accumulation of macrophages that secrete pro-inflammatory mediators in adipose tissue. The accumulation of macrophages and elevated levels of inflammatory mediators in adipose tissue were significantly inhibited in HGF-Tg mice as compared to wild-type mice. In the gWAT, the mRNA levels of the mature macrophage marker F4/80, the chemoattractants, MCP-1 and CXCL2, and the inflammatory cytokines, such as TNF-α and iNOS, were significantly increased in WT mice fed with HFD. However, these levels were markedly reduced in HGF-Tg mice fed with HFD. Additionally, activation of Akt by insulin administration was significantly reduced in the gWAT SM, and liver by HFD; however, this activation was restored in HGF-Tg mice. Moreover, insulin-induced Akt signaling was decreased in HGF-Ab groups as compared to saline group under HFD condition. Importantly, HFD significantly increased the level of HGF mRNA by approximately 2 fold in gWAT, SM, and liver without changing cMet expression. All together, these data indicate that the HGF as one of the systemic gWAT, SM, and liver-derived growth factor plays a role in compensatory mechanism against insulin-resistance through the at least anti-inflammatory effect in adipose tissue. The HFD-induced obesity in wild-type mice treated with HGF-neutralizing antibody showed an exacerbated response to the glucose tolerance test. Conclusion HGF suppresses inflammation in adipose tissue induced by a high-fat diet, and as a result improves systemic insulin resistance. These gain-of-function and loss-of-function studies demonstrated that the elevated HGF level induced by HFD have protective role against obesity and insulin resistance.


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