scholarly journals The preventive effect of total saponins from Panax japonicus on inflammation and insulin resistance in adipose tissue of mice induced by a high-fat diet

2021 ◽  
Vol 78 ◽  
pp. 104369
Author(s):  
Yue Shi ◽  
Zhengtai Liu ◽  
Liyue Gai ◽  
Yan Gao ◽  
Yumin He ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
High Fat Diet ◽  
Preventive Effect ◽  
High Fat ◽  
Panax Japonicus

scholarly journals Estrogens Protect against High-Fat Diet-Induced Insulin Resistance and Glucose Intolerance in Mice

Endocrinology ◽  
2009 ◽  
Vol 150 (5) ◽  
pp. 2109-2117 ◽  
Author(s):  
Elodie Riant ◽  
Aurélie Waget ◽  
Haude Cogo ◽  
Jean-François Arnal ◽  
Rémy Burcelin ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Glucose Intolerance ◽  
High Fat Diet ◽  
Chow Diet ◽  
High Fat ◽  
Normal Chow ◽  
Visceral Adipose ◽  
Deficient Mice ◽  
Normal Chow Diet

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.

Abstract 6260: Up-Regulated Expression of MicroRNA-143 in Association with Obesity in the Adipose Tissue of Mice Fed High Fat Diet

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Rieko Takanabe ◽  
Koh Ono ◽  
Tomohide Takaya ◽  
Takahiro Horie ◽  
Hiromichi Wada ◽  
...  
Keyword(s):  
Gene Expression ◽  
Insulin Resistance ◽  
Body Weight ◽  
Adipose Tissue ◽  
High Fat Diet ◽  
Control Cell ◽  
High Fat ◽  
Expression Levels ◽  
Mesenteric Fat ◽  
Regulated Expression

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.

scholarly journals Peripancreatic adipose tissue protects against high-fat-diet-induced hepatic steatosis and insulin resistance in mice

2020 ◽  
Vol 44 (11) ◽  
pp. 2323-2334
Author(s):  
Belén Chanclón ◽  
Yanling Wu ◽  
Milica Vujičić ◽  
Marco Bauzá-Thorbrügge ◽  
Elin Banke ◽  
...  
Keyword(s):  
Gene Expression ◽  
Insulin Resistance ◽  
Adipose Tissue ◽  
Hepatic Steatosis ◽  
High Fat Diet ◽  
Obese Mice ◽  
High Fat ◽  
Insulin Levels ◽  
Fat Depots ◽  
Fat Depot

Abstract Background/objectives Visceral adiposity is associated with increased diabetes risk, while expansion of subcutaneous adipose tissue may be protective. However, the visceral compartment contains different fat depots. Peripancreatic adipose tissue (PAT) is an understudied visceral fat depot. Here, we aimed to define PAT functionality in lean and high-fat-diet (HFD)-induced obese mice. Subjects/methods Four adipose tissue depots (inguinal, mesenteric, gonadal, and peripancreatic adipose tissue) from chow- and HFD-fed male mice were compared with respect to adipocyte size (n = 4–5/group), cellular composition (FACS analysis, n = 5–6/group), lipogenesis and lipolysis (n = 3/group), and gene expression (n = 6–10/group). Radioactive tracers were used to compare lipid and glucose metabolism between these four fat depots in vivo (n = 5–11/group). To determine the role of PAT in obesity-associated metabolic disturbances, PAT was surgically removed prior to challenging the mice with HFD. PAT-ectomized mice were compared to sham controls with respect to glucose tolerance, basal and glucose-stimulated insulin levels, hepatic and pancreatic steatosis, and gene expression (n = 8–10/group). Results We found that PAT is a tiny fat depot (~0.2% of the total fat mass) containing relatively small adipocytes and many “non-adipocytes” such as leukocytes and fibroblasts. PAT was distinguished from the other fat depots by increased glucose uptake and increased fatty acid oxidation in both lean and obese mice. Moreover, PAT was the only fat depot where the tissue weight correlated positively with liver weight in obese mice (R = 0.65; p = 0.009). Surgical removal of PAT followed by 16-week HFD feeding was associated with aggravated hepatic steatosis (p = 0.008) and higher basal (p < 0.05) and glucose-stimulated insulin levels (p < 0.01). PAT removal also led to enlarged pancreatic islets and increased pancreatic expression of markers of glucose-stimulated insulin secretion and islet development (p < 0.05). Conclusions PAT is a small metabolically highly active fat depot that plays a previously unrecognized role in the pathogenesis of hepatic steatosis and insulin resistance in advanced obesity.

SO023HEPATOCYTE GROWTH FACTOR (HGF) PRECLUDE HIGH-FAT DIET-INDUCED OBESITY AND IMPROVED INSULIN RESISTANCE IN MICE

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Jun Muratsu ◽  
Yoshiaki Taniyama ◽  
Fumihiro Sanada ◽  
Atsuyuki Morishima ◽  
Katsuhiko Sakaguchi ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Body Weight ◽  
Adipose Tissue ◽  
Growth Factor ◽  
Inflammatory Mediators ◽  
High Fat Diet ◽  
Neutralizing Antibody ◽  
Mrna Levels ◽  
Wild Type ◽  
High Fat

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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