scholarly journals Adiponectin Alleviates Diet-induced Inflammation in the Liver by Suppressing MCP-1 Expression and Macrophage Infiltration

2021 ◽  
Author(s):  
Jiyoon Ryu ◽  
Jason T. Hadley ◽  
Zhi Li ◽  
Feng Dong ◽  
Huan Xu ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Knockout Mice ◽  
High Fat Diet ◽  
Adaptor Protein ◽  
Macrophage Infiltration ◽  
Hepatic Inflammation ◽  
High Fat ◽  
Mtorc1 Signaling ◽  
Anti Inflammatory

Adiponectin is an adipokine that exerts insulin sensitizing and anti-inflammatory roles in insulin target tissues including liver. While the insulin sensitizing function of adiponectin has been extensively investigated, the precise mechanism by which adiponectin alleviates diet-induced hepatic inflammation remains elusive. Here, we report that hepatocyte-specific knockout of the adaptor protein APPL2 enhanced adiponectin sensitivity and prevented mice from high fat diet-induced inflammation, insulin resistance, and glucose intolerance, although it caused fatty liver. The improved anti-inflammatory and insulin sensitizing effects in the APPL2 hepatocyte-specific knockout mice were largely reversed by knocking out adiponectin. Mechanistically, hepatocyte APPL2 deficiency enhances adiponectin signaling in the liver, which blocks TNF-a-stimulated MCP-1 expression via inhibiting the mTORC1 signaling pathway, leading to reduced macrophage infiltration and thus reduced inflammation in the liver. Taken together, our study uncovers a mechanism underlying the anti-inflammatory role of adiponectin in the liver and reveals the hepatic APPL2-mTORC1-MCP-1 axis as a potential target for treating overnutrition-induced inflammation in the liver.

scholarly journals Adiponectin Alleviates Diet-induced Inflammation in the Liver by Suppressing MCP-1 Expression and Macrophage Infiltration

2021 ◽  
Author(s):  
Jiyoon Ryu ◽  
Jason T. Hadley ◽  
Zhi Li ◽  
Feng Dong ◽  
Huan Xu ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Knockout Mice ◽  
High Fat Diet ◽  
Adaptor Protein ◽  
Macrophage Infiltration ◽  
Hepatic Inflammation ◽  
High Fat ◽  
Mtorc1 Signaling ◽  
Anti Inflammatory

Adiponectin is an adipokine that exerts insulin sensitizing and anti-inflammatory roles in insulin target tissues including liver. While the insulin sensitizing function of adiponectin has been extensively investigated, the precise mechanism by which adiponectin alleviates diet-induced hepatic inflammation remains elusive. Here, we report that hepatocyte-specific knockout of the adaptor protein APPL2 enhanced adiponectin sensitivity and prevented mice from high fat diet-induced inflammation, insulin resistance, and glucose intolerance, although it caused fatty liver. The improved anti-inflammatory and insulin sensitizing effects in the APPL2 hepatocyte-specific knockout mice were largely reversed by knocking out adiponectin. Mechanistically, hepatocyte APPL2 deficiency enhances adiponectin signaling in the liver, which blocks TNF-a-stimulated MCP-1 expression via inhibiting the mTORC1 signaling pathway, leading to reduced macrophage infiltration and thus reduced inflammation in the liver. Taken together, our study uncovers a mechanism underlying the anti-inflammatory role of adiponectin in the liver and reveals the hepatic APPL2-mTORC1-MCP-1 axis as a potential target for treating overnutrition-induced inflammation in the liver.

Abstract P312: The Essential Role Of Prak In Preserving Cardiac Function And Insulin Resistance In High Fat Diet-induced Diabetes

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Yu T Zhao ◽  
Jianfeng Du ◽  
Thomas J Zhao ◽  
Hao Wang ◽  
Marshall Kadin ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Cardiac Function ◽  
Western Blot ◽  
Knockout Mice ◽  
High Fat Diet ◽  
Metabolic Disorders ◽  
Tolerance Test ◽  
Wild Type ◽  
High Fat

Background: p38 regulated/activated protein kinase (PRAK) plays a crucial role in modulating cell death and survival. However, the role of PRAK in mediating cardiac dysfunction and metabolic disorders remains unclear. We examined the effects of deletion of PRAK on modulating cardiac function and insulin resistance in mice exposed to a high fat diet (HFD). Methods: Wild type and PRAK -/- mice at 8 weeks old were exposed to either chow food or HFD for a consecutive 16 weeks. Glucose tolerance test and insulin tolerance test were employed to assess insulin resistance. Echocardiography was employed to assess myocardial function. Western blot was used to determine the molecular signaling involved in phosphorylation of IRS-1, AMPKα, ERK-44/42, and irisin. Real time-PCR was used to assess the hypertrophic genes of the myocardium. Histological analysis was employed to assess the hypertrophic response, interstitial myocardial fibrosis, and apoptosis in the heart. Results: HFD induced metabolic stress is indicated by glucose intolerance and insulin intolerance. PRAK knockout aggravated insulin resistance, as indicated by glucose intolerance and insulin intolerance testing as compared to wild type littermates. As compared to wild type, hyperglycemia and hypercholesterolemia were manifested in PRAK-knockout mice following high fat diet intervention. High fat diet intervention displayed a decline in fractional shortening (FS) and ejection fraction (EF). However, deletion of PRAK exacerbated the decline in EF and FS as compared to wild type mice following HFD treatment. In addition, PRAK knockout mice enhanced the expression of myocardial hypertrophic genes including ANP, BNP, and βMHC in HFD treatment, which was also associated with an increase in cardiomyocyte size and interstitial fibrosis. Western blot indicated that deletion of PRAK induces decreases in phosphorylation of IRS-1, AMPKα, and ERK44/42 as compared to wild type controls. Conclusion: Our finding indicates that deletion of PRAK promoted myocardial dysfunction, cardiac remodeling, and metabolic disorders in response to HFD.

scholarly journals The Essential Role of PRAK in Preserving Cardiac Function and Insulin Resistance in High-Fat Diet-Induced Diabetes

2021 ◽  
Vol 22 (15) ◽  
pp. 7995
Author(s):  
Jianfeng Du ◽  
Yu Tina Zhao ◽  
Hao Wang ◽  
Ling X. Zhang ◽  
Gangjian Qin ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Cardiac Function ◽  
Western Blot ◽  
Glucose Intolerance ◽  
Knockout Mice ◽  
High Fat Diet ◽  
Metabolic Disorders ◽  
Wild Type ◽  
High Fat

Regulated/activated protein kinase (PRAK) plays a crucial role in modulating biological function. However, the role of PRAK in mediating cardiac dysfunction and metabolic disorders remains unclear. We examined the effects of deletion of PRAK on modulating cardiac function and insulin resistance in mice exposed to a high-fat diet (HFD). Wild-type and PRAK−/− mice at 8 weeks old were exposed to either chow food or HFD for a consecutive 16 weeks. Glucose tolerance tests and insulin tolerance tests were employed to assess insulin resistance. Echocardiography was employed to assess myocardial function. Western blot was used to determine the molecular signaling involved in phosphorylation of IRS-1, AMPKα, ERK-44/42, and irisin. Real time-PCR was used to assess the hypertrophic genes of the myocardium. Histological analysis was employed to assess the hypertrophic response, interstitial myocardial fibrosis, and apoptosis in the heart. Western blot was employed to determine cellular signaling pathway. HFD-induced metabolic stress is indicated by glucose intolerance and insulin intolerance. PRAK knockout aggravated insulin resistance, as indicated by glucose intolerance and insulin intolerance testing as compared with wild-type littermates. As compared with wild-type mice, hyperglycemia and hypercholesterolemia were manifested in PRAK-knockout mice following high-fat diet intervention. High-fat diet intervention displayed a decline in fractional shortening and ejection fraction. However, deletion of PRAK exacerbated the decline in cardiac function as compared with wild-type mice following HFD treatment. In addition, PRAK knockout mice enhanced the expression of myocardial hypertrophic genes including ANP, BNP, and βMHC in HFD treatment, which was also associated with an increase in cardiomyocyte size and interstitial fibrosis. Western blot indicated that deletion of PRAK induces decreases in phosphorylation of IRS-1, AMPKα, and ERK44/42 as compared with wild-type controls. Our finding indicates that deletion of PRAK promoted myocardial dysfunction, cardiac remodeling, and metabolic disorders in response to HFD.

Altered bone metabolism after high fat diet and exercise: role of Wnt signaling and insulin resistance

2016 ◽  
Author(s):  
Ann-Kristin Picke ◽  
Lykke Sylow ◽  
Lisbeth L V Moller ◽  
Rasmus Kjobsted ◽  
Erik Richter ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Wnt Signaling ◽  
Bone Metabolism ◽  
High Fat Diet ◽  
High Fat ◽  
Diet And Exercise

scholarly journals Novel anti-inflammatory role of SLPI in adipose tissue and its regulation by high fat diet

2011 ◽  
Vol 8 (1) ◽  
pp. 5 ◽  
Author(s):  
Venkata J Adapala ◽  
Kimberly K Buhman ◽  
Kolapo M Ajuwon
Keyword(s):  
Adipose Tissue ◽  
High Fat Diet ◽  
High Fat ◽  
Anti Inflammatory

scholarly journals RANKL Is Involved in Runx2-Triggered Hepatic Infiltration of Macrophages in Mice with NAFLD Induced by a High-Fat Diet

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Li Zhong ◽  
Jianghan Yuan ◽  
Lu Huang ◽  
Shan Li ◽  
Liang Deng
Keyword(s):  
High Fat Diet ◽  
Macrophage Infiltration ◽  
Macrophage Migration ◽  
High Fat ◽  
Transwell Assay ◽  
Nonalcoholic Fatty Liver ◽  
Related Transcription Factor

Background. Receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL) is significant in the activation of inflammation. Runt-related transcription factor 2 (Runx2) promotes the hepatic infiltration of macrophages in nonalcoholic fatty liver disease (NAFLD). We studied how RANKL affects Runx2-triggered macrophage infiltration in NAFLD. Method. 30 male C57BL/6J mice at 4 weeks of age were utilized in this study, 20 mice received a high-fat diet (HFD), and 10 mice received standard rodent chow over 8 months. The histopathologic features of the liver were identified by H&E, Oil red O, and Masson staining. Runx2, RANKL, and F4/80 were analyzed by western blot, real-time PCR, and immunohistochemistry in vivo, respectively. Lentivirus or siRNA was utilized for transwell assay to investigate the role of RANKL in Runx2-induced macrophage migration in vitro. Results. Compared to controls, during NAFLD development, HFD increased Runx2 and RANKL in vivo in NASH (P<0.01). Meanwhile, a correlation between the expression of Runx2 and RANKL (P<0.05) was evident. In addition, the hepatic infiltration of macrophages was increased upon HFD feeding, and analysis showed that the macrophage infiltration was correlated with the expression of Runx2 or RANKL (P<0.05). In vitro, we found that overexpression or deficiency of Runx2 increased or decreased the production of RANKL in mHSCs. Then, transwell assay revealed that RANKL was involved in Runx2-induced macrophage migration. Conclusions. Overall, RANKL is involved in Runx2-triggered macrophage migration during NAFLD pathogenesis, which may provide an underlying therapeutic target for NAFLD.

scholarly journals CD44 contributes to hyaluronan-mediated insulin resistance in skeletal muscle of high-fat-fed C57BL/6 mice

2019 ◽  
Vol 317 (6) ◽  
pp. E973-E983 ◽  
Author(s):  
Annie Hasib ◽  
Chandani K. Hennayake ◽  
Deanna P. Bracy ◽  
Aimée R. Bugler-Lamb ◽  
Louise Lantier ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
High Fat Diet ◽  
Critical Role ◽  
Chow Diet ◽  
Wild Type ◽  
High Fat ◽  
Insulin Resistant ◽  
Beneficial Effects

Extracellular matrix hyaluronan is increased in skeletal muscle of high-fat-fed insulin-resistant mice, and reduction of hyaluronan by PEGPH20 hyaluronidase ameliorates diet-induced insulin resistance (IR). CD44, the main hyaluronan receptor, is positively correlated with type 2 diabetes. This study determines the role of CD44 in skeletal muscle IR. Global CD44-deficient ( cd44−/−) mice and wild-type littermates ( cd44+/+) were fed a chow diet or 60% high-fat diet for 16 wk. High-fat-fed cd44−/− mice were also treated with PEGPH20 to evaluate its CD44-dependent action. Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp (ICv). High-fat feeding increased muscle CD44 protein expression. In the absence of differences in body weight and composition, despite lower clamp insulin during ICv, the cd44−/− mice had sustained glucose infusion rate (GIR) regardless of diet. High-fat diet-induced muscle IR as evidenced by decreased muscle glucose uptake (Rg) was exhibited in cd44+/+ mice but absent in cd44−/− mice. Moreover, gastrocnemius Rg remained unchanged between genotypes on chow diet but was increased in high-fat-fed cd44−/− compared with cd44+/+ when normalized to clamp insulin concentrations. Ameliorated muscle IR in high-fat-fed cd44−/− mice was associated with increased vascularization. In contrast to previously observed increases in wild-type mice, PEGPH20 treatment in high-fat-fed cd44−/− mice did not change GIR or muscle Rg during ICv, suggesting a CD44-dependent action. In conclusion, genetic CD44 deletion improves muscle IR, and the beneficial effects of PEGPH20 are CD44-dependent. These results suggest a critical role of CD44 in promoting hyaluronan-mediated muscle IR, therefore representing a potential therapeutic target for diabetes.

scholarly journals Role of Supplementary Selenium on the Induction of Insulin Resistance and Oxidative Stress in NSY Mice Fed a High Fat Diet

2018 ◽  
Vol 41 (1) ◽  
pp. 92-98 ◽  
Author(s):  
Koichi Murano ◽  
Hirofumi Ogino ◽  
Tomofumi Okuno ◽  
Tomohiro Arakawa ◽  
Hitoshi Ueno
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
High Fat Diet ◽  
High Fat ◽  
And Oxidative Stress
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