scholarly journals Hepatic Mitogen-Activated Protein Kinase Phosphatase 1 Selectively Regulates Glucose Metabolism and Energy Homeostasis

2014 ◽  
Vol 35 (1) ◽  
pp. 26-40 ◽  
Author(s):  
Ahmed Lawan ◽  
Lei Zhang ◽  
Florian Gatzke ◽  
Kisuk Min ◽  
Michael J. Jurczak ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Protein Kinase ◽  
Glucose Metabolism ◽  
Energy Homeostasis ◽  
Mitogen Activated Protein Kinase ◽  
Hepatic Insulin Resistance ◽  
Fibroblast Growth Factor 21 ◽  
High Fat ◽  
Mitogen Activated Protein ◽  
Fat Feeding

The liver plays a critical role in glucose metabolism and communicates with peripheral tissues to maintain energy homeostasis. Obesity and insulin resistance are highly associated with nonalcoholic fatty liver disease (NAFLD). However, the precise molecular details of NAFLD remain incomplete. The p38 mitogen-activated protein kinase (MAPK) and c-Jun NH2-terminal kinase (JNK) regulate liver metabolism. However, the physiological contribution of MAPK phosphatase 1 (MKP-1) as a nuclear antagonist of both p38 MAPK and JNK in the liver is unknown. Here we show that hepatic MKP-1 becomes overexpressed following high-fat feeding. Liver-specific deletion of MKP-1 enhances gluconeogenesis and causes hepatic insulin resistance in chow-fed mice while selectively conferring protection from hepatosteatosis upon high-fat feeding. Further, hepatic MKP-1 regulates both interleukin-6 (IL-6) and fibroblast growth factor 21 (FGF21). Mice lacking hepatic MKP-1 exhibit reduced circulating IL-6 and FGF21 levels that were associated with impaired skeletal muscle mitochondrial oxidation and susceptibility to diet-induced obesity. Hence, hepatic MKP-1 serves as a selective regulator of MAPK-dependent signals that contributes to the maintenance of glucose homeostasis and peripheral tissue energy balance. These results also demonstrate that hepatic MKP-1 overexpression in obesity is causally linked to the promotion of hepatosteatosis.

scholarly journals 4-Phenylbutyric acid improves free fatty acid-induced hepatic insulin resistance in vivo

2021 ◽  
Vol 10 (8) ◽  
pp. 861-872
Author(s):  
Sandra Pereira ◽  
Jessy Moore ◽  
Jia-Xu Li ◽  
Wen Qin Yu ◽  
Husam Ghanim ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Protein Kinase ◽  
Er Stress ◽  
Mitogen Activated Protein Kinase ◽  
Hepatic Insulin Resistance ◽  
Initiation Factor ◽  
Fibroblast Growth Factor 21 ◽  
Chemical Chaperone ◽  
Fetuin A ◽  
Phenylbutyric Acid

Plasma free fatty acids (FFAs) are elevated in obesity and can induce insulin resistance via endoplasmic reticulum (ER) stress. However, it is unknown whether hepatic insulin resistance caused by the elevation of plasma FFAs is alleviated by chemical chaperones. Rats received one of the following i.v. treatments for 48 h: saline, intralipid plus heparin (IH), IH plus the chemical chaperone 4-phenylbutyric acid (PBA), or PBA alone and a hyperinsulinemic-euglycemic clamp was performed during the last 2 h. PBA co-infusion normalized IH-induced peripheral insulin resistance, similar to our previous findings with an antioxidant and an IκBα kinase β (IKKβ) inhibitor. Different from our previous results with the antioxidant and IKKβ inhibitor, PBA also improved IH-induced hepatic insulin resistance in parallel with activation of Akt. Unexpectedly, IH did not induce markers of ER stress in the liver, but PBA prevented IH-induced elevation of phosphorylated eukaryotic initiation factor-2α protein in adipose tissue. PBA tended to decrease circulating fetuin-A and significantly increased circulating fibroblast growth factor 21 (FGF21) without affecting markers of activation of hepatic protein kinase C-δ or p38 mitogen-activated protein kinase that we have previously involved in hepatic insulin resistance in this model. In conclusion: (i) PBA prevented hepatic insulin resistance caused by prolonged plasma FFA elevation without affecting hepatic ER stress markers; (ii) the PBA effect is likely due to increased FGF21 and/or decreased fetuin-A, which directly signal to upregulate Akt activation.

715 EXOGENOUS STEATOSIS AND HEPATIC INSULIN RESISTANCE ARE EARLY CONSEQUENCES OF HIGH FAT FEEDING

2009 ◽  
Vol 50 ◽  
pp. S262 ◽  
Author(s):  
N. Lanthier ◽  
M. Petit ◽  
V. Lebrun ◽  
O. Molendi ◽  
P.D. Cani ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Hepatic Insulin Resistance ◽  
High Fat ◽  
Fat Feeding

scholarly journals Resveratrol Ameliorates High-Fat-Diet-Induced Abnormalities in Hepatic Glucose Metabolism in Mice via the AMP-Activated Protein Kinase Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Caiping Lu ◽  
Hanying Xing ◽  
Linquan Yang ◽  
Kaiting Chen ◽  
Linyi Shu ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Protein Kinase ◽  
Glucose Metabolism ◽  
Glucose Uptake ◽  
High Fat Diet ◽  
Blood Glucose Concentration ◽  
Glycogen Synthesis ◽  
Liver Fat ◽  
High Fat ◽  
Amp Activated Protein Kinase

Diabetes mellitus is highly prevalent worldwide. High-fat-diet (HFD) consumption can lead to liver fat accumulation, impair hepatic glycometabolism, and cause insulin resistance and the development of diabetes. Resveratrol has been shown to improve the blood glucose concentration of diabetic mice, but its effect on the abnormal hepatic glycometabolism induced by HFD-feeding and the mechanism involved are unknown. In this study, we determined the effects of resveratrol on the insulin resistance of high-fat-diet-fed mice and a hepatocyte model by measuring serum biochemical indexes, key indicators of glycometabolism, glucose uptake, and glycogen synthesis in hepatocytes. We found that resveratrol treatment significantly ameliorated the HFD-induced abnormalities in glucose metabolism in mice, increased glucose absorption and glycogen synthesis, downregulated protein phosphatase 2A (PP2A) and activated Ca2+/CaM-dependent protein kinase kinase β (CaMKKβ), and increased the phosphorylation of AMP-activated protein kinase (AMPK). In insulin-resistant HepG2 cells, the administration of a PP2A activator or CaMKKβ inhibitor attenuated the effects of resveratrol, but the administration of an AMPK inhibitor abolished the effects of resveratrol. Resveratrol significantly ameliorates abnormalities in glycometabolism induced by HFD-feeding and increases glucose uptake and glycogen synthesis in hepatocytes. These effects are mediated through the activation of AMPK by PP2A and CaMKKβ.

scholarly journals Ganoderma lucidum Extract Reduces Insulin Resistance by Enhancing AMPK Activation in High-Fat Diet-Induced Obese Mice

Nutrients ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3338
Author(s):  
Hyeon A Lee ◽  
Jae-Han Cho ◽  
Qonita Afinanisa ◽  
Gi-Hong An ◽  
Jae-Gu Han ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Protein Kinase ◽  
Glucose Metabolism ◽  
High Fat Diet ◽  
Ganoderma Lucidum ◽  
Fatty Acid Synthase ◽  
Metabolic Diseases ◽  
Ampk Activation ◽  
High Fat ◽  
Amp Activated Protein Kinase

Ganoderma lucidum is used widely in oriental medicine to treat obesity and metabolic diseases. Bioactive substances extracted from G. lucidum have been shown to ameliorate dyslipidemia, insulin resistance, and type 2 diabetes in mice via multiple 5′ AMP-activated protein kinase (AMPK)-mediated mechanisms; however, further studies are required to elucidate the anti-obesity effects of G. lucidum in vivo. In this study, we demonstrated that 3% G. lucidum extract powder (GEP) can be used to prevent obesity and insulin resistance in a mouse model. C57BL/6 mice were provided with a normal diet (ND) or a high-fat diet (HFD) supplemented with 1, 3, or 5% GEP for 12 weeks and the effect of GEP on body weight, liver, adipose tissue, adipokines, insulin and glucose tolerance (ITT and GTT), glucose uptake, glucose-metabolism related proteins, and lipogenesis related genes was examined. GEP administration was found to reduce weight gain in the liver and fat tissues of the mice. In addition, serum parameters were significantly lower in the 3% and 5% GEP mice groups than in those fed a HFD alone, whereas adiponectin levels were significantly higher. We also observed that GEP improved glucose metabolism, reduced lipid accumulation in the liver, and reduced adipocyte size. These effects may have been mediated by enhanced AMPK activation, which attenuated the transcription and translation of lipogenic genes such as fatty acid synthase (FAS), stearoyl-CoA desaturase 1 (SCD1), and sterol regulatory element-binding protein-1c (SREBP1c). Moreover, AMP-activated protein kinase (AMPK) activation increased acetyl-CoA carboxylase (ACC), insulin receptor (IR), IR substrate 1 (IRS1), and Akt protein expression and activation, as well as glucose transporter type 1/4 (GLUT1/4) protein production, thereby improving insulin sensitivity and glucose metabolism. Together, these findings demonstrate that G. lucidum may effectively prevent obesity and suppress obesity-induced insulin resistance via AMPK activation.

scholarly journals Endothelial NO/cGMP/VASP Signaling Attenuates Kupffer Cell Activation and Hepatic Insulin Resistance Induced by High-Fat Feeding

Diabetes ◽  
2011 ◽  
Vol 60 (11) ◽  
pp. 2792-2801 ◽  
Author(s):  
Sanshiro Tateya ◽  
Norma O. Rizzo ◽  
Priya Handa ◽  
Andrew M. Cheng ◽  
Vicki Morgan-Stevenson ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Kupffer Cell ◽  
Cell Activation ◽  
Hepatic Insulin Resistance ◽  
High Fat ◽  
Fat Feeding
Sign in / Sign up

Export Citation Format

Share Document