Irisin inhibits hepatic gluconeogenesis and increases glycogen synthesis via the PI3K/Akt pathway in type 2 diabetic mice and hepatocytes

2015 ◽  
Vol 129 (10) ◽  
pp. 839-850 ◽  
Author(s):  
Tong-Yan Liu ◽  
Chang-Xiang Shi ◽  
Run Gao ◽  
Hai-Jian Sun ◽  
Xiao-Qing Xiong ◽  
...  

This study provide evidence that irisin reduces hepatic glucose production and the blood glucose level, increases hepatic glycogen synthesis and improves insulin resistance in type 2 diabetes. Irisin may be regarded as an effective therapeutic strategy for type 2 diabetes.

2020 ◽  
Vol 117 (12) ◽  
pp. 6733-6740 ◽  
Author(s):  
Thiago M. Batista ◽  
Sezin Dagdeviren ◽  
Shannon H. Carroll ◽  
Weikang Cai ◽  
Veronika Y. Melnik ◽  
...  

Insulin action in the liver is critical for glucose homeostasis through regulation of glycogen synthesis and glucose output. Arrestin domain-containing 3 (Arrdc3) is a member of the α-arrestin family previously linked to human obesity. Here, we show thatArrdc3is differentially regulated by insulin in vivo in mice undergoing euglycemic-hyperinsulinemic clamps, being highly up-regulated in liver and down-regulated in muscle and fat. Mice with liver-specific knockout (KO) of the insulin receptor (IR) have a 50% reduction inArrdc3messenger RNA, while, conversely, mice with liver-specific KO ofArrdc3(L-Arrdc3KO) have increased IR protein in plasma membrane. This leads to increased hepatic insulin sensitivity with increased phosphorylation of FOXO1, reduced expression of PEPCK, and increased glucokinase expression resulting in reduced hepatic glucose production and increased hepatic glycogen accumulation. These effects are due to interaction of ARRDC3 with IR resulting in phosphorylation of ARRDC3 on a conserved tyrosine (Y382) in the carboxyl-terminal domain. Thus,Arrdc3is an insulin target gene, and ARRDC3 protein directly interacts with IR to serve as a feedback regulator of insulin action in control of liver metabolism.


2009 ◽  
Vol 297 (5) ◽  
pp. E1137-E1146 ◽  
Author(s):  
Maziyar Saberi ◽  
David Bjelica ◽  
Simon Schenk ◽  
Takeshi Imamura ◽  
Gautam Bandyopadhyay ◽  
...  

The transcription factor TORC2 [transducer of regulated cAMP-responsive element-binding protein (CREB) activity 2] is a major regulator of hepatic gluconeogenesis and is increased in hyperglycemic rodent models. Because chronic hyperglycemia and increased hepatic glucose production, via increased gluconeogenesis, is a key feature of type 2 diabetes, an effective in vivo method to efficiently knock down TORC2 could provide a potential therapy for treating hyperglycemia and type 2 diabetes. To assess this, primary mouse hepatocytes, high-fat diet (HFD)-fed mice, and Zucker diabetic fatty (ZDF) rats were treated with a siRNA against TORC2 (siTORC2), which was delivered via a novel lipid nanoparticle system, or control siRNA (siCON). Compared with siCON, administration of siTORC2 resulted in highly efficient, sustained (1–3 wk) knockdown of TORC2 and its gluconeogenic target genes phospho enolpyruvate carboxykinase and glucose-6-phophatase in primary mouse hepatocytes and in the livers of HFD-fed mice. In mice, this knockdown was specific to the liver and did not occur in kidney, skeletal muscle, or adipose tissue. In HFD-fed mice, siTORC2 reduced in vivo gluconeogenic capacity, fasting hepatic glucose production, and hyperglycemia, and led to improved hepatic and skeletal muscle insulin sensitivity. siTORC2 treatment also improved systemic hyperglycemia in ZDF rats. In conclusion, these results demonstrate the importance of TORC2 in modulating HGP in vivo and highlight a novel, liver-specific siRNA approach for the potential treatment of hyperglycemia and type 2 diabetes.


2009 ◽  
Vol 94 (4) ◽  
pp. 1401-1408 ◽  
Author(s):  
Hua Wang ◽  
Nicholas P. Hays ◽  
Swapan K. Das ◽  
Rebekah L. Craig ◽  
Winston S. Chu ◽  
...  

Abstract Objective: Linkage to type 2 diabetes (T2D) is well replicated on chromosome 1q21-q23. Within this region, T2D was associated with common single nucleotide polymorphisms that marked an extended linkage disequilibrium block, including the liver pyruvate kinase gene (PKLR), in several European-derived populations. In this study we sought to determine the molecular basis for the association and the phenotypic consequences of the risk haplotype. Research Design and Methods: Genes surrounding PKLR were resequenced in European-American and African-American cases and controls, and association with T2D was tested. Copy number variants (CNVs) were tested for four regions with real-time PCR. Expression of genes in the region was tested in adipose and muscle from nondiabetic subjects with each genotype. Insulin secretion, insulin sensitivity, and hepatic glucose production were tested in nondiabetic individuals with each haplotype combination. Results: No coding variant in the region was associated with T2D. CNVs were rare and not associated with T2D. PKLR was not expressed in available tissues, but expression of genes HCN3, CLK2, SCAMP3, and FDPS was not associated with haplotype combinations in adipose or muscle. Haplotype combinations were not associated with insulin secretion or peripheral insulin sensitivity, but homozygous carriers of the risk haplotype had increased hepatic glucose production during hyperinsulinemia. Conclusions: Noncoding variants in the PKLR region likely alter gene expression of one or more genes. Our extensive physiological and molecular studies suggest increased hepatic glucose production and reduced hepatic insulin sensitivity, thus pointing to PKLR itself as the most likely candidate gene in this population.


1995 ◽  
Vol 269 (6) ◽  
pp. E1037-E1043 ◽  
Author(s):  
D. Massillon ◽  
W. Chen ◽  
M. Hawkins ◽  
R. Liu ◽  
N. Barzilai ◽  
...  

Mice were studied with the euglycemic hyperinsulinemic and the hyperglycemic clamp techniques after a 6-h fast: 1) euglycemic (6.7 +/- 0.2 mM) hyperinsulinemia (approximately 800 microU/ml); 2) hyperglycemic (15.3 +/- 0.4 mM) hyperinsulinemia (approximately 800 microU/ml). All mice received an infusion of [3-3H]glucose and [U-14C]lactate. Basal hepatic glucose production (HGP) averaged approximately 170 mumol.kg-1.min-1 in both groups. During euglycemic and hyperglycemic hyperinsulinemia, HGP decreased by 53% (to 76.7 +/- 11.1 mumol.kg-1.min-1; P < 0.01) and 74% (to 43.3 +/- 7.2 mumol.kg-1.min-1; P < 0.01), respectively. Hyperglycemia increased glucose cycling (by 2.1-fold; P < 0.01) and the contribution of gluconeogenesis to HGP (88 vs. 43%; P < 0.01) while decreasing that of glycogenolysis (12 vs. 57%; P < 0.01). The percentage of neosynthetized hepatic glycogen formed via the direct pathway was markedly increased during hyperglycemia (53 +/- 2% vs. 23 +/- 3%; P < 0.01): These data indicate that the assessment of hepatic glucose fluxes can be accomplished in conscious unrestrained mice and that, in the presence of hyperinsulinemia, hyperglycemia causes 1) a further inhibition of HGP mainly via inhibition of glycogenolysis and increase in hepatic glucose cycling; and 2) about a fivefold stimulation in the direct pathway of hepatic glycogen formation.


Sign in / Sign up

Export Citation Format

Share Document