Hyperglycemia and hyperinsulinemia induced hepatocellular autophagy in male mice

Document Type : Original Article

Authors

Department of Zoology, Faculty of Science, Assiut University, Assiut 71516, Egypt

Abstract

The aim of the present study is to investigate the role of hyperglycemia and hyperinsulinemia in autophagy induction in the liver of male mice. Autophagy is a catabolic cellular process that recycles the aged or damaged cellular organelles and inclusions under certain circumstances.  Hyperglycemia is induced by a single dose of alloxan IP injection (180 mg/kg) and hyperinsulinemia is induced by high fat diet together with glucose feeding for short period (2 weeks) and long period (3 months). Hyperglycemia and hyperinsulinemia were estimated by measuring blood glucose level by glucometer and insulin level by specific ELISA kit, respectively. Autophagy induction was investigated morphologically by electron microscopy examination and biochemically by immunodetection of microtubular associated light chain protein 3 (LC3) conversion from LC3I to LC3II form and by immunodetection of the phosphorylated and non-phosphorylated forms of mammalian target of Rapamycin (mTOR). Our results revealed that hyperglycemia and hyperinsulinemia independently induced hepatocellular autophagy as indicated by the accumulation of autophagosomes and autolysosomes in EM examination and by the increase of the level of LC3II and decrease of the phosphorylated form of mTOR in western blot analysis. This study throw the light on the autophagy of hepatocytes as a cellular mechanism induced under diabetic conditions which may contribute in better understanding of our knowledge concerning nutrients metabolic disorders.

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