Streptozotocin-induced Diabetes Increases the Adiponectin-mediated AMP-activated Protein Kinase Cascade in the Hippocampus of Mice

Abstract

Adiponectin is an adipocyte-derived protein with anti-diabetic and anti-angiogenesis properties that improves both glucose metabolism and insulin resistance via the adenosine monophosphate-activated protein kinase (AMPK) cascade. Diabetic cognitive deficits are correlated with dysregulation of energy metabolism in the hippocampus. In the present study, we investigated the expression of adiponectin-mediated AMPK cascade proteins in the hippocampus of streptozotocin (STZ)-induced diabetic mice. Diabetes was induced by STZ (55 mg/kg) injection intraperitoneally. Twenty-four weeks after induction of diabetes, mice were sacrificed. Results showed that decreased serum adiponectin levels and increased expression of hippocampal adiponectin receptor 1 (AdipoR1) was expressed in diabetic mice. Phosphorylated AMPK, acetyl CoA carboxylase (ACC), and eNOS expression levels were increased in the hippocampus of diabetic mice. The immunoreactivity of glucose transporter 1 in the endothelium of hippocampal blood vessels was also increased. These results indicate that adiponectin-mediated AMPK cascade activation may play a role in catabolic process that is involved in diabetic neurodegeneration.