DPP-4 inhibition resembles exercise in preventing type 2 diabetes development by inhibiting hepatic protein kinase C expression in a mouse model of hyperinsulinemia

Autor: Yu-peng Li, Jing Xiao, Xu Liang, Yu Pei, Xiao-fei Han, Chen-xi Li, Hui Tian
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Journal of International Medical Research, Vol 48 (2020)
Druh dokumentu: article
ISSN: 1473-2300
03000605
DOI: 10.1177/0300060520934635
Popis: Objective Interventions for hyperinsulinemia (HINS), an early indicator of type 2 diabetes mellitus (T2DM), can significantly reduce the T2DM risk. This study aims to determine how dipeptidyl peptidase-4 (DPP-4) inhibition prevents HINS progression to T2DM through ameliorating hepatic steatosis. Methods KKay mice were used as a HINS model and they underwent exercise or received a DPP-4 inhibitor, MK0626. Hepatic steatosis was examined and liver diacylglycerol levels were determined. Human hepatic cells (LO2) were treated with MK0626 or transfected with DPP-4 siRNA. Protein kinase C ε isoform (PKCε) and DPP-4 expression and insulin receptor substrate 1 (IRS-1) phosphorylation were assessed using immunohistochemistry and western blot. Results KKay mice developed HINS spontaneously at 7 weeks of age. Similar to exercise, MK0626 ameliorated hepatic steatosis and reduced the liver triglyceride and diacylglycerol content. Both exercise and MK0626 suppressed diacylglycerol-induced PKCε expression and restored insulin signaling, which was shown by tyrosine phosphorylation of IRS-1, in the livers of KKay mice. Additionally, silencing DPP-4 or MK0626 treatment decreased PKCε expression in LO2 cells. Conclusions Our data demonstrate that DPP-4 inhibition resembles exercise and effectively delays T2DM onset by suppressing hepatic PKCε expression in the HINS mouse model.
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