Dipeptidyl peptidase- IV inhibitor alogliptin improves stress-induced insulin resistance and prothrombotic state in a murine model

Background: Stress evokes lipolytic release of free fatty acid (FFA) and low-grade inflammation in visceral adipose tissue, mediated by increased adipokine secretion, and contributes to glucose metabolism disorder and prothrombotic state. We tested the hypothesis that alogliptin, a dipeptidyl peptidase-4 inhibitor, can ameliorate the biological effects of chronic stress in mice. Method and results: C57BL/6J mice were subjected to 2-week intermittent restraint stress and orally treated with vehicle or alogliptin (dose: 15 or 45 mg/kg/day). Plasma levels of lipids, proinflammatory cytokines (monocyte chemoattractant protein-1, tumor necrosis factor-alpha, and interleukin-6), and 8-hydroxydeoxyguanosine were measured with enzyme-linked immunosorbent assay. Monocyte/macrophage accumulation in inguinal white adipose tissue (WAT) was examined by CD11b-positive cell count and mRNA expression of CD68 and F4/80 was examined by immunohistochemistry and RTPCR, respectively. The mRNA levels of the above-mentioned proinflammatory cytokines, NADPH oxidase 4, adiponectin, and coagulation factors (plasminogen activation inhibitor-1 and tissue factor) in WAT were also assessed with RT-PCR. Glucose metabolism was assessed by glucose and insulin tolerance tests, plasma levels of DPP-4 activity, glucagon-like peptide-1, expression of DPP-4, insulin receptor substrate-1 and glucose transporter 4 in WAT and skeletal muscle. Alogliptin administration suppressed stress induced FFA release, oxidative stress, adipose tissue inflammation, DPP-4 activation, and prothrombotic state in a dose-dependent manner, and improved insulin sensitivity in stressed mice. Conclusions: The results indicate that alogliptin improves stress-induced prothrombotic state and insulin resistance; suggesting that alogliptin could have beneficial therapeutic effects against cardiovascular complications in diabetic patients under stress. (C) 2016 Elsevier Ltd. All rights reserved.