Liraglutide Attenuates Diabetic Cardiomyopathy via the ILK/PI3K/AKT/PTEN Signaling Pathway in Rats with Streptozotocin-Induced Type 2 Diabetes Mellitus

Abstract

One of the possible candidates for the treatment of diabetic cardiomyopathy is liraglutide, a glucagon-like peptide-1 receptor (GLP1R) agonist. In this study, the impacts of liraglutide on the integrin-linked kinase (ILK)-related PI3K/AKT axis in rats with type 2 diabetes induced via streptozotocin were examined. Twenty-four Wistar albino rats were distributed in four different groups, and a high-fat diet and streptozotocin were used to induce type 2 in two groups. Rats in the untreated control groups were administered 0.9% NaCl solution over a 6-week period, and those in the treatment groups were administered 0.9% NaCl for 3 weeks, followed by subcutaneous injection of liraglutide (150 μg/kg) for an additional 3 weeks. In the liraglutide-treated diabetic group, the heart-to-body weight ratio was significantly reduced, levels of cardiac biomarkers, troponin I and creatine-kinase-MB, were improved; activities of antioxidant enzymes, glutathione peroxidase and superoxide dismutase, were increased; and levels of malondialdehyde were decreased. Western blotting and immunohistochemical studies revealed increased levels of ILK, P-PI3K, P-AKT, and BCL2, as well as those of caspase 3, BAX, and P-PTEN, indicating mitigation of cardiomyocyte apoptosis. Our results show that liraglutide, by targeting GLP1Rs, enhances the expression of proteins in the ILK/PI3K/AKT/PTEN pathway and thereby exerts its cardioprotective effects in rats with DCM.

Keywords

• glucagon-like peptide-1 analog
• diabetic cardiomyopathy
• streptozotocin-induced type 2 diabetes
• integrin-linked kinase
• phosphatidylinositol 3-kinase
• protein kinase B