Teruo Jojima1, Kohsuke Uchida2, Kazumi Akimoto3, Takanori Tomotsune4, Kazunori Yanagi4, Toshie Iijima4, Kunihiro Suzuki4, Kikuo Kasai5, Yoshimasa Aso4. 1. Department of Endocrinology and Metabolism, Dokkyo Medical University, Tochigi, Japan. Electronic address: jojima@dokkyomed.ac.jp. 2. Medical Science for Nursing (Pharmacology), Dokkyo Medical University School of Nursing, Tochigi, Japan. 3. Division of Clinical Science, Research Support Center, Dokkyo Medical University, Mibu, Tochigi, Japan. 4. Department of Endocrinology and Metabolism, Dokkyo Medical University, Tochigi, Japan. 5. Department of Medicine, Ishibashi General Hospital, Tochigi, Japan.
Abstract
BACKGROUND AND AIMS: Several studies have demonstrated that both native glucagon-like peptide-1 (GLP-1) and GLP-1 receptor agonists suppress the progression of atherosclerosis in animal models. METHODS: We investigated whether liraglutide, a GLP-1 analogue, could prevent the development of atherosclerosis in apolipoprotein E knockout mice (ApoE-/-) on a high-fat diet. We also examined the influence of liraglutide on angiotensin II-induced proliferation of rat vascular smooth muscle cells (VSMCs) via enhancement of AMP-activated protein kinase (AMPK) signaling and regulation of cell cycle progression. RESULTS: Treatment of ApoE-/- mice with liraglutide (400 μg/day for 4 weeks) suppressed atherosclerotic lesions and increased AMPK phosphorylation in the aortic wall. Liraglutide also improved the endothelial function of thoracic aortas harvested from ApoE-/- mice in an ex vivo study. Furthermore, liraglutide increased AMPK phosphorylation in rat VSMCs, while liraglutide-induced activation of AMPK was abolished by exendin 9-39, a GLP-1 antagonist. Moreover, angiotensin (Ang) II-induced proliferation of VSMCs was suppressed by liraglutide in a dose-dependent manner, and flow cytometry of Ang II-stimulated VSMCs showed that liraglutide reduced the percentage of cells in G2/M phase (by arrest in G0/G1 phase). CONCLUSIONS: These findings suggest that liraglutide may inhibit Ang II-induced VSMC proliferation by activating AMPK signaling and inducing cell cycle arrest, thus delaying the progression of atherosclerosis independently of its glucose-lowering effect.
BACKGROUND AND AIMS: Several studies have demonstrated that both native glucagon-like peptide-1 (GLP-1) and GLP-1 receptor agonists suppress the progression of atherosclerosis in animal models. METHODS: We investigated whether liraglutide, a GLP-1 analogue, could prevent the development of atherosclerosis in apolipoprotein E knockout mice (ApoE-/-) on a high-fat diet. We also examined the influence of liraglutide on angiotensin II-induced proliferation of rat vascular smooth muscle cells (VSMCs) via enhancement of AMP-activated protein kinase (AMPK) signaling and regulation of cell cycle progression. RESULTS: Treatment of ApoE-/- mice with liraglutide (400 μg/day for 4 weeks) suppressed atherosclerotic lesions and increased AMPK phosphorylation in the aortic wall. Liraglutide also improved the endothelial function of thoracic aortas harvested from ApoE-/- mice in an ex vivo study. Furthermore, liraglutide increased AMPK phosphorylation in rat VSMCs, while liraglutide-induced activation of AMPK was abolished by exendin 9-39, a GLP-1 antagonist. Moreover, angiotensin (Ang) II-induced proliferation of VSMCs was suppressed by liraglutide in a dose-dependent manner, and flow cytometry of Ang II-stimulated VSMCs showed that liraglutide reduced the percentage of cells in G2/M phase (by arrest in G0/G1 phase). CONCLUSIONS: These findings suggest that liraglutide may inhibit Ang II-induced VSMC proliferation by activating AMPK signaling and inducing cell cycle arrest, thus delaying the progression of atherosclerosis independently of its glucose-lowering effect.
Authors: Joseph Bailey; Maha Coucha; Deanna R Bolduc; Faith N Burnett; Amy C Barrett; Mark Ghaly; Mohammed Abdelsaid Journal: Diabetologia Date: 2022-06-10 Impact factor: 10.460