Metformin Inhibits Vascular Calcification in Female Rat Aortic Smooth Muscle Cells via the AMPK-eNOS-NO Pathway

• Published in: Endocrinology (Philadelphia) 2013-10, Vol.154 (10), p.3680-3689
• Main Authors: Cao, Xiaorui, Li, Huan, Tao, Huiren, Wu, Ning, Yu, Lifeng, Zhang, Dawei, Lu, Xiaozhao, Zhu, Jinyu, Lu, Zifan, Zhu, Qingsheng
• Format: Article
• Language: English
• Subjects: Actin; Alkaline phosphatase; AMP-activated protein kinase; AMP-Activated Protein Kinases - antagonists & inhibitors; AMP-Activated Protein Kinases - chemistry; AMP-Activated Protein Kinases - metabolism; Animals; Antidiabetics; Aorta; Aorta - cytology; Aorta - drug effects; Aorta - metabolism; Aorta - pathology; Arginine; Biological and medical sciences; Bone loss; Bone morphogenetic protein 2; Calcification; Calcification (ectopic); Cbfa-1 protein; Cell Transdifferentiation - drug effects; Cells, Cultured; Deposition; Diabetes mellitus (non-insulin dependent); Diabetic Angiopathies - chemically induced; Diabetic Angiopathies - metabolism; Diabetic Angiopathies - pathology; Diabetic Angiopathies - prevention & control; Enzyme Activation - drug effects; Enzyme Inhibitors - adverse effects; Female; Females; Fundamental and applied biological sciences. Psychology; Glycerophosphate; Glycerophosphates - adverse effects; Glycerophosphates - antagonists & inhibitors; Hypoglycemic Agents - antagonists & inhibitors; Hypoglycemic Agents - pharmacology; Kinases; Metformin; Metformin - antagonists & inhibitors; Metformin - pharmacology; Muscle, Smooth, Vascular - cytology; Muscle, Smooth, Vascular - drug effects; Muscle, Smooth, Vascular - metabolism; Muscle, Smooth, Vascular - pathology; Muscles; Nitric oxide; Nitric Oxide - metabolism; Nitric Oxide Synthase Type III - antagonists & inhibitors; Nitric Oxide Synthase Type III - chemistry; Nitric Oxide Synthase Type III - metabolism; Nitric-oxide synthase; Phosphorylation; Phosphorylation - drug effects; Protein Kinase Inhibitors - adverse effects; Protein Processing, Post-Translational - drug effects; Proteins; Rats; Rats, Sprague-Dawley; Signal Transduction - drug effects; Smooth muscle; Vascular Calcification - chemically induced; Vascular Calcification - metabolism; Vascular Calcification - pathology; Vascular Calcification - prevention & control; Vertebrates: endocrinology; β-Glycerophosphoric acid
• ISSN: 0013-7227; 1945-7170
• DOI: 10.1210/en.2013-1002

Metformin exhibits diverse protective effects against diabetic complications, such as bone loss. Here, we investigated the effect of metformin on vascular calcification, another type 2 diabetes complication. In female rat aortic smooth muscle cells (RASMCs), we observed that metformin significantly alleviated β-glycerophosphate-induced Ca deposition and alkaline phosphatase activity, corresponding with reduced expression of some specific genes in osteoblast-like cells, including Runx2 and bone morphogenetic protein-2, and positive effects on α-actin expression, a specific marker of smooth muscle cells. Mechanistic analysis showed that phosphorylation levels of both AMP-activated protein kinase (AMPK) and endothelial nitric oxide synthase (eNOS) were increased with NO overproduction. After inhibition of either AMPK or eNOS with the pharmacologic inhibitors, compound C or Nω-Nitro-L-arginine methyl ester, NO production was lowered and metformin-meditated vascular protection against β-glycerophosphate-induced Ca deposition was removed. Our results support that metformin prevents vascular calcification via AMPK-eNOS-NO pathway.