Published in:
Open Access
01-12-2015 | Original investigation
Involvement of Rho-associated protein kinase (ROCK) and bone morphogenetic protein-binding endothelial cell precursor-derived regulator (BMPER) in high glucose-increased alkaline phosphatase expression and activity in human coronary artery smooth muscle cells
Authors:
Yuya Terao, Seimi Satomi-Kobayashi, Ken-ichi Hirata, Yoshiyuki Rikitake
Published in:
Cardiovascular Diabetology
|
Issue 1/2015
Login to get access
Abstract
Background
Vascular calcification is an independent risk factor for cardiovascular disease. Diabetes mellitus increases the incidence of vascular calcification; however, detailed molecular mechanisms of vascular calcification in diabetes mellitus remain unknown. We recently reported that bone morphogenetic protein-binding endothelial cell precursor-derived regulator (BMPER) regulates osteoblast-like trans-differentiation of human coronary artery smooth muscle cells (HCASMCs).
Methods
We investigated the effect of a hydroxymethylglutaryl-coenzyme A reductase inhibitor (statin), commonly used in patients with atherosclerotic diseases and diabetes mellitus, on alkaline phosphatase (ALP) mRNA expression in aortas of streptozotocin-induced diabetic mice. We also investigated the effects of the statin, Rho-associated protein kinase (ROCK) inhibitors and BMPER knockdown on ALP mRNA expression and activity in HCASMCs cultured in high glucose-containing media.
Results
Alkaline phosphatase mRNA expression was increased in aortas of streptozotocin-induced diabetic mice, and the increase was inhibited by rosuvastatin. ALP mRNA expression and activity were increased in HCASMCs cultured in high glucose-containing media, and the increases were suppressed by rosuvastatin. This suppression was reversed by the addition of mevalonate or geranylgeranyl pyrophosphate, but not farnesyl pyrophosphate. High glucose-increased ALP mRNA expression and activity were suppressed by ROCK inhibitors. Moreover, BMPER mRNA expression was increased in diabetic mouse aortas and in HCASMCs cultured in high glucose-containing media, but was not inhibited by rosuvastatin or ROCK inhibitors. Knockdown of BMPER suppressed high glucose-increased ALP activity, but not ROCK activity in HCASMCs.
Conclusions
There are at least two independent pathways in high glucose-induced ALP activation in HCASMCs: the Rho–ROCK signaling pathway and the BMPER-dependent pathway.