ENOS-Dependent Antisenscence Effect of a Calcium Channel Blocker in Human Endothelial Cells

Toshio Hayashi,Morihiko Maeda,Tomoe Yamaguchi,Kumiko Taguchi,Masafumi Kuzuya,Yuichi Hattori,Yasufumi Sakakibara,Ryuichi Morishita

doi:10.1371/journal.pone.0088391

Abstract

Senescence of vascular endothelial cells is an important contributor to the pathogenesis of age-associated vascular disorders such as atherosclerosis. We investigated the effects of antihypertensive agents on high glucose-induced cellular senescence in human umbilical venous endothelial cells (HUVECs). Exposure of HUVECs to high glucose (22 mM) for 3 days increased senescence-associated- β-galactosidase (SA-β-gal) activity, a senescence marker, and decreased telomerase activity, a replicative senescence marker. The calcium channel blocker nifedipine, but not the β1-adrenergic blocking agent atenolol or the angiotensin-converting enzyme inhibitor perindopril, reduced SA-β-gal positive cells and prevented a decrease in telomerase activity in a high-glucose environment. This beneficial effect of nifedipine was associated with reduced reactive oxygen species (ROS) and increased endothelial nitric oxide synthase (eNOS) activity. Thus, nifedipine prevented high glucose-induced ROS generation and increased basal eNOS phosphorylation level at Ser-1177. Treatment with N G-nitro-L-arginine (L-NAME) and transfection of small interfering RNA (siRNA) targeting eNOS eliminated the anti-senscence effect of nifedipine. These results demonstrate that nifedipine can prevent endothelial cell senescence in an eNOS-dependent manner. The anti-senescence action of nifedipine may represent a novel mechanism by which it protects against atherosclerosis.

Highlights

Aging is increasingly regarded as a major risk factor for the development of cardiovascular disorders, including atherosclerosis, hypertension, and their complications such as stroke and myocardial infarction [1,2]
Increasing medium concentration of Ca2+ from 1.8 to 3.6 mM resulted in a rather significant reduction in SA-b-gal activity under both normal and high glucose conditions (Figure S2), suggesting that the beneficial effect of nifedipine on endothelial cell senescence cannot be solely attributed to its calcium channel blocking action
We demonstrated that the calcium channel blocker, nifedipine significantly inhibited vascular endothelial cell senescence

Summary

Introduction

Aging is increasingly regarded as a major risk factor for the development of cardiovascular disorders, including atherosclerosis, hypertension, and their complications such as stroke and myocardial infarction [1,2]. The vasculature undergoes functional and structural impairment. Vascular aging is characterized by the transition of endothelial cells from an anti-atherosclerotic state to a proatherosclerotic one [3]. Senescence is characterized by specific changes in cell morphology and gene expression, which directly correlate with an impairment of endothelial integrity and function [4]. Some of these changes in endothelial cells, including decreased endothelial nitric oxide synthase (eNOS) activity and decreased nitric oxide (NO) production, can lead to a dysregulated vascular tone and a proatherosclerotic and prothrombotic environment [3,5,6]. Senescent endothelial cells have been identified at sites of atherosclerotic lesions in vivo [9,10]

Methods

Results

Conclusion