内质网应激介导了高糖引起的血管平滑肌细胞钙化

目的探讨内质网应激是否介导了高糖引起的血管平滑肌细胞(VSMC)钙化。方法体外高糖(35μmol/L D-葡萄糖)处理VSMC模拟糖尿病环境,观察高糖是否引起VSMC内质网应激反应和凋亡,探索高糖是否引起VSMC表型转化(收缩型转变为成骨样细胞),观察内质网应激诱导剂和抑制剂对VSMC钙化的影响,碱性磷酸酶(ALP)活性、钙沉积和骨分化转录因子(Runx2和Osterix)通过比色法、O-cresolphthalein法和Western blot测定。结果应用35μmol/L D-葡萄糖分别处理VSMC不同时间,可以上调VSMC内质网应激标志蛋白表达、ALP活性、钙沉积和骨分化标志蛋白;然而,4-PBA预处理抑制VSMC内质网应激反应的同时,也能阻断高糖引起的VSMC钙化,表现为ALP活性、钙沉积和骨分化标志蛋白下降。结论高糖可以激活VSMC的内质网应激和凋亡,进而促VSMC钙化的发生,提示可能内质网应激介导了此激活过程。

Endoplasmic Reticulum Stress Mediates High Glucose-induced Calcification of Vascular Smooth Muscular Cells

Aim To investigate whether high blood glucose-induced vascular calcification in diabetes mellitus is caused by the endoplasmic reticulum(ER) response and subsequent apoptosis. Methods We examined the effects of high glucose on the ER stress response and calcification of vascular smoothmuscle cells (VSMC). Alkaline phosphatase (ALP) activity, calcium content and osteogenic markers expression was measured by colorimetric assay, o-cresolphthalein method and Western blot analysis. Results High glucose induced osteoblastic differentiation and ER stress of VSMC,as evidenced by ALP activity, calcium content and osteogenic markers expression increase. 4-PBA treatment could inhibit ER stress and apoptosis of VSMC, therefore, high glucose-elicited VSMC calcification was retarded. Conclusion High glucose can activate ER stress and osteoblastic differentiation in VSMC, ER stress and apoptosis might mediate VSMC calcification induced by high glucose.