ABSTRACT
Objective: To explore the effect of autophagy on process of high phosphate salt induced vascular smooth muscle cell (VSMC) calciifcation in experimental rats. Methods: Rats’ model of VSMC calciifcation was induced by phosphate incubation. VSMC were divided into 3 groups:①Control group,②Calciifcation group which included 3 subgroups as 4-day subgroup, the cells were cultured by 3.2 mmol/L phosphate for 4 days, 6-day subgroup and 8-day subgroup,③Calciifcation+ 3-MA (autophagy inhibitor) group, in which the 8-day cells were cultured with 5mmol/L 3-MA. Calcium nodule formation and calcium deposition in VSMC were measured by Alizarin red staining and o-cresolphthaleincomplexone method, protein expressions of Runx2, α-SMA and LC3 II were examined by Western blot analysis, autophagosome formation in VSMC was measured by transmission electron microscope and the localization and expression of Runx2 and LC3 II in VSMC were observed by immunolfuorescent microscope. Results: Compared with Control group, the cells at 8-day subgroup showed more calcium nodules, higher calcium deposition, increased protein expressions of Runx2, LC3 II, more autophagosome and decreased α-SMA expression, allP<0.05. Compared with 8-day subgroup, the cells in Calcification+3-MA group presented increased calcium deposition, decreased lfuorescence distribution of LC3 II and more cells with positive Runx2 protein expression, all P<0.05. Conclusion: Autophagy has the protective effect on process of phosphate induced VSMC calciifcation in experimental rats.