BMP-2 In Vascular Smooth Muscle Mediated Homocysteine Promotes Vascular Calcification

Objective To investigate the involvement of bone morphogenetic protein-2(BMP2)in HHcy-induced vascular calcification(VC)Methods Human carotid specimens were obtained from the pathology department of Ningxia Medical University General Hospital.Apo E-/-mice were divided into three groups:normal diet,high-fat diet,or high-fat high-methionine diet(8/group).A7r5 cells were transfected with BMP2 vectors and treated with Hcy(50,100,200,and 400 μmol/L).Calcifications were determined using alizarin red and H&E.Protein expression was determined by western blot,immunohistochemistry,and immunofluorescence.Graph Pad Prism9.0 was used for analysis,and expressed as mean ± standard deviation.The in vitro data came from at least three separate experiments.All data were tested for normality and variance equality.The difference between the two groups was compared by independent t test,and multiple comparisons were performed by one-way or bidirectional analysis of variance.Pearson correlation was used for correlation analysis.P < 0.05 was the threshold of significant difference.Results The arterial specimens(humans and mice)showed increased expression of BMP2 in the calcified areas.HHcy significantly increased VC,VSMCs phenotypic transformation,and BMP2 expression.The Hcy concentrations were positively correlated with the calcification area.BMP2 was involved in Hhcy-induced phenotypic transformation in VC.After overexpression of BMP2,the levels of smooth muscle α actin(α-SMA)and smooth muscle myosin heavy chain(SM22α)of VSMCs were decreased and were correlated with phenotypic transformation and calcification formation.Silencing BMP2 inhibited phenotypic transformation and calcification.Hence,BMP2 can promote Hhcy-induced phenotypic transformation in VC.Immunofluorescence and correlation analyses demonstrated the role and interaction of the BMP2/RUNX2 pathway in HHcy-induced VC.Conclusion BMP2 is a key target gene in HHcy regulation of VSMCs phenotypic transformation leading to VC.The BMP2/RUNX2 pathway promotes VSMCs calcification phenotypic transformation.Targeting BMP2 could reduce VC in patients with HHcy.