Effects of bone marrow mesenchymal stem cells on the mineralization of calcified vascular smooth muscle cells

Abstract

Objective To study the effects of bone marrow mesenchymal stem cells(MSC)on the mineralization of calcified vascular smooth muscle cells(CSMC). Methods Osteogenic differentiation of vascular smooth muscle cells(SMC)was induced by osteogenic medium for 14 days.Then von Kossa staining was performed to observe the mineral deposits in SMC.The transwell system was used to establish the indirect co-culture environment.And hence, CSMC was indirectly co-cultured without or with MSC at a ratio of 1∶1 in the down plates or up plates.The cells were divided into 4 groups.Normal group included the normal SMC cultured with the normal medium.Calcification inducers group included the normal SMC cultured with the osteogenic medium.Calcified cells group included CSMC cultured with the normal medium.MSC intervention group included MSC and CSMC cultured with the normal medium.14 days later, SMC from 4 groups was harvested.Alkaline phosphatase(AKP)activity was detected to evaluate the severity of calcification.Moreover, the protein levels of Wnt5a and β-catenin were measured by Western blot analysis. Results Compared with normal group, the calcification inducers group showed that AKP activity, Wnt5a and β-catenin protein levels were notably increased.Additionally, AKP activity and the protein levels of Wnt5a, β-catenin were decreased in calcified cells group as compared with calcification inducers group.Furthermore, AKP activity and the protein levels of Wnt5a, β-catenin were significantly reduced(P<0.01)in MSC intervention group versus calcified cells group Conclusions When MSC is indirectly co-cultured with CSMC, MSC can relieve the vascular calcification, which might be mediated by blocking the Wnt5a/β-catenin signaling through immunomodulatory and paracrine. Key words: Mesenchymal stem cells; Muscle, Smooth, Vasculan; Calcification; The Wnt5a/β-catenin signaling