Role of the Wnt/β-catenin signaling pathway in regulating the phenotypic transformation of aortic valvular myofibroblasts to osteoblast-like cells / 中华老年医学杂志

ABSTRACT

Objective To elucidate the role of the Wnt/-catenin signaling pathway in regulating the phenotypic transformation of aortic valvular myofibroblasts to osteoblast-like cells.Methods Cultured primary valvular myofibroblastes isolated from porcine aortic valve leaflets were treated with oxidized low-density lipoprotein (ox-LDL) for different lengths of time24 h,48 h and 72 h.The Wnt signaling pathway inhibitor Dickkopf-1 (DDK-1) was co-incubated with ox-LDL for 72 h.After cells harvest,the expression of myofibroblastic or osteoblast-like phenotype related markers,a-smooth muscle actin (α-SMA),bone morphogenetic protein 2 (BMP2),alkaline phosphatase (ALP) and corebinding factora-1 (Cbfα 1),was detected by Western blotting.The expression and sub cellular localization of β3-catenin was assessed by immunocytochemistry.Changes of the Wnt/β-catenin signaling pathway and the transformation of aortic valvular myofibroblast to osteoblast-like cells were monitored.Results BMP2,ALP and Cbfa 1 protein expression was not or barely detectable in the control group.However,after ox-LDL treatment,the expression of α SMA,BMP2,ALP and Cbfa 1 increased significantly (each P＜0.01) in a time-dependent manner (each P＜0.05).Besides,ox-LDL was also able to up-regulate the protein expression of β-catenin in a time-dependent manner (P＜0.05) and promoted its nuclear translocation.After DKK-1 treatment,the protein expression of β3 catenin and osteogenesis related markers was down regulated (P＜0.05).Conclusions The Wnt/β-catenin signaling pathway may play a crucial role in regulating the transformation of aortic valvular myofibroblasts to an osteoblast like phenotype.