title: Effects of oxidized low density lipoprotein on transformation of valvular myofibroblasts to osteoblast-like phenotype.
abstract: In order to investigate the roles of Wnt signal pathway in transformation of cardiac valvular myofibroblasts to the osteoblast-like phenotype, the primary cultured porcine aortic valve myofibroblasts were incubated with oxidized low density lipoprotein (ox-LDL, 50 mg/L), and divided into four groups according to the ox-LDL treatment time: control group, ox-LDL 24-h group, ox-LDL 48-h group, and ox-LDL 72-h group. Wnt signal pathway blocker Dickkopf-1 (DDK-1, 100 μg/L) was added in ox-LDL 72-h group. The expression of a-smooth muscle actin (α-SMA), bone morphogenetic protein 2 (BMP2), alkaline phosphatase (ALP), and osteogenic transcription factor Cbfa-1 was detected by Western blotting, and that of β-catenin, a key mediator of Wnt signal pathway by immunocytochemical staining method. The Wnt/β-catenin was observed and the transformation of myofibroblasts to the osteoblast-like phenotype was examined. The expression of α-SMA, BMP2, ALP and Cbfa-1 proteins in the control group was weaker than in the ox-LDL-treated groups. In ox-LDL-treated groups, the protein expression of a-SMA, BMP2, ALP, and Cbfa-1 was significantly increased in a time-dependent manner as compared with the control group, and there was significant difference among the three ox-LDL-treated groups (P<0.05 for all); β-catenin protein was also up-regulated in the ox-LDL-treated groups in a time-dependent manner as compared with the control group (P<0.05), and its transfer from cytoplasm to nucleus and accumulation in the nucleus were increased in the same fashion (P<0.05). After addition of DKK-1, the expression of α-SMA, bone-related proteins and β-catenin protein was significantly reduced as compared with ox-LDL 72-h group (P<0.05). The Wnt/ β-catenin signaling pathway may play an important role in transformation of valvular myofibroblasts to the osteoblast-like phenotype.
authors.affiliation: Department of Emergency Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
authors.forename: Di
authors.initials: D
authors.lastname: Chen
authors.affiliation: Department of Emergency Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
authors.forename: Ying-Lian
authors.initials: YL
authors.lastname: Shen
authors.affiliation: Department of Emergency Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
authors.forename: Wei-Lin
authors.initials: WL
authors.lastname: Hu
authors.affiliation: Department of Emergency Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
authors.forename: Zheng-Ping
authors.initials: ZP
authors.lastname: Chen
authors.affiliation: Department of Emergency Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China. dr.ysli@hotmail.com.
authors.forename: Yong-Sheng
authors.initials: YS
authors.lastname: Li
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D001021:Aortic Valve / Q000166:cytology*; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000187:drug effects; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D058628:Myofibroblasts / Q000187:drug effects*; D010006:Osteoblasts / Q000502:physiology*; D010641:Phenotype; D013552:Swine; D060449:Wnt Signaling Pathway / Q000187:drug effects*; D051176:beta Catenin / Q000378:metabolism
chemical_list: D000199:Actins; D036341:Intercellular Signaling Peptides and Proteins; D008077:Lipoproteins, LDL; D051176:beta Catenin; C099252:oxidized low density lipoprotein