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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 time:24 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.
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BACKGROUND: Stimulating cerebellar fastigial nucleus can regulate, dilate blood vessels and greatly increase local blood flow. However, if its mechanism is to improve the function of vascular endothelium is still uncertain.OBJECTIVE: To study the effects of stimulating cerebellar fastigial nucleus by electricity to vascular relaxation of transient ischemic attack(TIA) patients which is induced by blood flow and explore its protective mechanism to blood vessels of TIA patients.DESIGN: Randomized case control study to patients based on diagnosis SETTING: Department of general diseases, rehabilitation room and ultrasound department of a university hospital.PARTICIPANTS: Forty-four TIA patients(＞ 60 years old) admitted into Department of General Diseases of Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology during February 2001 to October 2002 were selected after excluding cerebral hemorrhage or cerebral infarction, atrium fibrillation and other arrhythmia or heart failure and blood system diseases. They were randomly divided into treatmentgroup(22 cases)and control group(22 cases) which were conducted stimulating fastigial nucleus + routine treatment and only routine treatment respectively.METHODS: High resolution ultrasound technique and brachial artery congestion method were used to test the internal diameter change rate of brachial artery in TIA patients before and after treatment.MAIN OUTCOME MEASURES: The internal diameter change rate of brachial artery of TIA pat ients.RESULTS: The internal diameter change rate of brachial artery was (4.59 ± 3.32) % and ( 10. 34 ± 3.13 ) % respectively before and after conducting electric stimulus to fastigial nucleus with significant difference ( t = 5.91, P ＜ 0.01 ). There was significant difference on internal diameter change rate between treatment group and control group( t =5.41, P ＜ 0.01 )while there was no difference in control group before and after treatment [(4.68±3.20) %,(5.10±3.29) %](t=1.72, P＞ 0.05).CONCLUSION: Conducting electric stimulating to fatigial nucleus can greatly improve the reactively vascular congestive function of brachial artery internal diameter and it can improve the vascular endothelial functions of TIA patients.