Min Yang1, Li-Wei Xiao2, Er-Yuan Liao3, Qiao-Jing Wang2, Bei-Bei Wang2, Jia-Xuan Lei2. 1. Institute of Endocrinology and Metabolism, The Second Xiangya Hospital, Central South University Changsha, P. R. China ; Department of Internal Medicine, Affiliated Hospital of National Research for Rehabilitation Technical Aids Beijing, P. R. China. 2. Medical Center of Stomatology, The Second Xiangya Hospital, Central South University Changsha, P. R. China. 3. Institute of Endocrinology and Metabolism, The Second Xiangya Hospital, Central South University Changsha, P. R. China.
Abstract
OBJECTIVE: This study aims to explore the function of Integrin-β/FAK in the mechanical signal transduction and the connection with downstream ERK signal pathways. METHODS: Human osteosarcoma MG63 cell lines were used in this study. The effects of mechanical strain on the Integrin-β₁ expression, FAK and ERK signal pathway in Human osteosarcoma MG63 cells were detected using RT-PCR and Western-blotting methods. The localization of FAK in Human osteosarcoma MG63 cells were determined using immunofluorescent method. The interaction between Integrin-β₁ and FAK were detected by using co-immunoprecipitation method. RESULTS: The expression of Integrin-β₁ shows a notable bimodel distribution, mechanical strain stimulation can promote Integrin-β₁ expression and the phosphorylation of FAK and ERK, mechanical strain activated FAK and ERK mediated by Integrin-β₁. CONCLUSION: Integrin-β₁ may play an important role in osteoblast proliferation differentiation process, it might feel external strain stimulation through ECM composition and makes FAK phosphated through the interaction with FAK, thus causing a series of activation of signal molecules. Finally it reduces MAPK (ERK) activation and cellular responses to finish mechanical signal transduction.
OBJECTIVE: This study aims to explore the function of Integrin-β/FAK in the mechanical signal transduction and the connection with downstream ERK signal pathways. METHODS:Humanosteosarcoma MG63 cell lines were used in this study. The effects of mechanical strain on the Integrin-β₁ expression, FAK and ERK signal pathway in Humanosteosarcoma MG63 cells were detected using RT-PCR and Western-blotting methods. The localization of FAK in Humanosteosarcoma MG63 cells were determined using immunofluorescent method. The interaction between Integrin-β₁ and FAK were detected by using co-immunoprecipitation method. RESULTS: The expression of Integrin-β₁ shows a notable bimodel distribution, mechanical strain stimulation can promote Integrin-β₁ expression and the phosphorylation of FAK and ERK, mechanical strain activated FAK and ERK mediated by Integrin-β₁. CONCLUSION: Integrin-β₁ may play an important role in osteoblast proliferation differentiation process, it might feel external strain stimulation through ECM composition and makes FAK phosphated through the interaction with FAK, thus causing a series of activation of signal molecules. Finally it reduces MAPK (ERK) activation and cellular responses to finish mechanical signal transduction.
Entities:
Keywords:
ERK signal pathway; Integrin-β; focal adhesion kinase (FAK); human osteosarcoma MG63 cells; mechanical stimulation