MAPK-ERK1/2 signaling pathway regulates osteogenic gene expression in rat osteoblasts in vitro
DING Daofang
LI Linghui
SONG Yi
DU Guoqing
WEI Xiaoen
CAO Yuelong
Abstract：Objective To investigate the effect of inhibition and activation of MAPK-ERK1/2 pathway on the expression of osteogenic genes and proliferation of rat osteoblasts in vitro. Methods Primarily cultured rat osteoblasts, identified by cell morphology studies and ALP staining, were exposed to 1%or 5%rat serum for 24 h or to the specific MAPK-ERK1/2 inhibitor PD0325901. The downstream molecules of MAPK-ERK1/2 pathway including p-ERK1/2 and ERK1/2, osteogenic genes such as Runx2 and Type I collagen, and proliferating cell nuclear antigen (PCNA) were detected by Western Blotting, and alkaline phosphatase activities were analyzed quantitatively. Results Compared with 1%rat serum-treated cells, exposure of the cells to a higher concentration (5%) of rat serum caused a significantly increased phosphorylation level of p-ERK1/2 (P<0.05) and obviously enhanced expressions of the osteogenic genes (Runx2, type I collagen and ALP) and PCNA (P<0.05). Inhibition of the MAPK-ERK1/2 pathway with PD0325901 resulted in suppressed expressions of the osteogenic genes and PCNA. Conclusion The activation of MAPK-ERK1/2 pathway promotes the expression of osteogenic genes such as Runx2, type I collagen and ALP and enhances the proliferative activity of the osteoblasts, while inhibition of this pathway suppresses the expressions of these genes and the cell proliferation, suggesting that this pathway may potentially serve as a therapeutic target for osteoporosis.
Keywords：primary osteoblastsosteogenic expressionrat serumsignal pathway
Publication Date：2013-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 1432-1436 )