ABSTRACT
BACKGROUND:Matrix extracel ular phosphoglycoprotein phosphorylated extracel ular matrix glycoprotein (MEPE) gene plays an important role in bone mineralization and absorption as wel as the balance of osteoblasts and osteoclasts. Studies on the function and regulatory mechanism of MEPE can provide new ideas for the treatment of osteoporosis. OBJECTIVE:To analyze the regulatory effects of transcription factor Runx2 on MEPE promoter in mouse preosteoblasts, thereby preliminarily studying the Runx2 effects in the process of bone formation and development. METHODS:First of al , the Runx2 eukaryotic expression vector was built according to the gene sequence of Runx2 in Genebank;then the dual luciferase reporter assay was employed to analyze the effects of Runx2 on transcription activity of MEPE promoters with different lengths in order to determine the promoter region in which Runx2 has significant effect. Afterwards, the effects of Runx2 on transcipition activity of MEPE gene promoter which induced by three MAPK signaling pathway inhibitors were investigated. Final y, real-time PCR was used to analyze the expression activity of MEPE gene promoter regulated by Runx2. RESULTS AND CONCLUSION:We successful y constructed the Runx2 eukaryotic expression vector. Dual luciferase reporter assay showed that Runx2 could increase the transcription activity of MEPE gene promoter in preosteoblasts, and the fragment area in which Runx2 exhibited the more significant up-regulatory effectiveness was (-300 to+66)366 bp. Runx2 could increase the transcription activity of MEPE gene promoter by activating the MAPK single pathway. The real-time PCR verified that Runx2 increased the expression activity of MEPE gene promoter. These findings indicate that Runx2 can regulate the express of MEPE gene promoter by the MAPK single pathway, in order to build the basis for exploring the process of bone formation and development.