Zhao Ying, Guan Hong, Liu Shang-Feng, Wu Rong-Cong, Wang Zhao
Department of Biological Sciences and Biotechnology, Medical School, Tsinghua University, Beijing 100084, P.R. China.
Biol Pharm Bull. 2005 Aug;28(8):1371-6. doi: 10.1248/bpb.28.1371.
It has been reported that QM was highly expressed by cells isolated from epiphyseal cartilage as opposed to proliferative chondrocytes. In vitro investigation of the expression of QM revealed higher QM expression in nonmineralizing osteoblast and pericyte cultures as compared with mineralizing cultures. These evidences suggest that QM may play an essential role in cell differentiation before mineralization. However, our research results showed that QM overexpression in MC3T3-E1 enhanced cell differentiation and mineralization. In this study, alkaline phosphatase (ALP) activity and nodule mineralization were increased in MC3T3-E1 from QM overexpression cultures relative to normal expression QM cultures. RT-PCR revealed upregulation of the marker genes type I collagen, ALP, osteocalcin, osterix and BMP-2 and a slight decrease of a negative regulator osteopontin. These results suggest that the increasing of QM expression could stimulate osteoblast differentiation and mineralization in MC3T3-E1.
据报道，与增殖性软骨细胞相反，从骨骺软骨分离的细胞中QM高表达。对QM表达的体外研究显示，与矿化培养物相比，非矿化成骨细胞和周细胞培养物中QM表达更高。这些证据表明，QM可能在矿化前的细胞分化中起重要作用。然而，我们的研究结果表明，MC3T3-E1中QM的过表达增强了细胞分化和矿化。在本研究中，相对于正常表达QM的培养物，QM过表达培养物中的MC3T3-E1碱性磷酸酶（ALP）活性和结节矿化增加。RT-PCR显示I型胶原、ALP、骨钙素、osterix和BMP-2等标志物基因上调，负调节因子骨桥蛋白略有下降。这些结果表明，QM表达的增加可刺激MC3T3-E1中的成骨细胞分化和矿化。
