A STUDY OF GENES DIFFERENTIALLY EXPRESSED BY OSTEOCLASTOGENIC MOUSE STROMAL CELLS

点击翻译按钮获取中文摘要

Osteoclasts are multinucleated cells derived from hemopoietic cells. Osteoblastic/ stromal cell lineage contributes to the terminal differentiation of osteoclast precursor s through the direct cell-to-cell interaction mechanism (Takahashi et al., 1988). ST2 cells, mouse stromal cell line, support osteoclastogenesis in the coculture with hematopoietic cells in the presence of Vitamin D3 and Dexamethasone. We found the phenomenon of the passage-dependent reduction of osteoclastogenesis in the co-culture system of ST2 and hemopoietic cells. In this study we attempted to isolate the molecules of which gene expression is associated to the passage-dependent capability of supporting osteoclastogenesis, and got 1 .5 kb cDNA of that molecule.Recently osteoclast differentiation factor (RANKL/ TRANCE/ OPGL/ ODF) was identified by others (H.Yasuda et al., P.N.A.S., 1998 ; D.Lacy et al., Cell, 1998). We then cloned and analyzed of 5-flanking basic promoter region of the mouse RANKL gene and attempted to elucidate the regulatory mechanism of RANKL gene expression in relation to the passage-dependent capability of ST2 cells to support osteoclastogenesis. To assess the expression of genes involved in osteoclastogenesis on the bone tissues, we set up the system of in situ hybridization using decalcified bone specimen. We have presented our data at various international as well as domestic meetings, and publish a lot of scientific papers for academic journals.