Factors of Interaction between Osteoblasts and Bone Marrow Cells in Bone Remodeling

本研究旨在通过体外成骨细胞（OB）与骨髓细胞（BM）之间的细胞相互作用现象，揭示成骨细胞的生理性骨重塑机制。从4周龄小鼠长骨中获得的OB （1X10^6细胞），以millicell为分离剂，在CO_2培养箱中共培养14天，BM的数量增加，培养3天后，BM的细胞DNA中明显可见^ 3h -胸腺嘧啶的高掺入。然而，仅培养BM时，BM的数量和^ 3h -胸苷的吸收量并没有增加。经流式细胞术分析，增加的骨髓中含有Mac-1和LFA-1表面抗原。但与BM共培养的obd ALPase活性在培养3天后明显受到抑制，培养5天后ALPase活性降至对照的一半。这些结果清楚地表明，OB和BM对BM细胞中Mac-1和LFA-1阳性细胞的克隆生长以及OB与OB和BM共培养时OB的ALPase的抑制产生了一定的差异因子。提示OB和BM相互作用产生的因子可能调控生理性骨重塑的机制。

The purpose of this investigation was to reveal the physiological bone remodeling mechanism by means of cellular interaction phenomenon between osteoblasts (OB) and bone marrow cells (BM) in vitro.When OB ( 1X10^6 cells) obtained from 4 weeks old mouse long bones were co-cultivated by using millicell as separator in CO_2 incubator for 14 days, the number of BM was increased and the high incorporation of ^3H-thymidine into cellular DNA of BM was markedly recognized after 3 day incubation. However, the number of BM and uptake of ^3H-thymidine into BM did not increase in BM only cultivation. The increased BM were identified to have surface antigens of Mac-1 and LFA-1 by FACS analysis. But, ALPase activity of OBco-cultivated with BM was remarkably suppressed after 3 days incubation and reduced to one half of that of control after 5 days incubation. These results clearly indicated that both OB and BM produced some differential factors of the clonal growth of Mac-1 and LFA-1 positive cells from BM cells and suppression of ALPase of OB in co-cultivation with OB and BM. It was suggested that the factors produced from interaction between OB and BM might regulate the mechanism of physiological bone remodeling.