生长板软骨细胞对骨髓基质干细胞体外分化的影响

The effects of growth plate chondrocytes on differentiation of bone marrow stromal cells in vitro

目的观察大鼠骨髓基质干细胞(BMSCs)在与大鼠生长板软骨细胞体外共培养条件下,BMSCs碱性磷酸酶(ALP)活性变化及成骨分化的标志骨钙素与Ⅰ型胶原mRNA水平表达的影响,从而认识生长板软骨细胞旁分泌作用对BMSCs分化的影响,以期帮助认识生长板损伤后骨桥形成的发生机制。方法大鼠BMSCs在与生长板软骨细胞进行间接共培养,并设阴性对照。测定ALP活性,用RT-PCR方法,检测Ⅰ型胶原与骨钙素mRNA的表达。结果BMSCs随共培养时间的延长,ALP活性明显升高,Ⅰ型胶原mRNA表达丰度明显高于对照组,骨钙素mRNA在对照组中几乎未见PCR扩增产物,共培养组在终末期则有一定的表达。结论BMSCs在与大鼠生长板软骨细胞体外共培养后,出现成骨分化倾向:随时间延长效应愈加显著,提示生长板软骨细胞的旁分泌作用可以促进BMSCs向成骨分化。

Objective To investigate the effects of the alkaline phosphatase (ALP) activity and the mRNA expression of osteocalcin and type Ⅰ collagen as the marker on osteogenic differentiation of bone marrow stromal cells (BMSCs) co-cultured with physeal plate chondrocytes in vitro, and to explore the mechanism of bone bridge formation after physeal injury. Methods BMSCs and physeal plate chondrocytes were co-cultured indirectly. The negative control was set up. The value of ALP was measured twice every week. mRNA expression of osteocalcin and type Ⅰ collagen were evaluated with RT-PCR technique. Results The ALP value of BMSCs co-cultured increased obviously as the time passed and mRNA expression of type Ⅰ collagen was higher and increased time-dependently. mRNA expression of osteocalcin was almost undetectable in the control group, but in the co-culture group it was relatively higher. Conclusions BMSCs co-cultured with physeal plate chondrocyte display a tendency of osteogenic differentiation with time-dependent increase of ALP and mRNA expression of osteocalcin and type Ⅰ collagen. This implies that the paracrine of plate chondrocytes can promote osteogenic differentiation of BMSCs.