地塞米松磷酸钠对体外培养关节软骨细胞增殖的影响

背景:研究表明,地塞米松可以使关节软骨表层基质中的Ⅱ型胶原减少,Ⅰ型胶原增多,但糖皮质激素对关节软骨细胞增殖作用的机制尚不十分清楚.目的:验证地塞米松磷酸钠对体外培养兔关节软骨细胞增殖的影响.设计:对比观察.材料: 1月龄新西兰白兔用于软骨细胞的分离与培养.方法:兔关节软骨细胞常规培养后随机分为对照组和实验组,对照组用不含地塞米松磷酸钠的DMEM培养液培养,实验组则分别加入含不同质量浓度地塞米松磷酸钠(0.02,0.1,0.5 g/L)的DMEM培养液.主要观察指标:①原代及传代兔关节软骨细胞的形态学观察.②应用流式细胞术及免疫细胞化学法检测软骨细胞增殖及其合成Ⅱ型胶原能力.③透射电子显微镜观察软骨细胞超微结构的变化.结果:实验组软骨细胞贴壁、增殖较对照组缓慢.各实验组Ⅱ型胶原平均灰度值均显著高于对照组(P<0.05).实验组软骨细胞进入S期、G_2+M期的细胞比率较对照组软骨细胞减少、进入G_0/G_1期的细胞比率增加.电镜下见软骨细胞线粒体、粗面内质网数量减少.结论:地塞米松磷酸钠抑制软骨细胞的增殖,可能与抑制关节软骨细胞Ⅱ型胶原和蛋白的合成能力有关.

Effects of dexamethasone sodium phosphate on the proliferation of in vitro cultured rabbit articular chondrocytes

BACKGROUND: Studies have demonstrated that dexamethasone can reduce type Ⅱ collagen and increase type I collagen in articular cartilage surface matrix, but the action mechanism of glucocorticoid to articular chondrocyte proliferation remains unclear. OBJECTIVE: To investigate the effects of dexamethasone sodium phosphate on rabbit articular chondrocytes cultured in vitro. DESIGN: Comparative observation.MATERIALS: New Zealand rabbits, 1 month old, were used for chondrocyte isolation and culture.METHODS: Rabbit articular chondrocytes cultured in vitro were randomly divided into control and experimental groups. Cells of the control group were cultured in DMEM media without dexamethasone sodium phosphate. Cells of experimental groups were cultured in DMEM media with different concentrations of dexamethasone sodium phosphate (0.02, 0.1, 0.5 g/L), respectively. MAIN OUTCOME MEASURES: Primary and passage chondrocytes were observed. Flow cytometry and immunocytochemistry were used to observe the effect of dexamethasone sodium phosphate on cell proliferation and type Ⅱ collagen synthesis. The ultrastructural changes of cultured chondrocytes were observed by transmission electron microscopy. RESULTS: The attachment and proliferation of experimental group chondrocytes was slower than control group. There average gray scale values of the experimental groups were significantly greater than the control group (P < 0.05). The cellular proportions of S phase and G_2+M phase of the experimental groups decreased but the cellular proportions of G0/G1 period increased. Under transmission electron microscope the amount of rough endoplasmic reticulum and mitochondria of the experimental groups decreased. CONCLUSION: Dexamethasone sodium phosphate inhibited articular chondrocyte proliferation, possibly due to the decrease of type Ⅱcollagen and protein synthesis ability of chondrocyte.