【摘要】 目的:探讨细胞骨架蛋白α-SMA的表达与软骨细胞去分化之间的联系.方法:分离、培养大鼠肋生长板软骨细胞(RGCs),对原代至第5代RGCs进行细胞生长动力学分析,阿尔新兰染色、免疫细胞化学法和蛋白质印迹分别检测蛋白多糖,α-SMA和Ⅱ型胶原的表达.结果:随着传代次数的增加,前3代RGCs的每日倍增指数逐渐增加,随后不断下降.原代RGCs的阿尔新兰和Ⅱ型胶原染色均呈强阳性,仅个别细胞α-SMA弱阳性染色.随着传代次数的增加,阿尔新兰和Ⅱ型胶原阳性染色的细胞比例迅速下降,第3代以后的RGCs阿尔新兰染色均为阴性,第5代RGCs也仅有圆形细胞仍保持了Ⅱ型胶原阳性染色,而α-SMA阳性染色细胞的比例则不断增加.蛋白质印迹所揭示的Ⅱ型胶原和α-SMA蛋白表达的变化趋势与免疫细胞化学染色的结果一致.结论:α-SMA从无到有并随着RGCs去分化程度的增强而增加的表达模式,提示它是引起软骨细胞“去分化”的重要原因.更多还原

【Abstract】 AIM: To investigate the relationship between cytoskeleton α-SMA (alpha-smooth muscle actin) expression and dedifferentiation of chondrocyte. METHODS: Rat costochondral growth plate chondrocytes (RGCs) were isolated and cultured. Growth kinetics of RGCs during serial passage was analyzed, and α-SMA, collagen typeⅡ and GAG expressions of primary to 5th passage RGCs were detected by immunocytochemistry, Western Blot and Alcian blue staining, respectively. RESULTS: With increasing passage number, the index of duplication/day of RGCs rose during the first 3 passages and decreased afterwards. Primary RGCs expressed collagen type Ⅱ and were stained strongly for Alcian blue, and very few RGCs were positive for α-SMA. The percentage of collagen type Ⅱ and Alcian blue positive stained RGCs decreased with increasing passage number. Only the roundish cells of the 5th passage retained positive for collagen typeⅡ, and Alcian blue staining of 3rd passage was negative, while α-SMA positive stained RGCs increased gradually. Western Blot results were consistent with immunocytochemical outcomes. CONCLUSION: As the degrees of RGCs dedifferentiation rise, α-SMA expression increases gradually. The expression pattern of α-SMA suggests that it might be an important factor in inducing chondrocyte dedifferentiation.更多还原