中文摘要：

目的探讨Ⅱ型胶原（collagenⅡ）在体外促进大鼠骨髓间充质干细胞（bone mesenchymal stem cells,BMSCs）向软骨细胞的定向分化作用。方法体外培养BMSCs,分不同collagenⅡ接种浓度组（25、50、100、200μg/m L）和空白对照组,分别作用于BMSCs 7、14、21 d,采用CCK-8法检测各不同浓度组对BMSCs活性的影响;q PCR法和免疫荧光法检测不同浓度组处理BMSCs后,各浓度组与空白对照组相比,collagenⅡ、SOX9及aggrecan mRNA及蛋白表达量的差异。结果 1CCK-8检测结果显示各浓度组在7、14、21 d D（450）值差异无统计学意义（P〉0.05）;2q PCR检测结果显示21 d后,不同浓度组与空白对照组比较,collagenⅡ、SOX9及aggrecan mRNA表达量均升高（P〈0.05）,以100μg/m L组最高（P〈0.01）;14 d时,各浓度组collagenⅡ、SOX9及aggrecan mRNA以100μg/m L组上调最明显（P〈0.05）,而在7 d时,各组之间三者mRNA的表达差异无统计学意义（P〉0.05）;3各浓度组21 d时免疫荧光结果显示：在100μg/m LⅡ组collagenⅡ、SOX9及aggrecan mRNA蛋白的表达量较其他各组均明显上调（P〈0.05）。结论 collagenⅡ可在体外促进大鼠BMSCs向软骨细胞分化,其中以100μg/m L组促进作用最为明显。

英文摘要：

Objective To investigate the promotion of type Ⅱ collagen （collagen Ⅱ ） on differentiation of rat bone marrow mesenchymal stem cells （BMSCs） into chondrocytes. Methods BMSCs, seeded with different concentrations of type Ⅱ collagen （25, 50, 100 and 200 μg/mL） and control group, were assessed by CCK-8 assay on days 7, 14 and 21. qPCR and immunofluorescence assay were used to detect the mRNA and protein expression of collagen Ⅱ, SOX9 and aggrecan in different intervention groups. Results CCK-8 assay showed that the cell viability had no significance on days 7, 14 and 21 in different intervention groups （P 〉 0.05 ）. The mRNA expression of collagen Ⅱ , SOX9 and aggrecan was up-regulated on day 21 （P 〈0.05）, especially those in the 100 μg/mL intervention group most significant （P 〈0.01 ）, while the mRNA expression in group of 100 μg/mL was highly up-regulated on day 14 （P 〈 0.05 ）, but there was no significance on day 7, compared with control group （P 〉 0. 05 ）. Immunofluorescence assay results showed that the protein levels of collagen Ⅱ , SOX9 and aggrecan were obviously enhanced in the 100 μg/mL intervention group than the other groups （P 〈 0. 05 ）. Conclusion Collagen 11 promotes rat BMSCs differentiation into chondrocytes in vitro, with the dose of 100 μg/mL having the best efficiency.