基质细胞衍生因子-1对小鼠关节软骨细胞自噬水平的影响

目的：通过研究基质细胞衍生因子-1（stromal derived factor?1, SDF?1）对小鼠关节软骨细胞自噬的影响，探讨SDF?1在骨性关节炎中的作用及机制。方法分离并体外培养小鼠关节软骨细胞，分别予以0、1、10、100、1000μg/L浓度的五组重组SDF?1蛋白干预24 h。运用RT?PCR检测各组细胞的微管相关蛋白1轻链3（microtubule associated protein 1 light chain 3, LC3）和UNC?51样激酶复合物1（uncoordinated?51 like kinase 1, ULK1）mRNA表达情况，运用Western Blot方法检测LC3?Ⅱ、LC3?Ⅰ、ULK1及泛素连接蛋白62（ubiquitin?binding protein p62, p62）蛋白表达水平，通过透射电镜观察自噬溶酶体。结果 RT?PCR结果显示10、100、1000μg/L浓度条件下LC3、ULK1的mRNA水平明显高于对照组，且差异具有统计学意义（P＜0.05）。Western Blot结果显示1、10、100、1000μg/L的各组细胞的LC3?Ⅱ/LC3?Ⅰ比值、ULK?1表达水平较对照组升高，p62蛋白表达水平较对照组明显降低，差异具有统计学意义（P＜0.05）。透射电镜结果显示经SDF?1干预后，自噬溶酶体较对照组增多，差异具有统计学意义（P＜0.05）。结论 SDF?1可诱导小鼠关节软骨细胞自噬的发生，SDF?1可能通过调节软骨细胞自噬水平参与了骨性关节炎的进展。

Effect of stromal derived factor-1 on autophagy level of articular chondrocyte in mice

Objective To investigate the effect of stromal derived factor?1 (SDF?1) on autophagy level of articular chondrocyte in mice and to explore the effect and mechanism of SDF?1 in osteoarthritis. Methods The articular chondrocytes were obtained from 3?to 4?days?old C57BL/6 mice, cultured in vitro, and treated by recombinant SDF?1 protein for 24 h. The concentrations of SDF?1 were 0, 1, 10, 100 and 1 000μg/L respectively. The mRNA levels of LC3 and ULK1 were detected by the real?time polymerase chain reaction (RT?PCR). The expression levels of LC3?Ⅱ, LC3?Ⅰ,ULK1 and p62 proteins were examined by Western Blot. Results After chondrocytes were treated with SDF?1 of 10, 100 and 1 000 μg/L, the mRNA expression levels of LC3 and ULK1 were up?regulated as compared with control group. The ratio of LC3?Ⅱto LC3?Ⅰand the expression of ULK?1 protein were increased, and the expression of p62 protein was reduced in SDF?1?treated groups (1, 10, 100 and 1 000μg/L) as compared with control group (P<0.05 for all). Transmission electron microscopy revealed that as compared with control group, autophagic lysosomes were increased significantly after chondro?cytes were treated with SDF?1 (P<0.05). Conclusion SDF?1 can induce autophagy of articular chondrocytes in mice. SDF?1 maybe participate the progress of osteoarthritis through regulating autophagy level of articular chondrocyte.