Department of Orthopedic Surgery, Yijishan Hospital, Wannan Medical College, Wuhu, Anhui, China.
Chin Med J (Engl). 2013;126(11):2067-73.
C-Jun N-terminal kinase (JNK) signaling pathway and ankylosis gene (ANK) play a critical role in endplate chondrocytes degeneration. The purpose of this study was to investigate whether the expression levels of ANK was associated with the activation of JNK.
Cartilage endplates of 49 patients were divided into the control group (n = 19) and the experimental group (n = 30). The patients in the control group were graded 0 and those in the experimental group were graded I-III according to Miller's classification. Endplate chondrocytes were isolated by enzyme digestion and cultured in vitro. The inverted phase contrast microscope, teluidine blue staining, HE staining, real time RT-PCR, and MTT were used to observe morphological appearances, biological characteristics, and growth curve of endplate chondrocytes from the cartilage endplate of the two groups. Real time RT-PCR and Western blotting were used to analyze the mRNA and protein expression levels of associated factors in the degeneration process in the cultured endplate chondrocytes with or without subjected SP600125.
The expression levels of type II collagen, aggrecan, and ANK in endplate chondrocytes of experimental group were lower than that of control group and phosphorylation level of JNK in the experimental group which was higher than that in the control group. Application of JNK phosphorylation inhibitor to degeneration chondrocytes resulted in a marked decrease in the phosphorylation level of JNK and a significant increase in the expression levels of type II collagen, aggrecan, and ANK.
The degeneration of the human cervical endplate chondrocytes might be promoted by JNK phosphorylation by down-regulating the expression of ANK.
C-Jun N-末端激酶（JNK）信号通路和骨粘连蛋白（ANK）在终板软骨细胞退变中起关键作用。本研究旨在探讨ANK 的表达水平是否与 JNK 的激活有关。
将 49 例患者的软骨终板分为对照组（n=19）和实验组（n=30）。对照组患者按 Miller 分级分为 0 级，实验组患者分为 I-III 级。采用酶消化法分离软骨终板细胞，体外培养。倒置相差显微镜、甲苯胺蓝染色、HE 染色、实时 RT-PCR 和 MTT 观察两组软骨终板细胞的形态学表现、生物学特性和生长曲线。实时 RT-PCR 和 Western blot 分析培养的软骨终板细胞中相关因子在退变过程中的 mRNA 和蛋白表达水平。
实验组软骨终板细胞中 II 型胶原、聚集蛋白聚糖和 ANK 的表达水平低于对照组，实验组 JNK 的磷酸化水平高于对照组。用 JNK 磷酸化抑制剂处理退变软骨细胞后，JNK 的磷酸化水平显著降低，II 型胶原、聚集蛋白聚糖和 ANK 的表达水平显著升高。
通过下调 ANK 的表达，JNK 磷酸化可能促进人颈椎终板软骨细胞的退变。
