Xu Hong-guang, Yang Ming, Wang Hong, Jin Song, Chen Xue-wu, Wang Ling-ting
Department of Orthopedic Surgery, Yijishan Hospital, Wannan Medical College, Wuhu 241001, China.
Zhonghua Yi Xue Za Zhi. 2010 May 4;90(17):1192-6.
To observe the expression change of ANK protein in normal and degenerative vertebral endplate chondrocytes and explore the correlation between ANK gene expression and intervertebral disc degeneration.
Cartilaginous endplates of 45 patients were divided into experiment group (28 with cervical spondylotic myelopathy including 17 males and 11 females) and control group (17 with fracture or dislocation of cervical spine including 10 males and 7 females). The MRI examinations revealed that all the endplate in control group were grade 0 and grade I-III in experiment group according to Miller's classification. Pathological examination demonstrated that intervertebral discs were grade I in control group and grade III-V in experiment group according to Thompson's classification. The morphological appearances and calcification of cartilaginous endplates were observed by HE and Von kossa staining. Immunohistochemical SABC staining, RT-PCR and Western blot were used to detect the ANK mRNA and protein expression in chondrocytes.
More calcium deposit could be observed in the experiment group than in the control group by Von kossa staining. ANKH protein was found positive in cell membrane of chondrocytes. Compared with chondrocytes of control group, the expression of ANK mRNA in experiment group markedly decreased (P < 0.05). And the level of ANK protein expression decreased too (P < 0.05).
Following the degeneration of cartilaginous endplate, the intervertebral disc degeneration worsened and the expression level of ANK decreased in vertebral endplate chondrocytes. Also calcification is positively correlated with the degree of intervertebral disc degeneration. Modulating the expression of ANK in endplate chondrocytes may be a new approach to treat the degeneration of intervertebral disc.
观察ANK蛋白在正常及退变椎体终板软骨细胞中的表达变化，探讨ANK基因表达与椎间盘退变之间的相关性。
将45例患者的软骨终板分为实验组（28例脊髓型颈椎病患者，其中男性17例，女性11例）和对照组（17例颈椎骨折或脱位患者，其中男性10例，女性7例）。MRI检查显示，根据Miller分级，对照组所有终板为0级，实验组为I - III级。病理检查显示，根据Thompson分级，对照组椎间盘为I级，实验组为III - V级。采用HE染色和Von kossa染色观察软骨终板的形态及钙化情况。运用免疫组织化学SABC染色、RT - PCR及Western blot检测软骨细胞中ANK mRNA及蛋白表达。
Von kossa染色显示实验组钙盐沉积多于对照组。ANKH蛋白在软骨细胞膜呈阳性表达。与对照组软骨细胞相比，实验组ANK mRNA表达明显降低（P < 0.05），ANK蛋白表达水平也降低（P < 0.05）。
随着软骨终板退变，椎间盘退变加重，椎体终板软骨细胞中ANK表达水平降低，且钙化与椎间盘退变程度呈正相关。调节终板软骨细胞中ANK的表达可能是治疗椎间盘退变的新途径。
