大骨节病游离体软骨Bcl-2及Caspase-8的表达

Expression of Caspase-8 and Bcl-2 in the cartilage loose bodies in patients with Kashin-Beck disease

目的探讨细胞凋亡及相关调控因子在大骨节病关节游离体形成中的作用机制。方法收集50例成人大骨节病游离体软骨和10例正常对照关节软骨。采用抗生物素蛋白-生物素-碱性磷酸酶(B-SA)免疫组化法染色,观察成人大骨节病游离体软骨和对照组关节软骨Bcl-2、Caspase-8阳性细胞表达率与分布特点。结果 (1)大骨节病游离体软骨细胞Bcl-2及Caspase-8阳性表达率分别为(18.40±8.78)%和(67.54±12.29)%,显著高于对照组关节软骨细胞Bcl-2及Caspase-8阳性表达率[(12.25±1.58)%和(24.70±4.35)%]。(2)Bcl-2与Caspase-8参与了大骨节病游离体软骨细胞的凋亡。(3)Bcl-2与Caspase-8阳性表达细胞主要发生在深层肥大的软骨细胞,或者临近深部骨组织的细胞。结论大骨节病游离体软骨细胞凋亡及相关调控因子Caspase-8及Bcl-2表达显著高于对照组,Caspase-8的促进细胞凋亡作用较Bcl-2的抑制凋亡作用占优势。

Objective To investigate the role of Caspase-8 and Bcl-2 in the formation of loose bodies in Kashin-Beck disease（KBD）.Methods Specimens of cartilage loose bodies were collected from 50 adult patients with KBD,and the samples of articular cartilage were collected from 10 healthy adults to serve as control.Avidin-biotin alkaline phosphatase immunohistochemistry was employed to examine Bcl-2 and Caspase-8 positivities in the chondrocytes in the loose bodies.Results In KBD loose bodies,the percentage of chondrocytes positive for Bcl-2 and Caspase-8 [（18.40±8.78）% and（67.54±12.29）%,respectively] were significantly higher than those of the control group [（12.25±1.58）% and（24.70±4.35）%,respectively].Caspase-8 was found to promote chondrocyte apoptosis in the loose bodies,and this effect overrode the apoptosis-suppressing effect of Bcl-2.Bcl-2 and Caspase-8 positivities were found mainly in the deep hypertrophic chondrocytes in the cartilage or in cells adjacent to the bone tissues.Conclusions KBD loose bodies contain an increased percentage of apoptotic chondrocytes positive for Bcl-2 and Caspase-8.The apoptosis-inducing effect of Caspase-8 was a dominant feature in the cartilage pathology of KBD compared to the apoptosis-suppressing effect of Bcl-2.