Chondrocyte apoptosis and the expression of Bcl-2, Bax, Fas and iNos in articular cartilage in Kashin-Beck disease

OBJECTIVE: To investigate the characteristics of chondrocyte apoptosis and distribution of Bcl-2, Bax, Fas and iNos expressions in articular cartilage in Kashin-Beck disease (KBD). METHODS: Samples of articular cartilage were collected from 15 healthy children and 15 children with KBD diagnosed according to the Pathological Criteria of KBD Diagnosis in China. Chondrocyte apoptosis was detected by TUNEL method, and the articular chondrocytes positive for Bcl-2, Bax, Fas and iNos were stained by B-SA immunohistochemistry. RESULTS: The percentage of apoptotic chondrocytes positively stained by TUNEL in the middle layer of articular cartilage was significantly higher in KBD children than in the control group (33.60%+/-2.71% vs 1.33%+/-0.41%, t=11.59, P<0.01). Significant difference in Bcl-2, Bax, Fas and iNos expressions was observed between the upper, middle and deep layers of the articular cartilage of KBD children (F =73.49-114.42, P<0.01), and staining for Bcl-2, Bax, Fas and iNos in KBD children was prominent in the upper layer (41.93%+/-12.26%, 45.60%+/-15.78%, 53.60%+/-16.49%, and 45.47%+/-14.02%, respectively) and the middle layer (14.93%+/-3.50%, 13.87%+/-4.32%, 23.27%+/-4.83%, and 21.67%+/-6.82%, respectively) of the articular cartilage; the percentages of chondrocytes positively stained for Bcl-2, Bax, Fas and iNos were significantly higher than those of the control group (t=11.75-18.65, P<0.01). CONCLUSION: The percentages of apoptotic chondrocytes and chondrocytes positive for Bcl-2, Bax, Fas and iNos in the articular cartilage of children with KBD are significantly higher than those in healthy children.