Chondrocyte apoptosis in articular cartilage with Kashin-Beck disease

Objective: To investigate the apoptosis of articular chondrocyte and the expression of Bcl-2, Bax, Fas and iNos in articular cartilage with Kashin-Beck disease (KBD) in order to understand the pathogenesis of chondronecrosis in KBD. Methods: The collected samples of human articular cartilage were divided into two groups: control group (15 samples from 15 cases), KBD group (15 samples from 15 cases). KBD patients were diagnosed by "Pathological Criteria to Diagnose KBD in China". Chondrocyte apoptosis was detected by TUNEL staining, and the Bcl-2, Bax, Fas and iNos positive articular chondrocytes were stained by the B-SA of immunohistochemistry. Articular cartilage was classified three zones and the positive rate were counted by light microscope for cytoplasimic staining by polyclonal antibodies of Bcl-2, Bax, Fas and iNos and apoptotic chondrocytes by TUNEL. Results: 1 The percentage of positive apoptotic chondrocytes stained by TUNEL in the middle zone of articular cartilage from the KBD-children group(33.60±2.71%) was higher than that of the control (1.33±0.41% r=11.59, g=28, P<0.01). 2 The percentage of chondrocytes staining for Bcl-2, Bax, Fas and iNos among the upper and the middle zone in KBD group were significantly higher than that of the control (t=11.75-18.65, g=14, P<0.01); the remarkable difference in the expression of Bcl-2, Bax, Fas and iNos among the upper, the middle and the deep zones was also seen in KBD articular cartilage (F=73.49-114.42, g=42, P<0.01), and staining for Bcl-2, Bax, Fas and iNos in KBD children was prominent in the upper zone (41.93±12.26%, 45.60±15.78%, 53.60±16.49%, 45.47±14.02%) and the middle zone(14.93±3.50%, 13.87±4.32%, 23.27±4.83%, 21.67±6.82%) of articular cartilage, respectively. Conclusion: The chondrocyte apoptosis and the present of Bcl-2, Bax, Fas and iNos positive chondrocytes in articular cartilage of children with KBD were significantly higher than that of the control.