[Correlation of apoptosis of articular chondrocytes in osteoarthritis with degree of cartilage destruction and expression of apoptosis-related proteins: surviving, caspase-3, and Bcl-xl].

OBJECTIVE: To investigate the relationship of chondrocyte apoptosis to cartilage destruction in osteoarthritis (OA).

METHODS: Specimens of cartilage were collected from 20 OA patients and 8 patients with femoral neck fracture during operation. TUNEL method was performed to semi-quantitatively detect the distribution of apoptotic chondrocytes. Immunohistochemistry was used to detect the expression of the apoptosis-associated proteins: surviving (SVV), caspase-3, and apoptosis regulating protein Bcl-2.

RESULTS: Apoptotic chondrocytes were identified in a relatively early phase of cartilage destruction, and correlated positively and significantly with the degree of cartilage degeneration. In contrast, the specimens of normal subjects contained few cells with apoptotic changes (P = 0.000 < 0.05). The TUNRL positive cell rate of the OA group was significantly higher than that of the control group (P = 0.000). Protein expression of SVV was observed in the chondrocytes within the degraded lesions and in the chondrocytes of the superficial layers, and showed a kind of positive correlation with the number of TUNEL-stained cells. The distribution area of caspase-3 was greater than that of SVV, and could be detected in relatively normal cartilage areas. Protein expression of Bcl-xl was not definitely detected in cartilage tissue.

CONCLUSION: The degree of chondrocyte apoptosis is closely related to cartilage destruction. The protein expression of SVV and caspase-3 may reflect the involvement of these proteins in the apoptotic process in the articular chondrocytes in OA.