Reseach Of Apoptosis In Cartilage Cells Of Rabbit Induced By 5-aza-CdR

Objectives To investigate the role of hypomethylation in DNA methylation inhibitor 5-aza-CdR inducing apoptosis in cartilage cells of rabbit in OA.Methods Rabbit cartilage cells were treated with different concentrations of 5-aza-CdR at different time points(1-3d).Cell viability was measured by MTT assay.Apoptosis changes of the treated cells were observed by electron microscropy.The levels of NO in culture media were detected by nitrate reductase method.Nitric oxide synthase(iNOS)and Fas protein were measured by Western blotting assay.The relationship among 5-aza-CdR and NO and Fas was investigated by SPSS statistics assay.Results1.The results shows the dose-dependent and time-dependent effects in cell viability of 5-aza-CdR treated cartilage cells(p＜0.05).2.Apoptosis body was found in 5-aza-CdR-treated cells by electron microscropy.3.The level of NO in culture medium of 5-aza-CdR treated cells were higher than that of normal control.(p＜0.05)4.Overexpressions of iNOS protein were detected in 5-aza-CdR treated cells(p＜0.05),Overexpressions of Fas protein cannot be detected in 5aza-CdR treated cells(p＞0.10). 5.5-aza-CdR induced apoptosis was correlated with the level of NO production and the level of iNOS protein expression(p＜0.05),and had no correlation with Fas protein(p＞0.10).ConclusionsDNA hypomethylation participate in inducing cartilage cells apoptosis by enhancing NO production and the expression of iNOS.