Effects of stromal cell-derived factor-1 on the proliferation and apoptosis of articular chondrocytes in rabbits

Abstract

Objective To observe the effect of stromal cell-derived factor-1 (SDF-1) on the proliferation of articular chondrocytes in rabbits and discuss the role of SDF-1 in chondrocyte apoptosis.Methods The chondrocytes were isolated and cutured,then divided into 4 groups:control group,50 μg/L SDF-1 group,50 μg/L SDF-1 + 5 mg/L CXC chemokine receptor-4 specific antagonist (AMD3100) group,and 5 mg/L AMD3100 group.The MTT assay and methods for cell cycle were used to observe the proliferation of chondrocytes.In addition,each group was exposured to the condition of 250 μmol/L hydrogen peroxide.Then cell viability was detected by using trypan blue exclusion assay,apoptosis rate of chondrocytes was detected by using flow cytometry,and the dynamic changes of Caspase-3 were measured in each group.Furthermore,the apoptosis of chondrocytes was evaluated by TdT-mediated dUTP nick end labeling (TUNEL) assay.Results The absorbance value of SDF-1 set (0.504 ±0.024) was higher than other groups,and the S +G2/M cell ratio in SDF-1 group was higher than other groups with the differnce bing statistically significant (all P ＜0.05).In terms of apoptosis,the viable rate in SDF-1 group was higher than other groups (P ＜ 0.01),while the Annexin V-FITC (+) proportion of cartilage cells in the SDF-1 group (4.00 ± 0.92) ％ was lower than other groups (P ＜ 0.05).Caspase-3 activity in SDF-1 group [(40.03 ± 2.56) nmolpNA/(h·mg) protein] was lower than other groups (P ＜0.01),and in addition,the number of apoptotic cells in SDF-1 group was less than other groups (P ＜ 0.05),but there was no significant difference among control group,SDF-1 + AMD3100 group and AMD3100 group in all experiments.Conclusion SDF-1 could contribute to the proliferation of rabbit chondrocytes in vitro,and in 50 μg/L group the Proliferation activity is reasonable,meanwhile SDF-1 can protect the chondrocytes from apoptosis induced by hydrogen peroxide. Key words: Stromal cell-derived factor-1 ; Apoptosis; Proliferation; Chondrocyte; Rabbit