白藜芦醇对实验性兔骨关节炎软骨细胞凋亡及bcl-2 bax表达的影响

目的 研究白藜芦醇对兔实验性骨关节炎(OA)软骨细胞凋亡及凋亡调控基因bcl-2、bax表达的影响,探讨其治疗OA的机制.方法 30只新西兰大白兔随机平分为5组,A组(健康对照组)、B组(模型对照组)、C组(白藜芦醇高剂量干预组)、D组(白藜芦醇中剂量干预组)、E组(白藜芦醇低剂量干预组).除A组外,其他各组均以Hulth法复制膝OA模型.术后第4周开始,A组、B组每天以5 ml含0.1%二甲基亚砜的蒸馏水灌胃;白藜芦醇干预各组每天以相应剂量白藜芦醇溶液(浓度为60 mg/ml)灌胃,C、D、E组日剂量分别为120、60、30mg·kg-1·d-1,连续6周.第10周处死大白兔,取右膝关节股骨内髁内侧软骨,软骨组织切片用脱氧核糖核苷酸末端转移酶介导的缺口末端标记(TUNEL)法观察软骨细胞凋亡,免疫组织化学法观察软骨细胞bcl-2和bax的表达.结果 ①模型对照组关节软骨细胞凋亡率明显高于健康对照组;白藜芦醇干预各组可不同程度地降低OA软骨细胞凋亡率,差异有统计学意义(P＜0.05),且呈剂量依赖性.②与健康对照组相比,模型对照组关节软骨细胞bcl-2和bax阳性率均升高(P＜0.01),bcl-2/bax的比值降低;白藜芦醇干预后,bcl-2阳性率升高更为明显(P＜0.01);而bax阳性率有不同程度降低(P＜0.01);bcl-2/bax的比值均不同程度提高(P＜0.01).结论 白藜芦醇通过上调bcl-2的表达,下调bax的表达,提高bcl-2/bax的比值,以抑制兔实验性OA中软骨细胞的过度凋亡,达到保护软骨,防治OA的目的 .

Effect of resveratrol on apoptosis and expression of bal-2 and bax protein in articular chondrocytes of experimental osteoarthritis model

Objective To observe the effect of resveratrol on the apoptosis and expressions of bal-2 and bax protein in articular chondrecytes of rabbits experimental osteoarthritis (OA) model,and further explore the mechanisms of resveratrol in the treatment of OA.Methods Thirty Newzealand rabbits were randomly divided into 5 groups：group A (normal control group),group B (model control group),group C (resveratrol intervention high dosage group),group D(resveratrol intervention middle dosage group),group E (resveratrel intervention low dosage group).The model of OA was established with Hulth's modeling method in group B,C,D,E.Four weeks later,groups A and B received intragastric administration of distilled water containing 0.1% DMSO daily and group C,D,E received intragastric administration of resveratrol solution daily (concentration was 60 mg/ml) in different dosages for 6 weeks.Daily dosages of group C,D,E were 120,60,30 mg·kg-1·d-1,respectively.Then the rabbits were sacrificed and the cartilage sections of right femoral medial condyle were analyzed by immunohistochemistry for bcl-2 and bax,TUNEL for apoptosis.Results ① The apoptosis rates of chondrocytes in group B,C,D,E were significantly higher than those in group A (P＜0.01).The apoptosis rates of chandrocytes in group C,D,E were decreased compared with those in group B (P＜0.05).②The positive rates of bcl-2 and bax expression in chondrocytes in group B were significantly higher than those in group A (P＜0.01),but the ratio of the positive rate of bcl-2 expression to that of bax in group B was lower than that in group A (P＜0.01).The positive rates of bcl-2 expression in chondrocytes in group C,D,E were much higher compared with those in group B (P＜0.01).The positive rotes of bax expression in chondrocytes in group C,D,E were lower compared with those in group B (P＜0.01).The ratio of the positive rate of bcl-2 expression to that of bax was increased in group C,D,E compared with group B (P＜0.01).Conclusion Resveratrol can suppress the excessive apoptosis of chondrocytes in experimental OA by up-regulating the expression of bcl-2 while down-regulating the expression of bax and improving the ratio of bcl-2 to bax .Suppressing the excessive apoptosis of chondrocytes in experimental OA may be one of the mechanisms for resveratroi's effect in the treatment of osteoarthritis.