小凹蛋白1对氧化型低密度脂蛋白诱导RAW 264.7巨噬细胞衰老的影响

摘要

目的 探讨小凹蛋白1(caveolin-1)对氧化型低密度脂蛋白(oxLDL)诱导RAW 264.7细胞衰老的影响及可能机制.方法 不同浓度oxLDL(0、20、40、80和120 μg/ml)诱导RAW 264.7细胞衰老,依次为A、B、C、D和E组,检测细胞中caveolin-1的变化.通过RNA干扰(siRNA)的方式下调细胞caveolin-1表达,分为oxLDL组、质粒对照组、siRNA组和无血清对照组,观察oxLDL(60 μg/ml)诱导的RAW 264.7细胞衰老的影响,同时Western blot检测p47phox在膜蛋白中的表达,细胞上清液中丙二醛含量、超氧化物歧化酶(SOD)活性.结果 C、D和E组较A组细胞衰老阳性率增加(P＜0.05),同时caveolin-1表达增加,与p47phox表达增加一致,与oxLDL组比较,siRNA组细胞衰老活性率减少(P＜0.05),细胞膜p47phox表达下降,细胞上清液丙二醛含量明显下降[(7.12±1.26)nmol/ml vs (11.97±1.78) nmol/ml,P＜0.05],SOD活性明显增加[(79.98±3.94)U/ml vs (50.03±6.57) U/ml,P＜0.05].结论 caveolin-1可能通过氧化应激影响oxLDL诱导巨噬细胞的衰老过程,从而影响衰老相关性动脉粥样硬化过程.%Objective To study the effect of caveolin-1 on oxLDL-induced aging of RAW 264.7 macrophages and its mechanism.Methods The aging of RAW 264.7 macrophages was induced with oxLDL (at the concertrations of 20 μg/ml,40 μg/ml,80 μg/ml and 120 μg/ml).Cavevolin-1 protein in RAW 264.7 macrophages was assayed.Expression of cavevolin-1 was detected by interfering RNA.Effect of caveolin-1 on oxLDL (60 μg/ml)-induced aging of RAW 264.7 macrophages was observed.Exprcssion level of p47phox in membrane protein,MDA level in supernatant of RAW 264.7 macrophages,and activity of SOD were measured.Results The aging of RAW 264.7 macrophages and the expression level of caveolin-1 protein in RAW 264.7 macrophages and that of p47phox in membrane protein increased with the increasing oxLDL concentration.The number of aging RAW 264.7 macrophages was less and the expression level of p47phox in membrane protein and the MDA level in supernatant of RAW 264.7 macrophages were lower (7.12± 1.26nmol/mlvs 11.97±1.78 nmol/ml,P＜0.05) while the activity of SOD was higher (79.98±3.94 U/ml vs 50.03 ±6.57 U/ml,P＜0.05) after the expression of caveolin-1 was interfered with RNA than before the expression of caveolin-1 was interfered with RNA.Conclusion Caveolin-1 affects oxLDL-induced aging of RAW 264.7 macrophages by regulating oxidative stress and aging-related atherosclerosis.