HDL和阿托伐他汀对oxLDL刺激下脂肪细胞炎症反应的影响

摘要

目的 观察高密度脂蛋白(HDL)及阿托伐他汀对氧化型低密度脂蛋白(oxLDL)刺激下3T3-L1脂肪细胞肿瘤坏死因子-α(TNFα)分泌及mRNA表达的影响,并探讨其可能的作用机制.方法 3T3-L1脂肪细胞促分化成熟后,oxLDL刺激脂肪细胞,给予不同浓度的HDL(10～100 μg/mL)和阿托伐他汀(0.1～10 μM),及H-89(10 μM)+HDL(100 μg/mL)干预,收集细胞,测定脂肪细胞TNFα水平、TNFα mRNA表达水平、核因子-κB(NF-κB)活性及NF-κB抑制单位(IκB)蛋白浓度.结果 oxLDL刺激使3T3-L1脂肪细胞TNFα分泌、mRNA表达水平及NF-κB活性明显增强.阿托伐他汀浓度依赖性降低TNFα 分泌及mRNA表达,抑制NF-κB活化.10 μM阿托伐他汀使oxLDL诱导的脂肪细胞TNFα mRNA表达降低56.5%,NF-κB活性减少41.2%.HDL也呈浓度依赖性抑制TNFα分泌及mRNA表达,降低NF-κB活性,减少IκB降解.与oxLDL刺激组比较,100 μg/ml HDL使TNFα mRNA表达降低64.5%,NF-κB活性减少49%,并明显增加IκB蛋白水平.HDL的这些抗炎效应能被蛋白激酶A(PKA)抑制剂(应放在H89第一次出现之处)H-89部分抑制.结论 HDL能抑制oxLDL诱导的3T3-L1脂肪细胞TNFα分泌和mRNA表达,PKA-IκB-NF-κB信号通路可能是其中作用途径之一,该效应不需要HDL与oxLDL的直接接触作用.阿托伐他汀亦通过NF-κB途径抑制oxLDL诱导的3T3-L1脂肪细胞TNFα分泌和mRNA表达.HDL的抗炎作用强度与阿托伐他汀相似.%Objective To observe high density lipoprotein ( HDL ) and atorvastatin on the secretion and mR-NA expression of tumor necrosis factor-α ( TNF-α ) in 3T3-L1 adipocytes stimulated by oxidized low density lipoprotein ( oxLDL), and discuss the possible mechanism. Methods After differentiating and maturing, T3-L1 adipocytes were stimulated by oxLDL and given different doses of HDL ( 10-100 μg/mL ) and atorvastatin ( 0. 1-10 μM ), and then intervened with H-89 [ the inhibitor of protein kinase A ( PKA ), 10 μM ] and HDL ( 100 μg/mL ). 3T3-L1 adipocytes were collected for detecting TNF-α level, expression of TNF-α mRNA, activity of nuclear factor-kappa B ( NF-kB ) and protein concentration of NF-kB inhibition unit-IκB. Results The stimulation of oxLDL improved significantly the secretion of TNF-α, expression of TNF-α mRNA and activity of NF-kB in 3T3-L1 adipocytes. Atorvastatin reduced the secretion of TNF-α, expression of TNF-α mRNA and activation of NF-kB in a dose-dependent manner. Atorvastatin in the dose of 10 μM reduced the expression of TNF-α mRNA by 56. 5% and activity of NF-kB by 41. 2% . HDL also inhibited the secretion of TNF-α, expression of TNF-α mRNA and activity of NF-kB, and reduced the degradation of IκB in a dose-dependent manner. Compared with the stimulation of oxLDL, HDL in the dose of 100 μg/mL reduced the expression of TNF-α mRNA by 64. 5% , activity of NF-kB by 49% and increased significantly protein level of IκB. The anti-inflammatory effect of HDL could be partially inhibited by H-89. Conclusion HDL can inhibit the secretion of TNF-α and expression of TNF-α mRNA induced by oxLDL in 3T3-L1 adipocytes, and the signal pathway of PKA-IκB-NF-κB maybe one of its function ways, in which HDL and oxLDL have no any contact. Atorvastatin inhibits the secretion of TNF-α and expression of TNF-α mRNA induced by oxLDL in 3T3-L1 adipocytes through NF-κB pathway. The intensity of anti-inflammatory effect of HDL is similar to that of atorvastatin.