摘要目的 探讨Akt信号通路在白蛋白刺激人肾小管上皮细胞(HK-2)分泌单核细胞趋化因子-1(MCP-1)和核因子-κB(NF-κB)表达的作用.方法 体外培养HK-2细胞,分别加入不同质量浓度白蛋白(5,15,30 mg/mL)白蛋白和/或Akt抑制剂Ly294002.应用RT-PCR方法测定MCP-1mRNA表达,Western blot测定Akt和MCP-1蛋白的表达.应用凝胶电泳迁移率(EMSA)检测NF-κB活化.两两比较用q检验.结果 白蛋白呈浓度依赖性上调肾小管上皮细胞MCP-1mRNA表达[对照组:0.233±0.01,BSA组(5 mg/mL):0.285±0.04;BSA组(15 mg/mL):0.387±0.02;BSA组(30mg/mL):0.473±0.05;BSA(30 mg/mL)+Ly294002组:0.325±0.05,P＜0.05].MCP-1蛋白表达也增加[对照组:100±15.1,BSA组(5 mg/mL):148±19.3;BSA组(15 mg/mL):176±20.7;BSA组(30 mg/mL):263±18.1;BSA(30 mg/mL)+Ly294002组:175±18.0,P＜0.05].白蛋白激活NF-κB活性,增加磷酸化Akt表达.Ly294002能够抑制白蛋白引起的NF-κB活性以及MCP-1的表达.NF-κB活化与MCP-1表达呈显著正相关(r=0.68,P＜0.05).结论 白蛋白刺激肾小管上皮细胞分泌MCP-1和NF-κB的活性,其机制部分依赖于Akt的磷酸化作用.

abstractsObjective To investigate the role of Akt signal pathway on the expression of monocyte chemoattractant protein-1 ( MCP-1 ) and nuclear transcription factor-κB (NF-κB) in renal tubular epithelial cells (HK-2) stimulated by albumin and to explore the mechanisms of action. Method The HK-2 cells were incubated in the presence of albumin (5,15,30 mg/mL) with or without Ly294002 (an inhibitor of Akt). Expression of mRNA was analyzed by reverse transcription-polymerase chain reaction (RT-PCR).Expression of Akt and protein MCP-1 were assessed by Western blot. Electrophoretic mobility shift assay (EMSA) was used to detect the activation of NF-κB. q-test was used to evaluate the differences in means between groups. Results Compared with control group, the expression of MCP-1 mRNA remarkly increased. [Control group: 0.233 ±0.01; BSA(5 mg/mL) group: 0.285 ±0.04; BSA( 15 mg/mL) group:0.387 ± 0.02; BSA ( 30 mg/mL) group: 0.473 ± 0.05; BSA ( 30 mg/mL) + Ly294002 group: 0. 325 ±0.05, P ＜ 0.05 ]. The expression of MCP-1 protein in renal interstitum of operation group were remarkly increased too. [ Control group: 100 ± 15.1; BSA ( 5 mg/mL) group: 148 ± 19.3; BSA ( 15 mg/mL) group: 176±20.7; BSA(30 mg/mL) group: 263 ± 18.1; BSA(30 mg/mL) + Ly294002 group: 175 ± 18.0, P ＜0.05 ]. Albumin stimulated the expression of MCP-1mRNA and protein in a dose-dependent manner. Albumin remarkably increased the activity of NF-κB. Albumin enhanced the expression of Akt. Ly294002 inhibited albumin-induced the expression of NF-κB and partially decreased the level of MCP-1. Apositive correlation was noted between NF-κB activation and MCP-1 expression( r = 0.68 ,P ＜ 0.01 ). Conclusions Albumin-induces MCP-1 and NF-κB production via Akt signal pathway in renal tubular epithelial cells.