表面活性蛋白-A对脂多糖诱导的人肾小管近曲上皮细胞白介素-6表达的影响

目的：探讨表面活性蛋白-A（SP-A）的表达改变对脂多糖（LPS）诱导的人肾小管近曲上皮细胞（HK-2细胞）白介素-6（IL-6）表达的影响及机制。方法培养HK-2细胞，ELISA方法检测不同浓度的LPS（0、0．1、1、2、5、10 mg／L）作用8 h及5 mg／L的LPS于不同时间（0、2、4、8、16、24 h）作用HK-2细胞后IL-6蛋白表达的变化；应用脂质体转染法将SP-A SiRNA转染入HK-2细胞，筛选稳定转染细胞株，采用5 mg／L的LPS刺激SP-A SiRNA稳定转染的HK-2细胞8 h，ELISA方法检测细胞上清中IL-6的分泌量，Western印迹检测细胞NF-κB p65蛋白的表达。结果应用1、2、5、10 mg／L的LPS刺激HK-2细胞8 h后，IL-6蛋白表达水平较0、0．1 mg／L的LPS刺激后显著升高（P＜0．05）；同时，应用5 mg／L的LPS作用HK-2细胞4、8、16、24 h后，IL-6蛋白的表达水平较5 mg／L的LPS作用0、2 h显著升高（P＜0．05）。SP-A SiRNA转染的HK-2细胞经LPS刺激后，其NF-κBP65和IL-6蛋白表达较未转染经LPS刺激细胞明显升高（P＜0．05）。结论 SP-A可能通过抑制NF-κB p65的表达进而下调LPS诱导的HK-2细胞IL-6的表达，在脓毒症急性肾损伤时发挥保护作用。

Effects of surfactant protein A on lipopolysaccharide-induced interleukin-6 expression in human renal tubular epithelial cells

Objective To evaluate the effects and mechanisms of surfactant protein A（SP A）onlipopolysaccharide（LPS） induced interleukin 6（IL 6）expression in human renal tubular epithelial（HK 2）cells.Methods Cultured HK 2 cells were treated with various concentrations of LPS（0,0.1,1,2,5and 10 mg/L）for 8 h,and 5 mg/L of LPS at different time point（0,2,4,8,16 and 24 h）,and the changeof IL 6 expression was tested by the ELISA method.Then HK 2 cells were transfected with SP A siRNA.Stable transfected HK 2 cells were screened and stimulated with LPS（5 mg/L）for 8 h and NF kB P65 ex pression was evaluated by Western blot.Results The levels of IL 6 expression in HK 2 cells treated with1,2,5 and 10 mg/L of LPS were higher than these cells treated with 0 and 0.1 mg/L of LPS.After the 5mg/L of LPS treatment for 4,8,16 and 24 h,their IL 6 levels IN HK 2 cells were higher than these cellstreated for 0 and 2 h.Compared with those non transfected LPS treated HK 2 cells,the expressions of NF kB P65 and IL 6 in the transfected cells were elevated significantly（P 〈0.05）.Conclusion By inhibi ting the expression of NF kB P6,SP A may down regulate LPS induced IL 6 expression in HK 2 cells,which plays a protective role in sepsis and acute kidney injuries.