中文摘要：

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。

英文摘要：

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.