表面活性蛋白D高表达对脂多糖诱导人肾小管上皮细胞单核细胞趋化蛋白1表达的影响

目的 研究表面活性蛋白D(SP-D)高表达对脂多糖诱导人肾小管上皮细胞（HK-2）单核细胞趋化蛋白1（MCP-1）表达的影响及其机制。 方法 间接免疫荧光、Western印迹及RT-PCR检测SP-D蛋白及mRNA在HK-2细胞内的表达。脂多糖在不同浓度（0、0.1、1、2、5、10 mg/L）作用8 h及5 mg/L脂多糖作用HK-2细胞不同时间（0、2、4、8、16、24 h），采用Western印迹和实时定量PCR检测SP-D表达，ELISA和实时定量PCR检测MCP-1表达。脂质体转染法将pEE14-hSP-D质粒转染HK-2细胞，筛选稳定转染细胞株，Western印迹检测转染后SP-D蛋白表达。采用5 mg/L脂多糖刺激pEE14-hSP-D稳定转染的HK-2细胞8 h，ELISA和实时定量PCR检测HK-2细胞MCP-1表达。 结果 HK-2细胞表达SP-D。脂多糖可诱导MCP-1 mRNA及蛋白表达显著增高（P < 0.05）；并可诱导SP-D mRNA及蛋白表达显著降低（P < 0.05）。转染pEE14-hSP-D质粒使HK-2细胞高表达SP-D，并可下调脂多糖诱导的MCP-1表达（P < 0.01）。 结论 SP-D可通过下调脂多糖诱导的HK-2细胞MCP-1的表达，从而在肾脏炎性反应中起重要作用。

Effect of surfactant protein D overexpression on lipopolysaccharide-induced monocyte chemoattractant protein-1 expression in human renal proximal tubular epithelial cells

Objective To investigate the effect of surfactant protein D (SP-D) overexpression on lipopolysaccharide(LPS)-induced monocyte chemoattractant protein-1(MCP-1) expression in human renal proximal tubular epithelial cells (HK-2) and its mechanism. Methods HK-2 cells were treated with LPS at various concentrations(0, 0.1, 1, 2, 5, 10 mg/L) for 8 h and at 5 mg/L for various time points (0, 2, 4, 8, 16, 24 h). Expression of SP-D was detected by Western blotting and real-time PCR. Expression of MCP-1 was determined by ELISA and real-time PCR. Human SP-D cDNA eukaryotic expression vector pEE14-hSP-D was transfected to HK-2 cells. The changes in transfected cells of SP-D protein were observed by Western blotting. Expression of MCP-1 was detected by ELISA and real-time PCR. Results SP-D was expressed in HK-2 cells. The levels of SP-D protein and mRNA in HK-2 cells were significantly decreased after treatment with LPS (P<0.05). Expression of MCP-1 protein and mRNA was increased remarkably after treatment with LPS (P<0.05). HK-2 cells transfected with pEE14-hSP-D showed up-regulated expression of SP-D. The overexpression of SP-D inhibited the LPS-induced expression of MCP-1(P<0.01). Conclusions SP-D inhibits LPS-induced expression of MCP-1 in HK-2 cells. SP-D may play an important role in the modulation of renal inflammation.