DC-SIGN/TLR4调控肾小管上皮细胞炎症反应研究  

DC-SIGN/TLR4 regulate inflammatory response in renal tubular epithelial cells

作　　者：刘昕訸[1] 刘艳[2] 曹丽娟[2] 罗茂财 周思源[1] 蔡敏超[3] 杨克[2] 许春娣[1] 周同[1] 

机构地区：[1]上海交通大学医学院附属瑞金医院儿科,上海200025 [2]上海交通大学医学院附属瑞金医院心内科,上海200025 [3]上海交通大学附属第一人民医院肾内科,上海200080

出　　处：《现代免疫学》2015年第4期265-270,共6页Current Immunology

基　　金：国家自然科学基金项目(81070567;81270801;81470941;81200508)

摘　　要：探讨肾小管上皮细胞天然免疫分子DC-SIGN与TLR4相互作用,以及对肾小管上皮细胞炎症反应的调控影响。采用免疫组化检测慢性肾炎患者肾组织DC-SIGN及TLR4表达;体外培养肾小管上皮细胞株(HK-2)并经LPS刺激,采用免疫共沉淀实验和荧光免疫组化检测DC-SIGN与TLR4结合及细胞表面共定位状况;ELISA检测经转染DC-SIGN siRNA后HK-2分泌IFN-β、TNF-α的变化,以及western blot检测TLR4信号通路中IKKε、p38、JNK及NF-κB的磷酸化水平。结果显示,慢性肾炎患者肾小管上皮细胞均显著表达DC-SIGN及TLR4,利用HK-2模拟炎症状态给予LPS刺激后,DCSIGN与TLR4可发生相互结合并共定位于细胞表面,且HK-2明显分泌炎症因子IFN-β、TNF-α,这一状况可被经转染DC-SIGN siRNA后予以抑制,且发现在此状态下TLR4-MyD88依赖途径信号分子p38、JNK磷酸化水平则显著上升,而TLR4-MyD88非依赖途径的IKKε、NF-κB磷酸化水平无明显变化。结果表明,肾小管上皮细胞炎症状态下可通过表达DC-SIGN,并与TLR4结合且相互作用,促进炎症因子分泌,从而调节肾小管上皮细胞炎症反应。提示可能与DC-SIGN和TLR4发生信号串话,并调控TLR4-MyD88非依赖途径有关。The interaction between the innate immune molecules DC-SIGN and TI.R4 in renal tubular epithelial cells, as well as its regulation on the inflammatory response of renal tubular epithelial cells were investigated in this study. The expression of DC SIGN and TLR4 was observed by immunohistoehemistry in renal tissues of the patients witb chronic nephritis. Tubular epi thelial cells （HK-2） were cuhured in vitro with LPS. Co- and immunofluorescenee were conducted to detect the combination of DC SIGN and TLR4. Besides, DC-SIGN transfected with siRNA was investigated in order to observe the changes of IFN-β and TNF-α. The phosphorylation levels of IKKε, p38, JNK and NF-κB in TLR4-related signaling pathways was detected by West ern Blot. The results showed that the expression of DC-SIGN and TLR4 was significantly up-regulated in renal tubular epithelial cells from patients with chronic nephritis. This effect bad been confirmed by simulating HK-2 cells with LPS in vitro. Upon LPS stimulation, DC-SIGN and TLR4 can combined, and after transfection of DC-SIGN siRNA , secretion of IFN-β and TNF-α was inhibited. Under this condition MyD88-independent pathway signaling molecules IKKε and NF-κB phosphorylation levels had no significant change, while the MyD88 dependent pathway signaling molecules p38 and JNK phosphorylation levels in creased obviously. These results suggest that in the mechanism of chronic nephritis, renal tubular epithelial cells trans-differen tiated via expressing DC SIGN, and with the combination of DC SIGN and TLR4, renal tubular epithelial cells can promote the secretion of inflammatory factors so as to adjust inflammatory response of renal tubular epithelial cells. It is suggested that DC-SIGN has signal crosstalk with TLR4, and this may relate to the regulation and control of the MyD88 independent pathway.

关 键 词：肾小管间质炎症 肾小管上皮细胞 DC-SIGN TLR4 信号串话 

分 类 号：R392.11[医药卫生—免疫学]