摘要
目的探讨A型清道夫受体(SR-A)在人肾小球系膜细胞中的表达功能和受体特异性。方法采用脂质体转染法,将人SR-A cDNA转染入人肾小球系膜细胞,建立稳定高水平表达SR-A的人肾小球系膜细胞系(HMC-SCR)。RT-PCR法检测SR-A mRNA的表达,使用免疫荧光法、油红“O”细胞化学染色及激光共聚焦显微镜检测HMC-SCR对配体氧化低密度脂蛋白(Ox-LDL)和乙酰化低密度脂蛋白(Ac-LDL)的摄取及配体间的竞争作用。结果与未转染细胞相比,转染SR-A的HMCL对修饰低密度脂蛋白的摄取功能明显增强;40倍过量未标记的Ox-LDL、Ac-LDL竞争荧光D il标记的Ac-LDL的摄取,但未修饰的LDL对该受体无明显竞争抑制作用。结论Ox-LDL和Ac-LDL通过同一SR-A进入系膜细胞内,SR-A对修饰的低密度脂蛋白具有较高的亲和力和特异性。
Objective To determine the function and binding properties of SR-A in HMC. Methods A human mesangial cell line （HMCL） with high expression of type A SCR （HMCL-SCR） was established after stable transfection of expressive vector with cDNA encoding SR-A. Uptake of fluorescence Dil-labeled acetyhtted low density lipoprotein （DIl-Ac-LDL） and oxidized LDL （Ox-LDL） by HMC were evaluated by fluorescence microscopy, con-focal microscopy and Oil Red ＂O＂ staining respectively. SCR mRNA expression was examined with reverse transcriptionpolymerase chain reaction （RT-PCR）. Results More uptake of Ox-LDL and Ac-LDL was observed in HMCL-SCR than that in the untransfected HMCL. Unlabeled Ox-LDL and Ac-LDL at a 40-fold excess concentration competed significantly with the uptake of DIl-Ac-LDL by HMC. Otherwise this phenomenon was not observed when co-cul- tured with LDL. Conclusion This results suggest that SB-A mediates the uptake of modified-LDL with high affinity and high specificity in human mesangial cells.
出处
《基础医学与临床》
CSCD
北大核心
2006年第10期1125-1130,共6页
Basic and Clinical Medicine
