【摘要】 为观察低密度脂蛋白（ＬＤＬ）对肾上管上皮细胞的影响及涉及的相关信号传导机制，以人近曲行小管上皮细胞系（ＨＫ－２）为对象，采用３Ｈ－ＴｄＲ掺入与细胞计数测定增殖；特异性底物磷酸化法测定细胞外信号调节激酶（Ｅｎｇ）活性；凝胶迁移率法检测转录活化因于（ＡＰ－１）ＤＮＡ结合活性。发现ＬＤＬ１００～５００ｕｇ／ｍＬ刺激ＨＫ－２细胞７２ｈ可促进其增殖：加入ＬＤＬ２５０ｕｇ／ｍＬ后２～６０ｍｉｎ内可使该细胞ＥＲＫ活性明显增加，１０ｍｉｎ时达高峰；不同剂量（５０～５００ｕｇ／ｍＬ）刺激时，ＥＲＫ活性分别较对照组增加１．５６～２．１９倍。ＬＤＬ促使核内转录因子ＡＰ－１结合活性增加。ＥＩＵＬ特异性阻断剂ＰＤ（５０ｕｍｏｌ／Ｌ）可以分别阻断ＬＤＬ刺激的ＨＫ－２细胞ＥＲＫ活性和ＤＮＡ合成。ＲＭＡ阻断ＰＫＣ信号途径后，ＬＤＬ对于ＥＲＫ的活化效应明显减弱。更多还原

【Abstract】 In order to study the effect of low density lipoprotein(LDL)on the proliferation of human proximal tubular cells(HK-2) and its intercellular signal transduction mechanism, cell proliferation was assayed with ’H-TdR incorporation methods and cell counting. The activity ofextracellular signal regulated-protein kinase(Eax)was determined by specific substrate phosphorylation assay. Electrophoresis-mobility shift assay(EMSA) was used to detect the activity oftranscriptional complex AP-1. LDL increased 3H-TdR incorporation and cell number at concentration of 100mg/mL to 500mg/mL, the activity of Ear was stimulated by 250mg/mL of LDL from 2min. to 60min, and peaked at 10min. The induction of ERK activity by LDL was 1.56 ~2. 19 fold when compared with control. LDL also enhanced the activity of AP-1 in HK-2 cells. The inhibitor of ERK, PD blocked both proliferation and ERK activity of HK-2 cells. PMA, the inhibitor of protein kinase C, blocked the activity of Ear induced by LDL. It was concluded that LDL induced proliferation of HK-2 cells associated with ERK/AP-1 signal transduction pathway. Additionally, the activation of PKC may be implicated in the process.更多还原