Ox-LDL通过LOX-1促进NRK52E细胞摄取脂质的实验研究

目的 探讨血凝素样氧化低密度脂蛋白受体-1（LOX-1）在氧化低密度脂蛋白（oxLDL）刺激肾小管上皮细胞摄取脂质中的作用.方法 体外培养NRK52E,加入不同浓度（0,25,50,100μg/ml）的ox-LDL及预先与LOX-1阻滞剂多聚肌苷酸（polyinosonic acid,poly I）和爱兰苔胶（carrageenan）作用2 h,再加入50μg/ml的ox-LDL,24 h后用Realtime-PCR测定LOX-1 mRNA的表达水平,Western blot测定LOX-1蛋白表达,用油红O法测定细胞内脂质聚集情况.结果 在25～100μ/ml范围内随着ox-LDL浓度的增加,LOX-1 mRNA和蛋白的表达增加,分别为0 μg/ml的2.13、10.14、20.81倍和2.53、12.18、21.45倍,各组间比较差异均有统计学意义（P〈0.05）;而随着LOX-1 mRNA和蛋白的表达增加细胞内脂质聚集也增加,分别为0μg/ml的3.2,6.4和12.5倍（P〈0.05）;polyI或carrageenan使50μg/ml的ox-LDL诱导的LOX-1 mRNA和蛋白的表达分别下降（48%,47%）和（72%,65%）,同时细胞内脂质聚集减少41%和49%,LOX-1与细胞内脂质呈正相关（r=0.97,P〈0.05）.结论 ox-LDL诱导NRK52E细胞表达LOX-1,又通过LOX-1促进脂质在细胞内聚集从而损伤细胞,这种诱导作用可被LOX-1的阻断剂部分阻断.

Ox-LDL promote NRK52E cell intake lipid through LOX-1

Objective To investigate the effect of lectin like oxidized low density lipoprotein receptor 1 ( LOX-1 ) in NRK52E intaking lipid induced by oxidized low density lipoprotein ( ox-LDL). Methods NRK-52E was incubated with ox-LDL (0,25,50, and 100 g/ml ) for 24 hours or pre-treated with the chemical blocker of LOX-1 receptor- polyI or carrageenan, and then exposed to 50 μg/ml of ox-LDL. LOX-Ⅰ mRNA was examined by real-time PGR. LOX-1 protein was assessed by Western blot analysis. Lipid deposit was examined by oil red O. Results LOX-1 mRNA expression in 25,50,100 μg/ml ox-LDL group was 2. 13, 10. 14, 20. 81 times of that in 0 g/ml ox-LDL group ( P <0. 05 ,respectively). LOX-1 protein expression in 25,50,100 μg/ml ox-LDL group was 2. 53,12. 18,21.45 times of that in 0 μg/ml ox-LDL group( P <0. 05 ,respectively). Following the increased LOX-1, lipid intake increased. Pre-treatment with Poly Ⅰ or carrageenan, LOX-1 mRNA expression deceased by 48% or 47%, LOX-1 protein deceased by 72% or 65%, lipid intake induced by 41% or 49% ( P <0.05 ,respectively). Lipid had a close relationship with LOX-1 ( r = 0. 87, P < 0. 05). Conclusion Ox-LDL induced NRK52E to express LOX-1 and promoted NRK52E to intake lipid, and this effect could be partly blocked by LOX-1 blocker.