不同分子量尿毒血清组分对人肾小管上皮细胞CTGF基因和蛋白表达的影响

目的：探讨不同分子量尿毒血清组分对人肾小管上皮细胞结缔组织生长因子（CTGF）基因和蛋白表达的影响。方法:无菌条件下收集40份尿毒症病人血清和20例正常人血清，应用Centricon Plus 20 Centrifugal Filter Devices将尿毒血清分离成分子量 >10 000 D，5 000-10 000 D，<5 000 D 3个组分。应用Western blotting方法检测CTGF的蛋白表达，RT-PCR方法检测CTGF mRNA表达。结果:2.5%-20%浓度尿毒血清组CTGF基因表达均明显高于正常对照组，以10%尿毒血清组最高；分子量 <5 000 D尿毒血清组CTGF基因表达与正常对照组差异无显著，而分子量 5 000-10 000 D和 >10 000 D尿毒血清组CTGF基因表达均高于正常对照组，以分子量 >10 000 D尿毒血清组最高。不同浓度尿毒血清组CTGF蛋白表达均高于正常对照组，且有随着尿毒血清浓度的升高而增高，在不同分子量尿毒血清组中，以分子量 >10 000 D组增高最为显著。结论：尿毒症毒素通过影响人肾小管上皮细胞致纤维化细胞因子CTGF基因和蛋白表达从而在人肾小管-间质纤维化中起重要作用，而以分子量大于 10 000 D的尿毒症毒素在其中起主要作用。

Effects of uremic serum of different molecular weight groups ongene and protein expression of connective tissue growth factor gene and proteinexpression in human renal tubular epithelial cells

AIM:To investigate the effects of uremic serum of different molecular weight groups on gene and protein expression of connective tissue growth factor(CTGF)in human renal tubular epithelial cells.METHODS:The serum from 40 chronic renal failure patients and 20 healthy volunteers were collected and uremic serum was segregated to three groups:>10 000 D,5 000-10 000 D,<5 000 D by 10 000 D and 5 000 D molecular weight Centricon Plus 20 Centrifugal Filter Devices.The protein expression of CTGF was examined by Western blotting.The mRNA expression of CTGF was detected by RT-PCR.RESULTS:CTGF gene expression were increased in 2.5%-20% uremic serum groups compared with that in normal control group,and it was the highest in 10% uremic serum groups.CTGF gene expression was increased significantly in molecular weight >10 000 D and 5 000-10 000 D groups,and the highest was in >10 000 D group,but it was no significant difference in <5 000 D group compared with that in normal control group.CTGF protein was increased in different molecular weight uremic serum groups compared with that in normal control group,and gradually increased following the increasing of uremic serum concentration and it was the highest in molecular weight >10 000 D group.CONCLUSION:Human renal tubulointerstitial fibrosis was accelerated significantly by uremic toxin,especially molecular weight >10 000 D uremic toxin through promoting the gene and protein expression of CTGF in renal tubular epithelial cells in patients with chronic renal failure.