不同方式血液透析前、后尿毒血清对肾小管上皮细胞基质金属蛋白酶系统平衡的影响

Effects of uremic sera from different hemodialysis modalities on the MMPs/TIMPs balance of human renal tubular epithelial cells

目的探讨不同方式血液透析前、后尿毒血清对肾小管上皮细胞基质金属蛋白酶系统平衡的影响。方法选择慢性肾衰竭维持性透析(MHD)患者24例,随机分成3组,分别接受常规血液透析(HD)、高通量透析(HFHD)、血液透析滤过(HDF)后稀释法治疗,分别抽取患者透析前后的血清;ELISA法测定透析前后尿毒血清β2-微球蛋白(β2-MG)的水平。继之用各种透析前、后尿毒血清刺激体外培养的近端肾小管上皮细胞(HK-2细胞);应用RT-PCR法及ELISA法分别检测HK-2细胞MMP-1/TIMP-1 mRNA表达及蛋白分泌的变化。结果HFHD、HDF组透析后血清β2-MG浓度较透析前明显下降(P<0.01);HD组透析后与透析前比较差异无统计学意义(P>0.05)。HDF组透析后尿毒血清使HK-2细胞MMP-1 mRNA表达和蛋白分泌均增加、TIMP-1 mRNA表达和蛋白分泌均减少、MMP-1/TIMP-1 mRNA及蛋白分泌量的比值升高(P<0.01),HD、HFHD组透析后与透析前比较,差异均无统计学意义(P>0.05)。结论HDF可更有效地维持肾小管上皮细胞外基质分泌和降解平衡,从而对残肾功能具有更好的保护作用。

Objective To explore the effect of sera from different hemodialysis modalities on the matrix metalloproteinase system balance of human renal tubular epithelial cells.Methods 24 patients in maintenance hemodialysis were divided randomly into hemodialysis（HD）,high-flux hemodialysis（HFHD） and postdilution hemodiafiltration（HDF） groups.Sera samples were collected before and after blood purification therapies.Levels of beta2-microglobulin（β2-MG） in sera of pre-dialysis and post-dialysis were measured by enzyme-linked immunoadsordent assay （ELISA）.Human proximal epithelial cells（HK-2 cells） were incubated with 10% uremic sera.Expression of MMP-1/TIMP-1 mRNA and protein excretion level in HK-2 cells were measured by RT-PCR and ELISA respectively.Results The sera levels of β2-MG in post-HFHD and post-HDF significantly decreased than pre-HFHD and pre-HDF （P〈0.01）,while the difference between pre-HD and post-HD was not statistically significant （P〉0.05）.The expression of MMP-1 mRNA and excretion of MMP-1 were increased,while the expression of TIMP-1 mRNA and excretion of TIMP-1 were decreased in the HK-2 cells incubating with post-HDF sera compared to the HK-2 cells incubating with pre-HDF（P〈0.01）.As a result,MMP-1/TIMP-1 mRNA and MMP-1/TIMP-1 ratio significantly increased in post-HDF group when compared to pre-HDF group （P〈0.01）.However,the difference of MMP-1/TIMP1 mRNA ratio as well as MMP-1/TIMP-1 ratio were not different significantly between pre-HD and post-HD groups,as well as in pre-HFHD and post- HFHD groups （P〉0.05 respectively）.Conclusions HDF can more effectively maintain the secretion and degradation balance of ECM in renal tubulointerstitium,and thereby more effectively protect remnant renal function.