整合素连接激酶在大鼠慢性移植肾肾病中的作用与机制

目的探讨整合素连接激酶(ILK)在慢性移植肾肾病(CAN)中的作用与机制。方法实验组肾移植受者为雄性Lewis大鼠40只,供者为雄性F344大鼠40只,依照标准的慢性移植肾肾病大鼠模型要求行左肾原位移植。对照组分别为行单纯右肾切除的Lewis大鼠及F344大鼠各25只。于术后4、8、12、16及24周时分批处死大鼠,同时做肾功能与组织学检测,免疫组织化学与蛋白印迹法测定肾组织中ILK的表达,逆转录聚合酶链(RT-PCR)法检测ILK mRNA的表达,免疫组织化学方法检测基质金属蛋白酶9(MMP-9)的表达。结果CAN大鼠移植4周时肾间质可见单个核细胞浸润,12周时可见血管平滑肌细胞的移行与增殖,24周时可见轻度肾间质纤维化、血管硬化及管腔狭窄。CAN大鼠肾组织中ILK及ILK mRNA表达水平显著增高,且随着移植时间的延长有逐渐增高趋势。CAN大鼠肾移植术后8周前肾小管间质及肾小动脉MMP-9表达水平均显著高于同时段LEW对照组及F344对照组,16周后显著降低。Spearman等级相关分析结果显示:CAN大鼠肾组织中ILK表达水平与24 h尿蛋白定量、血清肌酐水平、肾间质单个核细胞浸润程度、肾小动脉平滑肌细胞数量、肾间质纤维化程度等呈显著正相关,与8周前MMP-9表达水平呈正相关,12周后无显著相关性。结论ILK在慢性移植肾肾病病理变化中发挥重要作用,移植早期肾小管间质及肾小动脉中MMP-9表达上调与ILK的作用机制有关。

The role and mechanism of integrin-linked kinase in chronic allograft nephropathy

Objective To investigate the expression and significance of integrin-linked kinase (ILK)in the rat kidney of chronic allograft nephropathy(CAN)model.Methods The kidneys of Fisher(F344)rats were orthotopically transplanted into Lewis recipients.Animals were harvested re- spectively at 4th,8th,12th,16th and 24th week after transplantation for renal function and histologycal examination.The expression of ILK protein was detected by using Western-blot and immunohistologi- cal assay and the mRNA expression by RT-PCR respectively,and the expression of matrix metallopro- teinase-9(MMP-9)was determined by immunohistochemistry.Results The 24-h urine protein excre- tion in CAN rats was significantly increased as compared to F344 controls or LEW controls on the 16 th week after operation.Mononuclear cells infiltration of allografts was markedly aggravated as com- pared to the controls.Allografts got severe interstitial fibrosis and tubular atrophy at week 16 and week 24.The expression of ILK mRNA and protein was up-regulated in the kidney of CAN rats,and increased significantly with the time after transplantation.The expression of ILK and ILK mRNA was significantly correlated with 24-h urine protein excretion,serum creatinine levels,the number of tubu- lointerstitial infiltrated mononuclear cells,the number of smooth muscle cells(SMC)in vascular wall and the extent of interstitial fibrosis.Conclusions ILK might play an key role in CAN,and the overex- pression of MMP-9 might be involved this pathogenesis in the early stage of CAN.