慢性移植性肾病大鼠尿液中结缔组织生长因子的检测价值

目的 探讨尿液中结缔组织生长因子(CTGF)成为慢性移植性肾病(CAN)的分子标记的可能性.方法 改良Kamada法建立雄性F344→Lewis大鼠原位同种异体CAN模型,同时设定假手术组作为对照.分别测定移植后4、8、12和16周的血清肌酐和移植肾的Banff评分;Western印迹测定移植肾CTGF的表达变化;间接酶联免疫吸附试验测定血液和尿液中CTGF的表达变化;每个时间点,模型组6只大鼠,假手术组3只大鼠.对尿CTGF变化与CAN的进程进行相关性分析.结果 4.8、12和16周模型组大鼠血清肌酐和移植肾的Banff评分逐渐升高,具有时间依赖性.模型组移植后肾组织中CTGF蛋白表达在术后4、8、12、16周分别为0.55±0.02、0.80±0.03、0.90±0.03和1.14±0.11.均明显高于假手术组(0.33±0.05,均P<0.01).模型组尿液和血清中CTGF表达从术后4周开始出现,高水平的表达保持到术后16周;尿液中CTGF在术后4、8、12和16周分别是(2.9±0.7)、(12.9±3.6)、(32.3±11.4)和(31.0±8.9)ng/mg肌酐,均明显高于假手术组[(0.7±0.3)ng/mg肌酐,均P<0.01].尿CTGF与血清肌酐(r=0.848)、Banff评分(r=0.874)和移植肾中CTGF表达(r=0.747)均具有明显的相关性(均P<0.01).结论 CTGF在CAN的的进程中可能扮演了重要角色,尿CTGF可以成为CAN的分子标记.

Urinary connective tissue growth factor as a biomarker chronic allograft nephropathy in a rat model

Objective To determine whether urinary connective tissue growth factor (CTGF) can be a molecular marker for chronic allograft nephropathy (CAN) in a rat model.Methods F344 rat renal grafts were orthotopically transplanted into Lewis rats (n= 24) .Lewis rats underwent sham operation as control group (n = 12).Kidney grafts were harvested at Weeks 4, 8, 12 and 16 respectively.Serum creatinine (SCr) was measured.The CAN grades were evaluated according to the Banff 97 schema.The expressions of CTGF in kidney, serum and urine were determined by Western blot and competitive indirect ELISA.Spearman correlation analysis was used to compare CTGF expression and the development of CAN.Results The expression of CTGF in the graft group was markedly elevated in comparison with the control group.Statistics analysis of CTGF protein in kidney detected by Western blot showed significant differences between these five groups (0.33 ± 0.05 for control, 0.55 ± 0.02 for Week 4, 0.80 ± 0.03 for Week 8,0.90 ±0.03 for Week 12 and 1.14 ±0.11 for Week 16, P <0.01 ).Both urine and serum CTGF increased by Week 4 and maintained a high level up to Week 16.The urinary CTGF of renal allografts was (2.9 ±0.7), (12.9±3.6), (32.3 ± 11.4) and (31.0 ±8.9) ng/mg creatinine for Weeks 4, 8, 12 and 16 respectively.The urinary levels were positively correlated with SCr, Banff scores and expression of CTGF in the graft kidney ( r = 0.848,0.874,0.747, all P < 0.01 ).Conclusions CTGF plays a significant role in the pathological changes of CAN after kidney transplantation.Urinary CTGF has the potential as a biomarker for predicating the chnical course of CAN.