阿霉素肾病小鼠肾组织中p53、p21表达及意义

目的探讨p53、p21在阿霉素肾病小鼠肾组织中的表达及意义。方法 将60只6周龄、雄性BALB/c小鼠随机分为阿霉素肾病模型组和对照组。两组分别于尾静脉注射阿霉素及生理盐水后第0、2、4、6周末随机选取6只小鼠处死,并检测24 h尿蛋白定量、血清白蛋白、血肌酐及总胆固醇。肾组织行HE、PAS染色,以半定量计分法计算各组肾小球硬化和肾小管间质损伤程度,免疫组化及RT-PCR法检测p53、p21蛋白及mRNA的表达。并分析p53、p21与其它指标的相关性。结果 从第2周开始模型组尿蛋白[(16.19±1.13) mg/24 h vs (2.02±0.47) mg/24 h]、总胆固醇[(7.56±1.10)mmol/L vs (2.17±0.15)mmol/L]明显高于对照组( P 均<0.05),白蛋白明显低于对照组[(19.63±1.28)g/L vs (36.77±1.81)g/L, P <0.05]。模型组肾小球硬化(0.535±0.116 vs 0.020±0.020, P <0.05)及肾小管间质损伤程度(1.133±0.136 vs 0.067±0.061, P <0.05)显著高于对照组,p53、p21蛋白及mRNA表达水平也显著高于对照组;模型组中p53、p21蛋白及mRNA表达水平分别与肾小球硬化、肾小管间质损伤、尿蛋白及总胆固醇呈正相关( r =0.877, r =0.830, r =0.456, r =0.576, P <0.05),与白蛋白呈负相关( r =-0.343, P <0.05)。结论 p53、p21在模型组第2周末即表达增加,且与病变程度呈正相关,提示衰老存在于阿霉素肾病,并参与疾病的发生、发展。

Expression and significance of p53 and p21 in mice with adriamycin-induced nephrosis

Purpose To investigate the expression and significance of p53 and p21 in mice with adriamycin-induced nephrosis. Methods 60 6-week-old male BALB/c mice were randomly divided into adriamycin nephropathy group and control group. The two groups were injected with adriamycin and saline in the caudal vein, 6 mice were killed at random at the end of 0, 2, 4 and 6 weeks. Then we detected 24 h urine protein, serum albumin, creatinine and total cholesterol. Renal tissue was stained with HE and PAS, and the degree of glomerulosclerosis and tubulointerstitial injury was calculated by semi-quantitative scoring method. The expression of protein and mRNA of p53 and p21 were detected by immunohistochemistry and RT-PCR method. Then the correlation between the expression of protein and mRNA p53, p21 and other indexes was analyzed. Results From the second week, urinary protein [(16.19±1.13)mg/24 h vs (2.02±0.47) mg/24 h, P <0.05), cholesterol [(7.56±1.10) mmol/L vs (2.17±0.15) mmol/L, P <0.05] and the degree of glomerulosclerosis (0.535±0.116 vs 0.020±0.020, P <0.05) and tubulointerstitial injury (1.133±0.136 vs 0.067±0.061, P <0.05) in model group were significantly higher than those in control group. Albumin was significantly lower than that in the control group [(19.63±1.28) g/L vs (36.77±1.81) g/L, P <0.05). The expression of p53, p21 protein and mRNA was also significantly higher than those in control group. In model group, the expression of p53, p21 protein and mRNA were positively correlated with glomerulosclerosis, tubulointerstitial injury, urinary protein and total cholesterol, respectively ( r =0.877, r =0.830, r =0.456, r =0.576, P <0.05), and negatively correlated with albumin ( r =-0.343, P <0.05). Conclusion The expression of p53 and p21 increased at the end of the 2nd week in the model group and was positively correlated with the severity of adriamycin nephropathy, suggesting that aging exists in adriamycin nephropathy and is involved in the occurrence and development of the disease.