N-myc下游调节基因-2在输尿管梗阻大鼠肾脏中的表达及意义

The expression and significance of N-myc downstream regulated gene-2 in rat kidney after ureteral obstruction

目的 观察N-myc下游调节基因-2(N-myc downstream regulated gene-2,NDRG2)在大鼠单侧输尿管梗阻(unilateral ureteral obstruction,UUO)模型上的表达,探讨肾脏纤维化发病的机制.方法 雄性Wistar大鼠48只,数字法随机分为假手术组(24只,行左侧输尿管分离术)和手术组(24只,行左侧输尿管结扎离断术),各组大鼠分别在术后3d、7d、14 d、21 d各6只取材,留取左肾标本.用HE、Masson染色观察肾小管损伤的病理变化,采用Western blot、免疫组化方法检测E-cadherin和α-SMA的表达情况,从而验证造模成功.用实时定量PCR、Western blot、免疫组化验证NDRG2的表达.结果 假手术组各时间点无差异.与假手术组相比,UUO组大鼠随着梗阻时间延长,肾小管损伤程度逐渐加重,E-cadherin蛋白表达减少(P＜0.05),α-SMA蛋白表达增加(P＜0.05).NDRG2蛋白表达在UUO组明显低于假手术组(P＜0.05),随梗阻时间延长递减.用ImagePro Plus 6.0分析NDRG2免疫组织化学OD值,在21 d时最低(14.33 ±2.45)×10-3;Westem blot结果采用目的蛋白与内参OD值之比,21 d时最低为0.03 ±0.01;实时PCR显示NDRG2 mRNA在UUO组显著降低(P＜0.05).结论 在UUO模型中,NDRG2表达下调,其有可能参与了肾脏纤维化的病理过程.

Objective To investigate the expression of N-myc downstream regulated gene-2 (NDRG2) on renal fibrosis in unilateral ureteral obstruction(UUO) rat model and the mechanism of renal fibrosis.Methods Forty-eight male Wistar rats (120-150g)were randomly divided into two groups:the sham-operation group (n =24)underwent the left ureteral dissection,the UUO group (n =24)underwent the left ureteral ligation.At the 3,7,14,21day after the operation,6 rats from each of the group were sacrificed and the obstructive kidneys were collected.The histopathological changes were observed through HE and Masson staining.E-cadherin and α-SMA were detected by Western blot and immunohistochemistry.NDRG2 were detected by Western blot,immunohistochemistry and real-time PCR.Results There is not diffenrence in the sham group at anytime.Compared with the sham-group,the fibrosis was obvious in UUO group.The protein of E-cadherin decreased(P ＜ 0.05) and α-SMA increased(P ＜0.05).The expression of NDRG2 in UUO group was lower than that in the sham group.The OD of immunohistochemistry was detected by ImagePro Plus 6.0.OD of NDRG2 was the lowest[(14.33 ± 2.45) x 10-3] in 21d group.The western blot showed that the ratio of NDRG2 to β-actin was the lowest(0.03 ± 0.01) in 21d group.The mRNA of NDRG2 decreased obverously in UUO group (P ＜ 0.05).Conclusion NDRG2 decreases in UUO group and NDRG2 might be involved in the pathologic process of renal fibrosis.