依普利酮抑制盐皮质激素受体活化减缓梗阻性肾病细胞自噬的研究

Inhibition of mineralocorticoid receptor activation by eplerenone to reduce autophagy in obstructive nephropathy

目的观察盐皮质激素受体阻断剂依普利酮对梗阻性肾病细胞自噬的作用和机制。方法36只♂Wistar大鼠随机分为假手术组、模型组和依普利酮组,通过结扎大鼠单侧输尿管制备动物模型。依普利酮组给予依普利酮100 mg·kg^-1·d^-1,10 d后摘取梗阻侧肾脏,激光共聚焦显微镜检测NR3C2表达,免疫组化和Western blot检测SGK-1、p-mTOR、Atg5、Beclin-1和LC3的表达。结果激光共聚焦显微镜下显示:NR3C2在假手术组表达于肾小管远端上皮细胞的细胞质,细胞核内未见表达,模型组较假手术组表达明显增强,主要见于细胞核,与模型组相比,依普利酮组NR3C2在细胞核表达明显减弱;免疫组化和Western blot结果显示,与假手术组比,模型组SGK-1、Atg5、Beclin-1、LC3Ⅱ/Ⅰ表达增强,p-mTOR表达减弱,给予依普利酮治疗后SGK-1、Atg5、Beclin-1、LC3Ⅱ/Ⅰ表达被下调,p-mTOR被上调。结论依普利酮可以通过抑制盐皮质激素受体活化,减缓梗阻性肾病细胞自噬的表达。

Aim To observe the effect of mineralocorticoid receptor blocker eplerenone on autophagy in obstructive nephropathy and its mechanism.Methods Totally 36 male Wistar rats were randomly divided into sham-operation group,model group and eplerenone group.The animal models were established with unilarteral urteral obstruction(UUO).The rats in eplerenone group were treated with eplerenone(100 mg·kg^-1·d^-1).The obstructed kidneys were collected 10d after UUO.The expression of NR3C2 was detected by laser confocal microscopy,the expression of serum and glucocorticoid-induced protein kinase 1(SGK-1),phosphorylated mammal target of rapamycin(p-mTOR),autophagy associated gene 5(Atg5),Beclin-1 and microtubular-associated protein 1 light chain 3(LC3)were detected by immunohistochemistry and Western blot.Results The expression of NR3C2 was detected in cytoplasm of renal tubular distal epithelial cells,but not in nucleus in sham-operation group with laser confocal microscopy.The expression of NR3C2 was enhanced significantly in model group,mainly in nucleus but significantly inhibited in eplerenone group.The immunohistochemistry and Western blot showed that the expressions of SGK-1,Atg5,Beclin-1 and the ratio of LC3Ⅱ/Ⅰin model group were up-regulated and down-regulated by eplerenone treated group.The expression of p-mTOR was down-regulated in model group compared with sham-operation group and up-regulated in eplerenone group.Conclusions Eplerenone plays a role in reducing autophagy in obstructive nephropathy via inhibiting the activation of mineralocorticoid receptor.