Inhibition of mineralocorticoid receptor activation by eplerenone to reduce autophagy in obstructive nephropathy / 中国药理学通报

ABSTRACT

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 lOd 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) , Be-clin-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 LC3 11/I in 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 mineralocorti-coid receptor.