[Effect of fermented cordyceps powder and prednisone on the Notch2/Hes-1 signaling activation in the kidney tubules of rats with acute aristolochic acid nephropathy].

OBJECTIVE

To investigate the effect of both fermented Cordyceps powder (CS) and prednisone on the Notch2/hes-1 signaling activation in the kidney tubules of rats with acute aristolochic acid nephropathy (AAAN).

METHODS

Totally 50 SD rats were randomly divided into 4 groups, i.e., the normal group, the model group, the CS group, the prednisone group, and the CS plus prednisone group, 10 in each group. The AAAN rat model was induced by intragastric administration of pure aristolochic acid A at the daily dose of 100 mg/kg for 3 days. Rats in the CS group were administered with CS at the daily dose of 5.0 g/kg by gastrogavage, while those in the prednisone group were administered with prednisone at the daily dose of 0.5 mg/kg. Rats in the CS plus prednisone group were treated by CS and prednisone. All treatment lasted for 3 successive weeks. Kidney functions [urea nitrogen (BUN) and serum creatinine (SCr)] were detected. The pathological changes of kidneys were observed by Hematoxylin-Eosin staining. The apoptosis of the renal tubular epithelial cells was detected by TUNEL. The protein expressions of Notch2 and Hes-1 in the renal tissue were detected by immunohistochemical assay and Western blot.

RESULTS

Results of HE staining showed the structure in the nephridial tissue was regular in rats of the normal group. The renal tubular necrosis occurred in the rats of the model group. The pathological changes of kidneys were obviously improved in the CS group, the prednisone group, and the CS plus prednisone group. Compared with the normal group, levels of BUN and SCr, semi-quantitative score of the tubular interstitial tissue, ratio of apoptotic cells, and expressions of Notch2 and Hes-1 proteins significantly increased in the model group (P < 0.01). Compared with the model group, the aforesaid indices significantly decreased in the 3 treatment groups (P < 0.01). All indices decreased most obviously in the CS plus prednisone group (P < 0.05, P < 0. 01).

CONCLUSIONS

Notch2/hes-1 signaling activation might be associated with apoptosis of renal tubular epithelial cells. Both CS and prednisone could play a nephroprotective role for AAAN. But CS plus prednisone could achieve the best effect. Inhabiting the Notch2/hes-1 signaling activation could be its nephroprotective mechanism.