Objective To explore effects of fosinopril and losartan on renal Klotho expression and oxidative stress in spontaneously hypertensive rats (SHR) and the mechanisms underlying the protection against renal damage. Methods Fifteen male SHRs (22 weeks old) were randomly divided into 3 groups (n=5 in each group): a SHR group, a fosinopril group ［10 mg/(kg?d)］, and a losartan group ［50 mg/(kg?d)］. Age-matched Wistar-Kyoto (WKY) rats were chosen for a control group. Eight weeks later, tail arterial pressure, 24 hours urinary protein (Upro)，urinary N-acetyl-β-D-glucosaminidase (NAGase) were measured. Renal pathological changes were examined under light microscopy by HE staining. The renal mRNA and protein expression of Klotho were determined by RT-PCR, immunohistochemical staining or Western blot. The levels of total antioxidant capacity (TAOC), malondialdehyde (MDA), Cu/Zn superoxide dismutase (Cu/Zn-SOD), Mn superoxide dismutase (Mn-SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were determined.Results The typical pathological characteristics of hypertensive renal damage were observed in the kidney of the SHR group．Compared with the SHR group, the systolic pressure, Upro, and urinary NAGase, the content of MDA and renal pathological damage was reduced while the renal Klotho expression and activities of TAOC, Cu/Zn-SOD, CAT, and GSH-Px were increased (P<0.05 or P<0.01) in the fosinopril or losartan group. There was no significant difference in renal Mn-SOD level among the 4 groups (P>0.05). Conclusion Fosinopril and losartan can exert protection against hypertensive renal damage through upregulating Klotho expression as well as reducing oxidative stress.

Objective To determine the effect of aldosterone and its antagonist, spironolactone on epithelial-mesenchymal transition (EMT) of normal rat kidney epithelial cells (NRK-52E) in a high glucose milieu,and to explore the mechanism of renoprotection in diabetic nephropathy (DN ) in rats involving aldosterone and spironolacton. Methods NRK-52E cells were simultaneously cultured in the serum-free Dulbecco's modification of Eagle's medium Dulbecco (DMEM) for 12 hours. Then the low glucose (LG) group was cultured in LG (1000 mg/L) DMEM:The high glucose (HG) group was cultured in high glucose (4 500 mg/L) DMEM. The aldosterone (Aldo) groups were cultured in high glucose DMEM with the addition of 10,50 and 100 nmol/L aldosterone respectively. The SP group was cultured in high glucose (4 500 mg/L) DMEM plus 10~(-7)mol/L spironolactone. Immunohistochemistry, RT-PCR and Western blot were used to detect E-cadherin and α smooth muscle actin(α-SMA) mRNA expression. Results RT-PCR showed that compared with the LG Group, E-cadherin mRNA expression in the HG group was significantly lower, and α-SMA mRNA expression was significantly increased(P＜0.05). E-cadherin mRNA expression in the 50 nmol/L Aldo group and 100 nmol/L Aldo group was significantly lower than that in the HG group, while the expression of α-SMA mRNA was significantly increased in the HG group(P＜0.05), with a dose-dependent relationship with aldosterone(r=-0.70,P＜0.05;r=0.67, P＜0.05). E-cadherin mRNA in the SP group was significantly higher,while α-SMA mRNA expression was lower than that in the HG group(P＜0.01). Immunohistochemistry and Western blot showed that compared with the LG group, E-cadherin protein expression was significantly reduced, and α-SMA expression was significantly increased in the HG group(P＜0.01). In the 10 nmol/L Aldo, 50 nmol/L Aldo, and the 100 nmol/L Aldo groups, E-cadherin protein expression was significantly lower, and α-SMA protein expression was significantly higher than that in the HG group(P＜0.05), with a dose-dependent relationship with aldosterone(r=-0.83,P＜0.05;r=0.81, P＜0.05). In the SP group, E-cadherin protein expression was higher, and α-SMA protein level was lower than that in the HG group(P＜0.05). Conclusion Aldosterone can promote EMT of tubular epithelial cells in a high sugar milieu, leading to renal interstitial fibrosis in Diabetic nephropathy. Spironolactone can inhibit high glucose-induced renal tubular epithelial cells EMT, which may be an important mechanism for the inhibition of renal interstitial fibrosis.

Objective To explore the effect of aldosterone on renal epithelialmesenchymal transition in streptozocin(STZ)-induced diabetic nephropathy rats. Methods Wistar rats were intraperitoneally injected with STZ(60 mg/kg)for the preparation of diabetic model.After 4 weeks,the rats with urinary protein＞30 mg/d were regarded as successful diabetic nephropathy(n=16),and were randomly divided into diabetic nephropathy(DN group,n=8)and spironolactone group(SP group,n=8).Then eight healthy rats were selected randomly as control group(N group,n=8).SP group rats were treated with spironolactone 40 mg·kg-1·d-1,and N group and DN group rats were given equal water.After 8 weeks,rats were sacrificed to collect urine,blood plasma,kidney tissue for detection of 24 h urinary protein,creatinine and renal pathological changes.Aldosterone concentration in plasma and kidney tissue was detected by mdioimmunoassay;E-cadherin,α-SMA protein expression by immunohistochemistry,Western blotting; E-cadherin,α-SMA mRNA expression by RT-PCR. Results Compared with N group,serum creatinine, urinary protein excretion in the DN rats were significantly higher (P＜0.01,respectively), E-cadhefin protein and mRNA were significantly reduced (P＜0.01, respectively),α-SMA protein and mRNA expression was up-regulated (P＜0.01, respectively). Aldosterone level of kidney tissue in DN rats was increased obviously [(24.71±5.30) ng/g vs (16.38±2.85) ng/g, P＜0.01], which was positively correlated with urinary protein excretion, serum creatinine and α-SMA protein (r=0.737, 0.574, 0.688, P＜0.01, respectively), and negatively correlated with E-cadherin protein (r=-0.659, P＜0.O1). While no significant difference was found in serum aldosterone among three groups. Compared with DN rats, urinary protein excretion, serum creatinine were reduced (P＜0.01, respectively), E-cadherin protein and mRNA were increased (P＜0.01, respectively), α-SMA protein and mRNA expression were decreased (P ＜0.01, respectively) in SP group rats.Conclusions Local aldosterone involves in renal epithelial-mesenchymal transition in diabetic nephropathy rat. Spironolactone can block the effect of aldosterone and play a role in renal protection.

OBJECTIVE: To examine the expressions of hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in the kidney of rats with diabetic nephropathy before and after the treatment of Cordyceps sinensis, and to explore the mechanism of Cordyceps sinensis against hypoxia. METHODS: The diabetes model was produced by intraperitoneal injection of 60 mg/kg streptozotocin, then the rats whose 24 h urine protein level was above 30 mg/d were thought to have suffered diabetic nephropathy. Thirty rats were randomly divided into a diabetic nephropathy group (DN group, n=15) and a Cordyceps sinensis group (CS group, n=15), and another 15 normal rats served as a normal control group (NC group, n=15). The CS group were intragastrically administered Cordyceps sinensis extract liquid [5.0 g/(kg.d)], the other groups were intragastrically administered drinking water of equal volume. Five rats in each group were killed after 2, 4, and 6 weeks. The 24 h urine protein excretion, urine β-N-acetyl glucosaminidase (NAGase) and serum creatinine were measured; the renal pathological changes were evaluated by HE and Masson staining; the mRNA and protein expressions of HIF-1α and VEGF were dectected by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry. RESULTS: Compared with the normal control group, the renal tubular vacuolar degeneration was obvious, and the glomerular mesangial matrix increased in the DN group. The 24 h urinary protein excretion, urine NAGase and serum creatinine also increased significantly (all P<0.05); the expressions of HIF-1α and VEGF in the renal tissue gradually increased with time, and the expression of HIF-1α was correlated with that of VEGF in the 2 groups (r=0.850, r=0.887, both P<0.05) . Compared with the DN group, the pathological changes were relieved, the 24 h urinary protein excretion, urine NAGase and serum creatinine level were decreased, and the expressions of HIF-1α and VEGF decreased in the CS group (all P<0.05), but they were still higher than those in the normal contral group (P<0.05). There was no significant difference in the mRNA and protein expression of HIF-1α between the 4th week and the 6th week after the treatment of CS (P>0.05). CONCLUSION The expressions of HIF-1α and VEGF increase in the kidney of rats with diabetic nephropathy, and the positive correlation suggests that there is chronic hypoxia in the renal tissue of diabetic nephropathy. Cordyceps sinensis may protect against chronic hypoxia injury in diabetic nephropathy by lowering the expressions of HIF-1α and VEGF.
Animals ; Cordyceps ; chemistry ; Diabetes Mellitus, Experimental ; complications ; metabolism ; Diabetic Nephropathies ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; metabolism ; Kidney ; metabolism ; Male ; Rats ; Rats, Wistar ; Vascular Endothelial Growth Factor A ; genetics ; metabolism