Expression of erythropoietin and its receptor in kidneys from normal and cyclosporine-treated rats

Norepinephrine alleviates cyclosporin A-induced nephrotoxicity by enhancing the expression of SFRP1

Norepinephrine (NE) has a certain effect on the improvement of renal function. However, whether NE can alleviate cyclosporin A (CsA)-induced nephrotoxicity needs further study. The effect of CsA (1.25, 2.5, 5, and 10 μM) on the human renal epithelial cell vitality, lactate dehydrogenase (LDH) activity, apoptosis, and secreted frizzled-related protein 1 (SFRP1) level was examined by cell counting kit-8, enzyme-linked immunosorbent assay, flow cytometer, and western blot. The effect of NE on the LDH activity, apoptosis, and SFRP1 level of human renal epithelial cells induced by CsA was examined again. After silencing of SFRP1 in human renal epithelial cells, the SFRP1 level, cell vitality, and apoptosis were examined again. CsA (1.25, 2.5, 5, and 10 μM) attenuated the cell vitality and SFRP1 level but enhanced the LDH activity and apoptosis in human renal epithelial cells, while the above effects were reversed by NE. Moreover, SFRP1 silencing reversed the regulation of NE on the SFRP1 level, cell vitality, and apoptosis in human renal epithelial cells induced by CsA. In conclusion, NE relieved CsA-induced nephrotoxicity via enhancing the expression of SFRP1.

Siwu Granules and Erythropoietin Synergistically Ameliorated Anemia in Adenine-Induced Chronic Renal Failure Rats

Objective

Renal anemia in patients with end-stage chronic kidney disease is closely related to the deterioration of cardiac function, renal function, and quality of life. This study involved adenine-induced renal anemic rat models and evaluated the treatment effect of Siwu granules and/or erythropoietin (EPO).

Methods

Fifty SD rats were randomly divided into 5 groups: control, model, Siwu, EPO, and Siwu plus EPO groups. The expression levels of NO, MDA, SOD, CAT, IL-6, TNF-α, EPO, EPOR, α-SMA, and TGF-β1 were detected in rats after 8 weeks of treatment with Siwu granules and/or EPO.

Results

After modeling, 47 rats entered the stage of treatment. Siwu plus EPO treatment significantly increased the rat hemoglobin content (p < 0.05) and reduced blood urea nitrogen (p < 0.05) and serum creatinine (p < 0.001). Compared with the control group, the expression of EPO and EPOR in the kidney of rats with renal failure was significantly decreased (p < 0.05). Moreover, the Siwu plus EPO group improved the level of oxidative stress in rats with chronic renal failure and reduced the expression of inflammatory factors. The expression of α-SMA and TGF-β1 in rats with renal failure was higher, but there was no expression in the control group.

Conclusion

Combined treatment of Siwu granules with EPO increased the expression of EPO and EPOR in the renal tissues and inhibited oxidative stress and inflammatory factors, improving the renal function and anemia.

Expression of brain-derived neurotrophic factor in kidneys from normal and cyclosporine-treated rats

BACKGROUND

Accumulating evidence suggests that a decrease in brain-derived neurotrophic factor (BDNF) level induces a variety of psychiatric and neurological disorders. However, the expression and role of BDNF in the kidney have not been explored. The present study examined the expression of BDNF and tropomyosin-related kinase (Trk) receptors in an experimental model of chronic cyclosporine A (CsA) nephropathy.

METHODS

Sprague-Dawley rats on a salt-deplete diet were treated daily for four weeks with vehicle or CsA. Urine profiles, apoptotic cell death, oxidative stress (8-hydroxy-2'-deoxyguanosine, 8-OHdG), and expression of BDNF and Trk receptors (TrkB and TrkC) were compared between groups. The impact of vasopressin infusion on the urine-concentrating ability was examined by measuring the expression of aquaporin-2 (AQP-2) and BDNF and urine profiles in normal and CsA-treated rats.

RESULTS

Compared with the vehicle-treated rats, rats given CsA had enhanced urine volume and declined urine osmolality. Immunohistochemistry and immunoblotting showed that BDNF and Trk receptors were constitutively expressed in kidneys from vehicle-treated rats. This was confirmed by double immunofluorescent staining for Na-K-ATPase-α1, AQP-1, and AQP-2. By contrast, the expression of these factors decreased in kidneys from CsA-treated rats (BDNF: 51.1 ± 19.5% vs. 102.0 ± 30.3%, p < 0.01). Downregulation of BDNF was accompanied by impairment of urine osmolality, and this was reversed by exogenous infusion of vasopressin. Notably, the number of TUNEL-positive cells correlated negatively with BDNF expression and positively with urinary 8-OHdG excretion.

CONCLUSIONS

BDNF is expressed in the collecting duct of the kidney and may be associated with urine-concentrating ability in an experimental model of chronic CsA-induced nephropathy. Our study provides a new avenue for further investigation of chronic CsA nephropathy.

Allicin ameliorates kidney function and urinary bladder sensitivity in cyclosporine A-treated rats

Cyclosporine-A (CsA) is an immunosuppressive drug which has been used to prevent rejection after organ transplantation and to treat certain autoimmune diseases. However, its therapeutic use is limited by nephrotoxicity. In this study, the modulator effect of allicin on the oxidative nephrotoxicity of CsA in rats was investigated. Furthermore, the effect of allicin on CsA-induced hypersensitivity of urinary bladder rings to acetylcholine (ACh) was estimated. Rats were divided into three groups, control, CsA (15 mg/kg, subcutaneously), and CsA/allicin (50 mg/kg, orally). At the end of the study, all rats were killed and then blood, urine samples, and kidneys were taken. CsA administration caused a severe nephrotoxicity which was evidenced by elevated kidney/body weight ratio, serum creatinine (Cr), blood urea nitrogen, lactate dehydrogenase, and urinary protein with a concomitant reduction in serum albumin and Cr clearance as compared with control. A significant increase in renal contents of malondialdehyde, myeloperoxidase, and tumor necrosis factor-alpha with a significant decrease in renal reduced glutathione, superoxide dismutase activities, and nitric oxide (NOx) content was detected upon CsA administration. Exposure to CsA increased the sensitivity of isolated urinary bladder rings to ACh. Histological analysis revealed that CsA caused tubular necrosis and moderate diffuse tubular atrophy. Allicin protected kidney tissue against the oxidative damage and the nephrotoxic effect of CsA and significantly reduced the responses of isolated bladder rings to ACh. Our study indicates that allicin administration has the potential to protect against CsA-induced renal injury by reducing oxidative stress and inflammation and restoring NOx level.

Protection against ischemia/reperfusion‑induced renal injury by co‑treatment with erythropoietin and sodium selenite

Ischemia/reperfusion injury (IRI) has lzong been an area of concern and focus of investigations. Erythropoietin (EPO) exhibits multiple protective effects, and selenium is an antioxidant trace element in the body, however, there have been no reports concerning the effects of EPO combined with sodium selenite on IRI. In the present study, a mouse model of renal IRI (RIRI) was pre–treated with EPO and sodium selenite to determine the most appropriate combination ratio of the two for further investigation. The results revealed that EPO and sodium selenite had synergistic protective effects in RIRI. EPO was identified as the predominant treatment component, with sodium selenite serving as an adjuvant, and combination treatment was markedly more effective, compared with treatment with either drug alone. The optimal ratio of treatment was 10:1 (10 IU EPO: 1 µg sodium selenite). The results indicated that RIRI markedly induced renal injury, as evidenced by elevated levels of blood urea nitrogen (BUN), as well as higher pathological scores, based on hematoxylin and eosin staining. Pre–treatment with EPO and sodium selenite significantly decreased serum expression levels of BUN and malonaldehyde, and increased the expression levels of superoxide dismutase, glutathione peroxidase and nitric oxide (NO), compared with the model group. Furthermore, co treatment with EPO and sodium selenite upregulated the protein expression levels of phosphatidylinositol 3 kinase (PI3K) in renal tissue samples. Together, the results suggested that co administration of EPO and sodium selenite effectively ameliorates IRI induced renal injury by reducing oxidative stress and activating the PI3K/NO signaling pathway.