Remote limb ischemic preconditioning (rIPC) activates antioxidant and antiapoptotic genes and inhibits proinflammatory cytokine genes in renal ischemia/reperfusion injury.

The mechanisms underlying the renoprotective effect for remote limb ischemic preconditioning (rIPC) against renal ischemia/reperfusion injury need further elucidation. In our work, one hundred and twenty male Sprague Dawley rats were randomized into 3 groups; sham, I/R group (left renal 45 min ischemia) and rIPC (as I/R group with 3 cycles of left femoral ischemic PC just before renal ischemia). Rats were sacrificed at 2 h, 24 h, 48 h and 7 days. Serum creatinine and urea were measured at the baseline and endpoints. Also, histopathological examination and assessment of the expression of inflammatory cytokines e.g. TNF-α, IL-1ß and ICAM-1 and antioxidant genes: Nrf2, HO-1 and NQO-1 and anti-apoptotic gene Bcl-2 in left kidney were done by the end of experiment. The results of this study demonstrated that, rIPC caused significant improvement in serum creatinine and BUN levels and in the expression of antioxidant genes and Bcl-2 antiapoptotic gene with significant attenuation of pro-inflammatory cytokines and histopathological damage score at all-time points compared to I/R group (p ≤ 0.05). In conclusion, inhibition of inflammatory cytokine (TNF-α, IL-1ß and ICAM-1) formation and activation of antioxidant genes: Nrf2, HO-1 and NQO-1 and anti-apoptotic gene Bcl-2 could be possible underlying mechanisms for the renoprotective effect of rIPC.

Renoprotective effect of local sildenafil administration in renal ischaemia-reperfusion injury: A randomised controlled canine study.

Objectives: To design a new canine model to assess the renoprotective effect of local sildenafil administration, as the renoprotective effect of systemic sildenafil administration in renal ischaemia-reperfusion (IR) injury in animal models has been shown but its local effects have not been established to date. Materials and methods: In all, 120 dogs were assigned to five groups: sham, oral control (OC) group (right nephrectomy + left renal ischaemia for 60 min), oral sildenafil (OS) group (oral sildenafil 1 mg/kg, 60 min before ischaemia), local control (LC) group (local renal perfusion with saline and heparin for 5 min) and local sildenafil (LS) group (perfusion with sildenafil 0.5 mg/kg). Renal functions, histopathological changes, expression of caspase-3, nuclear factor erythroid 2-related factor 2 (Nrf2), inflammatory cytokines (intracellular adhesion molecule 1, tumour necrosis factor α and interleukin 1ß) and endothelial nitric oxide synthase (eNOS) in renal tissues were assessed in all groups at 1, 3, 7 and 14 days. Results: There were significant improvements in renal functions and cortical and medullary damage scores in the sildenafil-treated groups compared to their control groups (P < 0.05). Also, the LS group showed significantly better improvement of renal functions and cortical and medullary damage scores than the OS group (P < 0.05). Moreover, sildenafil significantly decreased the expression of caspase-3 and inflammatory cytokines and increased the expression of Nrf2 and eNOS in renal tissue, which were statistically significant in the LS group. Conclusion: LS has a greater renoprotective effect against renal IR injury than systemic administration via anti-inflammatory, antioxidant and anti-apoptotic pathways. Abbreviations: BUN: blood urea nitrogen; Ct: cycle threshold; eNOS: endothelial nitric oxide synthase; GAPDH: glyceraldehyde 3-phosphate dehydrogenase; H&E: haematoxylin and eosin; IL-1ß: interleukin 1ß; NO: nitric oxide; Nrf2: nuclear factor erythroid 2-related factor 2; OC: oral control; OS: oral sildenafil; LC: local control; LS: local sildenafil.

Sildenafil activates antioxidant and antiapoptotic genes and inhibits proinflammatory cytokine genes in a rat model of renal ischemia/reperfusion injury.

OBJECTIVES: To study the possible renoprotective effect of sildenafil against renal ischemia/reperfusion (I/R) injury and its effect on the expression of some antioxidant, antiapoptotic gene and proinflammatory cytokine genes in rat model of renal I/R injury. MATERIALS AND METHODS: One hundred and twenty male Sprague Dawley rats were subdivided into three equal groups: sham (underwent right nephrectomy without ischemia), control (underwent right nephrectomy and left ischemia for 45 min) and study [as control with 1 mg/kg sildenafil (per oral) 60 min before anesthesia]. Serum creatinine and BUN were measured at the baseline and the study endpoints (2, 24, 48 h and 7 days), and the left kidney was harvested at study endpoints for histopathological examination as well as for assessment of the expression of antioxidant genes (Nrf-2, HO-1 and NQO-1), antiapoptotic gene (Bcl-2) and inflammatory cytokines, e.g., TNF-a, IL-1ß and ICAM-1. RESULTS: I/R caused significant increase in serum creatinine, BUN, histopathological damage score (p < 0.001) and significant reduction in antioxidant genes (nrf2, HO-1 and NQO-1) and antiapoptotic gene (Bcl2) with significant increase in TNF-a, IL-1ß and ICAM-1 genes in kidney tissues. Pretreatment with sildenafil caused significant attenuation of serum creatinine and BUN as well as significant increase in the expression of antioxidant genes and Bcl-2 genes with significant reduction in the expression of proinflammatory cytokine genes (p value < 0.001). CONCLUSION: The renoprotective effect of sildenafil against renal I/R might be due to the activation of antioxidant genes (Nrf2, HO-1 and NQO-1) and antiapoptotic gene (Bcl2) and attenuation of proinflammatory cytokines (TNF-a, IL-1ß and ICAM-1).

DNA fragmentation, caspase 3 and prostate-specific antigen genes expression induced by arsenic, cadmium, and chromium on nontumorigenic human prostate cells.

Prostate cancer is one of the most common cancers and the second cause of cancer-related deaths among men. Metals are recognized as chemical carcinogens where chronic exposures to such metals are implicated in the development of cancer, including prostate cancer. This in vitro study demonstrates the relative death sensitivity of prostatic (RWPE-1) cells to arsenic (As), cadmium (Cd), and chromium (Cr) as environmental pollutants through its apoptotic effects and the effect of these chemicals on prostate-specific antigen (PSA) gene expression as a marker for their carcinogecity. RWPE-1 cells were divided into three groups that were treated with As, Cd, and Cr in three replicates, at three different concentrations for each metal for 48 h. A control group consisted of untreated RWPE1 cells was used. Apoptosis was assessed using comet assay and caspase 3 gene expression; meanwhile, PSA gene expression was evaluated by semiqualitative real-time PCR (RT-PCR). One of the novel findings of this study is that arsenic and cadmium at low concentrations decreased apoptosis of RWPE-1 cells in a concentration-dependent manner while chromium induced significant concentration-dependent increase in apoptosis. Yet, at the highest concentrations, apoptosis was relatively more induced by all chemicals. Arsenic was the most chemical inhibiting apoptosis in RWPE-1 cells at low concentration. While at the moderate and highest concentrations, cadmium was the most inhibiting chemical of RWPE-1 cells' apoptosis. No distinct differences between treated and untreated cells for PSA gene expression were observed. It can be concluded that As and Cd, at low concentrations, can reduce apoptosis of prostatic cells in a concentration-dependent manner while chromium induced it; however, all metal salts used in this study did not induce PSA gene expression.