Predictive usefulness of urinary biomarkers for the identification of cyclosporine A-induced nephrotoxicity in a rat model

The effect of glycine on oxidative stress, inflammation and renin-angiotensin system in kidneys and aorta of cyclosporine-administered rats

Cyclosporine A (CsA) is an immunosuppressive drug, used in organ transplantations. Oxidative stress, inflammation and renin-angiotensin system (RAS) activation play an important role in CsA-toxicity. Glycine (Gly) has antioxidant and anti-inflammatory effects. In this study, Gly was investigated for its protective role against CsA-induced toxicity. CsA (20 mg/kg/day; subcutaneously) was administered to rats along with Gly injection (250 or 1000 mg/kg; intraperitoneally) for 21 days. Renal function markers [serum urea and creatinine and urinary protein and kidney injury molecule levels and creatinine clearance values] together with histopathological examinations were performed. Oxidative stress (reactive oxygen species, thiobarbutiric acid reactive substances, advanced oxidation products of protein, glutathione, ferric reducing anti-oxidant power and 4-hydroxynonenal levels), and inflammation (myeloperoxidase activity) were determined in kidney tissue. The RAS system [angiotensin II (Ang II) levels, and mRNA expressions of angiotensin converting enzyme (ACE), angiotensin II type-I receptor (AT1R)] and NADPH-oxidase 4 (NOX4) were measured in kidney and aorta. CsA caused significant disturbances in renal function markers, increases in oxidative stress and inflammation parameters and renal damage. Serum angiotensin II levels and mRNA expressions of ACE, AT1R and NOX4 elevated in the aorta and kidney of CsA-rats. Gly, especially its high-dose, alleviated renal function markers, oxidative stress, inflammation and renal damage in CsA-rats. Moreover, serum Ang II levels and mRNA expressions of ACE, AT1R and NOX4 decreased significantly in aorta and kidney in CsA-rats due to Gly treatment. Our results indicate that Gly may be useful for the prevention of CsA-induced renal and vascular toxicity.

Oleuropein attenuates the nephrotoxic effect of sunitinib in rats: Unraveling the potential role of SIRT6/Notch-1/NLRP-3/IL-1β axis

Sunitinib (SUN) is a chemotherapeutic agent clinically approved for treatment of metastatic renal carcinoma. Despite its remarkable benefits, various renal toxicities have been reported that limit its clinical uses. Oleuropein (OLE) is the main polyphenolic constituent of olive tree and mediates the majority of its valuable pharmacological activities. The current study examined the probable renoprotective effects of OLE against SUN-induced nephrotoxicity. Adult male albino rats were co-treated by SUN (25 mg/kg, 3 times/week, PO) with either a drug vehicle or OLE (60 mg/kg/day, daily, PO) for four weeks. A control group comprising of age-matched rats was used. Four weeks later, blood specimens were collected to assess kidney functions. Kidneys were harvested for biochemical and histopathological analyses. Administration of SUN induced kidney dysfunction, along with marked rises in endothelin-1 (ET-1) and monocyte chemotactic protein-1 (MCP-1) levels in renal tissues. Histological abnormalities were also detected in kidneys of SUN-treated rats including glomerular and tubular interstitial congestion along with interstitial fibrosis. On molecular levels, there was a decline in renal SIRT6 expression along with significant up-regulation of Notch-1, NLRP-3, interleukin -1β (IL-1β) and cleaved caspsase-3. All these changes were almost alleviated by OLE co-treatment. These findings suggest the implication of SIRT6/Notch-1/NLRP3/IL-1β axis in the pathogenesis of SUN-induced nephrotoxicity and highlight OLE as a prospective renoprotective agent during SUN chemotherapy to halt its renal toxicity likely through promotion of SIRT6 and suppression of Notch-1/NLRP3/IL-1β signaling pathway.

Cyclosporine-induced kidney damage was halted by sitagliptin and hesperidin via increasing Nrf2 and suppressing TNF-α, NF-κB, and Bax

Cyclosporine A (CsA) is employed for organ transplantation and autoimmune disorders. Nephrotoxicity is a serious side effect that hampers the therapeutic use of CsA. Hesperidin and sitagliptin were investigated for their antioxidant, anti-inflammatory, and tissue-protective properties. We aimed to investigate and compare the possible nephroprotective effects of hesperidin and sitagliptin. Male Wistar rats were utilized for induction of CsA nephrotoxicity (20 mg/kg/day, intraperitoneally for 7 days). Animals were treated with sitagliptin (10 mg/kg/day, orally for 14 days) or hesperidin (200 mg/kg/day, orally for 14 days). Blood urea, serum creatinine, albumin, cystatin-C (CYS-C), myeloperoxidase (MPO), and glucose were measured. The renal malondialdehyde (MDA), glutathione (GSH), catalase, and SOD were estimated. Renal TNF-α protein expression was evaluated. Histopathological examination and immunostaining study of Bax, Nrf-2, and NF-κB were performed. Sitagliptin or hesperidin attenuated CsA-mediated elevations of blood urea, serum creatinine, CYS-C, glucose, renal MDA, and MPO, and preserved the serum albumin, renal catalase, SOD, and GSH. They reduced the expressions of TNF-α, Bax, NF-κB, and pathological kidney damage. Nrf2 expression in the kidney was raised. Hesperidin or sitagliptin could protect the kidney against CsA through the mitigation of oxidative stress, apoptosis, and inflammation. Sitagliptin proved to be more beneficial than hesperidin.

The effects of TNF-α inhibitors on carbon tetrachloride-induced nephrotoxicity

OBJECTIVES

Carbon tetrachloride (CCl₄), employed in various industrial fields, can cause acute damage in renal tissues. This study investigated the therapeutic effect of the TNF-alpha inhibitor Infliximab on TGF-ß and apoptosis caused by acute kidney image induced by CCl₄.

METHODS

Twenty-four male Sprague-Dawley rats were assigned into control, CCl₄, and CCl₄+ Infliximab groups. The control group received an isotonic saline solution, and the CCl₄ group 2 mL/kg CCl₄ intraperitoneally (i.p). The CCl₄+ Infliximab group was given 7 mg/kg Infliximab 24 hours after administration of 2 mL/kg CCl₄. Kidney tissues were removed at the end of the experiment and subjected to histopathological and biochemical analysis.

RESULTS

The application of CCl₄ led to tubular necrosis, inflammation, vascular congestion, and increased Serum BUN and creatinine values. An increase in caspase-3 activity also occurred in the CCl₄ group. However, Infliximab exhibited an ameliorating effect on kidney injury by causing a decrease in the number of apoptotic cells. Tissue ADA and TGF-ß values of the CCL4 group were significantly higher than the values of the control group (p = .001, p < .001 respectively) and CCL₄+ Inf group (p = .004, p = .015, respectively).

CONCLUSIONS

This study shows that Infliximab ameliorates nephrotoxicity by reducing lipid peroxidation, oxidative stress, and apoptosis in acute kidney damage developing in association with CCl₄ administration. These findings are promising in terms of the ameliorating role of TNF-alpha inhibitors in acute kidney injury.

The Pattern of Cyclosporine Nephrotoxicity and Urinary Kidney Injury Molecule 1 in Allogenic Hematopoietic Stem Cell Transplant Patients

OBJECTIVES

The typical immunosuppressive regimen of hematopoietic stem cell transplant includes cyclosporine. However, cyclosporine nephrotoxicity is a concern. We studied cyclosporine nephrotoxicity epidemiology in hematopoietic stem cell transplant patients and compared the pattern and urinary levels of the KIM-1 kidney injury molecule versus serum and urine creatinine levels.

MATERIALS AND METHODS

The study covered 10 months at Namazi Hospital, Shiraz, Iran. All patients met the following criteria: > 15 years old, received allogenic hematopoietic stem cell transplant without history of acute or chronic kidney disease, and scheduled for at least 1 week of cyclosporine treatment. Urinary and serum levels of creatinine, urea, sodium, potassium, magnesium, and the KIM-1 kidney injury molecule were measured on days 0, 3, 5, 7, 10, and 14 of cyclosporine treatment.

RESULTS

Of 42 patients, one-third developed cyclosporine nephrotoxicity (30.95%), and median onset time was 15 days. Hypokalemia and hypomagnesemia were reported in 76.2% and 53.4% of the cohort, respectively. None of the demographic, clinical, and paraclinical parameters was significantly associated with cyclosporine nephrotoxicity. Median duration of hospital stay for patients with cyclosporine nephrotoxicity (41 days) was significantly higher (P < .001) than those without nephrotoxicity (29 days). Area under the curve for receiver operating characteristic showed that accuracy of serum creatinine (0.267; 95% CI, 0.11-0.43) at day 0 of cyclosporine treatment was significantly lower (P = .017) than the accuracy of urine creatinine (0.477; 95% CI, 0.28-0.67) and urine levels of the KIM-1 kidney injury molecule (0.594; 95% CI, 0.41-0.78).

CONCLUSIONS

Cyclosporine nephrotoxicity is a common adverse effect in the setting of hematopoietic stem cell transplant and occurs mostly within the first 2 weeks of cyclosporine treatment. Urine KIM-1 kidney injury molecule measurement had no overall superiority and no improved accuracy over serum or urine creatinine measurements for prediction or detection of cyclosporine nephrotoxicity.

Recent Advances on Biomarkers of Early and Late Kidney Graft Dysfunction

New biomarkers of early and late graft dysfunction are needed in renal transplant to improve management of complications and prolong graft survival. A wide range of potential diagnostic and prognostic biomarkers, measured in different biological fluids (serum, plasma, urine) and in renal tissues, have been proposed for post-transplant delayed graft function (DGF), acute rejection (AR), and chronic allograft dysfunction (CAD). This review investigates old and new potential biomarkers for each of these clinical domains, seeking to underline their limits and strengths. OMICs technology has allowed identifying many candidate biomarkers, providing diagnostic and prognostic information at very early stages of pathological processes, such as AR. Donor-derived cell-free DNA (ddcfDNA) and extracellular vesicles (EVs) are further promising tools. Although most of these biomarkers still need to be validated in multiple independent cohorts and standardized, they are paving the way for substantial advances, such as the possibility of accurately predicting risk of DGF before graft is implanted, of making a “molecular” diagnosis of subclinical rejection even before histological lesions develop, or of dissecting etiology of CAD. Identification of “immunoquiescent” or even tolerant patients to guide minimization of immunosuppressive therapy is another area of active research. The parallel progress in imaging techniques, bioinformatics, and artificial intelligence (AI) is helping to fully exploit the wealth of information provided by biomarkers, leading to improved disease nosology of old entities such as transplant glomerulopathy. Prospective studies are needed to assess whether introduction of these new sets of biomarkers into clinical practice could actually reduce the need for renal biopsy, integrate traditional tools, and ultimately improve graft survival compared to current management.

Effects of adjuvant-induced arthritis on the ventral prostate of rats treated with angiotensin AT1 receptor blocker

AIMS

To analyze the prostatic compartments, extracellular matrix, microvascularization, transforming growth factor-beta (TGF-β) and angiotensin II receptors type 1 (AT₁) levels, and histopathology of the ventral prostate in a rat model for rheumatoid arthritis, and to evaluate the effect of angiotensin II AT₁ receptor blocker (ARB) in the disease.

MAIN METHODS

Fifteen male rats (90 days old) were divided into three groups (n = 5/group): control, adjuvant-induced arthritis without (AIA) or with AT₁ receptor blocker (AIA + ARB). Animals were euthanized 60 days after immunization. The ventral prostate was collected, weighed, and processed for histological and immunohistochemical analysis.

KEY FINDINGS

Our results show that AIA increases production of the prostatic epithelium and extracellular matrix, accompanied by a reduction in the number of tissue capillaries. ARB treatment promotes decreased production of extracellular matrix and increased TGF-β and AT₁ receptor immunostaining.

SIGNIFICANCE

AIA may activate specific mechanisms that modify the prostatic environment; the use of ARB attenuates some altered prostate parameters in a rat model for arthritis.

The Many Faces of Calcineurin Inhibitor Toxicity-What the FK?

Calcineurin inhibitors (CNIs) are both the savior and Achilles' heel of kidney transplantation. Although CNIs have significantly reduced rates of acute rejection, their numerous toxicities can plague kidney transplant recipients. By 10 years, virtually all allografts will have evidence of CNI nephrotoxicity. CNIs have been strongly associated with hypertension, dyslipidemia, and new onset of diabetes after transplantation-significantly contributing to cardiovascular risk in the kidney transplant recipient. Multiple electrolyte derangements including hyperkalemia, hypomagnesemia, hypercalciuria, metabolic acidosis, and hyperuricemia may be challenging to manage for the clinician. Finally, CNI-associated tremor, gingival hyperplasia, and defects in hair growth can have a significant impact on the transplant recipient's quality of life. In this review, the authors briefly discuss the pharmacokinetics of CNI and discuss the numerous clinically relevant toxicities of commonly used CNIs, cyclosporine and tacrolimus.

Resveratrol ameliorates the cyclosporine-induced vascular and renal impairments: possible impact of the modulation of renin–angiotensin system

Cyclosporine, an immunosuppressive drug, exhibits a toxic effect on renal and vascular systems. The present study investigated whether resveratrol treatment alleviates renal and vascular injury induced by cyclosporine. Cyclosporine (25 mg/kg per day, s.c.) was given for 7 days to rats either alone or in combination with resveratrol (10 mg/kg per day, i.p.). Relaxation and contraction responses of aorta were examined. Serum levels of blood urea nitrogen, creatinine, angiotensin II, and angiotensin 1-7 were measured. Histopathological examinations as well as immunostaining for 4-hydroxynonenal and nitrotyrosine were performed in the kidney. RNA expressions of renin–angiotensin system components were also measured in renal and aortic tissues. Cyclosporine decreased the endothelium-dependent relaxation and increased vascular contraction in the aorta. It caused renal tubular degeneration and increased immunostaining for 4-hydroxynonenal, an oxidative stress marker. Cyclosporine also caused upregulations of the vasoconstrictive renin–angiotensin system components in renal (angiotensin-converting enzyme) and aortic (angiotensin II type 1 receptor) tissues. Resveratrol co-treatment prevented the cyclosporine-related deteriorations. Moreover, it induced the expressions of vasodilatory effective angiotensin-converting enzyme 2 and angiotensin II type 2 receptor in aorta and kidney, respectively. We conclude that resveratrol may be effective in preventing cyclosporine-induced renal tubular degeneration and vascular dysfunction at least in part by modulating the renin–angiotensin system.

Nephrotoxicity and Renal Pathophysiology: A Contemporary Perspective

The kidney consists of numerous cell types organized into the nephron, which is the basic functional unit of the kidney. Any stimuli that induce loss of these cells can induce kidney damage and renal failure. The cause of renal failure can be intrinsic or extrinsic. Extrinsic causes include cardiovascular disease, obesity, diabetes, sepsis, and lung and liver failure. Intrinsic causes include glomerular nephritis, polycystic kidney disease, renal fibrosis, tubular cell death, and stones. The kidney plays a prominent role in mediating the toxicity of numerous drugs, environmental pollutants and natural substances. Drugs known to be nephrotoxic include several cancer therapeutics, drugs of abuse, antibiotics, and radiocontrast agents. Environmental pollutants known to target the kidney include cadmium, mercury, arsenic, lead, trichloroethylene, bromate, brominated-flame retardants, diglycolic acid, and ethylene glycol. Natural nephrotoxicants include aristolochic acids and mycotoxins such as ochratoxin, fumonisin B1, and citrinin. There are several common characteristics between mechanisms of renal failure induced by nephrotoxicants and extrinsic causes. This common ground exists primarily due to similarities in the molecular mechanisms mediating renal cell death. This review summarizes the current state of the field of nephrotoxicity. It emphasizes integrating our understanding of nephrotoxicity with pathological-induced renal failure. Such approaches are needed to address major questions in the field, which include the diagnosis, prognosis and treatment of both acute and chronic renal failure, and the progression of acute kidney injury to chronic kidney disease.

Biomarkers for individualized dosage adjustments in immunosuppressive therapy using calcineurin inhibitors after organ transplantation

Calcineurin inhibitors (CNIs), such as cyclosporine A and tacrolimus, are widely used immunosuppressive agents for the prevention of post-transplantation rejection and have improved 1-year graft survival rates by up to 90%. However, CNIs can induce severe reactions, such as acute or chronic allograft nephropathy, hypertension, and neurotoxicity. Because CNIs have varied bioavailabilities, narrow therapeutic ranges, and individual propensities for toxic effects, therapeutic drug monitoring is necessary for all CNIs. Identifying the genetic polymorphisms in drug-metabolizing enzymes will help to determine personalized dosage regimens for CNIs, as CNIs are substrates for CYP3A5 and P-glycoprotein (P-gp, MDR1). CNIs are often concomitantly administered with voriconazole or proton pump inhibitors (PPIs), giving rise to drug interaction problems. Voriconazole and PPIs can increase the blood concentrations of CNIs, and both are primarily metabolized by CYP2C19. Thus, it is expected that interactions between CNIs and voriconazole or PPI would be affected by CYP2C19 and CYP3A5 polymorphisms. CNI-induced acute kidney injury (AKI) is a serious complication of transplantations. Neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule 1 (KIM-1) are noninvasive urinary biomarkers that are believed to be highly sensitive to CNI-induced AKI. In this article, we review the adverse events and pharmacokinetics of CNIs and the biomarkers related to CNIs, including CYP3A5, CYP2C19, MDR1, NGAL, and KIM-1. We hope that these data will help to identify the optimal biomarkers for monitoring CNI-based immunosuppressive therapy after organ transplantation.

Propofol-based anaesthesia versus sevoflurane-based anaesthesia for living donor kidney transplantation: results of the VAPOR-1 randomized controlled trial

Background

Kidney transplantation is associated with harmful processes affecting the viability of the graft. One of these processes is associated with the phenomenon of ischaemia-reperfusion injury. Anaesthetic conditioning is a widely described strategy to attenuate ischaemia-reperfusion injury. We therefore conducted the Volatile Anaesthetic Protection of Renal Transplants-1 trial, a pilot project evaluating the influence of two anaesthetic regimens, propofol- vs sevoflurane-based anaesthesia, on biochemical and clinical outcomes in living donor kidney transplantation.

Methods

Sixty couples were randomly assigned to the following three groups: PROP (donor and recipient propofol), SEVO (donor and recipient sevoflurane), and PROSE (donor propofol and recipient sevoflurane). The primary outcome was renal injury reflected by urinary biomarkers. The follow-up period was 2 yr.

Results

Three couples were excluded, leaving 57 couples for analysis. Concentrations of kidney injury molecule-1 (KIM-1), N -acetyl-β- d -glucosaminidase (NAG), and heart-type fatty acid binding protein (H-FABP) in the first urine upon reperfusion showed no differences. On day 2, KIM-1 concentrations were higher in SEVO [952.8 (interquartile range 311.8-1893.0) pg mmol -1 ] compared with PROP [301.2 (202.0-504.7) pg mmol -1 ]. This was the same for NAG: SEVO, 1.835 (1.162-2.457) IU mmol -1 vs PROP, 1.078 (0.819-1.713) IU mmol -1 . Concentrations of H-FABP showed no differences. Measured glomerular filtration rate at 3, 6, and 12 months showed no difference. After 2 yr, there was a difference in the acute rejection rate ( P =0.039). Post hoc testing revealed a difference between PROP (35%) and PROSE (5%; P =0.020). The difference between PROP and SEVO (11%) was not significant ( P =0.110).

Conclusions

The SEVO group showed higher urinary KIM-1 and NAG concentrations in living donor kidney transplantation on the second day after transplantation. This was not reflected in inferior graft outcome.

Clinical trial registration

NCT01248871.

Pharmacological treatment with galectin-1 protects against renal ischaemia-reperfusion injury

Galectin-1 protein (GAL-1) has important anti-inflammatory properties, but related pharmacologic approaches to effectively treat or prevent renal ischaemia and reperfusion injury are highly limited. Here, we investigated the effect of GAL-1 in a renal ischaemia-reperfusion injury rat model and an in vitro hypoxia-reoxygenation model with a proximal renal tubular epithelial cell line. In vivo, pretreatment with GAL-1 attenuated the renal parameters changed by ischaemia-reperfusion/hypoxia-reoxygenation, with recovery of renal function, protecting against influx of leukocytes, cell death and oxidative stress. Ischaemia-reperfusion/hypoxia-reoxygenation was also associated with increased renal endogenous expression of GAL-1 and intercellular adhesion molecule 1 (ICAM-1) plus augmented levels of proinflammatory cytokines IL-1β, TNF-α and MCP-1 and decreased anti-inflammatory IL-10 in urine, all of which were abrogated by GAL-1 treatment. In vitro studies demonstrated renal tubular epithelial cells as an important source of GAL-1 during hypoxia-reoxygenation and confirmed the protective effects of exogenous GAL-1 through downregulation of proinflammatory cytokine release by proximal renal tubular epithelial cells. Collectively, our findings confirm the important anti-inflammatory role of GAL-1 in kidney ischaemia and reperfusion injury and indicate its promising use as a therapeutic approach.

Mesenchymal Stem Cells Contribute to Improvement of Renal Function in a Canine Kidney Injury Model

BACKGROUND/AIM

The kidney excretes waste materials and regulates important metabolic functions, and renal disorders constitute a significant medical problem and can result in fatalities. In the present study, mesenchymal stem cells derived from canine umbilical cord blood (cUCB-MSCs) were isolated and evaluated for their ability to improve renal function in a canine model of acute kidney injury (AKI).

MATERIALS AND METHODS

The canine AKI model was developed by i.v. injection of cisplatin and gentamycin into 14 male beagle dogs. cUCB-MSCs were administered into the renal corticomedullary junction following AKI induction. Survival time, clinical signs, blood analysis and histological parameters were analyzed.

RESULTS

The group treated with AKI plus cUCB-MSCs had decreased blood urea nitrogen and creatinine levels, and showed an extended life-span and improved histological manifestations. MSCs were detected around the tubules of these kidneys at the histological level.

CONCLUSION

Taken together, our findings suggest that cUCB-MSCs could be an alternative therapeutic agent for canine AKI.

Inflammation and renal fibrosis: Recent developments on key signaling molecules as potential therapeutic targets

Chronic kidney disease (CKD) is a major public health issue. At the histological level, renal fibrosis is the final common pathway of progressive kidney disease irrespective of the initial injury. Considerable evidence now indicates that renal inflammation plays a central role in the initiation and progression of CKD. Some of the inflammatory signaling molecules involved in CKD include: monocyte chemoattractant protein-1 (MCP-1), bradykinin B₁ receptor (B₁R), nuclear factor κB (NF-κB), tumor necrosis factor-α (TNFα), transforming growth factor β (TGF-β), and platelet-derived growth factor (PDGF). Multiple antifibrotic factors, such as interleukin-10 (IL-10), interferon-γ (IFN-γ), bone morphogenetic protein-7 (BMP-7), hepatocyte growth factor (HGF) are also downregulated in CKD. Therefore, restoration of the proper balance between pro- and antifibrotic signaling pathways could serve as a guiding principle for the design of new antifibrotic strategies that simultaneously target many pathways. The purpose of this review is to summarize the existing body of knowledge regarding activation of cytokine pathways and infiltration of inflammatory cells as a starting point for developing novel antifibrotic therapies to prevent progression of CKD.

Amphotericin B-copper (II) complex alters transcriptional activity of genes encoding transforming growth factor-beta family members and related proteins in renal cells

BACKGROUND

Several chemical modifications have been developed to overcome the toxicity of amphotericin B (AmB). Oxidized forms of AmB (AmB-ox), which may occur in patient's circulation during therapy, are as toxic as AmB. Complexes with copper (II) ions (AmB-Cu²⁺) have been reported to be less toxic to human cells. Previous studies showed that AmB changed the expression of transforming growth factor-beta (TGF-β). Therefore, the objective of this study was to investigate the influence of AmB and its modified forms on the expression of genes encoding for TGF-β family members and related proteins in renal cells.

METHODS

Human renal proximal tubule cells (RPTEC) were treated with AmB-Cu²⁺, AmB, or the oxidized form AmB-ox. The expression of TGF-β family members and related genes was determined using oligonucleotide microarrays. TGF-β1 protein level was determined using ELISA method. The mRNA level of TGF-β isoforms, TGF-β receptors and differentiating genes was evaluated by real-time RT-qPCR.

RESULTS

AmB-Cu²⁺ increased the mRNA levels of TGF-β1 and TGF-β2 isoforms and two genes encoding receptors: TGFBR1 and TGFBR2. TGF-β1 protein level in culture medium was not increased after stimulation with AmB-Cu²⁺. Microarray analysis revealed changes in both pro-fibrotic and anti-fibrotic genes.

CONCLUSIONS

These results suggest that AmB-Cu²⁺ may induce repair mechanisms in renal proximal tubule cells via changes in the expression of genes involved in intracellular signaling.

miR-181c protects CsA-induced renal damage and fibrosis through inhibiting EMT

Cyclosporine A (CsA), a widely used immunosuppressive drug in organ transplantation and autoimmune disorders, frequently induces renal damage and fibrosis. Recent evidence has implicated epithelial-mesenchymal transition (EMT) in CsA-induced nephrotoxicity. Microarray analysis disclosed miR-181c as the microRNA most dramatically repressed by CsA. Downregulation of miR-181c expression at the transcriptional level by CsA is dependent on the transcription factor Nrf2. miR-181c mimics or inhibitors attenuate or aggravate CsA-induced EMT gene changes, respectively. Importantly, in Nrf2-/- mice, CsA-induced renal damage, fibrosis, and EMT gene changes are restored by miR-181c mimics. Mechanistically, we identified Notch2 as a potential target of miR-181c. Collectively, our data support the notion that miR-181c may serve as an important factor for protecting renal tissues from CsA-induced nephrotoxicity.

Effects of Losartan, Tempol, and Their Combination On Renal Nitric Oxide Synthases in the Animal Model of Chronic Kidney Disease

Down-regulation of nitric oxide synthase (NOS) and NO deficiency in the kidneys have been implicated in the pathogenesis of chronic kidney disease (CKD). In this study we examined the effects of losartan, tempol, and combined treatment on three NOS isoforms expressions, kidney NO content and NOS correlation with renal function and structure in the early stage of adriamycin (ADR)-induced CKD in spontaneously hypertensive rats (SHR). Rats were divided into control group, and four other groups which were treated with ADR and received vehicle, losartan (L, angiotensin II type 1 receptor blocker), tempol (T, redox-cycling nitroxide) or T+L treatment (by gavage) in a six-week study. Reduction of all NOS isoforms expressions were significantly improved by losartan or tempol, and correlated with proteinuria amelioration. Combined treatment induced down-regulation of constitutive NOS isoforms, whilst inducible NOS was up-regulated and followed by increased nitrite content and a significant decline in the glomerular filtration rate. Losartan or tempol prevented ADR-induced neoexpression of vimentin in the glomeruli and tubulointerstital areas, whereas de novo vimentin expression was still observed in the atrophic tubules and in the interstitial fibroblasts and myofibroblasts in combined treatment. It can be concluded that single treatments, contrary to combined, were effective in improving NO bioavailability and slowing down the progression of CKD.

The Usefulness of Determining Neutrophil Gelatinase-Associated Lipocalin Concentration Excreted in the Urine in the Evaluation of Cyclosporine A Nephrotoxicity in Children with Nephrotic Syndrome

Introduction. The use of cyclosporine (CsA) in the treatment of nephrotic syndrome (NS) contributed to a significant reduction in the amount of corticosteroids used in therapy and its cumulative side effects. One of the major drawbacks of CsA therapy is its nephrotoxicity. Prolonged CsA treatment protocols require sensitive, easily available, and simple to measure biomarkers of nephrotoxicity. NGAL is an antibacterial peptide, excreted by cells of renal tubules in response to their toxic or inflammatory damage. Aim of the Study. The aim of this study was to assess the suitability of the NGAL concentration in the urine as a potential biomarker of the CsA nephrotoxicity. Material and Methods. The study was performed on a group of 31 children with NS treated with CsA. The control group consisted of 23 children diagnosed with monosyptomatic enuresis. The relationship between NGAL excreted in urine and the time of CsA treatment, concentration of CsA in blood serum, and other biochemical parameters was assessed. Results. The study showed a statistically significant positive correlation between urine NGAL concentration and serum triglycerides concentration and no correlation between C0 CsA concentration and other observed parameters of NS. The duration of treatment had a statistically significant influence on the NGAL to creatinine ratio. Conclusions. NGAL cannot be used alone as a simple CsA nephrotoxicity marker during NS therapy. Statistically significant correlation between NGAL urine concentration and the time of CsA therapy indicates potential benefits of using this biomarker in the monitoring of nephrotoxicity in case of prolonged CsA therapy.

Renal Involvement in Inflammatory Bowel Diseases

The prevalence of extraintestinal manifestations in inflammatory bowel diseases varies from 6% to 46%. The aetiology of extraintestinal manifestations remains unclear. There are theories based on an immunological response influenced by genetic factors. Extraintestinal manifestations can involve almost every organ system. They may originate from the same pathophysiological mechanism of intestinal disease, or as secondary complications of inflammatory bowel diseases, or autoimmune diseases susceptibility. The most frequently involved organs are the joints, skin, eyes, liver and biliary tract. Renal involvement has been considered as an extraintestinal manifestation and has been described in both Crohn's disease and ulcerative colitis. The most frequent renal involvements in patients with inflammatory bowel disease are nephrolithiasis, tubulointerstitial nephritis, glomerulonephritis and amyloidosis. The aim of this review is to evaluate and report the most important data in the literature on renal involvement in patients with inflammatory bowel disease. Bibliographical searches were performed of the MEDLINE electronic database from January 1998 to January 2015 with the following key words (all fields): (inflammatory bowel disease OR Crohn's disease OR ulcerative colitis) AND (kidney OR renal OR nephrotoxicity OR renal function OR kidney disease OR renal disease OR glomerulonephritis OR interstitial nephritis OR amyloidosis OR kidney failure OR renal failure) AND (5-aminosalicylic acid OR aminosalicylate OR mesalazine OR TNF-α inhibitors OR cyclosporine OR azathioprine OR drugs OR pediatric).