Cilastatin attenuates cisplatin-induced proximal tubular cell damage

Untargeted metabolomics analysis of serum and urine unveils the protective effect of cilastatin on altered metabolic pathways during cisplatin-induced acute kidney injury

Acute kidney injury (AKI) is one of the most serious complications of cisplatin anticancer therapies. Cilastatin is a highly promising nephroprotective agent to eventually enter clinical use, but its biochemical mechanism is still not fully understood. We have employed an untargeted metabolomics approach based on capillary electrophoresis mass spectrometry (CE-MS) analysis of serum and urine from an in vivo rat model, to explore the metabolic pathways involved in cisplatin-induced AKI and cilastatin nephroprotection. A total of 155 and 76 identified metabolites were found to be significantly altered during cisplatin treatment in urine and serum, respectively. Most of these altered metabolites were either partially or totally recovered by cilastatin and cisplatin co-treatment. The main metabolic pathways disturbed by cisplatin during AKI involved diverse amino acids metabolism and biosynthesis, tricarboxylic acids (TCA) cycle, nicotinate and nicotinamide metabolism, among others. Cilastatin was proved to protect diverse cisplatin-altered pathways involving metabolites related to immunomodulation, inflammation, oxidative stress and amino acid metabolism in proximal tubules. However, cisplatin-altered mitochondrial metabolism (especially, the energy-producing TCA cycle) remained largely unprotected by cilastatin, suggesting an unresolved mitochondrial direct damage. Multivariate analysis allowed effective discrimination of cisplatin-induced AKI and cilastatin renoprotection based on metabolic features. A number of potential serum and urine biomarkers could also be foreseen for cisplatin-induced AKI detection and cilastatin nephroprotection.

The 2022 PSOGI International Consensus on HIPEC Regimens for Peritoneal Malignancies: Epithelial Ovarian Cancer

BACKGROUND AND AIM

We report the results of an international consensus on hyperthermic intraperitoneal chemotherapy (HIPEC) regimens for epithelial ovarian cancer (EOC) performed with the following goals: To define the indications for HIPEC To identify the most suitable HIPEC regimens for each indication in EOC To identify areas of future research on HIPEC To provide recommendations for some aspects of perioperative care for HIPEC METHODS: The Delphi technique was used with two rounds of voting. There were three categories of questions: evidence-based recommendations [using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system with the patient, intervention, comparator, and outcome (PICO) method], an opinion survey, and research recommendations.

RESULTS

Seventy-three (67.5%) of 108 invited experts responded in round I, and 68 (62.9%) in round II. Consensus was achieved for 34/38 (94.7%) questions. However, a strong positive consensus that would lead to inclusion in routine care was reached for only 6/38 (15.7%) questions. HIPEC in addition to interval cytoreductive surgery (CRS) received a strong positive recommendation that merits inclusion in routine care. Single-agent cisplatin was the only drug recommended for routine care, and OVHIPEC-1 was the most preferred regimen. The panel recommended performing HIPEC for a minimum of 60 min with a recommended minimum intraabdominal temperature of 41°C. Nephroprotection with sodium thiosulfate should be used for cisplatin HIPEC.

CONCLUSIONS

The results of this consensus should guide clinical decisions on indications of HIPEC and the choice and various parameters of HIPEC regimens and could fill current knowledge gaps. These outcomes should be the basis for designing future clinical trials on HIPEC in EOC.

Legal Performance-enhancing Drugs Alter Course and Treatment of Rhabdomyolysis-induced Acute Kidney Injury

INTRODUCTION

Rhabdomyolysis-induced acute kidney injury (RIAKI) can interrupt physical training and increase mortality in injured warfighters. The legal performance-enhancing drugs caffeine and ibuprofen, which can cause renal injury, are widely used by service members. Whether caffeine or ibuprofen affects RIAKI is unknown. Cilastatin treatment was recently identified as an experimental treatment to prevent RIAKI at injury. To determine potential interacting factors in RIAKI treatment, we test the hypothesis that caffeine and ibuprofen worsen RIAKI and interfere with treatment.

MATERIALS AND METHODS

In mice, RIAKI was induced by glycerol intramuscular injection. Simultaneously, mice received caffeine (3 mg/kg), ibuprofen (10 mg/kg), or vehicle. A second cohort received volume resuscitation (PlasmaLyte, 20 mL/kg) in addition to caffeine or ibuprofen. In a third cohort, cilastatin (200 mg/kg) was administered concurrently with drug and glycerol administration. Glomerular filtration rate (GFR), blood urea nitrogen (BUN), urine output (UOP), renal pathology, and renal immunofluorescence for kidney injury molecule 1 were quantified after 24 hours.

RESULTS

Caffeine did not worsen RIAKI; although BUN was modestly increased by caffeine administration, 24-hour GFR, UOP, and renal histopathology were similar between vehicle-treated, caffeine-treated, and caffeine + PlasmaLyte-treated mice. Ibuprofen administration greatly worsened RIAKI (GFR 14.3 ± 19.5 vs. 577.4 ± 454.6 µL/min/100 g in control, UOP 0.5 ± 0.4 in ibuprofen-treated mice vs. 2.7 ± 1.7 mL/24 h in control, and BUN 264 ± 201 in ibuprofen-treated mice vs. 66 ± 21 mg/dL in control, P < .05 for all); PlasmaLyte treatment did not reverse this effect. Cilastatin with or without PlasmaLyte did not reverse the deleterious effect of ibuprofen in RIAKI.

CONCLUSIONS

Caffeine does not worsen RIAKI. The widely used performance-enhancing drug ibuprofen greatly worsens RIAKI in mice. Standard or experimental treatment of RIAKI including the addition of cilastatin to standard resuscitation is ineffective in mice with RIAKI exacerbated by ibuprofen. These findings may have clinical implications for the current therapy of RIAKI and for translational studies of novel treatment.

ATP/ADP biosensor organoids for drug nephrotoxicity assessment

Drug nephrotoxicity is a common healthcare problem in hospitalized patients and a major limitation during drug development. Multi-segmented kidney organoids derived from human pluripotent stem cells may complement traditional cell culture and animal experiments for nephrotoxicity assessment. Here we evaluate the capability of kidney organoids to investigate drug toxicity in vitro. Kidney organoids express renal drug transporters, OAT1, OAT3, and OCT2, while a human proximal tubular cell line shows the absence of OAT1 and OAT3. Tenofovir and aristolochic acid (AA) induce proximal tubular injury in organoids which is ameliorated by an OAT inhibitor, probenecid, without damage to podocytes. Similarly, cisplatin causes proximal tubular damage that can be relieved by an OCT inhibitor, cimetidine, collectively suggesting the presence of functional OATs and OCTs in organoid proximal tubules. Puromycin aminonucleoside (PAN) induced segment-specific injury in glomerular podocytes in kidney organoids in the absence of tubular injury. Reporter organoids were generated with an ATP/ADP biosensor, which may be applicable to high-throughput screening in the future. In conclusion, the kidney organoid is a useful tool for toxicity assessment in the multicellular context and may contribute to nephrotoxicity assessment during drug development.

JBP485, A Dual Inhibitor of Organic Anion Transporters (OATs) and Renal Dehydropeptidase-I (DHP-I), Protects Against Imipenem-Induced Nephrotoxicity

Imipenem (IMP) possesses a broad spectrum of antibacterial activity; however, nephrotoxicity limits its clinical application in patients with renal insufficiency. In our previous studies, a dipeptide, JBP485, a dipeptide with the chemical structure cyclo-trans-4-L-hydroxyprolyl-L-serine, was found to attenuate drug-induced kidney injury. The current study aimed to explore whether JBP485 could relieve IMP-induced kidney injury and clarify the potential molecular pharmacokinetic mechanism. The effects of JBP485 on IMP nephrotoxicity were evaluated in rabbits and human kidney 2 (HK-2) cells. Drug-drug interactions (DDIs) mediated by organic anion transporters (OATs) and dehydropeptidase-I (DHP-I) were explored through pharmacokinetic studies in rats, metabolism assays in the kidney, and uptake studies in OAT-over-expressing cells. The results revealed that JBP485 significantly ameliorated IMP-induced nephrotoxicity in rabbits. Further, incubation of HK-2 cells with JBP485 or cilastatin markedly improved the cell survival rate, inhibited apoptosis and attenuated mitochondrial damage by improving the stability of IMP and reducing its intracellular accumulation. This suggests that DHP-I and OATs might be involved in the protective effect of JBP485. Furthermore, coadministration with JBP485 significantly increased the IMP's plasma concentration as well as the area under the plasma concentration-time curve (AUC), while decreasing IMP renal clearance and cumulative urinary excretion. Moreover, JBP485 reduced IMP uptake in kidney slices and OAT1/3-human embryonic kidney 293 (HEK293) cells. At the same time, the metabolism of IMP by DHP-I was inhibited by JBP485 with an IC₅₀ value of 12.15 ± 1.22 μM. Finally, the molecular docking assay revealed a direct interaction between JBP485 and OAT1/3 or DHP-I. In conclusion, JBP485 protected against IMP nephrotoxicity in rabbits and HK-2 cells by improving IMP stability and reducing its intracellular accumulation via simultaneous inhibition of renal OATs and DHP-I. JBP485 is a promising renoprotective agent and could serve as an effective supplement to reduce IMP-induced adverse renal reactions in the clinical setting.

FKBP51, AmotL2 and IQGAP1 Involvement in Cilastatin Prevention of Cisplatin-Induced Tubular Nephrotoxicity in Rats

The immunophilin FKBP51, the angiomotin AmotL2, and the scaffoldin IQGAP1 are overexpressed in many types of cancer, with the highest increase in leucocytes from patients undergoing oxaliplatin chemotherapy. Inflammation is involved in the pathogenesis of nephrotoxicity induced by platinum analogs. Cilastatin prevents renal damage caused by cisplatin. This functional and confocal microscopy study shows the renal focal-segmental expression of TNFα after cisplatin administration in rats, predominantly of tubular localization and mostly prevented by co-administration of cilastatin. FKBP51, AmotL2 and IQGAP1 protein expression increases slightly with cilastatin administration and to a much higher extent with cisplatin, in a cellular- and subcellular-specific manner. Kidney tubule cells expressing FKBP51 show either very low or no expression of TNFα, while cells expressing TNFα have low levels of FKBP51. AmotL2 and TNFα seem to colocalize and their expression is increased in tubular cells. IQGAP1 fluorescence increases with cilastatin, cisplatin and joint cilastatin-cisplatin treatment, and does not correlate with TNFα expression or localization. These data suggest a role for FKBP51, AmotL2 and IQGAP1 in cisplatin toxicity in kidney tubules and in the protective effect of cilastatin through inhibition of dehydropeptidase-I.

Protective and Therapeutic Efficacy of Hesperidin versus Cisplatin against Ehrlich Ascites Carcinoma-Induced Renal Damage in Mice

This study evaluates the antitumor efficacy of hesperidin (Hesp) versus cisplatin (Cis) in Ehrlich ascites carcinoma (EAC)-bearing mice, as well as its protective effect against Cis-triggered nephrotoxicity. Seventy female mice were allocated into control, Hesp, EAC, Hesp-protected, Hesp-treated, Cis-treated, and Cis+Hesp-treated groups. The inoculation of mice with EAC cells significantly reduced the mean survival time, while significantly increased the body weight, abdominal circumference, ascitic fluid volume, viable tumor cell count, and serum carcinoembryonic antigen, urea and creatinine levels, besides various hematological changes. Additionally, kidney tissue of EAC-bearing mice showed a significant increase in the malondialdehyde level, significant decreases in the reduced glutathione content and catalase activity, marked pathological alterations, and a strong Ki-67 expression with a weak caspase-3 expression in neoplastic cells infiltrating the renal capsule. Conversely, the administration of Hesp and/or Cis to the EAC-bearing mice induced, to various degrees, antitumor responses and alleviated the cytotoxic effects of EAC. In addition to the potent antitumor effect of the concomitant administration of Hesp and Cis, Hesp minimized the renal adverse side effects of Cis. In conclusion, Hesp may open new avenues for safe and effective cancer therapy and could be valuable for enhancing the antitumor potency and minimizing the renal adverse side effects of chemotherapeutic drugs.

Dipeptidase-1 governs renal inflammation during ischemia reperfusion injury

The mechanisms that drive leukocyte recruitment to the kidney are incompletely understood. Dipeptidase-1 (DPEP1) is a major neutrophil adhesion receptor highly expressed on proximal tubular cells and peritubular capillaries of the kidney. Renal ischemia reperfusion injury (IRI) induces robust neutrophil and monocyte recruitment and causes acute kidney injury (AKI). Renal inflammation and the AKI phenotype were attenuated in Dpep1^-/- mice or mice pretreated with DPEP1 antagonists, including the LSALT peptide, a nonenzymatic DPEP1 inhibitor. DPEP1 deficiency or inhibition primarily blocked neutrophil adhesion to peritubular capillaries and reduced inflammatory monocyte recruitment to the kidney after IRI. CD44 but not ICAM-1 blockade also decreased neutrophil recruitment to the kidney during IRI and was additive to DPEP1 effects. DPEP1, CD44, and ICAM-1 all contributed to the recruitment of monocyte/macrophages to the kidney following IRI. These results identify DPEP1 as a major leukocyte adhesion receptor in the kidney and potential therapeutic target for AKI.

Potential of Polyphenols to Restore SIRT1 and NAD+ Metabolism in Renal Disease

SIRT1 is an NAD⁺-dependent class III histone deacetylase that is abundantly expressed in the kidney, where it modulates gene expression, apoptosis, energy homeostasis, autophagy, acute stress responses, and mitochondrial biogenesis. Alterations in SIRT1 activity and NAD⁺ metabolism are frequently observed in acute and chronic kidney diseases of diverse origins, including obesity and diabetes. Nevertheless, in vitro and in vivo studies and clinical trials with humans show that the SIRT1-activating compounds derived from natural sources, such as polyphenols found in fruits, vegetables, and plants, including resveratrol, quercetin, and isoflavones, can prevent disease and be part of treatments for a wide variety of diseases. Here, we summarize the roles of SIRT1 and NAD⁺ metabolism in renal pathophysiology and provide an overview of polyphenols that have the potential to restore SIRT1 and NAD⁺ metabolism in renal diseases.

Lipidomics Reveals Cisplatin-Induced Renal Lipid Alterations during Acute Kidney Injury and Their Attenuation by Cilastatin

Nephrotoxicity is a major complication of cisplatin-based chemotherapy, leading to acute kidney injury in ca. 30% of patients, with no preventive intervention or treatment available for clinical use. Cilastatin has proved to exert a nephroprotective effect for cisplatin therapies in in vitro and in vivo models, having recently entered clinical trials. A deeper understanding at the molecular level of cisplatin-induced renal damage and the effect of potential protective agents could be key to develop successful nephroprotective therapies and to establish new biomarkers of renal damage and nephroprotection. A targeted lipidomics approach, using LC-MS/MS, was employed for the quantification of 108 lipid species (comprising phospholipids, sphingolipids, and free and esterified cholesterol) in kidney cortex and medulla extracts from rats treated with cisplatin and/or cilastatin. Up to 56 and 63 lipid species were found to be altered in the cortex and medulla, respectively, after cisplatin treatment. Co-treatment with cilastatin attenuated many of these lipid changes, either totally or partially with respect to control levels. Multivariate analysis revealed that lipid species can be used to discriminate renal damage and nephroprotection, with cholesterol esters being the most discriminating species, along with sulfatides and phospholipids. Potential diagnostic biomarkers of cisplatin-induced renal damage and cilastatin nephroprotection were also found.

Transcriptomic analysis reveals pro-inflammatory signatures associated with acute myeloid leukemia progression

Progression of AML is associated with pro-inflammatory mediators through altered expression levels of CR1, DPEP1, IL1R1, and ST18.

Upregulated CD6 and downregulated INSR are nodes in gene expression networks linked to AML relapse, according to machine learning analysis.

Numerous studies have been performed over the last decade to exploit the complexity of genomic and transcriptomic lesions driving the initiation of acute myeloid leukemia (AML). These studies have helped improve risk classification and treatment options. Detailed molecular characterization of longitudinal AML samples is sparse, however; meanwhile, relapse and therapy resistance represent the main challenges in AML care. To this end, we performed transcriptome-wide RNA sequencing of longitudinal diagnosis, relapse, and/or primary resistant samples from 47 adult and 23 pediatric AML patients with known mutational background. Gene expression analysis revealed the association of short event-free survival with overexpression of GLI2 and IL1R1, as well as downregulation of ST18. Moreover, CR1 downregulation and DPEP1 upregulation were associated with AML relapse both in adults and children. Finally, machine learning–based and network-based analysis identified overexpressed CD6 and downregulated INSR as highly copredictive genes depicting important relapse-associated characteristics among adult patients with AML. Our findings highlight the importance of a tumor-promoting inflammatory environment in leukemia progression, as indicated by several of the herein identified differentially expressed genes. Together, this knowledge provides the foundation for novel personalized drug targets and has the potential to maximize the benefit of current treatments to improve cure rates in AML.

Effect of Cilastatin on Cisplatin-Induced Nephrotoxicity in Patients Undergoing Hyperthermic Intraperitoneal Chemotherapy

Cisplatin is one of the most widely used chemotherapeutic agents in oncology, although its nephrotoxicity limits application and dosage. We present the results of a clinical study on prophylaxis of cisplatin-induced nephrotoxicity in patients with peritoneal carcinomatosis undergoing cytoreduction and hyperthermic intraperitoneal intraoperative chemotherapy (HIPEC-cisplatin). Prophylaxis was with imipenem/cilastatin. Cilastatin is a selective inhibitor of renal dehydropeptidase I in the proximal renal tubule cells that can reduce the nephrotoxicity of cisplatin. Unfortunately, cilastatin is not currently marketed alone, and can only be administered in combination with imipenem. The study has a retrospective part that serves as a control (n = 99 patients receiving standard surgical prophylaxis) and a prospective part with imipenem/cilastatin prophylaxis corresponding to the study group (n = 85 patients). In both groups, we collected specific data on preoperative risk factors of renal damage, fluid management, hemodynamic control, and urine volume during surgery (including the hyperthermic chemotherapy perfusion), as well as data on hemodynamic and renal function during the first seven days after surgery. The main finding of the study is that cilastatin may exert a nephroprotective effect in patients with peritoneal carcinomatosis undergoing cytoreduction and hyperthermic intraperitoneal cisplatin perfusion. Creatinine values remained lower than in the control group (ANOVA test, p = 0.037). This translates into easier management of these patients in the postoperative period, with significantly shorter intensive care unit (ICU) and hospital stay.

Combination therapy of cisplatin with cilastatin enables an increased dose of cisplatin, enhancing its antitumor effect by suppression of nephrotoxicity

Cisplatin, one of the most active anticancer agents, is widely used in standard chemotherapy for various cancers. Cisplatin is more poorly tolerated than other chemotherapeutic drugs, and the main dose-limiting toxicity of cisplatin is its nephrotoxicity, which is dose-dependent. Although less toxic methods of cisplatin administration have been established, cisplatin-induced nephrotoxicity remains an unsolved problem. Megalin is an endocytic receptor expressed at the apical membrane of proximal tubules. We previously demonstrated that nephrotoxic drugs, including cisplatin, are reabsorbed through megalin and cause proximal tubular cell injury. We further found that cilastatin blocked the binding of cisplatin to megalin in vitro. In this study, we investigated whether cilastatin could reduce cisplatin-induced nephrotoxicity without influencing the antitumor effects of cisplatin. Nephrotoxicity was decreased or absent in mice treated with cisplatin and cilastatin, as determined by kidney injury molecule-1 staining and the blood urea nitrogen content. Combined with cilastatin, a twofold dose of cisplatin was used to successfully treat the mice, which enhanced the antitumor effects of cisplatin but reduced its nephrotoxicity. These findings suggest that we can increase the dose of cisplatin when combined with cilastatin and improve the outcome of cancer patients.

Formononetin protects against cisplatin‑induced acute kidney injury through activation of the PPARα/Nrf2/HO‑1/NQO1 pathway

Acute kidney injury (AKI) is characterized by an abrupt deterioration of renal function. Formononetin (FOR) protects against cisplatin (CIS)‑induced AKI, and it has various potential pharmacological and biological effects, including anti‑inflammatory, antioxidative and anti‑apoptotic effects. The current study investigated the role of FOR in CIS‑induced AKI. Rats were treated with CIS to establish an AKI model, followed by treatment with FOR. HK‑2 cells were treated with CIS, FOR, GW6471 [a peroxisome proliferator‑activated receptor α (PPARα) antagonist], eupatilin (a PPARα agonist) and nuclear factor erythroid 2‑related factor 2 (Nrf2) small interfering RNA (siNrf2), and cell proliferation and apoptosis were determined by MTT and flow cytometry assays. The mRNA and proteins levels of PPARα, Nrf2, heme oxygenase‑1 (HO‑1) and NAD(P)H quinone dehydrogenase 1 (NQO1) were measured by reverse transcription‑quantitative PCR and western blotting. The results demonstrated that FOR attenuated the histopathological changes, the levels of blood urea nitrogen, creatinine, TNF‑α and IL‑1β, and the MDA content and MPO activity, whereas it enhanced CAT activity in the AKI rat model. Furthermore, FOR and eupatilin promoted cell viability and CAT activity, and increased the levels of PPARα, Nrf2 and HO‑1 and NQO1, but suppressed apoptosis and MPO activity, and reduced the levels of MDA, TNF‑α and IL‑1β in CIS‑treated HK‑2 cells. Notably, the aforementioned effects were reversed by GW6471 treatment or siNrf2 transfection. In conclusion, FOR protects against CIS‑induced AKI via activation of the PPARα/Nrf2/HO‑1/NQO1 pathway.

Nephroprotective Effect of Cilastatin against Gentamicin-Induced Renal Injury In Vitro and In Vivo without Altering Its Bactericidal Efficiency

Gentamicin is a used antibiotic that causes nephrotoxicity in 10-20% of treatment periods, which limits its use considerably. Our results have shown that cilastatin may be a promising therapeutic alternative in toxin-induced acute kidney injury (AKI). Here, we investigated its potential use as a nephroprotector against gentamicin-induced AKI in vitro and in vivo. Porcine renal cells and rats were treated with gentamicin and/or cilastatin. In vivo nephrotoxicity was analyzed by measuring biochemical markers and renal morphology. Different apoptotic, oxidative and inflammatory parameters were studied at cellular and systemic levels. Megalin, mainly responsible for the entry of gentamicin into the cells, was also analyzed. Results show that cilastatin protects cells from gentamicin-induced AKI. Cilastatin decreased creatinine, BUN, kidney injury molecule-1 (KIM-1) and severe morphological changes previously increased by gentamicin in rats. The interference of cilastatin with lipid rafts cycling leads to decreased expression of megalin, and therefore gentamicin uptake and myeloid bodies, resulting in a decrease of apoptotic, oxidative and inflammatory events. Moreover, cilastatin did not prevent bacterial death by gentamicin. Cilastatin reduced gentamicin-induced AKI by preventing key steps in the amplification of the damage, which is associated to the disruption of megalin-gentamicin endocytosis. Therefore, cilastatin might represent a novel therapeutic tool in the prevention and treatment of gentamicin-induced AKI in the clinical setting.

Cilastatin as a protective agent against drug-induced nephrotoxicity: a literature review

INTRODUCTION

Cilastatin, a dehydropeptidase I inhibitor, has been used alongside imipenem, a broad spectrum antibiotic, in order to reduce its renal metabolism, consequently increasing its urinary recovery and effectiveness for many years. However, this measure could be useful in preventing imipenem-induced renal damage and decreasing the number of nephrotoxicity reports with imipenem. In this review, the authors gathered all available studies focusing on cilastatin use as a nephroprotective agent, beside well-known nephrotoxic medications like vancomycin, cisplatin, cyclosporine, or tacrolimus.

AREAS COVERED

PubMed, Scopus, Google Scholar, and Medline databases were searched using key words like 'cilastatin,' 'nephroprotective,' 'nephroprotection,' 'vancomycin,' 'nephrotoxicity,' 'cisplatin,' 'cyclosporine,' 'tacrolimus,' and 'prevention' with varying combinations. All relevant animal and human studies up to the date of publication were included.

EXPERT OPINION

It seems that cilastatin could potentially be effective against drug-induced nephrotoxicity via mechanisms such as reducing reactive oxygen species (ROS) production, apoptosis, P-glycoprotein suppression, and morphological changes of renal cells. Nearly all the in vitro, in vivo and human studies have supported this hypothesis. Though since cilastatin protective effect has not extensively been researched in humans, its efficacy and widespread use with other nephrotoxic agents is yet to be defined in large well-designed human studies.

Cilastatin Preconditioning Attenuates Renal Ischemia-Reperfusion Injury via Hypoxia Inducible Factor-1α Activation

Cilastatin is a specific inhibitor of renal dehydrodipeptidase-1. We investigated whether cilastatin preconditioning attenuates renal ischemia-reperfusion (IR) injury via hypoxia inducible factor-1α (HIF-1α) activation. Human proximal tubular cell line (HK-2) was exposed to ischemia, and male C57BL/6 mice were subjected to bilateral kidney ischemia and reperfusion. The effects of cilastatin preconditioning were investigated both in vitro and in vivo. In HK-2 cells, cilastatin upregulated HIF-1α expression in a time- and dose-dependent manner. Cilastatin enhanced HIF-1α translation via the phosphorylation of Akt and mTOR was followed by the upregulation of erythropoietin (EPO) and vascular endothelial growth factor (VEGF). Cilastatin did not affect the expressions of PHD and VHL. However, HIF-1α ubiquitination was significantly decreased after cilastatin treatment. Cilastatin prevented the IR-induced cell death. These cilastatin effects were reversed by co-treatment of HIF-1α inhibitor or HIF-1α small interfering RNA. Similarly, HIF-1α expression and its upstream and downstream signaling were significantly enhanced in cilastatin-treated kidney. In mouse kidney with IR injury, cilastatin treatment decreased HIF-1α ubiquitination independent of PHD and VHL expression. Serum creatinine level and tubular necrosis, and apoptosis were reduced in cilastatin-treated kidney with IR injury, and co-treatment of cilastatin with an HIF-1α inhibitor reversed these effects. Thus, cilastatin preconditioning attenuated renal IR injury via HIF-1α activation.

Protective effect of cilastatin against diclofenac-induced nephrotoxicity through interaction with diclofenac acyl glucuronide via organic anion transporters

BACKGROUND AND PURPOSE

Diclofenac is a widely used nonsteroidal anti-inflammatory drug. However, adverse effects in the kidney limit its clinical application. The present study was aimed to evaluate the potential effect of cilastatin on diclofenac-induced acute kidney injury and to clarify the potential roles of renal organic anion transporters (OATs) in the drug-drug interaction between cilastatin and diclofenac.

EXPERIMENTAL APPROACH

The effect of cilastatin was evaluated in diclofenac-induced acute kidney injury in mice. Human OAT1/3-transfected HEK293 cells and renal primary proximal tubule cells (RPTCs) were used to investigate OAT1/3-mediated transport and the cytotoxicity of diclofenac.

KEY RESULTS

Cilastatin treatment decreased the pathological changes, renal dysfunction and elevated renal levels of oxidation products, cytokine production and apoptosis induced by diclofenac in mice. Moreover, cilastatin increased the plasma concentration and decreased the renal distribution of diclofenac and its glucuronide metabolite, diclofenac acyl glucuronide (DLF-AG). Similarly, cilastatin inhibited cytotoxicity and mitochondrial damage in RPTCs but did not change the intracellular accumulation of diclofenac. DLF-AG but not diclofenac exhibited OAT-dependent cytotoxicity and was identified as an OAT1/3 substrate. Cilastatin inhibited the intracellular accumulation and decreased the cytotoxicity of DLF-AG in RPTCs.

CONCLUSION AND IMPLICATIONS

Cilastatin alleviated diclofenac-induced acute kidney injury in mice by restoring the redox balance, suppressing inflammation, and reducing apoptosis. Cilastatin inhibited OATs and decreased the renal distribution of diclofenac and DLF-AG, which further ameliorated the diclofenac-induced nephrotoxicity in mice. Cilastatin can be potentially used in the clinic as a therapeutic agent to alleviate the adverse renal reaction to diclofenac.

Therapeutic Effects of the Combination of Alpha-Lipoic Acid (ALA) and Coenzyme Q10 (CoQ10) on Cisplatin-Induced Nephrotoxicity

Background

Nephrotoxicity of cisplatin has been recognized since its introduction more than 25 years ago. However, despite intense efforts to develop less toxic and equally effective alternatives, cisplatin continues to be widely prescribed. Aim and Objectives. The study is aimed at assessing the possible prophylactic effect of coenzyme Q10 (CoQ10) and alpha-lipoic acid (ALA) (separately or in combination) on experimentally cisplatin-induced nephrotoxicity. Subjects and Methods. An experimental study was performed on adult male albino rats (n = 40), weighing 200–250 g. Rats were randomly divided into 5 groups: group I (normal saline control), group II (cisplatin control), group III (CoQ10 and cisplatin), group IV (ALA and cisplatin), and group V (CoQ10, ALA, and cisplatin). CoQ10 and/or ALA were given as pretreatment for 9 days, followed by cisplatin injection in the 10th day of the study, followed by a short posttreatment course for 3 days. Renal functions, tissue antioxidant activity, and inflammatory markers (tumor necrosis factor, TNF) were estimated along with histopathological study.

Results

Renal function tests and urinary proteins were significantly higher within group II compared with other groups (P value <0.001). Creatinine clearance was significantly higher with combination therapy (group V compared to other groups). Both TNF and malondialdehyde (MDA) were significantly higher within group II whereas GSH content, catalase, and superoxide dismutase (SOD) were significantly lower in group II. MDA level was significantly lower when combination therapy was used. Marked renal damage was histologically detected in the cisplatin group, whereas the least renal damage was noticed in the combination group.

Conclusion

The study confirmed the role of antioxidants in preventing nephrotoxicity caused by cisplatin; the prophylactic effect of combined therapy with CoQ10 and ALA is superior to that of monotherapy.

Modulatory effect of zingerone against cisplatin or γ-irradiation induced hepatotoxicity by molecular targeting regulation

Zingerone (ZO) is an ingredient of ginger (Zingiber officinale) which has different pharmacological properties. The objective of this research was to evaluate the protective effect of ZO against Cisplatin (Cis) or γ-Irradiation (IR)-induced hepatotoxicity in rats. ZO was given orally for consecutive 14 days prior to the treatment with Cis or exposure to IR at 15th day. Animals were sacrificed at the 23rd day. Cis or IR induced a marked increase in MAPK signal transduction as evidenced by increased p38 MAPK, JNK and ErK1/2. CYP2E1 and NADPH oxidase were significantly up-regulated. Inflammatory markers (TLR4, iNOS, COX-2 and MPO) and liver enzymes (AST, ALT and ALP) activities were also increased. Administration of ZO significantly ameliorated the above mentioned parameters.

Cilastatin protects against imipenem-induced nephrotoxicity via inhibition of renal organic anion transporters (OATs)

Imipenem is a carbapenem antibiotic. However, Imipenem could not be marketed owing to its instability and nephrotoxicity until cilastatin, an inhibitor of renal dehydropeptidase-I (DHP-I), was developed. In present study, the potential roles of renal organic anion transporters (OATs) in alleviating the nephrotoxicity of imipenem by cilastatin were investigated in vitro and in rabbits. Our results indicated that imipenem and cilastatin were substrates of hOAT1 and hOAT3. Cilastatin inhibited hOAT1/3-mediated transport of imipenem with IC₅₀ values comparable to the clinical concentration, suggesting the potential to cause a clinical drug–drug interaction (DDI). Moreover, imipenem exhibited hOAT1/3-dependent cytotoxicity, which was alleviated by cilastatin and probenecid. Furthermore, cilastatin and probenecid ameliorated imipenem-induced rabbit acute kidney injury, and reduced the renal secretion of imipenem. Cilastatin and probenecid inhibited intracellular accumulation of imipenem and sequentially decreased the nephrocyte toxicity in rabbit primary proximal tubule cells. Renal OATs, besides DHP-I, was also the target of interaction between imipenem and cilastatin, and contributed to the nephrotoxicity of imipenem. This therefore gives in part the explanation about the mechanism by which cilastatin protected against imipenem-induced nephrotoxicity. Thus, OATs can potentially be used as a therapeutic target to avoid the renal adverse reaction of imipenem in clinic.

Cilastatin protects against tacrolimus-induced nephrotoxicity via anti-oxidative and anti-apoptotic properties

BACKGROUND

Cilastatin (CL) is an inhibitor of dehydropeptidase-I, which is safely used in clinical practice to prevent nephrotoxicity of antibiotics. Tacrolimus (TAC) is the most important immunosuppressant in renal transplantation, but it causes considerable nephrotoxicity. We evaluated the protective effects of CL against chronic TAC-induced nephropathy.

METHODS

Chronic nephropathy was induced by administering TAC (1.5 mg/kg/ day, subcutaneous injection) to rats on a low-salt diet for 4 weeks. CL (75 or 150 mg/kg/day, intraperitoneal injection) was concomitantly treated with TAC. Human proximal tubular cells were exposed to TAC (50 μg/mL) with or without CL (250 μg/mL). We investigated the effects of CL on TAC-induced injury in terms of renal function, tubulointerstitial fibrosis, and inflammation. The effects of CL on oxidative stress and apoptosis were evaluated in both in vivo and in vitro models of TAC nephrotoxicity.

RESULTS

CL treatment improved TAC-induced renal dysfunction and decreased renal interstitial fibrosis (reduced expression of e-cadherin and TGFβ-1) and interstitial inflammation (decreased infiltration of ED-1-positive and osteopontin-positive cells). Compared to TAC treatment alone, CL co-treatment reduced oxidative stress (serum 8-OHdG level and immunoreactivity of 8-OHdG and 4-HHE in renal tissue) and increased renal expression of anti-oxidant enzyme, manganese superoxide dismutase. CL treatment decreased apoptotic cell death (decreased TUNEL-positive cells and reduced expression of active caspase-3) in TAC-treated kidney. In vitro CL treatment prevented tubular cell death from TAC treatment and decreased number of annexin V-positive cells were observed in cilastatin-cotreated cells.

CONCLUSION

CL has protective effects against chronic TAC-induced nephrotoxicity owing to its anti-oxidative and anti-apoptotic properties.

Establishment of renal proximal tubule cell lines derived from the kidney of p53 knockout mice

The human cell line HK-2 is most commonly used as a model of renal proximal tubular epithelial cells (PTECs) for various studies despite the absence or low expression of transporters characteristic of parental PTECs. In an effort to develop reliable PTEC models, several human cell lines have been newly established over the last decade. In contrast, reliable mouse PTEC models are still unavailable. In this study, we established immortalized renal cortex tubule cell lines derived from p53 knockout mice and evaluated various PTEC characteristics toward the development of reliable mouse PTEC models. Here, we focus on MuRTE61, one of 13 newly established clonal cell lines. Albumin uptake in MuRTE61 cells was verified by incubation with fluorescent dye-labeled albumin. RT-PCR confirmed the expression of efflux transporter genes characteristic of PTECs in the MuRTE61 cells. MuRTE61 cells exhibited high sensitivity to treatment with cisplatin, a nephrotoxic agent, accompanied by upregulated expression of the uptake transporter Slc22a2 gene. Furthermore, MuRTE61 cells consistently formed spheroids with a lumen and apicobasal polarity in three-dimensional Matrigel cultures. Apical brush border microvilli were also observed in the spheroids by transmission electron microscopy. These data validate that MuRTE61 can be characterized as a reliable mouse PTEC line. In future, detailed analysis of reliable mouse and human PTEC lines will provide an accurate extrapolation of results of experiments using mice and humans, and may help resolve apparent inconsistencies between mouse and human nephrotoxicity.

Taurine Administration Mitigates Cisplatin Induced Acute Nephrotoxicity by Decreasing DNA Damage and Inflammation: An Immunocytochemical Study

Cisplatin (CDDP) is one of the most effective chemotherapeutic agent used in the treatment of many kind of solid tumors. Its primary side effect is nephrotoxicity. The aim of this study to investigate the effects of taurine on cisplatin-induced acute nephrotoxicity. A single intraperitoneal injection of CDDP (15 mg/kg, or 25 mg/kg) deteriorated the kidney functions as reflected by histopathological changes. Histopathological changes were observed in all cisplatin groups. In the cisplatin group, oxidative stress was evident in the cisplatin group by observing an increase in 8-OHdG expression, an indicator of oxidative DNA damage. CDDP also resulted to an increase in CD68 expression in the renal tissues of CDDP groups. Taurine transporter (TauT) was down-regulated, and p53 was up-regulated in renal tissues as indicated by immunohistochemical analysis. Administration with taurine prior to a cisplatin injection was able to protect against deterioration of kidney function, to abrogate the decline in anti-oxidants and to suppress the increase in DNA damage. Moreover, taurine inhibited p53 activation and improved the pathological changes induced by cisplatin. This study demonstrates the protective effects of taurine in attenuating the expression of pro-inflammatory mediators and in improving antioxidant capacity in the kidney of cisplatin-injected rats. Thus, taurine could be a beneficial dietary supplement to attenuate cisplatin induced nephrotoxicity.

Lipid imaging for visualizing cilastatin amelioration of cisplatin-induced nephrotoxicity

Nephrotoxicity is a major limitation to cisplatin antitumor therapies. Cilastatin, an inhibitor of renal dehydropeptidase-I, was recently proposed as a promising nephroprotector against cisplatin toxicity, preventing apoptotic cell death. In this work, cilastatin nephroprotection was further investigated in a rat model, with a focus on its effect on 76 renal lipids altered by cisplatin, including 13 new cisplatin-altered mitochondrial cardiolipin species. Lipid imaging was performed with MALDI mass spectrometry imaging (MALDI-MSI) in kidney sections from treated rats. Cilastatin was proved to significantly diminish the lipid distribution alterations caused by cisplatin, lipid levels being almost completely recovered to those of control samples. The extent of recovery of cisplatin-altered lipids by cilastatin turned out to be relevant for discriminating direct or secondary lipid alterations driven by cisplatin. Lipid peroxidation induced by cisplatin was also shown to be reduced when cilastatin was administered. Importantly, significant groups separation was achieved during multivariate analysis of cortex and outer-medullary lipids, indicating that damaged kidney can be discerned from the nephroprotected and healthy groups and classified according to lipid distribution. Therefore, we propose MALDI-MSI as a powerful potential tool offering multimolecule detection possibilities to visualize and evaluate nephrotoxicity and nephroprotection based on lipid analysis.

Renal immune surveillance and dipeptidase-1 contribute to contrast-induced acute kidney injury

Radiographic contrast agents cause acute kidney injury (AKI), yet the underlying pathogenesis is poorly understood. Nod-like receptor pyrin containing 3-deficient (Nlrp3-deficient) mice displayed reduced epithelial cell injury and inflammation in the kidney in a model of contrast-induced AKI (CI-AKI). Unexpectedly, contrast agents directly induced tubular epithelial cell death in vitro that was not dependent on Nlrp3. Rather, contrast agents activated the canonical Nlrp3 inflammasome in macrophages. Intravital microscopy revealed diatrizoate (DTA) uptake within minutes in perivascular CX3CR1+ resident phagocytes in the kidney. Following rapid filtration into the tubular luminal space, DTA was reabsorbed and concentrated in tubular epithelial cells via the brush border enzyme dipeptidase-1 in volume-depleted but not euvolemic mice. LysM-GFP+ macrophages recruited to the kidney interstitial space ingested contrast material transported from the urine via direct interactions with tubules. CI-AKI was dependent on resident renal phagocytes, IL-1, leukocyte recruitment, and dipeptidase-1. Levels of the inflammasome-related urinary biomarkers IL-18 and caspase-1 were increased immediately following contrast administration in patients undergoing coronary angiography, consistent with the acute renal effects observed in mice. Taken together, these data show that CI-AKI is a multistep process that involves immune surveillance by resident and infiltrating renal phagocytes, Nlrp3-dependent inflammation, and the tubular reabsorption of contrast via dipeptidase-1.

Renoprotective Effects of Hypoxylonol C and F Isolated from Hypoxylon truncatum against Cisplatin-Induced Cytotoxicity in LLC-PK1 Cells

Although cisplatin is the standard platinum-based anticancer drug used to treat various solid tumors, it can cause damage in normal kidney cells. Protective strategies against cisplatin-induced nephrotoxicity are, therefore, clinically important and urgently required. To address this challenge, we investigated the renoprotective effects of Hypoxylontruncatum, a ball-shaped wood-rotting fungus. Chemical investigation of the active fraction from the methanol extract of H.truncatum resulted in the isolation and identification of the renoprotective compounds, hypoxylonol C and F, which ameliorated cisplatin-induced nephrotoxicity to approximately 80% of the control value at 5 μM. The mechanism of this effect was further investigated using hypoxylonol F, which showed a protective effect at the lowest concentration. Upregulated phosphorylation of p38, extracellular signal-regulated kinases, and c-Jun N-terminal kinases following cisplatin treatment were markedly decreased after pre-treatment with hypoxylonol F. In addition, the protein expression level of cleaved caspase-3 was significantly reduced after co-treatment with hypoxylonol F. These results show that blocking the mitogen-activated protein kinase signaling cascade plays a critical role in mediating the renoprotective effect of hypoxylonol F isolated from H.truncatum fruiting bodies.

Cisplatin-induced renal inflammation is ameliorated by cilastatin nephroprotection

Background

Cisplatin is a potent chemotherapeutic drug whose nephrotoxic effect is a major complication and a dose-limiting factor for antitumoral therapy. There is much evidence that inflammation contributes to the pathogenesis of cisplatin-induced nephrotoxicity. We found that cilastatin, a renal dehydropeptidase-I inhibitor, has protective effects in vitro and in vivo against cisplatin-induced renal damage by inhibiting apoptosis and oxidation. Here, we investigated the potential use of cilastatin to protect against cisplatin-induced kidney injury and inflammation in rats.

Methods

Male Wistar rats were divided into four groups: control, cilastatin-control, cisplatin and cilastatin-cisplatin. Nephrotoxicity was assessed 5 days after administration of cisplatin based on blood urea nitrogen, creatinine, glomerular filtration rate (GFR), kidney injury molecule (KIM)-1 and renal morphology. Inflammation was measured using the electrophoretic mobility shift assay, immunohistochemical studies and evaluation of inflammatory mediators.

Results

Compared with the control rats, cisplatin-administered rats were affected by significant proximal tubule damage, decreased GFR, increased production of inflammatory mediators and elevations in urea, creatinine and tissue KIM-1 levels. Cilastatin prevented these changes in renal function and ameliorated histological damage in cisplatin-administered animals. Cilastatin also reduced pro-inflammatory cytokine levels, activation of nuclear factor-κB and CD68-positive cell concentrations.

Conclusions

Cilastatin reduces cisplatin-induced nephrotoxicity, which is associated with decreased inflammation in vivo. Although the exact role of decreased inflammation in nephroprotection has not been fully elucidated, treatment with cilastatin could be a novel strategy for the prevention of cisplatin-induced acute kidney injury.

Cyanidin ameliorates cisplatin-induced cardiotoxicity via inhibition of ROS-mediated apoptosis

Oxidative stress and apoptosis serve an essential role in cisplatin-induced cardiotoxicity, which limits its clinical use, and increases the risk of cardiovascular disease. As a natural drug, the antioxidant and antitumor effects of cyanidin have been recognized, but its protective effect on cisplatin-induced cardiomyocyte cytotoxicity remains unclear. H9c2 cells were treated with cisplatin (1–40 µM) in the presence or absence of cyanidin (40–80 µM), subsequently; oxidative stress, apoptosis and mitochondrial function were assessed using several techniques. The results demonstrated that cyanidin was able to dose-dependently reverse cisplatin-induced cell damage and apoptosis, attenuate the accumulation of reactive oxygen species (ROS), and mitochondrial membrane potential depolarization, downregulate the expression of Bcl-2 homologous antagonist/killer, upregulate the expression of apoptosis regulator Bcl-2, and reduce the activation of caspase 3, caspase 9, but not caspase 8. Furthermore, the results revealed that the translocation of apoptosis regulator Bax (Bax) from the cytoplasm to the mitochondrial membrane serves an essential role in cisplatin-induced apoptosis. Cyanidin was able to block the translocation of Bax and reduce the release of cytochrome c from cytoplasm. These data indicate that cyanidin attenuates cisplatin-induced cardiotoxicity by inhibiting ROS-mediated apoptosis, while the mitochondrial and extracellular regulated kinase signaling pathways may also serve important roles.

Hemodynamic and renal implications of sodium-glucose cotransporter- 2 inhibitors in type 2 diabetes mellitus

In DM2, there is increased expression of the proximal glucose transporter SGLT2. The increased glucose reabsorption from the urine to the proximal tubule and subsequently to the bloodstream, has three direct effects on the prognosis of patients with DM2: a) it increases the daily glucose load by raising the renal threshold for glucose, thus augmenting requirements for oral antidiabetics and insulin. This progressive increase occurs throughout the course of the disease and in parallel with the increase in renal mass (renal hypertrophy); b) because of the greater glucose reabsorption, glycosuria is lower than the level corresponding to glycaemia, decreasing the stimulus on the tubuloglomerular feedback system of the distal nephron. As a result, the glomerular vasodilation caused by hyperglycaemia is not arrested, maintaining glomerular hyperfiltration, and c) the excess glucose transported to the proximal tubular cells modifies their redox status, increasing local production of glycosylating products and activating local production of proinflammatory and profibrotic proliferative mediators. These mediators are responsible for the direct free radical damage to proximal tubular cells, for increased SGLT2 expression, increased production of collagen IV and extracellular matrix, and activation of monocyte/macrophages able to cause endothelial injury. The use of SGLT2 inhibitors not only reduces the reabsorption of glucose from the glomerular filtrate back into the circulationthus improving metabolic control in diabetesbut also restores tubuloglomerular feedback by increasing glycosuria and distal urinary flow. However, the most notable effect is due to inhibition of glucose entry to the proximal tubular cells. Glycosuria is toxic to the kidney: it harms glucosetransporting cells, that is, the proximal cells, which contain SGLT2. In animal models, SGLT2 inhibition reduces local production of oxygen-free radicals, the formation of mesangial matrix and collagen IV, glomerular infiltration by inflammatory cells and monocyte/macrophage-dependent arteriosclerosis. In humans, SGLT2 have a demonstrated ability to reduce renal injury and cardiovascular risk in patients with type 2 diabetes mellitus.

ELABELA and an ELABELA Fragment Protect against AKI

Renal ischemia-reperfusion (I/R) injury is the most common cause of AKI, which associates with high mortality and has no effective therapy. ELABELA (ELA) is a newly identified 32-residue hormone peptide highly expressed in adult kidney. To investigate whether ELA has protective effects on renal I/R injury, we administered the mature peptide (ELA32) or the 11-residue furin-cleaved fragment (ELA11) to hypoxia-reperfusion (H/R)-injured or adriamycin-treated renal tubular cells in vitro ELA32 and ELA11 significantly inhibited the elevation of the DNA damage response, apoptosis, and inflammation in H/R-injured renal tubular cells and suppressed adriamycin-induced DNA damage response. Similarly, overexpression of ELA32 or ELA11 significantly inhibited H/R-induced cell death, DNA damage response, and inflammation. Notably, treatment of mice with ELA32 or ELA11 but not an ELA11 mutant with a cysteine to alanine substitution at the N terminus (AE11C) inhibited I/R injury-induced renal fibrosis, inflammation, apoptosis, and the DNA damage response and markedly reduced the renal tubular lesions and renal dysfunction. Together, our results suggest that ELA32 and ELA11 may be therapeutic candidates for treating AKI.

Cilastatin attenuates vancomycin-induced nephrotoxicity via P-glycoprotein

BACKGROUND

Oxidative stress is one of the main pathogenic mechanisms in vancomycin-induced nephrotoxicity (VIN). Some studies suggest proximal renal tubular cell necrosis by vancomycin accumulation as a mechanism of nephrotoxicity, and other studies demonstrate that cilastatin has protective effects against drug-induced nephrotoxicity. We investigated whether cilastatin regulates p-gp expression and whether cilastation prevents VIN.

MATERIALS AND METHODS

We conducted an in vitro study using an immortalized proximal tubule epithelial cell line from a normal adult human kidney (HK-2) and an in vivo study using male C57BL/6J mice.

RESULTS

Vancomycin showed dose-dependent toxicity in the HK-2 cells, and cilastatin attenuated VIN. Vancomycin provoked the reactive oxygen species in a dose-dependent pattern on DCF-DA. Caspase 3/7 activity showed a dose-dependent increase at 6h. We confirmed apoptosis by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay at 24h (vancomcyin 2mM). Cilastatin attenuated vancomycin-induced ROS production and apoptosis, and it also attenuated vancomycin-induced P-gp suppression. In vivo, vancomycin (400mg/kg, 600mg/kg IP, 7days) induced acute kidney injury, as demonstrated by elevated blood urea nitrogen and creatinine. Histological examination of the sections indicated greater tubular damage in the vancomycin-treated kidney compared with the control. TUNEL-positive cells decreased significantly in the mouse kidney with cilastatin and vancomycin. Bax/Bcl-2 ratio were significantly increased in the vancomycin-treated kidney. Cilastatin 300mg/kg treatment significantly decreased the vancomycin concentrations in the blood and kidney.

CONCLUSION

Our study showed that mechanism of VIN might be involved, at least in part, in suppressing P-gp function, and cilastatin attenuated VIN.

Ameliorative effect of an oxovanadium (IV) complex against oxidative stress and nephrotoxicity induced by cisplatin

OBJECTIVE

The present study was designed to investigate the chemoprotective efficacy of an L-cysteine-based oxovanadium (IV) complex, namely, oxovanadium (IV)-L-cysteine methyl ester complex (VC-IV) against cisplatin (CDDP)-induced renal injury in Swiss albino mice.

METHODS

CDDP was administered intraperitoneally (5 mg/kg body weight) and VC-IV was administered orally (1 mg/kg body weight) in concomitant and 7 days pre-treatment schedule.

RESULTS

CDDP-treated mice showed marked kidney damage and renal failure. Administration of VC-IV caused significant attenuation of renal oxidative stress and elevation of antioxidant status. VC-IV also significantly decreased serum levels of creatinine and blood urea nitrogen, and improved histopathological lesions. Western blot analysis of the kidneys showed that VC-IV treatment resulted in nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) through modulation of cytosolic Kelch-like ECH-associated protein 1. Thus, VC-IV stimulated Nrf2-mediated activation of antioxidant response element (ARE) pathway and promoted expression of ARE-driven cytoprotective proteins, heme oxygenase 1 and NAD(P)H:quinone oxidoreductase 1, and enhanced activity of antioxidant enzymes. Interestingly, VC-IV did not alter the bioavailability and renal accumulation of CDDP in mice.

DISCUSSION

In this study, VC-IV exhibited strong nephroprotective efficacy by restoring antioxidant defense mechanisms and hence may serve as a promising chemoprotectant in cancer chemotherapy.

Safety assessment and attenuation of cisplatin induced nephrotoxicity by tuberous roots of Boerhaavia diffusa

Cisplatin (Cis-diaminedichloroplatinum II) is a chemotherapeutic agent having well documented adverse effect as nephrotoxicity. This study was designed to evaluate the nephroprotective role of Boerhaavia diffusa in cisplatin-induced acute kidney injury. Wistar rats (n = 6) were allocated into six groups constituting normal control, cisplatin-induced, Boerhaavia diffusa root extract in doses 50, 100 and 200 mg/kg and Boerhaavia diffusa per se group, administered orally for a period of ten days. Intraperitoneal injection of cisplatin was administered on day 7, to all groups except normal control and Boerhaavia diffusa per se group. On day 10, cisplatin resulted in substantial nephrotoxicity in Wistar rats with significant (p < 0.001) elevation in serum creatinine and blood urea nitrogen, decline in the concentrations of reduced glutathione and superoxide dismutase, elevation in TNF-α level in renal tissues. Boerhaavia diffusa at a dose of 200 mg/kg body weight significantly (p < 0.001) ameliorates increased in serum creatinine, blood urea nitrogen, oxidative stress and inflammatory markers. In parallel to this, it also exhibits antiapoptotic activity through the reduction of active caspase-3 expression in kidneys. Findings indicate that Boerhaavia diffusa is effective in mitigating cisplatin-induced nephrotoxicity and thus, for this the acute and sub-acute toxicity studies conducted to evaluate the safety profile of Boerhaavia diffusa. The no-observed adverse effect level (NOAEL) of tuberous roots of Boerhaavia diffusa root extract was 1000 mg/kg.

Biliverdin protects against cisplatin-induced apoptosis of renal tubular epithelial cells

Biliverdin (BV) has long been thought to be a cytotoxic metabolic waste product. It has also been demonstrated to have important cytoprotective functions during oxidative stress. The present study aimed to examine the cytoprotective effect of BV on NRK-52E cells, a proximal tubular cell line derived from rat kidney. Cells were treated with 50 µmol/L cisplatin for 24 h (cisplatin group) or pre-treated with BV for 30 min, then with 50 µmol/L cisplatin for 24 h (cisplatin+BV group). Those given no treatment served as a control. Cell apoptosis was evaluated by flow cytometry and cell viability by Cell Counting Kit-8 (CCK-8). The protein expressions of cleaved caspase3, Bax and Bcl-2 were assessed by Western blotting. Reactive oxygen species (ROS) levels were measured using carboxydichlorodihydrofluorescein diacetate (H2DCF). The results showed that cisplatin induced the apoptosis of NRK-52E cells, decreased cell viability, and increased the formation of ROS by upregulating the expression of cleaved caspase3 and Bax and decreasing Bcl-2 protein expression. These effects could be significantly reversed by pretreatment with BV. It was concluded that BV can protect against cisplatin-induced cell apoptosis through the anti-oxidative effects.

Protective Effects of Cilastatin against Vancomycin-Induced Nephrotoxicity

Vancomycin is a very effective antibiotic for treatment of severe infections. However, its use in clinical practice is limited by nephrotoxicity. Cilastatin is a dehydropeptidase I inhibitor that acts on the brush border membrane of the proximal tubule to prevent accumulation of imipenem and toxicity. The aim of this study was to investigate the potential protective effect of cilastatin on vancomycin-induced apoptosis and toxicity in cultured renal proximal tubular epithelial cells (RPTECs). Porcine RPTECs were cultured in the presence of vancomycin with and without cilastatin. Vancomycin induced dose-dependent apoptosis in cultured RPTECs, with DNA fragmentation, cell detachment, and a significant decrease in mitochondrial activity. Cilastatin prevented apoptotic events and diminished the antiproliferative effect and severe morphological changes induced by vancomycin. Cilastatin also improved the long-term recovery and survival of RPTECs exposed to vancomycin and partially attenuated vancomycin uptake by RPTECs. On the other hand, cilastatin had no effects on vancomycin-induced necrosis or the bactericidal effect of the antibiotic. This study indicates that cilastatin protects against vancomycin-induced proximal tubule apoptosis and increases cell viability, without compromising the antimicrobial effect of vancomycin. The beneficial effect could be attributed, at least in part, to decreased accumulation of vancomycin in RPTECs.

Grape seed proanthocyanidins ameliorates cadmium-induced renal injury and oxidative stress in experimental rats through the up-regulation of nuclear related factor 2 and antioxidant responsive elements

Cadmium (Cd) preferentially accumulates in the kidney, the major target for Cd-related toxicity. Cd-induced reactive oxygen species (ROS) have been considered crucial mediators for renal injury. The biologically significant ionic form of cadmium (Cd+) binds to many bio-molecules, and these interactions underlie the toxicity mechanisms of Cd. The present study was hypothesized to explore the protective effect of grape seed proanthocyanidins (GSP) on Cd-induced renal toxicity and to elucidate the potential mechanism. Male Wistar rats were treated with Cd as cadmium chloride (CdCl2, 5 mg·kg−1 bw, orally) and orally pre-administered with GSP (100 mg·kg−1 bw) 90 min before Cd intoxication for 4 weeks to evaluate renal damage of Cd and antioxidant potential of GSP. Serum renal function parameters (blood urea nitrogen and creatinine) levels in serum and urine, renal oxidative stress (lipid peroxidation, protein carbonylation, enzymatic, and non-enzymatic antioxidants), inflammatory (NF-κB p65, NO, TNF-α, IL-6), apoptotic (caspase-3, caspase-9, Bax, Bcl-2), membrane bound ATPases, and Nrf2 (HO-1, keap1, γ-GCS, and μ-GST) markers were evaluated in Cd-treated rats. Pretreatment with GSP revealed a significant improvement in renal oxidative stress markers in kidneys of Cd-treated rats. In addition, GSP treatment decreases the amount of iNOS, NF-κB, TNF-α, caspase-3, and Bax and increases the levels Bcl-2 protein expression. Similarly, mRNA and protein analyses substantiated that GSP treatment notably normalizes the renal expression of Nrf2/Keap1 and its downstream regulatory proteins in the Cd-treated rats. Histopathological and ultra-structural observations also demonstrated that GSP effectively protects the kidney from Cd-induced oxidative damage. These findings suggest that GSP ameliorates renal dysfunction and oxidative stress through the activation of Nrf2 pathway in Cd-intoxicated rats.

The pseudoginsenoside F11 ameliorates cisplatin-induced nephrotoxicity without compromising its anti-tumor activity in vivo

The clinical use of cisplatin was severely limited by its associated nephrotoxicity. In this study, we investigated whether the pseudoginsenoside F11 had protective effects against cisplatin-induced nephrotoxicity. To clarify it, one in vivo model of cisplatin-induced acute renal failure was performed. The results showed that pretreatment with F11 reduced cisplatin-elevated blood urea nitrogen and creatinine levels, as well as ameliorated the histophathological damage. Further studies showed that F11 could suppress P53 activation, inverse the ratio of Bax/Bcl2 and the anti-oxidative and free radical levels induced by cisplatin, which in turn inhibited tubular cell apoptosis. Importantly, F11 enhanced rather than inhibited the anti-tumor activity of cispaltin in murine melanoma and Lewis lung cancer xenograft tumor models. Our findings suggested that administering F11 with cisplatin might alleviate the associated nephrotoxicity without compromising its therapeutic efficiency. This finding provides a novel potential strategy in the clinical treatment of cancer.

Epigallocatechin gallate supplementation protects against renal injury induced by fluoride intoxication in rats: Role of Nrf2/HO-1 signaling

Fluoride intoxication generates free radicals, causing oxidative stress that plays a critical role in the progression of nephropathy. In the present study, we hypothesized that epigallocatechin gallate (EGCG), found in green tea, protects the kidneys of rats treated with fluoride by preventing oxidative stress, inflammation, and apoptosis. Pretreatment of fluoride-treated rats with EGCG resulted in a significant normalization of creatinine clearance and levels of urea, uric acid, and creatinine. Fluoride intoxication significantly increased renal oxidative stress markers and decreased the levels of renal enzymatic and non-enzymatic antioxidants. In addition, renal NO, TNF-α, IL-6 and NF-κB were also increased in the renal tissue of fluoride-treated rats. Further, EGCG pretreatment produced a significant improvement in renal antioxidant status and reduced lipid peroxidation, protein carbonylation and the levels of inflammatory markers in fluoride-treated kidney. Similarly, mRNA and protein analyses showed that EGCG pretreatment normalized the renal expression of Nrf2/Keap1 and its downstream regulatory proteins in fluoride-treated rat kidney. EGCG also effectively attenuated fluoride-induced renal apoptosis by the up-regulation of anti-apoptotic proteins such as Bcl-2 and down-regulation of Bax, caspase-3, caspase-9 and cytochrome c. Histology and immunohistochemical observations of Kim-1 provided further evidence that EGCG effectively protects the kidney from fluoride-mediated oxidative damage. These results suggest that EGCG ameliorates fluoride-induced oxidative renal injury by activation of the Nrf2/HO-1 pathway.

Renal protective effect of sirtuin 1

Silent information regulator 2 (Sir2) is a nicotinamide adenine dinucleotide- (NAD(+)-) dependent deacetylase. The homology of SIRT1 and Sir2 has been extensively studied. SIRT1 deacetylates target proteins using the coenzyme NAD(+) and is therefore linked to cellular energy metabolism and the redox state through multiple signalling and survival pathways. During the past decade, investigators have reported that SIRT1 activity is essential in cancer, neurodegenerative diseases, diabetes, cardiovascular disease, and other age-related diseases. In the kidneys, SIRT1 may inhibit renal cell apoptosis, inflammation, and fibrosis. Therefore its activation may also become a new therapeutic target in the patients with chronic kidney disease including diabetic nephropathy. In this paper, we would like to review the protective functions of sirtuins and the role of SIRT1 in the onset of kidney disease based on previous studies, including diabetic nephropathy, acute renal injury, chronic kidney disease as well as lupus nephritis.

Interleukin 18 as a marker of chronic nephropathy in children after anticancer treatment

Novel markers of nephrotoxicity, including kidney injury molecule 1 (KIM-1), interleukin 18 (IL-18), and beta-2 microglobulin, were used in the detection of acute renal injury. The aim of the study was to establish the frequency of postchemotherapy chronic kidney dysfunction in children and to assess the efficacy of IL-18, KIM-1, and beta-2 microglobulin in the detection of chronic nephropathy. We examined eighty-five patients after chemotherapy (median age of twelve years). The median age at the point of diagnosis was 4.2 years, and the median follow-up time was 4.6 years. We performed classic laboratory tests assessing kidney function and compared the results with novel markers (KIM-1, beta-2 microglobulin, and IL-18). Features of subclinical renal injury were identified in forty-eight children (56.3% of the examined group). Nephropathy, especially tubulopathy, appeared more frequently in patients treated with ifosfamide, cisplatin, and/or carboplatin, following nephrectomy or abdominal radiotherapy (P = 0.14, P = 0.11, and P = 0.08, resp.). Concentrations of IL-18 and beta-2 microglobulin were comparable with classic signs of tubulopathy (P = 0.0001 and P = 0.05). Concentrations of IL-18 were also significantly higher in children treated with highly nephrotoxic drugs (P = 0.0004) following nephrectomy (P = 0.0007) and abdominal radiotherapy (P = 0.01). Concentrations of beta-2 microglobulin were higher after highly toxic chemotherapy (P = 0.004) and after radiotherapy (P = 0.02). ROC curves created utilizing IL-18 data allowed us to distinguish between children with nephropathy (value 28.8 pg/mL) and tubulopathy (37.1 pg/mL). Beta-2 microglobulin and IL-18 seem to be promising markers of chronic renal injury in children after chemotherapy.