Metabolism of Cisplatin to a nephrotoxin in proximal tubule cells

Oral delivery of nanoparticle urolithin A normalizes cellular stress and improves survival in mouse model of cisplatin-induced AKI

The popular anticancer drug cisplatin causes many adverse side effects, the most serious of which is acute kidney injury (AKI). Emerging evidence from laboratory and clinical studies suggests that the AKI pathogenesis involves oxidative stress pathways; therefore, regulating such pathways may offer protection. Urolithin A (UA), a gut metabolite of the dietary tannin ellagic acid, possesses antioxidant properties and has shown promise in mouse models of AKI. However, therapeutic potential of UA is constrained by poor bioavailability. We aimed to improve oral bioavailability of UA by formulating it into biodegradable nanoparticles that use a surface-conjugated ligand targeting the gut-expressed transferrin receptor. Nanoparticle encapsulation of UA led to a sevenfold enhancement in oral bioavailability compared with native UA. Treatment with nanoparticle UA also significantly attenuated the histopathological hallmarks of cisplatin-induced AKI and reduced mortality by 63% in the mouse model. Expression analyses indicated that nanoparticle UA therapy coincided with oxidative stress mitigation and downregulation of nuclear factor erythroid 2-related factor 2- and P53-inducible genes. Additionally, normalization of miRNA (miR-192-5p and miR-140-5p) implicated in AKI, poly(ADP-ribose) polymerase 1 levels, antiapoptotic signaling, intracellular NAD+, and mitochondrial oxidative phosphorylation were observed in the treatment group. Our findings suggest that nanoparticles greatly increase the oral bioavailability of UA, leading to improved survival rates in AKI mice, in part by reducing renal oxidative and apoptotic stress.

Targeting Glutathione and Cystathionine β-Synthase in Ovarian Cancer Treatment by Selenium-Chrysin Polyurea Dendrimer Nanoformulation

Ovarian cancer is the main cause of death from gynecological cancer, with its poor prognosis mainly related to late diagnosis and chemoresistance (acquired or intrinsic) to conventional alkylating and reactive oxygen species (ROS)-generating drugs. We and others reported that the availability of cysteine and glutathione (GSH) impacts the mechanisms of resistance to carboplatin in ovarian cancer. Different players in cysteine metabolism can be crucial in chemoresistance, such as the cystine/glutamate antiporter system Xc (xCT) and the H2S-synthesizing enzyme cystathionine β-synthase (CBS) in the pathway of cysteine catabolism. We hypothesized that, by disrupting cysteine metabolic flux, chemoresistance would be reverted. Since the xCT transporter is also able to take up selenium, we used selenium-containing chrysin (SeChry) as a plausible competitive inhibitor of xCT. For that, we tested the effects of SeChry on three different ovarian cancer cell lines (ES2, OVCAR3, and OVCAR8) and in two non-malignant cell lines (HaCaT and HK2). Results showed that, in addition to being highly cytotoxic, SeChry does not affect the uptake of cysteine, although it increases GSH depletion, indicating that SeChry might induce oxidative stress. However, enzymatic assays revealed an inhibitory effect of SeChry toward CBS, thus preventing production of the antioxidant H2S. Notably, our data showed that SeChry and folate-targeted polyurea dendrimer generation four (SeChry@PUREG4-FA) nanoparticles increased the specificity for SeChry delivery to ovarian cancer cells, reducing significantly the toxicity against non-malignant cells. Collectively, our data support SeChry@PUREG4-FA nanoparticles as a targeted strategy to improve ovarian cancer treatment, where GSH depletion and CBS inhibition underlie SeChry cytotoxicity.

New Insights in the Pathogenesis of Cisplatin-Induced Nephrotoxicity

Cisplatin (cis-diamminedichloroplatinum II) is a widely used chemotherapeutic agent. However, efficacy and clinical utility of this drug is significantly limited by severe side effects such as nephrotoxicity which develops due to renal accumulation and bio-transformation in proximal tubular epithelial cells. Cisplatin-induced nephrotoxicity can be manifested as acute kidney injury (AKI), or as different types of tubulopathies, salt wasting, loss of urinary concentrating ability, and magnesium wasting. The attenuation of cisplatin-caused AKI is currently accomplished by hydration, magnesium supplementation or mannitol-induced forced diuresis. However, mannitol treatment causes over-diuresis and consequent dehydration, indicating an urgent need for the clinical use of newly designed, safe and efficacious renoprotective drug, as an additive therapy for high dose cisplatin-treated patients. Accordingly, we emphasized current knowledge regarding molecular mechanisms responsible for cisplatin-caused nephrotoxicity and we described in detail the main clinical manifestations of cisplatin-induced renal dysfunction in order to pave the way for the design of new therapeutic approaches that can minimize detrimental effects of cisplatin in the kidneys. Having in mind that most of cisplatin-induced cytotoxic effects against renal cells are, at the same time, involved in anti-tumor activity of cisplatin, new nephroprotective therapeutic strategies have to prevent renal injury and inflammation without affecting cisplatin-induced toxicity against malignant cells.

Insights Into Protective Mechanisms of Dandelion Leaf Extract Against Cisplatin-Induced Nephrotoxicity in Rats: Role of Inhibitory Effect on Inflammatory and Apoptotic Pathways

Cisplatin (CP) nephrotoxicity is associated with the induction of oxidative stress, inflammation, and apoptosis. Several studies demonstrated the antioxidant, anti-inflammatory, and antiapoptotic effects of dandelion leaf extract (DLE); therefore, this research aimed to investigate the protective effects of DLE against CP-induced nephrotoxicity. Thirty-two male Wistar rats were divided into 4 groups: normal control, DLE control received 500 mg/kg daily for 11 days, intoxicated group received vehicle daily for 11 days and a single dose of CP (7 mg/kg, intraperitonealp) on day 5, and DLE + CP group received DLE (500 mg/kg) daily for 11 days plus a single dose of CP (7 mg/kg) on day 5. The dose of DLE is selected based on a dose–effect study using different doses. Dandelion leaf extract pretreatment ameliorated CP-induced nephrotoxicity as evident by histopathological examination, alleviating CP-induced elevation in serum creatinine, blood urea nitrogen, oxidative stress marker (thiobarbituric acid reactive substances), tumor necrosis factor-α (as inflammatory cytokine), and caspase-9 and caspase-3 (as apoptotic markers). In addition, DLE reduced nuclear factor-κB and cytochrome c expression, and DNA fragmentation. It also maintained levels of reduced glutathione, superoxide dismutase, and serum albumin. Thus, the present study shows that DLE is a promising nephroprotective agent for CP-induced nephrotoxicity through antioxidant, anti-inflammatory, and antiapoptotic activities.

Bone invasion-targeted chemotherapy with a novel anionic platinum complex (3Pt) for oral squamous cell carcinoma

Cisplatin (CDDP) is an important drug for chemotherapy in patients with head and neck squamous cell carcinoma. Nephrotoxicity and lack of an effect on bone invasion are limitations of CDDP. To increase its antitumor effect on bone invasion and reduce toxicity problems, anionic Pt complex (3Pt) has been developed. The present study aimed to characterize the basis of the cytotoxicity of the novel platinum complex 3Pt in comparison with that of CDDP for oral squamous cell carcinoma. The ionic platinum complex was prepared to increase solubility and avoid platinum nephrotoxicity. Furthermore, 3Pt was designed to target bone hydroxyapatite and has germinal bisphosphonate moieties for drug delivery. In vitro antitumor activity was assayed in two oral squamous cell carcinoma cell lines. To investigate the antitumor and nephrotoxic effects of 3Pt, nude mice with OSC-19 were given 3Pt and CDDP. The in vitro growth-inhibitory effect of 3Pt was significantly less than that of CDDP. However, both 3Pt and CDDP showed equivalent antitumor effects in vivo. Mice injected with CDDP developed renal cell apoptosis; however, those injected with 3Pt were almost free of renal cell injury. In addition to similar in vivo antitumor effects, 3Pt decreased the volume of bone resorption compared to that with CDDP in a bone invasion model using OSC-19. In conclusion, considering the potential advantages in terms of noticeable antitumor activity on bone invasion and reduced nephrotoxicity, 3Pt represents a significant improvement in the development of bone-targeting platinum drugs.

Advances in Toxicological Research of the Anticancer Drug Cisplatin

Cisplatin is one of the most widely used chemotherapeutic agents for various solid tumors in the clinic due to its high efficacy and broad spectrum. The antineoplastic activity of cisplatin is mainly due to its ability to cross-link with DNA, thus blocking transcription and replication. Unfortunately, the clinical use of cisplatin is limited by its severe, dose-dependent toxic side effects. There are approximately 40 specific toxicities of cisplatin, among which nephrotoxicity is the most common one. Other common side effects include ototoxicity, neurotoxicity, gastrointestinal toxicity, hematological toxicity, cardiotoxicity, and hepatotoxicity. These side effects together reduce the life quality of patients and require lowering the dosage of the drug, even stopping administration, thus weakening the treatment effect. Few effective measures exist clinically against these side effects because the exact mechanisms of various side effects from cisplatin remain still unclear. Therefore, substantial effort has been made to explore the complicated biochemical processes involved in the toxicology of cisplatin, aiming to identify effective ways to reduce or eradicate its toxicity. This review summarizes and reviews the updated advances in the toxicological research of cisplatin. We anticipate to provide insights into the understanding of the mechanisms underlying the side effects of cisplatin and designing comprehensive therapeutic strategies involving cisplatin.

The ameliorative effects of ceftriaxone and vitamin E against cisplatin-induced nephrotoxicity

Nephrotoxicity is a common adverse effect of treatment with cisplatin (CDDP). This study was performed to evaluate the antioxidant and nephroprotective efficacy of ceftriaxone (CTX) and vitamin E (Vit.E), alone and in combination against CDDP-induced acute renal injury. Fifty-six male albino rats were equally divided into seven groups, receiving (I) normal saline, (II) CTX (100 mg/kg, intraperitoneal [i.p] injection), (III) Vit.E (100 mg/kg orally), (IV) CDDP (5 mg/kg i.p injection), (V) CDDP plus CTX, (VI) CDDP plus Vit.E, and (VII) CDDP plus CTX in combination with Vit.E. All treatments were administered daily for 10 days except CDDP, which was given as a single dose at the sixth day of the study. Compared to normal control rats, CDDP-injected rats showed significantly (p < 0.05) higher serum levels of renal injury biomarkers (uric acid, urea, and creatinine) and tumor necrosis factor-α (TNF-α), as well as increased renal tissue concentrations of malondialdehyde, nitric oxide, and TNF-α. Moreover, CDDP administration was associated with significantly lower (p < 0.05) renal tissue levels of reduced glutathione and activities of endogenous antioxidant enzymes (glutathione peroxidase, superoxide dismutase, and catalase) and total antioxidant capacity. All these alterations were significantly ameliorated in CDDP-injected rats, receiving CTX and/or Vit.E, compared to rats receiving CDDP alone. Interestingly, the antioxidant and anti-inflammatory effects were more marked in the CTX-Vit.E combination group, compared to groups receiving either drug alone. In conclusion, CTX and Vit.E (especially in combination) could counteract the nephrotoxic effect of CDDP, probably through their antioxidant activities.

The mercapturomic profile of health and non-communicable diseases

The mercapturate pathway is a unique metabolic circuitry that detoxifies electrophiles upon adducts formation with glutathione. Since its discovery over a century ago, most of the knowledge on the mercapturate pathway has been provided from biomonitoring studies on environmental exposure to toxicants. However, the mercapturate pathway-related metabolites that is formed in humans—the mercapturomic profile—in health and disease is yet to be established. In this paper, we put forward the hypothesis that these metabolites are key pathophysiologic factors behind the onset and development of non-communicable chronic inflammatory diseases. This review goes from the evidence in the formation of endogenous metabolites undergoing the mercapturate pathway to the methodologies for their assessment and their association with cancer and respiratory, neurologic and cardiometabolic diseases.

Loss of the Na+/H+ Exchange Regulatory Factor 1 Increases Susceptibility to Cisplatin-Induced Acute Kidney Injury

Na⁺/H⁺ exchange regulatory cofactor (NHERF)-1, a scaffolding protein, anchors multiple membrane proteins in renal proximal tubules. Cultured proximal tubule cells deficient in Nherf1 and proximal tubules from Nherf1-deficient mice exhibit aberrant trafficking. Nherf1-deficient cells also exhibit an altered transcription pattern and worse survival. These observations suggest that NHERF1 loss increases susceptibility to acute kidney injury (AKI). Male and female wild-type C57BL/6J and Nherf1 knockout mice were treated with saline or cisplatin (20 mg/kg dose i.p.) to induce AKI and were euthanized after 72 hours. Blood and urine were collected for assessments of blood urea nitrogen and neutrophil gelatinase-associated lipocalin, respectively. Kidneys were harvested for histology (hematoxylin and eosin, periodic acid-Schiff) and terminal deoxynucleotidyl transferase dUTP nick end labeling assay, Kim1 mRNA assessment, and Western blot analysis for cleaved caspase 3. Cisplatin treatment was associated with significantly greater severity of AKI in knockout compared with wild-type mice, as demonstrated by semiquantitative injury score (2.8 versus 1.89, P < 0.001), blood urea nitrogen (151.8 ± 17.2 mg/dL versus 97.8 ± 10.1 mg/dL, P < 0.05), and neutrophil gelatinase-associated lipocalin urine protein (55.6 ± 21.3 μg/mL versus 2.7 ± 0.53 μg/mL, P < 0.05). Apoptosis markers were significantly increased in cisplatin-treated Nherf1 knockout and wild-type mice compared to respective controls. These data suggest that NHERF1 loss increases susceptibility to AKI.

Molecular mechanisms of cisplatin-induced nephrotoxicity: a balance on the knife edge between renoprotection and tumor toxicity

Background

Cisplatin (cis-diamminedichloroplatinum II, CDDP) is one of the most effective chemotherapeutic agents. However, its clinical use is limited due to the severe side effects, including nephrotoxicity and acute kidney injury (AKI) which develop due to renal accumulation and biotransformation of CDDP. The alleviation or prevention of CDDP-caused nephrotoxicity is currently accomplished by hydration, magnesium supplementation or mannitol-induced forced diuresis which is considered for high-dose CDDP-treated patients. However, mannitol treatment causes over-diuresis and consequent dehydration in CDDP-treated patients, indicating an urgent need for the clinical use of safe and efficacious renoprotective drug as an additive therapy for high dose CDDP-treated patients.

Main body

In this review article we describe in detail signaling pathways involved in CDDP-induced apoptosis of renal tubular cells, oxidative stress and inflammatory response in injured kidneys in order to pave the way for the design of new therapeutic approaches that can minimize CDDP-induced nephrotoxicity. Most of these molecular pathways are, at the same time, crucially involved in cytotoxic activity of CDDP against tumor cells and potential alterations in their function might mitigate CDDP-induced anti-tumor effects.

Conclusion

Despite the fact that many molecules were designated as potential therapeutic targets for renoprotection against CDDP, modulation of CDDP-induced nephrotoxicity still represents a balance on the knife edge between renoprotection and tumor toxicity.

Comprehensive review on how platinum- and taxane-based chemotherapy of ovarian cancer affects biology of normal cells

One of the most neglected aspects of chemotherapy are changes, and possible consequences of these changes, that occur in normal somatic cells. In this review, we summarize effects of selected drugs used to treat ovarian cancer (platin derivatives-cisplatin and carboplatin; and taxanes-paclitaxel and docetaxel) on cellular metabolism, acquisition of reactive stroma features, cellular senescence, inflammatory reactions, apoptosis, autophagy, mitophagy, oxidative stress, DNA damage, and angiogenesis in various types of normal cells, including fibroblasts, epithelial cells, endothelial cells, and neurons. The activity of these drugs against the normal cells is presented from a broader perspective of their desirable anti-tumoral effects.

A human proximal tubule-on-a-chip to study renal disease and toxicity

Renal disease is a global problem with unsustainable health-care costs. There currently exists a lack of accurate human renal disease models that take into account the complex microenvironment of these tissues. Here, we present a reusable microfluidic model of the human proximal tubule and glomerulus, which allows for the growth of renal epithelial cells in a variety of conditions that are representative of renal disease states including altered glomerular filtration rate, hyperglycemia, nephrolithiasis, and drug-induced nephrotoxicity (cisplatin and cyclosporine). Cells were exposed to these conditions under fluid flow or in traditional static cultures to determine the effects of a dynamic microenvironment on the pathogenesis of these renal disease states. The results indicate varying stress-related responses (α-smooth muscle actin (α-SMA) expression, alkaline phosphatase activity, fibronectin, and neutrophil gelatinase-associated lipocalin secretion) to each of these conditions when comparing cells that had been grown in static and dynamic conditions, potentially indicating more realistic and sensitive predictions of human responses and a requirement for a more complex "fit for purpose" model.

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.

Persistent increase in mitochondrial superoxide mediates cisplatin-induced chronic kidney disease

Severe and recurrent cisplatin-induced acute kidney injury (AKI) as part of standard cancer therapy is a known risk factor for development of chronic kidney disease (CKD). The specific role of superoxide (O₂^•-)-mediated disruption of mitochondrial oxidative metabolism in CKD after cisplatin treatment is unexplored. Cisplatin is typically administered in weekly or tri-weekly cycles as part of standard cancer therapy. To investigate the role of O₂^•- in predisposing patients to future renal injury and in CKD, mice were treated with cisplatin and a mitochondrial-specific, superoxide dismutase (SOD) mimetic, GC4419. Renal function, biomarkers of oxidative stress, mitochondrial oxidative metabolism, and kidney injury markers, as well as renal histology, were assessed to evaluate the cellular changes that occur one week and one month (CKD phase) after the cisplatin insult. Cisplatin treatment resulted in persistent upregulation of kidney injury markers, increased steady-state levels of O₂^•-, increased O₂^•--mediated renal tubules damage, and upregulation of mitochondrial electron transport chain (ETC) complex I activity both one week and one month following cisplatin treatment. Treatment with a novel, clinically relevant, small-molecule superoxide dismutase (SOD) mimetic, GC4419, restored mitochondrial ETC complex I activity to control levels without affecting complexes II–IV activity, as well as ameliorated cisplatin-induced kidney injury. These data support the hypothesis that increased mitochondrial O₂^•- following cisplatin administration, as a result of disruptions of mitochondrial metabolism, may be an important contributor to both AKI and CKD progression.

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Cisplatin-induced AKI and CKD have a negative impact in long-term renal function.

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Cisplatin-induced CKD disrupts mitochondrial metabolism and increases O₂^•- levels.

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SOD mimetic, GC4419 mitigates renal damage and mitochondrial metabolism disruptions.

Precision toxicology shows that troxerutin alleviates ochratoxin A-induced renal lipotoxicity

Lipotoxicity is the most common cause of severe kidney disease, with few treatment options available today. Precision toxicology can improve detection of subtle intracellular changes in response to exogenous substrates; thus, it facilitates in-depth research on bioactive molecules that may interfere with the onset of certain diseases. In the current study, troxerutin significantly relieved nephrotoxicity, increased endurance, and improved systemic energy metabolism and renal inflammation in OTA-induced nephrotic mice. Lipidomics showed that troxerutin effectively reduced the levels of triglycerides, phosphatidylcholines, and phosphatidylethanolamines in nephropathy. The mechanism was partly attributable to troxerutin in alleviating the aberrantly up-regulated expression of sphingomyelinase, the cystic fibrosis transmembrane conductance regulator, and chloride channel 2. Renal tubular epithelial cells, the main site of toxin-induced accumulation of lipids in the kidney, were subjected to transcriptomic profiling, which uncovered several metabolic factors relevant to aberrant lipid and lipoprotein metabolism. Our work provides new insights into the molecular features of toxin-induced lipotoxicity in renal tubular epithelial cells in vivo and demonstrates the function of troxerutin in alleviating OTA-induced nephrosis and associated systemic energy metabolism disorders.-Yang, X., Xu, W., Huang, K., Zhang, B., Wang, H., Zhang, X., Gong, L., Luo, Y., He, X. Precision toxicology shows that troxerutin alleviates ochratoxin A-induced renal lipotoxicity.

Ameliorative effect of selenium nanoparticles and fish oil on cisplatin and gamma irradiation-induced nephrotoxicity in male albino rats

Cisplatin (CP) is a major antineoplastic drug for the treatment of solid tumors, however, its clinical utility is limited by nephrotoxicity. Also, radiotherapy is an important treatment modality for many malignancies. The present studies were performed to test whether fish oil (FO) and/or selenium nanoparticles (SeNPs) administration have an ameliorative effect on CP and γ-irradiation induced nephrotoxicity. FO and/or SeNPs were administered to male albino rats daily for 12 days before being intraperitoneally injected with a single dose of CP (10 mg/kg body weight) and whole body exposed to a single dose of γ-radiation (0.7 Gy). Biochemical analysis and histopathological examination were performed. Pretreatment with FO and/or SeNPs before the administration of CP and exposure to γ-radiation significantly reduced CP- and γ-radiation-induced high levels of serum urea and creatinine and renal tumor necrosis factor-α, caspase-3 and cyclooxygenase-2, also they significantly prevented renal total antioxidant capacity levels decrease and ameliorated the levels of most studied trace elements. The histopathological results supported the biochemical findings of this study. The administration of FO and/or SeNPs might be useful for preventing nephrotoxicity which can be caused by CP and radiotherapy during the treatment of various malignancies.

Activity profile of the cisplatin analogue PN149 in different tumor cell lines

The efficacy of the anticancer drug cisplatin is restricted by tumor cell resistance and occurrence of severe side effects. One strategy to overcome these limitations is the development of new, improved platinum drugs. Previous investigations showed that platinum(IV)-nitroxyl complexes are able to circumvent cisplatin resistance in bladder cancer cells. In the present study the mode of action of the platinum(IV)-nitroxyl complex PN149 was investigated in the bladder cancer cell line RT112 and the renal cell carcinoma cell line A498 on the molecular and cellular level. Gene expression analysis showed that PN149 induced genes related to DNA damage response (RRM2B, GADD45A), cell cycle regulation (CDKN1A, PLK3, PPM1D) as well as those coding for the pro-apoptotic factors PUMA and Noxa. These findings on the transcriptional level were confirmed on the functional level revealing that PN149 treatment increased levels of p53 and resulted in cell cycle arrest and drug-induced cytotoxicity via induction of apoptosis. Regarding the expression of oxidative-stress sensitive genes, PN149 induced FTH1, GCLC, HMOX1 and TXNRD1 but relevant effects were restricted to RT112 cells treated with 50 µM. The pro-inflammatory IL-8 was induced by PN149 in RT112 but not A498 cells indicating a cell-type specific activation. Taken together, PN149 possessed promising activity in different tumor cell lines rendering it an interesting alternative to cisplatin in chemotherapy.

Proximal Tubular Secretory Clearance: A Neglected Partner of Kidney Function

The secretion of small molecules by the proximal tubules of the kidneys represents a vital homeostatic function for rapidly clearing endogenous solutes and medications from the circulation. After filtration at the glomerulus, renal blood flow is directed through a network of peritubular capillaries, where transporters of the proximal tubules actively secrete putative uremic toxins and hundreds of commonly prescribed drugs into the urine, including protein-bound substances that cannot readily cross the glomerular basement membrane. Despite its central physiologic importance, tubular secretory clearance is rarely measured or even estimated in clinical or research settings. Major barriers to estimating tubular solute clearance include uncertainty regarding optimal endogenous secretory markers and a lack of standardized laboratory assays. The creation of new methods to measure tubular secretion could catalyze advances in kidney disease research and clinical care. Differences in secretory clearance relative to the GFR could help distinguish among the causes of CKD, particularly for disorders that primarily affect the tubulointerstitium. As the primary mechanism by which the kidneys excrete medications, tubular secretory clearance offers promise for improving kidney medication dosing, which is currently exclusively on the basis of filtration. The differing metabolic profiles of retained solutes eliminated by secretion versus glomerular filtration suggest that secretory clearance could uniquely inform uremic toxicity, refine existing measures of residual kidney function, and improve prediction of cardiovascular and kidney disease outcomes. Interdisciplinary research across clinical, translational, and laboratory medicine is needed to bring this often neglected kidney function into the limelight.

Venlafaxine mitigates cisplatin-induced nephrotoxicity via down-regulating apoptotic pathway in rats

The antidepressant venlafaxine, a norepinephrine and serotonin reuptake inhibitor, is recently identified for its anti-inflammatory role against many experimental models. In this study, the effect of venlafaxine against cisplatin-induced nephrotoxicity and bladder rings hypersensitivity towards acetylcholine were explored. Single injection of cisplatin (7 mg/kg, ip) in Sprague-Dawley rats instigated nephrotoxicity evidenced by hindering renal function (changes in kidney/body weight ratio, serum creatinine, BUN, albumin and urinary total protein levels which were supported by histopathology). In addition, cisplatin caused a profound oxidative stress, inflammation and apoptosis. Treatment with venlafaxine (50 mg/kg, po) managed to alleviate the nephrotoxicity indices and rehabilitate the antioxidant parameters (MDA, GSH, SOD and CAT) in addition to retaining NOx levels to the normal levels. Moreover, venlafaxine caused a decline in LDH and NF-κB levels supporting its anti-inflammatory effect. Additionally, the antiapoptotic effect was demonstrated by increasing Bcl-2, suppressing p53 and Bax renal levels, decreasing caspase-3 expression and by flow cytometry (annexin V and PI) that showed an increase in viable cells and a decrease in early apoptotic and necrotic cells. Furthermore, venlafaxine ameliorated bladder rings hyperreactivity to acetylcholine and improved histopathologic findings. In brief, venlafaxine ameliorated nephrotoxicity and bladder rings hyperreactivity caused by cisplatin through acting as an antioxidant, anti-inflammatory and antiapoptotic agent.

Analysis of adverse events of renal impairment related to platinum-based compounds using the Japanese Adverse Drug Event Report database

Objectives:

Platinum compounds cause several adverse events, such as nephrotoxicity, gastrointestinal toxicity, myelosuppression, ototoxicity, and neurotoxicity. We evaluated the incidence of renal impairment as adverse events are related to the administration of platinum compounds using the Japanese Adverse Drug Event Report database.

Methods:

We analyzed adverse events associated with the use of platinum compounds reported from April 2004 to November 2016. The reporting odds ratio at 95% confidence interval was used to detect the signal for each renal impairment incidence. We evaluated the time-to-onset profile of renal impairment and assessed the hazard type using Weibull shape parameter and used the applied association rule mining technique to discover undetected relationships such as possible risk factor.

Results:

In total, 430,587 reports in the Japanese Adverse Drug Event Report database were analyzed. The reporting odds ratios (95% confidence interval) for renal impairment resulting from the use of cisplatin, oxaliplatin, carboplatin, and nedaplatin were 2.7 (2.5–3.0), 0.6 (0.5–0.7), 0.8 (0.7–1.0), and 1.3 (0.8–2.1), respectively. The lower limit of the reporting odds ratio (95% confidence interval) for cisplatin was >1. The median (lower–upper quartile) onset time of renal impairment following the use of platinum-based compounds was 6.0–8.0 days. The Weibull shape parameter β and 95% confidence interval upper limit of oxaliplatin were <1. In the association rule mining, the score of lift for patients who were treated with cisplatin and co-administered furosemide, loxoprofen, or pemetrexed was high. Similarly, the scores for patients with hypertension or diabetes mellitus were high.

Conclusion:

Our findings suggest a potential risk of renal impairment during cisplatin use in real-world setting. The present findings demonstrate that the incidence of renal impairment following cisplatin use should be closely monitored when patients are hypertensive or diabetic, or when they are co-administered furosemide, loxoprofen, or pemetrexed. In addition, healthcare professionals should closely assess a patient’s background prior to treatment.

Cisplatin-induced gastrointestinal toxicity: An update on possible mechanisms and on available gastroprotective strategies

Cisplatin (cis-diamminedichloroplatinum [II], CP) is most widely prescribed in chemotherapy and efficaciously treats diverse human cancers, with remission rates > 90% in testicular cancers. However, clinical use of CP is associated with numerous untoward side effects, in particular, at the gastrointestinal level that reduces the therapeutic efficacy of CP and often results in withdrawal of its clinical usage in long term cancer chemotherapy. Substantial strides have been made to identify effective protective strategies against CP-induced nephrotoxicity, hepatotoxicity and ototoxicity. Unfortunately, very limited studies have focused on CP-induced gastrointestinal toxicity and advances in developing potent gastroprotective strategies/agents are still lacking. The current article reviews the metabolism and pharmacokinetics of CP, mechanisms underlying CP-induced gastrointestinal toxicity and lastly displays the potential approaches including plant-derived agents (phytochemicals) utilized to counteract CP-induced gastrointestinal dysfunction. Furthermore, the gastroprotective agents described in the experimental literature have shown partial protection against CP-induced intestinal damage. This stresses the need to ascertain new information on the underlying mechanism and to discover novel combinatorial strategies for the abrogation of CP-induced gastrointestinal toxicity.

Metabolic characterization of directly reprogrammed renal tubular epithelial cells (iRECs)

Fibroblasts can be directly reprogrammed to induced renal tubular epithelial cells (iRECs) using four transcription factors. These engineered cells may be used for disease modeling, cell replacement therapy or drug and toxicity testing. Direct reprogramming induces drastic changes in the transcriptional landscape, protein expression, morphological and functional properties of cells. However, how the metabolome is changed by reprogramming and to what degree it resembles the target cell type remains unknown. Using untargeted gas chromatography-mass spectrometry (GC-MS) and targeted liquid chromatography-MS, we characterized the metabolome of mouse embryonic fibroblasts (MEFs), iRECs, mIMCD-3 cells, and whole kidneys. Metabolic fingerprinting can distinguish each cell type reliably, revealing iRECs are most similar to mIMCD-3 cells and clearly separate from MEFs used for reprogramming. Treatment with the cytotoxic drug cisplatin induced typical changes in the metabolic profile of iRECs commonly occurring in acute renal injury. Interestingly, metabolites in the medium of iRECs, but not of mIMCD-3 cells or fibroblast could distinguish treated and non-treated cells by cluster analysis. In conclusion, direct reprogramming of fibroblasts into renal tubular epithelial cells strongly influences the metabolome of engineered cells, suggesting that metabolic profiling may aid in establishing iRECs as in vitro models for nephrotoxicity testing in the future.

Nephrotoxicity of anticancer treatment

Severe adverse systemic drug events occur commonly as a result of treatment of cancer patients. Nephrotoxicity of chemotherapeutic agents remains a significant complication limiting the efficacy of the treatment. A variety of renal disease and electrolyte disorders can result from the drugs that are used to treat malignant disease. The kidneys are a major elimination pathway for many antineoplastic drugs and their metabolites. Tumour lysis syndrome, an emergency in haematooncology, occurs most often after the initiation of cytotoxic therapy in patients with high-grade lymphomas and acute lymphoblastic leukaemia. Chemotherapeutic agents can affect the glomerulus, tubules, interstitium and renal microvasculature, with clinical manifestations that range from asymptomatic elevation of serum creatinine to acute renal failure requiring dialysis. Some factors such as intravascular volume depletion, as well as concomitant use of other drugs or radiographic ionic contrast media, can potentiate or contribute to the nephrotoxicity. Cytotoxic agents can cause nephrotoxicity by a variety of mechanisms. The most nephrotoxic chemotherapeutic drug is cisplatin, which is often associated with acute kidney injury. Many other drugs such as alkylating agents, antimetabolites, vascular endothelial growth factor pathway inhibitors and epidermal growth factor receptor pathway inhibitors may have toxic effects on the kidneys. The aim of this review is to discuss the issue of nephrotoxicity associated with chemotherapy. In routine clinical practice, monitoring of kidney function is mandatory in order to identify nephrotoxicity early, allowing dosage adjustments or withdrawal of the offending drug.

Capturing platinum in cisplatin: kinetic reactions with recombinant human apo-metallothionein 1a

Detailed mass spectra data show the stepwise sequence of cisplatin deconstruction by apo-metallothionein.

Urinary protein biomarkers of kidney injury in patients receiving cisplatin chemotherapy

Despite recent progress in the development of novel approaches to treat cancer, traditional antineoplastic drugs, such as cisplatin, remain a mainstay of regimens targeting solid tumors. Use of cisplatin is limited by acute kidney injury, which occurs in approximately 30% of patients. Current clinical measures, such as serum creatinine and estimated glomerular filtration rate, are inadequate in their ability to detect acute kidney injury, particularly when there is only a moderate degree of injury. Thus, there is an urgent need for improved diagnostic biomarkers to predict nephrotoxicity. There is also interest by the U.S. Food and Drug Administration to validate and implement new biomarkers to identify clinical and subclinical acute kidney injury in patients during the drug approval process. This minireview provides an overview of the current literature regarding the utility of urinary proteins (albumin, beta-2-microglobulin, N-acetyl-D-glucosaminidase, kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, and cystatin C) as biomarkers for cisplatin-induced AKI. Many of the well-studied urinary proteins (KIM-1, NGAL, B2M, albumin) as well as emerging biomarkers (calbindin, monocyte chemotactic protein-1, and trefoil factor 3) display distinct patterns of time-dependent excretion after cisplatin administration. Implementation of these biomarker proteins in the oncology clinic has been hampered by a lack of validation studies. To address these issues, large head-to-head studies are needed to fully characterize time-dependent responses and establish accurate cutoff values and ranges, particularly in cancer patients. Impact statement There is growing interest in using urinary protein biomarkers to detect acute kidney injury in oncology patients prescribed the nephrotoxic anticancer drug cisplatin. We aim to synthesize and organize the existing literature on biomarkers examined clinically in patients receiving cisplatin-containing chemotherapy regimens. This minireview highlights several proteins (kidney injury molecule-1, beta-2-microglobulin, neutrophil gelatinase-associated lipocalin, calbindin, monocyte chemotactic protein-1, trefoil factor 3) with the greatest promise for detecting cisplatin-induced acute kidney injury in humans. A comprehensive review of the existing literature may aid in the design of larger studies needed to implement the clinical use of these urinary proteins as biomarkers of kidney injury.

On the toxicity and transport mechanisms of cisplatin in kidney tissues in comparison to a gold-based cytotoxic agent

Mechanisms of toxicity and cellular transport of anticancer metallodrugs, including platinum-based agents, have not yet been fully elucidated. Here, we studied the toxic effects and accumulation mechanisms of cisplatin in healthy rat kidneys ex vivo, using the Precision Cut Tissue Slices (PCTS) method. In addition, for the first time, we investigated the nephrotoxic effects of an experimental anticancer cyclometallated complex [Au(py^b-H)(PTA)Cl]PF₆ (PTA = 1,3,5-triazaphosphaadamantane). The viability of the kidney slices after metallodrug treatment was evaluated by ATP content determination and histomorphology analysis. A concentration dependent decrease in viability of PCKS was observed after exposure to cisplatin or the Au(iii) complex, which correlated with the increase in slice content of Pt and Au, respectively. Metal accumulation in kidney slices was analysed by ICP-MS. The involvement of OCTs and MATE transporters in the accumulation of both metal compounds in kidneys was evaluated co-incubating the tissues with cimitedine, inhibitor of OCT and MATE. Studies of mRNA expression of the markers KIM-1, villin, p53 and Bax showed that cisplatin damages proximal tubules, whereas the Au(iii) complex preferentially affects the distal tubules. However, no effect of cimetidine on the toxicity or accumulation of cisplatin and the Au(iii) complex was observed. The effect of temperature on metallodrug accumulation in kidneys suggests the involvement of a carrier-mediated uptake process, other than OCT2, for cisplatin; while carrier-mediated excretion was suggested in the cases of the Au(iii) complex.

Oral thymoquinone administration ameliorates: the effect of cisplatin on brush border membrane enzymes, energy metabolism, and redox status in rat kidney

Therapeutic use of cisplatin (CP), an effective anticancer drug, is limited by dose dependent nephrotoxicity. Thymoquinone (TQ), the major Nigella sativa seed oil constituent has been shown to prevent progression of various renal disorders. The present study investigates the protective effect of TQ on CP-induced nephrotoxicity. Rats were divided into six groups viz. control, CP, CPTQ₁, CPTQ₂, CPTQ₃, and TQ alone group. Animals in CP and TQ combination groups were administered TQ (0.5, 1.5, and 3 mg/kg bwt, orally) with single intraperitoneal dose of CP (6 mg/kg bwt). The effect of TQ administration was determined on CP-induced alterations in various serum/urine parameters and on the enzymes of brush border membrane enzyme (BBM), carbohydrate metabolism, and antioxidant defense system in renal cortex and medulla. Oral administration of TQ in all the three doses prior to and following a single dose CP treatment caused significant recovery of serum creatinine and blood urea nitrogen levels; however, maximum recovery was seen in CPTQ₂ group. TQ administration averted CP-induced decline in BBM activities, both in the cortical and medullary homogenates and in isolated BBM vesicles. TQ administration also ameliorated CP-induced impairments in renal metabolic and antioxidant status. Histopathological studies supported these biochemical findings. TQ ameliorates CP-induced oxidative damage owing to its intrinsic antioxidant properties.

Identification of OAT1/OAT3 as Contributors to Cisplatin Toxicity

Cisplatin is among the most widely used anticancer drugs and known to cause a dose‐limiting nephrotoxicity, which is partially dependent on the renal uptake carrier OCT2. We here report a previously unrecognized, OCT2‐independent pathway of cisplatin‐induced renal injury that is mediated by the organic anion transporters OAT1 and OAT3. Using transporter‐deficient mouse models, we found that this mechanism regulates renal uptake of a mercapturic acid metabolite of cisplatin that acts as a precursor of a potent nephrotoxin. The function of these two transport systems can be simultaneously inhibited by the tyrosine kinase inhibitor nilotinib through noncompetitive mechanisms, without compromising the anticancer properties of cisplatin. Collectively, our findings reveal a novel pathway that explains the fundamental basis of cisplatin‐induced nephrotoxicity, with potential implications for its therapeutic management.

Pharmacogenomic Variants May Influence the Urinary Excretion of Novel Kidney Injury Biomarkers in Patients Receiving Cisplatin

Nephrotoxicity is a dose limiting side effect associated with the use of cisplatin in the treatment of solid tumors. The degree of nephrotoxicity is dictated by the selective accumulation of cisplatin in renal tubule cells due to: (1) uptake by organic cation transporter 2 (OCT2) and copper transporter 1 (CTR1); (2) metabolism by glutathione S-transferases (GSTs) and γ-glutamyltransferase 1 (GGT1); and (3) efflux by multidrug resistance-associated protein 2 (MRP2) and multidrug and toxin extrusion protein 1 (MATE1). The purpose of this study was to determine the significance of single nucleotide polymorphisms that regulate the expression and function of transporters and metabolism genes implicated in development of acute kidney injury (AKI) in cisplatin treated patients. Changes in the kidney function were assessed using novel urinary protein biomarkers and traditional markers. Genotyping was conducted by the QuantStudio 12K Flex Real-Time PCR System using a custom open array chip with metabolism, transport, and transcription factor polymorphisms of interest to cisplatin disposition and toxicity. Traditional and novel biomarker assays for kidney toxicity were assessed for differences according to genotype by ANOVA. Allele and genotype frequencies were determined based on Caucasian population frequencies. The polymorphisms rs596881 (SLC22A2/OCT2), and rs12686377 and rs7851395 (SLC31A1/CTR1) were associated with renoprotection and maintenance of estimated glomerular filtration rate (eGFR). Polymorphisms in SLC22A2/OCT2, SLC31A1/CTRI, SLC47A1/MATE1, ABCC2/MRP2, and GSTP1 were significantly associated with increases in the urinary excretion of novel AKI biomarkers: KIM-1, TFF3, MCP1, NGAL, clusterin, cystatin C, and calbindin. Knowledge concerning which genotypes in drug transporters are associated with cisplatin-induced nephrotoxicity may help to identify at-risk patients and initiate strategies, such as using lower or fractionated cisplatin doses or avoiding cisplatin altogether, in order to prevent AKI.

Inhibiting glucosylceramide synthase exacerbates cisplatin-induced acute kidney injury

Acute kidney injury (AKI), resulting from chemotherapeutic agents such as cisplatin, remains an obstacle in the treatment of cancer. Cisplatin-induced AKI involves apoptotic and necrotic cell death, pathways regulated by sphingolipids such as ceramide and glucosylceramide. Results from this study indicate that C57BL/6J mice treated with cisplatin had increased ceramide and hexosylceramide levels in the renal cortex 72 h following cisplatin treatment. Pretreatment of mice with inhibitors of acid sphingomyelinase and de novo ceramide synthesis (amitriptyline and myriocin, respectively) prevented accumulation of ceramides and hexosylceramide in the renal cortex and protected from cisplatin-induced AKI. To determine the role of ceramide metabolism to hexosylceramides in kidney injury, we treated mice with a potent and highly specific inhibitor of glucosylceramide synthase, the enzyme responsible for catalyzing the glycosylation of ceramides to form glucosylceramides. Inhibition of glucosylceramide synthase attenuated the accumulation of the hexosylceramides and exacerbated ceramide accumulation in the renal cortex following treatment of mice with cisplatin. Increasing ceramides and decreasing glucosylceramides in the renal cortex sensitized mice to cisplatin-induced AKI according to markers of kidney function, kidney injury, inflammation, cell stress, and apoptosis. Under conditions of high ceramide generation, data suggest that metabolism of ceramides to glucosylceramides buffers kidney ceramides and helps attenuate kidney injury.-Dupre, T. V., M. A. Doll, P. P. Shah, C. N. Sharp, D. Siow, J. Megyesi, J. Shayman, A. Bielawska, J. Bielawski, L. J. Beverly, M. Hernandez-Corbacho, C. J. Clarke, A. J. Snider, R. G. Schnellmann, L. M. Obeid, Y. A. Hannun, and L. J. Siskind. Inhibiting glucosylceramide synthase exacerbates cisplatin-induced acute kidney injury. J. Lipid Res 2017. 58: 1439-1452.

Pharmacogenetic variants in TPMT alter cellular responses to cisplatin in inner ear cell lines

Cisplatin is a highly-effective and widely-used chemotherapeutic agent that causes ototoxicity in many patients. Pharmacogenomic studies of key genes controlling drug biotransformation identified variants in thiopurine methyltransferase (TPMT) as predictors of cisplatin-induced ototoxicity, although the mechanistic basis of this interaction has not been reported. Expression constructs of TPMT*3A, *3B and *3C variants were generated and monitored in cultured cells. Cellular TPMT*3A levels were detected at >20-fold lower amounts than the wild type confirming the unstable nature of this variant. The expression of wild type TPMT (TPMT*1) in two murine ear cell lines, HEI-OC1 and UB/OC-1, significantly mitigated their susceptibility to cisplatin toxicity. Cisplatin treatment induced Tlr4 gene expression in HEI-OC1 cells and this response was blunted by the expression of wild type TPMT but not TPMT*3A. In line with the significant mitigation of TPMT*1-expressing cells to cisplatin cytotoxicity, these findings demonstrate a drug-gene interaction between increased TPMT activity and decreased susceptibility to cisplatin-induced toxicity of inner ear cells.

Renal Medulla is More Sensitive to Cisplatin than Cortex Revealed by Untargeted Mass Spectrometry-Based Metabolomics in Rats

Nephrotoxicity has long been the most severe and life-threatening side-effect of cisplatin, whose anticancer effect is therefore restricted. Previous pathological studies have shown that both renal cortex and medulla could be injured by cisplatin. Our TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling) assay results further uncovered that medulla subjected more severe injury than cortex. In order to depict the underlying metabolic mechanism of spatial difference in response to cisplatin, in the present study, mass spectrometry-based untargeted metabolomics approach was applied to profile renal cortex and medulla metabolites of rat after receiving a single dose of cisplatin (2.5, 5 or 10 mg/kg). Eventually, 53 and 55 differential metabolites in cortex and medulla were screened out, respectively. Random forest, orthogonal partial least squares-discriminant analysis and metabolic cumulative fold change analysis revealed that metabolic changes in medulla were more obviously dose-dependent than those in cortex, which confirmed the conclusion that medulla was more sensitive to cisplatin exposure. Furthermore, 29 intermediates were recognized as the most contributive metabolites for the sensitivity difference. Metabolic pathways interrupted by cisplatin mainly included amino acid, energy, lipid, pyrimidine, purine, and creatine metabolism. Our findings provide new insight into the mechanism study of cisplatin-induced nephrotoxicity.

Hyperhomocysteinemia Exacerbates Cisplatin-induced Acute Kidney Injury

Hyperhomocysteinemia (HHcy) has been linked to several clinical manifestations including chronic kidney disease. However, it is not known whether HHcy has a role in the development of acute kidney injury (AKI). In the present study, we reported that HHcy mice developed more severe renal injury after cisplatin injection and ischemia-reperfusion injury shown as more severe renal tubular damage and higher serum creatinine. In response to cisplatin, HHcy mice showed more prevalent tubular cell apoptosis and decreased tubular cell proliferation. Mechanistically, a heightened ER stress and a reduced Akt activity were observed in kidney tissues of HHcy mice after cisplatin injection. Stimulating cultured NRK-52E cells with Hcy significantly increased the fraction of cells in G2/M phase and cell apoptosis together with decreased Akt kinase activity. Akt agonist IGF-1 rescued HHcy-induced cell cycle arrest and cell apoptosis. In conclusion, the present study provides evidence that HHcy increases the sensitivity and severity of AKI.

Phase I-II clinical trial of hyaluronan-cisplatin nanoconjugate in dogs with naturally occurring malignant tumors

OBJECTIVE To conduct a phase I-II clinical trial of hyaluronan-cisplatin nanoconjugate (HA-Pt) in dogs with naturally occurring malignant tumors. ANIMALS 18 healthy rats, 9 healthy mice, and 16 dogs with cancer. PROCEDURES HA-Pt was prepared and tested by inductively coupled plasma mass spectrometry; DNA-platinum adduct formation and antiproliferation effects of cisplatin and HA-Pt were compared in vitro. Effects of cisplatin (IV) and HA-Pt (SC) in rodents were tested by clinicopathologic assays. In the clinical trial, dogs with cancer received 1 to 4 injections of HA-Pt (10 to 30 mg/m(2), intratumoral or peritumoral, q 3 wk). Blood samples were collected for pharmacokinetic analysis; CBC, serum BUN and creatinine concentration measurement, and urinalysis were conducted before and 1 week after each treatment. Some dogs underwent hepatic enzyme testing. Tumors were measured before the first treatment and 3 weeks after each treatment to assess response. RESULTS No adverse drug effects were detected in pretrial assessments in rodents. Seven of 16 dogs completed the study; 3 had complete tumor responses, 3 had stable disease, and 1 had progressive disease. Three of 7 dogs with oral and nasal squamous cell carcinoma (SCC) that completed the study had complete responses. Myelosuppression and cardiotoxicosis were identified in 6 and 2 dogs, respectively; none had nephrotoxicosis. Four of 5 dogs with hepatic enzymes assessed had increased ALT activities, attributed to diaquated cisplatin products in the HA-Pt. Pharmacokinetic data fit a 3-compartment model. CONCLUSIONS AND CLINICAL RELEVANCE HA-Pt treatment resulted in positive tumor responses in some dogs, primarily those with SCC. The adverse effect rate was high. IMPACT FOR HUMAN MEDICINE Oral SCC in dogs has characteristics similar to human head and neck SCC; these results could be useful in developing human treatments.

Risk Factors Associated with Cisplatin-Induced Nephrotoxicity in Patients with Advanced Lung Cancer

Cisplatin (CDDP) combination chemotherapy is widely administered to patients with advanced lung cancer. The dose depends on multiple factors, including whether the tumor is non-small-cell lung cancer (NSCLC) or small-cell lung cancer (SCLC). Although efficacy is limited by cisplatin-induced nephrotoxicity (CIN), little is known about the risk factors for this complication. The aim of this study was to identify the risk factors for CIN in patients with advanced lung cancer, both NSCLC and SCLC. We retrospectively reviewed clinical data for 148 patients who underwent initial chemotherapy including CDDP ≥50 mg/m² per patient per day for the first course at Kyushu Medical Center between October 2010 and September 2013. All data were collected from the electronic medical record system. Nephrotoxicity was defined as an increase in serum creatinine concentration of at least grade 2 during the first course of CDDP chemotherapy, as described by the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. CIN was observed in nine patients. Univariate analysis revealed that cardiac disease and lower baseline serum albumin (Alb) values conferred a higher risk of nephrotoxicity (p<0.05). The cut-off value of Alb was 3.8 g/dL, calculated by receiver operating characteristics (ROC) curves. Multivariable logistic regression analysis revealed that cardiac disease (odds ratio=11.7; p=0.002) and hypoalbuminemia (odds ratio=6.99 p=0.025 significantly correlated with nephrotoxicity. In conclusion, cardiac disease and low baseline Alb values are possible risk factors for CIN.

Histone deacetylase–mediated silencing of AMWAP expression contributes to cisplatin nephrotoxicity

Cisplatin-induced acute kidney injury is a serious problem in cancer patients during treatment of solid tumors. Currently, there are no therapies available to treat or prevent cisplatin nephrotoxicity. Since histone deacetylase (HDAC) inhibition augments cisplatin anti-tumor activity, we tested whether HDAC inhibitors can prevent cisplatin-induced nephrotoxicity and determined the underlying mechanism. Cisplatin upregulated the expression of several HDACs in the kidney. Inhibition of HDAC with clinically used trichostatin A suppressed cisplatin-induced kidney injury, inflammation, and epithelial cell apoptosis. Moreover, trichostatin A upregulated the novel anti-inflammatory protein, activated microglia/macrophage WAP domain protein (AMWAP), in epithelial cells which was enhanced with cisplatin treatment. Interestingly, HDAC1 and -2 specific inhibitors are sufficient to potently upregulate AMWAP in epithelial cells. Administration of recombinant AMWAP or its epithelial cell-specific overexpression reduced cisplatin-induced kidney dysfunction. Moreover, AMWAP treatment suppressed epithelial cell apoptosis, and siRNA-based knockdown of AMWAP expression abolished trichostatin A-mediated suppression of epithelial cell apoptosis in vitro. Thus, HDAC-mediated silencing of AMWAP may contribute to cisplatin nephrotoxicity. Hence, HDAC1 and -2 specific inhibitors or AMWAP could be useful therapeutic agents for the prevention of cisplatin nephrotoxicity.

High-throughput in vitro assay to evaluate the cytotoxicity of liberated platinum compounds for stimulating neural electrodes

BACKGROUND

It is currently unclear how the platinum (Pt) species released from platinum-containing stimulating electrodes may affect the health of the surrounding tissue. This study develops an effective system to assess the cytotoxicity of any electrode-liberated Pt over a short duration, to screen systems before future in vivo testing.

NEW METHOD

A platinum electrode was stimulated for two hours under physiologically relevant conditions to induce the liberation of Pt species. The total concentration of liberated Pt species was quantified and the concentration found was used to develop a range of Pt species for our model system comprised of microglia and neuron-like cells.

RESULTS

Under our stimulation conditions (k=2.3, charge density of 57.7μC/cm²), Pt was liberated to a concentration of 1ppm. Interestingly, after 24h of Pt exposure, the dose-dependent cytotoxicity plots revealed that cell death became statistically significant at 10ppm for microglia and 20ppm for neuronal cells. However, in neuron-like cell cultures, concentrations above 1ppm resulted in significant neurite loss after 24h.

COMPARISON WITH EXISTING METHODS

To our knowledge, there does not exist a simple, in vitro assay system for assessing the cytotoxicity of Pt liberated from stimulating neural electrodes.

CONCLUSIONS

This work describes a simple model assay that is designed to be applicable to almost any electrode and stimulation system where the electrode is directly juxtaposed to the neural target. Based on the application, the duration of stimulation and Pt exposure may be varied.

Comparative analysis of gene expression between renal cortex and papilla in nedaplatin-induced nephrotoxicity in rats

To elucidate the mechanism of nephrotoxicity caused by anti-neoplastic platinum complex, nedaplatin (NDP), treatment with a particular focus on the renal papillary toxicity, we analysed the gene expression profiles of two renal regions, the cortex (RC) and the papilla (RP) in rat kidneys. Male Wistar rats received a single administration of 10 mg/kg intravenous NDP or vehicle alone (5% xylitol solution) and were sacrificed six days later. The kidneys were dissected into the RC and RP and used for histopathological and microarray analyses. Histopathologically, NDP caused characteristic renal lesions, such as necrosis, single cell necrosis (with TUNEL TdT-mediated dUTP-biotin nick end labelling-positive) and regeneration/hyperplasia of the epithelial cells in both renal regions. Global gene expression analysis revealed that several genes involved in various functional categories were commonly deregulated in both renal regions, such as apoptosis, cell cycle regulation, DNA metabolism, cell migration/adhesion and cytoskeleton organization or genes induced as a perturbation of oxidative status and calcium homeostasis. Comparative analysis of gene expression between RC and RP revealed that genes encoding several subtypes of cytokeratins were identified as being specifically overexpressed in RP by the NDP treatment. Differential expression patterns of these selected genes observed by microarray analysis were further confirmed by quantitative real time RT-PCR and immunohistochemistry, which demonstrated increased expression of cytokeratins (CKs) 14 and 19 at the epithelium covering RP and/or collecting duct epithelium. Overall, the results contribute to understanding the renal molecular events of NDP-induced nephrotoxicity including novel potential biomarker genes encoding CKs 14 and 19 that may serve as indicators of renal papillary toxicity. Human & Experimental Toxicology (2007) 26, 767—780

Combined treatment of epigallocatechin gallate and Coenzyme Q10 attenuates cisplatin-induced nephrotoxicity via suppression of oxidative/nitrosative stress, inflammation and cellular damage

Cisplatin (CP), a platinum based anticancer drug is used as one of the first-line therapy for the treatment of different types of solid tumors. However, CP-induced side effects particularly, nephrotoxicity is a major concern. A single nephrotoxic dose (7 mg/kg body weight) of CP was administered in rats with or without, pre and post combined multidoses of epigallocatechin gallate (EGCG) and coenzyme Q10 (CoQ10) (15 and 5 mg/kg body weight respectively). CP administration resulted in marked increase in the nephrotoxic parameters with alterations in the oxidative and nitrosative stress markers. The concentration of inflammatory, as well as apoptotic markers were markedly up-regulated in the kidney of the CP-treated group. Furthermore, CP resulted in histological injury in the renal tissues. Combined antioxidant treatment significantly (p < 0.01) attenuated CP-induced oxidative stress, nitrosative stress, inflammatory and apoptotic parameters. Moreover, an improvement in the histopathological changes confirmed the nephroprotective effect of antioxidant treatment. In conclusion, our study indicates that the combinatorial multidoses of EGCG and CoQ10 ameliorate the cisplatin-mediated pathogenesis by improving renal oxidative/nitrosative status, inflammation and apoptosis and thus can be used as a promising protective agent to increase the efficacy of the drug by minimizing its major side effect i.e. nephrotoxicity.

Protective effect of ginsenosides Rk3 and Rh4 on cisplatin-induced acute kidney injury in vitro and in vivo

BACKGROUND

Nephrotoxicity is the major side effect in cisplatin chemotherapy. Previously, we reported that the ginsenosides Rk3 and Rh4 reduced cisplatin toxicity on porcine renal proximal epithelial tubular cells (LLC-PK1). Here, we aimed to evaluate the protective effect of ginsenosides Rk3 and Rh4 on kidney function and elucidate their antioxidant effect using in vitro and in vivo models of cisplatin-induced acute renal failure.

METHODS

An enriched mixture of ginsenosides Rk3 and Rh4 (KG-KH; 49.3% and 43.1%, respectively) was purified from sun ginseng (heat processed Panax ginseng). Cytotoxicity was induced by treatment of 20μM cisplatin to LLC-PK1 cells and rat model of acute renal failure was generated by single intraperitoneal injection of 5 mg/kg cisplatin. Protective effects were assessed by determining cell viability, reactive oxygen species generation, blood urea nitrogen, serum creatinine, antioxidant enzyme activity, and histopathological examination.

RESULTS

The in vitro assay demonstrated that KG-KH (50 μg/mL) significantly increased cell viability (4.6-fold), superoxide dismutase activity (2.8-fold), and glutathione reductase activity (1.5-fold), but reduced reactive oxygen species generation (56%) compared to cisplatin control cells. KG-KH (6 mg/kg, per os) also significantly inhibited renal edema (87% kidney index) and dysfunction (71.4% blood urea nitrogen, 67.4% creatinine) compared to cisplatin control rats. Of note, KG-KH significantly recovered the kidney levels of catalase (1.2-fold) and superoxide dismutase (1.5-fold).

CONCLUSION

Considering the oxidative injury as an early trigger of cisplatin nephrotoxicity, our findings suggest that ginsenosides Rk3 and Rh4 protect the kidney from cisplatin-induced oxidative injury and help to recover renal function by restoring intrinsic antioxidant defenses.