Cisplatin-induced apoptosis by translocation of endogenous Bax in mouse collecting duct cells

MicroRNAs Involved in Intrinsic Apoptotic Pathway during Cisplatin-Induced Nephrotoxicity: Potential Use of Natural Products against DDP-Induced Apoptosis

Cisplatin (cis-diamminedichloroplatinum (II), DDP) is an antineoplastic agent widely used in the treatment of solid tumors because of its extensive cytotoxic activity. However, the main limiting side effect of DDP use is nephrotoxicity, a rapid deterioration in kidney function due to toxic chemicals. Several studies have shown that epigenetic processes are involved in DDP-induced nephrotoxicity. Noncoding RNAs (ncRNAs), a class of epigenetic processes, are molecules that regulate gene expression under physiological and pathological conditions. MicroRNAs (miRNAs) are the most characterized class of ncRNAs and are engaged in many cellular processes. In this review, we describe how different miRNAs regulate some pathways leading to cell death by apoptosis, specifically the intrinsic apoptosis pathway. Accordingly, many classes of natural products have been tested for their ability to prevent DDP-induced apoptosis. The study of epigenetic regulation for underlying cell death is still being studied, which will allow new strategies for the diagnosis and therapy of this unwanted disease, which is presented as a side effect of antineoplastic treatment.

TRPA1 promotes cisplatin-induced nephrotoxicity through inflammation mediated by the MAPK/NF-κB signaling pathway

BACKGROUND

The nephrotoxicity induced by cisplatin (DDP) has been a severe obstacle for its clinical use in anticancer treatment. The apoptosis and inflammation induced by DDP are the main causes of the nephrotoxicity. Transient receptor potential ankyrin 1 (TRPA1) is a non-selective cation ligand-gated channel that is involved in the inflammation progress.

METHODS

The apoptosis, inflammation, MAPK/NF-κB signaling pathway, and TRPA1 expression were assessed after HEK293 cells had been induced by DDP, and the role of TRPA1 in apoptosis and inflammation of DDP-induced HEK293 cells treated with TRPA1 antagonist HC-030031 was also evaluated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), flow cytometry, and western blot assays.

RESULTS

The cell viability was reduced by DDP in both a time-dependent and dose-dependent manner with a minimal cytotoxic concentration of 10 μM. Moreover, DDP induced an enhancement of the apoptosis and inflammation in a dose-dependent manner, as indicated by the increase of the relative protein level of cleaved-caspase3 (cleaved-cas3), the cleavage product of caspase-3 substrate poly-ADP-ribose polymerase (cleaved-PARP) and inducible nitric oxide synthase (iNOS), and the messenger RNA (mRNA) expression level of interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), and interferon-γ (INF-γ). Additionally, DDP treatment increased the protein phosphorylation expression of IKKβ, JNK, ERK, and p38 in a dose-dependent manner, which was antagonized by the treatment of NF-κB-specific inhibitor BAY 11-7082 and pan-MAPK inhibitor U0126. It was also found that DDP upregulated the expression of TRPA1 at both the mRNA and protein levels in a dose-dependent manner. Besides, block of TRPA1 with HC-030031 relieved the apoptosis, diminished the level of IL-1β, IL-6, TNF-α, and INF-γ, reduced the level of cleaved-cas3, cleaved-PARP, and iNOS, decreased the p-IKKβ, p-JNK, p-ERK, and p-p38 expression, and enhanced the expression of IκBα.

CONCLUSIONS

Taken together, these results indicate that TRPA1 regulates DDP-induced nephrotoxicity via inflammation mediated by the MAPK/NF-κB signaling pathway in HEK293 cells.

Na/H Exchange Regulatory Factor 1 Deficient Mice Show Evidence of Oxidative Stress and Altered Cisplatin Pharmacokinetics

(1) Background: One third of patients who receive cisplatin develop an acute kidney injury. We previously demonstrated the Na/H Exchange Regulatory Factor 1 (NHERF1) loss resulted in increased kidney enzyme activity of the pentose phosphate pathway and was associated with more severe cisplatin nephrotoxicity. We hypothesized that changes in proximal tubule biochemical pathways associated with NHERF1 loss alters renal metabolism of cisplatin or response to cisplatin, resulting in exacerbated nephrotoxicity. (2) Methods: 2-4 month-old male wild-type and NHERF1 knock out littermate mice were treated with either vehicle or cisplatin (20 mg/kg dose IP), with samples taken at either 4, 24, or 72 h. Kidney injury was determined by urinary neutrophil gelatinase-associated lipocalin and histology. Glutathione metabolites were measured by HPLC and genes involved in glutathione synthesis were measured by qPCR. Kidney handling of cisplatin was assessed by a kidney cortex measurement of γ-glutamyl transferase activity, Western blot for γ-glutamyl transferase and cysteine S-conjugate beta lyase, and ICP-MS for platinum content. (3) Results: At 24 h knock out kidneys show evidence of greater tubular injury after cisplatin and exhibit a decreased reduced/oxidized glutathione ratio under baseline conditions in comparison to wild-type. KO kidneys fail to show an increase in γ-glutamyl transferase activity and experience a more rapid decline in tissue platinum when compared to wild-type. (4) Conclusions: Knock out kidneys show evidence of greater oxidative stress than wild-type accompanied by a greater degree of early injury in response to cisplatin. NHERF1 loss has no effect on the initial accumulation of cisplatin in the kidney cortex but is associated with an altered redox status which may alter the activity of enzymes involved in cisplatin metabolism.

Regulated cell death in cisplatin-induced AKI: relevance of myo-inositol metabolism

Regulated cell death (RCD), distinct from accidental cell death, refers to a process of well-controlled programmed cell death with well-defined pathological mechanisms. In the past few decades, various terms for RCDs were coined, and some of them have been implicated in the pathogenesis of various types of acute kidney injury (AKI). Cisplatin is widely used as a chemotherapeutic drug for a broad spectrum of cancers, but its usage was hampered because of being highly nephrotoxic. Cisplatin-induced AKI is commonly seen clinically, and it also serves as a well-established prototypic model for laboratory investigations relevant to acute nephropathy affecting especially the tubular compartment. Literature reports over a period of three decades have indicated that there are multiple types of RCDs, including apoptosis, necroptosis, pyroptosis, ferroptosis, and mitochondrial permeability transition-mediated necrosis, and some of them are pertinent to the pathogenesis of cisplatin-induced AKI. Interestingly, myo-inositol metabolism, a vital biological process that is largely restricted to the kidney, seems to be relevant to the pathogenesis of certain forms of RCDs. A comprehensive understanding of RCDs in cisplatin-induced AKI and their relevance to myo-inositol homeostasis may yield novel therapeutic targets for the amelioration of cisplatin-related nephropathy.

Advances in Our Understanding of the Molecular Mechanisms of Action of Cisplatin in Cancer Therapy

Cisplatin and other platinum-based chemotherapeutic drugs have been used extensively for the treatment of human cancers such as bladder, blood, breast, cervical, esophageal, head and neck, lung, ovarian, testicular cancers, and sarcoma. Cisplatin is commonly administered intravenously as a first-line chemotherapy for patients suffering from various malignancies. Upon absorption into the cancer cell, cisplatin interacts with cellular macromolecules and exerts its cytotoxic effects through a series of biochemical mechanisms by binding to Deoxyribonucleic acid (DNA) and forming intra-strand DNA adducts leading to the inhibition of DNA synthesis and cell growth. Its primary molecular mechanism of action has been associated with the induction of both intrinsic and extrinsic pathways of apoptosis resulting from the production of reactive oxygen species through lipid peroxidation, activation of various signal transduction pathways, induction of p53 signaling and cell cycle arrest, upregulation of pro-apoptotic genes/proteins, and down-regulation of proto-oncogenes and anti-apoptotic genes/proteins. Despite great clinical outcomes, many studies have reported substantial side effects associated with cisplatin monotherapy, while others have shown substantial drug resistance in some cancer patients. Hence, new formulations and several combinational therapies with other drugs have been tested for the purpose of improving the clinical utility of cisplatin. Therefore, this review provides a comprehensive understanding of its molecular mechanisms of action in cancer therapy and discusses the therapeutic approaches to overcome cisplatin resistance and side effects.

Protective Effect of Shikimic Acid against Cisplatin-Induced Renal Injury: In Vitro and In Vivo Studies

Nephrotoxicity is a serious side effect of cisplatin, which is one of the most frequently used drugs for cancer treatment. This study aimed to assess the renoprotective effect of Artemisia absinthium extract and its bioactive compound (shikimic acid) against cisplatin-induced renal injury. An in vitro assay was performed in kidney tubular epithelial cells (LLC-PK1) with 50, 100, and 200 µg/mL A. absinthium extract and 25 and 50 µM shikimic acid, and cytotoxicity was induced by 25 µM cisplatin. BALB/c mice (6 weeks old) were injected with 16 mg/kg cisplatin once and orally administered 25 and 50 mg/kg shikimic acid daily for 4 days. The results showed that the A. absinthium extract reversed the decrease in renal cell viability induced by cisplatin, whereas it decreased the reactive oxidative stress accumulation and apoptosis in LLC-PK1 cells. Shikimic acid also reversed the effect on cell viability but decreased oxidative stress and apoptosis in renal cells compared with the levels in the cisplatin-treated group. Furthermore, shikimic acid protected against kidney injury in cisplatin-treated mice by reducing serum creatinine levels. The protective effect of shikimic acid against cisplatin-mediated kidney injury was confirmed by the recovery of histological kidney injury in cisplatin-treated mice. To the best of our knowledge, this study is the first report on the nephroprotective effect of A. absinthium extract and its mechanism of action against cisplatin-induced renal injury.

Human umbilical cord-derived mesenchymal stem cells and human cord blood mononuclear cells protect against cisplatin-induced acute kidney injury in rat models

Human umbilical cord-derived mesenchymal stem cells (hUCMSCs) are a promising tool to attenuate cisplatin (CP)-induced acute kidney injury (AKI). However, whether the transplantation of human cord blood mononuclear cells (hCBMNCs) exhibits similar protective effects and their potential underlying mechanisms of action remain unclear. The present study aimed to determine the protective effects of hUCMSCs and hCBMNCs transplantation therapies on an established CP-induced rat model and explore their underlying mechanisms of action. A total of 24 Sprague-Dawley rats, selected based on body weight, were randomly assigned into 4 groups: i) normal control; ii) model (CP); iii) hCBMNCs (CP + hCBMNCs); and iv) hUCMSCs (CP + hUCMSCs). hUCMSCs (2.0x10⁶ cells) and hCBMNCs (2.0x10⁶ cells) were injected into the femoral vein of rats 24 h after CP (8 mg/kg) treatment. To determine the effects of hCBMNCs and hUCMSCs on CP-induced rats, renal function assessment and histological evaluations were performed. Expression levels of high mobility group box 1 (HMGB1) and the ratio of Bax/Bcl2 in renal tissues were detected to elucidate their underlying molecular mechanisms of action. The results demonstrated that transplantation of hUCMSCs and hCBMNCs significantly improved renal function in CP-induced AKI rats, as evidenced by the enhancement of renal morphology; decreased concentrations of blood urea nitrogen and serum creatinine; and a lower percentage of apoptotic renal tubular cells. The expression of HMGB1 and the ratio of Bax/Bcl-2 were significantly reduced in the hUCMSCs and hCBMNCs groups compared with CP group. In conclusion, the present study indicated that hCBMNCs exert similar protective effects to hUCMSCs on CP-induced AKI. hUCMSCs and hCBMNCs protect against CP-induced AKI by suppressing HMGB1 expression and preventing cell apoptosis.

Feasibility and efficacy of chemoradiotherapy with concurrent split-dose cisplatin after induction chemotherapy with docetaxel/cisplatin/5-fluorouracil for locally advanced head and neck cancer

Chemoradiotherapy (CRT) with concurrent high-dose cisplatin (CDDP) is a standard treatment for locally advanced squamous cell carcinoma of the head and neck (LA-SCCHN). Docetaxel plus CDDP and 5-fluorouracil (TPF) induction chemotherapy (ICT) prior to CRT is considered for patients at high risk of distant metastases. The purpose of the current study was to evaluate the feasibility and efficacy of CRT with split-dose CDDP after TPF-ICT for LA-SCCHN. A total of 21 LA-SCCHN patients treated with TPF-ICT followed by concurrent CRT with split-dose CDDP between January 2011 and December 2017 were retrospectively analysed. The patients' characteristics were i) median age 66 years (48-75 years); ii) male/female, 21/0; iii) performance status 0-1/2, 20/1; iv) larynx/hypopharynx/oropharynx/oral cavity, 4/8/8/1 and v) clinical stage III/IV, 3/18. The numbers of TPF-ICT cycles 1/2/3 were 2/3/16. Median cumulative doses of CDDP in TPF-ICT and CRT were 180.0 and 206.7 mg/m², respectively. All patients completed 70 Gy RT. The complete response rate was 76.2%. At a median follow-up of 51.5 months, median PFS and OS were not reached and 65.5 months, respectively. The most common grade 3 or worse toxicities during CRT-ICT were stomatitis (48%), dysphagia (21%), anorexia (17%) and leukopenia (14%). However, no grade 2 or worse nephrotoxicity, neurotoxicity or ototoxicity was observed. The results demonstrated that concurrent CRT with split-dose CDDP after TPF-ICT is feasible and effective for LA-SCCHN.

Isoorientin Attenuates Cisplatin-Induced Nephrotoxicity Through the Inhibition of Oxidative Stress and Apoptosis via Activating the SIRT1/SIRT6/Nrf-2 Pathway

Cisplatin (CDDP) is a widely used chemotherapeutic agent for various solid tumors, but its severe side effects, particularly nephrotoxicity, limit its clinical application. Isoorientin (Iso) is a flavonoid-like compound known to have antioxidant effects. As oxidative injury plays a vital role in CDDP-induced acute kidney injury (AKI), the effect of Iso on CDDP-induced nephrotoxicity has not yet been researched. We assessed the effects of Iso against CDDP-induced nephrotoxicity in vitro using mTEC cells and further explored the mechanisms underlying CDDP-induced renal dysfunction in vivo in WT and Nrf2^-/- mice. The results showed that Iso treatment significantly reduced CDDP-induced nephrotoxicity via attenuating cell damage in vitro and via ameliorating renal injury, as determined by biochemical markers, in mice. The molecular mechanism underlying this protection was also investigated. Iso up-regulated the expression levels of SIRT1 and SIRT6 in vivo and in vitro. In addition, Iso activated Nrf2 translocation and the expression levels of its downstream antioxidant enzymes, such as HO-1 and NQO1, whereas it inhibited the expression level of NOX4, thus decreasing oxidative stress. Notably, the protective effects of Iso observed in WT mice were completely abolished in Nrf2^-/- mice. Collectively, these data indicate that the protective effect of Iso on CDDP-induced nephrotoxicity by SIRT1- and SIRT6-mediated Nrf2 activation regulates oxidative stress, inflammation and apoptosis. The absence of Nrf2 exacerbates CDDP-induced renal damage, and the pharmacological activation of Nrf2 may represent a novel therapy to prevent kidney injury.

Effect of Suramin on Renal Proximal Tubular Cells Damage Induced by Cisplatin in Rats (Histological and Immunohistochemical Study)

Background:

Renal toxicity is the most common complication of cispaltin therapy that has broad-spectrum antitumor activity against a variety of human solid tumor. Suramin, a Food and Drug Administration-approved old drug is a polysulfonated compound of napthylurea originally designed to treat trypanosomiasis.

Aim:

The current work aimed to investigate the possible protective effect of different doses of suramin against cisplatin-induced renal proximal tubular cells (RPTCs) damage.

Material and Methods:

Fifty adult male rats were used and divided into five equal groups. Group I served as a control, group II received suramin alone (10 mg/kg). Groups III, IV and V were administered cisplatin once (5 mg/kg, intraperitoneally) alone or combined with low dosage suramin (5 mg/kg) or high dosage suramin (10 mg/kg) once intravenously respectively.

Results:

Compared with control rats, cisplatin administration caused proximal tubules damage, RPTCs vacuolation with pyknotic nuclei, loss of brush border and widespread caspase-3 immunostaining. Cisplatin-induced RPTCs toxicity was further confirmed morphometrically (a significantly decreased proximal tubular epithelium height and increased mean number of caspase-3-immunopositive cells). These changes were accompanied by biochemical alteration manifested as a significant increase of blood urea nitrogen and serum creatinine. Simultaneous administration of high-dose but not low-dose suramin to the cisplatin-treated rats improved the deleterious morphological and morphometrical effects on RPTCs and restored the aforementioned biochemical parameters to control values.

Conclusion:

In conclusion suramin in a dose dependant manner protects RPTCs from damage induced by cisplatin.

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.

Effect of cisplatin on pancreas and testies in Wistar rats: biochemical parameters and histology

Objective

To investigate effect of cisplatin on biochemical parameter and histology of pancreas and testis in Wistar rats.

Material and methods

Single dose cisplatin (10 mg/kg) was injected by intraperitoneal route in Wistar rats. Blood was withdrawn on 7^th day from cisplatin treated rats by retro-orbital sinus for biochemical estimation. Further rats were scarified and dissected out their pancreases and testes for estimation of antioxidant enzymes and histopathological study.

Results

The cisplatin-treated group showed a significantly (P < 0.01) increased blood glucose level, Glycosylated hemoglobin in blood on the 7^th day as compared to the control group. Whereas cisplatin-treated group showed significantly (p < 0.001) increased lipid peroxidation and decreased reduced glutathione, superoxide dismutase, catalase in pancreatic and testicular tissue as compared to the control group. Histopathological sections of the pancreatic tissue showed marked vasoconstriction and micro infiltration were observed however testicular tissue showed degeneration in some somniferous tubules and also greatly depleted of germ cells in cisplatin treated group.

Conclusion

These findings demonstrated that the cisplatin could be induced diabetes and testicular toxicity due to their free radical mediated oxidative stress.

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.

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.

Aristolochic acid I determine the phenotype and activation of macrophages in acute and chronic kidney disease

Acute and chronic kidney injuries are multifactorial traits that involve various risk factors. Experimental animal models are crucial to unravel important aspects of injury and its pathophysiological mechanisms. Translating knowledge obtained from experimental approaches into clinically useful information is difficult; therefore, significant attention needs to be paid to experimental procedures that mimic human disease. Herein, we compared aristolochic acid I (AAI) acute and chronic kidney injury model with unilateral ischemic-reperfusion injury (uIRI), cisplatin (CP)- or folic acid (FA)-induced renal damage. The administration of AAI showed significant changes in serum creatinine and BUN upon CKD. The number of neutrophils and macrophages were highly increased as well as AAI-induced CKD characterized by loss of tubular epithelial cells and fibrosis. The in vitro and in vivo data indicated that macrophages play an important role in the pathogenesis of AA-induced nephropathy (AAN) associated with an excessive macrophage accumulation and an alternative activated macrophage phenotype. Taken together, we conclude that AA-induced injury represents a suitable and relatively easy model to induce acute and chronic kidney injury. Moreover, our data indicate that this model is appropriate and superior to study detailed questions associated with renal macrophage phenotypes.

L-thyroxine modifies nephrotoxicity by regulating the apoptotic pathway: The possible role of CD38/ADP-ribosyl cyclase-mediated calcium mobilization

Thyroid hormones are well-established as a key regulator of many cellular metabolic pathways developed in various pathogeneses. Here, we dedicated the current work to investigate the role of thyroid hormone analogue (L-thyroxine, L-TH) in regulating the renal cytotoxicity using in vivo and in vitro models. Swiss mice were exposed to gamma radiation (IRR, 6Gy) or treated with cisplatin (CIS, 15 mg/kg, i.p.) for induction of nephrotoxicity. Remarkably, pretreatment with L-TH (1μg/kg) ameliorated the elevated kidney function biomarkers, oxidative stress and protected the renal tissue from the subsequent cellular damage. Likewise, L-TH inhibited the apoptotic cascade by down-regulating the extreme consumption of the cellular energy (ATP), the expression of caspase-3 and Bax, and the stimulation of cyclic ADP ribose (cADPR)/calcium mobilization. Moreover, incubation with L-TH (120nM/4h) significantly blocked the cytotoxicity of CIS on Vero cells and the depletion of NAD+ content as well as modified the ADP-ribose cyclase (CD38) enzymatic activity. High doses of L-TH (up to30 nM/4h) inversely increased the radiosensitivity of Vero cells towards IRR (up to 6Gy). On the other hand, L-TH did not interfere CIS-induced cytotoxicity of colorectal adenocarcinoma (Caco-2) cell line. In conclusion, pretreatment with L-TH could be a promising protective approach to the renal cellular damage induced during either CIS or IRR therapy by regulating the unbalanced oxidative status, the expression of pro-apoptotic biomarkers via modulation of cADPR mediated-calcium mobilization.

Depletion of Mitofusin-2 Causes Mitochondrial Damage in Cisplatin-Induced Neuropathy

Sensory neuropathy is a relevant side effect of the antineoplastic agent cisplatin. Mitochondrial damage is assumed to play a critical role in cisplatin-induced peripheral neuropathy, but the pathomechanisms underlying cisplatin-induced mitotoxicity and neurodegeneration are incompletely understood. In an animal model of cisplatin-induced neuropathy, we determined in detail the extent and spatial distribution of mitochondrial damage during cisplatin treatment. Changes in the total number of axonal mitochondria during cisplatin treatment were assessed in intercostal nerves from transgenic mice that express cyan fluorescent protein. Further, we explored the impact of cisplatin on the expression of nuclear encoded molecules of mitochondrial fusion and fission, including mitofusin-2 (MFN2), optic atrophy 1 (OPA1), and dynamin-related protein 1 (DRP1). Cisplatin treatment resulted in a loss of total mitochondrial mass in axons and in an abnormal mitochondrial morphology including atypical enlargement, increased vacuolization, and loss of cristae. These changes were observed in distal and proximal nerve segments and were more prominent in axons than in Schwann cells. Transcripts of fusion and fission proteins were reduced in distal nerve segments. Significant reduced expression levels of the fusion protein MFN2 was detected in nerves of cisplatin-exposed animals. In summary, we provide for the first time an evidence that cisplatin alters mitochondrial dynamics in peripheral nerves. Loss of MFN2, previously implicated in the pathogenesis of other neurodegenerative diseases, also contributes to the pathogenesis in cisplatin-induced neuropathy.

An integrative view of cisplatin-induced renal and cardiac toxicities: Molecular mechanisms, current treatment challenges and potential protective measures

Cisplatin is currently one of the most widely-used chemotherapeutic agents against various malignancies. Its clinical application is limited, however, by inherent renal and cardiac toxicities and other side effects, of which the underlying mechanisms are only partly understood. Experimental studies show cisplatin generates reactive oxygen species, which impair the cell's antioxidant defense system, causing oxidative stress and potentiating injury, thereby culminating in kidney and heart failure. Understanding the molecular mechanisms of cisplatin-induced renal and cardiac toxicities may allow clinicians to prevent or treat this problem better and may also provide a model for investigating drug-induced organ toxicity in general. This review discusses some of the major molecular mechanisms of cisplatin-induced renal and cardiac toxicities including disruption of ionic homeostasis and energy status of the cell leading to cell injury and cell death. We highlight clinical manifestations of both toxicities as well as (novel)biomarkers such as kidney injury molecule-1 (KIM-1), tissue inhibitor of metalloproteinase-1 (TIMP-1) and N-terminal pro-B-type natriuretic peptide (NT-proBNP). We also present some current treatment challenges and propose potential protective strategies including combination therapy with novel pharmacological compounds that might mitigate or prevent these toxicities, which include the use of hydrogen sulfide.

Indole-3-carbinol protects against cisplatin-induced acute nephrotoxicity: role of calcitonin gene-related peptide and insulin-like growth factor-1

Nephrotoxicity associated with the clinical use of the anticancer drug cisplatin is a limiting problem. Thus, searching for new protective measures is required. Indole-3-carbinol is a powerful anti-oxidant, anti-inflammatory and anti-tumor agent. The present study aimed to investigate the potential protective effect of indole-3-carbinol against cisplatin-induced acute nephrotoxicity in rats. Rats were pre-treated with 20 mg/kg indole-3-carbinol orally before giving cisplatin (7 mg/kg). Cisplatin-induced acute nephrotoxicity was demonstrated where relative kidney weight, BUN and serum creatinine were significantly increased. Increased oxidative stress was evident in cisplatin group where GSH and SOD tissue levels were significantly depleted. Also, lipid peroxidation and NOX-1 were increased as compared to the control. Additionally, renal expression of pro-inflammatory mediators was induced by cisplatin. Cisplatin-induced cell death was shown by increased caspase-3 and decreased expression of EGF, IGF-1 and IGF-1 receptor. Nephrotoxicity, oxidative stress, inflammation and apoptotic effects induced by cisplatin were significantly ameliorated by indole-3-carbinol pre-treatment. Besides, the role of CGRP in cisplatin-induced nephrotoxicity was explored. Furthermore, cisplatin cytotoxic activity was significantly enhanced by indole-3-carbinol pre-treatment in vitro. In conclusion, indole-3-carbinol provides protection against cisplatin-induced nephrotoxicity. Also, reduced expression of CGRP may play a role in the pathogenesis of cisplatin-induced renal injury.

A Comprehensive Review on the Genetic Regulation of Cisplatin-induced Nephrotoxicity

Cisplatin (CDDP) is a well-known antineoplastic drug which has been extensively utilized over the last decades in the treatment of numerous kinds of tumors. However, CDDP induces a wide range of toxicities in a dose-dependent manner, among which nephrotoxicity is of particular importance. Still, the mechanism of CDDP-induced renal damage is not completely understood; moreover, the knowledge about the role of microRNAs (miRNAs) in the nephrotoxic response is still unknown. miRNAs are known to interact with the representative members of a diverse range of regulatory pathways (including postnatal development, proliferation, inflammation and fibrosis) and pathological conditions, including kidney diseases: polycystic kidney diseases (PKDs), diabetic nephropathy (DN), kidney cancer, and drug-induced kidney injury. In this review, we shed light on the following important aspects: (i) information on genes/proteins and their interactions with previously known pathways engaged with CDDP-induced nephrotoxicity, (ii) information on newly discovered biomarkers, especially, miRNAs for detecting CDDP-induced nephrotoxicity and (iii) information to improve our understanding on CDDP. This information will not only help the researchers belonging to nephrotoxicity field, but also supply an indisputable help for oncologists to better understand and manage the side effects induced by CDDP during cancer treatment. Moreover, we provide up-to-date information about different in vivo and in vitro models that have been utilized over the last decades to study CDDP-induced renal injury. Taken together, this review offers a comprehensive network on genes, miRNAs, pathways and animal models which will serve as a useful resource to understand the molecular mechanism of CDDP-induced nephrotoxicity.

Elemental bioimaging of Cisplatin in Caenorhabditis elegans by LA-ICP-MS

cis-Diamminedichloroplatinum(II) (Cisplatin) is one of the most important and frequently used cytostatic drugs for the treatment of various solid tumors. Herein, a laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) method incorporating a fast and simple sample preparation protocol was developed for the elemental mapping of Cisplatin in the model organism Caenorhabditis elegans (C. elegans). The method allows imaging of the spatially-resolved elemental distribution of platinum in the whole organism with respect to the anatomic structure in L4 stage worms at a lateral resolution of 5 μm. In addition, a dose- and time-dependent Cisplatin uptake was corroborated quantitatively by a total reflection X-ray fluorescence spectroscopy (TXRF) method, and the elemental mapping indicated that Cisplatin is located in the intestine and in the head of the worms. Better understanding of the distribution of Cisplatin in this well-established model organism will be instrumental in deciphering Cisplatin toxicity and pharmacokinetics. Since the cytostatic effect of Cisplatin is based on binding the DNA by forming intra- and interstrand crosslinks, the response of poly(ADP-ribose)metabolism enzyme 1 (pme-1) deletion mutants to Cisplatin was also examined. Loss of pme-1, which is the C. elegans ortholog of human poly(ADP-ribose) polymerase 1 (PARP-1) led to disturbed DNA damage response. With respect to survival and brood size, pme-1 deletion mutants were more sensitive to Cisplatin as compared to wildtype worms, while Cisplatin uptake was indistinguishable.

Bcl-2 confers survival in cisplatin treated cervical cancer cells: circumventing cisplatin dose-dependent toxicity and resistance

Background

Cisplatin is the main chemotherapeutic drug for the treatment of cervical cancers, however resistance to cisplatin is increasingly common and therefore has limited the efficacy and use of this drug in the clinic. Dose-dependent toxicity poses an additional challenge since patients suffer long-term and often permanent side-effects after treatment. Bcl-2 up-regulation has been implicated in the resistance to cisplatin in a variety of cancer cell lines, however its role in cervical cancer is confounding.

Methods

A low, non-cytotoxic concentration of cisplatin was used in the treatment of HeLa and CaSki cells. Bcl-2 expression was determined through Western blotting and immunocytochemistry before and after treatment with cisplatin. To assess the reliance of the cervical cancer cells on Bcl-2 in the presence of cisplatin, Bcl-2 knock-down was achieved through RNA interference, where after apoptosis was assessed through PARP cleavage (Western blotting), Caspase activity (Caspase-Glo^©) and PI inclusion analysis (Flow cytometry). Finally, pre-malignant and malignant cervical tissue was analysed for the presence of Bcl-2 through Western blotting and immunofluorescence.

Results

Cervical cancer cells upregulate Bcl-2 when treated with a non-cytotoxic concentration of cisplatin, which when silenced, effectively enhanced cisplatin sensitivity, and therefore significantly induced apoptosis. Analysis of the expression profile of Bcl-2 in cervical tissue revealed its up-regulation in cervical carcinoma, which agrees with results obtained from the in vitro data.

Conclusions

Our data strongly suggest that utilising a lower dose of cisplatin is feasible when combined with Bcl-2 silencing as an adjuvant treatment, thereby improving both the dose-dependent toxicity, as well as cervical cancer resistance.

Histological, ultrastructural and immunohistochemical studies on the protective effect of ginger extract against cisplatin-induced nephrotoxicity in male rats

Cisplatin (CP) is a widely used anticancer drug; however, it has several side effects such as nephrotoxicity. Ginger, the rhizome of Zingiber officinale, consumed since ancient times has numerous health benefits. The objective of this work was to evaluate the protective effect of ginger extract (GE) against CP-induced nephrotoxicity. CP group displayed a marked renal failure characterized by a significant increase in serum creatinine and blood urea nitrogen (BUN) levels in addition to severe histopathological and ultrastructural renal alterations. Also, CP group showed an increase in the immunohistochemical expression of Bax proapoptotic protein. In contrast, GE+CP group showed significant decrease in the elevated serum creatinine and BUN levels and an improvement in the histopathological and ultrastructural renal injury induced by CP. The overexpression of Bax proapoptotic protein was significantly decreased in the GE+CP group. Hence, the present results indicated that GE has a protective effect against CP-induced renal damage in rats. Thereby, such findings recommended the usage of GE to prevent and/or decrease the renal damage induced by CP chemotherapeutic treatment.

An integrated view of cisplatin-induced nephrotoxicity and ototoxicity

Cisplatin is one of the most widely-used drugs to treat cancers. However, its nephrotoxic and ototoxic side-effects remain major clinical limitations. Recent studies have improved our understanding of the molecular mechanisms of cisplatin-induced nephrotoxicity and ototoxicity. While cisplatin binding to DNA is the major cytotoxic mechanism in proliferating (cancer) cells, nephrotoxicity and ototoxicity appear to result from toxic levels of reactive oxygen species and protein dysregulation within various cellular compartments. In this review, we discuss molecular mechanisms of cisplatin-induced nephrotoxicity and ototoxicity. We also discuss potential clinical strategies to prevent nephrotoxicity and ototoxicity and their current limitations.

Cisplatin-induced Kidney Dysfunction and Perspectives on Improving Treatment Strategies

Cisplatin is one of the most widely used and highly effective drug for the treatment of various solid tumors; however, it has dose-dependent side effects on the kidney, cochlear, and nerves. Nephrotoxicity is the most well-known and clinically important toxicity. Numerous studies have demonstrated that several mechanisms, including oxidative stress, DNA damage, and inflammatory responses, are closely associated with cisplatin-induced nephrotoxicity. Even though the establishment of cisplatin-induced nephrotoxicity can be alleviated by diuretics and pre-hydration of patients, the prevalence of cisplatin nephrotoxicity is still high, occurring in approximately one-third of patients who have undergone cisplatin therapy. Therefore it is imperative to develop treatments that will ameliorate cisplatin-nephrotoxicity. In this review, we discuss the mechanisms of cisplatin-induced renal toxicity and the new strategies for protecting the kidneys from the toxic effects without lowering the tumoricidal activity.

The synthesis of sulforaphane analogues and their protection effect against cisplatin induced cytotoxicity in kidney cells

A series of sulforaphane analogues were synthesized with various amines by treatment of carbon disulfide followed by Boc₂O and DMAP. These synthesized sulforaphane analogues were tested on cisplatin treated cultured LLC-PK1 kidney cell line. Among these analogues, several compounds including SF5 show a potent effect on kidney cell protection assay at the concentration of 2.5 μM. Further studies with compound SF5 revealed that the kidney cell protection effect was related by inhibiting the apoptosis pathway through JNK-p53-caspase apoptotic cascade. Compound SF5 may be considered as a promising candidate for the development of new kidney protection agent against drug induced acute kidney disease.

Angiotensin II type 1 receptor blockers increase tolerance of cells to copper and cisplatin

The human pathology Wilson disease (WD) is characterized by toxic copper (Cu) accumulation in brain and liver, resulting in, among other indications, mitochondrial dysfunction and apoptosis of hepatocytes. In an effort to identify novel compounds that can alleviate Cu-induced toxicity, we screened the Pharmakon 1600 repositioning library using a Cu-toxicity yeast screen. We identified 2 members of the drug class of Angiotensin II Type 1 receptor blockers (ARBs) that could increase yeast tolerance to Cu, namely Candesartan and Losartan. Subsequently, we show that specific ARBs can increase yeast tolerance to Cu and/or the chemotherapeutic agent cisplatin (Cp). The latter also induces mitochondrial dysfunction and apoptosis in mammalian cells. We further demonstrate that specific ARBs can prevent the prevalence of Cu-induced apoptotic markers in yeast, with Candesartan Cilexetil being the ARB which demonstrated most pronounced reduction of apoptosis-related markers. Next, we tested the sensitivity of a selection of yeast knockout mutants affected in detoxification of reactive oxygen species (ROS) and Cu for Candesartan Cilexetil rescue in presence of Cu. These data indicate that Candesartan Cilexetil increases yeast tolerance to Cu irrespectively of major ROS-detoxifying proteins. Finally, we show that specific ARBs can increase mammalian cell tolerance to Cu, as well as decrease the prevalence of Cu-induced apoptotic markers. All the above point to the potential of ARBs in preventing Cu-induced toxicity in yeast and mammalian cells.

Pathophysiology of cisplatin-induced acute kidney injury

Cisplatin and other platinum derivatives are the most widely used chemotherapeutic agents to treat solid tumors including ovarian, head and neck, and testicular germ cell tumors. A known complication of cisplatin administration is acute kidney injury (AKI). The nephrotoxic effect of cisplatin is cumulative and dose-dependent and often necessitates dose reduction or withdrawal. Recurrent episodes of AKI may result in chronic kidney disease. The pathophysiology of cisplatin-induced AKI involves proximal tubular injury, oxidative stress, inflammation, and vascular injury in the kidney. There is predominantly acute tubular necrosis and also apoptosis in the proximal tubules. There is activation of multiple proinflammatory cytokines and infiltration of inflammatory cells in the kidney. Inhibition of the proinflammatory cytokines TNF-α or IL-33 or depletion of CD4+ T cells or mast cells protects against cisplatin-induced AKI. Cisplatin also causes endothelial cell injury. An understanding of the pathogenesis of cisplatin-induced AKI is important for the development of adjunctive therapies to prevent AKI, to lessen the need for dose decrease or drug withdrawal, and to lessen patient morbidity and mortality.

Epoxyeicosatrienoic acids prevent cisplatin-induced renal apoptosis through a p38 mitogen-activated protein kinase-regulated mitochondrial pathway

Soluble epoxide hydrolase (sEH) catalyzes the conversion of epoxyeicosatrienoic acids into less active eicosanoids, and inhibitors of sEH have anti-inflammatory and antiapoptotic properties. Based on previous observations that sEH inhibition attenuates cisplatin-induced nephrotoxicity by modulating nuclear factor-κB signaling, we hypothesized that this strategy would also attenuate cisplatin-induced renal apoptosis. Inhibition of sEH with AR9273 [1-adamantan-1-yl-3-(1-methylsulfonyl-piperidin-4-yl-urea)] reduced cisplatin-induced apoptosis through mechanisms involving mitochondrial apoptotic pathways and by reducing reactive oxygen species. Renal mitochondrial Bax induction following cisplatin treatment was significantly decreased by treatment of mice with AR9273 and these antiapoptotic effects involved p38 mitogen-activated protein kinase signaling. Similar mechanisms contributed to reduced apoptosis in Ephx2(-/-) mice treated with cisplatin. Moreover, in pig kidney proximal tubule cells, cisplatin-induced mitochondrial trafficking of Bax and cytochrome c, caspase-3 activation, and oxidative stress are significantly attenuated in the presence of epoxyeicosatrienoic acids (EETs). Collectively, these in vivo and in vitro studies demonstrate a role for EETs in limiting cisplatin-induced renal apoptosis. Inhibition of sEH represents a novel therapeutic strategy for protection against cisplatin-induced renal damage.

Cisplatin toxicity reduced in human cultured renal tubular cells by oxygen pretreatment

Cisplatin is an effective and widely used chemotherapy agent and its side effects, particularly nephrotoxicity, limit its usage and related platinum-based drugs. Cisplatin nephrotoxicity is mainly due to extremely increase in reactive oxygen species (ROS) generation leading to kidney tubular cell death. Preconditioning with oxidative stress has been demonstrated to stimulate the cellular adaptation to subsequent severe oxidative stress. Short term oxygen pre-exposure as a mild oxidative stress may enhance some endogenous defense mechanisms, so its effect on Cisplatin induced cell death was investigated in present research. We studied the effects of hyperoxic environment pre-exposure on Cisplatin toxicity in an in-vitro model of cultured human embryonic tubular epithelial cells (AD293). Viability of AD293 cells, as evaluated by MTT-assay, was affected by Cisplatin in a time (1-4 h) dependent model. Biochemical markers of cell apoptosis were evaluated using immunoblotting. Pretreatment with nearly pure oxygen (≥90%) for 2 h significantly reduced the level of cell damage. Activated caspase 3 and Bax/Bcl-2 ratio were significantly increased in Cisplatin-treated cells. Oxygen pretreatment inhibited caspase 3 activation and decreased Bax/Bcl-2 ratio. Oxygen pre-treatment itself not showed any cytotoxicity in exposure times up to 3 h. Our data indicate that hyperoxic preconditioning reduces Cisplatin toxicity in cultured human tubular epithelial cells. The exact mechanism of protection is unclear, though enhancement of some endogenous defense mechanisms and subsequently scavenging of free oxygen radicals may play an important role.

Antitumor effect of blister beetles: an ethno-medicinal practice in Karbi community and its experimental evaluation against a murine malignant tumor model

ETHNOPHARMACOLOGICAL IMPORTANCE

The blister beetles Epicauta hirticornis and Mylabris cichorii are used as a folk medicine by the Karbi tribe in Karbi Anglong district of Assam, India for the treatment of different human ailments, including cancer cases.

AIM OF THE STUDY

It includes field survey related to zoo-therapeutic aspects of two blister beetles in Karbi community, isolation of bio-active compound and evaluation of its antitumor potential with possible mode of action against murine Ehrlich ascites carcinoma (EAC).

MATERIALS AND METHODS

The main bio-active compound of blister beetles was isolated from ethyl acetate extract and the structure was confirmed as cantharidin using NMR, IR, Mass and X-ray diffractometer. The effect of cantharidin on apoptosis, necrosis, autophagy and the apoptosis related signaling pathways were determined using different bioassays, including cell cycle analysis, mitochondrial membrane potential, western blot analysis of cytochrome c, caspases 9, 3/7 assays, and lactate dehydrogenase (LDH) assay.

RESULTS

Cantharidin induced apoptosis, necrosis and autophagy cell death in EAC cells. The decrease in mitochondrial membrane potential was observed, which may help to release cytochrome c from mitochondria to cytosol. Cantharidin treatment caused up-regulation of caspases 9 and -3/7 and a decrease in LDH activity in EAC cells.

CONCLUSION

The major bioactive compound of these blister beetles is cantharidin which induces severe apoptosis in EAC cells involving mitochondrial intrinsic pathway. Cantharidin-mediated inhibition of LDH activity may lead to short supply of NAD(+) and cut off energy and anabolic supply to cancer cells.

Antigenotoxic properties of chlorophyll b against cisplatin-induced DNA damage and its relationship with distribution of platinum and magnesium in vivo

The chemotherapeutic agent cisplatin (cDDP) is widely used to treat a variety of solid and hematological tumors. However, cDDP exerts severe side effects, such as nephrotoxicity, neurotoxicity, and bone-marrow suppression. The use of some dietary compounds to protect organs that are not targets in association with chemotherapy has been encouraged. This study evaluated the protective effects of chlorophyll b (CLb) on DNA damage induced by cDDP by use of single-cell gel electrophoresis (SCGE) assays. Further, this investigation also determined platinum (Pt) and magnesium (Mg) bioaccumulation in mice tissues after treatment with CLb alone and/or in association of cDDP (simultaneous treatment) by inductively coupled plasma-mass spectroscopy (ICP-MS). All parameters were studied in peripheral blood cells (PBC), kidneys, and liver of mice after administration of CLb (0.2 or 0.5 mg/kg of body weight [b.w.]), cDDP (6 mg/kg b.w.), and the combination CLb 0.2 plus cDDP or CLb 0.5 plus cDDP. Pt accumulation in liver and kidneys was higher than that found in PBC, while DNA damage was higher in kidneys and liver than in PBC. Further, treatment with CLb alone did not induce DNA damage. Evidence indicates that genotoxic effects produced by cDDP may not be related to Pt accumulation and distribution. In combined treatments, CLb decreased DNA damage in tissues, but the PT contents did not change and these treatments also showed that CLb may be an important source of Mg. Thus, our results indicate that consumption of CLb-rich foods may diminish the adverse health effects induced by cDDP exposure.

Computational modeling of apoptotic signaling pathways induced by cisplatin

Background

Apoptosis is an essential property of all higher organisms that involves extremely complex signaling pathways. Mathematical modeling provides a rigorous integrative approach for analyzing and understanding such intricate biological systems.

Results

Here, we constructed a large-scale, literature-based model of apoptosis pathways responding to an external stimulus, cisplatin. Our model includes the key elements of three apoptotic pathways induced by cisplatin: death receptor-mediated, mitochondrial, and endoplasmic reticulum-stress pathways. We showed that cisplatin-induced apoptosis had dose- and time-dependent characteristics, and the level of apoptosis was saturated at higher concentrations of cisplatin. Simulated results demonstrated that the effect of the mitochondrial pathway on apoptosis was the strongest of the three pathways. The cross-talk effect among pathways accounted for approximately 25% of the total apoptosis level.

Conclusions

Using this model, we revealed a novel mechanism by which cisplatin induces dose-dependent cell death. Our finding that the level of apoptosis was affected by not only cisplatin concentration, but also by cross talk among pathways provides in silico evidence for a functional impact of system-level characteristics of signaling pathways on apoptosis.

Antineoplastic drug, carboplatin, protects mice against visceral leishmaniasis

In the present study, the leishmanicidal effect of two doses (5 and 10 mg/kg body weight) of the carboplatin was studied in Leishmania donovani-infected BALB/c mice. Mice were infected intracardially with promastigotes of L. donovani, and a month after infection, they were treated intraperitoneally with the two doses of the drug (5 and 10 mg/kg body weight) for five continuous days. Animals were sacrificed on 1 and 15 posttreatment days. Hepatic parasite load was assessed on Geimsa-stained imprints. Immune responses were studied by measuring delayed-type hypersensitivity (DTH) responses, serum IgG isotype levels (IgG1 and IgG2a) and cytokine levels [γ-interferon (IFN-γ), interleukin (IL)-10 and IL-2] in spleen cell cultures by ELISA. To study the drug-induced side effects, various haematological (haemoglobin and total leukocyte count), biochemical (liver and kidney function tests) and histological investigations (kidney, liver and spleen) were carried out. The antileishmanial potential of the drug was revealed by significant reduction in the parasite burden. The infected and treated animals were also found to exhibit increased DTH responses, higher IgG2a levels, lower IgG1 levels and greater cytokine (IFN-γ, IL-10 and IL-2) concentrations pointing towards the generation of mixed Th1/Th2 response. Liver and kidney function tests and histological studies of kidney, liver and spleen of treated mice revealed no side effects. Carboplatin cures mice of visceral leishmaniasis without causing any serious side effects, and the drug was found be more effective at a dose of 10 mg/kg body weight as compared to 5 mg/kg body weight.

Epicatechin limits renal injury by mitochondrial protection in cisplatin nephropathy

Cisplatin nephropathy can be regarded as a mitochondrial disease. Intervention to halt such deleterious injury is under investigation. Recently, the flavanol (-)-epicatechin emerges as a novel compound to protect the cardiovascular system, owing in part to mitochondrial protection. Here, we have hypothesized that epicatechin prevents the progression of cisplatin-induced kidney injury by protecting mitochondria. Epicatechin was administered 8 h after cisplatin injury was induced in the mouse kidney. Cisplatin significantly induced renal dysfunction and tubular injury along with an increase in oxidative stress. Mitochondrial damages were also evident as a decrease in loss of mitochondrial mass with a reduction in the oxidative phosphorylation complexes and low levels of MnSOD. The renal damages and mitochondrial injuries were significantly prevented by epicatechin treatment. Consistent with these observations, an in vitro study using cultured mouse proximal tubular cells demonstrated that cisplatin-induced mitochondrial injury, as revealed by a decrease in mitochondrial succinate dehydrogenase activity, an induction of cytochrome c release, mitochondrial fragmentation, and a reduction in complex IV protein, was prevented by epicatechin. Such a protective effect of epicatechin might be attributed to decreased oxidative stress and reduced ERK activity. Finally, we confirmed that epicatechin did not perturb the anticancer effect of cisplatin in HeLa cells. In conclusion, epicatechin exhibits protective effects due in part to its ability to prevent the progression of mitochondrial injury in mouse cisplatin nephropathy. Epicatechin may be a novel option to treat renal disorders associated with mitochondrial dysfunction.

Genetic modification of mesenchymal stem cells to overexpress CXCR4 and CXCR7 does not improve the homing and therapeutic potentials of these cells in experimental acute kidney injury

The therapeutic potential of bone marrow mesenchymal stem cells (MSCs) in kidney failure has been examined in some studies. However, recent findings indicate that after transplantation, these cells home to kidneys at very low levels. Interaction of stromal derived factor-1 (SDF-1) with its receptor, CXCR4, is of pivotal importance in migration and homing. Recently, CXCR7 has also been recognized as another SDF-1 receptor that interacts with CXCR4 and modulates its functions. In this study, CXCR4 and CXCR7 were separately and simultaneously overexpressed in BALB/c bone marrow MSCs by using a lentiviral vector system and the homing and renoprotective potentials of these cells were evaluated in a mouse model of cisplatin-induced acute kidney injury. Using flow cytometry, immunohistochemistry, and real-time PCR methods for detection of GFP-labeled MSCs, we found that although considerably entrapped in lungs, native MSCs home very rarely to kidneys and bone marrow and this rate cannot be significantly affected by CXCR4 and/or CXCR7 upregulation. Transplantation of neither native nor genetically engineered MSCs ameliorated kidney failure. We concluded that overexpression of CXCR4 and CXCR7 receptors in murine MSCs cannot improve the homing and therapeutic potentials of these cells and it can be due to severe chromosomal abnormalities that these cells bear during ex vivo expansion.

Cisplatin-induced nephrotoxicity and targets of nephroprotection: an update

Cisplatin is a highly effective antitumor agent whose clinical application is limited by the inherent nephrotoxicity. The current measures of nephroprotection used in patients receiving cisplatin are not satisfactory, and studies have focused on the investigation of new possible protective strategies. Many pathways involved in cisplatin nephrotoxicity have been delineated and proposed as targets for nephroprotection, and many new potentially protective agents have been reported. The multiple pathways which lead to renal damage and renal cell death have points of convergence and share some common modulators. The most frequent event among all the described pathways is the oxidative stress that acts as both a trigger and a result. The most exploited pathways, the proposed protective strategies, the achievements obtained so far as well as conflicting data are summarized and discussed in this review, providing a general view of the knowledge accumulated with past and recent research on this subject.

Retracted: Modulation of p53 /Akt / phosphatase and tensin homolog expression by esculetin potentiates the anticancer activity of cisplatin and prevents its nephrotoxicity

This article has been retracted at the request of Editor‐in‐Chief and Authors, and is available online only.

The following article from Cancer Science , ‘Modulation of p53/Akt/phosphatase and tensin homolog expression by esculetin potentiates the anticancer activity of cisplatin and prevents its nephrotoxicity’ (doi: 10.1111/j.1349‐7006.2011.02091.x), by Kulbhushan Tikoo, Abhijit Babaji Shinde, Chanchal Gupta and Gopabandhu Jena, published online on 18 October 2011 in Wiley Online Library (http://onlinelibrary.wiley.com ), has been retracted by agreement between the authors, the journal Editor in Chief, Yusuke Nakamura, and Blackwell Publishing Asia Pty Ltd. The retraction has been agreed due to inappropriate image utilization in relation to Figure 2.

Yusuke Nakamura 
Editor‐in‐Chief 
Cancer Science

Investigation of protective effect of hydrogen-rich water against cisplatin-induced nephrotoxicity in rats using blood oxygenation level-dependent magnetic resonance imaging

PURPOSE

The aim of this study was to assess the mechanism of the protective effect of hydrogen-rich water (HW) against cisplatin (CP)-induced nephrotoxicity in rats using blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Apparent transverse relaxation time-weighted images (T2 WI) were acquired in 28 rats. The control group (n = 7) had free access to standard water (SW) and no CP injection. The CP group (n = 7) had free access to SW and was given a CP injection on day 0. The CP+HW group (n = 7) had free access to HW and had a CP injection. The HW group (n = 7) had free access to HW and no CP injection. The apparent transverse relaxation rate (R2) was estimated from T2 WI.

RESULTS

In the CP+HW group, the R2 value in the medulla normalized by the value of the day 0 was significantly greater than that in the CP group on days 4 and 7. The creatinine and blood urea nitrogen levels in the CP group were significantly higher than those in the control, CP+HW, and HW groups.

CONCLUSION

BOLD MRI may be useful for demonstrating the change in R2 in CP-induced nephrotoxicity in rats. The changes in the CP+HW group were suspected to be due to a reduction of cytotoxic oxygen radicals.

Activation of a nuclear factor of activated T-lymphocyte-3 (NFAT3) by oxidative stress in carboplatin-mediated renal apoptosis

BACKGROUND AND PURPOSE

Although carboplatin is currently used as a therapeutic drug for ovarian, breast, and non-small cell lung cancers, it has serious side effects including renal and cardiac toxicity. Herein, we examined the effect of carboplatin on murine renal tubular cell (RTC) apoptosis both in vivo and in vitro and the underlying molecular mechanisms associated with its activation of the nuclear factor of activated T-lymphocytes-3 (NFAT3).

EXPERIMENTAL APPROACH

Mechanisms of carboplatin-mediated renal apoptosis were examined using NFAT-reporter transgenic mice and RTCs with NFAT3 overexpression or knockdown.

KEY RESULTS

We demonstrated that carboplatin initiated an intrinsic apoptotic pathway of activating caspase-3 and -9, accompanied by a decrease in the ratio of Bcl-XL/Bax and a significant increase in Bcl-XS. Carboplatin increased NFAT activation in NFAT-luciferase reporter transgenic mice, RTCs and cells exogenously overexpressing NFAT3 that exacerbated cell death. Furthermore, the addition of either N-acetylcysteine (NAC, an antioxidant) or NFAT inhibitors, including FK-506 (tacrolimus), cyclosporin A (CsA, a calcineurin inhibitor), and BAPTA-AM (a calcium chelator) successfully reversed carboplatin-mediated cell apoptosis, which was further confirmed using siNFAT3. Additionally, NAC blocked NFAT3 activation by inhibition of NADPH oxidase activation, and ERK/JNK and PKC pathways, resulting in a decrease in cell apoptosis; the therapeutic effect of NAC was verified in vivo.

CONCLUSION AND IMPLICATIONS

The results presented herein show that carboplatin-mediated reactive oxygen species might signal calcineurin and NFAT3 activation in RTCs, whereas NAC and NFAT inhibitors reversed carboplatin-mediated RTC apoptosis, suggesting that oxidative stress-mediated NFAT3 activation is essential for carboplatin-mediated RTC apoptosis.

Mechanisms of Cisplatin nephrotoxicity

Cisplatin is a widely used and highly effective cancer chemotherapeutic agent. One of the limiting side effects of cisplatin use is nephrotoxicity. Research over the past 10 years has uncovered many of the cellular mechanisms which underlie cisplatin-induced renal cell death. It has also become apparent that inflammation provoked by injury to renal epithelial cells serves to amplify kidney injury and dysfunction in vivo. This review summarizes recent advances in our understanding of cisplatin nephrotoxicity and discusses how these advances might lead to more effective prevention.

The protective effect of royal jelly against cisplatin-induced renal oxidative stress in rats

BACKGROUND

The aim of this study was to investigate the effects of royal jelly on cisplatin-induced nephrotoxicity and oxidative stress in rats.

METHODS

Adult male Wistar albino rats were randomly divided into eight groups: the control, cisplatin, royal jelly, and royal jelly plus cisplatin groups. Biochemical and histopathological methods were utilized for evaluation of the nephrotoxicity. Blood was collected and analyzed for blood urea nitrogen (BUN), alanine aminotransferase, aspartate aminotransferase, triglyceride, total cholesterol, uric acid, total bilirubin, and total protein levels. The kidney samples were stored for the measurement of malondialdehyde (MDA), glutathione peroxidase (GSHPx), superoxide dismutase (SOD), and catalase (CAT) activities and processed for histopathological examinations.

RESULTS

Administration of cisplatin to rats induced a marked renal failure, characterized with a significant increase in serum BUN and uric acid concentrations, and they had higher kidney MDA and lower GSH-Px, SOD, and CAT activities. In the groups that were administered RJ in association with CP, improvement was observed in some oxidative stress parameters and certain other biochemical parameters, pre-treatment with RJ being more effective.

CONCLUSIONS

The CP-induced changes in histopathologic findings of kidneys were partially reversed by treatment with royal jelly. The results provide further insight into the mechanisms of CP-induced nephrotoxicity and confirm the antioxidant potential of royal jelly.

N-acetylcysteine attenuates glycerol-induced acute kidney injury by regulating MAPKs and Bcl-2 family proteins

BACKGROUND

Rhabdomyolysis-induced acute kidney injury (AKI) accounts for about 10 to 40% of all cases of AKI. It is known that N-acetylcysteine (NAC) is effective in various experimental renal injury models; however, little information is available about the rat model of glycerol-induced rhabdomyolysis. In this study, we hypothesize that NAC plays a renoprotective role via the anti-apoptotic pathway.

METHODS

Male Sprague-Dawley rats were divided into four groups: (i) saline control group, (ii) NAC-treated group (N-acetylcysteine) (150 mg/kg), (iii) glycerol-treated group (50%, 8 ml/kg, IM) and (iv) NAC plus glycerol-treated group. Rats were sacrificed at 24 h after glycerol injection, and the blood and renal tissues were harvested.

RESULTS

Glycerol administration caused severe renal dysfunction, which included marked renal oxidative stress, significantly increased blood urea nitrogen (BUN) and serum creatinine levels. Histopathological findings, such as cast formation and tubular necrosis, confirmed renal impairment. We noted a marked activation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), but not p-38, in the glycerol-treated group. We also observed high expression of Bax and Bad but only weak expression of Bcl-2 and Bcl-xL in the glycerol-treated group. However, NAC pretreatment significantly improved renal function and decreased the activation of ERK, JNK, Bax and Bad, whereas it increased Bcl-2 and Bcl-xL.

CONCLUSION

These results demonstrate that NAC protects against renal dysfunction, morphological damage and biochemical changes via the anti-apoptotic pathway in the glycerol-induced rhabdomyolysis model in rats.

5-Azacytidine prevents cisplatin induced nephrotoxicity and potentiates anticancer activity of cisplatin by involving inhibition of metallothionein, pAKT and DNMT1 expression in chemical induced cancer rats

5-Azactydine inhibits cell growth by direct cytotoxic action as well as by inhibition of DNA methyl transferase enzyme. Inhibitors of DNMT have been reported to potentiate the therapeutic activity of cisplatin in vitro. Dose dependent bone marrow toxicity, neurotoxicity and nephrotoxicity are the major side effects of cisplatin, limiting its use as an effective chemotherapeutic agent. The present study was aimed to reduce the nephrotoxic potential of cisplatin without compensating its potency. To best of our knowledge, this is the first report which shows that the combination of 5-azacytidine with cisplatin leads to remarkable reduction in nephrotoxicity, by involving inhibition of cisplatin induced metallothionein expression. 5-Azacytidine treatment with cisplatin leads to maximum reduction in tumor size in DMH induced colon cancer and tumor volume in DMBA induced breast cancer bearing SD rats. This combination regimen prevents phosphorylation and acetylation of histone H3 which may be involved in inhibition of aberrant gene expression in colon tumors. Further, 5-azacytidine potentiated cisplatin induced antitumor activity by involving decreased expression of pAKT, DNMT1 and an increased expression of p38 in colon tumors. Thus, combination of 5-azactydine with cisplatin attenuates the cisplatin induced nephrotoxicity and potentiates the anti-cancer activity which can have profound clinical implications.