Cisplatin nephrotoxicity involves mitochondrial injury with impaired tubular mitochondrial enzyme activity

The role of Testis-Specific Protein Y-encoded-Like 2 in kidney injury

Renal ischemia-reperfusion injury (IRI) is a major cause of acute kidney injury (AKI). Recent findings suggest that Testis-Specific Protein Y-encoded-Like 2 (TSPYL2) plays a fibrogenic role in diabetes-associated renal injury. However, the role of TSPYL2 in IRI-induced kidney damage is not entirely clear. In this study, we found that the expression of TSPYL2 was upregulated in a mouse model of AKI and in the hypoxia/reoxygenation (H/R) cell model. Knockdown of TSPYL2 attenuated kidney injury after IRI. More specifically, the knockdown of TSPYL2 or aminocarboxymuconate-semialdehyde decarboxylase (ACMSD) alleviated renal IRI-induced mitochondrial dysfunction and oxidative stress in vitro and in vivo. Further investigation showed that TSPYL2 regulated SREBP-2 acetylation by inhibiting SIRT1 and promoting p300 activity, thereby promoting the transcriptional activity of ACMSD. In conclusion, TSPYL2 was identified as a pivotal regulator of IRI-induced kidney damage by activating ACMSD, which may lead to NAD+ content and the damaging response in the kidney.

Mitochondrial dysfunction in the pathophysiology of renal diseases

Mitochondria are essential organelles in the human body, serving as the metabolic factory of the whole organism. When mitochondria are dysfunctional, it can affect all organs of the body. The kidney is rich in mitochondria, and its function is closely related to the development of kidney diseases. Studying the relationship between mitochondria and kidney disease progression is of great interest. In the past decade, scientists have made inspiring progress in investigating the role of mitochondria in the pathophysiology of renal diseases. This article discusses various mechanisms for maintaining mitochondrial quality, including mitochondrial energetics, mitochondrial biogenesis, mitochondrial dynamics, mitochondrial DNA repair, mitochondrial proteolysis and the unfolded protein response, mitochondrial autophagy, mitochondria-derived vesicles, and mitocytosis. The article also highlights the cross talk between mitochondria and other organelles, with a focus on kidney diseases. Finally, the article concludes with an overview of mitochondria-related clinical research.

Gentisic acid ameliorates cisplatin-induced reprotoxicity through suppressing endoplasmic reticulum stress and upregulating Nrf2 pathway

Reproductive toxicity is a serious side effect of cisplatin (CP) chemotherapy. Gentisic acid (GTA) is a phenolic acid with strong antioxidant properties. Here, we aimed to determine therapeutic effect of GTA against CP-induced testicular toxicity in rats for the first time. Male Sprague-Dawley rats received a single dose of CP (5 mg/kg; intraperitoneal) and treated with GTA (1.5 and 3 mg/kg; intraperitoneal; 3 consecutive days). The levels of oxidative stress (OS), inflammation, endoplasmic reticulum stress (ERS) and apoptosis biomarkers were assessed in the testicular tissue of rats. In addition, how CP affects the nuclear factor erythroid-2-related factor 2 (Nrf2) pathway and the effect of GTA on this situation were also addressed in the testicular tissue. CP administration induced histopathological changes in testicular tissue of rats with a significant increase in OS, inflammation, ERS and apoptosis biomarkers and a decrease in antioxidant capacity and Nrf2 expression levels. Administrations of GTA resulted in an amelioration of these altered parameters. These data suggest that GTA may be a potential therapeutic agent against CP-induced testicular toxicity. Activation of the Nrf2 pathway plays a key role of this therapeutic effect of GTA.

A Comparative Analysis of Selection Pressures Suffered by Mitochondrial Genomes in Two Planthopper Species with Divergent Climate Distributions

Mitochondrial DNA (mtDNA) has been widely used as a valuable tool in studies related to evolution and population genetics, under the implicit assumption of neutral evolution. However, recent studies suggest that natural selection also plays a significant role in shaping mitochondrial genome evolution, although the specific driving forces remain elusive. In this study, we aimed to investigate whether and how climate influences mitochondrial genome evolution by comparing the selection pressures acting on mitochondrial genomes between two rice planthoppers, Sogatella furcifera (Horváth) and Laodelphax striatellus (Fallén), which have different climate distributions. We employed the dN/dS method, MK test and Tajima's D tests for our analysis. Our results showed that the mitochondrial genomes of the two species appear to undergo predominantly purifying selection, consistent with the nearly neutral evolution model. However, we observed varied degrees of purifying selection among the 13 protein-coding genes. Notably, ND1, ND2, ND6, COIII, and ATP8 exhibited significantly stronger purifying selection and greater divergence between the two species compared to the other genes. Additionally, we observed relatively stronger purifying selection in the mitochondrial genomes of S. furcifera compared to L. striatellus. This difference could be attributed to varying metabolic requirements arising from distinct habitats or other factors that are unclear here. Furthermore, we speculate that mito-nuclear epistatic interactions may play a role in maintaining nonsynonymous polymorphisms, particularly for COI and COII. Overall, our results shed some light on the influence of climate on mitochondrial genome evolution.

C-type natriuretic peptide (CNP) inhibits 7,12-Dimethylbenz[a]anthracene (DMBA)/Croton oil-induced skin tumor growth by modulating inflammation in Swiss albino mice

C-type natriuretic peptide (CNP) exhibits anti-inflammatory activity besides its natriuretic and diuretic functions. The present study aimed to determine the anticancer and synergistic therapeutic activity of CNP against a 7,12-Dimethylbenz[a]anthracene (DMBA)/Croton oil-induced skin tumor mouse model. CNP (2.5 µg/kg body weight) was injected either alone and/or in combination with Cisplatin (CDDP) (2 mg/kg body weight) for 4 weeks. The dorsal skin tumor incidences/growth and mortality rate were recorded during the experimental period of 16 weeks. The serum C-reactive protein (CRP), and lactate dehydrogenase (LDH) levels, infiltrating mast cells, and AgNORs proliferating cells count were analyzed in control and experimental mice. Further, the expression profile of marker genes of proliferation, inflammation, and progression molecules were analyzed using Reverse transcriptase-polymerase chain reaction (RT-PCR)/quantitative PCR (qPCR), western blot, and immunohistochemistry. The DMBA/Croton oil-induced mice exhibited 100% tumor incidence. Whereas, CNP alone, CDDP alone, and CNP+CDDP combination-treated mice exhibited 58%, 46%, and 24% tumor incidence, respectively. Also, a marked reduction in the levels of serum CRP and LDH, the number of infiltrating mast cells count and AgNORs proliferating cells count were noticed in the mice skin sections. Further, a significant reduction in both mRNA and protein expression levels of proliferation, inflammation, and progression markers were noticed in CNP (p < 0.01), CDDP (p < 0.01), and CNP+CDDP combination (p < 0.001) treated mice, respectively. The results of the present study suggest that CNP has anticancer activity. Further, the CNP+CDDP treatment has more promising anticancer activity as compared with CNP or CDDP alone treatment, probably due to the synergistic antiproliferative and anti-inflammatory activities of CNP and CDDP.

A Novel Dual-Function Redox Modulator Relieves Oxidative Stress and Anti-Angiogenic Response in Placental Villus Explant Exposed to Hypoxia-Relevance for Preeclampsia Therapy

BACKGROUND

Preeclampsia (PE) is a severe, life-threatening complication during pregnancy (~5-7%), and no causative treatment is available. Early aberrant spiral artery remodeling is associated with placental stress and the release of oxygen radicals and other reactive oxygen species (ROS) in the placenta. This precedes the production of anti-angiogenic factors, which ultimately leads to endothelial and trophoblast damage and the key features of PE. We tested whether a novel dual-function redox modulator-AKT-1005-can effectively reduce placental oxidative stress and alleviate PE symptoms in vitro.

METHOD

Isolated human villous explants were exposed to hypoxia and assessed to determine whether improving cell-redox function with AKT-1005 diminished ROS production, mitochondrial stress, production of the transcription factor HIF1A, and downstream anti-angiogenic responses (i.e., sFLT1, sEng production). MitoTEMPO was used as a reference antioxidant.

RESULTS

In our villous explant assays, pretreatment with AKT-1005 reduced mitochondrial-derived ROS production, reduced HIF-1A, sFLT1, and sEng protein expression, while increasing VEGF in hypoxia-exposed villous trophoblast cells, with better efficiency than MitoTEMPO. In addition, AKT-1005 improved mitochondrial electron chain enzyme activity in the stressed explant culture.

CONCLUSIONS

The redox modulator AKT-1005 has the potential to intervene with oxidative stress and can be efficacious for PE therapy. Future studies are underway to assess the in vivo efficacy of HMP.

Nitroxide-HMP-Protects Human Trophoblast HTR-8/SVneo Cells from H2O2-Induced Oxidative Stress by Reducing the HIF1A Signaling Pathway

Preeclampsia (PE) is a pregnancy-specific syndrome affecting 5-7% of patients. There is no effective treatment available. Early abnormal placental development is associated with oxidative stress (OS) and a release of reactive oxygen species (ROS) in the placenta. This phenomenon leads to downstream signaling, Hypoxia Inducible Factor 1A (HIF1A) stabilization and transcription of the anti-angiogenic factors soluble fms-like tyrosine kinase 1 (sFLT1) and soluble endoglin (sEng), which are known to cause endothelial and trophoblast dysfunction and cardinal features of PE: hypertension, proteinuria and, in severe cases, eclampsia. We tested whether 3-(Hydroxymethyl)-1-oxy-2,2,5,5-tetramethylpyrrolidine (HMP)-a nitroxide-type antioxidant molecule-can reduce placental OS and mitigate PE symptoms in vitro. We induced OS in human trophoblast (HTR-8/SVneo) cells with hydrogen peroxide (H2O2) and assessed whether modulating cell redox function with HMP reduces cell injury, mitochondrial stress and HIF1A and sFLT1 production. Pre-treatment with HMP reduced mitochondrial-derived ROS production, restored LC3B expression and reduced HIF1A and sFLT1 expression in H2O2-exposed HTR-8/SVneo trophoblast cells. HMP improved the mitochondrial electron chain enzyme activity, indicating that a reduction in OS alleviates mitochondrial stress and also reduces anti-angiogenic responses. In reducing placental trophoblast OS, HMP presents a potential novel therapeutic approach for the treatment of PE. Future investigation is warranted regarding the in vivo use of HMP.

Mitochondrial Dysfunction in the Cardio-Renal Axis

Cardiovascular disease (CVD) frequently complicates chronic kidney disease (CKD). The risk of all-cause mortality increases from 20% to 500% in patients who suffer both conditions; this is referred to as the so-called cardio-renal syndrome (CRS). Preclinical studies have described the key role of mitochondrial dysfunction in cardiovascular and renal diseases, suggesting that maintaining mitochondrial homeostasis is a promising therapeutic strategy for CRS. In this review, we explore the malfunction of mitochondrial homeostasis (mitochondrial biogenesis, dynamics, oxidative stress, and mitophagy) and how it contributes to the development and progression of the main vascular pathologies that could be affected by kidney injury and vice versa, and how this knowledge may guide the development of novel therapeutic strategies in CRS.

Gum Acacia attenuates cisplatin toxic effect spermatogenesis dysfunction and infertility in rats

This study aimed to investigate the potential benefits Gum Arabic/Acacia Senegal (GA) in mitigating the harmful effects of cisplatin (CP) on spermatogenesis and testicular health in male adult rats. A total of forty albino rats were used in the study and divided into four groups; control, GA, CP, and Co-treated group, which received both CP and GA concurrently. The results revealed that CP caused a significant increase in oxidative stress and a decrease in antioxidant levels (CAT, SOD, and GSH), which disturbed the testicular machinery. This caused significant histological and ultrastructural damage to the testicular structure, including atrophied seminiferous tubules with severely reduced germinal epithelium. Additionally, CP caused a decrease in reproductive hormones (testosterone and LH), a decline in nucleic proliferation PCNA immunoexpression, and an increase in cytoplasmic apoptotic Caspase-3 protein expression in testicular tissue, when compared to the control and GA groups. Moreover, The CP treatment impaired spermatogenesis and decreased sperm number and motility with abnormal morphology. However, co-administration of GA with CP mitigated the dysfunction in spermatogenesis and reversed testicular damage caused by CP through significantly (P < 0.01) reducing oxidative stress (MDA) and increasing the activities of CAT, SOD, and GSH. Additionally, co-administration of GA elevated the levels of testosterone and luteinizing hormone in blood sera, significantly (P < 0.01) improved the histometric measurements of seminiferous tubules diameter, their epithelial height, Johnsen's score of spermatogenesis, 4-level histological grading scale Cosentino's score, immunohistochemical expression of nucleic PCNA, and cytoplasmic Caspase-3 proteins. Furthermore, TEM examination confirmed the synergistic effect of GA in restoring the germinal epithelial cells ultrastructure, the elongated and transverse sections of spermatozoa in the lumen, and the interstitial tissue. All of these effects resulted in a significant improvement in sperm quality in the Co-treated animals compared with the CP group, as well as, a significant decline in the morphological abnormalities of sperm in Co-treated rats compared to those in the CP group. GA is a valuable agent for ameliorating chemotherapy-related infertility.

Mitophagy alleviates cisplatin-induced renal tubular epithelial cell ferroptosis through ROS/HO-1/GPX4 axis

Cisplatin is widely recommended in combination for the treatment of tumors, thus inevitably increasing the incidence of cisplatin-induced acute kidney injury. Mitophagy is a type of mitochondrial quality control mechanism that degrades damaged mitochondria and maintains cellular homeostasis. Ferroptosis, a new modality of programmed cell death, is characterized by iron-dependent phospholipid peroxidation and oxidative membrane damage. However, the role of mitophagy in ferroptosis in kidney disease is unclear. Here, we investigated the mechanism underlying both BNIP3-mediated and PINK1-PARK2-mediated mitophagy-induced attenuation of ferroptosis in cisplatin-induced acute kidney injury. The results showed that cisplatin induced mitochondrial injury, ROS release, intracellular iron accumulation, lipid peroxidation and ferroptosis in the kidney, which were aggravated in Bnip3 knockout, Pink1 knockout or Park2 knockout cisplatin-treated mice. Ferrstatin-1, a synthetic antioxidative ferroptosis inhibitor, rescued iron accumulation, lipid peroxidation and ferroptosis caused by inhibition of mitophagy. Thus, the present study elucidated a novel mechanism by which both BNIP3-mediated and PINK1-PARK2-mediated mitophagy protects against cisplatin-induced renal tubular epithelial cell ferroptosis through the ROS/HO1/GPX4 axis.

Istradefylline protects from cisplatin-induced nephrotoxicity and peripheral neuropathy while preserving cisplatin antitumor effects

Cisplatin is a potent chemotherapeutic drug that is widely used in the treatment of various solid cancers. However, its clinical effectiveness is strongly limited by frequent severe adverse effects, in particular nephrotoxicity and chemotherapy-induced peripheral neuropathy. Thus, there is an urgent medical need to identify novel strategies that limit cisplatin-induced toxicity. In the present study, we show that the FDA-approved adenosine A2A receptor antagonist istradefylline (KW6002) protected from cisplatin-induced nephrotoxicity and neuropathic pain in mice with or without tumors. Moreover, we also demonstrate that the antitumoral properties of cisplatin were not altered by istradefylline in tumor-bearing mice and could even be potentiated. Altogether, our results support the use of istradefylline as a valuable preventive approach for the clinical management of patients undergoing cisplatin treatment.

The Cannabinoid-2 receptor agonist, 1-phenylisatin, protects against cisplatin-induced nephrotoxicity in mice

AIM

The present study investigated the potential protective effect of a selective Cannabinoid-2 (CB2) receptor agonist, 1-phenylisatin, in acute nephrotoxicity induced by cisplatin.

MATERIALS AND METHODS

Animals were arranged into 5 groups. Group I; normal saline, group II; 1-phenylisatin for 7 days, group III: received a single injection of cisplatin (20 mg/kg, i.p.) on day 5, group IV: 1-phenylisatin for 7 days and cisplatin on day 5 and group V: AM630, CB2 antagonist, 15 min before 1-phenylisatin for 7 days and a single injection of cisplatin on day 5. Mice were sacrificed 72 h after cisplatin injection. Kidneys were isolated for histopathological and biochemical analyses. Nephrotoxicity parameters including serum creatinine and urea were assessed as well as histopathological examination was done. Also, Oxidative stress markers; MDA and GSH, inflammatory markers; TNF-α, NF-κB (p65), MCP-1, MIP-2, and ICAM-1, along with apoptotic markers, Bax, Bcl2, and caspase-3 were studied. Further, CB2 receptor expression was investigated.

KEY FINDINGS

Cisplatin injection increased serum creatinine and urea levels, and increased lipid peroxidation, decreased glutathione level and increased the renal expression of pro-inflammatory markers, TNF-α, NF-κB, MCP-1, MIP-2, and ICAM-1, along with increased apoptotic markers and significantly reduced the expression of the anti-apoptotic Bcl2. Pretreatment with 1-phenylisatin significantly counteracted these effects. The CB2 receptor antagonist; AM630, increased the renal expression of caspase-3 and Bax whereas Bcl2 expression decreased.

SIGNIFICANCE

1-Phenylisatin protected against cisplatin-induced nephrotoxicity owing to its anti-apoptotic, anti-inflammatory, and antioxidant effects. These actions were mostly mediated through CB2 receptor.

Bone-Marrow-Derived Mesenchymal Stem Cells, Their Conditioned Media, and Olive Leaf Extract Protect against Cisplatin-Induced Toxicity by Alleviating Oxidative Stress, Inflammation, and Apoptosis in Rats

BACKGROUND

Hepatic and renal damage is a cisplatin (Cis)-induced deleterious effect that is a major limiting factor in clinical chemotherapy.

OBJECTIVES

The current study was designed to investigate the influence of pretreatment with olive leaf extract (OLE), bone-marrow-derived mesenchymal stem cells (BM-MSC), and their conditioned media (CM-MSC) against genotoxicity, nephrotoxicity, hepatotoxicity, and immunotoxicity induced by cisplatin in rats.

METHODS

The rats were randomly divided into six groups (six rats each) as follows: Control; OLE group, treated with OLE; Cis group, treated with a single intraperitoneal dose of Cis (7 mg/kg bw); Cis + OLE group, treated with OLE and cisplatin; Cis + CM-MSC group, treated with BM-MSC conditioned media and Cis; and Cis + MSC group, treated with BM-MSC in addition to Cis.

RESULTS

Cis resulted in a significant deterioration in hepatic and renal functions and histological structures. Furthermore, it increased inflammatory markers (TNF-α, IL-6, and IL-1β) and malondialdehyde (MDA) levels and decreased glutathione (GSH) content, total antioxidant capacity (TAC), catalase (CAT), and superoxide dismutase (SOD) activity in hepatic and renal tissues. Furthermore, apoptosis was evident in rat tissues. A significant increase in serum 8-hydroxy-2-deoxyguanosine (8-OH-dG), nitric oxide (NO) and lactate dehydrogenase (LDH), and a decrease in lysozyme activity were detected in Cis-treated rats. OLE, CM-MSC, and BM-MSC have significantly ameliorated Cis-induced deterioration in hepatic and renal structure and function and improved oxidative stress and inflammatory markers, with preference to BM-MSC. Moreover, apoptosis was significantly inhibited, evident from the decreased expression of Bax and caspase-3 genes and upregulation of Bcl-2 proteins in protective groups as compared to Cis group.

CONCLUSIONS

These findings indicate that BM-MSC, CM-MSC, and OLE have beneficial effects in ameliorating cisplatin-induced oxidative stress, inflammation, and apoptosis in the hepatotoxicity, nephrotoxicity, immunotoxicity, and genotoxicity in a rat model.

Acute Kidney Injury in Critically Ill Patients with Cancer

Advances in cancer therapy have significantly improved overall patient survival; however, AKI remains a common complication in patients with cancer, occurring in anywhere from 11% to 22% of patients, depending on patient-related or cancer-specific factors. Critically ill patients with cancer as well as patients with certain malignancies (e.g., leukemias, lymphomas, multiple myeloma, and renal cell carcinoma) are at highest risk of developing AKI. AKI may be a consequence of the underlying malignancy itself or from the wide array of therapies used to treat it. Cancer-associated AKI can affect virtually every compartment of the nephron and can present as subclinical AKI or as overt acute tubular injury, tubulointerstitial nephritis, or thrombotic microangiopathy, among others. AKI can have major repercussions for patients with cancer, potentially jeopardizing further eligibility for therapy and leading to greater morbidity and mortality. This review highlights the epidemiology of AKI in critically ill patients with cancer, risk factors for AKI, and common pathologies associated with certain cancer therapies, as well as the management of AKI in different clinical scenarios. It highlights gaps in our knowledge of AKI in patients with cancer, including the lack of validated biomarkers, as well as evidence-based therapies to prevent AKI and its deleterious consequences.

Irbesartan decreased mitochondrial stress related apoptosis in cisplatin induced acute kidney injury via regulating BCL-2/BAX signaling

BACKGROUND

Cisplatin (CPN) is used in the treatment of various cancers. However, the especially nephrotoxic effect is limiting its use. We aimed to evaluate the renoprotective effects of Irbesartan (IBN) on CPN-induced acute kidney injury via mitochondrial stress related apoptosis.

METHODS AND RESULTS

32 rats were divided into 4 groups as control, CPN, CPN + IBN and IBN. Water or IBN 50 mg/kg (orally) was administered for 7 days and a single dose of CPN (5 mg/kg) intraperitoneally was given CPN and CPN + IBN groups on fourth day of experiment. At the end of the experiment, serum BUN and creatinine (Cre) levels, which are the indicators of kidney function are measured. Bcl-2-associated X protein (Bax) and B-cell-lymphoma-2 (Bcl-2) mRNA levels were analyzed by using qRT-PCR from kidneys as a mitochondrial stress indicator. Also, active caspase-3(cas-3) protein and tumor necrosis factor alpha (TNF-α) expressions were examined by immunostaining of the kidney tissues. For evaluation of oxidative stress, malondialdehyde (MDA), total oxidant status (TOS) and total antioxidant status (TAS) levels of renal tissues were measured and oxidative stress index (OSI) were calculated. CPN increased serum BUN and creatinine levels. Also, MDA, TOS and OSI levels were significantly elevated and TAS levels decreased in the CPN group. Moreover, CPN elevated the levels of Bax, active cas-3 protein and TNF-α expressions and suppressed Bcl-2 levels. IBN treatment reversed all these changes.

CONCLUSIONS

IBN significantly regressed kidney damage by its anti-inflammatory and antioxidant activity via inhibiting mitochondrial stress. IBN could be used as a renoprotective agent in CPN-induced kidney injury.

Decabromodiphenyl ether induces ROS-mediated intestinal toxicity through the Keap1-Nrf2 pathway

Polybrominated diphenyl ethers (PBDEs) are widely used brominated flame retardants as commercial products. PBDEs have been demonstrated to induce hepatic, reproductive, neural, and thyroid toxicity effects. This study aimed to clarify the potential intestinal toxicity effects of decabrominated diphenyl ether (PBDE-209) in vivo and in vitro. First, we investigated the change of PBDE-209 on oxidative stress in the intestine of mice. Subsequently, the potential toxicity mechanism of PBDE-209 in vitro was investigated. Caco-2 cells were treated with different concentrations of PBDE-209 (1, 5, and 25 μmol/L) for 24  and 48 h. We determined the cell viability, reactive oxygen species (ROS) level, multiple cellular parameters, and relative mRNA expressions. The results showed that PBDE-209 significantly injured the colon of mice, increased the intestinal levels of malondialdehyde (MDA), and changed the antioxidant enzyme activities. PBDE-209 inhibited the proliferation and induced cytotoxicity of Caco-2 cells. The change in ROS production and mitochondrial membrane potential (MMP) revealed that PBDE-209 caused oxidative stress in Caco-2 cells. The real-time PCR assays revealed that PBDE-209 inhibited the mRNA expression level of antioxidative defense factor, nuclear factor erythroid 2-related factor 2 (Nrf2). Furthermore, the FAS and Cytochrome P450 1A1 (CYP1A1) mRNA expression levels were increased in Caco-2 cells. These results suggested that PBDE-209 exerts intestinal toxicity effects in vivo and in vitro and inhibits the antioxidative defense gene expression in Caco-2 cells. This study provides an opportunity to advance the understanding of toxicity by the persistent environmental pollutant PBDE-209 to the intestine.

Evaluation of Platinum Anticancer Drug-Induced Kidney Injury in Primary Culture of Rat Kidney Tissue Slices by Using Gas-Permeable Plates

The type of method adopted for the evaluation of drug-induced kidney injury (DIKI) plays an important role during the drug discovery process. In the present study, the usefulness of cultured rat kidney tissue slices maintained on gas-permeable poly(dimethylsiloxane) (PDMS) plates for DIKI was assessed by monitoring the ATP content as a marker of cell viability. The amount of ATP in the kidney slices cultured on the PDMS plates was higher than that in the slices cultured on gas-impermeable polystyrene plates. The protein expression of organic cation transporter-2 (Oct2) was maintained for 3 d. Cisplatin showed a time- and concentration-dependent reduction in ATP in the slices with a half-effective concentration value of 24 µM, which was alleviated by cimetidine, an Oct2 inhibitor, suggesting that cisplatin-induced kidney injury in the cultured slices was regulated by the basolateral uptake transporter Oct2. Furthermore, the intensity of platinum anticancer drug-induced nephrotoxicity in the cultured slices was consistent with that of the in vivo study. In conclusion, the primary culture of rat kidney tissue slices on gas-permeable plates is expected to aid in the prediction of the extent of nephrotoxicity of drugs, even when transporters are responsible for the accumulation of drugs in kidney tissues.

Diclofenac versus tramadol for mucositis related pain in head and neck cancer patients undergoing concurrent chemoradiation-a phase 3 study

Background

Oral mucositis related pain during CTRT in head and neck cancers is a common problem. Unfortunately, in spite of it being common, there is limited evidence for selection of systemic analgesic in this situation. Hence, this study was designed to compare the analgesic effect of a non-steroidal anti-inflammatory drug (diclofenac) versus a weak opioid (tramadol).

Patients and methods

This was an open-label, parallel design, superiority randomised controlled study. In this study, head and neck cancer patients undergoing radical or adjuvant chemoradiation, who had grade 1 or above mucositis (in accordance with Common Terminology Criteria for Adverse Events version 4.03) and had pain related to it were randomly assigned to either diclofenac or tramadol for mucositis related pain control. The primary endpoint was analgesia after the first dose. The secondary endpoints were the rate of change in analgesic within 1 week, adverse events and quality of life.

Results

One hundred and twenty-eight patients were randomised, 66 in diclofenac and 62 in tramadol arm. The median area under the curve for graph of pain across time after first dose of pain medication for the diclofenac arm and the tramadol arm was 348.936 units (range: 113.64–1,969.23) and 420.87 (101.97–1,465.96), respectively, (p = 0.05619). Five patients (8.1%) in the tramadol arm and 11 patients (16.7%) in the diclofenac arm required a change in analgesic within 1 week of starting the analgesic (p = 0.184). There was no statistically significant difference in any adverse events between the two arms. However, the rate of any grade of renal dysfunction was numerically higher in the diclofenac arm (10.6% versus 4.8%, p = 0.326).

Conclusion

In this phase 3 study, evaluating diclofenac and tramadol for chemoradiation induced mucositis pain, there was no statistical difference in analgesic activity of these two drugs.

VEGFR3 tyrosine kinase inhibition aggravates cisplatin nephrotoxicity

Expansion of renal lymphatic networks, or lymphangiogenesis (LA), is well recognized during development and is now being implicated in kidney diseases. Although LA is associated with multiple pathological conditions, very little is known about its role in acute kidney injury. The purpose of this study was to evaluate the role of LA in a model of cisplatin-induced nephrotoxicity. LA is predominately regulated by vascular endothelial growth factor (VEGF)-C and VEGF-D, ligands that exert their function through their cognate receptor VEGF receptor 3 (VEGFR3). We demonstrated that use of MAZ51, a selective VEGFR3 inhibitor, caused significantly worse structural and functional kidney damage in cisplatin nephrotoxicity. Apoptotic cell death and inflammation were also increased in MAZ51-treated animals compared with vehicle-treated animals following cisplatin administration. Notably, MAZ51 caused significant upregulation of intrarenal phospho-NF-κB, phospho-JNK, and IL-6. Cisplatin nephrotoxicity is associated with vascular congestion due to endothelial dysfunction. Using three-dimensional tissue cytometry, a novel approach to explore lymphatics in the kidney, we detected significant vascular autofluorescence attributed to erythrocytes in cisplatin alone-treated animals. Interestingly, no such congestion was detected in MAZ51-treated animals. We found increased renal vascular damage in MAZ51-treated animals, whereby MAZ51 caused a modest decrease in the endothelial markers endomucin and von Willebrand factor, with a modest increase in VEGFR2. Our findings identify a protective role for de novo LA in cisplatin nephrotoxicity and provide a rationale for the development of therapeutic approaches targeting LA. Our study also suggests off-target effects of MAZ51 on the vasculature in the setting of cisplatin nephrotoxicity.NEW & NOTEWORTHY Little is known about injury-associated LA in the kidney and its role in the pathophysiology of acute kidney injury (AKI). Observed exacerbation of cisplatin-induced AKI after LA inhibition was accompanied by increased medullary damage and cell death in the kidney. LA inhibition also upregulated compensatory expression of LA regulatory proteins, including JNK and NF-κB. These data support the premise that LA is induced during AKI and lymphatic expansion is a protective mechanism in cisplatin nephrotoxicity.

A Canadian Study of Cisplatin Metabolomics and Nephrotoxicity (ACCENT): A Clinical Research Protocol

Background:

Cisplatin, a chemotherapy used to treat solid tumors, causes acute kidney injury (AKI), a known risk factor for chronic kidney disease and mortality. AKI diagnosis relies on biomarkers which are only measurable after kidney damage has occurred and functional impairment is apparent; this prevents timely AKI diagnosis and treatment. Metabolomics seeks to identify metabolite patterns involved in cell tissue metabolism related to disease or patient factors. The A Canadian study of Cisplatin mEtabolomics and NephroToxicity (ACCENT) team was established to harness the power of metabolomics to identify novel biomarkers that predict risk and discriminate for presence of cisplatin nephrotoxicity, so that early intervention strategies to mitigate onset and severity of AKI can be implemented.

Objective:

Describe the design and methods of the ACCENT study which aims to identify and validate metabolomic profiles in urine and serum associated with risk for cisplatin-mediated nephrotoxicity in children and adults.

Design:

Observational prospective cohort study.

Setting:

Six Canadian oncology centers (3 pediatric, 1 adult and 2 both).

Patients:

Three hundred adults and 300 children planned to receive cisplatin therapy.

Measurements:

During two cisplatin infusion cycles, serum and urine will be measured for creatinine and electrolytes to ascertain AKI. Many patient and disease variables will be collected prospectively at baseline and throughout therapy. Metabolomic analyses of serum and urine will be done using mass spectrometry. An untargeted metabolomics approach will be used to analyze serum and urine samples before and after cisplatin infusions to identify candidate biomarkers of cisplatin AKI. Candidate metabolites will be validated using an independent cohort.

Methods:

Patients will be recruited before their first cycle of cisplatin. Blood and urine will be collected at specified time points before and after cisplatin during the first infusion and an infusion later during cancer treatment. The primary outcome is AKI, defined using a traditional serum creatinine-based definition and an electrolyte abnormality-based definition. Chart review 3 months after cisplatin therapy end will be conducted to document kidney health and survival.

Limitations:

It may not be possible to adjust for all measured and unmeasured confounders when evaluating prediction of AKI using metabolite profiles. Collection of data across multiple sites will be a challenge.

Conclusions:

ACCENT is the largest study of children and adults treated with cisplatin and aims to reimagine the current model for AKI diagnoses using metabolomics. The identification of biomarkers predicting and detecting AKI in children and adults treated with cisplatin can greatly inform future clinical investigations and practices.

Dephosphorylation of AMP-activated kinase exacerbates ischemia/reperfusion-induced acute kidney injury via mitochondrial dysfunction

Kidney tubular epithelial cells are high energy-consuming epithelial cells that depend mainly on fatty acid oxidation for an energy supply. AMP-activated protein kinase (AMPK) is a key regulator of energy production in most cells, but the function of AMPK in tubular epithelial cells in acute kidney disease is unclear. Here, we found a rapid decrease in Thr172-AMPKα phosphorylation after ischemia/reperfusion in both in vivo and in vitro models. Mice with kidney tubular epithelial cell-specific AMPKα deletion exhibited exacerbated kidney impairment and apoptosis of tubular epithelial cells after ischemia/reperfusion. AMPKα deficiency was accompanied by the accumulation of lipid droplets in the kidney tubules and the elevation of ceramides and free fatty acid levels following ischemia/reperfusion injury. Mechanistically, ischemia/reperfusion triggered ceramide production and activated protein phosphatase PP2A, which dephosphorylated Thr172-AMPKα. Decreased AMPK activity repressed serine/threonine kinase ULK1-mediated autophagy and impeded clearance of the dysfunctional mitochondria. Targeting the PP2A-AMPK axis by the allosteric AMPK activator C24 restored fatty acid oxidation and reduced tubular cell apoptosis during ischemia/reperfusion-induced injury, by antagonizing PP2A dephosphorylation and promoting the mitophagy process. Thus, our study reveals that AMPKα plays an important role in protecting against tubular epithelial cell injury in ischemia/reperfusion-induced acute kidney injury. Hence, activation of AMPK could be a potential therapeutic strategy for acute kidney injury treatment.

Autophagy in Cisplatin Nephrotoxicity during Cancer Therapy

Cisplatin is a widely used chemotherapeutic agent but its clinical use is often limited by nephrotoxicity. Autophagy is a lysosomal degradation pathway that removes protein aggregates and damaged or dysfunctional cellular organelles for maintaining cell homeostasis. Upon cisplatin exposure, autophagy is rapidly activated in renal tubule cells to protect against acute cisplatin nephrotoxicity. Mechanistically, the protective effect is mainly related to the clearance of damaged mitochondria via mitophagy. The role and regulation of autophagy in chronic kidney problems after cisplatin treatment are currently unclear, despite the significance of research in this area. In cancers, autophagy may prevent tumorigenesis, but autophagy may reduce the efficacy of chemotherapy by protecting cancer cells. Future research should focus on developing drugs that enhance the anti-tumor effects of cisplatin while protecting kidneys during cisplatin chemotherapy.

Mechanism Prediction of Astragalus membranaceus against Cisplatin-Induced Kidney Damage by Network Pharmacology and Molecular Docking

Background

Cisplatin is a frequently used and effective chemotherapy drug in clinical practice, but severe side effects limit its use, among which nephrotoxicity is considered the most serious and prolonged damage to the body. Astragalus membranaceus (AM) is a well-known herbal medicine, and modern pharmacological studies have confirmed its antioxidant, immunomodulatory, and antiapoptotic effects. Clinical studies have shown that AM and its active components can attenuate cisplatin-induced kidney damage, but the molecular mechanism has not been fully expounded.

Materials and Methods

First, the components and targets information of AM were collected from the TCMSP, and the relevant targets of cisplatin-induced kidney damage were accessed from the GeneCards and OMIM databases. Then, the core targets were selected by the Venn diagram and network topology analysis, which was followed by GO and KEGG pathway enrichment analysis. Finally, we construct a component-target-pathway network. Furthermore, molecular docking was carried out to identify the binding activity between active components and key targets.

Results

A total of 20 active components and 200 targets of AM and 646 targets related to cisplatin-induced kidney damage were obtained. 91 intersection targets were found between AM and cisplatin-induced kidney damage. Then, 16 core targets were identified, such as MAPK1, TNF-α, and p53. Furthermore, GO and KEGG pathway enrichment analysis suggested that MAPK, Toll-like receptor, and PI3K-Akt signaling pathways may be of significance in the treatment of cisplatin-induced kidney damage by AM. Molecular docking indicated that quercetin and kaempferol had high binding affinities with many core targets.

Conclusion

In summary, the active components, key targets, and signaling pathways of AM in the treatment of cisplatin-induced kidney damage were predicted in this study, which contributed to the development and application of AM.

Mitochondrial Superoxide Dismutase in Cisplatin-Induced Kidney Injury

Cisplatin is a chemotherapy agent commonly used to treat a wide variety of cancers. Despite the potential for both severe acute and chronic side effects, it remains a preferred therapeutic option for many malignancies due to its potent anti-tumor activity. Common cisplatin-associated side-effects include acute kidney injury (AKI) and chronic kidney disease (CKD). These renal injuries may cause delays and potentially cessation of cisplatin therapy and have long-term effects on renal function reserve. Thus, developing mechanism-based interventional strategies that minimize cisplatin-associated kidney injury without reducing efficacy would be of great benefit. In addition to its action of cross-linking DNA, cisplatin has been shown to affect mitochondrial metabolism, resulting in mitochondrially derived reactive oxygen species (ROS). Increased ROS formation in renal proximal convoluted tubule cells is associated with cisplatin-induced AKI and CKD. We review the mechanisms by which cisplatin may induce AKI and CKD and discuss the potential of mitochondrial superoxide dismutase mimetics to prevent platinum-associated nephrotoxicity.

A Novel Fluorogenic Assay for the Detection of Nephrotoxin-Induced Oxidative Stress in Live Cells and Renal Tissue

Drug-induced kidney injury frequently leads to aborted clinical trials and drug withdrawals. Sufficiently sensitive sensors capable of detecting mild signs of chemical insult in cell-based screening assays are critical to identifying and eliminating potential toxins in the preclinical stage. Oxidative stress is a common early manifestation of chemical toxicity, and biomolecule carbonylation is an irreversible repercussion of oxidative stress. Here, we present a novel fluorogenic assay using a sensor, TFCH, that responds to biomolecule carbonylation and efficiently detects modest forms of renal injury with much greater sensitivity than standard assays for nephrotoxins. We demonstrate that this sensor can be deployed in live kidney cells and in renal tissue. Our robust assay may help inform preclinical decisions to recall unsafe drug candidates. The application of this sensor in identifying and analyzing diverse pathologies is envisioned.

The Effect of Curcumin Nanoparticles on Cisplatin-Induced Cardiotoxicity in Male Wistar Albino Rats

The cardiotoxicity of chemotherapeutic drugs as cisplatin has become a major issue in recent years. The present study investigates the efficacy of curcumin nanoparticles against the cardiotoxic effects of cisplatin by assessment of oxidative stress parameters, Na+,K+-ATPase, acetylcholinesterase (AchE) and tumor necrosis factor-alpha (TNF-α) in cardiac tissue in addition to serum lactate dehydrogenase (LDH). Rats were divided into three groups: control rats that received saline for 14 days; cisplatin-treated rats that received a single intraperitoneal (i.p.) injection of cisplatin (12 mg/kg) followed by a daily oral administration of saline (0.9%) for 14 days and rats treated with a single i.p. injection of cisplatin (12 mg/kg) followed by a daily oral administration of curcumin nanoparticles (50 mg/kg) for 14 days. Cisplatin resulted in a significant increase in lipid peroxidation, nitric oxide (NO), and TNF-α and a significant decrease in reduced glutathione (GSH) levels and Na+, K+- ATPase activity. Moreover, significant increases in cardiac AchE and serum lactate dehydrogenase activities were recorded. Treatment of cisplatin-injected animals with curcumin nanoparticles ameliorated all the alterations induced by cisplatin in the heart of rats. This suggests that curcumin nanoparticles can be used as an important therapeutic adjuvant in chemotherapeutic and other toxicities mediated by oxidative stress and inflammation.

Mitochondrial Metabolism in Acute Kidney Injury

The kidney is a highly metabolic organ that requires substantial adenosine triphosphate for the active transport required to maintain water and solute reabsorption. Aberrations in energy availability and energy utilization can lead to cellular dysfunction and death. Mitochondria are essential for efficient energy production. The pathogenesis of acute kidney injury is complex and varies with different types of injury. However, multiple distinct acute kidney injury syndromes share a common dysregulation of energy metabolism. Pathways of energy metabolism and mitochondrial dysfunction are emerging as critical drivers of acute kidney injury and represent new potential targets for treatment. This review shows the basic metabolic pathways that all cells depend on for life; describes how the kidney optimizes those pathways to meet its anatomic, physiologic, and metabolic needs; summarizes the importance of metabolic and mitochondrial dysfunction in acute kidney injury; and analyzes the mitochondrial processes that become dysregulated in acute kidney injury including mitochondrial dynamics, mitophagy, mitochondrial biogenesis, and changes in mitochondrial energy metabolism.

Mitochondrial dysfunction in kidney injury, inflammation, and disease: Potential therapeutic approaches

Mitochondria are energy-producing organelles that not only satisfy the high metabolic demands of the kidney but sense and respond to kidney injury-induced oxidative stress and inflammation. Kidneys are rich in mitochondria. Mitochondrial dysfunction plays a critical role in the progression of acute kidney injury and chronic kidney disease. Mitochondrial responses to specific stimuli are highly regulated and synergistically modulated by tightly interconnected processes, including mitochondrial dynamics (fission, fusion) and mitophagy. The counterbalance between these processes is essential in maintaining a healthy network of mitochondria. Recent literature suggests that alterations in mitochondrial dynamics are implicated in kidney injury and the progression of kidney diseases. A decrease in mitochondrial fusion promotes fission-induced mitochondrial fragmentation, but a reduction in mitochondrial fission produces excessive mitochondrial elongation. The removal of dysfunctional mitochondria by mitophagy is crucial for their quality control. Defective mitochondrial function disrupts cellular redox potential and can cause cell death. Mitochondrial DNA derived from damaged cells also act as damage-associated molecular patterns to recruit immune cells and the inflammatory response can further exaggerate kidney injury. This review provides a comprehensive overview of the role of mitochondrial dysfunction in acute kidney injury and chronic kidney disease. We discuss the processes that control mitochondrial stress responses to kidney injury and review recent advances in understanding the role of mitochondrial dysfunction in inflammation and tissue damage through the use of different experimental models of kidney disease. We also describe potential mitochondria-targeted therapeutic approaches.

NHERF1 Loss Upregulates Enzymes of the Pentose Phosphate Pathway in Kidney Cortex

(1) Background: We previously showed Na/H exchange regulatory factor 1 (NHERF1) loss resulted in increased susceptibility to cisplatin nephrotoxicity. NHERF1-deficient cultured proximal tubule cells and proximal tubules from NHERF1 knockout (KO) mice exhibit altered mitochondrial protein expression and poor survival. We hypothesized that NHERF1 loss results in changes in metabolic pathways and/or mitochondrial dysfunction, leading to increased sensitivity to cisplatin nephrotoxicity. (2) Methods: Two to 4-month-old male wildtype (WT) and KO mice were treated with vehicle or cisplatin (20 mg/kg dose IP). After 72 h, kidney cortex homogenates were utilized for metabolic enzyme activities. Non-treated kidneys were used to isolate mitochondria for mitochondrial respiration via the Seahorse XF24 analyzer. Non-treated kidneys were also used for LC-MS analysis to evaluate kidney ATP abundance, and electron microscopy (EM) was utilized to evaluate mitochondrial morphology and number. (3) Results: KO mouse kidneys exhibit significant increases in malic enzyme and glucose-6 phosphate dehydrogenase activity under baseline conditions but in no other gluconeogenic or glycolytic enzymes. NHERF1 loss does not decrease kidney ATP content. Mitochondrial morphology, number, and area appeared normal. Isolated mitochondria function was similar between WT and KO. Conclusions: KO kidneys experience a shift in metabolism to the pentose phosphate pathway, which may sensitize them to the oxidative stress imposed by cisplatin.

The effects of mesenchymal stem cell mitochondrial transplantation on doxorubicin-mediated nephrotoxicity in rats

The effect of dysfunctional mitochondria in several cell pathologies has been reported in renal diseases, including diabetic nephropathy and acute kidney injury. Previous studies have reported that mitochondrial transplantation provided surprising results in myocardial and liver ischemia, as well as in Parkinson's disease. We aimed to investigate the beneficial effects of isolated mitochondria transplantation from mesenchymal stem cells (MSCs) in vivo, to mitigate renal damage that arises from doxorubicin-mediated nephrotoxicity and its action mechanism. In this study, a kidney model of doxorubicin-mediated nephrotoxicity was used and isolated mitochondria from MSCs were transferred to the renal cortex of rats. The findings showed that the rate of isolated mitochondria from MSCs maintains sufficient membrane integrity, and was associated with a beneficial renal therapeutic effect. Following doxorubicin-mediated renal injury, isolated mitochondria or vehicle infused into the renal cortex and rats were monitored for five days. This study found that mitochondrial transplantation decreased cellular oxidative stress and promoted regeneration of tubular cells after renal injury (P < .001, P = .009). Moreover, mitochondrial transplantation reduced protein accumulation of tubular cells and reversed renal deficits (P = .01, P < .001). Mitochondrial transplantation increased Bcl-2 levels, and caspase-3 levels decreased in injured renal cells (P < .015, P < .001). Our results provide a direct link between mitochondria dysfunction and doxorubicin-mediated nephrotoxicity and suggest a therapeutic effect of transferring isolated mitochondria obtained from MSCs against renal injury. To our knowledge, this study is the first study in the literature that showed good therapeutic effects of mitochondrial transplantation in a nephrotoxicity model, which is under-researched.

Suppression of Cisplatin-Induced Hepatic Injury in Rats Through Alarmin High-Mobility Group Box-1 Pathway by Ganoderma lucidum: Theoretical and Experimental Study

PURPOSE

Drug-induced liver injury (DILI) is the most common cause of acute liver failure. The aim of this study was to investigate the molecular mechanisms by which Ganoderma lucidum mushroom (GLM) may ameliorate cisplatin (CP)-induced hepatotoxicity theoretically and experimentally.

MATERIALS AND METHODS

Thirty-six male Sprague-Dawley (SD) rats were divided into six groups, two of them are normal and Ganoderma lucidum control groups. Liver injury was induced by a single dose of CP (12 mg/kg i.p) in four groups, one of them is CP control group. Besides cisplatin injection in day 1, rats in groups (4-6) were subjected to GLM (500 mg/kg/day) either every other day or daily oral dose or via i.p injection for 10 consecutive days.

RESULTS

In this study, GLM supplementation caused significant reduction of elevated high-mobility group box-1 (HMGB-1) with a concurrent decline in TNF-α and upregulation of IL-10 compared to the CP group (P<0.05). The histopathological and fibrosis evaluation significantly confirmed the improvement upon simultaneous treatment with GLM. Moreover, immunohistochemical examination also confirmed the recovery following GLM treatment indicated by downregulation of NF-κB, p53 and caspase-3 along with upsurge of B-cell lymphoma 2 (Bcl-2) expression (P<0.05). GLM treatment significantly decreased serum levels of hepatic injury markers; ALT, AST, T. bilirubin as well as oxidative stress markers; MDA and H2O2 with a concomitant increase in hepatic GSH and SOD. Also, the performed docking simulation of ganoderic acid exhibited good fitting and binding with HMGB-1 through hydrogen bond formation with conservative amino acids which gives a strong evidence for its hepatoprotective effect and may interpret the effect of Ganoderma lucidum.

CONCLUSION

GLM attenuated hepatic injury through downregulation of HMGB-1/NF-kB and caspase-3 resulted in modulation of the induced oxidative stress and the subsequent cross-talk between the inflammatory and apoptotic cascade indicating its promising role in DILI.

Ursodeoxycholic acid protects against cisplatin-induced acute kidney injury and mitochondrial dysfunction through acting on ALDH1L2

Mitochondrial dysfunction plays an important role in acute kidney injury (AKI). Thus, the agents improving the mitochondrial function could be beneficial for treating AKI. Ursodeoxycholic acid (UDCA) has been demonstrated to prevent mitochondrial dysfunction under pathology, however, its role in AKI and the underlying mechanism remain unknown. This study aimed to evaluate the effect of UDCA on cisplatin-induced AKI. In vivo, C57BL/6 J mice were treated with cisplatin (25 mg/kg) for 72 h to induce AKI through a single intraperitoneal (i.p.) injection with or without UDCA (60 mg/kg/day) administration by gavage. Renal function, mitochondrial function and oxidative stress were analyzed to evaluate kidney injury. In vitro, mouse proximal tubular cells (mPTCs) and human proximal tubule epithelial cells (HK2) were treated with cisplatin with or without UDCA treatment for 24 h. Transcriptomic RNA-seq was preformed to analyze possible targets of UDCA. Our results showed that cisplatin-induced increments of serum creatinine (Scr), blood urea nitrogen (BUN), and cystatin C were significantly reduced by UDCA along with ameliorated renal tubular injury evidenced by improved renal histology and blocked upregulation of neutrophil gelatinase associated lipocalin (NGAL) and kidney injury molecule 1 (KIM-1). Meanwhile, the apoptosis induced by cisplatin was also markedly attenuated by UDCA administration. In vitro, UDCA treatment protected against tubular cell apoptosis possibly through antagonizing mitochondrial dysfunction and oxidative stress by targeting ALDH1L2 which was screened out by an RNA-seq analysis. Knockout of ALDH1L2 by CRISPR/Cas9 greatly blunted the protective effects of UDCA in renal tubular cells. Moreover, UDCA did not diminish cisplatin's antineoplastic effect in human cancer cells. In all, our results demonstrated that UDCA protects against cisplatin-induced AKI through improving mitochondrial function through acting on the expression of ALDH1L2, suggesting a clinical potential of UDCA for the treatment of AKI.

The Mechanism of Zinc Sulfate in Improving Fertility in Obese Rats Analyzed by Sperm Proteomic Analysis

This study investigates the mechanism underlying the improving effect of zinc on fertility in obese rats using proteomics. The effects of three different doses of ZnSO₄ on spermatogenesis and hormone levels were studied. Testicular spermatogenesis was observed by HE staining. Serum estrogen and testosterone levels were measured by chemiluminescent microparticle immunoassay. Sperm proteomic analysis was performed by liquid chromatography-mass spectrometry. The DAVID database was used to perform the GO enrichment analysis and KEGG pathway analysis of the differentially expressed genes, and the STRING online database was used to construct a PPI network. The sperm count, sperm motility, and testosterone hormones of the ZnSO₄-treated rats group were increased. ZnSO₄ improved testicular structure and spermatogenesis abnormalities caused by obesity. Proteomic analysis showed that there were 401 differentially expressed proteins in a total of 6 sperm samples from the ZnSO₄-treated group and the obesity groups. Differential proteins were input into the DAVID website. The 341 identified proteins were then classified according to their biological functions. The KEGG analysis showed that the enriched signal pathways included glycolysis/gluconeogenesis, carbon metabolism, citrate cycle, fatty acid metabolism, and pyruvate metabolism. Some proteins were shown to be associated with valine, leucine, and isoleucine degradation pathways. STRING analysis obtained 36 node proteins. Cytoscape analysis showed that these proteins mainly participated in nine networks including metabolic process, oxidation-reduction, aerobic respiration, RNA splicing, and glutathione conjugation. ZnSO₄ may improve the fertility of obese male rats by regulating protein expression related to metabolism, inflammation, and sperm maturation.

The Role of PGC-1α and Mitochondrial Biogenesis in Kidney Diseases

Chronic kidney disease (CKD) is one of the fastest growing causes of death worldwide, emphasizing the need to develop novel therapeutic approaches. CKD predisposes to acute kidney injury (AKI) and AKI favors CKD progression. Mitochondrial derangements are common features of both AKI and CKD and mitochondria-targeting therapies are under study as nephroprotective agents. PGC-1α is a master regulator of mitochondrial biogenesis and an attractive therapeutic target. Low PGC-1α levels and decreased transcription of its gene targets have been observed in both preclinical AKI (nephrotoxic, endotoxemia, and ischemia-reperfusion) and in experimental and human CKD, most notably diabetic nephropathy. In mice, PGC-1α deficiency was associated with subclinical CKD and predisposition to AKI while PGC-1α overexpression in tubular cells protected from AKI of diverse causes. Several therapeutic strategies may increase kidney PGC-1α activity and have been successfully tested in animal models. These include AMP-activated protein kinase (AMPK) activators, phosphodiesterase (PDE) inhibitors, and anti-TWEAK antibodies. In conclusion, low PGC-1α activity appears to be a common feature of AKI and CKD and recent characterization of nephroprotective approaches that increase PGC-1α activity may pave the way for nephroprotective strategies potentially effective in both AKI and CKD.

Astragalus Polysaccharide Attenuates Cisplatin-Induced Acute Kidney Injury by Suppressing Oxidative Damage and Mitochondrial Dysfunction

Cisplatin is a widely used chemotherapeutic drug in the treatment of various solid tumors. However, the cisplatin-induced acute kidney injury remains a disturbing complication, which still lacks effective prevention. Cisplatin-induced oxidative damage and mitochondrial dysfunction are anticipated to be crucial in the occurrence of kidney injury. Astragalus polysaccharide (APS) has been reported to possess multiple biological activities including anti-inflammatory, antioxidant, and mitochondria protection. In this study, we investigated the potentially protective effect of APS against cisplatin-induced kidney injury both in vivo and in vitro. We found that APS pretreatment attenuated the cisplatin-induced renal dysfunction and histopathological damage in mice; in addition, it also protected the viability of HK-2 cells upon cisplatin exposure. APS attenuated the cisplatin-induced oxidative damage by reducing reactive oxygen species (ROS) generation and recovering the activities of total superoxide dismutase and glutathione peroxidase in mice kidney. In addition, electron microscope analysis indicated that cisplatin induced extensive mitochondrial vacuolization in mice kidney. However, APS administration reversed these mitochondrial morphology changes. In HK-2 cells, APS reduced the cisplatin-induced mitochondrial and intracellular ROS generation. Furthermore, APS protected the normal morphology of mitochondria, blocked the cisplatin-induced mitochondrial permeability transition pore opening, and reduced the cytochrome c leakage. Subsequently, APS reduced the cisplatin-induced apoptosis in mice renal and HK-2 cells. In conclusion, our data suggested that APS pretreatment might prevent cisplatin-induced kidney injury through attenuating oxidative damage, protecting mitochondria, and ameliorating mitochondrial-mediated apoptosis.

Transgenic zebrafish modeling low-molecular-weight proteinuria and lysosomal storage diseases

Epithelial cells lining the proximal tubule of the kidney reabsorb and metabolize most of the filtered low-molecular-weight proteins through receptor-mediated endocytosis and lysosomal processing. Congenital and acquired dysfunctions of the proximal tubule are consistently reflected by the inappropriate loss of solutes including low-molecular-weight proteins in the urine. The zebrafish pronephros shares individual functional segments with the human nephron, including lrp2a/megalin-dependent endocytic transport processes of the proximal tubule. Although the zebrafish has been used as a model organism for toxicological studies and drug discovery, there is no available assay that allows large-scale assessment of proximal tubule function in larval or adult stages. Here we establish a transgenic Tg(lfabp::½vdbp-mCherry) zebrafish line expressing in the liver the N-terminal region of vitamin D-binding protein coupled to the acid-insensitive, red monomeric fluorescent protein mCherry (½vdbp-mCherry). This low-molecular-weight protein construct is secreted into the bloodstream, filtered through the glomerulus, reabsorbed by receptor-mediated endocytosis and processed in the lysosomes of proximal tubule cells of the fish. Thus, our proof-of-concept studies using zebrafish larvae knockout for lrp2a and clcn7 or exposed to known nephrotoxins (gentamicin and cisplatin) demonstrate that this transgenic line is useful to monitor low-molecular-weight proteinuria and lysosomal processing. This represents a powerful new model organism for drug screening and studies of nephrotoxicity.

A glance at molecular mechanisms underlying cisplatin-induced nephrotoxicity and possible renoprotective strategies: a narrative review

Cisplatin is a platinum-based drug that is usually used for the treatment of many carcinomas. However, it comes with several devastating side effects, including nephrotoxicity. Cisplatin toxicity is a very complex process, which is exacerbated by the accumulation of cisplatin in renal tubular cells via passive diffusion and transporter-mediated processes. Once cisplatin enters these cells, it induces the formation of reactive oxygen species that cause cellular damage, including DNA damage, inflammation, and eventually cell death. On a small scale, these damages can be mitigated by cellular antioxidant defense mechanism. However, on a large scale, such as in chemotherapy, this defense mechanism may fail, resulting in nephrotoxicity. The current article reviews the molecular mechanisms underlying cisplatin-induced nephrotoxicity and possible renoprotective strategies to determine novel therapeutic interventions for alleviating this toxicity.

The effect of rutin on cisplatin-induced oxidative cardiac damage in rats

Objective:

Cisplatin is an anticancer drug used for treating childhood solid tumors. Symptoms related to cisplatin-induced cardiovascular adverse effects may be mild or severe. Rutin (vitamin P1) has many properties, including as antioxidant, anticancer, antidiabetic, antimicrobial, antiulcer, and tissue renewal properties. Therefore, we aimed to biochemically, histopathologically, and immunohistochemically demonstrate the effect of rutin on cisplatin-induced cardiotoxicity in rats.

Methods:

The rats included in our study were divided into four groups: Healthy group (HE), 5-mg/kg cisplatin group (CP), 50 mg/kg rutin+5-mg/kg cisplatin (CR-50), 100-mg/kg rutin+5-mg/kg cisplatin (CR-100) group.

Results:

CP group administered cisplatin had significantly increased blood, serum, and cardiac tissue malondialdehyde (MDA), interleukin 1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), troponin I, creatine kinase (CK), and CK-MB levels compared to the HE group, whereas there was a significant decrease in the total glutathione (tGSH) levels. Rutin was observed to prevent the increase in MDA, IL-1β, TNF-α, troponin I, CK, and CK-MB levels as well as prevent the decrease in tGSH levels more significantly when administered at a 100-mg/kg dose than at a 50-mg/kg dose. Histopathologically, cardiac necrosis, dilated/congested blood vessels, hemorrhage, polymorphonuclear leukocyte, edema, and cells with pyknotic nuclei were observed in the CP group. Rutin was shown to prevent cisplatin-induced cardiac damage more effectively when used at a100-mg/kg dose than at a 50-mg/kg dose.

Conclusion:

These results suggest that rutin is useful for preventing cisplatin-related cardiovascular damage

The footprints of mitochondrial impairment and cellular energy crisis in the pathogenesis of xenobiotics-induced nephrotoxicity, serum electrolytes imbalance, and Fanconi's syndrome: A comprehensive review

Fanconi's Syndrome (FS) is a disorder characterized by impaired renal proximal tubule function. FS is associated with a vast defect in the renal reabsorption of several chemicals. Inherited and/or acquired conditions seem to be connected with FS. Several xenobiotics including many pharmaceuticals are capable of inducing FS and nephrotoxicity. Although the pathological state of FS is well described, the exact underlying etiology and cellular mechanism(s) of xenobiotics-induced nephrotoxicity, serum electrolytes imbalance, and FS are not elucidated. Constant and high dependence of the renal reabsorption process to energy (ATP) makes mitochondrial dysfunction as a pivotal mechanism which could be involved in the pathogenesis of FS. The current review focuses on the footprints of mitochondrial impairment in the etiology of xenobiotics-induced FS. Moreover, the importance of mitochondria protecting agents and their preventive/therapeutic capability against FS is highlighted. The information collected in this review may provide significant clues to new therapeutic interventions aimed at minimizing xenobiotics-induced renal injury, serum electrolytes imbalance, and FS.

Embelin attenuates cisplatin-induced nephrotoxicity: Involving inhibition of oxidative stress and inflammation in addition with activation of Nrf-2/Ho-1 pathway

In kidneys, elevated levels of inflammatory cytokines and oxidative stress were observed in nephrotoxicity triggered by cisplatin. Embelin has the anti-inflammatory property. It also got anti-tumorigenic and antioxidant properties. In this research, we analyzed the actions of embelin on nephrotoxicity triggered by cisplatin and vital actions by which it increases antioxidant actions and corrects the inflammation after embelin administration during nephrotoxicity triggered by cisplatin. Kidney function markers including blood urea nitrogen; serum creatinine; the markers of oxidative stress like malondialdehyde (MDA), antioxidant systems like glutathione, superoxide dismutase, glutathione S-transferase, catalase, and glutathione reductase; inflammation markers like nuclear factor-κB (NF-κB), tumor necrosis factor-α (TNF-α), and interleukin-1 beta (IL-1β); and the extent of nuclear factor-erythroid-2 p45-related factor-2 (Nrf2) and heme oxygenase-1 (HO-1) were determined. Histopathology studies of kidneys were also used to analyze nephrotoxicity induced by cisplatin. Treatment with embelin (25 and 50 mg/kg) upgrades the function of kidneys, by elevating antioxidant levels and reducing the MDA level in cisplatin-administered rats. Embelin treatment demonstrated a significant curtailment of oxidative stress as well as increased the activities of antioxidant enzymes, endogenously. Cisplatin upregulates cytokines (i.e., TNF-α and IL-1β) and NF-κB, and downregulates Nrf2 and HO-1. Embelin treatment also reduced the infiltration of neutrophils in the renal tubules and thus reduced the level of histological impairment. The outcome of this study implements that the signaling pathway of Nrf2/HO-1 may be the principal mechanism of embelin for protection from nephrotoxicity triggered by cisplatin, and thus, embelin diminishes oxidative stress and inflammation by impeding NF-κB. © 2019 BioFactors, 45(3):471-478, 2019.

Intervention of mitochondrial activity attenuates cisplatin-induced acute kidney injury

OBJECTIVES

The dysfunction of mitochondrial respiratory chain induced by cisplatin results in overproduction of reactive oxygen species (ROS) which contributes to kidney injury. The current study aimed to evaluate the effect of a mitochondrial electron transport inhibitors of rotenone (mitochondrial complex I inhibitor) and azoxystrobin (mitochondrial complex III inhibitor), in cisplatin-induced kidney injury.

METHODS

In vivo, cisplatin was administered to male C57BL/6J mice by a single intraperitoneal (i.p.) injection (20 mg/kg). Then the mice were treated with or without 200 ppm rotenone in food. Mice were sacrificed after cisplatin administration for 72 h. The serum and the kidney tissues were collected for further analysis. In vitro, mouse proximal tubular cells (mPTCs) were treated with cisplatin (5 µg/mL) and rotenone/azoxystrobin for 24 h. Flow cytometry, Western blotting, and TUNEL staining were used to evaluate the cell injury.

RESULTS

In vivo, rotenone treatment obviously ameliorated cisplatin-induced renal tubular injury evidenced by the improved histology and blocked NGAL upregulation. Meanwhile, cisplatin-induced renal dysfunction shown by the increased levels of serum creatinine (Scr), blood urea nitrogen (BUN), and cystatin C were significantly reduced by rotenone treatment. Moreover, the increments of cleaved caspase-3 and transferase dUTP nick-end labeling (TUNEL)-positive cells were markedly decreased in line with the attenuated mitochondrial dysfunction and oxidative stress after rotenone administration. In vitro, rotenone and azoxystrobin protected against mitochondrial dysfunction, oxidative stress, and renal tubular cell apoptosis induced by cisplatin.

CONCLUSIONS

Our results demonstrated that inhibition of mitochondrial activity significantly attenuated cisplatin nephrotoxicity possibly by inhibiting mitochondrial oxidative stress.

TFEB-driven lysosomal biogenesis is pivotal for PGC1α-dependent renal stress resistance

Because injured mitochondria can accelerate cell death through the elaboration of oxidative free radicals and other mediators, it is striking that proliferator γ coactivator 1-α (PGC1α), a stimulator of increased mitochondrial abundance, protects stressed renal cells instead of potentiating injury. Here, we report that PGC1α’s induction of lysosomes via transcription factor EB (TFEB) may be pivotal for kidney protection. CRISPR and stable gene transfer showed that PGC1α-KO tubular cells were sensitized to the genotoxic stressor cisplatin, whereas Tg cells were protected. The biosensor mitochondrial-targeted Keima (mtKeima) unexpectedly revealed that cisplatin blunts mitophagy both in cells and mice. PGC1α and its downstream mediator NAD⁺ counteracted this effect. PGC1α did not consistently affect known autophagy pathways modulated by cisplatin. Instead RNA sequencing identified coordinated regulation of lysosomal biogenesis via TFEB. This effector pathway was sufficiently important that inhibition of TFEB or lysosomes unveiled a striking harmful effect of excess PGC1α in cells and conditional mice. These results uncover an unexpected effect of cisplatin on mitophagy and PGC1α’s reliance on lysosomes for kidney protection. Finally, the data illuminate TFEB as a potentially novel target for renal tubular stress resistance.

PGC1α is renoprotective in the setting of platinum-based chemotherapy through the induction of mitophagy and lysosomal biogenesis via transcription factor EB.

AP39, a Modulator of Mitochondrial Bioenergetics, Reduces Antiangiogenic Response and Oxidative Stress in Hypoxia-Exposed Trophoblasts: Relevance for Preeclampsia Pathogenesis

Although the cause of preeclampsia, a pregnancy complication with significant maternal and neonatal morbidity, has not been fully characterized, placental ischemia attributable to impaired spiral artery remodeling and abnormal secretion of antiangiogenic factors are thought to be important in the pathogenesis of the disease. Placental ischemia could impair trophoblast mitochondrial function and energy production, leading to the release of reactive oxygen species (ROS). ROS have been shown to stabilize hypoxia-inducible factor (HIF)-1α, which, in turn, may induce transcription of antiangiogenic factors, soluble fms-like tyrosine kinase 1 (sFLT1), and soluble endoglin in trophoblasts. Herein, we tested whether the angiogenic imbalance and oxidative stress in the preeclamptic placenta may be prevented by improving mitochondrial function. First, to evaluate the cause-effect relationship between mitochondrial function and sFLT1 production, a human trophoblast primary cell culture model was established in which hypoxia induced mitochondrial ROS production and concurrent sFLT1 increase. Second, treatment with AP39, a novel mitochondria-targeted hydrogen sulfide donor, prevented ROS production, reduced HIF-1α protein levels, and diminished sFLT1 production. Finally, AP39, a modulator of mitochondrial bioenergetics enhanced cytochrome c oxidase activity, reversed oxidative stress and antiangiogenic response in hypoxic trophoblasts. These results suggest that placental hypoxia induces ROS production, HIF-1α stabilization, and sFLT1 up-regulation; these pathophysiological alterations can be attenuated by mitochondrial-targeted antioxidants.

Immunopathogenesis of Acute Kidney Injury

Pathophysiologically, the classification of acute kidney injury (AKI) can be divided into three categories: (1) prerenal, (2) intrinsic, and (3) postrenal. Emerging evidence supports the involvement of renal tubular epithelial cells and the innate and adaptive arms of the immune system in the pathogenesis of intrinsic AKI. Pro-inflammatory damage-associated molecular patterns, pathogen-associated molecular patterns, hypoxia inducible factors, toll-like receptors, complement system, oxidative stress, adhesion molecules, cell death, resident renal dendritic cells, neutrophils, T and B lymphocytes, macrophages, natural killer T cells, cytokines, and secreted chemokines contribute to the immunopathogenesis of AKI. However, other immune cells and pathways such as M2 macrophages, regulatory T cells, progranulin, and autophagy exhibit anti-inflammatory properties and facilitate kidney tissue repair after AKI. Thus, therapies for AKI include agents such as anti-inflammatory (e.g., recombinant alkaline phosphatase), antioxidants (iron chelators), and apoptosis inhibitors. In preclinical toxicity studies, drug-induced kidney injury can be seen after exposure to a nephrotoxicant test article due to immune mechanisms and dysregulation of innate, and/or adaptive cellular immunity. The focus of this review will be on intrinsic AKI, as it relates to the immune and renal systems cross talks focusing on the cellular and pathophysiologic mechanisms of AKI.

Tempol, a superoxide dismutase mimetic agent, reduces cisplatin-induced nephrotoxicity in rats

Cisplatin (CP) is one of the most potent anti-cancer drugs used against different types of cancer. Its use is limited due to its nephrotoxicity. This study is aimed to evaluate the role of a super oxide dismutase (SOD) mimetic agent, tempol, in protection against CP nephrotoxicity in rats. Animals were divided into four groups: Group-1: Normal control group, Group-2: CP group (single dose of CP 6 mg/kg, i.p.), Group-3 and Group-4: Tempol-treated groups (50 mg/kg p.o. and 100 mg/kg p.o. respectively) daily for a week before CP injection and continued for an additional four days after CP injection. Urine and blood samples were collected for the evaluation of kidney function including serum creatinine, BUN, cystatin-c, and creatinine clearance. In addition, western blotting was used to determine urine lipocalin-2 content. Furthermore, kidney tissue was collected for the determination of oxidative stress markers, caspase-3 expression, and histopathological examination. We noticed that both doses of tempol significantly improved kidney function, which was deteriorated by CP injection. Tempol significantly elevated kidney glutathione (GSH) content and SOD activity, and decreased kidney lipid peroxidation and NOx production. Tempol also significantly decreased kidney caspase-3 expression which was elevated by CP toxicity. Thus, we conclude that tempol can protect against CP nephrotoxicity. We noticed that both doses of tempol are effective in ameliorating CP-nephrotoxicity.

Mitochondrial NADP+-dependent isocitrate dehydrogenase deficiency increases cisplatin-induced oxidative damage in the kidney tubule cells

Mitochondrial NADP⁺-dependent isocitrate dehydrogenase (IDH2) plays an important role in the formation of NADPH, which is critical for the maintenance of mitochondrial redox balance. Cis-diamminedichloroplatinum II (cisplatin), an effective anticancer drug, induces oxidative stress-related nephrotoxicity, limiting its use. Therefore, we investigated whether IDH2, which is a critical enzyme in the NADPH-associated mitochondrial antioxidant system, is involved in cisplatin nephrotoxicity. Idh2 gene-deleted (Idh2^−/−) mice and wild-type (Idh2^+/+) littermates were treated with cisplatin, with or without 2-(2,2,6,6-tetramethylpiperidin-1-oxyl-4-ylamino)-2-oxoethyl) triphenylphosphonium chloride (Mito-T), a mitochondria-specific antioxidant. Cisplatin-induced renal functional and morphological impairments were greater in Idh2^−/− mice than in Idh2^+/+ mice. Mito-T mitigated those impairments in both Idh2^−/− and Idh2^+/+ mice and this mitigation was greater in Idh2^−/− than in Idh2^+/+ mice. Cisplatin impaired IDH2 function in the mitochondria, decreasing mitochondrial NADPH and GSH levels and increasing H₂O₂ generation; protein, lipid, and DNA oxidation; mitochondrial damage; and apoptosis. These cisplatin-induced changes were much more severe in Idh2^−/− mice than in Idh2^+/+ mice. Mito-T treatment attenuated cisplatin-induced alterations in both Idh2^−/− and Idh2^+/+ mice and this mitigation was greater in Idh2^−/− than in Idh2^+/+ mice. Altogether, these data demonstrate that cisplatin induces the impairment of the mitochondrial IDH2-NADPH-GSH antioxidant system and IDH2 deficiency aggravates cisplatin-induced mitochondrial oxidative damage, inducing more severe nephrotoxicity. This suggests that the mitochondrial IDH2-NADPH-GSH antioxidant system is a target for the prevention of cisplatin-induced kidney cell death.