Oxidative Stress in the Pathophysiology of Kidney Disease: Implications for Noninvasive Monitoring and Identification of Biomarkers

Tacrolimus trough level and oxidative stress in Tunisian kidney transplanted patients

BACKGROUND

The effect of tacrolimus (TAC) on oxidative stress after kidney transplantation (KT) is unclear. This study aimed to evaluate the influence of TAC trough levels of oxidative stress status in Tunisian KT patients during the post-transplantation period (PTP).

METHODS

A prospective study including 90 KT patients was performed. TAC whole-blood concentrations were measured by the microparticle enzyme immunoassay method and adjusted according to the target range. Plasma levels of oxidants (malondialdehyde (MDA) and advanced oxidation protein products (AOPP)) and antioxidants (ascorbic acid, glutathione (GSH), glutathione peroxidase (GPx), and superoxide dismutase (SOD)) were measured using spectrophotometry. The subjects were subdivided according to PTP into three groups: patients with early, intermediate, and late PT. According to the TAC level, they were subdivided into LL-TAC, NL-TAC, and HL-TAC groups.

RESULTS

A decrease in MDA levels, SOD activity, and an increase in GSH levels and GPx activity were observed in patients with late PT compared to those with early and intermediate PT (p < 0.05). Patients with LL-TAC had lower MDA levels and higher GSH levels and GPx activity compared with the NL-TAC and HL-TAC groups (p < 0.05).

CONCLUSION

Our results have shown that in KT patients, despite the recovery of kidney function, the TAC reduced but did not normalize oxidative stress levels in long-term therapy, and the TAC effect significantly depends on the concentration used.

Sulforaphane upregulates the mRNA expression of NRF2 and NQO1 in non-dialysis patients with chronic kidney disease

Sulforaphane (SFN), found in cruciferous vegetables, is a known activator of NRF2 (master regulator of cellular antioxidant responses). Patients with chronic kidney disease (CKD) present an imbalance in the redox state, presenting reduced expression of NRF2 and increased expression of NF-κB. Therefore, this study aimed to evaluate the effects of SFN on the mRNA expression of NRF2, NF-κB and markers of oxidative stress in patients with CKD. Here, we observed a significant increase in the mRNA expression of NRF2 (p = 0.02) and NQO1 (p = 0.04) in the group that received 400 μg/day of SFN for 1 month. Furthermore, we observed an improvement in the levels of phosphate (p = 0.02), glucose (p = 0.05) and triglycerides (p = 0.02) also in this group. On the other hand, plasma levels of LDL-c (p = 0.04) and total cholesterol (p = 0.03) increased in the placebo group during the study period. In conclusion, 400 μg/day of SFN for one month improves the antioxidant system and serum glucose and phosphate levels in non-dialysis CKD patients.

Glutamine Defended the Kidneys Versus Lead Intoxication Via Elevating Endogenous Antioxidants, Reducing Inflammation and Carbonyl Stress, as well as Improving Insulin Resistance and Dyslipidemia

Kidneys are primarily sensitive to lead (Pb) poisoning due to their cardinal role in lead excretion. Then, we studied the effect of glutamine (Gln) on lead nephrotoxicity in rats by assessing the histopathological and biochemical parameters (the renal NF-kβ expression, metabolic profile, oxidative stress, inflammatory markers, methylglyoxal (MGO), and glyoxalase-I activity). Forty rats were allotted into four groups (ten rats in each): normal (N), Gln-treated N, Pb intoxication (Pbi), and Gln-treated Pbi. The treated groups took 0.1% Gln in drinking water for 1 month. To motivate lead poisoning, rats gained 50 mg/l lead acetate in drinking water for 1 month. Oxidative stress indices (total glutathione, its reduced and oxidized forms, their ratios, advanced protein oxidation products, malondialdehyde, and ferric ion reducing power) and inflammatory markers (renal nuclear factor-kβ expression, interleukin 1β level, and myeloperoxidase activity) were measured. Furthermore, metabolic profile (fasting blood sugar, insulin, insulin resistance, lipid profile, and atherogenic index) and renal dysfunction parameters were determined. Pb-induced renal histopathological alterations were investigated by a pathologist. In the kidney of Pbi rats, the glomerulus was damaged. Gln prevented kidney damage and reduced kidney dysfunction parameters. In addition, Gln decreased oxidative stress and inflammation in sera and kidney homogenates. In addition, it improved insulin resistance, dyslipidemia, and carbonyl stress (p < 0.001). Gln guarded the kidneys versus lead intoxication by improving insulin resistance and dyslipidemia, elevating antioxidant markers, and diminishing inflammation and carbonyl stress.

Human dementia with Lewy bodies brain shows widespread urea elevations

INTRODUCTION

Several recent studies have uncovered the presence of widespread urea elevations in multiple neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease dementia (PDD), vascular dementia (VaD), and Huntington's disease (HD). However, it is currently unknown whether dementia with Lewy bodies also shows these alterations in urea. This study aimed to investigate if and where urea is perturbed in the DLB brain.

METHODS

Tissues from ten brain regions were obtained from 20 diagnosed cases of DLB and 19 controls. Urea concentrations were measured using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Case-control differences were assessed by nonparametric Mann-Whitney U tests, and s-values, E-values, effect sizes, and risk ratios were determined for each brain region. The results were compared to those previously obtained for AD, PDD, VaD, and HD.

RESULTS

As with other previously investigated dementia diseases, DLB shows widespread urea elevations, affecting all ten regions investigated in the current study; the degree of these elevations is lower than that seen in AD or PDD, similar to that seen in HD, and higher than that observed in VaD. The highest urea fold-change was observed in the pons and the lowest in the primary visual cortex.

CONCLUSION

Urea elevations appear to be a shared alterations across at least five neurodegenerative diseases, despite their many differences in clinical and neuropathological presentation. The cause and effects of this perturbation should be the focus of future studies, for its possible contributions to the pathology of these conditions.

Harmine alleviated STZ-induced rat diabetic nephropathy: A potential role via regulating AMPK/Nrf2 pathway and deactivating ataxia-telangiectasia mutated (ATM) signaling

Diabetic nephropathy (DN) is a serious kidney disorder driven by diabetes and affects people all over the world. One of the mechanisms promoting NF-κB-induced renal inflammation and injury has been theorized to be ATM signaling. On the other hand, AMPK, which can be activated by the naturally occurring alkaloid harmine (HAR), has been proposed to stop that action. As a result, the goal of this study was to evaluate the therapeutic effectiveness of HAR against streptozotocin (STZ)-induced DN in rats through AMPK-mediated inactivation of ATM pathways. Twenty male Wistar rats were grouped into 4 groups, as follow: CONT, DN, HAR (10 mg/kg), DN + HAR, where HAR was daily administered I.P. once for 2 weeks. The renal AMPK and PGC-1α expressions, as well as Sirt1 levels, were assessed. To ascertain the oxidative reactions, renal Nrf2 expression, HO-1, MDA, and TAC concentrations were measured. As parts of ATM pathways, ATM and p53 expressions, in addition to GSK-3β levels were determined. Renal expression of NEMO, TNF-α, and IL-6 levels were also estimated. Moreover, histopathological and immunohistochemical detection of Bcl-2, Bax, and caspase 3 were reported. Results indicated that HAR intake notably alleviated STZ-induced kidney damage by triggering AMPK and Sirt1, which in turn boosted PGC-1α, improved NRf2/HO-1 axis, and lowered ROS production. As a consequence, HAR blocked the ATM-triggered renal inflammation and minimized caspase-3 expression by repressing the Bax/Bcl2 ratio. Because of its ability to activate AMPK/Nrf2 axis, HAR may represent an emerging avenue for future DN therapy by blocking ATM pathways.

The Ocean's Pharmacy: Health Discoveries in Marine Algae

Non-communicable diseases (NCDs) represent a global health challenge, constituting a major cause of mortality and disease burden in the 21st century. Addressing the prevention and management of NCDs is crucial for improving global public health, emphasizing the need for comprehensive strategies, early interventions, and innovative therapeutic approaches to mitigate their far-reaching consequences. Marine organisms, mainly algae, produce diverse marine natural products with significant therapeutic potential. Harnessing the largely untapped potential of algae could revolutionize drug development and contribute to combating NCDs, marking a crucial step toward natural and targeted therapeutic approaches. This review examines bioactive extracts, compounds, and commercial products derived from macro- and microalgae, exploring their protective properties against oxidative stress, inflammation, cardiovascular, gastrointestinal, metabolic diseases, and cancer across in vitro, cell-based, in vivo, and clinical studies. Most research focuses on macroalgae, demonstrating antioxidant, anti-inflammatory, cardioprotective, gut health modulation, metabolic health promotion, and anti-cancer effects. Microalgae products also exhibit anti-inflammatory, cardioprotective, and anti-cancer properties. Although studies mainly investigated extracts and fractions, isolated compounds from algae have also been explored. Notably, polysaccharides, phlorotannins, carotenoids, and terpenes emerge as prominent compounds, collectively representing 42.4% of the investigated compounds.

Quillaja saponin mitigates methotrexate-provoked renal injury; insight into Nrf-2/Keap-1 pathway modulation with suppression of oxidative stress and inflammation

BACKGROUND

Methotrexate (MTX) is an antineoplastic/immunosuppressive drug, whose clinical use is impeded owing to its serious adverse effects; one of which is acute kidney injury (AKI). Most of MTX complications emerged from the provoked pro-oxidant-, pro-inflammatory- and pro-apoptotic effects. Quillaja saponaria bark saponin (QBS) is a bioactive triterpene that has been traditionally used as an antitussive, anti-inflammatory supplement, and to boost the immune system due to its potent antioxidant- and anti-inflammatory activities. However, the protective/therapeutic potential of QBS against AKI has not been previously evaluated. This study aimed to assess the modulatory effect of QBS on MTX-induced reno-toxicity.

METHODS

Thirty-two male rats were divided into 4-groups. Control rats received oral saline (group-I). In group-II, rats administered QBS orally for 10-days. In group-III, rats were injected with single i.p. MTX (20 mg/kg) on day-5. Rats in group-IV received QBS and MTX. Serum BUN/creatinine levels were measured, as kidney-damage-indicating biomarkers. Renal malondialdehyde (MDA), reduced-glutathione (GSH) and nitric-oxide (NOx) were determined, as oxidative-stress indices. Renal expression of TNF-α protein and Nrf-2/Keap-1 mRNAs were evaluated as regulators of inflammation. Renal Bcl-2/cleaved caspase-3 immunoreactivities were evaluated as apoptosis indicators.

RESULTS

Exaggerated kidney injury upon MTX treatment was evidenced histologically and biochemically. QBS attenuated MTX-mediated renal degeneration, oxidant-burden enhancement, excessive inflammation, and proapoptotic induction. Histopathological analysis further confirmed the reno-protective microenvironment rendered by QBS.

CONCLUSIONS

In conclusion, our results suggest the prophylactic and/or therapeutic effects of QBS in treating MTX-induced AKI. Such reno-protection is most-likely mediated via Nrf-2 induction that interferes with oxidant load, inflammatory pathways, and proapoptotic signaling.

Multivariate canonical correlation analysis identifies additional genetic variants for chronic kidney disease

Chronic kidney diseases (CKD) have genetic associations with kidney function. Univariate genome-wide association studies (GWAS) have identified single nucleotide polymorphisms (SNPs) associated with estimated glomerular filtration rate (eGFR) and blood urea nitrogen (BUN), two complementary kidney function markers. However, it is unknown whether additional SNPs for kidney function can be identified by multivariate statistical analysis. To address this, we applied canonical correlation analysis (CCA), a multivariate method, to two individual-level CKD genotype datasets, and metaCCA to two published GWAS summary statistics datasets. We identified SNPs previously associated with kidney function by published univariate GWASs with high replication rates, validating the metaCCA method. We then extended discovery and identified previously unreported lead SNPs for both kidney function markers, jointly. These showed expression quantitative trait loci (eQTL) colocalisation with genes having significant differential expression between CKD and healthy individuals. Several of these identified lead missense SNPs were predicted to have a functional impact, including in SLC14A2. We also identified previously unreported lead SNPs that showed significant correlation with both kidney function markers, jointly, in the European ancestry CKDGen, National Unified Renal Translational Research Enterprise (NURTuRE)-CKD and Salford Kidney Study (SKS) datasets. Of these, rs3094060 colocalised with FLOT1 gene expression and was significantly more common in CKD cases in both NURTURE-CKD and SKS, than in the general population. Overall, by using multivariate analysis by CCA, we identified additional SNPs and genes for both kidney function and CKD, that can be prioritised for further CKD analyses.

Cisplatin induces acute kidney injury by downregulating miR-30e-5p that targets Galnt3 to activate the AMPK signaling pathway

Cisplatin nephrotoxicity is an etiological factor for acute kidney injury (AKI). MicroRNA (miRNA) expression is dysregulated in cisplatin-induced AKI (cAKI) although the underlying mechanisms are unclear. A cAKI model was established by intraperitoneally injecting cisplatin, and key miRNAs were screened using high-throughput miRNA sequencing. The functions of key miRNAs were determined using the cell viability, live/dead, reactive oxygen species (ROS), and 5-ethynyl-2'-deoxyuridine (EdU) proliferation assays. Additionally, the macrophage membrane was wrapped around a metal-organic framework (MOF) loaded with miRNA agomir to develop a novel composite material, macrophage/MOF/miRNA agomir nanoparticles (MMA NPs). High-throughput miRNA sequencing revealed that miR-30e-5p is a key miRNA that is downregulated in cAKI. The results of in vitro experiments demonstrated that miR-30e-5p overexpression partially suppressed the cisplatin-induced or lipopolysaccharide (LPS)-induced downregulation of cell viability, proliferation, upregulation of ROS production, and cell death. Meanwhile, the results of in vivo and in vitro experiments demonstrated that MMA NPs alleviated cAKI by exerting anti-inflammatory effects. Mechanistically, cisplatin downregulates the expression of miR-30e-5p, and the downregulated miR-30e-5p can target Galnt3 to activate the adenosine 5'-monophosphate activated protein kinase (AMPK) signaling pathway, which promotes the progression of AKI. Our study found that miR-30e-5p is a key downregulated miRNA in cAKI. The downregulated miR-30e-5p promotes AKI progression by targeting Galnt3 to activate the AMPK signaling pathway. The newly developed MMA NPs were found to have protective effects on cAKI, suggesting a potential novel strategy for preventing cAKI.

Angiotensin 1-7 exerts antioxidant effects, suppresses Mammalian Target of Rapamycin (mTOR) signaling, and inhibits apoptosis in renal proximal tubular cells

Oxidative stress is one of the crucial pathogenic factors involved in the progression of renal injury. Angiotensin (ANG) 1-7, a bioactive heptapeptide of the renin-angiotensin-aldosterone system is known to exert antioxidant and nephroprotective effects. However, the cellular mechanism involved in the beneficial effect of ANG 1-7 is not clear. Here, we assessed ANG 1-7's effect on H2O2-mediated oxidative damage in the human proximal tubular (HK2) cells and the underlying mechanisms. HK2 cells were incubated with H2O2 (500 µM, 4 h) pre-treated with and without ANG 1-7 (100 nM, 24 h), and reactive oxygen species (ROS) generation, mitochondrial dysfunction, endoplasmic reticulum (ER) stress, apoptosis and mammalian target of rapamycin (mTOR) signaling were determined H2O2 induced an increase in oxidative and ER stress together with loss of mitochondrial membrane potential, decreased ATP levels, and induced apoptosis in HK2 cells. Moreover, H2O2 treatment resulted in the activation of mTOR complexes (mTORC1 and mTORC2) in these cells. ANG 1-7 significantly attenuated H2O2-induced ROS generation, ER stress and apoptosis, and also improved mitochondrial function. Additionally, pre-treatment of ANG 1-7 inhibited the H2O2-mediated mTOR activation. These effects of ANG 1-7 were blocked by co-treatment with the Mas receptor (MasR) inhibitor, A779. Furthermore, transfection of HK2 cells with Mas receptor siRNA also abolished the inhibitory effect of ANG 1-7 on mTOR activities. In conclusion, ANG 1-7 via MasR mitigates oxidative stress, suppresses mTOR signaling, and protects HK2 cells from ER stress, mitochondrial dysfunction, and apoptosis, suggesting ANG 1-7-MasR renoprotective effects.

The role of matrix metalloproteinase 9 in fibrosis diseases and its molecular mechanisms

Fibrosis is a process of tissue repair that results in the slow creation of scar tissue to replace healthy tissue and can affect any tissue or organ. Its primary feature is the massive deposition of extracellular matrix (mainly collagen), eventually leading to tissue dysfunction and organ failure. The progression of fibrotic diseases has put a significant strain on global health and the economy, and as a result, there is an urgent need to find some new therapies. Previous studies have identified that inflammation, oxidative stress, some cytokines, and remodeling play a crucial role in fibrotic diseases and are essential avenues for treating fibrotic diseases. Among them, matrix metalloproteinases (MMPs) are considered the main targets for the treatment of fibrotic diseases since they are the primary driver involved in ECM degradation, and tissue inhibitors of metalloproteinases (TIMPs) are natural endogenous inhibitors of MMPs. Through previous studies, we found that MMP-9 is an essential target for treating fibrotic diseases. However, it is worth noting that MMP-9 plays a bidirectional regulatory role in different fibrotic diseases or different stages of the same fibrotic disease. Previously identified MMP-9 inhibitors, such as pirfenidone and nintedanib, suffer from some rather pronounced side effects, and therefore, there is an urgent need to investigate new drugs. In this review, we explore the mechanism of action and signaling pathways of MMP-9 in different tissues and organs, hoping to provide some ideas for developing safer and more effective biologics.

The pharmacology activities of Angelica keiskei Koidzumi and its efficacy and safety in humans

Chronic exposure to elevated levels of pro-oxidant factors may cause structural failings at the mitochondrial DNA level and alteration of antioxidant enzymes (glutathione peroxidase, catalase, and superoxide dismutase). Oxidative stress is an imbalance between the capacity of endogenous non-enzymatic antioxidants (glutathione, alpha-lipoic acid, uric acid, ferritin, metallothionein, melatonin, and bilirubin) and the occurrence of pro-oxidant factors which may lead to the pathogenesis of various diseases that affects the kidneys, pancreas, central nervous system, and cardiovascular system. Therefore, the utilization of medicinal plants with antioxidant activity, e.g., Angelica keiskei Koidzumi which contains chalcones, is interesting to be explored. Chalcones exhibit direct and indirect antioxidant activity and prevent oxidative stress by decreasing ROS, RNS, and superoxide production. In this review, we discuss the pharmacology activities of A. keiskei Koidzumi and its efficacy in humans. The articles were explored on PubMed and Google Scholar databases and based on the titles and abstracts related to the topic of interest, and 55 articles were selected. Two main chalcones of this plant, 4-hydroxyderricin and xanthoangelol, have been reported for their various pharmacology activities. The efficacy of A. keiskei was confirmed in anti-obesity, hepatoprotective, anti-diabetes mellitus, and increasing plasma antioxidants in patients with metabolic syndrome. A keiskei is safe as proven by only mild or no adverse events reported, thus it is prospective to be further developed as an antioxidant nutraceutical.

Urinary vanin-1, tubular injury, and graft failure in kidney transplant recipients

We investigated whether urinary vascular non-inflammatory molecule-1 (vanin-1), a promising early-onset tubular injury marker, correlates with other established tubular injury markers and is associated with graft failure in kidney transplant recipients (KTR). We measured 24 h urinary vanin-1 excretion in 656 KTR (age 53 ± 13 years, 43% female, estimated glomerular filtration rate (eGFR) 53 ± 21 mL/min/1.73 m2) who had undergone kidney transplantation ≥ 1 year. The median 24 h urinary vanin-1 excretion was 145 [51-331] pmol/24 h. 24 h urinary vanin-1 excretion correlated weakly but significantly with other tubular injury markers (ρ = 0.14, p < 0.001 with urinary liver-type fatty acid binding protein, ρ = 0.13, p = 0.001 with urinary post-translationally modified fetuin-A protein, and ρ = 0.10, p = 0.011 with plasma neutrophil gelatinase-associated lipocalin) and with eGFR (ρ = - 0.13, p = 0.001). During a median follow-up of 7.4 [4.9-8.0] years, 94 (14%) KTR developed death-censored graft failure. In multivariable Cox regression analyses, 24 h urinary vanin-1 excretion was not associated with an increased risk of death-censored graft failure (adjusted hazard ratio [95% confidence interval] = 0.96 [0.86-1.07], p = 0.5). In conclusion, our findings do not support the role of urinary vanin-1 as a biomarker of graft failure after kidney transplantation.

Interplay of oxidative stress, cellular communication and signaling pathways in cancer

Cancer remains a significant global public health concern, with increasing incidence and mortality rates worldwide. Oxidative stress, characterized by the production of reactive oxygen species (ROS) within cells, plays a critical role in the development of cancer by affecting genomic stability and signaling pathways within the cellular microenvironment. Elevated levels of ROS disrupt cellular homeostasis and contribute to the loss of normal cellular functions, which are associated with the initiation and progression of various types of cancer. In this review, we have focused on elucidating the downstream signaling pathways that are influenced by oxidative stress and contribute to carcinogenesis. These pathways include p53, Keap1-NRF2, RB1, p21, APC, tumor suppressor genes, and cell type transitions. Dysregulation of these pathways can lead to uncontrolled cell growth, impaired DNA repair mechanisms, and evasion of cell death, all of which are hallmark features of cancer development. Therapeutic strategies aimed at targeting oxidative stress have emerged as a critical area of investigation for molecular biologists. The objective is to limit the response time of various types of cancer, including liver, breast, prostate, ovarian, and lung cancers. By modulating the redox balance and restoring cellular homeostasis, it may be possible to mitigate the damaging effects of oxidative stress and enhance the efficacy of cancer treatments. The development of targeted therapies and interventions that specifically address the impact of oxidative stress on cancer initiation and progression holds great promise in improving patient outcomes. These approaches may include antioxidant-based treatments, redox-modulating agents, and interventions that restore normal cellular function and signaling pathways affected by oxidative stress. In summary, understanding the role of oxidative stress in carcinogenesis and targeting this process through therapeutic interventions are of utmost importance in combating various types of cancer. Further research is needed to unravel the complex mechanisms underlying oxidative stress-related pathways and to develop effective strategies that can be translated into clinical applications for the management and treatment of cancer. Video Abstract.

Adenine model of chronic renal failure in rats to determine whether MCC950, an NLRP3 inflammasome inhibitor, is a renopreventive

BACKGROUND

Chronic renal failure (CRF) is defined by a significant decline in renal function that results in decreased salt filtration and inhibition of tubular reabsorption, which ultimately causes volume enlargement. This study evaluated the potential renopreventive effects of the NLRP3 inflammasome inhibitor MCC950 in adenine-induced CRF in rats due to conflicting evidence on the effects of MCC950 on the kidney.

METHODS

Since the majority of the kidney tubular abnormalities identified in people with chronic renal disease are comparable to those caused by adding 0.75 percent of adenine powder to a rat's diet each day for four weeks, this method has received broad approval as a model for evaluating kidney damage. Throughout the test, blood pressure was checked weekly and at the beginning. Additionally, oxidative stress factors, urine sample examination, histological modifications, and immunohistochemical adjustments of caspase-3 and interleukin-1 beta (IL-1) levels in renal tissues were carried out.

RESULTS

Results revealed that MCC950, an inhibitor of the NLRP3 inflammasome, had a renopreventive effect, which was demonstrated by a reduction in blood pressure readings and an improvement in urine, serum, and renal tissue indicators that indicate organ damage. This was also demonstrated by the decrease in neutrophil gelatinase-associated lipocalin tubular expression (NGAL). The NLRP3 inflammasome inhibitor MCC950 was found to significantly alleviate the worsening renal cellular alterations evidenced by increased expression of caspase-3 and IL-1, according to immunohistochemical tests.

CONCLUSION

The NLRP3 inflammasome inhibitor MCC950 demonstrated renopreventive effects in the CRF rat model, suggesting that it might be used as a treatment strategy to stop the progression of CRF.

The role of apoptosis and oxidative stress in the pathophysiology of Acanthamoeba spp. infection in the kidneys of hosts with different immunological status

BACKGROUND

Acanthamoeba spp. are opportunistic pathogens that cause inflammation, mostly in the brain, lungs and cornea. Recent reports indicate kidney dysfunction in hosts with systemic acanthamoebiasis. The aim of the study was to analyze the gene expression and protein concentration of NADPH oxidase 2 and 4 (NOX2 and NOX4, respectively) and nuclear erythroid 2-related factor (Nrf2) in the kidneys of hosts with systemic acanthamoebiasis. We also aimed to determine the protein and gene expressions of Bcl2, Bax, caspases 3 and 9.

METHODS

 Mice were divided into four groups based on their immunological status and Acanthamoeba sp. infection: A, immunocompetent Acanthamoeba sp.-infected mice; AS, immunosuppressed Acanthamoeba sp.- infected mice; C, immunocompetent uninfected mice; CS, immunosuppressed uninfected mice. NOX2, NOX4 and Nrf2 were analyzed by quantitative reverse transcription PCR (qRT-PCR) and ELISA methods, while pro-apoptotic and anti-apoptotic proteins (Bax and Bcl-2, respectively), Cas9, Cas3 were analyzed by qRT-PCR and western blot methods.  RESULTS: Increased gene expression and/or protein concentration of NOX2 and NOX4 were found in both immunocompetent and immunosuppressed mice infected with Acanthamoeba sp. (groups A and AS, respectively). Gene expression and/or protein concentration of Nrf2 were higher in group A than in control animals. Compared to control mice, in the AS group the expression of the Nrf2 gene was upregulated while the concentration of Nrf2 protein was decreased. Additionally in A group, higher gene and protein expression of Bcl-2, and lower gene as well as protein expression of Bax, caspases 3 and 9 were noted. In contrast, the AS group showed lower gene and protein expression of Bcl-2, and higher gene as well as protein expression of Bax, caspases 3 and 9.

CONCLUSIONS

This study is the first to address the mechanisms occurring in the kidneys of hosts infected with Acanthamoeba sp. The contact of Acanthamoeba sp. with the host cell surface and/or the oxidative burst caused by elevated levels of NOXs lead to an antioxidant response enhanced by the Nrf2 pathway. Acanthamoeba sp. have various strategies concerning apoptosis. In immunocompetent hosts, amoebae inhibit the apoptosis of kidney cells, and in immunosuppressed hosts, they lead to increased apoptosis by the intrinsic pathway and thus to a more severe course of the disease.

Pharmacological potentials of lycopene against aging and aging-related disorders: A review

Aging and aging-related chronic disorders are one of the principal causes of death worldwide. The prevalence of these disorders is increasing gradually and globally. Considering this unwavering acceleration of the global burden, seeking alternatives to traditional medication to prevent the risk of aging disorders is needed. Among them, lycopene, a carotenoid, is abundant in many fruits and vegetables, including tomatoes, grapefruits, and watermelons, and it has a unique chemical structure to be a potent antioxidant compound. This nutraceutical also possesses several anti-aging actions, including combating aging biomarkers and ameliorating several chronic disorders. However, no systematic evaluation has yet been carried out that can comprehensively elucidate the effectiveness of lycopene in halting the course of aging and the emergence of chronic diseases linked to aging. This review, therefore, incorporates previous pre-clinical, clinical, and epidemiological studies on lycopene to understand its potency in treating aging disorders and its role as a mimic of caloric restriction. Lycopene-rich foods are found to prevent or attenuate aging disorders in various research. Based on the evidence, this review suggests the clinical application of lycopene to improve human health and alleviate the prevalence of aging and aging disorders.

Extracellular Vesicles as Source of Biomarkers in Glomerulonephritis

Kidney disease is a global health and healthcare burden. Glomerulonephritis (Gn), both primary and secondary, is generally characterized by an inflammatory glomerular injury and may lead to end-stage renal disease. Kidney biopsy is fundamental to the diagnosis; however, kidney biopsy presents some concerns that may partly hamper the clinical process. Therefore, more accurate diagnostic tools are needed. Extracellular vesicles (EVs) are membranous vesicles released by cells and found in bodily fluids, including urine. EVs mediate intercellular signaling both in health and disease. EVs can have both harmful and cytoprotective effects in kidney diseases, especially Gn. Previous findings reported that the specific cargo of urinary EV contains an aerobic metabolic ability that may either restore the recipient cell metabolism or cause oxidative stress production. Here, we provide an overview of the most recent proteomic findings on the role of EVs in several aspects of glomerulopathies, with a focus on this metabolic and redox potential. Future studies may elucidate how the ability of EVs to interfere with aerobic metabolism and redox status can shed light on aspects of Gn etiology which have remained elusive so far.

Small Ceria Nanoclusters with High ROS Scavenging Activity and Favorable Pharmacokinetic Parameters for the Amelioration of Chronic Kidney Disease

The over production of reactive oxygen species (ROS) plays a critical role in the progression of chronic kidney disease (CKD). Organic ROS scavengers currently used for CKD treatment do not satisfy low dosage and high efficiency requirements. Ceria nanomaterials featured with renewable ROS scavenging activity are potential candidates for CKD treatment. Herein, a method for the synthesis of ceria nanoclusters (NCs) featured with small size of ≈1.2 nm is reported. The synthesized NCs are modified by three hydrophilic ligands with different molecular weights, including succinic acid (SA), polyethylene glycol diacid 600 (PEG600), and polyethylene glycol diacid 2000 (PEG2000). The surface modified NCs exhibit excellent ROS scavenging activity due to the high Ce3+ /Ce4+ ratio in their crystal structures. Compared with bigger-sized ceria nanoparticles (NPs) (≈45 nm), NCs demonstrate smoother blood concentration-time curve, lower organ accumulation, and faster metabolic rate superiorities. The administration of NCs to CKD mice, especially PEG600 and PEG2000 modified NCs, can effectively inhibit oxidative stress, inflammation, renal fibrosis, and apoptosis in their kidneys. Due to these benefits, the constructed NCs can ameliorate the progression of CKD. These findings suggest that NCs is a potential redox nanomedicine for future clinical treatment of CKD.

Nicotinamide N-Methyl Transferase as a Predictive Marker of Tubular Fibrosis in CKD

Purpose

Chronic kidney disease (CKD) progression is complex. There are not standardized methods for predicting the prognosis of CKD. Nicotinamide N-methyltransferase (NNMT) has been shown to be associated with renal fibrosis. This study aimed to validate NNMT as a prognostic biomarker of progressive CKD.

Patients and Methods

We explored the relationship between NNMT expression and CKD-related outcome variables using the NephroseqV5 and GEO databases. Additionally, a validation set of 37 CKD patients was enrolled to measure the correlation between NNMT expression levels and CKD outcomes. Furthermore, single-cell RNA sequencing data and the Human Protein Atlas were reanalyzed to investigate the expression specificity of NNMT in the kidney. Finally, to detect the status of NNMT expression with tubular fibrosis in vivo, we constructed a unilateral ureteral obstruction (UUO) mouse treated with an NNMT inhibitor.

Results

Analyzing the datasets showed that NNMT was expressed mainly in proximal tubule compartments. And patients with high NNMT expression levels had a significantly lower overall survival rate compared to those with low NNMT expression levels (P = 0.013). NNMT was independent of prognosis factors in the multivariate Cox regression model, and the AUCs for CKD progression at 1, 3, and 5 years were 0.849, 0.775, and 0.877, respectively. Pathway enrichment analysis indicated that NNMT regulates the biological processes of tubulointerstitial fibrosis (TIF). In the validation group, NNMT levels were significantly higher in the CKD group combined with interstitial fibrosis. In vivo, NNMT was a high expression in the UUO group, peaking at postoperative day 21. Treatment with an NNMT inhibitor improved renal tubular interstitial fibrosis, and expression levels of FN, α-SMA, VIM, and TGF-β1 were decreased compared with UUO (P < 0.05).

Conclusion

NNMT was expressed mainly in tubular renal compartments, and associated with CKD prognosis. It holds potential as a diagnostic biomarker for tubular fibrosis in CKD.

Effects of Iranian propolis on renal function, prooxidant-antioxidant balance, metabolic status, and quality of life in patients with chronic kidney disease: A study protocol of an ongoing randomized, double-blind, placebo-controlled clinical trial

Background

Chronic kidney disease (CKD) is a prevalent and progressive disease that is impacted by hyperglycemia, hypertension (HTN), and oxidative stress (OS). Propolis, a natural resinous mixture produced by honeybees from plant materials, has been shown to possess antioxidant, anti-inflammatory, antihyperglycemic, and antihypertensive properties, along with hepato-renal protective effects. This study aims to evaluate the efficacy of propolis supplementation on patients with CKD.

Methods

This multi-centered, randomized, double-blind, placebo-controlled clinical trial will evaluate the effectiveness of propolis supplementation in 44 eligible patients with CKD. Participants will be randomly allocated to receive either propolis capsule (500 mg, containing 125 mg Iranian alcoholic propolis extract) or placebo, twice daily for three months. The primary outcome is improvement in kidney function parameters of CKD patients, while secondary outcomes include changes in prooxidant-antioxidant balance (PAB), glycemic status, quality of life, and blood pressure (BP). The study will be conducted at Tabriz University of Medical Sciences in Tabriz, Iran.

Discussion

If the results of this study reveal remarkable effectiveness of propolis in improving quality of life and clinical outcomes in patients with CKD, this compound may reach a new milestone as an adjunctive therapy for CKD and it opens a new window for further studies.

Trial registration

Iranian Registry of Clinical Trials, IRCT20191218045798N1. Prospectively registered on 07 June 2020. Updated on 30 August 2021. https://en.irct.ir/trial/48603.

The effects of propolis on pro-oxidant-antioxidant balance, glycemic control, and quality of life in chronic kidney disease: a randomized, double-blind, placebo-controlled trial

Chronic kidney disease (CKD) is a progressive kidney damage with an increasing prevalence. Some evidence suggests that propolis as a novel antioxidant, anti-inflammatory, and immunomodulatory agent may have beneficial effects in CKD. The aim of this study was to evaluate the efficacy of propolis on some kidney function parameters, pro-oxidant-antioxidant balance (PAB), glycemic status, quality of life, and blood pressure (BP) in patients with CKD. In this study, 44 patients with CKD were randomly assigned to receive propolis capsules at a dose of 250 mg daily or placebo for three months. Of 44 randomized individuals, 35 completed the trial. At the end of the intervention (end of month three), improvement in some dimensions of health-related quality of life (HRQoL) (derived from Kidney Disease and Quality of Life Short-Form (KDQOL-[Formula: see text], v. 1.3) questionnaire) were significantly higher in the propolis group than the placebo group, even after adjustment for baseline values, present of diabetes, and age (P < 0.05). Like systolic and diastolic BP, changes in serum creatinine, 24-h urine volume and protein, fasting blood sugar (FBS), hemoglobin A1C (HbA1C), insulin, homeostasis model of assessment-insulin resistance (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), and PAB did not differ significantly between the two groups (P > 0.05). No serious adverse events were reported throughout the study. Propolis supplementation may improve the HRQoL of CKD patients. More studies are needed to validate the adjunct use of propolis for metabolic control of CKD patients.

The Interplay between Immune and Metabolic Pathways in Kidney Disease

Kidney disease is a significant health problem worldwide, affecting an estimated 10% of the global population. Kidney disease encompasses a diverse group of disorders that vary in their underlying pathophysiology, clinical presentation, and outcomes. These disorders include acute kidney injury (AKI), chronic kidney disease (CKD), glomerulonephritis, nephrotic syndrome, polycystic kidney disease, diabetic kidney disease, and many others. Despite their distinct etiologies, these disorders share a common feature of immune system dysregulation and metabolic disturbances. The immune system and metabolic pathways are intimately connected and interact to modulate the pathogenesis of kidney diseases. The dysregulation of immune responses in kidney diseases includes a complex interplay between various immune cell types, including resident and infiltrating immune cells, cytokines, chemokines, and complement factors. These immune factors can trigger and perpetuate kidney inflammation, causing renal tissue injury and progressive fibrosis. In addition, metabolic pathways play critical roles in the pathogenesis of kidney diseases, including glucose and lipid metabolism, oxidative stress, mitochondrial dysfunction, and altered nutrient sensing. Dysregulation of these metabolic pathways contributes to the progression of kidney disease by inducing renal tubular injury, apoptosis, and fibrosis. Recent studies have provided insights into the intricate interplay between immune and metabolic pathways in kidney diseases, revealing novel therapeutic targets for the prevention and treatment of kidney diseases. Potential therapeutic strategies include modulating immune responses through targeting key immune factors or inhibiting pro-inflammatory signaling pathways, improving mitochondrial function, and targeting nutrient-sensing pathways, such as mTOR, AMPK, and SIRT1. This review highlights the importance of the interplay between immune and metabolic pathways in kidney diseases and the potential therapeutic implications of targeting these pathways.

Hepato-Nephroprotective Actions of Salvia officinalis Decoction Extract Against Extraintestinal Alterations Induced with Acetic Acid-Colitis Model in Rats

Inflammatory bowel disease is associated with multiple extraintestinal disorders, including hepato-nephrological disruptions. The aim of this study was to evaluate the hepato-nephroprotective effect of Salvia officinalis leaf decoction extract (SLDE) on acetic acid (AA)-induced colitis accompanied with liver and kidney injuries. Wistar albinos rats were pretreated with SLDE (50, 100, and 200 mg kg^-1, b.w., p.o.) during 10 days and intoxicated for 24 h by acute rectal administration of AA (3%, v/v, 5 mL kg^-1, b.w.). Our results showed that S. officinalis treatment protected against AA-induced liver and kidney injuries by plasma transaminase activities and preservation of the hepatic and renal tissue structures. The level of high-density lipoprotein-cholesterol was also reverted back to near normalcy by treatment. Lipid peroxidation was decreased significantly by officinal sage supplementation. Treatment with SLDE increased enzymatic (superoxide dismutase, catalase, and glutathione peroxidase) and nonenzymatic (-SH groups and reduced glutathione) antioxidants in liver and kidney tissues. Also, SLDE treatment significantly protected against inflammation markers and reversed all intracellular mediator perturbations. This study suggests that the S. officinalis has a beneficial effect in controlling kidney and liver injuries by reducing lipid peroxidation and increasing antioxidant enzyme activities and nonenzymatic contents, which reduce the risk of developing extraintestinal complications.

Medicinal and mechanistic overview of artemisinin in the treatment of human diseases

Artemisinin (ART) is a bioactive compound isolated from the plant Artemisia annua and has been traditionally used to treat conditions such as malaria, cancer, viral infections, bacterial infections, and some cardiovascular diseases, especially in Asia, North America, Europe and other parts of the world. This comprehensive review aims to update the biomedical potential of ART and its derivatives for treating human diseases highlighting its pharmacokinetic and pharmacological properties based on the results of experimental pharmacological studies in vitro and in vivo. Cellular and molecular mechanisms of action, tested doses and toxic effects of artemisinin were also described. The analysis of data based on an up-to-date literature search showed that ART and its derivatives display anticancer effects along with a wide range of pharmacological activities such as antibacterial, antiviral, antimalarial, antioxidant and cardioprotective effects. These compounds have great potential for discovering new drugs used as adjunctive therapies in cancer and various other diseases. Detailed translational and experimental studies are however needed to fully understand the pharmacological effects of these compounds.

Moringa oleifera Lam Leaf Extract Stimulates NRF2 and Attenuates ARV-Induced Toxicity in Human Liver Cells (HepG2)

The World Health Organization (WHO) reported that there are 37 million individuals living with the human immunodeficiency virus (HIV) worldwide, with the majority in South Africa. This chronic disease is managed by the effective use of antiretroviral (ARV) drugs. However, with prolonged use, ARV drug-induced toxicity remains a clinically complex problem. This study investigated the toxicity of ARV drugs on mitochondria and the NRF2 antioxidant pathway and its possible amelioration using Moringa oleifera Lam (MO) leaf extracts. This medicinal plant has a range of functional bioactive compounds. Liver (HepG2) cells were treated with individual ARV drugs: Tenofovir disoproxil fumarate (TDF), Emtricitabine (FTC), and Lamivudine (3TC) for 96 h, followed by MO leaf extracts for 24 h. Intracellular ROS, cytotoxicity, lipid peroxidation, total and reduced glutathione (GSH), ATP, and mitochondrial polarisation were determined. Finally, protein (pNRF2, NRF2, SOD2, CAT, and Sirt3) and mRNA (NRF2, CAT, NQO1 SOD2, Sirt3, and PGC1α) expression were measured using Western blot and qPCR, respectively. TDF, FTC, and 3TC significantly increased intracellular ROS and extracellular levels of both MDA and LDH. ARVs also reduced the GSH and ATP levels and altered the mitochondrial polarization. Further, ARVs reduced the expression of NRF2 SOD2, Sirt3, CAT, NQO1, UCP2 and PGC1α mRNA and consequently pNRF2, NRF2, SOD2, Sirt3 and CAT protein. In contrast, there was a significant reduction in the extracellular MDA and LDH levels post-MO treatment. MO significantly reduced intracellular ROS while significantly increasing GSH, ATP, and mitochondrial membrane polarization. The addition of MO to ARV-treated cells significantly upregulated the expression of NRF2, SOD2, Sirt3, CAT, UCP2, PGC1α, and NQO1 mRNA and pNRF2, NRF2, SOD2, Sirt3 proteins. Thus, MO ameliorates ARV-induced hepatotoxicity by scavenging oxidants by inducing the NRF2 antioxidant pathway. MO shows great therapeutic potential and may be considered a potential supplement to ameliorate ARV drug toxicity.

Cytoprotective remedies for ameliorating nephrotoxicity induced by renal oxidative stress

AIMS

Nephrotoxicity is the hallmark of anti-neoplastic drug metabolism that causes oxidative stress. External chemical agents and prescription drugs release copious amounts of free radicals originating from molecular oxidation and unless sustainably scavenged, they stimulate membrane lipid peroxidation and disruption of the host antioxidant mechanisms. This review aims to provide a comprehensive collection of potential cytoprotective remedies in surmounting the most difficult aspect of cancer therapy as well as preventing renal oxidative stress by other means.

MATERIALS AND METHODS

Over 400 published research and review articles spanning several decades were scrutinised to obtain the relevant data which is presented in 3 categories; sources, mechanisms, and mitigation of renal oxidative stress.

KEY-FINDINGS

Drug and chemical-induced nephrotoxicity commonly manifests as chronic or acute kidney disease, nephritis, nephrotic syndrome, and nephrosis. Renal replacement therapy requirements and mortalities from end-stage renal disease are set to rapidly increase in the next decade for which 43 different cytoprotective compounds which have the capability to suppress experimental nephrotoxicity are described.

SIGNIFICANCE

The renal system performs essential homeostatic functions that play a significant role in eliminating toxicants, and its accumulation and recurrence in nephric tissues results in tubular degeneration and subsequent renal impairment. Global statistics of the latest chronic kidney disease prevalence is 13.4 % while the end-stage kidney disease requiring renal replacement therapy is 4-7 million per annum. The remedial compounds discussed herein had proven efficacy against nephrotoxicity manifested consequent to impaired antioxidant mechanisms in preclinical models produced by renal oxidative stress activators.

L-Carnitine alleviates hepatic and renal mitochondrial-dependent apoptotic progression induced by letrozole in female rats through modulation of Nrf-2, Cyt c and CASP-3 signaling

Letrozole (LTZ) is a non-steroidal aromatase inhibitor that is commonly used in breast cancer therapy. It has several side effects that might lead to the drug's cessation and data of LTZ's potential adverse effects on the hepatorenal microenvironment was conflicting. In addition, searching for therapeutic interventions that could modulate its adverse effects will be very beneficial. So, this study aims to determine the impact of LTZ on the hepatorenal microenvironment in cyclic female rats with a proposed regulatory role of L-Carnitine (LC) supplementation giving molecular insights into its possible mechanism of action. LTZ (1 mg/kg using 0.5% carboxy methyl cellulose as a vehicle for 21 consecutive days orally) to assess its impact on hepatorenal microenvironment. After treatment with LC (100 mg/kg orally) for 14 days, hepatorenal redox state (lipid peroxides (MDA), reduced glutathione (GSH) and catalase enzyme (CAT)), as well as relative gene expression of nuclear factor erythroid 2-related factor 2 (Nrf-2), cytochrome-c (Cyt c) and caspase-3 (CASP-3) were evaluated. Histopathological examination and immunohistochemical staining of CASP-3 in both liver and kidney were done. LTZ altered hepatic and renal functions. Relative gene expression of hepatorenal Nrf-2, Cyt c and CASP-3 as well as redox state revealed significant deterioration. Also, the liver and kidney tissues showed several micromorphological changes and intense reaction to CASP-3 upon immunohistochemical staining. It can be concluded that LC alleviates LTZ induced hepatorenal oxidative stress (OS) and mitochondrial-dependent apoptotic progression through modulation of Nrf-2, Cyt c, and CASP-3 signaling in female rats.

Protective effect of spore oil-functionalized nano-selenium system on cisplatin-induced nephrotoxicity by regulating oxidative stress-mediated pathways and activating immune response

In clinical practice, cisplatin is the most commonly used chemotherapy drug to treat a range of malignancies. Severe ROS-regulated nephrotoxicity, however, restricts its applicability. Currently, the main mechanisms leading to cisplatin-induced nephrotoxicity in clinical settings involve hydration or diuresis. However, not all patients can be treated with massive hydration or diuretics. Therefore, it is crucial to develop a treatment modality that can effectively reduce nephrotoxicity through a foodborne route. Selenium has been reported to have strong antioxidant as well as anticancer effects when administered as spore oil. Herein, we established cellular and animal models of cisplatin-induced nephrotoxicity and synthesized spore oil-functionalized nano-selenium (GLSO@SeNPs). We found that GLSO@SeNPs inhibit the mitochondrial apoptotic pathway by maintaining oxidative homeostasis and regulating related signaling pathways (the MAPK, caspase, and AKT signaling pathways). In vivo, GLSO@SeNPs could effectively improve cisplatin-induced renal impairment, effectively maintaining oxidative homeostasis in renal tissues and thus inhibiting the process of renal injury. In addition, GLSO@SeNPs were converted into selenocysteine (SeCys2), which may exert protective effects. Furthermore, GLSO@SeNPs could effectively modulate the ratio of immune cells in kidneys and spleen, reducing the proportions of CD3⁺CD4⁺ T cells, CD3⁺CD8⁺ T cells, and M1 phenotype macrophages and increasing the proportion of anti-inflammatory regulatory T cells. In summary, in this study, we synthesized food-derived spore oil-functionalized nanomaterials, and we explored the mechanisms by which GLSO@SeNPs inhibit cisplatin-induced nephrotoxicity. Our study provides a basis and rationale for the inhibition of cisplatin-induced nephrotoxicity by food-derived nutrients.

Carbamazepine-induced renal toxicity may be associated with oxidative stress and apoptosis in male rat

Carbamazepine (CBZ) is the antiepileptic drug used in epilepsy and some psychiatric disorders. Besides its widely used, many adverse effects have been reported including hematotoxicity, hepatotoxicity, endocrine disorders, and testicular damages due to oxidative stress. However, the role of CBZ on renal toxicity is not fully known. In this study, we attempted to explain the connected mechanisms by focusing on the metabolism of CBZ-induced renal toxicity in rats. Twenty male Wistar-Albino rats were randomized into 2 groups (n = 10); control (1 mL/day distilled water, orally) and CBZ (25 mg/kg/day CBZ, orally) groups. After 60 days, TAS (total oxidant status) and TOS (total oxidant status) levels, histopathological features, some genes involved in apoptosis, 8-hydroxy-2-deoxyguanosine (8-OHdG) activity, and apoptotic cells were assessed of kidney tissue. The oxidative stress index (OSI) was measured from TAS and TOS levels. TOS levels and OSI significantly increased, while TAS levels decreased in the CBZ group relative to the control group. Histopathological observations, Caspase-3 (Casp3), Poly [ADP-ribose] polymerase-1 (PARP-1), 8-OHdG immunoreactivities, and apoptotic cells markedly raised in the CBZ group compared with the control group. Also, mRNA expression of Cytochrome c (Cytc) and CASP3 significantly increased in the CBZ group compared to the control group. In conclusion, long-term use of CBZ may promote renal damage in rats by inducing oxidative stress and apoptosis.

Hemin versus erythropoietin: Possible role in Nrf2/HO-1 signaling pathway in rats with nephrotoxicity

BACKGROUND AND AIM

Gentamycin-induced nephrotoxicity is related to stimulation of oxidative stress and inflammatory cascades leading to apoptotic renal damage. Heme oxygenase-1 (HO-1) induction considered to be an adaptive response against oxidative tissue damage. Our study aimed to investigate the possible nephroprotective role of HO-1 inducers (hemin and erythropoietin (EPO)) and elucidate their potential underlying molecular mechanisms by assessing their antioxidant, anti-apoptotic, and anti-inflammatory properties.

METHODS

Kidney function markers (urea and creatinine), lipid peroxidation and antioxidant markers (MDA and GPx), inflammation and apoptotic markers (IL-6 and Bcl-2), and the relative gene expression levels of Nrf2 and HO-1 were assessed. Histopathological changes of the kidney were examined.

RESULTS

Nephrotoxic rats pretreated with hemin showed significant decrease in serum level of urea, creatinine, and MDA, compared to non-treated group. The kidney tissues also showed significant elevation of Bcl2 level, but significant decrease of IL-6, compared to non-treated group. Moreover, hemin pre-treatment significantly upregulated gene expression of Nrf2 and HO-1 in kidney tissue to near the normal control group. On the other hand, pretreatment with EPO showed significant upregulation of HO-1 gene expression but didn't show significant difference in Nrf2 gene expression compared to control group. The histopathological examination of kidney supported the biochemical results.

CONCLUSION

The current results proved that hemin rather than EPO, showed reno-protective effects in rats, which was mediated by activation of Nrf2 signaling pathway. This could be also attributed to the observed anti-inflammatory, antioxidant, and anti-apoptotic properties of hemin. In this regard, EPO showed lower potency.

Turmeric supplementation with piperine is more effective than turmeric alone in attenuating oxidative stress and inflammation in hemodialysis patients: A randomized, double-blind clinical trial

PURPOSE

Turmeric has renop rotective effects that can act to reduce oxidative stress and inflammation in hemodialysis (HD) patients. Piperine has been indicated as a bioavailability enhancer of turmeric and consequently of its biological effects. However, data on the efficacy of the turmeric/piperine combination in HD patients are limited. We aimed to verify whether turmeric supplementation in combination with piperine has a superior effect to turmeric alone in increasing antioxidant capacity and reducing oxidative stress and inflammation in HD patients.

METHODS

This randomized, double-blind clinical trial was conducted in HD patients (age 20-75 years). Patients were supplemented with turmeric (3 g/day) or turmeric/piperine (3 g turmeric + 2 mg piperine/day) for 12 weeks. Malondialdehyde (MDA), antioxidant enzymes catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), high-sensitivity C-reactive protein (hs-CRP), and ferritin were evaluated at baseline and the end of the study.

RESULTS

There was a reduction in the MDA and ferritin levels in the turmeric/piperine group and in the comparison between groups at the end of the study [MDA: -0.08(-0.14/0.01) nmol/mL versus -0.003(-0.10/0.26) nmol/mL, p = 0.003; ferritin: -193.80 ± 157.29 mg/mL versus 51.99 ± 293.25 mg/mL, p = 0.018]. In addition, GPx activity reduced in the turmeric group (p = 0.029). No changes were observed for CAT, GR, and hs-CRP.

CONCLUSION

Turmeric plus piperine was superior to turmeric alone in decreasing MDA and ferritin levels. The use of a combination of turmeric and piperine as a dietary intervention may be beneficial for modulating the status oxidative and inflammation in HD patients.

BRAZILIAN REGISTRY OF CLINICAL TRIALS NUMBER

RBR-2t5zpd; Registration Date: May 2, 2018.

Asian Pigeonwing Plants (Clitoria ternatea) Synergized Mesenchymal Stem Cells by Modulating the Inflammatory Response in Rats with Cisplatin-Induced Acute Kidney Injury

Acute kidney injury is a heterogeneous set of disorders distinguished by a sudden decrease in the glomerular filtration rate, which is evidenced by an increase in the serum creatinine concentration or oliguria and categorized by stage and cause. It is an ever-growing health problem worldwide, with no reliable treatment. In the present study, we evaluated the role of Clitoria ternatea combined with mesenchymal stem cells in treating cisplatin-induced acute kidney injury in rats. Animals were challenged with cisplatin, followed by 400 mg/kg of Asian pigeonwing extract and/or mesenchymal stem cells (106 cells/150 g body weight). Kidney functions and enzymes were recorded, and histopathological sectioning was also performed. The expression profile of IL-1β, IL-6, and caspase-3 was assessed using the quantitative polymerase chain reaction. The obtained data indicated that mesenchymal stem cells combined with the botanical extract modulated the creatinine uric acid and urea levels. Cisplatin increased the level of malondialdehyde and decreased the levels of both superoxide dismutase and glutathione; however, the dual treatment was capable of restoring the normal levels. Furthermore, all treatments modulated the IL-6, IL-1β, and caspase-3 gene expression profiles. The obtained data shed some light on adjuvant therapy using C. ternatea and mesenchymal stem cells in treating acute kidney injury; however, further investigations are required to understand these agents’ synergistic mechanisms fully. The total RNA was extracted from the control, the positive control, and all of the therapeutically treated animals. The expression profiles of the IL-6, IL-1β, and caspase-3 genes were evaluated using the real-time polymerase chain reaction. Cisplatin treatment caused a significant upregulation in IL-6. All treatments could mitigate the IL-6-upregulating effect of cisplatin, with the mesenchymal stem cell treatment being the most effective. The same profile was observed in the IL-1β and caspase-3 genes, except that the dual treatment (mesenchymal stem cells and the botanical extract) was the most effective in ameliorating the adverse effect of cisplatin; it downregulated caspase-3 expression better than the positive control.

Antioxidant nanozymes for prevention of diseased kidney from failure

Oxidative stress is a state of excessive free radicals and is commonly found with diseased kidneys. Therefore, development of antioxidant-based therapy has been of great interest to biomedical scientists for kidney disease management. One of the drawbacks of using natural antioxidants is their low bioavailability, which limits their anti-free radical efficacy. This commentary discusses novel antioxidant gold-platinum nanoparticles and their potential for prevention of kidney failure in patients who are diagnosed with chronic kidney disease.

Molecular Mechanisms of Cellular Injury and Role of Toxic Heavy Metals in Chronic Kidney Disease

Chronic kidney disease (CKD) is a progressive disease that affects millions of adults every year. Major risk factors include diabetes, hypertension, and obesity, which affect millions of adults worldwide. CKD is characterized by cellular injury followed by permanent loss of functional nephrons. As injured cells die and nephrons become sclerotic, remaining healthy nephrons attempt to compensate by undergoing various structural, molecular, and functional changes. While these changes are designed to maintain appropriate renal function, they may lead to additional cellular injury and progression of disease. As CKD progresses and filtration decreases, the ability to eliminate metabolic wastes and environmental toxicants declines. The inability to eliminate environmental toxicants such as arsenic, cadmium, and mercury may contribute to cellular injury and enhance the progression of CKD. The present review describes major molecular alterations that contribute to the pathogenesis of CKD and the effects of arsenic, cadmium, and mercury on the progression of CKD.

Antioxidant and Anti-Inflammatory Properties of Hydroxyl Safflower Yellow a in Diabetic Nephropathy: A Meta-Analysis of Randomized Controlled Trials

Background: Diabetic kidney disease (DKD) is a chronic progressive disorder which is a leading cause of chronic kidney disease (CKD). As an important pathogenesis of DKD, the overproduction of reactive oxygen species (ROS) and the inflammatory response have been considered central mediators in the progression of DKD. Herbal products are increasingly being applied as antioxidants and anti-inflammatory agents. Of those, the effect of hydroxyl safflower yellow A (HSYA) on oxidative stress and inflammatory reactions has gradually been investigated for DKD treatment, which may provide therapies for DKD with new insights and promote its application in clinical practice.

Methods: We searched CNKI, the Chinese Biomedical Literature Database, the Wanfang Database, PubMed, and Embase from the establishment date of the database to 22 April 2022. The included literature in our study was randomized controlled trials (RCTs) using HSYA to treat DKD. We performed a meta-analysis by calculating the standard mean difference (SMD) with a 95% confidence interval (CI). The inverse-variance method with a random effect was used in our meta-analysis using Stata software and RevMan software.

Results: A total of 31 articles with 31 groups containing a total of 2487 participants were included in this meta-analysis. The pooled results showed a statistical improvement in the following measurements: fasting blood glucose (FBG), postprandial blood glucose (PBG), blood urea nitrogen (BUN), urinary albumin excretion rates (UAER), serum creatinine (SCR), hypersensitive C-reactive protein (hsCRP), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), fasting insulin (FINS), total cholesterol (TC), triglycerides (TGs), hemoglobin A1c (HbA1C), homeostasis model assessment insulin resistance (HOMA-IR), and malondialdehyde (MDA).

Conclusion: HSYA can effectively treat DKD by inhibiting inflammatory reactions and oxidative stress, decreasing blood glucose and blood lipids, and improving renal function indices. However, more RCTs are still needed in the future to further demonstrate the effect of HSYA on biomarkers of oxidative stress and inflammatory reactions in patients with DKD due to the low quality and small sample size of the literature included in this study.

Systematic Review Registration: PROSPERO: CRD 42021235689

Dose-response relationship between dietary inflammatory index and diabetic kidney disease in US adults

OBJECTIVE

The impact of the dietary potential inflammatory effect on diabetic kidney disease (DKD) has not been adequately investigated. The present study aimed to explore the association between dietary inflammatory index (DII) and DKD in US adults.

DESIGN

This is a cross-sectional study.

SETTING

Data from the National Health and Nutrition Examination Survey (2007-2016) were used. DII was calculated from 24-h dietary recall interviews. DKD was defined as diabetes with albuminuria, impaired glomerular filtration rate or both. Logistic regression and restricted cubic spline models were adopted to evaluate the associations.

PARTICIPANTS

Data from the National Health and Nutrition Examination Survey (2007-2016) were used, which can provide the information of participants.

RESULTS

Four thousand two-hundred and sixty-four participants were included in this study. The adjusted OR of DKD was 1·04 (95 % CI 0·81, 1·36) for quartile 2, 1·24 (95 % CI 0·97, 1·59) for quartile 3 and 1·64 (95 % CI 1·24, 2·17) for quartile 4, respectively, compared with the quartile 1 of DII. A linear dose-response pattern was observed between DII and DKD (Pnonlinearity = 0·73). In the stratified analyses, the OR for quartile 4 of DII were significant among adults with higher educational level (OR 1·83, 95 % CI 1·26, 2·66) and overweight or obese participants (OR 1·67, 95 % CI 1·23, 2·28), but not among the corresponding another subgroup. The interaction effects between DII and stratified factors on DKD were not statistically significant (all P values for interactions were >0·05).

CONCLUSIONS

Our findings suggest that a pro-inflammatory diet, shown by a higher DII score, is associated with increased odd of DKD.

Discovering the Potential Value of Coenzyme Q10 in Oxidative Stress: Enlightenment From a Synthesis of Clinical Evidence Based on Various Population

Background: Oxidative stress (OS) is associated with ferroptosis. Coenzyme Q10 (CoQ10), as an adjuvant treatment, has shown to be beneficial against OS. However, the efficacy of CoQ10 as a therapeutic agent against OS has not been promptly updated and systematically investigated.

Methods: A systematic literature search was performed using the Medline, EMBASE, Web of science, Cochrane Central Register of Controlled Trials, CNKI, CBM, Science direct and clinical trial. gov to identify randomized clinical trials evaluating the efficacy of CoQ10 supplementation on OS parameters. Standard mean differences and 95% confidence intervals were calculated for net changes in OS parameters using a random-effects model.

Results: Twenty-one randomized clinical studies met the eligibility criteria to be included in the meta-analysis. Overall, CoQ10 supplementation increased the levels of antioxidant enzymes [including superoxide dismutase (SOD) (SMD = 0.63; 95% CI: 0.38 to 0.88; p < 0.001), catalase (CAT) (SMD = 0.44; 95% CI:0.16 to 0.72; p = 0.002)] significantly and the levels of malondialdehyde (MDA) (SMD = -0.68; 95% CI: 0.93 to -0.43; p < 0.001) was decreased considerably. However, significant associations were not observed between this supplement and total antioxidant capacity (TAC), glutathione peroxidase (GPx) activity.

Conclusion: CoQ10 can improve OS as indicated by statistical significance in CAT and MDA concentrations, as well as SOD activity. Future studies focusing on long-term results and specific valuation of OS parameters are required to confirm the efficacy of CoQ10 on OS. We also believe that with the further research on ferroptosis, CoQ10 will gain more attention.

Systematic Review Registration: [https://inplasy.com/], identifier [INPLASY2021120123].

Renoprotective Effect of Pediococcus acidilactici GKA4 on Cisplatin-Induced Acute Kidney Injury by Mitigating Inflammation and Oxidative Stress and Regulating the MAPK, AMPK/SIRT1/NF-κB, and PI3K/AKT Pathways

Acute kidney injury (AKI) describes a sudden loss of kidney function and is associated with a high mortality. Pediococcus acidilactici is a potent producer of bacteriocin and inhibits the growth of pathogens during fermentation and food storage; it has been used in the food industry for many years. In this study, the potential of P. acidilactici GKA4 (GKA4) to ameliorate AKI was investigated using a cisplatin-induced animal model. First, mice were given oral GKA4 for ten days and intraperitoneally injected with cisplatin on the seventh day to create an AKI mode. GKA4 attenuated renal histopathological alterations, serum biomarkers, the levels of inflammatory mediators, and lipid oxidation in cisplatin-induced nephrotoxicity. Moreover, GKA4 significantly decreased the expression of inflammation-related proteins and mitogen-activated protein kinase (MAPK) in kidney tissues. Eventually, GKA4 also increased the levels of related antioxidant enzymes and pathways. Consistently, sirtuin 1 (SIRT1) upregulated the level of autophagy-related proteins (LC3B, p62, and Beclin1). Further studies are needed to check our results and advance our knowledge of the mechanism whereby PI3K inhibition (wortmannin) reverses the effect of GKA4 on cisplatin-treated AKI. Taken together, GKA4 provides a therapeutic target with promising clinical potential after cisplatin treatment by reducing oxidative stress and inflammation via the MAPK, AMP-activated protein kinase (AMPK)/SIRT1/nuclear factor kappa B (NF-κB), and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) axes.

NADPH oxidase family proteins: signaling dynamics to disease management

Reactive oxygen species (ROS) are pervasive signaling molecules in biological systems. In humans, a lack of ROS causes chronic and extreme bacterial infections, while uncontrolled release of these factors causes pathologies due to excessive inflammation. Professional phagocytes such as neutrophils (PMNs), eosinophils, monocytes, and macrophages use superoxide-generating NADPH oxidase (NOX) as part of their arsenal of antimicrobial mechanisms to produce high levels of ROS. NOX is a multisubunit enzyme complex composed of five essential subunits, two of which are localized in the membrane, while three are localized in the cytosol. In resting phagocytes, the oxidase complex is unassembled and inactive; however, it becomes activated after cytosolic components translocate to the membrane and are assembled into a functional oxidase. The NOX isoforms play a variety of roles in cellular differentiation, development, proliferation, apoptosis, cytoskeletal control, migration, and contraction. Recent studies have identified NOX as a major contributor to disease pathologies, resulting in a shift in focus on inhibiting the formation of potentially harmful free radicals. Therefore, a better understanding of the molecular mechanisms and the transduction pathways involved in NOX-mediated signaling is essential for the development of new therapeutic agents that minimize the hyperproduction of ROS. The current review provides a thorough overview of the various NOX enzymes and their roles in disease pathophysiology, highlights pharmacological strategies, and discusses the importance of computational modeling for future NOX-related studies.

Protective effect of food derived nutrients on cisplatin nephrotoxicity and its mechanism

Platinum-based metal complexes, especially cisplatin (cis-diamminedichloroplatinum II, CDDP), possess strong anticancer properties and a broad anticancer spectrum. However, the clinical application of CDDP has been limited by its side effects including nephrotoxicity, ototoxicity, and neurotoxicity. Furthermore, the therapeutic effects of current clinical protocols are imperfect. Accordingly, it is essential to identify key targets and effective clinical protocols to restrict CDDP-induced nephrotoxicity. Herein, we first analyzed the relevant molecular mechanisms during the process of CDDP-induced nephrotoxicity including oxidative stress, apoptosis, and inflammation. Evidence from current studies was collected and potential targets and clinical protocols are summarized. The evidence indicates an efficacious role of nutrition-based substances in CDDP-induced renal injury.

Lung-kidney interactions and their role in chronic kidney disease-associated pulmonary diseases

Chronic illnesses rarely present in a vacuum, devoid of other complications, and chronic kidney disease is hardly an exception. Comorbidities associated with chronic kidney disease lead to faster disease progression, expedited dialysis dependency, and a higher mortality rate. Although chronic kidney disease is most commonly accompanied by cardiovascular diseases and diabetes, there is clear cross talk between the lungs and kidneys pH balance, phosphate metabolism, and immune system regulation. Our present understanding of the exact underlying mechanisms that contribute to chronic kidney disease-related pulmonary disease is poor. This review summarizes the current research on kidney-pulmonary interorgan cross talk in the context of chronic kidney disease, highlighting various acute and chronic pulmonary diseases that lead to further complications in patient care. Treatment options for patients presenting with chronic kidney disease and lung disease are explored by assessing activated molecular pathways and the body's compensatory response mechanisms following homeostatic imbalance. Understanding the link between the lungs and kidneys will potentially improve health outcomes for patients and guide healthcare professionals to better understand how and when to treat each of the pulmonary comorbidities that can present with chronic kidney disease.

A systematic review and meta-analysis of the association between uric acid levels and chronic kidney disease

The function of uric acid (UA) in the genesis and evolution of chronic kidney disease (CKD) has motivated numerous studies, but the results remain inconclusive. We sought to conduct a systematic review and meta-analysis of cohort studies aiming to analyze the association of UA levels with the incidence and progression of CKD. Pubmed/Medline, Lilacs/Bireme and Web of Science were searched to identify eligible studies, following the PRISMA protocol. Data were presented for CKD incidence and progression separately. For the meta-analysis, studies with data stratified by subgroups according to serum UA levels were selected. The inverse variance-weighted random effects model was used to generate a combined effect estimate. Meta-regressions were performed to identify the causes of heterogeneity. The Newcastle-Ottawa Scale was used to assess the risk of bias. The publication bias was tested by funnel plot and Egger's test. Eighteen CKD incidence studies (n = 398,663) and six CKD progression studies (n = 13,575) were included. An inverse relationship was observed between UA levels and protection from CKD incidence and progression. Lower UA levels were protective for the risk of CKD incidence (RR 0.65 [95% CI 0.56-0.75]) and progression (RR 0.55 [95% CI 0.44-0.68]). UA seems to be implicated both in the genesis of CKD and its evolution.

Paeoniflorin Ameliorates Skeletal Muscle Atrophy in Chronic Kidney Disease via AMPK/SIRT1/PGC-1α-Mediated Oxidative Stress and Mitochondrial Dysfunction

Skeletal muscle atrophy is a common and serious complication of chronic kidney disease (CKD). Oxidative stress and mitochondrial dysfunction are involved in the pathogenesis of muscle atrophy. The aim of this study was to explore the effects and mechanisms of paeoniflorin on CKD skeletal muscle atrophy. We demonstrated that paeoniflorin significantly improved renal function, calcium/phosphorus disorders, nutrition index and skeletal muscle atrophy in the 5/6 nephrectomized model rats. Paeoniflorin ameliorated the expression of proteins associated with muscle atrophy and muscle differentiation, including muscle atrophy F-box (MAFbx/atrogin-1), muscle RING finger 1 (MuRF1), MyoD and myogenin (MyoG). In addition, paeoniflorin modulated redox homeostasis by increasing antioxidant activity and suppressing excessive accumulation of reactive oxygen species (ROS). Paeoniflorin alleviated mitochondrial dysfunction by increasing the activities of electron transport chain complexes and mitochondrial membrane potential. Furthermore, paeoniflorin also regulates mitochondrial dynamics. Importantly, paeoniflorin upregulated the expression of silent information regulator 1 (SIRT1), peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), and phosphorylation of AMP-activated protein kinase (AMPK). Similar results were observed in C2C12 myoblasts treated with TNF-α and paeoniflorin. Notably, these beneficial effects of paeoniflorin on muscle atrophy were abolished by inhibiting AMPK and SIRT1 and knocking down PGC-1α. Taken together, this study showed for the first time that paeoniflorin has great therapeutic potential for CKD skeletal muscle atrophy through AMPK/SIRT1/PGC-1α-mediated oxidative stress and mitochondrial dysfunction.

A Rheostat of Ceramide and Sphingosine-1-Phosphate as a Determinant of Oxidative Stress-Mediated Kidney Injury

Reactive oxygen species (ROS) modulate sphingolipid metabolism, including enzymes that generate ceramide and sphingosine-1-phosphate (S1P), and a ROS-antioxidant rheostat determines the metabolism of ceramide-S1P. ROS induce ceramide production by activating ceramide-producing enzymes, leading to apoptosis, while they inhibit S1P production, which promotes survival by suppressing sphingosine kinases (SphKs). A ceramide-S1P rheostat regulates ROS-induced mitochondrial dysfunction, apoptotic/anti-apoptotic Bcl-2 family proteins and signaling pathways, leading to apoptosis, survival, cell proliferation, inflammation and fibrosis in the kidney. Ceramide inhibits the mitochondrial respiration chain and induces ceramide channel formation and the closure of voltage-dependent anion channels, leading to mitochondrial dysfunction, altered Bcl-2 family protein expression, ROS generation and disturbed calcium homeostasis. This activates ceramide-induced signaling pathways, leading to apoptosis. These events are mitigated by S1P/S1P receptors (S1PRs) that restore mitochondrial function and activate signaling pathways. SphK1 promotes survival and cell proliferation and inhibits inflammation, while SphK2 has the opposite effect. However, both SphK1 and SphK2 promote fibrosis. Thus, a ceramide-SphKs/S1P rheostat modulates oxidant-induced kidney injury by affecting mitochondrial function, ROS production, Bcl-2 family proteins, calcium homeostasis and their downstream signaling pathways. This review will summarize the current evidence for a role of interaction between ROS-antioxidants and ceramide-SphKs/S1P and of a ceramide-SphKs/S1P rheostat in the regulation of oxidative stress-mediated kidney diseases.

Evaluation of Homocysteine and Gamma-Glutamyl Transferase Concentrations As Markers of Chronic Kidney Disease: An Indian Perspective

Background

Chronic kidney disease (CKD) involves a gradual loss of kidney function over months to years. Oxidative stress plays a critical role in the pathogenesis of CKD. Homocysteine (Hcy), an amino acid derivative, is a known risk factor for oxidative stress and endothelial damage. Gamma-glutamyl transferase (GGT), an enzyme abundant on the cell surface of liver and kidney cells, is raised during oxidative stress. The objectives of this study were to estimate the concentrations of serum Hcy and GGT among CKD patients and healthy controls and to determine whether there is an association between serum Hcy and GGT levels in CKD.

Methodology

A total of 246 participants were needed to meet the calculated sample size. A total of 123 CKD patients meeting the inclusion and exclusion criteria were recruited as cases from the Nephrology outpatient department of our institute. Equal numbers of age- and sex-matched healthy volunteers were recruited as controls. Biophysical profiling of participants was done. Baseline investigations were recorded. A blood sample was collected from each participant and analyzed for GGT and Hcy along with other routine parameters.

Results

Hcy and GGT concentrations were significantly high in CKD patients compared to healthy controls. There was a significant positive correlation between serum GGT and Hcy levels (r = 0.357).

Conclusions

Elevated levels of GGT and Hcy in CKD patients compared to healthy controls demonstrated the oxidative stress associated with the disease. GGT and Hcy can be used as prognostic markers of the disease.

Early Effects of Extracellular Vesicles Secreted by Adipose Tissue Mesenchymal Cells in Renal Ischemia Followed by Reperfusion: Mechanisms Rely on a Decrease in Mitochondrial Anion Superoxide Production

Acute kidney injury (AKI) caused by ischemia followed by reperfusion (I/R) is characterized by intense anion superoxide (O₂^•−) production and oxidative damage. We investigated whether extracellular vesicles secreted by adipose tissue mesenchymal cells (EVs) administered during reperfusion can suppress the exacerbated mitochondrial O₂^•− formation after I/R. We used Wistar rats subjected to bilateral renal arterial clamping (30 min) followed by 24 h of reperfusion. The animals received EVs (I/R + EVs group) or saline (I/R group) in the kidney subcapsular space. The third group consisted of false-operated rats (SHAM). Mitochondria were isolated from proximal tubule cells and used immediately. Amplex Red™ was used to measure mitochondrial O₂^•− formation and MitoTracker™ Orange to evaluate inner mitochondrial membrane potential (Δψ). In vitro studies were carried out on human renal proximal tubular cells (HK-2) co-cultured or not with EVs under hypoxic conditions. Administration of EVs restored O₂^•− formation to SHAM levels in all mitochondrial functional conditions. The gene expression of catalase and superoxide dismutase-1 remained unmodified; transcription of heme oxygenase-1 (HO-1) was upregulated. The co-cultures of HK-2 cells with EVs revealed an intense decrease in apoptosis. We conclude that the mechanisms by which EVs favor long-term recovery of renal structures and functions after I/R rely on a decrease of mitochondrial O₂^•− formation with the aid of the upregulated antioxidant HO-1/Nuclear factor erythroid 2-related factor 2 system, thus opening new vistas for the treatment of AKI.