Acute toxic kidney injury

Chronic Kidney Disease of Unknown Etiology: A Global Health Threat in Rural Agricultural Communities-Prevalence, Suspected Causes, Mechanisms, and Prevention Strategies

Chronic Kidney Disease of Unknown Etiology (CKDu) is a worldwide hidden health threat that is associated with progressive loss of kidney functions without showing any initial symptoms until reaching end-stage renal failure, eventually leading to death. It is a growing health problem in Asia, Central America, Africa, and the Middle East, with identified hotspots. CKDu disease mainly affects young men in rural farming communities, while its etiology is not related to hypertension, kidney stones, diabetes, or other known causes. The main suspected causal factors are heat-stress, dehydration, exposure to agrochemicals, heavy metals and use of hard water, infections, mycotoxins, nephrotoxic agents, altitude, and genetic factors. This review gives an overview of CKDu and sheds light on its medical history, geographic distribution, and worldwide prevalence. It also summarizes the suspected causal factors, their proposed mechanisms of action, as well as the main methods used in the CKDu prior detection and surveillance. In addition, mitigation measures to reduce the burden of CKDu are also discussed. Further investigation utilizing more robust study designs would provide a better understanding of the risk factors linked to CKDu and their comparison between affected regions.

Effect of mitochondrial coenzyme-Q10 precursor solanesol in gentamicin-induced experimental nephrotoxicity: Evidence from restoration of ETC-complexes and histopathological alterations

Nephrotoxicity occurs when the body is exposed to certain drugs or toxins. When kidney damage occurs, the kidney fails to eliminate excess urine and waste. Solanesol (C45H74O) is a tri-sesquiterpenoid alcohol first isolated from tobacco, and it is widely distributed in plants of the Solanaceae family. Solanesol (SNL) is an intermediate in the synthesis of coenzyme Q10 (CoQ10), an antioxidant which protects nerve cells. This study investigated the protective effect of SNL at doses of 30 and 60 mg/kg in gentamicin-induced nephrotoxicity in Wistar albino rats. Animals were distributed into six groups and administered 100 mg/kg gentamicin-intraperitoneal injection for 14 days. Biochemical assessments were performed on kidney homogenate, blood, and serum. Treatment with SNL was shown as lower serum levels of creatinine, blood urea nitrogen (BUN), thiobarbituric acid reactive substances (TBARS), and Tumor necrosis factor alpha)TNF-α ((p < .001). It also restored reduced glutathione (GSH) and mitochondrial complex enzymatic activity as protective measures against gentamicin-induced nephrotoxicity. SNL were shown to reduce inflammation and oxidative stress markers (p < .001). Histological findings furtherly augmented the protective effects of SNL. Long-term SNL therapy also restored mitochondrial electron transport chain complex enzymes, such as complex-I (p < .001). In conclusion, these findings suggest that SNL can represent a protective therapeutic option for drug-induced nephrotoxicity, a long-term adverse effect of aminoglycoside antibiotics such as gentamicin.

Poisoning-Induced Acute Kidney Injury: A Review

Acute kidney injury (AKI) is a debilitating, multi-etiological disease that is commonly seen in clinical practice and in the emergency department. In this review, we introduce the definition, symptoms, and causes of poisoning-related AKI; we also discuss its mechanisms, risk factors, and epidemiology, as well as elaborate on the relevant laboratory tests. Subsequently, we discuss the treatment strategies for toxin- and substance-related AKI caused by Glafenin, antimicrobial agents, lithium, contrast media, snake venom, herbicides, ethylene glycol, synthetic cannabinoids, cocaine, heroin, and amphetamines. Finally, for a comprehensive overview of poisoning-related AKI, we review the management, prevention, and outcomes of this condition.

Association of Acute Kidney Injury with Ammonia Poisoning: A Case Report

Ammonia may cause poisoning due to inhalation or ingestion. Renal involvement in ammonia poisoning has been reported only once. A 30-year-old male working in an ice factory was accidentally exposed to liquid ammonia from a leaking hose, following which he had burns over his face and neck and severe abdominal pain. On day 2, he had deranged renal function, which was progressive. He was referred to us due to persistent renal dysfunction. A kidney biopsy was performed due to slow recovery of renal failure, which was suggestive of acute tubular necrosis. He was managed conservatively and showed gradual improvement over 12 days of his hospital stay. Renal functions normalized after 14 days of discharge. This case highlights the occurrence of renal involvement in ammonia poisoning.

Hump-Nosed Pit Viper (Hypnale hypnale) Venom-Induced Irreversible Red Blood Cell Aggregation, Inhibition by Monovalent Anti-Venom and N-Acetylcysteine

Envenomation by the Hypnale hypnale in the Western Ghats of India (particularly in the Malabar region of Kerala) and the subcontinent island nation of Sri Lanka is known to inflict devastating mortality and morbidity. Currently, H. hypnale bites in India are devoid of anti-venom regimens. A detailed characterization of the venom is essential to stress the need for therapeutic anti-venom. Notably, the deleterious effects of this venom on human blood cells have largely remained less explored. Therefore, in continuation of our previous study, in the present study, we envisioned investigating the effect of venom on the morphological and physiological properties of red blood cells (RBCs). The venom readily induced deleterious morphological changes and, finally, the aggregation of washed RBCs. The aggregation process was independent of the ROS and the intracellular Ca2+ ion concentration. Confocal and scanning electron microscopy (SEM) images revealed the loss of biconcave morphology and massive cytoskeletal disarray. Crenation or serrated plasma membrane projections were evenly distributed on the surface of the RBCs. The venom did not cause the formation of methemoglobin in washed RBCs but was significantly induced in whole blood. Venom did not affect glucose uptake and Na+/K+ -ATPase activity but inhibited glucose 6 phosphate dehydrogenase activity and decreased the fluidity of the plasma membrane. Venom-induced RBC aggregates exhibited pro-coagulant activity but without affecting platelet aggregation. In pre-incubation or co-treatment studies, none of the bioactive compounds, such as melatonin, curcumin, fisetin, berberine, and quercetin, sugars such as mannose and galactose, and therapeutic polyvalent anti-venoms (Bharat and VINS) were inhibited, whereas only N-acetylcysteine and H. hypnale monovalent anti-venom could inhibit venom-induced deleterious morphological changes and aggregation of RBCs. In post-treatment studies, paradoxically, none of the bioactives and anti-venoms, including N-acetylcysteine and H. hypnale monovalent anti-venom, reversed the venom-induced RBC aggregates.

Construction of a mortality risk prediction model for patients with acute diquat poisoning based on clinically accessible data

BACKGROUND

To examine the risk factors associated with mortality in individuals suffering from acute diquat poisoning and to develop an effective prediction model using clinical data.

METHODS

A retrospective review was conducted on the clinical records of 107 individuals who were hospitalized for acute diquat poisoning at a tertiary hospital in Sichuan Province between January 2017 and September 30, 2023, and further categorized into survivor and nonsurvivor groups based on their mortality status within 30 days of poisoning. The patient's demographic information, symptoms within 24 h of admission, and details of the initial clinical ancillary examination, as well as the APACHE II score, were documented. The model was developed using backward stepwise logistic regression, and its performance was assessed using receiver operating characteristic curves, calibration curves, Brier scores, decision curve analysis curves, and bootstrap replicates for internal validation.

RESULTS

Multifactorial logistic regression analysis revealed that blood pressure (hypertension, OR 19.73, 95% CI 5.71-68.16; hypotension, OR 61.38, 95% CI 7.40-509.51), white blood count (OR 1.35, 95% CI 1.20-1.52), red cell distribution width-standard deviation (OR 1.22, 95% CI 1.08-1.38), and glomerular filtration rate (OR 0.96, 95% CI 0.94-0.97) were identified as independent risk factors for mortality in patients with diquat. Subsequently, a nomogram with an area under the curve of 0.97 (95% CI: 0.93-1) was developed. Internal bootstrap resampling (1000 repetitions) confirmed the model's adequate discriminatory power, with an area under the curve of 0.97. Decision curve analysis demonstrated greater net gains for the nomogram, while the clinical impact curves indicated greater predictive validity.

CONCLUSION

The nomogram model developed in this study using available clinical data enhances the prediction of risk for DQ patients and has the potential to provide valuable clinical insights to guide patient treatment decisions.

Di (2-ethylhexyl) phthalate induced lipophagy-related renal ferroptosis in quail (Coturnix japonica)

Di(2-ethylhexyl) phthalate (DEHP) is a synthetic chemical applied as a plasticizer. As an environmental toxicant, DEHP poses a serious health threat. Many studies have revealed that DEHP can cause lead to various degrees of damage to the kidney. However, the evidence of DEHP-induced renal ferroptosis has not been reported. The purpose of this work was to probe the specific role of lipophagy in DEHP-induced renal injury and to investigate the relationship between lipophagy and ferroptosis. Quail were treated with DEHP (250 mg/kg BW/day, 500 mg/kg BW/day and 750 mg/kg BW/day) for 45 days. Microstructural and ultrastructural observations showed that DEHP caused damage to glomerular and tubular cells, and autophagy with multilayer structures were observed, suggesting that DEHP can induce lipophagy. The results indicated that the iron homeostasis was abnormal and the lipid peroxidation was increased. SLC7A11 and SLC3A2 were down-regulated. PTGS2, ACSL4 and LPCAT3 were elevated. In conclusion, DEHP could induce lipid peroxidation, lead to ferroptosis, and damage renal cells. Therefore, the relationship between lipophagy and ferroptosis was elucidated, which provided a new basis for intervention and prevention of DEHP increased diseases.

Incidence and predictors of acute kidney injury after elective surgery for lumbar degenerative disease: A 13-year analysis of the US Nationwide Inpatient Sample

BACKGROUND

Acute kidney injury (AKI) is a severe postoperative complication associated with poor clinical outcomes, including the development of chronic kidney disease (CKD) and death. This study aimed to investigate the incidence and determinants of AKI following elective surgeries for degenerative lumbar spine disease.

METHODS

All patient data were extracted from the US Nationwide Inpatient Sample database. After surgery, AKI's incidence and risk factors were identified for lumbar degenerative disease. ICD-9 and ICD-10 codes defined lumbar spine degenerative disease, fusion, decompression, and AKI. The study cohort was categorized by type of surgery, that is, decompression alone or spinal fusion. Regression analysis was used to identify associations between AKI and risk factors organized by surgery type.

RESULTS

The incidence of AKI after decompression or fusion was 1.1% and 1.8%, respectively. However, the incidence of AKI in the United States is rising. The strongest predictor of AKI was underlying CKD, which was associated with an 9.0- to 12.9-fold more significant risk of AKI than in subjects without comorbid CKD. In this setting, older age, congestive heart failure, anemia, obesity, coagulopathy and hospital-acquired infections were also strong predictors of AKI. In contrast, long-term aspirin/anticoagulant usage was associated with lowered AKI risk.

CONCLUSION

Findings of this study inform risk stratification for AKI and may help to optimize treatment decisions and care planning after elective surgery for lumbar degenerative disease.

Acute Oral Toxicological Profile of Croton membranaceus Mull. Arg. Aqueous Stem Extract, a Herbal Treatment for Benign Prostate Hyperplasia, in Male Sprague-Dawley Rats

Croton membranaceus Mull. Arg. is a traditional medicinal plant frequently employed in Ghana for the treatment of benign prostatic hyperplasia and prostate cancer. The objective of this study was to determine the acute oral toxicity of the aqueous stem extract of Croton membranaceus (CMASE) in male Sprague-Dawley (S-D) rats. The acute toxicity of CMASE was evaluated using S-D rats randomly divided into four groups of five animals each. Three groups (low dose, median dose, and high dose) of rats received single oral doses of CMASE (1000, 2500, and 5000 mg/kg body weight, respectively) using an oral gavage. The control group was given distilled water. After 14 days of daily observations, hematological, biochemical, and histopathological analyses were conducted on the rats. From the results obtained, doses of CMASE up to 5000 mg/kg did not cause death or induce any clinical indications of toxicity during the study period. Also, the mean body weight and the hematological indices assessed were not significantly affected by the various doses of CMASE compared to the control group. However, serum uric acid and creatinine levels decreased significantly (p < 0.001) 14 days after the extract administration. Serum liver function enzyme levels, including alkaline phosphatase (ALP), alanine aminotransferases (ALT), and aspartate aminotransferases (AST), and serum proteins (total proteins and albumin) exhibited significant (p < 0.001) non dose-dependent changes (increases and decreases) in treated groups compared to the controls. Other biochemical indices, however, did not differ significantly between the treated groups and the controls. The gross pathological and histological analysis of the heart, liver, and kidney tissues did not reveal any significant changes in histoarchitecture. The oral LD50 of CMASE in rats was greater than 5000 mg/kg, indicating that the extract was relatively safe. It must, however, be used with care as a substitute for the roots.

Acute kidney injury comorbidity analysis based on international classification of diseases-10 codes

OBJECTIVE

Acute kidney injury (AKI) is a clinical syndrome that occurs as a result of a dramatic decline in kidney function caused by a variety of etiological factors. Its main biomarkers, serum creatinine and urine output, are not effective in diagnosing early AKI. For this reason, this study provides insight into this syndrome by exploring the comorbidities of AKI, which may facilitate the early diagnosis of AKI. In addition, organ crosstalk in AKI was systematically explored based on comorbidities to obtain clinically reliable results.

METHODS

We collected data from the Medical Information Mart for Intensive Care-IV database on patients aged [Formula: see text] 18 years in intensive care units (ICU) who were diagnosed with AKI using the criteria proposed by Kidney Disease: Improving Global Outcomes. The Apriori algorithm was used to mine association rules on the diagnoses of 55,486 AKI and non-AKI patients in the ICU. The comorbidities of AKI mined were validated through the Electronic Intensive Care Unit database, the Colombian Open Health Database, and medical literature, after which comorbidity results were visualized using a disease network. Finally, organ diseases were identified and classified from comorbidities to investigate renal crosstalk with other distant organs in AKI.

RESULTS

We found 579 AKI comorbidities, and the main ones were disorders of lipoprotein metabolism, essential hypertension, and disorders of fluid, electrolyte, and acid-base balance. Of the 579 comorbidities, 554 were verifiable and 25 were new and not previously reported. In addition, crosstalk between the kidneys and distant non-renal organs including the liver, heart, brain, lungs, and gut was observed in AKI with the strongest heart-kidney crosstalk, followed by lung-kidney crosstalk.

CONCLUSION

The comorbidities mined in this study using association rules are scientific and may be used for the early diagnosis of AKI and the construction of AKI predictive models. Furthermore, the organ crosstalk results obtained through comorbidities may provide supporting information for the management of short- and long-term treatment practices for organ dysfunction.

Molecular Mechanisms of Oxidative Stress in Acute Kidney Injury: Targeting the Loci by Resveratrol

Reactive oxygen species are a group of cellular molecules that stand as double-edged swords, their good and bad being discriminated by a precise balance. Several metabolic reactions in the biological system generate these molecules that interact with cellular atoms to regulate functions ranging from cell homeostasis to cell death. A prooxidative state of the cell concomitant with decreased clearance of such molecules leads to oxidative stress, which contributes as a prime pathophysiological mechanism in various diseases including renal disorders, such as acute kidney injury. However, targeting the generation of oxidative stress in renal disorders by an antioxidant, resveratrol, is gaining considerable therapeutic importance and is known to improve the condition in preclinical studies. This review aims to discuss molecular mechanisms of oxidative stress in acute kidney injury and its amelioration by resveratrol. The major sources of data were PubMed and Google Scholar, with studies from the last five years primarily included, with significant earlier data also considered. Mitochondrial dysfunction, various enzymatic reactions, and protein misfolding are the major sources of reactive oxygen species in acute kidney injury, and interrupting these loci of generation or intersection with other cellular components by resveratrol can mitigate the severity of the condition.

A bibliometric analysis of publications in Renal Failure in the last three decades

Publications in Renal Failure in Science Citation Index Expanded (SCI-EXPANDED) between 1992 and 2021 were analyzed. Six publication indicators: total, independent, collaborative, first author, corresponding author, and single author publications as well as their related citation indicators, were used to compare performances of countries, institutes, and authors. Comparison of the highly cited papers and journal's impact factor (IF) contributors was discussed. In addition, the main research topics in the journal were presented. Results show that China published the most total articles and reviews, as well as the first-author papers and corresponding-author papers in the journal. The Chang Gung Memorial Hospital in Taiwan ranked the top in five publication indicators: total, single-institution, inter-institutionally collaborative, first author, and corresponding-author papers. A low percentage of productive authors emerged as a journal IF contributor. Similarly, only a limited relationship between highly cited papers and IF contributing papers was found. Publications related to hemodialysis, chronic kidney disease, and acute kidney injury were the most popular topic, while meta-analysis was new focus in the last decade in the journal.

Nephrotoxicity Development of a Clinical Decision Support System Based on Tree-Based Machine Learning Methods to Detect Diagnostic Biomarkers from Genomic Data in Methotrexate-Induced Rats

Background: The purpose of this study was to carry out the bioinformatic analysis of lncRNA data obtained from the genomic analysis of kidney tissue samples taken from rats with nephrotoxicity induced by methotrexate (MTX) and from rats without pathology and modeling with the tree-based machine learning method. Another aim of the study was to identify potential biomarkers for the diagnosis of nephrotoxicity and to provide a better understanding of the nephrotoxicity formation process by providing the interpretability of the model with explainable artificial intelligence methods as a result of the modeling. Methods: To identify potential indicators of drug-induced nephrotoxicity, 20 female Wistar albino rats were separated into two groups: MTX-treated and the control. Kidney tissue samples were collected from the rats, and genomic, histological, and immunohistochemical analyses were performed. The dataset obtained as a result of genomic analysis was modeled with random forest (RF), a tree-based method. Modeling results were evaluated with sensitivity (Se), specificity (Sp), balanced accuracy (B-Acc), negative predictive value (Npv), accuracy (Acc), positive predictive value (Ppv), and F1-score performance metrics. The local interpretable model-agnostic annotations (LIME) method was used to determine the lncRNAs that could be biomarkers for nephrotoxicity by providing the interpretability of the RF model. Results: The outcomes of the histological and immunohistochemical analyses conducted in the study support the conclusion that MTX use caused kidney injury. According to the results of the bioinformatics analysis, 52 lncRNAs showed different expressions in the groups. As a result of modeling with RF for lncRNAs selected with Boruta variable selection, the B-Acc, Acc, Sp, Se, Npv, Ppv, and F1-score were 88.9%, 90%, 90.9%, 88.9%, 90.9%, 88.9%, and 88.9%, respectively. lncRNAs with id rnaXR_591534.3 rnaXR_005503408.1, rnaXR_005495645.1, rnaXR_001839007.2, rnaXR_005492056.1, and rna_XR_005492522.1. The lncRNAs with the highest variable importance values produced from RF modeling can be used as nephrotoxicity biomarker candidates. Furthermore, according to the LIME results, the high level of lncRNAs with id rnaXR_591534.3 and rnaXR_005503408.1 particularly increased the possibility of nephrotoxicity. Conclusions: With the possible biomarkers resulting from the analyses in this study, it can be ensured that the procedures for the diagnosis of drug-induced nephrotoxicity can be carried out easily, quickly, and effectively.

Safety Assessment of a Nucleoside Analogue FNC (2'-deoxy-2'- β-fluoro-4'-azidocytidine ) in Balb/c Mice: Acute Toxicity Study

OBJECTIVES

The present study aimed to provide an insight into the acute toxicity of a novel fluorinated nucleoside analogue (FNA), FNC (Azvudine or2'-deoxy-2'-β-fluoro-4'-azidocytidine). FNC showed potent anti-viral and anti-cancer activities and approved drug for high-load HIV patients, despite, its acute toxicity study being lacking.

MATERIALS AND METHODS

OECD-423 guidelines were followed during this study and the parameters were divided into four categories - behavioral parameters, physiological parameters, histopathological parameters, and supplementary tests. The behavioral parameters included feeding, body weight, belly size, organ weight and size, and mice behavior. The physiological parameters consisted of blood, liver, and kidney indicators. In histopathological parameters hematoxylin and eosin staining was performed to analyse the histological changes in the mice organs after FNC exposure. In addition, supplementary tests were conducted to assess cellular viability, DNA fragmentation and cytokine levels (IL-6 and TNF-α) in response to FNC.

RESULTS

In the behavioral parameters FNC induced changes in the mice-to-mice interaction and activities. Mice's body weight, belly size, organ weight, and size remained unchanged. Physiological parameters of blood showed that FNC increased the level of WBC, RBC, Hb, and neutrophils and decreased the % count of lymphocytes. Liver enzymes SGOT (AST), and ALP was increased. In the renal function test (RFT) cholesterol level was significantly decreased. Histopathological analysis of the liver, kidney, brain, heart, lungs, and spleen showed no sign of tissue damage at the highest FNC dose of 25 mg/kg b.wt. Supplementary tests for cell viability showed no change in viability footprint, through our recently developed dilution cum-trypan (DCT) assay, and Annexin/PI. No DNA damage or apoptosis was observed in DAPI or AO/EtBr studies. Pro-inflammatory cytokines IL-6 and TNF-α increased in a dose-dependent manner.

CONCLUSION

This study concluded that FNC is safe to use though higher concentration shows slight toxicity.

Artificial intelligence and machine learning disciplines with the potential to improve the nanotoxicology and nanomedicine fields: a comprehensive review

The use of nanomaterials in medicine depends largely on nanotoxicological evaluation in order to ensure safe application on living organisms. Artificial intelligence (AI) and machine learning (MI) can be used to analyze and interpret large amounts of data in the field of toxicology, such as data from toxicological databases and high-content image-based screening data. Physiologically based pharmacokinetic (PBPK) models and nano-quantitative structure-activity relationship (QSAR) models can be used to predict the behavior and toxic effects of nanomaterials, respectively. PBPK and Nano-QSAR are prominent ML tool for harmful event analysis that is used to understand the mechanisms by which chemical compounds can cause toxic effects, while toxicogenomics is the study of the genetic basis of toxic responses in living organisms. Despite the potential of these methods, there are still many challenges and uncertainties that need to be addressed in the field. In this review, we provide an overview of artificial intelligence (AI) and machine learning (ML) techniques in nanomedicine and nanotoxicology to better understand the potential toxic effects of these materials at the nanoscale.

Multi-Omics Analyses Reveal the Mechanisms of Early Stage Kidney Toxicity by Diquat

Diquat (DQ), a widely used bipyridyl herbicide, is associated with significantly higher rates of kidney injuries compared to other pesticides. However, the underlying molecular mechanisms are largely unknown. In this study, we identified the molecular changes in the early stage of DQ-induced kidney damage in a mouse model through transcriptomic, proteomic and metabolomic analyses. We identified 869 genes, 351 proteins and 96 metabolites that were differentially expressed in the DQ-treated mice relative to the control mice (p < 0.05), and showed significant enrichment in the PPAR signaling pathway and fatty acid metabolism. Hmgcs2, Cyp4a10, Cyp4a14 and Lpl were identified as the major proteins/genes associated with DQ-induced kidney damage. In addition, eicosapentaenoic acid, linoleic acid, palmitic acid and (R)-3-hydroxybutyric acid were the major metabolites related to DQ-induced kidney injury. Overall, the multi-omics analysis showed that DQ-induced kidney damage is associated with dysregulation of the PPAR signaling pathway, and an aberrant increase in Hmgcs2 expression and 3-hydroxybutyric acid levels. Our findings provide new insights into the molecular basis of DQ-induced early kidney damage.

Nephroprotective plant species used in traditional Mayan Medicine for renal-associated diseases

ETHNOPHARMACOLOGICAL RELEVANCE

The prevalence of kidney disease has increased rapidly in recent years and has emerged as one of the leading causes of mortality worldwide. Natural products have been suggested as valuable nephroprotective agents due to their multi-target and synergistic effects on modulating important proteins involved in kidney injury. There is a large number of plant species that have been used traditionally for kidney-related conditions in Mesoamerican medicine by different cultural groups that could provide a valuable source of nephroprotective therapeutic candidates and could lead to potential drug discovery.

AIM OF REVIEW

This review aims to provide an overview of the currently known efficacy of plant species used traditionally in Mesoamerica by Mayan groups to treat kidney-related conditions and to analyze the phytochemical, pharmacological, molecular, toxicological, and clinical evidence to contribute to public health efforts and for directing future research.

METHODS

Primary sources of plant use reports for traditional kidney-related disorders in Mesoamerica were searched systematically from library catalogs, theses, and scientific databases (PubMed, Google Scholar; and Science Direct), and were filtered according to usage frequency in Mayan groups and plant endemism. The database of traditional plants was further analyzed based on associations with published reports of the phytochemical, pharmacological, molecular, toxicological, and clinical evidence.

RESULTS

The most reported kidney-related conditions used traditionally in Mayan medicine involve reducing renal damage (a cultural interpretation that considers an inflammatory or infectious condition), cleaning or purifying the blood and kidney, reducing kidney pain, and eliminating kidney stones. A total of 208 plants used for kidney-related problems by 10 Mayan groups were found, representing 143 native species, where only 42 have reported pharmacological activity against kidney damage, mainly approached by in vitro and in vivo models of chemical- or drug-induced nephrotoxicity, diabetes nephropathy, and renal injury produced by hypertension. Nephroprotective effects are mainly mediated by reducing oxidative stress, inflammatory response, fibrosis mechanisms, and apoptosis in the kidney. The most common nephroprotective compounds associated with traditional Mayan medicine were flavonoids, terpenoids, and phenolic acids. The most widely studied traditional plants in terms of pharmacological evidence, bioactive compounds, and mechanisms of action, are Annona muricata L., Carica papaya L., Ipomoea batatas (L.) Lam., Lantana camara L., Sechium edule (Jacq.) Sw., Tagetes erecta L., and Zea mays L. Most of the plant species with reported pharmacological activity against kidney damage were considered safe in toxicological studies.

CONCLUSION

Available pharmacological reports suggest that several herbs used in traditional Mayan medicine for renal-associated diseases may have nephroprotective effects and consistent pharmacological evidence, nephroprotective compounds, and mechanisms of action in different models of kidney injury. However, more research is required to fully understand the potential of traditional Mayan medicine in drug discovery given the limited ethnobotanical studies and data available for most species with regards to identification on bioactive components, pharmacological mechanisms, and the scarce number of clinical studies.

Puromycin-induced kidney injury and subsequent regeneration in adult zebrafish

Puromycin treatment can cause glomerular injury to the kidney, leading to proteinuria. However, the pathogenesis of acute kidney injury and subsequent regeneration after puromycin administration in animal models remain unclear. In this work, we examined the characteristics of kidney injury and subsequent regeneration following puromycin treatment in adult zebrafish. We intraperitoneally injected 100 μg of puromycin into zebrafish; sacrificed them at 1, 3, 5, 7, or 14 days post-injection (dpi); and examined the morphological, functional, and molecular changes in the kidney. Puromycin-treated zebrafish presented more rapid clearance of rhodamine dextran than control animals. Morphological changes were observed immediately after the puromycin injection (1-7 dpi) and had recovered by 14 dpi. The mRNA production of lhx1a, a renal progenitor marker, increased during recovery from kidney injury. Levels of NFκB, TNFα, Nampt, and p-ERK increased significantly during nephron injury and regeneration, and Sirt1, FOXO1, pax2, and wt1b showed an increasing tendency. However, TGF-β1 and smad5 production did not show any changes after puromycin treatment. This study provides evidence that puromycin-induced injury in adult zebrafish kidneys is a potential tool for evaluating the mechanism of nephron injury and subsequent regeneration.

Thymic and Peripheral T-cell Polarization in an Experimental Model of Russell's Viper Venom-induced Acute Kidney Injury

Venom pathology is not restricted to the direct toxic effects of venom. Immunoinflammatory alteration as the etiology of snake venom-induced acute kidney injury (SAKI) is a less trodden path toward the development of alternative therapeutic approach. In the present study, we have associated the crest of renal damage stage to the immunological alteration, as reflected in thymic and peripheral T cell polarization in the murine model of SAKI. Renal injury in mice was confirmed from significant dysuresis and adversely altered biochemical renal markers. Histopathological alterations, as revealed by marked tubular and glomerular damage, reaffirmed kidney injury. SAKI is accompanied by significant inflammatory changes as indicated by neutrophilic leucocytosis, increased neutrophil to lymphocyte ratio and plasma CRP levels. Thymic immunophenotyping revealed significantly increased CD8+ cytotoxic T cell, and CD25+ both single positive population (p = .017-0.010) and CD44-CD25+ double negative population (DN3) (p = .002) accompanied by an insignificantly reduced CD4+ helper T cells (p = .451). Peripheral immunophenotyping revealed similar pattern as indicated by reduced helper T cells (p = .002) associated with significantly elevated cytotoxic T cells (p = .009) and CD25+ subset of both helper (p = .002) and cytotoxic (p = .024) T cells. The IL-10+ subset of both CD25+ and CD25- T cells were also found to be significantly elevated in the SAKI group (p ≤ 0.020) suggesting an immunosuppressive phenotype in SAKI. It can be concluded that T cells responds to venom-induced renal injury particularly through IL-10+ reparative phenotypes which are known for their immunosuppressive and anti-inflammatory activity.

Acute Kidney Failure among Brazilian Agricultural Workers: A Death-Certificate Case-Control Study

Recent evidence suggests that pesticides may play a role in chronic kidney disease. However, little is known about associations with acute kidney failure (AKF). We investigated trends in AKF and pesticide expenditures and associations with agricultural work in two Brazilian regions with intense use of pesticides, in the south and midwest. Using death certificate data, we investigated trends in AKF mortality (1980-2014). We used joinpoint regression to calculate annual percent changes in AKF mortality rates by urban/rural status and, in rural municipalities, by tertiles of per capita pesticide expenditures. We then compared AKF mortality in farmers and population controls from 2006 to 2014 using logistic regression to estimate odds ratios and 95% confidence intervals adjusted by age, sex, region, education, and race. AKF mortality increased in both regions regardless of urban/rural status; trends were steeper from the mid-1990s to 2000s, and in rural municipalities, they were higher by tertiles of pesticide expenditures. Agricultural workers were more likely to die from AKF than from other causes, especially at younger ages, among females, and in the southern municipalities. We observed increasing AKF mortality in rural areas with greater pesticide expenditures and an association of AKF mortality with agricultural work, especially among younger workers.

Association Between the Use of Sodium-Glucose Cotransporter-2 Inhibitors and Drug-Induced Acute Kidney Injury: Analysis of 2 Databases

The association between the use of sodium-glucose cotransporter-2 (SGLT-2) inhibitors and the occurrence of drug-induced kidney injury has not been evaluated. This study assessed whether the use of SGLT-2 inhibitors decreases the risk of drug-induced acute kidney injury (AKI) using the US Food and Drug Administration's Adverse Event Reporting System and the Medical Data Vision database. The occurrence of AKI in SGLT-2 inhibitor users and dipeptidyl peptidase-4 (DPP-4) inhibitor users was compared using both databases. In the US Food and Drug Administration's Adverse Event Reporting System analysis, disproportionality for AKI was observed between DPP-4 inhibitor users and SGLT-2 inhibitor users administered nonsteroidal anti-inflammatory drugs (reporting odds ratio, 0.65; 95%CI, 0.48-0.88; P < .01) and thiazide diuretics (reporting odds ratio, 0.78; 95%CI, 0.67-0.90; P < .01). In Medical Data Vision analysis, SGLT-2 inhibitor users administered nonsteroidal anti-inflammatory drugs (odds ratio [OR], 0.46; 95%CI, 0.41-0.53; P < .01), anti-herpes simplex virus drugs (OR, 0.20; 95%CI, 0.07-0.53; P < .01), thiazide diuretics (OR, 0.50; 95%CI, 0.36-0.71, P < .01), and loop diuretics (OR, 0.71; 95%CI, 0.62-0.83; P < .01) had a lower incidence of AKI compared with DPP-4 inhibitor users receiving the same drugs. No differences were observed in the risk of AKI between SGLT-2 and DPP-4 inhibitor users administered vancomycin and cisplatin in both databases. The use of SGLT-2 inhibitors might reduce the risk of drug-induced AKI caused by some drugs.

Toxic nephropathy: Adverse renal effects caused by drugs

This is a brief overview of toxic nephropathy, which is an increasingly recognised problem with the continual introduction of new drugs and novel drug modalities, especially in oncology, and the risks associated with polypharmacy in many patients; although it is important to remember that it may not always be caused by a drug. It is also important to note that several possibly harmful drugs are now available without prescription ('over-the-counter') and can be purchased easily over the internet, including some poorly characterised herbal remedies. Knowing exactly what our patients are taking as medication is not always easy and patients often fail to mention drugs that may not have been prescribed by a doctor or recommended by a pharmacist. Moreover, patients with several comorbidities often require care from more than one doctor in other specialties, which can also lead to drug prescribing in isolation. This article will summarise some key aspects of drug nephrotoxicity and provide a few clinical pointers to consider, bearing in mind that there is rarely any antidote available, and effective treatment relies on early detection, prompt drug withdrawal, and supportive care. This short review is intended only as a primer to highlight some of the more practical aspects of toxic nephropathy; its content is based on a lecture delivered during the 2021 European Congress of Internal Medicine.

Phosphodiesterase-5 inhibitor sildenafil attenuates kidney injury induced by Bothrops alternatus snake venom

Acute kidney injury pathogenesis in envenoming by snakes is multifactorial and involves immunologic reactions, hemodynamic disturbances, and direct nephrotoxicity. Sildenafil (SFC), a phosphodiesterase 5 inhibitor, has been reported to protect against pathological kidney changes.

OBJECTIVE

This study aimed to investigate the protective effect of sildenafil against Bothrops alternatus snake venom (BaV)-induced nephrotoxicity.

METHODS

Kidneys from Wistar rats (n = 6, weighing 260-300 g) were isolated and divided into four groups: (1) perfused with a modified Krebs-Henseleit solution (MKHS) containing 6 g% of bovine serum albumin; (2) administered 3 μg/mL SFC; (3) perfused with 3 μg/mL BaV; and (4) administered SFC + BaV, both at 3 μg/mL. Subsequently, the perfusion pressure (PP), renal vascular resistance (RVR), urinary flow (UF), glomerular filtration rate (GFR), and percentage of electrolyte tubular sodium and chloride transport (%TNa⁺, %TCl^-, respectively) were evaluated. The cyclic guanosine monophosphate (cGMP) levels were analyzed in the perfusate, and the kidneys were removed to perform oxidative stress and histopathological analyses.

RESULTS

All renal parameters evaluated were reduced with BaV. In the SFC + BaV group, SFC restored PP to normal values and promoted a significant increase in %TNa⁺ and %TCl^-. cGMP levels were increased in the SFC + BaV group. The oxidative stress biomarkers, malondialdehyde (MDA) and glutathione (GSH), were reduced by BaV. In the SFC + BaV group, a decrease in MDA without an increase in GSH was observed. These findings were confirmed by histological analysis, which showed improvement mainly in tubulis.

CONCLUSION

Our data suggest the involvement of phosphodiesterase-5 and cGMP in BaV-induced nephrotoxicity since its effects were attenuated by the administration of SFC.

Analysis of the Distribution of Urine Color and Its Relationship With Urine Dry Chemical Parameters Among College Students in Beijing, China - A Cross-Sectional Study

Objectives: The objective of this study was to provide a new classification method by analyzing the relationship between urine color (Ucol) distribution and urine dry chemical parameters based on image digital processing. Furthermore, this study aimed to assess the reliability of Ucol to evaluate the states of body hydration and health.

Methods: A cross-sectional study among 525 college students, aged 17–23 years old, of which 59 were men and 466 were women, was conducted. Urine samples were obtained during physical examinations and 524 of them were considered valid, including 87 normal samples and 437 abnormal dry chemistry parameters samples. The urinalysis included both micro- and macro-levels, in which the CIE L^*a^*b^* values and routine urine chemical examination were performed through digital imaging colorimetry and a urine chemical analyzer, respectively.

Results: The results showed that L^* (53.49 vs. 56.69) in the abnormal urine dry chemistry group was lower than the normal group, while b^* (37.39 vs. 33.80) was greater. Urine color can be initially classified based on shade by grouping b^*. Abnormal urine dry chemical parameter samples were distributed more in the dark-colored group. Urine dry chemical parameters were closely related to Ucol. Urine specific gravity (USG), protein, urobilinogen, bilirubin, occult blood, ketone body, pH, and the number of abnormal dry chemical parameters were all correlated with Ucol CIE L^*a^*b^*; according to a stepwise regression analysis, it was determined that more than 50% of the variation in the three-color space values came from the urine dry chemical parameters, and the b^* value was most affected by USG (standardized coefficient β = 0.734, p < 0.05). Based on a receiver operating characteristic curve (ROC) analysis, Ucol ≥ 4 provided moderate sensitivity and good specificity (AUC = 0.892) for the detection of USG ≥ 1.020.

Conclusions: Our findings on the Ucol analysis showed that grouping Ucol based on b^* value is an objective, simple, and practical method. At the same time, the results suggested that digital imaging colorimetry for Ucol quantification is a potential method for evaluating body hydration and, potentially, health.

Evaluation of Renoprotective Effects of Our Locally Grown Green Coffee Beans against Cisplatin-Induced Nephrotoxicity in Swiss Albino Mice

INTRODUCTION

Nephrotoxicity is the most common and severe side effect of cisplatin. Cisplatin causes nephrotoxicity through free radical production and debilitating cellular antioxidant capacity. Coffee is a commonly consumed drink and its ingredients have antioxidant roles that could bring benefits to patients affected by nephrotoxicity. Thus, the present study aimed to investigate the renoprotective effects of our locally grown green coffee beans against cisplatin-induced nephrotoxicity in Swiss albino mice.

METHODS

The posttest only control group design was employed on a total of thirty male Swiss albino mice. The mice were divided into five groups: group I (normal control group) received distilled water; group II (negative control group) received distilled water; and groups III-V (treatment groups) received 100, 200, and 300 mg/kg BW/day of green coffee bean extract for 14 days, respectively. Nephrotoxicity was induced in groups II-V by a single intraperitoneal injection of cisplatin (7.5 mg/kg). All mice were sacrificed after 14 days and blood was drawn to evaluate kidney function tests (serum creatinine and serum blood urea nitrogen). Besides, body weight, relative kidney weight, and kidney histopathology were investigated.

RESULT

Our results showed that treatment of cisplatin alone (group II mice) significantly increased serum creatinine, serum blood urea nitrogen, relative kidney weight, and pathological damage to the kidney with a decrease in final body weight. However, low-dose green coffee beans (group III), medium-dose green coffee beans (group IV), and high-dose green coffee beans (group V) mice showed a significant dose-dependent decrease in serum creatinine, serum blood urea nitrogen, and relative kidney weight. Furthermore, the dose-dependent treatment with green coffee bean extract prevented the decrease in body weight gain and pathological damage to the kidney in mice.

CONCLUSION

Our locally grown green coffee beans brought a dose-dependent ameliorative effect and a promising preventive approach against cisplatin-induced kidney damage in mice.

Cyclophilin D Promotes Acute, but Not Chronic, Kidney Injury in a Mouse Model of Aristolochic Acid Toxicity

The plant-derived toxin, aristolochic acid (AA), is the cause of Chinese Herb Nephropathy and Balkan Nephropathy. Ingestion of high dose AA induces acute kidney injury, while chronic low dose ingestion leads to progressive kidney disease. Ingested AA is taken up by tubular epithelial cells of the kidney, leading to DNA damage and cell death. Cyclophilin D (CypD) participates in mitochondrial-dependent cell death, but whether this mechanism operates in acute or chronic AA-induced kidney injury is unknown. We addressed this question by exposing CypD-/- and wild type (WT) mice to acute high dose, or chronic low dose, AA. Administration of 5 mg/kg AA to WT mice induced acute kidney injury 3 days later, characterised by loss of kidney function, tubular cell damage and death, and neutrophil infiltration. All of these parameters were significantly reduced in CypD-/- mice. Chronic low dose (2 mg/kg AA) administration in WT mice resulted in chronic kidney disease with impaired renal function and renal fibrosis by day 28. However, CypD-/- mice were not protected from AA-induced chronic kidney disease. In conclusion, CypD facilitates AA-induced acute kidney damage, but CypD does not contribute to the transition of acute kidney injury to chronic kidney disease during ongoing AA exposure.

Epidemiology and outcomes of dialysis requiring acute kidney injury: A single-center study

OBJECTIVES

Acute kidney injury (AKI) is a common diagnosis in hospitalized patients. Dialysis requiring AKI (AKI-D) is associated with adverse outcomes. This study aims to know the clinical profile and short-term outcomes at 3 months, in patients with AKI-D, at our center.

METHODS

A prospective observational study was done of all the patients admitted with AKI-D for 2 years, from July 2018 to June 2020. We recorded clinical parameters at baseline and postdischarge follow-up at 3 months.

RESULTS

One hundred twenty-eight patients had AKI-D over 2 years. Then, 116 (90.6%) patients had community-acquired AKI (CAAKI), and 12 (9.4%) patients had hospital-acquired AKI. The underlying causes of AKI-D were: toxins in 48 (37.5%), sepsis in 31 (24.2%), acute kidney disease in 15 (11.7%), acute gastroenteritis (AGE) in 9 (7%), and cardiogenic shock in 7 (5.5%) patients. The mean values of intact parathyroid hormone (available in 32% of patients) were 268 pg/mL. Intermittent hemodialysis was the commonest mode of dialysis (85.2%). A kidney biopsy was done in 23 (18%) patients. The most common diagnosis on kidney biopsy was glomerulonephritis (GN) in 12 patients (crescentic GN-9 and IgA nephropathy-3), followed by acute tubule-interstitial nephritis in 6 patients. In-hospital mortality was 29.7%. Overall, 39% regained serum creatinine in the normal range at 3 months, 36.7% died, 14.1% reached chronic kidney disease (CKD), 7.8% lost to follow-up, and 2.3% had reached end-stage renal disease.

CONCLUSION

The majority of AKI-D at our center was CAAKI. A significant chunk of AKI-D (68.7%) was caused by preventable causes like toxins, sepsis, and AGE. Dysregulation of mineral metabolism was conspicuous. In chemical toxin vs. biological toxins and undifferentiated sepsis vs. the identifiable cause of sepsis, formers had significantly more in-hospital mortality than the latter ones. AKI-D is associated with high in-hospital mortality, total mortality, and risk of progression to CKD at 3 months.

Exosomes: Emerging Therapy Delivery Tools and Biomarkers for Kidney Diseases

Exosomes are nanometer-sized small EVs coated with bilayer structure, which are released by prokaryotic and eukaryotic cells. Exosomes are rich in a variety of biologically active substances, such as proteins, nucleotides, and lipids. Exosomes are widely present in various body fluids and cell culture supernatants, and it mediates the physiological and pathological processes of the body through the shuttle of these active ingredients to target cells. In recent years, studies have shown that exosomes from a variety of cell sources can play a beneficial role in acute and chronic kidney disease. In particular, exosomes derived from mesenchymal stem cells have significant curative effects on the prevention and treatment of kidney disease in preclinical trials. Besides, some encapsulated substances are demonstrated to exert beneficial effects on various diseases, so they have attracted much attention. In addition, exosomes have extensive sources, stable biological activity, and good biocompatibility and are easy to store and transport; these advantages endow exosomes with superior diagnostic value. With the rapid development of liquid biopsy technology related to exosomes, the application of exosomes in the rapid diagnosis of kidney disease has become more prominent. In this review, the latest development of exosomes, including the biosynthesis process, the isolation and identification methods of exosomes are systematically summarized. The utilization of exosomes in diagnosis and their positive effects in the repair of kidney dysfunction are discussed, along with the specific mechanisms. This review is expected to be helpful for relevant studies and to provide insight into future applications in clinical practice.

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.

Downregulated expression of organic anion transporting polypeptide (Oatp) 2b1 in the small intestine of rats with acute kidney injury

The expression of transporters on the apical and basal membranes of renal tubular cells is modulated under acute kidney injury (AKI). However, little is known about alterations in non-renal transporters in the tissues other than the kidney under AKI situation. This study aimed to assess the modulation of organic anion transporting polypeptide (Oatp) 1a2 and Oatp2b1 expression/function in the small intestine of rats with drug-induced AKI. AKI was induced by intraperitoneal administration of cisplatin at a dose of 5 mg/kg. On day 3 after cisplatin administration, morphological changes in the small intestine, Oatp1a2 and Oatp2b1 expression, and absorption of pravastatin and theophylline were evaluated. Non-negligible atrophy was observed in the jejunum and ileum of the AKI rats. However, the absorption of theophylline was not affected. While intestinal Oatp2b1 expression was markedly decreased in the AKI rats, no alteration was observed in Oatp1a2 expression. The plasma levels of pravastatin after intraluminal administration declined significantly in the AKI rats. However, no such decline was observed after intravenous administration. This study suggested that the responses of intestinal Oatps to experimentally induced AKI was not unidirectional and that pravastatin absorption was governed more potently by Oatp2b1 than by Oatp1a2 in the rat intestine.

Aetiology, course and treatment of acute tubulointerstitial nephritis in paediatric patients: a cross-sectional web-based survey

BACKGROUND

Acute tubulointerstitial nephritis (TIN) is a significant cause of acute renal failure in paediatric and adult patients. There are no large paediatric series focusing on the aetiology, treatment and courses of acute TIN.

PATIENTS, DESIGN AND SETTING

We collected retrospective clinical data from paediatric patients with acute biopsy-proven TIN by means of an online survey. Members of four professional societies were invited to participate.

RESULTS

Thirty-nine physicians from 18 countries responded. 171 patients with acute TIN were included (54% female, median age 12 years). The most frequent causes were tubulointerstitial nephritis and uveitis syndrome in 31% and drug-induced TIN in 30% (the majority of these caused by non-steroidal anti-inflammatory drugs). In 28% of patients, no initiating noxae were identified (idiopathic TIN). Median estimated glomerular filtration rate (eGFR) rose significantly from 31 at time of renal biopsy to 86 mL/min/1.73 m² 3-6 months later (p<0.001). After 3-6 months, eGFR normalised in 41% of patients (eGFR ≥90 mL/min/1.73 m²), with only 3% having severe or end-stage impairment of renal function (<30 mL/min/1.73 m²). 80% of patients received corticosteroid therapy. Median eGFR after 3-6 months did not differ between steroid-treated and steroid-untreated patients. Other immunosuppressants were used in 18% (n=31) of patients, 21 of whom received mycophenolate mofetil.

CONCLUSIONS

Despite different aetiologies, acute paediatric TIN had a favourable outcome overall with 88% of patients showing no or mild impairment of eGFR after 3-6 months. Prospective randomised controlled trials are needed to evaluate the efficacy of glucocorticoid treatment in paediatric patients with acute TIN.

Downregulated expression of intestinal P-glycoprotein in rats with cisplatin-induced acute kidney injury causes amplification of its transport capacity to maintain "gatekeeper" function

The expression of transporters on the apical and basal membranes of renal proximal tubular cells are down- or upregulated to various extents under cisplatin (CDDP)-induced acute kidney injury (AKI). However, little is known about the changes in transporters in tissues other than the kidney under CDDP-induced AKI. This study aimed to investigate the modulation of the expression/function of intestinal efflux transporters, P-glycoprotein (P-gp) and breast cancer resistance protein (Bcrp), in CDDP-induced AKI rats. On day 3 after the intraperitoneal administration of CDDP (5 mg/kg) to rats, the expression levels of P-gp and Bcrp were compared with those of normal rats. Further, the absorption of three P-gp substrates (6α-methylprednisolone, rhodamine 123, and gatifloxacin) was evaluated in both groups using conventional loop techniques. In the CDDP-induced AKI rats, P-gp expression in the ileum was markedly decreased to approximately 38% of that in the normal rats. However, no significant changes in Bcrp expression were observed in the AKI rats. In contrast with the reduction in P-gp expression in the AKI rats, the absorption of the three P-gp substrates remained almost the same or decreased in the AKI group. The addition of verapamil (a potent P-gp inhibitor) increased the absorption of the three P-gp substrates to the values obtained from the normal rats. In conclusion, our results suggested that P-gp expression is downregulated in rats with CDDP-induced AKI but that P-gp maintains its potency as a "gatekeeper" against the absorption of xenobiotics by amplifying its individual transport capacity under these conditions.

Nephrotoxicity of Herbal Products in Europe-A Review of an Underestimated Problem

Currently in Europe, despite the many advances in production technology of synthetic drugs, the interest in natural herbal medicines continues to increase. One of the reasons for their popular use is the assumption that natural equals safe. However, herbal medicines contain pharmacologically active ingredients, some of which have been associated with adverse effects. Kidneys are particularly susceptible to injury induced by toxins, including poisonous constituents from medicinal plants. The most recognized herb-induced kidney injury is aristolochic acid nephropathy connected with misuse of certain Traditional Chinese herbal medicines. Data concerning nephrotoxicity of plant species of European origin are scarce. Here, we critically review significant data of the nephrotoxicity of several plants used in European phytotherapy, including Artemisia herba-alba, Glycyrrhiza glabra, Euphorbia paralias, and Aloe). Causative mechanisms and factors predisposing to intoxications from the use of herbs are discussed. The basic intention of this review is to improve pharmacovigilance of herbal medicine, especially in patients with chronic kidney diseases.

Promoting resolution in kidney disease: are we nearly there yet?

PURPOSE OF REVIEW

Nephrology lacks effective therapeutics for many of the presentations and diseases seen in clinical practice. In recent decades, we have come to understand the central place of inflammation in initiating and propagating kidney disease, and, research in more recent years has established that the resolution of inflammation is a highly regulated and active process. With this, has evolved an appreciation that this aspect of the host inflammatory response is defective in kidney disease and led to consideration of a therapeutic paradigm aiming to harness the activity of the molecular drivers of the resolution phase of inflammation. Fatty-acid-derived Specialized pro-resolving mediators (SPMs), partly responsible for resolution of inflammation have gained traction as potential therapeutics.

RECENT FINDINGS

We describe our current understanding of SPMs for this purpose in acute and chronic kidney disease. These studies cement the place of inflammation and its defective resolution in the pathogenesis of kidney disease, and highlight new avenues for therapy.

SUMMARY

Targeting resolution of inflammation is a viable approach to treating kidney disease. We optimistically look forward to translating these experimental advances into tractable therapeutics to treat kidney disease.

The Utility of Novel Renal Biomarkers in Assessment of Chronic Kidney Disease of Unknown Etiology (CKDu): A Review

Chronic Kidney Disease (CKD) is a globally prevalent non-communicable disease with significant mortality and morbidity. It is typically associated with diabetes and hypertension; however, over the last two decades, an emergence of CKD of unknown etiology (CKDu) has claimed thousands of lives in several tropical agricultural communities. CKDu is associated with gradual loss of renal function without initial symptoms until reaching complete kidney failure and eventually death. The most impacted are young adult males of lower socio-economic strata. Since the disease progression can be successfully attenuated through early detection, the development of superior screening and management measures is of utmost importance. In contrast to the conventional biomarkers, novel biomarkers with improved sensitivity and specificity are being discussed as promising tools for early diagnosis of the disease. This review summarizes emerging novel biomarkers used in assessing CKD and discusses the current utility and diagnostic potential of such biomarkers for CKDu screening in clinical settings of different communities impacted by CKDu. Our goal is to provide a framework for practitioners in CKDu impacted regions to consider the use of these novel biomarkers through this synthesis. The increased use of these biomarkers will not only help to validate their diagnostic power further and establish potential prognostic value but may also provide critical insights into sites and mechanisms of renal damage.

Acute Kidney Injury in Septic Patients Treated by Selected Nephrotoxic Antibiotic Agents-Pathophysiology and Biomarkers-A Review

Acute kidney injury is a common complication in critically ill patients with sepsis and/or septic shock. Further, some essential antimicrobial treatment drugs are themselves nephrotoxic. For this reason, timely diagnosis and adequate therapeutic management are paramount. Of potential acute kidney injury (AKI) biomarkers, non-protein-coding RNAs are a subject of ongoing research. This review covers the pathophysiology of vancomycin and gentamicin nephrotoxicity in particular, septic AKI and the microRNAs involved in the pathophysiology of both syndromes. PubMED, UptoDate, MEDLINE and Cochrane databases were searched, using the terms: biomarkers, acute kidney injury, antibiotic nephrotoxicity, sepsis, miRNA and nephrotoxicity. A comprehensive review describing pathophysiology and potential biomarkers of septic and toxic acute kidney injury in septic patients was conducted. In addition, five miRNAs: miR-15a-5p, miR-192-5p, miR-155-5p, miR-486-5p and miR-423-5p specific to septic and toxic acute kidney injury in septic patients, treated by nephrotoxic antibiotic agents (vancomycin and gentamicin) were identified. However, while these are at the stage of clinical testing, preclinical and clinical trials are needed before they can be considered useful biomarkers or therapeutic targets of AKI in the context of antibiotic nephrotoxicity or septic injury.

Coenzyme Q10 nullified khat-induced hepatotoxicity, nephrotoxicity and inflammation in a mouse model

Ethnopharmacological relevance

The consumption of khat (Catha Edulis, Forsk) is on the rise despite the much publicized associated deleterious health effects. How chemicals present in khat, affect various physiological and biochemical processes requires further scrutiny. A clear understanding of these processes will provide an avenue for countering khat-driven negative effects using appropriate pharmacological and/or nutritional interventions.

Aim of the study

The current study investigated the effect of khat on vital physiological and biochemical processes such as oxidative stress, inflammation and immune responses and the role of Coenzyme-Q₁₀ (CoQ₁₀), a potent antioxidant and anti-inflammatory, in modulating any negative effects due to khat exposure.

Methodology

Three (3) weeks old forty (40) Swiss albino mice were randomly assigned into four treatment groups (n = 10). The first group was the control that was not administered with khat or CoQ₁₀. The second group received 200 mg/kg body weight (b/w) of CoQ₁₀, while the third group received 1500 mg/kg b/w of khat extract and finally the forth group was co-treated with 200 mg/kg b/w of CoQ₁₀ and 1500 mg/kg b/w of khat extract. The experiment was conducted for 90 days after which samples were collected for physiological and biochemical analyses.

Results

The effects of khat and CoQ₁₀ on the weights of brain, liver, kidney and spleen was determined. Administration of khat decreased the levels of RBCs and its subtypes (MCV, MCH, RDW-SD and RDW-CV), a clear indicator of khat-induced normochromic microcytic anemia. White blood cells (lymphocytes, monocytes, neutrophils and eosinophil) which are vital in responding to infections were markedly elevated by khat. Moreover, these results provide evidence for khat-induced liver and kidney injury as shown by increased biomarkers; AST, ALT, GGT and creatinine respectively. Standard histopathological analysis confirmed this finding for khat-driven liver and kidney injury. Further studies showed evidence for khat-induced inflammation and oxidative stress as depicted by increased levels of the pro-inflammatory cytokine TNF-alpha and elevation of GSH in the brain, liver and spleen. Remarkably, this is the first study to demonstrate the potential of CoQ₁₀ in ameliorating khat-induced negative effects as outlined. CoQ₁₀ supplementation restored the khat-induced reduction in RBC subtypes, and was protective against liver and kidney injury as shown by the appropriate biomarkers and standard histopathology analysis. The other significant finding was the CoQ₁₀-driven normalization of GSH and TNF-α levels, indicating a protective effect from khat-driven oxidative stress and inflammation respectively.

Conclusion

From this study, we conclude that CoQ₁₀ may be useful in nullifying khat-driven deleterious events among chronic khat users.

Fibrosis and Immune Cell Infiltration Are Separate Events Regulated by Cell-Specific Receptor Notch3 Expression

BACKGROUND

Kidney injuries that result in chronic inflammation initiate crosstalk between stressed resident cells and infiltrating immune cells. In animal models, whole-body receptor Notch3 deficiency protects from leukocyte infiltration and organ fibrosis. However, the relative contribution of Notch3 expression in tissue versus infiltrating immune cells is unknown.

METHODS

Chimeric mice deficient for Notch3 in hematopoietic cells and/or resident tissue cells were generated, and kidney fibrosis and inflammation after unilateral ureteral obstruction (UUO) were analyzed. Adoptive transfer of labeled bone marrow-derived cells validated the results in a murine Leishmania ear infection model. In vitro adhesion assays, integrin activation, and extracellular matrix production were analyzed.

RESULTS

Fibrosis follows UUO, but inflammatory cell infiltration mostly depends upon Notch3 expression in hematopoietic cells, which coincides with an enhanced proinflammatory milieu (e.g., CCL2 and CCL5 upregulation). Notch3 expression on CD45⁺ leukocytes plays a prominent role in efficient cell transmigration. Functionally, leukocyte adhesion and integrin activation are abrogated in the absence of receptor Notch3. Chimeric animal models also reveal that tubulointerstitial fibrosis develops, even in the absence of prominent leukocyte infiltrates after ureteral obstruction. Deleting Notch3 receptors on resident cells blunts kidney fibrosis, ablates NF-κB signaling, and lessens matrix deposition.

CONCLUSIONS

Cell-specific receptor Notch3 signaling independently orchestrates leukocyte infiltration and organ fibrosis. Interference with Notch3 signaling may present a novel therapeutic approach in inflammatory as well as fibrotic diseases.

Prediction models for acute kidney injury in patients with gastrointestinal cancers: a real-world study based on Bayesian networks

Background

This study attempts to establish a Bayesian networks (BNs) based model for inferring the risk of AKI in gastrointestinal cancer (GI) patients, and to compare its predictive capacity with other machine learning (ML) models.

Methods

From 1 October 2014 to 30 September 2015, we recruited 6495 inpatients with GI cancers in a tertiary hospital in eastern China. Data on demographics, clinical and laboratory indicators were retrospectively extracted from the electronic medical record system. Predictors of AKI were selected in gLASSO regression, and further incorporated into BNs analysis.

Results

The incidences of AKI in patients with esophagus, stomach, and intestine cancer were 20.5%, 13.9%, and 12.5%, respectively. Through gLASSO, 11 predictors were screened out, including diabetes, cancer category, anti-tumor treatment, ALT, serum creatinine, estimated glomerular filtration rate (eGFR), serum uric acid (SUA), hypoalbuminemia, anemia, abnormal sodium, and potassium. BNs model revealed that cancer category, treatment, eGFR, and hypoalbuminemia had direct connections with AKI. Diabetes and SUA were indirectly linked to AKI through eGFR, and anemia created connections with AKI through affecting album level. Compared with other ML models, BNs model maintained a higher AUC value in both the internal and external validation (AUC: 0.823/0.790).

Conclusion

BNs model not only delineates the qualitative and quantitative relationship between AKI and its associated factors but shows the more robust generalizability in AKI prediction.

Acute Kidney Injury: Diagnosis and Management

Pediatric medicine is growing in complexity and an increasing number of children with co-morbidities are exposed to potential renal damage. Initially ill-defined and thought to be mostly a transient phenomenon in children, acute kidney injury (AKI) has now emerged as a complex clinical syndrome independently associated with increased mortality and morbidity, including the development of chronic renal sequelae. Recent advances in molecular nephrology have better elucidated the early phase of AKI, where evidence of renal tissue damage is associated with adverse outcomes even without decrease in glomerular filtration rate, illustrating the flaws of the old paradigm based solely on an insensitive filtration marker, the serum creatinine. Prevention, prompt evaluation and early interventions are of essence to decrease AKI incidence and severity. Emerging data reveal that AKI is commonly encountered in hospitalized children, especially critically ill ones, hence the importance for all clinicians to be able to identify high risk patients, recognize AKI early and be comfortable with the initial medical management. In recent years, significant advances have been made in AKI definition and prediction, allowing early preventive measures in high risk children that are now proven to reduce AKI incidence. This review covers recent advances in the diagnosis, risk stratification, prevention and management of AKI in children.

Autophagy in kidney disease: Advances and therapeutic potential

Autophagy is a highly conserved intracellular catabolic process for the degradation of cytoplasmic components that has recently gained increasing attention for its importance in kidney diseases. It is indispensable for the maintenance of kidney homeostasis both in physiological and pathological conditions. Investigations utilizing various kidney cell-specific conditional autophagy-related gene knockouts have facilitated the advancement in understanding of the role of autophagy in the kidney. Recent findings are raising the possibility that defective autophagy exerts a critical role in different pathological conditions of the kidney. An emerging body of evidence reveals that autophagy exhibits cytoprotective functions in both glomerular and tubular compartments of the kidney, suggesting the upregulation of autophagy as an attractive therapeutic strategy. However, there is also accumulating evidence that autophagy could be deleterious, which presents a formidable challenge in developing therapeutic strategies targeting autophagy. Here, we review the recent advances in research on the role of autophagy during different pathological conditions, including acute kidney injury (AKI), focusing on sepsis, ischemia-reperfusion injury, cisplatin, and heavy metal-induced AKI. We also discuss the role of autophagy in chronic kidney disease (CKD) focusing on the pathogenesis of tubulointerstitial fibrosis, podocytopathies including focal segmental glomerulosclerosis, diabetic nephropathy, IgA nephropathy, membranous nephropathy, HIV-associated nephropathy, and polycystic kidney disease.

The sympathetic nervous system in acute kidney injury

Acute kidney injury (AKI) is frequently accompanied by activation of the sympathetic nervous system (SNS). This may result from pre-exisiting chronic diseases associated with sympathetic activation prior to AKI or it may be induced by stressors that ultimately lead to AKI such as endotoxins and arterial hypotension in circulatory shock. Conversely, sympathetic activation may also result from acute renal injury. Focusing on studies in experimental renal ischaemia and reperfusion (IR), this review summarizes the current knowledge on how the SNS is activated in IR-induced AKI and on the consequences of sympathetic activation for the development of acute renal damage. Experimental studies show beneficial effects of sympathoinhibitory interventions on renal structure and function in response to IR. However, few clinical trials obtained in scenarios that correspond to experimental IR, namely major elective surgery, showed that peri-operative treatment with centrally acting sympatholytics reduced the incidence of AKI. Apparently, discrepant findings on how sympathetic activation influences renal responses to acute IR-induced injury are discussed and future areas of research in this field are identified.