Drug-associated renal dysfunction and injury

In-situ nanoplatform with synergistic neutrophil intervention and chemotherapy to prevent postoperative tumor recurrence and metastasis

In addition to residual tumor cells, surgery-induced inflammation significantly contributes to tumor recurrence and metastasis by recruiting polymorphonuclear neutrophils (PMNs) and promoting their involvement in tumor cell proliferation, invasion and immune evasion. Efficiently eliminating residual tumor cells while concurrently intervening in PMN function represents a promising approach for enhanced postoperative cancer treatment. Here, a chitosan/polyethylene oxide electrospun fibrous scaffold co-delivering celecoxib (CEL) and doxorubicin-loaded tumor cell-derived microparticles (DOX-MPs) is developed for postoperative in-situ treatment in breast cancer. This implant (CEL/DOX-MPs@CP) ensures prolonged drug retention and sustained release within the surgical tumor cavity. The released DOX-MPs effectively eliminate residual tumor cells, while the released CEL inhibits the function of inflammatory PMNs, suppressing their promotion of residual tumor cell proliferation, migration and invasion, as well as remodeling the tumor immune microenvironment. Importantly, the strategy is closely associated with interference in neutrophil extracellular trap (NET) released from inflammatory PMNs, leading to a substantial reduction in postoperative tumor recurrence and metastasis. Our results demonstrate that CEL/DOX-MPs@CP holds great promise as an implant to enhance the prognosis of breast cancer patients following surgery.

In silico prediction of drug-induced nephrotoxicity: current progress and pitfalls

INTRODUCTION

Due to its role in absorption and metabolism, the kidney is an important target for drug toxicity. Drug-induced nephrotoxicity (DIN) presents a significant challenge in clinical practice and drug development. Conventional methods for assessing nephrotoxicity have limitations, highlighting the need for innovative approaches. In recent years, in silico methods have emerged as promising tools for predicting DIN.

AREAS COVERED

A literature search was performed using PubMed and Web of Science, from 2013 to February 2023 for this review. This review provides an overview of the current progress and pitfalls in the in silico prediction of DIN, which discusses the principles and methodologies of computational models.

EXPERT OPINION

Despite significant advancements, this review identified issues accentuates the pivotal imperatives of data fidelity, model optimization, interdisciplinary collaboration, and mechanistic comprehension in sculpting the vista of DIN prediction. Integration of multiple data sources and collaboration between disciplines are essential for improving predictive models. Ultimately, a holistic approach combining computational, experimental, and clinical methods will enhance our understanding and management of DIN.

An early and stable mouse model of polymyxin-induced acute kidney injury

BACKGROUND

Polymyxins have been revived as a last-line therapeutic option for multi-drug resistant bacteria and continue to account for a significant proportion of global antibiotic usage. However, kidney injury is often a treatment limiting event with kidney failure rates ranging from 5 to 13%. The mechanisms underlying polymyxin-induced nephrotoxicity are currently unclear. Researches of polymyxin-associated acute kidney injury (AKI) models need to be more standardized, which is crucial for obtaining consistent and robust mechanistic results.

METHODS

In this study, male C57BL/6 mice received different doses of polymyxin B (PB) and polymyxin E (PE, also known as colistin) by different routes once daily (QD), twice daily (BID), and thrice daily (TID) for 3 days. We continuously monitored the glomerular filtration rate (GFR) and the AKI biomarkers, including serum creatinine (Scr), blood urea nitrogen (BUN), neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury molecule-1 (KIM-1). We also performed histopathological examinations to assess the extent of kidney injury.

RESULTS

Mice receiving PB (35 mg/kg/day subcutaneously) once daily exhibited a significant decrease in GFR and a notable increase in KIM-1 two hours after the first dose. Changes in GFR and KIM-1 at 24, 48 and 72 h were consistent and demonstrated the occurrence of kidney injury. Histopathological assessments showed a positive correlation between the severity of kidney injury and the changes in GFR and KIM-1 (Spearman's rho = 0.3167, P = 0.0264). The other groups of mice injected with PB and PE did not show significant changes in GFR and AKI biomarkers compared to the control group.

CONCLUSION

The group receiving PB (35 mg/kg/day subcutaneously) once daily consistently developed AKI at 2 h after the first dose. Establishing an early and stable AKI model facilitates researches into the mechanisms of early-stage kidney injury. In addition, our results indicated that PE had less toxicity than PB and mice receiving the same dose of PB in the QD group exhibited more severe kidney injury than the BID and TID groups.

MYH9-related inherited thrombocytopenia: the genetic spectrum, underlying mechanisms, clinical phenotypes, diagnosis, and management approaches

Inherited thrombocytopenias have been considered exceedingly rare for a long time, but recent advances have facilitated diagnosis and greatly enabled the discovery of new causative genes. MYH9-related disease (MYH9-RD) represents one of the most frequent forms of inherited thrombocytopenia, usually presenting with nonspecific clinical manifestations, which renders it difficult to establish an accurate diagnosis. MYH9-RD is an autosomal dominant-inherited thrombocytopenia caused by deleterious variants in the MYH9 gene encoding the heavy chain of nonmuscle myosin IIA. Patients with MYH9-RD usually present with thrombocytopenia and platelet macrocytosis at birth or in infancy, and most of them may develop one or more extrahematologic manifestations of progressive nephritis, sensorial hearing loss, presenile cataracts, and elevated liver enzymatic levels during childhood and adult life. Here, we have reviewed recent advances in the study of MYH9-RD, which aims to provide an updated and comprehensive summary of the current knowledge and improve our understanding of the genetic spectrum, underlying mechanisms, clinical phenotypes, diagnosis, and management approaches of this rare disease. Importantly, our goal is to enable physicians to better understand this rare disease and highlight the critical role of genetic etiologic analysis in ensuring accurate diagnosis, clinical management, and genetic counseling while avoiding ineffective and potentially harmful therapies for MYH9-RD patients.

Glyphosate: Hepatotoxicity, Nephrotoxicity, Hemotoxicity, Carcinogenicity, and Clinical Cases of Endocrine, Reproductive, Cardiovascular, and Pulmonary System Intoxication

Glyphosate (GLP) is an active agent of GLP-based herbicides (GBHs), i.e., broad-spectrum and postemergent weedkillers, commercialized by Monsanto as, e.g., Roundup and RangerPro formulants. The GBH crop spraying, dedicated to genetically engineered GLP-resistant crops, has revolutionized modern agriculture by increasing the production yield. However, abusively administered GBHs' ingredients, e.g., GLP, polyoxyethyleneamine, and heavy metals, have polluted environmental and industrial areas far beyond farmlands, causing global contamination and life-threatening risk, which has led to the recent local bans of GBH use. Moreover, preclinical and clinical reports have demonstrated harmful impacts of GLP and other GBH ingredients on the gut microbiome, gastrointestinal tract, liver, kidney, and endocrine, as well as reproductive, and cardiopulmonary systems, whereas carcinogenicity of these herbicides remains controversial. Occupational exposure to GBH dysregulates the hypothalamic-pituitary-adrenal axis, responsible for steroidogenesis and endocrinal secretion, thus affecting hormonal homeostasis, functions of reproductive organs, and fertility. On the other hand, acute intoxication with GBH, characterized by dehydration, oliguria, paralytic ileus, as well as hypovolemic and cardiogenic shock, pulmonary edema, hyperkalemia, and metabolic acidosis, may occur fatally. As no antidote has been developed for GBH poisoning so far, the detoxification is mainly symptomatic and supportive and requires intensive care based on gastric lavage, extracorporeal blood filtering, and intravenous lipid emulsion infusion. The current review comprehensively discusses the molecular and physiological basics of the GLP- and/or GBH-induced diseases of the endocrine and reproductive systems, and cardiopulmonary-, nephro-, and hepatotoxicities, presented in recent preclinical studies and case reports on the accidental or intentional ingestions with the most popular GBHs. Finally, they briefly describe modern and future healthcare methods and tools for GLP detection, determination, and detoxification. Future electronically powered, decision-making, and user-friendly devices targeting major GLP/GBH's modes of actions, i.e., dysbiosis and the inhibition of AChE, shall enable self-handled or point-of-care professional-assisted evaluation of the harm followed with rapid capturing GBH xenobiotics in the body and precise determining the GBH pathology-associated biomarkers levels.

Detection, Monitoring, and Mitigation of Drug-Induced Nephrotoxicity: A Pragmatic Approach

The kidneys play a pivotal role in elimination of most drugs; therefore, a comprehensive understanding of renal physiology and pathology is important for those involved in drug development. High filtration capacity and metabolic activity make the kidneys vulnerable to drug-induced nephrotoxicity (DIN). Acute DIN may manifest on a background of renal impairment that has resulted from underlying disease, previously administered nephrotoxic medications, congenital renal abnormalities, or the natural aging process. The ability of the kidneys to compensate for DIN depends on the degree of pre-insult renal function. Therefore, it can be difficult to identify. The discovery and development of novel biomarkers that can diagnose kidney damage earlier and more accurately than current clinical measures and may be effective in detecting DIN. The goal of this manuscript is to provide a pragmatic and evidence-based supportive guidance for the early identification and management of DIN during the drug development process for clinical trial participants of all ages. The overall objective is to minimize the impact of DIN on kidney function and to collect renal safety data enabling risk analysis and mitigation.

Assessment of osteopontin as an early nephrotoxicity indicator in human renal proximal tubule cells and its application in evaluating lanthanum-induced nephrotoxicity

Nephrotoxicity is a common adverse effect induced by various chemicals, necessitating the development of reliable toxicity screening models for nephrotoxicity assessment. In this study, we assessed a group of nephrotoxicity indicators derived from different toxicity pathways, including conventional endpoints and kidney tubular injury biomarkers such as clusterin (CLU), kidney injury molecule-I (KIM-1), osteopontin (OPN), and neutrophil gelatinase-associated lipocalin (NGAL), using HK-2 and induced pluripotent stem cells (iPSCs)-derived renal proximal tubular epithelial-like cells (PTLs). Among the biomarkers tested, OPN emerged as the most discerning and precise marker. The predictive potential of OPN was tested using a panel of 10 nephrotoxic and 5 non-nephrotoxic compounds. The results demonstrated that combining OPN with the half-maximal inhibitory concentration (IC50) enhanced the diagnostic accuracy in both cellular models. Additionally, PTLs cells showed superior predictive efficacy for nephrotoxicity compared to HK-2 cells in this investigation. The two cellular models were utilized to evaluate the nephrotoxicity of lanthanum. The findings indicated that lanthanum possesses nephrotoxic properties; however, the degree of nephrotoxicity was relatively low, consistent with the outcomes of in vivo experiments.

Valproic acid as an adjuvant analgesic: adult Fanconi syndrome

We report an 80-year-old woman who developed severe hypophosphataemia and elevated urinary phosphate levels while started on valproic acid. This occurred within 1-2 days of starting valproic acid. There are rare single-patient reports of the association of valproic acid with adult Fanconi syndrome. This generally occurs after long-term exposure to valproate. This is the first reported experience of Fanconi's syndrome in an adult with acute exposure to valproic acid. Clinicians should be aware of the possible association.

Evaluation of the knowledge, practices, and attitudes of community pharmacists towards adverse effects of non-steroidal anti-inflammatory drugs (NSAIDs): a cross-sectional study

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most commonly used over-the-counter medications for the treatment of pain, fever, and inflammation. Gastrointestinal problems and renal complications are the most frequently observed adverse effects associated with NSAID usage. Therefore, this study aims to evaluate the levels of knowledge, attitude, and practice regarding the adverse effects of non-prescription NSAIDs among community pharmacists in Egypt.

METHODS

A 4-month cross-sectional survey, including licenced community pharmacists in Egypt, was conducted. The anonymous Google Forms survey was accompanied by a cover letter explaining its purpose. The survey link was sent to 2000 verified community pharmacist email addresses with clear instructions to complete and submit the questionnaire within 3 weeks. Descriptive and inferential statistical analyses were conducted using IBM-SPSS version 26. The means of variables were compared using analysis of variance test. Pearson correlation was employed to assess the level of linear association between the overall knowledge, practice, and attitude scores. P-value ≤ 0.05 was considered statistically significant.

RESULTS

Approximately 80% of community pharmacists in Egypt exhibit moderate-to-good knowledge regarding the adverse effects of NSAIDs. Additionally, 60.6% of them demonstrated a positive attitude and 80.9% showed moderate-to-good practice scores towards preventing such adverse effects. The education level was the only demographic factor with significant effects on the NSAIDs-related knowledge, practice, and attitude scores. Community pharmacists primarily rely on internet sources for knowledge updates. Additionally, there was a significant positive linear correlation between knowledge and attitude (r = 0.384, P < 0.001), knowledge and practice (r = 0.178, P < 0.001), and between attitude and practice (r = 0.311, P < 0.001) among the participants.

CONCLUSION

Community pharmacists have a vital responsibility to perform screenings, assess patient risk elements, and share knowledge to guarantee the appropriate and safe utilisation of NSAIDs. Given that internet sources are presently the most accessible and used sources of information, governmental directions should prioritise the establishment and enhancement of freely accessible drug information sources for community pharmacists. Further research is necessary to assess the effectiveness of counselling and appropriate guidance provided by community pharmacies in promoting safe and proper drug usage.

Drug induced nephrotoxicity- A mechanistic approach

The main goal of the treatment of patients is its effectiveness and safety. However, all currently prescribed drugs being used also have certain adverse effects, which might be seen as an unavoidable but necessary cost of pharmacotherapy. The kidney is the primary organ for xenobiotics elimination, making it particularly susceptible to the harmful effects of drugs and their metabolites during their excretion from the body. Moreover, certain medications have a preferential nephrotoxicity potential, which means that using them increases the risk of kidney injury. Drug nephrotoxicity is, therefore, both a significant problem and a complication of pharmacotherapy. It should be noted that, there is presently no accepted definition of drug-induced nephrotoxicity and no established diagnostic criteria. The current review briefly describes the pathogenic mechanism of drug-induced nephrotoxicity, the various basic drugs with nephrotoxicity potential and the renal biomarkers for the treatment of the drug-related kidney damage.

A Multichannel Fluorescent Array Sensor for Discrimination of Different Types of Drug-Induced Kidney Injury

The differences in urinary proteins could provide a novel opportunity to distinguish the different types of drug-induced kidney injury (DIKI). In this research, Au nanoparticles-polyethyleneimine (AuNPs-PEI) and the three fluorophore-labeled proteins (FLPs) have been constructed as a multichannel fluorescent array sensor via electrostatic interaction, which was used to detect the subtle changes in urine collected from the pathological state of DIKI. Once the urine from different types of DIKI was introduced, the binding equilibrium between AuNPs-PEI and FLPs would be broken due to the competitive binding of urinary protein, and the corresponding fluorescence response pattern would be generated. Depending on the different fluorescence response patterns, the different types of DIKI were successfully identified by principal component analysis (PCA) and linear discriminant analysis (LDA). Accordingly, the strategy was expected to be a powerful technique for evaluating the potential unclear mechanisms of nephrotoxic drugs, which would provide a promising method for screening potential renal-protective drugs.

Mechanisms of Piperacillin/Tazobactam Nephrotoxicity: Piperacillin/Tazobactam-Induced Direct Tubular Damage in Mice

Piperacillin/tazobactam (PT) is one of the most commonly prescribed antibiotics for critically ill patients in intensive care. PT has been reported to cause direct nephrotoxicity; however, the underlying mechanisms remain unknown. We investigated the mechanisms underlying PT nephrotoxicity using a mouse model. The kidneys and sera were collected 24 h after PT injection. Serum blood urea nitrogen (BUN), creatinine, neutrophil gelatinase-associated lipocalin (NGAL), and renal pathologies, including inflammation, oxidative stress, mitochondrial damage, and apoptosis, were examined. Serum BUN, creatinine, and NGAL levels significantly increased in PT-treated mice. We observed increased IGFBP7, KIM-1, and NGAL expression in kidney tubules. Markers of oxidative stress, including 8-OHdG and superoxide dismutase, also showed a significant increase, accompanied by mitochondrial damage and apoptosis. The decrease in the acyl-coA oxidase 2 and Bcl2/Bax ratio also supports that PT induces mitochondrial injury. An in vitro study using HK-2 cells also demonstrated mitochondrial membrane potential loss, indicating that PT induces mitochondrial damage. PT appears to exert direct nephrotoxicity, which is associated with oxidative stress and mitochondrial damage in the kidney tubular cells. Given that PT alone or in combination with vancomycin is the most commonly prescribed antibiotic in patients at high risk of acute kidney injury, caution should be exercised.

A case of nephrogenic diabetes insipidus likely caused by anti-neutrophil cytoplastic antibody-associated vasculitis

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a relatively rare form of autoimmune disease. Diabetes insipidus (DI) is characterized by diluted polyuria and thirstiness, and is clinically categorized into central and nephrogenic DI depending on damaged organs. In most previously reported cases, ANCA-related disorders have been implicated in central DI, which is attributed to impaired secretion of arginine vasopressin (AVP) from the posterior pituitary. However, no previous case of AAV-related nephrogenic DI has been reported in the English literature. Herein, we report a case of nephrogenic DI likely caused by AAV. A 76-year-old man was admitted to our hospital for acute kidney injury. He showed dehydration, polyuria, and polydipsia. Laboratory tests demonstrated elevated levels of serum urea and creatinine and a high myeloperoxidase ANCA titer. In the present case, both plasma AVP concentration and response of AVP secretion to 5% saline load test were normal. In addition, 1-desmino-8-arginine vasopressin administration could not increase urinary osmolarity. Kidney biopsy specimen revealed tubulointerstitial nephritis with findings that appeared to indicate peritubular capillaritis. Therefore, the patient was diagnosed with nephrogenic DI likely owing to ANCA-associated tubulointerstitial nephritis. Immediately after prednisolone administration, urinary volume decreased, urinary osmolarity increased, and kidney function was improved. This case demonstrates that AAV that extensively affects the tubulointerstitial area can result in nephrogenic DI.

Piperacillin/tazobactam and risk of acute kidney injury in adults hospitalized with infection without vancomycin: a multi-centre real-world data analysis

BACKGROUND

There is uncertainty about whether piperacillin/tazobactam (PT) increases the risk of acute kidney injury (AKI) in patients without concomitant use of vancomycin. This study compared the risk of hospital-acquired AKI (HA-AKI) among adults treated with PT or antipseudomonal β-lactams (meropenem, ceftazidime) without concomitant use of vancomycin.

METHODS

This real-world study analysed the data from China Renal Data System and assessed the risk of HA-AKI in adults hospitalized with infection after exposure to PT, meropenem or ceftazidime in the absence of concomitant vancomycin. The primary outcome was any stage of HA-AKI according to the Kidney Disease Improving Global Outcomes guidelines. A multi-variable Cox regression model and different propensity score (PS) matching models were used.

RESULTS

Among the 29,441 adults [mean (standard deviation) age 62.44 (16.84) years; 17,980 females (61.1%)] included in this study, 14,721 (50%) used PT, 9081 (31%) used meropenem and 5639 (19%) used ceftazidime. During a median follow-up period of 8 days, 2601 (8.8%) develped HA-AKI. The use of PT was not associated with significantly higher risk of HA-AKI compared with meropenem [adjusted hazard ratio (aHR) 1.07, 95% confidence interval (CI) 0.97-1.19], ceftazidime (aHR 1.09, 95% CI 0.92-1.30) or both agents (aHR 1.07, 95% CI 0.97-1.17) after adjusting for confounders. Results were consistent in stratified analyses, PS matching using logistic regression or random forest methods to generate a PS, and in an analysis restricting outcomes to AKI stage 2-3.

CONCLUSIONS

Without concomitant use of vancomycin, the risk of AKI following PT therapy is comparable with that of meropenem or ceftazidime among adults hospitalized with infection.

Liraglutide ameliorates gentamicin-induced acute kidney injury in rats via PGC-1α- mediated mitochondrial biogenesis: Involvement of PKA/CREB and Notch/Hes-1 signaling pathways

Acute kidney injury (AKI) is a challenging side effect which may clinically impede the use of gentamicin (GM). The present study explored the impact of liraglutide (Lir) on GM-induced kidney injury in rats. Lir (0.2 and 0.4 mg/kg, s.c) was given for 10 days (a dose/day) starting 3 days before giving GM (100 mg/kg, i.p) once daily for 7 days. Interestingly, Lir notably ameliorated GM-induced elevated levels of renal injury markers; urea and creatinine. Moreover, Lir remarkably mitigated malondialdehyde (MDA) level and elevated glutathione (GSH) level as well as superoxide dismutase (SOD) activity. Also, Lir pre-treatment notably diminished inflammatory markers levels; interleukin-1β (IL-1β), tumor necrosis factor alpha (TNF-α), vascular cell adhesion molecule (VCAM), monocyte chemoattractant protein 1 (MCP-1) and interferon gamma (INF-γ). In addition, Lir significantly replenished expression of Peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1α), Protein kinase A (PKA), cAMP response element-binding protein (CREB), nuclear Nuclear factor erythroid 2-related factor 2 (Nrf2), heme Oxygenase-1 (HO-1), B-cell lymphoma 2 (Bcl-2), and remarkably attenuated expression of Notch homolog 1 (Notch1), Hairy and enhancer of split-1 (Hes-1), Bcl-2-associated X (Bax), cleaved caspase 3 and nuclear Nuclear factor Kappa B (NF-κB (p65)). The nephroprotective activity of Lir was further confirmed by histopathological examination as well as transmission electron microscopy (TEM). In conclusion Lir achieved its nephroprotective effects through the amelioration of oxidative stress, inflammatory and apoptotic manifestations. It is worth-mentioning that the current study is the first to focus on the involvement of mitochondrial biogenesis and its upstream regulators, PKA/CREB and Notch/Hes-1 signaling pathways in the nephroprotective potentials of Lir. The attenuation of the aforementioned injurious aspects is partially attributed to the improvement of the mitochondrial status as demonstrated by elevated PGC-1α expression via acceleration of PKA/CREB and abatement of Notch/Hes-1 signaling pathways.

Natural products for the prevention of antibiotic-associated kidney injury

Drug-induced acute kidney injury (AKI), especially from exposure to antibiotics, has a high prevalence secondary to their frequent prescription. Typically, drug-induced AKI results from acute tubular necrosis or acute interstitial nephritis. While some risk factors for the development of AKI in individuals treated with antibiotics are modifiable, others such as concomitant drug therapies to treat comorbidities, age, and pre-existing chronic kidney disease are not modifiable. As such, there is an urgent need to identify strategies to reduce the risk of AKI in individuals requiring antibiotic therapy. Natural products, especially those rich in active constituents possessing antioxidant properties are an attractive option to mitigate AKI risk. Given that mitochondrial dysfunction precedes AKI and natural products can restore mitochondrial health and counter the oxidative stress secondary to mitochondrial damage investigating their utility warrants further attention. The following review summarizes the available preclinical and clinical evidence that provides a foundation for future study.

3D proximal tubule-on-chip model derived from kidney organoids with improved drug uptake

Three-dimensional, organ-on-chip models that recapitulate kidney tissue are needed for drug screening and disease modeling. Here, we report a method for creating a perfusable 3D proximal tubule model composed of epithelial cells isolated from kidney organoids matured under static conditions. These organoid-derived proximal tubule epithelial cells (OPTECs) are seeded in cylindrical channels fully embedded within an extracellular matrix, where they form a confluent monolayer. A second perfusable channel is placed adjacent to each proximal tubule within these reusable multiplexed chips to mimic basolateral drug transport and uptake. Our 3D OPTEC-on-chip model exhibits significant upregulation of organic cation (OCT2) and organic anion (OAT1/3) transporters, which leads to improved drug uptake, compared to control chips based on immortalized proximal tubule epithelial cells. Hence, OPTEC tubules exhibit a higher normalized lactate dehydrogenase (LDH) release, when exposed to known nephrotoxins, cisplatin and aristolochic acid, which are diminished upon adding OCT2 and OAT1/3 transport inhibitors. Our integrated multifluidic platform paves the way for personalized kidney-on-chip models for drug screening and disease modeling.

Renal-clearable and biodegradable black phosphorus quantum dots for photoacoustic imaging of kidney dysfunction

The kidney is a vital organ and susceptible to various diseases. Photoacoustic (PA) imaging provides a powerful technique for studying kidney dysfunction, for which many smart photoacoustic imaging agents have been developed. But the complete clearance of the introduced contrast agents after imaging remains to be challenging, leading to long-term toxicity concerns. In this study, we synthesized black phosphorous quantum dots (BPQDs) with ultra-small size (1.74 ± 0.23 nm after surface modification) and strong PA signal for imaging kidney dysfunction. Importantly, the renal-clearance property and biodegradability of the developed BPQDs help circumvent the long-term toxicity issue for in vivo studies. Based on these BPQDs, both acute kidney injury and chronic kidney disease were successfully detected in the living mice by PA imaging, with higher detection sensitivity than the clinical serum indices examination method. This BPQDs-based PA imaging method should have a promising potential for the early diagnosis of kidney dysfunction in clinic.

Iopromide and Iodixanol in the Development of Postoperative Contrast Nephropathy in Patients with Renal Insufficiency: A Meta-Analysis

In order to compare the effects of iopromide and isoxazole on postoperative contrast-induced nephropathy in patients with renal insufficiency, the paper searches for randomized controlled trials and retrospective cohort studies comparing the effects of iopromide and iodixanol on renal function in patients with renal insufficiency after surgery. The data are extracted from eligible studies. We tried to assess the incidence of contrast-agent nephropathy, preoperative and postoperative serum creatinine indicators, and mortality. This paper includes 8 studies with a total of 1243 patients. The incidence of contrast-induced nephropathy in the iopromide group is higher than that in the iodixanol group, and there is no significant difference between the two groups in postoperative mortality and preoperative serum creatinine expression. Sensitivity analysis and funnel chart show that our research is robust and has low publication bias. Our research shows that in patients with renal insufficiency, the incidence of contrast-medium nephropathy in the iopromide group is higher than that in the iodixanol group. Iodixanol is safer and has less effect on patients' serum creatinine levels.

Nephroprotective potential of Panduratin A against colistin-induced renal injury via attenuating mitochondrial dysfunction and cell apoptosis

Colistin is a last-resort polypeptide antibiotic widely used to treat against multidrug-resistant Gram-negative bacterial infections. However, this treatment is associated with nephrotoxicity. The aim of this study was to examine the potential protective effect of panduratin A, a bioactive compound of Boesenbergia rotunda, on colistin-induced nephrotoxicity in both in vivo and in vitro models. Intraperitoneal injection of 15 mg/kg colistin for 7 days markedly promoted renal tubular degeneration, increased blood urea nitrogen (BUN) levels, and upregulated the expression of renal injury biomarker and apoptosis proteins. In addition, treatment with colistin increased oxidative stress and apoptosis in mice kidney tissues. Interestingly, these defects were attenuated when co-administered of colistin with panduratin A (2.5 or 25 mg/kg). The underlying mechanisms of panduratin A attenuating colistin toxicity was investigated in human renal proximal tubular cells (RPTEC/TERT1). The mechanisms by which colistin-triggered cytotoxicity was determined by analysis of cell death, reactive oxygen species (ROS) levels, mitochondria function as well as the expression of proteins related to apoptosis pathway. Colistin treatment (200 µg/ml) significantly increased cell apoptosis, elevated ROS production, reduced mitochondrial membrane potential, and decreased anti-apoptotic protein (Bcl-2) expression. These effects were notably suppressed by co-treatment with panduratin A (5 μM). Collectively, panduratin A exerts as a novel nephroprotective agent to protect against colistin-induced renal injury by attenuating mitochondrial damage and renal cell apoptosis.

Using intracellular metabolic profiling to identify novel biomarkers of cisplatin-induced acute kidney injury in NRK-52E cells

The aim of this study was to investigate changes in the intracellular metabolism resulting from cisplatin (CDDP)-induced nephrotoxicity in normal kidney tubular epithelial NRK-52E cells. Cytotoxicity, cell cycle analysis, and apoptotic cell death were all evaluated in NRK-52E cells treated with CDDP. Subsequently, proton nuclear magnetic resonance (¹H-NMR) spectroscopy was used to investigate cellular metabolic profiles. CDDP-induced nephrotoxicity was determined in vivo model. Cytotoxicity in the NRK-52E cells significantly rose following treatment with CDDP and these increases were found to be concentration-dependent. Both p53 and Bax protein expression was increased in CDDP-treated NRK-52E cells, correlating with enhanced cellular apoptosis. In addition, a number of metabolites were altered in both media and cell lysates in these cells. In cell lysates, citrate, creatinine, and acetate levels were dramatically reduced following treatment with 20 µM CDDP concentrations, while glutamate level was elevated. Lactate and acetate levels were significantly increased in culture media but citrate concentrations were reduced following high 20 µM CDDP concentrations incubation. In addition, excretion of clusterin, calbindin, neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), selenium binding protein 1 (SBP1), and pyruvate kinase M2 (PKM2) into the culture media was significantly increased in CDDP-treated cells while expression of acetyl CoA synthetase 1 (AceCS1) was markedly reduced in these cells. These findings suggest that acetate-dependent metabolic pathway may be a reliable and useful biomarker for detecting CDDP-induced nephrotoxicity. Taken together, data demonstrate that the discovery of novel biomarkers by metabolite profiling in target cells may contribute to the detection of nephrotoxicity and new drug development.

Drug Therapies Affecting Renal Function: An Overview

Undesirable side effects of medication are inevitable. Due to the role of the kidneys in clearance and filtration, the renal system faces a unique situation when it comes to the side effects of drugs. It has an important role for different classes of drugs to be excreted, and drugs are a key factor for this system to be at risk. Medications in articles were divided into classes using the standard set by the Saudi Pharmaceutical Journal. Many drug classes cause renal insults. The top six classes were pain killers, antibiotics, proton pump inhibitors, antidiabetics, antihyperlipidemics, and agents for erectile dysfunction. Renal insults caused by these agents could vary in severity. Some drugs could cause nephrotoxicity from one dose, while others may only need continuous monitoring. Different populations also operate under different rules, as some people need dose adjustments while others who are medically free of major illnesses do not. A variety of unfavorable outcomes for the kidney could take place, such as acute kidney injury, chronic kidney disease, and end-stage renal disease, and unfortunately, some of these issues could lead to the need for renal replacement therapies. The outcome of this review paper will help multidisciplinary physicians to understand the renal side effects of the most used drug classes in the Kingdom of Saudi Arabia, their destructive mechanisms, and most importantly, the clinical presentations of renal dysfunction in relation to each class. Emphasizing these adverse effects will prevent future unfavorable outcomes, especially in commonly used drugs that are frequently prescribed for different age groups. Moreover, some of these drugs are considered to be over-the-counter medications, which makes them a serious problem that needs to be handled cautiously.

Hematological and renoprotective effects of folic acid and lentil extract in diclofenac sodium exposed rats

Excessive intake of non-steroidal anti-inflammatory drugs such as, diclofenac sodium (DS) may lead to toxicity in the rats. In this work, we aimed to examine the protective impact of lentil extract (LE) and folic acid (FA) on the hematological markers, the kidney tissue oxidative stress and the renal function against diclofenac sodium (DS) in male albino rats. The rats (120-150 g) were divided into four equal groups randomly, the first group kept as the untreated control. The second group was administrated with DS (11.6 mg/kg b.wt. orally once/day). The third group was received DS+FA (11.6 mg/kg b.wt.+76.9 microgram/kg b.wt.) orally once/day. The fourth group was treated with DS+LE (11.6 mg/kg b.wt.+500 mg/kg b.wt.) orally once/day. After four weeks, the results revealed that DS produced a significant decrease in the values of red blood cells (RBCs), hemoglobin concentration (Hb), hematocrit (HCT) and white blood cells (WBCs). On the other hand, there was a significant increase in the platelets count. Also, DS induced a renal deterioration; this was evidenced by the significant increase in the serum levels of urea, creatinine, uric acid, Na, Ca, Mg as well as the nitric oxide (NO) level in the kidney tissue. Also, there were a significant reduction in the serum levels of potassium (K) and reduced glutathione (GSH) in the kidney homogenates. Moreover, the findings in the rats treated by DS+LE or DS+FA showed a potential protection on the hematological markers, oxidative stress in the kidney tissue and the renal function disturbed by DS. LE and FA could play a potent role for the prevention the adverse hematological, the kidney tissue oxidative stress and the renal dysfunction caused by DS via their anti-oxidative and bioactive phytochemicals.

Taurine alleviates kidney injury in a thioacetamide rat model by mediating Nrf2/HO-1, NQO-1 and MAPK/ NF-κB signaling pathways

This study aimed to investigate the molecular mechanisms by which taurine exerts its reno-protective effects in thioacetamide (TAA)-induced kidney injury in rats. Rats received taurine (100 mg/kg daily, intraperitoneally) either from day 1 of TAA injection (250 mg/kg twice weekly for 6 weeks) or after 6 weeks of TAA administration. Taurine treatment, either concomitant or later as a therapy, restored kidney functions, reduced BUN, creatinine, MDA, and increased renal levels of SOD and reversed the increase of KIM-1 and NGAL caused by TAA. Taurine treatment also led to a significant rise in Nrf2, HO-1, and NQO-1 levels, with significant suppression of ERK 1/2, NF-κB, and TNFα gene expressions, and IL-18 and TNFα protein levels compared to those in TAA kidney-injured rats. Taurine exhibited reno-protective potential in TAA-induced kidney injury through its anti-oxidant and anti-inflammatory effects. Taurine anti-oxidant activity is accredited to its effect on Nrf-2 induction and subsequent activation of HO-1 and NQO-1. In addition, taurine exerts its anti-inflammatory effect via regulating NF-κB transcription and subsequent production of pro-inflammatory mediators via MAPK signaling regulation.

Lowered Risk of Nephrotoxicity through Intervention against the Combined Use of Vancomycin and Tazobactam/Piperacillin: A Retrospective Cohort Study

The combined use of vancomycin (VCM) and tazobactam/piperacillin (TAZ/PIPC) is a major risk factor for nephrotoxicity. We sought to evaluate interventions against the combined use of VCM and TAZ/PIPC. This retrospective cohort study involved patients who considered the combined use of VCM and TAZ/PIPC as a treatment. Patients that had either or both antimicrobials replaced were assigned to the intervention group, whereas those who were continued on combination therapy were assigned to the comparison group. The primary endpoint was the incidence of acute kidney injury (AKI). The survival rate of patients on day 30 was evaluated as the secondary endpoint. The comparison and intervention groups were composed of 65 and 68 patients, respectively, and the incidence rates of AKI were 44.6% and 17.6%, respectively. Cox proportional hazard analysis identified the intervention as the only independent factor against AKI development, with a hazard ratio of 0.282 (95% confidence interval [CI], 0.141 to 0.565). For the incidence of AKI of grade greater than 1, the hazard ratio was 0.114 (95% CI, 0.025 to 0.497). The survival rates on day 30 in the comparison and intervention groups were 92.3% and 91.2%, respectively, with a relative risk of 0.988 (95% CI, 0.892 to 1.094). The trough VCM concentration was not associated with the incidence of AKI in patients receiving the combination therapy. This study demonstrated that intervention against the combined use of VCM and TAZ/PIPC can lower the risk of nephrotoxicity. IMPORTANCE The combined use of vancomycin (VCM) and tazobactam/piperacillin (TAZ/PIPC) is a major risk factor for nephrotoxicity. We retrospectively evaluated interventions against the combined use of VCM and TAZ/PIPC. Patients for whom either or both antimicrobials were replaced were assigned to the intervention group (65 patients), whereas those who were continued on combination therapy were assigned to the comparison group (68 patients). The primary endpoint was the incidence of acute kidney injury (AKI). The incidence rates of AKI in the intervention and comparison groups were 44.6% and 17.6%, respectively. Cox proportional hazard analysis identified intervention as the only independent factor against AKI development, with a hazard ratio of 0.282 (95% confidence interval [CI], 0.141 to 0.565). In conclusion, this study demonstrated that intervention against the combined use of VCM and TAZ/PIPC can lower the risk of nephrotoxicity.

Fluoro-photoacoustic polymeric renal reporter for real-time dual imaging of acute kidney injury

In this chapter, we introduced a diagnostic approach for acute kidney injury (AKI) via photoacoustic imaging. We provided detailed synthetic procedures of a biomarker-activatable photoacoustic agent (FPRR) with high renal clearance efficiency. We also provided protocols for in vitro characterization, live-cell imaging, and in vivo imaging in a drug-induced AKI mice model. Compared to near-infrared fluorescence imaging, photoacoustic imaging is more sensitive with higher signal-to-background ratio. As such, our approach serves as a general guideline in the development of photoacoustic agents for diagnosis of urological diseases. With this tool in hand, researchers in the field of optical imaging may be inspired to develop other photoacoustic agents for early stage disease diagnosis.

Prediction of drug-induced kidney injury in drug discovery

Drug induced kidney injury is one of the leading causes of failure of drug development programs in the clinic. Early prediction of renal toxicity potential of drugs is crucial to the success of drug candidates in the clinic. The dynamic nature of the functioning of the kidney and the presence of drug uptake proteins introduce additional challenges in the prediction of renal injury caused by drugs. Renal injury due to drugs can be caused by a wide variety of mechanisms and can be broadly classified as toxic or obstructive. Several biomarkers are available for in vitro and in vivo detection of renal injury. In vitro static and dynamic (microfluidic) cellular models and preclinical models can provide valuable information regarding the toxicity potential of drugs. Differences in pharmacology and subsequent disconnect in biomarker response, differences in the expression of transporter and enzyme proteins between in vitro to in vivo systems and between preclinical species and humans are some of the limitations of current experimental models. The progress in microfluidic (kidney-on-chip) platforms in combination with the ability of 3-dimensional cell culture can help in addressing some of these issues in the future. Finally, newer in silico and computational techniques like physiologically based pharmacokinetic modeling and machine learning have demonstrated potential in assisting prediction of drug induced kidney injury.

Acute kidney damage by PM2.5 exposure in a rat model

PM2.5 exposure is associated with a glomerular filtration rate (GFR) reduction, and renal tissue damage. The goal of this study was demonstrate the acute effect of PM2.5 on the kidney. Male rats were acutely exposed to PM2.5 or filtered air. Blood pressure was mesure and early kidney biomarkers were evaluated in serum and urine samples, and also IL-1β, IL-6 and TNFα were determined. Oxidative biomarkers, angiotensin/bradykinin-related proteins, KIM-1, IL-6 and histology were determined. Blood pressure, GFR, and early kidney damage biomarkers increase together with oxidative biomarkers and angiotensin/bradykinin endocrine-related proteins increased after exposure to PM2.5. Urinary IL-6 increased after exposure to PM2.5, whereas in kidney cortex decreased. Histological changes were observed and accompanied by the induction of KIM-1. Acute exposure to PM2.5 not decline kidney function. However, it can induce early kidney damage biomarkers, oxidative stress, inflammation and angiotensin mediators, which perhabs culminates in a lose of renal function.

Nephrotoxicity from Vancomycin Combined with Piperacillin-Tazobactam: A Comprehensive Review

BACKGROUND

Recent studies have identified the combination of vancomycin with piperacillin-tazobactam (VPT) to be associated with increased nephrotoxicity. Multiple, large cohort studies have found this widely used combination to have a higher risk of nephrotoxicity than other regimens in a variety of populations.

SUMMARY

This review summarizes the epidemiology and clinical features of VPT-associated acute kidney injury (AKI). Potential mechanisms involved in the pathogenesis of this phenomenon are also discussed. Key Message: VPT-associated nephrotoxicity is a recently recognized clinical entity. Clinical strategies to minimize the risk of toxicity in this setting include antimicrobial stewardship, monitoring of kidney function, and emerging data supporting the potential role for novel biomarkers in predicting and managing AKI.

Effect of Kaempferol on Tacrolimus-Induced Nephrotoxicity and Calcineurin B1 Expression Level in Animal Model

BACKGROUND

The kidneys are considered one of the most susceptible organs for adverse drug effects, particularly in post-transplant conditions. Tacrolimus (FK506), a calcineurin inhibitor immunosuppressant, is an essential component in the transplantation regimen. Despite that, nephrotoxicity is a severe drawback for its chronic utilization, where oxidative stress might be implicated. Kaempferol (KMF) is a natural flavonoid that has many adaptable biological activities, including antioxidant action.

OBJECTIVE

Exploring the KMF protective effect on FK506-induced nephrotoxicity and the underlying role of calcineurin B1.

METHODS

Twenty-four male albino-Wistar rats were randomly divided into three equal groups. The control group received solvents: propylene glycol, i.p. and 0.5% carboxymethyl cellulose, PO; FK506 group was injected with FK506 (0.6 mg/kg, i.p.), and FK506+KMF group was given FK506 (0.6 mg/kg, i.p.) and KMF (10 mg/kg, PO). The treatment regimen for all groups was once daily for 30 days. ELISA technique applied for measuring FK506 trough level and nephrotoxicity biomarkers in serum (cystatin C and urea) on days 15 and 30, and in kidney tissue homogenate (MDA and calcineurin B1) on day 30.

RESULTS

In FK506-treated rats, the FK506 trough level was 7.84 ± 1.31 ug/l on day 15 and 9.54 ± 1.45 ug/l on day 30. FK506 use has significantly (P<0.01) increased biomarkers levels of cystatin C (325% and 477%), urea (177% and 245%), MDA (1253%), except calcineurin B1 that has decreased (97%). The KMF combination has resulted in a significant reduction in the FK506 trough level by day 30 (6.79 ± 1.35 ug/l, P<0.01). KMF has significantly ameliorated the levels of cystatin C (46% and 73%, P<0.001), urea (38% and 68%, P<0.001), MDA (75%, P<0.001), and calcineurin B1 (1833%, P<0.05).

CONCLUSION

Oxidative stress and calcineurin B1 are contributing factors in FK506-induced nephrotoxicity. Hence, inhibition of calcineurin enzyme is not limited to the immune cells. KMF could be a novel nephroprotective antioxidant.

The Effect of Acetylcysteine on Renal Function in Experimental Models of Cyclophosphamide-and Ifosfamide-Induced Cystitis

Introduction

Urotoxicity is a characteristic attribute of cy-clophosphamide and ifosfamide. Acetylcysteine is perceived as a uroprotective and possible nephroprotective compound. The purpose of the study was to assess the effect of acetylcysteine treatment on the morphology of the kidneys and the urinary bladder, and renal function in rats with cystitis induced by cyclophosphamide or ifosfamide.

Methods

Cystitis was induced in rats belonging to groups 2 and 3, as well as 4 and 5, by five administrations of cyclophosphamide (75 mg/kg) or ifosfamide (80 mg/kg) respectively. Additionally, groups 3 and 5 received acetylcysteine (200 mg/kg). Group 1 was "sham treated" as a control. Upon conclusion of the experiment, the animals were euthanized and their kidneys and urinary bladders were collected for histopathological analysis. The assessment of renal function was based on classic nitrogen blood parameters (urea, creatinine, and uric acid), as well as proteinuria and cystatin C (CysC) and kidney injury molecule-1 (KIM-1) urinary concentrations, and their 24-hour elimination with urine.

Results

Reduction of blood urea nitrogen and uric acid, and urinary pH with a significant increase of CysC and KIM-1 urinary concentrations, and their 24-hour elimination with urine were observed in groups 2 and 4. The acetylcysteine treatment did not cause a significant change of blood parameters, but significantly decreased 24-hour elimination of CysC and KIM-1 with urine, and accounted for alleviation of the histopathological abnormalities of urinary bladders, with no significant effects on the structure of the kidneys.

Conclusions

Acetylcysteine used in the experimental model of cyclophosphamide- and ifosfamide-induced cystitis had a uroprotective effect and also reduced renal dysfunction, which suggests its potential use as a nephroprotective compound in cyclophosphamide/ifosfamide therapy.

A Review on Drug-Induced Nephrotoxicity: Pathophysiological Mechanisms, Drug Classes, Clinical Management, and Recent Advances in Mathematical Modeling and Simulation Approaches

A variety of marketed drugs belonging to various therapeutic classes are known to cause nephrotoxicity. Nephrotoxicity can manifest itself in several forms depending on the specific site involved as well as the underlying pathophysiological mechanisms. As they often coexist with other pathophysiological conditions, the steps that can be taken to treat them are often limited. Thus, drug-induced nephrotoxicity remains a major clinical challenge. Prior knowledge of risk factors associated with special patient populations and specific classes of drugs, combined with early diagnosis, therapeutic drug monitoring with dose adjustments, as well as timely prospective treatments are essential to prevent and manage them better. Most incident drug-induced renal toxicity is reversible only if diagnosed at an early stage and treated promptly. Hence, diagnosis at an early stage is the need of the hour to counter it. Significant recent advances in the identification of novel early biomarkers of nephrotoxicity are not beyond limitations. In such a scenario, mathematical modeling and simulation (M&S) approaches may help to better understand and predict toxicities in a clinical setting. This review summarizes pathophysiological mechanisms of drug-induced nephrotoxicity, classes of nephrotoxic drugs, management, prevention, and diagnosis in clinics. Finally, it also highlights some of the recent advancements in mathematical M&S approaches that could be used to better understand and predict drug-induced nephrotoxicity.

Acute interstitial nephritis and nephrogenic diabetes insipidus following treatment with sulfamethoxazole-trimethoprim and temozolomide

We report a case of acute interstitial nephritis with associated nephrogenic diabetes insipidus in a patient treated with temozolomide and sulfamethoxazole-trimethoprim for glioblastoma multiforme. Kidney biopsy demonstrated focal tubulointerstitial change with tubular dilatation, epithelial change and interstitial inflammation. The patient's kidney function improved with cessation of sulfamethoxazole-trimethoprim and treatment with hydrochlorothiazide for nephrogenic diabetes insipidus. Recommencement of temozolomide did not result in further deterioration in kidney function. In this case report, we discuss the novel association between sulfamethoxazole-trimethoprim-induced acute interstitial nephritis and nephrogenic diabetes insipidus, and suggest possible mechanisms involved.

Bioactive lipids, inflammation and chronic diseases

Endogenous bioactive lipids are part of a complex network that modulates a plethora of cellular and molecular processes involved in health and disease, of which inflammation represents one of the most prominent examples. Inflammation serves as a well-conserved defence mechanism, triggered in the event of chemical, mechanical or microbial damage, that is meant to eradicate the source of damage and restore tissue function. However, excessive inflammatory signals, or impairment of pro-resolving/anti-inflammatory pathways leads to chronic inflammation, which is a hallmark of chronic pathologies. All main classes of endogenous bioactive lipids - namely eicosanoids, specialized pro-resolving lipid mediators, lysoglycerophopsholipids and endocannabinoids - have been consistently involved in the chronic inflammation that characterises pathologies such as cancer, diabetes, atherosclerosis, asthma, as well as autoimmune and neurodegenerative disorders and inflammatory bowel diseases. This review gathers the current knowledge concerning the involvement of endogenous bioactive lipids in the pathogenic processes of chronic inflammatory pathologies.

Machine Learning for Identifying Medication-Associated Acute Kidney Injury

One of the prominent problems in clinical medicine is medication-induced acute kidney injury (AKI). Avoiding this problem can prevent patient harm and reduce healthcare expenditures. Several researches have been conducted to identify AKI-associated medications using statistical, data mining, and machine learning techniques. However, these studies are limited to assessing the impact of known nephrotoxic medications and do not comprehensively explore the relationship between medication combinations and AKI. In this paper, we present a population-based retrospective cohort study that employs automated data analysis techniques to identify medications and medication combinations that are associated with a higher risk of AKI. By integrating multivariable logistic regression, frequent itemset mining, and stratified analysis, this study is designed to explore the complex relationships between medications and AKI in such a way that has never been attempted before. Through an analysis of prescription records of one million older patients stored in the healthcare administrative dataset at ICES (an independent, non-profit, world-leading research organization that uses population-based health and social data to produce knowledge on a broad range of healthcare issues), we identified 55 AKI-associated medications among 595 distinct medications and 78 AKI-associated medication combinations among 7748 frequent medication combinations. In addition, through a stratified analysis, we identified 37 cases where a particular medication was associated with increasing the risk of AKI when used with another medication. We have shown that our results are consistent with previous studies through consultation with a nephrologist and an electronic literature search. This research demonstrates how automated analysis techniques can be used to accomplish data-driven tasks using massive clinical datasets.

Evaluation of biomarkers for in vitro prediction of drug-induced nephrotoxicity in RPTEC/TERT1 cells

There have been intensive efforts to identify in vivo biomarkers that can be used to monitor drug-induced kidney damage before significant impairment occurs. Kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, clusterin, β2-microglobulin and cystatin C (CysC) have been validated as clinical or preclinical biomarkers in urinary and plasma predictive of acute and chronic kidney injuries and diseases. A high-throughput in vitro assay predictive of nephrotoxicity could potentially be implemented in early drug discovery stage to reduce attrition at later stages of drug development. To assess the potential of these known in vivo biomarkers for in vitro evaluation of drug-induced nephrotoxicity, we selected four nephrotoxic agents (cisplatin, cyclosporin, aristolochic acid I and gentamicin) and detected their effects on the protein levels of nephrotoxic biomarkers in RPTEC/TERT1 cells. The protein levels of clusterin, CysC, GSTπ and TIMP-1 significantly increased in the conditioned media of RPTEC/TERT1 cells treated with cisplatin, cyclosporin, aristolochic acid I and gentamicin. The messenger RNA levels of clusterin, CysC, GSTπ and TIMP-1 also increased in RPTEC/TERT1 cells treated with cisplatin, cyclosporin, aristolochic acid I and gentamicin, indicating that drug-induced upregulation involves transcriptional activation. Taken together, the results clearly demonstrate that among the known in vivo nephrotoxic biomarkers, clusterin, CysC, GSTπ and TIMP-1 can be effectively used as in vitro biomarkers for drug-induced nephrotoxicity in RPTEC/TERT1 cells.

Acute kidney injury with combination vancomycin and piperacillin-tazobactam therapy in the ICU: A retrospective cohort study

Vancomycin and piperacillin-tazobactam are commonly used antibiotics. There is increasing evidence to indicate that these therapies in combination predispose patients to acute kidney injury (AKI). However, studies of intensive care unit (ICU) patients with these antibiotics have produced conflicting results. In this single-centre, retrospective cohort study, data was collected on ICU patients prescribed combination vancomycin and piperacillin-tazobactam (VPT) for at least 48 h, compared with patients prescribed vancomycin with either cefepime or meropenem (VMC) for the same time period. Primary outcome was incidence of AKI; secondary outcomes included a desirability of outcome ranking (DOOR) scale, and association between antibiotic duration and kidney injury. A total of 260 patients were included. AKI was observed in 27% of cases overall. Incidence of AKI was higher with VPT compared with VMC on bivariate (relative risk reduction [RRR] 1.9, 95% confidence interval [CI] 0.9-4.1, P = 0.08) and multivariate (RRR 2.2, 95% CI 1.0-4.9, P = 0.05) analyses. Longer duration of antibiotic therapy was associated with increased rates of AKI independent of which antibiotics were prescribed: RRR 4.9, 95% CI 2.1-11.1, P = <0.001 for 5-6 days compared with <5 days, and RRR 2.3, 95% CI 1.0-5.5, P = 0.05 for >7 days compared with <5 days. This study demonstrated an association between increased risk of nephrotoxicity and combination VPT therapy in ICU patients. The concept remains controversial, with recent suggestions that VPT does not truly cause nephrotoxicity. Given our findings and the weight of previous studies, there is a strong mandate to undertake prospective trials to resolve the issue.

A Systems Toxicology Approach for the Prediction of Kidney Toxicity and Its Mechanisms In Vitro

The failure to predict kidney toxicity of new chemical entities early in the development process before they reach humans remains a critical issue. Here, we used primary human kidney cells and applied a systems biology approach that combines multidimensional datasets and machine learning to identify biomarkers that not only predict nephrotoxic compounds but also provide hints toward their mechanism of toxicity. Gene expression and high-content imaging-derived phenotypical data from 46 diverse kidney toxicants were analyzed using Random Forest machine learning. Imaging features capturing changes in cell morphology and nucleus texture along with mRNA levels of HMOX1 and SQSTM1 were identified as the most powerful predictors of toxicity. These biomarkers were validated by their ability to accurately predict kidney toxicity of four out of six candidate therapeutics that exhibited toxicity only in late stage preclinical/clinical studies. Network analysis of similarities in toxic phenotypes was performed based on live-cell high-content image analysis at seven time points. Using compounds with known mechanism as reference, we could infer potential mechanisms of toxicity of candidate therapeutics. In summary, we report an approach to generate a multidimensional biomarker panel for mechanistic de-risking and prediction of kidney toxicity in in vitro for new therapeutic candidates and chemical entities.

Caffeine Overdose Complicated by Acute Kidney Injury despite Mild Creatine Kinase Elevation

Caffeine is a commonly used stimulant in our society. Prior case reports have described acute caffeine overdose resulting in rhabdomyolysis and acute kidney injury (AKI). We present the case of a 29-year-old man who presented to the emergency department after ingesting 20.1 g of caffeine in a suicide attempt and experienced AKI with only mildly elevated creatine kinase (CK). This case highlights the possibility that AKI can result from a caffeine overdose, even if the patient’s CK is only slightly elevated.

Subacute dermal toxicity of perfluoroalkyl carboxylic acids: comparison with different carbon-chain lengths in human skin equivalents and systemic effects of perfluoroheptanoic acid in Sprague Dawley rats

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are used in various fields but raise concerns regarding human health and environmental consequences. Among PFASs, perfluorooctanoic acid (PFOA) and short-chain perfluoroalkyl carboxylic acids (SC PFCAs) are detectable in skin-contact consumer products and have dermal absorption potential. Here, we investigated the effects of dermal exposure to PFOA and SC PFCAs using in vitro and in vivo models. Human skin equivalents were topically treated with 0.25 mM and 2.5 mM PFOA and SC PFCAs (perfluoropentanoic acid, PFPeA; perfluorohexanoic acid, PFHxA; and perfluoroheptanoic acid, PFHpA) for 6 days, and cell viability, interleukin (IL)-1α, oxidative stress markers (malondialdehyde, MDA; and 8-hydroxydeoxyguanosine, 8-OHdG), and histopathology were examined. MDA levels were significantly higher in the PFASs groups than in controls. Compared with SC PFCAs, 2.5 mM PFOA caused more IL-1α (p < 0.001) release, decreased skin thickness and microscopic abnormalities. To evaluate systemic effects, Sprague Dawley (SD) rats were dermally treated with 250 and 1000 mg/kg PFHpA for 2 weeks and clinical and anatomic pathology were assessed. At 1000 mg/kg, 83% of the rats died, with severe ulcerative dermatitis at the application site. Adverse PFHpA-treated systemic changes were observed in the kidney, liver and testes, and histopathologic lesions such as renal tubular necrosis, hepatocellular necrosis, and germ cell degeneration were seen at 250 and 1000 mg/kg. Our study suggests that SC PFCAs have fewer effects on the skin than PFOA, but SC PFCAs can have adverse effects on major organs with systemic exposure at high concentrations.

Mechanisms of antimicrobial-induced nephrotoxicity in children

Drug-induced nephrotoxicity is responsible for 20% to 60% of cases of acute kidney injury in hospitalized patients and is associated with increased morbidity and mortality in both children and adults. Antimicrobials are one of the most common classes of medications prescribed globally and also among the most common causes of nephrotoxicity. A broad range of antimicrobial agents have been associated with nephrotoxicity, but the features of kidney injury vary based on the agent, its mechanism of injury and the site of toxicity within the kidney. Distinguishing nephrotoxicity caused by an antimicrobial agent from other potential inciting factors is important to facilitate both early recognition of drug toxicity and prompt cessation of an offending drug, as well as to avoid unnecessary discontinuation of an innocuous therapy. This review will detail the different types of antimicrobial-induced nephrotoxicity: acute tubular necrosis, acute interstitial nephritis and obstructive nephropathy. It will also describe the mechanism of injury caused by specific antimicrobial agents and classes (vancomycin, aminoglycosides, polymyxins, antivirals, amphotericin B), highlight the toxicodynamics of these drugs and provide guidance on administration or monitoring practices that can mitigate toxicity, when known. Particular attention will be paid to paediatric patients, when applicable, in whom nephrotoxin exposure is an often-underappreciated cause of kidney injury.

A hairpin DNA-fueled nanoflare for simultaneous illumination of two microRNAs in drug-induced nephrotoxic cells with target catalytic recycling amplification

The detection of specific extracellular microRNAs (miRNAs) is beneficial for the prediction of drug-induced kidney injury. Here, a novel hairpin DNA-fueled nanoflare was developed for the simultaneous detection of drug-induced nephrotoxicity-related miRNA-21 and miRNA-200c with target catalytic recycling amplification. The nanoflare utilized gold nanoparticles (AuNPs) as the highly efficient quencher to ensure a low background signal. With the help of the fueled hairpin DNA, the miRNA targets could serve as the catalysts for the assembly of DNA duplexes. Therefore, the nanoflare could respond to the miRNAs to yield signal outputs of 1 : n (target : signal) rather than an equivalent reaction ratio of 1 : 1, achieving the signal amplified detection of low-abundant miRNAs. The targets can be concurrently detected with the detection limit of 18.1 and 21.1 pM for miRNA-21 and miRNA-200c, respectively, which are approximately 2 orders of magnitude lower than that of the non-catalytic probes. In addition, this nanoflare offered a high selectivity for determination between perfectly matched targets and single-base mismatched targets. It should be noted that the nanoflare was successfully employed to predict the drug-induced nephrotoxicity by the detection of miRNAs in culture media excreted from the drug-treated renal cells using a fluorescent microplate reader. Our hairpin DNA-fueled nanoflare could also accurately detect the divergence of miRNA-21 and miRNA-200c between drug-treated nephrotoxic cells and tumor cells, demonstrating a promising potential for exploring the pathogenesis of drugs and auxiliary diagnosis of drug-induced nephrotoxicity.

Effective reconstruction of functional organotypic kidney spheroid for in vitro nephrotoxicity studies

Stable and reproducible kidney cellular models could accelerate our understanding of diseases, help therapeutics development, and improve nephrotoxicity screenings. Generation of a reproducible in vitro kidney models has been challenging owing to the cellular heterogeneity and structural complexity of the kidney. We generated mixed immortalized cell lines that stably maintained their characteristic expression of renal epithelial progenitor markers for the different lineages of kidney cellular compartments via the BMP7 signaling pathway from a mouse and a human whole kidney. These cells were used to generate functional and matured kidney spheroids containing multiple renal lineages, such as the proximal tubule, loop of Henle, distal tubules, and podocytes, using extracellular matrix and physiological force, named spheroid-forming unit (SFU). They expressed all apical and basolateral transporters that are important for drug metabolism and displayed key functional aspects of the proximal tubule, including protein endocytosis and increased gamma-glutamyltransferase activity, and cyclic AMP responded to external cues, such as parathyroid hormone. Following exposure, cells fluxed and took up drugs via proximal tubule-specific apical or basolateral transporters, and displayed increased cell death and expression of renal injury marker. Here, we developed a new differentiation method to generate kidney spheroids that structurally recapitulate important features of the kidney effectively and reproducibly using mixed immortalized renal cells, and showed their application for renal toxicity studies.