Acute kidney injury and distant organ dysfunction-network system analysis

CircPICALM promotes neonatal acute kidney injury triggered by hypoxia/reoxygenation via sponging microRNA-204-5p

BACKGROUND

Circular RNAs (circRNAs) have been documented to regulate neonatal acute kidney injury (AKI). Based on previous RNA-sequence findings, circPICALM exhibited significantly disparate expression between AKI newborns and Controls. This study aimed to provide further insights into the regulatory mechanism of circPICALM in neonatal AKI.

METHODS

C57BL/6 mice born 7 days were divided into Control group and hypoxia groups (11%O2 and 8%O2 groups). Human tubule epithelial cells (HK-2) were stimulated with hypoxia/reoxygenation (H/R) to establish an AKI cell model. Through overexpression and knockdown techniques, the regulatory role of circPICALM in H/R-induced kidney injury was explored. Inflammatory cytokines, cell apoptosis, and oxidative stress were also detected to confirm the regulatory function of circPICALM in neonatal AKI.

RESULTS

RT-qPCR confirmed that circPICALM was highly expressed in the serum of AKI newborns, neonatal I/R mice and H/R-treated HK-2 cells. Functionally, circPICALM exacerbated H/R-induced HK-2 cell injury by aggravating apoptosis and mitochondrial oxidative stress, increasing the expression of inflammatory factors, including IL-6, IL-1β, and TNF-α. Conversely, inhibition of circPICALM alleviated H/R injury in the HK-2 cell line. The interaction between circPICALM and miR-204-5p was validated through RNA immunoprecipitation and luciferase assay. Finally, circPICALM functioned as a molecular sponge of miR-204-5p and promoted the upregulation of downstream IL-1β expression.

CONCLUSION

CircPICALM plays a critical role in H/R-induced neonatal AKI by sponging miR-204-5p and then activating the downstream IL-1β signaling axis. The inhibition of circPICALM and subsequent suppression of pro-inflammatory factors could serve as a promising biomarker and therapeutic target for early intervention in neonatal AKI.

Targeting Stat3 with conditional knockout or PROTAC technology alleviates renal injury by Limiting pyroptosis

BACKGROUND

Acute kidney injury (AKI) is a critical clinical syndrome with high morbidity, mortality, and no effective treatment in clinical practice. The role of the Signal Transducer and Activator of Transcription 3 (Stat3) in AKI remains controversial, and its complex regulatory mechanisms must be further explored.

METHODS

We generated renal tubular epithelial cells Stat3 conditional knockout (cKO) mice and used them in cecal ligation and puncture (CLP) and ischaemia-reperfusion (I/R) induced AKI models. Additionally, proteolysis-targeting chimaera (PROTAC) compound E034 was designed and synthesised. We also utilised human kidney tissues, mouse renal tubular epithelial cells (mTECs) and HK-2 cells for further studies, including immunohistochemistry, Western blot analysis, Real-time PCR, chromatin immunoprecipitation (ChIP) and RNA sequencing, scanning electron microscopy (SEM) and Co-Immunoprecipitation (Co-IP) assay.

FINDINGS

An upregulation of total Stat3 protein was observed in AKI mouse models, which correlated with patient biopsy results. This increase may be attributed to histone H3K27 acetylation. Stat3 knockout in renal tubular epithelial cells significantly reduced AKI injury and inflammation in mice. Mechanistically, Stat3 induces the transcription of tripartite motif-containing protein 21 (Trim21), triggering a cascade that activates gasdermin D (Gsdmd), resulting in pyroptosis. Administration of E034, which selectively targets Stat3 for ubiquitination and degradation, significantly alleviated renal injury in a low-dose, single-dose regimen.

INTERPRETATION

In the context of renal injury, PROTAC emerges as a promising modality by explicitly targeting the Stat3/Trim21/Gsdmd axis, which our study has identified as a potential therapeutic target, potentially endowing clinically significant therapeutic strategies.

FUNDING

This work was supported by the National Key R&D Program (2022YFC2502503), the National Natural Science Foundation of China (No. 82270738), the National Natural Science Foundation of China (No. 82400806) and the Graduate Research and Practice Innovation Project of Anhui Medical University (YJS20230059).

Acute kidney injury triggers hypoxemia by lung intravascular neutrophil retention that reduces capillary blood flow

Sterile acute kidney injury (AKI) is common in the clinic and frequently associated with unexplained hypoxemia that does not improve with dialysis. AKI induces remote lung inflammation with neutrophil recruitment in mice and humans, but which cellular cues establish neutrophilic inflammation and how it contributes to hypoxemia is not known. Here we report that AKI induced rapid intravascular neutrophil retention in lung alveolar capillaries without extravasation into tissue or alveoli, causing hypoxemia by reducing lung capillary blood flow in the absence of substantial lung interstitial or alveolar edema. In contrast to direct ischemic lung injury, lung neutrophil recruitment during remote lung inflammation did not require cues from intravascular nonclassical monocytes or tissue-resident alveolar macrophages. Instead, lung neutrophil retention depended on the neutrophil chemoattractant CXCL2 released by activated classical monocytes. Comparative single-cell RNA-Seq analysis of direct and remote lung inflammation revealed that alveolar macrophages were highly activated and produced CXCL2 only in direct lung inflammation. Establishing a CXCL2 gradient into the alveolus by intratracheal CXCL2 administration during AKI-induced remote lung inflammation enabled neutrophils to extravasate. We thus discovered important differences in lung neutrophil recruitment in direct versus remote lung inflammation and identified lung capillary neutrophil retention that negatively affected oxygenation by causing a ventilation-perfusion mismatch as a driver of AKI-induced hypoxemia.

Wuling San regulates AVPR2-cAMP-PKA-CREB pathway to delay cellular senescence and ameliorate acute kidney injury

ETHNOPHARMACOLOGICAL RELEVANCE

Cellular senescence in renal resident cells plays a pivotal role in the progression of acute kidney injury (AKI), necessitating the expansion of effective drug targets. Traditional Chinese medicine (TCM) formulations, characterized by their multi-target effects, offer a promising perspective for advancing research on AKI. Wuling San (WLS), a well-established compound used in treating urological disorders, has yet to elucidate its potential pharmacological targets and mechanisms in ameliorating AKI and delaying cellular senescence.

AIM OF THE STUDY

This study sought to elucidate the mechanisms by which WLS modulates the AVPR2-cAMP-PKA-CREB pathway to mitigate cellular senescence and promote recovery from AKI.

METHODS

We first prepared WLS-containing serum and performed RT-qPCR experiments to screen for GPCRs that were differentially expressed in response to WLS. Next, we established an in vitro AKI mouse model to assess the renal protective effects of the WLS by measuring renal function, renal pathology, and oxidative stress levels. After this, we performed RNA sequencing (RNA-Seq) profiling to identify differentially expressed genes (DEGs) affected by WLS treatment. We also conducted Gene Ontology (GO) functional enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses to identify potential signaling pathways involved. We then utilized the Gene Expression Omnibus (GEO) data to screen for cellular senescence related differentially expressed genes (CSRDEGs) in AKI patients and performed enrichment analysis, as well as a joint analysis of specific genes in relation to the RNA-Seq profiling results. We also examined how WLS affects the expression of proteins linked to cellular senescence in the AKI mouse model by targeting the AVPR2-cAMP-PKA-CREB pathway.

RESULTS

WLS markedly enhanced the expression of Arginine Vasopressin Receptor 2 (AVPR2) and ameliorated renal function indicators, as well as pathological changes and oxidative stress levels in the mouse model of AKI. RNA-Seq profiling revealed significant enrichment of the cAMP signaling pathway following WLS intervention. Bioinformatics analysis indicated that genes associated with cellular senescence in AKI patients were notably enriched in the p53 signaling pathway. Data mining from the GEO database, in conjunction with RNA-Seq profiling, demonstrated a substantial reduction in key genes after WLS treatment. Additionally, WLS elevated both the expression and phosphorylation of pivotal proteins within the AVPR2-cAMP-PKA-CREB pathway, while concurrently decreasing proteins associated with cellular senescence.

CONCLUSION

The results demonstrated that WLS significantly elevated the expression of AVPR2, which may underlie its nephroprotective effects and facilitate the mitigation of AKI by modulating the AVPR2-cAMP-PKA-CREB pathway, ultimately contributing to a delay in cellular senescence.

Inter-organ correlation based multi-task deep learning model for dynamically predicting functional deterioration in multiple organ systems of ICU patients

BACKGROUND

Functional deterioration (FD) of various organ systems is the major cause of death in ICU patients, but few studies propose effective multi-task (MT) model to predict FD of multiple organs simultaneously. This study propose a MT deep learning model named inter-organ correlation based multi-task model (IOC-MT), to dynamically predict FD in six organ systems.

METHODS

Three public ICU databases were used for model training and validation. The IOC-MT was designed based on the routine MT deep learning framework, but it used a Graph Attention Networks (GAT) module to capture inter-organ correlation and an adaptive adjustment mechanism (AAM) to adjust prediction. We compared the IOC-MT to five single-task (ST) baseline models, including three deep models (LSTM-ST, GRU-ST, Transformer-ST) and two machine learning models (GRU-ST, RF-ST), and performed ablation study to assess the contribution of important components in IOC-MT. Model discrimination was evaluated by AUROC and AUPRC, and model calibration was assessed by the calibration curve. The attention weight and adjustment coefficient were analyzed at both overall and individual level to show the AAM of IOC-MT.

RESULTS

The IOC-MT had comparable discrimination and calibration to LSTM-ST, GRU-ST and Transformer-ST for most organs under different gap windows in the internal and external validation, and obviously outperformed GRU-ST, RF-ST. The ablation study showed that the GAT, AAM and missing indicator could improve the overall performance of the model. Furthermore, the inter-organ correlation and prediction adjustment of IOC-MT were intuitive and comprehensible, and also had biological plausibility.

CONCLUSIONS

The IOC-MT is a promising MT model for dynamically predicting FD in six organ systems. It can capture inter-organ correlation and adjust the prediction for one organ based on aggregated information from the other organs.

hTERT and SV40LgT Renal Cell Lines Adjust Their Transcriptional Responses After Copy Number Changes from the Parent Proximal Tubule Cells

Primary mouse renal proximal tubule epithelial cells (moRPTECs) were immortalized by lentivirus transduction to create hTERT or SV40LgT (LgT) cell lines. Prior work showed a more pronounced injury and repair response in LgT versus hTERT cells after chemical challenge. We hypothesized that unique genomic changes occurred after immortalization, altering critical genes and pathways. RNA-seq profiling and whole-genome sequencing (WGS) of parent, hTERT, and LgT cells showed that 92.5% of the annotated transcripts were shared, suggesting a conserved proximal tubule expression pattern. However, the cell lines exhibited unique transcriptomic and genomic profiles different from the parent cells. Three transcript classes were quite relevant for chemical challenge response-Cyps, ion channels, and metabolic transporters-each important for renal function. A pathway analysis of the hTERT cells suggested alterations in intermediary and energy metabolism. LgT cells exhibited pathway activation in cell cycle and DNA repair that was consistent with replication stress. Genomic karyotyping by combining WGS and RNA-seq data showed increased gene copy numbers in chromosome 5 for LgT cells, while hTERT cells displayed gene copy losses in chromosomes 4 and 9. These data suggest that the exaggerated transcriptional responses of LgT cells versus hTERT cells result from differences in gene copy numbers, replication stress, and the unique selection processes underlying LgT or hTERT immortalization.

Acute kidney injury after lung transplantation, incidence, risk factors, and effects: A Swedish nationwide study

BACKGROUND

Acute kidney injury (AKI) is a serious complication after lung transplantation, but the reported incidence varies in the literature. No data on AKI have been published from the Swedish lung transplantation program.

METHODS

The aim of our study was to investigate the incidence, perioperative risk factors, and effects of early postoperative acute kidney injury (Kidney Disease Improving Global Outcomes [KDIGO] criteria) after lung transplantation. A retrospective, nationwide study of 568 lung-transplanted patients in Sweden between 2011 and 2020 was performed.

RESULTS

The incidence of AKI (any grade) was 42%. Renal replacement therapy was used in 5% of the patients. Preoperative factors independently associated with increased incidence of AKI were higher body mass index (odds ratio [OR]: 1.07, 95% CI: 1.02, 1.12) longer time on transplantation waiting list (OR: 1.05 [1.01, 1.09]), re-transplantation (OR: 2.24 [1.05, 4.80]) and moderate to severe tricuspid regurgitation (OR: 2.61 [1.36, 5.03]). Intraoperative factors independently associated with increased incidence of AKI were use of cardiopulmonary bypass (OR: 2.70 [1.57, 4.63]), increasing number of transfused red blood cell units, and use of immunosuppressive therapy other than routine (OR: 2,56 [1.47, 4.46]). A higher diuresis (OR: 0.70, 95% CI: 0.58-0.85) was associated with less incidence of acute kidney injury. Development of AKI was associated with increased time to extubation (median 30 h, IQR [9, 118] vs. 6 [3, 16]), length of stay in the intensive care unit (9 days [4, 25] vs. 3 [2, 5]) and increased rate of primary graft dysfunction (OR 2.33 [1.66, 3.29]) and 30-day mortality (OR: 10.8 [3.0, 69]).

CONCLUSIONS

Acute kidney injury is common after lung transplantation and affects clinical outcomes negatively. Preoperative factors may be used for risk assessment. The use of cardiopulmonary bypass is a potentially modifiable intraoperative risk factor.

EDITORIAL COMMENT

Acute kidney injury is a common complication after lung transplantation that severely influences patient outcomes. This large study of more than 500 patients treated over a decade identified potentially modifiable factors associated with the development of acute kidney injury.

CRISPR/Cas9 based knockout of lncRNA MALAT1 attenuates TGF-β1 induced Smad 2/3 mediated fibrosis during AKI-to-CKD transition

Acute kidney injury (AKI) is a significant clinical issue with potential long-term consequences, as even a single episode can progress to chronic kidney disease (CKD). The AKI-to-CKD transition involves complex pathophysiology, including persistent inflammation, apoptosis, and fibrosis. Long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been recognized as a potential therapeutic target for various kidney diseases, including AKI and CKD. In our previous study, we conducted the transcriptomic analysis of lncRNAs in-vitro and animal models of AKI-to-CKD transition and found several dysregulated lncRNAs such as MALAT1, MEG3, NEAT1, MIAT, and H19 in this transition. Among these, we have selected lncRNA MALAT1 to further validate its role in AKI-to-CKD transition as a therapeutic target via a cluster regularly intercept short palindromic protein (CRISPR) associated protein 9 (Cas9)-mediated knockout approach in NRK52E cells. Guide RNAs (gRNAs) were designed to target MALAT1, and the PX459 turbo green fluorescence protein (GFP) plasmid containing MALAT1 gRNA1&2 was transfected into NRK52E cells using CRISPRMAX. Results demonstrated that MALAT1 knockout significantly reduced MALAT1 expression and attenuated Smad2/3-mediated fibrosis by decreasing pSmad2, pSmad2/3, Smad4, vimentin, fibronectin, collagen-I, and α-SMA expression levels, while increasing Smad7, Smurf2, and E-cadherin levels. These findings suggest that targeting the MALAT1/Smad2/3 pathway could be a potential therapeutic target for mitigating fibrosis to prevent AKI-to-CKD transition.

Correlation between baseline anion gap and early acute kidney injury in patients with acute pancreatitis in the intensive care unit: A single-center retrospective cohort study

OBJECTIVE

Acute pancreatitis (AP) is an acute inflammatory disease that can lead to multiple system dysfunction, including acute kidney injury (AKI). AKI occurs in 10%-42% of AP patients, and studies have shown that early (48 hours) acute pancreatitis associated acute kidney injury (AP-AKI) can increases the risk of death in acute pancreatitis. Anion gap (AG) is a common index in clinical evaluation of acid-base imbalance and an important index in critically ill patients. The aim of this study was to investigate the relationship between baseline anion gap values and early acute kidney injury in patients with acute pancreatitis in intensive care unit.

METHODS

Our data were derived from inpatients admitted to Beth Israel Deaconess Medical Center (BIDMC) in the United States between 2008 and 2019. A total of 4,017 adult patients with acute pancreatitis admitted to the ICU were enrolled in the study, and 475 were enrolled according to the exclusion and inclusion criteria. Only the baseline value and one day after arrival to the intensive care unit (ICU) were considered for all laboratory test values. According to previous literature and clinical significance, AG was divided into two groups: low value (< 16mmol/L) group and high value (≥16mmol/L) group, and logistics univariate and multifactor regression analysis was applied to verify the relationship between anion gap and AKI risk.

RESULTS

Only 157 of the 475 AP cases had an AG level below 16 mmol/L, whereas 318 patients had an AG level over 16 mmol/L. Within 48 hours, 89 and 240 cases (56.7% and 75.5%) and the low- and high-AG groups had AKI. In AP cases, an elevated AG was related to an increased risk of AKI [odds ratio (OR) = 1.06, 95% confidence interval (CI): 1.03-1.1], and is a nonlinear relationship. When controlling for other factors, this correlation was still significant. Compared to the lower group, high-AG (≥16mmol/L) values can increase the risk of early acute kidney injury in patients with acute pancreatitis (OR = 2.35, CI: 1.57-3.53).

CONCLUSION

Anion gap (AG) is an independent risk factor for early acute kidney injury in patients with acute pancreatitis, and has a nonlinear relationship with 48-hour AKI. Higher AG(≥16mmol/L) values can significantly increase the risk of AP-AKI.

Chemiluminescent Probe for Enhanced Visualization of Renal Ischemia-Reperfusion Injury via Pyroglutamate Aminopeptidase-1 Activation

The absence of an effective imaging tool for diagnosing renal ischemia-reperfusion injury (RIRI) severely delays its treatment, and currently, no definitive clinical interventions are available. Pyroglutamate aminopeptidase-1 (PGP-1), a potential inflammatory cytokine, has shown considerable potential as a biomarker for tracing the inflammatory process in vivo. However, its exact role in the enhanced visualization of RIRI in complex biological systems has yet to be fully established. Chemiluminescence imaging (CLI) has proven to be one of the most promising diagnostic methods due to its ultrahigh-contrast imaging capabilities compared to fluorescence imaging. In this study, we developed an activatable Schaap's dioxetane chemiluminescent probe (PGP-PD) to explore the potential of PGP-1 as a marker for CLI of renal injury following ischemia-reperfusion, with the goal of achieving high-contrast in situ diagnostics for RIRI. In vitro, PGP-PD exhibited exceptional selectivity for exogenous PGP-1 and remarkable sensitivity, with a detection limit as low as 2.244 ng/mL. Moreover, in vivo studies successfully demonstrated a positive correlation between the RIRI and PGP-1 level. Notably, in situ imaging with PGP-PD generated a significant chemiluminescent signal within the RIRI-kidney, providing an exceptionally high contrast between injured and normal kidney tissue (∼9.4-fold) in the RIRI mouse model. We anticipate that this work may offer a valuable biomarker (PGP-1) and a powerful imaging tool for improving RIRI in situ diagnosis, thereby aiding treatment planning and surgical outcomes for RIRI patients.

Kidney immunology from pathophysiology to clinical translation

Kidney diseases are widespread and represent a considerable medical, social and economic burden. However, there has been marked progress in understanding the immunological aspects of kidney disease. This includes the identification of distinct intrarenal immunological niches and characterization of kidney disease endotypes according to the underlying molecular immunopathology, as well as a better understanding of the pathological roles for T cells, mononuclear phagocytes and B cells and the renal elements they target. These insights have improved the diagnosis of kidney disease. Here, we discuss new developments in our understanding of kidney immunology, focusing on immune mechanisms of disease and their translational implications for the diagnosis and treatment of kidney disease. We also describe the immune-mediated crosstalk between the kidney and other organs that influences kidney disease and extrarenal inflammation.

Monascus red pigment influence on hydroxyapatite nanoparticles-mediated renal toxicity in rats

Hydroxyapatite nanoparticles (HANPs) have been applied in several biomedical fields. However, its interaction with biological systems is less exploited. This study aimed to characterize HANPs, examine their influence on kidneys, and explore the potential protective effects of naturally extracted red pigment (RP) from Monascus purpureus against HANPs-induced renal toxicity. To this aim, forty eight adult male rats were randomly divided into 8 equal groups: a control group receiving 4% dimethyl sulfoxide (the solvent for HANPs), three groups receiving extracted RP at different doses of 10, 20, and 40 mg/kg, a group receiving HANPs at a dose of 88.3 mg/kg, and three more groups receiving a double treatment of HANPs associated with RP. The respective treatment was given daily by oral gavage to animals for 50 days which is the duration of the whole experiment. The renal toxicity caused by HANPs was manifested by aberrations in kidney function parameters, intensification of oxidative stress markers, and a decrease in the activity of antioxidant enzymes. Moreover, an increase in inflammatory (TNF-α and TGF-β) and apoptotic (caspace-3) markers, an elevation in gene-based kidney injuries markers (Kim-1 and lipocalin-2), and pathological tissue changes were determined. Meanwhile, co-treatment with different doses of biopigment and HANPs have reduced oxidative stress via their potent antioxidant effect. This was confirmed by pronounced improvement in the measured parameters along with the histological structural enhancement in a dose dependent manner compared to controls. To sum up, RP from M. purpureus has potential protective benefits in mitigating the adverse effects of HANPs.

[Clinical sub-phenotypes of acute kidney injury in children and their association with prognosis]

OBJECTIVES

To investigate the clinical sub-phenotype (SP) of pediatric acute kidney injury (AKI) and their association with clinical outcomes.

METHODS

General status and initial values of laboratory markers within 24 hours after admission to the pediatric intensive care unit (PICU) were recorded for children with AKI in the derivation cohort (n=650) and the validation cohort (n=177). In the derivation cohort, a least absolute shrinkage and selection operator (LASSO) regression analysis was used to identify death-related indicators, and a two-step cluster analysis was employed to obtain the clinical SP of AKI. A logistic regression analysis was used to develop a parsimonious classifier model with simplified metrics, and the area under the curve (AUC) was used to assess the value of this model. This model was then applied to the validation cohort and the combined derivation and validation cohort. The association between SPs and clinical outcomes was analyzed with all children with AKI as subjects.

RESULTS

In the derivation cohort, two clinical SPs of AKI (SP1 and SP2) were identified by the two-step cluster analysis using the 20 variables screened by LASSO regression, namely SPd1 group (n=536) and SPd2 group (n=114). The simplified classifier model containing eight variables (P<0.05) had an AUC of 0.965 in identifying the two clinical SPs of AKI (P<0.001). The validation cohort was clustered into SPv1 group (n=156) and SPv2 group (n=21), and the combined derivation and validation cohort was clustered into SP1 group (n=694) and SP2 group (n=133). After adjustment for confounding factors, compared with the SP1 group, the SP2 group had significantly higher incidence rates of multiple organ dysfunction syndrome and death during the PICU stay (P<0.001), and SP2 was significantly associated with the risk of death within 28 days after admission to the PICU (P<0.001).

CONCLUSIONS

This study establishes a parsimonious classifier model and identifies two clinical SPs of AKI with different clinical features and outcomes.The SP2 group has more severe disease and worse clinical prognosis.

Beyond hemoglobin: Critical role of 2,3-bisphosphoglycerate mutase in kidney function and injury

AIM

2,3-bisphosphoglycerate mutase (BPGM) is traditionally recognized for its role in modulating oxygen affinity to hemoglobin in erythrocytes. Recent transcriptomic analyses, however, have indicated a significant upregulation of BPGM in acutely injured murine and human kidneys, suggesting a potential renal function for this enzyme. Here we aim to explore the physiological role of BPGM in the kidney.

METHODS

A tubular-specific, doxycycline-inducible Bpgm-knockout mouse model was generated. Histological, immunofluorescence, and proteomic analyses were conducted to examine the localization of BPGM expression and the impact of its knockout on kidney structure and function. In vitro studies were performed to investigate the metabolic consequences of Bpgm knockdown under osmotic stress.

RESULTS

BPGM expression was localized to the distal nephron and was absent in proximal tubules. Inducible knockout of Bpgm resulted in rapid kidney injury within 4 days, characterized by proximal tubular damage and tubulointerstitial fibrosis. Proteomic analyses revealed involvement of BPGM in key metabolic pathways, including glycolysis, oxidative stress response, and inflammation. In vitro, Bpgm knockdown led to enhanced glycolysis, decreased reactive oxygen species elimination capacity under osmotic stress, and increased apoptosis. Furthermore, interactions between nephron segments and immune cells in the kidney suggested a mechanism for propagating stress signals from distal to proximal tubules.

CONCLUSION

BPGM fulfills critical functions beyond the erythrocyte in maintaining glucose metabolism in the distal nephron. Its absence leads to metabolic imbalances, increased oxidative stress, inflammation, and ultimately kidney injury.

Prolonged Retention of Albumin Nanoparticles Alleviates Renal Ischemia-Reperfusion Injury through Targeted Pyroptosis

Acute kidney injury (AKI) represents a prevalent and complex clinical event, characterized by irreversible damage to renal tubular epithelial cells and high intensive care unit (ICU) admission rates and mortality. The kidneys are highly susceptible to oxidative stress, inflammation, pyroptosis, and programmed cell death. Pyroptosis poses a significant risk, exacerbating the damage and inflammation of renal tubular cells. Disulfiram (DSF), an FDA-approved medication for alcohol cessation, inhibits the pyroptotic pore-forming protein Gasdermin-D (GSDMD), positioning it as a potential solution for emergency relief against an inflammatory response. However, current obstacles include poor water solubility, rapid metabolism, and off-target effects. Inspired by this discovery, bovine serum albumin (BSA), which has already entered clinical application, has been utilized to produce safe and long-lasting nanoparticles (BSA@DSF NPs), addressing the challenges posed by DSF's physicochemical properties. By targeting the GSDMD protein, the potent pro-inflammatory effects of pyroptosis were mitigated, leading to the alleviation of AKI induced by ischemia-reperfusion injury. This research offers a straightforward and efficient concept for treating AKI, potentially enhancing the transition to clinical practice.

Aurantiamide mitigates acute kidney injury by suppressing renal necroptosis and inflammation via GRPR-dependent mechanism

Acute kidney injury (AKI) manifests as a clinical syndrome characterised by the rapid accumulation of metabolic wastes, such as blood creatinine and urea nitrogen, leading to a sudden decline in renal function. Currently, there is a lack of specific therapeutic drugs for AKI. Previously, we identified gastrin-releasing peptide receptor (GRPR) as a pathogenic factor in AKI. In this study, we investigated the therapeutic potential of a novel Chinese medicine monomer, aurantiamide (AA), which exhibits structural similarities to our previously reported GRPR antagonist, RH-1402. We compared the therapeutic efficacy of AA with RH-1402 both in vitro and in vivo using various AKI models. Our results demonstrated that, in vitro, AA attenuated injury, necroptosis, and inflammatory responses in human renal tubular epithelial cells subjected to repeated hypoxia/reoxygenation and lipopolysaccharide stimulation. In vivo, AA ameliorated renal tubular injury and inflammation in mouse models of ischemia/reperfusion and cecum ligation puncture-induced AKI, surpassing the efficacy of RH-1402. Furthermore, molecular docking and cellular thermal shift assay confirmed GRPR as a direct target of AA, which was further validated in primary cells. Notably, in GRPR-silenced HK-2 cells and GRPR systemic knockout mice, AA failed to mitigate renal inflammation and injury, underscoring the importance of GRPR in AA's mechanism of action. In conclusion, our study has demonstrated that AA serve as a novel antagonist of GRPR and a promising clinical candidate for AKI treatment.

Effect of electronic alerts on the care and outcomes in patients with acute kidney injury: a meta-analysis and trial sequential analysis

BACKGROUND

Although electronic alerts are being increasingly implemented in patients with acute kidney injury (AKI), their effect remains unclear. Therefore, we conducted this meta-analysis aiming at investigating their impact on the care and outcomes of AKI patients.

METHODS

PubMed, Embase, Cochrane Library, and Clinical Trial Registries databases were systematically searched for relevant studies from inception to March 2024. Randomized controlled trials comparing electronic alerts with usual care in patients with AKI were selected.

RESULTS

Six studies including 40,146 patients met the inclusion criteria. The pooled results showed that electronic alerts did not improve mortality rates (relative risk (RR) = 1.02, 95% confidence interval (CI) = 0.97-1.08, P = 0.44) or reduce creatinine levels (mean difference (MD) =  - 0.21, 95% CI =  - 1.60-1.18, P = 0.77) and AKI progression (RR = 0.97, 95% CI = 0.90-1.04, P = 0.40). Instead, electronic alerts increased the odds of dialysis and AKI documentation (RR = 1.14, 95% CI = 1.05-1.25, P = 0.002; RR = 1.21, 95% CI = 1.01-1.44, P = 0.04, respectively), but the trial sequential analysis (TSA) could not confirm these results. No differences were observed in other care-centered outcomes including renal consults and investigations between the alert and usual care groups.

CONCLUSIONS

Electronic alerts increased the incidence of AKI and dialysis in AKI patients, which likely reflected improved recognition and early intervention. However, these changes did not improve the survival or kidney function of AKI patients. The findings warrant further research to comprehensively evaluate the impact of electronic alerts.

Renal tubular epithelial cells response to injury in acute kidney injury

Acute kidney injury (AKI) is a clinical syndrome characterized by a rapid and significant decrease in renal function that can arise from various etiologies, and is associated with high morbidity and mortality. The renal tubular epithelial cells (TECs) represent the central cell type affected by AKI, and their notable regenerative capacity is critical for the recovery of renal function in afflicted patients. The adaptive repair process initiated by surviving TECs following mild AKI facilitates full renal recovery. Conversely, when injury is severe or persistent, it allows the TECs to undergo pathological responses, abnormal adaptive repair and phenotypic transformation, which will lead to the development of renal fibrosis. Given the implications of TECs fate after injury in renal outcomes, a deeper understanding of these mechanisms is necessary to identify promising therapeutic targets and biomarkers of the repair process in the human kidney.

AST-120 alleviates renal ischemia-reperfusion injury by inhibiting HK2-mediated glycolysis

OBJECTIVE

Renal ischemia/reperfusion injury (IRI) is a major cause of acute kidney injury (AKI), which is associated with high incidence and mortality. AST-120 is an oral carbonaceous adsorbent that can alleviate kidney damage. This study aimed to explore the effects of AST-120 on renal IRI and the molecular mechanism.

METHODS

A renal IRI mouse model was established and administrated AST-120, and differentially expressed genes were screened using RNA sequencing. Renal function and pathology were analyzed in mice. Hypoxia/reoxygenation (H/R) cell model was generated, and glycolysis was evaluated by detecting lactate levels and Seahorse analysis. Histone lactylation was analyzed by western blotting, and its relationship with hexokinase 2 (HK2) was assessed using chromatin immunoprecipitation.

RESULTS

The results showed that HK2 expression was increased after IRI, and AST-120 decreased HK2 expression. Knockout of HK2 attenuated renal IRI and inhibits glycolysis. AST-120 inhibited renal IRI in the presence of HK2 rather than HK2 absence. In proximal tubular cells, knockdown of HK2 suppressed glycolysis and H3K18 lactylation caused by H/R. H3K18 lactylation was enriched in HK2 promoter and upregulated HK2 levels. Rescue experiments revealed that lactate reversed IRI that suppressed by HK2 knockdown.

CONCLUSIONS

In conclusion, AST-120 alleviates renal IRI via suppressing HK2-mediated glycolysis, which suppresses H3K18 lactylation and further reduces HK2 levels. This study proposes a novel mechanism by which AST-120 alleviates IRI.

Acute kidney injury in critically ill obstetric patients: Incidence and role of neutrophil gelatinase-associated lipocalcin - A prospective observational cohort study

Background and Aims

Data focussing on acute kidney injury (AKI) in obstetric patients admitted to the intensive care unit (ICU) are scarce and even more so regarding the role of neutrophil gelatinase-associated lipocalcin (NGAL) in detecting AKI or predicting outcomes in these patients. Hence, we aim to evaluate the incidence of AKI in obstetric ICU patients and validate the role of urinary and serum NGAL in predicting the onset of AKI and mortality.

Methods

This prospective observational cohort included 45 obstetric patients admitted in ICU, excluding those with prior renal dysfunction. Serum creatinine and urine output were monitored for the occurrence of AKI during the ICU stay. The outcome of the patient (survival or death) in the ICU and hospital was recorded, and serum and urinary NGAL were determined at the time of ICU admission.

Results

AKI occurred in 32 [71.1%; 95% confidence interval (CI): 55.4%, 86.8%] patients during their ICU stay. Serum NGAL showed an area under receiver operating characteristic curve (AUROCC) of 0.630 (95% CI: 0.417, 0.842) (P = 0.231) for AKI and 0.486 (95% CI: 0.295, 0.676) (P = 0.883) for ICU mortality. Urinary NGAL showed AUROC = 0.472 (95% CI: 0.285, 0.660) (P = 0.772) to predict AKI and 0.430 (95% CI: 0.268, 0.652) (P = 0.684) for ICU mortality.

Conclusions

AKI is common amongst critically ill obstetric ICU patients. However, serum and urinary NGAL cannot be advocated to discriminate between patients with or without AKI or between survivors and non-survivors in critically ill obstetric patients.

Acute Kidney Injury Requiring Dialysis After Pediatric Heart Transplant

BACKGROUND

Acute kidney injury (AKI) is a common complication of pediatric heart transplant, with a subset of patients developing severe AKI requiring dialysis (AKI-D). We aimed to identify the epidemiology, risk factors, and outcomes of postoperative AKI-D in pediatric heart transplant recipients.

METHODS

We retrospectively identified all pediatric first-time, single-organ heart transplants at our institution from 2014 to 2022. Postoperative AKI was defined as AKI within 2 weeks of transplant. Unadjusted and adjusted logistic regression were used to identify characteristics associated with AKI-D, and unadjusted time-to-event analyses were used to determine the association between AKI-D and survival free of kidney failure.

RESULTS

Among 177 patients included, 116 (66%) developed postoperative AKI of any stage, including 13 (7%) who developed AKI-D with median time from transplant to dialysis initiation of 6 days (IQR 3-13). In adjusted models, increased cardiopulmonary bypass time (OR 1.19, 95% CI 1.04-1.37, per 15 min increase in bypass time) and higher weight at transplant were associated with higher odds of AKI-D, whereas patient demographics and pretransplant kidney function were not associated with AKI-D. AKI-D was associated with greater mortality during initial hospitalization (46% vs. 1%, p < 0.001) and a lower rate of survival free of kidney failure.

CONCLUSIONS

The incidence of AKI-D after pediatric heart transplant was 7%, with extended cardiopulmonary bypass time associated with postoperative AKI-D even in adjusted models. Further research is needed to improve the prediction and management of AKI-D in this population.

Epigenetic Mechanisms in Sepsis-Associated Acute Kidney Injury

Sepsis, the dysregulated immune response of the host to infections, leads to numerous complications, including multiple organ dysfunction with sepsis-associated acute kidney injury (SA-AKI) being a frequent complication associated with increased risk of mortality and the progression toward chronic kidney disease (CKD). Several mechanisms have been widely investigated in understanding the complex pathophysiology of SA-AKI, including hemodynamic alterations, inflammation, oxidative stress, and direct cellular injury driven by pathogens or cell-derived products (pathogen-associated molecular patterns and damage-associated molecular patterns). Despite advancements in the management of septic patients, the prognosis of SA-AKI patients remains significantly poor and is associated with high in-hospital mortality and adverse long-term outcomes. Therefore, recent research has focused on the early identification of specific SA-AKI endotypes and subphenotypes through epigenetic analysis and the use of potential biomarkers, either alone or in combination with clinical data, to improve prognosis. Epigenetic regulation, such as DNA methylation, histone modifications, and noncoding RNA modulation, is crucial in modulating gene expression in response to stress and renal injury in SA-AKI. At the same time, these modifications are dynamic and reversible processes that can alter gene expression in several pathways implicated in the context of SA-AKI, including inflammation, immune response, and tolerance status. In addition, specific epigenetic modifications may exacerbate renal damage by causing persistent inflammation or cellular metabolic reprogramming, leading to progression toward CKD. This review aims to provide a comprehensive understanding of the epigenetic characteristics that define SA-AKI, also exploring targeted therapies that can improve patient outcomes and limit the chronic progression of this syndrome.

Modulation of angiopoietin-2 and Tie2: Organ specific effects of microvascular leakage and edema in mice

INTRODUCTION

Critical illness is associated with organ failure, in which endothelial hyperpermeability and tissue edema play a major role. The endothelial angiopoietin/Tie2 system, a regulator of endothelial permeability, is dysbalanced during critical illness. Elevated circulating angiopoietin-2 and decreased Tie2 receptor levels are reported, but it remains unclear whether they cause edema independent of other critical illness-associated alterations. Therefore, we have studied the effect of angiopoietin-2 administration and/or reduced Tie2 expression on microvascular leakage and edema under normal conditions.

METHODS

Transgenic male mice with partial deletion of Tie2 (heterozygous exon 9 deletion, Tie2+/-) and wild-type controls (Tie2+/+) received 24 or 72 pg/g angiopoietin-2 or PBS as control (n = 12 per group) intravenously. Microvascular leakage and edema were determined by Evans blue dye (EBD) extravasation and wet-to-dry weight ratio, respectively, in lungs and kidneys. Expression of molecules related to endothelial angiopoietin/Tie2 signaling were determined by ELISA and RT-qPCR.

RESULTS

In Tie2+/+ mice, angiopoietin-2 administration increased EBD extravasation (154 %, p < 0.05) and wet-to-dry weight ratio (133 %, p < 0.01) in lungs, but not in the kidney compared to PBS. Tie2+/- mice had higher pulmonary (143 %, p < 0.001), but not renal EBD extravasation, compared to wild-type control mice, whereas a more pronounced wet-to-dry weight ratio was observed in lungs (155 %, p < 0.0001), in contrast to a minor higher wet-to-dry weight ratio in kidneys (106 %, p < 0.05). Angiopoietin-2 administration to Tie2+/- mice did not further increase pulmonary EBD extravasation, pulmonary wet-to-dry weight ratio, or renal wet-to-dry weight ratio. Interestingly, angiopoietin-2 administration resulted in an increased renal EBD extravasation in Tie2+/- mice compared to Tie2+/- mice receiving PBS. Both angiopoietin-2 administration and partial deletion of Tie2 did not affect circulating angiopoietin-1, soluble Tie2, VEGF and NGAL as well as gene expression of angiopoietin-1, -2, Tie1, VE-PTP, ELF-1, Ets-1, KLF2, GATA3, MMP14, Runx1, VE-cadherin, VEGFα and NGAL, except for gene and protein expression of Tie2, which was decreased in Tie2+/- mice compared to Tie2+/+ mice.

CONCLUSIONS

In mice, the microvasculature of the lungs is more vulnerable to angiopoietin-2 and partial deletion of Tie2 compared to those in the kidneys with respect to microvascular leakage and edema.

LRG1 Contributes to the Pathogenesis of Multiple Kidney Diseases: A Comprehensive Review

Background

The increasing prevalence of kidney diseases has become a significant public health issue, with a global prevalence exceeding 10%. In order to accurately identify biochemical changes and treatment outcomes associated with kidney diseases, novel methods targeting specific genes have been discovered. Among these genes, leucine-rich α-2 glycoprotein 1 (LRG1) has been identified to function as a multifunctional pathogenic signaling molecule in multiple diseases, including kidney diseases. This study aims to provide a comprehensive overview of the current evidence regarding the roles of LRG1 in different types of kidney diseases.

Summary

Based on a comprehensive review, it was found that LRG1 was upregulated in the urine, serum, or renal tissues of patients or experimental animal models with multiple kidney diseases, such as diabetic nephropathy, kidney injury, IgA nephropathy, chronic kidney diseases, clear cell renal cell carcinoma, end-stage renal disease, canine leishmaniosis-induced kidney disease, kidney fibrosis, and aristolochic acid nephropathy. Mechanistically, the role of LRG1 in kidney diseases is believed to be detrimental, potentially through its regulation of various genes and signaling cascades, i.e., fibronectin 1, GPR56, vascular endothelial growth factor (VEGF), VEGFR-2, death receptor 5, GDF15, HIF-1α, SPP1, activin receptor-like kinase 1-Smad1/5/8, NLRP3-IL-1b, and transforming growth factor β pathway.

Key Messages

Further research is needed to fully comprehend the molecular mechanisms by which LRG1 contributes to the pathogenesis and pathophysiology of kidney diseases. It is anticipated that targeted treatments focusing on LRG1 will be utilized in clinical trials and implemented in clinical practice in the future.

Proximal tubular FHL2, a novel downstream target of hypoxia inducible factor 1, is a protector against ischemic acute kidney injury

Four-and-a-half LIM domains protein 2 (FHL2) is an adaptor protein that may interact with hypoxia inducible factor 1α (HIF-1α) or β-catenin, two pivotal protective signaling in acute kidney injury (AKI). However, little is known about the regulation and function of FHL2 during AKI. We found that FHL2 was induced in renal tubular cells in patients with acute tubular necrosis and mice model of ischemia-reperfusion injury (IRI). In cultured renal proximal tubular cells (PTCs), hypoxia induced FHL2 expression and promoted the binding of HIF-1 to FHL2 promoter. Compared with control littermates, mice with PTC-specific deletion of FHL2 gene displayed worse renal function, more severe morphologic lesion, more tubular cell death and less cell proliferation, accompanying by downregulation of AQP1 and Na, K-ATPase after IRI. Consistently, loss of FHL2 in PTCs restricted activation of HIF-1 and β-catenin signaling simultaneously, leading to attenuation of glycolysis, upregulation of apoptosis-related proteins and downregulation of proliferation-related proteins during IRI. In vitro, knockdown of FHL2 suppressed hypoxia-induced activation of HIF-1α and β-catenin signaling pathways. Overexpression of FHL2 induced physical interactions between FHL2 and HIF-1α, β-catenin, GSK-3β or p300, and the combination of these interactions favored the stabilization and nuclear translocation of HIF-1α and β-catenin, enhancing their mediated gene transcription. Collectively, these findings identify FHL2 as a direct downstream target gene of HIF-1 signaling and demonstrate that FHL2 could play a critical role in protecting against ischemic AKI by promoting the activation of HIF-1 and β-catenin signaling through the interactions with its multiple protein partners.

DRD4 alleviates acute kidney injury by suppressing ISG15/NOX4 axis-associated oxidative stress

Acute kidney injury (AKI) is a life-threatening health condition associated with increasing morbidity and mortality. Despite extensive research on the mechanisms underlying AKI, effective clinical tools for prediction and treatment remain scarce. Oxidative stress and mitochondrial damage play a critical role in AKI and dopamine D4 receptor (DRD4) has been confirmed to be associated with oxidative stress. In this study, we hypothesized that DRD4 could attenuate AKI through its antioxidative and antiapoptotic effects. In vivo, DRD4 was remarkably decreased in the kidneys of mice subjected to ischemia/reperfusion injury (IRI) or cisplatin treatment. Notably, DRD4 significantly attenuated nephrotoxicity by suppressing oxidative stress and enhancing mitochondrial bioenergetics through the downregulation of reactive oxygen species (ROS) generation and NADPH oxidase 4 (NOX4) expression. In vitro, DRD4 demonstrated the ability to ameliorate oxidative stress-induced apoptosis in HK-2 cells subjected to hypoxia/reoxygenation- or cisplatin treatment. Transcriptome sequencing revealed that, mechanistically, DRD4 reduced the expression of its downstream target, interferon-stimulated gene 15 (ISG15), suppressing NOX4 ISGylation, enhancing the ubiquitination of NOX4, leading to its degradation, and ultimately counteracting oxidative stress-induced AKI. Altogether, these findings underscore the significance of DRD4 in AKI and elucidate DRD4 as a potential protectant against IRI or cisplatin-induced nephrotoxicity.

Bioinspired BSA@polydopamine@Fe Nanoprobe with Self-Purification Capacity for Targeted Magnetic Resonance Imaging of Acute Kidney Injury

Contrast-enhanced magnetic resonance imaging (CE-MRI) of acute kidney injury (AKI) is severely hindered by the poor targeting capacity and potential toxicity of current contrast agents. Herein, we propose one-step fabrication of a bovine serum albumin@polydopamine@Fe (BSA@PDA@Fe, BPFe) nanoprobe with self-purification capacity for targeted CE-MRI of AKI. BSA endows the BPFe nanoprobe with renal tubule-targeting ability, and PDA is capable of completely inhibiting the intrinsic metal-induced reactive oxygen species (ROS), which are always involved in Fe/Mn-based agents. The as-prepared nanoprobe owns a tiny size of 2.7 nm, excellent solubility, good T1 MRI ability, superior biocompatibility, and powerful antioxidant capacity. In vivo CE-MRI shows that the BPFe nanoprobe can accumulate in the renal cortex due to the reabsorption effect toward the serum albumin. In the AKI model, impaired renal reabsorption function can be effortlessly detected via the diminishment of renal cortical signal enhancement. More importantly, the administration of the BPFe nanoprobe would not aggravate renal damage of AKI due to the outstanding self-purification capacity. Besides, the BPFe nanoprobe is employed for CE-MR angiography to visualize fine vessel structures. This work provides an MRI contrast agent with good biosafety and targeting ability for CE-MRI of kidney diseases.

Interorgan communication networks in the kidney-lung axis

The homeostasis and health of an organism depend on the coordinated interaction of specialized organs, which is regulated by interorgan communication networks of circulating soluble molecules and neuronal connections. Many diseases that seemingly affect one primary organ are really multiorgan diseases, with substantial secondary remote organ complications that underlie a large part of their morbidity and mortality. Acute kidney injury (AKI) frequently occurs in critically ill patients with multiorgan failure and is associated with high mortality, particularly when it occurs together with respiratory failure. Inflammatory lung lesions in patients with kidney failure that could be distinguished from pulmonary oedema due to volume overload were first reported in the 1930s, but have been largely overlooked in clinical settings. A series of studies over the past two decades have elucidated acute and chronic kidney-lung and lung-kidney interorgan communication networks involving various circulating inflammatory cytokines and chemokines, metabolites, uraemic toxins, immune cells and neuro-immune pathways. Further investigations are warranted to understand these clinical entities of high morbidity and mortality, and to develop effective treatments.

Tiliroside Protects against Lipopolysaccharide-Induced Acute Kidney Injury via Intrarenal Renin-Angiotensin System in Mice

Tiliroside, a natural flavonoid, has various biological activities and improves several inflammatory diseases in rodents. However, the effect of Tiliroside on lipopolysaccharide (LPS)-induced acute kidney injury (AKI) and the underlying mechanisms are still unclear. This study aimed to evaluate the potential renoprotective effect of Tiliroside on LPS-induced AKI in mice. Male C57BL/6 mice were intraperitoneally injected with LPS (a single dose, 3 mg/kg) with or without Tiliroside (50 or 200 mg/kg/day for 8 days). Tiliroside administration protected against LPS-induced AKI, as reflected by ameliorated renal dysfunction and histological alterations. LPS-stimulated renal expression of inflammatory cytokines, fibrosis markers, and kidney injury markers in mice was significantly abolished by Tiliroside. This flavonoid also stimulated autophagy flux but inhibited oxidative stress and tubular cell apoptosis in kidneys from LPS-injected mice. Mechanistically, our study showed the regulation of Tiliroside on the intrarenal renin-angiotensin system in LPS-induced AKI mice. Tiliroside treatment suppressed intrarenal AGT, Renin, ACE, and Ang II, but upregulated intrarenal ACE2 and Ang1-7, without affecting plasma Ang II and Ang1-7 levels. Collectively, our data highlight the renoprotective action of Tiliroside on LPS-induced AKI by suppressing inflammation, oxidative stress, and tubular cell apoptosis and activating autophagy flux via the shift towards the intrarenal ACE2/Ang1-7 axis and away from the intrarenal ACE/Ang II axis.

Sympathetic Nerve Activation in Acute Kidney Injury and Cardiorenal Syndrome

The interactions between the kidney and heart are well studied and frequently lumped together as cardiorenal syndrome. It is believed that the sympathetic nervous system is involved in the mechanism of kidney injury caused by heart failure, but direct evidence is still lacking. In chronic renal fibrosis, sympathetic nerve activation was demonstrated to be harmful by unilateral ureteral obstruction and post-ischemia reperfusion injury models. On the other hand, sympathetic nerve activation seemed protective in acute kidney injury models such as ischemia reperfusion injury and lipopolysaccharide injection. Our recent investigation showed that post-ischemic renal fibrosis was attenuated when preexisting heart failure was induced by transverse aortic constriction surgery and renal denervation canceled this protection. These findings suggest sympathetic nerve activation in cardiorenal syndrome may be protective on chronic renal fibrosis development caused by ischemic an insult.

Insights into Repeated Renal Injury Using RNA-Seq with Two New RPTEC Cell Lines

Renal proximal tubule epithelial cells (RPTECs) are a primary site for kidney injury. We created two RPTEC lines from CD-1 mice immortalized with hTERT (human telomerase reverse transcriptase) or SV40 LgT antigen (Simian Virus 40 Large T antigen). Our hypothesis was that low-level, repeated exposure to subcytotoxic levels of 0.25-2.5 μM cisplatin (CisPt) or 12.5-100 μM aflatoxin B1 (AFB1) would activate distinctive genes and pathways in these two differently immortalized cell lines. RNA-seq showed only LgT cells responded to AFB1 with 1139 differentially expressed genes (DEGs) at 72 h. The data suggested that AFB1 had direct nephrotoxic properties on the LgT cells. However, both the cell lines responded to 2.5 μM CisPt from 3 to 96 h expressing 2000-5000 total DEGs. For CisPt, the findings indicated a coordinated transcriptional program of injury signals and repair from the expression of immune receptors with cytokine and chemokine secretion for leukocyte recruitment; robust expression of synaptic and substrate adhesion molecules (SAMs) facilitating the expression of neural and hormonal receptors, ion channels/transporters, and trophic factors; and the expression of nephrogenesis transcription factors. Pathway analysis supported the concept of a renal repair transcriptome. In summary, these cell lines provide in vitro models for the improved understanding of repeated renal injury and repair mechanisms. High-throughput screening against toxicant libraries should provide a wider perspective of their capabilities in nephrotoxicity.