Treatment Of Acute Kidney Injury Research Articles

New Therapeutic Method for Alleviating Damage of Acute Kidney Injury Through BCL-2 Gene Promoter I-Motif

Acute kidney injury (AKI) is a global public health problem with its pathogenesis not fully understood. Excessive apoptosis of renal tubular epithelial cells is an important feature of AKI patients, and therefore an anti-apoptotic approach could be used in the treatment for AKI. Up-regulation of B-cell lymphoma-2 (BCL-2) gene and protein has been found to be correlated with anti-apoptosis of cells. It has been found that the presence of the C-rich sequence on the upstream region of the BCL-2 gene promoter could form DNA secondary i-motif structure, and its stabilization by small molecules could up-regulate gene transcription and translation. In the present study, we constructed AKI models through folic acid (FA) induction. With these in vitro and in vivo models, we demonstrated that the acridone derivative A22 could up-regulate the expression of BCL-2 by targeting its gene promoter i-motif to reduce renal tubular epithelial cell apoptosis and improve renal function in many ways. A22 could alleviate FA-induced oxidative stress injury, inflammatory response, and endoplasmic reticulum stress in mouse kidneys. Our results provided a potentially new anti-apoptotic approach for the treatment of early stages of AKI. Our employed model focused on its short-term effect on AKI, while its long-term efficacy and safety, particularly regarding the regeneration of renal tubular epithelial cells, require further investigation before clinical application. This study further demonstrated that promoter i-motif could be targeted for up-regulating BCL-2 expression for the treatment of important diseases caused by excessive apoptosis.

Protective effect and mechanism of CoQ10 in mitochondrial dysfunction in diquat-induced renal proximal tubular injury.

Coenzyme Q10 (CoQ10) plays an important role in improving mitochondrial function and has many beneficial effects on the kidney. However, whether CoQ10 protects against diquat (DQ)-induced acute kidney injury (AKI) remains unclear. In this study, we investigated the protective effects and mechanism of action of CoQ10 against DQ-induced AKI. Institute of Cancer Research (ICR) mice were intraperitoneally injected with DQ to induce AKI. The expression levels of serum creatinine (Cr), urea, and kidney injury molecule-1 (KIM-1) increased, those of aquaporin 1 (AQP-1) decreased, and those of mitochondrial reactive oxygen species (ROS) increased with increased depolarization of mitochondrial membranes and mitochondrial rupture. In contrast, treatment with CoQ10 significantly improved DQ-induced AKI. CoQ10 treatment reduced serum Cr, urea, and KIM-1 contents, increased the AQP-1 expression, and reduced ROS contents in mice with DQ poisoning. Our results suggest that AKI caused by DQ poisoning may be related to the disruption of mitochondrial homeostasis and that CoQ10 treatment protects against AKI caused by DQ poisoning by improving mitochondrial kinetic homeostasis. Thus, CoQ10 represents a new therapeutic option for the prevention and treatment of AKI caused by DQ poisoning.

Exploring the pharmacological mechanism of fermented Eucommia ulmoides leaf extract in the treatment of cisplatin-induced kidney injury in mice: Integrated traditional pharmacology, metabolomics and network pharmacology

Cisplatin (CP) is a widely utilized anticancer drug, which also produces significant side effects, notably acute kidney injury (AKI). Fermented Eucommia ulmoides leaf (FEUL), a medicinal and edible Chinese herbal remedy, is known for its renoprotective properties. However, the effect and underlying mechanism of FEUL in AKI therapy have remained largely unexplored. This research aimed to elucidate the protective roles of FEUL in an AKI mouse model through biochemical assays, histopathological examinations, and investigating the underlying mechanisms based on metabolomics and network pharmacology. The findings demonstrated that pretreatment with orally administered FEUL significantly reduced blood urea nitrogen (BUN), and serum creatinine (SCr) levels, and ameliorated CP-induced kidney histopathological injuries. Moreover, FEUL attenuated CP-induced endoplasmic reticulum (ER) stress by reducing the protein expressions of PERK, IRE 1α, GRP78, ATF6, ATF4, and CHOP. The metabolomics results indicated that a total of 31 metabolites, involved in taurine and hypotaurine metabolism, lysine degradation, and steroid hormone biosynthesis, were altered after FEUL administration. Furthermore, metabolomics integrated with network pharmacology revealed that 8 targets, 4 metabolites, and 3 key pathways including steroid hormone biosynthesis, purine metabolism, and tryptophan metabolism were the main mechanisms of FEUL in treating CP-induced AKI. These findings suggested that FEUL could offer valuable insights for potential CP-induced AKI treatment strategies.

Research Progress on Acute Kidney Injury in Patients with Cardiogenic Shock Undergoing Venoarterial Extracorporeal Membrane Oxygenation

Cardiogenic shock (CS) is a life-threatening syndrome characterized by peripheral hypoperfusion and organ dysfunction caused by primary heart disease. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is a temporary mechanical circulatory support device for CS, used in cases of profound shock, biventricular failure, respiratory failure, and cardiac arrest that require urgent maximal support. While VA-ECMO provides effective tissue perfusion and ensures oxygen supply to organs, it is also associated with severe complications, among which acute kidney injury (AKI) is one of the most common and serious. To date, no comprehensive review has been conducted on the pathophysiology, influencing factors, and treatment of AKI associated with VA-ECMO. This paper aims to elaborate on the pathophysiological mechanisms, influencing factors, and treatment options for AKI in patients with CS undergoing VA-ECMO, providing clinical and nursing references.

Dexmedetomidine ameliorates acute kidney injury by regulating mitochondrial dynamics via the α2-AR/SIRT1/PGC-1α pathway activation in rats

BackgroundSepsis-associated acute kidney injury (AKI) is a serious complication of systemic infection with high morbidity and mortality in patients. However, no effective drugs are available for AKI treatment. Dexmedetomidine (DEX) is an alpha 2 adrenal receptor agonist with antioxidant and anti-apoptotic effects. This study aimed to investigate the therapeutic effects of DEX on sepsis-associated AKI and to elucidate the role of mitochondrial dynamics during this process.MethodsA lipopolysaccharide (LPS)-induced AKI rat model and an NRK-52E cell model were used in the study. This study investigated the effects of DEX on sepsis-associated AKI and the molecular mechanisms using histologic assessment, biochemical analyses, ultrastructural observation, western blotting, immunofluorescence, immunohistochemistry, qRT-PCR, flow cytometry, and si-mRNA transfection.ResultsIn rats, the results showed that administration of DEX protected kidney structure and function from LPS-induced septic AKI. In addition, we found that DEX upregulated the α2-AR/SIRT1/PGC-1α pathway, protected mitochondrial structure and function, and decreased oxidative stress and apoptosis compared to the LPS group. In NRK-52E cells, DEX regulated the mitochondrial dynamic balance by preventing intracellular Ca2+ overloading and activating CaMKII.ConclusionsDEX ameliorated septic AKI by reducing oxidative stress and apoptosis in addition to modulating mitochondrial dynamics via upregulation of the α2-AR/SIRT1/PGC-1α pathway. This is a confirmatory study about DEX pre-treatment to ameliorate septic AKI. Our research reveals a novel mechanistic molecular pathway by which DEX provides nephroprotection.

M6A demethylase FTO transcriptionally activated by SP1 improves ischemia reperfusion-triggered acute kidney injury by activating Ambra1/ULK1-mediated autophagy.

Ischemia reperfusion (I/R) was considered as one of main causes of acute kidney injury (AKI). However, the exact mechanism remains unclear. Here, this study aimed to investigate the role and mechanism of the m6A demethylase fat mass and obesity-associated (FTO) protein in I/R-induced AKI. HK-2 cells and SD rats were utilized to establish hypoxia/reoxygenation (H/R) or I/R induced AKI models. The changes of RNAs and proteins were quantified using RT-qPCR, western blot, and immunofluorescence assays, respectively. Cell proliferation and apoptosis were assessed by CCK-8 and flow cytometry. Interactions between molecules were investigated using RIP, ChIP, Co-IP, RNA pull-down, and dual luciferase reporter assays. Global m6A quantification was evaluated by kits. TUNEL and HE staining were employed for histopathological examinations. Oxidative stress-related indicators and renal function were determined using ELISA assays. The FTO expression was downregulated in H/R-induced HK-2 cells and renal tissues from I/R-induced rats. Overexpression of FTO improved the cell viability but repressed apoptosis and oxidative stress in H/R-treated HK-2 cells, as well as enhanced renal function and alleviated kidney injury in I/R rats. Notably, the FTO overexpression significantly increased autophagy-related LC3 and ULK1 levels. When autophagy was inhibited, the protective effects of FTO in AKI were diminished. Notably, Ambra1, a crucial regulator of autophagy, was repressed in H/R-induced HK-2 cells. However, the FTO overexpression restored the Ambra1 expression by reducing m6A modification of its mRNA. SP1, acting as an upstream transcription factor, directly interacts with the FTO promoter to enhance FTO expression. Knockdown of SP1 or Ambra1 suppressed the beneficial effects of FTO upregulation on autophagy and oxidative stress injury in H/R-stimulated cells. FTO, transcriptionally activated by SP1, promoted autophagy by upregulating Ambra1/ULK1 signaling, thereby inhibiting oxidative stress and kidney injury. These findings may provide some novel insights for AKI treatment.

Inulin-based nanoparticles for targeted siRNA delivery in acute kidney injury

RNA interference has emerged as a promising therapeutic strategy to tackle acute kidney injury (AKI). Development of targeted delivery systems is highly desired for selective renal delivery of RNA and improved therapeutic outcomes in AKI. Inulin is a plant polysaccharide traditionally employed to measure glomerular filtration rate. Here, we describe the synthesis of inulin modified with α-cyclam-p-toluic acid (CPTA) to form a novel renal-targeted polymer, Inulin-CPTA (IC), which is capable of selective siRNA delivery to the injured kidneys. We show that conjugating CPTA to inulin imparts IC with targeting properties for cells that overexpress the C-X-C chemokine receptor 4 (CXCR4). Self-assembled IC/siRNA nanoparticles (polyplexes) demonstrated rapid accumulation in the injured kidneys with selective uptake and prolonged retention in injured renal tubules overexpressing the CXCR4 receptor. Tumor-suppressor protein p53 contributes significantly to the pathogenesis of AKI. siRNA-induced silencing of p53 has shown therapeutic potential in several preclinical studies, making it an important target in the treatment of AKI. Systemically administered nanoparticles formulated using IC and siRNA against p53 selectively accumulated in the injured kidneys and potently silenced p53 expression. Selective p53 knockdown led to positive therapeutic outcomes in mice with cisplatin-induced AKI, as seen by reduced tubular cell death, renal injury, inflammation, and overall improved renal function. These findings indicate that IC is a promising new carrier for renal-targeted delivery of RNA for the treatment of AKI.

Discovery of Propionic Acid Derivatives with a 5-THIQ Core as Potent and Orally Bioavailable Keap1-Nrf2 Protein-Protein Interaction Inhibitors for Acute Kidney Injury.

Keap1 plays a crucial role in regulating the Nrf2-mediated cytoprotective response and is increasingly targeted for oxidative stress-related diseases. Using small molecules to disrupt the Keap1-Nrf2 protein-protein interaction (PPI) has emerged as a new strategy for developing Nrf2 activators. Through extensive structure-activity relationship studies, we identified compound 56, which features a unique 5-tetrahydroisoquinoline scaffold and acts as a potent inhibitor of the Keap1-Nrf2 PPI. Compound 56 exhibited significant inhibitory activity (IC50 = 16.0 nM) and tight Keap1 binding affinity (Kd = 3.07 nM), along with acceptable oral bioavailability (F = 20%). Notably, 56 enhanced antioxidant defenses in HK-2 renal tubular epithelial cells and significantly reduced plasma creatinine and blood urea nitrogen levels in acute kidney injury (AKI) mice. These findings collectively position compound 56 as a promising candidate for the treatment of AKI.

Total alkaloids of Aconitum carmichaelii Debx alleviate cisplatin-induced acute renal injury by inhibiting inflammation and oxidative stress related to gut microbiota metabolism

BackgroundCisplatin-induced acute kidney injury (AKI) is a complex and serious clinical issue, representing a major cause of hospital-acquired AKI. Alkaloids are the main active constituents of Aconitum carmichaelii Debx, which exhibit protective effects in several kidney disease models and against other acute organ injuries. However, its activity and mechanism of action in AKI treatment remain unclear. PurposeThis study aimed to elucidate the effect of Aconitum carmichaelii Debx (ACA) in a model of cisplain-induced AKI and comprehensively investigate its underlying mechanisms. MethodsThe major alkaloids in ACA were analyzed using high-performance liquid chromatography. Blood urea nitrogen (BUN) and serum creatine levels were measured using automated biochemical instruments. 16S rRNA sequencing, short-chain fatty acid (SCFA) analysis, fecal microbiota transplantation (FMT), non-targeted metabolomics, and transcriptomics were performed to systematically identify prospective biomarkers after ACA treatment. Anti-inflammatory and anti-oxidative stress activities were monitored using ELISA and western blotting. ResultsFour main compounds (fuziline, neoline, talatisamine, and songorine) were identified in ACA. ACA significantly alleviated cisplatin-induced AKI by reducing (BUN) and serum creatine levels and improving histopathological scores. Moreover, ACA balanced cisplatin-mediated confoundments in microbial composition and function, including decreasing the levels of Escherichia-Shigella, Clostridium, and Ruminococcus, as well as increasing Ligilactobacillus, Anaerotruncus, Bacteroides and Desulfovibrio levels, accompanied by uremic toxin reduction, and augmenting serum SCFAs. The FMT experiments further confirmed that ACA exerts anti-AKI effects by affecting gut microbiota. A multi-omics study has shown that ACA regulates glutathione and tryptophan metabolism and mediates pathways that trigger inflammatory responses. Finally, ACA reduced serum levels of inflammatory factors (IL-1β, IL-6, and TNF-α), restored enzymes of the antioxidative system (SOD and CAT) and GSH values, and decreased monoester diterpene alkaloid levels in the kidney by inhibiting the expression of NF-κB pathway-related proteins and increasing Nrf2/HO-1 pathway-related protein expression. ConclusionACA protects against cisplatin-induced AKI through its anti-inflammatory and antioxidant functions, which may be associated with the restoration of gut microbiota metabolism. ACA is a potential drug for AKI and other forms of organ damage related to the disruption of the gut microbiota.

Paving the way ahead: protocol optimization of mouse models in crush syndrome related acute kidney injury research.

Crush syndrome (CS) is the leading cause of death after earthquakes, second only to direct trauma. Acute kidney injury (AKI) is the most severe complication of CS. Research based on the CS-AKI mouse model and kidney function assessment by glomerular filtration rate (GFR) helps to elucidate the pathogenesis of CS-AKI, which contributes to effective treatment measures. Mice were modeled by the multi-channel small animal crushing platform. We set up different CS-AKI modeling parameters by applying different crushing weights (0.5 kg, 1.0 kg, 1.5kg), crushing durations (6 h, 12 h, 16h), and decompression durations (6 h, 12 h, 24h). The GFR, serum creatinine (SCr), blood urea nitrogen (BUN), kidney tissue Kim-1 mRNA and Ngal mRNA expression levels, and HE staining were examined to evaluate the results of different protocols. The results showed that with the crushing weight increased, the kidney function assessment's gold standard GFR significantly decreased, and the levels of SCr and BUN increased. Meanwhile, the longer crushing durations found a higher extension of inflammatory cell infiltration in the kidney. The degree of kidney injury continued to worsen with the duration of decompression, indicating severe damage after reperfusion, which was associated with tubular injury and a sustained elevation of the inflammatory state. We successfully constructed CS-AKI mouse models with different severities under the above parameters. Applying 1.5kg for 16h and then decompressing for 24h induced severe AKI. These findings provide clues for further exploration of the mechanism and treatment of traumatic AKI.

A STUDY TO DETERMINE IF HEMATURIA IN PATIENTS WITH SNAKE BITE CAN BE USED AS A CRITERIA FOR FORCED ALKALINE DIURESISTO PREVENT AKI

Hematuria and Acute kidney injury (AKI) are important causes of morbidity and mortality among victims of snake bite. As per Ministry of Health & Family Welfare Government of India, if the patient has oliguria or dipstick positive for blood give a trial of forced alkaline diuresis (FAD) within first 24 hours of the bite to avoid pigment nephropathy leading to acute tubular necrosis (ATN)19. In the current study we aim to determine if hematuria can be used as criteria for Forced Alkaline Diuresis in patient who present with hematuria following snake bite who later develop AKI. Results depicted that majority of the study subjects i.e., 88% AKI was not observed. However, urine output in study subjects at 6 hours was not significantly differed with the urine output of study subjects at 12 hours (χ2 = 0.219) and at 24 hours (χ2 = 0.066). Microscopic RBCs were present in 40%, 28%, and 24% of study subjects urine sample at 6 hours,12 hours, and 24 hours respectively. Furthermore, presence of microscopic RBCs in urine samples of study subjects at 6 hours significantly differed with the microscopic RBCs in urine samples of study subjects at 12 hours (χ2 = 0.000) and at 24 hours (χ2 = 0.001). In conclusion, patient with snake bite with presence of hematuria do not have AKI as a complication & hence hematuria cannot be used as criteria for Forced Alkaline Diuresis for the treatment of AKI in snake bite.

5-Hydroxytryptamine 1F Receptor Agonist Lasmiditan Differentially Regulates Successful Repair and Failed Repair Genes in a Mouse Model of Acute Kidney Injury.

Increasing evidence substantiates the role of mitochondrial dysfunction, inflammation, fibrosis, and cell senescence in the onset and progression of acute kidney injury (AKI) to chronic kidney disease . The underlying governing cellular and transcriptional events, however, are not fully understood. Recently, the key factors that regulate successful and failed repair states in the proximal tubule have been identified at a single-cell resolution following bilateral ischemia-reperfusion (I/R) in a mouse model of AKI. Previously, our group showed that treatment with the FDA-approved selective 5-hydroxytryptamine receptor 1F agonist lasmiditan following AKI induces mitochondrial biogenesis , restores renal mitochondrial function, and increases renal and vascular recovery in vivo. Here, we assessed the effect of lasmiditan on transcriptional and translational changes that are responsible for successful repair, injury, and failed repair states in the renal cortex following I/R-induced AKI. Increased levels of successful repair genes such as acyl-coA synthase medium-chain family member 2a, low-density lipoprotein receptor-related protein 2, solute carrier family 5 member 12, and hepatocyte nuclear factor 4 alpha were observed with 6 and 12 days of lasmiditan treatment following AKI compared to vehicle control. While 6 days of lasmiditan treatment had no effect on failed repair genes, the administration of lasmiditan for 12 days decreased the levels of vascular cell adhesion protein 1, tumor necrosis factor α, and interleukin-1β, which drive maladaptive repair. These data reveal that lasmiditan treatment post-AKI differentially regulates successful and failed repair gene expression in the renal cortex, likely contributing to the restoration of renal function and providing a potential targeted therapeutic pathway for the treatment of AKI.

Early goal-directed renal replacement therapy in severe pneumonia associated acute kidney injury

Introduction Severe pneumonia is a crucial issue in the development of acute kidney injury (AKI). This study evaluated the efficacy of early goal-directed renal replacement therapy (GDRRT) for the treatment of severe pneumonia-associated AKI. Methods In this real-world retrospective cohort study, we recruited 180 patients with severe pneumonia who were hospitalized and received GDRRT in a third-class general hospital in East China between January 1, 2017, and December 31, 2021. Clinical data on baseline characteristics, biochemical indicators, and renal replacement therapy were collected. Patients were divided into Early and Late RRT groups according to fluid status, inflammation progression, and pulmonary radiology. We investigated in-hospital all-cause mortality (primary endpoint) and renal recovery (secondary endpoint) between the two groups. Results Among the 154 recruited patients, 80 and 74 were in the early and late RRT groups, respectively. There were no significant differences in the demographic characteristics between the two groups. The duration of admission to RRT initiation was significantly shorter in Early RRT group [2.5(1.0, 8.7) d vs. 5.0(1.5,13.5) d, p = 0.027]. At RRT initiation, the patients in the Early RRT group displayed a lower percentage of fluid overload, lower doses of vasoactive agents, higher CRP levels, and higher rates of radiographic progression than those in the Late RRT group. The all-cause in-hospital mortality was significantly lower in the Early RRT group than in Late group (52.5% vs. 86.5%, p < 0.001). Patients in the Early RRT group displayed a significantly higher proportion of complete renal recovery at discharge (40.0% vs. 8.1%, p < 0.001). Conclusion This study clarified that early GDRRT for the treatment of severe pneumonia-associated AKI based on fluid status and inflammation progression, was associated with reduced hospital mortality and better recovery of renal function. Our preliminary study suggests that early initiation of RRT may be an effective approach for severe pneumonia-associated AKI.

Nanotechnology-Based Drug Delivery Systems for Treating Acute Kidney Injury.

Acute kidney injury (AKI) is a disease that is characterized by a rapid decline in renal function and has a relatively high incidence in hospitalized patients. Sepsis, renal hypoperfusion, and nephrotoxic drug exposure are the main causes of AKI. The major therapy measures currently include supportive treatment, symptomatic treatment, and kidney transplantation. These methods are supportive treatments, and their results are not satisfactory. Fortunately, many new treatments that markedly improve the AKI therapy efficiency are emerging. These include antioxidant therapy, ferroptosis therapy, anti-inflammatory therapy, autophagy therapy, and antiapoptotic therapy. In addition, the development of nanotechnology has further promoted therapeutic effects on AKI. In this review, we highlight recent advances in the development of nanocarriers for AKI drug delivery. Emphasis has been placed on the latest developments in nanocarrier modification and design. We also summarize the applications of different nanocarriers in AKI treatment. Finally, the advantages and challenges of nanocarrier applications in AKI are summarized, and several nanomedicines that have been approved for clinical trials to treat diverse kidney diseases are listed.

Renal dysfunction in surgical patients.

To provide an overview of the current diagnostic criteria for acute kidney injury (AKI) including their limitations and to discuss prevention and treatment approaches in the perioperative setting. AKI is common in the perioperative period and is associated with worse short- and long-term outcomes. Current definitions of AKI have several limitations and lead to delayed recognition of kidney dysfunction which is why novel diagnostic approaches by using renal biomarkers may be helpful. In general, prevention of the development and progression of AKI is vital as a causal treatment for AKI is currently not available. Optimization of kidney perfusion and avoidance of nephrotoxic drugs reduce the occurrence of AKI in surgical patients. Angiotensin II as a new vasopressor, the use of remote ischemic preconditioning, and amino acids may be approaches with a positive effect on the kidneys. Evidence suggests that the implementation of supportive measures in patients at high risk for AKI might reduce the occurrence of AKI. Novel biomarkers can help allocating resources by detecting patients at high risk for AKI.

DUSP5 deficiency suppresses the progression of acute kidney injury by enhancing autophagy through AMPK/ULK1 pathway

Acute kidney injury (AKI) represents a critical clinical disease characterized by the rapid decline in renal function, carrying a substantial burden of morbidity and mortality. The treatment of AKI is frequently limited by its variable clinical presentations and intricate pathophysiology, highlighting the urgent need for a deeper understanding of its pathogenesis and potential therapeutic targets. Dual-specific protein phosphatase 5 (DUSP5), a member of the serine-threonine phosphatase family, possesses the capability to dephosphorylate extracellular regulated protein kinases (ERK). DUSP5 has emerged as a pivotal player in modulating metabolic signals, inflammatory responses, and cancer progression, while also being closely associated with various kidney diseases. This study systematically scrutinized the function and mechanism of DUSP5 in AKI for the first time, unveiling a substantial increase in DUSP5 expression during AKI. Moreover, DUSP5 knockdown was observed to attenuate the production of inflammatory factors and apoptotic cells in renal tubular epithelial cells by enhancing AMPK/ULK1-mediated autophagy, thus improving renal function. In a word, DUSP5 knockdown in AKI effectively impede disease progression by activating autophagy. This finding holds promise for introducing fresh perspectives and targets for AKI treatment.

Reactive Oxygen Species-Scavenging Mesoporous Poly(tannic acid) Nanospheres Alleviate Acute Kidney Injury by Inhibiting Ferroptosis.

Acute kidney injury (AKI), predominantly associated with the excess production of endogenous ROS, is a serious renal dysfunction syndrome. Ferroptosis characterized by iron-dependent regulated cell death has significant involvement in AKI pathogenesis. As symptomatic treatment of AKI remains clinically limited, a new class of effective therapies has emerged, which is referred to as nanozyme. In our research, a natural mesoporous poly(tannic acid) nanosphere (referred to as PTA) was developed that can successfully mimic the activity of superoxide dismutase (SOD) by Mussel-inspired interface deposition strategy, for effective ROS scavenging and thus inhibition of ferroptosis to attenuate AKI. As anticipated, PTA mitigated oxidative stress and inhibited ferroptosis, as opposed to other modes of cell death such as pyroptosis or necrosis. Furthermore, PTA exhibited favorable biocompatibility and safeguarded the kidney against ferroptosis by enhancing the expression of SLC7a11/glutathione peroxidase 4(GPX4) and Nrf2/HO-1, while reducing the levels of ACSL4 protein in the ischemia and reperfusion injury (IRI)-induced AKI model. Moreover, PTA effectively suppressed aberrant expression of inflammatory factors. Overall, this study introduced antioxidative nanozymes in the form of mesoporous polyphenol nanospheres, showcasing exceptional therapeutic efficacy in addressing ROS-related diseases. This novel approach holds promise for clinical AKI treatment and broadens the scope of biomedical applications for nanozymes.

Alliin mitigates the acute kidney injury by suppressing ferroptosis via regulating the Nrf2/GPX4 axis.

Acute kidney injury (AKI) is a clinical syndrome that is characterized by a sudden loss of kidney function, leading to severe metabolic disorders, multiple organ failure, and even death. Recent studies have strengthened the evidence for ferroptosis in AKI development. Alliin, a sulfur-containing amino acid with multiple pharmacological functions, was claimed with promising antioxidant and anti-inflammation effects in protecting organ damages. Herein, Alliin's potential in AKI treatment was investigated by exploring its impact on ferroptosis, providing a new strategy for clinical AKI treatments. Cecal ligation and puncture (CLP) modeling was performed on rats, followed by treated with 7.5 and 15mg/kg/day of alliin for 6days. A declined survival rate, severe renal pathological changes, renal dysfunction, and enhanced inflammatory state were observed in CLP-treated rats, which were remarkably alleviated by alliin. Moreover, increased MDA levels, declined SOD activity, and downregulated Nrf2, GPX4, and xCT in CLP-treated rats were notably reversed by alliin. To explore potential mechanisms of alliin, NRK-52E cells were stimulated with 1μg/mL LPS for 24h, followed by culturing with 30 and 100μM of alliin for 24h. Reduced cell viability, enhanced apoptosis, increased ROS production, boosted MDA level, and declined SOD activity were observed in LPS-stimulated NRK-52E cells, accompanied by downregulated Nrf2, GPX4, and xCT, which were strikingly ameliorated by alliin. Additionally, the influence of alliin on cell viability, oxidative stress (OS), and ferroptosis in LPS-stimulated NRK-52E cells were markedly abolished by silencing Nrf2. Collectively, alliin mitigated AKI by suppressing ferroptosis via regulating the Nrf2/GPX4 axis.

Protective effects of lupeol in rats with renal ischemia‑reperfusion injury.

Acute kidney injury (AKI) caused by ischemia and, exogenous or endogenous nephrotoxic agents poses a serious health issue. AKI is seen in 1% of all hospital admissions, 2-5% of hospitalizations and 67% of intensive care unit (ICU) patients. The in-hospital mortality rates for AKI is 40-50, and >50% for ICU patients. Ischemia-reperfusion (I/R) injury in the kidney can activate inflammatory responses and oxidative stress, resulting in AKI. The common endpoint in acute tubular necrosis is a cellular insult secondary to ischemia or direct toxins, which results in effacement of brush border, cell death and decreased function of tubular cells. The aim of the present study was to assess if the reported antioxidant and anti-inflammatory agent lupeol can exert any effects against renal I/R damage. In total, 24 Wistar Albino rats were randomly assigned into four groups of 6, namely Sham, lupeol, ischemia and therapy groups. In the lupeol group, intraperitoneal administration of 100 mg/kg lupeol was given 1 h before laparotomy, whilst only laparotomy was conducted in the sham group. The renal arteries of both kidneys were clamped for 45 min, 1 h after either intraperitoneal saline injection (in the ischemia group) or 100 mg/kg lupeol application (in the therapy group). The blood samples and renal tissues of all rats were collected after 24 h. In blood samples, blood urea nitrogen (BUN) was measured by the urease enzymatic method, and creatinine was measured by the kinetic Jaffe method. Using ELISA method, TNF-α and IL-6 levels were measured in the blood samples, whereas malondialdehyde (MDA), glutathione (GSH), caspase-3 levels were measured in kidney tissues. In addition, kidney histopathological analysis was performed by evaluating the degree of degeneration, tubular dilatation, interstitial lymphocyte infiltration, protein cylinders, necrosis and loss of brush borders. It was determined that renal damage occurred due to higher BUN, creatinine, MDA, TNF-α and caspase-3 values observed in the kidney tissues and blood samples of rats in ischemia group compared with the Sham group. Compared with those in the ischemia group, rats in the therapy group exhibited increased levels of GSH and reduced levels of BUN, TNF-α, MDA. Furthermore, the ischemia group also had reduced histopathological damage scores. Although differences in creatinine, IL-6 and caspase-3 levels were not statistically significant, they were markedly reduced in the treatment group. Taken together, these findings suggest that lupeol can prevent kidney damage as mainly evidenced by the reduced histopathological damage scores, decreased levels of oxidative stress and reduced levels of inflammatory markers. These properties may allow lupeol to be used in the treatment of AKI.

Selenium nanoparticles alleviate renal ischemia/reperfusion injury by inhibiting ferritinophagy via the XBP1/NCOA4 pathway

Acute kidney injury (AKI) is closely related to lysosomal dysfunction and ferroptosis in renal tubular epithelial cells (TECs), for which effective treatments are urgently needed. Although selenium nanoparticles (SeNPs) have emerged as promising candidates for AKI therapy, their underlying mechanisms have not been fully elucidated. Here, we investigated the effect of SeNPs on hypoxia/reoxygenation (H/R)-induced ferroptosis and lysosomal dysfunction in TECs in vitro and evaluated their efficacy in a murine model of ischemia/reperfusion (I/R)-AKI. We observed that H/R-induced ferroptosis was accompanied by lysosomal Fe2+ accumulation and dysfunction in TECs, which was ameliorated by SeNPs administration. Furthermore, SeNPs protected C57BL/6 mice against I/R-induced inflammation and ferroptosis. Mechanistically, we found that lysosomal Fe2+ accumulation and ferroptosis were associated with the excessive activation of NCOA4-mediated ferritinophagy, a process mitigated by SeNPs through the upregulation of X-box binding protein 1 (XBP1). Downregulation of XBP1 promoted ferritinophagy and partially counteracted the protective effects of SeNPs on ferroptosis inhibition in TECs. Overall, our findings revealed a novel role for SeNPs in modulating ferritinophagy, thereby improving lysosomal function and attenuating ferroptosis of TECs in I/R-AKI. These results provide evidence for the potential application of SeNPs as therapeutic agents for the prevention and treatment of AKI.