Global epidemiology and outcomes of acute kidney injury

Impact of electronic AKI alert/care bundle on AKI inpatient outcomes: a retrospective single-center cohort study

BACKGROUND

Outcomes among acute kidney injury (AKI) patients are poor in United Kingdom (UK) hospitals, and electronic alerts and care bundles may improve them. We implemented such a system at West Suffolk Hospital (WSH) called the 'AKI order set'. We aimed to assess its impact on all-cause mortality, length of stay (LOS) and renal function among AKI patients, and its utilization.

METHODS

Retrospective, single-center cohort study of patients ≥ 18 years old with AKI at WSH, a 430-bed general hospital serving a rural UK population of approximately 280,000. 7243 unique AKI events representing 5728 patients with full data were identified automatically from our electronic health record (EHR) between 02 September 2018 and 1 July 2021 (median age 78 years, 51% male). All-cause mortality, LOS and improvement in AKI stage, demographic and comorbidity data, medications and AKI order set use were automatically collected from the EHR.

RESULTS

The AKI order set was used in 9.8% of AKI events and was associated with 28% lower odds of all-cause mortality (multivariable odds ratio [OR] 0.72, 95% confidence interval [CI] 0.57-0.91). Median LOS was longer when the AKI order set was utilized than when not (11.8 versus 8.8 days, p < .001), but was independently associated with improvement in the AKI stage (28.9% versus 8.7%, p < .001; univariable OR 4.25, 95% CI 3.53-5.10, multivariable OR 4.27, 95% CI 3.54-5.14).

CONCLUSIONS

AKI order set use led to improvements in all-cause mortality and renal function, but longer LOS, among AKI patients at WSH.

Complement activation in wasp venom-induced acute kidney injury

Previous studies have highlighted the significant role of complement activation in kidney injuries induced by rhabdomyolysis, intravascular hemolysis, sepsis, and ischemia-reperfusion. Nevertheless, the specific role and mechanism of complement activation in acute kidney injury (AKI) caused by wasp venom remain unclear. The aim of this study was to elucidate the specific complement pathway activated and investigate complement activation in AKI induced by wasp venom. In this study, a complement-depleted mouse model was used to investigate the role of complement in wasp venom-induced AKI. Mice were randomly categorized into control, cobra venom factor (CVF), AKI, and CVF + AKI groups. Compared to the AKI group, the CVF + AKI group showed improved pathological changes in kidneys and reduced blood urea nitrogen (BUN) levels. The expression levels of renal complement 3 (C3), complement 5 (C5), complement 1q (C1q), factor B (FB), mannose-binding lectin (MBL), and C5b-9 in AKI group were upregulated compared with the control group. Conversely, the renal tissue expression levels of C3, C5, C1q, FB, MBL, and C5b-9 were decreased in the CVF + AKI group compared to those in the AKI group. Complement activation occurs through all three pathways in AKI induced by wasp venom. Furthermore, complement depletion by CVF attenuates wasp venom-induced nephrotoxicity, suggesting that complement activation plays a primary role in the pathogenesis of wasp venom-induced AKI.

Clinical significance of the lactate-to-albumin ratio on prognosis in critically ill patients with acute kidney injury

OBJECTIVE

To explore the relationship between lactate-to-albumin ratio (LAR) at ICU admission and prognosis in critically ill patients with acute kidney injury (AKI).

METHODS

A retrospective analysis was conducted. Patients were divided into low (<0.659) LAR and high LAR (≥0.659) groups. Least absolute shrinkage and selection operator regression analysis was conducted to select variables associated with the 30-day prognosis. Cox regression analyses were performed to assess the association between LAR and mortality. Kaplan-Meier curves were plotted to compare cumulative survival rates between high and low LAR groups. Subgroup analysis was employed to assess the stability of the results. ROC curve was used to determine the diagnostic efficacy of LAR on prognosis.

RESULTS

A nonlinear relationship was observed between LAR and the risk of 30-day and 360-day all-cause mortality in AKI patients (p < 0.001). Cox regulation showed that high LAR (≥ 0.659) was an independent risk factor for 30-day and 360-day all-cause mortality in patients with AKI (p < 0.001). The Kaplan-Meier survival curves demonstrated a noteworthy decrease in cumulative survival rates at both 30 and 360 days for the high LAR group in comparison to the low LAR group (p < 0.001). Subgroup analyses demonstrated the stability of the results. ROC curves showed that LAR had a diagnostic advantage when compared with lactate or albumin alone (p < 0.001).

CONCLUSION

High LAR (≥0.659) at ICU admission was an independent risk factor for both short-term (30-day) and long-term (360-day) all-cause mortality in patients with AKI.

Biomarkers of acute kidney injury: From discovery to the future of clinical practice

Purpose of this review Acute kidney injury (AKI) is a complex syndrome whose development is associated with an increased morbidity and mortality. Recent studies show that this syndrome is a common complication in critically ill and surgical patients the trajectory of which may differ. As AKI can be induced by different triggers, it is complex and therefore challenging to manage patients with AKI. This review strives to provide a brief historical perspective on AKI, elucidate recent developments in diagnosing and managing AKI, and show the current usage of novel biomarkers in both clinical routine and research. In addition, we provide a perspective on potential future developments and their impact of AKI understanding and management. Recent findings/developments Recent studies show the merits of stress and damage biomarkers, highlighting limitations of the current KDIGO definition that only uses the functional biomarkers serum creatinine and urine output. The use of novel biomarkers led to the introduction of the concept of "subclinical AKI". This new classification may allow a more distinct management of affected or at risk patients. Ongoing studies, such as BigpAK-2 and PrevProgAKI, investigate the implementation of biomarker-guided interventions in clinical practice and may demonstrate an improvement in patients' outcome. Summary The ongoing scientific efforts surrounding AKI have deepened our understanding of the syndrome prompting an expansion of existing concepts. A future integration of stress and damage biomarkers in AKI management, may lead to an individualized therapy in this area.

Effect of Serum Bilirubin Levels on Contrast-induced Acute Kidney Injury: A Systematic Evaluation and Meta-analysis

Contrast-induced acute kidney injury (CI-AKI) is an important complication following the use of iodinated contrast media. Bilirubin has a protective effect but may also aggravate CI-AKI. The purpose of this systematic review was to assess whether bilirubin is a risk factor for CI-AKI. We searched the databases PubMed, Embase, Web of Science, Cochrane Library, Scopus, Ovid Medline, CNKI (China National Knowledge Infrastructure), VPCS (Vip Paper Check System), Wanfang, and CBM (Chinese BioMedical Literature Database) from the initial date to May 6, 2023. We summarized the results by directly combining the effect-size odds ratio (OR) and 95% confidence interval (CI) and identified sources of heterogeneity through subgroup analysis, sensitivity analysis, and meta-regression analysis. A total of 10 studies (14 data sets) were included: 7 retrospective studies (10 data sets) and 3 prospective studies (4 data sets), involving 12776 participants. The incidence of CI-AKI of 16% (95% CI: 14-19%). Total bilirubin was positively associated with the occurrence of CI-AKI (OR = 1.80; 95% CI: 1.36-2.38). Both low and high bilirubin concentrations were risk factors for CI-AKI. The incidence of CI-AKI was higher in the low bilirubin group than in the high bilirubin group.

Epithelial cell states associated with kidney and allograft injury

The kidney epithelium, with its intricate arrangement of highly specialized cell types, constitutes the functional core of the organ. Loss of kidney epithelium is linked to the loss of functional nephrons and a subsequent decline in kidney function. In kidney transplantation, epithelial injury signatures observed during post-transplantation surveillance are strong predictors of adverse kidney allograft outcomes. However, epithelial injury is currently neither monitored clinically nor addressed therapeutically after kidney transplantation. Several factors can contribute to allograft epithelial injury, including allograft rejection, drug toxicity, recurrent infections and postrenal obstruction. The injury mechanisms that underlie allograft injury overlap partially with those associated with acute kidney injury (AKI) and chronic kidney disease (CKD) in the native kidney. Studies using advanced transcriptomic analyses of single cells from kidney or urine have identified a role for kidney injury-induced epithelial cell states in exacerbating and sustaining damage in AKI and CKD. These epithelial cell states and their associated expression signatures are also observed in transplanted kidney allografts, suggesting that the identification and characterization of transcriptomic epithelial cell states in kidney allografts may have potential clinical implications for diagnosis and therapy.

Effects of early recovery of renal function on adverse renal outcomes and mortality in patients with acute kidney injury: a systematic review and meta-analysis

AIM

This study intended to scrutinize the effect of RFR time on adverse renal outcomes and mortality and try to define the cutoff of early RFR.

METHODS

We conducted a literature search from database inception to February 2023. Outcome measures incorporated the progression of CKD, delivery of RRT, incidence of composite renal outcomes, and mortality. And pooled results were depicted as odds ratio (OR) and 95% confidence interval (CI).

RESULTS

A total of 11 studies were finally selected (507,989 patients, mean follow-up, 3.89 years). The results exhibited that the crude mortality was lower in patients with early RFR (OR = 0.39, 95% CI: 0.16-0.95, P = 0.037). In addition, patients with early RFR had a lower incidence of progression to CKD (OR = 0.38, 95% CI: 0.17-0.85, P < 0.018), RRT (OR = 0.37, 95% CI: 0.20-0.71, P = 0.03), and composite renal outcomes (OR = 0.18, 95% CI: 0.15-0.20, P < 0.001). CKD progression-related events were significantly higher in patients whose renal function recovered after 7 days (OR = 0.69, 95% CI: 0.47-1.09, P = 0.112) than in those whose renal function recovered within 7 days (OR = 0.23, 95% CI: 0.06-0.92, P = 0.038), and the risk of RRT was lower in patients who recovered within 7 days (OR = 0.32, 95% CI: 0.15-0.66, P = 0.002) than in those who recovered after 7 days (OR = 0.72, 95% CI: 0.17-3.09, P = 0.654) or longer.

CONCLUSION

Patients with early RFR had a lower risk of CKD progression, RRT, and composite renal outcomes, as well as lower crude mortality than those without early recovery, despite no marked difference in 30-day, 90-day, and 1-year mortality. We speculated that 7 days may be used as a cutoff for early RFR.

A Pilot Study of Renin-Guided Angiotensin-II Infusion to Reduce Kidney Stress After Cardiac Surgery

BACKGROUND

Vasoplegia is common after cardiac surgery, is associated with hyperreninemia, and can lead to acute kidney stress. We aimed to conduct a pilot study to test the hypothesis that, in vasoplegic cardiac surgery patients, angiotensin-II (AT-II) may not increase kidney stress (measured by [TIMP-2]*[IGFBP7]).

METHODS

We randomly assigned patients with vasoplegia (cardiac index [CI] > 2.1l/min, postoperative hypotension requiring vasopressors) and Δ-renin (4-hour postoperative-preoperative value) ≥3.7 µU/mL, to AT-II or placebo targeting a mean arterial pressure ≥65 mm Hg for 12 hours. The primary end point was the incidence of kidney stress defined as the difference between baseline and 12 hours [TIMP-2]*[IGFBP7] levels. Secondary end points included serious adverse events (SAEs).

RESULTS

We randomized 64 patients. With 1 being excluded, 31 patients received AT-II, and 32 received placebo. No significant difference was observed between AT-II and placebo groups for kidney stress (Δ-[TIMP-2]*[IGFBP7] 0.06 [ng/mL] 2 /1000 [Q1-Q3, -0.24 to 0.28] vs -0.08 [ng/mL] 2 /1000 [Q1-Q3, -0.35 to 0.14]; P = .19; Hodges-Lehmann estimation of the location shift of 0.12 [ng/mL] 2 /1000 [95% confidence interval, CI, -0.1 to 0.36]). AT-II patients received less fluid during treatment than placebo patients (2946 vs 3341 mL, P = .03), and required lower doses of norepinephrine equivalent (0.19 mg vs 4.18mg, P < .001). SAEs were reported in 38.7% of patients in the AT-II group and in 46.9% of patients in the placebo group.

CONCLUSIONS

The infusion of AT-II for 12 hours appears feasible and did not lead to an increase in kidney stress in a high-risk cohort of cardiac surgery patients. These findings support the cautious continued investigation of AT-II as a vasopressor in hyperreninemic cardiac surgery patients.

Monitoring the fluctuation of hydrogen peroxide with a near-infrared fluorescent probe for the diagnosis and management of kidney injury

Kidney injury has become an increasing concern for patients because of environmental hazards and physiological factors. However, the early diagnosis of kidney injury remains challenging. Studies have shown that oxidative stress was closely related to the occurrence and development of kidney injury, in which abnormal hydrogen peroxide (H2O2) production was a common characteristic. Consequently, monitoring H2O2 level changes is essential for the diagnosis and management of kidney injury. Herein, based on fluorescence imaging advantages, a near-infrared fluorescent probe DHX-1 was designed to detect H2O2. DHX-1 showed high sensitivity and selectivity toward H2O2, with a fast response time and excellent imaging capacity for H2O2 in living cells and zebrafish. DHX-1 could detect H2O2 in pesticide-induced HK-2 cells, revealing the main cause of kidney injury caused by pesticides. Moreover, we performed fluorescence imaging, which confirmed H2O2 fluctuation in kidney injury caused by uric acid. In addition, DHX-1 achieved rapid screening of active compounds to ameliorate pesticide-induced kidney injury. This study presents a tool and strategy for monitoring H2O2 levels that could be employed for the early diagnosis and effective management of kidney injury.

Protective roles of thrombomodulin in cisplatin-induced nephrotoxicity through the inhibition of oxidative and endoplasmic reticulum stress

Cisplatin is an effective chemotherapeutic agent widely used for the treatment of various solid tumors. However, cisplatin has an important limitation in its use; currently, there is no method to ameliorate cisplatin-induced acute kidney injury (AKI). Thrombomodulin (TM) is well known not only for its role as a cofactor in the clinically important natural anticoagulation pathway but also for its anti-inflammatory properties. Here, we investigated the effects of TM in cisplatin-induced AKI. In mice intraperitoneally injected with 15 mg/kg cisplatin, TM (10 mg/kg) or PBS was administered intravenously at 24 h after cisplatin injection. TM significantly attenuated cisplatin-induced nephrotoxicity with the suppressed elevation of blood urea nitrogen and serum creatinine, and reduced histological damages. Actually, TM treatment significantly alleviated oxidative stress-induced apoptosis by reducing reactive oxygen species (ROS) levels in cisplatin-treated renal proximal tubular epithelial cells (RPTECs) in vitro. Furthermore, TM clarified cisplatin-induced apoptosis by reducing caspase-3 levels. In addition, TM attenuated the endoplasmic reticulum (ER) stress signaling pathway in both renal tissues and RPTECs to protect the kidneys from cisplatin-induced AKI. These findings suggest that TM is a potential protectant against cisplatin-induced nephrotoxicity through suppressing ROS generation and ER stress in response to cisplatin.

AKI-Pro score for predicting progression to severe acute kidney injury or death in patients with early acute kidney injury after cardiac surgery

BACKGROUND

No reliable clinical tools exist to predict acute kidney injury (AKI) progression. We aim to explore a scoring system for predicting the composite outcome of progression to severe AKI or death within seven days among early AKI patients after cardiac surgery.

METHODS

In this study, we used two independent cohorts, and patients who experienced mild/moderate AKI within 48 h after cardiac surgery were enrolled. Eventually, 3188 patients from the MIMIC-IV database were used as the derivation cohort, while 499 patients from the Zhongshan cohort were used as external validation. The primary outcome was defined by the composite outcome of progression to severe AKI or death within seven days after enrollment. The variables identified by LASSO regression analysis were entered into logistic regression models and were used to construct the risk score.

RESULTS

The composite outcome accounted for 3.7% (n = 119) and 7.6% (n = 38) of the derivation and validation cohorts, respectively. Six predictors were assembled into a risk score (AKI-Pro score), including female, baseline eGFR, aortic surgery, modified furosemide responsiveness index (mFRI), SOFA, and AKI stage. And we stratified the risk score into four groups: low, moderate, high, and very high risk. The risk score displayed satisfied predictive discrimination and calibration in the derivation and validation cohort. The AKI-Pro score discriminated the composite outcome better than CRATE score, Cleveland score, AKICS score, Simplified renal index, and SRI risk score (all P < 0.05).

CONCLUSIONS

The AKI-Pro score is a new clinical tool that could assist clinicians to identify early AKI patients at high risk for AKI progression or death.

Dapagliflozin for Critically Ill Patients With Acute Organ Dysfunction: The DEFENDER Randomized Clinical Trial

Importance

Sodium-glucose cotransporter 2 (SGLT-2) inhibitors improve outcomes in patients with type 2 diabetes, heart failure, and chronic kidney disease, but their effect on outcomes of critically ill patients with organ failure is unknown.

Objective

To determine whether the addition of dapagliflozin, an SGLT-2 inhibitor, to standard intensive care unit (ICU) care improves outcomes in a critically ill population with acute organ dysfunction.

Design, Setting, and Participants

Multicenter, randomized, open-label, clinical trial conducted at 22 ICUs in Brazil. Participants with unplanned ICU admission and presenting with at least 1 organ dysfunction (respiratory, cardiovascular, or kidney) were enrolled between November 22, 2022, and August 30, 2023, with follow-up through September 27, 2023.

Intervention

Participants were randomized to 10 mg of dapagliflozin (intervention, n = 248) plus standard care or to standard care alone (control, n = 259) for up to 14 days or until ICU discharge, whichever occurred first.

Main Outcomes and Measures

The primary outcome was a hierarchical composite of hospital mortality, initiation of kidney replacement therapy, and ICU length of stay through 28 days, analyzed using the win ratio method. Secondary outcomes included the individual components of the hierarchical outcome, duration of organ support-free days, ICU, and hospital stay, assessed using bayesian regression models.

Results

Among 507 randomized participants (mean age, 63.9 [SD, 15] years; 46.9%, women), 39.6% had an ICU admission due to suspected infection. The median time from ICU admission to randomization was 1 day (IQR, 0-1). The win ratio for dapagliflozin for the primary outcome was 1.01 (95% CI, 0.90 to 1.13; P = .89). Among all secondary outcomes, the highest probability of benefit found was 0.90 for dapagliflozin regarding use of kidney replacement therapy among 27 patients (10.9%) in the dapagliflozin group vs 39 (15.1%) in the control group.

Conclusion and Relevance

The addition of dapagliflozin to standard care for critically ill patients and acute organ dysfunction did not improve clinical outcomes; however, confidence intervals were wide and could not exclude relevant benefits or harms for dapagliflozin.

Trial Registration

ClinicalTrials.gov Identifier: NCT05558098.

Single-Cell Spatial Transcriptomics Unveils Platelet-Fueled Cycling Macrophages for Kidney Fibrosis

With the increasing incidence of kidney diseases, there is an urgent need to develop therapeutic strategies to combat post-injury fibrosis. Immune cells, including platelets, play a pivotal role in this repair process, primarily through their released cytokines. However, the specific role of platelets in kidney injury and subsequent repair remains underexplored. Here, the detrimental role of platelets in renal recovery following ischemia/reperfusion injury and its contribution to acute kidney injury  to chronic kidney disease transition is aimed to investigated. In this study, it is shown that depleting platelets accelerates injury resolution and significantly reduces fibrosis. Employing advanced single-cell and spatial transcriptomic techniques, macrophages as the primary mediators modulated by platelet signals is identified. A novel subset of macrophages, termed "cycling M2", which exhibit an M2 phenotype combined with enhanced proliferative activity is uncovered. This subset emerges in the injured kidney during the resolution phase and is modulated by platelet-derived thrombospondin 1 (THBS1) signaling, acquiring profibrotic characteristics. Conversely, targeted inhibition of THBS1 markedly downregulates the cycling M2 macrophage, thereby mitigating fibrotic progression. Overall, this findings highlight the adverse role of platelet THBS1-boosted cycling M2 macrophages in renal injury repair and suggest platelet THBS1 as a promising therapeutic target for alleviating inflammation and kidney fibrosis.

Sensing Dying Cells in Health and Disease: The Importance of Kidney Injury Molecule-1

Kidney injury molecule-1 (KIM-1), also known as T-cell Ig and mucin domain-1 (TIM-1), is a widely recognized biomarker for AKI, but its biological function is less appreciated. KIM-1/TIM-1 belongs to the T-cell Ig and mucin domain family of conserved transmembrane proteins, which bear the characteristic six-cysteine Ig-like variable domain. The latter enables binding of KIM-1/TIM-1 to its natural ligand, phosphatidylserine, expressed on the surface of apoptotic cells and necrotic cells. KIM-1/TIM-1 is expressed in a variety of tissues and plays fundamental roles in regulating sterile inflammation and adaptive immune responses. In the kidney, KIM-1 is upregulated on injured renal proximal tubule cells, which transforms them into phagocytes for clearance of dying cells and helps to dampen sterile inflammation. TIM-1, expressed in T cells, B cells, and natural killer T cells, is essential for cell activation and immune regulatory functions in the host. Functional polymorphisms in the gene for KIM-1/TIM-1, HAVCR1 , have been associated with susceptibility to immunoinflammatory conditions and hepatitis A virus-induced liver failure, which is thought to be due to a differential ability of KIM-1/TIM-1 variants to bind phosphatidylserine. This review will summarize the role of KIM-1/TIM-1 in health and disease and its potential clinical applications as a biomarker and therapeutic target in humans.

Hippo pathway activated by circulating reactive oxygen species mediates cardiac diastolic dysfunction after acute kidney injury

Acute kidney injury (AKI) can cause distal cardiac dysfunction; however, the underlying mechanism is unknown. Oxidative stress is proved prominent in AKI-induced cardiac dysfunction, and a possible bridge role of oxidative-stress products in cardio-renal interaction has been reported. Therefore, this study aimed to investigate the critical role of circulating reactive oxygen species (ROS) in mediating cardiac dysfunction after bilateral renal ischemia-reperfusion injury (IRI). We observed the diastolic dysfunction in the mice following renal IRI, accompanied by reduced ATP levels, oxidative stress, and branched-chain amino acids (BCAA) accumulation in the heart. Notably, ROS levels showed a sequential increase in the kidneys, circulation, and heart. Treatment with tempol, an ROS scavenger, significantly restored cardiac diastolic function in the renal IRI mice, corroborating the bridge role of circulating ROS. Accumulating evidence has identified oxidative stress as upstream of Mst1/Hippo in cardiac injury, which could regulate the expression of downstream genes related to mitochondrial quality control, leading to lower ATP, higher ROS and metabolic disorder. To verify this, we examined the activation of the Mst1/Hippo pathway in the heart of renal IRI mice, which was alleviated by tempol treatment as well. In vitro, analysis revealed that Mst1-knockdown cardiomyocytes could be activated by hydrogen peroxide (H2O2). Analysis of Mst1-overexpression cardiomyocytes confirmed the critical role of the Mst1/Hippo pathway in oxidative stress and BCAA dysmetabolism. Therefore, our results indicated that circulating ROS following renal IRI activates the Mst1/Hippo pathway of myocardium, leading to cardiac oxidative stress and diastolic dysfunction. This finding provides new insights for the clinical exploration of improved treatment options for cardiorenal syndrome.

Risk factors for acute kidney injury and kidney relapse in patients with lupus podocytopathy

Background

Patients with lupus podocytopathy show a high incidence of acute kidney injury (AKI) and relapse, but the risk factors and mechanisms were unclear. This study analysed the clinicopathological features and risk factors for AKI and relapse in lupus podocytopathy patients.

Methods

The cohort of lupus podocytopathy was generated by screening the biopsies of patients with lupus nephritis (LN) from 2002 to 2022 and was divided into the mild glomerular lesion (MGL) and focal segmental glomerulosclerosis (FSGS) groups based on glomerular morphological characteristics. The acute (ATI) and chronic (CTI) tubulointerstitial lesions were semi-quantitatively scored. Logistic and Cox regressions were employed to identify the risk factors for AKI and relapse, respectively.

Results

Among 6052 LN cases, 98 (1.6%) were diagnosed as lupus podocytopathy, with 71 in the MGL group and 27 in the FSGS group. All patients presented with nephrotic syndrome and 33 (34.7%) of them had AKI. Seventy-seven (78.6%) patients achieved complete renal response (CRR) within 12 weeks of induction treatment, in which there was no difference in the CRR rate between glucocorticoid monotherapy and combination therapy with glucocorticoids plus immunosuppressants. Compared with the MGL group, patients in the FSGS group had significantly higher incidences of hypertension and haematuria; in addition, they had higher Systemic Lupus Erythematosus Disease Activity Index 2000, ATI and CTI scores but a significantly lower CRR rate. Urinary protein ≥7.0 g/24 h and serum C3 ≤0.750 g/l were independent risk factors for AKI. During a median follow-up of 78 months, 57 cases (60.0%) had relapse and none reached the kidney endpoint. Failure to achieve CRR within 12 weeks, maintenance with glucocorticoid monotherapy and AKI at onset were independent risk factors for kidney relapse.

Conclusions

In this study, histological subtypes of lupus podocytopathy were found to be associated with clinical features and treatment response. In addition, several risk factors associated with AKI occurrence and kidney relapse were identified.

Ultrasmall Polyphenol-NAD+ Nanoparticle-Mediated Renal Delivery for Mitochondrial Repair and Anti-Inflammatory Treatment of AKI-to-CKD Progression

As a central metabolic molecule, nicotinamide adenine dinucleotide (NAD+) can potentially treat acute kidney injury (AKI) and chronic kidney disease (CKD); however, its bioavailability is poor due to short half-life, instability, the deficiency of targeting, and difficulties in transmembrane transport. Here a physiologically adaptive gallic acid-NAD+ nanoparticle is designed, which has ultrasmall size and pH-responsiveness, passes through the glomerular filtration membrane to reach injured renal tubules, and efficiently delivers NAD+ into the kidneys. With an effective accumulation in the kidneys, it restores renal function, immune microenvironment homeostasis, and mitochondrial homeostasis of AKI mice via the NAD+-Sirtuin-1 axis, and exerts strong antifibrotic effects on the AKI-to-CKD transition by inhibiting TGF-β signaling. It also exhibits excellent stability, biodegradable, and biocompatible properties, ensuring its long-term safety, practicality, and clinical translational feasibility. The present study shows a potential modality of mitochondrial repair and immunomodulation through nanoagents for the efficient and safe treatment of AKI and CKD.

Protective Effect of CXCR7 Against Hypoxia/Reoxygenation Injury in Renal Tubular Epithelial Cells

Acute kidney injury (AKI) is a multifactorial syndrome with complex pathophysiology and prognosis. Ischaemia‒reperfusion injury (IRI) is a major cause of induced AKI. The aim of this study was to investigate the effect of upregulated CXCR7 expression on renal tubular epithelial cell apoptosis induced by hypoxia/reoxygenation (H/R). HK-2 cells were divided into three groups: control group (pcDNA3.1), hypoxia/reoxygenation + pcDNA3.1 group (H/R+pcDNA3.1) and CXCR7 overexpression + hypoxia/reoxygenation group (H/R+ Flag-CXCR7). Protein levels of renal tubular epithelial cell injury-, apoptosis- and autophagy-related markers were assessed by qRT‒PCR, Western blotting, flow cytometry (FCM), immunofluorescence and transmission electron microscopy (TEM). In addition, HK-2 cells were treated with the autophagy inhibitor 3-MA and divided into 3 groups: control group, 3-MA + pcDNA3.1 group, and 3-MA + Flag-CXCR7 group. Changes in autophagy and apoptosis in renal tubule epithelial cells were assessed by Western blotting and FCM. Compared with those in the control group, the protein and mRNA expression levels of CXCR7 in HK-2 cells were significantly lower under H/R conditions. Under H/R conditions, CXCR7 overexpression in HK-2 cells significantly downregulated the expression of NGAL. Moreover, CXCR7 overexpression significantly decreased H/R-induced cleaved PARP-1 and cleaved Caspase 3 levels, increased the level of the antiapoptotic protein BCL-2 and the autophagy-related molecules ATG5 and LC3B II, and significantly inhibited the expression of P62. Autophagy flow and TEM also showed that CXCR7 significantly promoted autophagy. CXCR7 significantly alleviated the 3-MA-induced inhibition of autophagy and increase in apoptosis. Upregulated CXCR7 expression can inhibit renal tubular epithelial cell apoptosis and damage by regulating autophagy. In conclusion, CXCR7 is a promising target for the prevention and/or treatment of AKI.

Heterogeneity in the definition of major adverse kidney events: a scoping review

Acute kidney injury (AKI) is associated with persistent renal dysfunction, the receipt of dialysis, dialysis dependence, and mortality. Accordingly, the concept of major adverse kidney events (MAKE) has been adopted as an endpoint for assessing the impact of AKI. However, applied criteria or observation periods for operationalizing MAKE appear to vary across studies. To evaluate this heterogeneity for MAKE evaluation, we performed a systematic scoping review of studies that employed MAKE as an AKI endpoint. Four major academic databases were searched, and we identified 122 studies with increasing numbers over time. We found marked heterogeneity in applied criteria and observation periods for MAKE across these studies, with some even lacking a description of criteria. Moreover, 13 different observation periods were employed, with 30 days and 90 days as the most common. Persistent renal dysfunction was evaluated by estimated glomerular filtration rate (34%) or serum creatinine concentration (48%); however, 37 different definitions for this component were employed in terms of parameters, cut-off criteria, and assessment periods. The definition for the dialysis component also showed significant heterogeneity regarding assessment periods and duration of dialysis requirement (chronic vs temporary). Finally, MAKE rates could vary by 7% [interquartile range: 1.7-16.7%] with different observation periods or by 36.4% with different dialysis component definitions. Our findings revealed marked heterogeneity in MAKE definitions, particularly regarding component assessment and observation periods. Dedicated discussion is needed to establish uniform and acceptable standards to operationalize MAKE in terms of selection and applied criteria of components, observation period, and reporting criteria for future trials on AKI and related conditions.

Therapeutic potential of urine-derived stem cells in renal regeneration following acute kidney injury: A comparative analysis with mesenchymal stem cells

BACKGROUND

Acute kidney injury (AKI) is a common clinical syndrome with high morbidity and mortality rates. The use of pluripotent stem cells holds great promise for the treatment of AKI. Urine-derived stem cells (USCs) are a novel and versatile cell source in cell-based therapy and regenerative medicine that provide advantages of a noninvasive, simple, and low-cost approach and are induced with high multidifferentiation potential. Whether these cells could serve as a potential stem cell source for the treatment of AKI has not been determined.

AIM

To investigate whether USCs can serve as a potential stem cell source to improve renal function and histological structure after experimental AKI.

METHODS

Stem cell markers with multidifferentiation potential were isolated from human amniotic fluid. AKI severe combined immune deficiency (SCID) mice models were induced by means of an intramuscular injection with glycerol. USCs isolated from human-voided urine were administered via tail veins. The functional changes in the kidney were assessed by the levels of blood urea nitrogen and serum creatinine. The histologic changes were evaluated by hematoxylin and eosin staining and transferase dUTP nick-end labeling staining. Meanwhile, we compared the regenerative potential of USCs with bone marrow-derived mesenchymal stem cells (MSCs).

RESULTS

Treatment with USCs significantly alleviated histological destruction and functional decline. The renal function was rapidly restored after intravenous injection of 5 × 105 human USCs into SCID mice with glycerol-induced AKI compared with injection of saline. Results from secretion assays conducted in vitro demonstrated that both stem cell varieties released a wide array of cytokines and growth factors. This suggests that a mixture of various mediators closely interacts with their biochemical functions. Two types of stem cells showed enhanced tubular cell proliferation and decreased tubular cell apoptosis, although USC treatment was not more effective than MSC treatment. We found that USC therapy significantly improved renal function and histological damage, inhibited inflammation and apoptosis processes in the kidney, and promoted tubular epithelial proliferation.

CONCLUSION

Our study demonstrated the potential of USCs for the treatment of AKI, representing a new clinical therapeutic strategy.

Mortality prediction and influencing factors for intensive care unit patients with acute tubular necrosis: random survival forest and cox regression analysis

Background: Patients with acute tubular necrosis (ATN) not only have severe renal failure, but also have many comorbidities, which can be life-threatening and require timely treatment. Identifying the influencing factors of ATN and taking appropriate interventions can effectively shorten the duration of the disease to reduce mortality and improve patient prognosis. Methods: Mortality prediction models were constructed by using the random survival forest (RSF) algorithm and the Cox regression. Next, the performance of both models was assessed by the out-of-bag (OOB) error rate, the integrated brier score, the prediction error curve, and area under the curve (AUC) at 30, 60 and 90 days. Finally, the optimal prediction model was selected and the decision curve analysis and nomogram were established. Results: RSF model was constructed under the optimal combination of parameters (mtry = 10, nodesize = 88). Vasopressors, international normalized ratio (INR)_min, chloride_max, base excess_min, bicarbonate_max, anion gap_min, and metastatic solid tumor were identified as risk factors that had strong influence on mortality in ATN patients. Uni-variate and multivariate regression analyses were used to establish the Cox regression model. Nor-epinephrine, vasopressors, INR_min, severe liver disease, and metastatic solid tumor were identified as important risk factors. The discrimination and calibration ability of both predictive models were demonstrated by the OOB error rate and the integrated brier score. However, the prediction error curve of Cox regression model was consistently lower than that of RSF model, indicating that Cox regression model was more stable and reliable. Then, Cox regression model was also more accurate in predicting mortality of ATN patients based on the AUC at different time points (30, 60 and 90 days). The analysis of decision curve analysis shows that the net benefit range of Cox regression model at different time points is large, indicating that the model has good clinical effectiveness. Finally, a nomogram predicting the risk of death was created based on Cox model. Conclusion: The Cox regression model is superior to the RSF algorithm model in predicting mortality of patients with ATN. Moreover, the model has certain clinical utility, which can provide clinicians with some reference basis in the treatment of ATN and contribute to improve patient prognosis.

Self-Assembling P38 Peptide Inhibitor Nanoparticles Ameliorate the Transition from Acute to Chronic Kidney Disease by Suppressing Ferroptosis

Accumulating evidence highlights p38 as a crucial factor highly activated during the process of acute kidney injury (AKI), but the application of p38 inhibitor in AKI is quite limited due to the low efficiency and poor kidney-targeting ability. Herein, a novel self-assembling peptide nanoparticle with specific p38-inhibiting activity is constructed, which linked mitogen-activated protein kinase kinase 3b (MKK3b), the functional domain of p38, with the cell-penetrating TAT sequence, ultimately self-assembling into TAT-MKK3b nanoparticles (TMNPs) through tyrosinase oxidation. Subsequent in vitro and in vivo studies demonstrated that TMNPs preferably accumulated in the renal tubular epithelial cells (RTECs) through forming protein coronas by binding to albumin, and strongly improved the reduced renal function of ischemia-reperfusion injury (IRI)-induced AKI and its transition to chronic kidney disease (CKD). Mechanically, TMNPs inhibited ferroptosis via its solute carrier family 7 member 11 (SLC7A11)/glutathione peroxidase 4 (GPX4) axis-inducing capacity and synergistic potent antioxidant property in AKI. The findings indicated that the multifunctional TMNPs exhibited renal targeting, ROS-scavenging, and ferroptosis-mitigating capabilities, which may serve as a promising therapeutic agent for the treatment of AKI and its progression to CKD.

Development and validation of a nomogram for predicting the occurrence of renal dysfunction after treatment of immune checkpoint inhibitor: a retrospective case-control study

PURPOSE

The administration of immune checkpoint inhibitors (ICIs) may lead to renal adverse events, notably including renal dysfunction. To early predict the probability of renal dysfunction after ICIs therapy, a retrospective case-control study was conducted.

METHODS

Clinical information on ICIs-treated patients was collected. Multivariable logistic regression was applied to identify risk factors for renal dysfunction after ICIs treatment. Moreover, a nomogram model was developed and validated internally.

RESULTS

A total of 442 patients were included, among which 35 (7.9%) experienced renal dysfunction after ICIs treatment. Lower baseline estimated glomerular filtration rate (eGFR) (OR 0.941; 95% CI 0.917 to 0.966; p<0.001), concurrent exposure of platinum(OR 4.014; 95% CI 1.557 to 10.346; p=0.004), comorbidities of hypertension (OR 3.478; 95% CI 1.600 to 7.562; p=0.002) and infection (OR 5.402; 95% CI 1.544 to 18.904; p=0.008) were found to be independent associated with renal dysfunction after ICIs treatment. To develop a predictive nomogram for the occurrence of renal dysfunction after ICIs treatment, the included cases were divided into training and validation groups in a ratio of 7:3 randomly. The above four independent risk factors were included in the model. The area under the receiver operating characteristic curves of the predictiive model were 0.822 (0.723-0.922) and 0.815 (0.699-0.930) in the training and validation groups, respectively.

CONCLUSIONS

Lower baseline eGFR, platinum exposure, comorbidities of hypertension and infection were predictors of renal dysfunction in ICIs-treated patients with cancer. A nomogram was developed to predict the probability of renal dysfunction after ICIs treatment, which might be operable and valuable in clinical practice.

NMR-based metabolomic analysis of plasma from elderly patients with CVD before and after using contrast media

Contrast-induced acute kidney injury (CI-AKI) is a growingly common kidney problem caused by medical procedures involving contrast media (CM), especially in older patients with existing health issues. It is crucial to pinpoint potential biomarkers for the early detection of CI-AKI. Previously, we observed that iodixanol affects glucose, choline, and glutathione metabolism in endothelial cells under laboratory conditions. In this study, we used 1H NMR-based metabolomics to examine the metabolic changes in the blood plasma of elderly patients with cardiovascular disease (CVD) before and after receiving iodixanol. We identified altered metabolites in plasma 24 and 48 h after iodixanol injection compared to levels before injection. Notably, metabolites such as glucose, unsaturated fatty acids (UFA), low-density lipoprotein (LDL)/very low-density lipoprotein (VLDL), pyruvate, choline, and glycine showed potential as biomarkers at 24 h post-injection compared to levels before injection. Similarly, glucose, pyruvate, lactate, choline, and glycine in plasma could serve as potential biomarkers at 48 h post-injection. Iodixanol notably affected pathways related to glycolysis, fatty acid breakdown, and amino acid metabolism according to our metabolic pathway analysis. The altered levels of specific metabolites in plasma could be indicative of CM-induced kidney injury. Overall, this research aids in understanding the physiological mechanisms involved and in identifying early biomarkers and prevention strategies for CI-AKI.

Cell-free DNA in patients with sepsis: long term trajectory and association with 28-day mortality and sepsis-associated acute kidney injury

Introduction

Outcome-prediction in patients with sepsis is challenging and currently relies on the serial measurement of many parameters. Standard diagnostic tools, such as serum creatinine (SCr), lack sensitivity and specificity for acute kidney injury (AKI). Circulating cell-free DNA (cfDNA), which can be obtained from liquid biopsies, can potentially contribute to the quantification of tissue damage and the prediction of sepsis mortality and sepsis-associated AKI (SA-AKI).

Methods

We investigated the clinical significance of cfDNA levels as a predictor of 28-day mortality, the occurrence of SA-AKI and the initiation of renal replacement therapy (RRT) in patients with sepsis. Furthermore, we investigated the long-term course of cfDNA levels in sepsis survivors at 6 and 12 months after sepsis onset. Specifically, we measured mitochondrial DNA (mitochondrially encoded NADH-ubiquinone oxidoreductase chain 1, mt-ND1, and mitochondrially encoded cytochrome C oxidase subunit III, mt-CO3) and nuclear DNA (nuclear ribosomal protein S18, n-Rps18) in 81 healthy controls and all available samples of 150 intensive care unit patients with sepsis obtained at 3 ± 1 days, 7 ± 1 days, 6 ± 2 months and 12 ± 2 months after sepsis onset.

Results

Our analysis revealed that, at day 3, patients with sepsis had elevated levels of cfDNA (mt-ND1, and n-Rps18, all p<0.001) which decreased after the acute phase of sepsis. 28-day non-survivors of sepsis (16%) had higher levels of cfDNA (all p<0.05) compared with 28-day survivors (84%). Patients with SA-AKI had higher levels of cfDNA compared to patients without AKI (all p<0.05). Cell-free DNA was also significantly increased in patients requiring RRT (all p<0.05). All parameters improved the AUC for SCr in predicting RRT (AUC=0.88) as well as APACHE II in predicting mortality (AUC=0.86).

Conclusion

In summary, cfDNA could potentially improve risk prediction models for mortality, SA-AKI and RRT in patients with sepsis. The predictive value of cfDNA, even with a single measurement at the onset of sepsis, could offer a significant advantage over conventional diagnostic methods that require repeated measurements or a baseline value for risk assessment. Considering that our data show that cfDNA levels decrease after the first insult, future studies could investigate cfDNA as a "memoryless" marker and thus bring further innovation to the complex field of SA-AKI diagnostics.

Renal macrophages and NLRP3 inflammasomes in kidney diseases and therapeutics

Macrophages are exceptionally diversified cell types and perform unique features and functions when exposed to different stimuli within the specific microenvironment of various kidney diseases. In instances of kidney tissue necrosis or infection, specific patterns associated with damage or pathogens prompt the development of pro-inflammatory macrophages (M1). These M1 macrophages contribute to exacerbating tissue damage, inflammation, and eventual fibrosis. Conversely, anti-inflammatory macrophages (M2) arise in the same circumstances, contributing to kidney repair and regeneration processes. Impaired tissue repair causes fibrosis, and hence macrophages play a protective and pathogenic role. In response to harmful stimuli within the body, inflammasomes, complex assemblies of multiple proteins, assume a pivotal function in innate immunity. The initiation of inflammasomes triggers the activation of caspase 1, which in turn facilitates the maturation of cytokines, inflammation, and cell death. Macrophages in the kidneys possess the complete elements of the NLRP3 inflammasome, including NLRP3, ASC, and pro-caspase-1. When the NLRP3 inflammasomes are activated, it triggers the activation of caspase-1, resulting in the release of mature proinflammatory cytokines (IL)-1β and IL-18 and cleavage of Gasdermin D (GSDMD). This activation process therefore then induces pyroptosis, leading to renal inflammation, cell death, and renal dysfunction. The NLRP3-ASC-caspase-1-IL-1β-IL-18 pathway has been identified as a factor in the development of the pathophysiology of numerous kidney diseases. In this review, we explore current progress in understanding macrophage behavior concerning inflammation, injury, and fibrosis in kidneys. Emphasizing the pivotal role of activated macrophages in both the advancement and recovery phases of renal diseases, the article delves into potential strategies to modify macrophage functionality and it also discusses emerging approaches to selectively target NLRP3 inflammasomes and their signaling components within the kidney, aiming to facilitate the healing process in kidney diseases.

Dialysis for paediatric acute kidney injury in Cape Town, South Africa

BACKGROUND

Dialysis is lifesaving for acute kidney injury (AKI), but access is poor in less resourced settings. A "peritoneal dialysis (PD) first" policy for paediatric AKI is more feasible than haemodialysis in low-resource settings.

METHODS

Retrospective review of modalities and outcomes of children dialysed acutely at Red Cross War Memorial Children's Hospital between 1998 and 2020.

RESULTS

Of the 593 children with AKI who received dialysis, 463 (78.1%) received PD first. Median age was 9.0 (range 0.03-219.3; IQR 13.0-69.6) months; 57.6% were < 1 year old. Weights ranged from 0.9 to 2.0 kg (median 7.0 kg, IQR 3.0-16.0 kg); 38.6% were < 5 kg. PD was used more in younger children compared to extracorporeal dialysis (ECD), with median ages 6.4 (IQR 0.9-30.4) vs. 73.9 (IQR 17.5-113.9) months, respectively (p = 0.001). PD was performed with Seldinger soft catheters (n = 480/578, 83%), predominantly inserted by paediatricians at the bedside (n = 412/490, 84.1%). Complications occurred in 127/560 (22.7%) children receiving PD. Overall, 314/542 (57.8%) children survived. Survival was significantly lower in neonates (< 1 month old, 47.5%) and infants (1-12 months old, 49.2%) compared with older children (> 1 year old, 70.4%, p < 0.0001). Survival was superior in the ECD (75.4%) than in the PD group (55.6%, p = 0.002).

CONCLUSIONS

"PD First for Paediatric AKI" is a valuable therapeutic approach for children with AKI. It is feasible in low-resourced settings where bedside PD catheter insertion can be safely taught and is an acceptable dialysis modality, especially in settings where children with AKI would otherwise not survive.

Machine learning derived serum creatinine trajectories in acute kidney injury in critically ill patients with sepsis

BACKGROUND

Current classification for acute kidney injury (AKI) in critically ill patients with sepsis relies only on its severity-measured by maximum creatinine which overlooks inherent complexities and longitudinal evaluation of this heterogenous syndrome. The role of classification of AKI based on early creatinine trajectories is unclear.

METHODS

This retrospective study identified patients with Sepsis-3 who developed AKI within 48-h of intensive care unit admission using Medical Information Mart for Intensive Care-IV database. We used latent class mixed modelling to identify early creatinine trajectory-based classes of AKI in critically ill patients with sepsis. Our primary outcome was development of acute kidney disease (AKD). Secondary outcomes were composite of AKD or all-cause in-hospital mortality by day 7, and AKD or all-cause in-hospital mortality by hospital discharge. We used multivariable regression to assess impact of creatinine trajectory-based classification on outcomes, and eICU database for external validation.

RESULTS

Among 4197 patients with AKI in critically ill patients with sepsis, we identified eight creatinine trajectory-based classes with distinct characteristics. Compared to the class with transient AKI, the class that showed severe AKI with mild improvement but persistence had highest adjusted risks for developing AKD (OR 5.16; 95% CI 2.87-9.24) and composite 7-day outcome (HR 4.51; 95% CI 2.69-7.56). The class that demonstrated late mild AKI with persistence and worsening had highest risks for developing composite hospital discharge outcome (HR 2.04; 95% CI 1.41-2.94). These associations were similar on external validation.

CONCLUSIONS

These 8 classes of AKI in critically ill patients with sepsis, stratified by early creatinine trajectories, were good predictors for key outcomes in patients with AKI in critically ill patients with sepsis independent of their AKI staging.

Validation of a Prediction Model for Acute Kidney Injury after Cardiac Surgery in a Retrospective Asian Cohort

Background: The incidence of postoperative acute kidney injury (AKI) is relatively high in some Asian regions. The objective of this study was to examine the performance of an AKI prediction model developed based on data from a White-dominant population in a retrospective Asian cohort of patients undergoing cardiovascular surgery. Methods: We retrospectively identified 549 patients who underwent elective major cardiovascular surgery (coronary artery bypass graft, valve surgery, and aorta surgery), and excluded those who underwent a percutaneous cardiovascular procedure. Patients with a baseline estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 were also excluded. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) definition. Performance of the prediction model for AKI was expressed as area under the receiver operating characteristic curve (AUC). Results: The prediction model had a good predictive accuracy for postoperative AKI (all AUC > 0.92). The AUC of the prediction model in subgroups of age (<65 years and ≥65 years), sex (male and female), hypertension, and diabetes were all >0.85 (all p values < 0.001). Conclusions: The model could be used to predict postoperative AKI in Asian patients undergoing cardiovascular surgery with a baseline eGFR ≥ 60 mL/min/1.73 m2.

Discovering a New Drug Against Acute Kidney Injury by Using a Tailored Photoacoustic Imaging Probe

Acute kidney injury (AKI) has become an increasing concern for patients due to the widespread clinical use of nephrotoxic drugs. Currently, the early diagnosis of AKI is still challenging and the available therapeutic drugs cannot meet the clinical demand. Herein, this work has investigated the key redox couple involved in AKI and develops a tailored photoacoustic (PA) imaging probe (AB-DiOH) which can reversibly respond to hypochlorite (ClO-)/glutathione (GSH) with high specificity and sensitivity. This probe enables the real-time monitoring of AKI by noninvasive PA imaging, with better detection sensitivity than the blood test. Furthermore, this probe is utilized for screening nephroprotective drugs among natural products. For the first time, astragalin is discovered to be a potential new drug for the treatment of AKI. After oral administration, astragalin can be efficiently absorbed by the animal body, alleviate kidney injury, and meanwhile induce no damage to other normal tissues. The treatment mechanism of astragalin has also been revealed to be the simultaneous inhibition of oxidative stress, ferroptosis, and cuproposis. The developed PA imaging probe and the discovered drug candidate provide a promising new tool and strategy for the early diagnosis and effective treatment of AKI.

Efficacy and safety of Yiqi Peiyuan granules for improving the short-term prognosis of patients with acute kidney injury: A multicenter, double-blind, placebo-controlled, randomized trial

BACKGROUND

Yiqi Peiyuan (YQPY) prescription, a composite prescription of traditional Chinese medicine, has been used to prevent or delay the continued deterioration of renal function after acute kidney injury (AKI) in some institutions and has shown considerable efficacy.

OBJECTIVE

This is the first randomized controlled trial to assess efficacy and safety of YQPY for improving short-term prognosis in adult patients with AKI.

DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS

This is a prospective, double-blind, multicenter, randomized, and placebo-controlled clinical trial. A total of 144 enrolled participants were randomly allocated to two groups according to a randomization schedule. Participants, caregivers and investigators assessing the outcomes were blinded to group assignment. Patients in the YQPY group received 36 g YQPY granules twice a day for 28 days. Patients in the placebo group received a placebo in the same dose as the YQPY granules.

MAIN OUTCOME MEASURES

The primary outcome was the change in the estimated glomerular filtration rate (eGFR) between baseline and after 4 and 24 weeks of treatment. The secondary outcomes were the change of serum creatinine (Scr) level between baseline and after treatment, and the incidence of endpoint events, defined as eGFR increasing by more than 25% above baseline, eGFR >75 mL/min per 1.73 m2 or the composite endpoint, which was defined as the sum of patients meeting either of the above criteria.

RESULTS

Data from a total of 114 patients (59 in the YQPY group and 55 in the control group) were analyzed. The mean changes in eGFR and Scr in weeks 4 and 24 had no difference between the two groups. In further subgroup analysis (22 in the YQPY group and 31 in the control group), the mean change in eGFR after treatment for 4 weeks was 27.39 mL/min per 1.73 m2 in the YQPY group and 5.78 mL/min per 1.73 m2 in the placebo group, and the mean difference between groups was 21.61 mL/min per 1.73 m2 (P < 0.001). Thirteen (59.1%) patients in the YQPY group and 5 (16.1%) in the placebo group reached the composite endpoints (P = 0.002). During the intervention, 2 and 4 severe adverse events were reported in the YQPY and placebo groups, respectively.

CONCLUSION

The YQPY granules can effectively improve the renal function of patients 4 weeks after the onset of AKI, indicating that it has good efficacy for improving short-term renal outcomes in patients with AKI. The YQPY granules may be a promising therapy for adults with AKI.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2100051723. Please cite this article as: Wu JJ, Zhang TY, Qi YH, Zhu MY, Fang Y, Qi CJ, Cao LO, Lu JF, Lu BH, Tang LM, Shen JX, Mou S. Efficacy and safety of Yiqi Peiyuan granules for improving the short-term prognosis of patients with acute kidney injury: a multicenter, double-blind, placebo-controlled, randomized trial. J Integr Med. 2024; 22(3): 279-285.

Development and Validation of a Predictive Model for Acute Kidney Injury in Sepsis Patients Based on Recursive Partition Analysis

BACKGROUND

Sepsis-associated acute kidney injury (SA-AKI) is a critical condition with significant clinical implications, yet there is a need for a predictive model that can reliably assess the risk of its development. This study is undertaken to bridge a gap in healthcare by creating a predictive model for SA-AKI with the goal of empowering healthcare providers with a tool that can revolutionize patient care and ultimately lead to improved outcomes.

METHODS

A cohort of 615 patients afflicted with sepsis, who were admitted to the intensive care unit, underwent random stratification into 2 groups: a training set (n = 435) and a validation set (n = 180). Subsequently, a multivariate logistic regression model, imbued with nonzero coefficients via LASSO regression, was meticulously devised for the prognostication of SA-AKI. This model was thoughtfully rendered in the form of a nomogram. The salience of individual risk factors was assessed and ranked employing Shapley Additive Interpretation (SHAP). Recursive partition analysis was performed to stratify the risk of patients with sepsis.

RESULTS

Among the panoply of clinical variables examined, hypertension, diabetes mellitus, C-reactive protein, procalcitonin (PCT), activated partial thromboplastin time, and platelet count emerged as robust and independent determinants of SA-AKI. The receiver operating characteristic curve analysis for SA-AKI risk discrimination in both the training set and validation set yielded an area under the curve estimates of 0.843 (95% CI: 0.805 to 0.882) and 0.834 (95% CI: 0.775 to 0.893), respectively. Notably, PCT exhibited the most conspicuous influence on the model's predictive capacity. Furthermore, statistically significant disparities were observed in the incidence of SA-AKI and the 28-day survival rate across high-risk, medium-risk, and low-risk cohorts (P < .05).

CONCLUSION

The composite predictive model, amalgamating the quintet of SA-AKI predictors, holds significant promise in facilitating the identification of high-risk patient subsets.

Highly Sensitive Early Diagnosis of Kidney Damage Using Renal Clearable Zwitterion-Coated Ferrite Nanoprobe via Magnetic Resonance Imaging In Vivo

Iron oxide nanoprobes exhibit substantial potential in magnetic resonance imaging (MRI) of kidney diseases and can eliminate the nephrotoxicity of gadolinium-based contrast agents (GBCAs). Nevertheless, there is an extreme shortage of highly sensitive and renal clearable iron oxide nanoprobes suitable for early kidney damage detection through MRI. Herein, a renal clearable ultra-small ferrite nanoprobe (UMFNPs@ZDS) is proposed for highly sensitive early diagnosis of kidney damage via structural and functional MRI in vivo for the first time. The nanoprobe comprises a ferrite core coated with a zwitterionic layer, and possesses a high T1 relaxivity (12.52 mm-1s-1), a small hydrodynamic size (6.43 nm), remarkable water solubility, excellent biocompatibility, and impressive renal clearable ability. In a rat model of unilateral ureteral obstruction (UUO), the nanoprobe-based MRI can not only accurately visualize the locations of renal injury, but also provide comprehensive functional data including peak value, peak time, relative renal function (RRF), and clearance percentage via MRI. The findings prove the immense potential of ferrite nanoprobes as a superior alternative to GBCAs for the early diagnosis of kidney damage.

A novel GSK3β inhibitor 5n attenuates acute kidney injury

Acute kidney injury (AKI) is a clinical syndrome with high morbidity and mortality caused by various factor. The specific strategies for AKI are still lacking. GSK3β is widely expressed in the kidneys. In acute models of injury, GSK3β promotes the systemic inflammatory response, increases the proinflammatory release of cytokines, induces apoptosis, and alters cell proliferation. We screened a series of 3-(4-pyridyl)-5-(4-sulfamido-phenyl)-1,2,4-oxadiazole derivatives which are recognized as new GSK3β inhibitors, and found that 5n had the least toxicity and the best cell protection. We then tested the anti-inflammatory and reno-protective effect of 5n in cisplatin-treated tubular epithelial cells. 5n had anti-inflammation effect indicated by phosphor-NF-κB detection. Finally, we found that 5n ameliorated renal injury and inflammation in cisplatin-induced AKI mouse model. Silencing GSK3β inhibited cell injury and inflammation induced by cisplatin. We found that GSK3β interacted with PP2Ac to modulate the activity of NF-κB. In conclusion, 5n, the novel GSK3β inhibitor, protects against AKI via PP2Ac-dependent mechanisms which may provide a potential strategy for the treatment of AKI in clinic.

Elevated Activated Partial Thromboplastin Time as a Predictor of 28-Day Mortality in Sepsis-Associated Acute Kidney Injury: A Retrospective Cohort Analysis

Purpose

To address the critical mortality rates among sepsis-associated acute kidney injury (SA-AKI) patients, early prognosis is vital. This study investigates the relationship between coagulation indices and the 28-day mortality rate in patients with SA-AKI.

Patients and Methods

This study was a retrospective cohort analysis including patients with SA-AKI admitted to the First Hospital of Fujian Medical University as a training cohort (n = 119) and patients admitted to the Third People's Hospital of Fujian University of Traditional Chinese Medicine as a validation cohort (n = 51). We examined the relationship between coagulation indices and 28-day mortality in SA-AKI, the cumulative mortality at different activated partial thromboplastin time (APTT) levels, and the nonlinear relationship between APTT and 28-day mortality. Receiver operating characteristic curves were plotted, and the area under the curve was calculated to assess the predictive power of APTT. Finally, subgroup analyses were performed to assess the robustness of the association.

Results

Overall, 119 participants with a mean±standard deviation age of 70.47±15.20 years were included in the training cohort: 54 died, 65 survived. According to univariate and multivariate COX regression analyses, APACHE II score, CRP level, Lac level, and APTT level were independent risk factors for 28-day adverse prognosis. After controlling for some variables, an elevated baseline APTT (≥ 37.7 s) was associated with an elevated risk of 28-day mortality (HR, 1.017; 95% CI, 1.001-1.032), and Kaplan-Meier analyses further confirmed the increased mortality in the group with a higher APTT. The same results were shown when the validation cohort was analyzed (HR, 1.024; 95% CI, 0.958-1.096). Subgroup analyses showed the stability of the association between APTT and poor prognosis in SA-AKI.

Conclusion

In essence, APTT elevation is synonymous with increased 28-day mortality rates, indicating a poor prognosis in SA-AKI scenarios.

Acute Kidney Injury Receiving Dialysis and Dialysis Care after Hospital Discharge

The number of patients with AKI receiving outpatient hemodialysis (AKI-D) is increasing. At present, on the basis of limited data, approximately one third of patients with AKI-D who receive outpatient dialysis after hospital discharge survive and regain sufficient kidney function to discontinue dialysis. Data to inform dialysis management strategies that promote kidney function recovery and processes of care among patients with AKI-D receiving outpatient dialysis are lacking. In this article, we detail current trends in the incidence, risk factors, clinical outcomes, proposed management, and health policy landscape for patients with AKI-D receiving outpatient dialysis and identify areas for further research.

Specific NOX4 Inhibition Preserves Mitochondrial Function and Dampens Kidney Dysfunction Following Ischemia-Reperfusion-Induced Kidney Injury

Background: Acute kidney injury (AKI) is a sudden episode of kidney failure which is frequently observed at intensive care units and related to high morbidity/mortality. Although AKI can have many different causes, ischemia-reperfusion (IR) injury is the main cause of AKI. Mechanistically, NADPH oxidases (NOXs) are involved in the pathophysiology contributing to oxidative stress following IR. Previous reports have indicated that knockout of NOX4 may offer protection in cardiac and brain IR, but there is currently less knowledge about how this could be exploited therapeutically and whether this could have significant protection in IR-induced AKI. Aim: To investigate the hypothesis that a novel and specific NOX4 inhibitor (GLX7013114) may have therapeutic potential on kidney and mitochondrial function in a mouse model of IR-induced AKI. Methods: Kidneys of male C57BL/6J mice were clamped for 20 min, and the NOX4 inhibitor (GLX7013114) was administered via osmotic minipump during reperfusion. Following 3 days of reperfusion, kidney function (i.e., glomerular filtration rate, GFR) was calculated from FITC-inulin clearance and mitochondrial function was assessed by high-resolution respirometry. Renal histopathological evaluations (i.e., hematoxylin-eosin) and TUNEL staining were performed for apoptotic evaluation. Results: NOX4 inhibition during reperfusion significantly improved kidney function, as evidenced by a better-maintained GFR (p < 0.05) and lower levels of blood urea nitrogen (p < 0.05) compared to untreated IR animals. Moreover, IR caused significant tubular injuries that were attenuated by simultaneous NOX4 inhibition (p < 0.01). In addition, the level of renal apoptosis was significantly reduced in IR animals with NOX4 inhibition (p < 0.05). These favorable effects of the NOX4 inhibitor were accompanied by enhanced Nrf2 Ser40 phosphorylation and conserved mitochondrial function, as evidenced by the better-preserved activity of all mitochondrial complexes. Conclusion: Specific NOX4 inhibition, at the time of reperfusion, significantly preserves mitochondrial and kidney function. These novel findings may have clinical implications for future treatments aimed at preventing AKI and related adverse events, especially in high-risk hospitalized patients.

Effect of care bundles for acute kidney injury: A systematic review and meta-analysis

PURPOSE

Acute kidney injury (AKI) is frequent among in-hospital patients with high incidence and mortality. Implementing a series of evidence-based AKI care bundles may improve patient outcomes by reducing changeable standards of care. The aim of this meta-analysis was therefore to appraise the influences of AKI care bundles on patient outcomes.

MATERIALS AND METHODS

We explored three international databases (PubMed, Embase, and Cochrane Central Register of Controlled Trials) and two Chinese databases (Wanfang Data and China National Knowledge Infrastructure) for studies from databases inception until November 30, 2022, comparing the impact of different AKI care bundles with usual standards of care in patients with or at risk for AKI. The study quality of non-randomized controlled trials and randomized controlled trials was evaluated by the NIH Study Quality Assessment Tool and the Cochrane risk of bias tool. Heterogeneity between studies was appraised by Cochran's Q test and I2 statistics. The possible origins of heterogeneity between studies were assessed adopting Meta-regression and subgroup analyses. Funnel plot asymmetry and Egger regression and Begg correlation tests were performed to discover potential publication bias. Data analysis was completed by software (RevMan 5.3 and Stata 15.0). The primary outcome was short- or long-term mortality. The secondary outcomes involved the incidence and severity of AKI.

RESULTS

Sixteen studies containing 25,690 patients and 25,903 AKI episodes were included. In high-risk AKI patients determined by novel biomarkers, electronic alert or risk prediction score, the application of AKI care bundles significantly reduced the AKI incidence (OR, 0.71; 95% CI, 0.53-0.96; p = 0.02; I2 = 84%) and AKI severity (OR, 0.59; 95% CI, 0.39-0.89; p = 0.01; I2 = 65%). No strong evidence is available to prove that care bundles can significantly reduce mortality (OR, 1.16; 95% CI, 0.58-2.30; p = 0.68; I2 = 97%).

CONCLUSIONS

The introduction of AKI care bundles in routine clinical practice can effectively improve the outcomes of patients with or at-risk of AKI. However, the accumulated evidence is limited and not strong enough to make definite conclusions.

Discovery, biosynthesis, organic synthesis, and bioactivities of meroterpenoids from Rhododendron species

Meroterpenoids discovered in Rhododendrons species possess unique chemical structures and biological activities and are expected to become new drug targets for Alzheimer's disease, metabolic disorders, and chronic kidney disease, and these compounds have attracted increasing attention in recent years. In this study, Rhododendron meroterpenoids and their structures, classifications, racemate distribution, biosynthetic pathways, chemical synthesis, and bioactivities are reviewed prior to 2023.

The protective mechanism of SIRT3 and potential therapy in acute kidney injury

Acute kidney injury (AKI) is a complex clinical syndrome with a poor short-term prognosis, which increases the risk of the development of chronic kidney diseases and end-stage kidney disease. However, the underlying mechanism of AKI remains to be fully elucidated, and effective prevention and therapeutic strategies are still lacking. Given the enormous energy requirements for filtration and absorption, the kidneys are rich in mitochondria, which are unsurprisingly involved in the onset or progression of AKI. Accumulating evidence has recently documented that Sirtuin 3 (SIRT3), one of the most prominent deacetylases highly expressed in the mitochondria, exerts a protective effect on AKI. SIRT3 protects against AKI by regulating energy metabolism, inhibiting oxidative stress, suppressing inflammation, ameliorating apoptosis, inhibiting early-stage fibrosis and maintaining mitochondrial homeostasis. Besides, a number of SIRT3 activators have exhibited renoprotective properties both in animal models and in vitro experiments, but have not yet been applied to clinical practice, indicating a promising therapeutic approach. In this review, we unravel and summarize the recent advances in SIRT3 research and the potential therapy of SIRT3 activators in AKI.

The Dual-specificity Phosphatase 3 (DUSP3): A Potential Target Against Renal Ischemia/Reperfusion Injury

Renal ischemia/reperfusion (I/R) injury is a common clinical challenge faced by clinicians in kidney transplantation. I/R is the leading cause of acute kidney injury, and it occurs when blood flow to the kidney is interrupted and subsequently restored. I/R impairs renal function in both short and long terms. Renal ischemic preconditioning refers to all maneuvers intended to prevent or attenuate ischemic damage. In this context, the present review focuses on the dual-specificity phosphatase 3 (DUSP3), also known as vaccinia H1-related phosphatase, an uncommon regulator of mitogen-activated protein kinase (MAPK) phosphorylation. DUSP3 has different biological functions: (1) it acts as a tumor modulator and (2) it is involved in the regulation of immune response, thrombosis, hemostasis, angiogenesis, and genomic stability. These functions occur either through MAPK-dependent or MAPK-independent mechanisms. DUSP3 genetic deletion dampens kidney damage and inflammation caused by I/R in mice, suggesting DUSP3 as a potential target for preventing renal I/R injury. Here, we discuss the putative role of DUSP3 in ischemic preconditioning and the potential mechanisms of such an attenuated inflammatory response via improved kidney perfusion and adequate innate immune response.

Characteristics, Risk Factors, and Outcomes in Acute Kidney Injury Patients: A Retrospective Cross-Sectional Study, Palestine

Background

Acute kidney injury (AKI) is a major medical problem affecting patients' quality of life and healthcare costs.

Objectives

This study evaluated the severity, risk factors, and outcomes of patients diagnosed with acute kidney injury (AKI), including community-acquired AKI (CA-AKI) and hospital-acquired AKI (HA-AKI), who were admitted to tertiary institutions in Palestine.

Methods

This retrospective cross-sectional study was conducted at multiple tertiary care hospitals in Palestine by reviewing patient charts from January 2020 to March 2023. The study included all patients aged ≥18 years who were admitted to the hospital and diagnosed with AKI at admission (CA-AKI) or who developed AKI 48 hours after admission (HA-AKI). Patients with incomplete medical records and those with no reported creatinine levels during their stay, pregnant women, kidney transplant patients, and end-stage renal disease patients were excluded. Data were analyzed using SPSS v22.0. The incidence of AKI in each group was compared using the chi-squared test.

Results

This study included 259 participants. HA-AKI was present in 27.3% of the patients, while CA-AKI was 72.7%. The most common stage among patients was stage 3 (55.7%, HA-AKI) (42.9%, CA-AKI), and the most common comorbidity contributing to AKI was CKD. NSAIDs, ACE-I/ARBs, and DIURETICs were the most nephrotoxic drugs contributing to AKI. Patients with hyperphosphatemia, hyperkalemia, severe metabolic acidosis, or stage 3 AKI require renal replacement therapy. In addition, our findings revealed a significant association among AKI mortality, age, and heart disease.

Conclusion

CA-AKI was more prevalent than HA-AKI in Palestinian patients admitted for AKI. Risk factors for AKI included diabetes, CKD, and medications (antibiotics, NSAID, diuretics, and ACE-I/ARB). Preventive measures, medication management, and disease state management are necessary to minimize AKI during hospital admission or in the community.

From Rare Disorders of Kidney Tubules to Acute Renal Injury: Progress and Prospective

Background

Acute kidney injury (AKI) is a severe condition marked by rapid renal function deterioration and elevated mortality, with traditional biomarkers lacking sensitivity and specificity. Rare tubulointerstitial diseases encompass a spectrum of disorders, primarily including monogenic diseases, immune-related conditions, and drug-induced tubulointerstitial diseases. The clinical manifestations vary from electrolyte and acid-base imbalances to kidney function insufficiency, which is associated with AKI in up to 20% of cases. Evidence indicated that rare tubulointerstitial diseases might provide new conceptual insights and perspectives for novel biomarkers and potential therapeutic strategies for AKI.

Summary

Autosomal dominant tubulointerstitial kidney disease (ADTKD) and Fanconi syndrome (FS) are rare tubulointerstitial diseases. In ADTKD, UMOD and REN are closely related to AKI by affecting oxidative stress and tubuloglomerular feedback, which provide potential new biomarkers for AKI. Both rare tubulointerstitial diseases and AKI share etiologies and treatment responses. From the mechanism standpoint, rare tubulointerstitial diseases and AKI involve tubular transporter injury, initially manifesting as tubular dysfunction in tubulointerstitial disorder and progressing to AKI because of the programmed cell death with apoptosis, pyroptosis, or necroptosis of proximal tubule cells. Additionally, mitochondrial dysfunction has been identified as a common mechanism in both tubulointerstitial diseases and AKI induced by drugs, pSS, or monoclonal diseases. In the end, both AKI and FS patients and animal models responded well to the therapy of the primary diseases.

Key Messages

In this review, we describe an overview of ADTKD and FS to identify their associations with AKI. Mitochondrial dysfunction contributes to rare tubulointerstitial diseases and AKI, which might provide a potential therapeutic target.

LXA4 protected mice from renal ischemia/reperfusion injury by promoting IRG1/Nrf2 and IRAK-M-TRAF6 signal pathways

Excessive inflammatory response and increased oxidative stress play an essential role in the pathophysiology of ischemia/reperfusion (I/R)-induced acute kidney injury (IRI-AKI). Emerging evidence suggests that lipoxin A4 (LXA4), as an endogenous negative regulator in inflammation, can ameliorate several I/R injuries. However, the mechanisms and effects of LXA4 on IRI-AKI remain unknown. In this study, A bilateral renal I/R mouse model was used to evaluate the role of LXA4 in wild-type, IRG1 knockout, and IRAK-M knockout mice. Our results showed that LXA4, as well as 5-LOX and ALXR, were quickly induced, and subsequently decreased by renal I/R. LXA4 pretreatment improved renal I/R-induced renal function impairment and renal damage and inhibited inflammatory responses and oxidative stresses in mice kidneys. Notably, LXA4 inhibited I/R-induced the activation of TLR4 signal pathway including decreased phosphorylation of TAK1, p36, and p65, but did not affect TLR4 and p-IRAK-1. The analysis of transcriptomic sequencing data and immunoblotting suggested that innate immune signal molecules interleukin-1 receptor-associated kinase-M (IRAK-M) and immunoresponsive gene 1 (IRG1) might be the key targets of LXA4. Further, the knockout of IRG1 or IRAK-M abolished the beneficial effects of LXA4 on IRI-AKI. In addition, IRG1 deficiency reversed the up-regulation of IRAK-M by LXA4, while IRAK-M knockout had no impact on the IRG1 expression, indicating that IRAK-M is a downstream molecule of IRG1. Mechanistically, we found that LXA4-promoted IRG1-itaconate not only enhanced Nrf2 activation and increased HO-1 and NQO1, but also upregulated IRAK-M, which interacted with TRAF6 by competing with IRAK-1, resulting in deactivation of TLR4 downstream signal in IRI-AKI. These data suggested that LXA4 protected against IRI-AKI via promoting IRG1/Itaconate-Nrf2 and IRAK-M-TRAF6 signaling pathways, providing the rationale for a novel strategy for preventing and treating IRI-AKI.

Apoptosis-related prognostic biomarkers and potential targets for acute kidney injury based on machine learning algorithm and in vivo experiments

Acute kidney injury (AKI) is a common critical illness in hospitalized patients, characterized by a rapid decline in kidney function over a short period, which can seriously endanger the patient's life. Currently, there is a lack of precise and universal AKI diagnostic biomarkers in clinical practice. In this study, weighted gene coexpression network analysis (WGCNA), differential expression analysis, univariate and multivariate logistic regression analyses, receiver operating characteristic (ROC) curves, and immune cell infiltration were performed to identify apoptosis-related biomarkers that can be used for AKI diagnosis. Three core apoptosis-related genes (ARGs), CBFB, EGF and COL1A1, were identified as AKI biomarkers. More importantly, an apoptosis-related signature containing three hub ARGs was validated as a diagnostic model. The hub genes exhibited good correlations with glomerular filtration rate (GFR) and serum creatinine (SCr) in the Nephroseq kidney disease database. Additionally, CIBERSORT immune infiltration analysis indicated that these core ARGs may affect immune cell recruitment and infiltration in AKI patients. Subsequently, we investigated the alteration of the expression levels of three core ARGs in AKI samples using single-cell RNA sequencing analysis and analyzed the cell types that mainly expressed these ARGs. More importantly, the expression of core ARGs was validated in folic acid- and cisplatin-induced AKI mouse models. In summary, our study identified three diagnostic biomarkers for AKI, explored the roles of ARGs in AKI progression and provided new ideas for the clinical diagnosis and treatment of AKI.

Site 1 protease aggravates acute kidney injury by promoting tubular epithelial cell ferroptosis through SIRT3-SOD2-mtROS signaling

Ischemia/reperfusion (I/R)-induced acute kidney injury (AKI) is a common clinical syndrome with high morbidity and mortality. Ferroptosis, a newly discovered form of oxidative cell death, is involved in the pathogenesis of renal I/R injury; however, the underlying mechanism remains to be explored. Here, we reported that site 1 protease (S1P) promotes ischemic kidney injury by regulating ferroptotic cell death of tubular epithelial cells. S1P abundance was measured in hypoxia/reoxygenation (H/R)-treated Boston University mouse proximal tubular (BUMPT) cells and I/R-induced murine kidney tissue. S1P expression in BUMPT cells and kidneys was initially activated by hypoxic stimulation, accompanied by the ferroptotic response. Blocking S1P blunted H/R-induced ferroptotic cell death, which also restored sirtuin 3 (SIRT3) expression and superoxide dismutase 2 (SOD2) activity in BUMPT cells. Next, inhibition of S1P expression restored I/R-suppressed SIRT3 abundance, SOD2 activity and reduced the elevated level of mitochondria reactive oxygen species (mtROS), which attenuated tubular cell ferroptosis and renal I/R injury. In conclusion, S1P promoted renal tubular epithelial cell ferroptosis under I/R status by activating SIRT3-SOD2-mtROS signaling, thereby accelerating kidney injury. Thus, targeting S1P signaling may serve as a promising strategy for I/R kidney injury.

Pyroptosis: The Determinator of Cell Death and Fate in Acute Kidney Injury

Background

Acute kidney injury (AKI) is kidney damage that leads to a rapid decline in function. AKI primarily occurs when the tubular epithelium is damaged, causing swelling, loss of brush margin, and eventual apoptosis. Research has shown that tubular epithelial cell damage in AKI is linked to cell cycle arrest, autophagy, and regulation of cell death.

Summary

Pyroptosis, a type of programmed cell death triggered by inflammation, is believed to play a role in the pathophysiology of AKI. Cumulative evidence has shown that pyroptosis is the main cause of tubular cell death in AKI. Thus, targeted intervention of pyroptosis may be a promising therapeutic approach for AKI. This review delves deep into the cutting-edge research surrounding pyroptosis in the context of AKI, shedding light on its intricate mechanisms and potential implications for clinical practice. Additionally, we explore the exciting realm of potential preclinical treatment options for AKI, aiming to pave the way for future therapeutic advancements.

Key Messages

Pyroptosis, a highly regulated form of cell death, plays a crucial role in determining the fate of cells during the development of AKI. This intricate process involves the activation of inflammasomes, which are multi-protein complexes that initiate pyroptotic cell death. By understanding the mechanisms underlying pyroptosis, researchers aim to gain insights into the pathogenesis of AKI and potentially identify new therapeutic targets for this condition.

Rodent models of AKI and AKI-CKD transition: an update in 2024

Despite known drawbacks, rodent models are essential tools in the research of renal development, physiology, and pathogenesis. In the past decade, rodent models have been developed and used to mimic different etiologies of acute kidney injury (AKI), AKI to chronic kidney disease (CKD) transition or progression, and AKI with comorbidities. These models have been applied for both mechanistic research and preclinical drug development. However, current rodent models have their limitations, especially since they often do not fully recapitulate the pathophysiology of AKI in human patients, and thus need further refinement. Here, we discuss the present status of these rodent models, including the pathophysiologic compatibility, clinical translational significance, key factors affecting model consistency, and their main limitations. Future efforts should focus on establishing robust models that simulate the major clinical and molecular phenotypes of human AKI and its progression.