Macrophage Ubiquitin-Activating Enzyme 1 Promotes Sepsis-Associated Acute Kidney Injury by Relieving Nucleoporin 35-Mediated Suppression of Nuclear Factor-κB Signaling.

Sepsis-associated acute kidney injury (SA-AKI) is a frequent complication of sepsis, yet the pathophysiologic mechanisms of SA-AKI are incompletely understood. PERSEVERE is a clinically validated serum biomarker panel with high sensitivity in predicting mortality from sepsis, and recent evidence suggests it can also predict severe, persistent SA-AKI at day 3 of hospitalization among septic children. We developed a murine model of PERSEVERE (mPERSEVERE) to further interrogate the sepsis-related biological underpinnings of SA-AKI using candidate biomarkers within mPERSEVERE. Eight-week-old C57BL/6 male mice underwent induction of sepsis by cecal ligation and puncture (CLP). mPERSEVERE biomarkers were collected at 8-hours and kidneys were harvested at 24-hours post-CLP Classification and regression tree analysis (CART) was used to generate a SA-AKI predictive model. Kidney gene expression levels of candidate biomarkers were quantified using real time polymerase chain reaction. Thirty- five mice underwent CLP Among mice identified by mPERSEVERE as high-risk for mortality, 70% developed SA-AKI at 24-hours compared to 22% of low-risk mice. CART analysis identified two mPERSEVERE biomarkers-C-C motif chemokine ligand 3 (CCL3) and keratinocyte-derived chemokine (KC)-as most predictive for SA-AKI with an area under the receiver operating curve of 0.90. In mice that developed SA-AKI, renal expression of KC was significantly increased compared to mice without SA-AKI (p = 0.013), whereas no difference was seen in renal expression of CCL3 in mice with SA-AKI vs. no SA-AKI. KC and CCL3 localized to renal tubule epithelial cells as opposed to infiltrating immune cells by immunohistochemistry. The combination of plasma CCL3+KC can predict SA-AKI development in mice at 24-hours following CLP Of these two biomarkers, only renal expression of KC is increased in mice with SA-AKI. Further studies are required to determine if KC directly contributes to the underlying pathobiology of SA-AKI.

Sepsis may be linked to oxidative stress and can be controlled by itaconate, an activator of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Nevertheless, the itaconate impact on sepsis-associated acute kidney injury (SA-AKI) has yet to be definitively established. We employed SA-AKI mouse model through a cecal ligation and puncture (CLP) procedure for the in vivo investigation of the potential nephroprotective effect of itaconate in this study. A plasmid was transfected into RAW264.7 cells to examine the Nrf2 pathway function after itaconate administration. Finally, the immune-responsive gene 1-knockout (IRG1-/-) mice were used to study the itaconate impacts on oxidative stress-induced SA-AKI. We have shown that 4-octyl itaconate (OI) significantly reduced CD11b-positive macrophage aggregation and activated the Nrf2 pathway in the bone marrow-derived macrophages (BMDM). The impacts of Nrf2 inhibitor ML385 on the anti-inflammatory and antioxidant properties of itaconate were found to be partial. OI inhibited lipopolysaccharide-induced oxidative stress injury in RAW264.7 macrophages and activated Nrf2 in the nucleus to hinder the expression of nuclear factor kappa B p65, thereby suppressing oxidative stress injury in the macrophages. Additionally, the introduction of the transfected plasmid resulted in a partial inhibition of the anti-inflammatory impact of itaconate. The kidney injury caused by sepsis exhibited greater severity in the IRG1-/- mice than in the wild type mice. Exogenous OI partially attenuated the kidney injury induced by sepsis in the IRG1-/- mice and suppressed the oxidative stress injury in macrophages. This investigation offers new proof to support the itaconate function in the development and progression of SA-AKI and shows a new possible therapeutic agent for the SA-AKI treatment.

Inhibiting SIRT2 attenuates sepsis-associated acute kidney injury via NEU1 acetylation-mediated CD44/PI3K/AKT pathway activation.

Cellular senescence has emerged as an important contributor to acute kidney injury (AKI); however, its role in sepsis-associated acute kidney injury (SA-AKI) remains insufficiently characterized. This study aimed to investigate the involvement of cellular senescence in SA-AKI and to determine the contribution of the Toll-like receptor (TLR)/MyD88 signaling pathway. A cecal ligation and puncture (CLP) mouse model was established to induce SA-AKI. Cellular senescence markers and inflammatory indices were evaluated at 24, 48, and 72h after injury using senescence-associated β-galactosidase (SA-β-Gal) staining, immunofluorescence, and quantitative real-time PCR (qPCR). Integrated transcriptomic and proteomic analyses were performed to identify candidate hub genes involved in SA-AKI. Human Kidney-2 (HK-2) cells were used to assess the role of MyD88 in tubular epithelial cell senescence, and mice with tubular epithelial cell-specific deletion of Myd88 were subsequently used to investigate the in vivo role of MyD88 in SA-AKI. At 72h after CLP, SA-AKI was associated with a marked increase in SA-β-Gal activity, p21 expression, DNA damage, and inflammatory cytokine production, together with decreased lamin B1 (LAMNB1) expression and reduced proliferative activity, indicating the induction of cellular senescence. Inflammatory cell infiltration was also evident at this time point. Integrated omics analysis identified MyD88 as a key candidate molecule. In HK-2 cells, pharmacological inhibition of MyD88 attenuated lipopolysaccharide-induced cellular senescence and inflammatory responses. Consistently, tubular epithelial cell-specific deletion of Myd88 significantly reduced cellular senescence, inflammatory infiltration, and renal injury following SA-AKI. These findings indicate that cellular senescence in SA-AKI is mediated, at least in part, by the TLR/MyD88 signaling pathway. Targeting this pathway may represent a potential therapeutic strategy for attenuating SA-AKI progression and improving renal outcomes.

Sepsis-associated acute kidney injury (SA-AKI) is a frequent and severe complication in critically ill patients, yet effective targeted therapies are lacking. Ferroptosis has been implicated in various forms of organ injury, but its role in SA-AKI and underlying regulatory mechanisms remain unclear. A SA-AKI mouse model was established using cecal ligation and puncture (CLP). Renal histopathology, kidney function assays, and spatial proteomics were employed to assess ferroptosis activation. In vivo and in vitro models were subjected to lipopolysaccharide (LPS) stimulation to evaluate ferroptosis-related markers, including reactive oxygen species (ROS), lipid peroxidation, ferrous iron levels, and mitochondrial membrane potential. DNA pull-down coupled with mass spectrometry identified potential upstream regulators of HO-1. Chromatin immunoprecipitation-quantitative polymerase chain reaction (ChIP-qPCR) and dual-luciferase reporter assays were used to validate transcriptional regulation by SMAD4. Functional studies assessed the impact of SMAD4 on HO-1 expression, ferroptosis, and renal function. Ferroptosis was markedly activated during SA-AKI progression. LPS stimulation induced significant ROS accumulation, lipid peroxidation, elevated ferrous iron levels, mitochondrial membrane potential disruption, and robust upregulation of heme oxygenase-1 (HO-1). SMAD4 was identified as a transcriptional repressor of HO-1. ChIP-qPCR and dual-luciferase assays confirmed SMAD4 binding to the HO-1 promoter and suppression of its transcription. SMAD4 overexpression reduced HO-1 expression, alleviated ferroptosis, and improved renal function in both in vivo and in vitro models. SMAD4 mitigates ferroptosis by transcriptionally repressing HO-1, exerting a protective effect in SA-AKI. This study identifies a novel SMAD4-HO-1 regulatory axis and suggests a potential therapeutic target for sepsis-induced kidney injury. Antioxid. Redox Signal. 45, 28-43.

Lactate accumulation exacerbates the severity of sepsis-associated acute kidney injury (SA-AKI), although the mechanism remains unclear. Since pyroptosis contributes to renal tubular epithelial cell (RTEC) death during SA-AKI, this study explores whether lactate exacerbates pathogenesis by promoting RTEC pyroptosis. The clinical correlation between lactate and SA-AKI was examined using the Medical Information Mart for Intensive Care IV (MIMIC-IV) database and patient samples. Lactate's role in RTEC pyroptosis was evaluated in lipopolysaccharide (LPS)-exposed HK-2 cells and in cecal ligation and puncture (CLP)-induced mice. Cross-analyzing bioinformatics and RNA-seq data from LPS/lactate-exposed HK-2 cells revealed pyroptosis genes associated with SA-AKI. Molecular mechanisms were explored via Western blot, ELISA, mitochondrial function assays, chromatin immunoprecipitation (ChIP), and co-immunoprecipitation (co-IP). High-throughput drugs screening was conducted to identify candidates acting on the Sphingosine kinase 1(SPHK1)/Sirtuin 1(SIRT1) axis, which were validated in vitro and in vivo. Lactate aggravated SA-AKI by promoting RTEC pyroptosis. Bioinformatic and functional studies identified SPHK1 as the key mediator. Both SPHK1 knockdown and its inhibitor PF-543 alleviated lactate-augmented pyroptosis. Drug screening identified nicotinamide adenine dinucleotide (NAD+), which simultaneously suppressed SPHK1 expression and the RTEC injury marker kidney injury molecule-1 (KIM-1). Combining NAD+ and PF-543 synergistically attenuated SA-AKI. Sepsis-induced lactate accumulation promoted P300-mediated histone H3 lysine 18 lactylation (H3K18la) at the SPHK1 promoter, epigenetically enhancing its transcription. SPHK1 then phosphorylated and degraded SIRT1, inducing peroxisome proliferator-activated receptor gamma co-activator 1α (PGC-1α) hyperacetylation, thereby impairing SIRT1/PGC-1α signaling and triggering NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome-driven pyroptosis. Reciprocally, SIRT1 acted as a delactylase delactylase to reduce H3K18la and inhibit SPHK1 transcription, forming a SPHK1-SIRT1 negative feedback loop. The study identifies an H3K18la-mediated SPHK1-SIRT1 axis as a key factor of RTEC pyroptosis in SA-AKI. The combined pharmacological strategy of NAD+ supplementation and SPHK1 inhibition represents a promising therapeutic strategy for SA-AKI.

Background: Hepcidin not only sustains systemic iron homeostasis but also functions as an antimicrobial peptide. During this study, we sought to analyze the ability of hepcidin to protect against sepsis-associated acute kidney injury (SAKI) and elucidated its underlying mechanisms in mediating ferroptotic pathways. Methods: A SAKI mouse model was created via cecal ligation and puncture (CLP), along with an LPS-induced Human Kidney-2 (HK-2) cell model, to study the protective mechanism of hepcidin against SAKI. Through the analysis of renal injury biomarkers and ferroptosis-related molecules, combined with quantitative detection of nuclear factor-erythroid 2-related factor-2 (Nrf2) nuclear translocation and glutathione peroxidase 4 (GPX4), a regulatory protein of ferroptosis, we uncovered the hepcidin-mediated mechanisms underlying ferroptosis in SAKI. Results: Hepcidin significantly attenuated renal function impairment in mice with SAKI and reduced the sepsis-driven increase in inflammatory mediators. As sepsis was associated with enhanced renal ferroptosis, hepcidin exerted a therapeutic effect by mitigating ferroptosis to a degree comparable with that of the ferroptosis inhibitor Ferrostatin-1 (Fer-1). Furthermore, hepcidin conferred renoprotective effects in SAKI by promoting the nuclear translocation of Nrf2, which in turn mediated the upregulation of the downstream anti-ferroptotic protein GPX4. Importantly, the Nrf2 inhibitor ML385 abrogated both the hepcidin-induced nuclear translocation of Nrf2 and the subsequent increase in GPX4 expression. Conclusions: Protective effects of hepcidin against SAKI are mediated by the Nrf2/GPX4 ferroptosis pathway, underscoring its therapeutic potential for SAKI.

Sepsis-associated acute kidney injury (SA-AKI) is a severe condition with high mortality rates and a lack of specific treatments. Dendrobine (DEN) has shown diverse pharmacological effects across different diseases. Nonetheless, its impact on SA-AKI remains unexplored. This study aimed to investigate DEN's therapeutic potential in SA-AKI and elucidate its mechanism of action. In vivo, SA-AKI models were induced through cecal ligation and puncture or lipopolysaccharide (LPS) administration, while in vitro model was established using LPS-stimulated HK-2 cells. We found that pre-treatment with DEN reduced levels of inflammation-related cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6), and improved kidney function in SA-AKI both in vitro and in vivo. RNA-seq analysis unveiled the critical role of mitophagy in DEN treatment for SA-AKI. We observed an initial increase in mitophagy-related proteins such as PINK1, PARKIN, and LC3B/A, peaking at 8h post-LPS stimulation, followed by a subsequent decline. Additionally, we demonstrated that DEN upregulated the expression of mitophagy-associated proteins in both in vitro and in vivo SA-AKI models. Notably, we found that carbonyl cyanide 3-chlorophenylhydrazone (CCCP) increased LC3B/A levels in DEN treatment for SA-AKI, whereas Mdivi-1 counteracted the effect of DEN on PINK1, PARKIN, and LC3B/A. These findings demonstrated that DEN enhances mitophagy through the activation of PINK1/PARKIN-mediated pathways, thus mitigating SA-AKI.

Background and Aims Sepsis is a severe and complex clinical syndrome resulting from the host's inflammatory response to infection. Acute kidney injury (AKI) is one of the major complications of sepsis with high morbidity and mortality, namely sepsis-associated acute kidney injury (S-AKI). Despite current advances, effective drugs for treatment of S-AKI are scarce. SKLB023 is a small molecule compound designed based on 5-benzylidene-thiazolidine-2,4-dione, which has a potent anti-inflammatory effect with favorable efficacy in rheumatoid arthritis. This study aims to evaluate the efficacy of SKLB023 in treating S-AKI and to explore the underlying mechanisms. Method S-AKI was induced by cecal ligation puncture (CLP) and intraperitoneal injection of LPS (10 mg/kg) in male C57BL/6 mice. SKLB023 (25 mg/kg, 50 mg/kg) was administrated by gavage three days in advance and 30 minutes earlier on the day of modeling. Mice death per group was recorded for 100 hours after CLP to evaluate the effect of SKLB023 on the survival rate of S-AKI mice. Other mice were sacrificed 16 hours after model establishment, blood and kidney specimens were collected. Renal function was measured by the detection of serum creatinine (SCr) and blood urea nitrogen (BUN). Kidney pathological injury was evaluated by the expression of kidney injury markers and the assessment of PAS/HE stainings. In vitro experiments were performed with LPS stimulation of TCMK-1 cells and SKLB023 intervention, and the doses were determined by CCK-8 assay. Possible molecular mechanisms involved in SKLB023 against S-AKI were screened by bioinformatics analysis and further validated in vivo and vitro. RT-PCR, western blot, immunofluorescence, and immunohistochemistry were applied to detect renal inflammation and apoptosis. To determine the role of TLR4, TLR4 siRNA and TLR4-KO mice were applied in S-AKI model, and TLR4 expression and the activities of NF-κB p65 and MAPK signaling pathway were assessed. One-way ANOVA was performed for comparison between groups, and logrank analysis was used for comparison of survival curve. P < 0.05 was considered as statistically significant. Results The S-AKI model was successfully established by CLP and LPS injection with obvious renal dysfunction and kidney pathological damage. The mice administrated with SKLB023 had a higher survival rate, lower levels of Scr and BUN, and improved kidney pathological injury than the mice in the CLP group. Transcriptomic analysis identified TLR4-mediated downstream signaling pathways as the potential mechanism of SKLB023 and further experiments in vivo and in vitro proved that SKLB023 regulated the expression of TLR4 and the activities of NF-κB p65 and MAPK signaling pathway in S-AKI mice and LPS-stimulated TCMK-1 cells. Moreover, TLR4 inhibited the expression of inflammatory cytokines including TNF-α, IL-1β, IL-6, iNOS, COX-2, HMGB-1 and alleviated kidney apoptosis in S-AKI mice and LPS-treated TCMK-1 cells. Additionally, knockout of TLR4 remarkably improved inflammation, apotosis, and kidney injury in LPS-treated mice and TCMK-1 cells. Conclusion SKLB023 confers renoprotective effects in S-AKI by modulating inflammation and apoptosis. TLR4 is a key target in S-AKI, and SKLB023 inhibits inflammation and apoptosis by inhibiting the activities of TLR4 mediated NF-κB p65 and MAPK pathways. SKLB023 may be proposed as one of the potential preventive and therapeutic agents for S-AKI.

Albiflorin contributes to Xuebijing-mediated protection against sepsis-associated acute kidney injury by modulating the succinate-PFKFB3 immunometabolic axis.

Patients with sepsis commonly endure severe renal dysfunction and damage, hastening to end-stage renal failure with high mortality, and effective treatment options are currently lacking. Growth differentiation factor 11 (GDF11), belonging to the transforming growth factor beta (TGF-β) superfamily, has shown therapeutic potential for numerous acute and chronic inflammatory conditions. Nevertheless, its function in sepsis-associated acute kidney injury (SAKI) remains unclear. This study sought to explore GDF11's role in SAKI and determine the signaling pathways it modulates. Alterations in GDF11 expression in the kidneys of mice with SAKI were analyzed. The influence of GDF11 knockdown and recombinant GDF11 (rGDF11) supplementation on cecal ligation and puncture (CLP)-induced SAKI in mice was determined. RNA sequencing, Western blot, real-time quantitative polymerase chain reaction (RT-qPCR), and kit assays were performed to explore the underlying mechanisms. Tubular epithelial cells and macrophages in the kidneys of CLP-induced SAKI mice exhibited high levels of GDF11 expression. Moreover, gene silencing of GDF11 using adeno-associated virus (AAV) aggravated renal dysfunction, increased tubular damage, and augmented renal apoptosis in CLP-induced SAKI mice. In contrast, replenishment of rGDF11 significantly mitigated these adverse effects. Further studies indicated that GDF11 stimulated the nuclear factor erythroid 2-related factor 2 (Nrf2)-regulated antioxidative pathways, primarily by inducing the expression of Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), which subsequently decreased excessive inflammation and coagulation. Additionally, these beneficial effects of GDF11 were largely diminished by AAV-mediated PGC-1α knockdown and depletion of Nrf2 in CLP-induced SAKI mice. In summary, these findings indicate that GDF11 is a potential therapeutic approach for SAKI and highlight the crucial role of PGC-1α/Nrf2 signaling in GDF11-mediated renal protection during SAKI.

Sepsis-associated acute kidney injury (SA-AKI) is a severe complication of sepsis, primarily driven by immune-inflammatory dysregulation and oxidative stress, and 1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) shows renoprotective potential, yet its molecular targets and mechanisms remain unclear. Transcriptomic data of SA-AKI from GEO were analyzed by ssGSEA for immune infiltration, differential expression analysis, WGCNA, and machine learning (LASSO, SVM-RFE, Random Forest) to identify the biomarkers. In vivo, SA-AKI was induced by cecal ligation and puncture (CLP) in mice treated with 1,25(OH)2D3, and renal function, histology, inflammatory cytokines, oxidative stress markers, and CMKLR1 expression were evaluated. In vitro, LPS-stimulated HK-2 cells were treated with 1,25(OH)2D3 with or without CMKLR1 overexpression to assess cytokines, cell viability, apoptosis, and oxidative stress. Four key biomarkers-CMKLR1, COL1A1, RPS19, and THBS1-were identified by machine learning, with CMKLR1 as the key target. In SA-AKI mice, 1,25(OH)2D3 downregulated CMKLR1, improved renal function, and reduced inflammation and oxidative stress. In LPS-stimulated HK-2 cells, it dose-dependently suppressed cytokine release, restored cell viability, and alleviated oxidative stress, while CMKLR1 overexpression partially reversed these effects. CMKLR1 was identified as a key immune inflammation target in SA-AKI. 1,25(OH)2D3 was protected against renal injury by suppressing CMKLR1, and mitigating inflammation, oxidative stress, and apoptosis, while CMKLR1 overexpression partially reversed these effects. These findings highlight CMKLR1 as a potential therapeutic target for SA-AKI.

Sepsis-associated acute kidney injury (S-AKI) is a prevalent and severe clinical complication in intensive care units (ICUs) and is associated with high mortality and poor prognosis. The dysfunction of renal tubular epithelial cells (TECs), particularly through their metabolic reprogramming, plays a critical role in the onset and progression of S-AKI. CITED2 is shown to regulate a variety of cellular processes, but its specific impact on TECs metabolism and S-AKI pathogenesis remains unclear. The aim of this study was to investigate the role of CITED2 in the metabolic reprogramming of TECs and its effects on inflammation and kidney injury in S-AKI. The C57BL/6 mouse model of S-AKI was established using cecal ligation and puncture (CLP). We assessed the inflammatory responses, glucose metabolism and CITED2 expression in the kidneys of septic mice. Additionally, the effect of CITED2 on TECs metabolism and inflammation was evaluated using in vivo and in vitro models. CITED2 silencing and overexpression were employed to elucidate its regulatory role, focusing on the AKT signaling pathway. S-AKI causes structural and functional kidney damage, aggravated inflammatory responses, and dysregulated glucose metabolism, accompanied by increased expression of CITED2. CITED2 silencing attenuated TECs metabolic dysfunction and reduced inflammation, thereby protecting the kidney from injury. Conversely, CITED2 overexpression exacerbated TECs metabolic dysfunction, promoted inflammatory responses, and worsened kidney injury. Mechanistically, CITED2 regulates TEC metabolism through the AKT signaling pathway, promoting S-AKI-related inflammation and contributing to kidney injury. CITED2 drives the metabolic reprogramming of TECs through the AKT signaling pathway, thereby aggravating the inflammatory response and leading to kidney injury, highlighting its critical role in S-AKI. Targeting CITED2 inhibition may represent a novel therapeutic approach for managing S-AKI.

Despite efforts to find effective drugs for sepsis-associated acute kidney injury (SA-AKI), mortality rates in patients with SA-AKI have not decreased. Our study evaluated the protective effects of isoflavone osajin (OSJ) on SA-AKI in rats by targeting inflammation, oxidative stress, and apoptosis, which represent the cornerstones in the pathophysiological mechanism of SA-AKI. Polymicrobial sepsis was induced in rats via the cecal ligation and puncture (CLP) technique. Markers of oxidative stress were evaluated in kidney tissues using biochemical methods. The expression of interleukin-33 (IL-33), 8-hydroxydeoxyguanosine (8-OHdG), caspase-3, and kidney injury molecule-1 (KIM-1) was evaluated as indicators of inflammation, DNA damage, apoptosis, and SA-AKI respectively in the kidney tissues using immunohistochemical and immunofluorescent detection methods. The CLP technique significantly (p < 0.001) increased lipid peroxidation (LPO) levels and significantly (p < 0.001) decreased the activities of superoxide dismutase and catalase in kidney tissues. In the renal tissues, strong expression of IL-33, 8-OHdG, caspase-3, and KIM-1 was observed with severe degeneration and necrosis in the tubular epithelium and intense interstitial nephritis. In contrast, the administration of OSJ significantly (p < 0.001) reduced the level of LPO, markedly improved biomarkers of antioxidant status, decreased the levels of serum creatinine and urea, lowered the expression of IL-33, 8-OHdG, caspase-3, and KIM-1 and alleviated changes in renal histopathology. A promising binding score was found via a molecular docking investigation of the OSJ-binding mode with mouse IL-33 (PDB Code: 5VI4). Therefore, OSJ protects against SA-AKI by suppressing the IL-33/LPO/8-OHdG/caspase-3 pathway and improving the antioxidant system.

BackgroundNeutrophils play a key role in sepsis-associated acute kidney injury (SAKI), a common and life-threatening complication of organ failure. High mobility group box 1 (HMGB1) modulates inflammatory responses and the formation of neutrophil extracellular traps (NETs). The present work aimed to explore whether HMGB1 lactylation promotes NET formation and exacerbates SAKI.MethodsVenous blood samples were collected from healthy volunteers and SAKI patients. A SAKI mouse model was established using the cecal ligation and puncture method. A coculture system of macrophage-derived exosomes and neutrophils was established. Macrophage-derived exosomes were isolated and identified. ELISAs, immunofluorescence staining, coimmunoprecipitation, and Western blotting were utilized to determine protein levels.ResultsElevated blood lactate levels were associated with increased HMGB1 levels in patients with SAKI. In mouse models, lactate increased HMGB1 expression, promoted NET formation, and exacerbated SAKI. Lactate stimulated M1 macrophages to secrete exosomes, leading to the accumulation and release of HMGB1 in the cytoplasm. Additionally, lactate promoted HMGB1 lactylation in macrophages, triggering the release of mitochondrial DNA from neutrophils and activating the cyclic GMP‒AMP synthase/stimulator of interferon genes pathway.ConclusionThis study revealed that lactate-induced HMGB1 lactylation in macrophages plays a role in promoting NET formation in SAKI through the cGAS/STING pathway. These findings suggest that HMGB1 could be a potential target for therapeutic intervention in SAKI.Graphical abstractLactate promotes the lactylation modification of HMGB1 in macrophages through H3K18lac, facilitating the secretion of HMGB1. After HMGB1 enters neutrophils, it induces the leakage of mitochondrial DNA (mtDNA) in neutrophils, activating the cGAS/STING pathway, promoting the formation of neutrophil extracellular traps (NETs), and exacerbating acute kidney injury in sepsis.