The China Mortality Prediction Model in Trauma, which is based on the International Classification of Disease Disorders (ICD)-10-CM lexicon (CMPMIT-ICD-10),is a new trauma scoring system. Our objective was to compare the prognostic performance of the CMPMIT-ICD10 with that of the Acute Physiology and Chronic Health Evaluation II (APACHEII), Sequential Organ Failure Assessment (SOFA), Injury Severity Score (ISS), and Abbreviated Injury Scale (AIS) for in-hospital mortality in patients with traumatic hemorrhagic shock(THS).This retrospective observational cohort study was conducted at a tertiary teaching hospital from May 1, 2013, to May 31, 2023.The area under the receiver operating characteristic curve (AUC), sensitivity, specificity, accuracy, and associations with outcomes of theCMPMIT-ICD-10, APACHE II, SOFA, ISS, and AIS scores for the prediction of in-hospital death were assessed. A total of 420 patients with THS were included. Forty-one (9.8%) patients died during hospitalization. For the prediction of in-hospital death, the CMPMIT-ICD-10 (0.8757) and APACHE II(0.8709) had greater AUCs compared with the AIS (0.6243), SOFA (0.7669), and ISS (0.6601). With the best cut-off value of 59.5, the CMPMIT-ICD10 had a highest sensitivity (85.4%) and good specificity(79.9%) and overall accuracy (80.4%). The CMPMIT-ICD10 (OR 1.057, 95% CI 1.028-1.087, p < 0.001) and APACHE II (OR 1.125, 95% CI 1.045-1.211, p = 0.002) were independently associated with in-hospital death. Comparable to the APACHE II but significantly better than the SOFA, ISS, and AIS, the CMPMIT-ICD-10 performed well in predicting the short-term mortality of patients with THS. These findings suggest that the CMPMIT-ICD-10 may have superior utility for predicting short-term death in THS patients.

IgG Fc gamma receptor I (FcγRI) belongs to the immunoglobulin superfamily and plays a pivotal role in immune regulation. The post-translational regulation of FcγRI and its effects on immune regulation are unclear. In this study, we identified the membrane-associated RING-CH-type finger (MARCH) E3 ubiquitin ligases MARCH2 and MARCH3 as physiological regulators of FcγRI. MARCH2 and MARCH3 associate with FcγRI and mediate its K27-linked polyubiquitination at K336 and K368, respectively, leading to subsequent lysosomal degradation. While deficiency of either MARCH2 or MARCH3 modestly increases FcγRI levels as well as LPS- and IgG-induced transcription of downstream genes, double knockout of MARCH2/3 has a more dramatic effect. Double knockout of MARCH2/3 increases LPS-induced transcription of downstream genes in wild-type but not FcγRI knockout cells, and reconstitution of FcγRIK336R/K368R into FcγRI-deficient cells increases LPS-induced transcription of the downstream genes to a higher degree than reconstitution with wild-type FcγRI. Individual knockout of MARCH2 or MARCH3 sensitizes mice to LPS-induced lung injury and Salmonella typhimurium-induced inflammation, and these effects are more severe in MARCH2/3 double-knockout mice. These findings suggest that MARCH2 and MARCH3 redundantly target FcγRI for K27-linked polyubiquitination and lysosomal degradation, thereby acting as host factors to limit the FcγRI-mediated inflammatory response and pathogenesis.

ABSTRACT Lower respiratory tract infections (LRTIs) are a major global health concern, complicated by rising antibiotic resistance driven by antibiotic resistance genes (ARGs). Despite its role in the treatment of respiratory diseases, the impact of corticosteroids on ARGs in LRTI patients remains underexplored. Bronchial alveolar lavage (BAL) samples were collected from LRTI patients from two intensive care units (ICUs). Patients were classified into the corticosteroid group (CS group) and the non-corticosteroid group (NCS group) based on corticosteroid use. Next-generation sequencing assessed ARGs and associated microbes, with multivariable logistic regression analyzing the relationship between corticosteroid therapy and ARG accumulation. Ninety-one patients were recruited; the CS group (n = 57) exhibited a distinct ARG profile, marked by higher alpha-diversity and increased prevalence of ARGs than the NCS group (n = 34). The duration of corticosteroid therapy was positively associated with ARG accumulation, with individuals receiving treatment for more than 30 days exhibiting the highest ARG burden. The duration of corticosteroid therapy and the underlying hematological diseases were two independent risk factors for ARG accumulation. Our data provide new evidence that, in patients with LRTIs, extended corticosteroid use is associated with the accumulation of ARGs and modifications in the microbial composition of the lower respiratory tract.IMPORTANCEThis research provides new evidence that prolonged use of corticosteroid drastically increases antibiotic resistance genes (ARGs) in the lungs of LRTI patients. It reveals a duration-dependent accumulation of ARGs, notably for common broad-spectrum antibiotics. These findings highlight the need to consider ARG burden when evaluating corticosteroid prescribing practices in patients with lower respiratory tract infections.

ESR1 mutation-driven endocrine therapy (ET) resistance remains a major challenge in breast cancer therapy. Herein, by integrating the advantages of PROTAC technology and coactivator-binding site (CBS) targeting strategy in overcoming drug resistance, we developed a class of novel and potent ERα PROTAC degraders against ET-resistant breast cancer. Among them, compound NCP07 could potently degrade ERα and inhibited proliferation (IC50 = 0.13-1.22 μM) in both wild-type and ESR1-mutated cell lines. Mechanistic studies confirmed that compound NCP07 could not only specifically bind to CBS followed by inducing the formation of ERα-NCP07-VHL ternary complex, but also induce apoptosis and cell cycle arrest in drug-resistant cells. Besides, compound NCP07 also exhibited favorable metabolic stability and high safety properties. Totally, the potent anti-breast cancer activity and favorable metabolic stability of compound NCP07 not only indicated that PROTAC degrader targeting ERα CBS was an effective dual-action strategy for overcoming ESR1 mutation, but also was a promising candidate for further developing potent drugs against ET-resistant breast cancer.

OBJECTIVE:To explore the risk factors associated with ventilator-associated pneumonia (VAP) in the patients with chest trauma in the intensive care unit (ICU). METHODS:A retrospective analysis was conducted on the clinical data of 124 adult trauma patients admitted to the surgical ICU of Peking University People' s Hospital between June 2019 and June 2023. These patients underwent tra-cheal intubation within 24 hours of admission and received mechanical ventilation for more than 48 hours. Based on whether VAP occurred during hospitalization, the patients were divided into a VAP group (46 cases) and a non-VAP group (78 cases). Lasso regression analysis was employed for variable selection, followed by Logistic regression analysis to determine the risk factors for VAP in these patients with chest trauma in the ICU. RESULTS:The multivariate regression analysis indicated that the injury severity score (ISS) (OR=1.08, 95%CI: 1.02-1.14, P=0.007) and tracheostomy (OR=4.61, 95%CI: 1.74-13.11, P=0.003) were independent risk factors for VAP in the patients with chest trauma (P < 0.05). Among all VAP cases, early-onset VAP was observed in 19 patients, while late-onset VAP was observed in 27 patients. The most common pathogen in all VAP cases was Klebsiella pneumoniae, identified in 18 cases (39.1%). In early-onset VAP, Klebsiella pneumoniae was the most frequently detected pathogen, found in 10 cases (52.6%). Conversely, in late-onset VAP, Pseudomonas aeruginosa and Acinetobacter baumannii were the most prevalent pathogens, each appearing in 10 cases (37.0%). CONCLUSION:The occurrence of VAP in the patients with chest trauma in the ICU was influenced by multiple factors. This study identified that a higher ISS and the presence of a tracheostomy were independent risk factors for VAP in these patients. These findings suggest that in clinical practice, special attention should be given to the chest trauma patients with high ISS scores, and the timing and necessity of tracheostomy should be carefully considered to reduce the incidence of VAP and improve patient outcomes. Furthermore, the study highlights the importance of early identification and appropriate management of the patients at higher risk for developing VAP. By recognizing the significance of these risk factors, healthcare providers can implement targeted interventions and preventive measures, such as optimizing ventilation strategies and enhancing infection control practices. Future research should further explore additional factors that may influence the occurrence of VAP and verify these findings to provide stronger evidence for the prevention and treatment of VAP. Additionally, multicenter studies with larger sample sizes are recommended to validate these results and develop comprehensive guidelines for managing the chest trauma patients in the ICU.

Monocyte-derived macrophages are usually recruited and play pivotal roles in establishing an immunosuppressive tumor microenvironment, and the interplay between tumor cells and tumor-associated macrophages (TAMs) is crucial for tumor development. However, the detailed mechanisms remain largely unelucidated in certain aggressive human cancers, such as melanoma. Here, through miRNA sequencing analysis, we found the microRNA miR-708-5p was highly enriched in melanoma exosomes, which was dependent on SFRS1. Treatment by melanoma exosomes facilitated M2 polarization of macrophages, while the polarized macrophages in turn promoted melanoma progression and metastasis both in vitro and in vivo. Mechanistically, miR-708-5p directly targets FOXN3, a member of the fork head/winged helix transcription factor family, and subsequently activates the PI3K/AKT/mTOR pathway in macrophages. Conversely, re-expression of FOXN3 in macrophages stably expressing miR-708-5p could reverse the impact on macrophages. In addition, downregulation of FOXN3 by miR-708-5p in macrophages reduced their phagocytic capacity and increased the secretion of IL-10 and TGF-β. Interestingly, we found that cellular retention of miR-708-5p could inhibit the proliferation and promote the apoptosis of melanoma cells, suggesting the necessity for secretion of this microRNA. In summary, our findings provide novel insights into the mechanism of melanoma-derived miR-708-5p in facilitating the formation of an immunosuppressive tumor microenvironment and indicate the potential of miR-708-5p and FOXN3 as therapeutic targets for the treatment of melanoma.

Interleukin 2 (IL-2) is a cytokine secreted by activated T cells that plays a central role in T cell proliferation and differentiation. In this study, we identified MARCH2, an E3 ubiquitin ligase of the MARCH family, as a negative regulator of IL-2 receptor alpha (IL-2Rα). MARCH2 interacts with IL-2Rα and catalyzes its K27-linked polyubiquitination and subsequent proteasomal degradation. Site-directed mutagenesis indicates that K267 of IL-2Rα is targeted by MARCH2 and mutation of this residue impairs MARCH2-mediated polyubiquitination and degradation of IL-2Rα. MARCH2-deficiency promotes IL-2-triggered STAT5 phosphorylation, effector gene expression, and proliferation of activated T cells. Our findings suggest that MARCH2 negatively regulates IL-2 signaling by targeting IL-2Rα for K27-linked polyubiquitination and proteasomal degradation, uncovering a post-translational mechanism that regulates T cell homeostasis.

During the course of an immune response, antigen-reactive T cells undergo clonal expansion and are subsequently eliminated by cytokine withdrawal-induced cell death (CWID), an intrinsic apoptotic program essential for immune homeostasis. However, the mechanisms orchestrating CWID remain poorly understood. Here, we performed genome-wide CRISPR-Cas9 knockout screens in CTLL-2 cells, which identified the transcriptional repressor Capicua (CIC) as a critical mediator of CWID. CIC mediates CWID but not apoptosis induced by staurosporine or etoposide. Deficiency of CIC attenuates IL-2 withdrawal-induced death of mouse primary CD8+ but not CD4+ T cells. CIC promotes CWID via a BIM-independent pathway, and simultaneous deletion of CIC and BIM fully abrogates CWID. Although CIC is activated upon IL-2 withdrawal to repress its target genes, its role in CWID is independent of its transcriptional repression. Instead, CIC promotes CWID by facilitating Cullin-3/KEAP1-mediated BCL2 degradation and disrupting the BAX-BCL2 interaction. In a Listeria monocytogenes infection model, CIC-deficiency suppresses apoptosis of activated CD8+ T cells, resulting in their increase in the later phase of infection. Our findings suggest that CIC plays a vital role in CWID through a noncanonical mechanism, providing new insights into how the immune system limits uncontrolled inflammation and immunopathology.

The tumor necrosis factor (TNF) receptor 1 (TNF-R1) plays critical roles in inflammatory response and autoimmune diseases. The underlying mechanisms on posttranslational regulation of TNF-R1 and its functional significance remain enigmatic. In this study, we identified the deubiquitinase USP22 as a positive regulator of TNF-R1. USP22 is minimally associated with TNF-R1, which is markedly increased following TNF stimulation. USP22 deconjugates K27-linked polyubiquitination of TNF-R1 at K340, which reverses its proteasomal degradation. USP22 deficiency reduces TNF-triggered signaling and transcriptional induction of proinflammatory genes in human cell lines and primary mouse immune cells. Conversely, the membrane-associated E3 ligase MARCH2 is constitutively associated with TNF-R1, resulting in K27-linked polyubiquitination of TNF-R1 at K340 and its proteasomal degradation. MARCH2 deficiency promotes TNF-triggered signaling in various cell types. In mice, USP22 deficiency alleviates imiquimod (IMQ)-induced psoriasis-like dermatitis with reduced inflammatory cell infiltration and splenomegaly. In an acute liver injury model, USP22 deficiency reduces TNF/D-gal-induced inflammatory cytokine expression, liver damage, and inflammatory death, whereas MARCH2 deficiency increases TNF/D-gal-induced inflammatory cytokine expression and exacerbates pathological features of acute liver injury. These findings demonstrate that MARCH2 and USP22 reciprocally regulate K27-linked polyubiquitination and stability of TNF-R1, revealing regulatory mechanisms on TNF-R1-mediated inflammatory response.

Glycine decarboxylase (GLDC) is overexpressed in multiple tumor types and contributes to tumorigenesis or immune evasion by unclarified mechanisms. Here we report that GLDC is polyubiquitinated at K636 following EGFR activation, which drives GLDC-dependent transcriptional inhibition of MHC-I genes and induces tumor cells to evade CD8+ T cell-mediated immunosurveillance. Mechanistically, EGFR activation triggers SRC-mediated FBXL3 phosphorylation at Y306, enabling its interaction with GLDC in nucleus. FBXL3 targets GLDCK636 for K63-linked polyubiquitination, and promotes the interaction of GLDC with SMARCE1/DMAP1 to inhibit STAT1-triggered transcriptional activation, resulting in transcriptional inhibition of downstream MHC-I genes. Phosphorylation of FBXL3Y306 decreases MHC-I levels in tumor cells and inhibits CD8+ T cells immunity in tumors. Consistently, inhibitors of SRC improves tumor-specific CD8+ T cells functions in TME and sensitizes antitumor effects of anti-PD-1 therapy. Our findings reveal an SRC-FBXL3-GLDC-MHC-I regulatory circuit that underlies CD8+ T cells immune evasion, and provide a potential therapeutic target to enhance ICB therapy.

The accumulation of senescent cells contributes to age-related inflammation and heightened susceptibility to viral infection. The mechanisms by which cellular senescence and aging exacerbate virus-associated diseases remain poorly understood. Here we show that innate antiviral immunity is progressively impaired with aging in mice, in parallel with systemic accumulation of senescent cells. Mechanistically, senescent cells suppress innate antiviral response mostly via four senescence-associated secretory phenotype (SASP) factors. GDF15 and IGF1 trigger AKT-MEK-mediated inactivation of GSK3β, leading to suppression of the TBK1-IRF3 axis. IL1α and IL6 induce expression of p52 and RelB to suppress transcription of antiviral genes. Consistently, combined blocking of GDF15, IGF1, IL1α, and IL6 promotes innate antiviral immunity in aged mice. These findings reveal that SASP factors antagonize innate antiviral immunity through distinct pathways and suggest a potential strategy to restore immune competence to defend viral infection in aged individuals by targeting the four SASP factors.

T helper 17 (TH17) cells are heterogeneous and able to adopt pathogenic and non-pathogenic phenotypes. Identifying factors controlling pathogenic TH17 cells is of importance for their vital role in inflammation and immune-pathology. Here, we demonstrated that HMGCS1, a cholesterol biosynthesis precursor enzyme, was highly induced by inflammatory cytokines and preferentially expressed by pathogenic TH17 cells in vitro and in vivo. HMGCS1 specifically dictated pathogenic TH17 cell differentiation and augmented autoimmune diseases, yet it has no discernible effect on nonpathogenic TH17 cells. Unexpectedly, this role is independent of its canonical function in cholesterol metabolism but requires its catalytic Cys129 residue. Notably, HMGCS1 governs pTH17 cell generation and pathogenicity by leveraging an IRE1α-XBP1s-dependent ER stress response, which in turn transcriptionally activates the lineage-defining factor RORγt (encoded by Rorc). Mechanistically, HMGCS1 is located to the ER membrane, where it bound and stabilized IRE1α protein. This stabilization is achieved by preventing IRE1α's interaction with the E3 ubiquitin ligase MARCH5, thereby inhibiting its K48-linked ubiquitination and subsequent degradation. Moreover, interfering with HMGCS1 or the ER stress response in T cells impedes pTH17 immunity and mitigates autoimmune disease in vivo. Therefore, our work unveils a noncanonical axis in which HMGCS1 sustains ER stress to license pTH17 differentiation during autoimmune responses.

IntroductionBile salt export pump (BSEP) inhibition is an important mechanistic risk factor for cholestatic drug-induced liver injury. Quantitative structure-activity relationship (QSAR) models may support early safety screening, but practical BSEP datasets are often limited in size and imbalanced.Methods We evaluated a machine-learning workflow combining molecular descriptors and fingerprints, Boruta feature selection, and class-imbalance training. Multiple algorithms were assessed using cross-validation, a held-out test set, and an independent external validation set composed of compounds synthesized in an industrial research setting.ResultsTree-based models generally showed the strongest external performance. In particular, models using RDKit2D descriptors achieved Matthews correlation coefficients (MCC) above 0.65 and a ROC-AUC of 0.87, while several other tree-based model representation combinations achieved MCC values around 0.45-0.50. Boruta markedly reduced feature dimensionality, but its effect on predictive performance depended on both the molecular representation and learning algorithm; it was most beneficial for selected high-dimensional fingerprints and tree-based models, while offering limited or unfavorable effects in some support vector machine settings. Applicability-domain and SHAP analyses further revealed representation-dependent generalization patterns and highlighted contributions from lipophilicity, polarity, solubility, and molecular complexity.Discussion Overall, the workflow maintained useful predictive performance under small and imbalanced conditions and provides a practical framework for early-stage BSEP risk screening.

The membrane-associated RING-CH (MARCH) family is a type of membrane-localized E3 ubiquitin ligase, which catalyze substrate ubiquitination via their characteristic RING-CH domains. MARCH proteins target their substrates for polyubiquitination of different linkage types and degradation via distinct routes. This review outlines recent advancements about the structural features, subcellular localizations, expression profiles of MARCH proteins and their roles in regulation of physiological processes and diseases, such as immune response, organelle homeostasis and tumorigenesis. Future studies would identify additional targets of the MARCH family and reveal the regulatory networks of MARCH family on substrates, offering an opportunity to target the MARCH family for development of drugs against severe human diseases.

Sepsis causes high mortality and resource strain, with neutrophil-derived reactive oxygen species (ROS) contributing to excessive inflammation. The secretory protein FAM19A4 modulates ROS release, but its role in sepsis is unclear. In this study, we find elevated FAM19A4 levels in septic patients and cecal ligation and puncture (CLP) mice, which correlate with increased mortality. Fam19a4 -/ - mice subjected to CLP show significantly improved survival and attenuated multiorgan injury without impaired peritoneal bacterial clearance or altered circulating neutrophil counts. FAM19A4 deficiency reduces the cell counts of neutrophils (Ly6G +) and macrophages (F4/80 +) in the lungs and liver, diminishes systemic ROS production tracked by bioluminescence, and decreases neutrophil extracellular trap (NET) formation in serum and lung tissue. In vitro, FAM19A4 enhances neutrophil phagocytosis and ROS generation but does not affect lipopolysaccharide-induced chemotaxis. Mechanistically, FAM19A4 drives neutrophil ROS release specifically through p38 MAPK signaling activation, as revealed by bulk RNA sequencing, western blot analysis, and treatment with p38 inhibitor SB203580. These results indicate that FAM19A4 is upregulated during sepsis and exacerbates outcomes by enhancing neutrophil ROS production via p38 MAPK, representing a promising therapeutic target for this condition.

Upon infection, viral DNA/RNA is detected by cGAS/RIG-I-like receptors, triggering the adaptor MITA/STING- or VISA/MAVS-dependent innate antiviral immune response respectively. Both adaptors recruit the conserved TRAF3 and TRAF6 to activate TBK1-IRF3 and TAK1-NF-κB pathways respectively, leading to collaborative induction of antiviral effector genes. How the functions of TRAF3 and TRAF6 bifurcate in innate antiviral signaling remains enigmatic. We identified HTATSF1 as a positive regulator of virus-triggered innate antiviral response. Upon viral infection, HTATSF1 promotes HECTD3-catalyzed K63-linked polyubiquitination of TRAF3, leading to its recruitment of TBK1 and activation of IRF3. In contrast, HTATSF1 promotes recruitment of TAK1 to TRAF6 and activation of the TAK1-IKK-NF-κB axis independently of HECTD3. HTATSF1-deficiency impairs induction of downstream antiviral genes, and HTATSF1-deficient mice exhibit decreased cytokine production and increased mortality upon viral infection. Our findings demonstrate that HTATSF1 is an essential regulator of innate antiviral immune response by orchestrating the TRAF3-IRF3 and TRAF6-NF-κB pathways.

Monkeypox virus (MPXV) causes severe diseases in immunocompromised individuals. How MPXV evades the host defense remain enigmatic. We performed expression screens and identified MPXV OPG147, a membrane fusion machinery protein, as an inhibitor of cGAS-MITA/STING-mediated innate immunity. OPG147 from other poxviruses including the prototypic vaccinia virus (VACV) shows similar functions. OPG147 is associated with MITA/STING and STIM1, a calcium sensor that retains MITA/STING in the ER. OPG147 does not block cGAMP binding to MITA, but inhibits its ISGylation, dimerization/oligomerization and trafficking, thereby suppressing its activation. Mutation of VACV OPG147 F55/T116/T117 to alanine (VACVOPG147/3A) has no effects on its infection and replication, but induces higher innate immune response compared with wild-type VACV in cells and mice. VACVOPG147/3A infection also results in lower viral loads and decreased disease severity in mice. Our findings suggest that OPG147 contributes to immune evasion and is a virulence factor of poxviruses.

Background:Cocaine-induced endoplasmic reticulum (ER) stress has been increasingly recognized, but its neuronal specificity and functional significance remain unclear. Because the ER is also a major site for lipid and sphingolipid biosynthesis, cocaine-triggered ER stress may influence metabolic pathways linked to cellular stress signaling. Here, we sought to define the cell-type specificity and downstream consequences of cocaine-induced ER stress in the nucleus accumbens (NAc). Methods:We combined cocaine administration with ultrastructural analysis of ER morphology, immunohistochemical and molecular profiling of ER stress pathways, and assays of sphingolipid biosynthesis in the NAc. We also evaluated the effects of pharmacological inhibition of ER stress and sphingolipid synthesis, and performed D1-MSN-specific knockdown of Atf4 and Sptlc1 to assess their contributions to cocaine-induced behavioral and neuroplastic adaptations. Results:Cocaine selectively activated ER stress in dopamine receptor 1 (D1)-expressing medium spiny neurons (MSNs), marked by induction of activating transcription factor 4 (ATF4). Cocaine also upregulated serine palmitoyltransferase long-chain base subunit 1 (SPTLC1), and promoter analysis with functional validation identified Sptlc1 as a direct target of ATF4. ATF4 activation was thus coupled to remodeling of sphingolipid metabolism. Blocking ER stress or sphingolipid synthesis-and D1-MSN-specific knockdown of Atf4 or Sptlc1-markedly reduced cocaine-induced behavioral and neuroplastic changes. Discussion:These findings identify a D1-MSN ER stress response that promotes cocaine-induced neuroadaptations via the ATF4-SPTLC1 signaling axis and suggest a potential therapeutic target for cocaine addiction.

The field of extracellular vesicle (EV) research has rapidly evolved, revealing their significant roles in various biological processes and clinical applications. Allergic diseases are prevalent immunological disorders characterized by exaggerated hypersensitivity reactions to allergens, leading to diverse clinical manifestations that can severely impact quality of life. Recently, studies have underscored the pivotal role of EVs in allergic conditions, including asthma, allergic rhinitis, and atopic dermatitis. In this review, we provide a comprehensive overview of recent advances in the separation and characterization of EVs, their roles in allergic diseases, and their diagnostic value as biomarkers. Additionally, we explore the therapeutic potential of EVs for the treatment and prevention of allergic conditions. Overall, the emerging insights into EVs present promising opportunities for enhancing the diagnosis, treatment, and management of allergic diseases.

BACKGROUND:Mitophagy dysfunction in Alzheimer's Disease (AD) accelerates disease progression, highlighting the need for novel therapeutic targets. Although Nucleotide oligomerization domain - like receptor X1 (NLRX1) regulates mitophagy, its role in AD remains unclear. This study aimed to elucidate NLRX1's function in AD - associated mitophagy and its therapeutic potential. METHODS:APP/PS1 transgenic mice and N2A - SW cells were used to establish AD models. Behavioral assays evaluated cognitive function in APP/PS1 mice, while transmission electron microscopy examined mitochondrial morphology. ELISA measured β - amyloid (Aβ)1-42 levels, and RT - qPCR and Western blot analyzed NLRX1 and mitophagy - related proteins after manipulating NLRX1 expression. RESULTS:APP/PS1 mice had cognitive impairment, elevated Aβ1-42, and abnormal mitochondrial morphology, with reduced NLRX1 expression. NLRX1 - RNAi worsened mitochondrial function, increased Aβ1-42 and mitochondrial ROS, decreased the LC3B - II/I ratio, and upregulated Cyt - C, HSP60, and TIM23, while NLRX1 overexpression alleviated these effects. Co-immunoprecipitation confirmed NLRX1's interaction with key mitophagy protein. CONCLUSION:NLRX1 is a key regulator of neuronal mitophagy in AD, and its downregulation impairs mitophagy, suggesting it as a potential therapeutic target.