Simulating the land use change effects on non-point source pollution in the Duliujian River Basin.

The uncertainty in the generation and formation of non-point source pollution makes it challenging to monitor and control this type of pollution. The SWAT model is frequently used to simulate non-point source pollution in watersheds and is mainly applied to natural watersheds that are less affected by human activities. This study focuses on the Duliujian River Basin (Xiqing section), which is characterized by a dense population and rapid urbanization. Based on the calibrated SWAT model, this study analyzed the effects of land use change on non-point source pollution both temporally and spatially. It was found that nitrogen and phosphorus non-point source pollution load losses were closely related to land use type, with agricultural land and high-density urban land (including rural settlements) being the main contributors to riverine nitrogen and phosphorus pollution. This indicates the necessity of analyzing the impact of land use changes on non-point source pollution loads by identifying critical source areas and altering the land use types that contribute heavily to pollution in these areas. The simulation results of land use type changes in these critical source areas showed that the reduction effect on non-point source pollution load is in the order of forest land > grassland > low-density residential area. To effectively curb surface source pollution in the study area, strategies such as modifying urban land use types, increasing vegetation cover and ground infiltration rate, and strictly controlling the discharge of domestic waste and sewage from urban areas can be implemented.

Drug Repurposing of ACT001 to Discover Novel Promising Sulfide Prodrugs with Improved Safety and Potent Activity for Neutrophil-Mediated Antifungal Immunotherapy.

Neutrophil-mediated immunotherapy is a promising strategy for treating Candida albicans infection due to its potential in dealing with drug-resistant events. Our previous study found that ACT001 exhibited good antifungal immunotherapeutic activity by inhibiting PD-L1 expression in neutrophils, but its strong cytotoxicity and high BBB permeability hindered its antifungal application. To address these deficiencies, a series of novel sulfide derivatives were designed and synthesized based on a slow-release prodrug strategy. Among these derivatives, compound 16 exhibited stronger inhibition of PD-L1 expression, less cytotoxicity to neutrophils, and lower BBB permeability than ACT001. Compound 16 also significantly enhanced neutrophil-mediated antifungal immunity in C. albicans infected mice, with acceptable pharmacokinetic properties and good oral safety. Moreover, pharmacological mechanism studies demonstrated that ACT001 and compound 16 reduced PD-L1 expression in neutrophils by directly targeting STAT3. Briefly, this study provided a novel prototype compound 16 which exhibited great potential in neutrophil-mediated antifungal immunotherapy.

Th2-skewed peripheral T-helper cells drive B-cells in allergic bronchopulmonary aspergillosis.

INTRODUCTION: Patients with allergic bronchopulmonary aspergillosis (ABPA) suffer from repeated exacerbations. The involvement of T-cell subsets remains unclear. METHODS: We enrolled ABPA patients, asthma patients and healthy controls. T-helper type 1 (Th1), 2 (Th2) and 17 (Th17) cells, regulatory T-cells (Treg) and interleukin (IL)-21+CD4+T-cells in total or sorted subsets of peripheral blood mononuclear cells and ABPA bronchoalveolar lavage fluid (BALF) were analysed using flow cytometry. RNA sequencing of subsets of CD4+T-cells was done in exacerbated ABPA patients and healthy controls. Antibodies of T-/B-cell co-cultures in vitro were measured. RESULTS: ABPA patients had increased Th2 cells, similar numbers of Treg cells and decreased circulating Th1 and Th17 cells. IL-5+IL-13+IL-21+CD4+T-cells were rarely detected in healthy controls, but significantly elevated in the blood of ABPA patients, especially the exacerbated ones. We found that IL-5+IL-13+IL-21+CD4+T-cells were mainly peripheral T-helper (Tph) cells (PD-1+CXCR5-), which also presented in the BALF of ABPA patients. The proportions of circulating Tph cells were similar among ABPA patients, asthma patients and healthy controls, while IL-5+IL-13+IL-21+ Tph cells significantly increased in ABPA patients. Transcriptome data showed that Tph cells of ABPA patients were Th2-skewed and exhibited signatures of follicular T-helper cells. When co-cultured in vitro, Tph cells of ABPA patients induced the differentiation of autologous B-cells into plasmablasts and significantly enhanced the production of IgE. CONCLUSION: We identified a distinctly elevated population of circulating Th2-skewed Tph cells that induced the production of IgE in ABPA patients. It may be a biomarker and therapeutic target for ABPA.

The therapeutic effect of wine-processed Corni Fructus on chronic renal failure in rats through the interference with the LPS/IL-1-mediated inhibition of RXR function.

ETHNOPHARMACOLOGICAL RELEVANCE: Corni Fructus, derived from the fruit of Cornus officinalis Sieb. et Zucc, is a widely utilized traditional Chinese medicine (TCM) with established efficacy in the treatment of diverse chronic kidney diseases. Crude Corni Fructus (CCF) and wine-processed Corni Fructus (WCF) are the main processed forms of Corni Fructus. Generally, TCM is often used after processing (paozhi). Despite the extensive use of processed TCM, the underlying mechanisms of processing for most TCMs have been unclear so far. AIM OF THE STUDY: In this study, an integrated strategy combined renal metabolomics with proteomics was established and investigated the potential processing mechanisms of CCF or WCF on chronic renal failure (CRF) models. MATERIALS AND METHODS: Firstly, the differences in biochemical parameters and pathological histology were compared to evaluate the effects of CCF and WCF on CRF model rats. Then, the tissue differential metabolites and proteins between CCF and WCF on CRF model rats were screened based on metabolomics and proteomics technology. Concurrently, a combined approach of metabolomics and proteomics was employed to investigate the underlying mechanisms associated with these marker metabolic products and proteins. RESULTS: Compared to the MG group, there were 27 distinct metabolites and 143 different proteins observed in the CCF-treatment group, while the WCF-treatment group exhibited 24 distinct metabolites and 379 different proteins. Further, the integration interactions analysis of the protein and lipid metabolite revealed that both WCF and CCF improved tryptophan degradation and LPS/IL-1-mediated inhibition of RXR function. WCF inhibited RXR function more than CCF via the modulation of LPS/IL-1 in the CRF model. Experimental results were validated by qRT-PCR and western blotting. Notably, the gene expression amount and protein levels of FMO3 and CYP2E1 among 8 genes influenced by WCF were higher compared to CCF. CONCLUSION: The results of this study provide a theoretical basis for further study of Corni Fructus with different processing techniques in CRF. The findings also offer guidance for investigating the mechanism of action of herbal medicines in diseases employing diverse processing techniques.

Northern Shanghai Study II: systematic assessment and management of early organ damage and its role in preventing and reducing cardiovascular risk-protocol of a prospective study.

INTRODUCTION: Cardiovascular diseases are the leading cause of death and disease burden in China. However, there is a lack of prospective cohort studies suitable for evaluating early organ damage and its role in preventing and reducing cardiovascular risk among Chinese residents. This study intends to establish the first database based on the phenotypes of all early structural and functional damage of cardiovascular organs in Chinese population. Moreover, a digital follow-up mechanism will be formed, a prospective population cohort will be established, a biological sample bank for early cardiovascular organ damage will be established, and an intervention and management system for early damage of cardiovascular organs will be explored. METHODS AND ANALYSIS: This study is a prospective cohort study built on the foundation of the Northern Shanghai Study I. People aged 18-75 years are enrolled. After the recruitment, first, corresponding physical measurements and clinical examinations are conducted to collect cardiovascular risk factors and establish the demographic baseline of the study population. Next, the latest equipment is used to evaluate early structural and functional cardiovascular organ damage including heart, macrovessels, microcirculation, renal function and fundus. Meanwhile, the blood, urine, faeces and other biological samples of participants are collected to establish the cardiometabolic and gut microbiota analysis databases. The population is followed up every 2 years. Comprehensive assessment of early organ damage will be used to predict cardiovascular risk, guide people to change lifestyles to achieve early prevention and provide corresponding treatment recommendations. ETHICS AND DISSEMINATION: This study was approved by the Shanghai Tenth People's Hospital Institutional Review Board. All participants signed a written consent form. The results of this study will be disseminated in peer-reviewed journals. Ethics approval: SHYS-IEC-5.0/22k148/P01. TRIAL REGISTRATION NUMBER: NCT05435898.

C-type lectin receptor 2d forms homodimers and heterodimers with TLR2 to negatively regulate IRF5-mediated antifungal immunity.

Dimerization of C-type lectin receptors (CLRs) or Toll-like receptors (TLRs) can alter their ligand binding ability, thereby modulating immune responses. However, the possibilities and roles of dimerization between CLRs and TLRs remain unclear. Here we show that C-type lectin receptor-2d (CLEC2D) forms homodimers, as well as heterodimers with TLR2. Quantitative ligand binding assays reveal that both CLEC2D homodimers and CLEC2D/TLR2 heterodimers have a higher binding ability to fungi-derived ß-glucans than TLR2 homodimers. Moreover, homo- or hetero-dimeric CLEC2D mediates ß-glucan-induced ubiquitination and degradation of MyD88 to inhibit the activation of transcription factor IRF5 and subsequent IL-12 production. Clec2d-deficient female mice are resistant to infection with Candida albicans, a human fungal pathogen, owing to the increase of IL-12 production and subsequent generation of IFN-γ-producing NK cells. Together, these data indicate that CLEC2D forms homodimers or heterodimers with TLR2, which negatively regulate antifungal immunity through suppression of IRF5-mediated IL-12 production. These homo- and hetero-dimers of CLEC2D and TLR2 provide an example of receptor dimerization to regulate host innate immunity against microbial infections.

STING negatively regulates antifungal immunity.

During viral infections, stimulator of interferon genes (STING) exerts a positive protective immune response. Chen et al. now shed light on the distinct role of STING in fungal infections. STING translocates to the phagosome to negatively regulate the immune response against Candida albicans infection through the inhibition of Src-involved Syk phosphorylation.

Heterozygous CARD9 mutation favors the development of allergic bronchopulmonary aspergillosis.

BACKGROUND: Previous research demonstrated that a homozygous mutation of g.136372044G>A (S12N) in caspase recruitment domain family member 9 ( CARD9 ) is critical for producing Aspergillus fumigatus -induced ( Af -induced) T helper 2 (T H 2)-mediated responses in allergic bronchopulmonary aspergillosis (ABPA). However, it remains unclear whether the CARD9S12N mutation, especially the heterozygous occurrence, predisposes the host to ABPA. METHODS: A total of 61 ABPA patients and 264 controls (including 156 healthy controls and 108 asthma patients) were recruited for sequencing the CARD9 locus to clarify whether patients with this heterozygous single-nucleotide polymorphisms are predisposed to the development of ABPA. A series of in vivo and in vitro experiments, such as quantitative real-time polymerase chain reaction, flow cytometry, and RNA isolation and quantification, were used to illuminate the involved mechanism of the disease. RESULTS: The presence of the p.S12N mutation was associated with a significant risk of ABPA in ABPA patients when compared with healthy controls and asthma patients, regardless of Aspergillus sensitivity. Relative to healthy controls without relevant allergies, the mutation of p.S12N was associated with a significant risk of ABPA (OR: 2.69 and 4.17 for GA and AA genotypes, P = 0.003 and 0.029, respectively). Compared with patients with asthma, ABPA patients had a significantly higher heterozygous mutation (GA genotype), indicating that p.S12N might be a significant ABPA-susceptibility locus ( aspergillus sensitized asthma: OR: 3.02, P = 0.009; aspergillus unsensitized asthma: OR: 2.94, P = 0.005). The mutant allele was preferentially expressed in ABPA patients with heterozygous CARD9S12N , which contributes to its functional alterations to facilitate Af -induced T H 2-mediated ABPA development. In terms of mechanism, Card9 wild-type ( Card9WT ) expression levels decreased significantly due to Af -induced decay of its messenger RNA compared to the heterozygous Card9S12N . In addition, ABPA patients with heterozygous CARD9S12N had increased Af -induced interleukin-5 production. CONCLUSION: Our study provides the genetic evidence showing that the heterozygous mutation of CARD9S12N , followed by allele expression imbalance of CARD9S12N , facilitates the development of ABPA.

Integrated metabolomics, network pharmacology, and molecular docking to reveal the mechanisms of Isodon excisoides against drug-induced liver injury.

Isodon excisoides (Y.Z.Sun ex C.H.Hu) H. Hara has been often used to treat liver diseases in folk medicine. However, the potential hepatoprotective mechanism of I. excisoides remains unclear. In this study, the mechanism of I. excisoides in alleviating drug-induced liver injury (DILI) was explored using a strategy combining metabolomics with network pharmacology for the first time. First, serum metabolomics was applied to identify differential metabolites and enrich metabolic pathways. The potential targets of I. excisoides for the treatment of DILI were investigated by network pharmacology. Subsequently, a comprehensive network of network pharmacology and metabolomics was established to find the key genes. Finally, molecular docking technology was used to further verify the key targets. As a result, four key genes including TYMS, IMPDH2, DHODH, and ASAH1 were identified. The proteins produced by these genes had high affinity with the corresponding diterpenoids. These results indicate that the components of I. excisoides play a liver-protective role by affecting the aforesaid key genes and key proteins. Our results offer a novel strategy for determining the pharmacological effects and potential targets of natural compounds.

Study on mechanism of hepatoprotective effect of Chrysanthemum morifolium Ramat. based on metabolomics with network analysis and network pharmacology.

Hangju (HJ), the dried flower heads of Chrysanthemum morifolium Ramat., has a significant hepatoprotective effect. However, its underlying protection mechanism against acute liver injury (ALI) has been unclear. An integrated strategy based on metabolomics with network analysis and network pharmacology was developed to explore the potential molecular mechanism of HJ on ALI protection. Firstly, differential endogenous metabolites were screened and identified by metabolomics approach and metabolic pathway analysis was performed by MetaboAnalyst. Secondly, marker metabolites were used to construct metabolite-response-enzyme-gene networks and discover hub metabolites and potential gene targets in network analysis. Thirdly, hub genes through the protein-protein interaction (PPI) network were acquired by the aid of network pharmacology. Finally, the gene targets were taken to intersect with the relevant active ingredients for validation by molecular docking. In total, 48 flavonoids were identified in HJ, which were associated with 8 potential therapeutic targets in network pharmacological analysis. Biochemistry and histopathology analysis demonstrated that HJ exerted hepatoprotective effects. 28 biomarkers were successfully identified as possible biomarkers for the prevention of ALI. The sphingolipid metabolic pathway and the glycerophospholipid metabolic pathway was considered a crucial signaling pathway by Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. In addition, phosphatidylcholine and sphingomyelin were considered as hub metabolites. Twelve enzymes and 38 genes were considered as potential targets in the network analysis. Based on the combined analysis above, HJ was shown to modulate 2 key upstream targets, including PLA2G2A and PLA2G4A. Molecular docking showed that active compounds of HJ had high binding affinity with these key targets. In conclusion, the flavonoid components of HJ can inhibit PLA2 and regulate glycerophospholipid and sphingolipid metabolism pathway to delay the pathological process of ALI, which may be a potential mechanism of HJ against ALI.

An Efficient Federated Learning Framework for Machinery Fault Diagnosis With Improved Model Aggregation and Local Model Training.

Due to device operating environment limitations and data privacy protection, it is frequently difficult to obtain sufficient high-quality labeled data from devices, resulting in an insufficient generalization ability of fault diagnosis model. Therefore, a high-performance federated learning framework is proposed in this work, which makes improvements in the procedure of model aggregation and local model training. In the model aggregation of central server, an optimization aggregation strategy in which forgetting Kalman filter (FKF) is combined with cubic exponential smoothing (CES) is proposed to improve the efficiency of federated learning. In the local model training of multiclient, a deep learning network combined with multiscale convolution, attention mechanism, and multistage residual connection is proposed, which is able to fully extract multiclient data features simultaneously. Meanwhile, experiments on two machinery fault datasets show that the proposed framework is capable of achieving high accuracy and strong generalization of fault diagnosis on the premise of protecting data privacy in actual industrial situations.

An integrated strategy to explore the wine-processed mechanism of Corni Fructus on chronic renal failure based on metabolomics, network analysis and bioinformatics approaches.

OBJECTIVES: Corni Fructus is one of the most famous traditional Chinese medicines (TCMs) for the treatment of various chronic kidney diseases. Wine-processed Corni Fructus (WCF) is the main processed form of Crude Corni Fructus (CCF). In this study, potential mechanisms of action of CCF and WCF on chronic renal failure (CRF) model were developed to explore wine-processed mechanism of Corni Fructus. METHODS: An integrated strategy combining metabolomics, network analysis and bioinformatics analysis has been established to investigate the therapeutic mechanisms of WCF and CCF in rats with CRF. KEY FINDINGS: The histopathological results showed that both WCF and CCF improved kidney injury and dysfunction of CRF rats, but WCF was more effective than CCF. Metabolic pathway analysis indicated that 24 metabolites and 5 major disturbed pathways associated with CCF, while WCF regulated 27 metabolites and 2 metabolic pathways. Bioinformatic analysis and network analysis revealed that 8 genes and 7 genes were regulated by CCF and WCF on CRF rats, respectively. The quantitative real-time polymerase chain reaction experiments verified the regulatory ability of CCF and WCF on the expression of 4 genes. CONCLUSIONS: An integrated strategy combined metabolomics, network analysis and bioinformatics was established to provide valuable holistic insight to explore the processing mechanism of TCMs.

PD-L1 negatively regulates antifungal immunity by inhibiting neutrophil release from bone marrow.

Programmed death ligand 1 (PD-L1) has been shown to be inducibly expressed on neutrophils to suppress host immunity during polymicrobial sepsis, virus and parasite infections. However, the role of PD-L1 on neutrophil-mediated antifungal immunity remains wholly unknown. Here, we show that the expression of PD-L1 on murine and human neutrophils was upregulated upon the engagement of C-type lectin receptor Dectin-1 with its ligand ß-glucans, exposed on fungal pathogen Candida albicans yeast. Moreover, ß-glucan stimulation induced PD-L1 translocation into nucleus to regulate the production of chemokines CXCL1 and CXCL2, which control neutrophil mobilization. Importantly, C. albicans infection-induced expression of PD-L1 leads to neutrophil accumulation in bone marrow, through mediating their autocrine secretion of CXCL1/2. Furthermore, neutrophil-specific deficiency of PD-L1 impaired CXCL1/2 secretion, which promoted neutrophil migration from bone marrow into the peripheral circulation, thereby conferring host resistance to C. albicans infection. Finally, either PD-L1 blockade or pharmacological inhibition of PD-L1 expression significantly increased neutrophil release from bone marrow to enhance host antifungal immunity. Our data together indicate that activation of Dectin-1/PD-L1 cascade by ß-glucans inhibits neutrophil release from bone marrow reserve, contributing to the negative regulation of antifungal innate immunity, which functions as a potent immunotherapeutic target against life-threatening fungi infections.

Screening and Capability Assessment of Tyrosinase Inhibitors in Isodon excisoides by Ultrafiltration Coupled with UHPLC-Q-TOF-MS and Molecular Docking Technology.

Tyrosinase inhibitors can alleviate the harm to the liver caused by tyrosinase. How to effectively screen out natural tyrosinase inhibitors becomes a focus. In this study, Isodon excisoides was first extracted with the ultrasound optimized by response surface methodology. Then, a method combined ultrafiltration with ultra-liquid chromatography mass spectrometry (UHPLC/MS) was built to screen and identify tyrosinase inhibitors. The binding energies of active ingredients to tyrosinase were calculated by molecular docking. The reliability of the results was validated by the IC50 of enzyme inhibition assay. As a result, the binding energies of 7 components including excisanin B, lasiokaurin, rabdophyllin G, rabdoserrin B, rabdosin D, rabdosinate and weisiensin were lower than that of resveratrol. It was indicated that these components had high tyrosinase inhibitory activity. The IC50 values of lasiokaurin and excisanin B were 177 and 142 µmol/mL, which were less than that of resveratrol (183 µmol/mL). It showed that this way was simple, rapid, reliable and effective, which provided a new strategy to screen natural bioactive compounds from plants.

Novel insight into the mechanism underlying synergistic cytotoxicity from two components in 5-Fluorouracil-phenylalanine co-crystal based on cell metabolomics.

Co-crystallization of active pharmaceutical ingredients (API) with co-formers can induce synergistic effects on cytotoxicity; however, the underlying mechanism is unclear. Here, cell metabolomics was used to gain insight into the mechanisms of synergistic effect from API and co-former in co-crystal. The 5-Fluorouracil-phenylalanine co-crystal system was selected as the model owing to the apparent difference of cytotoxicity occurring between co-crystal and physical mixture of two components (PM). The cytotoxicity of 5-FU, PM and co-crystal on B16 cells were evaluated by MTT assay. Based on the IC50 values from MTT assays, the cytotoxicity mechanism of 5-FU, PM and co-crystal was evaluated using a comprehensive non-targeted metabolomics strategy based on multivariate data analysis and statistics using UHPLC-Q-TOF-MS/MS platform with IDA data acquisition. Co-crystal showed higher cytotoxicity than PM against B16 cells. In the cell metabolomics study, a total of 12 differential metabolites were found. Pathway analysis indicated that differences in purine and glycerophospholipid metabolism occurred between PM and co-crystal. The downregulated deoxyguanosine diphosphate and adenosine diphosphate in the purine metabolism and downregulated L-glycerophosphocholine and upregulated C16-dihydroceramide in the glycerophospholipid metabolism were associated with cellular antiproliferation and apoptosis, which directly influenced the cytotoxicity. Cell metabolomics was used to investigate the cytotoxicity mechanism of the pharmaceutical co-crystal, providing an effective and innovative method for clarifying the synergistic mechanism of API and CCF in co-crystal.

Inhibition of myeloid-derived suppressor cell arginase-1 production enhances T-cell-based immunotherapy against Cryptococcus neoformans infection.

Cryptococcosis is a potentially lethal disease that is primarily caused by the fungus Cryptococcus neoformans, treatment options for cryptococcosis are limited. Here, we show glucuronoxylomannan, the major polysaccharide component of C. neoformans, induces the recruitment of neutrophilic myeloid-derived suppressor cells in mice and patients with cryptococcosis. Depletion of neutrophilic myeloid-derived suppressor cells enhances host defense against C. neoformans infection. We identify C-type lectin receptor-2d recognizes glucuronoxylomannan to potentiate the immunosuppressive activity of neutrophilic myeloid-derived suppressor cells by initiating p38-mediated production of the enzyme arginase-1, which inhibits T-cell mediated antifungal responses. Notably, pharmacological inhibition of arginase-1 expression by a specific inhibitor of p38, SB202190, or an orally available receptor tyrosine kinase inhibitor, vandetanib, significantly enhances T-cell mediated antifungal responses against cryptococcosis. These data reveal a crucial suppressive role of neutrophilic myeloid-derived suppressor cells during cryptococcosis and highlight a promising immunotherapeutic application by inhibiting arginase-1 production to combat infectious diseases.

CD69 mediates the protective role of adipose tissue-derived mesenchymal stem cells against Pseudomonas aeruginosa pulmonary infection.

BACKGROUND: Our previous study shows that Adipose tissue-derived mesenchymal stem cells (ASCs) are a promising strategy for cell-based therapy against pulmonary infection with Pseudomonas aeruginosa (P. aeruginosa), but the underlying mechanisms remain unclear. METHODS: cDNA microarray assay was performed to explore the transcriptome of ASCs primed by P. aeruginosa. Small interfering RNA (siRNA) was constructed to select the receptor candidates for P. aeruginosa recognition and granulocyte-macrophage colony-stimulating factor (GM-CSF) production in ASCs. The soluble protein chimeras containing the extracellular domain of human CD69 fused to the Fc region of human immunoglobulin IgG1 were used as a probe to validate the recognition of P. aeruginosa. The association between CD69 and extracellular regulated protein kinases 1/2 (ERK1/2) was explored via co-immunoprecipitation, siRNA, and inhibitor. The murine models of P. aeruginosa pneumonia treated with WT-ASCs, GM-CSF-/- -ASCs Cd69-/- -ASCs or Erk1-/- -ASCs were used to determine the role of GM-CSF, CD69, and ERK1 in ASCs against P. aeruginosa infection. RESULTS: We showed that C-type lectin receptor CD69 mediated the protective effects of ASCs partly through GM-CSF. CD69 could specifically recognize P. aeruginosa and regulate GM-CSF secretion of ASCs. CD69 regulated the production of GM-CSF via ERK1 in ASCs after P. aeruginosa infection. Moreover, the Administration of ASCs with deficiency of CD69 or ERK1 completely blocked its protective effects in a murine model of P. aeruginosa pneumonia. CONCLUSIONS: CD69 recognizes P. aeruginosa and further facilitates ERK1 activation, which plays a crucial role in ASCs-based therapy against P. aeruginosa pneumonia. CD69 may be a novel target molecule to improve ASCs-based therapy against P. aeruginosa infection.

TRIM31 facilitates K27-linked polyubiquitination of SYK to regulate antifungal immunity.

Spleen tyrosine kinase (SYK) is a non-receptor tyrosine kinase, which plays an essential role in both innate and adaptive immunity. However, the key molecular mechanisms that regulate SYK activity are poorly understood. Here we identified the E3 ligase TRIM31 as a crucial regulator of SYK activation. We found that TRIM31 interacted with SYK and catalyzed K27-linked polyubiquitination at Lys375 and Lys517 of SYK. This K27-linked polyubiquitination of SYK promoted its plasma membrane translocation and binding with the C-type lectin receptors (CLRs), and also prevented the interaction with the phosphatase SHP-1. Therefore, deficiency of Trim31 in bone marrow-derived dendritic cells (BMDCs) and macrophages (BMDMs) dampened SYK-mediated signaling and inhibited the secretion of proinflammatory cytokines and chemokines against the fungal pathogen Candida albicans infection. Trim31-/- mice were also more sensitive to C. albicans systemic infection than Trim31+/+ mice and exhibited reduced Th1 and Th17 responses. Overall, our study uncovered the pivotal role of TRIM31-mediated K27-linked polyubiquitination on SYK activation and highlighted the significance of TRIM31 in anti-C. albicans immunity.

MYO1F regulates antifungal immunity by regulating acetylation of microtubules.

Opportunistic fungal infections have become one of the leading causes of death among immunocompromised patients, resulting in an estimated 1.5 million deaths each year worldwide. The molecular mechanisms that promote host defense against fungal infections remain elusive. Here, we find that Myosin IF (MYO1F), an unconventional myosin, promotes the expression of genes that are critical for antifungal innate immune signaling and proinflammatory responses. Mechanistically, MYO1F is required for dectin-induced α-tubulin acetylation, acting as an adaptor that recruits both the adaptor AP2A1 and α-tubulin N-acetyltransferase 1 to α-tubulin; in turn, these events control the membrane-to-cytoplasm trafficking of spleen tyrosine kinase and caspase recruitment domain-containing protein 9 Myo1f-deficient mice are more susceptible than their wild-type counterparts to the lethal sequelae of systemic infection with Candida albicans Notably, administration of Sirt2 deacetylase inhibitors, namely AGK2, AK-1, or AK-7, significantly increases the dectin-induced expression of proinflammatory genes in mouse bone marrow-derived macrophages and microglia, thereby protecting mice from both systemic and central nervous system C. albicans infections. AGK2 also promotes proinflammatory gene expression in human peripheral blood mononuclear cells after Dectin stimulation. Taken together, our findings describe a key role for MYO1F in promoting antifungal immunity by regulating the acetylation of α-tubulin and microtubules, and our findings suggest that Sirt2 deacetylase inhibitors may be developed as potential drugs for the treatment of fungal infections.