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1.
ACS Appl Mater Interfaces ; 16(15): 18980-18990, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38577916

RESUMO

Although nonflammable electrolytes are beneficial for battery safety, they often adversely affect the electrochemical performance of lithium-ion batteries due to their poor compatibility with electrodes. Herein, we design a nonflammable electrolyte consisting of cyclic carbonate and 2,2-difluoroethyl acetate (DFEA) solvents paired with several surface-film-forming additives, significantly improving the safety and cycling performance of NMC811||SiOx/graphite pouch cells. The DFEA solvent exhibits not only good flame retardancy but also lower lowest unoccupied molecular orbital (LUMO) energy, promoting the formation of a robust inorganic-rich and gradient-architecture hybrid interface between the SiOx/graphite anode and electrolyte. The double insurance of good flame retardancy of the DFEA solvent and decreased exothermic effects of both bulk electrolyte and DFEA-derived solid electrolyte interphase (SEI) can ensure the high safety of the pouch cell. Moreover, the highly robust SEI can prevent the excessive reduction decomposition of the electrolyte and alleviate the structural decay of the anode, which can restrain the formation of lithium deposition on the anode surface and further suppress the structural decay of NMC materials. This contributes to the unprecedented cycling performance of the NMC811||SiOx/graphite pouch cells with a capacity retention of 80% after 1000 cycles at a 0.33C rate.

2.
Cell Death Differ ; 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38605168

RESUMO

Myddosome is an oligomeric complex required for the transmission of inflammatory signals from TLR/IL1Rs and consists of MyD88 and IRAK family kinases. However, the molecular basis for the self-assemble of Myddosome proteins and regulation of intracellular signaling remains poorly understood. Here, we identify OTUD5 acts as an essential regulator for MyD88 oligomerization and Myddosome formation. OTUD5 directly interacts with MyD88 and cleaves its K11-linked polyubiquitin chains at Lys95, Lys231 and Lys250. This polyubiquitin cleavage enhances MyD88 oligomerization after LPS stimulation, which subsequently promotes the recruitment of downstream IRAK4 and IRAK2 to form Myddosome and the activation of NF-κB and MAPK signaling and production of inflammatory cytokines. Consistently, Otud5-deficient mice are less susceptible to LPS- and CLP-induced sepsis. Taken together, our findings reveal a positive regulatory role of OTUD5 in MyD88 oligomerization and Myddosome formation, which provides new sights into the treatment of inflammatory diseases.

3.
Nat Commun ; 15(1): 36, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38167296

RESUMO

While canonical Wnt signaling is well recognized for its crucial regulatory functions in cell fate decisions, the role of non-canonical Wnt signaling in adult stem cells remains elusive and contradictory. Here, we identified Mcam, a potential member of the non-canonical Wnt signaling, as an important negative regulator of mammary gland epithelial cells (MECs) by genome-scale CRISPR-Cas9 knockout (GeCKO) library screening. Loss of Mcam increases the clonogenicity and regenerative capacity of MECs, and promotes the proliferation, differentiation, and ductal morphogenesis of mammary epithelial in knockout mice. Mechanically, Mcam knockout recruits and polarizes macrophages through the Il4-Stat6 axis, thereby promoting secretion of the non-canonical Wnt ligand Wnt5a and its binding to the non-canonical Wnt signaling receptor Ryk to induce the above phenotypes. These findings reveal Mcam roles in mammary gland development by orchestrating communications between MECs and macrophages via a Wnt5a/Ryk axis, providing evidences for non-canonical Wnt signaling in mammary development.


Assuntos
Proteínas Wnt , Via de Sinalização Wnt , Camundongos , Animais , Proteínas Wnt/genética , Proteínas Wnt/metabolismo , Proteína Wnt-5a/genética , Proteína Wnt-5a/metabolismo , Diferenciação Celular , Morfogênese , Camundongos Knockout , Macrófagos/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo
4.
PLoS Pathog ; 20(1): e1011902, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38166150

RESUMO

Fungal infections have emerged as a major concern among immunocompromised patients, causing approximately 2 million deaths each year worldwide. However, the regulatory mechanisms underlying antifungal immunity remain elusive and require further investigation. The E3 ligase Trim26 belongs to the tripartite motif (Trim) protein family, which is involved in various biological processes, including cell proliferation, antiviral innate immunity, and inflammatory responses. Herein, we report that Trim26 exerts protective antifungal immune functions after fungal infection. Trim26-deficient mice are more susceptible to fungemia than their wild-type counterparts. Mechanistically, Trim26 restricts inflammatory neutrophils infiltration and limits proinflammatory cytokine production, which can attenuate kidney fungal load and renal damage during Candida infection. Trim26-deficient neutrophils showed higher proinflammatory cytokine expression and impaired fungicidal activity. We further demonstrated that excessive neutrophils infiltration in the kidney was because of the increased production of chemokines CXCL1 and CXCL2, which are mainly synthesized in the macrophages or dendritic cells of Trim26-deficient mice after Candida albicans infections. Together, our study findings unraveled the vital role of Trim26 in regulating antifungal immunity through the regulation of inflammatory neutrophils infiltration and proinflammatory cytokine and chemokine expression during candidiasis.


Assuntos
Candidíase , Neutrófilos , Animais , Camundongos , Antifúngicos , Candida albicans , Candidíase/metabolismo , Candidíase/microbiologia , Citocinas/metabolismo , Infiltração de Neutrófilos , Proteínas com Motivo Tripartido , Ubiquitina-Proteína Ligases
5.
Proc Natl Acad Sci U S A ; 120(52): e2308853120, 2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-38109536

RESUMO

The enzyme cyclic GMP-AMP synthase (cGAS) is a key sensor for detecting misplaced double-stranded DNA (dsDNA) of genomic, mitochondrial, and microbial origin. It synthesizes 2'3'-cGAMP, which in turn activates the stimulator of interferon genes pathway, leading to the initiation of innate immune responses. Here, we identified Listerin as a negative regulator of cGAS-mediated innate immune response. We found that Listerin interacts with cGAS on endosomes and promotes its K63-linked ubiquitination through recruitment of the E3 ligase TRIM27. The polyubiquitinated cGAS is then recognized by the endosomal sorting complexes required for transport machinery and sorted into endosomes for degradation. Listerin deficiency enhances the innate antiviral response to herpes simplex virus 1 infection. Genetic deletion of Listerin also deteriorates the neuroinflammation and the ALS disease progress in an ALS mice model; overexpression of Listerin can robustly ameliorate disease progression in ALS mice. Thus, our work uncovers a mechanism for cGAS regulation and suggests that Listerin may be a promising therapeutic target for ALS disease.


Assuntos
Esclerose Lateral Amiotrófica , Ubiquitina-Proteína Ligases , Animais , Camundongos , Esclerose Lateral Amiotrófica/tratamento farmacológico , Esclerose Lateral Amiotrófica/imunologia , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Imunidade Inata/genética , Nucleotidiltransferases/metabolismo , Proteólise , Transdução de Sinais/fisiologia , Modelos Animais de Doenças , Ubiquitina-Proteína Ligases/antagonistas & inibidores , Ubiquitina-Proteína Ligases/imunologia , Ubiquitina-Proteína Ligases/metabolismo
8.
J Colloid Interface Sci ; 649: 510-518, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37356152

RESUMO

Electrochromic materials (ECMs) could exhibit reversible color changes upon application of the external electric field, which exhibits huge application prospects in smart windows, energy storage devices, and displays. For the practical application of ECMs, the fast response speed and long cyclic stability are urgent. In this work, the nanoporous Sm-doped WO3 (WSm) films were constructed using hydrothermal technology, then polydopamine (PDA) was modified on the surface of WSm film to obtain the WSm/Px (x = 0.25, 0.5, 1.0, and 2.0) hybrid films. WSm/Px hybrid films displayed high optical contrast and large areal capacitance. In addition, in comparison with WSm film, the WSm/Px hybrid films exhibited faster response speed and better cyclic stability because PDA film enhanced the interface ion transport ability and electrochemical structural stability of the nanoporous WSm film. Notably, the WSm/P1.0 hybrid film displayed the colored/bleached times of 7.4/2.9 s, retained 90.2% of the primitive optical contrast (68.5%) after 5000 electrochromic cycles. Furthermore, the areal capacitance of WSm film could be increased by 224% through the modification of the PDA. Therefore, WSm/Px hybrid films are great prospects for electrochromic energy-saving and storage windows.

9.
Materials (Basel) ; 16(10)2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37241391

RESUMO

Hydrophobic thin films have gained significant attention due to their broad applications in self-cleaning, anti-corrosion, anti-icing, medicine, oil-water separation, and other fields. The target hydrophobic materials can be deposited onto various surfaces thanks to the scalable and highly reproducible nature of magnetron sputtering, which is comprehensively overviewed in this review. While alternative preparation methods have been extensively analyzed, a systematic understanding of hydrophobic thin films fabricated using magnetron sputtering deposition is still absent. After outlining the fundamental mechanism of hydrophobicity, this review briefly summarizes three types of sputtering-deposited thin films that originate from oxides, polytetrafluoroethylene (PTFE), and diamond-like carbon (DLC), respectively, primarily focusing on the recent advances in their preparation, characteristics, and applications. Finally, the future applications, current challenges, and development of hydrophobic thin films are discussed, and a brief perspective on future research directions is provided.

10.
ACS Appl Mater Interfaces ; 15(17): 20800-20810, 2023 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-37078779

RESUMO

Amplifying the intracellular reactive oxygen species (ROS) level remains an urgent challenge for efficient sonodynamic therapy (SDT) of tumors. Herein, by loading ginsenoside Rk1 with manganese-doped hollow titania (MHT), a Rk1@MHT sonosensitizer was conceived to strengthen the outcome of tumor SDT. The results verify that manganese-doping remarkably elevates the UV-visible absorption and decreases the bandgap energy of titania from 3.2 to 3.0 eV, which improves ROS production under ultrasonic irradiation. Immunofluorescence and Western blot analysis demonstrate that ginsenoside Rk1 can block the critical protein of the glutathione synthesis pathway, glutaminase, thus enhancing intracellular ROS by eliminating the endogenous glutathione-depleted pathway of ROS. Manganese-doping confers the nanoprobe T1-weighted MRI function (r2/r1 = 1.41). Moreover, the in vivo tests confirm that Rk1@MHT-based SDT eradicates liver cancer in tumor-bearing mice via dual upregulation of intracellular ROS production. In summary, our study provides a new strategy for designing high-performance sonosensitizer to achieve noninvasive cancer treatment.


Assuntos
Manganês , Camundongos , Animais , Espécies Reativas de Oxigênio/metabolismo , Manganês/metabolismo , Linhagem Celular Tumoral , Regulação para Cima
11.
Nat Commun ; 14(1): 642, 2023 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-36746963

RESUMO

Pathogenic viral infections represent a major challenge to human health. Host immune responses to respiratory viruses are closely associated with microbiome and metabolism via the gut-lung axis. It has been known that host defense against influenza A virus (IAV) involves activation of the NLRP3 inflammasome, however, mechanisms behind the protective function of NLRP3 are not fully known. Here we show that an isolated bacterial strain, Bifidobacterium pseudolongum NjM1, enriched in the gut microbiota of Nlrp3-/- mice, protects wild-type but not Nlrp3 deficient mice against IAV infection. This effect depends on the enhanced production of type I interferon (IFN-I) mediated by NjM1-derived acetate. Application of exogenous acetate reproduces the protective effect of NjM1. Mechanistically, NLRP3 bridges GPR43 and MAVS, and promotes the oligomerization and signalling of MAVS; while acetate enhances MAVS aggregation upon GPR43 engagement, leading to elevated IFN-I production. Thus, our data support a model of NLRP3 mediating enhanced induction of IFN-I via acetate-producing bacterium and suggest that the acetate-GPR43-NLRP3-MAVS-IFN-I signalling axis is a potential therapeutic target against respiratory viral infections.


Assuntos
Vírus da Influenza A , Microbiota , Humanos , Animais , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Inflamassomos/metabolismo , Acetatos/farmacologia , Antivirais
12.
Intell Med ; 3(2): 85-96, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36694623

RESUMO

After the outbreak of COVID-19, the interaction of infectious disease systems and social systems has challenged traditional infectious disease modeling methods. Starting from the research purpose and data, researchers improved the structure and data of the compartment model or used agents and artificial intelligence based models to solve epidemiological problems. In terms of modeling methods, the researchers use compartment subdivision, dynamic parameters, agent-based model methods, and artificial intelligence related methods. In terms of factors studied, the researchers studied 6 categories: human mobility, nonpharmaceutical interventions (NPIs), ages, medical resources, human response, and vaccine. The researchers completed the study of factors through modeling methods to quantitatively analyze the impact of social systems and put forward their suggestions for the future transmission status of infectious diseases and prevention and control strategies. This review started with a research structure of research purpose, factor, data, model, and conclusion. Focusing on the post-COVID-19 infectious disease prediction simulation research, this study summarized various improvement methods and analyzes matching improvements for various specific research purposes.

13.
Arthritis Rheumatol ; 75(5): 842-855, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36529965

RESUMO

OBJECTIVE: The NLRP3 inflammasome has been shown to be involved in the development of uveitis, but the exact mechanism remains elusive. This study was undertaken to explore the role of NLRP3 in the development of uveitis. METHODS: First, Nlrp3-deficient mice were used to study the role of NLRP3 in experimental autoimmune diseases, such as experimental autoimmune uveitis (EAU) and experimental autoimmune encephalomyelitis (EAE). Next, the gathering of ASC, activation of caspase 1 and gasdermin D, and secretion of lactate dehydrogenase and interleukin-1ß were detected to confirm macrophage pyroptosis and AIM2 activation in the Nlrp3-/- mice. Additionally, RNA sequencing and chromatin immunoprecipitation-polymerase chain reaction were used to investigate the phosphorylated salt-inducible kinase 1 (p-SIK1)/sterol regulatory element binding transcription factor 1 (SREBF1) pathway, which regulates the transcription of Aim2. Finally, overexpression of Nlrp3 was applied to treat EAU. RESULTS: Surprisingly, our findings show that NLRP3 plays an antiinflammatory role in 2 models of EAU and EAE. Additionally, macrophages show an increased M1 activation and pyroptosis in Nlrp3-/- mice. Further experiments indicate that this pyroptosis of macrophages was mediated by the up-regulated transcription of Aim2 as a result of Nlrp3 deficiency. In mechanistic studies, Nlrp3 deficiency was implicated in the down-regulation of p-SIK1 and subsequently the up-regulation of SREBF1, which binds to Aim2 and then promotes the latter's transcription. Finally, Aim2 deficiency, RNA silencing of Aim2 or Srebf1, and overexpression of Nlrp3 resulted in attenuated inflammation of EAU. CONCLUSION: Our data demonstrate that NLRP3 inhibits AIM2 inflammasome-mediated EAU by regulating the p-SIK1/SREBF1 pathway, highlighting the therapeutic potential of targeting Nlrp3.


Assuntos
Inflamassomos , Uveíte , Animais , Camundongos , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Piroptose , Proteínas de Ligação a DNA/metabolismo , Inflamação , Caspase 1/metabolismo , Uveíte/genética , Fatores de Transcrição , Esteróis , Interleucina-1beta/metabolismo
14.
Intell Med ; 3(1): 36-43, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36373090

RESUMO

Faced with the current time-sensitive COVID-19 pandemic, the overburdened healthcare systems have resulted in a strong demand to develop newer methods to control the spread of the pandemic. Big data and artificial intelligence (AI) have been leveraged amid the COVID-19 pandemic; however, little is known about their use for supporting public health efforts. In epidemic surveillance and containment, efforts are needed to treat critical patients, track and manage the health status of residents, isolate suspected cases, and develop vaccines and antiviral drugs. The applications of emerging practices of artificial intelligence and big data have become powerful "weapons" to fight against the pandemic and provide strong support in pandemic prevention and control, such as early warning, analysis and judgment, interruption and intervention of epidemic, to achieve goals of early detection, early report, early diagnosis, early isolation and early treatment. These are the decisive factors to control the spread of the epidemic and reduce the mortality. This paper systematically summarized the application of big data and AI in epidemic, and describes practical cases and challenges with emphasis on epidemic prevention and control. The included studies showed that big data and AI have the potential strength to fight against COVID-19. However, many of the proposed methods are not yet widely accepted. Thus, the most rewarding research would be on methods that promise value beyond COVID-19. More efforts are needed for developing standardized reporting protocols or guidelines for practice.

15.
Proc Natl Acad Sci U S A ; 119(47): e2208274119, 2022 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-36383602

RESUMO

Lyme spirochetes have coevolved with ticks to optimize transmission to hosts using tick salivary molecules (TSMs) to counteract host defenses. TSMs modulate various molecular events at the tick-host interface. Lymphotoxin-beta receptor (LTßR) is a vital immune receptor and plays protective roles in host immunity against microbial infections. We found that Ltbr knockout mice were more susceptible to Lyme disease spirochetes, suggesting the involvement of LTßR signaling in tick-borne Borrelia infection. Further investigation showed that a 15-kDa TSM protein from Ixodes persulcatus (I. persulcatus salivary protein; IpSAP) functioned as an immunosuppressant to facilitate the transmission and infection of Lyme disease spirochetes. IpSAP directly interacts with LTßR to block its activation, thus inhibiting the downstream signaling and consequently suppressing immunity. IpSAP immunization provided mice with significant protection against I. persulcatus-mediated Borrelia garinii infection. Notably, the immunization showed considerable cross-protection against other Borrelia infections mediated by other ixodid ticks. One of the IpSAP homologs from other ixodid ticks showed similar effects on Lyme spirochete transmission. Together, our findings suggest that LTßR signaling plays an important role in blocking the transmission and pathogenesis of tick-borne Lyme disease spirochetes, and that IpSAP and its homologs are promising candidates for broad-spectrum vaccine development.


Assuntos
Grupo Borrelia Burgdorferi , Borrelia burgdorferi , Ixodes , Doença de Lyme , Camundongos , Animais , Borrelia burgdorferi/genética , Saliva , Ixodes/fisiologia , Receptor beta de Linfotoxina
16.
Front Cell Infect Microbiol ; 12: 905906, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35937685

RESUMO

E3 ubiquitin ligases determine the substrate specificity and catalyze the ubiquitination of lysine residues. HUWE1 is a catalytic HECT domain-containing giant E3 ligase that contains a substrate-binding ring structure, and mediates the ubiquitination of more than 40 diverse substrates. HUWE1 serves as a central node in cellular stress responses, cell growth and death, signal transduction, etc. The expanding atlas of HUWE1 substrates presents a major challenge for the potential therapeutic application of HUWE1 in a particular disease. In addition, HUWE1 has been demonstrated to play contradictory roles in certain aspects of tumor progression in either an oncogenic or a tumor-suppressive manner. We recently defined novel roles of HUWE1 in promoting the activation of multiple inflammasomes. Inflammasome activation-mediated immune responses might lead to multifunctional effects on tumor therapy, inflammation, and autoimmune diseases. In this review, we summarize the known substrates and pleiotropic functions of HUWE1 in different types of cells and models, including its involvement in development, cancer, neuronal disorder and infectious disease. We also discuss the advances in cryo-EM-structural analysis for a functional-mechanistic understanding of HUWE1 in modulating the multitudinous diverse substrates, and introduce the possibility of revisiting the comprehensive roles of HUWE1 in multiple aspects within one microenvironment, which will shed light on the potential therapeutic application of targeting giant E3 ligases like HUWE1.


Assuntos
Deficiência Intelectual , Neoplasias , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Carcinogênese , Humanos , Deficiência Intelectual/metabolismo , Neoplasias/metabolismo , Espermatogênese , Microambiente Tumoral
17.
Phys Chem Chem Phys ; 24(12): 7405-7414, 2022 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-35266492

RESUMO

Silicon monoxide is a potentially viable anode material for high-performance lithium-ion batteries (LIBs). However, a low initial coulombic efficiency and large volume expansion limit its commercial application. Pre-lithiation is an efficient solution, but is expensive because of limited "pre-lithiation" sources. In this work, we theoretically investigated a novel multiple pre-doping SiO system (Li-NaMg-SiO). By comparing its lithiation behavior to that of the traditional Li-doping system (Li-SiO), we revealed the different doping effects during lithiation. Similar to the traditional Li-doping system, the insertion of Na and Mg disintegrates the Si-O host matrix to form Na-O and Mg-O bonds and active Si clusters. At the end of lithiation, the O-Li coordination number (CN) tends to saturate at CNO-Li ≈ 5 in Li-Na-SiO, Li-Mg-SiO, and Li-NaMg-SiO systems, while the value of CNO-Li in the Li-SiO system is more than 6, which suggests that there are reorganizations between Li, Na, and Mg in the silicate matrix. Doping sources of both Na and Mg can prevent the active Li ions from being trapped by O-Li bonds and increase the initial coulombic efficiency. From the density of states (DOS), we notice that all the different pre-doping systems have similar electronic structures, and they can be expected to undergo the same lithiation process. Furthermore, the higher ion-conductivity and smaller volume expansion during the lithiation process characterized by root mean square deviation (RMSD) and volume analysis prove the advantages of the binary doping system (Li-NaMg-SiO) for the improvement of cycle stability for Si-based materials. These advantages benefit from the loose and amorphous structures of doping systems during lithiation. Our work highlights the doping effects of multiple sources and the promotion of "inert compounds" on the entire lithiation process, which provide valuable insight for high-performance anode design.

18.
Cell Immunol ; 374: 104498, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35334276

RESUMO

Basophils and mast cells play a critical role in allergic inflammation and provide protective immunity against certain types of parasitic infections. Expansion of basophils and mast cells to the critical numbers is believed to be an essential step in enabling basophils and mast cells to carry out their protective functions. However, factors that drive basophil and mast cell expansion are still incompletely understood. We tested the roles of cytokines and growth factors IL-3, TSLP, GM-CSF, IL-5, SCF, IL-7, IL-25, and IL-33 in promoting the differentiation of pre-basophil and mast cell progenitors (pre-BMPs)in vitro.We found that while GM-CSF only expanded basophils, IL-3 promoted the differentiation of pre-BMPs into both basophils and mast cells. We found that IL-3 expanded the number of pre-BMPsin vivo. We showed that IL-3 upregulatedIl3ramRNA and protein expression on pre-BMPs, supporting that IL-3 expands pre-BMPs in part by upregulating the IL-3 receptor expression. Although Gata2 mRNA expression was upregulated by IL-3 treatment in pre-BMPs, it is dispensable for IL-3-mediated upregulation of IL-3 receptor expression. Our study reveals a novel mechanism through which IL-3 expands basophil and mast cells.


Assuntos
Basófilos , Receptores de Interleucina-3 , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Interleucina-3 , Mastócitos
19.
Front Cell Dev Biol ; 9: 743335, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34869331

RESUMO

Bacterial infection tendentiously triggers inflammasome activation, whereas the roles of inflammasome activation in host defense against diverse infections remain unclear. Here, we identified that an ASC-dependent inflammasome activation played opposite roles in host defense against Francisella novicida wild-type (WT) U112 and mutant strain XWK4. Comparing with U112, XWK4 infection induced robust cytokine production, ASC-dependent inflammasome activation, and pyroptosis. Both AIM2 and NLRP3 were involved and played independent roles in XWK4-induced inflammasome activation. Type II interferon was partially required for XWK4-triggered inflammasome activation, which was different from type I interferon dependency in U112-induced inflammasome activation. Distinct from F. novicida U112 and Acinetobacter baumannii infection, Asc-/- mice were more resistant than WT mice response to XWK4 infection by limiting bacterial burden in vivo. The excessive inflammasome activation triggered by XWK4 infection caused dramatical cell death and pathological damage. Our study offers novel insights into mechanisms of inflammasome activation in host defense and provides potential therapeutic approach against bacterial infections and inflammatory diseases.

20.
Bio Protoc ; 11(17): e4151, 2021 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-34604456

RESUMO

An inflammasome is an intracellular multiprotein complex that plays important roles in host defense and inflammatory responses. Inflammasomes are typically composed of the adaptor protein apoptosis-associated speck-like protein containing a CARD (ASC), cytoplasmic sensor protein, and the effector protein pro-caspase-1. ASC assembly into a protein complex termed ASC speck is a readout for inflammasome activation. Here, we provide a step-by-step protocol for the detection of ASC speck by confocal microscopy in Bone marrow derived macrophages (BMBDs) triggered by chemical stimuli and bacterial pathogens. We also describe the detailed procedure for the generation of BMDMs, stimulating conditions for inflammasome activation, immunofluorescence cell staining of ASC protein, and microscopic examination. Thus far, this method is a simple and reliable manner to visualize and quantify the intracellular localization of ASC speck. Graphic abstract: Figure 1. Confocal microscopy detection of ASC speck formation in untreated WT BMDMs and WT BMDMs stimulated with LPS and ATP, transfected with dsDNA, and infected with F. novicida or Salmonella as indicated. Arrow indicates the ASC speck. Scale bars: 10 µm.

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