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1.
ACS Nano ; 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38885198

RESUMO

Adjuvants are effective tools to enhance vaccine efficacy and control the type of immune responses such as antibody and T helper 1 (Th1)- or Th2-type responses. Several studies suggest that interferon (IFN)-γ-producing Th1 cells play a significant role against infections caused by intracellular bacteria and viruses; however, only a few adjuvants can induce a strong Th1-type immune response. Recently, several studies have shown that lipid nanoparticles (LNPs) can be used as vaccine adjuvants and that each LNP has a different adjuvant activity. In this study, we screened LNPs to develop an adjuvant that can induce Th1 cells and antibodies using a conventional influenza split vaccine (SV) as an antigen in mice. We observed that LNP with 1,2-di-O-octadecenyl-3-trimethylammonium-propane (DOTMA) as a component lipid (DOTMA-LNP) elicited robust SV-specific IgG1 and IgG2 responses compared with SV alone in mice and was as efficient as SV adjuvanted with other adjuvants in mice. Furthermore, DOTMA-LNPs induced robust IFN-γ-producing Th1 cells without inflammatory responses compared to those of other adjuvants, which conferred strong cross-protection in mice. We also demonstrated the high versatility of DOTMA-LNP as a Th1 cell-inducing vaccine adjuvant using vaccine antigens derived from severe acute respiratory syndrome coronavirus 2 and Streptococcus pneumoniae. Our findings suggest the potential of DOTMA-LNP as a safe and effective Th1 cell-inducing adjuvant and show that LNP formulations are potentially potent adjuvants to enhance the effectiveness of other subunit vaccines.

2.
Front Pharmacol ; 14: 1250383, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37705538

RESUMO

Background: Humans are constantly exposed to various industrial, environmental, and endogenous particulates that result in inflammatory diseases. After being engulfed by immune cells, viz. Macrophages, such particulates lead to phagolysosomal dysfunction, eventually inducing pyroptosis, a form of cell death accompanied by the release of inflammatory mediators, including members of the interleukin (IL)-1 family. Phagolysosomal dysfunction results in the activation of the nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, an immune complex that induces pyroptosis upon exposure to various external stimuli. However, several particulates induce pyroptosis even if the NLRP3 inflammasome is inhibited; this indicates that such inhibition is not always effective in treating diseases induced by particulates. Therefore, discovery of drugs suppressing particulate-induced NLRP3-independent pyroptosis is warranted. Methods: We screened compounds that inhibit silica particle (SP)-induced cell death and release of IL-1α using RAW264.7 cells, which are incapable of NLRP3 inflammasome formation. The candidates were tested for their ability to suppress particulate-induced pyroptosis and phagolysosomal dysfunction using mouse primary macrophages and alleviate SP-induced NLRP3-independent lung inflammation. Results: Several Src family kinase inhibitors, including dasatinib, effectively suppressed SP-induced cell death and IL-1α release. Furthermore, dasatinib suppressed pyroptosis induced by other particulates but did not suppress that induced by non-particulates, such as adenosine triphosphate. Dasatinib reduced SP-induced phagolysosomal dysfunction without affecting phagocytosis of SPs. Moreover, dasatinib treatment strongly suppressed the increase in IL-1α levels and neutrophil counts in the lungs after intratracheal SP administration. Conclusion: Dasatinib suppresses particulate-induced pyroptosis and can be used to treat relevant inflammatory diseases.

3.
Sci Rep ; 13(1): 3484, 2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36922503

RESUMO

Metal homeostasis is tightly regulated in cells and organisms, and its disturbance is frequently observed in some diseases such as neurodegenerative diseases and metabolic disorders. Previous studies suggest that zinc and iron are necessary for the normal functions of pancreatic ß cells. However, the distribution of elements in normal conditions and the pathophysiological significance of dysregulated elements in the islet in diabetic conditions have remained unclear. In this study, to investigate the dynamics of elements in the pancreatic islets of a diabetic mouse model expressing human islet amyloid polypeptide (hIAPP): hIAPP transgenic (hIAPP-Tg) mice, we performed imaging analysis of elements using synchrotron scanning X-ray fluorescence microscopy and quantitative analysis of elements using inductively coupled plasma mass spectrometry. We found that in the islets, zinc significantly decreased in the early stage of diabetes, while iron gradually decreased concurrently with the increase in blood glucose levels of hIAPP-Tg mice. Notably, when zinc and/or iron were decreased in the islets of hIAPP-Tg mice, dysregulation of glucose-stimulated mitochondrial respiration was observed. Our findings may contribute to clarifying the roles of zinc and iron in islet functions under pathophysiological diabetic conditions.


Assuntos
Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Ilhotas Pancreáticas , Humanos , Camundongos , Animais , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Zinco/metabolismo , Ferro/metabolismo , Camundongos Transgênicos , Amiloide/metabolismo , Ilhotas Pancreáticas/metabolismo , Células Secretoras de Insulina/metabolismo , Diabetes Mellitus Tipo 2/metabolismo
4.
Int Immunol ; 34(10): 505-518, 2022 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-35759801

RESUMO

Nod-like receptor family pyrin domain-containing 3 (NLRP3) is a cytosolic innate immune receptor that senses organelle dysfunction induced by various stimuli, such as infectious, environmental, metabolic and drug stresses. Upon activation, NLRP3 forms an inflammasome with its adaptor protein apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and caspase-1, to trigger the release of inflammatory cytokines. The development of effective anti-inflammatory drugs targeting the NLRP3 inflammasome is in high demand as its aberrant activation often causes inflammatory diseases. Here, we found that nanaomycin A (NNM-A), a quinone-based antibiotic isolated from Streptomyces, effectively inhibited NLRP3 inflammasome-mediated inflammatory responses induced by imidazoquinolines, including imiquimod. Interestingly, its epoxy derivative nanaomycin E (NNM-E) showed a comparable inhibitory effect against the NLRP3 inflammasome-induced release of interleukin (IL)-1ß and IL-18 from macrophages, with a much lower toxicity than NNM-A. NNM-E inhibited ASC oligomerization and caspase-1 cleavage, both of which are hallmarks of NLRP3 inflammasome activation. NNM-E reduced mitochondrial damage and the production of reactive oxygen species, thereby preventing the activation of the NLRP3 inflammasome. NNM-E treatment markedly alleviated psoriasis-like skin inflammation induced by imiquimod. Collectively, NNM-E inhibits NLRP3 inflammasome activation by preventing mitochondrial dysfunction with little toxicity and showed an anti-inflammatory effect in vivo. Thus, NNM-E could be a potential lead compound for developing effective and safe anti-inflammatory agents for the treatment of NLRP3 inflammasome-mediated inflammatory diseases.


Assuntos
Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Caspase 1/metabolismo , Imiquimode/metabolismo , Imiquimode/farmacologia , Interleucina-1beta/metabolismo , Mitocôndrias/metabolismo , Naftoquinonas
5.
Int Immunol ; 34(10): 493-504, 2022 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-35639943

RESUMO

The human body is exposed to various particulates of industrial, environmental, or endogenous origin. Invading or intrinsic particulates can induce inflammation by aberrantly activating the immune system, thereby causing crystallopathies. When immune cells such as macrophages phagocytose the particulates, their phagolysosomal membranes undergo mechanical damage, eventually leading to pyroptotic cell death accompanied by the release of inflammatory cytokines, including interleukin (IL)-1α and IL-1ß. The nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is responsible for particulate-induced IL-1ß release and is therefore regarded as a potential therapeutic target for inflammation-mediated crystallopathies. However, IL-1α is released after particulate stimulation in an NLRP3 inflammasome-independent manner and plays a critical role in disease development. Therefore, drugs that exert potent anti-inflammatory effects by comprehensively suppressing particulate-induced responses, including IL-1ß release and IL-1α release, should be developed. Here, we found that oridonin, a diterpenoid isolated from Isodon japonicus HARA, strongly suppressed particulate-induced cell death, accompanied by the release of IL-1α and IL-1ß in mouse and human macrophages. Oridonin reduced particulate-induced phagolysosomal membrane damage in macrophages without affecting phagocytosis of particulates. Furthermore, oridonin treatment markedly suppressed the symptoms of silica particle-induced pneumonia, which was attributed to the release of IL-1α independently of NLRP3. Thus, oridonin is a potential lead compound for developing effective therapeutics for crystallopathies attributed to NLRP3-dependent as well as NLRP3-independent inflammation.


Assuntos
Diterpenos do Tipo Caurano , Interleucina-1beta , Pulmão , Proteína 3 que Contém Domínio de Pirina da Família NLR , Material Particulado , Pneumonia , Animais , Diterpenos do Tipo Caurano/farmacologia , Diterpenos do Tipo Caurano/uso terapêutico , Humanos , Inflamassomos/efeitos dos fármacos , Inflamassomos/imunologia , Interleucina-1beta/antagonistas & inibidores , Interleucina-1beta/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Material Particulado/toxicidade , Pneumonia/induzido quimicamente , Pneumonia/tratamento farmacológico , Pneumonia/imunologia
6.
Biol Pharm Bull ; 44(5): 599-604, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33952816

RESUMO

The purine nucleotide ATP is a fundamental unit in cellular energy metabolism. Extracellular ATP and its metabolites are also ligands for a family of receptors, known as purinergic receptors, which are expressed ubiquitously in almost every cell type. In the immune system, extracellular ATP and its signals regulate the migration and activation of immune cells to orchestrate the induction and resolution of inflammation. In this review, we provide an overview of purinergic receptors and their downstream signaling related to macrophage activation. We also discuss the roles of purinergic signaling for macrophage functions in physiological and pathological conditions.


Assuntos
Trifosfato de Adenosina/metabolismo , Inflamação/imunologia , Macrófagos/imunologia , Receptores Purinérgicos/metabolismo , Animais , Humanos , Macrófagos/metabolismo
7.
Cell Rep ; 34(6): 108734, 2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33567275

RESUMO

Macrophage recognition and phagocytosis of crystals is critical for the associated fibrosis and cancer. Of note, multi-walled carbon nanotubes (MWCNTs), the highly representative products of nanotechnology, induce macrophage NLRP3 inflammasome activation and cause asbestosis-like pathogenesis. However, it remains largely unknown how macrophages efficiently recognize MWCNTs on their cell surfaces. Here, we identify by a targeted screening of phagocyte receptors the phosphatidylserine receptors T cell immunoglobulin mucin 4 (Tim4) and Tim1 as the pattern-recognition receptors for carbon crystals. Docking simulation studies reveal spatiotemporally stable interfaces between aromatic residues in the extracellular IgV domain of Tim4 and one-dimensional carbon crystals. Further, CRISPR-Cas9-mediated deletion of Tim4 and Tim1 reveals that Tim4, but not Tim1, critically contributes to the recognition of MWCNTs by peritoneal macrophages and to granuloma development in a mouse model of direct mesothelium exposure to MWCNTs. These results suggest that Tim4 recognizes MWCNTs through aromatic interactions and mediates phagocytosis leading to granulomas.


Assuntos
Granuloma/metabolismo , Macrófagos Peritoneais/metabolismo , Proteínas de Membrana/metabolismo , Nanotubos de Carbono , Fagocitose , Animais , Granuloma/genética , Humanos , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Células NIH 3T3 , Células THP-1
8.
Ann Rheum Dis ; 78(10): 1430-1437, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31289104

RESUMO

OBJECTIVE: The first ever genome-wide association study (GWAS) of clinically defined gout cases and asymptomatic hyperuricaemia (AHUA) controls was performed to identify novel gout loci that aggravate AHUA into gout. METHODS: We carried out a GWAS of 945 clinically defined gout cases and 1003 AHUA controls followed by 2 replication studies. In total, 2860 gout cases and 3149 AHUA controls (all Japanese men) were analysed. We also compared the ORs for each locus in the present GWAS (gout vs AHUA) with those in the previous GWAS (gout vs normouricaemia). RESULTS: This new approach enabled us to identify two novel gout loci (rs7927466 of CNTN5 and rs9952962 of MIR302F) and one suggestive locus (rs12980365 of ZNF724) at the genome-wide significance level (p<5.0×10-8). The present study also identified the loci of ABCG2, ALDH2 and SLC2A9. One of them, rs671 of ALDH2, was identified as a gout locus by GWAS for the first time. Comparing ORs for each locus in the present versus the previous GWAS revealed three 'gout vs AHUA GWAS'-specific loci (CNTN5, MIR302F and ZNF724) to be clearly associated with mechanisms of gout development which distinctly differ from the known gout risk loci that basically elevate serum uric acid level. CONCLUSIONS: This meta-analysis is the first to reveal the loci associated with crystal-induced inflammation, the last step in gout development that aggravates AHUA into gout. Our findings should help to elucidate the molecular mechanisms of gout development and assist the prevention of gout attacks in high-risk AHUA individuals.


Assuntos
Contactinas/genética , Gota/genética , Hiperuricemia/genética , MicroRNAs/genética , Dedos de Zinco/genética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Adulto , Aldeído-Desidrogenase Mitocondrial/genética , Doenças Assintomáticas , Loci Gênicos/genética , Estudo de Associação Genômica Ampla , Técnicas de Genotipagem , Proteínas Facilitadoras de Transporte de Glucose/genética , Gota/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Fatores de Risco , Ácido Úrico/sangue
9.
Cell Rep ; 27(2): 502-513.e5, 2019 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-30970253

RESUMO

Autophagy is a cell survival process essential for the regulation of immune responses to infections. However, the role of T cell autophagy in anti-tumor immunity is less clear. Here, we demonstrate a cell-autonomous role for autophagy in the regulation of CD8+ T-cell-mediated control of tumors. Mice deficient for the essential autophagy genes Atg5, Atg14, or Atg16L1 display a dramatic impairment in the growth of syngeneic tumors. Moreover, T cells lacking Atg5 have a profound shift to an effector memory phenotype and produce greater amounts of interferon-γ (IFN-γ) and tumor necrosis factor α (TNF-α). Mechanistically, Atg5-/- CD8+ T cells exhibit enhanced glucose metabolism that results in alterations in histone methylation, increases in H3K4me3 density, and transcriptional upregulation of both metabolic and effector target genes. Nonetheless, glucose restriction is sufficient to suppress Atg5-dependent increases in effector function. Thus, autophagy-dependent changes in CD8+ T cell metabolism directly regulate anti-tumor immunity.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Neoplasias/imunologia , Animais , Autofagia , Humanos , Camundongos
10.
Circ J ; 83(4): 718-726, 2019 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-30787218

RESUMO

BACKGROUND: Intracellular uric acid is known to increase the protein level and channel current of atrial Kv1.5; however, mechanisms of the uric acid-induced enhancement of Kv1.5 expression remain unclear. Methods and Results: The effects of uric acid on mRNA and protein levels of Kv1.5, as well as those of Akt, HSF1 and Hsp70, in HL-1 cardiomyocytes were studied by using qRT-PCR and Western blotting. The uptake of uric acid was measured using radio-labeled uric acid. The Kv1.5-mediated channel current was also measured by using patch clamp techniques. Uric acid up-taken by HL-1 cells significantly increased the level of Kv1.5 proteins in a concentration-dependent manner, with this increase abolished by an uric acid transporter inhibitor. Uric acid slowed degradation of Kv1.5 proteins without altering its mRNA level. Uric acid enhanced phosphorylation of Akt and HSF1, and thereby increased both transcription and translation of Hsp70; these effects were abolished by a PI3K inhibitor. Hsp70 knockdown abolished the uric acid-induced increases of Kv1.5 proteins and channel currents. CONCLUSIONS: Intracellular uric acid could stabilize Kv1.5 proteins through phosphorylation of Akt and HSF1 leading to enhanced expression of Hsp70.


Assuntos
Proteínas de Choque Térmico HSP70/metabolismo , Fatores de Transcrição de Choque Térmico/metabolismo , Canal de Potássio Kv1.5/metabolismo , Miócitos Cardíacos/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ácido Úrico/farmacologia , Animais , Linhagem Celular , Canal de Potássio Kv1.5/efeitos dos fármacos , Camundongos , Fosforilação/efeitos dos fármacos , Biossíntese de Proteínas , Transcrição Gênica
11.
Commun Biol ; 2: 37, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30701202

RESUMO

Beclin 1 is a key regulator of autophagy and endocytosis. However, its autophagy-independent functions remain poorly understood. Here, we report that Beclin 1 regulates recycling endosome and is required for skin development in vivo. We first established keratinocyte-specific Beclin 1-knockout mice and found that these mutant mice died owing to severe impairment of epidermal barrier. Beclin 1 plays a role in autophagy and the endocytic pathway in cooperation with Atg14 and UVRAG, respectively, and keratinocyte-specific Atg14-knockout mice do not show any abnormal phenotypes, suggesting that Beclin 1 has a role in skin development via the endocytic pathway. Furthermore, we found that Beclin 1 deficiency causes mislocalization of integrins via a defect of recycling endosome, abnormal cell detachment of basal cells and their immature differentiation, and abnormal skin development. These results provide the first genetic evidence showing the roles of Beclin 1 in recycling endosome and skin development.


Assuntos
Proteína Beclina-1/genética , Endossomos/metabolismo , Organogênese/genética , Pele/embriologia , Pele/metabolismo , Animais , Autofagia/genética , Proteína Beclina-1/metabolismo , Diferenciação Celular , Células Cultivadas , Endocitose/genética , Epiderme/embriologia , Epiderme/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Queratinócitos/citologia , Queratinócitos/metabolismo , Camundongos , Camundongos Knockout , Fenótipo
12.
Immunol Rev ; 281(1): 62-73, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29248000

RESUMO

Inflammasomes are multiprotein complexes that control the maturation and production of interleukin-1 family members and play crucial roles in host defense against pathogens. However, dysregulated activation of inflammasomes is associated with intense inflammation, leading to the development of inflammatory diseases. Therefore, inflammasomes must be activated at a proper strength to protect against infection and avoid tissue damage. Recent studies have highlighted the cross-talk between inflammasome activation and autophagy, the cellular machinery associated with the degradation of intracellular components and maintenance of cellular homeostasis. Notably, deficiencies in autophagy-related proteins induce the aberrant activation of inflammasomes, causing severe tissue damage. In contrast, autophagy inducers ameliorate symptoms of inflammasome-related diseases. In this review, we discuss recent advances in the involvement of autophagy in regulating inflammasomes activation and in the development of inflammatory diseases.


Assuntos
Infecções Bacterianas/imunologia , Doença de Crohn/imunologia , Inflamassomos/metabolismo , Inflamação/imunologia , Interleucina-1/metabolismo , Animais , Autofagia/genética , Proteínas Relacionadas à Autofagia/genética , Homeostase , Humanos , Imunidade , Proteínas de Ligação a RNA/metabolismo
13.
Autophagy ; 14(5): 764-777, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-28513333

RESUMO

Conditional knockout mice for Atg9a, specifically in brain tissue, were generated to understand the roles of ATG9A in the neural tissue cells. The mice were born normally, but half of them died within one wk, and none lived beyond 4 wk of age. SQSTM1/p62 and NBR1, receptor proteins for selective autophagy, together with ubiquitin, accumulated in Atg9a-deficient neurosoma at postnatal d 15 (P15), indicating an inhibition of autophagy, whereas these proteins were significantly decreased at P28, as evidenced by immunohistochemistry, electron microscopy and western blot. Conversely, degenerative changes such as spongiosis of nerve fiber tracts proceeded in axons and their terminals that were occupied with aberrant membrane structures and amorphous materials at P28, although no clear-cut degenerative change was detected in neuronal cell bodies. Different from autophagy, diffusion tensor magnetic resonance imaging and histological observations revealed Atg9a-deficiency-induced dysgenesis of the corpus callosum and anterior commissure. As for the neurite extensions of primary cultured neurons, the neurite outgrowth after 3 d culturing was significantly impaired in primary neurons from atg9a-KO mouse brains, but not in those from atg7-KO and atg16l1-KO brains. Moreover, this tendency was also confirmed in Atg9a-knockdown neurons under an atg7-KO background, indicating the role of ATG9A in the regulation of neurite outgrowth that is independent of autophagy. These results suggest that Atg9a deficiency causes progressive degeneration in the axons and their terminals, but not in neuronal cell bodies, where the degradations of SQSTM1/p62 and NBR1 were insufficiently suppressed. Moreover, the deletion of Atg9a impaired nerve fiber tract formation.


Assuntos
Proteínas Relacionadas à Autofagia/deficiência , Axônios/metabolismo , Proteínas de Membrana/deficiência , Rede Nervosa/metabolismo , Proteínas de Transporte Vesicular/deficiência , Animais , Proteínas Relacionadas à Autofagia/metabolismo , Axônios/ultraestrutura , Células Cultivadas , Corpo Caloso/metabolismo , Corpo Caloso/patologia , Integrases/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas de Membrana/metabolismo , Camundongos Knockout , Neuritos/metabolismo , Neuritos/ultraestrutura , Fenótipo , Proteínas/metabolismo , Células de Purkinje/metabolismo , Células de Purkinje/ultraestrutura , Proteína Sequestossoma-1/metabolismo , Proteínas de Transporte Vesicular/metabolismo
14.
Cell Rep ; 20(12): 2944-2954, 2017 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-28930687

RESUMO

Cyclic GMP-AMP synthase (cGAS) is a cytosolic DNA sensor that induces the IFN antiviral response. However, the regulatory mechanisms that mediate cGAS-triggered signaling have not been fully explored. Here, we show the involvement of a small GTPase, RAB2B, and its effector protein, Golgi-associated RAB2B interactor-like 5 (GARIL5), in the cGAS-mediated IFN response. RAB2B-deficiency affects the IFN response induced by cytosolic DNA. Consistent with this, RAB2B deficiency enhances replication of vaccinia virus, a DNA virus. After DNA stimulation, RAB2B colocalizes with stimulator of interferon genes (STING), the downstream signal mediator of cGAS, on the Golgi apparatus. The GTP-binding activity of RAB2B is required for its localization on the Golgi apparatus and for recruitment of GARIL5. GARIL5 deficiency also affects the IFN response induced by cytosolic DNA and enhances replication of vaccinia virus. These findings indicate that the RAB2B-GARIL5 complex promotes IFN responses against DNA viruses by regulating the cGAS-STING signaling axis.


Assuntos
Citosol/metabolismo , DNA/metabolismo , Imunidade Inata , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Proteína rab2 de Ligação ao GTP/metabolismo , Animais , Antivirais/farmacologia , Embrião de Mamíferos/citologia , Fibroblastos/metabolismo , Guanosina Trifosfato/metabolismo , Células HEK293 , Humanos , Imunidade Inata/efeitos dos fármacos , Fator Regulador 3 de Interferon/metabolismo , Proteínas de Membrana/metabolismo , Camundongos , Nucleotidiltransferases/metabolismo , Fosforilação/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Vaccinia virus/efeitos dos fármacos , Vaccinia virus/fisiologia
15.
Adv Exp Med Biol ; 997: 187-197, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28815531

RESUMO

Mitochondria and the endoplasmic reticulum (ER) are fundamental organelles that coordinate high-order cell functions. Mitochondria are centers of energy production, whereas the ER is responsible for folding, transport, and degradation of proteins. In addition to their specific functions, mitochondria and ER actively communicate with each other to promote a variety of cellular events, such as material transfer and signal transduction. Recent studies have shown the critical involvement of these organelles in regulation of the innate immune system, which functions in host defense. The innate immune system utilizes a wide range of germ-line-encoded pattern recognition receptors (PRRs) to recognize pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) and induces inflammatory and antiviral responses. Contact sites between mitochondria and the ER function in assembly of the NLR family pyrin domain containing 3 (NLRP3)-inflammasome to promote the inflammatory response. The NLRP3-inflammasome is a protein complex composed of the receptor NLRP3 on the ER side and the adaptor apoptosis-associated speck-like protein containing a CARD on the mitochondrial side; it induces caspase-1-dependent maturation of proinflammatory cytokines such as interleukin (IL)-1ß and IL-18. Furthermore, ER-mitochondria contact sites function in initiation and mediation of signal transduction pathways downstream of intracellular PRRs, such as retinoic acid-inducible gene I-like receptor and cyclic GMP-AMP synthase, to promote the antiviral response. Therefore, ER-mitochondria contact sites, also known as mitochondria-associated membranes, play key roles in regulation of innate immune responses.


Assuntos
Retículo Endoplasmático/imunologia , Imunidade Inata , Inflamação/imunologia , Microdomínios da Membrana/imunologia , Mitocôndrias/imunologia , Membranas Mitocondriais/imunologia , Transdução de Sinais , Animais , Retículo Endoplasmático/metabolismo , Humanos , Inflamassomos/imunologia , Inflamassomos/metabolismo , Inflamação/metabolismo , Mediadores da Inflamação/imunologia , Mediadores da Inflamação/metabolismo , Microdomínios da Membrana/metabolismo , Mitocôndrias/metabolismo , Membranas Mitocondriais/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Receptores Imunológicos/imunologia , Receptores Imunológicos/metabolismo
16.
Nat Immunol ; 18(8): 899-910, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28604719

RESUMO

Mammalian autophagy-related 8 (Atg8) homologs consist of LC3 proteins and GABARAPs, all of which are known to be involved in canonical autophagy. In contrast, the roles of Atg8 homologs in noncanonical autophagic processes are not fully understood. Here we show a unique role of GABARAPs, in particular gamma-aminobutyric acid (GABA)-A-receptor-associated protein-like 2 (Gabarapl2; also known as Gate-16), in interferon-γ (IFN-γ)-mediated antimicrobial responses. Cells that lacked GABARAPs but not LC3 proteins and mice that lacked Gate-16 alone were defective in the IFN-γ-induced clearance of vacuolar pathogens such as Toxoplasma. Gate-16 but not LC3b specifically associated with the small GTPase ADP-ribosylation factor 1 (Arf1) to mediate uniform distribution of interferon-inducible GTPases. The lack of GABARAPs reduced Arf1 activation, which led to formation of interferon-inducible GTPase-containing aggregates and hampered recruitment of interferon-inducible GTPases to vacuolar pathogens. Thus, GABARAPs are uniquely required for antimicrobial host defense through cytosolic distribution of interferon-inducible GTPases.


Assuntos
Fator 1 de Ribosilação do ADP/imunologia , Autofagia/imunologia , Proteínas de Transporte/imunologia , Interferon gama/imunologia , Proteínas Associadas aos Microtúbulos/imunologia , Toxoplasma/imunologia , Toxoplasmose/imunologia , Fator 1 de Ribosilação do ADP/metabolismo , Animais , Proteínas Reguladoras de Apoptose , Família da Proteína 8 Relacionada à Autofagia , Sistemas CRISPR-Cas , Proteínas de Transporte/metabolismo , Simulação por Computador , Proteínas do Citoesqueleto/imunologia , Proteínas do Citoesqueleto/metabolismo , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Imunofluorescência , GTP Fosfo-Hidrolases/imunologia , GTP Fosfo-Hidrolases/metabolismo , Edição de Genes , Immunoblotting , Imunoprecipitação , Interferon gama/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas de Membrana/imunologia , Proteínas de Membrana/metabolismo , Camundongos , Proteínas Associadas aos Microtúbulos/metabolismo
17.
Proc Natl Acad Sci U S A ; 114(10): 2681-2686, 2017 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-28213497

RESUMO

The innate immune system senses RNA viruses by pattern recognition receptors (PRRs) and protects the host from virus infection. PRRs mediate the production of immune modulatory factors and direct the elimination of RNA viruses. Here, we show a unique PRR that mediates antiviral response. Tetrachlorodibenzo-p-dioxin (TCDD)-inducible poly(ADP ribose) polymerase (TIPARP), a Cysteine3 Histidine (CCCH)-type zinc finger-containing protein, binds to Sindbis virus (SINV) RNA via its zinc finger domain and recruits an exosome to induce viral RNA degradation. TIPARP typically localizes in the nucleus, but it accumulates in the cytoplasm after SINV infection, allowing targeting of cytoplasmic SINV RNA. Redistribution of TIPARP is induced by reactive oxygen species (ROS)-dependent oxidization of the nuclear pore that affects cytoplasmic-nuclear transport. BCL2-associated X protein (BAX) and BCL2 antagonist/killer 1 (BAK1), B-cell leukemia/lymphoma 2 (BCL2) family members, mediate mitochondrial damage to generate ROS after SINV infection. Thus, TIPARP is a viral RNA-sensing PRR that mediates antiviral responses triggered by BAX- and BAK1-dependent mitochondrial damage.


Assuntos
Imunidade Inata/genética , Poli(ADP-Ribose) Polimerases/genética , Vírus de RNA/genética , Receptores de Reconhecimento de Padrão/genética , Transporte Ativo do Núcleo Celular/genética , Transporte Ativo do Núcleo Celular/imunologia , Citoplasma/genética , Citoplasma/imunologia , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Mitocôndrias/genética , Mitocôndrias/patologia , Mitocôndrias/virologia , Proteínas de Transporte de Nucleosídeos , Poli(ADP-Ribose) Polimerases/imunologia , Vírus de RNA/imunologia , Espécies Reativas de Oxigênio/metabolismo , Receptores de Reconhecimento de Padrão/imunologia , Sindbis virus/genética , Sindbis virus/imunologia , Sindbis virus/patogenicidade , Proteína Killer-Antagonista Homóloga a bcl-2/genética , Proteína Killer-Antagonista Homóloga a bcl-2/imunologia , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/imunologia
18.
Nat Commun ; 7: 13391, 2016 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-27811852

RESUMO

Programmed cell death has a crucial role in various biological events, including developmental morphogenesis. Recent evidence indicates that necrosis contributes to programmed cell death in addition to apoptosis, but it is unclear whether necrosis acts as a compensatory mechanism for failure of apoptosis or has an intrinsic role during development. In contrast to apoptosis, there have been no techniques for imaging physiological necrosis in vivo. Here we employ vital staining using propidium iodide to identify cells with plasma membrane disruption (necrotic cells) in mouse embryos. We discover a form of necrosis at the bone surface, which does not occur in embryos with deficiency of the autophagy-related gene Atg9a, although it is unaffected by Atg5 knockout. We also find abnormalities of the bone surface in Atg9a knockout mice, suggesting an important role of Atg9a-dependent necrosis in bone surface formation. These findings suggest that necrosis has an active role in developmental morphogenesis.


Assuntos
Autofagia/fisiologia , Osso e Ossos/patologia , Necrose/patologia , Propídio/química , Coloração e Rotulagem/métodos , Animais , Proteína 5 Relacionada à Autofagia/genética , Proteína 5 Relacionada à Autofagia/metabolismo , Proteínas Relacionadas à Autofagia/genética , Proteínas Relacionadas à Autofagia/metabolismo , Osso e Ossos/citologia , Membrana Celular/patologia , Feminino , Indicadores e Reagentes/química , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Modelos Animais , Osteogênese/fisiologia , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo
19.
J Biol Chem ; 291(46): 23854-23868, 2016 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-27681594

RESUMO

Netrin 1 was initially identified as an axon guidance factor, and recent studies indicate that it inhibits chemokine-directed monocyte migration. Despite its importance as a neuroimmune guidance cue, the role of netrin 1 in osteoclasts is largely unknown. Here we detected high netrin 1 levels in the synovial fluid of rheumatoid arthritis patients. Netrin 1 is potently expressed in osteoblasts and synovial fibroblasts, and IL-17 robustly enhances netrin 1 expression in these cells. The binding of netrin 1 to its receptor UNC5b on osteoclasts resulted in activation of SHP1, which inhibited VAV3 phosphorylation and RAC1 activation. This significantly impaired the actin polymerization and fusion, but not the differentiation of osteoclast. Strikingly, netrin 1 treatment prevented bone erosion in an autoimmune arthritis model and age-related bone destruction. Therefore, the netrin 1-UNC5b axis is a novel therapeutic target for bone-destructive diseases.


Assuntos
Artrite Reumatoide/tratamento farmacológico , Reabsorção Óssea/prevenção & controle , Fatores de Crescimento Neural/farmacologia , Osteoclastos/metabolismo , Membrana Sinovial/metabolismo , Proteínas Supressoras de Tumor/farmacologia , Animais , Artrite Reumatoide/genética , Artrite Reumatoide/metabolismo , Artrite Reumatoide/patologia , Reabsorção Óssea/genética , Reabsorção Óssea/metabolismo , Reabsorção Óssea/patologia , Modelos Animais de Doenças , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos ICR , Camundongos Mutantes , Fatores de Crescimento Neural/biossíntese , Fatores de Crescimento Neural/genética , Receptores de Netrina , Netrina-1 , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Osteoclastos/patologia , Proteína Tirosina Fosfatase não Receptora Tipo 6/genética , Proteína Tirosina Fosfatase não Receptora Tipo 6/metabolismo , Proteínas Proto-Oncogênicas c-vav/genética , Proteínas Proto-Oncogênicas c-vav/metabolismo , Receptores de Superfície Celular/biossíntese , Receptores de Superfície Celular/genética , Membrana Sinovial/patologia , Proteínas Supressoras de Tumor/biossíntese , Proteínas Supressoras de Tumor/genética , Proteínas rac1 de Ligação ao GTP/genética , Proteínas rac1 de Ligação ao GTP/metabolismo
20.
Autophagy ; 12(10): 1876-1885, 2016 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-27463423

RESUMO

Autophagy is critical for maintaining cellular homeostasis. Organs such as the eye and brain are immunologically privileged. Here, we demonstrate that autophagy is essential for maintaining ocular immune privilege. Deletion of multiple autophagy genes in macrophages leads to an inflammation-mediated eye disease called uveitis that can cause blindness. Loss of autophagy activates inflammasome-mediated IL1B secretion that increases disease severity. Inhibition of caspase activity by gene deletion or pharmacological means completely reverses the disease phenotype. Of interest, experimental uveitis was also increased in a model of Crohn disease, a systemic autoimmune disease in which patients often develop uveitis, offering a potential mechanistic link between macrophage autophagy and systemic disease. These findings directly implicate the homeostatic process of autophagy in blinding eye disease and identify novel pathways for therapeutic intervention in uveitis.


Assuntos
Autofagia , Oftalmopatias/patologia , Inflamação/patologia , Macrófagos/patologia , Animais , Autofagia/genética , Proteína 5 Relacionada à Autofagia/metabolismo , Proteínas Relacionadas à Autofagia/genética , Citocinas/genética , Citocinas/metabolismo , Deleção de Genes , Regulação da Expressão Gênica , Humanos , Inflamassomos/metabolismo , Inflamação/genética , Interleucina-1beta/metabolismo , Macrófagos/ultraestrutura , Camundongos Knockout , Polimorfismo de Nucleotídeo Único/genética , Uveíte/complicações , Uveíte/genética , Uveíte/patologia
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