RESUMO
Dendritic cells (DCs) play a critical role in the immune response to viral infection through the facilitation of cell-intrinsic antiviral activity and the activation of adaptive immunity. HIV-1 infection of DCs triggers an IRF3-dependent innate immune response, which requires the activity of cyclic GAMP synthase (cGAS). We report the results of a targeted RNAi screen utilizing primary human monocyte-derived DCs (MDDCs) to identify immune regulators that directly interface with HIV-1-encoded features to initiate this innate response. Polyglutamine binding protein 1 (PQBP1) emerged as a strong candidate through this analysis. We found that PQBP1 directly binds to reverse-transcribed HIV-1 DNA and interacts with cGAS to initiate an IRF3-dependent innate response. MDDCs derived from Renpenning syndrome patients, who harbor mutations in the PQBP1 locus, possess a severely attenuated innate immune response to HIV-1 challenge, underscoring the role of PQBP1 as a proximal innate sensor of a HIV-1 infection.
Assuntos
Proteínas de Transporte/metabolismo , HIV-1/imunologia , Imunidade Inata , Proteínas Nucleares/metabolismo , Nucleotidiltransferases/metabolismo , Sequência de Bases , Linhagem Celular , Paralisia Cerebral/imunologia , DNA Viral/genética , Proteínas de Ligação a DNA , HIV-1/fisiologia , Humanos , Deficiência Intelectual Ligada ao Cromossomo X/imunologia , Dados de Sequência MolecularRESUMO
Several members of the NLR family of sensors activate innate immunity. In contrast, we found here that NLRC3 inhibited Toll-like receptor (TLR)-dependent activation of the transcription factor NF-κB by interacting with the TLR signaling adaptor TRAF6 to attenuate Lys63 (K63)-linked ubiquitination of TRAF6 and activation of NF-κB. We used bioinformatics to predict interactions between NLR and TRAF proteins, including interactions of TRAF with NLRC3. In vivo, macrophage expression of Nlrc3 mRNA was diminished by the administration of lipopolysaccharide (LPS) but was restored when cellular activation subsided. To assess biologic relevance, we generated Nlrc3(-/-) mice. LPS-treated Nlrc3(-/-) macrophages had more K63-ubiquitinated TRAF6, nuclear NF-κB and proinflammatory cytokines. Finally, LPS-treated Nlrc3(-/-) mice had more signs of inflammation. Thus, signaling via NLRC3 and TLR constitutes a negative feedback loop. Furthermore, prevalent NLR-TRAF interactions suggest the formation of a 'TRAFasome' complex.
Assuntos
NF-kappa B/imunologia , Receptores Acoplados a Proteínas G/imunologia , Transdução de Sinais/imunologia , Fator 6 Associado a Receptor de TNF/imunologia , Receptores Toll-Like/imunologia , Sequência de Aminoácidos , Animais , Retroalimentação Fisiológica , Células HEK293 , Humanos , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Dados de Sequência Molecular , NF-kappa B/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptores Acoplados a Proteínas G/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator 6 Associado a Receptor de TNF/metabolismo , Receptores Toll-Like/metabolismoRESUMO
Stimulator of interferon genes (STING, also named MITA, MYPS, or ERIS) is an intracellular DNA sensor that induces type I interferon through its interaction with TANK-binding kinase 1 (TBK1). Here we found that the nucleotide-binding, leucine-rich-repeat-containing protein, NLRC3, reduced STING-dependent innate immune activation in response to cytosolic DNA, cyclic di-GMP (c-di-GMP), and DNA viruses. NLRC3 associated with both STING and TBK1 and impeded STING-TBK1 interaction and downstream type I interferon production. By using purified recombinant proteins, we found NLRC3 to interact directly with STING. Furthermore, NLRC3 prevented proper trafficking of STING to perinuclear and punctated region, known to be important for its activation. In animals, herpes simplex virus 1 (HSV-1)-infected Nlrc3(-/-) mice exhibited enhanced innate immunity and reduced morbidity and viral load. This demonstrates the intersection of two key pathways of innate immune regulation, NLR and STING, to fine tune host response to intracellular DNA, DNA virus, and c-di-GMP.
Assuntos
DNA/imunologia , Imunidade Inata , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteínas de Membrana/metabolismo , Transdução de Sinais , Animais , Linhagem Celular , GMP Cíclico/análogos & derivados , GMP Cíclico/farmacologia , Citocinas/biossíntese , Herpes Simples/imunologia , Herpes Simples/metabolismo , Herpesvirus Humano 1/fisiologia , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/deficiência , Interferon Tipo I/biossíntese , Camundongos , Camundongos Knockout , Ligação Proteica , Proteínas Serina-Treonina Quinases/metabolismo , Transporte ProteicoRESUMO
BACKGROUND: Both diagnosis and treatment of hemoglobinopathies have been associated with an increased risk of fertility impairment. German guidelines recommend annual monitoring of fertility parameters to enable early detection of fertility impairment and/or to offer fertility preservation (FP) when indicated. We explored the general desire for parenthood, the frequency of recalling fertility counseling and testing, and the utilization of FP in adolescents and adults with hemoglobinopathies. PROCEDURE: In a cross-sectional study, patients aged 12-50 years, treated in Germany, Austria, or Switzerland, were surveyed on fertility-related aspects. Medical data, including fertility testing results, were collected from patient records. RESULTS: Overall, 116/121 eligible patients, diagnosed with sickle cell disease (70.7%), thalassemia (27.6%), or other hemoglobinopathy (1.7%), participated in our study (57.8% female, median age 17.0 years, range 12-50 years). All participants required treatment of the underlying hemoglobinopathy: 68.1% received hydroxyurea, 25.9% required regular blood transfusions, and 6.0% underwent hematopoietic stem cell transplantation (HSCT). Most patients (82/108, 75.9%) stated a considerable to strong desire for (future) parenthood, independent of sex, education, diagnosis, or subjective health status. Fertility counseling was only recalled by 32/111 patients (28.8%) and least frequently by younger patients (12-16 years) or those treated with regular blood transfusions or hydroxyurea. While fertility testing was documented for 59.5% (69/116) in medical records, only 11.6% (13/112) recalled previous assessments. FP was only used by 5.4% (6/111) of patients. CONCLUSION: Most patients with hemoglobinopathies wish to have biological children, yet only few recalled fertility counseling and testing. Adequate patient counseling should be offered to all patients at risk for infertility.
Assuntos
Anemia Falciforme , Preservação da Fertilidade , Hemoglobinopatias , Infertilidade , Criança , Humanos , Adulto , Feminino , Adolescente , Adulto Jovem , Pessoa de Meia-Idade , Masculino , Hidroxiureia , Estudos Transversais , Preservação da Fertilidade/métodos , AconselhamentoRESUMO
In vitro data suggest that a subgroup of NLR proteins, including NLRP12, inhibits the transcription factor NF-κB, although physiologic and disease-relevant evidence is largely missing. Dysregulated NF-κB activity is associated with colonic inflammation and cancer, and we found Nlrp12(-/-) mice were highly susceptible to colitis and colitis-associated colon cancer. Polyps isolated from Nlrp12(-/-) mice showed elevated noncanonical NF-κB activation and increased expression of target genes that were associated with cancer, including Cxcl13 and Cxcl12. NLRP12 negatively regulated ERK and AKT signaling pathways in affected tumor tissues. Both hematopoietic- and nonhematopoietic-derived NLRP12 contributed to inflammation, but the latter dominantly contributed to tumorigenesis. The noncanonical NF-κB pathway was regulated upon degradation of TRAF3 and activation of NIK. NLRP12 interacted with both NIK and TRAF3, and Nlrp12(-/-) cells have constitutively elevated NIK, p100 processing to p52 and reduced TRAF3. Thus, NLRP12 is a checkpoint of noncanonical NF-κB, inflammation, and tumorigenesis.
Assuntos
Transformação Celular Neoplásica/patologia , Colite/metabolismo , Colite/patologia , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , NF-kappa B/metabolismo , Animais , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Quimiocina CXCL12/genética , Quimiocina CXCL12/metabolismo , Quimiocina CXCL13/genética , Quimiocina CXCL13/metabolismo , Colite/genética , Neoplasias do Colo/genética , Progressão da Doença , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Fator 3 Associado a Receptor de TNF/genética , Fator 3 Associado a Receptor de TNF/metabolismo , Quinase Induzida por NF-kappaBRESUMO
The nucleotide-binding domain and leucine-rich-repeat-containing (NLR) proteins regulate innate immunity. Although the positive regulatory impact of NLRs is clear, their inhibitory roles are not well defined. We showed that Nlrx1(-/-) mice exhibited increased expression of antiviral signaling molecules IFN-ß, STAT2, OAS1, and IL-6 after influenza virus infection. Consistent with increased inflammation, Nlrx1(-/-) mice exhibited marked morbidity and histopathology. Infection of these mice with an influenza strain that carries a mutated NS-1 protein, which normally prevents IFN induction by interaction with RNA and the intracellular RNA sensor RIG-I, further exacerbated IL-6 and type I IFN signaling. NLRX1 also weakened cytokine responses to the 2009 H1N1 pandemic influenza virus in human cells. Mechanistically, Nlrx1 deletion led to constitutive interaction of MAVS and RIG-I. Additionally, an inhibitory function is identified for NLRX1 during LPS activation of macrophages where the MAVS-RIG-I pathway was not involved. NLRX1 interacts with TRAF6 and inhibits NF-κB activation. Thus, NLRX1 functions as a checkpoint of overzealous inflammation.
Assuntos
Vírus da Influenza A Subtipo H1N1/imunologia , Proteínas Mitocondriais/imunologia , Infecções por Orthomyxoviridae/imunologia , Transdução de Sinais , Proteínas Adaptadoras de Transdução de Sinal/imunologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Células Cultivadas , Interferon beta/biossíntese , Interferon beta/imunologia , Interleucina-6/biossíntese , Interleucina-6/imunologia , Macrófagos/imunologia , Proteínas de Membrana/imunologia , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , Proteínas Mitocondriais/deficiência , NF-kappa B/imunologia , NF-kappa B/metabolismo , Proteínas do Tecido Nervoso/imunologia , Proteínas do Tecido Nervoso/metabolismo , Receptores de Superfície Celular , Fator 6 Associado a Receptor de TNF/imunologia , Fator 6 Associado a Receptor de TNF/metabolismoRESUMO
Recently renewed interest in the therapeutic properties of honey has led to the search for new antimicrobial honeys. This study was undertaken to assess the antimicrobial activity and composition of a locally produced Portobello honey (PBH) on three bacteria known to infect wounds. Manuka honey (MH) was used for comparative purposes. Broth culture and agar disc diffusion assays were used to investigate the antimicrobial properties of honey. The honeys were tested at four concentrations: 75%, 50%, 10% and 1% (v/v) and compared with an untreated control. The composition of honey was determined by measuring: polyphenol content by Folin Ciocalteau method, antioxidant capacity by ferric ion reducing power assay, hydrogen peroxide (H2 O2 ) by catalase test, pH and sugar content by pH strips and refractometer, respectively. Both honeys at 75% and 50% inhibited the majority of the three bacteria tested. 10% PBH exhibited antimicrobial activity to the lesser extent than 10% MH. The difference was very significant (p ≤ 0.001). Both honeys were acidic with pH 4, and both produced H2 O2 . The sugar content of PBH was higher than MH, but the difference was not significant. The MH had significantly higher levels of the polyphenols and antioxidant activity than PBH.
Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Mel , Antibacterianos/química , Antioxidantes/química , Carboidratos/química , Peróxido de Hidrogênio/análise , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Polifenóis/químicaRESUMO
The interplay between innate and adaptive immunity is important in multiple sclerosis (MS). The inflammasome complex, which activates caspase-1 to process pro-IL-1beta and pro-IL-18, is rapidly emerging as a pivotal regulator of innate immunity, with nucleotide-binding domain, leucine-rich repeat containing protein family, pyrin domain containing 3 (NLRP3) (cryopyrin or NALP3) as a prominent player. Although the role of NLRP3 in host response to pathogen associated molecular patterns and danger associated molecular patterns is well documented, its role in autoimmune diseases is less well studied. To investigate the role of NLRP3 protein in MS, we used a mouse model of MS, experimental autoimmune encephalomyelitis (EAE). Nlrp3 expression was elevated in the spinal cords during EAE, and Nlrp3(-/-) mice had a dramatically delayed course and reduced severity of disease. This was accompanied by a significant reduction of the inflammatory infiltrate including macrophages, dendritic cells, CD4, and CD8(+) T cells in the spinal cords of the Nlrp3(-/-) mice, whereas microglial accumulation remained the same. Nlrp3(-/-) mice also displayed improved histology in the spinal cords with reduced destruction of myelin and astrogliosis. Nlrp3(-/-) mice with EAE produced less IL-18, and the disease course was similar to Il18(-/-) mice. Furthermore, Nlrp3(-/-) and Il18(-/-) mice had similarly reduced IFN-gamma and IL-17 production. Thus, NLRP3 plays a critical role in the induction of the EAE, likely through effects on capase-1-dependent cytokines which then influence Th1 and Th17.
Assuntos
Proteínas de Transporte/fisiologia , Encefalomielite Autoimune Experimental/imunologia , Esclerose Múltipla/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Células Th1/imunologia , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Caspase 1/genética , Caspase 1/metabolismo , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/patologia , Encefalomielite Autoimune Experimental/fisiopatologia , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Gliose/imunologia , Gliose/metabolismo , Gliose/patologia , Humanos , Immunoblotting , Interferon gama/metabolismo , Interleucina-17/metabolismo , Interleucina-18/genética , Interleucina-18/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Esclerose Múltipla/patologia , Esclerose Múltipla/fisiopatologia , Bainha de Mielina/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR , Índice de Gravidade de Doença , Medula Espinal/imunologia , Medula Espinal/metabolismo , Medula Espinal/patologia , Linfócitos T Auxiliares-Indutores/metabolismo , Células Th1/metabolismoRESUMO
Nucleotide-binding domain leucine-rich repeat (NLR) proteins are regulators of inflammation and immunity. Although first described 8 y ago, a physiologic role for NLRP12 has remained elusive until now. We find that murine Nlrp12, an NLR linked to atopic dermatitis and hereditary periodic fever in humans, is prominently expressed in dendritic cells (DCs) and neutrophils. Nlrp12-deficient mice exhibit attenuated inflammatory responses in two models of contact hypersensitivity that exhibit features of allergic dermatitis. This cannot be attributed to defective Ag processing/presentation, inflammasome activation, or measurable changes in other inflammatory cytokines. Rather, Nlrp12(-/-) DCs display a significantly reduced capacity to migrate to draining lymph nodes. Both DCs and neutrophils fail to respond to chemokines in vitro. These findings indicate that NLRP12 is important in maintaining neutrophils and peripheral DCs in a migration-competent state.
Assuntos
Quimiotaxia de Leucócito/imunologia , Células Dendríticas/imunologia , Dermatite de Contato/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Células Mieloides/imunologia , Animais , Células Dendríticas/metabolismo , Dermatite de Contato/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células Mieloides/metabolismo , Reação em Cadeia da PolimeraseRESUMO
Maintaining soil quality for agricultural production is a critical challenge, especially in the tropics. Due to the focus on environmental performance and the provision of soil ecosystem services, organic farming and agroforestry systems are proposed as alternative options to conventional monoculture farming. Soil processes underlying ecosystem services are strongly mediated by microbes; thus, increased understanding of the soil microbiome is crucial for the development of sustainable agricultural practices. Therefore, we measured and related soil quality indicators to bacterial and fungal community structures in five cocoa production systems, managed either organically or conventionally for 12 years, with varying crop diversity, from monoculture to agroforestry. In addition, a successional agroforestry system was included, which uses exclusively on-site pruning residues as soil inputs. Organic management increased soil organic carbon, nitrogen and labile carbon contents compared to conventional. Soil basal respiration and nitrogen mineralisation rates were highest in the successional agroforestry system. Across the field sites, fungal richness exceeded bacterial richness and fungal community composition was distinct between organic and conventional management, as well as between agroforestry and monoculture. Bacterial community composition differed mainly between organic and conventional management. Indicator species associated with organic management were taxonomically more diverse compared to taxa associated with conventionally managed systems. In conclusion, our results highlight the importance of organic management for maintaining soil quality in agroforestry systems for cocoa production.
Assuntos
Cacau , Microbiota , Agricultura/métodos , Bactérias , Carbono , Nitrogênio/análise , Solo/química , Microbiologia do SoloRESUMO
The number of people in the United States living with Alzheimer disease (AD) is growing, resulting in significant clinical and economic impact. Substantial research investment has led to drug development in stages of AD before symptomatic dementia, such as preclinical AD. Although there are no treatments approved for preclinical AD, there are currently 6 phase 3 clinical trials for preclinical AD treatments. In this article, we review these clinical trials and highlight considerations for future coverage decisions. In line with the definition of preclinical AD, enrollment in these trials focuses on cognitively unimpaired patients that are at high risk of AD because of family history and then genetic testing or brain imaging. Enrollment in most of these trials also allows for younger patients, including those aged under 65 years. Primary clinical trial endpoints focus on cognition often 4 or more years after treatment. Secondary endpoints include other measures of cognition and function, as well as biomarkers. Review of these trials brings to light a few potential considerations when covering these new medications in the future. First, novel and potentially costly approaches involving genetic testing and/or positron emission tomography imaging may be needed to identify appropriate patients and should be developed efficiently. Second, the long duration of these clinical trials suggest that there may be a need for alternative payment approaches in the United States that encourage early payers to pay for a medication for which the long-term benefits may not be realized until after the beneficiary is no longer with the health plan. Third, the value of AD treatments may differ across populations, creating a potential role for indication-based or population-based contracting. Finally, considering the potentially high budgetary impact and little real-world evidence for a new drug class, payers and manufacturers may want to consider outcomes-based payment approaches and coverage with evidence development to mitigate uncertainty about the value of the treatment demonstrated in well-defined populations in clinical trials versus more heterogeneous real-world settings. DISCLOSURES: This work was funded through a generous gift from the Global CEO Initiative on Alzheimer Disease. Hung reports grants from Agency for Healthcare Research and Quality and Pharmaceutical Research and Manufacturers of America outside the submitted work and past employment at CVS Health and BlueCross BlueShield Association. McClellan is an independent board member on the boards of Johnson & Johnson, Cigna, Alignment Healthcare, and Seer; co-chairs the Accountable Care Learning Collaborative and the Guiding Committee for the Health Care Payment Learning and Action Network; and receives fees for serving as an advisor for Cota and MITRE. Hamilton Lopez and Schneider have nothing to disclose. Part of this work was presented at the 2019 AMCP Nexus Meeting, October 29-November 1, 2019, in National Harbor, MD.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Ensaios Clínicos Fase III como Assunto/métodos , Custos de Medicamentos , Desenvolvimento de Medicamentos/métodos , Doença de Alzheimer/economia , Doença de Alzheimer/epidemiologia , Ensaios Clínicos Fase III como Assunto/economia , Desenvolvimento de Medicamentos/economia , Avaliação Pré-Clínica de Medicamentos/economia , Avaliação Pré-Clínica de Medicamentos/métodos , Determinação de Ponto Final/economia , Determinação de Ponto Final/métodos , HumanosRESUMO
Farmers expect yield reduction of cash crops like cocoa when growing in agroforestry systems compared to monocultures, due to competition for resources, e.g. nutrients and water. However, complementarities between species in the use of resources may improve resource use efficiency and result in higher system performance. Cocoa trees have a shallow rooting system while the rooting characteristics of the associated trees are mainly unknown. This work investigates fine root distribution and production in five cocoa production systems: two monocultures and two agroforestry systems under conventional and organic farming, and a successional agroforestry system. In the organic systems a perennial leguminous cover crop was planted and compost was added, while herbicides and chemical fertilizers were applied in the conventional ones. We measured cocoa fine root parameters in the top 10cm of soil and annual total fine root production at 0-25 and 25-50cm depth. We related the root data with both the aboveground performance (tree and herbaceous biomass), and the cocoa and system yields. Cocoa fine roots were homogenously distributed over the plot area. Around 80% of the total fine roots were located in the upper 25cm of soil. The total fine root production was 4-times higher in the agroforestry systems and the organic monoculture than in the conventional monoculture. The roots of the associated tree species were located in the same soil space as the cocoa roots and, in principle, competed for the same soil resources. The cocoa yield was lower in the agroforestry systems, but the additional crops generated a higher system yield and aboveground biomass than the conventional cocoa monocultures, implying effective resource exploitation. The leguminous cover crop in the organic monoculture competed with the cocoa trees for nutrients, which may explain the lower cocoa yield in this system in contrast with the conventional monoculture.
Assuntos
Cacau/crescimento & desenvolvimento , Produção Agrícola/métodos , Agricultura Florestal/métodos , Bolívia , Agricultura Orgânica , Raízes de Plantas/crescimento & desenvolvimento , Árvores/crescimento & desenvolvimentoRESUMO
As part of a multifactorial approach to address weak incentives for innovative antimicrobial drug development, market entry rewards (MERs) are an emerging solution. Recently, the Duke-Margolis Center for Health Policy released the Priority Antimicrobial Value and Entry (PAVE) Award proposal, which combines a MER with payment reforms, transitioning from volume-based to "value-based" payments for antimicrobials. Here, the PAVE Award and similar MERs are reviewed, focusing on further refinement and avenues for implementation.
Assuntos
Antibacterianos/economia , Descoberta de Drogas/economia , Resistência Microbiana a Medicamentos , Política de Saúde , Humanos , Recompensa , Participação no Risco Financeiro , Estados UnidosRESUMO
Cocoa beans are produced all across the humid tropics under different environmental conditions provided by the region but also by the season and the type of production system. Agroforestry systems compared to monocultures buffer climate extremes and therefore provide a less stressful environment for the understory cocoa, especially under seasonally varying conditions. We measured the element concentration as well as abiotic stress indicators (polyamines and total phenolic content) in beans derived from five different production systems comparing monocultures and agroforestry systems and from two harvesting seasons. Concentrations of N, Mg, S, Fe, Mn, Na, and Zn were higher in beans produced in agroforestry systems with high stem density and leaf area index. In the dry season, the N, Fe, and Cu concentration of the beans increased. The total phenolic content increased with proceeding of the dry season while other abiotic stress indicators like spermine decreased, implying an effect of the water availability on the chemical composition of the beans. Agroforestry systems did not buffer the variability of stress indicators over the seasons compared to monocultures. The effect of environmental growing conditions on bean chemical composition was not strong but can contribute to variations in cocoa bean quality.
Assuntos
Cacau/crescimento & desenvolvimento , Extratos Vegetais/química , Sementes/química , Cacau/química , Ecossistema , Meio Ambiente , Fenóis/química , Estações do Ano , Sementes/crescimento & desenvolvimentoRESUMO
Capsaicin is the chemical responsible for making some peppers spicy hot, but additionally it is used as a pharmaceutical to alleviate different pain conditions. Capsaicin binds to the vanilloid receptor TRPV1, which plays a role in coordinating chemical and physical painful stimuli. A number of reports have also shown that capsaicin inserts in membranes and its capacity to modify them may be part of its molecular mode of action, affecting the activity of other membrane proteins. We have used differential scanning calorimetry, X-ray diffraction, (31)P NMR, and (2)H NMR spectroscopy to show that capsaicin increases the fluidity and disorder of 1,2-palmitoyl-sn-glycero-3-phosphocholine membrane models. By using (1)H NOESY MAS NMR based on proton-proton cross-peaks between capsaicin and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine resonances, we determined the location profile of this molecule in a fluid membrane concluding that it occupies the upper part of the phospholipid monolayer, between the lipid-water interface and the double bond of the acyl chain in position sn-2. This location explains the disorganization of the membrane of both the lipid-water interface and the hydrophobic palisade.
Assuntos
Capsaicina/química , Capsaicina/metabolismo , Bicamadas Lipídicas/metabolismo , Água/química , Varredura Diferencial de Calorimetria , Humanos , Interações Hidrofóbicas e Hidrofílicas , Espectroscopia de Ressonância Magnética , Modelos Químicos , Fosfatidilcolinas/química , Fosfatidilcolinas/metabolismo , Isótopos de Fósforo , Trítio , Difração de Raios XRESUMO
The inflammasome activates caspase-1 and the release of interleukin-1ß (IL-1ß) and IL-18, and several inflammasomes protect against intestinal inflammation and colitis-associated colon cancer (CAC) in animal models. The absent in melanoma 2 (AIM2) inflammasome is activated by double-stranded DNA, and AIM2 expression is reduced in several types of cancer, but the mechanism by which AIM2 restricts tumor growth remains unclear. We found that Aim2-deficient mice had greater tumor load than Asc-deficient mice in the azoxymethane/dextran sodium sulfate (AOM/DSS) model of colorectal cancer. Tumor burden was also higher in Aim2(-/-)/Apc(Min/+) than in APC(Min/+) mice. The effects of AIM2 on CAC were independent of inflammasome activation and IL-1ß and were primarily mediated by a non-bone marrow source of AIM2. In resting cells, AIM2 physically interacted with and limited activation of DNA-dependent protein kinase (DNA-PK), a PI3K-related family member that promotes Akt phosphorylation, whereas loss of AIM2 promoted DNA-PK-mediated Akt activation. AIM2 reduced Akt activation and tumor burden in colorectal cancer models, while an Akt inhibitor reduced tumor load in Aim2(-/-) mice. These findings suggest that Akt inhibitors could be used to treat AIM2-deficient human cancers.
Assuntos
Neoplasias do Colo/prevenção & controle , Proteína Quinase Ativada por DNA/fisiologia , Proteínas de Ligação a DNA/fisiologia , Inflamassomos/fisiologia , Proteínas Proto-Oncogênicas c-akt/fisiologia , Animais , Colite/complicações , Feminino , Células HCT116 , Humanos , Pólipos Intestinais/prevenção & controle , Masculino , Camundongos , Camundongos Endogâmicos C57BL , FosforilaçãoRESUMO
Innate immune sensors such as Toll-like receptors (TLRs) differentially utilize adaptor proteins and additional molecular mediators to ensure robust and precise immune responses to pathogen challenge. Through a gain-of-function genetic screen, we identified the gamma catalytic subunit of protein phosphatase 1 (PP1-γ) as a positive regulator of MyD88-dependent proinflammatory innate immune activation. PP1-γ physically interacts with the E3 ubiquitin ligase TRAF6, and enhances the activity of TRAF6 towards itself and substrates such as IKKγ, whereas enzymatically inactive PP1-γ represses these events. Importantly, these activities were found to be critical for cellular innate responses to pathogen challenge and microbial clearance in both mouse macrophages and human monocyte lines. These data indicate that PP1-γ phosphatase activity regulates overall TRAF6 E3 ubiquitin ligase function and promotes NF-κB-mediated innate signaling responses.
Assuntos
Células Dendríticas/imunologia , Regulação da Expressão Gênica , Imunidade Inata , Macrófagos/imunologia , Proteína Fosfatase 1/fisiologia , Infecções Estreptocócicas/imunologia , Fator 6 Associado a Receptor de TNF/metabolismo , Animais , Western Blotting , Células Cultivadas , Células Dendríticas/metabolismo , Células Dendríticas/microbiologia , Ensaio de Imunoadsorção Enzimática , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imunoprecipitação , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos , Mutação/genética , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/genética , NF-kappa B/metabolismo , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Infecções Estreptocócicas/metabolismo , Infecções Estreptocócicas/microbiologia , Streptococcus/patogenicidade , Fator 6 Associado a Receptor de TNF/antagonistas & inibidores , Fator 6 Associado a Receptor de TNF/genética , Receptores Toll-Like/genética , Receptores Toll-Like/metabolismoRESUMO
Peritoneal macrophages are invaluable for gaining an understanding of innate immune responses due to their physiological relevance. These macrophages can be harvested from the peritoneum to give a resident population or can be elicited through the use of thioglycollate. This chapter describes how to collect each type of macrophage.
Assuntos
Imunidade Inata/genética , Macrófagos Peritoneais/citologia , Tioglicolatos/administração & dosagem , Animais , Células da Medula Óssea/citologia , Linhagem da Célula , CamundongosRESUMO
Colitis is a chronic inflammatory disease of the colon that is characterized by recurring, acute episodes. Mouse models of colitis allow for the study of multiple aspects of this disease, including the innate immune response, epithelial and intestinal cell response, and wound healing. The following protocols cover acute, chronic, and cancer-associated colitis models.