Navegando por Palavras-chave "Inflammasome"
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- ItemAcesso aberto (Open Access)Análise da contribuição do inflamassoma na heterogeneidade clínica de pacientes com doença falciforme(Universidade Federal de São Paulo (UNIFESP), 2019-11-21) Dutra, Valeria De Freitas [UNIFESP]; Figueiredo, Maria Stella [UNIFESP]; Pontillo, Alessandra [UNIFESP]; http://lattes.cnpq.br/0736747630522639; http://lattes.cnpq.br/1049389129901440; Universidade Federal de São Paulo (UNIFESP)In spite of having a molecular basis, Sickle cell disease (SCD) is an inflammatory state with abnormal cell activation. Physiopathological factors are not completely understood, but it is known that interleukins plays an important role in inflammation. Inflammasome complex is an innate immune pathway involved in the production of active IL-1β and IL-18. The participation of this complex in sickle cell disease is still not clear. Polymorphisms of inflammasome are simple amino acid substitution that can lead to a loss or gain of function and may be associated with clinical manifestations. NLRP3 is the most studied and well-known inflammasome, associated especially to auto-inflammatory diseases. Aim: To analyze the contribution of inflammasome to the clinical heterogeneity of SCD. To this, the association of inflammasome gene polymorphisms and a functional in vitro study were performed. Methods: In the association study 161 patients were included. Retrospective data were collected to fill clinical and laboratorial information. Patients were classified in two different groups: mild (0-1) or severe (> 2 organ damage). DNA samples were collected from 88 patients and 73 were used from a biorepository (BR- 116). Minor allelic frequency and literature information were used to choose 10 SNPs. Real-time PCR technique with allele and specific probes was used in TaqMan® assays (Applied Biosystms, Thermo Fisher Scientific). To functional study (n=7), PBMC and monocytes from healthy patients and controls were challenged with LPS and / or ATP, with subsequent IL-1β dosage by the ELISA method. All volunteers received a free and informed consent form. Multivariate analysis were performed by the software R Studio 3.5.3 (www.r-project.org), SNP association package. Mann-Whitney test was applied to group comparison. Results: The gain-offunction polymorphism rs16944 has resulted in a significant protection factor for SCD severity. The loss of function variant in the IL18 gene (rs1834481) was associated to high count of monocytes and leucocytes. In the functional test, patients with SCD tend to have less inflammasome activation when compared to controls. Conclusion: The promoter variant -511 C>T in IL1β resulted significantly associated to mild presentation in SCD patients (padj=0.001). PBM analysis showed that SCD cells seems to be less prone to activate inflammasome than HD.
- ItemSomente MetadadadosEstudo do efeito in vitro do parthenolide sobre a modulação das vias de ativação dos receptores TLR e NLR induzida por SOD1G93A(Universidade Federal de São Paulo (UNIFESP), 2021) Castro, Patricia Oliveira De [UNIFESP]; Barboza, Renato [UNIFESP]; Universidade Federal de São PauloAmyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease that affects motor neurons. The disease progresses gradually, leading to muscle atrophy, paralysis and even death from respiratory failure. Among the causes of familial ALS is the presence of mutations in the protein Superoxide Dismutase 1 (SOD1), an enzyme responsible for dismuting superoxide into oxygen. Its toxicity is associated with several mechanisms such as: abnormal accumulation of protein inclusions, mitochondrial damage, and endoplasmic reticulum stress. In this disorder, neuroinflammation plays a crucial role, characterized by chronic activation of glial cells mediated by pattern recognition receptors. Among them are the Toll-like receptores, which are responsible for the translocation of the NF-κB transcription factor; and the inflammasomes, which are protein complexes that, when activated, cleave pro-caspase, which results in the maturation of pro-inflammatory cytokines transcribed by NF-κB, and which will mediate inflammation and the innate immune response. In this work we use an in vitro model of neuroinflammation in BV2 cells induced by SOD1WT and SOD1G93A proteins in their soluble and aggregated state. We found an increase in factors linked to neuroinflammation such as TNF-α, IL-6, NLRP3, RAGE and HMGB1. To modulate inflammation, we used the NF-κB translocation inhibitor, Parthenolide. We found evidence to suggest the presence of SOD1 in a soluble or aggregated state in relation to the period of disease progression and directly associated with neuroinflammatory processes. The SOD1G93A protein in its soluble state may act as a first signal via the TLR in the inflammatory cascade, while in its aggregated state it corroborates the chronicity of inflammation and perpetuation of inflammasome activation. In addition, Parthenolide showed a decrease in TNF-α levels, but further studies are needed to analyze its pharmaceutical potential.
- ItemSomente MetadadadosA investigação do inflamassoma NLRP3 no desenvolvimento da glomeruloesclerose segmentar e focal experimental(Universidade Federal de São Paulo (UNIFESP), 2020-01-30) Santos, Amandda Rakel Peixoto Dos [UNIFESP]; Silva Filho, Alvaro Pacheco E [UNIFESP]; Universidade Federal de São PauloIntroduction. Chronic inflammation has been associated with several diseases including chronic kidney disease (CKD), and among those, focal segmental glomerulosclerosis (FSGS), a glomerulopathy in which inflammatory and degenerative mechanisms are implicated in podocyte damage. FSGS is a disease in which 50% of the patients are resistant to corticotherapy. In the past decades, the innate immune sensor system called NLRP3 inflammasome has been widely studied, showing its important contribution to the immune response. However, little has been investigated about FSGS and NLRP3 inflammasome. Aims. As it has been observed in other diseases, we speculated that NLRP3 inflammasome may also contribute to the development of FSGS. Therefore, we have investigated NLRP3 inflammasome components in experimental FSGS in order to unravel new mechanisms of the immune responses in renal diseases. Methods. Through Adriamycin Nephropathy (DOX) in wild type mice, C57BL/6J, mutants, such as NLRP3 KO, ASC KO, CASP-1 KO, and CRE Lox transgenic mice, we evaluated and compared NLRP3 inflammasome activation. We studied renal function, as well as gene and protein expression of molecules associated with podocytopathy, inflammation and tissue repair. Results. Our data showed that NLRP3 inflammasome activation happened early, in the second day of the nephropathy model, in C57BL/6J, with increased expression of nlrp3 (p=0,0275), casp-1 (p=0,0038), pro-il-18 (p<0,0001) and serum IL-18 (p<0,0001), associated with diminished expression of genes responsible for structural podocytes proteins and slit diaphragm proteins, actn4, synpo, nphs1 and kirrel (p<0,0001), we have also found diminished numbers of podocytes, WT1 (p=0,0009), and podocyte effacement through transmission electron microscopy (TEM). Among the knockout and CRE Lox transgenic mice, we pointed out that NLRP3 KO were protected against DOX- induced injury, podocytes mainly, not showing differences in podocytes molecules expression between the groups (p>0,05), or significant changes in podocytes structure by TEM; and, although they have presented increased expression of col4a1 (p=0,0056), fsp-1 (p=0,0217) and il-33 (p=0,0132), the mmp9/timp1 ratio was decreased (p<0,0001), indicating less extracellular matrix deposit when nlrp3 is not present. Conclusions. Our results indicated that NLRP3 inflammasome participates in experimental FSGS development, specially through IL-18 and IL-33 modulation. We believe that NLRP3 inflammasome activation promotes severe podocyte damage through IL-18, but, on the other hand, without NLRP3 inflammasome, IL-33 is not inactivated by caspase-1, and without this important limiting mechanism, IL-33 induces cellular infiltration and augmented expression of pro-fibrotic molecules. Thus, NLRP3 inflammasome and FSGS relation should be deeply investigated to guide the development of drugs that act accurately, blocking podocyte damage, without compromising the surveillance of this important innate immunity component.
- ItemSomente MetadadadosPapel do inflamassoma NLRC4 na indução e secreção de IL-1alpha em resposta à flagelina(Universidade Federal de São Paulo, 2014-08-29) Freitas, Carla Longo de [UNIFESP]; Bortoluci, Karina Ramalho [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)The flagellin monomer, structural protein that composes a subunit of bacterial flagellum, is recognized by the innate immune system by TLR5, but is transported to cytosol by secretion system of pathogenic bacterias where it is capable to active the NAIP5/NLRC4 inflammasome. The NAIP5/NLRC4 inflammasome can also contain the adaptor molecule ASC, inducing particular responses according to the formed complex. NLRC4 inflammasomes that recruit the adaptor molecule ASC induce autoproteolytic cleavege of caspase-1 and IL-1β and IL-18 pro-cytokines processing. In a different manner, NLRC4 ASC-independent inflammasomes activate caspase-1 but do not induce an autoproteolytic cleavage, leading to a rapid cell death by pyroptosis. In the last years, our group has been studying new effector mechanisms triggered by cytosolic flagellin, such as the release of the damage associated molecular pattern, IL-1α. Recent data suggest inflammasomes are involved in IL-1α secretion, however, little is known about this cytokine regulation. In this work, we demonstrate that cytosolic flagellin is capable of induce IL-1α secretion in a NLRC4, ASC and caspase-1 partially dependent manner. Interestingly, cytosolic flagellin also was capable of induce IL-1α production in cells lysates. However, this effect was not altered in the absence of NLRC4. Furthermore the induction of IL-1α secretion in response to cytosolic flagellin was inhibited in the presence of CA074-Me, pharmacological inhibitor of cathepsin B,a lysossomal enzyme, suggesting that more than one pathway can be triggered by cytosolic flagellin to induce production of IL-1α. Finally, we performed an assay that allowed us to evaluate secretion of IL-1α and cellular viability all together. Our data suggest that induction of IL-1α secretion in response to cytosolic flagellin envolves different molecular machineries. Still, secretion of IL-1α seems to preceed cell detah or occurs in a cell death independent manner, a fact that defy previous data tha indicate passive release of this cytokine by dead cells.
- ItemSomente MetadadadosPolymorphisms in inflammasome genes and risk of asthma in Brazilian children(Pergamon-Elsevier Science Ltd, 2018) Cordeiro Leal, Vinicius Nunes; Genov, Isabel Rugue [UNIFESP]; Mallozi, Marcia C. [UNIFESP]; Sole, Dirceu [UNIFESP]; Pontillo, AlessandraConsidering its role in inflammation and recently described "alternative" roles in epithelial homeostasis and Th1/Th2 balance, we hypothesize that inflammasome genetics could contribute to the development of asthma. Selected functional polymorphisms in inflammasome genes are evaluated in a cohort of asthmatic children and their families. Gain-of-function NLRP1 variants rs11651270, rs12150220 and rs2670660 resulted significantly associated to asthma in trios (TDT) analysis; and rs11651270 and rs2670660 also with asthma severity and total IgE level in asthmatic children. NLRP1 activators in humans are still unknown, however we hypothesized that individuals with gain-of-function SNPs in NLRP1 could be more prone in activating inflammasome in the presence of asthma-related cell stressors (i.e. ER stress or ROS), and this activation contribute to exacerbate inflammatory response and asthma development. Gain-of-function IL1A rs17561 resulted significantly associated with a reduced pulmonary capacity in asthmatic children. IL18 rs5744256 which lead to lower serum level of IL-18 appeared to be associated to a worse response to bronchodilators. Concluding, this work provides evidences about the contribution of inflammasome genetics in the development of paediatric asthma, both considering its inflammatory role in alveolar macrophages (i.e.: NLRP1) or its homeostatic role in lung epithelial cells (i.e.: IL1A, IL18).
- ItemAcesso aberto (Open Access)Uma revisão narrativa sobre a influencia do imunometabolismo na ativação dos inflamassomas em resposta ao toxoplasma gondii(Universidade Federal de São Paulo, 2022-12-19) Souza, Rafael Queiroz [UNIFESP]; Bortoluci, Karina Ramalho [UNIFESP]; http://lattes.cnpq.br/0159648961678651; https://lattes.cnpq.br/7588780705511651A imunidade inata é a primeira linha de defesa do nosso organismo contra os patógenos e as células dessa imunidade possuem um repertório de receptores restritos a padrões moleculares. Esses receptores são capazes de reconhecer padrões moleculares associados a patógenos e a danos celulares. A família de receptores NLR constituem o maior grupo de receptores citoplasmáticos e podem formar estruturas denominadas inflamassomas. Os inflamassomas são complexos multiproteicos capazes de ativar a caspase-1 e montar uma resposta inflamatória. Um processo muito importante decorrente da ativação da caspase 1 é a morte celular denominada piroptose e a clivagem das citocinas pró inflamatórias IL-1β e IL-18. Já é estabelecido pela literatura que as vias metabólicas e o metabolismo celular são de extrema importância no estudo da imunologia e estão intrinsecamente ligados com as respostas das células do sistema imune. O itaconato é um metabólito importante no contexto inflamatório, com grande efetividade no controle bacteriano , e um dos mecanismos que possibilita essa ação antimicrobiana é a sua ação inibitória sobre a enzima isocitrato liase bacteriana. Outro metabólito de importância no contexto imunológico é o fumarato. Foi observado que o dimetil fumarato (DMF) e o fumarato endógeno são capazes de reagir com a gasdermina D (GSDMD), molécula efetora da piroptose, inibindo esse processo. Um componente celular de grande importância quando falamos de uma resposta imunológica é a mitocôndria, pois desempenha um papel central na regulação de vias de receptores da imunidade inata. O Toxoplasma gondii é um protozoário do filo Apicomplexa que é capaz de subverter o sistema imune inato do hospedeiro pois recruta mitocôndrias do mesmo para o vacúolo parasitóforo. Assim, o objetivo desse trabalho é entender a influência do metabolismo de células imunes na ativação dos inflamassomas durante a infecção pelo T. gondii por meio da revisão de artigos disponíveis em bases dados. Esse entendimento é de grande importância para o campo pois trará embasamento e questões relevantes a serem abordadas em pesquisas futuras.