RESUMO
INTRODUCTION AND OBJECTIVES: The absence of melanoma 2 (AIM2) protein triggers the activation of the inflammasome cascade. It is unclear whether AIM2 plays a role in hepatocellular carcinoma (HCC) and radiofrequency ablation (RFA), which uses radiofrequency waves to treat tumors. In this study, we investigated if RFA could induce pyroptosis, also called cell inflammatory necrosis, in HCC through AIM2-inflammasome signaling in vivo and in vitro. MATERIALS AND METHODS: BALB/c nude mice were used to generate HepG2 or SMMC-7721 cell-derived tumor xenografts. HCC cells with knockdown or overexpression of AIM2 were created using short hairpin RNA (shRNA) and expression vector transfection, respectively, for functional and mechanistic studies. Downstream effects were examined using flow cytometry, qRT-PCR, ELISAs, and other molecular assays. RESULTS: RFA significantly suppressed tumor growth in HCC cell xenografts. Flow cytometry analysis revealed that RFA could induce pyroptosis. Furthermore, AIM2, NLRP3, caspase-1, γ-H2AX, and DNA-PKc had significantly greater expression levels in liver tissues from mice treated with RFA compared with those of the controls. Additionally, interleukin (IL)-1ß and IL-18 expression levels were significantly higher in the HCC cell-derived xenograft mice treated with RFA compared with those without RFA. Notably, a significantly greater effect was achieved in the RFA complete ablation group versus the partial ablation group. Knockdown or overexpression of AIM2 in HCC cells demonstrated that AIM2 exerted a role in RFA-induced pyroptosis. CONCLUSIONS: RFA can suppress HCC tumor growth by inducing pyroptosis via AIM2. Therefore, therapeutically intervening with AIM2-mediated inflammasome signaling may help improve RFA treatment outcomes for HCC patients.
RESUMO
Abstract Atherosclerosis has been defined as an inflammatory disease. Three decades of research have pointed to a pivotal role of interleukin 6 for many aspects of cardiovascular disease, not the least of which is atherosclerosis. In this review, experimental and clinical studies are reported on a timeline, exploring mechanisms and possible explanations that form the basis of current knowledge. Some successful clinical trials were proof of concept studies, showing that not only inflammatory biomarkers are related to cardiovascular outcomes, but also that decreasing inflammation can reduce cardiovascular events. Great advances have been made in the management of residual cardiovascular risk due to cholesterol, thrombosis, and metabolic diseases, but the next frontier now seems to be targeting inflammation. In the upcoming years, the importance of inflammation will be evaluated in high-risk patients with chronic kidney disease, after acute coronary heart disease or heart failure with preserved ejection fraction. Inflammation seems to precede the development of cardiovascular risk factors. Moreover, counseling for a heathy lifestyle and, when necessary, the use of cardiometabolic therapies capable of decreasing inflammation, might be important.
RESUMO
Characterizing immune regulatory pathways is critical to understand physiological and pathophysiological processes as well as to identify novel immunotherapeutic targets. The cation channel TMEM176B has emerged in the last years as a potential new immunoregulatory player and pharmacological target. Here, we review how expression data, clinical associations of genetic variants and functional studies support a dual role for TMEM176B in regulating immune responses. Thus, TMEM176B can inhibit effector immune responses in some settings whereas it may also promote immunity by supporting antigen presentation in others. We also discuss a potential role for TMEM176B in regulating type 2 and 3 immunity and comment recent data on modulation of DC biology and inflammasome activation as well as CD8+ T cell responses. Understanding the role of TMEM176B in immunity is critical to propose rational pharmacological approaches targeting this channel.
RESUMO
Liver cancer is one of the most lethal malignancies and is commonly diagnosed as hepatocellular carcinoma (HCC), a tumor type that affects about 90% of patients. Non-alcoholic steatohepatitis (NASH) and obesity are both risk factors for this disease. HCC initiation and progression are deeply linked with changes in the hepatic microenvironment, with cytokines playing key roles. The understanding of the pathogenic pathways that connect these disorders to liver cancer remains poor. However, the inflammasome-mediated cytokines associated with both diseases are central actors in liver cancer progression. The release of the pro-inflammatory cytokines IL-1ß and IL-18 during inflammasome activation leads to several detrimental effects on the liver microenvironment. Considering the critical crosstalk between obesity, NASH, and HCC, this review will present the connections of IL-1ß and IL-18 from obesity-associated NASH with HCC and will discuss approaches to using these cytokines as therapeutic targets against HCC.
RESUMO
Trichoderma spp. are usually considered safe and normally used as biocontrol and biofertilization. Safety for human health is evaluated by several tests that detect various effects such as allergenicity, toxicity, infectivity, and pathogenicity. However, they do not evaluate the effects of the agent upon the immune system. The aim of this study was to investigate the interaction between T. stromaticum spores and mammalian cells to assess the immunomodulatory potential of the spores of this fungus. First, mouse macrophage cell line J774 and human macrophages were exposed to fungal spores and analyzed for structural features, through scanning and transmission electron microscopy. Then, various analysis were performed in human macrophages as to their effect in some functional and molecular aspects of the immune system through immunocytochemistry, flow cytometry and gene expression assays. We demonstrated that T. stromaticum spores induces autophagy and autophagy-related genes (ATGs) and downmodulate inflammatory mediators, including ROS, NLRP3, the cytokines IL-1ß, IL-18, IL-12 and IL-10, as well as TLR2, TLR4, miR-146b and miR-155, which may lead to an augmented susceptibility to pathogens. Our study shows the extension of damages the biofungicide Tricovab® can cause in the innate immune response. Further studies are necessary to elucidate other innate and adaptive immune responses and, consequently, the safety of this fungus when in contact with humans.
RESUMO
Introduction: HIV-1 infection induces a chronic inflammatory state in which inflammasomes participate. The increase in inflammatory parameters is higher in individuals with active viral replication (progressors) than in those with viral control (HIV-1 controllers). This process triggers metabolic alterations related to changes in the lipid profile, which could increase the risk of cardiovascular events, even in patients with antiretroviral therapy. Objective: To establish whether there was a correlation between the expression of inflammasome components and cardiovascular risk markers in HIV-1 controllers and progressors with or without antiretroviral therapy. Materials and methods: We studied 13 HIV-1 controllers and 40 progressors (19 without antiretroviral therapy and 31 with therapy) and evaluated in them classic markers of cardiovascular risk. Using RT-PCR we quantified the expression of inflammasome components (NLRP1, NLRP3, NLRC4, AIM2, ASC, IL-1ß, IL-18, and caspase-1), TLR2, TLR4, TGF-ß, and IL-10. Results: Progressors with antiretroviral therapy had an increased expression of TLR2, TLR4, and IL-18 compared to HIV-1 controllers. They also showed high levels of triglycerides and VLDL, which positively correlated with the expression of the inflammasome components NLRP1, NLRP3, NLRC4, AIM2, ASC, and caspase-1. Conclusion: Progressors receiving antiretroviral therapy exhibited an increased expression of the inflammasome components, which correlated with the levels of triglycerides and VLDL. This supports the role of inflammation in cardiovascular risk during HIV-1 infection.
Introducción. La infección por el HIV-1 induce un estado de inflamación crónico en el que participan los inflamasomas. El incremento de los parámetros inflamatorios es mayor en individuos con replicación viral activa que en aquellos con control de la replicación viral. Este proceso desencadena alteraciones metabólicas relacionadas con cambios en el perfil lipídico, lo cual podría incrementar el riesgo de eventos cardiovasculares, incluso en pacientes con terapia antirretroviral. Objetivo. Establecer si existe correlación entre la expresión de los componentes de los inflamasomas y los marcadores de riesgo cardiovascular en individuos con control de la replicación viral y en aquellos con replicación viral activa con terapia antirretroviral o sin ella. Materiales y métodos. Se estudiaron 13 individuos con control de la replicación viral y 40 con replicación viral activa (19 sin terapia antirretroviral y 31 con terapia). Se evaluaron los marcadores clásicos de riesgo cardiovascular y se cuantificó mediante RT-PCR la expresión de los componentes de los inflamasomas (NLRP1, NLRP3, NLRC4, AIM2, ASC, IL-1ß, IL-18 y caspasa-1), TLR2, TLR4, TGF-ß e IL-10. Resultados. Se observó que los pacientes con replicación viral activa y con terapia antirretroviral presentaron un incremento en la expresión de TLR2, TLR4 e IL-18, comparados con los controladores del HIV-1. Además, mostraron grandes valores de triglicéridos y lipoproteína de muy baja densidad (Very Low Density Lipopretein, VLDL), lo que se correlaciona positivamente con la expresión de los componentes de los inflamasomas NLRP1, NLRP3, NLRC4, AIM2, ASC y caspasa-1. Conclusión. El aumento en la expresión de los componentes de los inflamasomas en los individuos con replicación viral activa y con terapia antirretroviral se correlacionó con las concentraciones de triglicéridos y VLDL, lo que sugiere el papel de la activación inmunitaria y la terapia antirretroviral en el riesgo cardiovascular.
Assuntos
HIV-1 , Interleucina-18 , Proteína 3 que Contém Domínio de Pirina da Família NLR , Estudos Retrospectivos , Receptor 2 Toll-Like , Receptor 4 Toll-LikeRESUMO
Introducción. La infección por el HIV-1 induce un estado de inflamación crónico en el que participan los inflamasomas. El incremento de los parámetros inflamatorios es mayor en individuos con replicación viral activa que en aquellos con control de la replicación viral. Este proceso desencadena alteraciones metabólicas relacionadas con cambios en el perfil lipídico, lo cual podría incrementar el riesgo de eventos cardiovasculares, incluso en pacientes con terapia antirretroviral. Objetivo. Establecer si existe correlación entre la expresión de los componentes de los inflamasomas y los marcadores de riesgo cardiovascular en individuos con control de la replicación viral y en aquellos con replicación viral activa con terapia antirretroviral o sin ella. Materiales y métodos. Se estudiaron 13 individuos con control de la replicación viral y 40 con replicación viral activa (19 sin terapia antirretroviral y 31 con terapia). Se evaluaron los marcadores clásicos de riesgo cardiovascular y se cuantificó mediante RT-PCR la expresión de los componentes de los inflamasomas (NLRP1, NLRP3, NLRC4, AIM2, ASC, IL-1ß, IL-18 y caspasa-1), TLR2, TLR4, TGF-ß e IL-10. Resultados. Se observó que los pacientes con replicación viral activa y con terapia antirretroviral presentaron un incremento en la expresión de TLR2, TLR4 e IL-18, comparados con los controladores del HIV-1. Además, mostraron grandes valores de triglicéridos y lipoproteína de muy baja densidad (Very Low Density Lipopretein, VLDL), lo que se correlaciona positivamente con la expresión de los componentes de los inflamasomas NLRP1, NLRP3, NLRC4, AIM2, ASC y caspasa-1. Conclusión. El aumento en la expresión de los componentes de los inflamasomas en los individuos con replicación viral activa y con terapia antirretroviral se correlacionó con las concentraciones de triglicéridos y VLDL, lo que sugiere el papel de la activación inmunitaria y la terapia antirretroviral en el riesgo cardiovascular.
Introduction: HIV-1 infection induces a chronic inflammatory state in which inflammasomes participate. The increase in inflammatory parameters is higher in individuals with active viral replication (progressors) than in those with viral control (HIV-1 controllers). This process triggers metabolic alterations related to changes in the lipid profile, which could increase the risk of cardiovascular events, even in patients with antiretroviral therapy. Objective: To establish whether there was a correlation between the expression of inflammasome components and cardiovascular risk markers in HIV-1 controllers and progressors with or without antiretroviral therapy. Materials and methods: We studied 13 HIV-1 controllers and 40 progressors (19 without antiretroviral therapy and 31 with therapy) and evaluated in them classic markers of cardiovascular risk. Using RT-PCR we quantified the expression of inflammasome components (NLRP1, NLRP3, NLRC4, AIM2, ASC, IL-1ß, IL-18, and caspase-1), TLR2, TLR4, TGF-ß, and IL-10. Results: Progressors with antiretroviral therapy had an increased expression of TLR2, TLR4, and IL-18 compared to HIV-1 controllers. They also showed high levels of triglycerides and VLDL, which positively correlated with the expression of the inflammasome components NLRP1, NLRP3, NLRC4, AIM2, ASC, and caspase-1. Conclusion: Progressors receiving antiretroviral therapy exhibited an increased expression of the inflammasome components, which correlated with the levels of triglycerides and VLDL. This supports the role of inflammation in cardiovascular risk during HIV-1 infection.
Assuntos
HIV-1 , Inflamassomos , Replicação Viral , CardiopatiasRESUMO
BACKGROUND: The organism's defense against aggressive agents is performed by the innate immune system, via activation of pattern-recognition receptors (PRRs). Initially, these agents are recognized by the immune system, resulting in the inflammatory response that activates the pathogen elimination and tissue repair. Inflammasomes are macromolecules related to the host's response to endo or exogenous aggressive agents. Thus, inflammation mediated by inflammasomes plays an important role in the pathogenesis of diseases, such as neurodegenerative disorders, autoimmune diseases, and type 2 diabetes, justifying their attractiveness as drug targets. One of the most important tasks remains in the ATPase nucleotide-binding oligomerization domain nucleotide-binding domain leucine-rich repeat-containing receptors protein 3 (NLRP3), in which the blocking of its oligomerization is related to the functional inhibition of inflammasomes. Here, we performed molecular docking and dynamics simulations for NP3-146, an analog of MCC950, and to obtain information about the complex stability and main interactions with amino acid residues from NLRP3. METHODS: Using the crystalized structure recently deposited in the protein data bank (7alv), molecular docking in GOLD software and Molecular dynamics simulations in GROMACS software were performed, to generate the RMSD, RMSF, Rg, SASA, and H-bond plots. RESULTS: The results of RMSD, RMSF, Rg, SASA, and H-bond plots of both complexes confirmed the stability at the active site. Besides, the analyses of the most stable conformation showed that the main interactions are performed with Ala227, Ala228, Pro352, Ile411, Phe575, and Arg578 residues. CONCLUSION: This report confirmed the stability of NP3-146, similar to the know inhibitor MCC950, and provides various information useful to design NLRP3 inhibitors.
RESUMO
Abstract Background: Phospholipase C-like 1 (PLCL1), a protein that lacks catalytic activity, has similar structures to the PLC family. The aim of this research was to find the function and underlying mechanisms of PLCL1 in fibroblast-like synoviocyte (FLS) of rheumatoid arthritis (RA). Methods: In this study, we first analyzed the expression of PLCL1 in the synovial tissue of RA patients and K/BxN mice by immunohistochemical staining. Then silencing or overexpressing PLCL1 in FLS before stimulating by TNF-α. The levels of IL-6, IL-1β and CXCL8 in FLS and supernatants were detected by Western Blot (WB), Real-Time Quantitative PCR and Enzyme Linked Immunosorbent Assay. We used INF39 to specifically inhibit the activation of NLRP3 inflammasomes, and detected the expression of NLRP3, Cleaved Caspase-1, IL-6 and IL-1β in FLS by WB. Result: When PLCL1 was silenced, the level of IL-6, IL-1β and CXCL8 were down-regulated. When PLCL1 was overexpressed, the level of IL-6, IL-1β and CXCL8 were unregulated. The previous results demonstrated that the mechanism of PLCL1 regulating inflammation in FLS was related to NLRP3 inflammasomes. INF39 could counteract the release of inflammatory cytokines caused by overexpression of PLCL1. Conclusion: Result showed that the function of PLCL1 in RA FLS might be related to the NLRP3 inflammasomes. We finally confirmed our hypothesis with the NLRP3 inhibitor INF39. Our results suggested that PLCL1 might promote the inflammatory response of RA FLS by regulating the NLRP3 inflammasomes.
RESUMO
This study evaluated the in vitro modulatory effect of progesterone (PG) and vitamin D (VD) on NLRP1/NLRP3 inflammasomes and TLR4/NF-κB pathway in monocytes from pregnant women with preeclampsia (PE). Monocytes from 20 preeclamptic and 20 normotensive (NT) pregnant women, and THP-1 cells were cultured with/without hyaluronan (HA), PG, or VD to determine gene and protein expression of TLR4 receptor, phosphorylated NF-κB, IκBα, TLR4, MYD88, NF-κB, NLRP1, NLRP3, caspase-1, IL-1ß, IL-18, TNF-α, and IL-10. Higher endogenous activation of inflammatory genes and higher protein expression of TLR4 and NF-κB was detected in monocytes of PE group and decreased after PG or VD treatment. Monocyte from PE stimulated with HA increased while treatment with PG or VD decreased the expression of genes and proteins related to the inflammasomes. THP-1 cells showed a similar immune response profile as monocytes from PE. These results demonstrate that PG and VD play an immunomodulatory role in monocyte activation.