RESUMO
Intracellular protein complexes, known as inflammasomes, activate caspase-1 and induce the secretion of pro-inflammatory cytokines, namely interleukin (IL)-1ß and -18. Korean Red Ginseng extract (RGE) is a known immunomodulator and a potential candidate for the regulation of inflammasomes. The saponins, such as ginsenosides, of RGE inhibit inflammasome signaling, while non-saponin substances containing amino sugars promote the priming step, up-regulating inflammasome components (pro-IL-1ß, NLRP3, caspase-1, and Asc). In this study, the amino sugar-enriched fraction (ASEF), which increases only non-saponin components, including amino sugars, without changing the concentration of saponin substances, was used to investigate whether saponin or non-saponin components of RGE would have a greater impact on the priming step. When murine macrophages were treated with ASEF, the gene expression of inflammatory cytokines (IL-1α, TNFα, IL-6, and IL-10) increased. Additionally, ASEF induced the priming step but did not affect the inflammasome activation step, such as the secretion of IL-1ß, cleavage of caspase-1, and formation of Asc pyroptosome. Furthermore, the upregulation of gene expression of inflammasome components by ASEF was blocked by inhibitors of Toll-like receptor 4 signaling. Maltol, the main constituent of ASEF, promoted the priming step but inhibited the activation step of the inflammasome, while arginine, sugars, arginine-fructose-glucose, and fructose-arginine, the other main constituents of ASEF, had no effect on either step. Thus, certain amino sugars in RGE, excluding maltol, are believed to be the components that induce the priming step. The priming step that prepares the NLRP3 inflammasome for activation appears to be induced by amino sugars in RGE, thereby contributing to the immune-boosting effects of RGE.
Assuntos
Ginsenosídeos , Inflamassomos , Animais , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Amino Açúcares , Arginina , Caspase 1 , Frutose , Interleucina-1alfa , Interleucina-1beta , Extratos Vegetais/farmacologiaRESUMO
Inflammasome activation induces the maturation and secretion of interleukin (IL)-1ß and -18, and is dependent on NF-κB signaling to induce the transcription of the inflammasome components, called the priming step. This study elucidated the role of IκBζ, an atypical IκBs (inhibitor of κB) and a coactivator of NF-κB target genes, on the activation of inflammasome. Bone marrow-derived macrophages (BMDMs) that originated from IκBζ-encoding Nfkbiz gene depletion mice presented a defect in NLRP3 inflammasome activation. In addition, the Nfkbiz+/- and Nfkbiz-/- mice significantly attenuated serum IL-1ß secretion in response to a monosodium urate injection, a NLRP3 trigger, when compared with Nfkbiz-+/+ mice. The lack of IκBζ in BMDMs produced a disability in the expression of Nlrp3 and pro-Il1ß mRNAs during the priming step. In addition, ectopic IκBζ expression enhanced the Nlrp3 promoter activity, and Nlrp3 and pro-Il1ß transcription. Overall, IκBζ controlled the activation of NLRP3 inflammasome by upregulating the Nlrp3 gene during the priming step.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Inflamassomos/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Regulação para Cima/genética , Animais , Células Cultivadas , Macrófagos/metabolismo , Camundongos , Regiões Promotoras Genéticas/genética , Células RAW 264.7 , RNA Mensageiro/genética , Transdução de Sinais/genética , Transcrição Gênica/genéticaRESUMO
Sulforaphane (SFN), a compound within the isothiocyanate group of organosulfur compounds originating from cruciferous vegetables, has gained attention for its antioxidant, anti-inflammatory, and cancer chemopreventive properties. However, the effects of SFN on inflammasomes, which are multi-protein complexes that induce maturation of interleukin (IL)-1ß, have been poorly studied. In this study, we investigated the effects of SFN on the assembly of NLRP3, NLRC4, and AIM2 inflammasomes as well as on the priming step of NLRP3 inflammasome in murine macrophages. In our results, SFN attenuated activation of NLRP3 and NLRC4 inflammasomes but not AIM2 inflammasome. In addition, SFN blocked expression of the NLRP3 gene and pro-IL-1ß during the priming step. SFN further attenuated IL-1ß secretion of monosodium uric acid-induced peritonitis in mice. Lastly, SFN inhibited generation of mitochondrial reactive oxygen species, which trigger NLRP3 inflammasome activation. Thus, SFN is suggested as an anti-inflammasome molecule for NLRP3 and NLRC4 inflammasome activation.
Assuntos
Anti-Inflamatórios/farmacologia , Isotiocianatos/farmacologia , Macrófagos/efeitos dos fármacos , Mitocôndrias/metabolismo , Peritonite/tratamento farmacológico , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Brassicaceae/imunologia , Proteínas de Ligação ao Cálcio/metabolismo , Células Cultivadas , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Inflamassomos/metabolismo , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Peritonite/induzido quimicamente , Peritonite/imunologia , Sulfóxidos , Ácido ÚricoRESUMO
Methylsulfonylmethane (MSM) is an organosulfur compound and the health benefits associated with MSM include inflammation. Although MSM has been shown to have various physiological effects, no study has yet focused on inflammasome activation. The inflammasome is a multiprotein complex that serves as a platform for caspase 1-dependent proteolytic maturation and secretion of interleukin-1ß (IL-1ß). In this study, we tested the effect of MSM on inflammasome activation using mouse and human macrophages. In our results, MSM significantly attenuated NLRP3 inflammasome activation in lipopolysaccharide-primed macrophages, although it had no effect on NLCR4 or AIM2 inflammasome activation. Extracts of MSM-enriched vegetables presented the same inhibitory effect on NLRP3 inflammasome activation as MSM. MSM also attenuated the transcriptional expression of IL-1α, IL-1ß, IL-6, and NLRP3. Taken together, these results show that MSM has anti-inflammatory characteristics, interrupts NLRP3 inflammasome activation, and inhibits pro-cytokine expression. We further confirmed the intracellular mechanism of MSM in relation to NLRP3 inflammasome activation, followed by comparison with that of DMSO. Both chemicals showed a synergic effect on anti-NLRP3 activation and attenuated production of mitochondrial reactive oxygen species (ROS). Thus, MSM is a selective inhibitor of NLRP3 inflammasome activation and can be developed as a supplement to control several metabolic disorders.
Assuntos
Proteínas de Transporte/imunologia , Dimetil Sulfóxido/imunologia , Inflamassomos/imunologia , Sulfonas/imunologia , Animais , Anti-Inflamatórios/imunologia , Anti-Inflamatórios/farmacologia , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Linhagem Celular Tumoral , Células Cultivadas , Citocinas/genética , Citocinas/imunologia , Citocinas/metabolismo , Dimetil Sulfóxido/farmacologia , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/imunologia , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/imunologia , Humanos , Immunoblotting , Inflamassomos/efeitos dos fármacos , Inflamassomos/metabolismo , Mediadores da Inflamação/imunologia , Mediadores da Inflamação/metabolismo , Interleucina-1alfa/genética , Interleucina-1alfa/imunologia , Interleucina-1alfa/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Interleucina-1beta/metabolismo , Interleucina-6/genética , Interleucina-6/imunologia , Interleucina-6/metabolismo , Lipopolissacarídeos/imunologia , Lipopolissacarídeos/farmacologia , Listeria monocytogenes/imunologia , Listeria monocytogenes/fisiologia , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos Endogâmicos C57BL , Proteína 3 que Contém Domínio de Pirina da Família NLR , Espécies Reativas de Oxigênio/imunologia , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Salmonella typhimurium/imunologia , Salmonella typhimurium/fisiologia , Sulfonas/farmacologiaRESUMO
Sonic vibration (SV), or vibroacoustic therapy, is applied to enhance local and systemic blood circulation and alleviate pain using low-frequency sine wave vibrations. However, there is limited scientific data on the mechanisms through which the benefits are achieved. In this study, we investigated the impact of SV on inflammatory responses by assessing cytokine secretion in both in vivo and in vitro models. After inducing inflammatory responses in mice and macrophages, we studied cytokine expression and the symptoms of inflammatory diseases in response to three frequencies (14, 45, or 90â Hz) of SV stimulation at 0.5â m/s2 of amplitude. The results showed that SV at 90 Hz significantly increased interelukin-10 (IL-10) secretion in mice who were administered lipopolysaccharides (LPS) and increased the expression of IL-10 transcripts in peritoneal exudate cells and macrophages. Furthermore, SV at 90â Hz improved LPS-induced lethality and alleviated symptoms in a colitis model. In conclusion, this study scientifically proves the anti-inflammatory effects of vibration therapy through its ability to increase IL-10 expression.
RESUMO
Inflammasomes are cytosolic multi-protein complexes that play an important role in the innate immune system, inducing cytokine maturation and pyroptosis. Trained immunity is the induction of memory in innate immune cells by epigenetic reprogramming due to repeated inflammatory stimuli that alter the inflammatory response and increase resistance to infection or disease. Although it is speculated that nucleotide-binding oligomerization domain (NOD), leucine-rich repeat (LRR), and the NLR family pyrin domain containing 3 (NLRP3) inflammasomes respond to various inflammatory stimuli and are associated with trained immunity, the exact relationship is still unclear. This paper aims to introduce data from recent research on the role of inflammasomes in trained immunity through cellular immunometabolic and epigenetic reprogramming. It also suggests a new therapeutic strategy for inflammatory diseases through the complementary regulation of inflammasomes and trained immunity.
Assuntos
Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Imunidade Treinada , Citocinas/imunologia , Inflamassomos/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Piroptose/imunologia , Imunidade Treinada/imunologia , Humanos , AnimaisRESUMO
BACKGROUND: Inflammasomes recognize endogenous and exogenous danger signals, and subsequently induce the secretion of IL-1ß. Studying inflammasomes in the red fox (Vulpes vulpes) is crucial for wildlife veterinary medicine, as it can help control inflammatory diseases in foxes. METHODS: We investigated the activation and intracellular mechanisms of three inflammasomes (NLRP3, AIM2, and NLRC4) in fox peripheral blood mononuclear cells (PBMCs), using established triggers and inhibitors derived from humans and mice. RESULTS: Fox PBMCs exhibited normal activation and induction of IL-1ß secretion in response to representative inflammasome triggers (ATP and nigericin for NLRP3, dsDNA for AIM2, flagellin for NLRC4). Additionally, PBMCs showed normal IL-1ß secretion when inoculated with inflammasome-activating bacteria. In inhibitors of the inflammasome signaling pathway, fox inflammasome activation was compared with mouse inflammasomes. MCC950, a selective NLRP3 inhibitor, suppressed the secretion of dsDNA- and flagellin-mediated IL-1ß in foxes, unlike mice. CONCLUSIONS: These findings suggest that NLRP3 may have a common role in dsDNA- and flagellin-mediated inflammasome activation in the red fox. It implies that this fox inflammasome biology can be applied to the treatment of inflammasome-mediated diseases in the red fox.
RESUMO
Maltol (3-hydroxy-2-methyl-4-pyrone) is used widely as a food and cosmetic supplement, and it has antioxidant and anti-inflammatory activities. Inflammasome causes the maturation and secretion of interleukin (IL)-1ß and -18 through the activation of caspase-1 (Casp1), which contributes to various inflammatory diseases. This study examined the effects of maltol on the inflammasome activation in macrophages and mice. Lipopolysaccharide (LPS)-primed macrophages were treated with a trigger of NLRP3, NLRC4, AIM2, or non-canonical (NC) inflammasomes in the presence of maltol. The secretion of IL-1ß and IL-18 and the cleavage of Casp1 were analyzed as indices of inflammasome activation. Mice were injected with LPS and an NLRP3 trigger with or without maltol, and the peritoneal IL-1ß secretions were observed. The effects of maltol on reactive oxygen species (ROS) production and Casp1 activity were analyzed to determine the mechanism. Maltol inhibited the activation of NLRP3 and NC inflammasomes, but it did not alter the other inflammasomes. Maltol also attenuated IL-1ß secretion resulting from the inflammasome activation in mice. The anti-inflammatory mechanism of maltol was revealed by the inhibition of ROS production and Casp1 activity. Maltol is suggested to be promising as a anti-inflammasome molecule.
RESUMO
Dysregulation of inflammasome activation induces chronic and excess inflammation resulting in several disorders, such as metabolic disorders and cancers. Thus, screening for its regulator derived from natural materials has been conducted progressively. JC2-11 (JC) was designed to enhance the antioxidant activity based on a chalcone, which is abundant in edible plants and a precursor of flavonoids. This study examined the effects of JC on inflammasome activation in human and murine macrophages. JC inhibited the secretion of interleukin (IL)-1ß and lactate dehydrogenases, and the cleavage of caspase-1 and gasdermin D in response to the tested activators (i.e., NLRP3, NLRC4, AIM2, and non-canonical inflammasome triggers). In addition, JC attenuated IL-1ß secretion from lipopolysaccharide (LPS)-injected mice, an inflammasome-mediating disease model. Mechanistically, JC blocked the expression of the inflammasome components during the priming step of the inflammasome, and interrupted the production of mitochondrial reactive oxygen species. In addition, JC inhibited the activity of caspase-1. In conclusion, JC may be a candidate pan-inflammasome inhibitor.
Assuntos
Chalcona , Inflamassomos , Humanos , Animais , Camundongos , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Chalcona/farmacologia , Macrófagos/metabolismo , Caspase 1/metabolismo , Interleucina-1beta/metabolismo , Lipopolissacarídeos/farmacologia , Lipopolissacarídeos/metabolismoRESUMO
Gout is a recurrent and chronic form of arthritis caused by the deposition of monosodium urate (MSU) crystals in the joints. Macrophages intake MSU crystals, the trigger for NLRP3 inflammasome activation, which leads to the release of interleukin (IL)-1ß and results in the flaring of gout. The effects of temperature, an environmental factor for MSU crystallization, on IL-1ß secretion have not been well studied. This study examined the effects of temperature on inflammasome activation. Specific triggers activated canonical inflammasomes (NLRP3, NLRC4, and AIM2) in murine macrophages at various temperatures (25, 33, 37, 39, and 42 °C). The maturation of IL-1ß and caspase-1 was measured as an indicator for inflammasome activation. As expected, the optimal temperature of inflammasome activation was 37 °C. The MSU crystal-mediated activation of inflammasome increased at temperatures lower than 37 °C and decreased at higher temperatures. MSU crystals at lower temperatures enhanced IL-1ß secretion via the NLRP3 inflammasome pathway. A lower temperature promoted the formation of MSU crystals without changing phagocytosis. Overall, lower temperatures form more MSU crystals and enhance NLRP3 inflammasome activation. In light of these findings, it is possible that hyperthermia therapy may reduce gout flaring.
Assuntos
Gota/metabolismo , Inflamassomos/metabolismo , Macrófagos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Temperatura , Ácido Úrico/química , Animais , Caspase 1/metabolismo , Cristalização , Interleucina-1beta/metabolismo , Macrófagos/imunologia , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologiaRESUMO
Parabens are synthetic chemicals widely used as preservatives in cosmetics, pharmaceuticals, and foods. Although parabens, i.e., ethyl- and methyl-parabens, are considered relatively safe, study of possible health hazards has been undertaken due to the frequent exposure to parabens and their accumulation in the body. In this study, we elucidated the effect of parabens on inflammasome induction of inflammatory responses in innate immunity, such as interleukin (IL)-1ß maturation and gasdermin D (GSDMD)-mediating pyroptosis. Parabens attenuated the inflammatory responses to intracellular lipopolysaccharide (LPS) triggering of non-canonical (NC) inflammasome activation, but did not alter canonical inflammasome (i.e., NLRP3, NLRC4 and AIM2) responses. The NC inflammasome is assembled by the interaction of murine caspase (Casp)-11 (Casp4/5 in human) with cytosolic LPS, inducing endotoxin sepsis. Parabens selectively inhibited NC inflammasome activation in both human and murine macrophages and diminished the peritoneal IL-1ß production in LPS-injected mice. Parabens blocked the cleavage of GSDMD, Casp1, and Casp4, but did not change the expression of Casp11 or the activity of Casp1. Taken together, the results indicate that parabens could disrupt Gram-negative pathogen infection through the inhibition of NC inflammasome activation.
Assuntos
Inflamassomos/efeitos dos fármacos , Parabenos/farmacologia , Animais , Western Blotting , Feminino , Interleucina-1beta/metabolismo , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
BACKGROUND: Keratinocytes form a physical barrier and act as an innate immune cell in skin. Keratinocytes secrete pro-inflammatory cytokines, such as interleukin (IL)-1ß, resulting from inflammasome activation when exposed to ultraviolet (UV) irradiation. Korean Red Ginseng extracts (RGE) have been well-studied as modulators of inflammasome activation in immune cells, such as macrophages. In the study, we elucidated the role of RGE on the UV-mediated inflammasome activation in keratinocytes compared with that in macrophages. METHODS: Human skin keratinocyte cells (HaCaT), human epidermal keratinocytes (HEK), human monocyte-like cells (THP-1), and mouse macrophages were treated with RGE or a saponin fraction (SF) or non-saponin fraction (NS) of RGE before and after UV irradiation. The secretion levels of IL-1ß, as an indicator of inflammasome activation, were analyzed. RESULTS: The treatment of RGE or SF in macrophages after UV irradiation inhibited IL-1ß secretion, but similar treatment in HaCaT cells did not. However, the treatment of RGE or SF in HaCaT cells in the presence of poly I:C, a toll-like receptor (TLR) 3 ligand, before UV exposure elicited the inhibition of the IL-1ß secretion. The inhibition was caused by the disruption by RGE or SF of the TLR mediating up-regulation of the pro-IL-1ß and NLRP3 genes during the priming step. CONCLUSION: RGE and its saponins inhibit IL-1ß secretion in response to UV exposure in both keratinocytes and macrophages. In particular, RGE treatment interrupted only the priming step in keratinocytes, although it did attenuate both the priming and activation steps in macrophages.
RESUMO
Lipocalin-2 (LCN2), a small secretory glycoprotein, is upregulated by toll-like receptor (TLR) signaling in various cells and tissues. LCN2 inhibits bacterial growth by iron sequestration and regulates the innate immune system. Inflammasome activates the inflammatory caspases leading to pyroptosis and cytokine maturation. This study examined the effects of inflammasome activation on LCN2 secretion in response to TLR signaling. The triggers of NLRP3 inflammasome activation attenuated LCN2 secretion while it induced interleukin-1ß in mouse macrophages. In mice, NLRP3 inflammasome activation inhibited TLR-mediated LCN2 secretion. The inhibition of NLRP3 triggers on LCN2 secretion was caused by the inhibited transcription and translation of LCN2. At the same time, no changes in the other cytokines and IκBζ, a well-known transcriptional factor of Lcn2 transcription, were observed. Overall, NLRP3 triggers are a regulator of LCN2 expression suggesting a new linkage of inflammasome activation and LCN2 secretion in the innate immunity.
Assuntos
Inflamassomos/imunologia , Interleucina-1beta/imunologia , Lipocalina-2/imunologia , Macrófagos/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/imunologia , Trifosfato de Adenosina/farmacologia , Animais , Feminino , Fêmur/citologia , Fêmur/imunologia , Regulação da Expressão Gênica , Imunidade Inata , Inflamassomos/efeitos dos fármacos , Inflamassomos/genética , Interleucina-1beta/genética , Lipocalina-2/genética , Lipopolissacarídeos/farmacologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Nigericina/farmacologia , Cultura Primária de Células , Células RAW 264.7 , Transdução de Sinais , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacos , Células-Tronco/imunologia , Tíbia/citologia , Tíbia/imunologia , Transcrição GênicaRESUMO
Riboflavin is commonly taken as a nutritional supplement, and it converts to coenzymes during the process of energy production from carbohydrates, fats, and proteins. Although riboflavin is considered to be an anti-inflammatory vitamin because of its antioxidant properties, the effects of riboflavin on inflammasome have been not reported. Inflammasome, a cytosolic surveillance protein complex, leads to the activation of caspase-1, cytokine maturation, and pyroptosis. In the present study, riboflavin attenuated the indicators of NLRP3 inflammasome activation in macrophages, such as the maturation and secretion of interleukin (IL)-1ß, IL-18, and caspase-1; the formation of Asc pyroptosome; and the cleavage of gasdermin D. In addition, the oral and peritoneal administration of riboflavin inhibited the peritoneal production of IL-1ß and IL-18 in a mouse model. Mechanistically, riboflavin prevented mitochondrial perturbations, such as mitochondrial ROS production and mitochondrial DNA release, which trigger the NLRP3 inflammasome assembly. Riboflavin was further confirmed to disrupt the activity of caspase-1, and it also inhibited the AIM2, NLRC4, and non-canonical inflammasomes. Therefore, riboflavin has both an antioxidant effect and an anti-inflammasome property that regulates the inflammatory response.
Assuntos
Caspase 1/metabolismo , Inflamassomos/efeitos dos fármacos , Inflamassomos/metabolismo , Riboflavina/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Inibidores de Caspase/farmacologia , Células Cultivadas , Proteínas de Ligação a DNA/metabolismo , Feminino , Humanos , Inflamassomos/imunologia , Interleucina-18/biossíntese , Interleucina-1beta/biossíntese , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Células THP-1RESUMO
BACKGROUND: Korean Red Ginseng extract (RGE) has been reported to act as an inflammasome modulator. Ginsenosides, saponin molecules of RGE, selectively inhibit activation of NLRP3 and AIM2 inflammasomes, while non-saponin molecules of RGE upregulate inflammasome components associated with the initiation of NLRP3 inflammasome activation. In this study, we investigated the effect of non-saponin components of RGE on AIM2 inflammasome activation. METHODS: The role of non-saponins of RGE on AIM2 inflammasomes was tested in mouse bone marrow-derived macrophages, a human monocyte-like cell line, and a mouse animal model. Cells or mice were transfected with dsDNA or inoculated with Listeria monocytogenes to activate AIM2 inflammasomes. Several indices of inflammasome activation were examined via immunoblot or ELISA analysis. RESULTS: The non-saponin fraction and saponin-eliminating fraction (SEF) of RGE selectively attenuated the activation of AIM2 inflammasomes, but not that of NLRP3 or NLRC4 inflammasomes. Fructose-arginine, an amino-sugar, was shown to be effective against AIM2 inflammasome activation. CONCLUSION: Non-saponins of RGE, such as fructose-arginine, might be effective in regulating infectious and autoimmune diseases resulting from AIM2 inflammasome activation.
RESUMO
Inflammasome, a cytosolic multi-protein complex, assembly is a response to sensing intracellular pathogenic and endogenic danger signals followed by caspase-1 activation, which maturates precursor cytokines such as interleukin (IL)-1ß. Most inflammasome research has been undertaken in humans and rodents, and inflammasomes in veterinary species have not been well-characterized. In this study, we observed the effects of well-known inflammasome activators on equine peripheral blood monocytes (PBMCs). The NLRP3 inflammasome triggers include ATP, nigericin, aluminum crystals, and monosodium urate crystals, and NLRP3 activation induces IL-1ß secretion in a dose-dependent manner. Activators of NLRC4 and AIM2 inflammasomes include cytosolic flagellin and dsDNA, and their activation induces IL-1ß secretion. The bacterial inflammasome triggers Salmonella Typhimurium and Listeria monocytogenes also induce IL-ß releases. To elucidate the role of potassium efflux as an upstream signal of NLRP3 inflammasome activation, equine PBMCs were treated with blockers of potassium efflux in the presence of NLRP3 triggers. As a result, the IL-1ß secretion stemming from equine NLRP3 inflammasome activation was not completely attenuated by the inhibition of potassium efflux. Taken together, the results indicate that equine PBMCs normally secrete IL-1ß in response to well-known inflammasome activators, although equine NLRP3 inflammasome activation might not be dependent on potassium efflux.
Assuntos
Cavalos/imunologia , Inflamassomos/imunologia , Monócitos/imunologia , Trifosfato de Adenosina/farmacologia , Alumínio/farmacologia , Animais , DNA/farmacologia , Flagelina/farmacologia , Inflamassomos/efeitos dos fármacos , Interleucina-1beta/imunologia , Listeria monocytogenes/imunologia , Nigericina/farmacologia , Salmonella typhimurium/imunologia , Ácido Úrico/farmacologiaRESUMO
BACKGROUND: Ginsenosides of Korean Red Ginseng extracts (RGE) and its saponin components suppress secretion of inflammasome-mediating cytokines, whereas the nonsaponin fraction (NS) of RGE oppositely stimulates cytokine secretion. Although direct exposure of NS to macrophages in mice induces cytokine production, oral administration of NS has not been studied in inflammasome-related disease in animal models. METHODS: Mice were fed RGE or NS for 7 days and then developed peritonitis. Peritoneal cytokines were measured, and peritoneal exudate cells (PECs) were collected to assay expression levels of a set of toll-like receptors (TLRs) and cytokines in response to NS ingestion. In addition, the role of intestinal bacteria in NS-fed mice was assessed. The effect of preexposure to NS in bone marrow-derived macrophages (BMDMs) on cytokine production was further confirmed. RESULTS: NS ingestion attenuated secretion of peritoneal cytokines resulting from peritonitis. In addition, the isolated PECs from NS-fed mice presented lower TLR transcription levels than PECs from control diet-fed mice. BMDMs treated with NS showed downregulation of TLR4 mRNA and protein expression, which was mediated by the TLR4-MyD88-NFκB signal pathway. BMDMs pretreated with NS produced less cytokines in response to TLR4 ligands. CONCLUSION: NS administration directly inhibits TLR4 expression in inflammatory cells such as macrophages, thereby reducing secretion of cytokines during peritonitis.
RESUMO
BACKGROUND: Obovatol, a biphenolic chemical originating from Magnolia obovata, has been utilized as a traditional medicine for the treatment of inflammatory diseases. Inflammasome induces maturation of inflammatory cytokines in response to intracellular danger signals, and its dysregulation induces inflammatory diseases. PURPOSE: The effect of obovatol on inflammasome activation has not been reported, although its anti-inflammatory properties have been studied. STUDY DESIGN/METHODS: Obovatol was treated to macrophages with inflammasome triggers, and secretions of interleukin (IL)-1ß, IL-18, and caspase-1 were measured as readouts of inflammasome activation. In addition, Asc pyroptosome formation, caspase-1 activity, and mitochondrial reactive oxygen species (ROS) production were analyzed in mechanical studies. Anti-inflammasome properties of obovatol were confirmed in an animal model. RESULTS: Obovatol inhibited NLRP3, AIM2, and non-canonical inflammasomes through inhibition of Asc pyroptosome formation and mitochondrial ROS generation. In addition, obovatol disrupted the priming step of inflammasome activation and inhibited transcription of inflammatory cytokines. In mice, obovatol attenuated serum IL-1ß elevation in response to monosodium urate crystals. CONCLUSION: Obovatol is suggested as an inhibitor of NLRP3, AIM2, and non-canonical inflammasomes.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Compostos de Bifenilo/farmacologia , Proteínas de Ligação a DNA/antagonistas & inibidores , Inflamassomos/efeitos dos fármacos , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Éteres Fenílicos/farmacologia , Animais , Anti-Inflamatórios não Esteroides/química , Compostos de Bifenilo/química , Caspase 1/metabolismo , Citocinas/genética , Citocinas/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos Endogâmicos C57BL , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Peritonite/tratamento farmacológico , Éteres Fenílicos/química , Espécies Reativas de Oxigênio/metabolismo , Ácido Úrico/farmacologiaRESUMO
Pigs are an important livestock and serve as a large animal model due to physiological and anatomical similarities with humans. Thus, components of the porcine immune system such as inflammasomes need to be characterized for disease control, vaccination, and translational research purposes. Previously, we and others elucidated porcine nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family Pyrin domain containing 3 (NLRP3) inflammasome activation. However, until now, porcine NLR family caspase recruitment domain (CARD)-containing 4 (NLRC4) and absent in melanoma 2 (AIM2) inflammasomes have been not well studied. In this study, we treated well defined NLRC4 and AIM2 inflammasome triggers to porcine peripheral blood mononuclear cells (PBMCs) and murine bone-marrow derived macrophages (BMDMs) and observed interleukin (IL)-1ß maturation as a readout of inflammasome activation. NLRC4 (flagellin) and AIM2 (dsDNA) triggers led to IL-1ß secretion in both porcine PBMCs and mice macrophages. In addition, porcine and mouse NLRC4 and AIM2 inflammasomes responded differently to NLRP3 inhibitors. Bacterial inflammasome triggers, Salmonella enterica serovar Typhimurium, Listeria monocytogenes, and Escherichia coli, also induced IL-1ß secretion in porcine PBMCs. Taken together, we suggest that known triggers of NLRC4 and AIM2 inflammasomes in mice induce IL-1ß secretion in porcine PBMCs.
Assuntos
Proteínas de Ligação a DNA/metabolismo , Inflamassomos/metabolismo , Interleucina-1beta/metabolismo , Proteínas Adaptadoras de Sinalização NOD/metabolismo , Animais , Western Blotting , Ensaio de Imunoadsorção Enzimática , Feminino , Inflamassomos/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Salmonelose Animal/imunologia , Salmonelose Animal/metabolismo , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/metabolismo , Doenças dos Suínos/microbiologiaRESUMO
Poly-gamma-glutamic acid (γ-PGA) is a natural, edible and non-toxic polymer synthesized by Bacillus subtilis and is suggested as a safe biomaterial for the use in hydrogels and vaccine adjuvants. However, the effect of γ-PGA on inflammasome activation has not yet been studied in macrophages. Inflammasomes, which are intracellular multi-protein complexes, promote acute and chronic inflammation via interleukin-1ß or interleukin-18 maturation, and they are known targets for metabolic syndromes and cancer. In this study, we observed that γ-PGA attenuated NLRP3, NLRC4 and AIM2 inflammasome activation, whereas it upregulated pro-inflammatory cytokine expression in human and murine macrophages. Although γ-PGA had conflicting effects on cytokine production and maturation, it clearly alleviated the severity of lipopolysaccharide-induced endotoxin shock in an animal model. Thus, we suggest γ-PGA as a candidate to control inflammasome-mediated disorders.