Inflammasomes are high-molecular-weight, multiprotein complexes in cells, which are assembled after cytoplasmic nucleotide-binding oligomerization domain like receptors (NLRs) sense pathogens and danger signals. The inflammasome can activate caspase-1, and later makes the pro-IL-1β, proIL-18 precursor mature by cleavaging, thereby mediates the innate immunity. Dysregulation of inflammasomes plays an important role in the development of sepsis and other immune inflammatory diseases, thus inflammasome may be a new target for prevention and treatment of sepsis.
Caspase 1 ; immunology ; metabolism ; Humans ; Inflammasomes ; chemistry ; immunology ; metabolism ; Interleukin-18 ; immunology ; metabolism ; Interleukin-1beta ; immunology ; metabolism ; Sepsis ; immunology ; metabolism ; Signal Transduction

Inflammasomes are large multi-protein complexes that serve as a platform for caspase-1 activation, and this process induces subsequent maturation and secretion of the proinflammatory cytokines IL-1β and IL-18, as well as pyroptosis. As an important component of the innate immune system, early activation of inflammasomes in a variety of immune cell subsets can mediate inflammatory response and immunological conditions after burn injury. Here, we review the current knowledge of inflammasomes and its role in immunological and inflammatory response at the early stage of burn injury.
Apoptosis ; Burns ; immunology ; Caspase 1 ; metabolism ; Cytokines ; Humans ; Inflammasomes ; physiology ; Inflammation Mediators ; immunology ; Interleukin-18 ; immunology ; physiology ; Interleukin-1beta ; immunology ; physiology

The NLRP3 inflammasome, a protein complex belonging to the family of nucleotide-binding and oligomerization domain like receptors (NLRs), plays a vital role in the innate immune system. It promotes pro-caspase 1 cleavage into active caspase-1, which contributes to maturation and releases of IL-1β and IL-18 in response to the harmful signals and participates in the host immune response and sterile inflammation. Recently a large number of studies have shown that NLRP3 inflammasome closely relates to the pathogenesis of the vascular diseases. NLRP3 inflammasome, which involves in the sterile inflammation of the vascular wall, plays an important role in the pathogenesis of main, middle and small arteries.
Caspase 1 ; immunology ; metabolism ; Gene Expression Regulation ; genetics ; immunology ; Humans ; Inflammasomes ; immunology ; Inflammation ; complications ; genetics ; Interleukin-18 ; genetics ; immunology ; Interleukin-1beta ; genetics ; immunology ; NLR Family, Pyrin Domain-Containing 3 Protein ; immunology ; Signal Transduction ; genetics ; immunology ; Vascular Diseases ; etiology ; genetics ; immunology

The inflammasome is an emerging new pathway in innate immune defense against microbial infection or endogenous danger signals. The inflammasome stimulates activation of inflammatory caspases, mainly caspase-1. Caspase-1 activation is responsible for processing and secretion of IL-1β and IL-18 as well as for inducing macrophage pyroptotic death. Assembly of the large cytoplasmic inflammasome complex is thought to be mediated by members of NOD-like receptor (NLR) family. While functions of most of the NLR proteins remain to be defined, several NLR proteins including NLRC4 have been shown to assemble distinct inflammasome complexes. These inflammasome pathways, particularly the NLRC4 inflammasome, play a critical role in sensing and restricting diverse types of bacterial infections. Here we review recent advances in defining the exact bacterial ligands and the ligand-binding receptors involved in NLRC4 inflammasome activation. Implications of the discovery of the NAIP family of inflammasome receptors for bacterial flagellin and type III secretion apparatus on future inflammasome and bacterial infection studies are also discussed.
Animals ; Bacteria ; immunology ; Bacterial Infections ; immunology ; metabolism ; CARD Signaling Adaptor Proteins ; immunology ; metabolism ; Caspase 1 ; metabolism ; Flagellin ; immunology ; metabolism ; Humans ; Immunity, Innate ; immunology ; Macrophages ; immunology ; metabolism ; microbiology ; Neuronal Apoptosis-Inhibitory Protein ; immunology ; metabolism

The progression of renal damage in diabetic nephropathy(DN)is closely related to Nod-like receptor protein3(NLRP3)inflammasome activation. The characteristics of NLRP3 inflammasome activation include the changed expression and combination levels of NLRP3, apoptosis-associated speck-like protein(ASC)and pro-caspase-1, the increased expression levels of caspase-1, interleukin(IL)-1β and IL-18 and the excessive release levels of the relative inflammatory mediators. Its molecular regulative mechanisms involve the activation of multiple signaling pathways including reactive oxygen species(ROS)/thioredoxin-interacting protein(TXNIP)pathway, nuclear factor(NF)-κB pathway, nuclear factor erythroid-related factor 2(Nrf2)pathway, long non-coding RNA(lncRNA)pathway and mitogen-activated protein kinases(MAPKs)pathway. In addition, more importantly, never in mitosis aspergillus-related kinase 7(Nek7), as a kinase regulator, could target-combine with NLRP3 at upstream to activate NLRP3 inflammasome. Some extracts of Chinese herbal medicines(CHMs)such as quercetin, curcumin, cepharanthine, piperine and salidroside, as well as Chinese herbal compound prescriptions such as Wumei Pills both could treat NLRP3 inflammasome to ameliorate inflammatory renal damage in DN. Therefore, accurately clarifying the targets of anti-inflammatory CHMs and Chinese herbal compound prescriptions delaying DN progression by targeting the molecular regulative mechanisms of NLRP3 inflammasome activation will be one of the development directions in the future.
Caspase 1/immunology* ; Diabetes Mellitus/drug therapy* ; Diabetic Nephropathies/immunology* ; Drugs, Chinese Herbal/therapeutic use* ; Humans ; Inflammasomes/immunology* ; Interleukin-18/immunology* ; Interleukin-1beta/immunology* ; NIMA-Related Kinases ; NLR Family, Pyrin Domain-Containing 3 Protein/immunology*

The inflammasome is a multi-protein complex that induces maturation of inflammatory cytokines interleukin (IL)-1beta and IL-18 through activation of caspase-1. Several nucleotide binding oligomerization domain-like receptor family members, including NLRP3, recognize unique microbial and danger components and play a central role in inflammasome activation. The NLRP3 inflammasome is critical for maintenance of homeostasis against pathogenic infections. However, inflammasome activation acts as a double-edged sword for various bacterial infections. When the IL-1 family of cytokines is secreted excessively, they cause tissue damage and extensive inflammatory responses that are potentially hazardous for the host. Emerging evidence has shown that diverse bacterial pathogens or their components negatively regulate inflammasome activation to escape the immune response. In this review, we discuss the current knowledge of the roles and regulation of the NLRP3 inflammasome during bacterial infections. Activation and regulation of the NLRP3 inflammasome should be tightly controlled to prevent virulence and pathology during infections. Understanding the roles and regulatory mechanisms of the NLRP3 inflammasome is essential for developing potential treatment approaches against pathogenic infections.
Bacterial Infections/immunology/metabolism/pathology/prevention & control ; Carrier Proteins/*metabolism ; Caspase 1/metabolism ; Humans ; Inflammasomes/immunology/*metabolism ; Interleukin-1beta/metabolism ; Signal Transduction

Streptococcus mutans (S. mutans), a major aetiologic agent of dental caries, is involved in systemic diseases, such as bacterial endocarditis, if it enters the bloodstream through temporary bacteraemia. Interleukin (IL)-1β, a proinflammatory cytokine, is related to the host defences against pathogens, and its synthesis, maturation, and secretion are tightly regulated by the activation of the inflammasome, an inflammatory signalling complex. This study examined the signalling mechanism of IL-1β secretion and the inflammasome pathway induced by S. mutans to explain the molecular mechanism through which systemic infection by oral streptococci can occur. After infection of THP-1 cells with S. mutans, the expression of inflammasome components was detected using various methods. S. mutans induced IL-1β secretion via caspase-1 activation, and S. mutans-induced IL-1β secretion required absent in melanoma (AIM2), NLR family pyrin domain-containing 3 (NLRP3) and NLR family CARD domain-containing 4 (NLRC4) inflammasome activation. In particular, the S. mutans-induced NLRP3 inflammasome was mediated by adenosine triphosphate (ATP) release, potassium depletion and lysosomal damage. Our study provides novel insight into the innate immune response against S. mutans infection.
Blotting, Western ; CARD Signaling Adaptor Proteins ; immunology ; Calcium-Binding Proteins ; immunology ; Caspase 1 ; immunology ; DNA-Binding Proteins ; immunology ; Enzyme-Linked Immunosorbent Assay ; Humans ; Immunity, Innate ; Inflammasomes ; immunology ; Interleukin-1beta ; immunology ; Macrophages ; immunology ; NLR Family, Pyrin Domain-Containing 3 Protein ; immunology ; Signal Transduction ; Streptococcus mutans ; immunology ; Tumor Necrosis Factor-alpha ; immunology

Bamboo salt (BS) is a traditional Korean food, and has been reported to have anti-cancer, anti-inflammatory, and anti-metastatic effects. However, the anti-atopic dermatitis (AD) activity of BS has not been described yet. In the present study, we examined the preventive effect of BS on AD. The effect of oral administration of BS was tested in a 2, 4-dinitrofluorobenzene (DNFB)-induced AD animal model, by histological analysis, enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction, caspase-1 assay, and Western blotting analysis. BS administration reduced the total clinical severity and scratching frequencies, compared with the AD group. In the serum of DNFB-induced AD mice, the levels of IgE, histamine, thymic stromal lymphopoietin (TSLP), interleukin (IL)-5, and IL-13 were significantly reduced by BS treatment. BS significantly reduced the protein and mRNA expression of TSLP, IL-6, and tumor necrosis factor-α in the AD skin lesions. BS markedly reduced the infiltration of inflammatory cells. Furthermore, the activation of caspase-1 was reduced by BS in the AD skin lesions. Our results suggested that BS should be considered as a candidate treatment for allergic inflammatory diseases including AD.
Animals ; Caspase 1 ; genetics ; immunology ; Dermatitis, Atopic ; chemically induced ; drug therapy ; genetics ; immunology ; Dinitrofluorobenzene ; adverse effects ; Disease Models, Animal ; Female ; Histamine ; immunology ; Humans ; Immunoglobulin E ; immunology ; Interleukin-13 ; genetics ; immunology ; Interleukin-5 ; genetics ; immunology ; Mice ; Mice, Inbred BALB C ; Sodium Chloride, Dietary ; administration & dosage

Animals ; Carrier Proteins ; metabolism ; Caspase 1 ; metabolism ; Humans ; Inflammasomes ; metabolism ; Interleukin-1beta ; metabolism ; Lipopolysaccharides ; toxicity ; Mice ; Monocytes ; drug effects ; immunology ; metabolism ; NLR Family, Pyrin Domain-Containing 3 Protein ; Signal Transduction ; drug effects

Inflammasomes are multiprotein complexes that serve as a platform for caspase-1 activation and interleukin-1β (IL-1β) maturation as well as pyroptosis. Though a number of inflammasomes have been described, the NLRP3 inflammasome is the most extensively studied. NLRP3 inflammasome is triggered by a variety of stimuli, including infection, tissue damage and metabolic dysregulation, and then activated through an integrated cellular signal. Many regulatory mechanisms have been identified to attenuate NLRP3 inflammasome signaling at multiple steps. Here, we review the developments in the negative regulation of NLRP3 inflammasome that protect host from inflammatory damage.
Animals ; Autophagy ; Carrier Proteins ; antagonists & inhibitors ; metabolism ; Caspase 1 ; metabolism ; Humans ; Inflammasomes ; metabolism ; Interferon Type I ; metabolism ; MicroRNAs ; metabolism ; NLR Family, Pyrin Domain-Containing 3 Protein ; Nitric Oxide ; metabolism ; Signal Transduction ; T-Lymphocytes ; immunology ; metabolism