scholarly journals Caspase-8 mediates inflammation and disease in rodent malaria

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Larissa M. N. Pereira ◽  
Patrícia A. Assis ◽  
Natalia M. de Araújo ◽  
Danielle F. Durso ◽  
Caroline Junqueira ◽  
...  
Keyword(s):  
Septic Shock ◽  
Human Disease ◽  
Caspase 8 ◽  
Inflammasome Activation ◽  
Plasmodium Chabaudi ◽  
Experimental Cerebral Malaria ◽  
Rodent Malaria ◽  
Canonical Pathways ◽  
Inflammatory Caspases

Abstract Earlier studies indicate that either the canonical or non-canonical pathways of inflammasome activation have a limited role on malaria pathogenesis. Here, we report that caspase-8 is a central mediator of systemic inflammation, septic shock in the Plasmodium chabaudi-infected mice and the P. berghei-induced experimental cerebral malaria (ECM). Importantly, our results indicate that the combined deficiencies of caspases-8/1/11 or caspase-8/gasdermin-D (GSDM-D) renders mice impaired to produce both TNFα and IL-1β and highly resistant to lethality in these models, disclosing a complementary, but independent role of caspase-8 and caspases-1/11/GSDM-D in the pathogenesis of malaria. Further, we find that monocytes from malaria patients express active caspases-1, -4 and -8 suggesting that these inflammatory caspases may also play a role in the pathogenesis of human disease.

Intestinal dysbiosis augments liver disease progression via NLRP3 in a murine model of primary sclerosing cholangitis

Gut ◽  
2019 ◽  
Vol 68 (8) ◽  
pp. 1477-1492 ◽  
Author(s):  
Lijun Liao ◽  
Kai Markus Schneider ◽  
Eric J C Galvez ◽  
Mick Frissen ◽  
Hanns-Ulrich Marschall ◽  
...  
Keyword(s):  
Immune Response ◽  
Liver Injury ◽  
Sclerosing Cholangitis ◽  
Functional Role ◽  
Innate Immune ◽  
Caspase 8 ◽  
Inflammasome Activation ◽  
Intestinal Dysbiosis ◽  
Nlrp3 Inflammasome Activation

ObjectiveThere is a striking association between human cholestatic liver disease (CLD) and inflammatory bowel disease. However, the functional implications for intestinal microbiota and inflammasome-mediated innate immune response in CLD remain elusive. Here we investigated the functional role of gut–liver crosstalk for CLD in the murine Mdr2 knockout (Mdr2−/−) model resembling human primary sclerosing cholangitis (PSC).DesignMale Mdr2−/−, Mdr2−/− crossed with hepatocyte-specific deletion of caspase-8 (Mdr2−/−/Casp8∆hepa) and wild-type (WT) control mice were housed for 8 or 52 weeks, respectively, to characterise the impact of Mdr2 deletion on liver and gut including bile acid and microbiota profiling. To block caspase activation, a pan-caspase inhibitor (IDN-7314) was administered. Finally, the functional role of Mdr2−/−-associated intestinal dysbiosis was studied by microbiota transfer experiments.ResultsMdr2−/− mice displayed an unfavourable intestinal microbiota signature and pronounced NLRP3 inflammasome activation within the gut–liver axis. Intestinal dysbiosis in Mdr2−/− mice prompted intestinal barrier dysfunction and increased bacterial translocation amplifying the hepatic NLRP3-mediated innate immune response. Transfer of Mdr2−/− microbiota into healthy WT control mice induced significant liver injury in recipient mice, highlighting the causal role of intestinal dysbiosis for disease progression. Strikingly, IDN-7314 dampened inflammasome activation, ameliorated liver injury, reversed serum bile acid profile and cholestasis-associated microbiota signature.ConclusionsMDR2-associated cholestasis triggers intestinal dysbiosis. In turn, translocation of endotoxin into the portal vein and subsequent NLRP3 inflammasome activation contribute to higher liver injury. This process does not essentially depend on caspase-8 in hepatocytes, but can be blocked by IDN-7314.

scholarly journals Inflammasome Regulation: Therapeutic Potential for Inflammatory Bowel Disease

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1725
Author(s):  
Qiuyun Xu ◽  
Xiaorong Zhou ◽  
Warren Strober ◽  
Liming Mao
Keyword(s):  
Inflammatory Bowel Disease ◽  
Bowel Disease ◽  
Therapeutic Potential ◽  
Experimental Colitis ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation ◽  
Genetic Abnormalities ◽  
Inflammatory Bowel ◽  
Inflammatory Caspases

Inflammasomes are multiprotein complexes formed to regulate the maturation of pro-inflammatory caspases, in response to intracellular or extracellular stimulants. Accumulating studies showed that the inflammasomes are implicated in the pathogenesis of inflammatory bowel disease (IBD), although their activation is not a decisive factor for the development of IBD. Inflammasomes and related cytokines play an important role in the maintenance of gut immune homeostasis, while its overactivation might induce excess immune responses and consequently cause tissue damage in the gut. Emerging studies provide evidence that some genetic abnormalities might induce enhanced NLRP3 inflammasome activation and cause colitis. In these cases, the colonic inflammation can be ameliorated by blocking NLRP3 activation or its downstream cytokine IL-1β. A number of natural products were shown to play a role in preventing colon inflammation in various experimental colitis models. On the other hand, lack of inflammasome function also causes intestinal abnormalities. Thus, an appropriate regulation of inflammasomes might be a promising therapeutic strategy for IBD intervention. This review aims at summarizing the main findings in these studies and provide an outline for further studies that might contribute to our understanding of the role of inflammasomes in the pathogenesis and therapeutic treatment of IBD.

scholarly journals AIM2 inflammasome is activated by pharmacological disruption of nuclear envelope integrity

2016 ◽  
Vol 113 (32) ◽  
pp. E4671-E4680 ◽  
Author(s):  
Antonia Di Micco ◽  
Gianluca Frera ◽  
Jérôme Lugrin ◽  
Yvan Jamilloux ◽  
Erh-Ting Hsu ◽  
...  
Keyword(s):  
Immune System ◽  
Nuclear Envelope ◽  
Structural Component ◽  
Inflammasome Activation ◽  
Aspartyl Protease ◽  
Dna Sensor ◽  
Dna Release ◽  
Stress Signals ◽  
Inflammatory Caspases

Inflammasomes are critical sensors that convey cellular stress and pathogen presence to the immune system by activating inflammatory caspases and cytokines such as IL-1β. The nature of endogenous stress signals that activate inflammasomes remains unclear. Here we show that an inhibitor of the HIV aspartyl protease, Nelfinavir, triggers inflammasome formation and elicits an IL-1R–dependent inflammation in mice. We found that Nelfinavir impaired the maturation of lamin A, a structural component of the nuclear envelope, thereby promoting the release of DNA in the cytosol. Moreover, deficiency of the cytosolic DNA-sensor AIM2 impaired Nelfinavir-mediated inflammasome activation. These findings identify a pharmacologic activator of inflammasome and demonstrate the role of AIM2 in detecting endogenous DNA release upon perturbation of nuclear envelope integrity.

scholarly journals The Understanding and Management of Organism Toxicity in Septic Shock

2018 ◽  
Vol 10 (5-6) ◽  
pp. 502-514 ◽  
Author(s):  
Kelly Roveran Genga ◽  
Tadanaga Shimada ◽  
John H. Boyd ◽  
Keith R. Walley ◽  
James A. Russell
Keyword(s):  
Septic Shock ◽  
Immune Responses ◽  
Host Response ◽  
Therapeutic Strategies ◽  
Organ Injury ◽  
Inflammasome Activation ◽  
Current Therapies ◽  
Subsequent Activation ◽  
Molecular Patterns

The toxicity caused by different organisms in septic shock is substantially complex and characterized by an intricate pathogenicity that involves several systems and pathways. Immune cells’ pattern recognition receptors initiate the host response to pathogens after the recognition of pathogen-associated molecular patterns. In essence, the subsequent activation of downstream pathways may progress to infection resolution or to a dysregulated host response that represents the hallmark of organ injury in septic shock. Likewise, the management of organism toxicity in septic shock is complicated and comprises a multiplicity of suitable targets. In this review, the classic immune responses to pathogens are discussed as well as other factors that are relevant in the pathogenicity of septic shock, including sepsis-induced immune suppression, inflammasome activation, intestinal permeability, and the role of lipids and proprotein convertase subtilisin/kexin type 9. Current therapies aiming to eliminate the organisms causing septic shock, recent and ongoing trials in septic shock treatment, and potential new therapeutic strategies are also explored.

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