NLRP3 Inflammasome Deficiency Protects against Microbial Sepsis via Increased Lipoxin B4 Synthesis

Rationale: Sepsis, a life‐threatening organ dysfunction caused by a dysregulated host response to infection, is a major public health concern with high mortality and morbidity. Although inflammatory responses triggered by infection are crucial for host defense against invading microbes, the excessive inflammation often causes tissue damage leading to organ dysfunction. Resolution of inflammation, an active immune process mediated by endogenous lipid mediators (LMs), is important to maintain host homeostasis. Objectives: We sought to determine the role of the nucleotide‐binding domain, leucine‐rich repeat‐containing receptor, pyrin domain‐containing‐3 (NLRP3) inflammasome in polymicrobial sepsis and regulation of LM biosynthesis. Methods: We performed cecal ligation and puncture (CLP) using mice lacking NLRP3 inflammasome‐associated molecules to assess mortality. Inflammation was evaluated by using biologic fluids including plasma, bronchoalveolar, and peritoneal lavage fluid. Local acting LMs in peritoneal lavage fluid from polymicrobacterial septic mice were assessed by mass spectrometry‐based metabololipidomics. Measurements and Main Results: Genetic deficiency of NLRP3 inhibited inflammatory responses and enhanced survival of CLP‐induced septic mice. NLRP3 deficiency reduced proinflammatory LMs and increased proresolving LM, lipoxin B4 (LXB4) in septic mice, and in macrophages stimulated with LPS and ATP. Activation of the NLRP3 inflammasome induced caspase‐7 cleavage and pyroptosis. Caspase‐7 deficiency similarly reduced inflammation and mortality in CLP‐induced sepsis, and increased LXB4 production in vivo and in vitro. Exogenous application of LXB4 reduced inflammation, pyroptosis, and mortality of mice after CLP. Conclusions: Genetic deficiency of NLRP3 promoted resolution of inflammation in polymicrobial sepsis by relieving caspase‐7‐dependent repression of LXB4 biosynthesis, and increased survival potentially via LXB4 production and inhibition of proinflammatory cytokines.

[1]  Adil Rafiq Rather,et al.  The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3) , 2015 .

[2]  G. Maurer,et al.  Mitochondrial DNA and Toll-Like Receptor-9 Are Associated With Mortality in Critically Ill Patients , 2015, Critical care medicine.

[3]  Haitao Guo,et al.  Inflammasomes: mechanism of action, role in disease, and therapeutics , 2015, Nature Medicine.

[4]  K. Nakahira,et al.  The roles of Mitochondrial DAMPs in Diseases. , 2015 .

[5]  H. Saito,et al.  A New Cecal Slurry Preparation Protocol with Improved Long-Term Reproducibility for Animal Models of Sepsis , 2014, PloS one.

[6]  B. Levy,et al.  Lipoxin B4 promotes the resolution of allergic inflammation in the upper and lower airways of mice , 2014, Mucosal Immunology.

[7]  Vishva M. Dixit,et al.  Mechanisms and Functions of Inflammasomes , 2014, Cell.

[8]  D. Gilroy,et al.  Proresolving lipid mediators and mechanisms in the resolution of acute inflammation. , 2014, Immunity.

[9]  T. Vanden Berghe,et al.  Simultaneous targeting of IL-1 and IL-18 is required for protection against inflammatory and septic shock. , 2014, American journal of respiratory and critical care medicine.

[10]  R. Bueno,et al.  Circulating Mitochondrial DNA in Patients in the ICU as a Marker of Mortality: Derivation and Validation , 2013, PLoS medicine.

[11]  C. Sprung,et al.  Surviving Sepsis Campaign: International Guidelines for Management of Severe Sepsis and Septic Shock 2012 , 2013, Critical care medicine.

[12]  C. Serhan,et al.  Specific lipid mediator signatures of human phagocytes: microparticles stimulate macrophage efferocytosis and pro-resolving mediators. , 2012, Blood.

[13]  S. Leppla,et al.  Rapid induction of inflammatory lipid mediators by the inflammasome in vivo , 2012, Nature.

[14]  Cheng-Hsien Lu,et al.  Plasma nuclear and mitochondrial DNA levels as predictors of outcome in severe sepsis patients in the emergency room , 2012, Journal of Translational Medicine.

[15]  B. Spur,et al.  Lipoxin A4 Increases Survival by Decreasing Systemic Inflammation and Bacterial Load in Sepsis , 2011, Shock.

[16]  R. Flavell,et al.  NLRP3 inflammasome plays a critical role in the pathogenesis of hydroxyapatite-associated arthropathy , 2011, Proceedings of the National Academy of Sciences.

[17]  S. Ryter,et al.  Autophagy proteins regulate innate immune responses by inhibiting the release of mitochondrial DNA mediated by the NALP3 inflammasome. , 2011, Nature immunology.

[18]  Eva Szomolanyi-Tsuda,et al.  The AIM2 inflammasome is essential for host-defense against cytosolic bacteria and DNA viruses , 2010, Nature Immunology.

[19]  W. Junger,et al.  Circulating Mitochondrial DAMPs Cause Inflammatory Responses to Injury , 2009, Nature.

[20]  M. Perretti,et al.  Resolvin D2 is a potent regulator of leukocytes and controls microbial sepsis , 2009, Nature.

[21]  D. Green,et al.  Caspase-7 deficiency protects from endotoxin-induced lymphocyte apoptosis and improves survival. , 2009, Blood.

[22]  B. Cookson,et al.  Pyroptosis: host cell death and inflammation , 2009, Nature Reviews Microbiology.

[23]  Takao Shimizu,et al.  Lipid mediators in health and disease: enzymes and receptors as therapeutic targets for the regulation of immunity and inflammation. , 2009, Annual review of pharmacology and toxicology.

[24]  T. Vanden Berghe,et al.  Targeted Peptidecentric Proteomics Reveals Caspase-7 as a Substrate of the Caspase-1 Inflammasomes *S , 2008, Molecular & Cellular Proteomics.

[25]  M. Levy,et al.  Surviving Sepsis Campaign: International guidelines for management of severe sepsis and septic shock: 2008 , 2007, Intensive Care Medicine.

[26]  E. Alnemri,et al.  The pyroptosome: a supramolecular assembly of ASC dimers mediating inflammatory cell death via caspase-1 activation , 2007, Cell Death and Differentiation.

[27]  Charles N. Serhan,et al.  Resolvin E1 and protectin D1 activate inflammation-resolution programmes , 2007, Nature.

[28]  Keisuke Kuida,et al.  Caspases 3 and 7: Key Mediators of Mitochondrial Events of Apoptosis , 2006, Science.

[29]  John Savill,et al.  Resolution of inflammation: the beginning programs the end , 2005, Nature Immunology.

[30]  Mitchell M. Levy,et al.  Surviving Sepsis Campaign guidelines for management of severe sepsis and septic shock , 2004, Critical care medicine.

[31]  C. Coopersmith,et al.  Antibiotics Improve Survival and Alter the Inflammatory Profile in a Murine Model of Sepsis From Pseudomonas aeruginosa Pneumonia , 2003, Shock.

[32]  R. Hotchkiss,et al.  The pathophysiology and treatment of sepsis. , 2003, The New England journal of medicine.

[33]  N. Petasis,et al.  Lipoxins, aspirin-triggered epi-lipoxins, lipoxin stable analogues, and the resolution of inflammation: stimulation of macrophage phagocytosis of apoptotic neutrophils in vivo. , 2002, Journal of the American Society of Nephrology : JASN.

[34]  Charles N. Serhan,et al.  Lipid mediator class switching during acute inflammation: signals in resolution , 2001, Nature Immunology.

[35]  Beverly H. Koller,et al.  Altered Cytokine Production in Mice Lacking P2X7Receptors* , 2001, The Journal of Biological Chemistry.

[36]  S. Akira,et al.  Defective NK cell activity and Th1 response in IL-18-deficient mice. , 1998, Immunity.

[37]  C. Serhan,et al.  Lipoxin A4 and B4 inhibit leukotriene-stimulated interactions of human neutrophils and endothelial cells. , 1996, Journal of immunology.

[38]  C. Serhan,et al.  Lipoxin A4 and B4 are potent stimuli for human monocyte migration and adhesion: selective inactivation by dehydrogenation and reduction , 1996, The Journal of experimental medicine.

[39]  J. Drazen,et al.  Human alveolar macrophages have 15-lipoxygenase and generate 15(S)-hydroxy-5,8,11-cis-13-trans-eicosatetraenoic acid and lipoxins. , 1993, The Journal of clinical investigation.

[40]  S. Dahlén,et al.  Leukotrienes and lipoxins: structures, biosynthesis, and biological effects. , 1987, Science.

[41]  S. Dahlén,et al.  Lipoxin A. Stereochemistry and biosynthesis. , 1986, The Journal of biological chemistry.

[42]  B. Samuelsson.  Leukotrienes: mediators of immediate hypersensitivity reactions and inflammation. , 1983, Science.

[43]  B. Levy,et al.  Human Sepsis Eicosanoid and Proresolving Lipid Mediator Temporal Profiles: Correlations With Survival and Clinical Outcomes , 2017, Critical care medicine.

[44]  J. Tschopp,et al.  The Inflammasomes , 2010, Cell.