Dataset Information

NLRP3 inflammasome activation in neutrophils directs early inflammatory response in murine peritonitis.

ABSTRACT: NLR family pyrin domain containing 3 (NLRP3) inflammasome mediates caspase-1-dependent processing of inflammatory cytokines such as IL-1β, an essential endothelial activator, and contributes to the pathology of inflammatory diseases. To evaluate the role of NLRP3 in neutrophils in endothelial activation, which is still elusive, we used the thioglycollate-induced peritonitis model characterized by an early neutrophil influx, on Nlrp3^-/- and Nlrp3^+/+ mice. Nlrp3^-/- mice recruited fewer neutrophils than Nlrp3^+/+ into the peritoneum and showed lower IL-1β in peritoneal lavage fluid. The higher production of IL-1β in Nlrp3^+/+ was neutrophil-dependent as neutrophil depletion prevented the IL-1β production. The Nlrp3^+/+ neutrophils collected from the peritoneal fluid formed significantly more filaments (specks) than Nlrp3^-/- neutrophils of ASC (apoptosis-associated speck-like protein containing a caspase activating and recruitment domain), a readout for inflammasome activation. Intravital microscopy revealed that leukocytes rolled significantly slower in Nlrp3^+/+ venules than in Nlrp3^-/-. Nlrp3^-/- endothelial cells isolated from mesenteric vessels demonstrated a lower percentage of P-selectin-positive cells with lower intensity of surface P-selectin expression than the Nlrp3^+/+ endothelial cells evaluated by flow cytometry. We conclude that neutrophils orchestrate acute thioglycollate-induced peritonitis by producing IL-1β in an NLRP3-dependent manner. This increases endothelial P-selectin expression and leukocyte transmigration.

SUBMITTER: Fukui S

PROVIDER: S-EPMC9734191 | biostudies-literature | 2022 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

NLRP3 inflammasome activation in neutrophils directs early inflammatory response in murine peritonitis.

Fukui Saeko S Fukui Shoichi S Van Bruggen Stijn S Shi Lai L Sheehy Casey E CE Chu Long L Wagner Denisa D DD

Scientific reports 20221209 1

NLR family pyrin domain containing 3 (NLRP3) inflammasome mediates caspase-1-dependent processing of inflammatory cytokines such as IL-1β, an essential endothelial activator, and contributes to the pathology of inflammatory diseases. To evaluate the role of NLRP3 in neutrophils in endothelial activation, which is still elusive, we used the thioglycollate-induced peritonitis model characterized by an early neutrophil influx, on Nlrp3-/- and Nlrp3+/+ mice. Nlrp3-/- ...[more]

PMID: 36494392

Similar Datasets

Project description:BackgroundNeospora caninum is an intracellular parasite that causes significant economic losses in cattle industry. Understanding the host resistance mechanisms in the innate immune response to neosporosis could facilitate the exploration of approaches for controlling N. caninum infection. The NLR inflammasome is a multiprotein platform in the cell cytoplasm and plays critical roles in the host response against microbes.MethodsNeospora caninum-infected wild-type (WT) macrophages and Nlrp3 -/- macrophages, and inhibitory approaches were used to investigate inflammasome activation and its role in N. caninum infection. Inflammasome RT Profiler PCR Arrays were used to identify the primary genes involved in N. caninum infection. The expression of the sensor protein NLRP3, processing of caspase-1, secretion of IL-1β and cell death were detected. Neospora caninum replication in macrophages was also assessed.ResultsMany NLR molecules participated in the recognition of N. caninum, especially the sensor protein NLRP3, and further study revealed that the NLRP3 distribution became punctate in the cell cytoplasm, which facilitated inflammasome activation. Inflammasome activation-mediated caspase-1 processing and IL-1β cleavage in response to N. caninum infection were observed and were correlated with the time of infection and number of infecting parasites. LDH-related cell death was also observed, and this death was regarded as beneficial for the clearance of N. caninum. Treatment of N. caninum-infected macrophages with caspase-1, pan-caspase and NLRP3 inhibitors led to the impaired release of active IL-1β and a failure to restrict parasite replication. And Neospora caninum infected peritoneal macrophages from Nlrp3-deficient mice displayed greatly decreased release of active IL-1β and the failure of caspase-1 cleavage.ConclusionsThe NLRP3 inflammasome can be activated in N. caninum-infected macrophages, and plays a protective role in the host response to control N. caninum.

Project description:BackgroundGranulocyte-macrophage colony-stimulating factor (GM-CSF) has emerged as a crucial cytokine that activates myeloid cells to initiate tissue inflammation. However, the molecular actions of GM-CSF against innate immunity are still poorly characterized. Here, we investigated the in vitro effects of GM-CSF on the activation of human myeloid lineages, neutrophils, and the underlying intracellular signaling mechanism, including inflammasome activation.MethodsHuman neutrophils were stimulated with GM-CSF in the presence or absence of tofacitinib. The cellular supernatants were analyzed for interleukin-1 beta (IL-1β) and caspase-1 by enzyme-linked immunosorbent assay (ELISA) methods. Pro-IL-1β mRNA expressions in human neutrophils were analyzed by real-time polymerase chain reaction. Protein phosphorylation of neutrophils was assessed by Western blot using phospho-specific antibodies.ResultsStimulation with GM-CSF alone, but not tumor necrosis factor-alpha, was shown to increase the release of IL-1β and cleaved caspase-1 (p20) from human neutrophils. Tofacitinib, which inhibits GM-CSF-induced Janus kinase 2 (Jak2)-mediated signal transduction, completely abrogated GM-CSF-induced IL-1β and caspase-1 (p20) secretion from neutrophils. GM-CSF stimulation also induced pro-IL-1β mRNA expression in neutrophils and induced NLR family pyrin domain-containing 3 (NLRP3) protein expression. Although tofacitinib pretreatment marginally inhibited GM-CSF-induced pro-IL-1β mRNA expression, tofacitinib completely abrogated NLRP3 protein expression in neutrophils.ConclusionsThese results indicate that GM-CSF signaling induces NLRP3 expression and subsequent IL-1β production by affecting neutrophils, which may cause the activation of innate immunity. Therefore, GM-CSF is a key regulator of the NLRP3 inflammasome and IL-1β production by activating innate immune cells. This process can be blocked by tofacitinib, which interferes with JAK/STAT signaling pathways.

Dataset Information

NLRP3 inflammasome activation in neutrophils directs early inflammatory response in murine peritonitis.

Publications

NLRP3 inflammasome activation in neutrophils directs early inflammatory response in murine peritonitis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets