CD36-mediated lipid-accumulation in reactive microglia drives retinal degeneration through Nlrp3-IL-1β pathway
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE333417 | GEO | 2026/07/26
REPOSITORIES: GEO
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Project description:Lipid accumulation in microglia through CD36 enhances Nlrp3 inflammasome activation, contributing to retinal neurodegeneration.
2026-07-26 | GSE324526 | GEO
Project description:Lipid accumulation in microglia through CD36 enhances Nlrp3 inflammasome activation, contributing to retinal neurodegeneration.
2026-07-26 | GSE301932 | GEO
Project description:Lipid accumulation in microglia through CD36 enhances Nlrp3 inflammasome activation, contributing to retinal neurodegeneration.
2026-07-26 | GSE301934 | GEO
Project description:Microglia are central regulators of retinal immune homeostasis, yet their dysregulated responses can trigger neuroinflammation and drive retinal degeneration, a leading cause of irreversible blindness with limited therapeutic options. The specific pathogenic subsets and underlying mechanisms remain poorly defined. In this study, using single-cell RNA sequencing and spatial transcriptomics, we identified a distinct subset of lipid-accumulated reactive microglia (aLARM), predominantly localized to the ventral inferior retina in NaIO3-induced retinal degeneration mice, a region partially analogous to the human macula in terms of its susceptibility to neurodegenerative injury. In both patients and mouse models, this aLARM uniquely expresses high levels of CD36, which is critical for their formation and pathogenic function. Importantly, microglia-specific CD36 deletion abolished the aLARM-mediated retinal inflammation and degeneration, while subretinal transplantation of isolated CD36+ aLARM exacerbated the destruction of retinal structures and functional impairment. Furthermore, these aLARM subsets exhibited NLRP3 inflammasome activation and IL-1β production, which would activate IL-1R1 on microglia/macrophages and pericytes/ smooth muscle cells, amplifying a feed-forward inflammatory loop that worsened neurodegeneration. Finally, therapeutic blockade of CD36 using by the neutralizing antibody FA6-152 effectively reduced aLARM formationand protected against retinal degeneration. Together, our findings highlight CD36+ aLARM as a novel and targetable pathogenic microglial population that linksneuroinflammation to retinal degeneration, providing a potential foundation for microglia-based precision therapies in retinal degenerative disorders.
2026-07-26 | GSE324535 | GEO
Project description:Diabetic kidney disease (DKD) is the leading cause of end-stage kidney diseases resulting enormous social-economic burden. Accumulated evidence has indicated that C-reactive protein (CRP) exacerbates DKD by enhancing renal inflammation and fibrosis through TGF-β/Smad3 signaling. NLRP3 inflammasome is the key sensor contributing to renal inflammation. However, whether CRP enhances inflammation in DKD via NLRP3 inflammasome related pathway remains unknown. In this study, we demonstrate that CRP promotes DKD via Smad3-mediated NLRP3 inflammasome activation as mice overexpressing human CRP gene exhibits accelerated renal inflammation in diabetic kidneys, which is associated with the activation of Smad3 and NLRP3 inflammasome. In contrast, blockade of CPR signaling with a neutralizing anti-CD32 antibody attenuates CRP-induced activation of Smad3 and NLRP3 in vitro. Importantly, genetic deletion or pharmacological inhibition of Smad3 also mitigates CRP-induced activation of NLRP3 in diabetic kidneys or in high glucose treated cells. Mechanistically, we reveal that Smad3 binds to the NLRP3 gene promoter which is enhanced by CRP. Taken together, we conclude that CRP induces renal inflammation in DKD via to the Smad3-NLRP3 inflammasome-dependent mechanism. Thus, targeting CRP or Smad3-NLRP3 pathways may be a new therapeutic potential for DKD.
2025-01-29 | GSE271870 | GEO
Project description:Activation of the NACHT, LRR family pyrin domain containing 3 (NLRP3) inflammasome complex is an essential innate immune signalling mechanism. To reveal how NLRP3 inflammasome assembly and activation are controlled, in particular by components of the ubiquitin system, proximity labelling, affinity purification and RNAi screening approaches were performed. Our study provides an intricate time-resolved molecular map of different phases of NLRP3 inflammasome activation. We discovered that ubiquitin C-terminal hydrolase 1 (UCH-L1) interacts with the NACHT domain of NLRP3, and downregulation of UCH-L1 decreases pro-IL-1β levels. UCH-L1 chemical inhibition with small molecules interfered with NLRP3 puncta formation and ASC oligomerisation, leading to altered IL-1β cleavage and secretion, particularly in microglia cells, which exhibited elevated UCH-L1 expression as compared to monocytes/macrophages. Altogether, we profiled NLRP3 inflammasome activation dynamics and highlight UCH-L1 as an important modulator of NLRP3-mediated IL-1β production, suggesting that a pharmacological inhibitor of UCH-L1 may decrease inflammation-associated pathologies.
2024-04-24 | PXD045862 | Pride
Project description:Inflammasome, activated by pathogen-derived and host-derived danger signals, constitutes a multimolecular signaling complex that serves as a platform for caspase-1 (CASP1) activation and interleukin-1beta (IL1B) maturation. The activation of NLRP3 inflammasome requires two-step signals. The first “priming” signal (Signal 1) enhances gene expression of inflammasome components. The second “activation” signal (Signal 2) promotes the assembly of inflammasome components. Deregulated activation of NLRP3 inflammasome contributes to the pathological processes of Alzheimer’s disease (AD) and multiple sclerosis (MS). However, at present, the precise mechanism regulating NLRP3 inflammasome activation and deactivation remains largely unknown. By genome-wide gene expression profiling, we studied the molecular network of NLRP3 inflammasome activation-responsive genes in a human monocyte cell line THP-1 sequentially given two-step signals. We identified the set of 83 NLRP3 inflammasome activation-responsive genes. Among them, we found the NR4A nuclear receptor family NR4A1, NR4A2, and NR4A3, the EGR family EGR1, EGR2, and EGR3, the IkappaB family NFKBIZ, NFKBID, and NFKBIA as a key group of the genes that possibly constitute a negative feedback loop for shutting down inflammation following NLRP3 inflammasome activation. By molecular network analysis, we identified a complex network of NLRP3 inflammasome activation-responsive genes involved in cellular development and death, and immune and inflammatory responses, where transcription factors AP-1, NR4A, and EGR serve as a hub. Thus, NLRP3 inflammasome activation-responsive genes constitute the molecular network composed of a set of negative feedback regulators for prompt resolution of inflammation. To load the Signal 1 (S1), THP-1 cells were incubated for 3 hours in the culture medium with or without inclusion of 0.2 microgram/ml lipopolysaccharide (LPS). To load the Signal 2 (S2), they were incubated further for 2 hours in the culture medium with inclusion of 10 microM nigericin sodium salt dissolved in ethanol or the equal v/v% concentration of ethanol (vehicle), followed by processing for microarray analysis on Human Gene 1.0 ST Array (Affymetrix).
2014-07-01 | E-GEOD-58959 | biostudies-arrayexpress
Project description:The NLRP3 inflammasome is a multi-protein complex that triggers the activation of the inflammatory protein caspase-1 and the maturation of the cytokine IL-1 in response to microbes and other danger signals in host cells. Here, we sought a deeper understanding of how the NLRP3 inflammasome is regulated. We found that inflammasome activation induced the Src family kinase Lyn to phosphorylate NLRP3 at Tyr918, and that this phosphorylation of NLRP3 correlated with a subsequent increase in its ubiquitination, which facilitated its proteasome-mediated degradation. NLRP3 tyrosine phosphorylation and ubiquitination was abrogated in Lyn-deficient macrophages, which produced increased amounts of IL-1. Furthermore, mice lacking Lyn were highly susceptible to LPS-induced septic shock in an NLRP3-dependent manner. Our data demonstrate that Lyn-mediated tyrosine phosphorylation of NLRP3 is a prerequisite for its ubiquitination, thus dampening NLRP3 inflammasome activity.
2022-05-19 | PXD028582 | Pride
Project description:Cryopyrin-associated periodic syndrome (CAPS) is an autoinflammatory condition resulting from monoallelic NLRP3 variants that exacerbate IL-1 production. Although these are gain-of-function variants, the exact regulatory mechanism of the NLRP3-inflammasome in CAPS is not yet well understood. Despite being considered a hypersensitive inflammasome triggered by cell priming, patients with CAPS and animal models of the disease may present inflammatory flares even in the absence of identifiable external triggers. Herein, we found that CAPS-associated variants result in constitutively active NLRP3-inflammasome, which induce an increased basal cleavage of gasdermin D, IL-18 release and pyroptosis, with a concurrent basal pro-inflammatory gene expression signature, including the induction of nuclear receptors 4A. The constitutively active NLRP3-inflammasome was blocked by MCC950 and was dependent on NLRP3 expression level, further regulated by deubiquitination. Additionally, we determined that the activation of the NF-B pathway with lipopolysaccharide or other endogenous molecules (palmitate, S100A9, IL-6) further modulated the activation of the NLRP3-inflammasome in CAPS, thus expanding the repertoire of molecules secreted from patients’ macrophages involved in disease pathogenesis. NLRP3-inflammasomes with CAPS-associated variants mainly affected the immunometabolism of the myeloid compartment, leading to disruptions in lipids and amino acid pathways and impaired glycolysis, limiting IL-1β production. These findings demonstrate that NLRP3 variants causing CAPS form a constitutively active inflammasome that induces basal pyroptosis and IL-18 release without cell priming, favouring the host's innate defense against pathogens while also tempering the onset of IL-1β–dependent inflammatory episodes through immunometabolism modulation.
2023-12-13 | GSE246713 | GEO
Project description:Caspase-1 signaling in myeloid suppressor cells can promote T-cell independent cancer progression, but the regulation of inflammasome signaling within the highly heterogeneous myeloid cells in the tumor milieu remains elusive. To resolve this complexity, scRNA-seq of human head & neck carcinoma identified distinct inflammasome complex genes within specific clusters of tumor-infiltrating myeloid cells. Among these myeloid cells, NLRP3 sensor and downstream effector IL-1β transcripts were enriched in multiple monocytic and macrophage subtypes in the TME. In vivo, we showed that NLRP3, and not AIM2, phenocopied the caspase-1/IL-1β dependent tumor progression. Paradoxically, we found that myeloid-intrinsic caspase-1 signaling within the TME increased myeloid survival without significant intratumoral trafficking as would be predicted from their canonical pyroptotic function. Mechanistically, this myeloid NLRP3/IL-1β signaling axis promotion of tumor growth was found to be gasdermin D independent. When we probed for the tumor intrinsic factors that regulated NLRP3/IL-1β signaling, we found that mononuclear phagocyte-mediated efferocytosis of dying tumor cells in the TME directly activated NLRP3 dependent inflammasome signaling to drive IL-1β secretion and to promote tumor growth. Dynamic RNA velocity analysis of the single cell transcriptomic dataset showed a strong directional flow from efferocytosis gene-sethigh macrophages to an inflammasome gene-sethigh macrophage population. Cumulatively, we provide a novel inflammasome signaling axis between tumor apoptosis and myeloid cells that characterizes chronic inflammation induced malignancy.
2022-04-13 | GSE200560 | GEO