Caspase-8 and FADD prevent spontaneous ZBP1 expression and necroptosis
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE208744 | GEO | 2022/09/19
REPOSITORIES: GEO
Similar Datasets
Project description:Necroptosis is a lytic form of cell death that is mediated by the kinase RIPK3 and the pseudokinase MLKL when caspase-8 is inhibited downstream of death receptors, toll-like receptor 3 (TLR3), TLR4, and the intracellular Z-form nucleic acid sensor ZBP1. Oligomerization and activation of RIPK3 is driven by interactions with the kinase RIPK1, the TLR adaptor TRIF, or ZBP1. In this study, we use immunohistochemistry (IHC) and in situ hybridization (ISH) assays to generate a tissue atlas characterizing RIPK1, RIPK3, Mlkl, and ZBP1 expression in mouse tissues. RIPK1, RIPK3, and Mlkl were co-expressed in most immune cell populations, endothelial cells, and many mucosal epithelia. ZBP1 was expressed in many immune populations, but had more variable expression in epithelia compared to RIPK1, RIPK3, and Mlkl. Intriguingly, expression of ZBP1 was elevated in Casp8-/- Tnfr1-/- embryos prior to their succumbing to aberrant necroptosis around embryonic day 15. ZBP1 contributed to this embryonic lethality because rare Casp8-/- Tnfr1-/- Zbp1-/- mice survived until after birth. Necroptosis mediated by TRIF contributed to the demise of Casp8-/- Tnfr1-/- Zbp1-/- pups in the perinatal period. Of note, Casp8-/- Tnfr1-/- Trif-/- Zbp1-/- mice exhibited autoinflammation and morbidity, typically within 5-7 weeks of being born, which is not seen in Casp8-/- Ripk1-/- Trif-/- Zbp1-/-, Casp8-/- Ripk3-/-, or Casp8-/- Mlkl-/- mice. Therefore, after birth, loss of caspase-8 probably unleashes RIPK1-dependent necroptosis driven by death receptors other than TNFR1.
2024-04-01 | GSE254754 | GEO
Project description:Ionizing radiation promotes cytosolic DNA sensing and consequent antitumor immune responses. But how tumor cell-intrinsic cytosolic DNA sensing is initiated by radiation remains poorly defined. Here, we demonstrated that STING-mediated type I interferon production in tumor cells after radiation relied on the engagement of MLKL-mediated necroptosis, which was elicited by the ZBP1-RIPK3 signaling axis. Physiologically, tumor cell-intrinsic ZBP1-MLKL cascade augmented antitumor immune responses after radiation largely by regulating STING signaling. Mechanistically, ZBP1-MLKL-dependent necroptosis maintained the enrichment of mitochondria DNA inside the cytosol of tumor cells after radiation in a cell-density dependent fashion, contributing to type I interferon responses. In contrast, ablation of caspase-8 unleashed ZBP1-MLKL cascade to gain enhanced cytosolic DNA sensing, and in turn potentiated therapeutic effects of radiation. Thus, our findings uncover an unanticipated mechanism that ZBP1-MLKL-dependent necroptosis drives cytosolic DNA sensing-mediated antitumor immunity after radiation, and provide new strategy to improve radiotherapy by inhibiting caspase-8 cascade.
2021-10-13 | GSE168016 | GEO
Project description:FADD-IEC KO and CASP8 IEC-KO mice spontaneously develop chronic colitis charcterized by inflammatory gene expression. We characterized the role of MLKL, RIPK3, ZBP1, in the upregulation of inlflammatory genes in these mice. We used microarray to study the effect of MLKL, RIPK3 and ZBP1 on the gene expression profile in FADD IEC-KO and/or CASP8 IEC-KO mice and detect effects on specific inflammatory genes.
2020-05-01 | GSE137281 | GEO
Project description:FADD-IEC KO and CASP8 IEC-KO mice spontaneously develop chronic ileitis charcterized by inflammatory gene expression. We characterized the role of MLKL, RIPK3, ZBP1, in the upregulation of inlflammatory genes in these mice. We used microarray to study the effect of MLKL, RIPK3 and ZBP1 on the gene expression profile in FADD IEC-KO and/or CASP8 IEC-KO mice and detect effects on specific inflammatory genes.
2020-05-01 | GSE137280 | GEO
Project description:Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a well-known inducer of apoptosis via formation of the primary death-inducing signaling complex (TRAIL-DISC) at the level of membrane death receptors (DR4 and DR5) which recruit successively FADD and caspase-8. TRAIL can also induce necroptosis when caspases are inhibited. Necroptosis is a regulated cell death dependent on the formation of a cytosolic necrosome complex which includes RIPK1, RIPK3 and MLKL proteins. Elucidating the molecular mechanisms involved in TRAIL-induced necroptosis might provide new insights into the TRAIL death signaling pathway. Here, we report the analysis by mass spectrometry of endogenous RIPK3-dependent necrosome complex constituents upon necroptosis induced by TRAIL/z-VAD/Birinapant (TzB) in HT29 cells. Besides characterization of RIPK1, RIPK3, MLKL, FADD, caspase-8, we find TRIM21 as a new constituent of the necrosome complex. Moreover RIPK1, RIPK3, MLKL, P-MLKL, FADD, caspase-8 and TRIM21 are also found associated to the native TRAIL-DISC upon TzB stimulation showing initiation of the necrotic pathway at the level of TRAIL death receptors in HT29 cells. Finally, TRIM21 may positively modulate necroptosis induction by downregulating NF-kB activation.
2021-03-18 | PXD003383 | Pride
Project description:The RNA editing enzyme ADAR1 is essential for suppression of innate immune activation and pathology caused by aberrant recognition of self-RNA, a role it carries out by disrupting the duplex structure of endogenous double-stranded RNA species. A point mutation in the Z-nucleic-acid binding domain (ZBD) of ADAR1 is associated with severe autoinflammatory disease. ZBP1 is the only other ZBD-containing mammalian protein and its activation can trigger both cell death and transcriptional responses via the kinases RIPK1 and RIPK3, and the protease caspase-8. Here, we show that the pathology caused by ADAR1 ZBD mutation is driven by activation of ZBP1. We found that ablation of ZBP1 fully rescued the overt pathology caused by ADAR1 mutation, without reversing the underlying inflammatory program caused by this mutation. While loss of RIPK3 partially phenocopied the protective effects of ZBP1 ablation, combined deletion of caspase-8 and RIPK3, or of caspase-8 and MLKL, unexpectedly exacerbated the pathogenic effects of ADAR1 mutation. These findings indicate that ADAR1 is a negative regulator of sterile ZBP1 activation, and that ZBP1-dependent signaling underlies the autoinflammatory pathology caused by mutation of ADAR1.
2022-06-11 | GSE200854 | GEO
Project description:The RNA editing enzyme ADAR1 is essential for suppression of innate immune activation and pathology caused by aberrant recognition of self-RNA, a role it carries out by disrupting the duplex structure of endogenous double-stranded RNA species. A point mutation in the Z-nucleic-acid binding domain (ZBD) of ADAR1 is associated with severe autoinflammatory disease. ZBP1 is the only other ZBD-containing mammalian protein and its activation can trigger both cell death and transcriptional responses via the kinases RIPK1 and RIPK3, and the protease caspase-8. Here, we show that the pathology caused by ADAR1 ZBD mutation is driven by activation of ZBP1. We found that ablation of ZBP1 fully rescued the overt pathology caused by ADAR1 mutation, without reversing the underlying inflammatory program caused by this mutation. While loss of RIPK3 partially phenocopied the protective effects of ZBP1 ablation, combined deletion of caspase-8 and RIPK3, or of caspase-8 and MLKL, unexpectedly exacerbated the pathogenic effects of ADAR1 mutation. These findings indicate that ADAR1 is a negative regulator of sterile ZBP1 activation, and that ZBP1-dependent signaling underlies the autoinflammatory pathology caused by mutation of ADAR1.
2022-08-10 | GSE200985 | GEO
Project description:The RNA editing enzyme ADAR1 is essential for suppression of innate immune activation and pathology caused by aberrant recognition of self-RNA, a role it carries out by disrupting the duplex structure of endogenous double-stranded RNA species. A point mutation in the Z-nucleic-acid binding domain (ZBD) of ADAR1 is associated with severe autoinflammatory disease. ZBP1 is the only other ZBD-containing mammalian protein and its activation can trigger both cell death and transcriptional responses via the kinases RIPK1 and RIPK3, and the protease caspase-8. Here, we show that the pathology caused by ADAR1 ZBD mutation is driven by activation of ZBP1. We found that ablation of ZBP1 fully rescued the overt pathology caused by ADAR1 mutation, without reversing the underlying inflammatory program caused by this mutation. While loss of RIPK3 partially phenocopied the protective effects of ZBP1 ablation, combined deletion of caspase-8 and RIPK3, or of caspase-8 and MLKL, unexpectedly exacerbated the pathogenic effects of ADAR1 mutation. These findings indicate that ADAR1 is a negative regulator of sterile ZBP1 activation, and that ZBP1-dependent signaling underlies the autoinflammatory pathology caused by mutation of ADAR1.
2022-08-10 | GSE200986 | GEO
Project description:Mixed lineage kinase domain-like (MLKL) is the executioner in the caspase 8-independent form of programmed cell death called necroptosis. Once Receptor Interacting serine/threonine Protein Kinase 3 (RIPK3) is activated by upstream cell death signals, it phosphorylates MLKL and triggers the oligomerization and membrane translocation required for MLKL induced membrane disruption. Besides phosphorylation, MLKL also undergoes ubiquitylation during the early stages of necroptosis, yet neither the mechanism nor the significance of this event has been demonstrated. Here we show that necroptosis-specific, multi-mono-ubiquitylation of MLKL occurs on biological membranes, and requires its activation and oligomerisation. Inactive MLKL mutants recruited to membranes during necroptosis are ubiquitylated but this results in their proteasome and lysosome dependent turnover. We identified several ubiquitylated lysines however mutation of these did not affect MLKL ubiquitylation in response to a necroptotic stimulus.
2021-04-28 | PXD015537 | Pride
Project description:Necroptosis is a caspase-independent, pro-inflammatory mode of programmed cell death which relies on the activation of the terminal effector, MLKL, by the upstream protein kinase RIPK3. To mediate necroptosis, RIPK3 must stably interact with, and phosphorylate the pseudokinase domain of MLKL. While the precise molecular cue that prompts RIPK3 to activate MLKL is incompletely understood, it is known that RIPK3 is highly regulated by phosphorylation. Here, we sought to identify phosphorylation sites of RIPK3 and dissect their regulatory functions. Phosphoproteomics identified 21 phosphorylation sites in HT29 cells overexpressing human RIPK3. By comparing cells expressing wild-type and kinase-inactive D142N RIPK3, autophosphorylation sites and substrates of other cellular kinases were distinguished. Of these 21 phosphosites, extensive mutational analyses identified only pT224 and pS227 as crucial, synergistic sites for stable interaction with MLKL to promote necroptosis, while the recently reported activation loop phosphorylation at S164/T165 negatively regulate the kinase activity of RIPK3. Despite being able to phosphorylate MLKL to a similar or higher extent than the wild-type RIPK3, mutation of T224, S227, and RHIM in RIPK3 attenuated or compromised their abilities to mediate necroptosis. This finding highlights the stable recruitment of human MLKL by RIPK3 to the necrosome as an essential checkpoint in necroptosis signaling, which is independent from and precedes the phosphorylation of MLKL.
2022-07-30 | PXD033488 | Pride