Project description:The blood-brain barrier (BBB) protects the central nervous system (CNS) from external assaults by pathogenic or harmful substances. BBB impairment frequently occurs during infection, inflammatory, or other pathological conditions, which causes or exacerbates a wide range of CNS diseases. Using single cell transcriptomics, we show in this study that during systemic LPS challenges, brain endothelial cells undergo Gsdmd-mediated pyroptosis and impair the integrity of the BBB, leading to profound changes in the transcriptomic landscape of brain parenchymal populations. Analyses of the scRNA-seq dataset reveal that brain endothelial cells responded strongly to systemic LPS challenge. Further analyses of the transcriptional signatures revealed that the brain parenchymal populations displayed heterogeneous responses to BBB leakage accompanied by systemic inflammation.
Project description:Gasdermin D (GSDMD) is the executioner of pyroptosis, which is important for host defense against pathogen infection. After activation, caspase-mediated cleavage of GSDMD liberates an N-terminal fragment (GSDMD-NT), which oligomerizes and forms pores in the plasma membrane, leading to cell death and subsequent release of proinflammatory cytokines. How this process is spatiotemporally controlled to promote pyroptosis in cells has been a fundamental, unaddressed question. Here, we identify GSDMD as a substrate for reversible S-palmitoylation on cysteine 192 (Cys192) in response to lipopolysaccharide (LPS) stimulation. We found that the palmitoyl acyltransferase DHHC7palmitoylates GSDMD to direct its cleavage by caspases in pyroptosis by promoting the interaction of GSDMD and caspases. We further show that after GSDMD cleavage, palmitoylation of GSDMD-NTpromotes its plasma membrane translocation and binding, and then acyl protein thioesterase 2 (APT2) depalmitoylates GSDMD-NT to unmask the Cys192 residue to promote oxidation-mediated oligomerization and pyroptosis. Perturbation of either palmitoylation or depalmitoylation suppresses pyroptosis, extends the survival of mice from LPS-induced lethal septic shock and sensitizes mice to bacterial infection. Thus. our findings reveal a model through which a palmitoylation-depalmitoylationrelay spatially and temporally controls GSDMD activation in pyroptosis.
Project description:Gasdermin D (GSDMD) is the executioner of pyroptosis, which is important for host defense against pathogen infection. After activation, caspase-mediated cleavage of GSDMD liberates an N-terminal fragment (GSDMD-NT), which oligomerizes and forms pores in the plasma membrane, leading to cell death and subsequent release of proinflammatory cytokines. How this process is spatiotemporally controlled to promote pyroptosis in cells has been a fundamental, unaddressed question. Here, we identify GSDMD as a substrate for reversible S-palmitoylation on cysteine 192 (Cys192) in response to lipopolysaccharide (LPS) stimulation. We found that the palmitoyl acyltransferase DHHC7palmitoylates GSDMD to direct its cleavage by caspases in pyroptosis by promoting the interaction of GSDMD and caspases. We further show that after GSDMD cleavage, palmitoylation of GSDMD-NTpromotes its plasma membrane translocation and binding, and then acyl protein thioesterase 2 (APT2) depalmitoylates GSDMD-NT to unmask the Cys192 residue to promote oxidation-mediated oligomerization and pyroptosis. Perturbation of either palmitoylation or depalmitoylation suppresses pyroptosis, extends the survival of mice from LPS-induced lethal septic shock and sensitizes mice to bacterial infection. Thus. our findings reveal a model through which a palmitoylation-depalmitoylationrelay spatially and temporally controls GSDMD activation in pyroptosis.
Project description:We identified that GSDMD protected against DDS-induced colitis, and GSDMD deficiency in macrophages promoted the development of DSS-induced colitis.The purpose of this experiment was to identify how GSDMD protected against DSS-induced colitis.
Project description:We constructed one-cell stage embryos by maternal pronuclear (mPN) transfer having B6 ooplasm, B6 paternal PN (pPN), and either B6 or C3H mPN (BBB and BCB, respectively). We collected embryos of each type that were either treated (BBB+a, BCB+a) or untreated with α-amanitin (BBB, BCB) at the two-cell stage for microarray analysis. Comparison of the transcriptomes of these different kinds of embryos revealed genes for which expression differs according to maternal PN strain of origin, and the α-amanitin data revealed which of these differences is due to gene transcription, as opposed to any transcription-independent differences attributable to ooplasm-derived maternal mRNA pools. There are 4 replicates for each kind/treatment two-cell embryos (BBB, BCB, BBB+a, BCB+a).
Project description:A monolayer of hCMEC/D3 (BBB-EC) was grown in an insert. After reaching confluency, BBB-EC were treated with TNFa and IFNg for 24h. Next, BBB-EC were washed. Tregs were isolated from human blood (both healthy donors (HD)and untreated RRMS patients) and added to the upper chamber of the insert or were cultured in the BBB-EC medium as control (untouched_1). They were let to migrate for 24h and the upper fraction (non-migrated_2) and lower fraction (migrated_3) were collected.
Project description:We identified that GSDMD was required for the pathogenesis of EAE, and GSDMD deficiency in peripheral myeloid cells impaired the infiltration of immune cells into the CNS , leading to the suppression of neuroinflammation and demyelination.The purpose of this experiment was to identify how GSDMD induces EAE.
Project description:The NLRP3 inflammasome and IL-1β are essential for scleroderma pathogenesis. Nevertheless, the role of pyroptosis executor gasdermin D(GSDMD), which is a downstream molecule of NLRP3 and is required for IL-1β release in some situations, has not yet been well elucidated in scleroderma. The purpose of this study was to explore the differences in the degree of skin fibrosis between GSDMD-/- and wild type mice in a bleomycin-induced scleroderma model, and the molecular pathways that may be involved.Total RNA from skin biopsies from GSDMD-/- and wild type mice after subcutaneous injection of BLM to induce skin fibrosis was examined by nextGen RNA sequencing
Project description:Acute kidney injury(AKI) is associated with an increased risk of chronic kidney disease(CKD). There is still a lack of effective prevention for AKI-CKD transition. In the present study, we simultaneously explored the contribution of GSDMD and GSDME in folic acid (FA)-induced nephropathy, a model mimicking the essential components of the AKI-CKD transition. We found that blockage of both GSDMD and GSDME-mediated pyroptosis could have accumulative protection against FA-induced AKI-CKD transition. GSDME-mediated pyroptosis played a crucial role in tubular cell damage. GSDMD could exert important functions in infiltration of inflammatory cells and NETs formation. Pyroptotic tubular cells triggered NETs generation and macrophage polarization. NETs promoted macrophage-to-myofibroblast transition. Our results illustrated the orchestration of GSDMD and GSDME in AKI-CKD transition, providing new insights into the molecular mechanism for the clinical dilemma.