Local restriction of sterile inflammation by auto-inhibitory regulation of S100A8/S100A9-alarmin activity
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ABSTRACT:
PROVIDER: PRJNA430869 | ENA |
REPOSITORIES: ENA
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Project description:Autoimmune diseases, like psoriasis or arthritis, show a patchy distribution of inflammation despite systemic dysregulation of adaptive immunity. Thus, additional tissue-derived signals like Danger-Associated Molecular Pattern molecules (DAMPs) are indispensable for manifestation of local inflammation. S100A8/100A9-complexes are the most abundant DAMPs in many autoimmune diseases. However, regulatory mechanisms locally restricting DAMP-activities are barely understood. We now unravel for the first time a novel mechanism of auto-inhibition in mice and man restricting S100-DAMP activity to local sites of inflammation. Combining protease degradation, pull-down assays, mass spectrometry and targeted mutations we identified specific peptide sequences within the second calcium-binding EF-hands triggering TLR4/MD2-dependent inflammation. These binding sites are free when S100A8/S100A9-heterodimers are released at sites of inflammation. Subsequently, S100A8/S100A9-activities are locally restricted by calcium-induced (S100A8/S100A9)2-tetramer formation now hiding the TLR4/MD2-binding site within the tetramer interphase thus preventing undesirable systemic effects. Loss of this auto-inhibitory mechanism in vivo results in TNFa-driven fatal inflammation as shown by lack of tetramer formation crossing S100A9-/- mice with two independent TNFa-transgene mouse strains. Since S100A8/S100A9 is the most abundant DAMP in many inflammatory diseases, specifically blocking of the TLR4-binding site of active S100-dimers represents an innovative approach for local suppression of inflammatory diseases avoiding systemic side effects.
2019-04-08 | GSE109426 | GEO
Project description:In order to explore how S100A8 and S100A9 may participate in the kidney stone formation, we used recombinant S100A8, recombinant S100A9, or recombinant S100A8/S100A9 heterodimer to culture the HK-2 cells and then sequenced total cellular mRNAS.
2024-11-06 | GSE265848 | GEO
Project description:We identified the alarmin S100A9 as a novel intracellular antiretroviral factor expressed in human monocyte-derived and skin-derived Langerhans cells (LC). The expression of S100A9 is significantly upregulated by the transforming growth factor beta in human monocyte-derived cells. We showed that S100A9 intracellular expression is decreased upon maturation and inversely correlated with an enhanced inversely correlates with the maturation level of LC and susceptibilityility to HIV-1 infection of LC. Furthermore, silencing of S100A9 in primary human LC relieves HIV-1 restriction while ectopic expression of S100A9 in various cell lines established an intrinsic resistance to both HIV-1 and MMLV infection by acting on reverse transcription. Mechanistically, the intracellular expression of S100A9 alters viral capsid uncoating and reverse transcription in a distal manner. Also, S100A9 demonstrates potent inhibitory effect against HIV-1 and MMLV reverse transcriptase (RTase) activity in-vitro in a divalent cation-dependent context. Our findings uncover an unexpected intracellular antiretroviral function of the human alarmin S100A9 and highlight a novel crosstalk betweenregulating antiretroviral immunity in Langerhans cells
2021-05-06 | GSE173939 | GEO
Project description:In an inducible model of human breast cellular transformation, we map genome-wide chromatin binding of S100A8, S100A9 and Pol II. We show that the calcium-dependent cytokines S100A8 and S100A9 are recruited to numerous promoters and enhancers. This recruitment is associated with multiple DNA sequence motifs recognized by DNA-binding transcription factors that are linked to transcriptional activation and are important for transformation. Nuclear-specific expression of S100A8/A9 promotes oncogenic transcription and leads to enhanced breast transformation phenotype. These results suggest that, in addition to its classical cytokine function, S100A8/A9 can act as a transcriptional co-activator.
2021-01-01 | GSE155421 | GEO
Project description:Autoimmune diseases, such as psoriasis and arthritis, show a patchy distribution of inflammation despite systemic dysregulation of adaptive immunity. Thus, additional tissue-derived signals, such as danger-associated molecular patterns (DAMPs), are indispensable for manifestation of local inflammation. S100A8/S100A9 complexes are the most abundant DAMPs in many autoimmune diseases. However, regulatory mechanisms locally restricting DAMP activities are barely understood. We now unravel for the first time, to our knowledge, a mechanism of autoinhibition in mice and humans restricting S100-DAMP activity to local sites of inflammation. Combining protease degradation, pull-down assays, mass spectrometry, and targeted mutations, we identified specific peptide sequences within the second calcium-binding EF-hands triggering TLR4/MD2-dependent inflammation. These binding sites are free when S100A8/S100A9 heterodimers are released at sites of inflammation. Subsequently, S100A8/S100A9 activities are locally restricted by calcium-induced (S100A8/S100A9)2 tetramer formation hiding the TLR4/MD2-binding site within the tetramer interphase, thus preventing undesirable systemic effects. Loss of this autoinhibitory mechanism in vivo results in TNF-α-driven fatal inflammation, as shown by lack of tetramer formation in crossing S100A9-/- mice with 2 independent TNF-α-transgene mouse strains. Since S100A8/S100A9 is the most abundant DAMP in many inflammatory diseases, specifically blocking the TLR4-binding site of active S100 dimers may represent a promising approach for local suppression of inflammatory diseases, avoiding systemic side effects.
| S-EPMC5919817 | biostudies-literature
Project description:Damage-associated molecular pattern (DAMP) molecules S100A8 and S100A9 with well-known functions in inflammation, tumor growth and metastasis. It has been found to have promote tumor cell proliferation activity at low concentration . However, the mechanism underlying this remains unclear. In the current study, we performed genome expression profiling analysis using the Affymetrix genome wide microarray system to identify broad scale changes in gene expression associated with S100a8 or S100a9 recombinant protein stimulation in murine colon carcinoma cell line CT26.WT.
2015-11-29 | GSE53735 | GEO
Project description:Biological effects of recombinant S100A8, recombinant S100A9, and recombinant S100A8/S100A9 on human renal tubular epithelial cells (HK-2)
| PRJNA1104534 | ENA
Project description:Alarmins S100A8 and S100A9 are endogenous molecules released in response to environmental triggers and cellular damage. They are constitutively expressed in immune cells such as monocytes and neutrophils and their expression is upregulated under inflammatory conditions. The molecular mechanisms that regulate inflammatory pathways in tendinopathy are largely unknown therefore identifying early immune effectors is essential to understanding the pathology. Based on our previous investigations highlighting tendinopathy as an alarmin mediated pathology we sought evidence of S100A8 & A9 expression in a human model of tendinopathy and thereafter, to explore mechanisms whereby S100 proteins may regulate release of inflammatory mediators and matrix synthesis in human tenocytes. Immunohistochemistry and quantitative RT-PCR showed S100A8 & A9 expression was significantly upregulated in tendinopathic tissue compared with control. Furthermore, treating primary human tenocytes with exogenous S100A8 & A9 significantly increased protein release of IL-6, IL-8, CCL2, CCL20 and CXCL10; however, no alterations in genes associated with matrix remodelling were observed at a transcript level. We propose S100A8 & A9 participate in early pathology by modulating the stromal microenvironment and influencing the inflammatory profile observed in tendinopathy. S100A8 and S100A9 may participate in a positive feedback mechanism involving enhanced leukocyte recruitment and release of pro-inflammatory cytokines from tenocytes that perpetuates the inflammatory response within the tendon in the early stages of disease.
| S-EPMC6365574 | biostudies-literature
Project description:Setd2, the histone H3 lysine 36 methyltransferase, plays an important role in the pathogenesis of hematologic malignancies. The research on the role of Setd2 in leukemogenesis has made great progress, but its role in MDS is still unknown. Here, we knock out Setd2 in the NUP98-HOXD13 transgenic (NHD13 Tg) mouse, and demonstrate that loss of Setd2 accelerates the transformation of MDS into AML. The conditional deletion of Setd2 also interferes the differentiation of hematopoietic stem and progenitor cells (HSPCs), and results in the decrease of granulocyte monocyte progenitor (GMP) cells, increase of megakaryocyte erythroid progenitor (MEP) cells and common myeloid progenitor (CMP) cells. Loss of Setd2 impairs erythroid differentiation, includes cell cycle arrest in G2-M and enhances the selt-renewal ability of HSPCS. Our RNA-seq,ChIP-seq and WGBS analysis indicats that S100A8 and S100A9 are direct target genes of H3K36me3 and expression of heterodimeric S100 calcium-binding proteins S100A8 and S100A9 are downregulated in HSPCs when Setd2 deficiency. Addition of recombinant S100A8 or S100A9 weakens the clonogenic progenitors of Setd2 deficient HSPCs. Therefore, our results demonstrate that loss of Setd2 promotes the transformation of MDS into AML, which proves Setd2 as a tumor suppressor in MDS, and provides a potential therapeutic target for MDS associated leukemia.
2020-07-02 | GSE129691 | GEO
Project description:Previous studies showed that S100A8 and S100A9 are involved in neovascularization as well as in tumor development. At high concentrations, S100A8 and S100A9 cause inflammatory response or apoptosis mediated damage in vascular endothelial cells. But the effect of low concentrations of such proteins on endothelial cells remains unknown. This assay was performed to screen for genes that are involved in the response of Human Unbilican Vascular Endothelial Cells to low concentrations of S100A8. Human Umblical Vascular Endothelial Cells (HUVEC) were cultuered and treated with 10ug/mL S100A8 proteins for 4 or 24 hours. Gene profiling was carried out using two-color microarray. Two-condition experiment, S100A8 treatment vs. non-treatment. Two time points: 4 hours and 24 hours. Biological replicates at each time point: 3 control replicates, 3 treatment replicates.
2011-11-20 | E-GEOD-33768 | biostudies-arrayexpress