Project description:Human blood monocytes were differentiated over six days with either 100 ng/ml M-CSF or 1 umol/l CXCL4 In atherosclerotic arteries, blood monocytes differentiate to macrophages in the presence of growth factors like macrophage colony-stimulation factor (MCSF) and chemokines like platelet factor 4 (CXCL4). To compare the gene expression signature of CXCL4-induced macrophages with MCSF-induced macrophages or macrophages polarized with IFN-γ/LPS (M1) or IL-4 (M2), we cultured primary human peripheral blood monocytes for six days. mRNA expression was measured by Affymetrix gene chips and differences were analyzed by Local Pooled Error test, Profile of Complex Functionality and Gene Set Enrichment Analysis. 375 genes were differentially expressed between MCSF- and CXCL4-induced macrophages, 206 of them overexpressed in CXCL4 macrophages coding for genes implicated in the inflammatory/immune response, antigen processing/presentation, and lipid metabolism. CXCL4-induced macrophages overexpressed some M1 and M2 genes and the corresponding cytokines at the protein level, however, their transcriptome clustered with neither M1 nor M2 transcriptomes. They almost completely lost the ability to phagocytose zymosan beads. Genes linked to atherosclerosis were not consistently up- or downregulated. Scavenger receptors showed lower and cholesterol efflux transporters higher expression in CXCL4- than MCSF-induced macrophages, resulting in lower LDL content. We conclude that CXCL4 induces a unique macrophage transcriptome distinct from known macrophage types, defining a new macrophage differentiation that we propose to call M4. two MCSF samples and two CXCL4 samples
Project description:Human blood monocytes were differentiated over six days with either 100 ng/ml M-CSF or 1 umol/l CXCL4 In atherosclerotic arteries, blood monocytes differentiate to macrophages in the presence of growth factors like macrophage colony-stimulation factor (MCSF) and chemokines like platelet factor 4 (CXCL4). To compare the gene expression signature of CXCL4-induced macrophages with MCSF-induced macrophages or macrophages polarized with IFN-γ/LPS (M1) or IL-4 (M2), we cultured primary human peripheral blood monocytes for six days. mRNA expression was measured by Affymetrix gene chips and differences were analyzed by Local Pooled Error test, Profile of Complex Functionality and Gene Set Enrichment Analysis. 375 genes were differentially expressed between MCSF- and CXCL4-induced macrophages, 206 of them overexpressed in CXCL4 macrophages coding for genes implicated in the inflammatory/immune response, antigen processing/presentation, and lipid metabolism. CXCL4-induced macrophages overexpressed some M1 and M2 genes and the corresponding cytokines at the protein level, however, their transcriptome clustered with neither M1 nor M2 transcriptomes. They almost completely lost the ability to phagocytose zymosan beads. Genes linked to atherosclerosis were not consistently up- or downregulated. Scavenger receptors showed lower and cholesterol efflux transporters higher expression in CXCL4- than MCSF-induced macrophages, resulting in lower LDL content. We conclude that CXCL4 induces a unique macrophage transcriptome distinct from known macrophage types, defining a new macrophage differentiation that we propose to call M4.
Project description:To investigate the function of RIPK3 in regulation of IFN response and inflammatory response in human monocytes stimulated with CXCL4 and TLR8, We blocks (CXCL4 + TLR8)-induced pyroptosis and RIPK3 activation using necrosulfonamide (NSA, 5 µM) and GSK'872 (10 µM) and measure gene expression genome-wide with RNA-seq.
Project description:Analyze the effect of TLR9 deficiency on immue cell function at the gene expression level. Our hypothesis was that TLR9 deficiency promotes CD73 expression in T cells thus regulates autoimmune diabetes development in NOD mice.
Project description:Fibrosis is a condition shared by numerous inflammatory diseases. The molecular mechanisms underlying fibrosis have remained incompletely understood severely hampering drug development. CXCL4 is associated with the onset and extent of fibrosis development in systemic sclerosis (SSc), a prototypic inflammatory and fibrotic disease. Here, we integrated 65 paired sequential whole genome transcriptional and methylation profiles from monocyte-derived cells as they respond to CXCL4 exposure. Using data-driven gene regulatory network analyses, we demonstrate that CXCL4 dramatically alters monocyte differentiation trajectory inducing a novel pro-inflammatory and pro-fibrotic phenotype mediated via key regulators such as CIITA and IRF8. Importantly, these CXCL4 exposed pro-inflammatory cells trigger a fibrosis cascade by directly producing ECM molecules and by inducing myofibroblast differentiation. Underscoring the computationally identified gene regulatory network, inhibition of CIITA mimicked CXCL4 inducing pro-inflammatory and pro-fibrotic phenotype. Our study uncovers CXCL4 as the endogenous ligand driving innate immune training and forming the long-sought link between inflammation and fibrosis. This SuperSeries is composed of the SubSeries listed below. Correspondence to: Prof. Timothy RDJ Radstake (T.R.D.J.Radstake@umcutrecht.nl) and Dr. Aridaman Pandit (A.Pandit@umcutrecht.nl)
Project description:Analyze the effect of TLR9 deficiency on immue cell function at the gene expression level. Our hypothesis was that TLR9 deficiency promotes CD73 expression in T cells thus regulates autoimmune diabetes development in NOD mice. Sorted TCRb+ cells were pooled from several mice for furhter RNA extraction and cRNA labeling.
Project description:Fibrosis is a condition shared by numerous inflammatory diseases. The molecular mechanisms underlying fibrosis have remained incompletely understood severely hampering drug development. CXCL4 is associated with the onset and extent of fibrosis development in systemic sclerosis (SSc), a prototypic inflammatory and fibrotic disease. Here, we integrated 65 paired sequential whole genome transcriptional and methylation profiles from monocyte-derived cells as they respond to CXCL4 exposure. Using data-driven gene regulatory network analyses, we demonstrate that CXCL4 dramatically alters monocyte differentiation trajectory inducing a novel pro-inflammatory and pro-fibrotic phenotype mediated via key regulators such as CIITA and IRF8. Importantly, these CXCL4 exposed pro-inflammatory cells trigger a fibrosis cascade by directly producing ECM molecules and by inducing myofibroblast differentiation. Underscoring the computationally identified gene regulatory network, inhibition of CIITA mimicked CXCL4 inducing pro-inflammatory and pro-fibrotic phenotype. Our study uncovers CXCL4 as the endogenous ligand driving innate immune training and forming the long-sought link between inflammation and fibrosis. Correspondence to: Prof. Timothy RDJ Radstake (T.R.D.J.Radstake@umcutrecht.nl) and Dr. Aridaman Pandit (A.Pandit@umcutrecht.nl)
Project description:Fibrosis is a condition shared by numerous inflammatory diseases. The molecular mechanisms underlying fibrosis have remained incompletely understood severely hampering drug development. CXCL4 is associated with the onset and extent of fibrosis development in systemic sclerosis (SSc), a prototypic inflammatory and fibrotic disease. Here, we integrated 65 paired sequential whole genome transcriptional and methylation profiles from monocyte-derived cells as they respond to CXCL4 exposure. Using data-driven gene regulatory network analyses, we demonstrate that CXCL4 dramatically alters monocyte differentiation trajectory inducing a novel pro-inflammatory and pro-fibrotic phenotype mediated via key regulators such as CIITA and IRF8. Importantly, these CXCL4 exposed pro-inflammatory cells trigger a fibrosis cascade by directly producing ECM molecules and by inducing myofibroblast differentiation. Underscoring the computationally identified gene regulatory network, inhibition of CIITA mimicked CXCL4 inducing pro-inflammatory and pro-fibrotic phenotype. Our study uncovers CXCL4 as the endogenous ligand driving innate immune training and forming the long-sought link between inflammation and fibrosis. Correspondence to: Prof. Timothy RDJ Radstake (T.R.D.J.Radstake@umcutrecht.nl) and Dr. Aridaman Pandit (A.Pandit@umcutrecht.nl)
Project description:CXCL4 activates myeloid cells and augments endosomal TLR responses contributing to the pathogenesis of inflammatory and fibrotic diseases. However, the underlying mechanisms are not well defined because the receptor(s) that mediates CXCL4 inflammatory responses is not known and downstream signaling pathways leading to gene induction are not well characterized. Here we report that CXCL4 activates inflammatory and tissue repair/fibrotic gene expression in human primary macrophages ex vivo and regulates macrophage skin infiltration and promotes skin wound healing in vivo.