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: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: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:To gain a comprehensive understanding of gene regulation in CXCL4 and TLR8 signaling crosstalk, we treated primary human blood monocytes with CXCL4 and TLR8 ssRNA ligand ORN8L for 6 h and performed transcriptomic analysis via RNA-seq. We observed that CXCL4 interacted with TLR8 ssRNA ligand and triggered inflammatory cytokine storm including IL6, IL12p40, TNF and IFNβ, and pro-fibrotic gene expression and activated NLRP3 inflammasome leading to interleukin-1β (IL-1β) secretion and pyroptosis in human blood monocytes.
Project description:To gain a comprehensive understanding of gene regulation in CXCL4 and TLR8 signaling crosstalk, we treated primary human blood monocytes with CXCL4 and TLR8 ssRNA ligand ORN8L for 6 h and performed transcriptomic analysis via RNA-seq. We observed that CXCL4 interacted with TLR8 ssRNA ligand and triggered inflammatory cytokine storm including IL6, IL12p40, TNF and IFNβ, and pro-fibrotic gene expression and activated NLRP3 inflammasome leading to interleukin-1β (IL-1β) secretion and pyroptosis in human blood monocytes.
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:Patients with resectable solid primary cancers and even limited number of metastases are potentially curable. However, most patients develop recurrences despite surgery. Also, early detection of lung cancer with low dose CT screening may cure patients at an early stage. Circulating and disseminated tumor cell (CTC/DTC) and circulating cell-free (cf) DNA isolation from the blood, urine and bone marrow will increase understanding of cancer spread and advance knowledge to develop individualized therapies and improve screening.