title: STAT1-dependent signal integration between IFNγ and TLR4 in vascular cells reflect pro-atherogenic responses in human atherosclerosis.
abstract: Signal integration between IFNγ and TLRs in immune cells has been associated with the host defense against pathogens and injury, with a predominant role of STAT1. We hypothesize that STAT1-dependent transcriptional changes in vascular cells involved in cross-talk between IFNγ and TLR4, reflect pro-atherogenic responses in human atherosclerosis. Genome-wide investigation identified a set of STAT1-dependent genes that were synergistically affected by interactions between IFNγ and TLR4 in VSMCs. These included the chemokines Cxcl9, Ccl12, Ccl8, Ccrl2, Cxcl10 and Ccl5, adhesion molecules Cd40, Cd74, and antiviral and antibacterial genes Rsad2, Mx1, Oasl1, Gbp5, Nos2, Batf2 and Tnfrsf11a. Among the amplified genes was also Irf8, of which Ccl5 was subsequently identified as a new pro-inflammatory target in VSMCs and ECs. Promoter analysis predicted transcriptional cooperation between STAT1, IRF1, IRF8 and NFκB, with the novel role of IRF8 providing an additional layer to the overall complexity. The synergistic interactions between IFNγ and TLR4 also resulted in increased T-cell migration and impaired aortic contractility in a STAT1-dependent manner. Expression of the chemokines CXCL9 and CXCL10 correlated with STAT1 phosphorylation in vascular cells in plaques from human carotid arteries. Moreover, using data mining of human plaque transcriptomes, expression of a selection of these STAT1-dependent pro-atherogenic genes was found to be increased in coronary artery disease (CAD) and carotid atherosclerosis. Our study provides evidence to suggest that in ECs and VSMCs STAT1 orchestrates a platform for cross-talk between IFNγ and TLR4, and identifies a STAT1-dependent gene signature that reflects a pro-atherogenic state in human atherosclerosis.
authors.affiliation: Department of Nephrology, Klinikum rechts der Isar, Technical University Munich, Munich, Germany; Department of Human Molecular Genetics, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University Poznan, Poznan, Poland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Chmielewski
authors.affiliation: Department of Human Molecular Genetics, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University Poznan, Poznan, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Olejnik
authors.affiliation: Department of Human Molecular Genetics, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University Poznan, Poznan, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Sikorski
authors.affiliation: Department of Vascular and Endovascular Surgery, Klinikum rechts der Isar, Technical University Munich, Munich, Germany.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Pelisek
authors.affiliation: Department of Human Molecular Genetics, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University Poznan, Poznan, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Błaszczyk
authors.affiliation: Department of Nephrology, Klinikum rechts der Isar, Technical University Munich, Munich, Germany.
authors.forename: Cristiane
authors.initials: C
authors.lastname: Aoqui
authors.affiliation: Laboratory of High-throughput Technologies, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University Poznan, Poznan, Poland.
authors.forename: Hanna
authors.initials: H
authors.lastname: Nowicka
authors.affiliation: Department of Vascular and Endovascular Surgery, Klinikum rechts der Isar, Technical University Munich, Munich, Germany; German Centre for Cardiovascular Research, partner site Munich Heart Alliance, Munich, Germany.
authors.forename: Alma
authors.initials: A
authors.lastname: Zernecke
authors.affiliation: Department of Nephrology, Klinikum rechts der Isar, Technical University Munich, Munich, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Heemann
authors.affiliation: Laboratory of High-throughput Technologies, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University Poznan, Poznan, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Wesoly
authors.affiliation: Department of Nephrology, Klinikum rechts der Isar, Technical University Munich, Munich, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Baumann
authors.affiliation: Department of Human Molecular Genetics, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University Poznan, Poznan, Poland.
authors.forename: Hans A R
authors.initials: HA
authors.lastname: Bluyssen
mesh_terms: D050197:Atherosclerosis / Q000235:genetics* / Q000473:pathology; D001773:Blood Cells; D054370:Chemokine CXCL9 / Q000096:biosynthesis; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D050856:Interferon Regulatory Factor-1 / Q000096:biosynthesis; D007371:Interferon-gamma / Q000096:biosynthesis / Q000235:genetics; D016328:NF-kappa B / Q000096:biosynthesis / Q000235:genetics; D010766:Phosphorylation; D050794:STAT1 Transcription Factor / Q000096:biosynthesis / Q000235:genetics*; D015398:Signal Transduction / Q000235:genetics; D051197:Toll-Like Receptor 4 / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D054370:Chemokine CXCL9; C494257:IRF1 protein, human; D050856:Interferon Regulatory Factor-1; D016328:NF-kappa B; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D007371:Interferon-gamma