title: Differential regulation of angiogenic cellular processes and claudin-5 by histamine and VEGF via PI3K-signaling, transcription factor SNAI2 and interleukin-8.
abstract: OBJECTIVE
  Histamine and vascular endothelial growth factor A (VEGF) are central regulators in vascular pathologies. Their gene regulation leading to vascular remodeling has remained obscure. In this study, EC regulation mechanisms of histamine and VEGF were compared by RNA sequencing of primary endothelial cells (ECs), functional in vitro assays and in vivo permeability mice model.
  
  
  RESULTS
  By RNA sequencing, similar transcriptional alterations of genes involved in activation of primary ECs, cell proliferation and adhesion were observed between histamine and VEGF. Seventy-six commonly regulated genes were found, representing ~53% of all VEGF-regulated transcripts and ~26% of all histamine-regulated transcripts. Both factors regulated tight junction formation and expression of pro-angiogenic transcription factors (TFs) affecting EC survival, migration and tube formation. Novel claudin-5 upstream regulatory genes were identified. VEGF was demonstrated to regulate expression of SNAI2, whereas pro-angiogenic TFs NR4A1, MYCN and RCAN1 were regulated by both histamine and VEGF. Claudin-5 was shown to be regulated VEGFR2/PI3K-Akt dependently by VEGF and PI3K-Akt independently by histamine. Interleukin-8 was shown to downregulate claudin-5 by histamine. Additionally, SNAI2, NR4A1 and MYCN were shown to mediate EC survival, migration and tube formation and to regulate expression of claudin-5. Further systemic delivery of VEGF and histamine was shown to induce a fast vascular hyperpermeability response in intact vasculature of C57/Bl6 mice followed by regulation of NR4A1 and MYCN.
  
  
  CONCLUSIONS
  Our study identifies novel claudin-5 upstream regulatory genes of histamine and VEGF that induce cellular angiogenic processes. Our results increase knowledge of angiogenic EC phenotype and provide novel treatment targets for vascular pathologies.
authors.affiliation: Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland. johanna.p.laakkonen@uef.fi.
authors.forename: Johanna P
authors.initials: JP
authors.lastname: Laakkonen
authors.affiliation: Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.
authors.forename: Jari P
authors.initials: JP
authors.lastname: Lappalainen
authors.affiliation: Department of Pathology, CARIM, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Theelen
authors.affiliation: Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.
authors.forename: Pyry I
authors.initials: PI
authors.lastname: Toivanen
authors.affiliation: Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.
authors.forename: Tiina
authors.initials: T
authors.lastname: Nieminen
authors.affiliation: Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.
authors.forename: Suvi
authors.initials: S
authors.lastname: Jauhiainen
authors.affiliation: Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.
authors.forename: Minna U
authors.initials: MU
authors.lastname: Kaikkonen
authors.affiliation: Department of Pathology, CARIM, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Judith C
authors.initials: JC
authors.lastname: Sluimer
authors.affiliation: Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.
authors.forename: Seppo
authors.initials: S
authors.lastname: Ylä-Herttuala
mesh_terms: D000818:Animals; D002199:Capillary Permeability / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D062507:Claudin-5 / Q000235:genetics / Q000378:metabolism*; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D063990:Gene Ontology; D017228:Hepatocyte Growth Factor / Q000378:metabolism; D006632:Histamine / Q000494:pharmacology*; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism*; D008297:Male; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D018919:Neovascularization, Physiologic / Q000187:drug effects* / Q000235:genetics; D009928:Organ Specificity / Q000187:drug effects; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D000071250:Snail Family Transcription Factors / Q000378:metabolism*; D019108:Tight Junctions / Q000187:drug effects / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D059467:Transcriptome; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
chemical_list: D062507:Claudin-5; D016209:Interleukin-8; C000604408:SNAI2 protein, human; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; D042461:Vascular Endothelial Growth Factor A; D017228:Hepatocyte Growth Factor; D006632:Histamine; D019869:Phosphatidylinositol 3-Kinases; D040301:Vascular Endothelial Growth Factor Receptor-2
keywords: Angiogenesis; Endothelial cell proliferation; Histamine; Vascular endothelial growth factors; Vascular permeability