title: Uncovering a new role for peroxidase enzymes as drivers of angiogenesis.
abstract: Peroxidases are heme-containing enzymes released by activated immune cells at sites of inflammation. To-date their functional role in human health has mainly been limited to providing a mechanism for oxidative defence against invading bacteria and other pathogenic microorganisms. Our laboratory has recently identified a new functional role for peroxidase enzymes in stimulating fibroblast migration and collagen biosynthesis, offering a new insight into the causative association between inflammation and the pro-fibrogenic events that mediate tissue repair and regeneration. Peroxidases are found at elevated levels within and near blood vessels however, their direct involvement in angiogenesis has never been reported. Here we report for the first time that myeloperoxidase (MPO) and eosinophil peroxidase (EPO) are readily internalised by human umbilical vein endothelial cells (HUVEC) where they promote cellular proliferation, migration, invasion, and stimulate angiogenesis both in vitro and in vivo. These pro-angiogenic effects were attenuated using the specific peroxidase inhibitor 4-ABAH, indicating the enzyme's catalytic activity is essential in mediating this response. Mechanistically, we provide evidence that MPO and EPO regulate endothelial FAK, Akt, p38 MAPK, ERK1/2 phosphorylation and stabilisation of HIF-2α, culminating in transcriptional regulation of key angiogenesis pathways. These findings uncover for the first time an important and previously unsuspected role for peroxidases as drivers of angiogenesis, and suggest that peroxidase inhibitors may have therapeutic potential for the treatment of angiogenesis related diseases driven by inflammation.
authors.affiliation: School of Medicine, Discipline of Surgery, Basil Hetzel Institute, University of Adelaide, Adelaide, SA, Australia.
authors.forename: Vasilios
authors.initials: V
authors.lastname: Panagopoulos
authors.affiliation: School of Medicine, Discipline of Surgery, Basil Hetzel Institute, University of Adelaide, Adelaide, SA, Australia.
authors.forename: Irene
authors.initials: I
authors.lastname: Zinonos
authors.affiliation: School of Medicine, Discipline of Surgery, Basil Hetzel Institute, University of Adelaide, Adelaide, SA, Australia.
authors.forename: Damien A
authors.initials: DA
authors.lastname: Leach
authors.affiliation: School of Medicine, Discipline of Surgery, Basil Hetzel Institute, University of Adelaide, Adelaide, SA, Australia.
authors.forename: Shelley J
authors.initials: SJ
authors.lastname: Hay
authors.affiliation: School of Medicine, Discipline of Surgery, Basil Hetzel Institute, University of Adelaide, Adelaide, SA, Australia.
authors.forename: Vasilios
authors.initials: V
authors.lastname: Liapis
authors.affiliation: School of Medicine, Discipline of Surgery, Basil Hetzel Institute, University of Adelaide, Adelaide, SA, Australia.
authors.forename: Aneta
authors.initials: A
authors.lastname: Zysk
authors.affiliation: School of Medicine, Discipline of Surgery, Basil Hetzel Institute, University of Adelaide, Adelaide, SA, Australia.
authors.forename: Wendy V
authors.initials: WV
authors.lastname: Ingman
authors.affiliation: School of Medicine, Discipline of Surgery, Basil Hetzel Institute, University of Adelaide, Adelaide, SA, Australia.
authors.forename: Mark O
authors.initials: MO
authors.lastname: DeNichilo
authors.affiliation: School of Medicine, Discipline of Surgery, Basil Hetzel Institute, University of Adelaide, Adelaide, SA, Australia. Electronic address: andreas.evdokiou@adelaide.edu.au.
authors.forename: Andreas
authors.initials: A
authors.lastname: Evdokiou
mesh_terms: D000814:Aniline Compounds / Q000494:pharmacology*; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D001681:Biological Assay; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D003094:Collagen / Q000737:chemistry; D004338:Drug Combinations; D004705:Endocytosis / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D047209:Eosinophil Peroxidase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D005260:Female; D051417:Focal Adhesion Kinase 1 / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D007797:Laminin / Q000737:chemistry; D051379:Mice; D008807:Mice, Inbred BALB C; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D009195:Peroxidase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D011509:Proteoglycans / Q000737:chemistry; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D000814:Aniline Compounds; D051792:Basic Helix-Loop-Helix Proteins; D003094:Collagen; D004338:Drug Combinations; D004791:Enzyme Inhibitors; D047209:Eosinophil Peroxidase; D051417:Focal Adhesion Kinase 1; D007797:Laminin; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D009195:Peroxidase; D011509:Proteoglycans; D051057:Proto-Oncogene Proteins c-akt; D048051:p38 Mitogen-Activated Protein Kinases; D000099162:Endothelial PAS Domain-Containing Protein 1; C059485:matrigel; C034343:4-aminobenzhydrazide; C496050:PTK2 protein, human; C535150:MAPK1 protein, human
keywords: Angiogenesis; Eosinophil peroxidase; Inflammation; Myeloperoxidase