title: Endothelial protein C receptor and protease-activated receptor-1 mediate induction of a wound-healing phenotype in human keratinocytes by activated protein C.
abstract: Activated protein C (APC) is a natural anticoagulant and inhibitor of inflammation that can stimulate keratinocyte wound repair in vitro and promote wound healing in vivo. The signaling mechanisms, however, are unknown and a keratinocyte receptor for APC has not been identified. Here, we show that cultured human keratinocytes from neonatal foreskins express the endothelial protein C receptor (EPCR). EPCR was also strongly expressed by lower epidermal layers of neonatal foreskin as determined by immunohistochemistry. In cultured keratinocytes, EPCR expression was upregulated by the addition of APC and inhibited by tumor necrosis factor-alpha. Addition of APC stimulated cell proliferation, production of matrix metalloproteinase-2, activation of ERK and p38 kinase signaling pathways, and expression of protease-activated receptor (PAR)-1. A monoclonal antibody, RCR252, which blocks APC binding to EPCR, or a blocking antibody to PAR-1, abolished APC's effects on keratinocytes. In summary, this study demonstrates that EPCR, a major receptor of protein C pathway, is expressed by human keratinocytes, and facilitates APC's function on keratinocytes via activation of PAR-1 pathway. Our findings highlight a possible new role for the protein C pathway in skin physiology and help elucidate the mechanisms of action by which APC promotes wound healing.
authors.affiliation: Sutton Arthritis Research Laboratory, Institute of Bone and Joint Research, University of Sydney at Royal North Shore Hospital, St Leonards, NSW, Australia. m1xue@med.usyd.edu.au
authors.forename: Meilang
authors.initials: M
authors.lastname: Xue
authors.forename: David
authors.initials: D
authors.lastname: Campbell
authors.forename: Phillip N
authors.initials: PN
authors.lastname: Sambrook
authors.forename: Kenji
authors.initials: K
authors.lastname: Fukudome
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Jackson
mesh_terms: D000941:Antigens / Q000235:genetics / Q000378:metabolism*; D015703:Antigens, CD; D001779:Blood Coagulation Factors / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D002455:Cell Division; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D000074283:Endothelial Protein C Receptor; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007231:Infant, Newborn; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D011486:Protein C / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D044463:Receptor, PAR-1 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D014945:Wound Healing / Q000187:drug effects / Q000502:physiology*
chemical_list: D000941:Antigens; D015703:Antigens, CD; D001779:Blood Coagulation Factors; D000074283:Endothelial Protein C Receptor; D006023:Glycoproteins; C478370:PROCR protein, human; D011486:Protein C; D012333:RNA, Messenger; D044463:Receptor, PAR-1; D011956:Receptors, Cell Surface; D014409:Tumor Necrosis Factor-alpha