title: Metalloproteinase-mediated, context-dependent function of amphiregulin and HB-EGF in human keratinocytes and skin.
abstract: Human keratinocytes (KCs) express multiple EGF receptor (EGFR) ligands; however, their functions in specific cellular contexts remain largely undefined. To address this issue, first we measured mRNA and protein levels for multiple EGFR ligands in KCs and skin. Amphiregulin (AREG) was by far the most abundant EGFR ligand in cultured KCs, with >19 times more mRNA and >7.5 times more shed protein than any other family member. EGFR ligand expression in normal skin was low (<8 per thousand of RPLP0/36B4); however, HB-EGF and AREG mRNAs were strongly induced in human skin organ culture. KC migration in scratch wound assays was highly metalloproteinase (MP)- and EGFR dependent, and was markedly inhibited by EGFR ligand antibodies. However, lentivirus-mediated expression of soluble HB-EGF, but not soluble AREG, strongly enhanced KC migration, even in the presence of MP inhibitors. Lysophosphatidic acid (LPA)-induced ERK phosphorylation was also strongly EGFR and MP dependent and markedly inhibited by neutralization of HB-EGF. In contrast, autocrine KC proliferation and ERK phosphorylation were selectively blocked by neutralization of AREG. These data show that distinct EGFR ligands stimulate KC behavior in different cellular contexts, and in an MP-dependent fashion.
authors.affiliation: Department of Dermatology, University of Michigan Medical School, Ann Arbor, MI, USA. sstoll@umich.edu
authors.forename: Stefan W
authors.initials: SW
authors.lastname: Stoll
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Johnson
authors.forename: Ajay
authors.initials: A
authors.lastname: Bhasin
authors.forename: Andrew
authors.initials: A
authors.lastname: Johnston
authors.forename: Johann E
authors.initials: JE
authors.lastname: Gudjonsson
authors.forename: Laure
authors.initials: L
authors.lastname: Rittié
authors.forename: James T
authors.initials: JT
authors.lastname: Elder
mesh_terms: D066258:Amphiregulin; D019898:Autocrine Communication / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002465:Cell Movement / Q000502:physiology*; D002478:Cells, Cultured; D066255:EGF Family of Proteins; D066246:ErbB Receptors / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D066257:Heparin-binding EGF-like Growth Factor; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism*; D016086:Lentivirus / Q000235:genetics; D008024:Ligands; D008070:Lipopolysaccharides / Q000494:pharmacology; D045726:Metalloproteases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009924:Organ Culture Techniques; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D012867:Skin / Q000166:cytology
chemical_list: C587848:AREG protein, human; D066258:Amphiregulin; D066255:EGF Family of Proteins; D006023:Glycoproteins; C587883:HBEGF protein, human; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D008024:Ligands; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D066246:ErbB Receptors; D048049:Extracellular Signal-Regulated MAP Kinases; D045726:Metalloproteases