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 ‰ 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 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 a MP-dependent fashion.

ARNT controls the expression of epidermal differentiation genes through HDAC- and EGFR-dependent pathways

“…In line with recent findings (Stoll et al, 2010a), our data showed that AREG is the most highly transcribed EGFR ligand in normal (control) N-TERT keratinocytes (about 70% of GAPDH expression level). TGFa message was detected at the level of about 10% of GAPDH while other EGFR ligands showed no or negligible expression in control cells (Fig.…”

“…In line with previous reports designating AREG as a principal EGFR ligand mediating autocrine growth in epidermal keratinocytes (Piepkorn et al, 1994;Nylander et al, 1998;Stoll et al, 2010a) we showed that AREG is the most abundant EGFR ligand in normal N-TERT cells. In N-KO keratinocytes AREG declined significantly at both mRNA and protein levels and its nuclear positivity was completely lost (Fig.…”

The EGFR Ligands Amphiregulin and Heparin-Binding EGF-like Growth Factor Promote Peritoneal Carcinomatosis in CXCR4-Expressing Gastric Cancer

“…Amphiregulin and HB-EGF show different biological activities in target cells (21), with amphiregulin mainly stimulating cell proliferation (22) and HB-EGF stimulating chemotaxis (23). Amphiregulin binds to ErbB1 (EGFR), whereas HB-EGF binds to both ErbB1 (EGFR) and ErbB4 (24).…”

MicroRNA-132 enhances transition from inflammation to proliferation during wound healing

“…In this study, we focused on one target of miR-132 -HB-EGF -which is one of the EGFR ligands, in addition to TGFα, amphiregulin (AR), epiregulin (EREG), and β cellulin, that is expressed by keratinocytes in an autocrine fashion (39,40). Unlike the other EGFs, overexpression of HB-EGF in keratinocytes was previously reported to lead to a large decrease in cell Inhibition of miR-132 delays reepithelialization of human ex vivo skin wounds.…”