Wound-induced ATP release and EGF receptor activation in epithelial cells.
We have shown previously that wounding of human corneal epithelial (HCE) cells resulted in epidermal growth factor receptor (EGFR) transactivation through ectodomain shedding of heparin-binding EGF-like growth factor (HB-EGF). However, the initial signal to trigger these signaling events in response to cell injury remains elusive. In the present study, we investigated the role of ATP released from the injured cells in EGFR transactivation in HCE cells as well as in BEAS 2B cells, a bronchial epithelial cell line. Wounding of epithelial monolayer resulted in the release of ATP into the culture medium. The wound-induced rapid activation of phosphatidylinositol-3-kinase (PI3K) and extracellular signal-regulated kinase (ERK) pathways in HCE cells was attenuated by eliminating extracellular ATP, ADP and adenosine. The nonhydrolyzable ATP analog ATP-gamma-S induced rapid and sustained EGFR activation that depended on HB-EGF shedding and ADAM (a disintegrin and metalloproteinase). Targeting pathways leading to HB-EGF shedding and EGFR activation attenuated ATP-gamma-S-enhanced closure of small scratch wounds. The purinoceptor antagonist reactive blue 2 decreased wound closure and attenuated ATP-gamma-S induced HB-EGF shedding. Taken together, our data suggest that ATP, released upon epithelial injury, acts as an early signal to trigger cell responses including an increase in HB-EGF shedding, subsequent EGFR transactivation and its downstream signaling, resulting in wound healing.
Yin
Jia
J
Kresge Eye Institute, Department of Ophthalmology, Wayne State University School of Medicine, 4717 St Antoine Blvd, Detroit, MI 48201, USA.
Xu
Keping
K
Zhang
Jing
J
Kumar
Ashok
A
Yu
Fu-Shin X
FS
D051722:ADAM Proteins / Q000494:pharmacology; D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D004815:Epidermal Growth Factor / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D066257:Heparin-binding EGF-like Growth Factor; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008954:Models, Biological; D010766:Phosphorylation / Q000187:drug effects; D058919:Purinergic P2 Receptor Antagonists; D015398:Signal Transduction / Q000187:drug effects; D013314:Stress, Mechanical
C587883:HBEGF protein, human; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D058919:Purinergic P2 Receptor Antagonists; C022571:adenosine 5'-O-(3-thiotriphosphate); D000244:Adenosine Diphosphate; D004815:Epidermal Growth Factor; D000255:Adenosine Triphosphate; D066246:ErbB Receptors; D048049:Extracellular Signal-Regulated MAP Kinases; D020928:Mitogen-Activated Protein Kinases; D051722:ADAM Proteins; D002118:Calcium