Membrane-associated HB-EGF modulates HGF-induced cellular responses in MDCK cells.
In MDCK cells, hepatocyte growth factor/scatter factor (HGF/SF) induces epithelial cell dissociation, scattering, migration, growth and formation of branched tubular structures. By contrast, these cells neither scatter nor form tubular structures in response to the epidermal growth factor (EGF) family of growth factors. Heparin-binding EGF-like growth factor (HB-EGF) is a member of the EGF family of growth factors and is synthesized as a membrane-associated precursor molecule (proHB-EGF). ProHB-EGF is proteolytically cleaved to release a soluble ligand (sHB-EGF) that activates the EGF receptor. Although recent studies suggest possible physiological functions, the role of proHB-EGF remains largely undefined. Using MDCK cells stably expressing proHB-EGF, a noncleavable deletion mutant of proHB-EGF or soluble HB-EGF, we show that epithelial cell functions differ depending on the form of HB-EGF being expressed. Expression of noncleavable membrane-anchored HB-EGF promoted cell-matrix and cell-cell interactions and decreased cell migration, HGF/SF-induced cell scattering and formation of tubular structures. By contrast, expression of soluble HB-EGF induced increased cell migration, decreased cell-matrix and cell-cell interactions and promoted the development of long unbranched tubular structures in response to HGF/SF. These findings suggest that HB-EGF can not only modulate HGF/SF-induced cellular responses in MDCK cells but also that membrane-bound HB-EGF and soluble HB-EGF give rise to distinctly different effects on cell-cell and cell-extracellular matrix interactions.
Singh
Amar B
AB
Department of Medicine, Vanderbilt University, Nashville, TN 37232-4794, USA.
Tsukada
Toshiaki
T
Zent
Roy
R
Harris
Raymond C
RC
D000818:Animals; D015153:Blotting, Western; D002450:Cell Communication / Q000187:drug effects; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D002642:Chick Embryo; D003094:Collagen / Q000378:metabolism; D004285:Dogs; D017097:Electric Impedance; D004815:Epidermal Growth Factor / Q000502:physiology*; D004847:Epithelial Cells / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D017353:Gene Deletion; D066257:Heparin-binding EGF-like Growth Factor; D017228:Hepatocyte Growth Factor / Q000494:pharmacology* / Q000502:physiology; D036341:Intercellular Signaling Peptides and Proteins; D011233:Precipitin Tests; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism*; D012995:Solubility
D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D011498:Protein Precursors; D004815:Epidermal Growth Factor; D017228:Hepatocyte Growth Factor; D003094:Collagen