title: Epidermal growth factor induces adult human islet cell dedifferentiation.
abstract: Given the inherent therapeutic potential of the morphogenetic plasticity of adult human islets, the identification of factors controlling their cellular differentiation is of interest. The epidermal growth factor (EGF) family has been identified previously in the context of pancreatic organogenesis. We examined the role of EGF in an in vitro model whereby adult human islets are embedded in a collagen gel and dedifferentiated into duct-like epithelial structures (DLS). We demonstrated that DLS formation was EGF dependent, while residual DLS formation in the absence of added EGF was abrogated by EGF receptor inhibitor treatment. With respect to signaling, EGF administration led to an increase in c-Jun NH2-terminal kinase (JNK) phosphorylation early in DLS formation and in AKT and extracellular signal-regulated kinase (ERK) phosphorylation late in the process of DLS formation, concomitant with the increased proliferation of dedifferentiated cells. In the absence of EGF, these phosphorylation changes are not seen and the typical increase in DLS epithelial cell proliferation seen after 10 days in culture is attenuated. Thus, in our model, EGF is necessary for islet cell dedifferentiation, playing an important role in both the onset of DLS formation (through JNK) and in the proliferation of these dedifferentiated cells (through AKT and ERK).
authors.affiliation: Department of Surgery, McGill University, Montreal, Quebec, Canada.
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Hanley
authors.forename: Béatrice
authors.initials: B
authors.lastname: Assouline-Thomas
authors.forename: Julia
authors.initials: J
authors.lastname: Makhlin
authors.forename: Lawrence
authors.initials: L
authors.lastname: Rosenberg
mesh_terms: D000328:Adult; D001483:Base Sequence; D054337:Cell Dedifferentiation / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D017931:DNA Primers / Q000235:genetics; D004815:Epidermal Growth Factor / Q000378:metabolism / Q000494:pharmacology*; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000235:genetics; D005260:Female; D015870:Gene Expression; D006801:Humans; D066298:In Vitro Techniques; D007515:Islets of Langerhans / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008024:Ligands; D008297:Male; D008875:Middle Aged; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D017931:DNA Primers; D008024:Ligands; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D051057:Proto-Oncogene Proteins c-akt; D048031:JNK Mitogen-Activated Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases