title: Growth of intestinal epithelium in organ culture is dependent on EGF signalling.
abstract: Differentiation of endoderm into intestinal epithelium is initiated at E13.5 of mouse development when there are significant changes in morphology resulting in the conversion of undifferentiated stratified epithelium into a mature epithelial monolayer. Here we demonstrate that monolayer formation is associated with the selective apoptosis of superficial cells lining the lumen while cell proliferation is progressively restricted to cells adjacent to the basement membrane. We describe an innovative embryonic gut culture system that maintains the three-dimensional architecture of gut and in which these processes are recapitulated in vitro. Explants taken from specific regions of the gut and placed into organ culture develop and express molecular markers (Cdx1, Cdx2 and A33 antigen) in the same spatial and temporal pattern observed in vivo indicating that regional specification is maintained. Inhibition of the epidermal growth factor receptor (EGFR) tyrosine kinase using the specific inhibitor AG1478 significantly reduced the proliferation and survival of cells within the epithelial cell layer of cultured gut explants. This demonstrates an essential role for the EGF signalling pathway during the early stages of intestinal development.
authors.affiliation: Ludwig Institute for Cancer Research, Royal Melbourne Hospital, PO Box 2008, Parkville, Victoria 3050, Australia. helen.abud@ludwig.edu.au
authors.forename: Helen E
authors.initials: HE
authors.lastname: Abud
authors.forename: Nadine
authors.initials: N
authors.lastname: Watson
authors.forename: Joan K
authors.initials: JK
authors.lastname: Heath
mesh_terms: D000818:Animals; D017209:Apoptosis; D019521:Body Patterning; D049109:Cell Proliferation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000502:physiology*; D004848:Epithelium / Q000187:drug effects / Q000196:embryology / Q000502:physiology; D066246:ErbB Receptors / Q000037:antagonists & inhibitors; D005260:Female; D007422:Intestines / Q000187:drug effects / Q000196:embryology* / Q000502:physiology; D051379:Mice; D008813:Mice, Inbred ICR; D009924:Organ Culture Techniques; D011247:Pregnancy; D011799:Quinazolines; D015398:Signal Transduction; D020032:Tyrphostins / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D011799:Quinazolines; D020032:Tyrphostins; C101044:RTKI cpd; D004815:Epidermal Growth Factor; D066246:ErbB Receptors