The effects of epidermal growth factor, transforming growth factors alpha and beta and platelet-derived growth factor on murine palatal shelves in organ culture

• Published in: Archives of oral biology Vol. 37; no. 5; pp. 395 - 410
• Main Authors: Dixon, M.J., Ferguson, M.W.J.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1992; Elsevier Science
• Subjects: Animals; Biological and medical sciences; Cell Differentiation - drug effects; Dentistry; Embryology: invertebrates and vertebrates. Teratology; epidermal growth factor; Epidermal Growth Factor - pharmacology; Epithelial Cells; Epithelium - drug effects; Experimental organogenesis; extracellular matrix; Extracellular Matrix - drug effects; Extracellular Matrix - ultrastructure; Fundamental and applied biological sciences. Psychology; Mice; Organ Culture Techniques; Organogenesis. Physiological fonctions; Palate - cytology; Palate - drug effects; Palate - embryology; palate development; platelet-derived growth factor; Platelet-Derived Growth Factor - pharmacology; Time Factors; transforming growth factor alpha; Transforming Growth Factor alpha - pharmacology; transforming growth factor beta; Transforming Growth Factor beta - pharmacology; PBS; transforming growth factor beta; DCS; EGF; PDGF; transforming growth factor alpha; TGFβ; platelet-derived growth factor; TGFα; epidermal growth factor; extracellular matrix; palate development; Embryonic development; Immunocytochemistry; Transforming growth factor; Rodentia; Tissue culture; Histology; Osseous palate; Epithelium; Oral cavity; Vertebrata; Mammalia; Epidermal growth factor; Mouse; Fetus; Extracellular matrix; Palate; Differentiation; Platelet derived growth factor
• ISSN: 0003-9969; 1879-1506
• DOI: 10.1016/0003-9969(92)90024-3

Palatal shelves isolated from day-13 embryonic mice were explanted on to the surfaces of collagen gels either singly or in pairs with their medial edges in contact, and cultured submerged in a 1:1 mixture of Dulbecco's modified Eagle's medium/Ham's F12 medium. The medium was supplemented with either 10 ng/ml epidermal growth factor (EGF), 10 ng/ml transforming growth factor alpha (TGFα), 1 ng/ml transforming growth factor beta (TGFβ 1) or 2ng/ml platelet-derived growth factor (PDGF) all in the presence or absence of 2.5% donor calf serum (DCS). Cultures were terminated after 0, 24, 48 or 72 h and processed for histological and immunocytochemical examination. In serum-free medium and medium supplemented with 2.5% DCS the palatal epithelia differentiated in a manner similar to that seen in vivo (oral, keratinization; nasal, pseudostratified, ciliated columnar cells and medial edge, epithelial degeneration). A similar pattern was obtained in serum-free medium supplemented with either EGF or TGFα. However in cultures with either EGF or TGFα plus 2.5% DCS present in the medium, medial-edge epithelial degeneration was inhibited and the oral epithelia were more heavily keratinized. The mesenchyme of such cultures stained more intensely for various extracellular matrix molecules. In TGFβ 1-supplemented cultures (with, but especially without, serum supplementation) the epithelia were thin, medial-edge epithelial degeneration was marked, and the fibronectin content of the mesenchyme was increased. PDGF prevented medial-edge epithelial degeneration in the presence, but not in the absence, of serum; mesenchymal extracellular molecules were not as prevalent as with the EGF treatment. These results indicate that exogenous growth factors (including those present in serum) exert effects on organ-cultured mouse palatal shelves in a fashion similar to their effects in cell culture and that controlled physiological levels of such factors may be important in mouse palatal development.