Significant role of laminin‐1 in branching morphogenesis of mouse salivary epithelium cultured in basement membrane matrix

• Published in: Development, growth & differentiation growth & differentiation, 1999-04, Vol.41 (2), p.207-216
• Main Authors: Hosokawa, Yukio, Takahashi, Yu, Kadoya, Yuichi, Yamashina, Shohei, Nomizu, Motoyoshi, Yamada, Yoshihiko, Nogawa, Hiroyuki
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Basement Membrane - drug effects; Basement Membrane - ultrastructure; branching morphogenesis; Collagen; Drug Combinations; Epithelium - drug effects; Epithelium - embryology; Epithelium - ultrastructure; Laminin - chemistry; Laminin - physiology; laminin‐1; Matrigel; mesenchyme‐free culture; Mice; Mice, Inbred ICR; Molecular Sequence Data; Morphogenesis; mouse salivary gland; Peptide Fragments - pharmacology; Proteoglycans; Submandibular Gland - drug effects; Submandibular Gland - embryology; Submandibular Gland - ultrastructure
• ISSN: 0012-1592; 1440-169X
• DOI: 10.1046/j.1440-169x.1999.00419.x

Mouse submandibular epithelium shows branching morphogenesis in mesenchyme‐free conditions when covered with a basement membrane matrix (Matrigel) in medium supplemented with epidermal growth factor. In the present study, the role of laminin‐1 (LN1), a major glycoprotein of Matrigel, in this culture system was defined. When the epithelium was cultured in a LN1‐nidogen gel, the epithelium showed much branching, comparable to that observed with Matrigel. By electron microscopy, only a felt‐like matrix was formed on the epithelial surface in the LN1‐nidogen gel cultures, while an organized basal lamina structure was formed on the epithelial surface in direct or transfilter recombination cultures with mesenchyme. Next, the epithelium covered with Matrigel was cultured in medium containing either biologically active peptides from LN1, IKVAV‐including peptide (2097–2108), AG10 (2183–2194), AG32 (2370–2381) or AG73 (2719–2730) from the α1 chain, or YIGSR‐including peptide (926–933) from the β1 chain. Only AG73 (RKRLQVQLSIRT from the α1 chain carboxyl‐terminal globular domain) inhibited the epithelial branching in Matrigel. These results suggest that LN1‐nidogen can support the branching morphogenesis of submandibular epithelium even if LN1‐nidogen is not assembled into an intact basal lamina, and that the AG73 sequence is an important site on LN1, which interacts with submandibular epithelial cells.