title: Endothelial cell regulation of salivary gland epithelial patterning.
abstract: Perfusion-independent regulation of epithelial pattern formation by the vasculature during organ development and regeneration is of considerable interest for application in restoring organ function. During murine submandibular salivary gland development, the vasculature co-develops with the epithelium during branching morphogenesis; however, it is not known whether the vasculature has instructive effects on the epithelium. Using pharmacological inhibitors and siRNA knockdown in embryonic organ explants, we determined that VEGFR2-dependent signaling is required for salivary gland epithelial patterning. To test directly for a requirement for endothelial cells in instructive epithelial patterning, we developed a novel ex vivo cell fractionation/reconstitution assay. Immuno-depletion of CD31+endothelial cells in this assay confirmed a requirement for endothelial cells in epithelial patterning of the gland. Depletion of endothelial cells or inhibition of VEGFR2 signaling in organ explants caused an aberrant increase in cells expressing the ductal proteins K19 and K7, with a reduction in Kit+progenitor cells in the endbuds of reconstituted glands. Addition of exogenous endothelial cells to reconstituted glands restored epithelial patterning, as did supplementation with the endothelial cell-regulated mesenchymal factors IGFBP2 and IGFBP3. Our results demonstrate that endothelial cells promote expansion of Kit+progenitor cells and suppress premature ductal differentiation in early developing embryonic submandibular salivary gland buds.
authors.affiliation: Department of Biological Sciences, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA.|Graduate Program in Molecular, Cellular, Developmental, and Neural Biology, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA.
authors.forename: Hae Ryong
authors.initials: HR
authors.lastname: Kwon
authors.affiliation: Department of Biological Sciences, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA.
authors.forename: Deirdre A
authors.initials: DA
authors.lastname: Nelson
authors.affiliation: Department of Biological Sciences, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA.|Graduate Program in Molecular, Cellular, Developmental, and Neural Biology, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA.
authors.forename: Kara A
authors.initials: KA
authors.lastname: DeSantis
authors.affiliation: Department of Biological Sciences, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Morrissey
authors.affiliation: Department of Biological Sciences, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA mlarsen@albany.edu.
authors.forename: Melinda
authors.identifier: 0000-0002-5026-2012
authors.initials: M
authors.lastname: Larsen
mesh_terms: D000818:Animals; D019521:Body Patterning; D002454:Cell Differentiation; D002478:Cells, Cultured; D004622:Embryo, Mammalian; D042783:Endothelial Cells / Q000166:cytology / Q000502:physiology*; D004847:Epithelial Cells / Q000166:cytology / Q000502:physiology*; D004848:Epithelium / Q000196:embryology*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D051379:Mice; D009024:Morphogenesis / Q000502:physiology; D011247:Pregnancy; D012469:Salivary Glands / Q000196:embryology*; D015398:Signal Transduction; D013363:Submandibular Gland / Q000166:cytology / Q000201:enzymology*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology
chemical_list: C000592875:Kdr protein, mouse; D040301:Vascular Endothelial Growth Factor Receptor-2
keywords: Ductal differentiation; Endothelial cell; Endothelial cells; Epithelial patterning; Mouse; Progenitor cell; Salivary gland development