title: Molecular Profiling of the Developing Lacrimal Gland Reveals Putative Role of Notch Signaling in Branching Morphogenesis.
abstract: Although normal function of the lacrimal gland is essential for vision (and thus for human well-being), the lacrimal gland remains rather poorly understood at a molecular level. The purpose of this study was to identify new genes and signaling cascades involved in lacrimal gland development.
  
  
  
  To identify these genes, we used microarray analysis to compare the gene expression profiles of developing (embryonic) and adult lacrimal glands. Differential data were validated by quantitative RT-PCR, and several corresponding proteins were confirmed by immunohistochemistry and Western blot analysis. To evaluate the role of NOTCH signaling in lacrimal gland (LG) development, we used the NOTCH inhibitor DAPT and conditional Notch1 knockouts.
  
  
  
  Our microarray data and an in silico reconstruction of cellular networks revealed significant changes in the expression patterns of genes from the NOTCH, WNT, TGFβ, and Hedgehog pathways, all of which are involved in the regulation of epithelial-to-mesenchymal transition (EMT). Our study also revealed new putative lacrimal gland stem cell/progenitor markers. We found that inhibiting Notch signaling both increases the average number of lacrimal gland lobules and reduces the size of each lobule.
  
  
  
  Our findings suggest that NOTCH-, WNT-, TGFβ-, and Hedgehog-regulated EMT transition are critical mechanisms in lacrimal gland development and morphogenesis. Our data also supports the hypothesis that NOTCH signaling regulates branching morphogenesis in the developing lacrimal gland by suppressing cleft formation.
authors.affiliation: Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida, United States.
authors.forename: Galina
authors.initials: G
authors.lastname: Dvoriantchikova
authors.affiliation: Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida, United States.
authors.forename: Wensi
authors.initials: W
authors.lastname: Tao
authors.affiliation: Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida, United States.
authors.forename: Steve
authors.initials: S
authors.lastname: Pappas
authors.affiliation: Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida, United States.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Gaidosh
authors.affiliation: Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida, United States.
authors.forename: David T
authors.initials: DT
authors.lastname: Tse
authors.affiliation: Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida, United States 2Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, Florida, United States.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Ivanov
authors.affiliation: Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida, United States 3Department of Biomedical Engineering, University of Miami Miller School of Medicine, Coral Gables, Florida, United States.
authors.forename: Daniel
authors.initials: D
authors.lastname: Pelaez
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D058750:Epithelial-Mesenchymal Transition; D018507:Gene Expression Regulation, Developmental; D053823:Hedgehog Proteins / Q000096:biosynthesis / Q000235:genetics*; D007150:Immunohistochemistry; D007765:Lacrimal Apparatus / Q000254:growth & development* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D023421:Models, Animal; D009024:Morphogenesis; D012313:RNA / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D051880:Receptors, Notch / Q000378:metabolism*; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000096:biosynthesis / Q000235:genetics*; D051153:Wnt Proteins / Q000096:biosynthesis / Q000235:genetics
chemical_list: D053823:Hedgehog Proteins; D051880:Receptors, Notch; D016212:Transforming Growth Factor beta; D051153:Wnt Proteins; D012313:RNA