Gene expression profiles of mouse submandibular gland development: FGFR1 regulates branching morphogenesis in vitro through BMP- and FGF-dependent mechanisms.
Analyses of gene expression profiles at five different stages of mouse submandibular salivary gland development provide insight into gland organogenesis and identify genes that may be critical at different stages. Genes with similar expression profiles were clustered, and RT-PCR was used to confirm the developmental changes. We focused on fibroblast growth factor receptor 1 (FGFR1), as its expression is highest early in gland development. We extended our array results and analyzed the developmental expression patterns of other FGFR and FGF isoforms. The functional significance of FGFR1 was confirmed by submandibular gland organ culture. Antisense oligonucleotides decreased expression of FGFR1 and reduced branching morphogenesis of the glands. Inhibiting FGFR1 signaling with SU5402, a FGFR1 tyrosine kinase inhibitor, reduced branching morphogenesis. SU5402 treatment decreased cell proliferation but did not increase apoptosis. Fgfr, Fgf and Bmp gene expression was localized to either the mesenchyme or the epithelium by PCR, and then measured over time by real time PCR after SU5402 treatment. FGFR1 signaling regulates Fgfr1, Fgf1, Fgf3 and Bmp7 expression and indirectly regulates Fgf7, Fgf10 and Bmp4. Exogenous FGFs and BMPs added to glands in culture reveal distinct effects on gland morphology. Glands cultured with SU5402 were then rescued with exogenous BMP7, FGF7 or FGF10. Taken together, our results suggest specific FGFs and BMPs play reciprocal roles in regulating branching morphogenesis and FGFR1 signaling plays a central role by regulating both FGF and BMP expression.
Hoffman
Matthew P
MP
Craniofacial Developmental Biology and Regeneration Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, MSC 4370, Bethesda, MD 20892-4370, USA. mhoffman@mail.nih.gov
Kidder
Benjamin L
BL
Steinberg
Zachary L
ZL
Lakhani
Saba
S
Ho
Susan
S
Kleinman
Hynda K
HK
Larsen
Melinda
M
D000818:Animals; D017209:Apoptosis; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins / Q000378:metabolism; D002455:Cell Division; D004305:Dose-Response Relationship, Drug; D051526:Fibroblast Growth Factor 10; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D008648:Mesoderm / Q000378:metabolism / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout; D020411:Oligonucleotide Array Sequence Analysis; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D009924:Organ Culture Techniques; D020033:Protein Isoforms; D011758:Pyrroles / Q000494:pharmacology; D020794:Receptor Protein-Tyrosine Kinases / Q000502:physiology*; D051496:Receptor, Fibroblast Growth Factor, Type 1; D017468:Receptors, Fibroblast Growth Factor / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013363:Submandibular Gland / Q000196:embryology*; D013997:Time Factors; D016212:Transforming Growth Factor beta
D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins; C496464:Fgf10 protein, mouse; C496454:Fgf7 protein, mouse; D051526:Fibroblast Growth Factor 10; D016376:Oligonucleotides, Antisense; D020033:Protein Isoforms; D011758:Pyrroles; D017468:Receptors, Fibroblast Growth Factor; C105686:SU 5402; D016212:Transforming Growth Factor beta; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors; C496349:Fgfr1 protein, mouse; D020794:Receptor Protein-Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1