The fully linked HTML version of this article has now been published.
Development ePress online publication date 16 Feb 2005
doi: 10.1242/dev.01690
Research article
FGFR2b signaling regulates ex vivo submandibular gland epithelial cell proliferation and branching morphogenesis
Zachary Steinberg,
Christopher Myers,
Vernon M. Heim,
Colin A. Lathrop,
Ivan T. Rebustini,
Julian S. Stewart,
Melinda Larsen,
and
Matthew P. Hoffman*
* Author for correspondence (e-mail: mhoffman{at}mail.nih.gov)
Branching morphogenesis of mouse submandibular glands is regulated by multiple growth factors. Here, we report that ex vivo branching of intact submandibular glands decreases when either FGFR2 expression is downregulated or soluble recombinant FGFR2b competes out the endogenous growth factors. However, a combination of neutralizing antibodies to FGF1, FGF7 and FGF10 is required to inhibit branching in the intact gland, suggesting that multiple FGF isoforms are required for branching. Exogenous FGFs added to submandibular epithelial rudiments cultured without mesenchyme induce distinct morphologies. FGF7 induces epithelial budding, whereas FGF10 induces duct elongation, and both are inhibited by FGFR or ERK1/2 signaling inhibitors. However, a PI3-kinase inhibitor also decreases FGF7-mediated epithelial budding, suggesting that multiple signaling pathways exist. We immunolocalized FGF receptors and analyzed changes in FGFR, FGF and MMP gene expression to identify the mechanisms of FGF-mediated morphogenesis. FGFR1b and FGFR2b are present throughout the epithelium, although FGFR1b is more highly expressed around the periphery of the buds and the duct tips. FGF7 signaling increases FGFR1b and FGF1 expression, and MMP2 activity, when compared with FGF10, resulting in increased cell proliferation and expansion of the epithelial bud, whereas FGF10 stimulates localized proliferation at the tip of the duct. FGF7- and FGF10-mediated morphogenesis is inhibited by an MMP inhibitor and a neutralizing antibody to FGF1, suggesting that both FGF1 and MMPs are essential downstream mediators of epithelial morphogenesis. Taken together, our data suggests that FGFR2b signaling involves a regulatory network of FGFR1b/FGF1/MMP2 expression that mediates budding and duct elongation during branching morphogenesis.

CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati
Twitter What's this?
This article has been cited by other articles:

|
 |

|
 |
 
H. P. Makarenkova, M. P. Hoffman, A. Beenken, A. V. Eliseenkova, R. Meech, C. Tsau, V. N. Patel, R. A. Lang, and M. Mohammadi
Differential Interactions of FGFs with Heparan Sulfate Control Gradient Formation and Branching Morphogenesis
Sci. Signal.,
September 15, 2009;
2(88):
ra55 - ra55.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. Kalinina, S. A. Byron, H. P. Makarenkova, S. K. Olsen, A. V. Eliseenkova, W. J. Larochelle, M. Dhanabal, S. Blais, D. M. Ornitz, L. A. Day, et al.
Homodimerization Controls the Fibroblast Growth Factor 9 Subfamily's Receptor Binding and Heparan Sulfate-Dependent Diffusion in the Extracellular Matrix
Mol. Cell. Biol.,
September 1, 2009;
29(17):
4663 - 4678.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Y. Ueda, Y. Karasawa, Y. Satoh, S. Nishikawa, J. Imaki, and M. Ito
Purification and Characterization of Mouse Lacrimal Gland Epithelial Cells and Reconstruction of an Acinarlike Structure in Three-Dimensional Culture
Invest. Ophthalmol. Vis. Sci.,
May 1, 2009;
50(5):
1978 - 1987.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. Yamamoto, E. Fukumoto, K. Yoshizaki, T. Iwamoto, A. Yamada, K. Tanaka, H. Suzuki, S. Aizawa, M. Arakaki, K. Yuasa, et al.
Platelet-derived Growth Factor Receptor Regulates Salivary Gland Morphogenesis via Fibroblast Growth Factor Expression
J. Biol. Chem.,
August 22, 2008;
283(34):
23139 - 23149.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
V. N. Patel, K. M. Likar, S. Zisman-Rozen, S. N. Cowherd, K. S. Lassiter, I. Sher, E. A. Yates, J. E. Turnbull, D. Ron, and M. P. Hoffman
Specific Heparan Sulfate Structures Modulate FGF10-mediated Submandibular Gland Epithelial Morphogenesis and Differentiation
J. Biol. Chem.,
April 4, 2008;
283(14):
9308 - 9317.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
W. P. Daley, S. B. Peters, and M. Larsen
Extracellular matrix dynamics in development and regenerative medicine
J. Cell Sci.,
February 1, 2008;
121(3):
255 - 264.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
V. N. Patel, S. M. Knox, K. M. Likar, C. A. Lathrop, R. Hossain, S. Eftekhari, J. M. Whitelock, M. Elkin, I. Vlodavsky, and M. P. Hoffman
Heparanase cleavage of perlecan heparan sulfate modulates FGF10 activity during ex vivo submandibular gland branching morphogenesis
Development,
December 1, 2007;
134(23):
4177 - 4186.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
L. Chung, T.-L. Yang, H.-R. Huang, S.-M. Hsu, H.-J. Cheng, and P.-H. Huang
Semaphorin signaling facilitates cleft formation in the developing salivary gland
Development,
August 15, 2007;
134(16):
2935 - 2945.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
X. Zhang, O. A. Ibrahimi, S. K. Olsen, H. Umemori, M. Mohammadi, and D. M. Ornitz
Receptor Specificity of the Fibroblast Growth Factor Family: THE COMPLETE MAMMALIAN FGF FAMILY
J. Biol. Chem.,
June 9, 2006;
281(23):
15694 - 15700.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
X. Zhang, T. S. Stappenbeck, A. C. White, K. J. Lavine, J. I. Gordon, and D. M. Ornitz
Reciprocal epithelial-mesenchymal FGF signaling is required for cecal development
Development,
January 1, 2006;
133(1):
173 - 180.
[Abstract]
[Full Text]
[PDF]
|
 |
|
© The Company of Biologists Ltd 2005