Conclusion

To investigate the genetic and biochemical mechanisms used by FGFR3 to regulate chondrocyte growth and differentiation, we have constructed transgenic mice that either lack a functional Fgfr3 gene or that express the activating FGFR3 mutation (G380R) that causes achondroplasia. The effects on proliferation and differentiation of epiphyseal chondrocytes showed that activation of FGFR3 dramatically inhibits both chondrocyte proliferation and differentiation. The consequence of this effect on chondrogenesis is a histologically shortened growth plate and a gross phenotype resembling the human skeletal disorder, achondroplasia. In contrast, loss of FGFR3 activity results in an opposite phenotype in which proliferation is increased, the size and longevity of the growth plate is extended and skeletal overgrowth ensues. Examination of signalling pathways that regulate chondrocyte differentiation showed that FGFR3 signalling inhibits Ihh signalling and BMP4 expression in cartilage and perichondrium. These data place Fgfr3 genetically upstream of Ihh and suggest that FGFR3 and its endogenous ligand may globally regulate chondrogenesis and osteogenesis.

This work was supported by grants HD35692 and CA60673 from the National Institutes of Health, USA.

References

Angle B, Hersh JH, Christensen KM 1998 Molecularly proven hypochondroplasia with cloverleaf skull deformity: a novel association. Clin Genet 54:417—420 Basilico C, Moscatelli D 1992 The FGF family of growth factors and oncogenes. Adv Cancer Res

Bellus GA, Mcintosh I, Smith EA et al 1995 A recurrent mutation in the tyrosine kinase domain of fibroblast growth factor receptor 3 causes hypochondroplasia. Nat Genet 10:357—359 Briner J, Giedion A, Spycher MA 1991 Variation of quantitative and qualitative changes of enchondral ossification in heterozygous achondroplasia. Pathol Res Pract 187:271—278 Caplan AI, PechakDG 1987 The cellular and molecular embryology of bone formation. In: Peck

WA (ed) Bone and mineral research, vol 5. Elsevier Science, New York, p 117—183 Chellaiah A, Yuan W, Chellaiah M, Ornitz DM 1999 Mapping ligand binding domains in chimeric fibroblast growth factor receptor molecules. Multiple regions determine ligand binding specificity. J Biol Chem 274:34785—34794 Coffin JD, Florkiewicz RZ, Neumann J et al 1995 Abnormal bone growth and selective translational regulation in basic fibroblast growth factor (FGF-2) transgenic mice. Mol Biol Cell 6:1861—1873

Cohen MM Jr 1997 Short-limb skeletal dysplasias and craniosynostosis: what do they have in common? Pediatr Radiol 27:442—446 Colvin JS, Bohne BA, Harding GW, McEwen DG, Ornitz DM 1996 Skeletal overgrowth and deafness in mice lacking fibroblast growth factor receptor 3. Nat Genet 12:390—397 Delezoide AL, Benoist-Lasselin C, Legeai-Mallet L et al 1998 Spatio-temporal expression of

FGFR 1, 2 and 3 genes during human embryo-fetal ossification. Mech Dev 77:19—30 Deng C, Wynshaw-Boris A, Zhou F, Kuo A, Leder P 1996 Fibroblast growth factor receptor 3 is a negative regulator of bone growth. Cell 84:911—921 Dono R, Texido G, Dussel R, Ehmke H, Zeller R 1998 Impaired cerebral cortex development and blood pressure regulation in FGF-2-deficient mice. EMBO J 17:42134—225 Erlebacher A, Filvaroff EH, Gitelman SE, Derynck R 1995 Toward a molecular understanding of skeletal development. Cell 80:371—378 Gospodarowicz D, Mescher AL 1977 A comparison of the responses of cultured myoblasts and chondrocytes to fibroblast and epidermal growth factors. J Cell Physiol 93:117—127 Hanks SK, Quinn AM, Hunter T 1988 The protein kinase family: conserved features and deduced phylogeny of the catalytic domains. Science 241:42—52 Henderson JE, Naski MC, Stregger S et al 1999 Inhibition of cell growth in chondrocytes expressing FGFR3^^ is linked to disruption of signaling through a5jß1 integrin. J Bone Miner Res, in press

Ikegawa S, Fukushima Y, Isomura M, Takada F, Nakamura Y 1995 Mutations of the fibroblast growth factor receptor-3 gene in one familial and six sporadic cases of achondroplasia in Japanese patients. Hum Genet 96:309—311 Iseki S, Wilkie AO, Morriss-Kay GM 1999 Fgfrl and Fgfr2 have distinct differentiation- and proliferation-related roles in the developing mouse skull vault. Development 126:5611—5620 Johnson DE, Lee PL, Lu J, Williams LT 1990 Diverse forms of a receptor for acidic and basic fibroblast growth factors. Mol Cell Biol 10:4728—4736

Jones KL, Addison J 1975 Pituitary fibroblast growth factor as a stimulator of growth in cultured rabbit articular chondrocytes. Endocrinology 97:359—365 Kato Y, Iwamoto M 1990 Fibroblast growth factor is an inhibitor of chondrocyte terminal differentiation. J Biol Chem 265:5903—5909 Kim HJ, Rice DP, Kettunen PJ, Thesleff I 1998 FGF-, BMP- and Shh-mediated signalling pathways in the regulation of cranial suture morphogenesis and calvarial bone development. Development 125:1241—1251 Klagsburn M, Langner R, Levenson R, Smith S, Lillehei C 1977 The stimulation of DNA synthesis and cell division in chondrocytes and 3T3 cells by a growth factor isolated from cartilage. Exp Cell Res 105:99—108 Lanske B, Karaplis AC, Lee K et al 1996 PTH/PTHrP receptor in early development and Indian hedgehog-regulated bone growth. Science 273:663—666 Legeai-Mallet L, Benoist-Lasselin C, Delezoide AL, Munnich A, Bonaventure J 1998 Fibroblast growth factor receptor 3 mutations promote apoptosis but do not alter chondrocyte proliferation in thanatophoric dysplasia. J Biol Chem 273:13007—13014 (erratum: 1998 J Biol Chem 273:19358)

Li CL, Chen L, Iwata T, Kitagawa M, Fu XY, Deng CX 1999 A Lys644Glu substitution in fibroblast growth factor receptor 3 (FGFR3) causes dwarfism in mice by activation of STATs and ink4 cell cycle inhibitors. Hum Mol Genet 8:35—44 Li Y, Mangasarian K, Mansukhani A, Basilico C 1997 Activation ofFGF receptors by mutations in the transmembrane domain. Oncogene 14:1397—1406 Lin HY, Xu JS, Ornitz DM, Halegoua S, Hayman MJ 1996 The fibroblast growth factor receptor-1 is necessary for the induction of neurite outgrowth in PC12 cells by aFGF. J Neurosci 16:4579—4587

Lin HY, Xu JS, Ischenko I, Ornitz DM, Halegoua S, Hayman MJ 1998 Identification of the cytoplasmic regions of fibroblast growth factor (FGF) receptor 1 which play important roles in the induction of neurite outgrowth in PC12 cells by FGF-1. Mol Cell Biol 18:3762— 3770

Mohammadi M, Schlessinger J, Hubbard SR1996 Structure of the FGF receptor tyrosine kinase domain reveals a novel autoinhibitory mechanism. Cell 86:577—587 Naski MC, Ornitz DM 1998 FGF signaling in skeletal development. Front Biosci 3:D781—D794 Naski MC, Wang Q, Xu J, Ornitz DM 1996 Graded activation of fibroblast growth factor receptor 3 by mutations causing achondroplasia and thanatophoric dysplasia. Nat Genet 13:233—237

Naski MC, Colvin JS, Coffin JD, Ornitz DM 1998 Repression of hedgehog signaling and BMP4 expression in growth plate cartilage by fibroblast growth factor receptor 3. Development 125:4977—4988

Ornitz DM 2000 Fibroblast growth factors, chondrogenesis and related clinical disorders. In: Canalis E (ed) Skeletal growth factors. Lippincott Williams & Wilkins, Philadelphia, PA, p 197—209

Ornitz DM, Xu J, Colvin JS et al 1996 Receptor specificity of the fibroblast growth factor family.

J Biol Chem 271:15292—15297 Peters KG, Werner S, Chen G, Williams LT 1992 Two FGF receptor genes are differentially expressed in epithelial and mesenchymal tissues during limb formation and organogenesis in the mouse. Development 114:233—243 Peters K, Ornitz DM, Werner S, Williams L 1993 Unique expression pattern of the FGF receptor

3 gene during mouse organogenesis. Dev Biol 155:423—430 Plotnikov AN, Schlessinger J, Hubbard SR, Mohammadi M 1999 Structural basis for FGF

receptor dimerization and activation. Cell 98:641—650 Ponseti IV 1970 Skeletal growth in achondroplasia. J Bone Joint Surg (Am) 52:701—716

Quarto R, Campanile G, Cancedda R, Dozin B 1997 Modulation of commitment, proliferation, and differentiation of chondrogenic cells in defined culture medium. Endocrinology 138:4966-4976

Reddi AH 1994 Bone and cartilage differentiation. Curr Opin Genet Dev 4:737-744 Rimoin DL, Lachman RS 1993 Genetic disorders of the osseous skeleton. In: McKusick's

Heritable disorders of connective tissue, 5th edn. Mosby-Year Book, St Louis, p 557-689 Rimoin DL, Hughes GN, Kaufman RL, Rosenthal RE, McAlister WH, Silberberg R 1970

Endochondral ossification in achondroplastic dwarfism. N Engl J Med 283:728-735 Rousseau F, Bonaventure J, Legeai-Mallet L et al 1994 Mutations in the gene encoding fibroblast growth factor receptor-3 in achondroplasia. Nature 371:252-254 Rousseau F, Saugier P, Le Merrer M et al 1995 Stop codon FGFR3 mutations in thanatophoric dwarfism type 1. Nat Genet 10:11-12 Rousseau F, el Ghouzzi V, Delezoide AL et al 1996 Missense FGFR3 mutations create cysteine residues in thanatophoric dwarfism type 1 (TD1). Hum Mol Genet 5:509-512 Sahni M, Ambrosetti DC, Mansukhani A, Gertner R, Levy D, Basilico C 1999 FGF signaling inhibits chondrocyte proliferation and regulates bone development through the STAT-1 pathway. Genes Dev 13:1361-1366 Shiang R, Thompson LM, Zhu YZ et al 1994 Mutations in the transmembrane domain of FGFR3 cause the most common genetic form of dwarfism, achondroplasia. Cell 78:335-342 Stanescu R, Stanescu V, Maroteaux P 1990 Homozygous achondroplasia: morphologic and biochemical study of cartilage. Am J Med Genet 37:412-421 Su WCS, Kitagawa M, Xue NR et al 1997 Activation of Stat1 by mutant fibroblast growth-factor receptor in thanatophoric dysplasia type II dwarfism. Nature 386:288-292 Superti-Furga A, Eich G, Bucher HU et al 1995. A glycine 375-to-eysteine substitution in the transmembrane domain of the fibroblast growth factor receptor-3 in a newborn with achondroplasia. Eur J Pediatr 154:215-219 Tavormina PL, Rimoin DL, Cohn DH, Zhu YZ, Shiang R, Wasmuth JJ 1995a Another mutation that results in the substitution of an unpaired cysteine residue in the extracellular domain of FGFR3 in thanatophoric dysplasia type 1. Hum Mol Genet 4:2175-2177 Tavormina PL, Shiang R, Thompson LM et al 1995b Thanatophoric dysplasia (types I and II)

caused by distinct mutations in fibroblast growth factor receptor 3. Nat Genet 9:321-328 Tobe T, Ortega S, Luna JD et al 1998 Targeted disruption of the FGF2 gene does not prevent choroidal neovascularization in a murine model. Am J Pathol 153:1641-1646 Twal WO, Vasilatos-Younken R, Gay CV, Leach RM Jr 1994 Isolation and localization of basic fibroblast growth factor-immunoreactive substance in the epiphyseal growth plate. J Bone Miner Res 9:1737-1744

Vortkamp A, Lee K, Lanske B, Segre GV, Kronenberg HM, Tabin CJ 1996 Regulation of rate of cartilage differentiation by Indian hedgehog and PTH-related protein. Science 273:613-622 Wang F, Kan M, Yan G, Xu J, McKeehan WL 1995 Alternately spliced NH2-terminal immunoglobulin-like loop I in the ectodomain of the fibroblast growth factor (FGF) receptor 1 lowers affinity for both heparin and FGF-1. J Biol Chem 270:10231-10235 Wang F, Kan M, McKeehan K, Jang JH, Feng SJ, McKeehan WL 1997 A homeo-interaction sequence in the ectodomain of the fibroblast growth factor receptor. J Biol Chem 272:2388723895

Wang YC, Spatz MK, Kannan K et al 1999 A mouse model for achondroplasia produced by targeting fibroblast growth factor receptor 3. Proc Natl Acad Sci USA 96:4455-4460 Webster MK, Donoghue DJ 1996 Constitutive activation of fibroblast growth factor receptor 3 by the transmembrane domain point mutation found in achondroplasia. EMBO J 15:520-527 Webster MK, Donoghue DJ 1997 FGFR activation in skeletal disorders: too much of a good thing. Trends Genet 13:178-182

Webster MK, D'Avis PY, Robertson SC, Donoghue DJ 1996 Profound ligand-independent kinase activation of fibroblast growth factor receptor 3 by the activation loop mutation responsible for a lethal skeletal dysplasia, thanatophoric dysplasia type II. Mol Cell Biol 16:4081-4087

Wilkie AOM 1997 Craniosynostosis — genes and mechanisms. Hum Mol Genet 6:1647-1656 Xu J, Lawshe A, MacArthur CA, Ornitz DM 1999 Genomic structure, mapping, activity and expression of fibroblast growth factor 17. Mech Dev 83:165-178 Zhou M, Sutliff RL, Paul RJ et al 1998 Fibroblast growth factor 2 control of vascular tone. Nat Med 4:201-207

Was this article helpful?

0 0
How to Stay Young

How to Stay Young

For centuries, ever since the legendary Ponce de Leon went searching for the elusive Fountain of Youth, people have been looking for ways to slow down the aging process. Medical science has made great strides in keeping people alive longer by preventing and curing disease, and helping people to live healthier lives. Average life expectancy keeps increasing, and most of us can look forward to the chance to live much longer lives than our ancestors.

Get My Free Ebook


Post a comment