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The Journal of Neuroscience : the... Apr 2010We explored the effect of single-nucleotide polymorphisms (SNPs) in the fibroblast growth factor 20 gene (FGF20) associated with risk for Parkinson's disease on brain...
We explored the effect of single-nucleotide polymorphisms (SNPs) in the fibroblast growth factor 20 gene (FGF20) associated with risk for Parkinson's disease on brain structure and function in a large sample of healthy young-adult human subjects and also in elderly subjects to look at the interaction between genetic variations and age (N = 237; 116 men; 18-87 years). We analyzed high-resolution anatomical magnetic resonance images using voxel-based morphometry, a quantitative neuroanatomical technique. We also measured FGF20 mRNA expression in postmortem human brain tissue to determine the molecular correlates of these SNPs (N = 108; 72 men; 18-74 years). We found that the T allele carriers of rs12720208 in the 3'-untranslated region had relatively larger hippocampal volume (p = 0.0059) and diminished verbal episodic memory (p = 0.048) and showed steeper decreases of hippocampal volume with normal aging (p = 0.026). In postmortem brain, T allele carriers had greater expression of hippocampal FGF20 mRNA (p = 0.037), consistent with a previously characterized microRNA mechanism. The C allele matches a predicted miR-433 microRNA binding domain, whereas the T allele disrupts it, resulting in higher FGF20 protein translation. The strong FGF20 genetic effects in hippocampus are presumably mediated by activation of the FGFR1 (FGF receptor 1), which is expressed in mammalian brain most abundantly in the hippocampus. These associations, from mRNA expression to brain morphology to cognition and an interaction with aging, confirm a role of FGF20 in human brain structure and function during development and aging.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Aging; Alleles; Cognition; Female; Fibroblast Growth Factors; Genotype; Hippocampus; Humans; Male; MicroRNAs; Middle Aged; Organ Size; Polymorphism, Single Nucleotide; RNA, Messenger; Receptor, Fibroblast Growth Factor, Type 1; Young Adult
PubMed: 20427658
DOI: 10.1523/JNEUROSCI.5773-09.2010 -
Cancer Science Oct 2009To comprehensively screen for genetic events underlying colorectal cancer, we performed suppression subtraction hybridization analysis on an advanced colon cancer....
To comprehensively screen for genetic events underlying colorectal cancer, we performed suppression subtraction hybridization analysis on an advanced colon cancer. Because Dickkopf-4, a member of the Dickkopf family acting as a Wnt-signaling modulator, was identified as one of the upregulated genes in this specimen, we investigated expression profiles of all the Dickkopf family members in 55 colorectal tumors (21 cancers and 34 adenomas). We also investigated mechanisms regulating the expression of Dickkopf-4 in these cancers in vitro and in vivo. Compared with normal adjacent mucosae, Dickkopf-4 (median 27.4, P < 0.01) and -2 (median 51.4, P < 0.01) were strongly expressed in colorectal cancers. The level of Dickkopf-4 was positively correlated with fibroblast growth factor-20 (r(s) = 0.61, P = 0.00017), a representative beta-catenin transcriptional target gene, and with the degree of nuclear accumulation of beta-catenin in colorectal tumors. Dickkopf-4 was induced by activated beta-catenin in vitro. Reciprocally, recombinant Dickkopf-4 significantly inhibited T-cell factor/lymphocyte enhancer factor reporter activity stimulated by recombinant Wnt3a in human embryonic kidney 293 cells. We conclude that Dickkopf-4 and -2 are significantly upregulated in most colorectal tumors, and that Dickkopf-4 upregulation reflects activation of the Wnt/canonical pathway.
Topics: Aged; Aged, 80 and over; Biomarkers, Tumor; Blotting, Western; Colorectal Neoplasms; Female; Fibroblast Growth Factors; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Intercellular Signaling Peptides and Proteins; Male; Middle Aged; RNA, Messenger; ROC Curve; Reverse Transcriptase Polymerase Chain Reaction; Transfection; Up-Regulation; Wnt Proteins; beta Catenin
PubMed: 19659606
DOI: 10.1111/j.1349-7006.2009.01272.x -
Molecular and Cellular Biology Sep 2009Uncontrolled fibroblast growth factor (FGF) signaling can lead to human diseases, necessitating multiple layers of self-regulatory control mechanisms to keep its...
Uncontrolled fibroblast growth factor (FGF) signaling can lead to human diseases, necessitating multiple layers of self-regulatory control mechanisms to keep its activity in check. Herein, we demonstrate that FGF9 and FGF20 ligands undergo a reversible homodimerization, occluding their key receptor binding sites. To test the role of dimerization in ligand autoinhibition, we introduced structure-based mutations into the dimer interfaces of FGF9 and FGF20. The mutations weakened the ability of the ligands to dimerize, effectively increasing the concentrations of monomeric ligands capable of binding and activating their cognate FGF receptor in vitro and in living cells. Interestingly, the monomeric ligands exhibit reduced heparin binding, resulting in their increased radii of heparan sulfate-dependent diffusion and biologic action, as evidenced by the wider dilation area of ex vivo lung cultures in response to implanted mutant FGF9-loaded beads. Hence, our data demonstrate that homodimerization autoregulates FGF9 and FGF20's receptor binding and concentration gradients in the extracellular matrix. Our study is the first to implicate ligand dimerization as an autoregulatory mechanism for growth factor bioactivity and sets the stage for engineering modified FGF9 subfamily ligands, with desired activity for use in both basic and translational research.
Topics: Amino Acid Sequence; Animals; Cells, Cultured; Crystallography, X-Ray; Diffusion; Dimerization; Extracellular Matrix; Female; Fibroblast Growth Factor 9; Fibroblast Growth Factors; Heparitin Sulfate; Humans; Ligands; Mice; Mice, Inbred C57BL; Models, Molecular; Molecular Sequence Data; Mutation; Pregnancy; Protein Multimerization; Protein Structure, Quaternary; Receptor, Fibroblast Growth Factor, Type 1; Signal Transduction
PubMed: 19564416
DOI: 10.1128/MCB.01780-08 -
Movement Disorders : Official Journal... Feb 2009Genetic variation in fibroblast growth factor 20 (FGF20) has been associated with risk of Parkinson's disease (PD). Functional evidence suggested the T allele of one...
Genetic variation in fibroblast growth factor 20 (FGF20) has been associated with risk of Parkinson's disease (PD). Functional evidence suggested the T allele of one SNP, rs12720208 C/T, altered PD risk by increasing FGF20 and alpha-synuclein protein levels. Herein we report our association study of FGF20 and PD risk in four patient-control series (total: 1,262 patients and 1,881 controls), and measurements of FGF20 and alpha-synuclein protein levels in brain samples (nine patients). We found no evidence of association between FGF20 variability and PD risk, and no relationship between the rs12720208 genotype, FGF20 and alpha-synuclein protein levels.
Topics: Adult; Aged; Aged, 80 and over; Female; Fibroblast Growth Factors; Humans; Male; Middle Aged; Parkinson Disease; alpha-Synuclein
PubMed: 19133659
DOI: 10.1002/mds.22442 -
American Journal of Human Genetics Feb 2008Parkinson disease (PD) is a common neurodegenerative disorder caused by environmental and genetic factors. We have previously shown linkage of PD to chromosome 8p.... (Comparative Study)
Comparative Study
Parkinson disease (PD) is a common neurodegenerative disorder caused by environmental and genetic factors. We have previously shown linkage of PD to chromosome 8p. Subsequently, fibroblast growth factor 20 (FGF20) at 8p21.3-22 was identified as a risk factor in several association studies. To identify the risk-conferring polymorphism in FGF20, we performed genetic and functional analysis of single-nucleotide polymorphisms within the gene. In a sample of 729 nuclear families with 1089 affected and 1165 unaffected individuals, the strongest evidence of association came from rs12720208 in the 3' untranslated region of FGF20. We show in several functional assays that the risk allele for rs12720208 disrupts a binding site for microRNA-433, increasing translation of FGF20 in vitro and in vivo. In a cell-based system and in PD brains, this increase in translation of FGF20 is correlated with increased alpha-synuclein expression, which has previously been shown to cause PD through both overexpression and point mutations. We suggest a novel mechanism of action for PD risk in which the modulation of the susceptibility gene's translation by common variations interfere with the regulation mechanisms of microRNA. We propose this is likely to be a common mechanism of genetic modulation of individual susceptibility to complex disease.
Topics: 3' Untranslated Regions; Binding Sites; DNA Primers; Fibroblast Growth Factors; Gene Expression Regulation; Gene Frequency; Genetic Predisposition to Disease; Humans; Linkage Disequilibrium; Luciferases; MicroRNAs; Parkinson Disease; Polymorphism, Single Nucleotide; alpha-Synuclein
PubMed: 18252210
DOI: 10.1016/j.ajhg.2007.09.021 -
Anticancer Research 2006The effects of two recently discovered heparin binding growth factors, FGF-19 and FGF-20, on the human embryonal carcinoma derived cell line Tera 2 were examined.
BACKGROUND
The effects of two recently discovered heparin binding growth factors, FGF-19 and FGF-20, on the human embryonal carcinoma derived cell line Tera 2 were examined.
MATERIALS AND METHODS
Cell numbers, as well as cell migration were examined at the clonal level by light microscopy.
RESULTS
FGF-19, as well as FGF-20 promoted Tera 2 cell multiplication. Whereas FGF-20 promoted cell multiplication at low doses, FGF-19 was required at high doses to achieve a comparable effect. Moreover, FGF-19 did not significantly stimulate cell locomotion, while FGF-20 promoted cell motility at high doses.
CONCLUSION
FGF-19 and FGF-20 qualitatively exert different effects on cell survival and cell locomotion.
Topics: Carcinoma, Embryonal; Cell Movement; Cell Proliferation; Fibroblast Growth Factors; Humans; In Vitro Techniques; Recombinant Proteins; Tumor Cells, Cultured
PubMed: 17094445
DOI: No ID Found -
The Journal of Biological Chemistry Dec 2006The anticoagulant serpin antithrombin acquires a potent antiangiogenic activity upon undergoing conformational alterations to cleaved or latent forms. Here we show that...
Antiangiogenic antithrombin blocks the heparan sulfate-dependent binding of proangiogenic growth factors to their endothelial cell receptors: evidence for differential binding of antiangiogenic and anticoagulant forms of antithrombin to proangiogenic heparan sulfate domains.
The anticoagulant serpin antithrombin acquires a potent antiangiogenic activity upon undergoing conformational alterations to cleaved or latent forms. Here we show that antithrombin antiangiogenic activity is mediated at least in part through the ability of the conformationally altered serpin to block the proangiogenic growth factors fibroblast growth factor (FGF)-2 and vascular endothelial growth factor (VEGF) from forming signaling competent ternary complexes with their protein receptors and heparan sulfate co-receptors on endothelial cells. Cleaved and latent but not native forms of antithrombin blocked the formation of FGF-2-FGF receptor-1 ectodomain-heparin ternary complexes, and the dimerization of these complexes in solution and similarly inhibited the formation of FGF-2-heparin binary complexes and their dimerization. Only antiangiogenic forms of antithrombin likewise inhibited (125)I-FGF-2 binding to its low affinity heparan sulfate co-receptor and blocked FGF receptor-1 autophosphorylation and p42/44 MAP kinase phosphorylation in cultured human umbilical vein endothelial cells (HUVECs). Moreover, treatment of HUVECs with heparinase III to specifically eliminate the FGF-2 heparan sulfate co-receptor suppressed the ability of antiangiogenic antithrombin to inhibit growth factor-stimulated proliferation. Antiangiogenic antithrombin inhibited full-length VEGF(165) stimulation of HUVEC proliferation but did not affect the stimulation of cells by the heparin-binding domain-deleted VEGF(121). Taken together, these results demonstrate that antiangiogenic forms of antithrombin block the proangiogenic effects of FGF-2 and VEGF on endothelial cells by competing with the growth factors for binding the heparan sulfate co-receptor, which mediates growth factor-receptor interactions. Moreover, the inability of native antithrombin to bind this co-receptor implies that native and conformationally altered forms of antithrombin differentially bind proangiogenic heparan sulfate domains.
Topics: Angiogenesis Inhibitors; Anticoagulants; Antithrombins; Cell Proliferation; Cells, Cultured; Endothelial Cells; Fibroblast Growth Factors; Heparin; Heparin Lyase; Heparitin Sulfate; Humans; Protein Binding; Receptor, Fibroblast Growth Factor, Type 1; Receptors, Vascular Endothelial Growth Factor; Signal Transduction; Vascular Endothelial Growth Factor A
PubMed: 17040907
DOI: 10.1074/jbc.M604905200 -
The Journal of Neuroscience : the... Sep 2006The specific expression of fibroblast growth factor 20 (FGF-20) in the adult substantia nigra and the association between FGF-20 mutations and Parkinson's disease... (Comparative Study)
Comparative Study
The specific expression of fibroblast growth factor 20 (FGF-20) in the adult substantia nigra and the association between FGF-20 mutations and Parkinson's disease provoked exploration of the function of this growth factor. We show by gain- and loss-of-function in vitro experiments that FGF-20 promotes survival and stimulates dopamine (DA) release in a calbindin-negative subset of cells that are preferentially lost in Parkinson's disease. FGF-20 selectively activates tyrosine hydroxylase in calbindin-negative neurons. In the adult substantia nigra, calbindin-negative neurons specifically express high levels of FGFR1 (FGF receptor 1). These data show that FGF signals to elevate DA levels and protect the specific midbrain neuron type at most risk in Parkinson's patients.
Topics: Animals; Cell Survival; Cells, Cultured; Dopamine; Fibroblast Growth Factors; Humans; Mesencephalon; Parkinson Disease; Rats; Risk; Substantia Nigra
PubMed: 16988046
DOI: 10.1523/JNEUROSCI.2745-06.2006 -
BMC Neurology Jun 2005Fibroblast growth factor 20 (FGF20) is a neurotrophic factor preferentially expressed in the substantia nigra of rat brain and could be involved in dopaminergic neurons... (Comparative Study)
Comparative Study
BACKGROUND
Fibroblast growth factor 20 (FGF20) is a neurotrophic factor preferentially expressed in the substantia nigra of rat brain and could be involved in dopaminergic neurons survival. Recently, a strong genetic association has been found between FGF20 gene and the risk of suffering from Parkinson's disease (PD). Our aim was to replicate this association in two independent populations.
METHODS
Allelic, genotypic, and haplotype frequencies of four biallelic polymorphisms were assessed in 151 sporadic PD cases and 186 controls from Greece, and 144 sporadic PD patients and 135 controls from Finland.
RESULTS
No association was found in any of the populations studied.
CONCLUSION
Taken together, these findings suggest that common genetic variants in FGF20 are not a risk factor for PD in, at least, some European populations.
Topics: Adult; Aged; Aged, 80 and over; Alleles; Case-Control Studies; Fibroblast Growth Factors; Finland; Gene Frequency; Genotype; Greece; Humans; Linkage Disequilibrium; Middle Aged; Parkinson Disease; Polymorphism, Genetic; Prospective Studies
PubMed: 15967032
DOI: 10.1186/1471-2377-5-11 -
The EMBO Journal Jan 2005beta-catenin is the major effector of the canonical Wnt signaling pathway. Mutations in components of the pathway that stabilize beta-catenin result in augmented gene...
beta-catenin is the major effector of the canonical Wnt signaling pathway. Mutations in components of the pathway that stabilize beta-catenin result in augmented gene transcription and play a major role in many human cancers. We employed microarrays to identify transcriptional targets of deregulated beta-catenin in a human epithelial cell line (293) engineered to produce mutant beta-catenin and in ovarian endometrioid adenocarcinomas characterized with respect to mutations affecting the Wnt/beta-catenin pathway. Two genes strongly induced in both systems-FGF20 and DKK1-were studied in detail. Elevated levels of FGF20 RNA were also observed in adenomas from mice carrying the Apc(Min)allele. Both XFGF20 and Xdkk-1 are expressed early in Xenopus embryogenesis under the control of the Wnt signaling pathway. Furthermore, FGF20 and DKK1 appear to be direct targets for beta-catenin/TCF transcriptional regulation via LEF/TCF-binding sites. Finally, by using small inhibitory RNAs specific for FGF20, we show that continued expression of FGF20 is necessary for maintenance of the anchorage-independent growth state in RK3E cells transformed by beta-catenin, implying that FGF-20 may be a critical element in oncogenesis induced by the Wnt signaling pathway.
Topics: Adenocarcinoma; Adenoma; Animals; Cell Line; Cytoskeletal Proteins; Epithelial Cells; Female; Fibroblast Growth Factors; Gene Expression Profiling; Gene Expression Regulation; Humans; Intercellular Signaling Peptides and Proteins; Intestinal Mucosa; Mice; Neoplasms; Oligonucleotide Array Sequence Analysis; Ovarian Neoplasms; Promoter Regions, Genetic; Proteins; RNA, Small Interfering; Signal Transduction; Trans-Activators; Transcription, Genetic; Wnt Proteins; Xenopus Proteins; Xenopus laevis; beta Catenin
PubMed: 15592430
DOI: 10.1038/sj.emboj.7600460