scholarly journals Fibroblast Growth Factor Receptor-Mediated Rescue of x-Ephrin B1-Induced Cell Dissociation in XenopusEmbryos

2000 ◽  
Vol 20 (2) ◽  
pp. 724-734 ◽  
Author(s):  
Lisa D. Chong ◽  
Eui Kyun Park ◽  
Erin Latimer ◽  
Robert Friesel ◽  
Ira O. Daar

ABSTRACT The Eph family of receptor tyrosine kinases and their membrane-bound ligands, the ephrins, have been implicated in regulating cell adhesion and migration during development by mediating cell-to-cell signaling events. Genetic evidence suggests that ephrins may transduce signals and become tyrosine phosphorylated during embryogenesis. However, the induction and functional significance of ephrin phosphorylation is not yet clear. Here, we report that when we used ectopically expressed proteins, we found that an activated fibroblast growth factor (FGF) receptor associated with and induced the phosphorylation of ephrin B1 on tyrosine. Moreover, this phosphorylation reduced the ability of overexpressed ephrin B1 to reduce cell adhesion. In addition, we identified a region in the cytoplasmic tail of ephrin B1 that is critical for interaction with the FGF receptor; we also report FGF-induced phosphorylation of ephrins in a neural tissue. This is the first demonstration of communication between the FGF receptor family and the Eph ligand family and implicates cross talk between these two cell surface molecules in regulating cell adhesion.

2002 ◽  
Vol 361 (2) ◽  
pp. 231-241 ◽  
Author(s):  
Sujata G. PANDIT ◽  
Prasanthi GOVINDRAJ ◽  
Joachim SASSE ◽  
Peter J. NEAME ◽  
John R. HASSELL

Point mutations in the human fibroblast growth factor (FGF) receptor 3 gene (Fgfr3) produce a constitutively active receptor, which disrupts chondrocyte differentiation in the growth plate and results in skeletal dysplasias with severe shortening of the limbs. Alternative splicing of the Fgfr3 transcript gives rise to two isoforms, IIIc and IIIb, which vary in their specificity for FGF ligands. We examined the expression of these FGFR3 isoforms in the bovine fetal rib growth plate to determine whether levels of FGFR3 expression are zone-related. Transcripts for both Fgfr3 isoforms are expressed in rib growth plate, with maximum expression in the hypertrophic region and the least expression in the reserve zone. Fgfr3 IIIc is the predominant isoform in the growth plate. Western-blot analysis revealed the presence of full-length FGFR3 (135kDa) for both isoforms in the reserve zone, a major 98kDa fragment in all zones and smaller fragments primarily in the hypertrophic zone. Immunostaining localized FGFR3 to the pericellular region of reserve chondrocytes and to the extracellular matrix in the hypertrophic zone. These results suggest that the transmembrane form of FGFR3 increasingly undergoes proteolytic cleavage towards the hypertrophic zone to produce an extracellular-domain fragment of FGFR3, which is present in large amounts in the matrix of hypertrophic cells. These findings suggest a proteolytic regulatory mechanism for FGFR3, whereby Fgfr3 fragments could control availability of FGF for the intact receptor, and by which proteolysis could inactivate the receptor.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Haiyan Tai ◽  
Zhiyong Wu ◽  
Su’an Sun ◽  
Zhigang Zhang ◽  
Congjian Xu

Fibroblast growth factor receptor-like-1 (FGFRL1) has been identified as the fifth fibroblast growth factor receptor. So far, little is known about its biological functions, particularly in cancer development. Here, for the first time, we demonstrated the roles of FGFRL1 in ovarian carcinoma (OC). An array and existing databases were used to investigate the expression profile of FGFRL1 and the relationship between FGFRL1 expression and clinicopathological parameters. FGFRL1 was significantly upregulated in OC patients, and high FGFRL1 expression was correlated with poor prognosis. In vitro cell proliferation, apoptosis and migration assays, and in vivo subcutaneous xenograft tumor models were used to determine the role of FGFRL1. Loss of function of FGFRL1 significantly influenced cell proliferation, apoptosis, and migration of OC cells in vitro and tumor growth in vivo. Chromatin immunoprecipitation PCR analysis and microarray hybridization were performed to uncover the mechanism. FGFRL1 expression could be induced by hypoxia through hypoxia-inducible factor 1α, which directly binds to the promoter elements of FGFRL1. FGFRL1 promoted tumor progression by crosstalk with Hedgehog (Hh) signaling. Taken together, FGFRL1 is a potential predictor and plays an important role in tumor growth and Hh signaling which could serve as potential therapeutic targets for the treatment of OC.


Development ◽  
1992 ◽  
Vol 116 (4) ◽  
pp. 1051-1058 ◽  
Author(s):  
R. Friesel ◽  
S.A. Brown

The fibroblast growth factors (FGFs) play a role in Xenopus laevis embryonic development, particularly in the induction of ventral-type mesoderm. We have isolated a full-length cDNA from Xenopus that we have designated Xenopus fibroblast growth factor receptor-2 (XFGFR-2), with significant amino acid sequence similarity to the previously described bek gene (FGFR-2). We expressed the XFGFR-2 cDNA in COS1 cells and showed that it functions as an FGF receptor by binding radiolabeled FGF-2. RNA gel blot analysis demonstrates that unlike Xenopus fibroblast growth factor receptor-1 (XFGFR-1), XFGFR-2 mRNA expression begins during gastrulation and continues through early tadpole stages. Whole-mount in situ hybridization demonstrates that XFGFR-2 mRNA is localized to the anterior neural plate in early neurula stage embryos. Later in development, XFGFR-2 expression is found in the eye anlagen, midbrain-hindbrain boundary and the otic vesicle. In addition, XFGFR-2 transcripts are expressed in animal caps in a manner that is independent of mesoderm-inducing factors. These results indicate that XFGFR-2 may have a role in development that is distinct from that of XFGFR-1.


2018 ◽  
Vol 19 (9) ◽  
pp. 2638 ◽  
Author(s):  
Erika Terzuoli ◽  
Federico Corti ◽  
Ginevra Nannelli ◽  
Antonio Giachetti ◽  
Sandra Donnini ◽  
...  

Elevated levels of bradykinin (BK) and fibroblast growth factor-2 (FGF-2) have been implicated in the pathogenesis of inflammatory and angiogenic disorders. In angiogenesis, both stimuli induce a pro-inflammatory signature in endothelial cells, activating an autocrine/paracrine amplification loop that sustains the neovascularization process. Here we investigated the contribution of the FGF-2 pathway in the BK-mediated human endothelial cell permeability and migration, and the role of the B2 receptor (B2R) of BK in this cross-talk. BK (1 µM) upregulated the FGF-2 expression and promoted the FGF-2 signaling, both in human umbilical vein endothelial cells (HUVEC) and in retinal capillary endothelial cells (HREC) by the activation of Fibroblast growth factor receptor-1 (FGFR-1) and its downstream signaling (fibroblast growth factor receptor substrate: FRSα, extracellular signal–regulated kinases1/2: ERK1/2, and signal transducer and activator of transcription 3: STAT3 phosphorylation). FGFR-1 phosphorylation triggered by BK was c-Src mediated and independent from FGF-2 upregulation. Either HUVEC and HREC exposed to BK showed increased permeability, disassembly of adherens and tight-junction, and increased cell migration. B2R blockade by the selective antagonist, fasitibant, significantly inhibited FGF-2/FGFR-1 signaling, and in turn, BK-mediated endothelial cell permeability and migration. Similarly, the FGFR-1 inhibitor, SU5402, and the knock-down of the receptor prevented the BK/B2R inflammatory response in endothelial cells. In conclusion, this work demonstrates the existence of a BK/B2R/FGFR-1/FGF-2 axis in endothelial cells that might be implicated in propagation of angiogenic/inflammatory responses. A B2R blockade, by abolishing the initial BK stimulus, strongly attenuated FGFR-1-driven cell permeability and migration.


Blood ◽  
2007 ◽  
Vol 110 (12) ◽  
pp. 4111-4119 ◽  
Author(s):  
Linlin Wang ◽  
Thomas C. Schulz ◽  
Eric S. Sherrer ◽  
Derek S. Dauphin ◽  
Soojung Shin ◽  
...  

Abstract Despite progress in developing defined conditions for human embryonic stem cell (hESC) cultures, little is known about the cell-surface receptors that are activated under conditions supportive of hESC self-renewal. A simultaneous interrogation of 42 receptor tyrosine kinases (RTKs) in hESCs following stimulation with mouse embryonic fibroblast (MEF) conditioned medium (CM) revealed rapid and prominent tyrosine phosphorylation of insulin receptor (IR) and insulin-like growth factor-1 receptor (IGF1R); less prominent tyrosine phosphorylation of epidermal growth factor receptor (EGFR) family members, including ERBB2 and ERBB3; and trace phosphorylation of fibroblast growth factor receptors. Intense IGF1R and IR phosphorylation occurred in the absence of MEF conditioning (NCM) and was attributable to high concentrations of insulin in the proprietary KnockOut Serum Replacer (KSR). Inhibition of IGF1R using a blocking antibody or lentivirus-delivered shRNA reduced hESC self-renewal and promoted differentiation, while disruption of ERBB2 signaling with the selective inhibitor AG825 severely inhibited hESC proliferation and promoted apoptosis. A simple defined medium containing an IGF1 analog, heregulin-1β (a ligand for ERBB2/ERBB3), fibroblast growth factor-2 (FGF2), and activin A supported long-term growth of multiple hESC lines. These studies identify previously unappreciated RTKs that support hESC proliferation and self-renewal, and provide a rationally designed medium for the growth and maintenance of pluripotent hESCs.


Tumor Biology ◽  
2017 ◽  
Vol 39 (5) ◽  
pp. 101042831769837 ◽  
Author(s):  
Shuwei Wang ◽  
Zhongyang Ding

Fibroblast growth factor receptors are growth factor receptor tyrosine kinases, exerting their roles in embryogenesis, tissue homeostasis, and development of breast cancer. Recent genetic studies have identified some subtypes of fibroblast growth factor receptors as strong genetic loci associated with breast cancer. In this article, we review the recent epidemiological findings and experiment results of fibroblast growth factor receptors in breast cancer. First, we summarized the structure and physiological function of fibroblast growth factor receptors in humans. Then, we discussed the common genetic variations in fibroblast growth factor receptors that affect breast cancer risk. In addition, we also introduced the potential roles of each fibroblast growth factor receptors isoform in breast cancer. Finally, we explored the potential therapeutics targeting fibroblast growth factor receptors for breast cancer. Based on the biological mechanisms of fibroblast growth factor receptors leading to the pathogenesis in breast cancer, targeting fibroblast growth factor receptors may provide new opportunities for breast cancer therapeutic strategies.


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