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Sample records for fgf signaling controls

  1. Cochlear progenitor number is controlled through mesenchymal FGF receptor signaling

    PubMed Central

    Huh, Sung-Ho; Warchol, Mark E; Ornitz, David M

    2015-01-01

    The sensory and supporting cells (SCs) of the organ of Corti are derived from a limited number of progenitors. The mechanisms that regulate the number of sensory progenitors are not known. Here, we show that Fibroblast Growth Factors (FGF) 9 and 20, which are expressed in the non-sensory (Fgf9) and sensory (Fgf20) epithelium during otic development, regulate the number of cochlear progenitors. We further demonstrate that Fgf receptor (Fgfr) 1 signaling within the developing sensory epithelium is required for the differentiation of outer hair cells and SCs, while mesenchymal FGFRs regulate the size of the sensory progenitor population and the overall cochlear length. In addition, ectopic FGFR activation in mesenchyme was sufficient to increase sensory progenitor proliferation and cochlear length. These data define a feedback mechanism, originating from epithelial FGF ligands and mediated through periotic mesenchyme that controls the number of sensory progenitors and the length of the cochlea. DOI: http://dx.doi.org/10.7554/eLife.05921.001 PMID:25915623

  2. Diverse FGF receptor signaling controls astrocyte specification and proliferation

    SciTech Connect

    Kang, Kyungjun; Song, Mi-Ryoung

    2010-05-07

    During CNS development, pluripotency neuronal progenitor cells give rise in succession to neurons and glia. Fibroblast growth factor-2 (FGF-2), a major signal that maintains neural progenitors in the undifferentiated state, is also thought to influence the transition from neurogenesis to gliogenesis. Here we present evidence that FGF receptors and underlying signaling pathways transmit the FGF-2 signals that regulate astrocyte specification aside from its mitogenic activity. Application of FGF-2 to cortical progenitors suppressed neurogenesis whereas treatment with an FGFR antagonist in vitro promoted neurogenesis. Introduction of chimeric FGFRs with mutated tyrosine residues into cortical progenitors and drug treatments to specifically block individual downstream signaling pathways revealed that the overall activity of FGFR rather than individual autophosphorylation sites is important for delivering signals for glial specification. In contrast, a signal for cell proliferation by FGFR was mainly delivered by MAPK pathway. Together our findings indicate that FGFR activity promotes astrocyte specification in the developing CNS.

  3. Evolution of the Role of RA and FGF Signals in the Control of Somitogenesis in Chordates.

    PubMed

    Bertrand, Stéphanie; Aldea, Daniel; Oulion, Silvan; Subirana, Lucie; de Lera, Angel R; Somorjai, Ildiko; Escriva, Hector

    2015-01-01

    During vertebrate development, the paraxial mesoderm becomes segmented, forming somites that will give rise to dermis, axial skeleton and skeletal muscles. Although recently challenged, the "clock and wavefront" model for somitogenesis explains how interactions between several cell-cell communication pathways, including the FGF, RA, Wnt and Notch signals, control the formation of these bilateral symmetric blocks. In the cephalochordate amphioxus, which belongs to the chordate phylum together with tunicates and vertebrates, the dorsal paraxial mesendoderm also periodically forms somites, although this process is asymmetric and extends along the whole body. It has been previously shown that the formation of the most anterior somites in amphioxus is dependent upon FGF signalling. However, the signals controlling somitogenesis during posterior elongation in amphioxus are still unknown. Here we show that, contrary to vertebrates, RA and FGF signals act independently during posterior elongation and that they are not mandatory for posterior somites to form. Moreover, we show that RA is not able to buffer the left/right asymmetry machinery that is controlled through the asymmetric expression of Nodal pathway actors. Our results give new insights into the evolution of the somitogenesis process in chordates. They suggest that RA and FGF pathways have acquired specific functions in the control of somitogenesis in vertebrates. We propose that the "clock and wavefront" system was selected specifically in vertebrates in parallel to the development of more complex somite-derived structures but that it was not required for somitogenesis in the ancestor of chordates.

  4. Evolution of the Role of RA and FGF Signals in the Control of Somitogenesis in Chordates

    PubMed Central

    Bertrand, Stéphanie; Aldea, Daniel; Oulion, Silvan; Subirana, Lucie; de Lera, Angel R.; Somorjai, Ildiko; Escriva, Hector

    2015-01-01

    During vertebrate development, the paraxial mesoderm becomes segmented, forming somites that will give rise to dermis, axial skeleton and skeletal muscles. Although recently challenged, the "clock and wavefront" model for somitogenesis explains how interactions between several cell-cell communication pathways, including the FGF, RA, Wnt and Notch signals, control the formation of these bilateral symmetric blocks. In the cephalochordate amphioxus, which belongs to the chordate phylum together with tunicates and vertebrates, the dorsal paraxial mesendoderm also periodically forms somites, although this process is asymmetric and extends along the whole body. It has been previously shown that the formation of the most anterior somites in amphioxus is dependent upon FGF signalling. However, the signals controlling somitogenesis during posterior elongation in amphioxus are still unknown. Here we show that, contrary to vertebrates, RA and FGF signals act independently during posterior elongation and that they are not mandatory for posterior somites to form. Moreover, we show that RA is not able to buffer the left/right asymmetry machinery that is controlled through the asymmetric expression of Nodal pathway actors. Our results give new insights into the evolution of the somitogenesis process in chordates. They suggest that RA and FGF pathways have acquired specific functions in the control of somitogenesis in vertebrates. We propose that the "clock and wavefront" system was selected specifically in vertebrates in parallel to the development of more complex somite-derived structures but that it was not required for somitogenesis in the ancestor of chordates. PMID:26371756

  5. Evolution of the Role of RA and FGF Signals in the Control of Somitogenesis in Chordates.

    PubMed

    Bertrand, Stéphanie; Aldea, Daniel; Oulion, Silvan; Subirana, Lucie; de Lera, Angel R; Somorjai, Ildiko; Escriva, Hector

    2015-01-01

    During vertebrate development, the paraxial mesoderm becomes segmented, forming somites that will give rise to dermis, axial skeleton and skeletal muscles. Although recently challenged, the "clock and wavefront" model for somitogenesis explains how interactions between several cell-cell communication pathways, including the FGF, RA, Wnt and Notch signals, control the formation of these bilateral symmetric blocks. In the cephalochordate amphioxus, which belongs to the chordate phylum together with tunicates and vertebrates, the dorsal paraxial mesendoderm also periodically forms somites, although this process is asymmetric and extends along the whole body. It has been previously shown that the formation of the most anterior somites in amphioxus is dependent upon FGF signalling. However, the signals controlling somitogenesis during posterior elongation in amphioxus are still unknown. Here we show that, contrary to vertebrates, RA and FGF signals act independently during posterior elongation and that they are not mandatory for posterior somites to form. Moreover, we show that RA is not able to buffer the left/right asymmetry machinery that is controlled through the asymmetric expression of Nodal pathway actors. Our results give new insights into the evolution of the somitogenesis process in chordates. They suggest that RA and FGF pathways have acquired specific functions in the control of somitogenesis in vertebrates. We propose that the "clock and wavefront" system was selected specifically in vertebrates in parallel to the development of more complex somite-derived structures but that it was not required for somitogenesis in the ancestor of chordates. PMID:26371756

  6. FGF signaling regulates Wnt ligand expression to control vulval cell lineage polarity in C. elegans

    PubMed Central

    Minor, Paul J.; He, Ting-Fang; Sohn, Chang Ho; Asthagiri, Anand R.; Sternberg, Paul W.

    2013-01-01

    The interpretation of extracellular cues leading to the polarization of intracellular components and asymmetric cell divisions is a fundamental part of metazoan organogenesis. The Caenorhabditis elegans vulva, with its invariant cell lineage and interaction of multiple cell signaling pathways, provides an excellent model for the study of cell polarity within an organized epithelial tissue. Here, we show that the fibroblast growth factor (FGF) pathway acts in concert with the Frizzled homolog LIN-17 to influence the localization of SYS-1, a component of the Wnt/β-catenin asymmetry pathway, indirectly through the regulation of cwn-1. The source of the FGF ligand is the primary vulval precursor cell (VPC) P6.p, which controls the orientation of the neighboring secondary VPC P7.p by signaling through the sex myoblasts (SMs), activating the FGF pathway. The Wnt CWN-1 is expressed in the posterior body wall muscle of the worm as well as in the SMs, making it the only Wnt expressed on the posterior and anterior sides of P7.p at the time of the polarity decision. Both sources of cwn-1 act instructively to influence P7.p polarity in the direction of the highest Wnt signal. Using single molecule fluorescence in situ hybridization, we show that the FGF pathway regulates the expression of cwn-1 in the SMs. These results demonstrate an interaction between FGF and Wnt in C. elegans development and vulval cell lineage polarity, and highlight the promiscuous nature of Wnts and the importance of Wnt gradient directionality within C. elegans. PMID:23946444

  7. FGF-receptor signalling controls neural cell diversity in the zebrafish hindbrain by regulating olig2 and sox9.

    PubMed

    Esain, Virginie; Postlethwait, John H; Charnay, Patrick; Ghislain, Julien

    2010-01-01

    The mechanisms underlying the generation of neural cell diversity are the subject of intense investigation, which has highlighted the involvement of different signalling molecules including Shh, BMP and Wnt. By contrast, relatively little is known about FGF in this process. In this report we identify an FGF-receptor-dependent pathway in zebrafish hindbrain neural progenitors that give rise to somatic motoneurons, oligodendrocyte progenitors and differentiating astroglia. Using a combination of chemical and genetic approaches to conditionally inactivate FGF-receptor signalling, we investigate the role of this pathway. We show that FGF-receptor signalling is not essential for the survival or maintenance of hindbrain neural progenitors but controls their fate by coordinately regulating key transcription factors. First, by cooperating with Shh, FGF-receptor signalling controls the expression of olig2, a patterning gene essential for the specification of somatic motoneurons and oligodendrocytes. Second, FGF-receptor signalling controls the development of both oligodendrocyte progenitors and astroglia through the regulation of sox9, a gliogenic transcription factor the function of which we show to be conserved in the zebrafish hindbrain. Overall, for the first time in vivo, our results reveal a mechanism of FGF in the control of neural cell diversity. PMID:20023158

  8. FGF signalling controls anterior extraembryonic and embryonic fate in the beetle Tribolium.

    PubMed

    Sharma, Rahul; Beermann, Anke; Schröder, Reinhard

    2013-09-01

    Fibroblast growth factor (FGF) signalling plays a key role in early embryonic development and cell migration in vertebrates and in invertebrates. To gain novel insights into FGF signalling in an arthropod, we characterized the fgf1b ortholog in the beetle Tribolium that is not represented in the Drosophila genome. We found that FGF1b dependent signalling organizes the anterior to posterior axis of the early embryo. The loss of Tc-fgf1b function in Tribolium by RNA interference resulted in the reduction of the anteriormost extraembryonic fate, in an anterior shift of embryonic fate and in the loss or malformation of anterior embryonic structures. Without intact extraembryonic membranes the serosa and the amnion, Tc-fgf1b(RNAi) embryos did not undergo morphogenetic movements and remained posteriorly localized throughout embryogenesis. Only weakly affected embryos developed into a cuticle that show dorsally curved bodies with head defects and a dorsal opening. Except for the posterior dorsal amnion, the overall topology of the dorsal-ventral axis seemed unaffected. Moreover, FGF signalling was not required for the onset of mesoderm formation but for fine-tuning this tissue during later development. We also show that in affected embryos the dorsal epidermis was expanded and expressed Tc-dpp at a higher level. We conclude that in the Tribolium blastoderm embryo, FGF1-signalling organizes patterning along the AP-axis and also balances the expression level of Dpp in the dorsal epidermis, a tissue critically involved in dorsal closure.

  9. FGF signaling regulates the number of posterior taste papillae by controlling progenitor field size.

    PubMed

    Petersen, Camille I; Jheon, Andrew H; Mostowfi, Pasha; Charles, Cyril; Ching, Saunders; Thirumangalathu, Shoba; Barlow, Linda A; Klein, Ophir D

    2011-06-01

    The sense of taste is fundamental to our ability to ingest nutritious substances and to detect and avoid potentially toxic ones. Sensory taste buds are housed in papillae that develop from epithelial placodes. Three distinct types of gustatory papillae reside on the rodent tongue: small fungiform papillae are found in the anterior tongue, whereas the posterior tongue contains the larger foliate papillae and a single midline circumvallate papilla (CVP). Despite the great variation in the number of CVPs in mammals, its importance in taste function, and its status as the largest of the taste papillae, very little is known about the development of this structure. Here, we report that a balance between Sprouty (Spry) genes and Fgf10, which respectively antagonize and activate receptor tyrosine kinase (RTK) signaling, regulates the number of CVPs. Deletion of Spry2 alone resulted in duplication of the CVP as a result of an increase in the size of the placode progenitor field, and Spry1(-/-);Spry2(-/-) embryos had multiple CVPs, demonstrating the redundancy of Sprouty genes in regulating the progenitor field size. By contrast, deletion of Fgf10 led to absence of the CVP, identifying FGF10 as the first inductive, mesenchyme-derived factor for taste papillae. Our results provide the first demonstration of the role of epithelial-mesenchymal FGF signaling in taste papilla development, indicate that regulation of the progenitor field size by FGF signaling is a critical determinant of papilla number, and suggest that the great variation in CVP number among mammalian species may be linked to levels of signaling by the FGF pathway. PMID:21655085

  10. FGF/MAPK signaling sets the switching threshold of a bistable circuit controlling cell fate decisions in embryonic stem cells.

    PubMed

    Schröter, Christian; Rué, Pau; Mackenzie, Jonathan Peter; Martinez Arias, Alfonso

    2015-12-15

    Intracellular transcriptional regulators and extracellular signaling pathways together regulate the allocation of cell fates during development, but how their molecular activities are integrated to establish the correct proportions of cells with particular fates is not known. Here we study this question in the context of the decision between the epiblast (Epi) and the primitive endoderm (PrE) fate that occurs in the mammalian preimplantation embryo. Using an embryonic stem cell (ESC) model, we discover two successive functions of FGF/MAPK signaling in this decision. First, the pathway needs to be inhibited to make the PrE-like gene expression program accessible for activation by GATA transcription factors in ESCs. In a second step, MAPK signaling levels determine the threshold concentration of GATA factors required for PrE-like differentiation, and thereby control the proportion of cells differentiating along this lineage. Our findings can be explained by a simple mutual repression circuit modulated by FGF/MAPK signaling. This might be a general network architecture to integrate the activity of signal transduction pathways and transcriptional regulators, and serve to balance proportions of cell fates in several contexts.

  11. Roles of FGF Signals in Heart Development, Health, and Disease

    PubMed Central

    Itoh, Nobuyuki; Ohta, Hiroya; Nakayama, Yoshiaki; Konishi, Morichika

    2016-01-01

    The heart provides the body with oxygen and nutrients and assists in the removal of metabolic waste through the blood vessels of the circulatory system. It is the first organ to form during embryonic morphogenesis. FGFs with diverse functions in development, health, and disease are signaling proteins, mostly as paracrine growth factors or endocrine hormones. The human/mouse FGF family comprises 22 members. Findings obtained from mouse models and human diseases with FGF signaling disorders have indicated that several FGFs are involved in heart development, health, and disease. Paracrine FGFs including FGF8, FGF9, FGF10, and FGF16 act as paracrine signals in embryonic heart development. In addition, paracrine FGFs including FGF2, FGF9, FGF10, and FGF16 play roles as paracrine signals in postnatal heart pathophysiology. Although FGF15/19, FGF21, and FGF23 are typical endocrine FGFs, they mainly function as paracrine signals in heart development or pathophysiology. In heart diseases, serum FGF15/19 levels or FGF21 and FGF23 levels decrease or increase, respectively, indicating their possible roles in heart pathophysiology. FGF2 and FGF10 also stimulate the cardiac differentiation of cultured stem cells and cardiac reprogramming of cultured fibroblasts. These findings provide new insights into the roles of FGF signaling in the heart and potential therapeutic strategies for cardiac disorders. PMID:27803896

  12. Up-regulation of fibroblast growth factor (FGF) 9 expression and FGF-WNT/β-catenin signaling in laser-induced wound healing.

    PubMed

    Zheng, Zhenlong; Kang, Hye-Young; Lee, Sunha; Kang, Shin-Wook; Goo, Boncheol; Cho, Sung Bin

    2014-01-01

    Fibroblast growth factor (FGF) 9 is secreted by both mesothelial and epithelial cells, and plays important roles in organ development and wound healing via WNT/β-catenin signaling. The aim of this study was to evaluate FGF9 expression and FGF-WNT/β-catenin signaling during wound healing of the skin. We investigated FGF9 expression and FGF-WNT/β-catenin signaling after laser ablation of mouse skin and adult human skin, as well as in cultured normal human epidermal keratinocytes (NHEKs) upon stimulation with recombinant human (rh) FGF9 and rh-transforming growth factor (TGF)-β1. Our results showed that laser ablation of both mouse skin and human skin leads to marked overexpression of FGF9 and FGF9 mRNA. Control NHEKs constitutively expressed FGF9, WNT7b, WNT2, and β-catenin, but did not show Snail or FGF receptor (FGFR) 2 expression. We also found that FGFR2 was significantly induced in NHEKs by rhFGF9 stimulation, and observed that FGFR2 expression was slightly up-regulated on particular days during the wound healing process after ablative laser therapy. Both WNT7b and WNT2 showed up-regulated protein expression during the laser-induced wound healing process in mouse skin; moreover, we discerned that the stimulatory effect of rhFGF9 and rhTGF-β1 activates WNT/β-catenin signaling via WNT7b in cultured NHEKs. Our data indicated that rhFGF9 and/or rhTGF-β1 up-regulate FGFR2, WNT7b, and β-catenin, but not FGF9 and Snail; pretreatment with rh dickkopf-1 significantly inhibited the up-regulation of FGFR2, WNT7b, and β-catenin. Our results suggested that FGF9 and FGF-WNT/β-catenin signaling may play important roles in ablative laser-induced wound healing processes.

  13. FGF signaling induces mesoderm in the hemichordate Saccoglossus kowalevskii.

    PubMed

    Green, Stephen A; Norris, Rachael P; Terasaki, Mark; Lowe, Christopher J

    2013-03-01

    FGFs act in vertebrate mesoderm induction and also play key roles in early mesoderm formation in ascidians and amphioxus. However, in sea urchins initial characterizations of FGF function do not support a role in early mesoderm induction, making the ancestral roles of FGF signaling and mechanisms of mesoderm specification in deuterostomes unclear. In order to better characterize the evolution of mesoderm formation, we have examined the role of FGF signaling during mesoderm development in Saccoglossus kowalevskii, an experimentally tractable representative of hemichordates. We report the expression of an FGF ligand, fgf8/17/18, in ectoderm overlying sites of mesoderm specification within the archenteron endomesoderm. Embryological experiments demonstrate that mesoderm induction in the archenteron requires contact with ectoderm, and loss-of-function experiments indicate that both FGF ligand and receptor are necessary for mesoderm specification. fgf8/17/18 gain-of-function experiments establish that FGF8/17/18 is sufficient to induce mesoderm in adjacent endomesoderm. These experiments suggest that FGF signaling is necessary from the earliest stages of mesoderm specification and is required for all mesoderm development. Furthermore, they suggest that the archenteron is competent to form mesoderm or endoderm, and that FGF signaling from the ectoderm defines the location and amount of mesoderm. When considered in a comparative context, these data support a phylogenetically broad requirement for FGF8/17/18 signaling in mesoderm specification and suggest that FGF signaling played an ancestral role in deuterostome mesoderm formation.

  14. FGF signaling induces mesoderm in the hemichordate Saccoglossus kowalevskii

    PubMed Central

    Green, Stephen A.; Norris, Rachael P.; Terasaki, Mark; Lowe, Christopher J.

    2013-01-01

    FGFs act in vertebrate mesoderm induction and also play key roles in early mesoderm formation in ascidians and amphioxus. However, in sea urchins initial characterizations of FGF function do not support a role in early mesoderm induction, making the ancestral roles of FGF signaling and mechanisms of mesoderm specification in deuterostomes unclear. In order to better characterize the evolution of mesoderm formation, we have examined the role of FGF signaling during mesoderm development in Saccoglossus kowalevskii, an experimentally tractable representative of hemichordates. We report the expression of an FGF ligand, fgf8/17/18, in ectoderm overlying sites of mesoderm specification within the archenteron endomesoderm. Embryological experiments demonstrate that mesoderm induction in the archenteron requires contact with ectoderm, and loss-of-function experiments indicate that both FGF ligand and receptor are necessary for mesoderm specification. fgf8/17/18 gain-of-function experiments establish that FGF8/17/18 is sufficient to induce mesoderm in adjacent endomesoderm. These experiments suggest that FGF signaling is necessary from the earliest stages of mesoderm specification and is required for all mesoderm development. Furthermore, they suggest that the archenteron is competent to form mesoderm or endoderm, and that FGF signaling from the ectoderm defines the location and amount of mesoderm. When considered in a comparative context, these data support a phylogenetically broad requirement for FGF8/17/18 signaling in mesoderm specification and suggest that FGF signaling played an ancestral role in deuterostome mesoderm formation. PMID:23344709

  15. Genetic insights into the mechanisms of Fgf signaling

    PubMed Central

    Brewer, J. Richard; Mazot, Pierre; Soriano, Philippe

    2016-01-01

    The fibroblast growth factor (Fgf) family of ligands and receptor tyrosine kinases is required throughout embryonic and postnatal development and also regulates multiple homeostatic functions in the adult. Aberrant Fgf signaling causes many congenital disorders and underlies multiple forms of cancer. Understanding the mechanisms that govern Fgf signaling is therefore important to appreciate many aspects of Fgf biology and disease. Here we review the mechanisms of Fgf signaling by focusing on genetic strategies that enable in vivo analysis. These studies support an important role for Erk1/2 as a mediator of Fgf signaling in many biological processes but have also provided strong evidence for additional signaling pathways in transmitting Fgf signaling in vivo. PMID:27036966

  16. Altered FGF signalling in congenital craniofacial and skeletal disorders.

    PubMed

    Moosa, Shahida; Wollnik, Bernd

    2016-05-01

    The fibroblast growth factor (FGF) signalling pathway has been the focus of intense genetic and functional research for several decades. The emerging data implicate FGF signalling in diverse regulatory processes, both in the developing embryo as well as in the adult organism. Alterations in this tightly regulated pathway can lead to a number of pathological conditions, ranging from well-recognized congenital disorders to cancer. In order to mediate their cellular processes, FGFs signal through a subfamily of tyrosine kinase receptors, called FGF receptors (FGFRs). In humans, four FGFRs are described, and, to date, mutations in FGFR1, FGFR2, and FGFR3 have been shown to underlie human developmental disorders. FGFs/FGFRs are known to be key players in both endochondral and intramembranous bone development. In this review, we focus on the major developmental craniofacial and skeletal disorders which result from altered FGF signalling. PMID:26686047

  17. The single fgf receptor gene in the beetle Tribolium castaneum codes for two isoforms that integrate FGF8- and Branchless-dependent signals.

    PubMed

    Sharma, Rahul; Beer, Katharina; Iwanov, Katharina; Schmöhl, Felix; Beckmann, Paula Indigo; Schröder, Reinhard

    2015-06-15

    The precise regulation of cell-cell communication by numerous signal-transduction pathways is fundamental for many different processes during embryonic development. One important signalling pathway is the evolutionary conserved fibroblast-growth-factor (FGF)-pathway that controls processes like cell migration, axis specification and mesoderm formation in vertebrate and invertebrate animals. In the model insect Drosophila, the FGF ligand / receptor combinations of FGF8 (Pyramus and Thisbe) / Heartless (Htl) and Branchless (Bnl) / Breathless (Btl) are required for the migration of mesodermal cells and for the formation of the tracheal network respectively with both the receptors functioning independently of each other. However, only a single fgf-receptor gene (Tc-fgfr) has been identified in the genome of the beetle Tribolium. We therefore asked whether both the ligands Fgf8 and Bnl could transduce their signal through a common FGF-receptor in Tribolium. Indeed, we found that the function of the single Tc-fgfr gene is essential for mesoderm differentiation as well as for the formation of the tracheal network during early development. Ligand specific RNAi for Tc-fgf8 and Tc-bnl resulted in two distinct non-overlapping phenotypes of impaired mesoderm differentiation and abnormal formation of the tracheal network in Tc-fgf8- and Tc-bnl(RNAi) embryos respectively. We further show that the single Tc-fgfr gene encodes at least two different receptor isoforms that are generated through alternative splicing. We in addition demonstrate through exon-specific RNAi their distinct tissue-specific functions. Finally, we discuss the structure of the fgf-receptor gene from an evolutionary perspective.

  18. FGF signaling transforms non-neural ectoderm into neural crest.

    PubMed

    Yardley, Nathan; García-Castro, Martín I

    2012-12-15

    The neural crest arises at the border between the neural plate and the adjacent non-neural ectoderm. It has been suggested that both neural and non-neural ectoderm can contribute to the neural crest. Several studies have examined the molecular mechanisms that regulate neural crest induction in neuralized tissues or the neural plate border. Here, using the chick as a model system, we address the molecular mechanisms by which non-neural ectoderm generates neural crest. We report that in response to FGF the non-neural ectoderm can ectopically express several early neural crest markers (Pax7, Msx1, Dlx5, Sox9, FoxD3, Snail2, and Sox10). Importantly this response to FGF signaling can occur without inducing ectopic mesodermal tissues. Furthermore, the non-neural ectoderm responds to FGF by expressing the prospective neural marker Sox3, but it does not express definitive markers of neural or anterior neural (Sox2 and Otx2) tissues. These results suggest that the non-neural ectoderm can launch the neural crest program in the absence of mesoderm, without acquiring definitive neural character. Finally, we report that prior to the upregulation of these neural crest markers, the non-neural ectoderm upregulates both BMP and Wnt molecules in response to FGF. Our results provide the first effort to understand the molecular events leading to neural crest development via the non-neural ectoderm in amniotes and present a distinct response to FGF signaling. PMID:23000357

  19. FGF signalling in prostate development, tissue homoeostasis and tumorigenesis.

    PubMed

    Lin, Yongshun; Wang, Fen

    2010-04-09

    The FGFs (fibroblast growth factors) regulate a broad spectrum of biological activities by activating transmembrane FGFR (FGF receptor) tyrosine kinases and their coupled intracellular signalling pathways. In the prostate, the mesenchymal-epithelial interactions mediated by androgen signalling and paracrine factors are essential for gland organogenesis, homoeostasis and tumorigenesis. FGFs mediate these mesenchymal-epithelial interactions in the prostate by paracrinal crosstalk through a diverse set of ligands and receptors. Gain- and loss-of-function studies in mouse models have demonstrated the requirement for the FGF signalling axis in prostate development and homoeostasis. The aberrant induction of this axis in either compartment of the prostate results in developmental disorders, disrupts the homoeostatic balance and leads to prostate carcinogenesis. FGFs are also implicated in mediating androgen signalling in the prostate between mesenchymal and epithelial compartments. Therefore studying FGF signalling in the prostate will help us to better understand the underlying molecular mechanisms by which the gland develops, maintains homoeostasis and undergoes carcinogenesis; as well as yield clues on how androgens mediate these processes and how advanced-tumour prostate cells escape strict androgen regulations.

  20. Neuron-glia interactions through the Heartless FGF receptor signaling pathway mediate morphogenesis of Drosophila astrocytes.

    PubMed

    Stork, Tobias; Sheehan, Amy; Tasdemir-Yilmaz, Ozge E; Freeman, Marc R

    2014-07-16

    Astrocytes are critically important for neuronal circuit assembly and function. Mammalian protoplasmic astrocytes develop a dense ramified meshwork of cellular processes to form intimate contacts with neuronal cell bodies, neurites, and synapses. This close neuron-glia morphological relationship is essential for astrocyte function, but it remains unclear how astrocytes establish their intricate morphology, organize spatial domains, and associate with neurons and synapses in vivo. Here we characterize a Drosophila glial subtype that shows striking morphological and functional similarities to mammalian astrocytes. We demonstrate that the Fibroblast growth factor (FGF) receptor Heartless autonomously controls astrocyte membrane growth, and the FGFs Pyramus and Thisbe direct astrocyte processes to ramify specifically in CNS synaptic regions. We further show that the shape and size of individual astrocytes are dynamically sculpted through inhibitory or competitive astrocyte-astrocyte interactions and Heartless FGF signaling. Our data identify FGF signaling through Heartless as a key regulator of astrocyte morphological elaboration in vivo.

  1. Bone proteins PHEX and DMP1 regulate fibroblastic growth factor Fgf23 expression in osteocytes through a common pathway involving FGF receptor (FGFR) signaling.

    PubMed

    Martin, Aline; Liu, Shiguang; David, Valentin; Li, Hua; Karydis, Anastasios; Feng, Jian Q; Quarles, L Darryl

    2011-08-01

    Fibroblastic growth factor 23 (FGF23) is a circulating phosphaturic hormone. Inactivating mutations of the endopeptidase PHEX or the SIBLING protein DMP1 result in equivalent intrinsic bone mineralization defects and increased Fgf23 expression in osteocytes. The mechanisms whereby PHEX and DMP1 regulate Fgf23 expression are unknown. We examined the possibility that PHEX and DMP1 regulate Fgf23 through a common pathway by analyzing the phenotype of compound Phex and Dmp1 mutant mice (Hyp/Dmp1(-/-)). Compared to single-mutant littermates, compound-mutant Hyp/Dmp1(-/-) mice displayed nonadditive elevations of serum FGF23 (1912 ± 183, 1715 ± 178, and 1799 ± 181 pg/ml), hypophosphatemia (P(i): 6.0 ± 0.3, 5.8 ± 0.2, and 5.4 ± 0.1 mg/dl), and severity of rickets/osteomalacia (bone mineral density: -36, -36, and -30%). Microarray analysis of long bones identified gene expression profiles implicating common activation of the FGFR pathway in all the mutant groups. Furthermore, inhibiting FGFR signaling using SU5402 in Hyp- and Dmp1(-/-)-derived bone marrow stromal cells prevented the increase in Fgf23 mRNA expression (129- and 124-fold increase in Hyp and Dmp1(-/-) vs. 1.3-fold in Hyp+SU5402 and 2.5-fold in Dmp1(-/-)+SU5402, P<0.05). For all analyses, samples collected from nonmutant wild-type littermates served as controls. These findings indicate that PHEX and DMP1 control a common pathway regulating bone mineralization and FGF23 production, the latter involving activation of the FGFR signaling in osteocytes.

  2. Pax9 regulates a molecular network involving Bmp4, Fgf10, Shh signaling and the Osr2 transcription factor to control palate morphogenesis.

    PubMed

    Zhou, Jing; Gao, Yang; Lan, Yu; Jia, Shihai; Jiang, Rulang

    2013-12-01

    Cleft palate is one of the most common birth defects in humans. Whereas gene knockout studies in mice have shown that both the Osr2 and Pax9 transcription factors are essential regulators of palatogenesis, little is known about the molecular mechanisms involving these transcription factors in palate development. We report here that Pax9 plays a crucial role in patterning the anterior-posterior axis and outgrowth of the developing palatal shelves. We found that tissue-specific deletion of Pax9 in the palatal mesenchyme affected Shh expression in palatal epithelial cells, indicating that Pax9 plays a crucial role in the mesenchyme-epithelium interactions during palate development. We found that expression of the Bmp4, Fgf10, Msx1 and Osr2 genes is significantly downregulated in the developing palatal mesenchyme in Pax9 mutant embryos. Remarkably, restoration of Osr2 expression in the early palatal mesenchyme through a Pax9(Osr2KI) allele rescued posterior palate morphogenesis in the absence of Pax9 protein function. Our data indicate that Pax9 regulates a molecular network involving the Bmp4, Fgf10, Shh and Osr2 pathways to control palatal shelf patterning and morphogenesis.

  3. FXR Primes the Liver for Intestinal FGF15 Signaling by Transient Induction of β-Klotho.

    PubMed

    Fu, Ting; Kim, Young-Chae; Byun, Sangwon; Kim, Dong-Hyun; Seok, Sunmi; Suino-Powell, Kelly; Xu, H Eric; Kemper, Byron; Kemper, Jongsook Kim

    2016-01-01

    The bile acid (BA)-sensing nuclear receptor, farnesoid X receptor (FXR), regulates postprandial metabolic responses, including inhibition of BA synthesis, by inducing the intestinal hormone, fibroblast growth factor (FGF)15 (FGF19 in human). In this study, we tested a novel hypothesis that FXR not only induces intestinal FGF15 but also primes the liver for effectively responding to the signal by transcriptional induction of the obligate coreceptor for FGF15, β-Klotho (βKL). Activation of FXR by a synthetic agonist, GW4064, in mice increased occupancy of FXR and its DNA-binding partner, retinoid X receptor-α, at FGF15-signaling component genes, particularly βKL, and induced expression of these genes. Interestingly, mRNA levels of Fgfr4, the FGF15 receptor, were not increased by GW4064, but protein levels increased as a result of βKL-dependent increased protein stability. Both FGF receptor 4 and βKL protein levels were substantially decreased in FXR-knockout (KO) mice, and FGF19 signaling, monitored by phosphorylated ERK, was blunted in FXR-KO mice, FXR-KO mouse hepatocytes, and FXR-down-regulated human hepatocytes. Overexpression of βKL in FXR-lacking hepatocytes partially restored FGF19 signaling and inhibition by FGF19 of Cyp7a1, which encodes the rate-limiting BA biosynthetic enzyme. In mice, transient inductions of intestinal Fgf15 and hepatic βKL were temporally correlated after GW4064 treatment, and pretreatment of hepatocytes with GW4064 before FGF19 treatment enhanced FGF19 signaling, which was abolished by transcriptional inhibition or βKL down-regulation. This study identifies FXR as a gut-liver metabolic coordinator for FGF15/19 action that orchestrates transient induction of hepatic βKL and intestinal Fgf15/19 in a temporally correlated manner.

  4. FGF signaling inhibitor, SPRY4, is evolutionarily conserved target of WNT signaling pathway in progenitor cells.

    PubMed

    Katoh, Yuriko; Katoh, Masaru

    2006-03-01

    WNT, FGF and Hedgehog signaling pathways network together during embryogenesis, tissue regeneration, and carcinogenesis. FGF16, FGF18, and FGF20 genes are targets of WNT-mediated TCF/LEF-beta-catenin-BCL9/BCL9L-PYGO transcriptional complex. SPROUTY (SPRY) and SPRED family genes encode inhibitors for receptor tyrosine kinase signaling cascades, such as those of FGF receptor family members and EGF receptor family members. Here, transcriptional regulation of SPRY1, SPRY2, SPRY3, SPRY4, SPRED1, SPRED2, and SPRED3 genes by WNT/beta-catenin signaling cascade was investigated by using bioinformatics and human intelligence (humint). Because double TCF/LEF-binding sites were identified within the 5'-promoter region of human SPRY4 gene, comparative genomics analyses on SPRY4 orthologs were further performed. SPRY4-FGF1 locus at human chromosome 5q31.3 and FGF2-NUDT6-SPATA5-SPRY1 locus at human chromosome 4q27-q28.1 were paralogous regions within the human genome. Chimpanzee SPRY4 gene was identified within NW_107083.1 genome sequence. Human, chimpanzee, rat and mouse SPRY4 orthologs, consisting of three exons, were well conserved. SPRY4 gene was identified as the evolutionarily conserved target of WNT/beta-catenin signaling pathway based on the conservation of double TCF/LEF-binding sites within 5'-promoter region of mammalian SPRY4 orthologs. Human SPRY4 mRNA was expressed in embryonic stem (ES) cells, brain, pancreatic islet, colon cancer, head and neck tumor, melanoma, and pancreatic cancer. WNT signaling activation in progenitor cells leads to the growth regulation of progenitor cells themselves through SPRY4 induction, and also to the growth stimulation of proliferating cells through FGF secretion. Epigenetic silencing and loss-of-function mutations of SPRY4 gene in progenitor cells could lead to carcinogenesis. SPRY4 is the pharmacogenomics target in the fields of oncology and regenerative medicine. PMID:16465403

  5. Development of A Cell-Based Assay to Identify Small Molecule Inhibitors of FGF23 Signaling.

    PubMed

    Diener, Susanne; Schorpp, Kenji; Strom, Tim-Matthias; Hadian, Kamyar; Lorenz-Depiereux, Bettina

    2015-10-01

    Fibroblast growth factor 23 (FGF23) is a bone-derived endocrine key regulator of phosphate homeostasis. It inhibits renal tubular phosphate reabsorption by activating receptor complexes composed of FGF receptor 1c (FGFR1c) and the co-receptor Klotho. As a major signaling pathway mitogen-activated protein kinase (MAPK) pathway is employed. In this study, we established an FGF23-inducible cell model by stably expressing human Klotho in HEK293 cells (HEK293-KL cells) containing endogenous FGF receptors. To identify novel small molecule compounds that modulate FGF23/FGFR1c/Klotho signaling, we developed and optimized a cell-based assay that is suited for high-throughput screening. The assay monitors the phosphorylation of endogenous extracellular signal-regulated kinase 1 and 2 in cellular lysates of HEK293-KL cells after induction with FGF23. This cell-based assay was highly robust (Z' factor >0.5) and the induction of the system is strictly dependent on the presence of FGF23. The inhibitor response curves generated using two known MAPK pathway inhibitors correlate well with data obtained by another assay format. This assay was further used to identify small molecule modulators of the FGF23 signaling cascade by screening the 1,280 food and drug administration-approved small molecule library of Prestwick Chemical. The primary hit rate was 2% and false positives were efficiently identified by retesting the hits in primary and secondary validation screening assays and in western blot analysis. Intriguingly, by using a basic FGF (bFGF)/FGFR counterscreening approach, one validated hit compound retained specificity toward FGF23 signaling, while bFGF signaling was not affected. Since increased plasma concentrations of FGF23 are the main cause of many hypophosphatemic disorders, a modulation of its effect could be a potential novel strategy for therapeutic intervention. Moreover, this strategy may be valuable for other disorders affecting phosphate homeostasis. PMID:26461432

  6. Extracellular sulfatases support cartilage homeostasis by regulating BMP and FGF signaling pathways

    PubMed Central

    Otsuki, Shuhei; Hanson, Sarah R.; Miyaki, Shigeru; Grogan, Shawn P.; Kinoshita, Mitsuo; Asahara, Hiroshi; Wong, Chi-Huey; Lotz, Martin K.

    2010-01-01

    The balance between anabolic and catabolic signaling pathways is critical in maintaining cartilage homeostasis and its disturbance contributes to joint diseases such as osteoarthritis (OA). A unique mechanism that modulates the activity of cell signaling pathways is controlled by extracellular heparan endosulfatases Sulf-1 and Sulf-2 (Sulfs) that are overexpressed in OA cartilage. This study addressed the role of Sulfs in cartilage homeostasis and in regulating bone morphogenetic protein (BMP)/Smad and fibroblast growth factor (FGF)/Erk signaling in articular cartilage. Spontaneous cartilage degeneration and surgically induced OA were significantly more severe in Sulf-1−/− and Sulf-2−/− mice compared with wild-type mice. MMP-13, ADAMTS-5, and the BMP antagonist noggin were elevated whereas col2a1 and aggrecan were reduced in cartilage and chondrocytes from Sulf−/− mice. Articular cartilage and cultured chondrocytes from Sulf−/− mice showed reduced Smad1 protein expression and Smad1/5 phosphorylation, whereas Erk1/2 phosphorylation was increased. In human chondrocytes, Sulfs siRNA reduced Smad phosphorylation but enhanced FGF-2-induced Erk1/2 signaling. These findings suggest that Sulfs simultaneously enhance BMP but inhibit FGF signaling in chondrocytes and maintain cartilage homeostasis. Approaches to correct abnormal Sulf expression have the potential to protect against cartilage degradation and promote cartilage repair in OA. PMID:20479257

  7. ATP oscillations mediate inductive action of FGF and Shh signalling on prechondrogenic condensation.

    PubMed

    Kwon, Hyuck Joon

    2013-01-01

    Skeletal patterns are prefigured by prechondrogenic condensation. Morphogens such as fibroblast growth factor (FGF) and sonic hedgehog (Shh) specify the skeletal patterns in limb development. However, how morphogens regulate prechondrogenic condensation has remained unclear. Recently, it was demonstrated that synchronized Adenosine triphosphate (ATP) oscillations play a critical role in prechondrogenic condensation. Thus, the present study has focused on whether ATP oscillations mediate the actions of major developmental morphogens such as FGF and Shh on prechondrogenic condensation. It has been shown that both FGF and Shh signalling promoted cellular condensation but not chondrogenic differentiation and also induced ATP oscillations. In addition, blockage of FGF and Shh signalling prevented both ATP oscillations and prechondrogenic condensation. Furthermore, it was found that inhibition of ATP oscillations suppressed FGF/Shh-induced prechondrogenic condensation. These results indicate that ATP oscillations mediate the actions of FGF and Shh signalling on prechondrogenic condensation. This study proposes that morphogens organize skeletal patterns via ATP oscillations.

  8. Prolonged FGF signaling is necessary for lung and liver induction in Xenopus

    PubMed Central

    2012-01-01

    Background FGF signaling plays numerous roles during organogenesis of the embryonic gut tube. Mouse explant studies suggest that different thresholds of FGF signaling from the cardiogenic mesoderm induce lung, liver, and pancreas lineages from the ventral foregut progenitor cells. The mechanisms that regulate FGF dose in vivo are unknown. Here we use Xenopus embryos to examine the hypothesis that a prolonged duration of FGF signaling from the mesoderm is required to induce foregut organs. Results We show that both mesoderm and FGF signaling are required for liver and lung development in Xenopus; formally demonstrating that this important step in organ induction is conserved with other vertebrate species. Prolonged contact with the mesoderm and persistent FGF signaling through both MEK and PI3K over an extended period of time are required for liver and lung specification. Inhibition of FGF signaling results in reduced liver and lung development, with a modest expansion of the pancreas/duodenum progenitor domain. Hyper-activation of FGF signaling has the opposite effect expanding liver and lung gene expression and repressing pancreatic markers. We show that FGF signaling is cell autonomously required in the endoderm and that a dominant negative FGF receptor decreases the ability of ventral foregut progenitor cells to contribute to the lung and liver buds. Conclusions These results suggest that the liver and lungs are specified at progressively later times in development requiring mesoderm contact for different lengths of time. Our data suggest that this is achieved at least in part through prolonged FGF signaling. In addition to providing a foundation for further mechanistic studies on foregut organogenesis using the experimental advantages of the Xenopus system, these data have implications for the directed differentiation of stem cells into foregut lineages. PMID:22988910

  9. FGF21 signalling pathway and metabolic traits – genetic association analysis

    PubMed Central

    Kaess, Bernhard M; Barnes, Timothy A; Stark, Klaus; Charchar, Fadi J; Waterworth, Dawn; Song, Kijoung; Wang, William Y S; Vollenweider, Peter; Waeber, Gerard; Mooser, Vincent; Zukowska-Szczechowska, Ewa; Samani, Nilesh J; Hengstenberg, Christian; Tomaszewski, Maciej

    2010-01-01

    Fibroblast growth factor 21 (FGF21) is a novel master regulator of metabolic profile. The biological actions of FGF21 are elicited upon its klotho beta (KLB)-facilitated binding to FGF receptor 1 (FGFR1), FGFR2 and FGFR3. We hypothesised that common polymorphisms in the FGF21 signalling pathway may be associated with metabolic risk. At the screening stage, we examined associations between 63 common single-nucleotide polymorphisms (SNPs) in five genes of this pathway (FGF21, KLB, FGFR1, FGFR2, FGFR3) and four metabolic phenotypes (LDL cholesterol – LDL-C, HDL-cholesterol – HDL-C, triglycerides and body mass index) in 629 individuals from Silesian Hypertension Study (SHS). Replication analyses were performed in 5478 unrelated individuals of the Swiss CoLaus cohort (imputed genotypes) and in 3030 directly genotyped individuals of the German Myocardial Infarction Family Study (GerMIFS). Of 54 SNPs that met quality control criteria after genotyping in SHS, 4 (rs4733946 and rs7012413 in FGFR1; rs2071616 in FGFR2 and rs7670903 in KLB) showed suggestive association with LDL-C (P=0.0006, P=0.0013, P=0.0055, P=0.011, respectively) and 1 (rs2608819 in KLB) was associated with body mass index (P=0.011); all with false discovery rate q<0.5. Of these, only one FGFR2 polymorphism (rs2071616) showed replicated association with LDL-C in both CoLaus (P=0.009) and men from GerMIFS (P=0.017). The direction of allelic effect of rs2071616 upon LDL-C was consistent in all examined populations. These data show that common genetic variations in FGFR2 may be associated with LDL-C in subjects of white European ancestry. PMID:20717167

  10. Circadian control of bile acid synthesis by a KLF15-Fgf15 axis

    PubMed Central

    Han, Sean (Shuxin); Zhang, Rongli; Jain, Rajan; Shi, Hong; Zhang, Lilei; Zhou, Guangjin; Sangwung, Panjamaporn; Tugal, Derin; Atkins, G. Brandon; Prosdocimo, Domenick A.; Lu, Yuan; Han, Xiaonan; Tso, Patrick; Liao, Xudong; Epstein, Jonathan A.; Jain, Mukesh K.

    2015-01-01

    Circadian control of nutrient availability is critical to efficiently meet the energetic demands of an organism. Production of bile acids (BAs), which facilitate digestion and absorption of nutrients, is a major regulator of this process. Here we identify a KLF15-Fgf15 signalling axis that regulates circadian BA production. Systemic Klf15 deficiency disrupted circadian expression of key BA synthetic enzymes, tissue BA levels and triglyceride/cholesterol absorption. Studies in liver-specific Klf15-knockout mice suggested a non-hepatic basis for regulation of BA production. Ileal Fgf15 is a potent inhibitor of BA synthesis. Using a combination of biochemical, molecular and functional assays (including ileectomy and bile duct catheterization), we identify KLF15 as the first endogenous negative regulator of circadian Fgf15 expression. Elucidation of this novel pathway controlling circadian BA production has important implications for physiologic control of nutrient availability and metabolic homeostasis. PMID:26040986

  11. Association between insulin resistance and impairment of FGF21 signal transduction in skeletal muscles.

    PubMed

    Jeon, Ja Young; Choi, Sung-E; Ha, Eun Suk; Kim, Tae Ho; Jung, Jong Gab; Han, Seung Jin; Kim, Hae Jin; Kim, Dae Jung; Kang, Yup; Lee, Kwan-Woo

    2016-07-01

    Fibroblast growth factor (FGF) 21, was identified as a potent metabolic regulator of glucose and lipid metabolism. We investigated whether the levels and signalings of FGF21 changed in the skeletal muscle of type 2 diabetes mellitus (T2DM) patients, participants with impaired glucose tolerance (IGT), human skeletal muscle myotubes (HSMMs) under insulin-resistant conditions, and mice with diet-induced obesity (DIO). A percutaneous biopsy sample of the vastus lateralis muscle of T2DM patients, IGT subjects, and participants with normal glucose tolerance was obtained and the levels and signalings of FGF21 were assessed. We determined whether the expression and signalings of FGF21 in HSMMs altered according to palmitate concentrations and exposure time. Also, we confirmed whether changes of FGF21 signal transduction resulted in the alteration of FGF21 functions. DIO mice were treated intravenously with recombinant FGF21, and the levels and signalings of FGF21 were assessed in their soleus muscles. We checked whether or not FGF21 played a role in the gene transcription related to lipid oxidation. Levels of FGF21 increased, whereas levels of phosphorylated FGF receptor (p-FGFR), phosphorylated FGFR substrates 2α (p-FRS2α), and phosphorylated extracellular signal-regulated kinases (p-ERK) decreased in the skeletal muscle of both T2DM patients and IGT subjects. In vitro, palmitate increased the levels of FGF21 and significantly reduced the levels of β-klotho, p-FGFR, p-FRS2α, and p-ERK1/2 in HSMMs exposed to palmitate. Palmitate also decreased glucose uptake and glycogen contents of FGF21. Consistently, the levels of FGF21 were significantly higher and the levels of β-klotho and p-FGFR were lower in the DIO mice than in normal lean mice. The levels of FGF21 increased but its signal transduction and actions were impaired in skeletal muscles of T2DM patients, IGT subjects, in insulin-resistant HSMMs, and DIO mice.

  12. A high-content screening assay in transgenic zebrafish identifies two novel activators of fgf signaling.

    PubMed

    Saydmohammed, Manush; Vollmer, Laura L; Onuoha, Ezenwa Obi; Vogt, Andreas; Tsang, Michael

    2011-09-01

    Zebrafish have become an invaluable vertebrate animal model to interrogate small molecule libraries for modulators of complex biological pathways and phenotypes. We have recently described the implementation of a quantitative, high-content imaging assay in multi-well plates to analyze the effects of small molecules on Fibroblast Growth Factor (FGF) signaling in vivo. Here we have evaluated the capability of the assay to identify compounds that hyperactivate FGF signaling from a test cassette of agents with known biological activities. Using a transgenic zebrafish reporter line for FGF activity, we screened 1040 compounds from an annotated library of known bioactive agents, including FDA-approved drugs. The assay identified two molecules, 8-hydroxyquinoline sulfate and pyrithione zinc, that enhanced FGF signaling in specific areas of the brain. Subsequent studies revealed that both compounds specifically expanded FGF target gene expression. Furthermore, treatment of early stage embryos with either compound resulted in dorsalized phenotypes characteristic of hyperactivation of FGF signaling in early development. Documented activities for both agents included activation of extracellular signal-related kinase (ERK), consistent with FGF hyperactivation. To conclude, we demonstrate the power of automated quantitative high-content imaging to identify small molecule modulators of FGF. PMID:21932436

  13. FGF2 and insulin signaling converge to regulate cyclin D expression in multipotent neural stem cells.

    PubMed

    Adepoju, Adedamola; Micali, Nicola; Ogawa, Kazuya; Hoeppner, Daniel J; McKay, Ronald D G

    2014-03-01

    The ex vivo expansion of stem cells is making major contribution to biomedical research. The multipotent nature of neural precursors acutely isolated from the developing central nervous system has been established in a series of studies. Understanding the mechanisms regulating cell expansion in tissue culture would support their expanded use either in cell therapies or to define disease mechanisms. Basic fibroblast growth factor (FGF2) and insulin, ligands for tyrosine kinase receptors, are sufficient to sustain neural stem cells (NSCs) in culture. Interestingly, real-time imaging shows that these cells become multipotent every time they are passaged. Here, we analyze the role of FGF2 and insulin in the brief period when multipotent cells are present. FGF2 signaling results in the phosphorylation of Erk1/2, and activation of c-Fos and c-Jun that lead to elevated cyclin D mRNA levels. Insulin signals through the PI3k/Akt pathway to regulate cyclins at the post-transcriptional level. This precise Boolean regulation extends our understanding of the proliferation of multipotent NSCs and provides a basis for further analysis of proliferation control in the cell states defined by real-time mapping of the cell lineages that form the central nervous system.

  14. Altered FGF Signaling Pathways Impair Cell Proliferation and Elevation of Palate Shelves.

    PubMed

    Wu, Weijie; Gu, Shuping; Sun, Cheng; He, Wei; Xie, Xiaohua; Li, Xihai; Ye, Wenduo; Qin, Chunlin; Chen, Yiping; Xiao, Jing; Liu, Chao

    2015-01-01

    In palatogenesis, palatal shelves are patterned along the mediolateral axis as well as the anteroposterior axis before the onset of palatal fusion. Fgf10 specifically expressed in lateral mesenchyme of palate maintains Shh transcription in lateral epithelium, while Fgf7 activated in medial mesenchyme by Dlx5, suppressed the expansion of Shh expression to medial epithelium. How FGF signaling pathways regulate the cell behaviors of developing palate remains elusive. In our study, we found that when Fgf8 is ectopically expressed in the embryonic palatal mesenchyme, the elevation of palatal shelves is impaired and the posterior palatal shelves are enlarged, especially in the medial side. The palatal deformity results from the drastic increase of cell proliferation in posterior mesenchyme and decrease of cell proliferation in epithelium. The expression of mesenchymal Fgf10 and epithelial Shh in the lateral palate, as well as the Dlx5 and Fgf7 transcription in the medial mesenchyme are all interrupted, indicating that the epithelial-mesenchymal interactions during palatogenesis are disrupted by the ectopic activation of mesenchymal Fgf8. Besides the altered Fgf7, Fgf10, Dlx5 and Shh expression pattern, the reduced Osr2 expression domain in the lateral mesenchyme also suggests an impaired mediolateral patterning of posterior palate. Moreover, the ectopic Fgf8 expression up-regulates pJak1 throughout the palatal mesenchyme and pErk in the medial mesenchyme, but down-regulates pJak2 in the epithelium, suggesting that during normal palatogenesis, the medial mesenchymal cell proliferation is stimulated by FGF/Erk pathway, while the epithelial cell proliferation is maintained through FGF/Jak2 pathway.

  15. Altered FGF Signaling Pathways Impair Cell Proliferation and Elevation of Palate Shelves

    PubMed Central

    Wu, Weijie; Gu, Shuping; Sun, Cheng; He, Wei; Xie, Xiaohua; Li, Xihai; Ye, Wenduo; Qin, Chunlin; Chen, Yiping; Xiao, Jing; Liu, Chao

    2015-01-01

    In palatogenesis, palatal shelves are patterned along the mediolateral axis as well as the anteroposterior axis before the onset of palatal fusion. Fgf10 specifically expressed in lateral mesenchyme of palate maintains Shh transcription in lateral epithelium, while Fgf7 activated in medial mesenchyme by Dlx5, suppressed the expansion of Shh expression to medial epithelium. How FGF signaling pathways regulate the cell behaviors of developing palate remains elusive. In our study, we found that when Fgf8 is ectopically expressed in the embryonic palatal mesenchyme, the elevation of palatal shelves is impaired and the posterior palatal shelves are enlarged, especially in the medial side. The palatal deformity results from the drastic increase of cell proliferation in posterior mesenchyme and decrease of cell proliferation in epithelium. The expression of mesenchymal Fgf10 and epithelial Shh in the lateral palate, as well as the Dlx5 and Fgf7 transcription in the medial mesenchyme are all interrupted, indicating that the epithelial-mesenchymal interactions during palatogenesis are disrupted by the ectopic activation of mesenchymal Fgf8. Besides the altered Fgf7, Fgf10, Dlx5 and Shh expression pattern, the reduced Osr2 expression domain in the lateral mesenchyme also suggests an impaired mediolateral patterning of posterior palate. Moreover, the ectopic Fgf8 expression up-regulates pJak1 throughout the palatal mesenchyme and pErk in the medial mesenchyme, but down-regulates pJak2 in the epithelium, suggesting that during normal palatogenesis, the medial mesenchymal cell proliferation is stimulated by FGF/Erk pathway, while the epithelial cell proliferation is maintained through FGF/Jak2 pathway. PMID:26332583

  16. An Fgf-Shh signaling hierarchy regulates early specification of the zebrafish skull

    PubMed Central

    McCarthy, Neil; Sidik, Alfire; Bertrand, Julien Y.; Eberhart, Johann K.

    2016-01-01

    The neurocranium generates most of the craniofacial skeleton and consists of prechordal and postchordal regions. Although development of the prechordal is well studied, little is known of the postchordal region. Here we characterize a signaling hierarchy necessary for postchordal neurocranial development involving Fibroblast growth factor (Fgf) signaling for early specification of mesodermally-derived progenitor cells. The expression of hyaluron synthetase 2 (has2) in the cephalic mesoderm requires Fgf signaling and Has2 function, in turn, is required for postchordal neurocranial development. While Hedgehog (Hh)-deficient embryos also lack a postchordal neurocranium, this appears primarily due to a later defect in chondrocyte differentiation. Inhibitor studies demonstrate that postchordal neurocranial development requires early Fgf and later Hh signaling. Collectively, our results provide a mechanistic understanding of early postchordal neurocranial development and demonstrate a hierarchy of signaling between Fgf and Hh in the development of this structure. PMID:27060628

  17. Ectodysplasin regulates activator-inhibitor balance in murine tooth development through Fgf20 signaling.

    PubMed

    Häärä, Otso; Harjunmaa, Enni; Lindfors, Päivi H; Huh, Sung-Ho; Fliniaux, Ingrid; Åberg, Thomas; Jernvall, Jukka; Ornitz, David M; Mikkola, Marja L; Thesleff, Irma

    2012-09-01

    Uncovering the origin and nature of phenotypic variation within species is the first step in understanding variation between species. Mouse models with altered activities of crucial signal pathways have highlighted many important genes and signal networks regulating the morphogenesis of complex structures, such as teeth. The detailed analyses of these models have indicated that the balanced actions of a few pathways regulating cell behavior modulate the shape and number of teeth. Currently, however, most mouse models studied have had gross alteration of morphology, whereas analyses of more subtle modification of morphology are required to link developmental studies to evolutionary change. Here, we have analyzed a signaling network involving ectodysplasin (Eda) and fibroblast growth factor 20 (Fgf20) that subtly affects tooth morphogenesis. We found that Fgf20 is a major downstream effector of Eda and affects Eda-regulated characteristics of tooth morphogenesis, including the number, size and shape of teeth. Fgf20 function is compensated for by other Fgfs, in particular Fgf9 and Fgf4, and is part of an Fgf signaling loop between epithelium and mesenchyme. We showed that removal of Fgf20 in an Eda gain-of-function mouse model results in an Eda loss-of-function phenotype in terms of reduced tooth complexity and third molar appearance. However, the extra anterior molar, a structure lost during rodent evolution 50 million years ago, was stabilized in these mice.

  18. FGF signaling is required for anterior but not posterior specification of the murine liver bud

    PubMed Central

    Wang, Jikui; Rhee, Siyeon; Palaria, Amrita; Tremblay, Kimberly D.

    2014-01-01

    Background The definitive endoderm arises as a naive epithelial sheet that produces the entire gut tube and associated organs including the liver, pancreas and lungs. Murine explant studies demonstrate that Fibroblast Growth Factor (FGF) signaling from adjacent tissues is required to induce hepatic gene expression from isolated foregut endoderm. The requirement of FGF signaling during liver development is examined via small molecule inhibition during whole embryo culture. Results Loss of FGF signaling prior to hepatic induction results in morphological defects and gene expression changes that are confined to the anterior liver bud. In contrast the posterior portion of the liver bud remains relatively unaffected. Because FGF is thought to act as a morphogen during endoderm organogenesis, the ventral pancreas was also examined after FGF inhibition. Although the size of the ventral pancreas is not affected, loss of FGF signaling results in a significantly higher density of ventral pancreas cells. Conclusions The requirement for FGF-mediated induction of hepatic gene expression differs across the anterior-posterior axis of the developing liver bud. These results underscore the importance of studying tissue differentiation in the context of the whole embryo. PMID:25302779

  19. FGF23 signaling impairs neutrophil recruitment and host defense during CKD

    PubMed Central

    Rossaint, Jan; Oehmichen, Jessica; Van Aken, Hugo; Reuter, Stefan; Pavenstädt, Hermann J.; Meersch, Melanie; Unruh, Mark

    2016-01-01

    Chronic kidney disease (CKD) has been associated with impaired host response and increased susceptibility to infections. Leukocyte recruitment during inflammation must be tightly regulated to protect the host against pathogens. FGF23 levels are increased in blood during CKD, and levels of this hormone have been associated with a variety of adverse effects in CKD patients. Here, we have shown that CKD impairs leukocyte recruitment into inflamed tissue and host defense in mice and humans. FGF23 neutralization during CKD in murine models restored leukocyte recruitment and host defense. Intravital microscopy of animals with chronic kidney failure showed that FGF23 inhibits chemokine-activated leukocyte arrest on the endothelium, and downregulation of FGF receptor 2 (FGFR2) on PMNs rescued host defense in these mice. In vitro, FGF23 inhibited PMN adhesion, arrest under flow, and transendothelial migration. Mechanistically, FGF23 binding to FGFR2 counteracted selectin- and chemokine-triggered β2 integrin activation on PMNs by activating protein kinase A (PKA) and inhibiting activation of the small GTPase Rap1. Moreover, knockdown of PKA abolished the inhibitory effect of FGF23 on integrin activation. Together, our data reveal that FGF23 acts directly on PMNs and dampens host defense by direct interference with chemokine signaling and integrin activation. PMID:26878171

  20. FGF Signaling Is Necessary for Neurogenesis in Young Mice and Sufficient to Reverse Its Decline in Old Mice

    PubMed Central

    Kang, Wenfei

    2015-01-01

    The mechanisms regulating hippocampal neurogenesis remain poorly understood. Particularly unclear is the extent to which age-related declines in hippocampal neurogenesis are due to an innate decrease in precursor cell performance or to changes in the environment of these cells. Several extracellular signaling factors that regulate hippocampal neurogenesis have been identified. However, the role of one important family, FGFs, remains uncertain. Although a body of literature suggests that FGFs can promote the proliferation of cultured adult hippocampal precursor cells, their requirement for adult hippocampal neurogenesis in vivo and the cell types within the neurogenic lineage that might depend on FGFs remain unclear. Here, specifically targeting adult neural precursor cells, we conditionally express an activated form of an FGF receptor or delete the FGF receptors that are expressed in these cells. We find that FGF receptors are required for neural stem-cell maintenance and that an activated receptor expressed in all precursors can increase the number of neurons produced. Moreover, in older mice, an activated FGF receptor can rescue the age-related decline in neurogenesis to a level found in young adults. These results suggest that the decrease in neurogenesis with age is not simply due to fewer stem cells, but also to declining signals in their niche. Thus, enhancing FGF signaling in precursors can be used to reverse age-related declines in hippocampal neurogenesis. SIGNIFICANCE STATEMENT Hippocampal deficits can result from trauma, neurodegeneration, or aging and can lead to loss of memory and mood control. The addition of new neurons to the hippocampus facilitates memory formation, but how this process is regulated and how we might manipulate it to reverse hippocampal dysfunction remains unclear. The FGF signaling pathway has been hypothesized to be important, but its role in generating new neurons had been poorly defined. Our study indicates that FGF signaling

  1. FGF8 signaling sustains progenitor status and multipotency of cranial neural crest-derived mesenchymal cells in vivo and in vitro.

    PubMed

    Shao, Meiying; Liu, Chao; Song, Yingnan; Ye, Wenduo; He, Wei; Yuan, Guohua; Gu, Shuping; Lin, Congxin; Ma, Liang; Zhang, Yanding; Tian, Weidong; Hu, Tao; Chen, YiPing

    2015-10-01

    The cranial neural crest (CNC) cells play a vital role in craniofacial development and regeneration. They are multi-potent progenitors, being able to differentiate into various types of tissues. Both pre-migratory and post-migratory CNC cells are plastic, taking on diverse fates by responding to different inductive signals. However, what sustains the multipotency of CNC cells and derivatives remains largely unknown. In this study, we present evidence that FGF8 signaling is able to sustain progenitor status and multipotency of CNC-derived mesenchymal cells both in vivo and in vitro. We show that augmented FGF8 signaling in pre-migratory CNC cells prevents cell differentiation and organogenesis in the craniofacial region by maintaining their progenitor status. CNC-derived mesenchymal cells with Fgf8 overexpression or control cells in the presence of exogenous FGF8 exhibit prolonged survival, proliferation, and multi-potent differentiation capability in cell cultures. Remarkably, exogenous FGF8 also sustains the capability of CNC-derived mesenchymal cells to participate in organogenesis such as odontogenesis. Furthermore, FGF8-mediated signaling strongly promotes adipogenesis but inhibits osteogenesis of CNC-derived mesenchymal cells in vitro. Our results reveal a specific role for FGF8 in the maintenance of progenitor status and in fate determination of CNC cells, implicating a potential application in expansion and fate manipulation of CNC-derived cells in stem cell-based craniofacial regeneration. PMID:26243590

  2. FGF8 signaling sustains progenitor status and multipotency of cranial neural crest-derived mesenchymal cells in vivo and in vitro

    PubMed Central

    Shao, Meiying; Liu, Chao; Song, Yingnan; Ye, Wenduo; He, Wei; Yuan, Guohua; Gu, Shuping; Lin, Congxin; Ma, Liang; Zhang, Yanding; Tian, Weidong; Hu, Tao; Chen, YiPing

    2015-01-01

    The cranial neural crest (CNC) cells play a vital role in craniofacial development and regeneration. They are multi-potent progenitors, being able to differentiate into various types of tissues. Both pre-migratory and post-migratory CNC cells are plastic, taking on diverse fates by responding to different inductive signals. However, what sustains the multipotency of CNC cells and derivatives remains largely unknown. In this study, we present evidence that FGF8 signaling is able to sustain progenitor status and multipotency of CNC-derived mesenchymal cells both in vivo and in vitro. We show that augmented FGF8 signaling in pre-migratory CNC cells prevents cell differentiation and organogenesis in the craniofacial region by maintaining their progenitor status. CNC-derived mesenchymal cells with Fgf8 overexpression or control cells in the presence of exogenous FGF8 exhibit prolonged survival, proliferation, and multi-potent differentiation capability in cell cultures. Remarkably, exogenous FGF8 also sustains the capability of CNC-derived mesenchymal cells to participate in organogenesis such as odontogenesis. Furthermore, FGF8-mediated signaling strongly promotes adipogenesis but inhibits osteogenesis of CNC-derived mesenchymal cells in vitro. Our results reveal a specific role for FGF8 in the maintenance of progenitor status and in fate determination of CNC cells, implicating a potential application in expansion and fate manipulation of CNC-derived cells in stem cell-based craniofacial regeneration. PMID:26243590

  3. Cations modulate polysaccharide structure to determine FGF-FGFR signaling: a comparison of signaling and inhibitory polysaccharide interactions with FGF-1 in solution.

    PubMed

    Guimond, Scott E; Rudd, Timothy R; Skidmore, Mark A; Ori, Alessandro; Gaudesi, Davide; Cosentino, Cesare; Guerrini, Marco; Edge, Ruth; Collison, David; McInnes, Eric; Torri, Giangiacomo; Turnbull, Jeremy E; Fernig, David G; Yates, Edwin A

    2009-06-01

    For heparan sulfate (HS) to bind and regulate the activity of proteins, the polysaccharide must present an appropriate sequence and adopt a suitable conformation. The conformations of heparin derivatives, as models of HS, are altered via a change in the associated cations, and this can drastically modify their FGF signaling activities. Here, we report that changing the cations associated with an N-acetyl-enriched heparin polysaccharide, from sodium to copper(II), converted it from supporting signaling through the fibroblast growth factor receptor (FGF-1-FGFR1c) tyrosine kinase signaling system to being inhibitory in a cell-based BaF3 assay. Nuclear magnetic resonance and synchrotron radiation circular dichroism (SRCD) spectroscopy demonstrated that the polysaccharide conformation differed in the presence of sodium or copper(II) cations. Electron paramagnetic resonance confirmed the environment of the copper(II) ion on the N-acetyl-enriched polysaccharide was distinct from that previously observed with intact heparin, which supported signaling. Secondary structures in solution complexes of polysaccharides with FGF-1 (which either supported signaling through FGFR1c or were inhibitory) were determined by SRCD. This allowed direct comparison of the two FGF-1-polysaccharide complexes in solution, containing identical molecular components and differing only in their cation content. Subtle structural differences were revealed, including a reduction in the level of disordered structure in the inhibitory complex. PMID:19400583

  4. Hepatic mTORC1 controls locomotor activity, body temperature, and lipid metabolism through FGF21.

    PubMed

    Cornu, Marion; Oppliger, Wolfgang; Albert, Verena; Robitaille, Aaron M; Trapani, Francesca; Quagliata, Luca; Fuhrer, Tobias; Sauer, Uwe; Terracciano, Luigi; Hall, Michael N

    2014-08-12

    The liver is a key metabolic organ that controls whole-body physiology in response to nutrient availability. Mammalian target of rapamycin (mTOR) is a nutrient-activated kinase and central controller of growth and metabolism that is negatively regulated by the tumor suppressor tuberous sclerosis complex 1 (TSC1). To investigate the role of hepatic mTOR complex 1 (mTORC1) in whole-body physiology, we generated liver-specific Tsc1 (L-Tsc1 KO) knockout mice. L-Tsc1 KO mice displayed reduced locomotor activity, body temperature, and hepatic triglyceride content in a rapamycin-sensitive manner. Ectopic activation of mTORC1 also caused depletion of hepatic and plasma glutamine, leading to peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α)-dependent fibroblast growth factor 21 (FGF21) expression in the liver. Injection of glutamine or knockdown of PGC-1α or FGF21 in the liver suppressed the behavioral and metabolic defects due to mTORC1 activation. Thus, mTORC1 in the liver controls whole-body physiology through PGC-1α and FGF21. Finally, mTORC1 signaling correlated with FGF21 expression in human liver tumors, suggesting that treatment of glutamine-addicted cancers with mTOR inhibitors might have beneficial effects at both the tumor and whole-body level.

  5. Functional components of fibroblast growth factor (FGF) signal transduction in pituitary cells. Identification of FGF response elements in the prolactin gene.

    PubMed

    Schweppe, R E; Frazer-Abel, A A; Gutierrez-Hartmann, A; Bradford, A P

    1997-12-01

    Fibroblast growth factors (FGFs) have been implicated in pituitary lactotroph tumorigenesis; however, little is known about the molecular mechanisms of FGF signal transduction. We used a transient transfection approach, in GH4 cells, to identify components of the FGF signaling pathway leading to activation of the rat prolactin (rPRL) promoter. Using dominant-negative constructs of p21(Ras), Raf-1 kinase, and mitogen-activated protein (MAP) kinase, we show that FGF activation of the rPRL promoter is independent of Ras and Raf-1 but requires MAP kinase. Furthermore, MAP kinase but not Raf-1 kinase catalytic activity is stimulated by FGFs. The rPRL promoter FGF response maps to two Ets binding sites, centered at -212 (FRE1) and -96 (FRE2), and co-transfection of dominant-negative Ets inhibits FGF activation. FRE1 co-localizes with a composite, Ets/GHF-1, Ras response element. However, overexpression of Ets-1 and GHF-1, which potentiate the Ras response, inhibits FGF stimulation of the rPRL promoter, implying that Ras and FGF signaling pathways target distinct factors to elicit their effects. These data suggest that Ets factors serve to sort and integrate MAP kinase-dependent growth factor signals, allowing highly specific transcriptional responses to be mediated via the interaction of distinct Ets proteins and cofactors at common response elements.

  6. Buttressing a balanced brain: Target-derived FGF signaling regulates excitatory/inhibitory tone and adult neurogenesis within the maturating hippocampal network.

    PubMed

    Dabrowski, Ania; Umemori, Hisashi

    2016-01-01

    Brain development involves multiple levels of molecular coordination in forming a functional nervous system. The hippocampus is a brain area that is important for memory formation and spatial reasoning. During early postnatal development of the hippocampal circuit, Fibroblast growth factor 22 (FGF22) and FGF7 act to establish a balance of excitatory and inhibitory tone. Both FGFs are secreted from CA3 dendrites, acting on excitatory or inhibitory axon terminals formed onto CA3 dendrites, respectively. Mechanistically, FGF22 utilizes FGFR2b and FGFR1b to induce synaptic vesicle recruitment within axons of dentate granule cells (DGCs), and FGF7 utilizes FGFR2b to induce synaptic vesicle recruitment within interneuron axons. FGF signaling eventually induces gene expression in the presynaptic neurons; however, the effects of FGF22-induced gene expression within DGCs and FGF7-induced gene expression within interneurons in the context of a developing hippocampal circuit have yet to be explored. Here, we propose one hypothetical mechanism of FGF22-induced gene expression in controlling adult neurogenesis. PMID:27605441

  7. Bmp signaling mediates endoderm pouch morphogenesis by regulating Fgf signaling in zebrafish.

    PubMed

    Lovely, C Ben; Swartz, Mary E; McCarthy, Neil; Norrie, Jacqueline L; Eberhart, Johann K

    2016-06-01

    The endodermal pouches are a series of reiterated structures that segment the pharyngeal arches and help pattern the vertebrate face. Multiple pathways regulate the complex process of endodermal development, including the Bone morphogenetic protein (Bmp) pathway. However, the role of Bmp signaling in pouch morphogenesis is poorly understood. Using genetic and chemical inhibitor approaches, we show that pouch morphogenesis requires Bmp signaling from 10-18 h post-fertilization, immediately following gastrulation. Blocking Bmp signaling during this window results in morphological defects to the pouches and craniofacial skeleton. Using genetic chimeras we show that Bmp signals directly to the endoderm for proper morphogenesis. Time-lapse imaging and analysis of reporter transgenics show that Bmp signaling is necessary for pouch outpocketing via the Fibroblast growth factor (Fgf) pathway. Double loss-of-function analyses demonstrate that Bmp and Fgf signaling interact synergistically in craniofacial development. Collectively, our analyses shed light on the tissue and signaling interactions that regulate development of the vertebrate face. PMID:27122171

  8. Neural crest induction by paraxial mesoderm in Xenopus embryos requires FGF signals.

    PubMed

    Monsoro-Burq, Anne-Hélène; Fletcher, Russell B; Harland, Richard M

    2003-07-01

    At the border of the neural plate, the induction of the neural crest can be achieved by interactions with the epidermis, or with the underlying mesoderm. Wnt signals are required for the inducing activity of the epidermis in chick and amphibian embryos. Here, we analyze the molecular mechanisms of neural crest induction by the mesoderm in Xenopus embryos. Using a recombination assay, we show that prospective paraxial mesoderm induces a panel of neural crest markers (Slug, FoxD3, Zic5 and Sox9), whereas the future axial mesoderm only induces a subset of these genes. This induction is blocked by a dominant negative (dn) form of FGFR1. However, neither dnFGFR4a nor inhibition of Wnt signaling prevents neural crest induction in this system. Among the FGFs, FGF8 is strongly expressed by the paraxial mesoderm. FGF8 is sufficient to induce the neural crest markers FoxD3, Sox9 and Zic5 transiently in the animal cap assay. In vivo, FGF8 injections also expand the Slug expression domain. This suggests that FGF8 can initiate neural crest formation and cooperates with other DLMZ-derived factors to maintain and complete neural crest induction. In contrast to Wnts, eFGF or bFGF, FGF8 elicits neural crest induction in the absence of mesoderm induction and without a requirement for BMP antagonists. In vivo, it is difficult to dissociate the roles of FGF and WNT factors in mesoderm induction and neural patterning. We show that, in most cases, effects on neural crest formation were parallel to altered mesoderm or neural development. However, neural and neural crest patterning can be dissociated experimentally using different dominant-negative manipulations: while Nfz8 blocks both posterior neural plate formation and neural crest formation, dnFGFR4a blocks neural patterning without blocking neural crest formation. These results suggest that different signal transduction mechanisms may be used in neural crest induction, and anteroposterior neural patterning. PMID:12783784

  9. An FGF3-BMP Signaling Axis Regulates Caudal Neural Tube Closure, Neural Crest Specification and Anterior-Posterior Axis Extension

    PubMed Central

    Anderson, Matthew J.; Schimmang, Thomas; Lewandoski, Mark

    2016-01-01

    During vertebrate axis extension, adjacent tissue layers undergo profound morphological changes: within the neuroepithelium, neural tube closure and neural crest formation are occurring, while within the paraxial mesoderm somites are segmenting from the presomitic mesoderm (PSM). Little is known about the signals between these tissues that regulate their coordinated morphogenesis. Here, we analyze the posterior axis truncation of mouse Fgf3 null homozygotes and demonstrate that the earliest role of PSM-derived FGF3 is to regulate BMP signals in the adjacent neuroepithelium. FGF3 loss causes elevated BMP signals leading to increased neuroepithelium proliferation, delay in neural tube closure and premature neural crest specification. We demonstrate that elevated BMP4 depletes PSM progenitors in vitro, phenocopying the Fgf3 mutant, suggesting that excessive BMP signals cause the Fgf3 axis defect. To test this in vivo we increased BMP signaling in Fgf3 mutants by removing one copy of Noggin, which encodes a BMP antagonist. In such mutants, all parameters of the Fgf3 phenotype were exacerbated: neural tube closure delay, premature neural crest specification, and premature axis termination. Conversely, genetically decreasing BMP signaling in Fgf3 mutants, via loss of BMP receptor activity, alleviates morphological defects. Aberrant apoptosis is observed in the Fgf3 mutant tailbud. However, we demonstrate that cell death does not cause the Fgf3 phenotype: blocking apoptosis via deletion of pro-apoptotic genes surprisingly increases all Fgf3 defects including causing spina bifida. We demonstrate that this counterintuitive consequence of blocking apoptosis is caused by the increased survival of BMP-producing cells in the neuroepithelium. Thus, we show that FGF3 in the caudal vertebrate embryo regulates BMP signaling in the neuroepithelium, which in turn regulates neural tube closure, neural crest specification and axis termination. Uncovering this FGF3-BMP signaling axis is

  10. FGF22 signaling regulates synapse formation during post-injury remodeling of the spinal cord

    PubMed Central

    Jacobi, Anne; Loy, Kristina; Schmalz, Anja M; Hellsten, Mikael; Umemori, Hisashi; Kerschensteiner, Martin; Bareyre, Florence M

    2015-01-01

    The remodeling of axonal circuits after injury requires the formation of new synaptic contacts to enable functional recovery. Which molecular signals initiate such axonal and synaptic reorganisation in the adult central nervous system is currently unknown. Here, we identify FGF22 as a key regulator of circuit remodeling in the injured spinal cord. We show that FGF22 is produced by spinal relay neurons, while its main receptors FGFR1 and FGFR2 are expressed by cortical projection neurons. FGF22 deficiency or the targeted deletion of FGFR1 and FGFR2 in the hindlimb motor cortex limits the formation of new synapses between corticospinal collaterals and relay neurons, delays their molecular maturation, and impedes functional recovery in a mouse model of spinal cord injury. These results establish FGF22 as a synaptogenic mediator in the adult nervous system and a crucial regulator of synapse formation and maturation during post-injury remodeling in the spinal cord. PMID:25766255

  11. Role of FGF/FGFR signaling in skeletal development and homeostasis: learning from mouse models

    PubMed Central

    Su, Nan; Jin, Min; Chen, Lin

    2014-01-01

    Fibroblast growth factor (FGF)/fibroblast growth factor receptor (FGFR) signaling plays essential roles in bone development and diseases. Missense mutations in FGFs and FGFRs in humans can cause various congenital bone diseases, including chondrodysplasia syndromes, craniosynostosis syndromes and syndromes with dysregulated phosphate metabolism. FGF/FGFR signaling is also an important pathway involved in the maintenance of adult bone homeostasis. Multiple kinds of mouse models, mimicking human skeleton diseases caused by missense mutations in FGFs and FGFRs, have been established by knock-in/out and transgenic technologies. These genetically modified mice provide good models for studying the role of FGF/FGFR signaling in skeleton development and homeostasis. In this review, we summarize the mouse models of FGF signaling-related skeleton diseases and recent progresses regarding the molecular mechanisms, underlying the role of FGFs/FGFRs in the regulation of bone development and homeostasis. This review also provides a perspective view on future works to explore the roles of FGF signaling in skeletal development and homeostasis. PMID:26273516

  12. HSPG synthesis by zebrafish Ext2 and Extl3 is required for Fgf10 signalling during limb development.

    PubMed

    Norton, William H J; Ledin, Johan; Grandel, Heiner; Neumann, Carl J

    2005-11-01

    Heparan sulphate proteoglycans (HSPGs) are known to be crucial for signalling by the secreted Wnt, Hedgehog, Bmp and Fgf proteins during invertebrate development. However, relatively little is known about their effect on developmental signalling in vertebrates. Here, we report the analysis of daedalus, a novel zebrafish pectoral fin mutant. Positional cloning identified fgf10 as the gene disrupted in daedalus. We find that fgf10 mutants strongly resemble zebrafish ext2 and extl3 mutants, which encode glycosyltransferases required for heparan sulphate biosynthesis. This suggests that HSPGs are crucial for Fgf10 signalling during limb development. Consistent with this proposal, we observe a strong genetic interaction between fgf10 and extl3 mutants. Furthermore, application of Fgf10 protein can rescue target gene activation in fgf10, but not in ext2 or extl3 mutants. By contrast, application of Fgf4 protein can activate target genes in both ext2 and extl3 mutants, indicating that ext2 and extl3 are differentially required for Fgf10, but not Fgf4, signalling during limb development. This reveals an unexpected specificity of HSPGs in regulating distinct vertebrate Fgfs. PMID:16221725

  13. mTORC1 Is a Major Regulatory Node in the FGF21 Signaling Network in Adipocytes.

    PubMed

    Minard, Annabel Y; Tan, Shi-Xiong; Yang, Pengyi; Fazakerley, Daniel J; Domanova, Westa; Parker, Benjamin L; Humphrey, Sean J; Jothi, Raja; Stöckli, Jacqueline; James, David E

    2016-09-27

    FGF21 improves the metabolic profile of obese animals through its actions on adipocytes. To elucidate the signaling network responsible for mediating these effects, we quantified dynamic changes in the adipocyte phosphoproteome following acute exposure to FGF21. FGF21 regulated a network of 821 phosphosites on 542 proteins. A major FGF21-regulated signaling node was mTORC1/S6K. In contrast to insulin, FGF21 activated mTORC1 via MAPK rather than through the canonical PI3K/AKT pathway. Activation of mTORC1/S6K by FGF21 was surprising because this is thought to contribute to deleterious metabolic effects such as obesity and insulin resistance. Rather, mTORC1 mediated many of the beneficial actions of FGF21 in vitro, including UCP1 and FGF21 induction, increased adiponectin secretion, and enhanced glucose uptake without any adverse effects on insulin action. This study provides a global view of FGF21 signaling and suggests that mTORC1 may act to facilitate FGF21-mediated health benefits in vivo. PMID:27681418

  14. Cooperative inputs of Bmp and Fgf signaling induce tail regeneration in urodele amphibians.

    PubMed

    Makanae, Aki; Mitogawa, Kazumasa; Satoh, Akira

    2016-02-01

    Urodele amphibians have remarkable organ regeneration ability. They can regenerate not only limbs but also a tail throughout their life. It has been demonstrated that the regeneration of some organs are governed by the presence of neural tissues. For instance, limb regeneration cannot be induced without nerves. Thus, identifying the nerve factors has been the primary focus in amphibian organ regeneration research. Recently, substitute molecules for nerves in limb regeneration, Bmp and Fgfs, were identified. Cooperative inputs of Bmp and Fgfs can induce limb regeneration in the absence of nerves. In the present study, we investigated whether similar or same regeneration mechanisms control another neural tissue governed organ regeneration, i.e., tail regeneration, in Ambystoma mexicanum. Neural tissues in a tail, which is the spinal cord, could transform wound healing responses into organ regeneration responses, similar to nerves in limb regeneration. Furthermore, the identified regeneration inducer Fgf2+Fgf8+Bmp7 showed similar inductive effects. However, further analysis revealed that the blastema cells induced by Fgf2+Fgf8+Bmp7 could participate in the regeneration of several tissues, but could not organize a patterned tail. Regeneration inductive ability of Fgf2+Fgf8+Bmp7 was confirmed in another urodele, Pleurodeles waltl. These results suggest that the organ regeneration ability in urodele amphibians is controlled by a common mechanism.

  15. Cooperative inputs of Bmp and Fgf signaling induce tail regeneration in urodele amphibians.

    PubMed

    Makanae, Aki; Mitogawa, Kazumasa; Satoh, Akira

    2016-02-01

    Urodele amphibians have remarkable organ regeneration ability. They can regenerate not only limbs but also a tail throughout their life. It has been demonstrated that the regeneration of some organs are governed by the presence of neural tissues. For instance, limb regeneration cannot be induced without nerves. Thus, identifying the nerve factors has been the primary focus in amphibian organ regeneration research. Recently, substitute molecules for nerves in limb regeneration, Bmp and Fgfs, were identified. Cooperative inputs of Bmp and Fgfs can induce limb regeneration in the absence of nerves. In the present study, we investigated whether similar or same regeneration mechanisms control another neural tissue governed organ regeneration, i.e., tail regeneration, in Ambystoma mexicanum. Neural tissues in a tail, which is the spinal cord, could transform wound healing responses into organ regeneration responses, similar to nerves in limb regeneration. Furthermore, the identified regeneration inducer Fgf2+Fgf8+Bmp7 showed similar inductive effects. However, further analysis revealed that the blastema cells induced by Fgf2+Fgf8+Bmp7 could participate in the regeneration of several tissues, but could not organize a patterned tail. Regeneration inductive ability of Fgf2+Fgf8+Bmp7 was confirmed in another urodele, Pleurodeles waltl. These results suggest that the organ regeneration ability in urodele amphibians is controlled by a common mechanism. PMID:26703427

  16. The PPARα - FGF21 hormone axis contributes to metabolic regulation by the hepatic JNK signaling pathway

    PubMed Central

    Vernia, Santiago; Cavanagh-Kyros, Julie; Garcia-Haro, Luisa; Sabio, Guadalupe; Barrett, Tamera; Jung, Dae Young; Kim, Jason K.; Xu, Jia; Shulha, Hennady P.; Garber, Manuel; Gao, Guangping; Davis, Roger J.

    2014-01-01

    The cJun NH2-terminal kinase (JNK) stress signaling pathway is implicated in the metabolic response to the consumption of a high fat diet, including the development of obesity and insulin resistance. These metabolic adaptations involve altered liver function. Here we demonstrate that hepatic JNK potently represses the nuclear hormone receptor peroxisome proliferator-activated receptor α (PPARα). JNK therefore causes decreased expression of PPARα target genes that increase fatty acid oxidation / ketogenesis and promote the development of insulin resistance. We show that the PPARα target gene fibroblast growth factor 21 (Fgf21) plays a key role in this response because disruption of the hepatic PPARα - FGF21 hormone axis suppresses the metabolic effects of JNK-deficiency. This analysis identifies the hepatokine FGF21 as a critical mediator of JNK signaling in the liver. PMID:25043817

  17. Inhibition of FGF Signalling Pathway Augments the Expression of Pluripotency and Trophoblast Lineage Marker Genes in Porcine Parthenogenetic Blastocyst.

    PubMed

    Li, L Y; Li, M M; Yang, S F; Zhang, J; Li, Z; Zhang, H; Zhu, L; Zhu, X; Verma, V; Liu, Q; Shi, D; Huang, B

    2016-10-01

    The consistent failure to isolate bona fide pluripotent cell lines from livestock indicates that the underlying mechanisms of early lineage specification are poorly defined. Unlike other species, the contrivances of segregation have been comprehensively studied in the mouse. In mouse, FGF/MAPK signalling pathway dictates the segregation of hypoblast (primitive endoderm). However, it is not evident whether this mechanism is also conserved in livestock. Here, in this study, we examined the roles of FGF/MAP kinase signalling pathways in porcine parthenogenetic embryos during the early development. Porcine parthenogenetic embryos were cultured in the medium addition with FGFR inhibitor BGJ398 (10 μm) or DEMOS. Pluripotency- and lineage-related gene expressions in the early porcine embryos were determined. Compared to control, total cell numbers on day 7 were significantly higher (55 ± 5.96 vs 47 ± 1.97, p < 0.05) in embryos cultured in the presence of BGJ398, but had no significant effect on the rate of blastocyst development (47% vs 44%, p > 0.05). Nonetheless, BGJ398 treatment significantly augmented the expression of pluripotency and trophoblast marker genes (SOX2, OCT4, KLF4 and CDX2), but did not significantly change the expression of NANOG and hypoblast marker gene (GATA4). Furthermore, the addition of FGF signalling agonist (FGF2) during the embryo development significantly decreased the expression of pluripotency and trophoblast marker genes (SOX2, NANOG, KLF4 and CDX2), but no significant effect on the expression of OCT4 and GATA4 was observed. Here, we exhibit that inhibition of FGF signalling could improve the quality of the porcine embryo and escalate the chance to capture pluripotency. Besides, it also promotes the trophoblast development of porcine parthenogenetic embryo. In addition, the data suggested that FGF signalling pathway is dispensable for the segregation of hypoblast and epiblast lineages in porcine embryo during the early

  18. WT1 targets Gas1 to maintain nephron progenitor cells by modulating FGF signals.

    PubMed

    Kann, Martin; Bae, Eunnyung; Lenz, Maximilian O; Li, Liangji; Trannguyen, BaoTran; Schumacher, Valerie A; Taglienti, Mary E; Bordeianou, Liliana; Hartwig, Sunny; Rinschen, Markus M; Schermer, Bernhard; Benzing, Thomas; Fan, Chen-Ming; Kreidberg, Jordan A

    2015-04-01

    Development of the metanephric kidney depends on tightly regulated interplay between self-renewal and differentiation of a nephron progenitor cell (NPC) pool. Several key factors required for the survival of NPCs have been identified, including fibroblast growth factor (FGF) signaling and the transcription factor Wilms' tumor suppressor 1 (WT1). Here, we present evidence that WT1 modulates FGF signaling by activating the expression of growth arrest-specific 1 (Gas1), a novel WT1 target gene and novel modulator of FGF signaling. We show that WT1 directly binds to a conserved DNA binding motif within the Gas1 promoter and activates Gas1 mRNA transcription in NPCs. We confirm that WT1 is required for Gas1 expression in kidneys in vivo. Loss of function of GAS1 in vivo results in hypoplastic kidneys with reduced nephron mass due to premature depletion of NPCs. Although kidney development in Gas1 knockout mice progresses normally until E15.5, NPCs show decreased rates of proliferation at this stage and are depleted as of E17.5. Lastly, we show that Gas1 is selectively required for FGF-stimulated AKT signaling in vitro. In summary, our data suggest a model in which WT1 modulates receptor tyrosine kinase signaling in NPCs by directing the expression of Gas1.

  19. BMP-FGF Signaling Axis Mediates Wnt-Induced Epidermal Stratification in Developing Mammalian Skin

    PubMed Central

    Zhu, Xiao-Jing; Liu, YuDong; Dai, Zhong-Min; Zhang, Xiaoyun; Yang, XueQin; Li, Yan; Qiu, Mengsheng; Fu, Jiang; Hsu, Wei; Chen, YiPing; Zhang, Zunyi

    2014-01-01

    Epidermal stratification of the mammalian skin requires proliferative basal progenitors to generate intermediate cells that separate from the basal layer and are replaced by post-mitotic cells. Although Wnt signaling has been implicated in this developmental process, the mechanism underlying Wnt-mediated regulation of basal progenitors remains elusive. Here we show that Wnt secreted from proliferative basal cells is not required for their differentiation. However, epidermal production of Wnts is essential for the formation of the spinous layer through modulation of a BMP-FGF signaling cascade in the dermis. The spinous layer defects caused by disruption of Wnt secretion can be restored by transgenically expressed Bmp4. Non-cell autonomous BMP4 promotes activation of FGF7 and FGF10 signaling, leading to an increase in proliferative basal cell population. Our findings identify an essential BMP-FGF signaling axis in the dermis that responds to the epidermal Wnts and feedbacks to regulate basal progenitors during epidermal stratification. PMID:25329657

  20. Suramin blocks interaction between human FGF1 and FGFR2 D2 domain and reduces downstream signaling activity.

    PubMed

    Wu, Zong-Sian; Liu, Che Fu; Fu, Brian; Chou, Ruey-Hwang; Yu, Chin

    2016-09-01

    The extracellular portion of the human fibroblast growth factor receptor2 D2 domain (FGFR2 D2) interacts with human fibroblast growth factor 1 (hFGF1) to activate a downstream signaling cascade that ultimately affects mitosis and differentiation. Suramin is an antiparasiticdrug and a potent inhibitor of FGF-induced angiogenesis. Suramin has been shown to bind to hFGF1, and might block the interaction between hFGF1 and FGFR2 D2. Here, we titrated hFGF1 with FGFR2 D2 and suramin to elucidate their interactions using the detection of NMR. The docking results of both hFGF1-FGFR2 D2 domain and hFGF1-suramin complex were superimposed. The results indicate that suramin blocks the interaction between hFGF1 and FGFR2 D2. We used the PyMOL software to show the hydrophobic interaction of hFGF1-suramin. In addition, we used a Water-soluble Tetrazolium salts assay (WST1) to assess hFGF1 bioactivity. The results will be useful for the development of new antimitogenic activity drugs.

  1. A bi-modal function of Wnt signalling directs an FGF activity gradient to spatially regulate neuronal differentiation in the midbrain.

    PubMed

    Dyer, Carlene; Blanc, Eric; Hanisch, Anja; Roehl, Henry; Otto, Georg W; Yu, Tian; Basson, M A; Knight, Robert

    2014-01-01

    FGFs and Wnts are important morphogens during midbrain development, but their importance and potential interactions during neurogenesis are poorly understood. We have employed a combination of genetic and pharmacological manipulations in zebrafish to show that during neurogenesis FGF activity occurs as a gradient along the anterior-posterior axis of the dorsal midbrain and directs spatially dynamic expression of the Hairy gene her5. As FGF activity diminishes during development, Her5 is lost and differentiation of neuronal progenitors occurs in an anterior-posterior manner. We generated mathematical models to explain how Wnt and FGFs direct the spatial differentiation of neurons in the midbrain through Wnt regulation of FGF signalling. These models suggested that a negative-feedback loop controlled by Wnt is crucial for regulating FGF activity. We tested Sprouty genes as mediators of this regulatory loop using conditional mouse knockouts and pharmacological manipulations in zebrafish. These reveal that Sprouty genes direct the positioning of early midbrain neurons and are Wnt responsive in the midbrain. We propose a model in which Wnt regulates FGF activity at the isthmus by driving both FGF and Sprouty gene expression. This controls a dynamic, posteriorly retracting expression of her5 that directs neuronal differentiation in a precise spatiotemporal manner in the midbrain.

  2. Frs2α-deficiency in cardiac progenitors disrupts a subset of FGF signals required for outflow tract morphogenesis

    PubMed Central

    Zhang, Jue; Lin, Yongshun; Zhang, Yongyou; Lan, Yongsheng; Lin, Chunhong; Moon, Anne M.; Schwartz, Robert J.; Martin, James F.; Wang, Fen

    2009-01-01

    Summary The cardiac outflow tract (OFT) is a developmentally complex structure derived from multiple lineages and is often defective in human congenital anomalies. While emerging evidence shows that the fibroblast growth factor (FGF) is essential for OFT development, the downstream pathways mediating FGF-signaling in cardiac progenitors remain poorly understood. Here, we report that FRS2α, an adaptor protein that links FGF receptor kinases to multiple signaling pathways, mediates critical aspects of FGF-dependent OFT development. Ablation of Frs2α in mesodermal OFT progenitor cells that originate in the second heart field (SHF) affects their expansion into the OFT myocardium, resulting in OFT misalignment and hypoplasia. Moreover, Frs2α mutants had defective endothelial-mesenchymal-transition and neural crest cell recruitment into the OFT cushions, resulting in OFT septation defects. The results provide new insight into the signaling molecules downstream of FGF receptor tyrosine kinases in cardiac progenitors. PMID:18832393

  3. Churchill and Sip1a repress FGF signaling during zebrafish somitogenesis

    PubMed Central

    Kok, Fatma O.; Shepherd, Iain T.; Sirotkin, Howard I.

    2010-01-01

    Cell-type specific regulation of a small number of growth factor signal transduction pathways generates diverse developmental outcomes. The zinc finger protein Churchill (ChCh) is a key effector of Fibroblast Growth Factor (FGF) signaling during gastrulation. ChCh is largely thought to act by inducing expression of the multifunctional Sip1 (Smad Interacting Protein 1). We investigated the function of ChCh and Sip1a during zebrafish somitogenesis. Knockdown of ChCh or Sip1a results in misshapen somites that are short and narrow. As in wild-type embryos, cycling gene expression occurs in the developing somites in ChCh and Sip1a compromised embryos, but expression of her1 and her7 is maintained in formed somites. In addition, tailbud fgf8 expression is expanded anteriorly in these embryos. Finally, we found that blocking FGF8 restores somite morphology in ChCh and Sip1a compromised embryos. These results demonstrate a novel role for ChCh and Sip1a in repression of FGF activity. PMID:20034103

  4. Polysaccharides purified from wild Cordyceps activate FGF2/FGFR1c signaling

    NASA Astrophysics Data System (ADS)

    Zeng, Yangyang; Han, Zhangrun; Yu, Guangli; Hao, Jiejie; Zhang, Lijuan

    2015-02-01

    Land animals as well as all organisms in ocean synthesize sulfated polysaccharides. Fungi split from animals about 1.5 billion years ago. As fungi make the evolutionary journey from ocean to land, the biggest changes in their living environment may be a sharp decrease in salt concentration. It is established that sulfated polysaccharides interact with hundreds of signaling molecules and facilitate many signaling transduction pathways, including fibroblast growth factor (FGF) and FGF receptor signaling pathway. The disappearance of sulfated polysaccharides in fungi and plants on land might indicate that polysaccharides without sulfation might be sufficient in facilitating protein ligand/receptor interactions in low salinity land. Recently, it was reported that plants on land start to synthesize sulfated polysaccharides in high salt environment, suggesting that fungi might be able to do the same when exposed in such environment. Interestingly, Cordyceps, a fungus habituating inside caterpillar body, is the most valued traditional Chinese Medicine. One of the important pharmaceutical active ingredients in Cordyceps is polysaccharides. Therefore, we hypothesize that the salty environment inside caterpillar body might allow the fungi to synthesize sulfated polysaccharides. To test the hypothesis, we isolated polysaccharides from both lava and sporophore of wild Cordyceps and also from Cordyceps militaris cultured without or with added salts. We then measured the polysaccharide activity using a FGF2/FGFR1c signaling-dependent BaF3 cell proliferation assay and found that polysaccharides isolated from wild Cordyceps activated FGF2/FGFR signaling, indicating that the polysaccharides synthesized by wild Cordyceps are indeed different from those by the cultured mycelium.

  5. Tbx2 Terminates Shh/Fgf Signaling in the Developing Mouse Limb Bud by Direct Repression of Gremlin1

    PubMed Central

    Farin, Henner F.; Lüdtke, Timo H-W.; Schmidt, Martina K.; Placzko, Susann; Schuster-Gossler, Karin; Petry, Marianne; Christoffels, Vincent M.; Kispert, Andreas

    2013-01-01

    Vertebrate limb outgrowth is driven by a positive feedback loop that involves Sonic hedgehog (Shh) and Gremlin1 (Grem1) in the posterior limb bud mesenchyme and Fibroblast growth factors (Fgfs) in the overlying epithelium. Proper spatio-temporal control of these signaling activities is required to avoid limb malformations such as polydactyly. Here we show that, in Tbx2-deficient hindlimbs, Shh/Fgf4 signaling is prolonged, resulting in increased limb bud size and duplication of digit 4. In turn, limb-specific Tbx2 overexpression leads to premature termination of this signaling loop with smaller limbs and reduced digit number as phenotypic manifestation. We show that Tbx2 directly represses Grem1 in distal regions of the posterior limb mesenchyme allowing Bone morphogenetic protein (Bmp) signaling to abrogate Fgf4/9/17 expression in the overlying epithelium. Since Tbx2 itself is a target of Bmp signaling, our data identify a growth-inhibiting positive feedback loop (Bmp/Tbx2/Grem1). We propose that proliferative expansion of Tbx2-expressing cells mediates self-termination of limb bud outgrowth due to their refractoriness to Grem1 induction. PMID:23633963

  6. Opposing Shh and Fgf signals initiate nasotemporal patterning of the zebrafish retina

    PubMed Central

    Hernández-Bejarano, María; Gestri, Gaia; Spawls, Lana; Nieto-López, Francisco; Picker, Alexander; Tada, Masazumi; Brand, Michael; Bovolenta, Paola; Wilson, Stephen W.; Cavodeassi, Florencia

    2015-01-01

    The earliest known determinants of retinal nasotemporal identity are the transcriptional regulators Foxg1, which is expressed in the prospective nasal optic vesicle, and Foxd1, which is expressed in the prospective temporal optic vesicle. Previous work has shown that, in zebrafish, Fgf signals from the dorsal forebrain and olfactory primordia are required to specify nasal identity in the dorsal, prospective nasal, optic vesicle. Here, we show that Hh signalling from the ventral forebrain is required for specification of temporal identity in the ventral optic vesicle and is sufficient to induce temporal character when activated in the prospective nasal retina. Consequently, the evaginating optic vesicles become partitioned into prospective nasal and temporal domains by the opposing actions of Fgfs and Shh emanating from dorsal and ventral domains of the forebrain primordium. In absence of Fgf activity, foxd1 expression is established irrespective of levels of Hh signalling, indicating that the role of Shh in promoting foxd1 expression is only required in the presence of Fgf activity. Once the spatially complementary expression of foxd1 and foxg1 is established, the boundary between expression domains is maintained by mutual repression between Foxd1 and Foxg1. PMID:26428010

  7. Expression of osterix Is Regulated by FGF and Wnt/β-Catenin Signalling during Osteoblast Differentiation

    PubMed Central

    Felber, Katharina; Elks, Philip M.; Lecca, Maria; Roehl, Henry H.

    2015-01-01

    Osteoblast differentiation from mesenchymal cells is regulated by multiple signalling pathways. Here we have analysed the roles of Fibroblast Growth Factor (FGF) and canonical Wingless-type MMTV integration site (Wnt/β-Catenin) signalling pathways on zebrafish osteogenesis. We have used transgenic and chemical interference approaches to manipulate these pathways and have found that both pathways are required for osteoblast differentiation in vivo. Our analysis of bone markers suggests that these pathways act at the same stage of differentiation to initiate expression of the osteoblast master regulatory gene osterix (osx). We use two independent approaches that suggest that osx is a direct target of these pathways. Firstly, we manipulate signalling and show that osx gene expression responds with similar kinetics to that of known transcriptional targets of the FGF and Wnt pathways. Secondly, we have performed ChIP with transcription factors for both pathways and our data suggest that a genomic region in the first intron of osx mediates transcriptional activation. Based upon these data, we propose that FGF and Wnt/β-Catenin pathways act in part by directing transcription of osx to promote osteoblast differentiation at sites of bone formation. PMID:26689368

  8. Opposing Shh and Fgf signals initiate nasotemporal patterning of the zebrafish retina.

    PubMed

    Hernández-Bejarano, María; Gestri, Gaia; Spawls, Lana; Nieto-López, Francisco; Picker, Alexander; Tada, Masazumi; Brand, Michael; Bovolenta, Paola; Wilson, Stephen W; Cavodeassi, Florencia

    2015-11-15

    The earliest known determinants of retinal nasotemporal identity are the transcriptional regulators Foxg1, which is expressed in the prospective nasal optic vesicle, and Foxd1, which is expressed in the prospective temporal optic vesicle. Previous work has shown that, in zebrafish, Fgf signals from the dorsal forebrain and olfactory primordia are required to specify nasal identity in the dorsal, prospective nasal, optic vesicle. Here, we show that Hh signalling from the ventral forebrain is required for specification of temporal identity in the ventral optic vesicle and is sufficient to induce temporal character when activated in the prospective nasal retina. Consequently, the evaginating optic vesicles become partitioned into prospective nasal and temporal domains by the opposing actions of Fgfs and Shh emanating from dorsal and ventral domains of the forebrain primordium. In absence of Fgf activity, foxd1 expression is established irrespective of levels of Hh signalling, indicating that the role of Shh in promoting foxd1 expression is only required in the presence of Fgf activity. Once the spatially complementary expression of foxd1 and foxg1 is established, the boundary between expression domains is maintained by mutual repression between Foxd1 and Foxg1.

  9. Lhx9 gene expression during early limb development in mice requires the FGF signalling pathway.

    PubMed

    Yang, Yisheng; Wilson, Megan J

    2015-01-01

    Lhx9 is a member of the LIM-homeodomain gene family necessary for the correct development of many organs including gonads, limbs, heart and the nervous system. In the context of limb development, Lhx9 has been implicated as an integrator for Fibroblast growth factor (FGF) and Sonic hedgehog (Shh) signalling required for proximal-distal (PD) and anterior-posterior (AP) development of the limb. Three splice variants of the Lhx9 transcript are expressed during development, two of which are predicted to act in a dominant negative fashion, competing with the DNA binding version of Lhx9 for binding to cofactors via the LIM-domain. We examined the expression pattern for the three alternative splice forms of Lhx9; Lhx9α, Lhx9β and Lhx9c during early limb development. We have found that of the three Lhx9 isoforms, only Lhx9α and Lhx9c (intact homeodomain) are expressed during early limb development, each with their own distinct expression pattern. Additionally we determined that Lhx9 expression overlaps with FGF10 expression in the developing limb bud mesenchyme. Limb bud explant cultures, in the presence of signalling pathway inhibitors, also indicated that Lhx9 mRNA expression in the limb bud was dependent on FGF signalling. PMID:26220830

  10. An Essential Role for FGF Receptor Signaling in Lens Development

    PubMed Central

    Robinson, Michael L.

    2007-01-01

    Since the days of Hans Spemann, the ocular lens has served as one of the most important developmental systems for elucidating fundamental processes of induction and differentiation. More recently, studies in the lens have contributed significantly to our understanding of cell cycle regulation and apoptosis. Over twenty years of accumulated evidence using several different vertebrate species has suggested that fibroblast growth factors (FGFs) and/or fibroblast growth factor receptors (FGFRs) play a key role in lens development. FGFR signaling has been implicated in lens induction, lens cell proliferation and survival, lens fiber differentiation and lens regeneration. Here we will review and discuss historical and recent evidence suggesting that (FGFR) signaling plays a vital and universal role in multiple aspects of lens development. PMID:17116415

  11. Diverse ETS transcription factors mediate FGF signaling in the Ciona anterior neural plate.

    PubMed

    Gainous, T Blair; Wagner, Eileen; Levine, Michael

    2015-03-15

    The ascidian Ciona intestinalis is a marine invertebrate belonging to the sister group of the vertebrates, the tunicates. Its compact genome and simple, experimentally tractable embryos make Ciona well-suited for the study of cell-fate specification in chordates. Tunicate larvae possess a characteristic chordate body plan, and many developmental pathways are conserved between tunicates and vertebrates. Previous studies have shown that FGF signals are essential for neural induction and patterning at sequential steps of Ciona embryogenesis. Here we show that two different ETS family transcription factors, Ets1/2 and Elk1/3/4, have partially redundant activities in the anterior neural plate of gastrulating embryos. Whereas Ets1/2 promotes pigment cell formation in lateral lineages, both Ets1/2 and Elk1/3/4 are involved in the activation of Myt1L in medial lineages and the restriction of Six3/6 expression to the anterior-most regions of the neural tube. We also provide evidence that photoreceptor cells arise from posterior regions of the presumptive sensory vesicle, and do not depend on FGF signaling. Cells previously identified as photoreceptor progenitors instead form ependymal cells and neurons of the larval brain. Our results extend recent findings on FGF-dependent patterning of anterior-posterior compartments in the Ciona central nervous system.

  12. Cytodifferentiation potentiates aFGF-induced p21(ras)/Erk signaling pathway in rat cultured astrocytes.

    PubMed

    Asada, S; Kasuya, Y; Hama, H; Masaki, T; Goto, K

    1999-07-01

    MBP kinase detection assay revealed that acidic FGF (aFGF) augmented MBP kinase activity in a dose-dependent manner in astrocytes (AC). The molar potency of this action of aFGF in dibutyryl cyclic AMP (DBcAMP)-treated AC was significantly higher than that in quiescent AC. Consistently, the molar potency of accumulation of p21(ras)-GTP by aFGF was significantly higher in DBcAMP-treated AC than in quiescent AC. However, binding study showed that B(max) and K(D) for [(125)I]aFGF in DBcAMP-treated AC were quite similar to those in quiescent AC. Furthermore, the expression levels of Grb2, SOS, and p21(ras) were not changed by treatment of AC with DBcAMP. These results suggest that cytodifferentiation potentiates the p21(ras)/Erk signaling pathway in AC in response to aFGF without changing the expression levels of signaling molecules mediating from the FGF receptor to p21(ras).

  13. Early mouse caudal development relies on crosstalk between retinoic acid, Shh and Fgf signalling pathways.

    PubMed

    Ribes, Vanessa; Le Roux, Isabelle; Rhinn, Muriel; Schuhbaur, Brigitte; Dollé, Pascal

    2009-02-01

    The progressive generation of embryonic trunk structures relies on the proper patterning of the caudal epiblast, which involves the integration of several signalling pathways. We have investigated the function of retinoic acid (RA) signalling during this process. We show that, in addition to posterior mesendoderm, primitive streak and node cells transiently express the RA-synthesizing enzyme Raldh2 prior to the headfold stage. RA-responsive cells (detected by the RA-activated RARE-lacZ transgene) are additionally found in the epiblast layer. Analysis of RA-deficient Raldh2(-/-) mutants reveals early caudal patterning defects, with an expansion of primitive streak and mesodermal markers at the expense of markers of the prospective neuroepithelium. As a result, many genes involved in neurogenesis and/or patterning of the embryonic spinal cord are affected in their expression. We demonstrate that RA signalling is required at late gastrulation stages for mesodermal and neural progenitors to respond to the Shh signal. Whole-embryo culture experiments indicate that the proper response of cells to Shh requires two RA-dependent mechanisms: (1) a balanced antagonism between Fgf and RA signals, and (2) a RA-mediated repression of Gli2 expression. Thus, an interplay between RA, Fgf and Shh signalling is likely to be an important mechanism underpinning the tight regulation of caudal embryonic development. PMID:19168680

  14. FGF signaling activates a Sox9-Sox10 pathway for the formation and branching morphogenesis of mouse ocular glands.

    PubMed

    Chen, Ziyan; Huang, Jie; Liu, Ying; Dattilo, Lisa K; Huh, Sung-Ho; Ornitz, David; Beebe, David C

    2014-07-01

    Murine lacrimal, harderian and meibomian glands develop from the prospective conjunctival and eyelid epithelia and produce secretions that lubricate and protect the ocular surface. Sox9 expression localizes to the presumptive conjunctival epithelium as early as E11.5 and is detected in the lacrimal and harderian glands as they form. Conditional deletion showed that Sox9 is required for the development of the lacrimal and harderian glands and contributes to the formation of the meibomian glands. Sox9 regulates the expression of Sox10 to promote the formation of secretory acinar lobes in the lacrimal gland. Sox9 and FGF signaling were required for the expression of cartilage-associated extracellular matrix components during early stage lacrimal gland development. Fgfr2 deletion in the ocular surface epithelium reduced Sox9 and eliminated Sox10 expression. Sox9 deletion from the ectoderm did not affect Fgf10 expression in the adjacent mesenchyme or Fgfr2 expression in the epithelium, but appeared to reduce FGF signaling. Sox9 heterozygotes showed a haploinsufficient phenotype, in which the exorbital branch of the lacrimal gland was absent in most cases. However, enhancement of epithelial FGF signaling by expression of a constitutively active FGF receptor only partially rescued the lacrimal gland defects in Sox9 heterozygotes, suggesting a crucial role of Sox9, downstream of FGF signaling, in regulating lacrimal gland branching and differentiation.

  15. Foxi transcription factors promote pharyngeal arch development by regulating formation of FGF signaling centers.

    PubMed

    Edlund, Renée K; Ohyama, Takahiro; Kantarci, Husniye; Riley, Bruce B; Groves, Andrew K

    2014-06-01

    The bones of the vertebrate face develop from transient embryonic branchial arches that are populated by cranial neural crest cells. We have characterized a mouse mutant for the Forkhead family transcription factor Foxi3, which is expressed in branchial ectoderm and endoderm. Foxi3 mutant mice are not viable and display severe branchial arch-derived facial skeleton defects, including absence of all but the most distal tip of the mandible and complete absence of the inner, middle and external ear structures. Although cranial neural crest cells of Foxi3 mutants are able to migrate, populate the branchial arches, and display some elements of correct proximo-distal patterning, they succumb to apoptosis from embryonic day 9.75 onwards. We show this cell death correlates with a delay in expression of Fgf8 in branchial arch ectoderm and a failure of neural crest cells in the arches to express FGF-responsive genes. Zebrafish foxi1 is also expressed in branchial arch ectoderm and endoderm, and morpholino knock-down of foxi1 also causes apoptosis of neural crest in the branchial arches. We show that heat shock induction of fgf3 in zebrafish arch tissue can rescue cell death in foxi1 morphants. Our results suggest that Foxi3 may play a role in the establishment of signaling centers in the branchial arches that are required for neural crest survival, patterning and the subsequent development of branchial arch derivatives.

  16. Initiating Hox gene expression: in the early chick neural tube differential sensitivity to FGF and RA signaling subdivides the HoxB genes in two distinct groups.

    PubMed

    Bel-Vialar, Sophie; Itasaki, Nobue; Krumlauf, Robb

    2002-11-01

    findings suggest a model whereby, over the window of early development we examined, all HoxB genes are actually competent to interpret an FGF signal via a CDX-dependent pathway. However, mechanisms that axially restrict the Cdx domains of expression, serve to prevent 3' genes from responding to FGF signaling in the hindbrain. FGF may have a dual role in both modulating the accessibility of the HoxB complex along the axis and in activating the expression of Cdx genes. The position of the shift in RA or FGF responsiveness of Hox genes may be time dependent. Hence, the specific Hox genes in each of these complementary groups may vary in later stages of development or other tissues. These results highlight the key role of Cdx genes in integrating the input of multiple signaling pathways, such as FGFs and RA, in controlling initiation of Hox expression during development and the importance of understanding regulatory events/mechanisms that modulate Cdx expression. PMID:12399303

  17. Stem cells with FGF4-bFGF fused gene enhances the expression of bFGF and improves myocardial repair in rats

    SciTech Connect

    Chen, Xiang-Qi; Chen, Liang-Long Fan, Lin; Fang, Jun; Chen, Zhao-Yang; Li, Wei-Wei

    2014-04-25

    Highlights: • BFGF exists only in the cytoplasm of live cells. • BFGF cannot be secreted into the extracellular space to promote cell growth. • We combine the secretion-promoting signal peptide of FGF4. • We successfully modified BMSCs with the fused genes of FGF4-bFGF. • We promoted the therapeutic effects of transplanted BMSCs in myocardial infarction. - Abstract: The aim of this study was to investigate whether the modification of bone marrow-derived mesenchymal stem cells (BMSCs) with the fused FGF4 (fibroblast growth factor 4)-bFGF (basic fibroblast growth factor) gene could improve the expression and secretion of BFGF, and increase the efficacies in repairing infarcted myocardium. We used In-Fusion technique to construct recombinant lentiviral vectors containing the individual gene of bFGF, enhanced green fluorescent protein (EGFP), or genes of FGF4-bFGF and EGFP, and then transfected these lentiviruses into rat BMSCs. We conducted an in vitro experiment to compare the secretion of bFGF in BMSCs infected by these lentiviruses and also examined their therapeutic effects in the treatment of myocardial infraction in a rodent study. Sixty rats were tested in the following five conditions: Group-SHAM received only sham operation as controls; Group-AMI received only injection of placebo PBS buffer; Group-BMSC, Group-bFGF and Group-FGF4-bFGF received implantation of BMSCs with empty lentivirus, bFGF lentivirus, and FGF4-bFGF lentivirus, respectively. Our results found out that the transplanted FGF4-bFGF BMSCs had the highest survival rate, and also the highest myocardial expression of bFGF and microvascular density as evidenced by Western blotting and immunohistochemistry, respectively. As compared to other groups, the Group-FGF4-BFGF rats had the lowest myocardial fibrotic fraction, and the highest left ventricular ejection fraction. These results suggest that the modification of BMSCs with the FGF4-bFGF fused gene can not only increase the expression of

  18. Selective synaptic targeting of the excitatory and inhibitory presynaptic organizers FGF22 and FGF7

    PubMed Central

    Terauchi, Akiko; Timmons, Kendall M.; Kikuma, Koto; Pechmann, Yvonne; Kneussel, Matthias; Umemori, Hisashi

    2015-01-01

    ABSTRACT Specific formation of excitatory and inhibitory synapses is crucial for proper functioning of the brain. Fibroblast growth factor 22 (FGF22) and FGF7 are postsynaptic-cell-derived presynaptic organizers necessary for excitatory and inhibitory presynaptic differentiation, respectively, in the hippocampus. For the establishment of specific synaptic networks, these FGFs must localize to appropriate synaptic locations – FGF22 to excitatory and FGF7 to inhibitory postsynaptic sites. Here, we show that distinct motor and adaptor proteins contribute to intracellular microtubule transport of FGF22 and FGF7. Excitatory synaptic targeting of FGF22 requires the motor proteins KIF3A and KIF17 and the adaptor protein SAP102 (also known as DLG3). By contrast, inhibitory synaptic targeting of FGF7 requires the motor KIF5 and the adaptor gephyrin. Time-lapse imaging shows that FGF22 moves with SAP102, whereas FGF7 moves with gephyrin. These results reveal the basis of selective targeting of the excitatory and inhibitory presynaptic organizers that supports their different synaptogenic functions. Finally, we found that knockdown of SAP102 or PSD95 (also known as DLG4), which impairs the differentiation of excitatory synapses, alters FGF7 localization, suggesting that signals from excitatory synapses might regulate inhibitory synapse formation by controlling the distribution of the inhibitory presynaptic organizer. PMID:25431136

  19. Lysophosphatidic acid and bFGF control different modes in proliferating myoblasts

    PubMed Central

    1996-01-01

    Myogenic cells provide excellent in vitro models for studying the cell growth and differentiation. In this study we report that lysophosphatidic acid (LPA), a bioactive phospholipid contained in serum, stimulates the growth and inhibits the differentiation of mouse C2C12 myoblast cells, in a distinct manner from basic fibroblast growth factor (bFGF) whose mitotic and anti-differentiation actions have been well investigated. These actions of LPA were both blocked by pertussis toxin, suggesting the involvement of Gi class of G proteins, whereas bFGF acts through receptor tyrosine kinases. Detailed analysis revealed that LPA and bFGF act differently in regulating the myogenic basic helix-loop-helix (bHLH) proteins, the key players in myogenic differentiation process. LPA stimulates the proliferation of undifferentiated myoblasts allowing the continued expression of MyoD, but in contrast, bFGF does so with the MyoD expression suppressed at the mRNA level. Both compounds maintain the myf-5 expression, and suppress the myogenin expression. In addition, while LPA did not inhibit cell-cell contact-induced differentiation, bFGF strongly inhibited this process. Furthermore, LPA and bFGF act cooperatively in their mitogenic and anti-differentiation abilities. These findings indicate that LPA and bFGF differently stimulate intracellular signaling pathways, resulting in proliferating myoblasts each bearing a distinct expression pattern of myogenic bHLH proteins and distinct differentiation potentials in response to cell-cell contact, and illustrate the biological significance of Gi-mediated and tyrosine kinase-mediated signals. PMID:8567722

  20. ESCRT-II/Vps25 constrains digit number by endosome-mediated selective modulation of FGF-SHH signaling

    PubMed Central

    Handschuh, Karen; Feenstra, Jennifer; Koss, Matthew; Ferretti, Elisabetta; Risolino, Maurizio; Zewdu, Rediet; Sahai, Michelle A.; Bénazet, Jean-Denis; Peng, Xiao P.; Depew, Michael J.; Quintana, Laura; Sharpe, James; Wang, Baolin; Alcorn, Heather; Rivi, Roberta; Butcher, Stephen; Manak, J Robert; Vaccari, Thomas; Weinstein, Harel; Anderson, Kathryn V.; Lacy, Elizabeth; Selleri, Licia

    2014-01-01

    Summary Sorting and degradation of receptors and associated signaling molecules maintain homeostasis of conserved signaling pathways during cell specification and tissue development. Yet, whether machineries that sort signaling proteins act preferentially on different receptors and ligands in different contexts remains mysterious. Here we show that Vacuolar protein sorting 25, Vps25, a component of ESCRT-II (Endosomal Sorting Complex Required for Transport II), directs preferential endosome-mediated modulation of FGF signaling in limbs. By ENU-induced mutagenesis we isolated a polydactylous mouse line carrying a hypomorphic mutation of Vps25 (Vps25ENU). Unlike Vps25-null embryos we generated, Vps25ENU/ENU mutants survive until late gestation. Their limbs display FGF signaling enhancement and consequent hyper-activation of the FGF-SHH feedback loop causing polydactyly, whereas WNT and BMP signaling remain unperturbed. Notably, Vps25ENU/ENU Mouse Embryonic Fibroblasts exhibit aberrant FGFR trafficking and degradation; however SHH signaling is unperturbed. These studies establish that the ESCRT-II machinery selectively limits FGF signaling in vertebrate skeletal patterning. PMID:25373905

  1. Fibroblast growth factor (FGF) signaling regulates transforming growth factor beta (TGFβ)-dependent smooth muscle cell phenotype modulation.

    PubMed

    Chen, Pei-Yu; Qin, Lingfeng; Li, Guangxin; Tellides, George; Simons, Michael

    2016-01-01

    Smooth muscle cells (SMCs) in normal blood vessels exist in a highly differentiate state characterized by expression of SMC-specific contractile proteins ("contractile phenotype"). Following blood vessel injury in vivo or when cultured in vitro in the presence of multiple growth factors, SMC undergo a phenotype switch characterized by the loss of contractile markers and appearance of expression of non-muscle proteins ("proliferative phenotype"). While a number of factors have been reported to modulate this process, its regulation remains uncertain. Here we show that induction of SMC FGF signaling inhibits TGFβ signaling and converts contractile SMCs to the proliferative phenotype. Conversely, inhibition of SMC FGF signaling induces TGFβ signaling converting proliferating SMCs to the contractile phenotype, even in the presence of various growth factors in vitro or vascular injury in vivo. The importance of this signaling cross-talk is supported by in vivo data that show that an SMC deletion of a pan-FGF receptor adaptor Frs2α (fibroblast growth factor receptor substrate 2 alpha) in mice profoundly reduces neointima formation and vascular remodelling following carotid artery ligation. These results demonstrate that FGF-TGFβ signaling antagonism is the primary regulator of the SMC phenotype switch. Manipulation of this cross-talk may be an effective strategy for treatment of SMC-proliferation related diseases. PMID:27634335

  2. Fibroblast growth factor (FGF) signaling regulates transforming growth factor beta (TGFβ)-dependent smooth muscle cell phenotype modulation

    PubMed Central

    Chen, Pei-Yu; Qin, Lingfeng; Li, Guangxin; Tellides, George; Simons, Michael

    2016-01-01

    Smooth muscle cells (SMCs) in normal blood vessels exist in a highly differentiate state characterized by expression of SMC-specific contractile proteins (“contractile phenotype”). Following blood vessel injury in vivo or when cultured in vitro in the presence of multiple growth factors, SMC undergo a phenotype switch characterized by the loss of contractile markers and appearance of expression of non-muscle proteins (“proliferative phenotype”). While a number of factors have been reported to modulate this process, its regulation remains uncertain. Here we show that induction of SMC FGF signaling inhibits TGFβ signaling and converts contractile SMCs to the proliferative phenotype. Conversely, inhibition of SMC FGF signaling induces TGFβ signaling converting proliferating SMCs to the contractile phenotype, even in the presence of various growth factors in vitro or vascular injury in vivo. The importance of this signaling cross-talk is supported by in vivo data that show that an SMC deletion of a pan-FGF receptor adaptor Frs2α (fibroblast growth factor receptor substrate 2 alpha) in mice profoundly reduces neointima formation and vascular remodelling following carotid artery ligation. These results demonstrate that FGF-TGFβ signaling antagonism is the primary regulator of the SMC phenotype switch. Manipulation of this cross-talk may be an effective strategy for treatment of SMC-proliferation related diseases. PMID:27634335

  3. Retinoic Acid Receptor β Controls Development of Striatonigral Projection Neurons through FGF-Dependent and Meis1-Dependent Mechanisms.

    PubMed

    Rataj-Baniowska, Monika; Niewiadomska-Cimicka, Anna; Paschaki, Marie; Szyszka-Niagolov, Monika; Carramolino, Laura; Torres, Miguel; Dollé, Pascal; Krężel, Wojciech

    2015-10-28

    The mammalian striatum controls sensorimotor and psychoaffective functions through coordinated activities of its two striatonigral and striatopallidal output pathways. Here we show that retinoic acid receptor β (RARβ) controls development of a subpopulation of GABAergic, Gad65-positive striatonigral projection neurons. In Rarb(-/-) knock-out mice, concomitant reduction of Gad65, dopamine receptor D1 (Drd1), and substance P expression at different phases of prenatal development was associated with reduced number of Drd1-positive cells at birth, in contrast to normal numbers of striatopallidal projection neurons expressing dopamine receptor D2. Fate mapping using BrdU pulse-chase experiments revealed that such deficits may originate from compromised proliferation of late-born striosomal neurons and lead to decreased number of Drd1-positive cells retaining BrdU in postnatal day (P) 0 Rarb(-/-) striatum. Reduced expression of Fgf3 in the subventricular zone of the lateral ganglionic eminence (LGE) at embryonic day 13.5 may underlie such deficits by inducing premature differentiation of neuronal progenitors, as illustrated by reduced expression of the proneural gene Ascl1 (Mash1) and increased expression of Meis1, a marker of postmitotic LGE neurons. In agreement with a critical role of FGF3 in this control, reduced number of Ascl1-expressing neural progenitors, and a concomitant increase of Meis1-expressing cells, were observed in primary cell cultures of Rarb(-/-) LGE. This defect was normalized by addition of fibroblast growth factor (FGF). Such data point to role of Meis1 in striatal development, also supported by reduced neuronal differentiation in the LGE of Meis1(-/-) embryos. Our data unveil a novel mechanism of development of striatonigral projection neurons involving retinoic acid and FGF, two signals required for positioning the boundaries of Meis1-expressing cells.

  4. Cell proliferation potency is independent of FGF4 signaling in trophoblast stem cells derived from androgenetic embryos

    PubMed Central

    OGAWA, Hidehiko; TAKYU, Ryuichi; MORIMOTO, Hiromu; TOEI, Shuntaro; SAKON, Hiroshi; GOTO, Shiori; MORIYA, Shota; KONO, Tomohiro

    2015-01-01

    We previously established trophoblast stem cells from mouse androgenetic embryos (AGTS cells). In this study, to further characterize AGTS cells, we compared cell proliferation activity between trophoblast stem (TS) cells and AGTS cells under fibroblast growth factor 4 (FGF4) signaling. TS cells continued to proliferate and maintained mitotic cell division in the presence of FGF4. After FGF4 deprivation, the cell proliferation stopped, the rate of M-phase cells decreased, and trophoblast giant cells formed. In contrast, some of AGTS cells continued to proliferate, and the rate of M-phase cells did not decrease after FGF4 deprivation, although the other cells differentiated into giant cells. RO3306, an ATP competitor that selectively inhibits CDK1, inhibited the cell proliferation of both TS and AGTS cells. Under RO3306 treatment, cell death was induced in AGTS cells but not in TS cells. These results indicate that RO3306 caused TS cells to shift mitotic cell division to endoreduplication but that some of AGTS cells did not shift to endoreduplication and induced cell death. In conclusion, the paternal genome facilitated the proliferation of trophoblast cells without FGF4 signaling. PMID:26498204

  5. Cell surface localization of importin α1/KPNA2 affects cancer cell proliferation by regulating FGF1 signalling

    PubMed Central

    Yamada, Kohji; Miyamoto, Yoichi; Tsujii, Akira; Moriyama, Tetsuji; Ikuno, Yudai; Shiromizu, Takashi; Serada, Satoshi; Fujimoto, Minoru; Tomonaga, Takeshi; Naka, Tetsuji; Yoneda, Yoshihiro; Oka, Masahiro

    2016-01-01

    Importin α1 is involved in nuclear import as a receptor for proteins with a classical nuclear localization signal (cNLS). Here, we report that importin α1 is localized to the cell surface in several cancer cell lines and detected in their cultured medium. We also found that exogenously added importin α1 is associated with the cell membrane via interaction with heparan sulfate. Furthermore, we revealed that the cell surface importin α1 recognizes cNLS-containing substrates. More particularly, importin α1 bound directly to FGF1 and FGF2, secreted cNLS-containing growth factors, and addition of exogenous importin α1 enhanced the activation of ERK1/2, downstream targets of FGF1 signalling, in FGF1-stimulated cancer cells. Additionally, anti-importin α1 antibody treatment suppressed the importin α1−FGF1 complex formation and ERK1/2 activation, resulting in decreased cell growth. This study provides novel evidence that functional importin α1 is located at the cell surface, where it accelerates the proliferation of cancer cells. PMID:26887791

  6. FGF-2 signal promotes proliferation of cerebellar progenitor cells and their oligodendrocytic differentiation at early postnatal stage

    SciTech Connect

    Naruse, Masae; Shibasaki, Koji; Ishizaki, Yasuki

    2015-08-07

    The origins and developmental regulation of cerebellar oligodendrocytes are largely unknown, although some hypotheses of embryonic origins have been suggested. Neural stem cells exist in the white matter of postnatal cerebellum, but it is unclear whether these neural stem cells generate oligodendrocytes at postnatal stages. We previously showed that cerebellar progenitor cells, including neural stem cells, widely express CD44 at around postnatal day 3. In the present study, we showed that CD44-positive cells prepared from the postnatal day 3 cerebellum gave rise to neurospheres, while CD44-negative cells prepared from the same cerebellum did not. These neurospheres differentiated mainly into oligodendrocytes and astrocytes, suggesting that CD44-positive neural stem/progenitor cells might generate oligodendrocytes in postnatal cerebellum. We cultured CD44-positive cells from the postnatal day 3 cerebellum in the presence of signaling molecules known as mitogens or inductive differentiation factors for oligodendrocyte progenitor cells. Of these, only FGF-2 promoted survival and proliferation of CD44-positive cells, and these cells differentiated into O4+ oligodendrocytes. Furthermore, we examined the effect of FGF-2 on cerebellar oligodendrocyte development ex vivo. FGF-2 enhanced proliferation of oligodendrocyte progenitor cells and increased the number of O4+ and CC1+ oligodendrocytes in slice cultures. These results suggest that CD44-positive cells might be a source of cerebellar oligodendrocytes and that FGF-2 plays important roles in their development at an early postnatal stage. - Highlights: • CD44 is expressed in cerebellar neural stem/progenitor cells at postnatal day 3 (P3). • FGF-2 promoted proliferation of CD44-positive progenitor cells from P3 cerebellum. • FGF-2 promoted oligodendrocytic differentiation of CD44-positive progenitor cells. • FGF-2 increased the number of oligodendrocytes in P3 cerebellar slice culture.

  7. Control of retinoic acid synthesis and FGF expression in the nasal pit is required to pattern the craniofacial skeleton.

    PubMed

    Song, Y; Hui, J N; Fu, K K; Richman, J M

    2004-12-15

    Endogenous retinoids are important for patterning many aspects of the embryo including the branchial arches and frontonasal region of the embryonic face. The nasal placodes express retinaldehyde dehydrogenase-3 (RALDH3) and thus retinoids from the placode are a potential patterning influence on the developing face. We have carried out experiments that have used Citral, a RALDH antagonist, to address the function of retinoid signaling from the nasal pit in a whole embryo model. When Citral-soaked beads were implanted into the nasal pit of stage 20 chicken embryos, the result was a specific loss of derivatives from the lateral nasal prominences. Providing exogenous retinoic acid residue development of the beak demonstrating that most Citral-induced defects were produced by the specific blocking of RA synthesis. The mechanism of Citral effects was a specific increase in programmed cell death on the lateral (lateral nasal prominence) but not the medial side (frontonasal mass) of the nasal pit. Gene expression studies were focused on the Bone Morphogenetic Protein (BMP) pathway, which has a well-established role in programmed cell death. Unexpectedly, blocking RA synthesis decreased rather than increased Msx1, Msx2, and Bmp4 expression. We also examined cell survival genes, the most relevant of which was Fgf8, which is expressed around the nasal pit and in the frontonasal mass. We found that Fgf8 was not initially expressed along the lateral side of the nasal pit at the start of our experiments, whereas it was expressed on the medial side. Citral prevented upregulation of Fgf8 along the lateral edge and this may have contributed to the specific increase in programmed cell death in the lateral nasal prominence. Consistent with this idea, exogenous FGF8 was able to prevent cell death, rescue most of the morphological defects and was able to prevent a decrease in retinoic acid receptorbeta (Rarbeta) expression caused by Citral. Together, our results demonstrate that

  8. Fucoidan/FGF-2 induces angiogenesis through JNK- and p38-mediated activation of AKT/MMP-2 signalling.

    PubMed

    Kim, Beom Su; Park, Ji-Yun; Kang, Hyo-Jin; Kim, Hyung-Jin; Lee, Jun

    2014-08-01

    Angiogenesis is an important biological process in tissue development and repair. Fucoidan has previously been shown to potentiate in vitro tube formation in the presence of basic fibroblast growth factor (FGF-2). However, the underlying molecular mechanism remains largely unknown. This study was designed to investigate the action of fucoidan in angiogenesis in human umbilical vein endothelial cells (HUVECs) and to explore fucoidan-signalling pathways. First, we evaluated the effect of fucoidan on cell proliferation. Matrigel-based tube formation and wound healing assays were performed to investigate angiogenesis. Matrix metalloproteinase-2 (MMP-2) mRNA expression and activity levels were analysed by reverse transcription polymerase chain reaction (RT-PCR) and zymography, respectively. Additionally, phosphorylation of mitogen-activated protein kinases (MAPKs) and protein kinase B (AKT) was detected by Western blot. The results indicate that fucoidan treatment significantly increased cell proliferation in the presence of FGF-2. Moreover, compared to the effect of FGF-2 alone, fucoidan and FGF-2 had a greater effect on tube formation and cell migration, and this effect was found to be synergistic. Furthermore, fucoidan enhanced the phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38, and AKT. MMP-2 activation was also significantly increased. Specific inhibitors of p38 (SB203580) and JNK (SP600125) inhibited tube formation and wound healing, while an ERK inhibitor (PD98059) did not. MMP-2 activation and AKT phosphorylation were also attenuated and associated with the suppression of p38 and JNK phosphorylation, but not with that of ERK. These results indicate that fucoidan, in the presence of FGF-2, induces angiogenesis through AKT/MMP-2 signalling by activating p38 and JNK. These findings provide basic molecular information on the effect of fucoidan on angiogenesis in the presence of FGF-2.

  9. Developmental plasticity is bound by pluripotency and the Fgf and Wnt signaling pathways.

    PubMed

    Morris, Samantha A; Guo, Yu; Zernicka-Goetz, Magdalena

    2012-10-25

    Plasticity is a well-known feature of mammalian development, and yet very little is known about its underlying mechanism. Here, we establish a model system to examine the extent and limitations of developmental plasticity in living mouse embryos. We show that halved embryos follow the same strict clock of developmental transitions as intact embryos, but their potential is not equal. We have determined that unless a minimum of four pluripotent cells is established before implantation, development will arrest. This failure can be rescued by modulating Fgf and Wnt signaling to enhance pluripotent cell number, allowing the generation of monozygotic twins, which is an otherwise rare phenomenon. Knowledge of the minimum pluripotent-cell number required for development to birth, as well as the different potentials of blastomeres, allowed us to establish a protocol for splitting an embryo into one part that develops to adulthood and another that provides embryonic stem cells for that individual.

  10. Fucoidan/FGF-2 induces angiogenesis through JNK- and p38-mediated activation of AKT/MMP-2 signalling

    SciTech Connect

    Kim, Beom Su; Park, Ji-Yun; Kang, Hyo-Jin; Kim, Hyung-Jin; Lee, Jun

    2014-08-08

    Graphical abstract: Schematic diagram of the angiogenic activity mechanism by FGF-2/fucoidan treatment in HUVECs. Fucoidan enhances the FGF-2-induced phosphorylation of p38, JNK, and ERK MAPKs. However, p38 and JNK were involved in AKT phosphorylation and MMP-2 activation and resulted in enhanced angiogenic activity, such as tube formation and migration, in HUVECs. - Highlights: • The angiogenic activity of fucoidan in HUVECs was explored. • Fucoidan enhanced HUVEC proliferation, migration, and tube formation. • Fucoidan enhanced angiogenesis through p38 and JNK but not ERK in HUVECs. • Fucoidan targeted angiogenesis-mediated AKT/MMP-2 signalling in HUVECs. - Abstract: Angiogenesis is an important biological process in tissue development and repair. Fucoidan has previously been shown to potentiate in vitro tube formation in the presence of basic fibroblast growth factor (FGF-2). However, the underlying molecular mechanism remains largely unknown. This study was designed to investigate the action of fucoidan in angiogenesis in human umbilical vein endothelial cells (HUVECs) and to explore fucoidan-signalling pathways. First, we evaluated the effect of fucoidan on cell proliferation. Matrigel-based tube formation and wound healing assays were performed to investigate angiogenesis. Matrix metalloproteinase-2 (MMP-2) mRNA expression and activity levels were analysed by reverse transcription polymerase chain reaction (RT-PCR) and zymography, respectively. Additionally, phosphorylation of mitogen-activated protein kinases (MAPKs) and protein kinase B (AKT) was detected by Western blot. The results indicate that fucoidan treatment significantly increased cell proliferation in the presence of FGF-2. Moreover, compared to the effect of FGF-2 alone, fucoidan and FGF-2 had a greater effect on tube formation and cell migration, and this effect was found to be synergistic. Furthermore, fucoidan enhanced the phosphorylation of extracellular signal-regulated kinase (ERK

  11. FGF19 promotes epithelial-mesenchymal transition in hepatocellular carcinoma cells by modulating the GSK3β/β- catenin signaling cascade via FGFR4 activation

    PubMed Central

    Zhao, Huakan; Lv, Fenglin; Liang, Guizhao; Huang, Xiaobin; Wu, Gang; Zhang, Wenfa; Yu, Le; Shi, Lei; Teng, Yong

    2016-01-01

    Compelling evidence suggests that the epithelial-mesenchymal transition (EMT) correlates with aggressiveness of tumors and poor survival. FGF19 has been shown to be involved in EMT in cholangiocarcinoma and colorectal cancer, however, molecular mechanisms underlying FGF19-induced EMT process in hepatocellular carcinoma (HCC) remain largely unknown. Here, we show the expression of FGF19 is significantly elevated and negatively associated with the expression of E-cadherin in HCC tissues and cell lines. Ectopic FGF19 expression promotes EMT and invasion in epithelial-like HCC cells through repression of E-cadherin expression, whereas FGF19 knockdown enhances E-cadherin expression and hence diminishes EMT traits in mesenchymal-like HCC cells, suggesting FGF19 exerts its tumor progressing functions as an EMT inducer. Interestingly, depletion of FGF19 cannot abrogate EMT traits in the presence of GSK3β inhibitors. Furthermore, FGF19-induced EMT can be markedly attenuated when FGFR4 is knocked out. These observations clearly indicate that FGFR4/GSK3β/β-catenin axis may play a pivotal role in FGF19-induced EMT in HCC cells. As FGF19 and its specific receptor FGFR4 are frequently amplified in HCC cells, selective targeting this signaling node may lend insights into a potential effective therapeutic approach for blocking metastasis of HCC. PMID:26498355

  12. Opposite-sex housing reactivates the declining GnRH system in aged transgenic male mice with FGF signaling deficiency

    PubMed Central

    Chung, Wilson C. J.; Hayes, Tyrone B.; Tsai, Pei-San

    2012-01-01

    The continued presence of gonadotropin-releasing hormone (GnRH) neurons is required for a healthy reproductive lifespan, but factors that maintain postnatal GnRH neurons have not been identified. To begin to understand these factors, we investigated whether 1) fibroblast growth factor (FGF) signaling and 2) interactions with the opposite sex are involved in the maintenance of the postnatal GnRH system. A transgenic mouse model (dnFGFR mouse) with the targeted expression of a dominant-negative FGF receptor (dnFGFR) in GnRH neurons was used to examine the consequence of FGF signaling deficiency on postnatal GnRH neurons. Male dnFGFR mice suffered a significant loss of postnatal GnRH neurons within the first 100 days of life. Interestingly, this loss was reversed after cohabitation with female, but not male, mice for 300–550 days. Along with a rescue in GnRH neuron numbers, opposite-sex housing in dnFGFR males also increased hypothalamic GnRH peptide levels, promoted a more mature GnRH neuronal morphology, facilitated litter production, and enhanced testicular morphology. Last, mice hypomorphic for FGFR3 exhibited a similar pattern of postnatal GnRH neuronal loss as dnFGFR males, suggesting FGF signaling acts, in part, through FGFR3 to enhance the maintenance of the postnatal GnRH system. In summary, we have shown that FGF signaling is required for the continued presence of postnatal GnRH neurons. However, this requirement is not absolute, since sexual interactions can compensate for defects in FGFR signaling, thereby rescuing the declining GnRH system. This suggests the postnatal GnRH system is highly plastic and capable of responding to environmental stimuli throughout adult life. PMID:23047985

  13. FGF2 regulates proliferation, migration, and invasion of ECA109 cells through PI3K/Akt signalling pathway in vitro.

    PubMed

    Shi, Hui; Xu, Jingjing; Zhao, Rui; Wu, Huiqun; Gu, Luo; Chen, Yijiang

    2016-05-01

    Esophageal cancer is one of the most common malignant cancers that arise from esophagus tissues. Fibroblast growth factor 2 (FGF2) has been implicated in multiple biological functions and was considered as an oncogenic factor in tumorigenesis. However, the effects of FGF2 in esophageal carcinoma are yet to be fully elucidated. To better understand the function of FGF2 in esophageal cancer, we used the esophageal cancer cell line ECA109 as a cell model and downregulated FGF2 expression using RNAi; the results showed that insufficient expression of FGF2 inhibited cells proliferation, migration, and invasion of ECA109 cells. Meanwhile, the proliferation, migration, and invasion abilities were stimulated after treatment of exogenous FGF2. In addition, a PI3K/Akt signalling pathway inhibitor (LY294002) alleviated the tumorigenic effects of FGF2. These findings implied that the oncogenic effects of FGF2 was mediated, at least in part, through the PI3K/Akt signalling pathway and FGF2 may be a potential therapeutic target to constrain the tumorigenesis of esophageal cancer. PMID:26833879

  14. Attractive action of FGF-signaling contributes to the postnatal developing hippocampus.

    PubMed

    Cuccioli, V; Bueno, C; Belvindrah, R; Lledo, P-M; Martinez, S

    2015-04-01

    During brain development neural cell migration is a crucial, well-orchestrated, process, which leads to the proper whole brain structural organization. As development proceeds, new neurons are continuously produced, and this protracted neurogenesis is maintained throughout life in specialized germinative areas inside the telencephalon: the subventricular zone (SVZ) and the dentate gyrus (DG) of the hippocampus. In the anterior SVZ, newly generated neurons migrate through long distances, along the rostral migratory stream (RMS), before reaching their final destinations in the olfactory bulb (OB). Intriguingly, recent observations pointed out the existence of other postnatal tangential routes of migration alternative to the RMS but still starting from the SVZ. The presence of such dynamic and heterogeneous cell movements contributes to important features in the postnatal brain such as neural cell replacement and plasticity in cortical regions. In this work, we asked whether a caudal migratory pathway starting from the caudal SVZ continues through life. Strikingly, in vivo analysis of this caudal migration revealed the presence of a postnatal contribution of SVZ to the hippocampus. In vitro studies of the caudal migratory stream revealed the role of FGF signaling in attracting caudally the migrating neuroblasts during postnatal stages. Our findings demonstrate a postnatal neuronal contribution from the caudal ganglionic eminence (CGE) CGE-SVZ to the hippocampus through an FGF-dependent migrating mechanism. All together our data emphasizes the emerging idea that a developmental program is still operating in discrete domains of the postnatal brain and may contribute to the regulation of neural cell replacement processes in physiological plasticity and/or pathological circumstances.

  15. Hedgehog Is a Positive Regulator of FGF Signalling during Embryonic Tracheal Cell Migration

    PubMed Central

    Butí, Elisenda; Mesquita, Duarte; Araújo, Sofia J.

    2014-01-01

    Cell migration is a widespread and complex process that is crucial for morphogenesis and for the underlying invasion and metastasis of human cancers. During migration, cells are steered toward target sites by guidance molecules that induce cell direction and movement through complex intracellular mechanisms. The spatio-temporal regulation of the expression of these guidance molecules is of extreme importance for both normal morphogenesis and human disease. One way to achieve this precise regulation is by combinatorial inputs of different transcription factors. Here we used Drosophila melanogaster mutants with migration defects in the ganglionic branches of the tracheal system to further clarify guidance regulation during cell migration. By studying the cellular consequences of overactivated Hh signalling, using ptc mutants, we found that Hh positively regulates Bnl/FGF levels during embryonic stages. Our results show that Hh modulates cell migration non-autonomously in the tissues surrounding the action of its activity. We further demonstrate that the Hh signalling pathway regulates bnl expression via Stripe (Sr), a zinc-finger transcription factor with homology to the Early Growth Response (EGR) family of vertebrate transcription factors. We propose that Hh modulates embryonic cell migration by participating in the spatio-temporal regulation of bnl expression in a permissive mode. By doing so, we provide a molecular link between the activation of Hh signalling and increased chemotactic responses during cell migration. PMID:24651658

  16. FGF, Insulin, and SMAD Signaling Cooperate for Avian Primordial Germ Cell Self-Renewal

    PubMed Central

    Whyte, Jemima; Glover, James D.; Woodcock, Mark; Brzeszczynska, Joanna; Taylor, Lorna; Sherman, Adrian; Kaiser, Pete; McGrew, Michael J.

    2015-01-01

    Summary Precise self-renewal of the germ cell lineage is fundamental to fertility and reproductive success. The early precursors for the germ lineage, primordial germ cells (PGCs), survive and proliferate in several embryonic locations during their migration to the embryonic gonad. By elucidating the active signaling pathways in migratory PGCs in vivo, we were able to create culture conditions that recapitulate this embryonic germ cell environment. In defined medium conditions without feeder cells, the growth factors FGF2, insulin, and Activin A, signaling through their cognate-signaling pathways, were sufficient for self-renewal of germline-competent PGCs. Forced expression of constitutively active MEK1, AKT, and SMAD3 proteins could replace their respective upstream growth factors. Unexpectedly, we found that BMP4 could replace Activin A in non-clonal growth conditions. These defined medium conditions identify the key molecular pathways required for PGC self-renewal and will facilitate efforts in biobanking of chicken genetic resources and genome editing. PMID:26677769

  17. Combinatorial Fgf and Bmp signalling patterns the gastrula ectoderm into prospective neural and epidermal domains

    PubMed Central

    Kudoh, Tetsuhiro; Concha, Miguel L.; Houart, Corinne; Dawid, Igor B.; Wilson, Stephen W.

    2009-01-01

    Summary Studies in fish and amphibia have shown that graded Bmp signalling activity regulates dorsal-to-ventral (DV) patterning of the gastrula embryo. In the ectoderm, it is thought that high levels of Bmp activity promote epidermal development ventrally, whereas secreted Bmp antagonists emanating from the organiser induce neural tissue dorsally. However, in zebrafish embryos, the domain of cells destined to contribute to the spinal cord extends all the way to the ventral side of the gastrula, a long way from the organiser. We show that in vegetal (trunk and tail) regions of the zebrafish gastrula, neural specification is initiated at all DV positions of the ectoderm in a manner that is unaffected by levels of Bmp activity and independent of organiser-derived signals. Instead, we find that Fgf activity is required to induce vegetal prospective neural markers and can do so without suppressing Bmp activity. We further show that Bmp signalling does occur within the vegetal prospective neural domain and that Bmp activity promotes the adoption of caudal fate by this tissue. PMID:15262889

  18. Ampelopsin Improves Insulin Resistance by Activating PPARγ and Subsequently Up-Regulating FGF21-AMPK Signaling Pathway

    PubMed Central

    Qin, Yu; Liu, Lei; Wan, Jing; Zou, Lingyun; Zhang, Qianyong; Zhu, Jundong; Mi, Mantian

    2016-01-01

    Ampelopsin (APL), a major bioactive constituent of Ampelopsis grossedentata, exerts a number of biological effects. Here, we explored the anti-diabetic activity of APL and elucidate the underlying mechanism of this action. In palmitate-induced insulin resistance of L6 myotubes, APL treatment markedly up- regulated phosphorylated insulin receptor substrate-1 and protein kinase B, along with a corresponding increase of glucose uptake capacity. APL treatment also increased expressions of fibroblast growth factor (FGF21) and phosphorylated adenosine 5’-monophosphate -activated protein kinase (p-AMPK), however inhibiting AMPK by Compound C or AMPK siRNA, or blockage of FGF21 by FGF21 siRNA, obviously weakened APL -induced increases of FGF21 and p-AMPK as well as glucose uptake capacity in palmitate -pretreated L6 myotubes. Furthermore, APL could activate PPAR γ resulting in increases of glucose uptake capacity and expressions of FGF21 and p-AMPK in palmitate -pretreated L6 myotubes, whereas all those effects were obviously abolished by addition of GW9662, a specific inhibitor of peroxisome proliferator- activated receptor –γ (PPARγ), and PPARγsiRNA. Using molecular modeling and the luciferase reporter assays, we observed that APL could dock with the catalytic domain of PPARγ and dose-dependently up-regulate PPARγ activity. In summary, APL maybe a potential agonist of PPARγ and promotes insulin sensitization by activating PPARγ and subsequently regulating FGF21- AMPK signaling pathway. These results provide new insights into the protective health effects of APL, especially for the treatment of Type 2 diabetes mellitus. PMID:27391974

  19. Subcellular trafficking of FGF controls tracheal invasion of Drosophila flight muscle

    PubMed Central

    Peterson, Soren J.; Krasnow, Mark A.

    2015-01-01

    SUMMARY To meet the extreme oxygen demand of insect flight muscle, tracheal (respiratory) tubes ramify not only on its surface, as in other tissues, but also within T-tubules and ultimately surrounding every mitochondrion. Although this remarkable physiological specialization has long been recognized, its cellular and molecular basis is unknown. Here we show that Drosophila tracheoles invade flight muscle T-tubules through transient surface openings. Like other tracheal branching events, invasion requires the Branchless FGF pathway. However, localization of the FGF chemoattractant changes from all muscle membranes to T-tubules as invasion begins. Core regulators of epithelial basolateral membrane identity localize to T-tubules, and knockdown of AP-1γ, required for basolateral trafficking, redirects FGF from T-tubules to surface, increasing tracheal surface ramification and preventing invasion. We propose that tracheal invasion is controlled by an AP-1-dependent switch in FGF trafficking. Thus, subcellular targeting of a chemoattractant can direct outgrowth to specific domains including inside the cell. PMID:25557078

  20. FGF-1/-3/FGFR4 signaling in cancer-associated fibroblasts promotes tumor progression in colon cancer through Erk and MMP-7

    PubMed Central

    Bai, Yu-Pan; Shang, Kun; Chen, Huan; Ding, Fei; Wang, Zhen; Liang, Chen; Xu, Ye; Sun, Meng-Hong; LI, Ying-Yi

    2015-01-01

    Cancer-associated fibroblasts (CAFs), as the activated fibroblasts in the tumor stroma, are important modifiers of tumour progression. In the present study, we observed that azoxymethane and dextran sodium sulfate treatments induced increasingly severe colorectal mucosal inflammation and the intratumoural accumulation of CAFs. Fibroblast growth factor (FGF)-1 and FGF-3 were detected in infiltrating cells, and FGFR4, the specific receptor for FGF-1 and FGF-3, was detected in colon cancer tissues. The phosphorylation of FGFR4 enhanced the production of metalloproteinase (MMP)-7 and mitogen-activated protein kinase kinase (Mek)/extracellular signal-regulated kinase (Erk), which was accompanied by excessive vessel generation and cell proliferation. Moreover, we separated CAFs, pericarcinoma fibroblasts (PFs), and normal fibroblasts (NFs) from human colon tissue specimens to characterize the function of CAFs. We observed that CAFs secrete more FGF-1/-3 than NFs and PFs and promote cancer cell growth and angiogenesis through the activation of FGFR4, which is followed by the activation of Mek/Erk and the modulation of MMP-7 expression. The administration of FGF-1/-3-neutralizing antibodies or the treatment of cells with FGFR4 siRNA or the FGFR4 inhibitor PD173074 markedly suppressed colon cancer cell proliferation and neovascularization. These observations suggest a crucial role for CAFs and FGF signaling in the initiation and progression of colorectal cancer. The inhibition of the FGF signaling pathway may be a useful strategy for the treatment of colon cancer. PMID:26183471

  1. Fgf3-Fgf4-cis: A new mouse line for studying Fgf functions during mouse development.

    PubMed

    Anderson, Matthew J; Southon, Eileen; Tessarollo, Lino; Lewandoski, Mark

    2016-02-01

    The fibroblast growth factor (FGF) family consists of 22 ligands in mice and humans. FGF signaling is vital for embryogenesis and, when dysregulated, can cause disease. Loss-of-function genetic analysis in the mouse has been crucial for understanding FGF function. Such analysis has revealed that multiple Fgfs sometimes function redundantly. Exploring such redundancy between Fgf3 and Fgf4 is currently impossible because both genes are located on chromosome 7, about 18.5 kb apart, making the frequency of interallelic cross-over between existing mutant alleles too infrequent to be practicable. Therefore, we retargeted Fgf3 and Fgf4 in cis, generating an Fgf3 null allele and a conditional Fgf4 allele, subject to Cre inactivation. To increase the frequency of cis targeting, we used an F1 embryonic stem cell line that contained 129/SvJae (129) and C57BL/6J (B6) chromosomes and targeting constructs isogenic to the 129 chromosome. We confirmed cis targeting by assaying for B6/129 allele-specific single-nucleotide polymorphisms. We demonstrated the utility of the Fgf3(Δ)-Fgf4(flox)-cis mouse line by showing that the caudal axis extension defects found in the Fgf3 mutants worsen when Fgf4 is also inactivated. This Fgf3(Δ)-Fgf4(flox)-cis line will be useful to study redundancy of these genes in a variety of tissues and stages in development.

  2. The MAPKERK-1,2 pathway integrates distinct and antagonistic signals from TGF alpha and FGF7 in morphogenesis of mouse mammary epithelium

    SciTech Connect

    Fata, Jimmie E; Mori, Hidetoshi; Ewald, Andrew J; Zhang, Hui; Yao, Evelyn; Werb, Zena; Bissell, Mina J

    2006-10-03

    Transforming growth factor-{alpha} (TGF{alpha}) and fibroblast growth factor-7 (FGF7) exhibit distinct expression patterns in the mammary gland. Both factors signal through mitogen-activated kinase/extracellular regulated kinase-1,2 (MAPK{sup ERK1,2}); however, their unique and/or combined contributions to mammary morphogenesis have not been examined. In ex vivo mammary explants, we show that a sustained activation of MAPK{sup ERK1,2} for 1 h, induced by TGF{alpha}, was necessary and sufficient to initiate branching morphogenesis, whereas a transient activation (15 min) of MAPK{sup ERK1,2}, induced by FGF7, led to growth without branching. Unlike TGF{alpha}, FGF7 promoted sustained proliferation as well as ectopic localization of, and increase in, keratin-6 expressing cells. The response of the explants to FGF10 was similar to that to FGF7. Simultaneous stimulation by FGF7 and TGF{alpha} indicated that the FGF7-induced MAPK{sup ERK1,2} signaling and associated phenotypes were dominant: FGF7 may prevent branching by suppression of two necessary TGF{alpha}-induced morphogenetic effectors, matrix metalloproteinase-3 (MMP-3/stromelysin-1), and fibronectin. Our findings indicate that expression of morphogenetic effectors, proliferation, and cell-type decisions during mammary organoid morphogenesis are intimately dependent on the duration of activation of MAPK{sup ERK1,2} activation.

  3. Differential Activation of Multiple Signaling Pathways Dictates eNOS Upregulation by FGF2 but not VEGF in Placental Artery Endothelial Cells1

    PubMed Central

    Mata-Greenwood, Eugenia; Liao, Wu-Xiang; Zheng, Jing; Chen, Dong-Bao

    2008-01-01

    Fibroblast growth factor (FGF2), but not vascular endothelial growth factor (VEGF), upregulates endothelial nitric oxide synthase (eNOS) protein expression, at least in part, via activation of extracellular signal-regulated kinase 2/1 (ERK2/1) in ovine fetoplacental artery endothelial (oFPAE) cells. Herein we further investigated the temporal effects of FGF2 and VEGF on other signaling pathways including members (Jun N-terminal kinase JNK1/2 and p38MAPK) of mitogen-activated protein kinases (MAPK), phosphatidylinositol 3 kinase/v-akt murine thymoma viral oncogene homolog 1 (PI3K/AKT1), and the tyrosine kinase c-SRC, and examined if either one or more of these pathways play a role in the differential regulation of eNOS by FGF2 and VEGF. We first confirmed that in oFPAE cells, FGF2, but not VEGF, increased eNOS protein. FGF2 stimulated eNOS protein in a time and concentration dependent manner, which also depended on cell density. FGF2 provoked sustained (5 min to 12 h) whereas VEGF only stimulated transient (5 min) ERK2/1 phosphorylation. FGF2 was 1.7-fold more potent in stimulating ERK2/1 phosphorylation than VEGF. FGF2 and VEGF only transiently activated JNK1/2 and AKT1 within 5 min; however, FGF2 was a stronger stimulus than VEGF. FGF2 and VEGF did not significantly activate p38MAPK at 5 min; however, VEGF stimulated p38MAPK phosphorylation at 60 min. VEGF but not FGF2 significantly stimulated c-SRC phosphorylation. Inhibitors of MEK-ERK2/1 (PD98059), JNK1/2 (SP600125) and PI3K (wortmannin), but not p38MAPK (SB203580) and SRC (PP2), decreased the FGF2-increased eNOS protein expression. Thus, the FGF2-induced eNOS protein expression requires activation of multiple signaling pathways including ERK2/1, JNK1/2 and PI3K/AKT1. Differences in intensity and temporal patterns of activation of these pathways by FGF2 and VEGF may account for their differential effects on eNOS expression in OFPAE cells. PMID:18571718

  4. Postsynaptic SDC2 induces transsynaptic signaling via FGF22 for bidirectional synaptic formation

    PubMed Central

    Hu, Hsiao-Tang; Umemori, Hisashi; Hsueh, Yi-Ping

    2016-01-01

    Functional synapse formation requires tight coordination between pre- and post-synaptic termini. Previous studies have shown that postsynaptic expression of heparan sulfate proteoglycan syndecan-2 (SDC2) induces dendritic spinogenesis. Those SDC2-induced dendritic spines are frequently associated with presynaptic termini. However, how postsynaptic SDC2 accelerates maturation of corresponding presynaptic termini is unknown. Because fibroblast growth factor 22 (FGF22), a heparan sulfate binding growth factor, has been shown to act as a presynaptic organizer released from the postsynaptic site, it seems possible that postsynaptic SDC2 presents FGF22 to the presynaptic FGF receptor to promote presynaptic differentiation. Here, we show that postsynaptic SDC2 uses its ectodomain to interact with and facilitate dendritic filopodial targeting of FGF22, triggering presynaptic maturation. Since SDC2 also enhances filopodial targeting of NMDAR via interaction with the CASK-mLIN7-MINT1 adaptor complex, presynaptic maturation promoted by FGF22 further feeds back to activate NMDAR at corresponding postsynaptic sites through increased neurotransmitter release and, consequently, promotes the dendritic filopodia-spines (F-S) transition. Meanwhile, via regulation of the KIF17 motor, CaMKII (activated by the NMDAR pathway) may further facilitate FGF22 targeting to dendritic filopodia that receive presynaptic stimulation. Our study suggests a positive feedback that promotes the coordination of postsynaptic and presynaptic differentiation. PMID:27627962

  5. SEQUENTIAL EXPOSURE TO FIBROBLAST GROWTH FACTORS (FGF) 2, 9 AND 18 ENHANCES hMSC CHONDROGENIC DIFFERENTIATION

    PubMed Central

    Correa, Diego; Somoza, Rodrigo A.; Lin, Paul; Greenberg, Steven; Rom, Eran; Duesler, Lori; Welter, Jean F.; Yayon, Avner; Caplan, Arnold I.

    2015-01-01

    Objective To test the effects of sequential exposure to FGF2, 9 and 18 on human Mesenchymal Stem Cells (hMSC) differentiation during in vitro chondrogenesis. Design Control and FGF2-expanded hMSC were cultured in aggregates in the presence of rhFGF9, rhFGF18 or rhFGFR3-specific signaling FGF variants, starting at different times during the chondroinductive program. qRT-PCR and immunocytochemistry were performed at different stages. The aggregate cultures were switched to a hypertrophy-inducing medium along with rhFGFs and neutralizing antibodies against FGFR1 and FGFR3. Histological/immunohistochemical/biochemical analyses were performed. Results FGF2-exposed hMSC during expansion up-regulated Sox9 suggesting an early activation of the chondrogenic machinery. FGF2, FGF9 and 18 modulated the expression profile of FGFR1 and FGFR3 in hMSC during expansion and chondrogenesis. In combination with TGF-β, FGF9 and FGF18 inhibited chondrogenesis when added at the beginning of the program (≤d7), while exhibiting an anabolic effect when added later (≥d14), an effect mediated by FGFR3. Finally, FGFR3 signaling induced by either FGF9 or FGF18 delayed the appearance of spontaneous and induced hypertrophy-related changes. Conclusions The stage of hMSC-dependent chondrogenesis at which the growth factors are added impacts the progression of the differentiation program: increased cell proliferation and priming (FGF2); stimulated early chondrogenic differentiation (TGF-β, FGF9/FGF18) by shifting the chondrogenic program earlier; augmented ECM production (FGF9/FGF18); and delayed terminal hypertrophy (FGF9/FGF18). Collectively, these factors could be used to optimize pre-implantation conditions of hMSC when used to engineer cartilage grafts. PMID:25464167

  6. Mitochondrial mass, a new metabolic biomarker for stem-like cancer cells: Understanding WNT/FGF-driven anabolic signaling.

    PubMed

    Lamb, Rebecca; Bonuccelli, Gloria; Ozsvári, Béla; Peiris-Pagès, Maria; Fiorillo, Marco; Smith, Duncan L; Bevilacqua, Generoso; Mazzanti, Chiara Maria; McDonnell, Liam A; Naccarato, Antonio Giuseppe; Chiu, Maybo; Wynne, Luke; Martinez-Outschoorn, Ubaldo E; Sotgia, Federica; Lisanti, Michael P

    2015-10-13

    Here, we developed an isogenic cell model of "stemness" to facilitate protein biomarker discovery in breast cancer. For this purpose, we used knowledge gained previously from the study of the mouse mammary tumor virus (MMTV). MMTV initiates mammary tumorigenesis in mice by promoter insertion adjacent to two main integration sites, namely Int-1 (Wnt1) and Int-2 (Fgf3), which ultimately activates Wnt/β-catenin signaling, driving the propagation of mammary cancer stem cells (CSCs). Thus, to develop a humanized model of MMTV signaling, we over-expressed WNT1 and FGF3 in MCF7 cells, an ER(+) human breast cancer cell line. We then validated that MCF7 cells over-expressing both WNT1 and FGF3 show a 3.5-fold increase in mammosphere formation, and that conditioned media from these cells is also sufficient to promote stem cell activity in untransfected parental MCF7 and T47D cells, as WNT1 and FGF3 are secreted factors. Proteomic analysis of this model system revealed the induction of i) EMT markers, ii) mitochondrial proteins, iii) glycolytic enzymes and iv) protein synthesis machinery, consistent with an anabolic CSC phenotype. MitoTracker staining validated the expected WNT1/FGF3-induced increase in mitochondrial mass and activity, which presumably reflects increased mitochondrial biogenesis. Importantly, many of the proteins that were up-regulated by WNT/FGF-signaling in MCF7 cells, were also transcriptionally over-expressed in human breast cancer cells in vivo, based on the bioinformatic analysis of public gene expression datasets of laser-captured patient samples. As such, this isogenic cell model should accelerate the discovery of new biomarkers to predict clinical outcome in breast cancer, facilitating the development of personalized medicine.Finally, we used mitochondrial mass as a surrogate marker for increased mitochondrial biogenesis in untransfected MCF7 cells. As predicted, metabolic fractionation of parental MCF7 cells, via MitoTracker staining, indicated

  7. Specific induction of cranial placode cells from Xenopus ectoderm by modulating the levels of BMP, Wnt, and FGF signaling.

    PubMed

    Watanabe, Tomoko; Kanai, Yuna; Matsukawa, Shinya; Michiue, Tatsuo

    2015-10-01

    The neural-epidermal boundary tissues include the neural crest and preplacodal ectoderm (PPE) as primordial constituents. The PPE region is essential for the development of various sensory and endocrine organs, such as the anterior lobe of the pituitary, olfactory epithelium, lens, trigeminal ganglion, and otic vesicles. During gastrulation, a neural region is induced in ectodermal cells that interacts with mesendodermal tissue and responds to several secreted factors. Among them, inhibition of bone morphogenetic protein (BMP) in the presumptive neuroectoderm is essential for the induction of neural regions, and formation of a Wnt and fibroblast growth factor (FGF) signaling gradient along the midline determines anterior-posterior patterning. In this study, we attempted to specifically induce PPE cells from undifferentiated Xenopus cells by regulating BMP, Wnt, and FGF signaling. We showed that the proper level of BMP inhibition with an injection of truncated BMP receptor or treatment with a chemical antagonist triggered the expression of PPE genes. In addition, by varying the amount of injected chordin, we optimized specific expression of the PPE genes. PPE gene expression is increased by adding an appropriate dose of an FGF receptor antagonist. Furthermore, co-injection with either wnt8 or the Wnt inhibitor dkk-1 altered the expression levels of several region-specific genes according to the injected dose. We specifically induced PPE cell differentiation in animal cap cells from early-stage Xenopus embryos by modulating BMP, Wnt, and FGF signaling. This is not the first research on placode induction, but our simple method could potentially be applied to mammalian stem cell systems. PMID:26249012

  8. Manipulation of Fgf and Bmp signaling in teleost fishes suggests potential pathways for the evolutionary origin of multicuspid teeth.

    PubMed

    Jackman, William R; Davies, Shelby H; Lyons, David B; Stauder, Caitlin K; Denton-Schneider, Benjamin R; Jowdry, Andrea; Aigler, Sharon R; Vogel, Scott A; Stock, David W

    2013-01-01

    Teeth with two or more cusps have arisen independently from an ancestral unicuspid condition in a variety of vertebrate lineages, including sharks, teleost fishes, amphibians, lizards, and mammals. One potential explanation for the repeated origins of multicuspid teeth is the existence of multiple adaptive pathways leading to them, as suggested by their different uses in these lineages. Another is that the addition of cusps required only minor changes in genetic pathways regulating tooth development. Here we provide support for the latter hypothesis by demonstrating that manipulation of the levels of Fibroblast growth factor (Fgf) or Bone morphogenetic protein (Bmp) signaling produces bicuspid teeth in the zebrafish (Danio rerio), a species lacking multicuspid teeth in its ancestry. The generality of these results for teleosts is suggested by the conversion of unicuspid pharyngeal teeth into bicuspid teeth by similar manipulations of the Mexican Tetra (Astyanax mexicanus). That these manipulations also produced supernumerary teeth in both species supports previous suggestions of similarities in the molecular control of tooth and cusp number. We conclude that despite their apparent complexity, the evolutionary origin of multicuspid teeth is positively constrained, likely requiring only slight modifications of a pre-existing mechanism for patterning the number and spacing of individual teeth.

  9. Manipulation of Fgf and Bmp signaling in teleost fishes suggests potential pathways for the evolutionary origin of multicuspid teeth.

    PubMed

    Jackman, William R; Davies, Shelby H; Lyons, David B; Stauder, Caitlin K; Denton-Schneider, Benjamin R; Jowdry, Andrea; Aigler, Sharon R; Vogel, Scott A; Stock, David W

    2013-01-01

    Teeth with two or more cusps have arisen independently from an ancestral unicuspid condition in a variety of vertebrate lineages, including sharks, teleost fishes, amphibians, lizards, and mammals. One potential explanation for the repeated origins of multicuspid teeth is the existence of multiple adaptive pathways leading to them, as suggested by their different uses in these lineages. Another is that the addition of cusps required only minor changes in genetic pathways regulating tooth development. Here we provide support for the latter hypothesis by demonstrating that manipulation of the levels of Fibroblast growth factor (Fgf) or Bone morphogenetic protein (Bmp) signaling produces bicuspid teeth in the zebrafish (Danio rerio), a species lacking multicuspid teeth in its ancestry. The generality of these results for teleosts is suggested by the conversion of unicuspid pharyngeal teeth into bicuspid teeth by similar manipulations of the Mexican Tetra (Astyanax mexicanus). That these manipulations also produced supernumerary teeth in both species supports previous suggestions of similarities in the molecular control of tooth and cusp number. We conclude that despite their apparent complexity, the evolutionary origin of multicuspid teeth is positively constrained, likely requiring only slight modifications of a pre-existing mechanism for patterning the number and spacing of individual teeth. PMID:25098636

  10. FGF signaling via MAPK is required early and improves Activin A-induced definitive endoderm formation from human embryonic stem cells

    SciTech Connect

    Sui, Lina; Mfopou, Josue K.; Geens, Mieke; Sermon, Karen; Bouwens, Luc

    2012-09-28

    Highlights: Black-Right-Pointing-Pointer Deep study the FGF signaling role during DE specification in the context of hESCs. Black-Right-Pointing-Pointer DE differentiation from hESCs has an early dependence on FGF signaling. Black-Right-Pointing-Pointer A serum-free DE protocol is developed based on the findings. Black-Right-Pointing-Pointer The DE cells showed potential to differentiate into pancreatic progenitor cells. -- Abstract: Considering their unlimited proliferation and pluripotency properties, human embryonic stem cells (hESCs) constitute a promising resource applicable for cell replacement therapy. To facilitate this clinical translation, it is critical to study and understand the early stage of hESCs differentiation wherein germ layers are defined. In this study, we examined the role of FGF signaling in Activin A-induced definitive endoderm (DE) differentiation in the absence of supplemented animal serum. We found that activated FGF/MAPK signaling is required at the early time point of Activin A-induced DE formation. In addition, FGF activation increased the number of DE cells compared to Activin A alone. These DE cells could further differentiate into PDX1 and NKX6.1 positive pancreatic progenitors in vitro. We conclude that Activin A combined with FGF/MAPK signaling efficiently induce DE cells in the absence of serum. These findings improve our understanding of human endoderm formation, and constitute a step forward in the generation of clinical grade hESCs progenies for cell therapy.

  11. Fibroblast Growth Factor (FGF) Signaling during Gastrulation Negatively Modulates the Abundance of MicroRNAs That Regulate Proteins Required for Cell Migration and Embryo Patterning*

    PubMed Central

    Bobbs, Alexander S.; Saarela, Aleksi V.; Yatskievych, Tatiana A.; Antin, Parker B.

    2012-01-01

    FGF signaling plays a pivotal role in regulating cell movements and lineage induction during gastrulation. Here we identify 44 microRNAs that are expressed in the primitive streak region of gastrula stage chicken embryos. We show that the primary effect of FGF signaling on microRNA abundance is to negatively regulate the levels of miR-let-7b, -9, -19b, -107, -130b, and -218. LIN28B inhibits microRNA processing and is positively regulated by FGF signaling. Gain- and loss-of-function experiments show that LIN28B negatively regulates the expression of miR-19b, -130b, and let-7b, whereas negative modulation of miR-9, -107, and -218 appears to be independent of LIN28B function. Predicted mRNA targets of the FGF-regulated microRNAs are over-represented in serine/threonine and tyrosine kinase receptors, including ACVR1, ACVR2B, PDGFRA, TGFBR1, and TGFBR3. Luciferase assays show that these and other candidates are targeted by FGF-regulated microRNAs. PDGFRA, a receptor whose activity is required for cell migration through the primitive streak, is a target of miR-130b and -218 in vivo. These results identify a novel mechanism by which FGF signaling regulates gene expression by negatively modulating microRNA abundance through both LIN28B-dependent and LIN28B-independent pathways. PMID:22995917

  12. The timing of emergence of muscle progenitors is controlled by an FGF/ERK/SNAIL1 pathway.

    PubMed

    Delfini, Marie-Claire; De La Celle, Marie; Gros, Jérome; Serralbo, Olivier; Marics, Irène; Seux, Mylène; Scaal, Martin; Marcelle, Christophe

    2009-09-15

    In amniotes, the dermomyotome is the source of all skeletal muscles of the trunk and the limbs. Trunk skeletal muscles form in two sequential stages: in the first stage, cells located at the four borders of the epithelial dermomyotome delaminate to generate the primary myotome, composed of post-mitotic, mononucleated myocytes. The epithelio-mesenchymal transition (EMT) of the central dermomyotome initiates the second stage of muscle formation, characterised by a massive entry of mitotic muscle progenitors from the central region of the dermomyotome into the primary myotome. The signals that regulate the timing of the dermomyotome EMT are unknown. Here, we propose that this process is regulated by an FGF signal emanating from the primary myotome, a known source of FGF. The over-expression of FGF results in a precocious EMT of the dermomyotome, while on the contrary, the inhibition of FGF signalling by the electoporation of a dominant-negative form of FGFR4 delays this process. Within the dermomyotome, FGF signalling triggers a MAPK/ERK pathway that leads to the activation of the transcription factor Snail1, a known regulator of EMT in a number of cellular contexts. The activation or the inhibition of the MAPK/ERK pathway and of Snail1 mimics that of FGF signalling and leads to an early or delayed EMT of the dermomyotome, respectively. Altogether, our results indicate that in amniotes, the primary myotome is an organizing center that regulates the timely entry of embryonic muscle progenitors within the muscle masses, thus initiating the growth phase of the trunk skeletal muscles.

  13. FGF2 inhibits endothelial-mesenchymal transition through microRNA-20a-mediated repression of canonical TGF-β signaling.

    PubMed

    Correia, Ana C P; Moonen, Jan-Renier A J; Brinker, Marja G L; Krenning, Guido

    2016-02-01

    Endothelial-to-mesenchymal transition (EndMT) is characterized by the loss of endothelial cell markers and functions, and coincides with de novo expression of mesenchymal markers. EndMT is induced by TGFβ1 and changes endothelial microRNA expression. We found that miR-20a is decreased during EndMT, and that ectopic expression of miR-20a inhibits EndMT induction. TGFβ1 induces cellular hypertrophy in human umbilical vein endothelial cells and abrogates VE-cadherin expression, reduces endothelial sprouting capacity and induces the expression of the mesenchymal marker SM22α (also known as TAGLN). We identified ALK5 (also known as TGFBR1), TGFBR2 and SARA (also known as ZFYVE9) as direct miR-20a targets. Expression of miR-20a mimics abrogate the endothelial responsiveness to TGFβ1, by decreasing ALK5, TGFBR2 and SARA, and inhibit EndMT, as indicated by the maintenance of VE-cadherin expression, the ability of the cells to sprout and the absence of SM22α expression. FGF2 increases miR-20a expression and inhibits EndMT in TGFβ1-stimulated endothelial cells. In summary, FGF2 controls endothelial TGFβ1 signaling by regulating ALK5, TGFBR2 and SARA expression through miR-20a. Loss of FGF2 signaling combined with a TGFβ1 challenge reduces miR-20a levels and increases endothelial responsiveness to TGFβ1 through elevated receptor complex levels and activation of Smad2 and Smad3, which culminates in EndMT. PMID:26729221

  14. Fibroblast growth factor 21 (FGF21) inhibits macrophage-mediated inflammation by activating Nrf2 and suppressing the NF-κB signaling pathway.

    PubMed

    Yu, Yinhang; He, Jinjiao; Li, Siming; Song, Liying; Guo, Xiaochen; Yao, Wenbing; Zou, Dehua; Gao, Xinyu; Liu, Yunye; Bai, Fuliang; Ren, Guiping; Li, Deshan

    2016-09-01

    Our previous report has shown that FGF21 has anti-inflammatory properties in a collagen-induced arthritis (CIA) model. In this study, the underlying molecular mechanisms of action were also investigated using RAW 264.7 cells, a murine monocyte-macrophage. RAW 264.7 cells were pre-incubated with various concentrations (2000, 500, 100ng/ml) of FGF21 and stimulated with LPS to induce oxidative stress and inflammation. The result of flow cytometry showed that β-Klotho, FGF21 specific receptor, was expressed in murine splenic macrophages and RAW 264.7. In vitro, FGF21 reduced the expression of TNF-α, IL-1β, IL-6 and IFN-γ and increased the level of IL-10 in a dose-dependent manner in LPS-stimulated RAW 264.7 macrophages. FGF21 also suppressed profound elevation of ROS production and oxidative stress, as evidenced by an increase of the MDA level and depletion of the intracellular GSH level, and restored the activities of antioxidant enzymes SOD and GSH-Px in LPS-stimulated RAW 264.7 macrophages. Moreover, FGF21 inhibited LPS-induced nuclear factor-κB (NF-κB) activation, including degradation of I-κB and nuclear translocation of p65. In addition, the result of Western blot and real-time PCR showed that FGF21 induced heme oxygenase-1 (HO-1) expression and increased the nuclear transcription factor-E2-related factor 2 (Nrf2) levels in a dose-dependent manner in LPS-stimulated RAW 264.7 macrophages. In conclusion, the results suggest that macrophages are the targets for the anti-inflammatory effects of FGF21, and FGF21 exerted an anti-inflammatory effect mainly via enhancing Nrf2-mediated anti-oxidant capacity and suppressing NF-κB signaling pathway.

  15. Fibroblast growth factor 21 (FGF21) inhibits macrophage-mediated inflammation by activating Nrf2 and suppressing the NF-κB signaling pathway.

    PubMed

    Yu, Yinhang; He, Jinjiao; Li, Siming; Song, Liying; Guo, Xiaochen; Yao, Wenbing; Zou, Dehua; Gao, Xinyu; Liu, Yunye; Bai, Fuliang; Ren, Guiping; Li, Deshan

    2016-09-01

    Our previous report has shown that FGF21 has anti-inflammatory properties in a collagen-induced arthritis (CIA) model. In this study, the underlying molecular mechanisms of action were also investigated using RAW 264.7 cells, a murine monocyte-macrophage. RAW 264.7 cells were pre-incubated with various concentrations (2000, 500, 100ng/ml) of FGF21 and stimulated with LPS to induce oxidative stress and inflammation. The result of flow cytometry showed that β-Klotho, FGF21 specific receptor, was expressed in murine splenic macrophages and RAW 264.7. In vitro, FGF21 reduced the expression of TNF-α, IL-1β, IL-6 and IFN-γ and increased the level of IL-10 in a dose-dependent manner in LPS-stimulated RAW 264.7 macrophages. FGF21 also suppressed profound elevation of ROS production and oxidative stress, as evidenced by an increase of the MDA level and depletion of the intracellular GSH level, and restored the activities of antioxidant enzymes SOD and GSH-Px in LPS-stimulated RAW 264.7 macrophages. Moreover, FGF21 inhibited LPS-induced nuclear factor-κB (NF-κB) activation, including degradation of I-κB and nuclear translocation of p65. In addition, the result of Western blot and real-time PCR showed that FGF21 induced heme oxygenase-1 (HO-1) expression and increased the nuclear transcription factor-E2-related factor 2 (Nrf2) levels in a dose-dependent manner in LPS-stimulated RAW 264.7 macrophages. In conclusion, the results suggest that macrophages are the targets for the anti-inflammatory effects of FGF21, and FGF21 exerted an anti-inflammatory effect mainly via enhancing Nrf2-mediated anti-oxidant capacity and suppressing NF-κB signaling pathway. PMID:27276443

  16. Fgf and Hh signalling act on a symmetrical pre-pattern to specify anterior and posterior identity in the zebrafish otic placode and vesicle.

    PubMed

    Hammond, Katherine L; Whitfield, Tanya T

    2011-09-01

    Specification of the otic anteroposterior axis is one of the earliest patterning events during inner ear development. In zebrafish, Hedgehog signalling is necessary and sufficient to specify posterior otic identity between the 10 somite (otic placode) and 20 somite (early otic vesicle) stages. We now show that Fgf signalling is both necessary and sufficient for anterior otic specification during a similar period, a function that is completely separable from its earlier role in otic placode induction. In lia(-/-) (fgf3(-/-)) mutants, anterior otic character is reduced, but not lost altogether. Blocking all Fgf signalling at 10-20 somites, however, using the pan-Fgf inhibitor SU5402, results in the loss of anterior otic structures and a mirror image duplication of posterior regions. Conversely, overexpression of fgf3 during a similar period, using a heat-shock inducible transgenic line, results in the loss of posterior otic structures and a duplication of anterior domains. These phenotypes are opposite to those observed when Hedgehog signalling is altered. Loss of both Fgf and Hedgehog function between 10 and 20 somites results in symmetrical otic vesicles with neither anterior nor posterior identity, which, nevertheless, retain defined poles at the anterior and posterior ends of the ear. These data suggest that Fgf and Hedgehog act on a symmetrical otic pre-pattern to specify anterior and posterior otic identity, respectively. Each signalling pathway has instructive activity: neither acts simply to repress activity of the other, and, together, they appear to be key players in the specification of anteroposterior asymmetries in the zebrafish ear.

  17. Fgf and Hh signalling act on a symmetrical pre-pattern to specify anterior and posterior identity in the zebrafish otic placode and vesicle

    PubMed Central

    Hammond, Katherine L.; Whitfield, Tanya T.

    2011-01-01

    Specification of the otic anteroposterior axis is one of the earliest patterning events during inner ear development. In zebrafish, Hedgehog signalling is necessary and sufficient to specify posterior otic identity between the 10 somite (otic placode) and 20 somite (early otic vesicle) stages. We now show that Fgf signalling is both necessary and sufficient for anterior otic specification during a similar period, a function that is completely separable from its earlier role in otic placode induction. In lia–/– (fgf3–/–) mutants, anterior otic character is reduced, but not lost altogether. Blocking all Fgf signalling at 10-20 somites, however, using the pan-Fgf inhibitor SU5402, results in the loss of anterior otic structures and a mirror image duplication of posterior regions. Conversely, overexpression of fgf3 during a similar period, using a heat-shock inducible transgenic line, results in the loss of posterior otic structures and a duplication of anterior domains. These phenotypes are opposite to those observed when Hedgehog signalling is altered. Loss of both Fgf and Hedgehog function between 10 and 20 somites results in symmetrical otic vesicles with neither anterior nor posterior identity, which, nevertheless, retain defined poles at the anterior and posterior ends of the ear. These data suggest that Fgf and Hedgehog act on a symmetrical otic pre-pattern to specify anterior and posterior otic identity, respectively. Each signalling pathway has instructive activity: neither acts simply to repress activity of the other, and, together, they appear to be key players in the specification of anteroposterior asymmetries in the zebrafish ear. PMID:21831919

  18. FGF21 represses cerebrovascular aging via improving mitochondrial biogenesis and inhibiting p53 signaling pathway in an AMPK-dependent manner.

    PubMed

    Wang, Xiao-Mei; Xiao, Hang; Liu, Ling-Lin; Cheng, Dang; Li, Xue-Jun; Si, Liang-Yi

    2016-08-15

    Cerebrovascular aging has a high relationship with stroke and neurodegenerative disease. In the present study, we evaluated the influence of fibroblast growth factor 21 (FGF21) on angiotensin (Ang II)-mediated cerebrovascular aging in human brain vascular smooth muscle cells (hBVSMCs). Ang II induced remarkable aging-phenotypes in hBVSMCs, including enhanced SA-β-gal staining and NBS1 protein expression. First, we used immunoblotting assay to confirm protein expression of FGF21 receptor (FGFR1) and the co-receptor β-Klotho in cultured hBVSMCs. Second, we found that FGF21 treatment partly prevented the aging-related changes induced by Ang II. FGF21 inhibited Ang II-enhanced ROS production/superoxide anion levels, rescued the Ang II-reduced Complex IV and citrate synthase activities, and suppressed the Ang II-induced meprin protein expression. Third, we showed that FGF21 not only inhibited the Ang II-induced p53 activation, but also blocked the action of Ang II on Siah-1-TRF signaling pathway which is upstream factors for p53 activation. At last, either chemical inhibition of AMPK signaling pathway by a specific antagonist Compound C or knockdown of AMPKα1/2 isoform using siRNA, successfully abolished the anti-aging action of FGF21 in hBVSMCs. These results indicate that FGF21 protects against Ang II-induced cerebrovascular aging via improving mitochondrial biogenesis and inhibiting p53 activation in an AMPK-dependent manner, and highlight the therapeutic value of FGF21 in cerebrovascular aging-related diseases such as stroke and neurodegenerative disease. PMID:27364911

  19. bFGF-containing electrospun gelatin scaffolds with controlled nano-architectural features for directed angiogenesis.

    PubMed

    Montero, Ramon B; Vial, Ximena; Nguyen, Dat Tat; Farhand, Sepehr; Reardon, Mark; Pham, Si M; Tsechpenakis, Gavriil; Andreopoulos, Fotios M

    2012-05-01

    Current therapeutic angiogenesis strategies are focused on the development of biologically responsive scaffolds that can deliver multiple angiogenic cytokines and/or cells in ischemic regions. Herein, we report on a novel electrospinning approach to fabricate cytokine-containing nanofibrous scaffolds with tunable architecture to promote angiogenesis. Fiber diameter and uniformity were controlled by varying the concentration of the polymeric (i.e. gelatin) solution, the feed rate, needle to collector distance, and electric field potential between the collector plate and injection needle. Scaffold fiber orientation (random vs. aligned) was achieved by alternating the polarity of two parallel electrodes placed on the collector plate thus dictating fiber deposition patterns. Basic fibroblast growth factor (bFGF) was physically immobilized within the gelatin scaffolds at variable concentrations and human umbilical vein endothelial cells (HUVEC) were seeded on the top of the scaffolds. Cell proliferation and migration was assessed as a function of growth factor loading and scaffold architecture. HUVECs successfully adhered onto gelatin B scaffolds and cell proliferation was directly proportional to the loading concentrations of the growth factor (0-100 bFGF ng/mL). Fiber orientation had a pronounced effect on cell morphology and orientation. Cells were spread along the fibers of the electrospun scaffolds with the aligned orientation and developed a spindle-like morphology parallel to the scaffold's fibers. In contrast, cells seeded onto the scaffolds with random fiber orientation, did not demonstrate any directionality and appeared to have a rounder shape. Capillary formation (i.e. sprouts length and number of sprouts per bead), assessed in a 3-D in vitro angiogenesis assay, was a function of bFGF loading concentration (0 ng, 50 ng and 100 ng per scaffold) for both types of electrospun scaffolds (i.e. with aligned or random fiber orientation).

  20. SRC Homology 2 Domain Binding Sites in Insulin, IGF-1 and FGF receptor mediated signaling networks reveal an extensive potential interactome

    PubMed Central

    2012-01-01

    Specific peptide ligand recognition by modular interaction domains is essential for the fidelity of information flow through the signal transduction networks that control cell behavior in response to extrinsic and intrinsic stimuli. Src homology 2 (SH2) domains recognize distinct phosphotyrosine peptide motifs, but the specific sites that are phosphorylated and the complement of available SH2 domains varies considerably in individual cell types. Such differences are the basis for a wide range of available protein interaction microstates from which signaling can evolve in highly divergent ways. This underlying complexity suggests the need to broadly map the signaling potential of systems as a prerequisite for understanding signaling in specific cell types as well as various pathologies that involve signal transduction such as cancer, developmental defects and metabolic disorders. This report describes interactions between SH2 domains and potential binding partners that comprise initial signaling downstream of activated fibroblast growth factor (FGF), insulin (Ins), and insulin-like growth factor-1 (IGF-1) receptors. A panel of 50 SH2 domains screened against a set of 192 phosphotyrosine peptides defines an extensive potential interactome while demonstrating the selectivity of individual SH2 domains. The interactions described confirm virtually all previously reported associations while describing a large set of potential novel interactions that imply additional complexity in the signaling networks initiated from activated receptors. This study of pTyr ligand binding by SH2 domains provides valuable insight into the selectivity that underpins complex signaling networks that are assembled using modular protein interaction domains. PMID:22974441

  1. Fgf receptors Fgfr1a and Fgfr2 control the function of pharyngeal endoderm in late cranial cartilage development.

    PubMed

    Larbuisson, Arnaud; Dalcq, Julia; Martial, Joseph A; Muller, Marc

    2013-01-01

    Cranial cartilage derives mainly from cranial neural crest cells and its formation requires fibroblast growth factor (Fgf) signaling for early differentiation and survival of developing chondrocytes as well as patterning of the endodermal pouches. Here, we investigate the role of Fgf receptors in chondrocyte maturation at later stages, beyond 24 hpf. Using inducible expression of a dominant-negative Fgf receptor, we show that Fgf signaling is required around 30 hpf for correct cartilage formation. The receptor genes fgfr1a and fgr2 are expressed in pharyngeal endodermal pouches after 24 hpf or 26 hpf, respectively. Depletion of any of these two receptors by microinjection of antisense morpholinos results in severe defects in cartilage formation at 4 dpf and a decrease in expression of the late chondrocyte markers barx1 and runx2b. Although endodermal pouches are correctly formed and patterned, receptor knock down leads to decreased expression of runx3, egr1 and sox9b in this tissue, while expression of fsta, coding for a secreted BMP/Tgfß inhibitor, is clearly increased. Rescue experiments revealed that each Fgfr1a or Fgfr2 receptor is able to compensate for the loss of the other. Thus, we show that minimal amounts of Fgfr1a or Fgfr2 are required to initiate a regulatory cascade in pharyngeal endoderm reducing expression of fsta, thereby allowing correct BMP signaling to the maturing chondrocytes of the head cartilage. PMID:24176552

  2. Wnt9b-dependent FGF signaling is crucial for outgrowth of the nasal and maxillary processes during upper jaw and lip development.

    PubMed

    Jin, Yong-Ri; Han, Xiang Hua; Taketo, Makoto M; Yoon, Jeong Kyo

    2012-05-01

    Outgrowth and fusion of the lateral and medial nasal processes and of the maxillary process of the first branchial arch are integral to lip and primary palate development. Wnt9b mutations are associated with cleft lip and cleft palate in mice; however, the cause of these defects remains unknown. Here, we report that Wnt9b(-/-) mice show significantly retarded outgrowth of the nasal and maxillary processes due to reduced proliferation of mesenchymal cells, which subsequently results in a failure of physical contact between the facial processes that leads to cleft lip and cleft palate. These cellular defects in Wnt9b(-/-) mice are mainly caused by reduced FGF family gene expression and FGF signaling activity resulting from compromised canonical WNT/β-catenin signaling. Our study has identified a previously unknown regulatory link between WNT9B and FGF signaling during lip and upper jaw development.

  3. FGF2 activates TRPC and Ca(2+) signaling leading to satellite cell activation.

    PubMed

    Liu, Yewei; Schneider, Martin F

    2014-01-01

    Satellite cells, as stem cells of adult skeletal muscle, are tightly associated with the differentiated muscle fibers and remain quiescent in the absence of muscle damage. In response to an injury, the quiescent satellite cell is activated by soluble factors, including FGFs released from injured myofibers. Using immunostaining, we here first show that TRPC1 channels are highly expressed in satellite cells attached to muscle fibers. Since CD34, a traditional stem cell marker, was recently found to be expressed in skeletal muscle satellite cells we labeled living satellite cells in their physiological niche associated with host FDB fibers using anti-CD34-FITC antibody. We then monitored intra-cellular calcium in anti-CD34-FITC labeled satellite cells attached to muscle fibers using the calcium sensitive dye X rhod-1 which has little fluorescence cross talk with FITC. FGF2 increased intracellular calcium in satellite cells, which was antagonized by the TRPC channel blocker SKF 96365. Immunostaining showed that NFATc3 is highly expressed in satellite cells, but not in host FDB fibers. Elevation of intracellular calcium by FGF2 is accompanied by nuclear translocation of NFATc3 and NFATc2 and by an increase in the number of MyoD positive cells per muscle fiber, both of which were attenuated by TRPC blocker SKF 96365. Our results suggest a novel pathway of satellite cell activation where FGF2 enhances calcium influx through a TRPC channel, and the increased cytosolic calcium leads to both NFATc3 and NFATc2 nuclear translocation and enhanced number of MyoD positive satellite cells per muscle fiber.

  4. Genetic analysis of the roles of Hh, FGF8, and nodal signaling during catecholaminergic system development in the zebrafish brain.

    PubMed

    Holzschuh, Jochen; Hauptmann, Giselbert; Driever, Wolfgang

    2003-07-01

    CNS catecholaminergic neurons can be distinguished by their neurotransmitters as dopaminergic or noradrenergic and form in distinct regions at characteristic embryonic stages. This raises the question of whether all catecholaminergic neurons of one transmitter type are specified by the same set of factors. Therefore, we performed genetic analyses to define signaling requirements for the specification of distinct clusters of catecholaminergic neurons in zebrafish. In mutants affecting midbrain- hindbrain boundary (MHB) organizer formation, the earliest ventral diencephalic dopaminergic neurons appear normal. However, after 2 d of development, we observed fewer cells than in wild types, which suggests that the MHB provides proliferation or survival factors rather than specifying ventral diencephalic dopaminergic clusters. In hedgehog (Hh) pathway mutants, the formation of catecholaminergic neurons is affected only in the pretectal cluster. Surprisingly, neither fibroblast growth factor 8 (FGF8) alone nor in combination with Hh signaling is required for specification of early developing dopaminergic neurons. We analyzed the formation of prosomeric territories in the forebrain of Hh and Nodal pathway mutants to determine whether the absence of specific dopaminergic clusters may be caused by early patterning defects ablating corresponding parts of the CNS. In Nodal pathway mutants, ventral diencephalic and pretectal catecholaminergic neurons fail to develop, whereas both anatomical structures form at least in part. This suggests that Nodal signaling is required for catecholaminergic neuron specification. In summary, our results do not support the previously suggested dominant roles for sonic hedgehog and Fgf8 in specification of the first catecholaminergic neurons, but instead indicate a novel role for Nodal signaling in this process. PMID:12843251

  5. Soluble FGFR4 extracellular domain inhibits FGF19-induced activation of FGFR4 signaling and prevents nonalcoholic fatty liver disease

    SciTech Connect

    Chen, Qiang; Jiang, Yuan; An, Yuan; Zhao, Na; Zhao, Yang; Yu, Chundong

    2011-06-17

    Highlights: {yields} Soluble FGFR4 extracellular domain (FGFR4-ECD) was effectively expressed. {yields} FGFR4-ECD inhibited FGF19-induced activation of FGFR4 signaling. {yields} FGFR4-ECD reduced palmitic acid-induced steatosis of HepG2 cells. {yields} FGFR4-ECD reduced tetracycline-induced fatty liver in mice. {yields} FGFR4-ECD partially restored tetracycline-repressed PPAR{alpha} expression. -- Abstract: Fibroblast growth factor receptor 4 (FGFR4) is a transmembrane tyrosine kinase receptor that plays a crucial role in the regulation of hepatic bile acid and lipid metabolism. FGFR4 underlies high-fat diet-induced hepatic steatosis, suggesting that inhibition of FGFR4 activation may be an effective way to prevent or treat nonalcoholic fatty liver disease (NAFLD). To determine whether neutralization of FGFR4 ligands by soluble FGFR4 extracellular domain (FGFR4-ECD) can inhibit the activation of FGFR4, we constructed FGFR4-ECD expression vector and showed that FGFR4-ECD was effectively expressed in cells and secreted into culture medium. FGFR4-ECD inhibited FGF19-induced activation of FGFR4 signaling and reduced steatosis of HepG2 induced by palmitic acid in vitro. Furthermore, in a tetracycline-induced fatty liver model, expression of FGFR4-ECD in mouse liver reduced the accumulation of hepatic lipids and partially restored the expression of peroxisome proliferator-activated receptor {alpha} (PPAR{alpha}), which promotes the mitochondrial fatty acid beta-oxidation but is repressed by tetracycline. Taken together, these results demonstrate that FGFR4-ECD can block FGFR4 signaling and prevent hepatic steatosis, highlighting the potential value of inhibition of FGFR4 signaling as a method for therapeutic intervention against NAFLD.

  6. Hedgehog and Fgf Signaling Pathways Regulate the Development of tphR-Expressing Serotonergic Raphe Neurons in Zebrafish Embryos

    PubMed Central

    Teraoka, H.; Russell, C.; Regan, J.; Chandrasekhar, A.; Concha, M. L.; Yokoyama, R.; Higashi, K.; Take-uchi, M.; Dong, W.; Hiraga, T.; Holder, N.; Wilson, S. W.

    2009-01-01

    Serotonin (5HT) plays major roles in the physiological regulation of many behavioral processes, including sleep, feeding, and mood, but the genetic mechanisms by which serotonergic neurons arise during development are poorly understood. In the present study, we have investigated the development of serotonergic neurons in the zebrafish. Neurons exhibiting 5HT-immunoreactivity (5HT-IR) are detected from 45 h postfertilization (hpf) in the ventral hindbrain raphe, the hypothalamus, pineal organ, and pretectal area. Tryptophan hydroxylases encode rate-limiting enzymes that function in the synthesis of 5HT. As part of this study, we cloned and analyzed a novel zebrafish tph gene named tphR. Unlike two other zebrafish tph genes (tphD1 and tphD2), tphR is expressed in serotonergic raphe neurons, similar to tph genes in mammalian species. tphR is also expressed in the pineal organ where it is likely to be involved in the pathway leading to synthesis of melatonin. To better understand the signaling pathways involved in the induction of the serotonergic phenotype, we analyzed tphR expression and 5HT-IR in embryos in which either Hh or Fgf signals are abrogated. Hindbrain 5HT neurons are severely reduced in mutants lacking activity of either Ace/Fgf8 or the transcription factor Noi/Pax2.1, which regulates expression of ace/fgf8, and probably other genes encoding signaling proteins. Similarly, serotonergic raphe neurons are absent in embryos lacking Hh activity confirming a conserved role for Hh signals in the induction of these cells. Conversely, over-activation of the Hh pathway increases the number of serotonergic neurons. As in mammals, our results are consistent with the transcription factors Nk2.2 and Gata3 acting downstream of Hh activity in the development of serotonergic raphe neurons. Our results show that the pathways involved in induction of hindbrain serotonergic neurons are likely to be conserved in all vertebrates and help establish the zebrafish as a model

  7. Regional effects of endocannabinoid, BDNF and FGF receptor signalling on neuroblast motility and guidance along the rostral migratory stream.

    PubMed

    Zhou, Ya; Oudin, Madeleine J; Gajendra, Sangeetha; Sonego, Martina; Falenta, Katarzyna; Williams, Gareth; Lalli, Giovanna; Doherty, Patrick

    2015-01-01

    During development and after birth neural stem cells in the subventricular zone (SVZ) generate neuroblasts that migrate along the rostral migratory stream (RMS) to populate the olfactory bulb (OB) with neurons. Multiple factors promote neuroblast migration, but the contribution that many of these make to guidance within the intact RMS is not known. In the present study we have characterised in detail how endocannabinoid (eCB), BDNF and FGF receptor (FGFR) signalling regulates motility and guidance, and also determined whether any of these receptors operate in a regionally restricted manner. We used in vivo electroporation in postnatal mice to fluorescently label neuroblasts, and live cell imaging to detail their migratory properties. Cannabinoid receptor antagonists rendered neuroblasts less mobile, and when they did move guidance was lost. Similar results were obtained when eCB synthesis was blocked with diacylglycerol lipase (DAGL) inhibitors, and importantly eCB function is required for directed migration at both ends of the RMS. Likewise, inhibition of BDNF signalling disrupted motility and guidance in a similar manner along the entire RMS. In contrast, altering FGFR signalling inhibits motility and perturbs guidance, but only at the beginning of the stream. Inhibition of FGFR signalling in vivo also reduces the length of the leading process on migratory neuroblasts in a graded manner along the RMS. These results provide evidence for a guidance function for all three of the above receptor systems in the intact RMS, but show that FGFR signalling is unique as it is required in a regionally specific manner.

  8. FGF21 ameliorates the neurocontrol of blood pressure in the high fructose-drinking rats.

    PubMed

    He, Jian-Li; Zhao, Miao; Xia, Jing-Jun; Guan, Jian; Liu, Yang; Wang, Lu-Qi; Song, Dong-Xue; Qu, Mei-Yu; Zuo, Meng; Wen, Xin; Yu, Xue; Huo, Rong; Pan, Zhen-Wei; Ban, Tao; Zhang, Yan; Zhu, Jiu-Xin; Shou, Weinian; Qiao, Guo-Fen; Li, Bai-Yan

    2016-01-01

    Fibroblast growth factor-21 (FGF21) is closely related to various metabolic and cardiovascular disorders. However, the direct targets and mechanisms linking FGF21 to blood pressure control and hypertension are still elusive. Here we demonstrated a novel regulatory function of FGF21 in the baroreflex afferent pathway (the nucleus tractus solitarii, NTS; nodose ganglion, NG). As the critical co-receptor of FGF21, β-klotho (klb) significantly expressed on the NTS and NG. Furthermore, we evaluated the beneficial effects of chronic intraperitoneal infusion of recombinant human FGF21 (rhFGF21) on the dysregulated systolic blood pressure, cardiac parameters, baroreflex sensitivity (BRS) and hyperinsulinemia in the high fructose-drinking (HFD) rats. The BRS up-regulation is associated with Akt-eNOS-NO signaling activation in the NTS and NG induced by acute intravenous rhFGF21 administration in HFD and control rats. Moreover, the expressions of FGF21 receptors were aberrantly down-regulated in HFD rats. In addition, the up-regulated peroxisome proliferator-activated receptor-γ and -α (PPAR-γ/-α) in the NTS and NG in HFD rats were markedly reversed by chronic rhFGF21 infusion. Our study extends the work of the FGF21 actions on the neurocontrol of blood pressure regulations through baroreflex afferent pathway in HFD rats. PMID:27387420

  9. FGF21 ameliorates the neurocontrol of blood pressure in the high fructose-drinking rats

    PubMed Central

    He, Jian-Li; Zhao, Miao; Xia, Jing-Jun; Guan, Jian; Liu, Yang; Wang, Lu-Qi; Song, Dong-Xue; Qu, Mei-Yu; Zuo, Meng; Wen, Xin; Yu, Xue; Huo, Rong; Pan, Zhen-Wei; Ban, Tao; Zhang, Yan; Zhu, Jiu-Xin; Shou, Weinian; Qiao, Guo-Fen; Li, Bai-Yan

    2016-01-01

    Fibroblast growth factor-21 (FGF21) is closely related to various metabolic and cardiovascular disorders. However, the direct targets and mechanisms linking FGF21 to blood pressure control and hypertension are still elusive. Here we demonstrated a novel regulatory function of FGF21 in the baroreflex afferent pathway (the nucleus tractus solitarii, NTS; nodose ganglion, NG). As the critical co-receptor of FGF21, β-klotho (klb) significantly expressed on the NTS and NG. Furthermore, we evaluated the beneficial effects of chronic intraperitoneal infusion of recombinant human FGF21 (rhFGF21) on the dysregulated systolic blood pressure, cardiac parameters, baroreflex sensitivity (BRS) and hyperinsulinemia in the high fructose-drinking (HFD) rats. The BRS up-regulation is associated with Akt-eNOS-NO signaling activation in the NTS and NG induced by acute intravenous rhFGF21 administration in HFD and control rats. Moreover, the expressions of FGF21 receptors were aberrantly down-regulated in HFD rats. In addition, the up-regulated peroxisome proliferator-activated receptor-γ and -α (PPAR-γ/-α) in the NTS and NG in HFD rats were markedly reversed by chronic rhFGF21 infusion. Our study extends the work of the FGF21 actions on the neurocontrol of blood pressure regulations through baroreflex afferent pathway in HFD rats. PMID:27387420

  10. FGF23 is elevated in multiple myeloma and increases heparanase expression by tumor cells

    PubMed Central

    Suvannasankha, Attaya; Tompkins, Douglas R.; Edwards, Daniel F.; Petyaykina, Katarina V.; Crean, Colin D.; Fournier, Pierrick G.; Parker, Jamie M.; Sandusky, George E.; Ichikawa, Shoji; Imel, Erik A.; Chirgwin, John M.

    2015-01-01

    Multiply myeloma (MM) grows in and destroys bone, where osteocytes secrete FGF23, a hormone which affects phosphate homeostasis and aging. We report that multiple myeloma (MM) cells express receptors for and respond to FGF23. FGF23 increased mRNA for EGR1 and its target heparanase, a pro-osteolytic factor in MM. FGF23 signals through a complex of klotho and a classical FGF receptor (FGFR); both were expressed by MM cell lines and patient samples. Bone marrow plasma cells from 42 MM patients stained positively for klotho, while plasma cells from 8 patients with monoclonal gammopathy of undetermined significance (MGUS) and 6 controls were negative. Intact, active FGF23 was increased 2.9X in sera of MM patients compared to controls. FGF23 was not expressed by human MM cells, but co-culture with mouse bone increased its mRNA. The FGFR inhibitor NVP-BGJ398 blocked the heparanase response to FGF23. NVP-BGJ398 did not inhibit 8226 growth in vitro but significantly suppressed growth in bone and induction of the osteoclast regulator RANK ligand, while decreasing heparanase mRNA. The bone microenvironment provides resistance to some anti-tumor drugs but increased the activity of NVP-BGJ398 against 8226 cells. The FGF23/klotho/heparanase signaling axis may offer targets for treatment of MM in bone. PMID:25944690

  11. Muscle mitochondrial stress adaptation operates independently of endogenous FGF21 action

    PubMed Central

    Ost, Mario; Coleman, Verena; Voigt, Anja; van Schothorst, Evert M.; Keipert, Susanne; van der Stelt, Inge; Ringel, Sebastian; Graja, Antonia; Ambrosi, Thomas; Kipp, Anna P.; Jastroch, Martin; Schulz, Tim J.; Keijer, Jaap; Klaus, Susanne

    2015-01-01

    Objective Fibroblast growth factor 21 (FGF21) was recently discovered as stress-induced myokine during mitochondrial disease and proposed as key metabolic mediator of the integrated stress response (ISR) presumably causing systemic metabolic improvements. Curiously, the precise cell-non-autonomous and cell-autonomous relevance of endogenous FGF21 action remained poorly understood. Methods We made use of the established UCP1 transgenic (TG) mouse, a model of metabolic perturbations made by a specific decrease in muscle mitochondrial efficiency through increased respiratory uncoupling and robust metabolic adaptation and muscle ISR-driven FGF21 induction. In a cross of TG with Fgf21-knockout (FGF21−/−) mice, we determined the functional role of FGF21 as a muscle stress-induced myokine under low and high fat feeding conditions. Results Here we uncovered that FGF21 signaling is dispensable for metabolic improvements evoked by compromised mitochondrial function in skeletal muscle. Strikingly, genetic ablation of FGF21 fully counteracted the cell-non-autonomous metabolic remodeling and browning of subcutaneous white adipose tissue (WAT), together with the reduction of circulating triglycerides and cholesterol. Brown adipose tissue activity was similar in all groups. Remarkably, we found that FGF21 played a negligible role in muscle mitochondrial stress-related improved obesity resistance, glycemic control and hepatic lipid homeostasis. Furthermore, the protective cell-autonomous muscle mitohormesis and metabolic stress adaptation, including an increased muscle proteostasis via mitochondrial unfolded protein response (UPRmt) and amino acid biosynthetic pathways did not require the presence of FGF21. Conclusions Here we demonstrate that although FGF21 drives WAT remodeling, the adaptive pseudo-starvation response under elevated muscle mitochondrial stress conditions operates independently of both WAT browning and FGF21 action. Thus, our findings challenge FGF21 as key

  12. Retrograde fibroblast growth factor 22 (FGF22) signaling regulates insulin-like growth factor 2 (IGF2) expression for activity-dependent synapse stabilization in the mammalian brain

    PubMed Central

    Terauchi, Akiko; Johnson-Venkatesh, Erin M; Bullock, Brenna; Lehtinen, Maria K; Umemori, Hisashi

    2016-01-01

    Communication between pre- and postsynaptic cells promotes the initial organization of synaptic specializations, but subsequent synaptic stabilization requires transcriptional regulation. Here we show that fibroblast growth factor 22 (FGF22), a target-derived presynaptic organizer in the mouse hippocampus, induces the expression of insulin-like growth factor 2 (IGF2) for the stabilization of presynaptic terminals. FGF22 is released from CA3 pyramidal neurons and organizes the differentiation of excitatory nerve terminals formed onto them. Local application of FGF22 on the axons of dentate granule cells (DGCs), which are presynaptic to CA3 pyramidal neurons, induces IGF2 in the DGCs. IGF2, in turn, localizes to DGC presynaptic terminals and stabilizes them in an activity-dependent manner. IGF2 application rescues presynaptic defects of Fgf22-/- cultures. IGF2 is dispensable for the initial presynaptic differentiation, but is required for the following presynaptic stabilization both in vitro and in vivo. These results reveal a novel feedback signal that is critical for the activity-dependent stabilization of presynaptic terminals in the mammalian hippocampus. DOI: http://dx.doi.org/10.7554/eLife.12151.001 PMID:27083047

  13. The Role of bFGF in the Excessive Activation of Astrocytes Is Related to the Inhibition of TLR4/NFκB Signals

    PubMed Central

    Ye, Libing; Yang, Ying; Zhang, Xie; Cai, Pingtao; Li, Rui; Chen, Daqing; Wei, Xiaojie; Zhang, Xuesong; Xu, Huazi; Xiao, Jian; Li, Xiaokun; Lin, Li; Zhang, Hongyu

    2015-01-01

    Astrocytes have critical roles in immune defense, homeostasis, metabolism, and synaptic remodeling and function in the central nervous system (CNS); however, excessive activation of astrocytes with increased intermediate filaments following neuronal trauma, infection, ischemia, stroke, and neurodegenerative diseases results in a pro-inflammatory environment and promotes neuronal death. As an important neurotrophic factor, the secretion of endogenous basic fibroblast growth factor (bFGF) contributes to the protective effect of neuronal cells, but the mechanism of bFGF in reactive astrogliosis is still unclear. In this study, we demonstrated that exogenous bFGF attenuated astrocyte activation by reducing the expression of glial fibrillary acidic protein (GFAP) and other markers, including neurocan and vimentin, but not nestin and decreased the levels of pro-inflammatory cytokines, such as interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), via the regulation of the upstream toll-like receptor 4/nuclear factor κB (TLR4/NFκB) signaling pathway. Our study suggests that the function of bFGF is not only related to the neuroprotective and neurotrophic effect but also involved in the inhibition of excessive astrogliosis and glial scarring after neuronal injury. PMID:26729092

  14. Retinoic Acid Controls Expression of Tissue Remodeling Genes Hmgn1 and Fgf18 at the Digit-Interdigit Junction

    PubMed Central

    Zhao, Xianling; Brade, Thomas; Cunningham, Thomas J.; Duester, Gregg

    2009-01-01

    Previous studies on retinoic acid receptor (RAR) mutants suggested that retinoic acid (RA) is required for loss of interdigital mesenchyme during digit formation. Here, we report that the RA-generating enzyme retinaldehyde dehydrogenase-2 (Raldh2) is expressed in the interdigital mesenchyme whereas Cyp26b1, controlling RA degradation, is expressed in digits, limiting autopodal RA action to the interdigital zones. E13.5 Raldh2−/− mouse embryos lose expression of the RARE-lacZ RA-reporter transgene and matrix metalloproteinase-11 (Mmp11) throughout the interdigital mesenchyme, while expression of RARb, Fgf18, and high mobility group N1 (Hmgn1) is lost at the digit-interdigit junction. Raldh2−/− autopods exhibit reduced interdigital apoptosis associated with loss of Bmp7 expression, but Bmp2, Bmp4, Msx2, and Fgf8 were unaffected. Although interdigital expression of Hmgn1 was greatly down-regulated in Raldh2−/− autopods, complementary expression of Sox9 in digit cartilage was unaffected. Regulation of Hmgn1 and Fgf18 at the digit-interdigit junction suggests RA controls tissue remodeling as well as apoptosis. PMID:20034106

  15. Modulation of Fgf8 activity during vertebrate brain development.

    PubMed

    Echevarria, Diego; Belo, Jose Antonio; Martinez, Salvador

    2005-09-01

    In recent years much emphasis has been placed on investigation of the precise control of FGF signaling during brain development. Such control is achieved in part by regulatory elements that determine the domains and levels of expression of genes coding for the diverse FGF ligands via specific molecular signaling pathways. There is new knowledge on the operation of such mechanisms in regions of the neural tube involved in the correct patterning of adjacent territories (known as secondary organizers of neural tube pattern). In the present minireview we intend to summarize recent evidence and emerging conclusions on potent modulators that govern the activity of Fgf8 signals in the developing vertebrate brain, focusing our attention on the best known secondary organizer, the isthmic organizer.

  16. Neural progenitor cell survival in mouse brain can be improved by co-transplantation of helper cells expressing bFGF under doxycycline control.

    PubMed

    Liang, Yajie; Ågren, Louise; Lyczek, Agatha; Walczak, Piotr; Bulte, Jeff W M

    2013-09-01

    Cell-based therapy of neurological disorders is hampered by poor survival of grafted neural progenitor cells (NPCs). We hypothesized that it is possible to enhance the survival of human NPCs (ReNcells) by co-transplantation of helper cells expressing basic fibroblast growth factor (bFGF) under control of doxycycline (Dox). 293 cells or C17.2 cells were transduced with a lentiviral vector encoding the fluorescent reporter mCherry and bFGF under tetracycline-regulated transgene expression (Tet-ON). The bFGF secretion level in the engineered helper cells was positively correlated with the dose of Dox (Pearson correlation test; r=0.95 and 0.99 for 293 and C17.2 cells, respectively). Using bioluminescence imaging (BLI) as readout for firefly luciferase-transduced NPC survival, the addition of both 293-bFGF and C17.2-bFGF helper cells was found to significantly improve cell survival up to 6-fold in vitro, while wild-type (WT, non-transduced) helper cells had no effect. Following co-transplantation of 293-bFGF or C17.2-bFGF cells in the striatum of Rag2(-/-) immunodeficient mice, in vivo human NPC survival could be significantly improved as compared to no helper cells or co-transplantation of WT cells for the first two days after co-transplantation. This enhancement of survival in C17.2-bFGF group was not achieved without Dox administration, indicating that the neuroprotective effect was specific for bFGF. The present results warrant further studies on the use of engineered helper cells, including those expressing other growth factors injected as mixed cell populations.

  17. Mapping the response of human fibroblast growth factor 21 (FGF21) promoter to serum availability and lipoic acid in HepG2 hepatoma cells.

    PubMed

    Xia, Mengna; Erickson, Anjeza; Yi, Xiaohua; Moreau, Régis

    2016-03-01

    The hormone-like polypeptide, fibroblast growth factor 21 (FGF21), is a major modulator of lipid and glucose metabolism and an exploratory treatment strategy for obesity related metabolic disorders. The costs of recombinant FGF21 and mode of delivery by injection are important constraints to its wide therapeutic use. The stimulation of endogenous FGF21 production through diet is being explored as an alternative approach. To that end, we examined the mechanism(s) by which serum manipulation and lipoic acid (a dietary activator of FGF21) induce FGF21 in human hepatocellular carcinoma HepG2 cells. Serum withdrawal markedly induced FGF21 mRNA levels (88 fold) and FGF21 secreted in the media (19 fold). Lipoic acid induced FGF21 mRNA 7 fold above DMSO-treated control cells and FGF21 secretion 3 fold. These effects were several-fold greater than those of PPARα agonist, Wy14643, which failed to induce FGF21 above and beyond the induction seen with serum withdrawal. The use of transcription inhibitor, actinomycin D, revealed that de novo mRNA synthesis drives FGF21 secretion in response to serum starvation. Four previously unrecognized loci in FGF21 promoter were nucleosome depleted and enriched in acetylated histone H3 revealing their role as transcriptional enhancers and putative transcription factor binding sites. FGF21 did not accumulate to a significant degree in induced HepG2 cells, which secreted FGF21 time dependently in media. We conclude that lipoic acid cell signaling connects with the transcriptional upregulation of FGF21 and it may prove to be a safe and affordable means to stimulate FGF21 production. PMID:26691139

  18. Region-specific regulation of cell proliferation by FGF receptor signaling during the Wolffian duct development

    PubMed Central

    Okazawa, Mika; Murashima, Aki; Harada, Masayo; Nakagata, Naomi; Noguchi, Masafumi; Morimoto, Mitsuru; Kimura, Tadashi; Ornitz, David M.; Yamada, Gen

    2015-01-01

    The Wolffian duct (WD) is a primordium of the male reproductive tract and kidney collecting duct system. Fibroblast growth factor receptors (FGFRs), members of the receptor tyrosine kinase (RTK) family, are essential for kidney development. Although the functions of FGFR signaling in kidney morphogenesis have been analyzed, their function in WD development has not been comprehensively investigated. Here, we demonstrate that Fgfr2 is the major Fgfr gene expressed throughout the WD epithelia and that it is essential for the maintenance of the WD, specifically in the caudal part of the WD. Hoxb7-Cre mediated inactivation of Fgfr2 in the mouse WD epithelia resulted in the regression of the caudal part of the WD and abnormal male reproductive tract development. Cell proliferation and expression of the downstream target genes of RTK signaling (Etv4 and Etv5) were decreased in the caudal part of the WD epithelia in the mutant embryos. Cranial (rostral) WD formation and ureteric budding were not affected. Ret, Etv4, and Etv5 expression were sustained in the ureteric bud of the mutant embryos. Taken together, these data suggest region-specific requirements for FGFR2 signaling in the developing caudal WD epithelia. PMID:25678108

  19. Nuclear receptor corepressors Ncor1 and Ncor2 (Smrt) are required for retinoic acid-dependent repression of Fgf8 during somitogenesis.

    PubMed

    Kumar, Sandeep; Cunningham, Thomas J; Duester, Gregg

    2016-10-01

    Retinoic acid (RA) repression of Fgf8 is required for many different aspects of organogenesis, however relatively little is known about how endogenous RA controls gene repression as opposed to gene activation. Here, we show that nuclear receptor corepressors NCOR1 and NCOR2 (SMRT) redundantly mediate the ability of RA to repress Fgf8. Ncor1;Ncor2 double mutants generated by CRISPR/Cas9 gene editing exhibited a small somite and distended heart phenotype similar to that of RA-deficient Raldh2-/- embryos, associated with increased Fgf8 expression and FGF signaling in caudal progenitors and heart progenitors. Embryo chromatin immunoprecipitation studies revealed that NCOR1/2 but not coactivators are recruited to the Fgf8 RA response element (RARE) in an RA-dependent manner, whereas coactivators but not NCOR1/2 are recruited RA-dependently to a RARE near Rarb that is activated by RA. CRISPR/Cas9-mediated genomic deletion of the Fgf8 RARE in mouse embryos often resulted in a small somite defect with Fgf8 derepression caudally, but no defect was observed in heart development or heart Fgf8 expression. This suggests the existence of another DNA element whose function overlaps with the Fgf8 RARE to mediate Fgf8 repression by RA and NCOR1/2. Our studies support a model in which NCOR1/2 mediates direct RA-dependent repression of Fgf8 in caudal progenitors in order to control somitogenesis.

  20. Fundamentals of FGF19 & FGF21 action in vitro and in vivo.

    PubMed

    Adams, Andrew C; Coskun, Tamer; Rovira, Armando R Irizarry; Schneider, Michael A; Raches, David W; Micanovic, Radmila; Bina, Holly A; Dunbar, James D; Kharitonenkov, Alexei

    2012-01-01

    Fibroblast growth factors 19 (FGF19) and 21 (FGF21) have emerged as key regulators of energy metabolism. Several studies have been conducted to understand the mechanism of FGF19 and FGF21 action, however, the data presented has often been inconsistent and at times contradictory. Here in a single study we compare the mechanisms mediating FGF19/FGF21 actions, and how similarities/differences in actions at the cellular level between these two factors translate to common/divergent physiological outputs. Firstly, we show that in cell culture FGF19/FGF21 are very similar, however, key differences are still observed differentiating the two. In vitro we found that both FGF's activate FGFRs in the context of βKlotho (KLB) expression. Furthermore, both factors alter ERK phosphorylation and glucose uptake with comparable potency. Combination treatment of cells with both factors did not have additive effects and treatment with a competitive inhibitor, the FGF21 delta N17 mutant, also blocked FGF19's effects, suggestive of a shared receptor activation mechanism. The key differences between FGF21/FGF19 were noted at the receptor interaction level, specifically the unique ability of FGF19 to bind/signal directly via FGFR4. To determine if differential effects on energy homeostasis and hepatic mitogenicity exist we treated DIO and ob/ob mice with FGF19/FGF21. We find comparable efficacy of the two proteins to correct body weight and serum glucose in both DIO and ob/ob mice. Nevertheless, FGF21 and FGF19 had distinctly different effects on proliferation in the liver. Interestingly, in vivo blockade of FGF21 signaling in mice using ΔN17 caused profound changes in glycemia indicative of the critical role KLB and FGF21 play in the regulation of glucose homeostasis. Overall, our data demonstrate that while subtle differences exist in vitro the metabolic effects in vivo of FGF19/FGF21 are indistinguishable, supporting a shared mechanism of action for these two hormones in the

  1. Antagonistic signals between BMP4 and FGF8 define the expression of Pitx1 and Pitx2 in mouse tooth-forming anlage.

    PubMed

    St Amand, T R; Zhang, Y; Semina, E V; Zhao, X; Hu, Y; Nguyen, L; Murray, J C; Chen, Y

    2000-01-15

    Members of the Pitx/RIEG family of homeodomain-containing transcription factors have been implicated in vertebrate organogenesis. In this study, we examined the expression and regulation of Pitx1 and Pitx2 during mouse tooth development. Pitx1 expression is detected in early development in a widespread pattern, in both epithelium and mesenchyme, covering the tooth-forming region in the mandible, and is then maintained in the dental epithelium from the bud stage to the late bell stage. Pitx2 expression, on the other hand, is restricted to the dental epithelium throughout odontogenesis. Interestingly, from E9.5 to E10.5, the expression domains of Pitx1 and Pitx2, in the developing mandible, overlap with that of Fgf8 but are exclusive to the zone of Bmp4 expression. Bead implantation experiments demonstrate that ectopic expression of Fgf8 can induce/maintain the expression of both Pitx1 and Pitx2 at E9.5. In contrast, Bmp4-expressing tissues and BMP4-soaked beads were able to repress Pitx1 expression in mandibular mesenchyme and Pitx2 expression in the presumptive dental epithelium, respectively. However, the effects of FGF8 and BMP4 are transient. It thus appears that the early expression patterns of Pitx1 and Pitx2 in the developing mandible are regulated by the antagonistic effects of FGF8 and BMP4 such that the Pitx1 and Pitx2 expression patterns are defined. These results indicate that the epithelial-derived signaling molecules are responsible not only for restricting specific gene expression in the dental mesenchyme, but also for defining gene expression in the dental epithelium.

  2. ERK1/2 signaling is essential for the chemoattraction exerted by human FGF2 and human anosmin-1 on newborn rat and mouse OPCs via FGFR1.

    PubMed

    Murcia-Belmonte, Verónica; Medina-Rodríguez, Eva M; Bribián, Ana; de Castro, Fernando; Esteban, Pedro F

    2014-03-01

    Signaling through fibroblast growth factor receptors (FGFRs) is essential for many cellular processes including proliferation and migration, as well as differentiation events such as myelination. Anosmin-1 is an extracellular matrix (ECM) glycoprotein that interacts with the fibroblast growth factor receptor 1 (FGFR1) to exert its biological actions through this receptor, although the intracellular pathways underlying anosmin-1 signaling remain largely unknown. This protein is defective in the X-linked form of Kallmann syndrome (KS) and has a prominent role in the migration of neuronal and oligodendroglial precursors. We have shown that anosmin-1 exerts a chemotactic effect via FGFR1 on neuronal precursors from the subventricular zone (SVZ) and the essential role of the ERK1/2 signaling. We report here the positive chemotactic effect of FGF2 and anosmin-1 on rat and mouse postnatal OPCs via FGFR1. The same effect was observed with the truncated N-terminal region of anosmin-1 (A1Nt). The introduction in anosmin-1 of the missense mutation F517L found in patients suffering from KS annulled the chemotactic activity; however, the mutant form carrying the disease-causing mutation E514K also found in KS patients, behaved as the wild-type protein. The chemoattraction exhibited by FGF2 and anosmin-1 on OPCs was blocked by the mitogen-activated protein kinase (MAPK) inhibitor U0126, suggesting that the activation of the ERK1/2 MAPK signaling pathway following interaction with the FGFR1 is necessary for FGF2 and anosmin-1 to exert their chemotactic effect. In fact, both proteins were able to induce the phosphorylation of the ERK1/2 kinases after the activation of the FGFR1 receptor.

  3. Fibroblast growth factor signalling in multiple sclerosis: inhibition of myelination and induction of pro-inflammatory environment by FGF9.

    PubMed

    Lindner, Maren; Thümmler, Katja; Arthur, Ariel; Brunner, Sarah; Elliott, Christina; McElroy, Daniel; Mohan, Hema; Williams, Anna; Edgar, Julia M; Schuh, Cornelia; Stadelmann, Christine; Barnett, Susan C; Lassmann, Hans; Mücklisch, Steve; Mudaliar, Manikhandan; Schaeren-Wiemers, Nicole; Meinl, Edgar; Linington, Christopher

    2015-07-01

    Remyelination failure plays an important role in the pathophysiology of multiple sclerosis, but the underlying cellular and molecular mechanisms remain poorly understood. We now report actively demyelinating lesions in patients with multiple sclerosis are associated with increased glial expression of fibroblast growth factor 9 (FGF9), which we demonstrate inhibits myelination and remyelination in vitro. This inhibitory activity is associated with the appearance of multi-branched 'pre-myelinating' MBP+ / PLP+ oligodendrocytes that interact with axons but fail to assemble myelin sheaths; an oligodendrocyte phenotype described previously in chronically demyelinated multiple sclerosis lesions. This inhibitory activity is not due to a direct effect of FGF9 on cells of the oligodendrocyte lineage but is mediated by factors secreted by astrocytes. Transcriptional profiling and functional validation studies demonstrate that these include effects dependent on increased expression of tissue inhibitor of metalloproteinase-sensitive proteases, enzymes more commonly associated with extracellular matrix remodelling. Further, we found that FGF9 induces expression of Ccl2 and Ccl7, two pro-inflammatory chemokines that contribute to recruitment of microglia and macrophages into multiple sclerosis lesions. These data indicate glial expression of FGF9 can initiate a complex astrocyte-dependent response that contributes to two distinct pathogenic pathways involved in the development of multiple sclerosis lesions. Namely, induction of a pro-inflammatory environment and failure of remyelination; a combination of effects predicted to exacerbate axonal injury and loss in patients.

  4. Mesendodermal signals required for otic induction: Bmp-antagonists cooperate with Fgf and can facilitate formation of ectopic otic tissue

    PubMed Central

    Kwon, Hye-Joo; Riley, Bruce B.

    2010-01-01

    Induction of otic placodes requires Fgf from surrounding tissues. We tested the hypothesis that mesendodermally derived Bmp-antagonists Chordin, Follistatin-a and Crossveinless-2 cooperate in this process. Injecting morpholinos for all three genes, or treatment with the Nodal inhibitor SB431542 to block mesoderm-formation, reduces otic induction and strongly enhances the effects of disrupting fgf3 or fgf8. In contrast, using a lower dose of SB431542, combined with partial loss of Fgf, causes a dramatic medial expansion of otic tissue and formation of a single, large otic vesicle spanning the width of the hindbrain. Under these conditions, paraxial cephalic mesoderm forms ectopically at the midline, migrates into the head and later transfates to form otic tissue beneath the hindbrain. Blocking expression of Bmp-antagonists blocks formation of medial otic tissue. These data show the importance of mesendodermal Bmp-antagonists for otic induction and that paraxial cephalic mesendoderm can facilitate its own otic differentiation under certain circumstances. PMID:19418450

  5. Sprouty2 controls proliferation of palate mesenchymal cells via fibroblast growth factor signaling

    SciTech Connect

    Matsumura, Kaori; Taketomi, Takaharu; Yoshizaki, Keigo; Arai, Shinsaku; Sanui, Terukazu; Yoshiga, Daigo; Yoshimura, Akihiko; Nakamura, Seiji

    2011-01-28

    Research highlights: {yields} Sprouty2-deficient mice exhibit cleft palate as a result of failure of palatal shelf elevation. {yields} We examined palate cell proliferation in Sprouty2-deficient mice. {yields} Palate mesenchymal cell proliferation was increased in Sprouty2 KO mice. {yields} Sprouty2 plays roles in murine palatogenesis by regulating cell proliferation. -- Abstract: Cleft palate is one of the most common craniofacial deformities. The fibroblast growth factor (FGF) plays a central role in reciprocal interactions between adjacent tissues during palatal development, and the FGF signaling pathway has been shown to be inhibited by members of the Sprouty protein family. In this study, we report the incidence of cleft palate, possibly caused by failure of palatal shelf elevation, in Sprouty2-deficient (KO) mice. Sprouty2-deficient palates fused completely in palatal organ culture. However, palate mesenchymal cell proliferation estimated by Ki-67 staining was increased in Sprouty2 KO mice compared with WT mice. Sprouty2-null palates expressed higher levels of FGF target genes, such as Msx1, Etv5, and Ptx1 than WT controls. Furthermore, proliferation and the extracellular signal-regulated kinase (Erk) activation in response to FGF was enhanced in palate mesenchymal cells transfected with Sprouty2 small interfering RNA. These results suggest that Sprouty2 regulates palate mesenchymal cell proliferation via FGF signaling and is involved in palatal shelf elevation.

  6. Astragalus polysaccharides affect insulin resistance by regulating the hepatic SIRT1-PGC-1α/PPARα-FGF21 signaling pathway in male Sprague Dawley rats undergoing catch-up growth.

    PubMed

    Gu, Chengying; Zeng, Yipeng; Tang, Zhaosheng; Wang, Chaoxun; He, Yanju; Feng, Xinge; Zhou, Ligang

    2015-11-01

    The present study investigated the effects of Astragalus polysaccharides (APS) on insulin resistance by modulation of hepatic sirtuin 1 (SIRT1)‑peroxisome proliferator‑activated receptor (PPAR)‑γ coactivator (PGC)‑1α/PPARα‑fibroblast growth factor (FGF)21, and glucose and lipid metabolism. Thirty male Sprague Dawley rats were divided into three groups: A normal control group, a catch‑up growth group and an APS‑treated (APS-G) group. The latter two groups underwent food restriction for 4 weeks, prior to being provided with a high fat diet, which was available ad libitum. The APS‑G group was orally treated with APS for 8 weeks, whereas the other groups were administered saline. Body weight was measured and an oral glucose tolerance test (OGTT) was conducted after 8 weeks. The plasma glucose and insulin levels obtained from the OGTT were assayed, and hepatic morphology was observed by light and transmission electron microscopy. In addition, the mRNA expression levels of PGC‑1α/PPARα, and the protein expression levels of SIRT1, FGF21 and nuclear factor‑κB were quantified in the liver and serum. APS treatment suppressed abnormal glycolipid metabolism and insulin resistance following 8 weeks of catch‑up growth by improving hepatic SIRT1‑PPARα‑FGF21 intracellular signaling and reducing chronic inflammation, and by partially attenuating hepatic steatosis. The suppressive effects of APS on liver acetylation and glycolipid metabolism‑associated molecules contributed to the observed suppression of insulin resistance. However, the mechanism underlying the effects of APS on insulin resistance requires further research in order to be elucidated. Rapid and long‑term treatment with APS may provide a novel, safe and effective therapeutic strategy for type 2 diabetes. PMID:26323321

  7. Co-operative Bmp- and Fgf-signaling inputs convert skin wound healing to limb formation in urodele amphibians.

    PubMed

    Makanae, Aki; Mitogawa, Kazumasa; Satoh, Akira

    2014-12-01

    Urodele amphibians have remarkable organ regeneration capability, and their limb regeneration capability has been investigated as a representative phenomenon. In the early 19th century, nerves were reported to be an essential tissue for the successful induction of limb regeneration. Nerve substances that function in the induction of limb regeneration responses have long been sought. A new experimental system called the accessory limb model (ALM) has been established to identify the nerve factors. Skin wounding in urodele amphibians results in skin wound healing but never in limb induction. However, nerve deviation to the wounded skin induces limb formation in ALM. Thus, nerves can be considered to have the ability to transform skin wound healing to limb formation. In the present study, co-operative Bmp and Fgf application, instead of nerve deviation, to wounded skin transformed skin wound healing to limb formation in two urodele amphibians, axolotl (Ambystoma mexicanum) and newt (Pleurodeles waltl). Our findings demonstrate that defined factors can induce homeotic transformation in postembryonic bodies of urodele amphibians. The combination of Bmp and Fgf(s) may contribute to the development of novel treatments for organ regeneration.

  8. Co-operative Bmp- and Fgf-signaling inputs convert skin wound healing to limb formation in urodele amphibians.

    PubMed

    Makanae, Aki; Mitogawa, Kazumasa; Satoh, Akira

    2014-12-01

    Urodele amphibians have remarkable organ regeneration capability, and their limb regeneration capability has been investigated as a representative phenomenon. In the early 19th century, nerves were reported to be an essential tissue for the successful induction of limb regeneration. Nerve substances that function in the induction of limb regeneration responses have long been sought. A new experimental system called the accessory limb model (ALM) has been established to identify the nerve factors. Skin wounding in urodele amphibians results in skin wound healing but never in limb induction. However, nerve deviation to the wounded skin induces limb formation in ALM. Thus, nerves can be considered to have the ability to transform skin wound healing to limb formation. In the present study, co-operative Bmp and Fgf application, instead of nerve deviation, to wounded skin transformed skin wound healing to limb formation in two urodele amphibians, axolotl (Ambystoma mexicanum) and newt (Pleurodeles waltl). Our findings demonstrate that defined factors can induce homeotic transformation in postembryonic bodies of urodele amphibians. The combination of Bmp and Fgf(s) may contribute to the development of novel treatments for organ regeneration. PMID:25286122

  9. Impaired cerebral cortex development and blood pressure regulation in FGF-2-deficient mice.

    PubMed

    Dono, R; Texido, G; Dussel, R; Ehmke, H; Zeller, R

    1998-08-01

    Fibroblast growth factor-2 (FGF-2) has been implicated in various signaling processes which control embryonic growth and differentiation, adult physiology and pathology. To analyze the in vivo functions of this signaling molecule, the FGF-2 gene was inactivated by homologous recombination in mouse embryonic stem cells. FGF-2-deficient mice are viable, but display cerebral cortex defects at birth. Bromodeoxyuridine pulse labeling of embryos showed that proliferation of neuronal progenitors is normal, whereas a fraction of them fail to colonize their target layers in the cerebral cortex. A corresponding reduction in parvalbumin-positive neurons is observed in adult cortical layers. Neuronal defects are not limited to the cerebral cortex, as ectopic parvalbumin-positive neurons are present in the hippocampal commissure and neuronal deficiencies are observed in the cervical spinal cord. Physiological studies showed that FGF-2-deficient adult mice are hypotensive. They respond normally to angiotensin II-induced hypertension, whereas neural regulation of blood pressure by the baroreceptor reflex is impaired. The present genetic study establishes that FGF-2 participates in controlling fates, migration and differentiation of neuronal cells, whereas it is not essential for their proliferation. The observed autonomic dysfunction in FGF-2-deficient adult mice uncovers more general roles in neural development and function. PMID:9687490

  10. Impaired cerebral cortex development and blood pressure regulation in FGF-2-deficient mice.

    PubMed

    Dono, R; Texido, G; Dussel, R; Ehmke, H; Zeller, R

    1998-08-01

    Fibroblast growth factor-2 (FGF-2) has been implicated in various signaling processes which control embryonic growth and differentiation, adult physiology and pathology. To analyze the in vivo functions of this signaling molecule, the FGF-2 gene was inactivated by homologous recombination in mouse embryonic stem cells. FGF-2-deficient mice are viable, but display cerebral cortex defects at birth. Bromodeoxyuridine pulse labeling of embryos showed that proliferation of neuronal progenitors is normal, whereas a fraction of them fail to colonize their target layers in the cerebral cortex. A corresponding reduction in parvalbumin-positive neurons is observed in adult cortical layers. Neuronal defects are not limited to the cerebral cortex, as ectopic parvalbumin-positive neurons are present in the hippocampal commissure and neuronal deficiencies are observed in the cervical spinal cord. Physiological studies showed that FGF-2-deficient adult mice are hypotensive. They respond normally to angiotensin II-induced hypertension, whereas neural regulation of blood pressure by the baroreceptor reflex is impaired. The present genetic study establishes that FGF-2 participates in controlling fates, migration and differentiation of neuronal cells, whereas it is not essential for their proliferation. The observed autonomic dysfunction in FGF-2-deficient adult mice uncovers more general roles in neural development and function.

  11. Impaired cerebral cortex development and blood pressure regulation in FGF-2-deficient mice.

    PubMed Central

    Dono, R; Texido, G; Dussel, R; Ehmke, H; Zeller, R

    1998-01-01

    Fibroblast growth factor-2 (FGF-2) has been implicated in various signaling processes which control embryonic growth and differentiation, adult physiology and pathology. To analyze the in vivo functions of this signaling molecule, the FGF-2 gene was inactivated by homologous recombination in mouse embryonic stem cells. FGF-2-deficient mice are viable, but display cerebral cortex defects at birth. Bromodeoxyuridine pulse labeling of embryos showed that proliferation of neuronal progenitors is normal, whereas a fraction of them fail to colonize their target layers in the cerebral cortex. A corresponding reduction in parvalbumin-positive neurons is observed in adult cortical layers. Neuronal defects are not limited to the cerebral cortex, as ectopic parvalbumin-positive neurons are present in the hippocampal commissure and neuronal deficiencies are observed in the cervical spinal cord. Physiological studies showed that FGF-2-deficient adult mice are hypotensive. They respond normally to angiotensin II-induced hypertension, whereas neural regulation of blood pressure by the baroreceptor reflex is impaired. The present genetic study establishes that FGF-2 participates in controlling fates, migration and differentiation of neuronal cells, whereas it is not essential for their proliferation. The observed autonomic dysfunction in FGF-2-deficient adult mice uncovers more general roles in neural development and function. PMID:9687490

  12. Irx1 and Irx2 Are Coordinately Expressed and Regulated by Retinoic Acid, TGFβ and FGF Signaling during Chick Hindlimb Development

    PubMed Central

    Díaz-Hernández, Martha Elena; Bustamante, Marcia; Galván-Hernández, Claudio Iván; Chimal-Monroy, Jesús

    2013-01-01

    The Iroquois homeobox (Irx) genes play a crucial role in the regionalization and patterning of tissues and organs during metazoan development. The Irx1 and Irx2 gene expression pattern during hindlimb development has been investigated in different species, but its regulation during hindlimb morphogenesis has not been explored yet. The aim of this study was to evaluate the gene expression pattern of Irx1 and Irx2 as well as their regulation by important regulators of hindlimb development such as retinoic acid (RA), transforming growth factor β (TGFβ) and fibroblast growth factor (FGF) signaling during chick hindlimb development. Irx1 and Irx2 were coordinately expressed in the interdigital tissue, digital primordia, joints and in the boundary between cartilage and non-cartilage tissue. Down-regulation of Irx1 and Irx2 expression at the interdigital tissue coincided with the onset of cell death. RA was found to down-regulate their expression by a bone morphogenetic protein-independent mechanism before any evidence of cell death. Furthermore, TGFβ protein regulated Irx1 and Irx2 in a stage-dependent manner at the interdigital tissue, it inhibited their expression when it was administered to the interdigital tissue at developing stages before their normal down-regulation. TGFβ administered to the interdigital tissue at developing stages after normal down-regulation of Irx1 and Irx2 evidenced that expression of these genes marked the boundary between cartilage tissue and non-cartilage tissue. It was also found that at early stages of hindlimb development FGF signaling inhibited the expression of Irx2. In conclusion, the present study demonstrates that Irx1 and Irx2 are coordinately expressed and regulated during chick embryo hindlimb development as occurs in other species of vertebrates supporting the notion that the genomic architecture of Irx clusters is conserved in vertebrates. PMID:23505533

  13. Membrane and Integrative Nuclear Fibroblastic Growth Factor Receptor (FGFR) Regulation of FGF-23*

    PubMed Central

    Han, Xiaobin; Xiao, Zhousheng; Quarles, L. Darryl

    2015-01-01

    Fibroblastic growth factor receptor 1 (FGFR1) signaling pathways are implicated in the regulation of FGF-23 gene transcription, but the molecular pathways remain poorly defined. We used low molecular weight (LMW, 18 kDa) FGF-2 and high molecular weight (HMW) FGF-2 isoforms, which, respectively, activate cell surface FGF receptors and intranuclear FGFR1, to determine the roles of membrane FGFRs and integrative nuclear FGFR1 signaling (INFS) in the regulation of FGF-23 gene transcription in osteoblasts. We found that LMW-FGF-2 induced NFAT and Ets1 binding to conserved cis-elements in the proximal FGF-23 promoter and stimulated FGF-23 promoter activity through PLCγ/calcineurin/NFAT and MAPK pathways in SaOS-2 and MC3T3-E1 osteoblasts. In contrast, HMW-FGF-2 stimulated FGF-23 promoter activity in osteoblasts through a cAMP-dependent binding of FGFR1 and cAMP-response element-binding protein (CREB) to a conserved cAMP response element (CRE) contiguous with the NFAT binding site in the FGF-23 promoter. Mutagenesis of the NFAT and CRE binding sites, respectively, inhibited the effects of LMW-FGF-2 and HMW-FGF-23 to stimulate FGF-23 promoter activity. FGF-2 activation of both membrane FGFRs and INFS-dependent FGFR1 pathways may provide a means to integrate systemic and local regulation of FGF-23 transcription under diverse physiological and pathological conditions. PMID:25752607

  14. Central action of FGF19 reduces hypothalamic AGRP/NPY neuron activity and improves glucose metabolism.

    PubMed

    Marcelin, Geneviève; Jo, Young-Hwan; Li, Xiaosong; Schwartz, Gary J; Zhang, Ying; Dun, Nae J; Lyu, Rong-Ming; Blouet, Clémence; Chang, Jaw K; Chua, Streamson

    2014-02-01

    Tight control of glucose excursions has been a long-standing goal of treatment for patients with type 2 diabetes mellitus in order to ameliorate the morbidity and mortality associated with hyperglycemia. Fibroblast growth factor (FGF) 19 is a hormone-like enterokine released postprandially that emerged as a potential therapeutic agent for metabolic disorders, including diabetes and obesity. Remarkably, FGF19 treatment has hypoglycemic actions that remain potent in models of genetic and acquired insulin resistance. Here, we provided evidence that the central nervous system responds to FGF19 administered in the periphery. Then, in two mouse models of insulin resistance, leptin-deficiency and high-fat diet feeding, third intra-cerebro-ventricular infusions of FGF19 improved glycemic status, reduced insulin resistance and potentiated insulin signaling in the periphery. In addition, our study highlights a new mechanism of central FGF19 action, involving the suppression of AGRP/NPY neuronal activity. Overall, our work unveils novel regulatory pathways induced by FGF19 that will be useful in the design of novel strategies to control diabetes in obesity. PMID:24567901

  15. Dimerization effect of sucrose octasulfate on rat FGF1

    PubMed Central

    Kulahin, N.; Kiselyov, V.; Kochoyan, A.; Kristensen, O.; Kastrup, Jette S.; Berezin, V.; Bock, E.; Gajhede, M.

    2008-01-01

    Fibroblast growth factors (FGFs) constitute a family of at least 23 structurally related heparin-binding proteins that are involved in regulation of cell growth, survival, differentiation and migration. Sucrose octasulfate (SOS), a chemical analogue of heparin, has been demonstrated to activate FGF signalling pathways. The structure of rat FGF1 crystallized in the presence of SOS has been determined at 2.2 Å resolution. SOS-mediated dimerization of FGF1 was observed, which was further supported by gel-filtration experiments. The major contributors to the sulfate-binding sites in rat FGF1 are Lys113, Lys118, Arg122 and Lys128. An arginine at position 116 is a consensus residue in mammalian FGF molecules; however, it is a serine in rat FGF1. This difference may be important for SOS-mediated FGF1 dimerization in rat. PMID:18540049

  16. The interaction of epithelial Ihha and mesenchymal Fgf10 in zebrafish esophageal and swimbladder development.

    PubMed

    Korzh, Svitlana; Winata, Cecilia Lanni; Zheng, Weiling; Yang, Shulan; Yin, Ao; Ingham, Phillip; Korzh, Vladimir; Gong, Zhiyuan

    2011-11-15

    Developmental patterning and growth of the vertebrate digestive and respiratory tracts requires interactions between the epithelial endoderm and adjacent mesoderm. The esophagus is a specialized structure that connects the digestive and respiratory systems and its normal development is critical for both. Shh signaling from the epithelium regulates related aspects of mammalian and zebrafish digestive organ development and has a prominent effect on esophageal morphogenesis. The mechanisms underlying esophageal malformations, however, are poorly understood. Here, we show that zebrafish Ihha signaling from the epithelium acting in parallel, but independently of Shh, controls epithelial and mesenchymal cell proliferation and differentiation of smooth muscles and neurons in the gut and swimbladder. In zebrafish ihha mutants, the esophageal and swimbladder epithelium is dysmorphic, and expression of fgf10 in adjacent mesenchymal cells is affected. Analysis of the development of the esophagus and swimbladder in fgf10 mutant daedalus (dae) and compound dae/ihha mutants shows that the Ihha-Fgf10 regulatory interaction is realized through a signaling feedback loop between the Ihha-expressing epithelium and Fgf10-expressing mesenchyme. Disruption of this loop further affects the esophageal and swimbladder epithelium in ihha mutants, and Ihha acts in parallel to but independently of Shha in this process. These findings contribute to the understanding of epithelial-mesenchymal interactions and highlight an interaction between Hh and Fgf signaling pathways during esophagus and swimbladder development. PMID:21925490

  17. Renal expression of FGF23 and peripheral resistance to elevated FGF23 in rodent models of polycystic kidney disease.

    PubMed

    Spichtig, Daniela; Zhang, Hongbo; Mohebbi, Nilufar; Pavik, Ivana; Petzold, Katja; Stange, Gerti; Saleh, Lanja; Edenhofer, Ilka; Segerer, Stephan; Biber, Jürg; Jaeger, Philippe; Serra, Andreas L; Wagner, Carsten A

    2014-06-01

    Fibroblast growth factor 23 (FGF23) regulates phosphate homeostasis and is linked to cardiovascular disease and all-cause mortality in chronic kidney disease. FGF23 rises in patients with CKD stages 2-3, but in patients with autosomal dominant polycystic kidney disease, the increase of FGF23 precedes the first measurable decline in renal function. The mechanisms governing FGF23 production and effects in kidney disease are largely unknown. Here we studied the relation between FGF23 and mineral homeostasis in two animal models of PKD. Plasma FGF23 levels were increased 10-fold in 4-week-old cy/+ Han:SPRD rats, whereas plasma urea and creatinine concentrations were similar to controls. Plasma calcium and phosphate levels as well as TmP/GFR were similar in PKD and control rats at all time points examined. Expression and activity of renal phosphate transporters, the vitamin D3-metabolizing enzymes, and the FGF23 co-ligand Klotho in the kidney were similar in PKD and control rats through 8 weeks of age, indicating resistance to FGF23, although phosphorylation of the FGF receptor substrate 2α protein was enhanced. In the kidneys of rats with PKD, FGF23 mRNA was highly expressed and FGF23 protein was detected in cells lining renal cysts. FGF23 expression in bone and spleen was similar in control rats and rats with PKD. Similarly, in an inducible Pkd1 knockout mouse model, plasma FGF23 levels were elevated, FGF23 was expressed in kidneys, but renal phosphate excretion was normal. Thus, the polycystic kidney produces FGF23 but is resistant to its action.

  18. Plasma FGF23 levels increase rapidly after acute kidney injury

    PubMed Central

    Christov, Marta; Waikar, Sushrut; Pereira, Renata; Havasi, Andrea; Leaf, David E.; Goltzman, David; Pajevic, Paola Divieti; Wolf, Myles; Jüppner, Harald

    2013-01-01

    Emerging evidence suggests that fibroblast growth factor 23 (FGF23) levels are elevated in patients with acute kidney injury (AKI). In order to determine how early this increase occurs we used a murine folic acid nephropathy model and found that plasma FGF23 levels increased significantly from baseline already after 1 hour of AKI, with an 18-fold increase at 24 hours. Similar elevations of FGF23 levels were found when AKI was induced in mice with osteocyte-specific parathyroid hormone receptor ablation or the global deletion of parathyroid hormone or vitamin D receptor, indicating that the increase in FGF23 was independent of parathyroid hormone and vitamin D signaling. Furthermore, FGF23 levels increased to a similar extent in wild-type mice maintained on normal or phosphate-depleted diets prior to induction of AKI, indicating that the marked FGF23 elevation is at least partially independent of dietary phosphate. Bone production of FGF23 was significantly increased in AKI. The half-life of intravenously administered recombinant FGF23 was only modestly increased. Consistent with the mouse data, plasma FGF23 levels rose 15.9-fold by 24 hours following cardiac surgery in patients who developed AKI. The levels were significantly higher than in those without postoperative AKI. Thus, circulating FGF23 levels rise rapidly during AKI in rodents and humans. In mice this increase is independent of established modulators of FGF23 secretion. PMID:23657144

  19. Endoderm-specific deletion of Tbx1 reveals an FGF-independent role for Tbx1 in pharyngeal apparatus morphogenesis

    PubMed Central

    Jackson, Abigail; Kasah, Sahrunizam; Mansour, Suzanne L.; Morrow, Bernice; Basson, M. Albert

    2015-01-01

    Background The T-box transcription factor Tbx1, is essential for the normal development of multiple organ systems in the embryo. One of the most striking phenotypes in Tbx1−/− embryos is the failure of the caudal pharyngeal pouches to evaginate from the foregut endoderm. Despite considerable interest in the role of Tbx1 in development, the mechanisms whereby Tbx1 controls caudal pouch formation have remained elusive. In particular, the question as to how Tbx1 expression in the pharyngeal endoderm regulates pharyngeal pouch morphogenesis in the mouse embryo is not known. Results To address this question, we produced mouse embryos in which Tbx1 was specifically deleted from the pharyngeal endoderm and as expected, embryos failed to form caudal pharyngeal pouches. To determine the molecular mechanism, we examined expression of Fgf3 and Fgf8 ligands and downstream effectors. Although Fgf8 expression is greatly reduced in Tbx1-deficient endoderm, FGF signaling levels are unaffected. Furthermore, pouch morphogenesis is only partially perturbed by the loss of both Fgf3 and Fgf8 from the endoderm, indicating that neither are required for pouch formation. Conclusions Tbx1 deletion from the pharyngeal endoderm is sufficient to cause caudal pharyngeal arch segmentation defects by FGF-independent effectors that remain to be identified. PMID:24812002

  20. FGF19 functions as autocrine growth factor for hepatoblastoma

    PubMed Central

    Elzi, David J.; Song, Meihua; Blackman, Barron; Weintraub, Susan T.; López-Terrada, Dolores; Chen, Yidong; Tomlinson, Gail E.; Shiio, Yuzuru

    2016-01-01

    Hepatoblastoma is the most common liver cancer in children, accounting for over 65% of all childhood liver malignancies. Hepatoblastoma is distinct from adult liver cancer in that it is not associated with hepatitis virus infection, cirrhosis, or other underlying liver pathology. The paucity of appropriate cell and animal models has been hampering the mechanistic understanding of hepatoblastoma pathogenesis. Consequently, there is no molecularly targeted therapy for hepatoblastoma. To gain insight into cytokine signaling in hepatoblastoma, we employed mass spectrometry to analyze the proteins secreted from Hep293TT hepatoblastoma cell line we established and identified the specific secretion of fibroblast growth factor 19 (FGF19), a growth factor for liver cells. We determined that silencing FGF19 by shRNAs or neutralizing secreted FGF19 by anti-FGF19 antibody inhibits the proliferation of hepatoblastoma cells. Furthermore, blocking FGF19 signaling by an FGF receptor kinase inhibitor suppressed hepatoblastoma growth. RNA expression analysis in hepatoblastoma tumors revealed that the high expression of FGF19 signaling pathway components as well as the low expression of FGF19 signaling repression targets correlates with the aggressiveness of the tumors. These results suggest the role of FGF19 as autocrine growth factor for hepatoblastoma. PMID:27382436

  1. FGF-23 regulates CYP27B1 transcription in the kidney and in extra-renal tissues.

    PubMed

    Chanakul, Ankanee; Zhang, Martin Y H; Louw, Andrew; Armbrecht, Harvey J; Miller, Walter L; Portale, Anthony A; Perwad, Farzana

    2013-01-01

    The mitochondrial enzyme 25-hydroxyvitamin D 1α-hydroxylase, which is encoded by the CYP27B1 gene, converts 25OHD to the biological active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)2D). Renal 1α-hydroxylase activity is the principal determinant of the circulating 1,25(OH)2D concentration and enzyme activity is tightly regulated by several factors. Fibroblast growth factor-23 (FGF-23) decreases serum 1,25(OH)2D concentrations by suppressing CYP27B1 mRNA abundance in mice. In extra-renal tissues, 1α-hydroxylase is responsible for local 1,25(OH)2D synthesis, which has important paracrine actions, but whether FGF-23 regulates CYP27B1 gene expression in extra-renal tissues is unknown. We sought to determine whether FGF-23 regulates CYP27B1 transcription in the kidney and whether extra-renal tissues are target sites for FGF-23-induced suppression of CYP27B1. In HEK293 cells transfected with the human CYP27B1 promoter, FGF-23 suppressed promoter activity by 70%, and the suppressive effect was blocked by CI-1040, a specific inhibitor of extracellular signal regulated kinase 1/2. To examine CYP27B1 transcriptional activity in vivo, we crossed fgf-23 null mice with mice bearing the CYP27B1 promoter-driven luciferase transgene (1α-Luc). In the kidney of FGF-23 null/1α-Luc mice, CYP27B1 promoter activity was increased by 3-fold compared to that in wild-type/1α-Luc mice. Intraperitoneal injection of FGF-23 suppressed renal CYP27B1 promoter activity and protein expression by 26% and 60% respectively, and the suppressive effect was blocked by PD0325901, an ERK1/2 inhibitor. These findings provide evidence that FGF-23 suppresses CYP27B1 transcription in the kidney. Furthermore, we demonstrate that in FGF-23 null/1α-Luc mice, CYP27B1 promoter activity and mRNA abundance are increased in several extra-renal sites. In the heart of FGF-23 null/1α-Luc mice, CYP27B1 promoter activity and mRNA were 2- and 5-fold higher, respectively, than in control mice. We also

  2. New insights into the FGF23-Klotho axis.

    PubMed

    Olauson, Hannes; Vervloet, Marc G; Cozzolino, Mario; Massy, Ziad A; Ureña Torres, Pablo; Larsson, Tobias E

    2014-11-01

    Abnormal mineral metabolism is a hallmark in patients with advanced chronic kidney disease (CKD). Hyperphosphatemia, and the homeostatic mechanisms controlling phosphate metabolism, have received particular attention over the past decade. The phosphate-regulating hormone fibroblast growth factor-23 (FGF23) was discovered through studies of rare hypophosphatemic disorders, whereas Klotho, which subsequently turned out to be a co-receptor for FGF23, was identified in a mouse model showing hyperphosphatemia and multiple aging-like traits. The FGF23-Klotho endocrine axis is a pivotal regulator of mineral metabolism. In CKD, early onset of Klotho deficiency contributes to renal FGF23 resistance and a maladaptive increase in circulating FGF23. FGF23 is an early biomarker of renal injury and increased FGF23 predicts adverse clinical outcomes, in particular cardiovascular disease. A paradigm of FGF23 excess and Klotho deficiency is proposed, in which FGF23 preferentially stimulates left ventricular hypertrophy, and loss of Klotho augments fibrosis, endothelial dysfunction, and vascular calcification. The clinical benefit of FGF23 and Klotho measurements remain uncertain, nevertheless, the FGF23-Klotho axis is a solid candidate for a novel diagnostic and therapeutic target in CKD. PMID:25498378

  3. A Sox9/Fgf feed-forward loop maintains pancreatic organ identity

    PubMed Central

    Seymour, Philip A.; Shih, Hung Ping; Patel, Nisha A.; Freude, Kristine K.; Xie, Ruiyu; Lim, Christopher J.; Sander, Maike

    2012-01-01

    All mature pancreatic cell types arise from organ-specific multipotent progenitor cells. Although previous studies have identified cell-intrinsic and -extrinsic cues for progenitor cell expansion, it is unclear how these cues are integrated within the niche of the developing organ. Here, we present genetic evidence in mice that the transcription factor Sox9 forms the centerpiece of a gene regulatory network that is crucial for proper organ growth and maintenance of organ identity. We show that pancreatic progenitor-specific ablation of Sox9 during early pancreas development causes pancreas-to-liver cell fate conversion. Sox9 deficiency results in cell-autonomous loss of the fibroblast growth factor receptor (Fgfr) 2b, which is required for transducing mesenchymal Fgf10 signals. Likewise, Fgf10 is required to maintain expression of Sox9 and Fgfr2 in epithelial progenitors, showing that Sox9, Fgfr2 and Fgf10 form a feed-forward expression loop in the early pancreatic organ niche. Mirroring Sox9 deficiency, perturbation of Fgfr signaling in pancreatic explants or genetic inactivation of Fgf10 also result in hepatic cell fate conversion. Combined with previous findings that Fgfr2b or Fgf10 are necessary for pancreatic progenitor cell proliferation, our results demonstrate that organ fate commitment and progenitor cell expansion are coordinately controlled by the activity of a Sox9/Fgf10/Fgfr2b feed-forward loop in the pancreatic niche. This self-promoting Sox9/Fgf10/Fgfr2b loop may regulate cell identity and organ size in a broad spectrum of developmental and regenerative contexts. PMID:22874919

  4. Photoperiodic regulation of FGF21 production in the Siberian hamster.

    PubMed

    Samms, Ricardo J; Fowler, Maxine J; Cooper, Scott; Emmerson, Paul; Coskun, Tamer; Adams, Andrew C; Kharitonenkov, Alexei; Tsintzas, Kostas; Ebling, Francis J P

    2014-06-01

    This article is part of a Special Issue "Energy Balance". FGF21 is an endocrine member of the fibroblast growth factor superfamily that has been shown to play an important role in the physiological response to nutrient deprivation. Food restriction enhances hepatic FGF21 production, which serves to engage an integrated response to energy deficit. Specifically, elevated FGF21 levels lead to reduced gluconeogenesis and increased hepatic ketogenesis. However, circulating FGF21 concentrations also paradoxically rise in states of metabolic dysfunction such as obesity. Furthermore, multiple peripheral tissues also produce FGF21 in addition to the liver, raising questions as to its endocrine and paracrine roles in the control of energy metabolism. The objectives of this study were to measure plasma FGF21 concentrations in the Siberian hamster, a rodent which undergoes a seasonal cycle of fattening and body weight gain in the long days (LD) of summer, followed by reduction of appetite and fat catabolism in the short days (SD) of winter. Groups of adult male hamsters were raised in long days, and then exposed to SD for up to 12 weeks. Chronic exposure of LD animals to SD led to a significant increase in circulating FGF21 concentrations. This elevation of circulating FGF21 was preceded by an increase in liver FGF21 protein production evident as early as 4 weeks of exposure to SD. FGF21 protein abundance was also increased significantly in interscapular brown adipose tissue, with a positive correlation between plasma levels of FGF21 and BAT protein abundance throughout the experimental period. Epididymal white adipose tissue and skeletal muscle (gastrocnemius) also produced FGF21, but levels did not change in response to a change in photoperiod. In summary, a natural programmed state of fat catabolism was associated with increased FGF21 production in the liver and BAT, consistent with the view that FGF21 has a role in adapting hamsters to the hypophagic winter state.

  5. FGF23 associated bone diseases.

    PubMed

    Liao, Eryuan

    2013-03-01

    Recently, fibroblast growth factor 23 (FGF23) has sparked widespread interest because of its potential role in regulating phosphate and vitamin D metabolism. In this review, we summarized the FGF superfamily, the mechanism of FGF23 on phosphate and vitamin D metabolism, and the FGF23 related bone disease.

  6. Cellular Responses Modulated by FGF-2 Adsorbed on Albumin/Heparin Layer-by-Layer Assemblies

    PubMed Central

    Kumorek, Marta; Kubies, Dana; Filová, Elena; Houska, Milan; Kasoju, Naresh; Mázl Chánová, Eliška; Matějka, Roman; Krýslová, Markéta; Bačáková, Lucie; Rypáček, František

    2015-01-01

    In a typical cell culture system, growth factors immobilized on the cell culture surfaces can serve as a reservoir of bio-signaling molecules, without the need to supplement them additionally into the culture medium. In this paper, we report on the fabrication of albumin/heparin (Alb/Hep) assemblies for controlled binding of basic fibroblast growth factor (FGF-2). The surfaces were constructed by layer-by-layer adsorption of polyelectrolytes albumin and heparin and were subsequently stabilized by covalent crosslinking with glutaraldehyde. An analysis of the surface morphology by atomic force microscopy showed that two Alb/Hep bilayers are required to cover the surface of substrate. The formation of the Alb/Hep assemblies was monitored by the surface plasmon resonance (SPR), the infrared multiinternal reflection spectroscopy (FTIR MIRS) and UV/VIS spectroscopy. The adsorption of FGF-2 on the cross-linked Alb/Hep was followed by SPR. The results revealed that FGF-2 binds to the Alb/Hep assembly in a dose and time-dependent manner up to the surface concentration of 120 ng/cm2. The bioactivity of the adsorbed FGF-2 was assessed in experiments in vitro, using calf pulmonary arterial endothelial cells (CPAE). CPAE cells could attach and proliferate on Alb/Hep surfaces. The adsorbed FGF-2 was bioactive and stimulated both the proliferation and the differentiation of CPAE cells. The improvement was more pronounced at a lower FGF-2 surface concentration (30 ng/cm2) than on surfaces with a higher concentration of FGF-2 (120 ng/cm2). PMID:25945799

  7. Parathyroid hormone 1 receptor is essential to induce FGF23 production and maintain systemic mineral ion homeostasis.

    PubMed

    Fan, Yi; Bi, Ruiye; Densmore, Michael J; Sato, Tadatoshi; Kobayashi, Tatsuya; Yuan, Quan; Zhou, Xuedong; Erben, Reinhold G; Lanske, Beate

    2016-01-01

    Parathyroid-hormone-type 1 receptor (PTH1R) is extensively expressed in key regulatory organs for systemic mineral ion homeostasis, including kidney and bone. We investigated the bone-specific functions of PTH1R in modulating mineral ion homeostasis by generating a novel mouse model in which PTH1R is ablated in the limb mesenchyme using Prx1Cre transgenic mice. Such ablation decreased FGF23 protein and serum levels by 50%, despite normal Fgf23 mRNA levels in long bones. Circulating calcium and PTH levels were unchanged, but inorganic phosphate and 1,25(OH)2D3 levels were significantly decreased and accompanied by elevated urinary calcium and phosphate wasting. Key renal genes for balancing mineral ion homeostasis, calbindinD28k, Klotho, and Napi2a were suppressed by 30-40%. Intermittent hPTH(1-34) injections increased Fgf23 mRNA (7.3-fold), Nurr1 mRNA (3.1-fold), and serum intact-FGF23 (1.6-fold) in controls, but failed to induce Fgf23, Nurr1 mRNA, or intact FGF23 production in mutants. Moreover, a significant elevation in serum C-terminal-FGF23 levels (4-fold) was detected in both genotypes. PTH markedly downregulated Galnt3 expression (2.7-fold) in controls but not in mutants. These results demonstrate the pivotal role of PTH1R in long bones to regulate systemic mineral ion homeostasis and the direct induction of FGF23 by PTH1R signaling.

  8. Circulating FGF21 proteolytic processing mediated by fibroblast activation protein

    PubMed Central

    Zhen, Eugene Y.; Jin, Zhaoyan; Ackermann, Bradley L.; Thomas, Melissa K.; Gutierrez, Jesus A.

    2015-01-01

    Fibroblast growth factor 21 (FGF21), a hormone implicated in the regulation of glucose homoeostasis, insulin sensitivity, lipid metabolism and body weight, is considered to be a promising therapeutic target for the treatment of metabolic disorders. Despite observations that FGF21 is rapidly proteolysed in circulation rending it potentially inactive, little is known regarding mechanisms by which FGF21 protein levels are regulated. We systematically investigated human FGF21 protein processing using mass spectrometry. In agreement with previous reports, circulating human FGF21 was found to be cleaved primarily after three proline residues at positions 2, 4 and 171. The extent of FGF21 processing was quantified in a small cohort of healthy human volunteers. Relative abundance of FGF21 proteins cleaved after Pro-2, Pro-4 and Pro-171 ranged from 16 to 30%, 10 to 25% and 10 to 34%, respectively. Dipeptidyl peptidase IV (DPP-IV) was found to be the primary protease responsible for N-terminal cleavages after residues Pro-2 and Pro-4. Importantly, fibroblast activation protein (FAP) was implicated as the protease responsible for C-terminal cleavage after Pro-171, rendering the protein inactive. The requirement of FAP for FGF21 proteolysis at the C-terminus was independently demonstrated by in vitro digestion, immunodepletion of FAP in human plasma, administration of an FAP-specific inhibitor and by human FGF21 protein processing patterns in FAP knockout mouse plasma. The discovery that FAP is responsible for FGF21 inactivation extends the FGF21 signalling pathway and may enable novel approaches to augment FGF21 actions for therapeutic applications. PMID:26635356

  9. Antidepressant-Like Effects of Intracerebroventricular FGF2 in Rats

    PubMed Central

    Turner, Cortney A.; Gula, Edny L.; Taylor, Larry P.; Watson, Stanley J.; Akil, Huda

    2008-01-01

    The fibroblast growth factor (FGF) system is altered in post-mortem brains of individuals with major depressive disorder (MDD), but the functional relevance of this observation remains to be elucidated. To this end, we tested whether administering agents that act on FGF receptors would have antidepressant-like effects in rodents. We microinjected either FGF2 (200ng, i.c.v.) or the FG loop (FGL) of neural cell adhesion molecule (NCAM) (5μg, i.c.v.) into the lateral ventricle of rats and tested them on the forced swim test. Activating FGF receptors acutely had an antidepressant-like effect in the forced swim test. Furthermore, chronic FGF2 decreased depression-like behavior as assessed by two independent tests. Finally, the FGF system itself was altered after FGF2 administration. Specifically, there was an increase in FGFR1 mRNA in the dentate gyrus 24 h post FGF2, suggesting the potential for self-amplification of the initial signal. These results support the potential therapeutic use of FGF2 or related molecules in the treatment of MDD and point to alternate mechanisms of neuronal remodeling that may be critical in this treatment. PMID:18586016

  10. Regulation of osteoblast and osteoclast functions by FGF-6.

    PubMed

    Bosetti, Michela; Leigheb, Massimiliano; Brooks, Roger A; Boccafoschi, Francesca; Cannas, Mario F

    2010-11-01

    Fibroblast growth factor-6 (FGF-6) is known to be the key ligand for fibroblast growth factor receptor 4 (FGFR4) during muscle regeneration but its role in bone has yet to be verified. FGFR signaling is known to be important in the initiation and regulation of osteogenesis, so in this study the actions of FGF-6 on human osteoblasts and osteoclasts were investigated. Human primary osteoblasts (hOB) were used to study the effect of FGF-6 on proliferation (by ATP quantification), signal transduction (by ERK and AKT phosphorylation), differentiation (by alkaline phosphatase activity, APA), and mineralization (by calcein staining). To study FGF-6 activity on osteoclast differentiation, human bone marrow cells were used and tartrate-resistant acid phosphatase (TRAP) multinucleated cells together with actin filaments arrangements were quantified. Human primary mature osteoclasts were used to evaluate the effect of FGF-6 on osteoclast reabsorbing activity by reabsorbed pit measurements. FGF-6 >10(-9) M as FGF-2 10(-7) M induced hOB proliferation mediated by pERK together with a reduction in APA and reduced mineralization of the treated cells. Moreover FGF-6 increased the formation of TRAP-positive multinucleated cells in a dose-dependent manner (maximal effect at 10(-8) M). FGF-6-treated cells showed also a greater percentage of cells that formed typical osteoclast sealing zones. Mature osteoclasts cultured on dentine slice increased the area of reabsorption with a maximal effect of FGF-6 at 10(-12) M. FGF-6 may be considered a regulator of bone metabolism as shown by its activity on both osteoblasts and osteoclasts.

  11. FGF5 as a regulator of the hair growth cycle: evidence from targeted and spontaneous mutations.

    PubMed

    Hébert, J M; Rosenquist, T; Götz, J; Martin, G R

    1994-09-23

    Fibroblast growth factor 5 (FGF5) is a secreted signaling protein. Mice homozygous for a predicted null allele of the Fgf5 gene, fgf5neo, produced by gene targeting in embryonic stem cells, have abnormally long hair. This phenotype appears identical to that of mice homozygous for the spontaneous mutation angora (go). The fgf5neo and go mutations fail to complement one another, and exon 1 of Fgf5 is deleted in DNA from go homozygotes, demonstrating that go is a mutant allele of Fgf5. Expression of Fgf5 is detected in hair follicles from wild-type mice and is localized to the outer root sheath during the anagen VI phase of the hair growth cycle. These findings provide evidence that FGF5 functions as an inhibitor of hair elongation, thus identifying a molecule whose normal function is apparently to regulate one step in the progression of the follicle through the hair growth cycle.

  12. FGF23 is endogenously phosphorylated in bone cells.

    PubMed

    Lindberg, Iris; Pang, Hong Weng; Stains, Joseph P; Clark, David; Yang, Austin J; Bonewald, Lynda; Li, Kevin Z

    2015-03-01

    Levels of serum phosphate are controlled by the peptide hormone FGF23, secreted from bone osteocytes. Elevated levels of circulating FGF23 are a key factor in several hypophosphatemic disorders and play a role in chronic kidney disease. Posttranslational processing of FGF23 includes multi-site O-glycosylation, which reduces intracellular cleavage by proprotein convertases. The FGF23 protein also contains four serine phosphorylation consensus sequences (S-X-D/E); in this work, we asked whether FGF23 is a substrate for secretory phosphorylation. Both HEK cells as well as IDG-SW3 cells, an osteocyte model, incorporated radiolabeled orthophosphate into intact FGF23, as well as into the 14-kDa carboxy-terminal-but not the 17-kDa N-terminal-fragment. Sequential serine-to-alanine site-directed mutagenesis of four kinase consensus sites showed that labeling occurred on three serines within the carboxy-terminal fragment, Ser180 (adjacent to the cleavage site), Ser207, and Ser212. Liquid chromatography-coupled mass spectroscopy indicated the presence of phosphate at Ser212 in recombinant R&D mouse FGF23(R179Q) , confirming labeling results. A phosphopeptide-specific antibody was raised against phospho-Ser212 and exhibited immunoreactivity in osteocytes present in mouse long bone, providing further evidence that FGF23 is naturally phosphorylated in bone. Bone SIBLING proteins are serine-phosphorylated by the ubiquitous Golgi secretory kinase FAM20C. Cotransfection of HEK and MC3T3 cells with FGF23 and active, but not inactive, FAM20C kinase increased the storage and release of FGF23 in radiolabeling experiments, indicating potential effects of phosphorylation on FGF23 stability. Collectively, these data point to an important role for phosphorylation of FGF23 in bone.

  13. The Hand1, Stra13 and Gcm1 transcription factors override FGF signaling to promote terminal differentiation of trophoblast stem cells.

    PubMed

    Hughes, Martha; Dobric, Nikolina; Scott, Ian C; Su, Lin; Starovic, Maja; St-Pierre, Benoit; Egan, Sean E; Kingdom, John C P; Cross, James C

    2004-07-01

    The trophoblast cell lineage is an interesting model system because it is composed of a limited number of cell types that are spatially patterned. Trophoblast stem (TS) cells reside within a layer called the chorion and either remain as stem cells or differentiate into spongiotrophoblast (SpT), trophoblast giant (TG) cells or syncytiotrophoblast cells (SynT) of the labyrinth. Maintenance of the TS phenotype is dependent on stimulation by FGF4, whereas differentiation and/or maintenance of the differentiated derivatives are dependent on key transcription factors: Mash2 for SpT, Hand1 for TG cells and Gcm1 for SynT cells. TS cells proliferate and retain their stem cell phenotype in culture in response to FGF4 and an additional factor(s) that can be provided by conditioned medium from embryonic fibroblast feeder cells (CM). To understand the functions of Hand1, Mash2 and Gcm1 at a cellular level, we tested the effects of their ectopic and over-expression on the ability of TS cells to either continue to proliferate or differentiate into their alternative fates. Expression of Mash2 alone had no effects on TS cell differentiation. However, Mash2-transfected cells continued to divide longer after withdrawal of FGF/CM. Hand1 promoted TGC differentiation, even in the continued presence of FGF4/CM. Stra13, another bHLH factor gene that is expressed in TG cells, also induced TG differentiation. Gcm1 induced a rapid arrest of TS proliferation but, in contrast to Hand1 and Stra13, blocked TG cell differentiation. Although Gcm1 was not sufficient to promote SynT formation, expression of an antisense Gcm1 transcript blocked SynT differentiation. These data suggest that Mash2 functions to promote transient FGF4-independent amplification of trophoblast cells that are progressing towards the SpT and TG cell phenotype. By contrast, Hand1 and Stra13 promote cell cycle exit and restrict cells towards the TG fate, whereas Gcm1 promotes cell cycle exit and restriction towards the Syn

  14. Fgf8 Dosage Determines Midfacial Integration and Polarity within the Nasal and Optic Capsules

    PubMed Central

    Griffin, John N.; Compagnucci, Claudia; Hu, Diane; Fish, Jennifer; Klein, Ophir; Marcucio, Ralph; Depew, Michael J.

    2014-01-01

    Craniofacial development requires an exquisitely timed and positioned cross-talk between the embryonic cephalic epithelia and mesenchyme. This cross-talk underlies the precise translation of patterning processes and information into distinct, appropriate skeletal morphologies. The molecular and cellular dialogue includes communication via secreted signaling molecules, including Fgf8, and effectors of their interpretation. Herein, we use genetic attenuation of Fgf8 in mice and perform gain-of-function mouse-chick chimeric experiments to demonstrate that significant character states of the frontonasal and optic skeletons are dependent on Fgf8. Notably, we show that the normal orientation and polarity of the nasal capsules and their developing primordia are dependent on Fgf8. We further demonstrate that Fgf8 is required for midfacial integration, and provide evidence for a role for Fgf8 in optic capsular development. Taken together, our data highlight Fgf8 signaling in craniofacial development as a plausible target for evolutionary selective pressures. PMID:23201021

  15. Inhibition of H3K9me2 Reduces Hair Cell Regeneration after Hair Cell Loss in the Zebrafish Lateral Line by Down-Regulating the Wnt and Fgf Signaling Pathways.

    PubMed

    Tang, Dongmei; Lin, Qin; He, Yingzi; Chai, Renjie; Li, Huawei

    2016-01-01

    The activation of neuromast (NM) supporting cell (SC) proliferation leads to hair cell (HC) regeneration in the zebrafish lateral line. Epigenetic mechanisms have been reported that regulate HC regeneration in the zebrafish lateral line, but the role of H3K9me2 in HC regeneration after HC loss remains poorly understood. In this study, we focused on the role of H3K9me2 in HC regeneration following neomycin-induced HC loss. To investigate the effects of H3K9me2 in HC regeneration, we took advantage of the G9a/GLP-specific inhibitor BIX01294 that significantly reduces the dimethylation of H3K9. We found that BIX01294 significantly reduced HC regeneration after neomycin-induced HC loss in the zebrafish lateral line. BIX01294 also significantly reduced the proliferation of NM cells and led to fewer SCs in the lateral line. In situ hybridization showed that BIX01294 significantly down-regulated the Wnt and Fgf signaling pathways, which resulted in reduced SC proliferation and HC regeneration in the NMs of the lateral line. Altogether, our results suggest that down-regulation of H3K9me2 significantly decreases HC regeneration after neomycin-induced HC loss through inactivation of the Wnt/β-catenin and Fgf signaling pathways. Thus H3K9me2 plays a critical role in HC regeneration. PMID:27303264

  16. Inhibition of H3K9me2 Reduces Hair Cell Regeneration after Hair Cell Loss in the Zebrafish Lateral Line by Down-Regulating the Wnt and Fgf Signaling Pathways

    PubMed Central

    Tang, Dongmei; Lin, Qin; He, Yingzi; Chai, Renjie; Li, Huawei

    2016-01-01

    The activation of neuromast (NM) supporting cell (SC) proliferation leads to hair cell (HC) regeneration in the zebrafish lateral line. Epigenetic mechanisms have been reported that regulate HC regeneration in the zebrafish lateral line, but the role of H3K9me2 in HC regeneration after HC loss remains poorly understood. In this study, we focused on the role of H3K9me2 in HC regeneration following neomycin-induced HC loss. To investigate the effects of H3K9me2 in HC regeneration, we took advantage of the G9a/GLP-specific inhibitor BIX01294 that significantly reduces the dimethylation of H3K9. We found that BIX01294 significantly reduced HC regeneration after neomycin-induced HC loss in the zebrafish lateral line. BIX01294 also significantly reduced the proliferation of NM cells and led to fewer SCs in the lateral line. In situ hybridization showed that BIX01294 significantly down-regulated the Wnt and Fgf signaling pathways, which resulted in reduced SC proliferation and HC regeneration in the NMs of the lateral line. Altogether, our results suggest that down-regulation of H3K9me2 significantly decreases HC regeneration after neomycin-induced HC loss through inactivation of the Wnt/β-catenin and Fgf signaling pathways. Thus H3K9me2 plays a critical role in HC regeneration. PMID:27303264

  17. Diabetes: Models, Signals, and Control

    PubMed Central

    Cobelli, Claudio; Man, Chiara Dalla; Sparacino, Giovanni; Magni, Lalo; De Nicolao, Giuseppe; Kovatchev, Boris P.

    2010-01-01

    The control of diabetes is an interdisciplinary endeavor, which includes a significant biomedical engineering component, with traditions of success beginning in the early 1960s. It began with modeling of the insulin-glucose system, and progressed to large-scale in silico experiments, and automated closed-loop control (artificial pancreas). Here, we follow these engineering efforts through the last, almost 50 years. We begin with the now classic minimal modeling approach and discuss a number of subsequent models, which have recently resulted in the first in silico simulation model accepted as substitute to animal trials in the quest for optimal diabetes control. We then review metabolic monitoring, with a particular emphasis on the new continuous glucose sensors, on the analyses of their time-series signals, and on the opportunities that they present for automation of diabetes control. Finally, we review control strategies that have been successfully employed in vivo or in silico, presenting a promise for the development of a future artificial pancreas and, in particular, discuss a modular architecture for building closed-loop control systems, including insulin delivery and patient safety supervision layers. We conclude with a brief discussion of the unique interactions between human physiology, behavioral events, engineering modeling and control relevant to diabetes. PMID:20936056

  18. AHNAK2 participates in the stress-induced nonclassical FGF1 secretion pathway

    PubMed Central

    Kirov, Aleksandr; Kacer, Doreen; Conley, Barbara A.; Vary, Calvin P.H.; Prudovsky, Igor

    2015-01-01

    FGF1 is a nonclassically released growth factor that regulates carcinogenesis, angiogenesis and inflammation. In vitro and in vivo, FGF1 export is stimulated by cell stress. Upon stress, FGF1 is transported to the plasma membrane where it localizes prior to transmembrane translocation. To determine which proteins participate in the submembrane localization of FGF1 and its export, we used immunoprecipitation mass spectrometry to identify novel proteins that associate with FGF1 during heat shock. The heat shock-dependent association of FGF1 with the large protein AHNAK2 was observed. Heat shock induced the translocation of FGF1 and AHNAK2 to the cytoskeletal fraction. In heat-shocked cells, FGF1 and the C-terminal fragment of AHNAK2 colocalized with F-actin in the vicinity of the cell membrane. Depletion of AHNAK2 resulted in a drastic decrease of stress-induced FGF1 export but did not affect spontaneous FGF2 export and FGF1 release induced by the inhibition of Notch signaling. Thus, AHNAK2 is an important element of the FGF1 nonclassical export pathway. PMID:25560297

  19. Fibroblast growth factor signaling in mammalian tooth development.

    PubMed

    Li, Chun-Ying; Prochazka, Jan; Goodwin, Alice F; Klein, Ophir D

    2014-01-01

    In this review, we discuss the central role of fibroblast growth factor (FGF) signaling in mammalian tooth development. The FGF family consists of 22 members, most of which bind to four different receptor tyrosine kinases, which in turn signal through a cascade of intracellular proteins. This signaling regulates a number of cellular processes, including proliferation, differentiation, cell adhesion and cell mobility. FGF signaling first becomes important in the presumptive dental epithelium at the initiation stage of tooth development, and subsequently, it controls the invagination of the dental epithelium into the underlying mesenchyme. Later, FGFs are critical in tooth shape formation and differentiation of ameloblasts and odontoblasts, as well as in the development and homeostasis of the stem cell niche that fuels the continuously growing mouse incisor. In addition, FGF signaling is critical in human teeth, as mutations in genes encoding FGF ligands or receptors result in several congenital syndromes characterized by alterations in tooth number, morphology or enamel structure. The parallel roles of FGF signaling in mouse and human tooth development demonstrate the conserved importance of FGF signaling in mammalian odontogenesis.

  20. DLX5, FGF8 and the Pin1 isomerase control ΔNp63α protein stability during limb development: a regulatory loop at the basis of the SHFM and EEC congenital malformations

    PubMed Central

    Restelli, Michela; Lopardo, Teresa; Lo Iacono, Nadia; Garaffo, Giulia; Conte, Daniele; Rustighi, Alessandra; Napoli, Marco; Del Sal, Giannino; Perez-Morga, David; Costanzo, Antonio; Merlo, Giorgio Roberto; Guerrini, Luisa

    2014-01-01

    Ectrodactyly, or Split-Hand/Foot Malformation (SHFM), is a congenital condition characterized by the loss of central rays of hands and feet. The p63 and the DLX5;DLX6 transcription factors, expressed in the embryonic limb buds and ectoderm, are disease genes for these conditions. Mutations of p63 also cause the ectodermal dysplasia–ectrodactyly–cleft lip/palate (EEC) syndrome, comprising SHFM. Ectrodactyly is linked to defects of the apical ectodermal ridge (AER) of the developing limb buds. FGF8 is the key signaling molecule in this process, able to direct proximo-distal growth and patterning of the skeletal primordial of the limbs. In the limb buds of both p63 and Dlx5;Dlx6 murine models of SHFM, the AER is poorly stratified and FGF8 expression is severely reduced. We show here that the FGF8 locus is a downstream target of DLX5 and that FGF8 counteracts Pin1–ΔNp63α interaction. In vivo, lack of Pin1 leads to accumulation of the p63 protein in the embryonic limbs and ectoderm. We show also that ΔNp63α protein stability is negatively regulated by the interaction with the prolyl-isomerase Pin1, via proteasome-mediated degradation; p63 mutant proteins associated with SHFM or EEC syndromes are resistant to Pin1 action. Thus, DLX5, p63, Pin1 and FGF8 participate to the same time- and location-restricted regulatory loop essential for AER stratification, hence for normal patterning and skeletal morphogenesis of the limb buds. These results shed new light on the molecular mechanisms at the basis of the SHFM and EEC limb malformations. PMID:24569166

  1. Foxp1 maintains hair follicle stem cell quiescence through regulation of Fgf18

    PubMed Central

    Leishman, Erin; Howard, Jeffrey M.; Garcia, Gloria E.; Miao, Qi; Ku, Amy T.; Dekker, Joseph D.; Tucker, Haley; Nguyen, Hoang

    2013-01-01

    Hair follicles cyclically degenerate and regenerate throughout adult life and require regular stem cell activation to drive the cycle. In the resting phase of the hair cycle, hair follicle stem cells are maintained in a quiescent state until they receive signals to proliferate. We found that the forkhead transcription factor Foxp1 is crucial for maintaining the quiescence of hair follicle stem cells. Loss of Foxp1 in skin epithelial cells leads to precocious stem cell activation, resulting in drastic shortening of the quiescent phase of the hair cycle. Conversely, overexpression of Foxp1 in keratinocytes prevents cell proliferation by promoting cell cycle arrest. Finally, through both gain- and loss-of-function studies, we identify fibroblast growth factor 18 (Fgf18) as the key downstream target of Foxp1. We show that exogenously supplied FGF18 can prevent the hair follicle stem cells of Foxp1 null mice from being prematurely activated. As Fgf18 controls the length of the quiescent phase and is a key downstream target of Foxp1, our data strongly suggest that Foxp1 regulates the quiescent stem cell state in the hair follicle stem cell niche by controlling Fgf18 expression. PMID:23946441

  2. FGF-7 expression enhances the performance of bioengineered skin.

    PubMed

    Erdag, Gulsun; Medalie, Daniel A; Rakhorst, Hinne; Krueger, Gerald G; Morgan, Jeffrey R

    2004-07-01

    To improve the performance of bioengineered skin, we used a recombinant retrovirus encoding FGF-7 to modify diploid human keratinocytes genetically. Control or FGF-7-expressing keratinocytes were seeded onto acellular human dermis to form bioengineered skin. Gene-modified skin secreted significant levels of FGF-7 and formed a thicker and hyperproliferative epidermis with about four times the number of cells per square centimeter. Secretion of an endogenous trophic factor, VEGF, was increased approximately 5-fold. Migration of FGF-7-expressing keratinocytes was stimulated as was the self-healing of bioengineered skin expressing FGF-7. When tested in a bacterial infection model, the antimicrobial properties of FGF-7-expressing skin were increased >500-fold against both gram-negative and gram-positive bacteria. After transplantation to full-thickness wounds on athymic mice, skin expressing FGF-7 was revascularized more rapidly. These results demonstrate that genetic modification can be used to enhance performance and that expression of FGF-7 augments several properties important to the wound-healing properties of bioengineered skin. PMID:15233944

  3. FGF receptors: cancer biology and therapeutics.

    PubMed

    Katoh, Masaru; Nakagama, Hitoshi

    2014-03-01

    Fibroblast growth factors (FGFs) are involved in a variety of cellular processes, such as stemness, proliferation, anti-apoptosis, drug resistance, and angiogenesis. Here, FGF signaling network, cancer genetics/genomics of FGF receptors (FGFRs), and FGFR-targeted therapeutics will be reviewed. FGF signaling to RAS-MAPK branch and canonical WNT signaling cascade mutually regulate transcription programming. FGF signaling to PI3K-AKT branch and Hedgehog, Notch, TGFβ, and noncanonical WNT signaling cascades regulate epithelial-to-mesenchymal transition (EMT) and invasion. Gene amplification of FGFR1 occurs in lung cancer and estrogen receptor (ER)-positive breast cancer, and that of FGFR2 in diffuse-type gastric cancer and triple-negative breast cancer. Chromosomal translocation of FGFR1 occurs in the 8p11 myeloproliferative syndrome and alveolar rhabdomyosarcoma, as with FGFR3 in multiple myeloma and peripheral T-cell lymphoma. FGFR1 and FGFR3 genes are fused to neighboring TACC1 and TACC3 genes, respectively, due to interstitial deletions in glioblastoma multiforme. Missense mutations of FGFR2 are found in endometrial uterine cancer and melanoma, and similar FGFR3 mutations in invasive bladder tumors, and FGFR4 mutations in rhabdomyosarcoma. Dovitinib, Ki23057, ponatinib, and AZD4547 are orally bioavailable FGFR inhibitors, which have demonstrated striking effects in preclinical model experiments. Dovitinib, ponatinib, and AZD4547 are currently in clinical trial as anticancer drugs. Because there are multiple mechanisms of actions for FGFR inhibitors to overcome drug resistance, FGFR-targeted therapy is a promising strategy for the treatment of refractory cancer. Whole exome/transcriptome sequencing will be introduced to the clinical laboratory as the companion diagnostic platform facilitating patient selection for FGFR-targeted therapeutics in the era of personalized medicine.

  4. Lineage-specific loss of FGF17 within the avian orders Galliformes and Passeriformes

    PubMed Central

    Abramyan, John

    2015-01-01

    The genomic and developmental complexity of vertebrates is commonly attributed to two rounds of whole genome duplications which occurred at the base of the vertebrate radiation. These duplications led to the rise of several, multi-gene families of developmental proteins like the Fibroblast growth factors (FGFs); a signaling protein family which functions at various stages of embryonic development. One of the major FGF assemblages arising from these duplications is the FGF8 subfamily, which includes FGF8, FGF17, and FGF18 in tetrapods. While FGF8 and FGF18 are found in all tetrapods and are critical for embryonic survival, genomic analyses suggest putative loss of FGF17 in various lineages ranging from frogs and fish, to the chicken. This study utilizes 27 avian genomes in conjunction with molecular analyses of chicken embryos to confirm the loss of FGF17 in chicken as a true, biological occurrence. FGF17 is also missing in the turkey, black grouse, Japanese quail and the northern bobwhite genomes. These species, along with chicken, form a monophyletic clade in the order Galliformes. Four additional species, members of the clade Passeroidea, within the order Passeriformes, are also missing FGF17. Additionally, analysis of intact FGF17 in other avian lineages reveals that it is still under strong purifying selection, despite being seemingly dispensable. Thus, FGF17 likely represents a molecular spandrel arising from a genome duplication event and due to its high connectivity with FGF8/FGF18, and potential for interference with their function, is retained under strong purifying selection, despite itself not having a strong selective advantage. PMID:25791492

  5. FGF and BMP derived from dorsal root ganglia regulate blastema induction in limb regeneration in Ambystoma mexicanum.

    PubMed

    Satoh, Akira; Makanae, Aki; Nishimoto, Yurie; Mitogawa, Kazumasa

    2016-09-01

    Urodele amphibians have a remarkable organ regeneration ability that is regulated by neural inputs. The identification of these neural inputs has been a challenge. Recently, Fibroblast growth factor (Fgf) and Bone morphogenic protein (Bmp) were shown to substitute for nerve functions in limb and tail regeneration in urodele amphibians. However, direct evidence of Fgf and Bmp being secreted from nerve endings and regulating regeneration has not yet been shown. Thus, it remained uncertain whether they were the nerve factors responsible for successful limb regeneration. To gather experimental evidence, the technical difficulties involved in the usage of axolotls had to be overcome. We achieved this by modifying the electroporation method. When Fgf8-AcGFP or Bmp7-AcGFP was electroporated into the axolotl dorsal root ganglia (DRG), GFP signals were detectable in the regenerating limb region. This suggested that Fgf8 and Bmp7 synthesized in neural cells in the DRG were delivered to the limbs through the long axons. Further knockdown experiments with double-stranded RNA interference resulted in impaired limb regeneration ability. These results strongly suggest that Fgf and Bmp are the major neural inputs that control the organ regeneration ability.

  6. FGF and BMP derived from dorsal root ganglia regulate blastema induction in limb regeneration in Ambystoma mexicanum.

    PubMed

    Satoh, Akira; Makanae, Aki; Nishimoto, Yurie; Mitogawa, Kazumasa

    2016-09-01

    Urodele amphibians have a remarkable organ regeneration ability that is regulated by neural inputs. The identification of these neural inputs has been a challenge. Recently, Fibroblast growth factor (Fgf) and Bone morphogenic protein (Bmp) were shown to substitute for nerve functions in limb and tail regeneration in urodele amphibians. However, direct evidence of Fgf and Bmp being secreted from nerve endings and regulating regeneration has not yet been shown. Thus, it remained uncertain whether they were the nerve factors responsible for successful limb regeneration. To gather experimental evidence, the technical difficulties involved in the usage of axolotls had to be overcome. We achieved this by modifying the electroporation method. When Fgf8-AcGFP or Bmp7-AcGFP was electroporated into the axolotl dorsal root ganglia (DRG), GFP signals were detectable in the regenerating limb region. This suggested that Fgf8 and Bmp7 synthesized in neural cells in the DRG were delivered to the limbs through the long axons. Further knockdown experiments with double-stranded RNA interference resulted in impaired limb regeneration ability. These results strongly suggest that Fgf and Bmp are the major neural inputs that control the organ regeneration ability. PMID:27432514

  7. Exome sequencing identified FGF12 as a novel candidate gene for Kashin-Beck disease.

    PubMed

    Zhang, Feng; Dai, Lanlan; Lin, Weimin; Wang, Wenyu; Liu, Xuanzhu; Zhang, Jianguo; Yang, Tielin; Liu, Xiaogang; Shen, Hui; Chen, Xiangding; Tan, Lijun; Tian, Qing; Deng, Hong-Wen; Xu, Xun; Guo, Xiong

    2016-01-01

    The objective of this study was to identify novel causal genes involved in the pathogenesis of Kashin-Beck disease (KBD). A representative grade III KBD sib pair with serious skeletal growth and development failure was subjected to exome sequencing using the Illumina Hiseq2000 platform. The detected gene mutations were then filtered against the data of 1000 Genome Project, dbSNP database, and BGI inhouse database, and replicated by a genome-wide association study (GWAS) of KBD. Ninety grade II or III KBD patients with extreme KBD phenotypes and 1627 healthy controls were enrolled in the GWAS. Affymetrix Genome-Wide Human SNP Array 6.0 was applied for genotyping. PLINK software was used for association analysis. We identified a novel 106T>C at the 3'UTR of the FGF12 gene, which has not been reported by now. Sequence alignment observed high conversation at the mutated 3'UTR+106T>C locus across various vertebrates. In the GWAS of KBD, we detected nine SNPs of the FGF12 gene showing association evidence (P value < 0.05) with KBD. The most significant association signal was observed at rs1847340 (P value = 1.90 × 10(-5)). This study suggests that FGF12 was a susceptibility gene of KBD. Our results provide novel clues for revealing the pathogenesis of KBD and the biological function of FGF12. PMID:26290467

  8. Loss of FGF21 in diabetic mouse during hepatocellular carcinogenetic transformation

    PubMed Central

    Zhang, Quan; Li, Yan; Liang, Tingting; Lu, Xuemian; Liu, Xingkai; Zhang, Chi; Jiang, Xin; Martin, Robert C; Cheng, Mingliang; Cai, Lu

    2015-01-01

    Diabetes associated metabolic syndrome has been shown to be an independent risk factor for the development of hepatocellular carcinoma (HCC). Cirrhosis, in fact, was not always a prerequisite of HCC development and this might particularly apply to the metabolic abnormality associated HCC. This study was to investigate diabetes associated HCC and the potential role of FGF21 during carcinogenetic transformation of HCC. Dimethylnitrosamine (DEN) was used to induce HCC in the diabetic OVE26 mice. Pronounced damage characterized by steatohepatitis was found in the liver of diabetic mice. Steatohepatitis accompanied by constant cell proliferation and tumor cell growth were also found in the hepatic tissues of diabetic OVE26 mice when DEN being administrated. FGF21 protein level increased in liver tissues at an early stage along with steatohepatitis in diabetic OVE26 mice, but decreased in liver tissues later when HCC was developed. In addition, decreased FGF21 protein level was associated with cancerous hyper-proliferation and aberrant p53 and TGF-β/Smad signaling during HCC development. Loss of FGF21 may play an important role in HCC carcinogenetic transformation during metabolic liver injury in diabetic animals. The present finding calls attention to the need to control metabolic disorders associated with diabetes and may further develop a protective strategy against HCC. PMID:26175944

  9. Identification of a Mutation in FGF23 Involved in Mandibular Prognathism

    PubMed Central

    Chen, Fengshan; Li, Qin; Gu, Mingliang; Li, Xin; Yu, Jun; Zhang, Yong-Biao

    2015-01-01

    Mandibular prognathism (MP) is a severe maxillofacial disorder with undetermined genetic background. We collected a Chinese pedigree with MP which involved in 23 living members of 4 generations. Genome-wide linkage analysis were carried out to obtain the information in this family and a new MP-susceptibility locus, 12pter-p12.3 was identified. Whole-exome sequencing identified a novel heterozygous mutation in fibroblast growth factor (FGF) 23 (; p.A12D) which well segregated with MP in this pedigree within the locus. The mutation was also detected in 3 cases out of 65 sporadic MP patients, but not in any of the 342 control subjects. The p.A12D mutation may disrupt signal peptide function and inhibit secretory in FGF23. Furthermore, mutant FGF23 was overexpressed in 293T cells, increased cytoplasmic accumulation was observed compared with the wild type. We have discovered that c.35C>A mutation in FGF23 strongly associated with MP, which expand our understanding of the genetic contribution to MP pathogenesis. PMID:26059428

  10. Remote Control of Neuronal Signaling

    PubMed Central

    Rogan, Sarah C.

    2011-01-01

    A significant challenge for neuroscientists is to determine how both electrical and chemical signals affect the activity of cells and circuits and how the nervous system subsequently translates that activity into behavior. Remote, bidirectional manipulation of those signals with high spatiotemporal precision is an ideal approach to addressing that challenge. Neuroscientists have recently developed a diverse set of tools that permit such experimental manipulation with varying degrees of spatial, temporal, and directional control. These tools use light, peptides, and small molecules to primarily activate ion channels and G protein-coupled receptors (GPCRs) that in turn activate or inhibit neuronal firing. By monitoring the electrophysiological, biochemical, and behavioral effects of such activation/inhibition, researchers can better understand the links between brain activity and behavior. Here, we review the tools that are available for this type of experimentation. We describe the development of the tools and highlight exciting in vivo data. We focus primarily on designer GPCRs (receptors activated solely by synthetic ligands, designer receptors exclusively activated by designer drugs) and microbial opsins (e.g., channelrhodopsin-2, halorhodopsin, Volvox carteri channelrhodopsin) but also describe other novel techniques that use orthogonal receptors, caged ligands, allosteric modulators, and other approaches. These tools differ in the direction of their effect (activation/inhibition, hyperpolarization/depolarization), their onset and offset kinetics (milliseconds/minutes/hours), the degree of spatial resolution they afford, and their invasiveness. Although none of these tools is perfect, each has advantages and disadvantages, which we describe, and they are all still works in progress. We conclude with suggestions for improving upon the existing tools. PMID:21415127

  11. FGF-21: promising biomarker for detecting ketosis in dairy cows.

    PubMed

    Xu, Chuang; Xu, Qiushi; Chen, Yuanyuan; Yang, Wei; Xia, Cheng; Yu, Hongjiang; Zhu, Kuilin; Shen, Taiyu; Zhang, Ziyang

    2016-03-01

    The objective of this study was to investigate the measurement of serum fibroblast growth factor-21 (FGF-21), a protein mainly synthesized by the liver, as a sensitive biomarker for diagnosis of ketosis in dairy cows. Ninety Holstein-Friesian dairy cows (60 healthy and 30 ketosis cases) were selected and divided into a Ketosis group (K), and a Control group (C). We measured serum FGF-21 and other biochemical parameters by commercial ELISA kits. In a combined population of all 90 cows, we found that serum FGF-21 level was lower (P < 0.001) in cows suffering from ketosis. When the β-hydroxybutyric acid (BHBA) level increased over 1.2 mmol/L, the FGF-21 level tended to decline below 300.85 pg/ml. The area under the receiver operating characteristic curve (AUC-ROC) for serum FGF-21 for diagnosis of fatty liver was 0.952-0.025 [95% confidence interval (CI) 0.904, 1.000] which was higher than the AUC-ROC for glucose (Glc) and other tested parameters. We concluded that FGF-21 could be a diagnostic parameter in the evaluation and auxiliary diagnosis of changes in the energy metabolism state, and serum FGF-21 measurement would have a considerable clinical impact and lead to greater profitability in the dairy industry.

  12. FGF-21: promising biomarker for detecting ketosis in dairy cows.

    PubMed

    Xu, Chuang; Xu, Qiushi; Chen, Yuanyuan; Yang, Wei; Xia, Cheng; Yu, Hongjiang; Zhu, Kuilin; Shen, Taiyu; Zhang, Ziyang

    2016-03-01

    The objective of this study was to investigate the measurement of serum fibroblast growth factor-21 (FGF-21), a protein mainly synthesized by the liver, as a sensitive biomarker for diagnosis of ketosis in dairy cows. Ninety Holstein-Friesian dairy cows (60 healthy and 30 ketosis cases) were selected and divided into a Ketosis group (K), and a Control group (C). We measured serum FGF-21 and other biochemical parameters by commercial ELISA kits. In a combined population of all 90 cows, we found that serum FGF-21 level was lower (P < 0.001) in cows suffering from ketosis. When the β-hydroxybutyric acid (BHBA) level increased over 1.2 mmol/L, the FGF-21 level tended to decline below 300.85 pg/ml. The area under the receiver operating characteristic curve (AUC-ROC) for serum FGF-21 for diagnosis of fatty liver was 0.952-0.025 [95% confidence interval (CI) 0.904, 1.000] which was higher than the AUC-ROC for glucose (Glc) and other tested parameters. We concluded that FGF-21 could be a diagnostic parameter in the evaluation and auxiliary diagnosis of changes in the energy metabolism state, and serum FGF-21 measurement would have a considerable clinical impact and lead to greater profitability in the dairy industry. PMID:26728033

  13. FGF21 Is Associated with Acanthosis Nigricans in Obese Patients

    PubMed Central

    Huang, Yueye; Yang, Jie; Li, Yan; Chen, Jiaqi; Song, Kexiu; Wang, Xingchun; Bu, Le; Cheng, Xiaoyun; Wang, Jiying; Qu, Shen

    2016-01-01

    Objective. We aimed to investigate the relationship between FGF21 and obesity-related acanthosis nigricans (AN). Methods. 40 obese patients without AN (OB group), 40 obese patients with AN (AN group), and 40 healthy volunteers (control group, CON) were included in this study. Weight, BMI, lipid profile, FFA, UA, and CRP were measured in all participants. Oral glucose tolerance tests (OGTT) were performed and serum glucose and plasma insulin were measured. Serum FGF21 was measured by ELISA. Results. Compared with OB group, AN group had higher levels of fasting insulin and homeostasis model of assessment for insulin resistance (HOMA-IR) (P < 0.05), but lower serum levels of blood glucose. The difference of FGF21 among three groups was significant and AN group showed the highest serum level of FGF21 (P < 0.05). Serum FGF21 was most positively correlated with fasting insulin and HOMA-IR. Multiple logistic analysis showed that FGF21 was the independent risk factor for AN (OR 4.550; 95% CI 1.054–19.635; P = 0.042). Conclusion. AN patients had more serious hyperinsulinemia but better serum levels of blood glucose than OB. Increased FGF21 is associated with AN in obese patients and may be considered as compensatory response to the decreased insulin sensitivity. PMID:27190511

  14. Fibroblast growth factor 21 in breast milk controls neonatal intestine function.

    PubMed

    Gavaldà-Navarro, Aleix; Hondares, Elayne; Giralt, Marta; Mampel, Teresa; Iglesias, Roser; Villarroya, Francesc

    2015-09-02

    FGF21 is a hormonal factor with important functions in the control of metabolism. FGF21 is found in rodent and human milk. Radiolabeled FGF21 administered to lactating dams accumulates in milk and is transferred to neonatal gut. The small intestine of neonatal (but not adult) mice highly expresses β-Klotho in the luminal area. FGF21-KO pups fed by FGF21-KO dams showed decreased expression and circulating levels of incretins (GIP and GLP-1), reduced gene expression of intestinal lactase and maltase-glucoamylase, and low levels of galactose in plasma, all associated with a mild decrease in body weight. When FGF21-KO pups were nursed by wild-type dams (expressing FGF21 in milk), intestinal peptides and digestive enzymes were up-regulated, lactase enzymatic activity was induced, and galactose levels and body weight were normalized. Neonatal intestine explants were sensitive to FGF21, as evidenced by enhanced ERK1/2 phosphorylation. Oral infusion of FGF21 into neonatal pups induced expression of intestinal hormone factors and digestive enzymes, lactase activity and lactose absorption. These findings reveal a novel role of FGF21 as a hormonal factor contributing to neonatal intestinal function via its presence in maternal milk. Appropriate signaling of FGF21 to neonate is necessary to ensure optimal digestive and endocrine function in developing intestine.

  15. Fibroblast growth factor 21 in breast milk controls neonatal intestine function

    PubMed Central

    Gavaldà-Navarro, Aleix; Hondares, Elayne; Giralt, Marta; Mampel, Teresa; Iglesias, Roser; Villarroya, Francesc

    2015-01-01

    FGF21 is a hormonal factor with important functions in the control of metabolism. FGF21 is found in rodent and human milk. Radiolabeled FGF21 administered to lactating dams accumulates in milk and is transferred to neonatal gut. The small intestine of neonatal (but not adult) mice highly expresses β-Klotho in the luminal area. FGF21-KO pups fed by FGF21-KO dams showed decreased expression and circulating levels of incretins (GIP and GLP-1), reduced gene expression of intestinal lactase and maltase-glucoamylase, and low levels of galactose in plasma, all associated with a mild decrease in body weight. When FGF21-KO pups were nursed by wild-type dams (expressing FGF21 in milk), intestinal peptides and digestive enzymes were up-regulated, lactase enzymatic activity was induced, and galactose levels and body weight were normalized. Neonatal intestine explants were sensitive to FGF21, as evidenced by enhanced ERK1/2 phosphorylation. Oral infusion of FGF21 into neonatal pups induced expression of intestinal hormone factors and digestive enzymes, lactase activity and lactose absorption. These findings reveal a novel role of FGF21 as a hormonal factor contributing to neonatal intestinal function via its presence in maternal milk. Appropriate signaling of FGF21 to neonate is necessary to ensure optimal digestive and endocrine function in developing intestine. PMID:26329882

  16. Caveolin-1 Orchestrates Fibroblast Growth Factor 2 Signaling Control of Angiogenesis in Placental Artery Endothelial Cell Caveolae

    PubMed Central

    Feng, Lin; Liao, Wu-xiang; Luo, Quan; Zhang, Hong-hai; Wang, Wen; Zheng, Jing; Chen, Dong-bao

    2011-01-01

    Fibroblast growth factor (FGF) receptor 1 (FGFR1) protein was expressed as the long and short as well as some truncated forms in ovine fetoplacental artery ex vivo and in vitro. Upon FGF2 stimulation, both the long and short FGFR1s were tyrosine phosphorylated and the PI3K/AKT1 and ERK1/2 pathways were activated in a concentration- and time- dependent manner in ovine fetoplacental artery endothelial (oFPAE) cells. Blockade of the PI3K/AKT1 pathway attenuated FGF2-stimulated cell proliferation and migration as well as tube formation; blockade of the ERK1/2 pathway abolished FGF2-stimulated tube formation and partially inhibited cell proliferation and did not alter cell migration. Both AKT1 and ERK1/2 were co-fractionated with caveolin-1 and activated by FGF2 in the caveolae. Disruption of caveolae by methyl-β-cyclodextrin inhibited FGF2 activation of AKT1 and ERK1/2. FGFR1 was found in the caveolae where it physically binds to caveolin-1. FGF2 stimulated dissociation of FGFR1 from caveolin-1. Downregulation of caveolin-1 significantly attenuated the FGF2-induced activation of AKT1 and ERK1/2 and inhibited FGF2-induced cell proliferation, migration and tube formation in oFPAE cells. Pretreatment with a caveolin-1 scaffolding domain peptide to mimic caveolin-1 overexpression also inhibited these FGF2-induced angiogenic responses. These data demonstrate that caveolae function as a platform for regulating FGF2-induced angiogenesis through spatiotemporally compartmentalizing FGFR1 and the AKT1 and ERK1/2 signaling modules; the major caveolar structural protein caveolin-1 interacts with FGFR1 and paradoxically regulates FGF2-induced activation of PI3K/AKT1 and ERK1/2 pathways that coordinately regulate placental angiogenesis. PMID:21830216

  17. FGF21 Promotes Endothelial Cell Angiogenesis through a Dynamin-2 and Rab5 Dependent Pathway

    PubMed Central

    Yaqoob, Usman; Jagavelu, Kumaravelu; Shergill, Uday; de Assuncao, Thiago; Cao, Sheng; Shah, Vijay H.

    2014-01-01

    Binding of angiogenic molecules with cognate receptor tyrosine kinases (RTK) is required for angiogenesis however the precise link between RTK binding, endocytosis, and signaling requires further investigation. Here, we use FGFR1 as a model to test the effects of the large GTPase and endocytosis regulatory molecule dynamin-2 on angiogenic signaling in context of distinct FGF ligands. In vitro, overexpression of dominant negative dynamin-2 (DynK44A) attenuates FGFR1 activation of Erk and tubulogenesis by FGF2. Furthermore, we identify FGF21, a non-classical, FGF ligand implicated in diverse human pathologies as an angiogenic molecule acting through FGFR1 and β-Klotho coreceptor. Disruption of FGFR1 activation of ERK by FGF21 is achieved by perturbation of the function of both dynamin-2 and Rab5 GTPase. In vivo, mice harboring endothelial selective overexpression of DynK44A, show impaired angiogenesis in response to FGF21. In conclusion, dynamin dependent endocytosis of FGFR1 is required for in vitro and in vivo angiogenesis in response to FGF2 and the non-classical FGF ligand, FGF21. These studies extend our understanding of the relationships between RTK binding, internalization, endosomal targeting, and angiogenic signaling. PMID:24848261

  18. The effects of luminescent ruthenium(II) polypyridyl functionalized selenium nanoparticles on bFGF-induced angiogenesis and AKT/ERK signaling.

    PubMed

    Sun, Dongdong; Liu, Yanan; Yu, Qianqian; Zhou, Yanhui; Zhang, Rong; Chen, Xiaojia; Hong, An; Liu, Jie

    2013-01-01

    Anti-angiogenesis is an effective strategy for cancer treatment because uncontrolled tumor growth depends on tumor angiogenesis and sufficient blood supply. Thus, blocking angiogenesis could be a strategy to arrest tumor growth. The function and mechanism of luminescent ruthenium-modified selenium nanoparticles (Ru-SeNPs) in angiogenesis have not been elucidated to date. Here, we found that Ru-SeNPs significantly inhibited human umbilical vascular endothelial cell (HUVEC) proliferation, migration and tube formation. Ru-SeNPs was also tested in vivo in the chicken chorioallantoic membrane (CAM) assay and found to inhibit bFGF-treated CAMs development like suramin. Moreover, we showed that Ru-SeNPs inhibited the activations of FGFR1 and its downstream protein kinases, such ErK and AKT. Furthermore, by using fluorescence confocal microscopy and TEM imaging studies, we have demonstrated their cellular uptake and localization within the cytoplasm of HepG2 and HUVEC cells. These findings indicate that Ru-SeNPs inhibits angiogenesis and may be a viable drug candidate in anti-angiogenesis and anticancer therapies. PMID:23059005

  19. Hoxc8 initiates an ectopic mammary program by regulating Fgf10 and Tbx3 expression and Wnt/β-catenin signaling

    PubMed Central

    Carroll, Lara S.; Capecchi, Mario R.

    2015-01-01

    The role of Hox genes in the formation of cutaneous accessory organs such as hair follicles and mammary glands has proved elusive, a likely consequence of overlapping function and expression among various homeobox factors. Lineage and immunohistochemical analysis of Hoxc8 in mice revealed that this midthoracic Hox gene has transient but strong regional expression in ventrolateral surface ectoderm at E10.5, much earlier than previously reported. Targeted mice were generated to conditionally misexpress Hoxc8 from the Rosa locus using select Cre drivers, which significantly expanded the domain of thoracic identity in mutant embryos. Accompanying this expansion was the induction of paired zones of ectopic mammary development in the cervical region, which generated between three and five pairs of mammary placodes anterior to the first wild-type mammary rudiment. These rudiments expressed the mammary placode markers Wnt10b and Tbx3 and were labeled by antibodies to the mammary mesenchyme markers ERα and androgen receptor. Somitic Fgf10 expression, which is required for normal mammary line formation, was upregulated in mutant cervical somites, and conditional ablation of ectodermal Tbx3 expression eliminated all normally positioned and ectopic mammary placodes. We present evidence that Hoxc8 participates in regulating the initiation stages of mammary placode morphogenesis, and suggest that this and other Hox genes are likely to have important roles during regional specification and initiation of these and other cutaneous accessory organs. PMID:26459221

  20. Hoxc8 initiates an ectopic mammary program by regulating Fgf10 and Tbx3 expression and Wnt/β-catenin signaling.

    PubMed

    Carroll, Lara S; Capecchi, Mario R

    2015-12-01

    The role of Hox genes in the formation of cutaneous accessory organs such as hair follicles and mammary glands has proved elusive, a likely consequence of overlapping function and expression among various homeobox factors. Lineage and immunohistochemical analysis of Hoxc8 in mice revealed that this midthoracic Hox gene has transient but strong regional expression in ventrolateral surface ectoderm at E10.5, much earlier than previously reported. Targeted mice were generated to conditionally misexpress Hoxc8 from the Rosa locus using select Cre drivers, which significantly expanded the domain of thoracic identity in mutant embryos. Accompanying this expansion was the induction of paired zones of ectopic mammary development in the cervical region, which generated between three and five pairs of mammary placodes anterior to the first wild-type mammary rudiment. These rudiments expressed the mammary placode markers Wnt10b and Tbx3 and were labeled by antibodies to the mammary mesenchyme markers ERα and androgen receptor. Somitic Fgf10 expression, which is required for normal mammary line formation, was upregulated in mutant cervical somites, and conditional ablation of ectodermal Tbx3 expression eliminated all normally positioned and ectopic mammary placodes. We present evidence that Hoxc8 participates in regulating the initiation stages of mammary placode morphogenesis, and suggest that this and other Hox genes are likely to have important roles during regional specification and initiation of these and other cutaneous accessory organs.

  1. Fibroblast Growth Factor (FGF-2) and Its Receptors FGFR-2 and FGFR-3 May Be Putative Biomarkers of Malignant Transformation of Potentially Malignant Oral Lesions into Oral Squamous Cell Carcinoma

    PubMed Central

    Nayak, Seema; Goel, Madhu Mati; Makker, Annu; Bhatia, Vikram; Chandra, Saumya; Kumar, Sandeep; Agarwal, S. P.

    2015-01-01

    There are several factors like angiogenesis, lymphangiogenesis, genetic alterations, mutational factors that are involved in malignant transformation of potentially malignant oral lesions (PMOLs) to oral squamous cell carcinoma (OSCC). Fibroblast growth factor-2 (FGF-2) is one of the prototypes of the large family of growth factors that bind heparin. FGF-2 induces angiogenesis and its receptors may play a role in synthesis of collagen. FGFs are involved in transmission of signals between the epithelium and connective tissue, and influence growth and differentiation of a wide variety of tissue including epithelia. The present study was undertaken to analyze expression of FGF-2 and its receptors FGFR-2 and FGFR-3 in 72 PMOLs, 108 OSCC and 52 healthy controls, and their role in risk assessment for malignant transformation of Leukoplakia (LKP) and Oral submucous fibrosis (OSMF) to OSCC. Immunohistochemistry was performed using antibodies against FGF-2, FGFR-2 and FGFR-3. IHC results were validated by Real Time PCR. Expression of FGF-2, FGFR-2 and FGFR-3 was upregulated from PMOLs to OSCC. While 90% (9/10) of PMOLs which showed malignant transformation (transformed) expressed FGF-2, only 24.19% cases (15/62) of PMOLs which were not transformed (untransformed) to OSCC expressed FGF-2. Similarly, FGFR-2 expression was seen in 16/62 (25.81%) of untransformed PMOLs and 8/10 (80%) cases of transformed PMOLs. FGFR-3 expression was observed in 23/62 (37.10%) cases of untransformed PMOLs and 6/10 (60%) cases of transformed PMOLs. A significant association of FGF-2 and FGFR-2 expression with malignant transformation from PMOLs to OSCC was observed both at phenotypic and molecular level. The results suggest that FGF-2 and FGFR-2 may be useful as biomarkers of malignant transformation in patients with OSMF and LKP. PMID:26465941

  2. Fibroblast Growth Factor (FGF-2) and Its Receptors FGFR-2 and FGFR-3 May Be Putative Biomarkers of Malignant Transformation of Potentially Malignant Oral Lesions into Oral Squamous Cell Carcinoma.

    PubMed

    Nayak, Seema; Goel, Madhu Mati; Makker, Annu; Bhatia, Vikram; Chandra, Saumya; Kumar, Sandeep; Agarwal, S P

    2015-01-01

    There are several factors like angiogenesis, lymphangiogenesis, genetic alterations, mutational factors that are involved in malignant transformation of potentially malignant oral lesions (PMOLs) to oral squamous cell carcinoma (OSCC). Fibroblast growth factor-2 (FGF-2) is one of the prototypes of the large family of growth factors that bind heparin. FGF-2 induces angiogenesis and its receptors may play a role in synthesis of collagen. FGFs are involved in transmission of signals between the epithelium and connective tissue, and influence growth and differentiation of a wide variety of tissue including epithelia. The present study was undertaken to analyze expression of FGF-2 and its receptors FGFR-2 and FGFR-3 in 72 PMOLs, 108 OSCC and 52 healthy controls, and their role in risk assessment for malignant transformation of Leukoplakia (LKP) and Oral submucous fibrosis (OSMF) to OSCC. Immunohistochemistry was performed using antibodies against FGF-2, FGFR-2 and FGFR-3. IHC results were validated by Real Time PCR. Expression of FGF-2, FGFR-2 and FGFR-3 was upregulated from PMOLs to OSCC. While 90% (9/10) of PMOLs which showed malignant transformation (transformed) expressed FGF-2, only 24.19% cases (15/62) of PMOLs which were not transformed (untransformed) to OSCC expressed FGF-2. Similarly, FGFR-2 expression was seen in 16/62 (25.81%) of untransformed PMOLs and 8/10 (80%) cases of transformed PMOLs. FGFR-3 expression was observed in 23/62 (37.10%) cases of untransformed PMOLs and 6/10 (60%) cases of transformed PMOLs. A significant association of FGF-2 and FGFR-2 expression with malignant transformation from PMOLs to OSCC was observed both at phenotypic and molecular level. The results suggest that FGF-2 and FGFR-2 may be useful as biomarkers of malignant transformation in patients with OSMF and LKP. PMID:26465941

  3. Estrogen mediated epithelial proliferation in the uterus is directed by stromal Fgf10 and Bmp8a.

    PubMed

    Chung, Daesuk; Gao, Fei; Jegga, Anil G; Das, Sanjoy K

    2015-01-15

    To define endometrial stromal-derived paracrine mediators that participate in estradiol-17β (E2)-induced epithelial proliferation, microarray analysis of gene expression was carried out in mouse uterine epithelial-stromal co-culture systems under the condition of E2 or vehicle (control). Our results demonstrated gene alteration by E2: in epithelial cells, we found up-regulation of 119 genes and down-regulation of 28 genes, while in stroma cells we found up-regulation of 144 genes and down-regulation of 184 genes. A functional enrichment analysis of the upregulated epithelial genes implicated them for proliferation, while upregulated stromal genes were associated with extracellular functions. Quantitative RT-PCR and in situ hybridization results confirmed differential gene expression in both cell cultures and ovariectomized uteri after the above treatments. Based on our identification of stromal secretory factors, we found evidence that suppression by siRNA specifically for Bmp8a and/or Fgf10 in the stromal layer caused significant inhibition of proliferation by E2 in the co-culture system, suggesting Bmp8a and Fgf10 act as paracrine mediators during E2-dependent control of uterine proliferation. The localization of receptors and receptor activation signaling in epithelial cells in both the co-culture system and uteri was consistent with their involvement in ligand-receptor signaling. Interestingly, loss of Bmp8a or Fgf10 also caused abrogation of E2-regulated epithelial receptor signaling in co-culture systems, suggesting that stroma-derived Fgf10 and Bmp8a are responsible for epithelial communication. Overall, stromal Fgf10 and Bmp8a serve as potential paracrine factors for E2-dependent regulation of epithelial proliferation in the uterus.

  4. Estrogen mediated epithelial proliferation in the uterus is directed by stromal Fgf10 and Bmp8a

    PubMed Central

    Chung, Daesuk; Gao, Fei; Jegga, Anil G.; Das, Sanjoy K.

    2014-01-01

    To define endometrial stromal-derived paracrine mediators that participate in estradiol-17β (E2)-induced epithelial proliferation, microarray analysis of gene expression was carried out in mouse uterine epithelial–stromal co-culture systems under the condition of E2 or vehicle (control). Our results demonstrated gene alteration by E2: in epithelial cells, we found up-regulation of 119 genes and down-regulation of 28 genes, while in stroma cells we found up-regulation of 144 genes and down-regulation of 184 genes. A functional enrichment analysis of the upregulated epithelial genes implicated them for proliferation, while upregulated stromal genes were associated with extracellular functions. Quantitative RT-PCR and in situ hybridization results confirmed differential gene expression in both cell cultures and ovariectomized uteri after the above treatments. Based on our identification of stromal secretory factors, we found evidence that suppression by siRNA specifically for Bmp8a and/or Fgf10 in the stromal layer caused significant inhibition of proliferation by E2 in the co-culture system, suggesting Bmp8a and Fgf10 act as paracrine mediators during E2-dependent control of uterine proliferation. The localization of receptors and receptor activation signaling in epithelial cells in both the co-culture system and uteri was consistent with their involvement in ligand–receptor signaling. Interestingly, loss of Bmp8a or Fgf10 also caused abrogation of E2-regulated epithelial receptor signaling in co-culture systems, suggesting that stroma-derived Fgf10 and Bmp8a are responsible for epithelial communication. Overall, stromal Fgf10 and Bmp8a serve as potential paracrine factors for E2-dependent regulation of epithelial proliferation in the uterus. PMID:25451979

  5. Nuclear translocation of fibroblast growth factor-2 (FGF2) is regulated by Karyopherin-β2 and Ran GTPase in human glioblastoma cells.

    PubMed

    Wang, Feng; Yang, Lijun; Shi, Lin; Li, Qian; Zhang, Gengshen; Wu, Jianliang; Zheng, Jun; Jiao, Baohua

    2015-08-28

    Human glioblastoma multiforme (GBM) is the most malignant tumor of the central nervous system (CNS). Fibroblast growth factor-2 (FGF2) belongs to the FGF superfamily and functions as a potential oncoprotein in GBM. FGF2 has low molecular weight (18K) and high molecular weight (HMW) isoforms. Nuclear accumulation of HMW-FGF2 strongly promotes glioblastoma cell proliferation, yet mechanism governing such cellular distribution remains unexplored. We investigated the mechanisms regulating FGF2 cellular localization in T98G human brain glioblastoma cells. We found HMW-FGF2, but not 18K-FGF2, is primarily located in the nucleus and interacts with nuclear transport protein Karyopherin-β2/Transportin (Kapβ2). SiRNA-directed Kapβ2 knockdown significantly reduced HMW-FGF2's nuclear translocation. Moreover, inhibiting Ran GTPase activity also resulted in decreased HMW-FGF2 nuclear accumulation. Proliferation of T98G cells is greatly enhanced with transfections HMW-FGF2. Decreased PTEN expression and activated Akt signaling were observed upon HMW-FGF2 overexpression and might mediate pro-survival effect of FGF2. Interestingly, addition of nuclear localization signal (NLS) to 18K-FGF2 forced its nuclear import and dramatically increased cell proliferation and Akt activation. These findings demonstrated for the first time the molecular mechanisms for FGF2's nuclear import, which promotes GBM cell proliferation and survival, providing novel insights to the development of GBM treatments. PMID:26056081

  6. Nuclear translocation of fibroblast growth factor-2 (FGF2) is regulated by Karyopherin-β2 and Ran GTPase in human glioblastoma cells.

    PubMed

    Wang, Feng; Yang, Lijun; Shi, Lin; Li, Qian; Zhang, Gengshen; Wu, Jianliang; Zheng, Jun; Jiao, Baohua

    2015-08-28

    Human glioblastoma multiforme (GBM) is the most malignant tumor of the central nervous system (CNS). Fibroblast growth factor-2 (FGF2) belongs to the FGF superfamily and functions as a potential oncoprotein in GBM. FGF2 has low molecular weight (18K) and high molecular weight (HMW) isoforms. Nuclear accumulation of HMW-FGF2 strongly promotes glioblastoma cell proliferation, yet mechanism governing such cellular distribution remains unexplored. We investigated the mechanisms regulating FGF2 cellular localization in T98G human brain glioblastoma cells. We found HMW-FGF2, but not 18K-FGF2, is primarily located in the nucleus and interacts with nuclear transport protein Karyopherin-β2/Transportin (Kapβ2). SiRNA-directed Kapβ2 knockdown significantly reduced HMW-FGF2's nuclear translocation. Moreover, inhibiting Ran GTPase activity also resulted in decreased HMW-FGF2 nuclear accumulation. Proliferation of T98G cells is greatly enhanced with transfections HMW-FGF2. Decreased PTEN expression and activated Akt signaling were observed upon HMW-FGF2 overexpression and might mediate pro-survival effect of FGF2. Interestingly, addition of nuclear localization signal (NLS) to 18K-FGF2 forced its nuclear import and dramatically increased cell proliferation and Akt activation. These findings demonstrated for the first time the molecular mechanisms for FGF2's nuclear import, which promotes GBM cell proliferation and survival, providing novel insights to the development of GBM treatments.

  7. FGF-23 Regulates CYP27B1 Transcription in the Kidney and in Extra-Renal Tissues

    PubMed Central

    Chanakul, Ankanee; Zhang, Martin Y. H.; Louw, Andrew; Armbrecht, Harvey J.; Miller, Walter L.; Portale, Anthony A.; Perwad, Farzana

    2013-01-01

    The mitochondrial enzyme 25-hydroxyvitamin D 1α-hydroxylase, which is encoded by the CYP27B1 gene, converts 25OHD to the biological active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)2D). Renal 1α-hydroxylase activity is the principal determinant of the circulating 1,25(OH)2D concentration and enzyme activity is tightly regulated by several factors. Fibroblast growth factor-23 (FGF-23) decreases serum 1,25(OH)2D concentrations by suppressing CYP27B1 mRNA abundance in mice. In extra-renal tissues, 1α-hydroxylase is responsible for local 1,25(OH)2D synthesis, which has important paracrine actions, but whether FGF-23 regulates CYP27B1 gene expression in extra-renal tissues is unknown. We sought to determine whether FGF-23 regulates CYP27B1 transcription in the kidney and whether extra-renal tissues are target sites for FGF-23-induced suppression of CYP27B1. In HEK293 cells transfected with the human CYP27B1 promoter, FGF-23 suppressed promoter activity by 70%, and the suppressive effect was blocked by CI-1040, a specific inhibitor of extracellular signal regulated kinase 1/2. To examine CYP27B1 transcriptional activity in vivo, we crossed fgf-23 null mice with mice bearing the CYP27B1 promoter-driven luciferase transgene (1α-Luc). In the kidney of FGF-23 null/1α-Luc mice, CYP27B1 promoter activity was increased by 3-fold compared to that in wild-type/1α-Luc mice. Intraperitoneal injection of FGF-23 suppressed renal CYP27B1 promoter activity and protein expression by 26% and 60% respectively, and the suppressive effect was blocked by PD0325901, an ERK1/2 inhibitor. These findings provide evidence that FGF-23 suppresses CYP27B1 transcription in the kidney. Furthermore, we demonstrate that in FGF-23 null/1α-Luc mice, CYP27B1 promoter activity and mRNA abundance are increased in several extra-renal sites. In the heart of FGF-23 null/1α-Luc mice, CYP27B1 promoter activity and mRNA were 2- and 5-fold higher, respectively, than in control mice. We also

  8. Blending Gyro Signals To Improve Control Stability

    NASA Technical Reports Server (NTRS)

    Lee, J. F. L.

    1986-01-01

    Interference by structural vibrations reduced by adding signals from spatially separated gyros. Technique involves blending signals from rate gyroscopes located at different parts of structure to obtain composite signal that more nearly represents rotation of entire structure. Aircraft vibrations perpendicular to pitch axis contribute to rotations sensed by pitch-rate gyros. Proper blending of signals from gyros suppress contribution of dominant vibrational mode. Most likely applications of concept are flight-control systems for aircraft.

  9. FGF23 deficiency leads to mixed hearing loss and middle ear malformation in mice.

    PubMed

    Lysaght, Andrew C; Yuan, Quan; Fan, Yi; Kalwani, Neil; Caruso, Paul; Cunnane, MaryBeth; Lanske, Beate; Stanković, Konstantina M

    2014-01-01

    Fibroblast growth factor 23 (FGF23) is a circulating hormone important in phosphate homeostasis. Abnormal serum levels of FGF23 result in systemic pathologies in humans and mice, including renal phosphate wasting diseases and hyperphosphatemia. We sought to uncover the role FGF23 plays in the auditory system due to shared molecular mechanisms and genetic pathways between ear and kidney development, the critical roles multiple FGFs play in auditory development and the known hearing phenotype in mice deficient in klotho (KL), a critical co-factor for FGF23 signaling. Using functional assessments of hearing, we demonstrate that Fgf[Formula: see text] mice are profoundly deaf. Fgf[Formula: see text] mice have moderate hearing loss above 20 kHz, consistent with mixed conductive and sensorineural pathology of both middle and inner ear origin. Histology and high-voltage X-ray computed tomography of Fgf[Formula: see text] mice demonstrate dysplastic bulla and ossicles; Fgf[Formula: see text] mice have near-normal morphology. The cochleae of mutant mice appear nearly normal on gross and microscopic inspection. In wild type mice, FGF23 is ubiquitously expressed throughout the cochlea. Measurements from Fgf[Formula: see text] mice do not match the auditory phenotype of Kl-/- mice, suggesting that loss of FGF23 activity impacts the auditory system via mechanisms at least partially independent of KL. Given the extensive middle ear malformations and the overlap of initiation of FGF23 activity and Eustachian tube development, this work suggests a possible role for FGF23 in otitis media.

  10. Essential roles of zebrafish bmp2a, fgf10, and fgf24 in the specification of the ventral pancreas

    PubMed Central

    Naye, François; Voz, Marianne L.; Detry, Nathalie; Hammerschmidt, Matthias; Peers, Bernard; Manfroid, Isabelle

    2012-01-01

    In vertebrates, pancreas and liver arise from bipotential progenitors located in the embryonic gut endoderm. Bone morphogenic protein (BMP) and fibroblast growth factor (FGF) signaling pathways have been shown to induce hepatic specification while repressing pancreatic fate. Here we show that BMP and FGF factors also play crucial function, at slightly later stages, in the specification of the ventral pancreas. By analyzing the pancreatic markers pdx1, ptf1a, and hlxb9la in different zebrafish models of BMP loss of function, we demonstrate that the BMP pathway is required between 20 and 24 h postfertilization to specify the ventral pancreatic bud. Knockdown experiments show that bmp2a, expressed in the lateral plate mesoderm at these stages, is essential for ventral pancreas specification. Bmp2a action is not restricted to the pancreatic domain and is also required for the proper expression of hepatic markers. By contrast, through the analysis of fgf10−/−; fgf24−/− embryos, we reveal the specific role of these two FGF ligands in the induction of the ventral pancreas and in the repression of the hepatic fate. These mutants display ventral pancreas agenesis and ectopic masses of hepatocytes. Overall, these data highlight the dynamic role of BMP and FGF in the patterning of the hepatopancreatic region. PMID:22219376

  11. Optogenetic control of intracellular signaling pathways.

    PubMed

    Zhang, Kai; Cui, Bianxiao

    2015-02-01

    Cells employ a plethora of signaling pathways to make their life-and-death decisions. Extensive genetic, biochemical, and physiological studies have led to the accumulation of knowledge about signaling components and their interactions within signaling networks. These conventional approaches, although useful, lack the ability to control the spatial and temporal aspects of signaling processes. The recently emerged optogenetic tools open exciting opportunities by enabling signaling regulation with superior temporal and spatial resolution, easy delivery, rapid reversibility, fewer off-target side effects, and the ability to dissect complex signaling networks. Here we review recent achievements in using light to control intracellular signaling pathways and discuss future prospects for the field, including integration of new genetic approaches into optogenetics.

  12. Optogenetic control of intracellular signaling pathways

    PubMed Central

    Zhang, Kai; Cui, Bianxiao

    2014-01-01

    Cells employ a plethora of signaling pathways to make their life-and-death decisions. Extensive genetic, biochemical, and physiological studies have led to the accumulation of knowledge about signaling components and their interactions within signaling networks. These conventional approaches, though useful, lack the ability to control the spatial and temporal aspects of signaling processes. The recently emerged optogenetic tools open up exciting opportunities by enabling signaling regulation with superior temporal and spatial resolution, easy delivery, rapid reversibility, fewer off-target side effects, and the ability to dissect complex signaling networks. Here we review recent achievements in using light to control intracellular signaling pathways, and discuss future prospects for the field, including integration of new genetic approaches into optogenetics. PMID:25529484

  13. Identification and Characterization of FGF2-Dependent mRNA: microRNA Networks During Lens Fiber Cell Differentiation

    PubMed Central

    Wolf, Louise; Gao, Chun S.; Gueta, Karen; Xie, Qing; Chevallier, Tiphaine; Podduturi, Nikhil R.; Sun, Jian; Conte, Ivan; Zelenka, Peggy S.; Ashery-Padan, Ruth; Zavadil, Jiri; Cvekl, Ales

    2013-01-01

    MicroRNAs (miRNAs) and fibroblast growth factor (FGF) signaling regulate a wide range of cellular functions, including cell specification, proliferation, migration, differentiation, and survival. In lens, both these systems control lens fiber cell differentiation; however, a possible link between these processes remains to be examined. Herein, the functional requirement for miRNAs in differentiating lens fiber cells was demonstrated via conditional inactivation of Dicer1 in mouse (Mus musculus) lens. To dissect the miRNA-dependent pathways during lens differentiation, we used a rat (Rattus norvegicus) lens epithelial explant system, induced by FGF2 to differentiate, followed by mRNA and miRNA expression profiling. Transcriptome and miRNome analysis identified extensive FGF2-regulated cellular responses that were both independent and dependent on miRNAs. We identified 131 FGF2-regulated miRNAs. Seventy-six of these miRNAs had at least two in silico predicted and inversely regulated target mRNAs. Genes modulated by the greatest number of FGF-regulated miRNAs include DNA-binding transcription factors Nfib, Nfat5/OREBP, c-Maf, Ets1, and N-Myc. Activated FGF signaling influenced bone morphogenetic factor/transforming growth factor-β, Notch, and Wnt signaling cascades implicated earlier in lens differentiation. Specific miRNA:mRNA interaction networks were predicted for c-Maf, N-Myc, and Nfib (DNA-binding transcription factors); Cnot6, Cpsf6, Dicer1, and Tnrc6b (RNA to miRNA processing); and Ash1l, Med1/PBP, and Kdm5b/Jarid1b/Plu1 (chromatin remodeling). Three miRNAs, including miR-143, miR-155, and miR-301a, down-regulated expression of c-Maf in the 3′-UTR luciferase reporter assays. These present studies demonstrate for the first time global impact of activated FGF signaling in lens cell culture system and predicted novel gene regulatory networks connected by multiple miRNAs that regulate lens differentiation. PMID:24142921

  14. Retinoid signaling in control of progenitor cell differentiation during mouse development

    PubMed Central

    Duester, Gregg

    2013-01-01

    The vitamin A metabolite retinoic acid (RA) serves as a ligand for nuclear RA receptors that control differentiation of progenitor cells important for vertebrate development. Genetic studies in mouse embryos deficient for RA-generating enzymes have been invaluable for deciphering RA function. RA first begins to act during early organogenesis when RA generated in trunk mesoderm begins to function as a diffusible signal controlling progenitor cell differentiation. In neuroectoderm, RA functions as an instructive signal to stimulate neuronal differentiation of progenitor cells in the hindbrain and spinal cord. RA is not required for early neuronal differentiation of the forebrain, but at later stages RA stimulates neuronal differentiation in forebrain basal ganglia. RA also acts as a permissive signal for differentiation by repressing fibroblast growth factor (FGF) signaling in differentiated cells as they emerge from progenitor populations in the caudal progenitor zone and second heart field. In addition, RA signaling stimulates differentiation of spermatogonial germ cells and induces meiosis in male but not female gonads. A more complete understanding of the normal functions of RA signaling during development will guide efforts to use RA as a differentiation agent for therapeutic purposes. PMID:23973941

  15. Alterations in Hepatic FGF21, Co-Regulated Genes, and Upstream Metabolic Genes in Response to Nutrition, Ketosis and Inflammation in Peripartal Holstein Cows.

    PubMed

    Akbar, Haji; Batistel, Fernanda; Drackley, James K; Loor, Juan J

    2015-01-01

    In rodents, fibroblast growth factor 21 (FGF21) has emerged as a key metabolic regulator produced by liver. To gather preliminary data on the potential importance of FGF1, co-regulated genes, and upstream metabolic genes, we examined the hepatic mRNA expression in response to nutrition and inflammation in dairy cows. In experiment 1, induction of ketosis through feed restriction on d 5 postpartum upregulated FGF21, its co-receptor KLB, and PPARA but only elicited a numerical increase in serum FGF21 concentration. In experiment 2, cows in control (CON) or receiving 50 g/d of L-carnitine (C50) from -14 through 21 d had increased FGF21, PPARA, and NFIL3 on d 10 compared with d 2 postpartum. In contrast, compared with CON and C50, 100 g/d L-carnitine (C100) resulted in lower FGF21, KLB, ANGPTL4, and ARNTL expression on d 10. In experiment 3, cows were fed during the dry period either a higher-energy (OVE; 1.62 Mcal/kg DM) or lower-energy (CON; 1.34 Mcal/kg DM) diet and received 0 (OVE:N, CON:N) or 200 μg of LPS (OVE:Y, CON:Y) into the mammary gland at d 7 postpartum. For FGF21 mRNA expression in CON, the LPS challenge (CON:Y) prevented a decrease in expression between d 7 and 14 postpartum such that cows in CON:N had a 4-fold lower expression on d 14 compared with d 7. The inflammatory stimulus induced by LPS in CON:Y resulted in upregulation of PPARA on d 14 to a similar level as cows in OVE:N. In OVE:Y, expression of PPARA was lower than CON:N on d 7 and remained unchanged on d 14. On d 7, LPS led to a 4-fold greater serum FGF21 only in OVE but not in CON cows. In fact, OVE:Y reached the same serum FGF21 concentration as CON:N, suggesting a carryover effect of dietary energy level on signaling mechanisms within liver. Overall, results indicate that nutrition, ketosis, and inflammation during the peripartal period can alter hepatic FGF21, co-regulated genes, and upstream metabolic genes to various extents. The functional outcome of these changes merits further study

  16. Alterations in Hepatic FGF21, Co-Regulated Genes, and Upstream Metabolic Genes in Response to Nutrition, Ketosis and Inflammation in Peripartal Holstein Cows

    PubMed Central

    Akbar, Haji; Batistel, Fernanda; Drackley, James K.; Loor, Juan J.

    2015-01-01

    In rodents, fibroblast growth factor 21 (FGF21) has emerged as a key metabolic regulator produced by liver. To gather preliminary data on the potential importance of FGF1, co-regulated genes, and upstream metabolic genes, we examined the hepatic mRNA expression in response to nutrition and inflammation in dairy cows. In experiment 1, induction of ketosis through feed restriction on d 5 postpartum upregulated FGF21, its co-receptor KLB, and PPARA but only elicited a numerical increase in serum FGF21 concentration. In experiment 2, cows in control (CON) or receiving 50 g/d of L-carnitine (C50) from -14 through 21 d had increased FGF21, PPARA, and NFIL3 on d 10 compared with d 2 postpartum. In contrast, compared with CON and C50, 100 g/d L-carnitine (C100) resulted in lower FGF21, KLB, ANGPTL4, and ARNTL expression on d 10. In experiment 3, cows were fed during the dry period either a higher-energy (OVE; 1.62 Mcal/kg DM) or lower-energy (CON; 1.34 Mcal/kg DM) diet and received 0 (OVE:N, CON:N) or 200 μg of LPS (OVE:Y, CON:Y) into the mammary gland at d 7 postpartum. For FGF21 mRNA expression in CON, the LPS challenge (CON:Y) prevented a decrease in expression between d 7 and 14 postpartum such that cows in CON:N had a 4-fold lower expression on d 14 compared with d 7. The inflammatory stimulus induced by LPS in CON:Y resulted in upregulation of PPARA on d 14 to a similar level as cows in OVE:N. In OVE:Y, expression of PPARA was lower than CON:N on d 7 and remained unchanged on d 14. On d 7, LPS led to a 4-fold greater serum FGF21 only in OVE but not in CON cows. In fact, OVE:Y reached the same serum FGF21 concentration as CON:N, suggesting a carryover effect of dietary energy level on signaling mechanisms within liver. Overall, results indicate that nutrition, ketosis, and inflammation during the peripartal period can alter hepatic FGF21, co-regulated genes, and upstream metabolic genes to various extents. The functional outcome of these changes merits further study

  17. Impaired mitochondrial fat oxidation induces FGF21 in muscle

    PubMed Central

    Vandanmagsar, Bolormaa; Warfel, Jaycob D.; Wicks, Shawna E.; Ghosh, Sujoy; Salbaum, J. Michael; Burk, David; Dubuisson, Olga S.; Mendoza, Tamra M.; Zhang, Jingying; Noland, Robert C.; Mynatt, Randall L.

    2016-01-01

    SUMMARY Fatty acids are the primary fuel source for skeletal muscle during most of our daily activities and impaired fatty acid oxidation (FAO) is associated with insulin resistance. We have developed a mouse model of impaired FAO by deleting carnitine palmitoyltransferase-1b specifically in skeletal muscle (Cpt1bm−/−). Cpt1bm−/− mice have increased glucose utilization and are resistant to diet induced obesity. Here we show that inhibition of mitochondrial FAO induces FGF21 expression specifically in skeletal muscle. The induction of FGF21 in Cpt1b-deficient muscle is dependent on AMPK and Akt1 signaling but independent on the stress signaling pathways. FGF21 appears to act in a paracrine manner to increase glucose uptake under low insulin conditions, but does not contribute to the resistance to diet induced obesity. PMID:27184848

  18. TGF-{beta}2 inhibits AKT activation and FGF-2-induced corneal endothelial cell proliferation

    SciTech Connect

    Lu Jiawei; Lu Zhenyu; Reinach, Peter

    2006-11-01

    The corneal endothelial cells form a boundary layer between anterior chamber and cornea. This single cell layer is important to maintain cornea transparency by eliciting net fluid transport into the anterior chamber. Injuries of the corneal endothelial layer in humans lead to corneal swelling and translucence. This hindrance is thought to be due to limited proliferative capacity of the endothelial layer. Fibroblast growth factor 2 (FGF-2) and transforming growth factor-beta 2 (TGF-{beta}2) are both found in aqueous humor, and these two cytokines promote and inhibit cell growth, respectively. The intracellular signaling mechanisms by which TGF-{beta}2 suppresses the mitogenic response to FGF-2, however, remain unclear. We have addressed this question by investigating potential crosstalk between FGF-2-induced and TGF-{beta}2-regulated intracellular signaling events in cultured bovine corneal endothelial (BCE) cells. We found that TGF-{beta}2 and FGF-2 oppositely affect BCE cell proliferation and TGF-{beta}2 can override the stimulating effects of FGF-2 by increasing COX-2 expression in these cells. Consistent with these findings, overexpression of COX-2 significantly reduced FGF-2-induced cell proliferation whereas a COX-2 specific inhibitor NS398 reversed the effect of TGF-{beta}2 on FGF-2-induced cell proliferation. The COX-2 product prostaglandin E2 (PGE-2) blocks FGF-2-induced cell proliferation. Whereas FGF-2 stimulates cell proliferation by activating the AKT pathway, TGF-{beta}2 and PGE-2 both inhibit this pathway. In accordance with the effect of PGE-2, cAMP also inhibits FGF-2-induced AKT activation. These findings suggest that the mitogenic response to FGF-2 in vivo in the corneal endothelial layer may be inhibited by TGF-{beta}2-induced suppression of the PI3-kinase/AKT signaling pathway.

  19. Dilated cardiomyopathy and impaired cardiac hypertrophic response to angiotensin II in mice lacking FGF-2

    PubMed Central

    Pellieux, Corinne; Foletti, Alessandro; Peduto, Giovanni; Aubert, Jean-François; Nussberger, Jürg; Beermann, Friedrich; Brunner, Hans-R.; Pedrazzini, Thierry

    2001-01-01

    FGF-2 has been implicated in the cardiac response to hypertrophic stimuli. Angiotensin II (Ang II) contributes to maintain elevated blood pressure in hypertensive individuals and exerts direct trophic effects on cardiac cells. However, the role of FGF-2 in Ang II–induced cardiac hypertrophy has not been established. Therefore, mice deficient in FGF-2 expression were studied using a model of Ang II–dependent hypertension and cardiac hypertrophy. Echocardiographic measurements show the presence of dilated cardiomyopathy in normotensive mice lacking FGF-2. Moreover, hypertensive mice without FGF-2 developed no compensatory cardiac hypertrophy. In wild-type mice, hypertrophy was associated with a stimulation of the c-Jun N-terminal kinase, the extracellular signal regulated kinase, and the p38 kinase pathways. In contrast, mitogen-activated protein kinase (MAPK) activation was markedly attenuated in FGF-2–deficient mice. In vitro, FGF-2 of fibroblast origin was demonstrated to be essential in the paracrine stimulation of MAPK activation in cardiomyocytes. Indeed, fibroblasts lacking FGF-2 expression have a defective capacity for releasing growth factors to induce hypertrophic responses in cardiomyocytes. Therefore, these results identify the cardiac fibroblast population as a primary integrator of hypertrophic stimuli in the heart, and suggest that FGF-2 is a crucial mediator of cardiac hypertrophy via autocrine/paracrine actions on cardiac cells. PMID:11748268

  20. Novel Regulation of Fibroblast Growth Factor 2 (FGF2)-mediated Cell Growth by Polysialic Acid*

    PubMed Central

    Ono, Sayaka; Hane, Masaya; Kitajima, Ken; Sato, Chihiro

    2012-01-01

    Polysialic acid (polySia) is a unique polysaccharide that modifies neural cell adhesion molecule (NCAM) spatiotemporally. Recently, we demonstrated that polySia functions as a reservoir for several neurotrophic factors and neurotransmitters. Here, we showed the direct interaction between polySia and fibroblast growth factor-2 (FGF2) by native-PAGE, gel filtration, and surface plasmon resonance. The minimum chain length of polySia required for the interaction with FGF2 was 17. Compared with heparan sulfate, a well known glycosaminoglycan capable of forming a complex with FGF2, polySia formed a larger complex with distinct properties in facilitating oligomerization of FGF2, as well as in binding to FGF receptors. In polySia-NCAM-expressing NIH-3T3 cells, which were established by transfecting cells with either of the plasmids for the expression of the polysialyltransferases ST8SiaII/STX and ST8SiaIV/PST that can polysialylate NCAM, FGF2-stimulated cell growth, but not cell survival, was inhibited. Taken together, these results suggest that polySia-NCAM might be involved in the regulation of FGF2-FGF receptor signaling through the direct binding of FGF2 in a manner distinct from heparan sulfate. PMID:22158871

  1. Endocrinization of FGF1 produces a neomorphic and potent insulin sensitizer

    PubMed Central

    Suh, Jae Myoung; Jonker, Johan W.; Ahmadian, Maryam; Goetz, Regina; Lackey, Denise; Osborn, Olivia; Huang, Zifeng; Liu, Weilin; Yoshihara, Eiji; van Dijk, Theo; Havinga, Rick; Fan, Weiwei; Yin, Yun-Qiang; Yu, Ruth T.; Liddle, Christopher; Atkins, Annette R.; Olefsky, Jerrold M.; Mohammadi, Moosa; Downes, Michael; Evans, Ronald M.

    2014-01-01

    FGF1 is an autocrine/paracrine regulator whose binding to heparan sulfate proteoglycans effectively precludes its circulation 1,2. Though known as a mitogenic factor, FGF1 knockout mice develop insulin resistance when stressed by a high fat diet, suggesting a potential role in nutrient homeostasis 3,4. Here we show that parenteral delivery of a single dose of recombinant FGF1 (rFGF1) results in potent, insulin-dependent glucose lowering in diabetic mice that is dose-dependent, but does not lead to hypoglycemia. Chronic pharmacological rFGF1 treatment increases insulin-dependent glucose uptake in skeletal muscle and suppresses hepatic glucose production to achieve whole-body insulin sensitization. The sustained glucose lowering and insulin sensitization attributed to rFGF1 are not accompanied by the side effects of weight gain, liver steatosis and bone loss associated with current insulin sensitizing therapies. Furthermore, we demonstrate that the glucose lowering activity of FGF1 can be dissociated from its mitogenic activity and is mediated predominantly via FGF receptor 1 (FGFR1) signaling. In summary, we have uncovered an unexpected, neomorphic insulin sensitizing action for exogenous non-mitogenic human FGF1 with therapeutic potential for treatment of insulin resistance and type 2 diabetes. PMID:25043058

  2. The K-fgf/hst oncogene induces transformation through an autocrine mechanism that requires extracellular stimulation of the mitogenic pathway.

    PubMed Central

    Talarico, D; Basilico, C

    1991-01-01

    The K-fgf/hst oncogene encodes a secreted growth factor of the fibroblast growth factor (FGF) family. The ability of K-fgf-transformed cells to grow in soft agar and in serum-free medium is inhibited by anti-K-FGF neutralizing antibodies, consistent with an autocrine mechanism of transformation. The transformed properties of clones that express high levels of K-FGF are, however, only partially affected. To better define the autocrine mechanism of transformation by K-fgf and to determine whether receptor activation could occur intracellularly, we constructed two mutants of the K-fgf cDNA. Deletion of the sequences encoding the signal peptide suppressed K-fgf ability to induce foci in NIH 3T3 cells. A few morphologically transformed colonies were observed in cotransfection experiments, and they were found to express high levels of cytoplasmic K-FGF. However, their ability to grow in serum-free medium and in soft agar was inhibited by anti-K-FGF antibodies. Addition of a sequence encoding the KDEL endoplasmic reticulum and Golgi retention signal to the K-fgf cDNA led to accumulation of the growth factor in intracellular compartments. The ability of the KDEL mutant to induce foci in NIH 3T3 cells was much lower than that of the wild-type cDNA, and also in this case the transformed phenotype was reverted by anti-K-FGF antibodies. These and other findings indicate that the transformed phenotype of cells expressing a nonsecretory K-FGF is due to the extracellular activation of the receptor by the small amounts of growth factor that these cells still release. Thus, transformation by K-fgf appears to be due to an autocrine growth mechanisms that requires activation of the mitogenic pathway at the cell surface. Images PMID:1990270

  3. Distributed traffic signal control using fuzzy logic

    NASA Technical Reports Server (NTRS)

    Chiu, Stephen

    1992-01-01

    We present a distributed approach to traffic signal control, where the signal timing parameters at a given intersection are adjusted as functions of the local traffic condition and of the signal timing parameters at adjacent intersections. Thus, the signal timing parameters evolve dynamically using only local information to improve traffic flow. This distributed approach provides for a fault-tolerant, highly responsive traffic management system. The signal timing at an intersection is defined by three parameters: cycle time, phase split, and offset. We use fuzzy decision rules to adjust these three parameters based only on local information. The amount of change in the timing parameters during each cycle is limited to a small fraction of the current parameters to ensure smooth transition. We show the effectiveness of this method through simulation of the traffic flow in a network of controlled intersections.

  4. FGF21 attenuates pathological myocardial remodeling following myocardial infarction through the adiponectin-dependent mechanism.

    PubMed

    Joki, Yusuke; Ohashi, Koji; Yuasa, Daisuke; Shibata, Rei; Ito, Masanori; Matsuo, Kazuhiro; Kambara, Takahiro; Uemura, Yusuke; Hayakawa, Satoko; Hiramatsu-Ito, Mizuho; Kanemura, Noriyoshi; Ogawa, Hayato; Daida, Hiroyuki; Murohara, Toyoaki; Ouchi, Noriyuki

    2015-03-27

    Ischemic heart disease is one of the leading causes of death. Fibroblast growth factor 21 (FGF21) is a circulating factor with an anti-diabetic property. Skeletal muscle is an important source of FGF21 production. Here, we investigated whether skeletal muscle-derived FGF21 modulates cardiac remodeling in a murine model of myocardial infarction. Myocardial infarction was produced in C57BL/6J wild-type (WT) mice by the permanent ligation of the left anterior descending coronary artery (LAD). Adenoviral vectors expressing FGF21 (Ad-FGF21) or control β-galactosidase were intramuscularly injected into mice at 3 days before permanent LAD ligation. Intramuscular injection of Ad-FGF21 increased plasma FGF21 levels in WT mice compared with control. Treatment of WT mice with Ad-FGF21 led to improvement of left ventricular systolic dysfunction and dilatation at 2 weeks after LAD ligation. Ad-FGF21 administration to WT mice also led to enhancement of capillary density in the infarct border zone, and reduction of myocyte apoptosis in the remote zone, which were accompanied by decreased expression of pro-inflammatory cytokines. Furthermore, treatment of WT mice with Ad-FGF21 increased plasma levels of adiponectin, which is a cardioprotective adipokine. The beneficial effects of Ad-FGF21 on cardiac dysfunction and inflammatory response after myocardial infarction were diminished in adiponectin-knockout mice. These data suggest that muscle-derived FGF21 ameliorates adverse cardiac remodeling after myocardial infarction, at least in part, through an adiponectin-dependent mechanism.

  5. Dynamic range control of audio signals by digital signal processing

    NASA Astrophysics Data System (ADS)

    Gilchrist, N. H. C.

    It is often necessary to reduce the dynamic range of musical programs, particularly those comprising orchestral and choral music, for them to be received satisfactorily by listeners to conventional FM and AM broadcasts. With the arrival of DAB (Digital Audio Broadcasting) a much wider dynamic range will become available for radio broadcasting, although some listeners may prefer to have a signal with a reduced dynamic range. This report describes a digital processor developed by the BBC to control the dynamic range of musical programs in a manner similar to that of a trained Studio Manager. It may be used prior to transmission in conventional broadcasting, replacing limiters or other compression equipment. In DAB, it offers the possibility of providing a dynamic range control signal to be sent to the receiver via an ancillary data channel, simultaneously with the uncompressed audio, giving the listener the option of the full dynamic range or a reduced dynamic range.

  6. Cognitive Control Signals for Neural Prosthetics

    NASA Astrophysics Data System (ADS)

    Musallam, S.; Corneil, B. D.; Greger, B.; Scherberger, H.; Andersen, R. A.

    2004-07-01

    Recent development of neural prosthetics for assisting paralyzed patients has focused on decoding intended hand trajectories from motor cortical neurons and using this signal to control external devices. In this study, higher level signals related to the goals of movements were decoded from three monkeys and used to position cursors on a computer screen without the animals emitting any behavior. Their performance in this task improved over a period of weeks. Expected value signals related to fluid preference, the expected magnitude, or probability of reward were decoded simultaneously with the intended goal. For neural prosthetic applications, the goal signals can be used to operate computers, robots, and vehicles, whereas the expected value signals can be used to continuously monitor a paralyzed patient's preferences and motivation.

  7. A long pentraxin-3-derived pentapeptide for the therapy of FGF8b-driven steroid hormone-regulated cancers.

    PubMed

    Giacomini, Arianna; Matarazzo, Sara; Pagano, Katiuscia; Ragona, Laura; Rezzola, Sara; Corsini, Michela; Di Salle, Emanuela; Presta, Marco; Ronca, Roberto

    2015-05-30

    Fibroblast growth factor-8b (FGF8b) affects the epithelial/stromal compartments of steroid hormone-regulated tumors by exerting an autocrine activity on cancer cells and a paracrine pro-angiogenic function, thus contributing to tumor progression. The FGF8b/FGF receptor (FGFR) system may therefore represent a target for the treatment of steroid hormone-regulated tumors. The soluble pattern recognition receptor long pentraxin-3 (PTX3) binds various FGFs, including FGF2 and FGF8b, thus inhibiting the angiogenic and tumorigenic activity of androgen-regulated tumor cells. Nevertheless, the complex/proteinaceous structure of PTX3 hampers its pharmacological exploitation. In this context, the acetylated pentapeptide Ac-ARPCA-NH2 (ARPCA), corresponding to the N-terminal amino acid sequence PTX3(100-104), was identified as a minimal FGF2-binding peptide able to antagonize the biological activity of FGF2. Here, we demonstrate that ARPCA binds FGF8b and inhibits its capacity to form FGFR1-mediated ternary complexes with heparan sulphate proteoglycans. As a FGF8b antagonist, ARPCA inhibits FGFR1 activation and signalling in endothelial cells, hampering the angiogenic activity exerted in vitro and in vivo by FGF8b. Also, ARPCA suppresses the angiogenic and tumorigenic potential of prototypic androgen/FGF8b-dependent Shionogi 115 mammary carcinoma cells and of androgen/FGF8b/FGF2-dependent TRAMP-C2 prostate cancer cells. In conclusion, ARPCA represents a novel FGF8b antagonist with translational implications for the therapy of steroid hormone-regulated tumors.

  8. Transforming growth factor (TGF)beta, fibroblast growth factor (FGF) and retinoid signalling pathways promote pancreatic exocrine gene expression in mouse embryonic stem cells.

    PubMed Central

    Skoudy, Anouchka; Rovira, Meritxell; Savatier, Pierre; Martin, Franz; León-Quinto, Trinidad; Soria, Bernat; Real, Francisco X

    2004-01-01

    Extracellular signalling cues play a major role in the activation of differentiation programmes. Mouse embryonic stem (ES) cells are pluripotent and can differentiate into a wide variety of specialized cells. Recently, protocols designed to induce endocrine pancreatic differentiation in vitro have been designed but little information is currently available concerning the potential of ES cells to differentiate into acinar pancreatic cells. By using conditioned media of cultured foetal pancreatic rudiments, we demonstrate that ES cells can respond in vitro to signalling pathways involved in exocrine development and differentiation. In particular, modulation of the hedgehog, transforming growth factor beta, retinoid, and fibroblast growth factor pathways in ES cell-derived embryoid bodies (EB) resulted in increased levels of transcripts encoding pancreatic transcription factors and cytodifferentiation markers, as demonstrated by RT-PCR. In EB undergoing spontaneous differentiation, expression of the majority of the acinar genes (i.e. amylase, carboxypeptidase A and elastase) was induced after the expression of endocrine genes, as occurs in vivo during development. These data indicate that ES cells can undergo exocrine pancreatic differentiation with a kinetic pattern of expression reminiscent of pancreas development in vivo and that ES cells can be coaxed to express an acinar phenotype by activation of signalling pathways known to play a role in pancreatic development and differentiation. PMID:14733613

  9. Investigating the mechanism of the assembly of FGF1-binding heparan sulfate motifs

    PubMed Central

    Nguyen, Thao Kim Nu; Raman, Karthik; Trana, Vy My; Kuberan, Balagurunathan

    2011-01-01

    Heparan sulfate (HS) chains play crucial biological roles by binding to various signaling molecules including fibroblast growth factors (FGFs). Distinct sulfation patterns of HS chains are required for their binding to FGFs/FGF receptors (FGFRs). These sulfation patterns are putatively regulated by biosynthetic enzyme complexes, called GAGOSOMES, in the Golgi. While the structural requirements of HS-FGF interactions have been described previously, it is still unclear how the FGF-binding motif is assembled in vivo. In this study, we generated HS structures using biosynthetic enzymes in a sequential or concurrent manner to elucidate the potential mechanism by which the FGF1-binding HS motif is assembled. Our results indicate that the HS chains form ternary complexes with FGF1/FGFR when enzymes carry out modifications in a specific manner. PMID:21803043

  10. 125I-labeled anti-bFGF monoclonal antibody inhibits growth of hepatocellular carcinoma

    PubMed Central

    Hu, Peng-Hui; Pan, Lan-Hong; Wong, Patrick Ting-Yat; Chen, Wen-Hui; Yang, Yan-Qing; Wang, Hong; Xiang, Jun-Jian; Xu, Meng

    2016-01-01

    AIM: To investigate the inhibitory efficacy of 125I-labeled anti-basic fibroblast growth factor (bFGF) monoclonal antibody (mAb) in hepatocellular carcinoma (HCC). METHODS: bFGF mAb was prepared by using the 1G9B9 hybridoma cell line with hybridization technology and extracted from ascites fluid through a Protein G Sepharose affinity column. After labeling with 125I through the chloramine-T method, bFGF mAb was further purified by a Sephadex G-25 column. Gamma radiation counter GC-1200 detected radioactivity of 125I-bFGF mAb. The murine H22 HCC xenograft model was established and randomized to interventions with control (phosphate-buffered saline), 125I-bFGF mAb, 125I plus bFGF mAb, bFGF mAb, or 125I. The ratios of tumor inhibition were then calculated. Expression of bFGF, fibroblast growth factor receptor (FGFR), platelet-derived growth factor, and vascular endothelial growth factor (VEGF) mRNA was determined by quantitative reverse transcriptase real-time polymerase chain reaction. RESULTS: The purified bFGF mAb solution was 8.145 mg/mL with a titer of 1:2560000 and was stored at -20 °C. After coupling, 125I-bFGF mAb was used at a 1: 1280000 dilution, stored at 4 °C, and its specific radioactivity was 37 MBq/mg. The corresponding tumor weight in the control, 125I, bFGF mAb, 125I plus bFGF mAb, and 125I-bFGF mAb groups was 1.88 ± 0.25, 1.625 ± 0.21, 1.5 ± 0.18, 1.41 ± 0.16, and 0.98 ± 0.11 g, respectively. The tumor inhibition ratio in the 125I, bFGF mAb, 125I plus bFGF mAb, and 125I-bFGF mAb groups was 13.6%, 20.2%, 25.1%, and 47.9%, respectively. Growth of HCC xenografts was inhibited significantly more in the 125I-bFGF mAb group than in the other groups (P < 0.05). Expression of bFGF and FGFR mRNA in the 125I-bFGF mAb group was significantly decreased in comparison with other groups (P < 0.05). Groups under interventions revealed increased expression of VEGF mRNA (except for 125I group) compared with the control group. CONCLUSION: 125I-bFGF m

  11. Sphingosine Kinase 1 is a Critical Component of the Copper-Dependent FGF1 Export Pathway

    PubMed Central

    Soldi, Raffaella; Mandinova, Anna; Venkataraman, Krishnan; Hla, Timoty; Vadas, Mathew; Pitson, Stuart; Duarte, Maria; Graziani, Irene; Kolev, Vihren; Kacer, Doreen; Kirov, Aleksandr; Maciag, Thomas; Prudovsky, Igor

    2007-01-01

    Sphingosine kinase 1 catalyzes the formation of sphingosine-1-phosphate, a lipid mediator involved in the regulation of angiogenesis. Sphingosine kinase 1 is constitutively released from cells, even though it lacks a classical signal peptide sequence. Because copper-dependent non-classical stress-induced release of FGF1 also regulates angiogenesis, we questioned whether sphingosine kinase 1 is involved in the FGF1 release pathway. We report that (i) the coexpression of sphingosine kinase 1 with FGF1 inhibited the release of sphingosine kinase 1 at 37°C; (ii) sphingosine kinase 1 was released at 42°C in complex with FGF1; (iii) sphingosine kinase 1 null cells failed to release FGF1 at stress; (iv) sphingosine kinase 1 is a high affinity copper-binding protein which formed a complex with FGF1 in a cell-free system, and (v) sphingosine kinase 1 over expression rescued the release of FGF1 from inhibition by the copper chelator, tetrathiomolybdate. We propose that sphingosine kinase 1 is a component of the copper-dependent FGF1 release pathway. PMID:17643421

  12. Novel Regulators of Fgf23 Expression and Mineralization in Hyp Bone

    PubMed Central

    Liu, Shiguang; Tang, Wen; Fang, Jianwen; Ren, Jinyu; Li, Hua; Xiao, Zhousheng; Quarles, L. D.

    2009-01-01

    We used gene array analysis of cortical bone to identify Phex-dependent gene transcripts associated with abnormal Fgf23 production and mineralization in Hyp mice. We found evidence that elevation of Fgf23 expression in osteocytes is associated with increments in Fgf1, Fgf7, and Egr2 and decrements in Sost, an inhibitor in the Wnt-signaling pathway, were observed in Hyp bone. β-Catenin levels were increased in Hyp cortical bone, and TOPflash luciferase reporter assay showed increased transcriptional activity in Hyp-derived osteoblasts, consistent with Wnt activation. Moreover, activation of Fgf and Wnt-signaling stimulated Fgf23 promoter activity in osteoblasts. We also observed reductions in Bmp1, a metalloproteinase that metabolizes the extracellular matrix protein Dmp1. Alterations were also found in enzymes regulating the posttranslational processing and stability of Fgf23, including decrements in the glycosyltransferase Galnt3 and the proprotein convertase Pcsk5. In addition, we found that the Pcsk5 and the glycosyltransferase Galnt3 were decreased in Hyp bone, suggesting that reduced posttranslational processing of FGF23 may also contribute to increased Fgf23 levels in Hyp mice. With regard to mineralization, we identified additional candidates to explain the intrinsic mineralization defect in Hyp osteoblasts, including increases in the mineralization inhibitors Mgp and Thbs4, as well as increases in local pH-altering factors, carbonic anhydrase 12 (Car12) and 3 (Car3) and the sodium-dependent citrate transporter (Slc13a5). These studies demonstrate the complexity of gene expression alterations in bone that accompanies inactivating Phex mutations and identify novel pathways that may coordinate Fgf23 expression and mineralization of extracellular matrix in Hyp bone. PMID:19556340

  13. Neonatal iron deficiency causes abnormal phosphate metabolism by elevating FGF23 in normal and ADHR mice.

    PubMed

    Clinkenbeard, Erica L; Farrow, Emily G; Summers, Lelia J; Cass, Taryn A; Roberts, Jessica L; Bayt, Christine A; Lahm, Tim; Albrecht, Marjorie; Allen, Matthew R; Peacock, Munro; White, Kenneth E

    2014-02-01

    Fibroblast growth factor 23 (FGF23) gain of function mutations can lead to autosomal dominant hypophosphatemic rickets (ADHR) disease onset at birth, or delayed onset following puberty or pregnancy. We previously demonstrated that the combination of iron deficiency and a knock-in R176Q FGF23 mutation in mature mice induced FGF23 expression and hypophosphatemia that paralleled the late-onset ADHR phenotype. Because anemia in pregnancy and in premature infants is common, the goal of this study was to test whether iron deficiency alters phosphate handling in neonatal life. Wild-type (WT) and ADHR female breeder mice were provided control or iron-deficient diets during pregnancy and nursing. Iron-deficient breeders were also made iron replete. Iron-deficient WT and ADHR pups were hypophosphatemic, with ADHR pups having significantly lower serum phosphate (p < 0.01) and widened growth plates. Both genotypes increased bone FGF23 mRNA (>50 fold; p < 0.01). WT and ADHR pups receiving low iron had elevated intact serum FGF23; ADHR mice were affected to a greater degree (p < 0.01). Iron-deficient mice also showed increased Cyp24a1 and reduced Cyp27b1, and low serum 1,25-dihydroxyvitamin D (1,25D). Iron repletion normalized most abnormalities. Because iron deficiency can induce tissue hypoxia, oxygen deprivation was tested as a regulator of FGF23, and was shown to stimulate FGF23 mRNA in vitro and serum C-terminal FGF23 in normal rats in vivo. These studies demonstrate that FGF23 is modulated by iron status in young WT and ADHR mice and that hypoxia independently controls FGF23 expression in situations of normal iron. Therefore, disturbed iron and oxygen metabolism in neonatal life may have important effects on skeletal function and structure through FGF23 activity on phosphate regulation.

  14. A Shh-Foxf-Fgf18-Shh Molecular Circuit Regulating Palate Development.

    PubMed

    Xu, Jingyue; Liu, Han; Lan, Yu; Aronow, Bruce J; Kalinichenko, Vladimir V; Jiang, Rulang

    2016-01-01

    Cleft palate is among the most common birth defects in humans. Previous studies have shown that Shh signaling plays critical roles in palate development and regulates expression of several members of the forkhead-box (Fox) family transcription factors, including Foxf1 and Foxf2, in the facial primordia. Although cleft palate has been reported in mice deficient in Foxf2, whether Foxf2 plays an intrinsic role in and how Foxf2 regulates palate development remain to be elucidated. Using Cre/loxP-mediated tissue-specific gene inactivation in mice, we show that Foxf2 is required in the neural crest-derived palatal mesenchyme for normal palatogenesis. We found that Foxf2 mutant embryos exhibit altered patterns of expression of Shh, Ptch1, and Shox2 in the developing palatal shelves. Through RNA-seq analysis, we identified over 150 genes whose expression was significantly up- or down-regulated in the palatal mesenchyme in Foxf2-/- mutant embryos in comparison with control littermates. Whole mount in situ hybridization analysis revealed that the Foxf2 mutant embryos exhibit strikingly corresponding patterns of ectopic Fgf18 expression in the palatal mesenchyme and concomitant loss of Shh expression in the palatal epithelium in specific subdomains of the palatal shelves that correlate with where Foxf2, but not Foxf1, is expressed during normal palatogenesis. Furthermore, tissue specific inactivation of both Foxf1 and Foxf2 in the early neural crest cells resulted in ectopic activation of Fgf18 expression throughout the palatal mesenchyme and dramatic loss of Shh expression throughout the palatal epithelium. Addition of exogenous Fgf18 protein to cultured palatal explants inhibited Shh expression in the palatal epithelium. Together, these data reveal a novel Shh-Foxf-Fgf18-Shh circuit in the palate development molecular network, in which Foxf1 and Foxf2 regulate palatal shelf growth downstream of Shh signaling, at least in part, by repressing Fgf18 expression in the palatal

  15. A Shh-Foxf-Fgf18-Shh Molecular Circuit Regulating Palate Development.

    PubMed

    Xu, Jingyue; Liu, Han; Lan, Yu; Aronow, Bruce J; Kalinichenko, Vladimir V; Jiang, Rulang

    2016-01-01

    Cleft palate is among the most common birth defects in humans. Previous studies have shown that Shh signaling plays critical roles in palate development and regulates expression of several members of the forkhead-box (Fox) family transcription factors, including Foxf1 and Foxf2, in the facial primordia. Although cleft palate has been reported in mice deficient in Foxf2, whether Foxf2 plays an intrinsic role in and how Foxf2 regulates palate development remain to be elucidated. Using Cre/loxP-mediated tissue-specific gene inactivation in mice, we show that Foxf2 is required in the neural crest-derived palatal mesenchyme for normal palatogenesis. We found that Foxf2 mutant embryos exhibit altered patterns of expression of Shh, Ptch1, and Shox2 in the developing palatal shelves. Through RNA-seq analysis, we identified over 150 genes whose expression was significantly up- or down-regulated in the palatal mesenchyme in Foxf2-/- mutant embryos in comparison with control littermates. Whole mount in situ hybridization analysis revealed that the Foxf2 mutant embryos exhibit strikingly corresponding patterns of ectopic Fgf18 expression in the palatal mesenchyme and concomitant loss of Shh expression in the palatal epithelium in specific subdomains of the palatal shelves that correlate with where Foxf2, but not Foxf1, is expressed during normal palatogenesis. Furthermore, tissue specific inactivation of both Foxf1 and Foxf2 in the early neural crest cells resulted in ectopic activation of Fgf18 expression throughout the palatal mesenchyme and dramatic loss of Shh expression throughout the palatal epithelium. Addition of exogenous Fgf18 protein to cultured palatal explants inhibited Shh expression in the palatal epithelium. Together, these data reveal a novel Shh-Foxf-Fgf18-Shh circuit in the palate development molecular network, in which Foxf1 and Foxf2 regulate palatal shelf growth downstream of Shh signaling, at least in part, by repressing Fgf18 expression in the palatal

  16. A Shh-Foxf-Fgf18-Shh Molecular Circuit Regulating Palate Development

    PubMed Central

    Xu, Jingyue; Liu, Han; Lan, Yu; Aronow, Bruce J.; Kalinichenko, Vladimir V.; Jiang, Rulang

    2016-01-01

    Cleft palate is among the most common birth defects in humans. Previous studies have shown that Shh signaling plays critical roles in palate development and regulates expression of several members of the forkhead-box (Fox) family transcription factors, including Foxf1 and Foxf2, in the facial primordia. Although cleft palate has been reported in mice deficient in Foxf2, whether Foxf2 plays an intrinsic role in and how Foxf2 regulates palate development remain to be elucidated. Using Cre/loxP-mediated tissue-specific gene inactivation in mice, we show that Foxf2 is required in the neural crest-derived palatal mesenchyme for normal palatogenesis. We found that Foxf2 mutant embryos exhibit altered patterns of expression of Shh, Ptch1, and Shox2 in the developing palatal shelves. Through RNA-seq analysis, we identified over 150 genes whose expression was significantly up- or down-regulated in the palatal mesenchyme in Foxf2-/- mutant embryos in comparison with control littermates. Whole mount in situ hybridization analysis revealed that the Foxf2 mutant embryos exhibit strikingly corresponding patterns of ectopic Fgf18 expression in the palatal mesenchyme and concomitant loss of Shh expression in the palatal epithelium in specific subdomains of the palatal shelves that correlate with where Foxf2, but not Foxf1, is expressed during normal palatogenesis. Furthermore, tissue specific inactivation of both Foxf1 and Foxf2 in the early neural crest cells resulted in ectopic activation of Fgf18 expression throughout the palatal mesenchyme and dramatic loss of Shh expression throughout the palatal epithelium. Addition of exogenous Fgf18 protein to cultured palatal explants inhibited Shh expression in the palatal epithelium. Together, these data reveal a novel Shh-Foxf-Fgf18-Shh circuit in the palate development molecular network, in which Foxf1 and Foxf2 regulate palatal shelf growth downstream of Shh signaling, at least in part, by repressing Fgf18 expression in the palatal

  17. Fgf is required to regulate anterior-posterior patterning in the Xenopus lateral plate mesoderm.

    PubMed

    Deimling, Steven J; Drysdale, Thomas A

    2011-01-01

    Given that the lateral plate mesoderm (LPM) gives rise to the cardiovascular system, identifying the cascade of signalling events that subdivides the LPM into distinct regions during development is an important question. Retinoic acid (RA) is known to be necessary for establishing the expression boundaries of important transcription factors that demarcate distinct regions along the anterior posterior axis of the LPM. Here, we demonstrate that fibroblast growth factor (Fgf) signalling is also necessary for regulating the expression domains of the same transcription factors (nkx2.5, foxf1, hand1 and sall3) by restricting the RA responsive LPM domains. When Fgf signalling is inhibited in neurula stage embryos, the more posterior LPM expression domains are lost, while the more anterior domains are extended further posterior. The domain changes are maintained throughout development as Fgf inhibition results in similar domain changes in late stage embryos. We also demonstrate that Fgf signalling is necessary for both the initiation of heart specification, and for maintaining heart specification until overt differentiation occurs. Fgf signalling is also necessary to restrict vascular patterning and create a vascular free domain in the posterior end of the LPM that correlates with the expression of hand1. Finally, we show cross talk between the RA and Fgf signalling pathways in the patterning of the LPM. We suggest that this tissue wide patterning event, active during the neurula stage, is an initial step in regional specification of the LPM, and this process is an essential early event in LPM patterning.

  18. Optically Controlled Signal Amplification for DNA Computation.

    PubMed

    Prokup, Alexander; Hemphill, James; Liu, Qingyang; Deiters, Alexander

    2015-10-16

    The hybridization chain reaction (HCR) and fuel-catalyst cycles have been applied to address the problem of signal amplification in DNA-based computation circuits. While they function efficiently, these signal amplifiers cannot be switched ON or OFF quickly and noninvasively. To overcome these limitations, a light-activated initiator strand for the HCR, which enabled fast optical OFF → ON switching, was developed. Similarly, when a light-activated version of the catalyst strand or the inhibitor strand of a fuel-catalyst cycle was applied, the cycle could be optically switched from OFF → ON or ON → OFF, respectively. To move the capabilities of these devices beyond solution-based operations, the components were embedded in agarose gels. Irradiation with customizable light patterns and at different time points demonstrated both spatial and temporal control. The addition of a translator gate enabled a spatially activated signal to travel along a predefined path, akin to a chemical wire. Overall, the addition of small light-cleavable photocaging groups to DNA signal amplification circuits enabled conditional control as well as fast photocontrol of signal amplification. PMID:25621535

  19. Fibroblast growth factor (Fgf) 21 is a novel target gene of the aryl hydrocarbon receptor (AhR)

    SciTech Connect

    Cheng, Xingguo; Vispute, Saurabh G.; Liu, Jie; Cheng, Christine; Kharitonenkov, Alexei; Klaassen, Curtis D.

    2014-07-01

    The toxic effects of dioxins, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), mainly through activation of the aryl hydrocarbon receptor (AhR) are well documented. Fibroblast growth factor (Fgf) 21 plays critical roles in metabolic adaptation to fasting by increasing lipid oxidation and ketogenesis in the liver. The present study was performed to determine whether activation of the AhR induces Fgf21 expression. In mouse liver, TCDD increased Fgf21 mRNA in both dose- and time-dependent manners. In addition, TCDD markedly increased Fgf21 mRNA expression in cultured mouse and human hepatocytes. Moreover, TCDD increased mRNA (in liver) and protein levels (in both liver and serum) of Fgf21 in wild-type mice, but not in AhR-null mice. Chromatin immunoprecipitation assays showed that TCDD increased AhR protein binding to the Fgf21 promoter (− 105/+ 1 base pair). Fgf21-null mice administered 200 μg/kg of TCDD died within 20 days, whereas wild-type mice receiving the same treatment were still alive at one month after administration. This indicates that TCDD-induced Fgf21 expression protects against TCDD toxicity. Diethylhexylphthalate (DEHP) pretreatment attenuated TCDD-induced Fgf21 expression in mouse liver and white adipose tissue, which may explain a previous report that DEHP pretreatment decreases TCDD-induced wasting. In conclusion, Fgf21 appears to be a target gene of AhR-signaling pathway in mouse and human liver. - Highlights: • TCDD induced Fgf21 expression at both mRNA and protein levels. • Fgf21 induction by TCDD is AhR-dependent. • DEHP attenuated TCDD-induced Fgf21 expression.

  20. A comparative transcriptome analysis identifying FGF23 regulated genes in the kidney of a mouse CKD model.

    PubMed

    Dai, Bing; David, Valentin; Martin, Aline; Huang, Jinsong; Li, Hua; Jiao, Yan; Gu, Weikuan; Quarles, L Darryl

    2012-01-01

    Elevations of circulating Fibroblast growth factor 23 (FGF23) are associated with adverse cardiovascular outcomes and progression of renal failure in chronic kidney disease (CKD). Efforts to identify gene products whose transcription is directly regulated by FGF23 stimulation of fibroblast growth factor receptors (FGFR)/α-Klotho complexes in the kidney is confounded by both systemic alterations in calcium, phosphorus and vitamin D metabolism and intrinsic alterations caused by the underlying renal pathology in CKD. To identify FGF23 responsive genes in the kidney that might explain the association between FGF23 and adverse outcomes in CKD, we performed comparative genome wide analysis of gene expression profiles in the kidney of the Collagen 4 alpha 3 null mice (Col4a3(-/-)) model of progressive kidney disease with kidney expression profiles of Hypophosphatemic (Hyp) and FGF23 transgenic mouse models of elevated FGF23. The different complement of potentially confounding factors in these models allowed us to identify genes that are directly targeted by FGF23. This analysis found that α-Klotho, an anti-aging hormone and FGF23 co-receptor, was decreased by FGF23. We also identified additional FGF23-responsive transcripts and activation of networks associated with renal damage and chronic inflammation, including lipocalin 2 (Lcn2), transforming growth factor beta (TGF-β) and tumor necrosis factor-alpha (TNF-α) signaling pathways. Finally, we found that FGF23 suppresses angiotensin-converting enzyme 2 (ACE2) expression in the kidney, thereby providing a pathway for FGF23 regulation of the renin-angiotensin system. These gene products provide a possible mechanistic links between elevated FGF23 and pathways responsible for renal failure progression and cardiovascular diseases.

  1. Novel Insights into the Cardio-Protective Effects of FGF21 in Lean and Obese Rat Hearts

    PubMed Central

    Chen, Jing; Ramanjaneya, Manjunath; Bari, Muhammad F.; Bhudia, Sunil K.; Hillhouse, Edward W.; Tan, Bee K.; Randeva, Harpal S.

    2014-01-01

    Aims Fibroblast growth factor 21 (FGF21) is a hepatic metabolic regulator with pleotropic actions. Its plasma concentrations are increased in obesity and diabetes; states associated with an increased incidence of cardiovascular disease. We therefore investigated the direct effect of FGF21 on cardio-protection in obese and lean hearts in response to ischemia. Methods and Results FGF21, FGF21-receptor 1 (FGFR1) and beta-Klotho (βKlotho) were expressed in rodent, human hearts and primary rat cardiomyocytes. Cardiac FGF21 was expressed and secreted (real time RT-PCR/western blot and ELISA) in an autocrine-paracrine manner, in response to obesity and hypoxia, involving FGFR1-βKlotho components. Cardiac-FGF21 expression and secretion were increased in response to global ischemia. In contrast βKlotho was reduced in obese hearts. In isolated adult rat cardiomyocytes, FGF21 activated PI3K/Akt (phosphatidylinositol 3-kinase/Akt), ERK1/2(extracellular signal-regulated kinase) and AMPK (AMP-activated protein kinase) pathways. In Langendorff perfused rat [adult male wild-type wistar] hearts, FGF21 administration induced significant cardio-protection and restoration of function following global ischemia. Inhibition of PI3K/Akt, AMPK, ERK1/2 and ROR-α (retinoic-acid receptor alpha) pathway led to significant decrease of FGF21 induced cardio-protection and restoration of cardiac function in response to global ischemia. More importantly, this cardio-protective response induced by FGF21 was reduced in obesity, although the cardiac expression profiles and circulating FGF21 levels were increased. Conclusion In an ex vivo Langendorff system, we show that FGF21 induced cardiac protection and restoration of cardiac function involving autocrine-paracrine pathways, with reduced effect in obesity. Collectively, our findings provide novel insights into FGF21-induced cardiac effects in obesity and ischemia. PMID:24498293

  2. Effects of bFGF incorporated into a gelatin sheet on wound healing.

    PubMed

    Miyoshi, Michiyo; Kawazoe, Takeshi; Igawa, Hiroharu H; Tabata, Yasuhiko; Ikada, Yoshito; Suzuki, Shigehiko

    2005-01-01

    Basic fibroblast growth factor (bFGF) is well known to promote the proliferation of almost all cells associated with wound healing. However, as the activation duration of bFGF is very short in vivo, we incorporated bFGF into an acidic gelatin hydrogel and studied the sustained release of bFGF in vivo. In addition, we investigated the effects of the acidic gelatin sheet containing bFGF on wound healing. To distinguish wound contraction from neoepithelialization, we measured both the wound area and neoepithelium length. Other histological parameters such as thickness of granulation tissue and number of capillaries were also determined as indices of wound healing. Fibrous tissue was assessed using an Elastica van Gieson and Azan stain. A skin defect (1.5 x 1.5 cm) of full thickness was created on the back of each test mouse and the wound was covered with an acidic gelatin hydrogel, referred to as a gelatin sheet in this study (2 x 2 cm), with bFGF (100 microg/site) (A) or without bFGF (B). 1, 2, 3, 5, 7 and 14 days after covering, mice were killed and an enzyme-linked immunosorbent assay (ELISA) was performed to estimate the concentration of bFGF in the plasma. In another experiment, each wound was covered with (A), (B) or a hydrogel dressing (control group, C) and the wound area was measured 1 or 2 weeks postoperatively with a computer planimeter. The histological parameters, as mentioned above, were assessed using a light microscope. Sustained release of bFGF from the gelatin sheet was observed and the gelatin sheet containing bFGF promoted neoepithelialization, granulation, neovascularization and wound closure. This gelatin sheet containing bFGF was concluded to be effective for wound healing and promising for clinical use. PMID:16128295

  3. An ES-Like Pluripotent State in FGF-Dependent Murine iPS cells

    PubMed Central

    Ungaro, Federica; Prigione, Alessandro; Chen, Hsu-Hsin; Welling, Maaike; Eijpe, Maureen; Mostoslavsky, Gustavo; Tesar, Paul; Adjaye, James; Geijsen, Niels; Broccoli, Vania

    2010-01-01

    Recent data demonstrates that stem cells can exist in two morphologically, molecularly and functionally distinct pluripotent states; a naïve LIF-dependent pluripotent state which is represented by murine embryonic stem cells (mESCs) and an FGF-dependent primed pluripotent state represented by murine and rat epiblast stem cells (EpiSCs). We find that derivation of induced pluripotent stem cells (iPSCs) under EpiSC culture conditions yields FGF-dependent iPSCs from hereon called FGF-iPSCs) which, unexpectedly, display naïve ES-like/ICM properties. FGF-iPSCs display X-chromosome activation, multi-lineage differentiation, teratoma competence and chimera contribution in vivo. Our findings suggest that in 129 and Bl6 mouse strains, iPSCs can dominantly adopt a naive pluripotent state regardless of culture growth factor conditions. Characterization of the key molecular signalling pathways revealed FGF-iPSCs to depend on the Activin/Nodal and FGF pathways, while signalling through the JAK-STAT pathway is not required for FGF-iPS cell maintenance. Our findings suggest that in 129 and Bl6 mouse strains, iPSCs can dominantly adopt a naive pluripotent state regardless of culture growth factor conditions. PMID:21209851

  4. Muenke syndrome mutation, FgfR3P²⁴⁴R, causes TMJ defects.

    PubMed

    Yasuda, T; Nah, H D; Laurita, J; Kinumatsu, T; Shibukawa, Y; Shibutani, T; Minugh-Purvis, N; Pacifici, M; Koyama, E

    2012-07-01

    Muenke syndrome is characterized by various craniofacial deformities and is caused by an autosomal-dominant activating mutation in fibroblast growth factor receptor 3 (FGFR3(P250R) ). Here, using mice carrying a corresponding mutation (FgfR3(P244R) ), we determined whether the mutation affects temporomandibular joint (TMJ) development and growth. In situ hybridization showed that FgfR3 was expressed in condylar chondroprogenitors and maturing chondrocytes that also expressed the Indian hedgehog (Ihh) receptor and transcriptional target Patched 1(Ptch1). In FgfR3(P244R) mutants, the condyles displayed reduced levels of Ihh expression, H4C-positive proliferating chondroprogenitors, and collagen type II- and type X-expressing chondrocytes. Primary bone spongiosa formation was also disturbed and was accompanied by increased osteoclastic activity and reduced trabecular bone formation. Treatment of wild-type condylar explants with recombinant FGF2/FGF9 decreased Ptch1 and PTHrP expression in superficial/polymorphic layers and proliferation in chondroprogenitors. We also observed early degenerative changes of condylar articular cartilage, abnormal development of the articular eminence/glenoid fossa in the TMJ, and fusion of the articular disc. Analysis of our data indicates that the activating FgfR3(P244R) mutation disturbs TMJ developmental processes, likely by reducing hedgehog signaling and endochondral ossification. We suggest that a balance between FGF and hedgehog signaling pathways is critical for the integrity of TMJ development and for the maintenance of cellular organization. PMID:22622662

  5. Muenke Syndrome Mutation, FgfR3P244R, Causes TMJ Defects

    PubMed Central

    Yasuda, T.; Nah, H.D.; Laurita, J.; Kinumatsu, T.; Shibukawa, Y.; Shibutani, T.; Minugh-Purvis, N.; Pacifici, M.; Koyama, E.

    2012-01-01

    Muenke syndrome is characterized by various craniofacial deformities and is caused by an autosomal-dominant activating mutation in fibroblast growth factor receptor 3 (FGFR3P250R). Here, using mice carrying a corresponding mutation (FgfR3P244R), we determined whether the mutation affects temporomandibular joint (TMJ) development and growth. In situ hybridization showed that FgfR3 was expressed in condylar chondroprogenitors and maturing chondrocytes that also expressed the Indian hedgehog (Ihh) receptor and transcriptional target Patched 1(Ptch1). In FgfR3P244R mutants, the condyles displayed reduced levels of Ihh expression, H4C-positive proliferating chondroprogenitors, and collagen type II- and type X-expressing chondrocytes. Primary bone spongiosa formation was also disturbed and was accompanied by increased osteoclastic activity and reduced trabecular bone formation. Treatment of wild-type condylar explants with recombinant FGF2/FGF9 decreased Ptch1 and PTHrP expression in superficial/polymorphic layers and proliferation in chondroprogenitors. We also observed early degenerative changes of condylar articular cartilage, abnormal development of the articular eminence/glenoid fossa in the TMJ, and fusion of the articular disc. Analysis of our data indicates that the activating FgfR3P244R mutation disturbs TMJ developmental processes, likely by reducing hedgehog signaling and endochondral ossification. We suggest that a balance between FGF and hedgehog signaling pathways is critical for the integrity of TMJ development and for the maintenance of cellular organization. PMID:22622662

  6. Plasticity in Interactions of Fibroblast Growth Factor 1 (FGF1) N Terminus with FGF Receptors Underlies Promiscuity of FGF1*

    PubMed Central

    Beenken, Andrew; Eliseenkova, Anna V.; Ibrahimi, Omar A.; Olsen, Shaun K.; Mohammadi, Moosa

    2012-01-01

    Tissue-specific alternative splicing in the second half of Ig-like domain 3 (D3) of fibroblast growth factor receptors 1–3 (FGFR1 to -3) generates epithelial FGFR1b-FGFR3b and mesenchymal FGFR1c-FGFR3c splice isoforms. This splicing event establishes a selectivity filter to restrict the ligand binding specificity of FGFRb and FGFRc isoforms to mesenchymally and epithelially derived fibroblast growth factors (FGFs), respectively. FGF1 is termed the “universal FGFR ligand” because it overrides this specificity barrier. To elucidate the molecular basis for FGF1 cross-reactivity with the “b” and “c” splice isoforms of FGFRs, we determined the first crystal structure of FGF1 in complex with an FGFRb isoform, FGFR2b, at 2.1 Å resolution. Comparison of the FGF1-FGFR2b structure with the three previously published FGF1-FGFRc structures reveals that plasticity in the interactions of the N-terminal region of FGF1 with FGFR D3 is the main determinant of FGF1 cross-reactivity with both isoforms of FGFRs. In support of our structural data, we demonstrate that substitution of three N-terminal residues (Gly-19, His-25, and Phe-26) of FGF2 (a ligand that does not bind FGFR2b) for the corresponding residues of FGF1 (Phe-16, Asn-22, and Tyr-23) enables the FGF2 triple mutant to bind and activate FGFR2b. These findings taken together with our previous structural data on receptor binding specificity of FGF2, FGF8, and FGF10 conclusively show that sequence divergence at the N termini of FGFs is the primary regulator of the receptor binding specificity and promiscuity of FGFs. PMID:22057274

  7. Action Mechanism of Fibroblast Growth Factor-2 (FGF-2) in the Promotion of Periodontal Regeneration in Beagle Dogs

    PubMed Central

    Nagayasu-Tanaka, Toshie; Anzai, Jun; Takaki, Shu; Shiraishi, Noriko; Terashima, Akio; Asano, Taiji; Nozaki, Takenori; Kitamura, Masahiro; Murakami, Shinya

    2015-01-01

    Fibroblast growth factor-2 (FGF-2) enhances the formation of new alveolar bone, cementum, and periodontal ligament (PDL) in periodontal defect models. However, the mechanism through which FGF-2 acts in periodontal regeneration in vivo has not been fully clarified yet. To reveal the action mechanism, the formation of regenerated tissue and gene expression at the early phase were analyzed in a beagle dog 3-wall periodontal defect model. FGF-2 (0.3%) or the vehicle (hydroxypropyl cellulose) only were topically applied to the defect in FGF-2 and control groups, respectively. Then, the amount of regenerated tissues and the number of proliferating cells at 3, 7, 14, and 28 days and the number of blood vessels at 7 days were quantitated histologically. Additionally, the expression of osteogenic genes in the regenerated tissue was evaluated by real-time PCR at 7 and 14 days. Compared with the control, cell proliferation around the existing bone and PDL, connective tissue formation on the root surface, and new bone formation in the defect at 7 days were significantly promoted by FGF-2. Additionally, the number of blood vessels at 7 days was increased by FGF-2 treatment. At 28 days, new cementum and PDL were extended by FGF-2. Moreover, FGF-2 increased the expression of bone morphogenetic protein 2 (BMP-2) and osteoblast differentiation markers (osterix, alkaline phosphatase, and osteocalcin) in the regenerated tissue. We revealed the facilitatory mechanisms of FGF-2 in periodontal regeneration in vivo. First, the proliferation of fibroblastic cells derived from bone marrow and PDL was accelerated and enhanced by FGF-2. Second, angiogenesis was enhanced by FGF-2 treatment. Finally, osteoblastic differentiation and bone formation, at least in part due to BMP-2 production, were rapidly induced by FGF-2. Therefore, these multifaceted effects of FGF-2 promote new tissue formation at the early regeneration phase, leading to enhanced formation of new bone, cementum, and PDL. PMID

  8. FGF-23 in fibrous dysplasia of bone and its relationship to renal phosphate wasting.

    PubMed

    Riminucci, Mara; Collins, Michael T; Fedarko, Neal S; Cherman, Natasha; Corsi, Alessandro; White, Kenneth E; Waguespack, Steven; Gupta, Anurag; Hannon, Tamara; Econs, Michael J; Bianco, Paolo; Gehron Robey, Pamela

    2003-09-01

    FGF-23, a novel member of the FGF family, is the product of the gene mutated in autosomal dominant hypophosphatemic rickets (ADHR). FGF-23 has been proposed as a circulating factor causing renal phosphate wasting not only in ADHR (as a result of inadequate degradation), but also in tumor-induced osteomalacia (as a result of excess synthesis by tumor cells). Renal phosphate wasting occurs in approximately 50% of patients with McCune-Albright syndrome (MAS) and fibrous dysplasia of bone (FD), which result from postzygotic mutations of the GNAS1 gene. We found that FGF-23 is produced by normal and FD osteoprogenitors and bone-forming cells in vivo and in vitro. In situ hybridization analysis of FGF-23 mRNA expression identified "fibrous" cells, osteogenic cells, and cells associated with microvascular walls as specific cellular sources of FGF-23 in FD. Serum levels of FGF-23 were increased in FD/MAS patients compared with normal age-matched controls and significantly higher in FD/MAS patients with renal phosphate wasting compared with those without, and correlated with disease burden bone turnover markers commonly used to assess disease activity. Production of FGF-23 by FD tissue may play an important role in the renal phosphate-wasting syndrome associated with FD/MAS.

  9. Interpretation of the FGF8 morphogen gradient is regulated by endocytic trafficking.

    PubMed

    Nowak, Matthias; Machate, Anja; Yu, Shuizi Rachel; Gupta, Mansi; Brand, Michael

    2011-02-01

    Forty years ago, it was proposed that during embryonic development and organogenesis, morphogen gradients provide positional information to the individual cells within a tissue leading to specific fate decisions. Recently, much insight has been gained into how such morphogen gradients are formed and maintained; however, which cellular mechanisms govern their interpretation within target tissues remains debated. Here we used in vivo fluorescence correlation spectroscopy and automated image analysis to assess the role of endocytic sorting dynamics on fibroblast growth factor 8 (Fgf8) morphogen gradient interpretation. By interfering with the function of the ubiquitin ligase Cbl, we found an expanded range of Fgf target gene expression and a delay of Fgf8 lysosomal transport. However, the extracellular Fgf8 morphogen gradient remained unchanged, indicating that the observed signalling changes are due to altered gradient interpretation. We propose that regulation of morphogen signalling activity through endocytic sorting allows fast feedback-induced changes in gradient interpretation during the establishment of complex patterns.

  10. Disruption of the Suprachiasmatic Nucleus in Fibroblast Growth Factor Signaling-Deficient Mice

    PubMed Central

    Miller, Ann V.; Kavanaugh, Scott I.; Tsai, Pei-San

    2016-01-01

    Fibroblast growth factor (Fgf) 8 is essential for the development of multiple brain regions. Previous studies from our laboratory showed that reduced Fgf8 signaling led to the developmental alterations of neuroendocrine nuclei that originated within the diencephalon, including the paraventricular (PVN) and supraoptic (SON) nuclei. To further understand the role of Fgf8 in the development of other hypothalamic nuclei, we examined if Fgf8 and its cognate receptor, Fgfr1, also impact the integrity of the suprachiasmatic nuclei (SCN). The SCN control an organism’s circadian rhythm and contain vasoactive intestinal peptide (VIP)-producing neurons as the main input neurons. Mice hypomorphic for Fgf8, Fgfr1, or both were examined for their SCN volume and the number of VIP neurons on postnatal day (PN) 0; adult hypomorphic mice were further examined for SCN function by quantifying SCN neuronal activation using cFos as a marker. On PN0, mice homozygous for Fgf8 hypomorphy displayed the most severe reduction of the SCN volume and VIP neurons. Those heterozygous for Fgf8 hypomorphy alone or Fgf8 combined with Fgfr1 hypomorphy, called double heterozygotes (DH), showed normal SCN volume but significantly reduced VIP neurons, albeit less severely than the homozygotes. Adult wild type, heterozygous Fgf8 hypomorphs (F8 Het), and DH mice were also examined for SCN cFos activation at three time points: 1 h (morning), 6 h (afternoon), and 11 h (evening) after light onset. In F8 Het mice, a significant change in the pattern of cFos immunostaining that may reflect delayed morning SCN activation was observed. Overall, our studies provide evidence supporting that deficiencies in Fgf8 not only impact the structural integrity of the SCN but also the pattern of SCN activation in response to light. PMID:26903947

  11. Characterization of a novel fibroblast growth factor 10 (Fgf10) knock-in mouse line to target mesenchymal progenitors during embryonic development.

    PubMed

    El Agha, Elie; Al Alam, Denise; Carraro, Gianni; MacKenzie, Breanne; Goth, Kerstin; De Langhe, Stijn P; Voswinckel, Robert; Hajihosseini, Mohammad K; Rehan, Virender K; Bellusci, Saverio

    2012-01-01

    Fibroblast growth factor 10 (Fgf10) is a key regulator of diverse organogenetic programs during mouse development, particularly branching morphogenesis. Fgf10-null mice suffer from lung and limb agenesis as well as cecal and colonic atresia and are thus not viable. To date, the Mlcv1v-nLacZ-24 transgenic mouse strain (referred to as Fgf10(LacZ)), which carries a LacZ insertion 114 kb upstream of exon 1 of Fgf10 gene, has been the only strain to allow transient lineage tracing of Fgf10-positive cells. Here, we describe a novel Fgf10(Cre-ERT2) knock-in line (Fgf10(iCre)) in which a Cre-ERT2-IRES-YFP cassette has been introduced in frame with the ATG of exon 1 of Fgf10 gene. Our studies show that Cre-ERT2 insertion disrupts Fgf10 function. However, administration of tamoxifen to Fgf10(iCre); Tomato(flox) double transgenic embryos or adult mice results in specific labeling of Fgf10-positive cells, which can be lineage-traced temporally and spatially. Moreover, we show that the Fgf10(iCre) line can be used for conditional gene inactivation in an inducible fashion during early developmental stages. We also provide evidence that transcription factors located in the first intron of Fgf10 gene are critical for maintaining Fgf10 expression over time. Thus, the Fgf10(iCre) line should serve as a powerful tool to explore the functions of Fgf10 in a controlled and stage-specific manner. PMID:22719891

  12. Neither absence nor excess of FGF23 disturbs murine fetal-placental phosphorus homeostasis or prenatal skeletal development and mineralization.

    PubMed

    Ma, Yue; Samaraweera, Manoharee; Cooke-Hubley, Sandra; Kirby, Beth J; Karaplis, Andrew C; Lanske, Beate; Kovacs, Christopher S

    2014-05-01

    Fibroblast growth factor-23 (FGF23) controls serum phosphorus largely through actions on the kidneys to excrete phosphorus and reduce calcitriol. Although these actions are well established in adults and children, the role that FGF23 plays in regulating fetal phosphorus metabolism has not been previously studied. We used several mouse models to study the effect of endogenous deficiency or excess of FGF23 on fetal phosphorus metabolism. We found that intact FGF23 does not cross the placenta from mother to fetus, but wild-type fetuses normally have intact FGF23 levels that approximately equal the maternal level. Deletion of Fgf23 or 7.8-fold higher serum FGF23 levels did not disturb any parameter of fetal mineral homeostasis, including serum and amniotic fluid phosphorus, skeletal morphology, skeletal mineral content, and placental phosphorus transport. Placentas and fetal kidneys abundantly express FGF23 target genes. Cyp24a1 was significantly reduced in Fgf23 null kidneys and was significantly increased in Phex null placentas and fetal kidneys. Phex null kidneys also showed reduced expression of Klotho. However, these changes in gene expression did not disturb any physiological parameter related to phosphorus. A 50% reduction in FGF23 also failed to affect renal phosphorus excretion into amniotic fluid when either PTH or the vitamin D receptor were absent. In conclusion, FGF23 is not an important regulator of fetal phosphorous metabolism. The active delivery of phosphorus across the placenta does not require FGF23, and that process overrides any effects that absence or excess of FGF23 might otherwise have on phosphate handling by the fetal kidneys.

  13. Calcium regulates FGF-23 expression in bone.

    PubMed

    David, Valentin; Dai, Bing; Martin, Aline; Huang, Jinsong; Han, Xiaobin; Quarles, L Darryl

    2013-12-01

    Calcium has recently been shown to regulate fibroblast growth factor 23 (FGF-23), a bone-derived phosphate and vitamin D-regulating hormone. To better understand the regulation of FGF-23 by calcium, phosphorus, 1,25 dihydroxyvitamin D3 [1,25(OH)2D], and PTH, we examined FGF-23 expression under basal conditions and in response to PTH, doxercalciferol, or high-calcium diet treatment in Gcm2(-/-) and Cyp27b1(-/-) mutant mice. Gcm2(-/-) mice exhibited low serum PTH and 1,25(OH)2D concentrations, hypocalcemia, and hyperphosphatemia, whereas Cyp27b1(-/-) mice had high PTH, undetectable 1,25(OH)2D, hypocalcemia, and hypophosphatemia. Serum FGF-23 levels were decreased in both mutant models. Doxercalciferol administration increased serum FGF-23 levels in both mutant models. PTH administration to Gcm2(-/-) mice also increased serum FGF-23 levels, in association with an increase in both 1,25(OH)2D and calcium concentrations. Multiple regression analysis of pooled data indicated that changes in FGF-23 were positively correlated with serum calcium and 1,25(OH)2D but not related to changes in serum phosphate concentrations. A high-calcium diet also increased serum FGF-23 concentrations in Cyp27b1(-/-) mice in the absence of 1,25(OH)2D and in Gcm2(-/-) mice with low PTH. The addition of calcium to the culture media also stimulated FGF-23 message expression in MC3T3-E1 osteoblasts. In addition, FGF-23 promoter activity in cultured osteoblasts was inhibited by the L-calcium-channel inhibitor nifedipine and stimulated by calcium ionophores. The effects of chronic low calcium to prevent 1,25(OH)2D and PTH stimulation of FGF-23 in these mutant mouse models suggest that suppression of FGF-23 plays an important physiological adaptive response to hypocalcemia.

  14. Fgf10 overexpression enhances the formation of tissue-engineered small intestine.

    PubMed

    Torashima, Yasuhiro; Levin, Daniel E; Barthel, Erik R; Speer, Allison L; Sala, Frédéric G; Hou, Xiaogang; Grikscheit, Tracy C

    2016-02-01

    Short bowel syndrome (SBS) is a morbid and mortal condition characterized in most patients by insufficient intestinal surface area. Current management strategies are inadequate, but tissue-engineered small intestine (TESI) offers a potential therapy. A barrier to translation of TESI is the generation of scalable mucosal surface area to significantly increase nutritional absorption. Fibroblast growth factor 10 (Fgf10) is a critical growth factor essential for the development of the gastrointestinal tract. We hypothesized that overexpression of Fgf10 would improve the generation of TESI. Organoid units, the multicellular donor tissue that forms TESI, were derived from Rosa26(rtTA/+), tet(o)Fgf10/(-) or Fgf10(Mlc-nlacZ-v24) (hereafter called Fgf10(lacZ)) mice. These were implanted into the omentum of NOD/SCID γ-chain-deficient mice and induced with doxycycline in the case of tet(o)Fgf10/(-). Resulting TESI were explanted at 4 weeks and studied by histology, quantitative RT-PCR and immunofluorescence. Four weeks after implantation, Fgf10 overexpressing TESI was larger and weighed more than the control tissues. Within the mucosa, the villus height was significantly longer and crypts contained a greater percentage of proliferating epithelial cells. A fully differentiated intestinal epithelium with enterocytes, goblet cells, enteroendocrine cells and Paneth cells was identified in the Fgf10-overexpressing TESI, comparable to native small intestine. β-Galactosidase expression was found in both the epithelium and the mesenchyme of the TESI derived from the Fgf10(LacZ) duodenum. However, this was not the case with TESI generated from jejunum and ileum. We conclude that Fgf10 enhances the formation of TESI.

  15. A New Role for FGF2 as an Endogenous Inhibitor of Anxiety

    PubMed Central

    Perez, Javier A.; Clinton, Sarah M.; Turner, Cortney A.; Watson, Stanley J.; Akil, Huda

    2009-01-01

    Human postmortem studies have demonstrated that FGF2 expression is decreased in the brain of depressed individuals. It remained unclear, however, whether this is a consequence of the illness or whether FGF2 plays a primary role in the control of mood and emotions. In this series of studies, we first ask whether endogenous FGF2 expression correlates with spontaneous anxiety, a trait associated with vulnerability to severe mood disorders in humans. This is tested in two genetically distinct groups of rats selectively bred to differ dramatically in their response to novelty and anxiety-provoking conditions (HRs= Low-Anxiety/High Response to Novelty vs. LRs= High-Anxiety/Low Response to Novelty). We demonstrate that High-Anxiety LRs have significantly lower levels of hippocampal FGF2 mRNA relative to Low-Anxiety HRs. We then demonstrate that FGF2 expression is modifiable by environmental factors that alter anxiety--thus environmental complexity (EC) reduces anxiety behavior and induces FGF2 expression in hippocampus, particularly in High-Anxiety LRs. Finally, we directly test the role of FGF2 as an anxiolytic and show that a 3-week treatment regimen of peripherally administered FGF2 is highly effective at blunting anxiety behavior, specifically in High-Anxiety LRs. This treatment is accompanied by an increase in survival of adult-born hippocampal cells, both neurons and astrocytes, most clearly in LRs. These findings implicate hippocampal FGF2 as a central integrator of genetic and environmental factors that modify anxiety, point to hippocampal neurogenesis and gliogenesis as key in this modulation, and underscore FGF2’s potential as a new target for treatment of depression and anxiety disorders. PMID:19439615

  16. Roles of FGFs As Paracrine or Endocrine Signals in Liver Development, Health, and Disease

    PubMed Central

    Itoh, Nobuyuki; Nakayama, Yoshiaki; Konishi, Morichika

    2016-01-01

    The liver plays important roles in multiple processes including metabolism, the immune system, and detoxification and also has a unique capacity for regeneration. FGFs are growth factors that have diverse functions in development, health, and disease. The FGF family now comprises 22 members. Several FGFs have been shown to play roles as paracrine signals in liver development, health, and disease. FGF8 and FGF10 are involved in embryonic liver development, FGF7 and FGF9 in repair in response to liver injury, and FGF5, FGF8, FGF9, FGF17, and FGF18 in the development and progression of hepatocellular carcinoma. In contrast, FGF15/19 and FGF21 are endocrine signals. FGF15/19, which is produced in the ileum, is a negative regulator of bile acid metabolism and a stimulator of gallbladder filling. FGF15/19 is a postprandial, insulin-independent activator of hepatic protein and glycogen synthesis. It is also required for hepatocellular carcinoma and liver regeneration. FGF21 is a hepatokine produced in the liver. FGF21 regulates glucose and lipid metabolism in white adipose tissue. Serum FGF21 levels are elevated in non-alcoholic fatty liver. FGF21 also protects against non-alcoholic fatty liver. These findings provide new insights into the roles of FGFs in the liver and potential therapeutic strategies for hepatic disorders. PMID:27148532

  17. Regulation and function of the FGF23/klotho endocrine pathways.

    PubMed

    Martin, Aline; David, Valentin; Quarles, L Darryl

    2012-01-01

    Calcium (Ca(2+)) and phosphate (PO(4)(3-)) homeostasis are coordinated by systemic and local factors that regulate intestinal absorption, influx and efflux from bone, and kidney excretion and reabsorption of these ions through a complex hormonal network. Traditionally, the parathyroid hormone (PTH)/vitamin D axis provided the conceptual framework to understand mineral metabolism. PTH secreted by the parathyroid gland in response to hypocalcemia functions to maintain serum Ca(2+) levels by increasing Ca(2+) reabsorption and 1,25-dihydroxyvitamin D [1,25(OH)(2)D] production by the kidney, enhancing Ca(2+) and PO(4)(3-) intestinal absorption and increasing Ca(2+) and PO(4)(3-) efflux from bone, while maintaining neutral phosphate balance through phosphaturic effects. FGF23 is a recently discovered hormone, predominately produced by osteoblasts/osteocytes, whose major functions are to inhibit renal tubular phosphate reabsorption and suppress circulating 1,25(OH)(2)D levels by decreasing Cyp27b1-mediated formation and stimulating Cyp24-mediated catabolism of 1,25(OH)(2)D. FGF23 participates in a new bone/kidney axis that protects the organism from excess vitamin D and coordinates renal PO(4)(3-) handling with bone mineralization/turnover. Abnormalities of FGF23 production underlie many inherited and acquired disorders of phosphate homeostasis. This review discusses the known and emerging functions of FGF23, its regulation in response to systemic and local signals, as well as the implications of FGF23 in different pathological and physiological contexts.

  18. Enhancement of FGF-1 release along with cytosolic proteins from rat astrocytes by hydrogen peroxide.

    PubMed

    Ito, Jin-Ichi; Nagayasu, Yuko; Hoshikawa, Mariko; Kato, Koichi H; Miura, Yutaka; Asai, Kiyofumi; Hayashi, Hideki; Yokoyama, Shinji; Michikawa, Makoto

    2013-07-19

    We previously observed that the production and release of fibroblast growth factor (FGF-1) are increased in rat astrocytes during in vitro long-term culture, that FGF-1 enhances the generation of apoE-containing high density lipoproteins (apoE/HDL), and that the wound healing of brain cryoinjury delays in apoE-deficient mouse. The detail mechanism underlying these phenomena remains unknown. In this study, we examined effects of oxidative stress on release of FGF-1 from cultured rat astrocytes. The treatment of rat astrocytes with 100µM hydrogen peroxide (H2O2) for 10min enhanced FGF-1 release without inducing apoptosis. The conditioned medium prepared from the cells cultured in a fresh medium after the treatment with H2O2 had the FGF-1-like activities, which enhanced cholesterol synthesis, signalings to phosphorylate Akt and ERK, and apoE secretion. The oxidative stress induced by H2O2 enhanced the release of cytosolic proteins such as HSP70 and HSP90 in addition to FGF-1. Antioxidants such as ascorbic acid and ebselen suppressed the release of cytosolic proteins induced by H2O2 treatment. The addition of lipoproteins such as low density lipoproteins (LDL), furthermore, canceled H2O2-induced release of FGF-1 and cytosolic proteins. Proteolysis of cytosolic proteins in the H2O2-treated rat astrocytes was enhanced in the presence of exogenous trypsin, which was attenuated by the pretreatment with LDL, suggesting that H2O2 increases the permeability of the membrane of cells, which was prevented by the addition of lipoproteins. These findings suggest that oxidative stress is one of the candidates which triggers FGF-1 release from astrocytes in the brain, and that the lipid homeostasis in the cell membrane may regulate H2O2-induced release of FGF-1. PMID:23727614

  19. FGF9, activin and TGFβ promote testicular characteristics in an XX gonad organ culture model.

    PubMed

    Gustin, Sonja E; Stringer, Jessica M; Hogg, Kirsten; Sinclair, Andrew H; Western, Patrick S

    2016-11-01

    Testis development is dependent on the key sex-determining factors SRY and SOX9, which activate the essential ligand FGF9. Although FGF9 plays a central role in testis development, it is unable to induce testis formation on its own. However, other growth factors, including activins and TGFβs, also present testis during testis formation. In this study, we investigated the potential of FGF9 combined with activin and TGFβ to induce testis development in cultured XX gonads. Our data demonstrated differing individual and combined abilities of FGF9, activin and TGFβ to promote supporting cell proliferation, Sertoli cell development and male germ line differentiation in cultured XX gonads. FGF9 promoted proliferation of supporting cells in XX foetal gonads at rates similar to those observed in vivo during testis cord formation in XY gonads but was insufficient to initiate testis development. However, when FGF9, activin and TGFβ were combined, aspects of testicular development were induced, including the expression of Sox9, morphological reorganisation of the gonad and deposition of laminin around germ cells. Enhancing β-catenin activity diminished the testis-promoting activities of the combined growth factors. The male promoting activity of FGF9 and the combined growth factors directly or indirectly extended to the germ line, in which a mixed phenotype was observed. FGF9 and the combined growth factors promoted male germ line development, including mitotic arrest, but expression of pluripotency genes was maintained, rather than being repressed. Together, our data provide evidence that combined signalling by FGF9, activin and TGFβ can induce testicular characteristics in XX gonads.

  20. FGF9, activin and TGFβ promote testicular characteristics in an XX gonad organ culture model.

    PubMed

    Gustin, Sonja E; Stringer, Jessica M; Hogg, Kirsten; Sinclair, Andrew H; Western, Patrick S

    2016-11-01

    Testis development is dependent on the key sex-determining factors SRY and SOX9, which activate the essential ligand FGF9. Although FGF9 plays a central role in testis development, it is unable to induce testis formation on its own. However, other growth factors, including activins and TGFβs, also present testis during testis formation. In this study, we investigated the potential of FGF9 combined with activin and TGFβ to induce testis development in cultured XX gonads. Our data demonstrated differing individual and combined abilities of FGF9, activin and TGFβ to promote supporting cell proliferation, Sertoli cell development and male germ line differentiation in cultured XX gonads. FGF9 promoted proliferation of supporting cells in XX foetal gonads at rates similar to those observed in vivo during testis cord formation in XY gonads but was insufficient to initiate testis development. However, when FGF9, activin and TGFβ were combined, aspects of testicular development were induced, including the expression of Sox9, morphological reorganisation of the gonad and deposition of laminin around germ cells. Enhancing β-catenin activity diminished the testis-promoting activities of the combined growth factors. The male promoting activity of FGF9 and the combined growth factors directly or indirectly extended to the germ line, in which a mixed phenotype was observed. FGF9 and the combined growth factors promoted male germ line development, including mitotic arrest, but expression of pluripotency genes was maintained, rather than being repressed. Together, our data provide evidence that combined signalling by FGF9, activin and TGFβ can induce testicular characteristics in XX gonads. PMID:27495231

  1. A muscle-liver-fat signalling axis is essential for central control of adaptive adipose remodelling

    PubMed Central

    Shimizu, Noriaki; Maruyama, Takako; Yoshikawa, Noritada; Matsumiya, Ryo; Ma, Yanxia; Ito, Naoki; Tasaka, Yuki; Kuribara-Souta, Akiko; Miyata, Keishi; Oike, Yuichi; Berger, Stefan; Schütz, Günther; Takeda, Shin’ichi; Tanaka, Hirotoshi

    2015-01-01

    Skeletal muscle has a pleiotropic role in organismal energy metabolism, for example, by storing protein as an energy source, or by excreting endocrine hormones. Muscle proteolysis is tightly controlled by the hypothalamus-pituitary-adrenal signalling axis via a glucocorticoid-driven transcriptional programme. Here we unravel the physiological significance of this catabolic process using skeletal muscle-specific glucocorticoid receptor (GR) knockout (GRmKO) mice. These mice have increased muscle mass but smaller adipose tissues. Metabolically, GRmKO mice show a drastic shift of energy utilization and storage in muscle, liver and adipose tissues. We demonstrate that the resulting depletion of plasma alanine serves as a cue to increase plasma levels of fibroblast growth factor 21 (FGF21) and activates liver-fat communication, leading to the activation of lipolytic genes in adipose tissues. We propose that this skeletal muscle-liver-fat signalling axis may serve as a target for the development of therapies against various metabolic diseases, including obesity. PMID:25827749

  2. Universal signals control slime mold stalk formation.

    PubMed

    van Es, S; Nieuwenhuijsen, B W; Lenouvel, F; van Deursen, E M; Schaap, P

    1994-08-16

    The primitive slime mold Dictyostelium minutum does not display oscillations during aggregation, cannot form migrating slugs, and does not form a prestalk/prespore pattern, all of which are characteristic for development of its advanced relative Dictyostelium discoideum. We used D. minutum to investigate whether slime molds share common mechanisms controlling development. In D. discoideum, the morphogen differentiation inducing factor (DIF) can induce stalk-cell differentiation in vitro. However, stalk formation in vivo is supposedly triggered by local depletion of DIF antagonists such as ammonia or cAMP. A homologue of the D. discoideum stalk gene ecmB was cloned in D. minutum that encodes a 3.4-kb mRNA, and its deduced amino acid sequence shows repeats of 24 amino acids that are characteristic for the D. discoideum ecmB gene. Remarkably, DIF effectively induces expression of the D. minutum ecmB gene and ammonia inhibits its expression. D. discoideum cells were transformed with a construct of the D. minutum ecmB promoter fused to the lacZ reporter gene and showed expression in the stalk, but not in the upper and lower cup of the fruiting body, which also express the D. discoideum ecmB gene. In D. discoideum, the D. minutum ecmB and the ecmB promoter are similarly activated by DIF and repressed by both cAMP and ammonia, suggesting that additional signaling is required for ecmB expression in upper and lower cup cells. Our data indicate that the extracellular signals controlling stalk formation and their intracellular signaling cascades including gene regulatory proteins remained highly conserved during slime mold evolution. PMID:8058783

  3. Spatiotemporal control of opioid signaling and behavior

    PubMed Central

    Siuda, Edward R.; Copits, Bryan A.; Schmidt, Martin J.; Baird, Madison A.; Al-Hasani, Ream; Planer, William J.; Funderburk, Samuel C.; McCall, Jordan G.; Gereau, Robert W.; Bruchas, Michael R.

    2015-01-01

    Summary Optogenetics is now a widely accepted tool for spatiotemporal manipulation of neuronal activity. However, a majority of optogenetic approaches use binary on/off control schemes. Here we extend the optogenetic toolset by developing a neuromodulatory approach using a rationale-based design to generate a Gi-coupled, optically-sensitive, mu-opioid-like receptor, we term opto-MOR. We demonstrate that opto-MOR engages canonical mu-opioid signaling through inhibition of adenylyl cyclase, activation of MAPK and G protein-gated inward rectifying potassium (GIRK) channels, and internalizes with similar kinetics as the mu-opioid receptor. To assess in vivo utility we expressed a Cre-dependent viral opto-MOR in RMTg/VTA GABAergic neurons, which led to a real-time place preference. In contrast, expression of opto-MOR in GABAergic neurons of the ventral pallidum hedonic cold spot, led to real-time place aversion. This tool has generalizable application for spatiotemporal control of opioid signaling and, furthermore, can be used broadly for mimicking endogenous neuronal inhibition pathways. PMID:25937173

  4. Characterization of FGF23-Dependent Egr-1 Cistrome in the Mouse Renal Proximal Tubule

    PubMed Central

    Portale, Anthony A.; Zhang, Martin Y. H.; David, Valentin; Martin, Aline; Jiao, Yan; Gu, Weikuan; Perwad, Farzana

    2015-01-01

    Fibroblast growth factor 23 (FGF23) is a potent regulator of phosphate (Pi) and vitamin D homeostasis. The transcription factor, early growth response 1 (egr-1), is a biomarker for FGF23-induced activation of the ERK1/2 signaling pathway. We have shown that ERK1/2 signaling blockade suppresses renal egr-1 gene expression and prevents FGF23-induced hypophosphatemia and 1,25-dihydroxyvitamin D (1,25(OH)2D) suppression in mice. To test whether egr-1 itself mediates these renal actions of FGF23, we administered FGF23 to egr-1-/- and wild-type (WT) mice. In WT mice, FGF23 induced hypophosphatemia and suppressed expression of the renal Na/Pi cotransporters, Npt2a and Npt2c. In FGF23-treated egr-1-/- mice, hypophosphatemic response was greatly blunted and Na/Pi cotransporter expression was not suppressed. In contrast, FGF23 induced equivalent suppression of serum 1,25(OH)2D concentrations by suppressing renal cyp27b1 and stimulating cyp24a1 mRNA expression in both groups of mice. Thus, downstream of receptor binding and ERK1/2 signaling, we can distinguish the effector pathway that mediates FGF23-dependent inhibition of Pi transport from the pathway that mediates inhibition of 1,25(OH)2D synthesis in the kidney. Furthermore, we demonstrate that the hypophosphatemic effect of FGF23 is significantly blunted in Hyp/egr-1-/- mice; specifically, serum Pi concentrations and renal Npt2a and Npt2c mRNA expression are significantly higher in Hyp/egr-1-/- mice than in Hyp mice. We then characterized the egr-1 cistrome in the kidney using ChIP-sequencing and demonstrate recruitment of egr-1 to regulatory DNA elements in proximity to several genes involved in Pi transport. Thus, our data demonstrate that the effect of FGF23 on Pi homeostasis is mediated, at least in part, by activation of egr-1. PMID:26588476

  5. Characterization of FGF23-Dependent Egr-1 Cistrome in the Mouse Renal Proximal Tubule.

    PubMed

    Portale, Anthony A; Zhang, Martin Y H; David, Valentin; Martin, Aline; Jiao, Yan; Gu, Weikuan; Perwad, Farzana

    2015-01-01

    Fibroblast growth factor 23 (FGF23) is a potent regulator of phosphate (Pi) and vitamin D homeostasis. The transcription factor, early growth response 1 (egr-1), is a biomarker for FGF23-induced activation of the ERK1/2 signaling pathway. We have shown that ERK1/2 signaling blockade suppresses renal egr-1 gene expression and prevents FGF23-induced hypophosphatemia and 1,25-dihydroxyvitamin D (1,25(OH)2D) suppression in mice. To test whether egr-1 itself mediates these renal actions of FGF23, we administered FGF23 to egr-1-/- and wild-type (WT) mice. In WT mice, FGF23 induced hypophosphatemia and suppressed expression of the renal Na/Pi cotransporters, Npt2a and Npt2c. In FGF23-treated egr-1-/- mice, hypophosphatemic response was greatly blunted and Na/Pi cotransporter expression was not suppressed. In contrast, FGF23 induced equivalent suppression of serum 1,25(OH)2D concentrations by suppressing renal cyp27b1 and stimulating cyp24a1 mRNA expression in both groups of mice. Thus, downstream of receptor binding and ERK1/2 signaling, we can distinguish the effector pathway that mediates FGF23-dependent inhibition of Pi transport from the pathway that mediates inhibition of 1,25(OH)2D synthesis in the kidney. Furthermore, we demonstrate that the hypophosphatemic effect of FGF23 is significantly blunted in Hyp/egr-1-/- mice; specifically, serum Pi concentrations and renal Npt2a and Npt2c mRNA expression are significantly higher in Hyp/egr-1-/- mice than in Hyp mice. We then characterized the egr-1 cistrome in the kidney using ChIP-sequencing and demonstrate recruitment of egr-1 to regulatory DNA elements in proximity to several genes involved in Pi transport. Thus, our data demonstrate that the effect of FGF23 on Pi homeostasis is mediated, at least in part, by activation of egr-1.

  6. Bile Acids as Hormones: The FXR-FGF15/19 Pathway

    PubMed Central

    Kliewer, Steven A.; Mangelsdorf, David J.

    2015-01-01

    While it has long been recognized that bile acids are essential for solubilizing lipophilic nutrients in the small intestine, the discovery in 1999 that bile acids serve as ligands for the nuclear receptor FXR opened the floodgates in terms of characterizing their actions as selective signaling molecules. Bile acids act on FXR in ileal enterocytes to induce the expression of fibroblast growth factor (FGF) 15/19, an atypical FGF that functions as a hormone. FGF15/19 subsequently acts on a cell surface receptor complex in hepatocytes to repress bile acid synthesis and gluconeogenesis and to stimulate glycogen and protein synthesis. FGF15/19 also stimulates gallbladder filling. Thus, the bile acid-FXR-FGF15/19 signaling pathway regulates diverse aspects of the postprandial enterohepatic response. Pharmacologically, this endocrine pathway provides exciting new opportunities for treating metabolic disease and bile acid-related disorders such as primary biliary cirrhosis and bile acid diarrhea. Both FXR agonists and FGF19 analogs are currently in clinical trials. PMID:26045265

  7. Bile Acids as Hormones: The FXR-FGF15/19 Pathway.

    PubMed

    Kliewer, Steven A; Mangelsdorf, David J

    2015-01-01

    While it has long been recognized that bile acids are essential for solubilizing lipophilic nutrients in the small intestine, the discovery in 1999 that bile acids serve as ligands for the nuclear receptor farnesoid X receptor (FXR) opened the floodgates in terms of characterizing their actions as selective signaling molecules. Bile acids act on FXR in ileal enterocytes to induce the expression of fibroblast growth factor (FGF)15/19, an atypical FGF that functions as a hormone. FGF15/19 subsequently acts on a cell surface receptor complex in hepatocytes to repress bile acid synthesis and gluconeogenesis, and to stimulate glycogen and protein synthesis. FGF15/19 also stimulates gallbladder filling. Thus, the bile acid-FXR-FGF15/19 signaling pathway regulates diverse aspects of the postprandial enterohepatic response. Pharmacologically, this endocrine pathway provides exciting new opportunities for treating metabolic disease and bile acid-related disorders such as primary biliary cirrhosis and bile acid diarrhea. Both FXR agonists and FGF19 analogs are currently in clinical trials. PMID:26045265

  8. The Effect of Covalently Immobilized FGF-2 on Biphasic Calcium Phosphate Bone Substitute on Enhanced Biological Compatibility and Activity

    PubMed Central

    Moon, Kyung-Suk; Choi, Eun-Joo; Oh, Seunghan; Kim, Sungtae

    2015-01-01

    The purpose of this research was to covalently graft fibroblast growth factor 2 (FGF-2) onto biphasic calcium phosphate (BCP) via a bifunctional cross-linker technique and to estimate the optimal dose of FGF-2 resulting in the best osteogenic differentiation of human mesenchymal stem cells (hMSCs). SEM observation revealed that the surface of the 100 ng FGF-2 coated BCP was completely covered with the nanoparticles expected to be from the silane coupling agent. XRD, FT-IR, and XPS analysis showed that silane treatment, bifunctional cross-linker coating, and FGF-2 covalent grafts were conducted successfully without deforming the crystalline structure of BCP. An MTT assay demonstrated that FGF-2 coated BCP had good biocompatibility, regardless of the concentration of FGF-2, after 24 or 48 h of incubation. An alkaline phosphatase (ALP) activity assay (14 days of incubation) and the ALP gene expression level of real-time PCR analysis (7 days of incubation) revealed that 50, 100, and 200 ng FGF-2 coated BCP induced the highest activities among all experimental groups and control group (P < 0.05). Thus, low concentrations of FGF-2 facilitated excellent osteogenesis and were effective at enhancing osteogenic potential. Also, the bifunctional cross-linker technique is expected to be a more feasible way to induce osteogenic differentiation while minimizing the risk of FGF-2 overdose. PMID:26436096

  9. Inverse Modelling to Obtain Head Movement Controller Signal

    NASA Technical Reports Server (NTRS)

    Kim, W. S.; Lee, S. H.; Hannaford, B.; Stark, L.

    1984-01-01

    Experimentally obtained dynamics of time-optimal, horizontal head rotations have previously been simulated by a sixth order, nonlinear model driven by rectangular control signals. Electromyography (EMG) recordings have spects which differ in detail from the theoretical rectangular pulsed control signal. Control signals for time-optimal as well as sub-optimal horizontal head rotations were obtained by means of an inverse modelling procedures. With experimentally measured dynamical data serving as the input, this procedure inverts the model to produce the neurological control signals driving muscles and plant. The relationships between these controller signals, and EMG records should contribute to the understanding of the neurological control of movements.

  10. 49 CFR 236.205 - Signal control circuits; requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Signal control circuits; requirements. 236.205... Block Signal Systems Standards § 236.205 Signal control circuits; requirements. The circuits shall be so... fouling point derail equipped with switch circuit controller is not in derailing position, (d) When...

  11. 49 CFR 236.205 - Signal control circuits; requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Signal control circuits; requirements. 236.205... Block Signal Systems Standards § 236.205 Signal control circuits; requirements. The circuits shall be so... fouling point derail equipped with switch circuit controller is not in derailing position, (d) When...

  12. 49 CFR 236.205 - Signal control circuits; requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Signal control circuits; requirements. 236.205... Block Signal Systems Standards § 236.205 Signal control circuits; requirements. The circuits shall be so... fouling point derail equipped with switch circuit controller is not in derailing position, (d) When...

  13. 49 CFR 236.205 - Signal control circuits; requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Signal control circuits; requirements. 236.205... Block Signal Systems Standards § 236.205 Signal control circuits; requirements. The circuits shall be so... fouling point derail equipped with switch circuit controller is not in derailing position, (d) When...

  14. Mechanism of FGF receptor dimerization and activation

    PubMed Central

    Sarabipour, Sarvenaz; Hristova, Kalina

    2016-01-01

    Fibroblast growth factors (fgfs) are widely believed to activate their receptors by mediating receptor dimerization. Here we show, however, that the FGF receptors form dimers in the absence of ligand, and that these unliganded dimers are phosphorylated. We further show that ligand binding triggers structural changes in the FGFR dimers, which increase FGFR phosphorylation. The observed effects due to the ligands fgf1 and fgf2 are very different. The fgf2-bound dimer structure ensures the smallest separation between the transmembrane (TM) domains and the highest possible phosphorylation, a conclusion that is supported by a strong correlation between TM helix separation in the dimer and kinase phosphorylation. The pathogenic A391E mutation in FGFR3 TM domain emulates the action of fgf2, trapping the FGFR3 dimer in its most active state. This study establishes the existence of multiple active ligand-bound states, and uncovers a novel molecular mechanism through which FGFR-linked pathologies can arise. PMID:26725515

  15. Overexpression of high molecular weight FGF-2 forms inhibits glioma growth by acting on cell-cycle progression and protein translation

    SciTech Connect

    Lemiere, Sylvie; Azar, Rania; Belloc, Francis; Guersel, Demir; Pyronnet, Stephane; Bikfalvi, Andreas Auguste, Patrick

    2008-12-10

    In order to clarify the role of HMW FGF-2 in glioma development and angiogenesis, we over-expressed different human FGF-2 isoforms in C6 rat glioma cell line using a tetracycline-regulated expression system. Phenotypic modifications were analyzed in vitro and compared to untransfected cells or to cells over-expressing 18 kDa FGF-2 or all FGF-2 isoforms. In particular, we demonstrate that HMW FGF-2 has unique features in inhibiting glioma cell proliferation. HMW FGF-2 expressing cells showed a cell-cycle arrest at the G2M, demonstrating a role of HMW FGF-2 in controlling the entry in mitosis. Moreover, hydroxyurea was ineffective in blocking cells at the G1S boundary when HMW FGF-2 was expressed. We also show that the HMW FGF-2 isoforms inhibit 4E-BP1 phosphorylation at critical sites restoring the translation inhibitory activity of 4E-BP1. In vivo, inhibition of tumor growth was observed when cells expressed HMW FGF-2. This indicates that HMW FGF-2 inhibits tumor growth in glioma cells by acting on cell-cycle progression and protein translation.

  16. A Self-regulatory System of Interlinked Signaling Feedback Loops Controls Mouse Limb Patterning

    NASA Astrophysics Data System (ADS)

    Benazet, Jean-Denis; Bischofberger, Mirko; Tiecke, Eva; Gonalves, Alexandre; Martin, James F.; Zuniga, Aime; Naef, Felix; Zeller, Rolf

    Developmental pathways need to be robust against environmental and genetic variation to enable reliable morphogenesis. Here, we take a systems biology approach to explain how robustness is achieved in the developing mouse limb, a classical model of organogenesis. By combining quantitative genetics with computational modeling we established a computational model of multiple interlocked feedback modules, involving sonic hedgehog (SHH) morphogen, fibroblast growth factor (FGFs) signaling, bone morphogenetic protein (BMP) and its antagonist GREM1. Earlier modeling work had emphasized the versatile kinetic characteristics of interlocked feedback loops operating at different time scales. Here we develop and then validate a similar computational model to show how BMP4 first initiates and SHH then propagates feedback in the network through differential transcriptional regulation of Grem1 to control digit specification. This switch occurs by linking a fast BMP4/GREM1 module to a slower SHH/GREM1/FGF feedback loop. Simulated gene expression profiles modeled normal limb development as well those of single-gene knockouts. Sensitivity analysis showed how the model was robust and insensitive to variability in parameters. A surprising prediction of the model was that an early Bmp4 signal is essential to kick-start Grem1 expression and the digit specification system. We experimentally validated the prediction using inducible alleles and showed that early, but not late, removal of Bmp4 dramatically disrupted limb development. Sensitivity analysis showed how robustness emerges from this circuitry. This study shows how modeling and computation can help us understand how self-regulatory signaling networks achieve robust regulation of limb development, by exploiting interconnectivity among the three signaling pathways. We expect that similar computational analyses will shed light on the origins of robustness in other developmental systems, and I will discuss some recent examples from

  17. Fibroblast growth factor signaling is essential for self-renewal of dental epithelial stem cells.

    PubMed

    Chang, Julia Yu Fong; Wang, Cong; Liu, Junchen; Huang, Yanqing; Jin, Chengliu; Yang, Chaofeng; Hai, Bo; Liu, Fei; D'Souza, Rena N; McKeehan, Wallace L; Wang, Fen

    2013-10-01

    A constant supply of epithelial cells from dental epithelial stem cell (DESC) niches in the cervical loop (CL) enables mouse incisors to grow continuously throughout life. Elucidation of the cellular and molecular mechanisms underlying this unlimited growth potential is of broad interest for tooth regenerative therapies. Fibroblast growth factor (FGF) signaling is essential for the development of mouse incisors and for maintenance of the CL during prenatal development. However, how FGF signaling in DESCs controls the self-renewal and differentiation of the cells is not well understood. Herein, we report that FGF signaling is essential for self-renewal and the prevention of cell differentiation of DESCs in the CL as well as in DESC spheres. Inhibiting the FGF signaling pathway decreased proliferation and increased apoptosis of the cells in DESC spheres. Suppressing FGFR or its downstream signal transduction pathways diminished Lgr5-expressing cells in the CL and promoted cell differentiation both in DESC spheres and the CL. Furthermore, disruption of the FGF pathway abrogated Wnt signaling to promote Lgr5 expression in DESCs both in vitro and in vivo. This study sheds new light on understanding the mechanism by which the homeostasis, expansion, and differentiation of DESCs are regulated.

  18. Biphasic Effects of Vitamin D and FGF23 on Human Osteoclast Biology.

    PubMed

    Allard, Lise; Demoncheaux, Nathalie; Machuca-Gayet, Irma; Georgess, Dan; Coury-Lucas, Fabienne; Jurdic, Pierre; Bacchetta, Justine

    2015-07-01

    Vitamin D and FGF23 play a major role in calcium/phosphate balance. Vitamin D may control bone resorption but the potential role of FGF23 has never been evaluated. The objective of this study was therefore to compare the effects of vitamin D and FGF23 on osteoclast differentiation and activity in human monocyte-derived osteoclasts. Human monocytes, purified from blood of healthy donors, were incubated with M-CSF and RANKL to obtain mature multinucleated osteoclasts (MNC). Experiments were carried out to assess the effects of FGF23 as compared to native vitamin D (25-D) and active vitamin D (1,25-D) on osteoclast differentiation and on bone-resorbing osteoclast activity. Additional experiments with the pan fibroblast growth factor receptor inhibitor (FGFR-i) were performed. Phosphorylation Akt and Erk pathways were analyzed by Western blot analyses. Both 1,25-D and FGF23, to a lesser extent, significantly inhibited osteoclastogenesis at early stages; when adding FGFR-i, osteoclast formation was restored. Biochemical experiments showed an activation of the Akt and Erk pathways under FGF23 treatment. In contrast, in terms of activity, 1,25-D had no effect on resorption, whereas FGF23 slightly but significantly increased bone resorption; 25-D had no effects on either differentiation or on activity. These data show that 1,25-D inhibits osteoclastogenesis without regulating osteoclast-mediated bone resorption activity; FGF23 has biphasic effects on osteoclast physiology, inhibiting osteoclast formation while stimulating slightly osteoclast activity. These results may be of importance and taken into account in chronic kidney disease when therapies modulating FGF23 are available.

  19. Insulin-like growth factor-binding protein-3 inhibits IGF-1-induced proliferation of human hepatocellular carcinoma cells by controlling bFGF and PDGF autocrine/paracrine loops.

    PubMed

    Ma, Yang; Han, Chen-Chen; Li, Yifan; Wang, Yang; Wei, Wei

    2016-09-16

    Basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF) produced by hepatocellular carcinoma (HCC) cells are responsible for the growth of HCC cells. Accumulating evidence shows that insulin-like growth factor-binding protein-3 (IGFBP-3) suppresses HCC cell proliferation in both IGF-dependent and independent manners. It's unknown, however, whether treatment with exogenous IGFBP-3 inhibits bFGF and PDGF production in HCC cells. The present study demonstrates that IGFBP-3 suppressed IGF-1-induced bFGF and PDGF expression while it does not affect their expression in the absence of IGF-1. To delineate the underlying mechanism, western-blot and RT-PCR assays confirmed that the transcription factor early growth response protein 1 (EGR1) is involved in IGFBP-3 regulation of bFGF and PDGF. IGFBP-3 inhibition of type 1 insulin-like growth factor receptor (IGF1R), ERK and AKT activation is IGF-1-dependent. Furthermore, transient transfection with constitutively activated AKT or MEK partially blocks the IGFBP-3 inhibition of EGR1, bFGF and PDGF expression. In conclusion, these findings suggest that IGFBP-3 suppresses transcription of EGR1 and its target genes bFGF and PDGF through inhibiting IGF-1-dependent ERK and AKT activation. It demonstrates the importance of IGFBP-3 in the regulation of HCC cell proliferation, suggesting that IGFBP-3 could be a target for the treatment of HCC. PMID:27521890

  20. VEGF and FGF2 Improve Revascularization, Survival, and Oocyte Quality of Cryopreserved, Subcutaneously-Transplanted Mouse Ovarian Tissues

    PubMed Central

    Li, Sheng-Hsiang; Hwu, Yuh-Ming; Lu, Chung-Hao; Chang, Hsiao-Ho; Hsieh, Cheng-En; Lee, Robert Kuo-Kuang

    2016-01-01

    This study was conducted to investigate the effect of the vascular endothelial growth factor (VEGF) and fibroblast growth factor 2 (FGF2) on revascularization, survival, and oocyte quality of cryopreserved, subcutaneously-transplanted mouse ovarian tissue. Autologous subcutaneous transplantation of vitrified-thawed mouse ovarian tissues treated with (experimental group) or without (control group) VEGF and FGF2 was performed. After transplantation to the inguinal region for two or three weeks, graft survival, angiogenesis, follicle development, and oocyte quality were examined after gonadotropin administration. VEGF coupled with FGF2 (VEGF/FGF2) promoted revascularization and significantly increased the survival rate of subcutaneously-transplanted cryopreserved ovarian tissues compared with untreated controls. The two growth factors did not show long-term effects on the ovarian grafts. In contrast to the untreated ovarian grafts, active folliculogenesis was revealed as the number of follicles at various stages and of mature oocytes in antral follicles after gonadotropin administration were remarkably higher in the VEGF/FGF2-treated groups. Although the fertilization rate was similar between the VEGF/FGF2 and control groups, the oocyte quality was much better in the VEGF/FGF2-treated grafts as demonstrated by the higher ratio of blastocyst development. Introducing angiogenic factors, such as VEGF and FGF2, may be a promising strategy to improve revascularization, survival, and oocyte quality of cryopreserved, subcutaneously-transplanted mouse ovarian tissue. PMID:27483256

  1. VEGF and FGF2 Improve Revascularization, Survival, and Oocyte Quality of Cryopreserved, Subcutaneously-Transplanted Mouse Ovarian Tissues.

    PubMed

    Li, Sheng-Hsiang; Hwu, Yuh-Ming; Lu, Chung-Hao; Chang, Hsiao-Ho; Hsieh, Cheng-En; Lee, Robert Kuo-Kuang

    2016-01-01

    This study was conducted to investigate the effect of the vascular endothelial growth factor (VEGF) and fibroblast growth factor 2 (FGF2) on revascularization, survival, and oocyte quality of cryopreserved, subcutaneously-transplanted mouse ovarian tissue. Autologous subcutaneous transplantation of vitrified-thawed mouse ovarian tissues treated with (experimental group) or without (control group) VEGF and FGF2 was performed. After transplantation to the inguinal region for two or three weeks, graft survival, angiogenesis, follicle development, and oocyte quality were examined after gonadotropin administration. VEGF coupled with FGF2 (VEGF/FGF2) promoted revascularization and significantly increased the survival rate of subcutaneously-transplanted cryopreserved ovarian tissues compared with untreated controls. The two growth factors did not show long-term effects on the ovarian grafts. In contrast to the untreated ovarian grafts, active folliculogenesis was revealed as the number of follicles at various stages and of mature oocytes in antral follicles after gonadotropin administration were remarkably higher in the VEGF/FGF2-treated groups. Although the fertilization rate was similar between the VEGF/FGF2 and control groups, the oocyte quality was much better in the VEGF/FGF2-treated grafts as demonstrated by the higher ratio of blastocyst development. Introducing angiogenic factors, such as VEGF and FGF2, may be a promising strategy to improve revascularization, survival, and oocyte quality of cryopreserved, subcutaneously-transplanted mouse ovarian tissue. PMID:27483256

  2. Control of the segmentation process by graded MAPK/ERK activation in the chick embryo.

    PubMed

    Delfini, Marie-Claire; Dubrulle, Julien; Malapert, Pascale; Chal, Jérome; Pourquié, Olivier

    2005-08-01

    The regular spacing of somites during vertebrate embryogenesis involves a dynamic gradient of FGF signaling that controls the timing of maturation of cells in the presomitic mesoderm (PSM). How the FGF signal is transduced by PSM cells is unclear. Here, we first show that the FGF gradient is translated into graded activation of the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) pathway along the PSM in the chicken embryo. Using in ovo electroporation of PSM cells, we demonstrate that constitutive activation of ERK signaling in the PSM blocks segmentation by preventing maturation of PSM cells, thus phenocopying the overexpression of FGF8. Conversely, inhibition of ERK phosphorylation mimics a loss of function of FGF signaling in the PSM. Interestingly, video microscopy analysis of cell movements shows that ERK regulates the motility of PSM cells, suggesting that the decrease of cell movements along the PSM enables mesenchymal PSM cells to undergo proper segmentation. Together, our data demonstrate that ERK is the effector of the gradient of FGF in the PSM that controls the segmentation process.

  3. FGF, TGFβ and Wnt crosstalk: embryonic to in vitro cartilage development from mesenchymal stem cells.

    PubMed

    Cleary, Mairéad A; van Osch, Gerjo J V M; Brama, Pieter A; Hellingman, Catharine A; Narcisi, Roberto

    2015-04-01

    Articular cartilage is easily damaged, yet difficult to repair. Cartilage tissue engineering seems a promising therapeutic solution to restore articular cartilage structure and function, with mesenchymal stem cells (MSCs) receiving increasing attention for their promise to promote cartilage repair. It is known from embryology that members of the fibroblast growth factor (FGF), transforming growth factor-β (TGFβ) and wingless-type (Wnt) protein families are involved in controlling different differentiation stages during chondrogenesis. Individually, these pathways have been extensively studied but so far attempts to recapitulate embryonic development in in vitro MSC chondrogenesis have failed to produce stable and functioning articular cartilage; instead, transient hypertrophic cartilage is obtained. We believe a better understanding of the simultaneous integration of these factors will improve how we relate embryonic chondrogenesis to in vitro MSC chondrogenesis. This narrative review attempts to define current knowledge on the crosstalk between the FGF, TGFβ and Wnt signalling pathways during different stages of mesenchymal chondrogenesis. Connecting embryogenesis and in vitro differentiation of human MSCs might provide insights into how to improve and progress cartilage tissue engineering for the future.

  4. Evaluation of bone formation guided by DNA/protamine complex with FGF-2 in an adult rat calvarial defect model.

    PubMed

    Shinozaki, Yosuke; Toda, Masako; Ohno, Jun; Kawaguchi, Minoru; Kido, Hirofumi; Fukushima, Tadao

    2014-11-01

    DNA/protamine complex paste (D/P) and D/P complex paste with Fibroblast Growth Factor-2 (FGF-2) (D/P-FGF) were prepared to investigate their new bone formation abilities using an ∼40-week-old rat calvarial defect model. It was found that D/P could release FGF-2 proportionally in an in vitro experiment with an enzyme-linked immunosorbent assay. It was also found that aging adversely affected self-bone healing of rats by comparison with the results in a previous study using 10-week-old rats. Microcomputed tomography and histopathological examinations showed that new bone formation abilities of D/P and D/P-FGF were superior to that of the control (sham operation). Control, D/P and D/P-FGF showed newly formed bone areas of 6.7, 58.3, and 67.0%, respectively, 3 months after the operation. Moreover, it was found that FGF-2 could support the osteoanagenesis ability of D/P. It was considered that FGF-2 could play an important role in new bone formation at early stages because it induced the genes such as collagen I, CBFA, OSX, and OPN, which are initiated first in the process of osteogenesis. Therefore, D/P-FGF will be a useful injectable biomaterial with biodegradable properties for the repair of bone defects in the elderly.

  5. FGF5 is a crucial regulator of hair length in humans

    PubMed Central

    Higgins, Claire A.; Petukhova, Lynn; Harel, Sivan; Ho, Yuan Y.; Drill, Esther; Shapiro, Lawrence; Wajid, Muhammad; Christiano, Angela M.

    2014-01-01

    Mechanisms that regulate the growth of eyelashes have remained obscure. We ascertained two families from Pakistan who presented with familial trichomegaly, or extreme eyelash growth. Using a combination of whole exome sequencing and homozygosity mapping, we identified distinct pathogenic mutations within fibroblast growth factor 5 (FGF5) that underlie the disorder. Subsequent sequencing of this gene in several additional trichomegaly families identified an additional mutation in FGF5. We further demonstrated that hair fibers from forearms of these patients were significantly longer than hairs from control individuals, with an increased proportion in the growth phase, anagen. Using hair follicle organ cultures, we show that FGF5 induces regression of the human hair follicle. We have identified FGF5 as a crucial regulator of hair growth in humans for the first time, to our knowledge, and uncovered a therapeutic target to selectively regulate eyelash growth. PMID:24989505

  6. Tissue-specific Actions of the Metabolic Hormones FGF15/19 and FGF21

    PubMed Central

    Owen, Bryn M.; Mangelsdorf, David J.; Kliewer, Steven A.

    2014-01-01

    Fibroblast growth factors (FGFs) 15/19 and 21 belong to a subfamily of FGFs that function as hormones. Produced in response to specific nutritional cues, they act on overlapping sets of cell surface receptors composed of classic FGF receptors in complex with βKlotho, and regulate metabolism and related processes during periods of fluctuating energy availability. Pharmacologically, both FGF15/19 and FGF21 cause weight loss and improve both insulin sensitivity and lipid parameters, in rodent and primate models of metabolic disease. Recently, FGF21 was shown to have similar effects in obese patients with type 2 diabetes. Here, we discuss emerging concepts in FGF15/19 and FGF21 tissue specific actions and critically assess their putative role as candidate targets for treating metabolic disease. PMID:25476453

  7. Longitudinal FGF23 and Klotho axis characterization in children treated with chronic peritoneal dialysis

    PubMed Central

    Cano, Francisco J.; Freundlich, Michael; Ceballos, Maria L.; Rojo, Angelica P.; Azocar, Marta A.; Delgado, Iris O.; Ibacache, Maria J.; Delucchi, Maria A.; Lillo, Ana M.; Irarrázabal, Carlos E.; Ugarte, Maria F.

    2014-01-01

    Background Fibroblast Growth Factor-23 (FGF23) and cofactor Klotho are key regulators of mineral metabolism in chronic kidney disease (CKD), but little is known about the mechanisms that regulate their production. This study evaluates longitudinal changes of FGF23 and Klotho levels and their regulatory factors in children on chronic peritoneal dialysis (PD). Methods FGF23, Klotho, 25(OH) vitamin D, 1,25-dihydroxyvitamin D and parathyroid hormone (PTH) plasma concentrations were measured during 1 year of follow-up in PD children. Anthropometric and dialytical parameters were evaluated in addition to mineral metabolism variables. Results Thirty-one patients under chronic PD were followed for 12 months. FGF23 mean plasma levels at Month 1 were significantly increased compared with controls, 215.1 ± 303.6 versus 9.4 ± 5.7 pg/mL, respectively (P < 0.001). Baseline Klotho levels were 41% lower in patients compared with controls, 132.1 ± 58 versus 320 ± 119.4 pg/mL, respectively (P < 0.001), and did not correlate with FGF23 and phosphorus levels. At Month 12, FGF23 (195 ± 300 pg/mL) and Klotho levels (130 ± 34 pg/mL) remained similar to baseline values. Log-FGF23 correlated significantly with height/age Z score (r= −0.38) and residual renal function (r = −0.44), but no correlation was found with serum phosphorus, phosphate intake, PTH and vitamin D levels. The log-FGF23 strongly correlated with calcium levels at Months 1, 6 and 12, however, this relationship was blunted if serum phosphorus was >6 mg/dL. By multiple regression analysis, calcium was the strongest variable determining FGF23 levels. Conclusions In this longitudinal study, FGF23 levels are markedly increased, and Klotho levels are reduced in PD children compared with controls. FGF23 levels appeared to be regulated primarily by serum calcium, showing a significant correlation at each time of measurement. This relationship was lost in patients with phosphorus >6 mg/dL. These observations may have

  8. Signalling and obfuscation for congestion control

    NASA Astrophysics Data System (ADS)

    Mareček, Jakub; Shorten, Robert; Yu, Jia Yuan

    2015-10-01

    We aim to reduce the social cost of congestion in many smart city applications. In our model of congestion, agents interact over limited resources after receiving signals from a central agent that observes the state of congestion in real time. Under natural models of agent populations, we develop new signalling schemes and show that by introducing a non-trivial amount of uncertainty in the signals, we reduce the social cost of congestion, i.e., improve social welfare. The signalling schemes are efficient in terms of both communication and computation, and are consistent with past observations of the congestion. Moreover, the resulting population dynamics converge under reasonable assumptions.

  9. Roles for FGF in lamprey pharyngeal pouch formation and skeletogenesis highlight ancestral functions in the vertebrate head.

    PubMed

    Jandzik, David; Hawkins, M Brent; Cattell, Maria V; Cerny, Robert; Square, Tyler A; Medeiros, Daniel M

    2014-02-01

    A defining feature of vertebrates (craniates) is a pronounced head supported and protected by a cellularized endoskeleton. In jawed vertebrates (gnathostomes), the head skeleton is made of rigid three-dimensional elements connected by joints. By contrast, the head skeleton of modern jawless vertebrates (agnathans) consists of thin rods of flexible cellular cartilage, a condition thought to reflect the ancestral vertebrate state. To better understand the origin and evolution of the gnathostome head skeleton, we have been analyzing head skeleton development in the agnathan, lamprey. The fibroblast growth factors FGF3 and FGF8 have various roles during head development in jawed vertebrates, including pharyngeal pouch morphogenesis, patterning of the oral skeleton and chondrogenesis. We isolated lamprey homologs of FGF3, FGF8 and FGF receptors and asked whether these functions are ancestral features of vertebrate development or gnathostome novelties. Using gene expression and pharmacological agents, we found that proper formation of the lamprey head skeleton requires two phases of FGF signaling: an early phase during which FGFs drive pharyngeal pouch formation, and a later phase when they directly regulate skeletal differentiation and patterning. In the context of gene expression and functional studies in gnathostomes, our results suggest that these roles for FGFs arose in the first vertebrates and that the evolution of the jaw and gnathostome cellular cartilage was driven by changes developmentally downstream from pharyngeal FGF signaling.

  10. Fibroblast growth factor (Fgf) 21 is a novel target gene of the aryl hydrocarbon receptor (AhR).

    PubMed

    Cheng, Xingguo; Vispute, Saurabh G; Liu, Jie; Cheng, Christine; Kharitonenkov, Alexei; Klaassen, Curtis D

    2014-07-01

    The toxic effects of dioxins, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), mainly through activation of the aryl hydrocarbon receptor (AhR) are well documented. Fibroblast growth factor (Fgf) 21 plays critical roles in metabolic adaptation to fasting by increasing lipid oxidation and ketogenesis in the liver. The present study was performed to determine whether activation of the AhR induces Fgf21 expression. In mouse liver, TCDD increased Fgf21 mRNA in both dose- and time-dependent manners. In addition, TCDD markedly increased Fgf21 mRNA expression in cultured mouse and human hepatocytes. Moreover, TCDD increased mRNA (in liver) and protein levels (in both liver and serum) of Fgf21 in wild-type mice, but not in AhR-null mice. Chromatin immunoprecipitation assays showed that TCDD increased AhR protein binding to the Fgf21 promoter (-105/+1 base pair). Fgf21-null mice administered 200μg/kg of TCDD died within 20days, whereas wild-type mice receiving the same treatment were still alive at one month after administration. This indicates that TCDD-induced Fgf21 expression protects against TCDD toxicity. Diethylhexylphthalate (DEHP) pretreatment attenuated TCDD-induced Fgf21 expression in mouse liver and white adipose tissue, which may explain a previous report that DEHP pretreatment decreases TCDD-induced wasting. In conclusion, Fgf21 appears to be a target gene of AhR-signaling pathway in mouse and human liver.

  11. Fibroblast growth factor (Fgf) 21 is a novel target gene of the aryl hydrocarbon receptor (AhR).

    PubMed

    Cheng, Xingguo; Vispute, Saurabh G; Liu, Jie; Cheng, Christine; Kharitonenkov, Alexei; Klaassen, Curtis D

    2014-07-01

    The toxic effects of dioxins, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), mainly through activation of the aryl hydrocarbon receptor (AhR) are well documented. Fibroblast growth factor (Fgf) 21 plays critical roles in metabolic adaptation to fasting by increasing lipid oxidation and ketogenesis in the liver. The present study was performed to determine whether activation of the AhR induces Fgf21 expression. In mouse liver, TCDD increased Fgf21 mRNA in both dose- and time-dependent manners. In addition, TCDD markedly increased Fgf21 mRNA expression in cultured mouse and human hepatocytes. Moreover, TCDD increased mRNA (in liver) and protein levels (in both liver and serum) of Fgf21 in wild-type mice, but not in AhR-null mice. Chromatin immunoprecipitation assays showed that TCDD increased AhR protein binding to the Fgf21 promoter (-105/+1 base pair). Fgf21-null mice administered 200μg/kg of TCDD died within 20days, whereas wild-type mice receiving the same treatment were still alive at one month after administration. This indicates that TCDD-induced Fgf21 expression protects against TCDD toxicity. Diethylhexylphthalate (DEHP) pretreatment attenuated TCDD-induced Fgf21 expression in mouse liver and white adipose tissue, which may explain a previous report that DEHP pretreatment decreases TCDD-induced wasting. In conclusion, Fgf21 appears to be a target gene of AhR-signaling pathway in mouse and human liver. PMID:24769090

  12. Spatial and temporal control of signaling through lipid rafts.

    PubMed

    Golub, Tamara; Wacha, Stefan; Caroni, Pico

    2004-10-01

    Sphingolipid- and cholesterol-dependent microdomains (rafts) order proteins at biological membranes and have been implicated in most signaling processes at the cell surface, but the principles and mechanisms through which lipid rafts influence signaling are not well understood. Recent studies have revealed how lipid rafts are rapidly redistributed and assembled locally in response to extracellular signals, and how components of raft-based signaling domains undergo rapid and regulated rearrangements influencing signal quality, duration, and strength. These findings highlight the exquisitely dynamic properties of signaling domains based on lipid rafts, and suggest that processes of raft trafficking and assembly take central roles in mediating spatial and temporal control of signaling.

  13. Neural Networks for Signal Processing and Control

    NASA Astrophysics Data System (ADS)

    Hesselroth, Ted Daniel

    Neural networks are developed for controlling a robot-arm and camera system and for processing images. The networks are based upon computational schemes that may be found in the brain. In the first network, a neural map algorithm is employed to control a five-joint pneumatic robot arm and gripper through feedback from two video cameras. The pneumatically driven robot arm employed shares essential mechanical characteristics with skeletal muscle systems. To control the position of the arm, 200 neurons formed a network representing the three-dimensional workspace embedded in a four-dimensional system of coordinates from the two cameras, and learned a set of pressures corresponding to the end effector positions, as well as a set of Jacobian matrices for interpolating between these positions. Because of the properties of the rubber-tube actuators of the arm, the position as a function of supplied pressure is nonlinear, nonseparable, and exhibits hysteresis. Nevertheless, through the neural network learning algorithm the position could be controlled to an accuracy of about one pixel (~3 mm) after two hundred learning steps. Applications of repeated corrections in each step via the Jacobian matrices leads to a very robust control algorithm since the Jacobians learned by the network have to satisfy the weak requirement that they yield a reduction of the distance between gripper and target. The second network is proposed as a model for the mammalian vision system in which backward connections from the primary visual cortex (V1) to the lateral geniculate nucleus play a key role. The application of hebbian learning to the forward and backward connections causes the formation of receptive fields which are sensitive to edges, bars, and spatial frequencies of preferred orientations. The receptive fields are learned in such a way as to maximize the rate of transfer of information from the LGN to V1. Orientational preferences are organized into a feature map in the primary visual

  14. A 1-bp deletion in Fgf5 causes male-dominant long hair in the Syrian hamster.

    PubMed

    Yoshizawa, Yasuhiro; Wada, Kenta; Shimoi, Gaku; Shiomi, Gaku; Kameyama, Yuichi; Wakabayashi, Yuichi; Fukuta, Katsuhiro; Hashizume, Ryoichi

    2015-12-01

    Hair length in mammals is generally regulated by the hair cycle, and its disruption leads to abnormal hair morphogenesis in several species. FGF5, one of the hair cycle regulators, has a role in inducing catagen, and that mutation causes abnormal hair length in both sexes in humans, mice, dogs, and cats. Male-dominant long-haired coat (MALC) is an inbred strain of Syrian hamster exhibiting spontaneous long hair in males. After castration, MALC exhibited significantly shorter hair than the control individuals, but testosterone administration to castrated MALC showed reversion to the original phenotype. Moreover, flutamide administration led to MALC phenotype repression. Histological analysis revealed that hair follicle regression was shown in the wild-type 4 weeks after depilation, but that of MALC remained in the anagen phase. We detected a c.546delG of Fgf5 in MALC (Fgf5malc) that might lead to truncation resulting from a frame shift in FGF5 (p.Arg184GlyfsX6). Additionally, homozygous Fgf5malc was only detected in long-haired (Slc:Syrian×MALC)F2 and (J-2-Nn×MALC)F2 progenies, and all homozygous wild and heterozygous Fgf5malc individuals showed normal hair length. Thus, Fgf5malc leads to male-dominant long hair via a prolonged anagen phase which is affected by testosterone in hamsters. To our knowledge, this report is the first to present the sexual dimorphism of hair length caused by the Fgf5 mutation.

  15. Subcellular optogenetics – controlling signaling and single-cell behavior

    PubMed Central

    Karunarathne, W. K. Ajith; O'Neill, Patrick R.; Gautam, Narasimhan

    2015-01-01

    ABSTRACT Variation in signaling activity across a cell plays a crucial role in processes such as cell migration. Signaling activity specific to organelles within a cell also likely plays a key role in regulating cellular functions. To understand how such spatially confined signaling within a cell regulates cell behavior, tools that exert experimental control over subcellular signaling activity are required. Here, we discuss the advantages of using optogenetic approaches to achieve this control. We focus on a set of optical triggers that allow subcellular control over signaling through the activation of G-protein-coupled receptors (GPCRs), receptor tyrosine kinases and downstream signaling proteins, as well as those that inhibit endogenous signaling proteins. We also discuss the specific insights with regard to signaling and cell behavior that these subcellular optogenetic approaches can provide. PMID:25433038

  16. Comparative Study of Heparin-Poloxamer Hydrogel Modified bFGF and aFGF for in Vivo Wound Healing Efficiency.

    PubMed

    Wu, Jiang; Zhu, Jingjing; He, Chaochao; Xiao, Zecong; Ye, Jingjing; Li, Yi; Chen, Anqi; Zhang, Hongyu; Li, Xiaokun; Lin, Li; Zhao, Yingzheng; Zheng, Jie; Xiao, Jian

    2016-07-27

    Wound therapy remains a clinical challenge. Incorporation of growth factors (GFs) into heparin-functionalized polymer hydrogel is considered as a promising strategy to improve wound healing efficiency. However, different GFs incorporation into the same heparin-based hydrogels often lead to different wound healing effects, and the underlying GF-induced wound healing mechanisms still remain elusive. Herein, we developed a thermos-sensitive heparin-poloxamer (HP) hydrogel to load and deliver different GFs (aFGF and bFGF) for wound healing in vivo. The resulting GFs-based hydrogels with and without HP hydrogels were systematically evaluated and compared for their wound healing efficiency by extensive in vivo tests, including wound closure rate, granulation formation, re-epithelization, cell proliferation, collagen, and angiogenesis expressions. While all GFs-based dressings with and without HP hydrogels exhibited better wound healing efficacy than controls, both HP-aFGF and HP-bFGF hydrogels demonstrated their superior healing activity to improve wound closure, granulation formation, re-epithelization, and blood vessel density by up-regulation of PCNA proliferation and collagen synthesis, as compared to GF dressings alone. More importantly, HP-aFGF dressings exhibited the higher healing efficacy than HP-bFGF dressings, indicating that different a/bFGF surface properties lead to different binding and release behaviors in HP hydrogels, both of which will affect different wound healing efficiency. On the basis of experimental observations, the working mechanisms of different healing effects of HP-GFs on full skin removal wound were proposed. This work provides different views of the design and development of an effective hydrogel-based delivery system for GFs toward rapid wound healing.

  17. Human fibroblast growth factor 20 (FGF-20; CG53135-05): a novel cytoprotectant with radioprotective potential.

    PubMed

    Maclachlan, T; Narayanan, B; Gerlach, V L; Smithson, G; Gerwien, R W; Folkerts, O; Fey, E G; Watkins, B; Seed, T; Alvarez, E

    2005-08-01

    The aim was to evaluate the radioprotective properties of recombinant human fibroblast growth factor 20 (FGF-20; CG53135-05) in vitro and in vivo and to examine its effects on known cellular pathways of radioprotection. Relative transcript levels of the cyclooxygenase 2 (COX2), Mn-super oxide dismutase (SOD), CuZn-SOD, extracellular (EC)-SOD, nuclear respiratory factor 2 (Nrf2), glutathione peroxidase 1 (GPX1) and intestinal trefoil factor 3 (ITF3) genes, which are involved in radiation response pathways, were assessed by reverse transcriptase-polymerase chain reaction (RT-PCR) in NIH/3T3, IEC18, CCD-18Co, CCD-1070sk and human umbilical vein endothelial cells (HUVEC) cells exposed to FGF-20. Activation of the radioprotective signal transduction pathways initiating with the serine/threonine Akt kinase and the extracellular regulated kinase (ERK) were analysed. Levels of intracellular hydrogen peroxide and cytosolic redox potential were also measured in irradiated and unirradiated cells in the presence or absence of FGF-20. The effects of FGF-20 on cell survival in vitro following ionizing radiation were evaluated using clonogenic assays. To test the potential activity of FGF-20 as a radioprotectant in vivo, mice were administered a single dose of FGF-20 (4 mg kg(-1), intraperitoneally (i.p.) 1 day before lethal total-body irradiation and evaluated for survival. In vitro exposure to FGF-20 increased expression of the Nrf2 transcription factor and oxygen radical scavenging enzymes such as MnSOD, activated signal transduction pathways (ERK and Akt) and resulted in increased survival of irradiated cells in vitro. FGF-20 treatment also resulted in a concomitant reduction in intracellular levels of injurious reactive oxygen species (ROS) following acute ionizing irradiation. Finally, prophylactic administration of FGF-20 to mice before potentially lethal, whole-body X-irradiation led to significant increases in overall survival. FGF-20 reduced the lethal effects of acute

  18. Human fibroblast growth factor 20 (FGF-20; CG53135-05): a novel cytoprotectant with radioprotective potential.

    PubMed

    Maclachlan, T; Narayanan, B; Gerlach, V L; Smithson, G; Gerwien, R W; Folkerts, O; Fey, E G; Watkins, B; Seed, T; Alvarez, E

    2005-08-01

    The aim was to evaluate the radioprotective properties of recombinant human fibroblast growth factor 20 (FGF-20; CG53135-05) in vitro and in vivo and to examine its effects on known cellular pathways of radioprotection. Relative transcript levels of the cyclooxygenase 2 (COX2), Mn-super oxide dismutase (SOD), CuZn-SOD, extracellular (EC)-SOD, nuclear respiratory factor 2 (Nrf2), glutathione peroxidase 1 (GPX1) and intestinal trefoil factor 3 (ITF3) genes, which are involved in radiation response pathways, were assessed by reverse transcriptase-polymerase chain reaction (RT-PCR) in NIH/3T3, IEC18, CCD-18Co, CCD-1070sk and human umbilical vein endothelial cells (HUVEC) cells exposed to FGF-20. Activation of the radioprotective signal transduction pathways initiating with the serine/threonine Akt kinase and the extracellular regulated kinase (ERK) were analysed. Levels of intracellular hydrogen peroxide and cytosolic redox potential were also measured in irradiated and unirradiated cells in the presence or absence of FGF-20. The effects of FGF-20 on cell survival in vitro following ionizing radiation were evaluated using clonogenic assays. To test the potential activity of FGF-20 as a radioprotectant in vivo, mice were administered a single dose of FGF-20 (4 mg kg(-1), intraperitoneally (i.p.) 1 day before lethal total-body irradiation and evaluated for survival. In vitro exposure to FGF-20 increased expression of the Nrf2 transcription factor and oxygen radical scavenging enzymes such as MnSOD, activated signal transduction pathways (ERK and Akt) and resulted in increased survival of irradiated cells in vitro. FGF-20 treatment also resulted in a concomitant reduction in intracellular levels of injurious reactive oxygen species (ROS) following acute ionizing irradiation. Finally, prophylactic administration of FGF-20 to mice before potentially lethal, whole-body X-irradiation led to significant increases in overall survival. FGF-20 reduced the lethal effects of acute

  19. Myeloid Cell-Specific Lipin-1 Deficiency Stimulates Endocrine Adiponectin-FGF15 Axis and Ameliorates Ethanol-Induced Liver Injury in Mice

    PubMed Central

    Wang, Jiayou; Kim, Chunki; Jogasuria, Alvin; Han, Yoonhee; Hu, Xudong; Wu, Jiashin; Shen, Hong; Chrast, Roman; Finck, Brian N.; You, Min

    2016-01-01

    Lipin-1 is a phosphatidate phosphohydrolase (PAP) required for the generation of diacylglycerol during glycerolipid synthesis, and exhibits dual functions in the regulation of lipid metabolism. Lipin-1 has been implicated in the pathogenesis of alcoholic liver disease (ALD). In the present study, we assessed lipin-1 function in myeloid cells in ALD using a myeloid cell-specific lipin-1 knockout (mLipin-1KO) mouse model. Utilizing the Gao-binge ethanol feeding protocol, matched mLipin-1KO mice and littermate loxP control (WT) mice were pair-fed with either an ethanol-containing diet or an ethanol-free diet (control). Surprisingly, deletion of lipin-1 in myeloid cells dramatically attenuated liver inflammatory responses and ameliorated liver injury that would normally occur following the ethanol feeding protocol, but slightly exacerbated the ethanol-induced steatosis in mice. Mechanistically, myeloid cell-specific lipin-1 deficiency concomitantly increased the fat-derived adiponectin and ileum-derived fibroblast growth factor (FGF) 15. In concordance with concerted elevation of circulating adiponectin and FGF15, myeloid cell-specific lipin-1 deficiency diminished hepatic nuclear factor kappa B (NF-κB) activity, limited liver inflammatory responses, normalized serum levels of bile acids, and protected mice from liver damage after ethanol challenge. Our novel data demonstrate that myeloid cell-specific deletion of lipin-1 ameliorated inflammation and alcoholic hepatitis in mice via activation of endocrine adiponectin-FGF15 signaling. PMID:27666676

  20. Gli3-mediated somitic Fgf10 expression gradients are required for the induction and patterning of mammary epithelium along the embryonic axes.

    PubMed

    Veltmaat, Jacqueline M; Relaix, Frédéric; Le, Lendy T; Kratochwil, Klaus; Sala, Frédéric G; van Veelen, Wendy; Rice, Ritva; Spencer-Dene, Bradley; Mailleux, Arnaud A; Rice, David P; Thiery, Jean Paul; Bellusci, Saverio

    2006-06-01

    Little is known about the regulation of cell fate decisions that lead to the formation of five pairs of mammary placodes in the surface ectoderm of the mouse embryo. We have previously shown that fibroblast growth factor 10 (FGF10) is required for the formation of mammary placodes 1, 2, 3 and 5. Here, we have found that Fgf10 is expressed only in the somites underlying placodes 2 and 3, in gradients across and within these somites. To test whether somitic FGF10 is required for the formation of these two placodes, we analyzed a number of mutants with different perturbations of somitic Fgf10 gradients for the presence of WNT signals and ectodermal multilayering, markers for mammary line and placode formation. The mammary line is displaced dorsally, and formation of placode 3 is impaired in Pax3ILZ/ILZ mutants, which do not form ventral somitic buds. Mammary line formation is impaired and placode 3 is absent in Gli3Xt-J/Xt-J and hypomorphic Fgf10 mutants, in which the somitic Fgf10 gradient is shortened dorsally and less overall Fgf10 is expressed, respectively. Recombinant FGF10 rescued mammogenesis in Fgf10(-/-) and Gli3Xt-J/Xt-J flanks. We correlate increasing levels of somitic FGF10 with progressive maturation of the surface ectoderm, and show that full expression of somitic Fgf10, co-regulated by GLI3, is required for the anteroposterior pattern in which the flank ectoderm acquires a mammary epithelial identity. We propose that the intra-somitic Fgf10 gradient, together with ventral elongation of the somites, determines the correct dorsoventral position of mammary epithelium along the flank.

  1. Single ingestion of soy β-conglycinin induces increased postprandial circulating FGF21 levels exerting beneficial health effects

    PubMed Central

    Hashidume, Tsutomu; Kato, Asuka; Tanaka, Tomohiro; Miyoshi, Shoko; Itoh, Nobuyuki; Nakata, Rieko; Inoue, Hiroyasu; Oikawa, Akira; Nakai, Yuji; Shimizu, Makoto; Inoue, Jun; Sato, Ryuichiro

    2016-01-01

    Soy protein β-conglycinin has serum lipid-lowering and anti-obesity effects. We showed that single ingestion of β-conglycinin after fasting alters gene expression in mouse liver. A sharp increase in fibroblast growth factor 21 (FGF21) gene expression, which is depressed by normal feeding, resulted in increased postprandial circulating FGF21 levels along with a significant decrease in adipose tissue weights. Most increases in gene expressions, including FGF21, were targets for the activating transcription factor 4 (ATF4), but not for peroxisome proliferator-activated receptor α. Overexpression of a dominant-negative form of ATF4 significantly reduced β-conglycinin-induced increases in hepatic FGF21 gene expression. In FGF21-deficient mice, β-conglycinin effects were partially abolished. Methionine supplementation to the diet or primary hepatocyte culture medium demonstrated its importance for activating liver or hepatocyte ATF4-FGF21 signaling. Thus, dietary β-conglycinin intake can impact hepatic and systemic metabolism by increasing the postprandial circulating FGF21 levels. PMID:27312476

  2. Immunolocalization of fibroblast growth factor-2 (FGF-2) in the developing root and supporting structures of the murine tooth.

    PubMed

    Madan, A K; Kramer, Beverley

    2005-03-01

    Epithelio-mesenchymal interactions are active during the development of the root of the tooth and are regulated by a variety of growth factors, such as fibroblast growth factors. FGF-2, 3, 4, and 8 have all been shown to play a role in the development of the crown of the tooth, but less is known about the factors that govern root formation, particularly FGF-2. The aim of this study was thus to elucidate the spatial and temporal expression of FGF-2 in the root of the developing tooth, as this growth factor is believed to be a mediator of epithelio-mesenchymal interactions. Parasagittal sections of the maxillary and mandibular arches of post-natal mice were utilized and the roots of the molar teeth were studied. Immunocytochemistry utilizing an antibody to FGF-2 was performed on sections of teeth at various stages of development. Intense immunostaining for FGF-2 was observed in differentiating odontoblasts at the apical end of the tooth and in the furcation zone of the developing root at all the stages examined. FGF-2 localization was also observed in cementoblasts on post-natal days 16, 20 and 24. The pattern of localization of FGF-2 in the developing root suggests that this growth factor may participate in the signaling network associated with root development.

  3. Single ingestion of soy β-conglycinin induces increased postprandial circulating FGF21 levels exerting beneficial health effects.

    PubMed

    Hashidume, Tsutomu; Kato, Asuka; Tanaka, Tomohiro; Miyoshi, Shoko; Itoh, Nobuyuki; Nakata, Rieko; Inoue, Hiroyasu; Oikawa, Akira; Nakai, Yuji; Shimizu, Makoto; Inoue, Jun; Sato, Ryuichiro

    2016-01-01

    Soy protein β-conglycinin has serum lipid-lowering and anti-obesity effects. We showed that single ingestion of β-conglycinin after fasting alters gene expression in mouse liver. A sharp increase in fibroblast growth factor 21 (FGF21) gene expression, which is depressed by normal feeding, resulted in increased postprandial circulating FGF21 levels along with a significant decrease in adipose tissue weights. Most increases in gene expressions, including FGF21, were targets for the activating transcription factor 4 (ATF4), but not for peroxisome proliferator-activated receptor α. Overexpression of a dominant-negative form of ATF4 significantly reduced β-conglycinin-induced increases in hepatic FGF21 gene expression. In FGF21-deficient mice, β-conglycinin effects were partially abolished. Methionine supplementation to the diet or primary hepatocyte culture medium demonstrated its importance for activating liver or hepatocyte ATF4-FGF21 signaling. Thus, dietary β-conglycinin intake can impact hepatic and systemic metabolism by increasing the postprandial circulating FGF21 levels. PMID:27312476

  4. Long-term Observation of Regenerated Periodontium Induced by FGF-2 in the Beagle Dog 2-Wall Periodontal Defect Model

    PubMed Central

    Anzai, Jun; Nagayasu-Tanaka, Toshie; Terashima, Akio; Asano, Taiji; Yamada, Satoru; Nozaki, Takenori; Kitamura, Masahiro; Murakami, Shinya

    2016-01-01

    The long-term stability and qualitative characteristics of periodontium regenerated by FGF-2 treatment were compared with normal physiological healing tissue controls in a Beagle dog 2-wall periodontal defect model 13 months after treatment by assessing tissue histology and three-dimensional microstructure using micro-computed tomography (μCT). After FGF-2 (0.3%) or vehicle treatment at the defect sites, serial changes in the bone mineral content (BMC) were observed using periodic X-ray imaging. Tissues were harvested at 13 months, evaluated histomorphometrically, and the cortical bone volume and trabecular bone structure of the newly formed bone were analyzed using μCT. FGF-2 significantly increased the BMC of the defect area at 2 months compared with that of the control group, and this difference was unchanged through 13 months. The cortical bone volume was significantly increased by FGF-2, but there was no difference between the groups in trabecular bone structure. Bone maturation was occurring in both groups because of the lower cortical volume and denser trabecular bone than what is found in intact bone. FGF-2 also increased the area of newly formed bone as assessed histomorphometrically, but the ratios of trabecular bone in the defect area were similar between the control and FGF-2 groups. These results suggest that FGF-2 stimulates neogenesis of alveolar bone that is of similar quality to that of the control group. The lengths of the regenerated periodontal ligament and cementum, measured as the distance from the defect bottom to the apical end of the gingival epithelium, and height and area of the newly formed bone in the FGF-2 group were larger than those in the control group. The present study demonstrated that, within the limitation of artificial periodontal defect model, the periodontal tissue regenerated by FGF-2 was maintained for 13 months after treatment and was qualitatively equivalent to that generated through the physiological healing process

  5. Conditional Gene Inactivation Reveals Roles for Fgf10 and Fgfr2 in Establishing a Normal Pattern of Epithelial Branching in the Mouse Lung

    PubMed Central

    Abler, Lisa L.; Mansour, Suzanne L.; Sun, Xin

    2012-01-01

    Fibroblast growth factor 10 (FGF10) signaling through FGF receptor 2 (FGFR2) is required for lung initiation. While studies indicate that Fgf10 and Fgfr2 are also important at later stages of lung development, their roles in early branching events remain unclear. We addressed this question through conditional inactivation of both genes in mouse subsequent to lung initiation. Inactivation of Fgf10 in lung mesenchyme resulted in smaller lobes with a reduced number of branches. Inactivation of Fgfr2 in lung epithelium resulted in disruption of lobes and small epithelial outgrowths that arose arbitrarily along the main bronchi. In both mutants, there was an increase in cell death. Also, the expression patterns of key signaling molecules implicated in branching morphogenesis were altered and a proximal lung marker was expanded distally. Our results indicate that both Fgf10 and Fgfr2 are required for a normal branching program and for proper proximal-distal patterning of the lung. PMID:19618463

  6. Bone mineralization is regulated by signaling cross talk between molecular factors of local and systemic origin: the role of fibroblast growth factor 23.

    PubMed

    Sapir-Koren, Rony; Livshits, Gregory

    2014-01-01

    Body phosphate homeostasis is regulated by a hormonal counter-balanced intestine-bone-kidney axis. The major systemic hormones involved in this axis are parathyroid hormone (PTH), 1,25-dihydroxyvitamin-D, and fibroblast growth factor-23 (FGF23). FGF23, produced almost exclusively by the osteocytes, is a phosphaturic hormone that plays a major role in regulation of the bone remodeling process. Remodeling composite components, bone mineralization and resorption cycles create a continuous influx-efflux loop of the inorganic phosphate (Pi) through the skeleton. This "bone Pi loop," which is formed, is controlled by local and systemic factors according to phosphate homeostasis demands. Although FGF23 systemic actions in the kidney, and for the production of PTH and 1,25-dihydroxyvitamin-D are well established, its direct involvement in bone metabolism is currently poorly understood. This review presents the latest available evidence suggesting two aspects of FGF23 bone local activity: (a) Regulation of FGF23 production by both local and systemic factors. The suggested local factors include extracellular levels of Pi and pyrophosphate (PPi), (the Pi/PPi ratio), and another osteocyte-derived protein, sclerostin. In addition, 1,25-dihydroxyvitamin-D, synthesized locally by bone cells, may contribute to regulation of FGF23 production. The systemic control is achieved via PTH and 1,25-dihydroxyvitamin-D endocrine functions. (b) FGF23 acts as a local agent, directly affecting bone mineralization. We support the assumption that under balanced physiological conditions, sclerostin, by para- autocrine signaling, upregulates FGF23 production by the osteocyte. FGF23, in turn, acts as a mineralization inhibitor, by stimulating the generation of the major mineralization antagonist-PPi.

  7. FGF21 improves cognition by restored synaptic plasticity, dendritic spine density, brain mitochondrial function and cell apoptosis in obese-insulin resistant male rats.

    PubMed

    Sa-Nguanmoo, Piangkwan; Tanajak, Pongpan; Kerdphoo, Sasiwan; Satjaritanun, Pattarapong; Wang, Xiaojie; Liang, Guang; Li, Xiaokun; Jiang, Chao; Pratchayasakul, Wasana; Chattipakorn, Nipon; Chattipakorn, Siriporn C

    2016-09-01

    Fibroblast growth factor 21 (FGF21) is an endocrine hormone which exerts beneficial effects on metabolic regulation in obese and diabetic models. However, the effect of FGF21 on cognition in obese-insulin resistant rats has not been investigated. We hypothesized that FGF21 prevented cognitive decline in obese-insulin resistant rats by improving hippocampal synaptic plasticity, dendritic spine density, brain mitochondrial function and brain FGF21 signaling as well as decreasing brain cell apoptosis. Eighteen male Wistar rats were divided into two groups, and received either a normal diet (ND) (n=6) or a high fat diet (HFD) (n=12) for 12weeks. At week 13, the HFD-fed rats were subdivided into two subgroups (n=6/subgroup) to receive either vehicle or recombinant human FGF21 (0.1mg/kg/day) for four weeks. ND-fed rats were given vehicle for four weeks. At the end of the treatment, cognitive function, metabolic parameters, pro-inflammatory markers, brain mitochondrial function, cell apoptosis, hippocampal synaptic plasticity, dendritic spine density and brain FGF21 signaling were determined. The results showed that vehicle-treated HFD-fed rats developed obese-insulin resistance and cognitive decline with impaired hippocampal synaptic plasticity, decreased dendritic spine density, brain mitochondrial dysfunction and increased brain cell apoptosis. Impaired brain FGF 21 signaling was found in these obese-insulin resistant rats. FGF21-treated obese-insulin resistant rats had improved peripheral insulin sensitivity, increased hippocampal synaptic plasticity, increased dendritic spine density, restored brain mitochondrial function, attenuated brain cells apoptosis and increased brain FGF21 signaling, leading to a prevention of cognitive decline. These findings suggest that FGF21 treatment exerts neuroprotection in obese-insulin resistant rats. PMID:27566237

  8. Excessive Osteocytic Fgf23 Secretion Contributes to Pyrophosphate Accumulation and Mineralization Defect in Hyp Mice

    PubMed Central

    Murali, Sathish K.; Andrukhova, Olena; Clinkenbeard, Erica L.; White, Kenneth E.; Erben, Reinhold G.

    2016-01-01

    X-linked hypophosphatemia (XLH) is the most frequent form of inherited rickets in humans caused by mutations in the phosphate-regulating gene with homologies to endopeptidases on the X-chromosome (PHEX). Hyp mice, a murine homologue of XLH, are characterized by hypophosphatemia, inappropriately low serum vitamin D levels, increased serum fibroblast growth factor-23 (Fgf23), and osteomalacia. Although Fgf23 is known to be responsible for hypophosphatemia and reduced vitamin D hormone levels in Hyp mice, its putative role as an auto-/paracrine osteomalacia-causing factor has not been explored. We recently reported that Fgf23 is a suppressor of tissue nonspecific alkaline phosphatase (Tnap) transcription via FGF receptor-3 (FGFR3) signaling, leading to inhibition of mineralization through accumulation of the TNAP substrate pyrophosphate. Here, we report that the pyrophosphate concentration is increased in Hyp bones, and that Tnap expression is decreased in Hyp-derived osteocyte-like cells but not in Hyp-derived osteoblasts ex vivo and in vitro. In situ mRNA expression profiling in bone cryosections revealed a ~70-fold up-regulation of Fgfr3 mRNA in osteocytes versus osteoblasts of Hyp mice. In addition, we show that blocking of increased Fgf23-FGFR3 signaling with anti-Fgf23 antibodies or an FGFR3 inhibitor partially restored the suppression of Tnap expression, phosphate production, and mineralization, and decreased pyrophosphate concentration in Hyp-derived osteocyte-like cells in vitro. In vivo, bone-specific deletion of Fgf23 in Hyp mice rescued the suppressed TNAP activity in osteocytes of Hyp mice. Moreover, treatment of wild-type osteoblasts or mice with recombinant FGF23 suppressed Tnap mRNA expression and increased pyrophosphate concentrations in the culture medium and in bone, respectively. In conclusion, we found that the cell autonomous increase in Fgf23 secretion in Hyp osteocytes drives the accumulation of pyrophosphate through auto-/paracrine suppression

  9. Pheromonal control: reconciling physiological mechanism with signalling theory.

    PubMed

    Peso, Marianne; Elgar, Mark A; Barron, Andrew B

    2015-05-01

    Pheromones are intraspecific chemical signals. They can have profound effects on the behaviour and/or physiology of the receiver, and it is still common to hear pheromones described as controlling of the behaviour of the receiver. The discussion of pheromonal control arose initially from a close association between hormones and pheromones in the comparative physiological literature, but the concept of a controlling pheromone is at odds with contemporary signal evolution theory, which predicts that a manipulative pheromonal signal negatively affecting the receiver's fitness should not be stable over evolutionary time. Here we discuss the meaning of pheromonal control, and the ecological circumstances by which it might be supported. We argue that in discussing pheromonal control it is important to differentiate between control applied to the effects of a pheromone on a receiver's physiology (proximate control), and control applied to the effects of a pheromone on a receiver's fitness (ultimate control). Critically, a pheromone signal affecting change in the receiver's behaviour or physiology need not necessarily manipulate the fitness of a receiver. In cases where pheromonal signalling does lead to a reduction in the fitness of the receiver, the signalling system would be stable if the pheromone were an honest signal of a social environment that disadvantages the receiver, and the physiological and behavioural changes observed in the receiver were an adaptive response to the new social circumstances communicated by the pheromone. PMID:24925630

  10. Fgf8-Deficient Mice Compensate for Reduced GnRH Neuronal Population and Exhibit Normal Testicular Function.

    PubMed

    Zhang, Wei; Johnson, Joshua I; Tsai, Pei-San

    2015-01-01

    Gonadotropin-releasing hormone (GnRH) is critical for the onset and maintenance of reproduction in vertebrates. The development of GnRH neurons is highly dependent on fibroblast growth factor (Fgf) signaling. Mice with a hypomorphic Fgf8 allele (Fgf8 Het) exhibited a ~50% reduction in GnRH neuron number at birth. Female Fgf8 Het mice were fertile but showed significantly delayed puberty. However, it was unclear if these mice suffered additional loss of GnRH neurons after birth, and if male Fgf8 Het mice had normal pubertal transition and testicular function. In this study, we examined postnatal GnRH neuron number and hypothalamic GnRH content in Fgf8 Het mice from birth to 120 days of age. Further, we examined seminal vesicle and testicular growth, testicular histology, and circulating luteinizing hormone (LH) around and after pubertal transition. Our results showed that GnRH neuron numbers were significantly and consistently reduced in Fgf8 Het mice of both sexes in all ages examined, suggesting these animals were born with an inherently defective GnRH system, and no further postnatal loss of GnRH neurons had occurred. Despite an innately compromised GnRH system, male and female Fgf8 mice exhibited normal levels of immunoassayable hypothalamic GnRH peptide at all ages examined except on 60 days of age, suggesting increased GnRH synthesis or reduced turnover as a compensatory mechanism. Fgf8 Het males also had normal seminal vesicle and testicular mass/body mass ratios, testicular histology, and circulating LH. Overall, our data speak to the extraordinary ability of a GnRH system permanently compromised by developmental defect to overcome pre-existing deficiencies to ensure pubertal progression and reproduction. PMID:26441841

  11. Fgf8-Deficient Mice Compensate for Reduced GnRH Neuronal Population and Exhibit Normal Testicular Function

    PubMed Central

    Zhang, Wei; Johnson, Joshua I.; Tsai, Pei-San

    2015-01-01

    Gonadotropin-releasing hormone (GnRH) is critical for the onset and maintenance of reproduction in vertebrates. The development of GnRH neurons is highly dependent on fibroblast growth factor (Fgf) signaling. Mice with a hypomorphic Fgf8 allele (Fgf8 Het) exhibited a ~50% reduction in GnRH neuron number at birth. Female Fgf8 Het mice were fertile but showed significantly delayed puberty. However, it was unclear if these mice suffered additional loss of GnRH neurons after birth, and if male Fgf8 Het mice had normal pubertal transition and testicular function. In this study, we examined postnatal GnRH neuron number and hypothalamic GnRH content in Fgf8 Het mice from birth to 120 days of age. Further, we examined seminal vesicle and testicular growth, testicular histology, and circulating luteinizing hormone (LH) around and after pubertal transition. Our results showed that GnRH neuron numbers were significantly and consistently reduced in Fgf8 Het mice of both sexes in all ages examined, suggesting these animals were born with an inherently defective GnRH system, and no further postnatal loss of GnRH neurons had occurred. Despite an innately compromised GnRH system, male and female Fgf8 mice exhibited normal levels of immunoassayable hypothalamic GnRH peptide at all ages examined except on 60 days of age, suggesting increased GnRH synthesis or reduced turnover as a compensatory mechanism. Fgf8 Het males also had normal seminal vesicle and testicular mass/body mass ratios, testicular histology, and circulating LH. Overall, our data speak to the extraordinary ability of a GnRH system permanently compromised by developmental defect to overcome pre-existing deficiencies to ensure pubertal progression and reproduction. PMID:26441841

  12. Release of FGF1 and p40 synaptotagmin 1 correlates with their membrane destabilizing ability.

    PubMed Central

    Graziani, Irene; Bagalá, Cinzia; Duarte, Maria; Soldi, Raffaella; Kolev, Vihren; Tarantini, Francesca; Suresh Kumar, Thallapuranam Krishnaswamy; Doyle, Andrew; Neivandt, David; Yu, Chin; Maciag, Thomas; Prudovsky, Igor

    2006-01-01

    Fibroblast growth factor (FGF)1 is released from cells as a constituent of a complex that contains the small calcium binding protein S100A13, and the p40 kDa form of synaptotagmin (Syt)1, through an ER-Golgi-independent stress-induced pathway. FGF1 and the other components of its secretory complex are signal peptide-less proteins. We examined their capability to interact with lipid bilayers by studying protein-induced carboxyfluorescein release from liposomes of different phospholipid (pL) compositions. FGF1, p40 Syt1, and S100A13 induced destabilization of liposomes composed of acidic but not of zwitterionic pL. We produced mutants of FGF1 and p40 Syt1, in which specific basic amino acid residues in the regions that bind acidic pL were substituted. The ability of these mutants to induce liposomes destabilization was strongly attenuated, and they exhibited drastically diminished spontaneous and stress-induced release. Apparently, the non-classical release of FGF1 and p40 Syt1 involves destabilization of membranes containing acidic pL. PMID:16930531

  13. A Randomized Clinical Trial Evaluating rh-FGF-2/β-TCP in Periodontal Defects.

    PubMed

    Cochran, D L; Oh, T-J; Mills, M P; Clem, D S; McClain, P K; Schallhorn, R A; McGuire, M K; Scheyer, E T; Giannobile, W V; Reddy, M S; Abou-Arraj, R V; Vassilopoulos, P J; Genco, R J; Geurs, N C; Takemura, A

    2016-05-01

    Biological mediators have been used to enhance periodontal regeneration. The aim of this prospective randomized controlled study was to evaluate the safety and effectiveness of 3 doses of fibroblast growth factor 2 (FGF-2) when combined with a β-tricalcium phosphate (β-TCP) scaffold carrier placed in vertical infrabony periodontal defects in adult patients. In this double-blinded, dose-verification, externally monitored clinical study, 88 patients who required surgical intervention to treat a qualifying infrabony periodontal defect were randomized to 1 of 4 treatment groups-β-TCP alone (control) and 0.1% recombinant human FGF-2 (rh-FGF-2), 0.3% rh-FGF-2, and 0.4% rh-FGF-2 with β-TCP-following scaling and root planing of the tooth prior to a surgical appointment. Flap surgery was performed with EDTA conditioning of the root prior to device implantation. There were no statistically significant differences in patient demographics and baseline characteristics among the 4 treatment groups. When a composite outcome of gain in clinical attachment of 1.5 mm was used with a linear bone growth of 2.5 mm, a dose response pattern detected a plateau in the 0.3% and 0.4% rh-FGF-2/β-TCP groups with significant improvements over control and 0.1% rh-FGF-2/β-TCP groups. The success rate at 6 mo was 71% in the 2 higher-concentration groups, as compared with 45% in the control and lowest treatment groups. Percentage bone fill in the 2 higher-concentration groups was 75% and 71%, compared with 63% and 61% in the control and lowest treatment group. No increases in specific antibody to rh-FGF-2 were detected, and no serious adverse events related to the products were reported. The results from this multicenter trial demonstrated that the treatment of infrabony vertical periodontal defects can be enhanced with the addition of rh-FGF-2/β-TCP (ClinicalTrials.gov NCT01728844). PMID:26908630

  14. A Randomized Clinical Trial Evaluating rh-FGF-2/β-TCP in Periodontal Defects.

    PubMed

    Cochran, D L; Oh, T-J; Mills, M P; Clem, D S; McClain, P K; Schallhorn, R A; McGuire, M K; Scheyer, E T; Giannobile, W V; Reddy, M S; Abou-Arraj, R V; Vassilopoulos, P J; Genco, R J; Geurs, N C; Takemura, A

    2016-05-01

    Biological mediators have been used to enhance periodontal regeneration. The aim of this prospective randomized controlled study was to evaluate the safety and effectiveness of 3 doses of fibroblast growth factor 2 (FGF-2) when combined with a β-tricalcium phosphate (β-TCP) scaffold carrier placed in vertical infrabony periodontal defects in adult patients. In this double-blinded, dose-verification, externally monitored clinical study, 88 patients who required surgical intervention to treat a qualifying infrabony periodontal defect were randomized to 1 of 4 treatment groups-β-TCP alone (control) and 0.1% recombinant human FGF-2 (rh-FGF-2), 0.3% rh-FGF-2, and 0.4% rh-FGF-2 with β-TCP-following scaling and root planing of the tooth prior to a surgical appointment. Flap surgery was performed with EDTA conditioning of the root prior to device implantation. There were no statistically significant differences in patient demographics and baseline characteristics among the 4 treatment groups. When a composite outcome of gain in clinical attachment of 1.5 mm was used with a linear bone growth of 2.5 mm, a dose response pattern detected a plateau in the 0.3% and 0.4% rh-FGF-2/β-TCP groups with significant improvements over control and 0.1% rh-FGF-2/β-TCP groups. The success rate at 6 mo was 71% in the 2 higher-concentration groups, as compared with 45% in the control and lowest treatment groups. Percentage bone fill in the 2 higher-concentration groups was 75% and 71%, compared with 63% and 61% in the control and lowest treatment group. No increases in specific antibody to rh-FGF-2 were detected, and no serious adverse events related to the products were reported. The results from this multicenter trial demonstrated that the treatment of infrabony vertical periodontal defects can be enhanced with the addition of rh-FGF-2/β-TCP (ClinicalTrials.gov NCT01728844).

  15. 49 CFR 236.13 - Spring switch; selection of signal control circuits through circuit controller.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... circuits through circuit controller. 236.13 Section 236.13 Transportation Other Regulations Relating to...; selection of signal control circuits through circuit controller. The control circuits of signals governing... circuit controller, or through the contacts of relay repeating the position of such circuit...

  16. 49 CFR 236.13 - Spring switch; selection of signal control circuits through circuit controller.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... circuits through circuit controller. 236.13 Section 236.13 Transportation Other Regulations Relating to...; selection of signal control circuits through circuit controller. The control circuits of signals governing... circuit controller, or through the contacts of relay repeating the position of such circuit...

  17. 49 CFR 236.13 - Spring switch; selection of signal control circuits through circuit controller.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... circuits through circuit controller. 236.13 Section 236.13 Transportation Other Regulations Relating to...; selection of signal control circuits through circuit controller. The control circuits of signals governing... circuit controller, or through the contacts of relay repeating the position of such circuit...

  18. 49 CFR 236.13 - Spring switch; selection of signal control circuits through circuit controller.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... circuits through circuit controller. 236.13 Section 236.13 Transportation Other Regulations Relating to...; selection of signal control circuits through circuit controller. The control circuits of signals governing... circuit controller, or through the contacts of relay repeating the position of such circuit...

  19. A respiratory chain controlled signal transduction cascade in the mitochondrial intermembrane space mediates hydrogen peroxide signaling.

    PubMed

    Patterson, Heide Christine; Gerbeth, Carolin; Thiru, Prathapan; Vögtle, Nora F; Knoll, Marko; Shahsafaei, Aliakbar; Samocha, Kaitlin E; Huang, Cher X; Harden, Mark Michael; Song, Rui; Chen, Cynthia; Kao, Jennifer; Shi, Jiahai; Salmon, Wendy; Shaul, Yoav D; Stokes, Matthew P; Silva, Jeffrey C; Bell, George W; MacArthur, Daniel G; Ruland, Jürgen; Meisinger, Chris; Lodish, Harvey F

    2015-10-20

    Reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) govern cellular homeostasis by inducing signaling. H2O2 modulates the activity of phosphatases and many other signaling molecules through oxidation of critical cysteine residues, which led to the notion that initiation of ROS signaling is broad and nonspecific, and thus fundamentally distinct from other signaling pathways. Here, we report that H2O2 signaling bears hallmarks of a regular signal transduction cascade. It is controlled by hierarchical signaling events resulting in a focused response as the results place the mitochondrial respiratory chain upstream of tyrosine-protein kinase Lyn, Lyn upstream of tyrosine-protein kinase SYK (Syk), and Syk upstream of numerous targets involved in signaling, transcription, translation, metabolism, and cell cycle regulation. The active mediators of H2O2 signaling colocalize as H2O2 induces mitochondria-associated Lyn and Syk phosphorylation, and a pool of Lyn and Syk reside in the mitochondrial intermembrane space. Finally, the same intermediaries control the signaling response in tissues and species responsive to H2O2 as the respiratory chain, Lyn, and Syk were similarly required for H2O2 signaling in mouse B cells, fibroblasts, and chicken DT40 B cells. Consistent with a broad role, the Syk pathway is coexpressed across tissues, is of early metazoan origin, and displays evidence of evolutionary constraint in the human. These results suggest that H2O2 signaling is under control of a signal transduction pathway that links the respiratory chain to the mitochondrial intermembrane space-localized, ubiquitous, and ancient Syk pathway in hematopoietic and nonhematopoietic cells.

  20. A respiratory chain controlled signal transduction cascade in the mitochondrial intermembrane space mediates hydrogen peroxide signaling

    PubMed Central

    Patterson, Heide Christine; Gerbeth, Carolin; Thiru, Prathapan; Vögtle, Nora F.; Knoll, Marko; Shahsafaei, Aliakbar; Samocha, Kaitlin E.; Huang, Cher X.; Harden, Mark Michael; Song, Rui; Chen, Cynthia; Kao, Jennifer; Shi, Jiahai; Salmon, Wendy; Shaul, Yoav D.; Stokes, Matthew P.; Silva, Jeffrey C.; Bell, George W.; MacArthur, Daniel G.; Ruland, Jürgen; Meisinger, Chris; Lodish, Harvey F.

    2015-01-01

    Reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) govern cellular homeostasis by inducing signaling. H2O2 modulates the activity of phosphatases and many other signaling molecules through oxidation of critical cysteine residues, which led to the notion that initiation of ROS signaling is broad and nonspecific, and thus fundamentally distinct from other signaling pathways. Here, we report that H2O2 signaling bears hallmarks of a regular signal transduction cascade. It is controlled by hierarchical signaling events resulting in a focused response as the results place the mitochondrial respiratory chain upstream of tyrosine-protein kinase Lyn, Lyn upstream of tyrosine-protein kinase SYK (Syk), and Syk upstream of numerous targets involved in signaling, transcription, translation, metabolism, and cell cycle regulation. The active mediators of H2O2 signaling colocalize as H2O2 induces mitochondria-associated Lyn and Syk phosphorylation, and a pool of Lyn and Syk reside in the mitochondrial intermembrane space. Finally, the same intermediaries control the signaling response in tissues and species responsive to H2O2 as the respiratory chain, Lyn, and Syk were similarly required for H2O2 signaling in mouse B cells, fibroblasts, and chicken DT40 B cells. Consistent with a broad role, the Syk pathway is coexpressed across tissues, is of early metazoan origin, and displays evidence of evolutionary constraint in the human. These results suggest that H2O2 signaling is under control of a signal transduction pathway that links the respiratory chain to the mitochondrial intermembrane space-localized, ubiquitous, and ancient Syk pathway in hematopoietic and nonhematopoietic cells. PMID:26438848

  1. Micromachined microwave signal control device and method for making same

    DOEpatents

    Forman, Michael A.

    2008-09-02

    A method for fabricating a signal controller, e.g., a filter or a switch, for a coplanar waveguide during the LIGA fabrication process of the waveguide. Both patterns for the waveguide and patterns for the signal controllers are created on a mask. Radiation travels through the mask and reaches a photoresist layer on a substrate. The irradiated portions are removed and channels are formed on the substrate. A metal is filled into the channels to form the conductors of the waveguide and the signal controllers. Micromachined quasi-lumped elements are used alone or together as filters. The switch includes a comb drive, a spring, a metal plunger, and anchors.

  2. Method for making a micromachined microwave signal control device

    DOEpatents

    Forman, Michael A.

    2011-02-15

    A method for fabricating a signal controller, e.g., a filter or a switch, for a coplanar waveguide during the LIGA fabrication process of the waveguide. Both patterns for the waveguide and patterns for the signal controllers are created on a mask. Radiation travels through the mask and reaches a photoresist layer on a substrate. The irradiated portions are removed and channels are formed on the substrate. A metal is filled into the channels to form the conductors of the waveguide and the signal controllers. Micromachined quasi-lumped elements are used alone or together as filters. The switch includes a comb drive, a spring, a metal plunger, and anchors.

  3. Fibroblast Growth Factor-10 (FGF-10) Mobilizes Lung-resident Mesenchymal Stem Cells and Protects Against Acute Lung Injury

    PubMed Central

    Tong, Lin; Zhou, Jian; Rong, Linyi; Seeley, Eric J.; Pan, Jue; Zhu, Xiaodan; Liu, Jie; Wang, Qin; Tang, Xinjun; Qu, Jieming; Bai, Chunxue; Song, Yuanlin

    2016-01-01

    FGF-10 can prevent or reduce lung specific inflammation due to traumatic or infectious lung injury. However, the exact mechanisms are poorly characterized. Additionally, the effect of FGF-10 on lung-resident mesenchymal stem cells (LR-MSCs) has not been studied. To better characterize the effect of FGF-10 on LR-MSCs, FGF-10 was intratracheally delivered into the lungs of rats. Three days after instillation, bronchoalveolar lavage was performed and plastic-adherent cells were cultured, characterized and then delivered therapeutically to rats after LPS intratracheal instillation. Immunophenotyping analysis of FGF-10 mobilized and cultured cells revealed expression of the MSC markers CD29, CD73, CD90, and CD105, and the absence of the hematopoietic lineage markers CD34 and CD45. Multipotency of these cells was demonstrated by their capacity to differentiate into osteocytes, adipocytes, and chondrocytes. Delivery of LR-MSCs into the lungs after LPS injury reduced the inflammatory response as evidenced by decreased wet-to-dry ratio, reduced neutrophil and leukocyte recruitment and decreased inflammatory cytokines compared to control rats. Lastly, direct delivery of FGF-10 in the lungs of rats led to an increase of LR-MSCs in the treated lungs, suggesting that the protective effect of FGF-10 might be mediated, in part, by the mobilization of LR-MSCs in lungs. PMID:26869337

  4. Human ECG signal parameters estimation during controlled physical activity

    NASA Astrophysics Data System (ADS)

    Maciejewski, Marcin; Surtel, Wojciech; Dzida, Grzegorz

    2015-09-01

    ECG signal parameters are commonly used indicators of human health condition. In most cases the patient should remain stationary during the examination to decrease the influence of muscle artifacts. During physical activity, the noise level increases significantly. The ECG signals were acquired during controlled physical activity on a stationary bicycle and during rest. Afterwards, the signals were processed using a method based on Pan-Tompkins algorithms to estimate their parameters and to test the method.

  5. A computer controlled signal preprocessor for laser fringe anemometer applications

    NASA Technical Reports Server (NTRS)

    Oberle, Lawrence G.

    1987-01-01

    The operation of most commercially available laser fringe anemometer (LFA) counter-processors assumes that adjustments are made to the signal processing independent of the computer used for reducing the data acquired. Not only does the researcher desire a record of these parameters attached to the data acquired, but changes in flow conditions generally require that these settings be changed to improve data quality. Because of this limitation, on-line modification of the data acquisition parameters can be difficult and time consuming. A computer-controlled signal preprocessor has been developed which makes possible this optimization of the photomultiplier signal as a normal part of the data acquisition process. It allows computer control of the filter selection, signal gain, and photo-multiplier voltage. The raw signal from the photomultiplier tube is input to the preprocessor which, under the control of a digital computer, filters the signal and amplifies it to an acceptable level. The counter-processor used at Lewis Research Center generates the particle interarrival times, as well as the time-of-flight of the particle through the probe volume. The signal preprocessor allows computer control of the acquisition of these data.Through the preprocessor, the computer also can control the hand shaking signals for the interface between itself and the counter-processor. Finally, the signal preprocessor splits the pedestal from the signal before filtering, and monitors the photo-multiplier dc current, sends a signal proportional to this current to the computer through an analog to digital converter, and provides an alarm if the current exceeds a predefined maximum. Complete drawings and explanations are provided in the text as well as a sample interface program for use with the data acquisition software.

  6. FGF23 in Acute and Chronic Illness

    PubMed Central

    Schnedl, Christian; Fahrleitner-Pammer, Astrid; Pietschmann, Peter; Amrein, Karin

    2015-01-01

    FGF23 is a bone-derived phosphaturic hormone that may become a useful biomarker for the identification of high-risk patients in chronic but also acute disease. It rises early in chronic kidney disease and is strongly and independently associated with excess morbidity and mortality. Emerging data suggest that FGF23 is also elevated in different scenarios of acute illness. In this review, we give an overview on the role of this interesting disease marker and potential and proven interventional strategies and discuss a blueprint for future research. PMID:26491212

  7. Autologous fibrin scaffolds cultured dermal fibroblasts and enriched with encapsulated bFGF for tissue engineering.

    PubMed

    de la Puente, Pilar; Ludeña, Dolores; Fernández, Ana; Aranda, Jose L; Varela, Gonzalo; Iglesias, Javier

    2011-12-15

    Autologous fibrin scaffolds (AFSs) enriched with cells and specific growth factors represent a promising biocompatible scaffold for tissue engineering. Here, we analyzed the in vitro behavior of dermal fibroblasts (DFs) (cellular attachment, distribution, viability and proliferation, histological and immunohistochemical changes), comparing AFS with and without alginate microcapsules loaded with basic fibroblast growth factor (bFGF), to validate our scaffold in a future animal model in vivo. In all cases, DFs showed good adhesion and normal distribution, while in scaffolds with bFGF at 14 days, the cell counts detected in proliferation and viability assays were greatly improved, as was the proliferative state, and there was a decrease in muscle specific actin expression and collagen synthesis in comparison with the scaffolds without bFGF. In addition, the use of plasma without fibrinogen concentration methods, together with the maximum controlled release of bFGF at 14 days, favored cell proliferation. To conclude, we have been able to create an AFS enriched with fully functional DFs and release-controlled bFGF that could be used in multiple applications for tissue engineering.

  8. Basic fibroblast growth factor (basic FGF) in isolated ovine thyroid follicles: thyrotropin stimulation and effects of basic FGF on DNA synthesis, iodine uptake and organification, and the release of insulin-like growth factors (IGFs) and IGF-binding proteins.

    PubMed

    Hill, D J; Phillips, I D; Wang, J F; Becks, G P

    1994-01-01

    We examined the effects of thyroid-stimulating hormone (TSH) on basic fibroblast growth factor (basic FGF) expression in isolated ovine thyroid follicles in vitro, and the effects of exogenous basic FGF on thyroid growth and function, to elucidate the significance of increased basic FGF expression during TSH-induced rat thyroid hyperplasia in vivo. Primary cultures of ovine thyroid follicles were maintained in serum-free Ham's modified F-12M medium containing transferrin, somatostatin, and glycyl-histidyl-lysine (designated 3H) with or without basic FGF alone, or in combination with TSH (100 microU/mL) and cortisol (10 nM). Following 48 h incubation, cells were harvested and total RNA prepared for the detection of basic FGF mRNA using Northern blot analysis and ribonuclease protection assay. Basic FGF in the cytoplasm and extracellular matrix fractions was quantified by radioimmunoassay. Basic FGF mRNA transcripts of 3.7, 3.0, and 2.2 kb, respectively, were found in thyroid follicles cultured in 3H medium, and the abundance of each increased between 2- and 3-fold following incubation with 10-50 microU/mL TSH, although higher concentrations of TSH were less effective. Similar results were seen using a more sensitive ribonuclease protection assay. Cells cultured in control, 3H medium contained 2.4 +/- 0.5 fmol immunoreactive basic FGF/micrograms cell DNA within the cytoplasm and 21.1 +/- 1.5 fmol/micrograms DNA within the extracellular matrix (mean +/- SD, n = 6). A significant increase (p < 0.05) in basic FGF content was seen in both cell compartments following incubation with 50 or 100 microU/mL TSH, while 250 microU/mL was less effective.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7519916

  9. Finite Energy and Bounded Attacks on Control System Sensor Signals

    SciTech Connect

    Djouadi, Seddik M; Melin, Alexander M; Ferragut, Erik M; Laska, Jason A

    2014-01-01

    Control system networks are increasingly being connected to enterprise level networks. These connections leave critical industrial controls systems vulnerable to cyber-attacks. Most of the effort in protecting these cyber-physical systems (CPS) has been in securing the networks using information security techniques and protection and reliability concerns at the control system level against random hardware and software failures. However, besides these failures the inability of information security techniques to protect against all intrusions means that the control system must be resilient to various signal attacks for which new analysis and detection methods need to be developed. In this paper, sensor signal attacks are analyzed for observer-based controlled systems. The threat surface for sensor signal attacks is subdivided into denial of service, finite energy, and bounded attacks. In particular, the error signals between states of attack free systems and systems subject to these attacks are quantified. Optimal sensor and actuator signal attacks for the finite and infinite horizon linear quadratic (LQ) control in terms of maximizing the corresponding cost functions are computed. The closed-loop system under optimal signal attacks are provided. Illustrative numerical examples are provided together with an application to a power network with distributed LQ controllers.

  10. Signal processing device to control microwave output

    NASA Astrophysics Data System (ADS)

    Pinto, J. G.

    1989-08-01

    The development of an electronic device to control the operation of a commercial microwave oven is discussed. This device when installed in conjunction with the existing circuitry of SHARP MICROWAVE OVEN (model R-9524) is capable of automatically advancing through a sequence of thawing recipes programmed and stored in the memory bank of the oven. The device therefore eliminates or minimizes human operator action needed in previous prototype version of a blood thawing device.

  11. Raised FGF-21 and Triglycerides Accompany Increased Energy Intake Driven by Protein Leverage in Lean, Healthy Individuals: A Randomised Trial

    PubMed Central

    Gosby, Alison K.; Lau, Namson S.; Tam, Charmaine S.; Iglesias, Miguel A.; Morrison, Christopher D.; Caterson, Ian D.; Brand-Miller, Jennie; Conigrave, Arthur D.; Raubenheimer, David; Simpson, Stephen J.

    2016-01-01

    A dominant appetite for protein drives increased energy intake in humans when the proportion of protein in the diet is reduced down to approximately 10% of total energy. Compensatory feeding for protein is apparent over a 1–2 d period but the mechanisms driving this regulation are not fully understood. Fibroblast growth factor-21 (FGF-21) has been identified as a candidate protein signal as levels increase in the circulation when dietary protein is low. The aim of this randomised controlled trial was to assess whether changes in percent dietary protein over a 4 d ad libitum experimental period in lean, healthy participants influenced energy intake, metabolic health, circulating FGF-21 and appetite regulating hormones including ghrelin, glucagon like peptide-1 and cholecystokinin. Twenty-two lean, healthy participants were fed ad libitum diets containing 10, 15 and 25% protein, over three, 4 d controlled, in-house experimental periods. Reduced dietary protein intake from 25% to 10% over a period of 4 d was associated with 14% increased energy intake (p = 0.02) as previously reported, and a 6-fold increase in fasting circulating plasma FGF-21 levels (p<0.0001), a 1.5-fold increase in serum triglycerides (p<0.0001), and a 0.9-fold decrease in serum total cholesterol (p = 0.02). Serum HDL cholesterol was reduced with a reduction in dietary protein from 15% to 10% (p = 0.01) over 4 d but not from 25% to 10% (p = 0.1) and the change from baseline was not different between diets. Plasma fasting insulin levels following the 4 d study period were significantly lower following the 25% ad libitum study period compared to the 15% protein period (p = 0.014) but not the 10% protein period (p = 0.2). Variability in interstitial glucose during each study period increased with a decrease in dietary protein from 25% to 15% and 10% (p = 0.001 and p = 0.04, respectively). Ghrelin, glucagon-like peptide-1 and cholecystokinin were unchanged. Increases in energy intake, plasma FGF-21

  12. Brushless DC motor control system responsive to control signals generated by a computer or the like

    NASA Technical Reports Server (NTRS)

    Packard, Douglas T. (Inventor); Schmitt, Donald E. (Inventor)

    1987-01-01

    A control system for a brushless DC motor responsive to digital control signals is disclosed. The motor includes a multiphase wound stator and a permanent magnet rotor. The rotor is arranged so that each phase winding, when energized from a DC source, will drive the rotor through a predetermined angular position or step. A commutation signal generator responsive to the shaft position provides a commutation signal for each winding. A programmable control signal generator such as a computer or microprocessor produces individual digital control signals for each phase winding. The control signals and commutation signals associated with each winding are applied to an AND gate for that phase winding. Each gate controls a switch connected in series with the associated phase winding and the DC source so that each phase winding is energized only when the commutation signal and the control signal associated with that phase winding are present. The motor shaft may be advanced one step at a time to a desired position by applying a predetermined number of control signals in the proper sequence to the AND gates and the torque generated by the motor may be regulated by applying a separate control signal to each AND gate which is pulse width modulated to control the total time that each switch connects its associated winding to the DC source during each commutation period.

  13. Brushless DC motor control system responsive to control signals generated by a computer or the like

    NASA Technical Reports Server (NTRS)

    Packard, D. T. (Inventor)

    1985-01-01

    A control system for a brushless DC motor responsive to digital control signals is disclosed. The motor includes a multiphase wound stator and a permanent magnet rotor. The motor is arranged so that each phase winding, when energized from a DC source, will drive the rotor through a predetermined angular position or step. A commutation signal generator responsive to the shaft position provides a commutation signal for each winding. A programmable control signal generator such as a computer or microprocessor produces individual digital control signals for each phase winding. The control signals and commutation signals associated with each winding are applied to an AND gate for that phase winding. Each gate controls a switch connected in series with the associated phase winding and the DC source so that each phase winding is energized only when the commutation signal and the control signal associated with that phase winding are present. The motor shaft may be advanced one step at a time to a desired position by applying a predetermined number of control signals in the proper sequence to the AND gates and the torque generated by the motor be regulated by applying a separate control signal and each AND gate which is pulse width modulated to control the total time that each switch connects its associated winding to the DC source during each commutation period.

  14. Brushless DC motor control system responsive to control signals generated by a computer or the like

    NASA Astrophysics Data System (ADS)

    Packard, D. T.

    1985-04-01

    A control system for a brushless DC motor responsive to digital control signals is disclosed. The motor includes a multiphase wound stator and a permanent magnet rotor. The motor is arranged so that each phase winding, when energized from a DC source, will drive the rotor through a predetermined angular position or step. A commutation signal generator responsive to the shaft position provides a commutation signal for each winding. A programmable control signal generator such as a computer or microprocessor produces individual digital control signals for each phase winding. The control signals and commutation signals associated with each winding are applied to an AND gate for that phase winding. Each gate controls a switch connected in series with the associated phase winding and the DC source so that each phase winding is energized only when the commutation signal and the control signal associated with that phase winding are present. The motor shaft may be advanced one step at a time to a desired position by applying a predetermined number of control signals in the proper sequence to the AND gates and the torque generated by the motor be regulated by applying a separate control signal and each AND gate which is pulse width modulated to control the total time that each switch connects its associated winding to the DC source during each commutation period.

  15. Fibroblast growth factor receptor signaling in oligodendrocytes regulates myelin sheath thickness.

    PubMed

    Furusho, Miki; Dupree, Jeffrey L; Nave, Klaus-Armin; Bansal, Rashmi

    2012-05-01

    Formation of the CNS white matter is developmentally tightly regulated, but the molecules and mechanisms of myelination control in the postnatal CNS are poorly understood. Here, we show that myelin growth is controlled by fibroblast growth factor (FGF) signaling, originally identified as a proliferative signal for oligodendrocyte precursor cells (OPCs) in vitro. We created two lines of mice lacking both FGF receptor 1 (Fgfr1) and Fgfr2 in oligodendrocyte-lineage cells but found that in these mice OPC proliferation and differentiation were unaffected. In addition, axonal ensheathment and the initiation of myelination were on time. However, the rapid growth of CNS myelin, normally occurring in the second postnatal week, was strongly inhibited. Throughout adulthood, the myelin sheath remained disproportionately thin relative to the axon caliber. In adult mice, mutant oligodendrocytes were normal in number, whereas the transcription of major myelin genes was reduced. This FGF receptor-mediated stimulation of mature oligodendrocytes could also be modeled in vitro, demonstrating that enhanced expansion of oligodendroglial processes requires signaling by extracellular signal regulated kinase-1 and -2 (Erk1/2), downstream mediators of mitogen-activated protein kinase (MAPK). In vivo, Erk1/2-MAPK activity was reduced in the hypomyelinated CNS of Fgfr1/Fgfr2 mutant mice. These studies reveal a previously unrecognized function of FGF receptor signaling in oligodendrocytes that contributes to the regulation of myelin sheath thickness and that uncouples the initiation of ensheathment from the later phase of continued myelin growth.

  16. Effects of Low Dose FGF-2 and BMP-2 on Healing of Calvarial Defects in Old Mice

    PubMed Central

    Charles, Lyndon F.; Woodman, Jessica L.; Ueno, Daisuke; Gronowicz, Gloria; Hurley, Marja M.; Kuhn, Liisa T.

    2015-01-01

    There is an age-associated reduction in the bone healing activity of bone morphogenetic protein -2 (BMP-2) that is currently addressed by administering higher doses of BMP-2 in elderly patients. The unwanted medical complications from high dose BMP-2 motivated this investigation to determine whether the addition of a low dose of fibroblast growth factor 2 (FGF-2) could enhance the ability of a lower dose of BMP-2 to heal calvarial bone defects in old mice (18-20 months old). FGF-2 (5 ng) and BMP-2 (2 μg) were administered by a controlled release two-phase biomaterial scaffold placed into the bone defect. FGF-2 released more rapidly and completely in vitro than BMP-2 (40% vs 2%). In vivo, both BMP-2 and FGF-2+BMP-2 groups formed more new bone in calvarial defects than scaffold alone (p <0.001) or FGF-2 only groups (p < 0.01). The overall total volume of new bone was not statistically increased by the addition of FGF-2 to BMP-2 as measured by microCT, but the pattern of bone deposition was different. In old mice, but not young, there was enhanced bony fill in the central bone defect area when the BMP-2 was supplemented with FGF-2. Histological analysis of the center of the defect revealed an increased bone volume (%BV/TV (p = 0.004)) from the addition of FGF-2. These studies suggest that combining a low dose of FGF-2 with a low dose of BMP-2 has the potential to increase bone healing in old mice relative to BMP-2 alone. PMID:25681640

  17. FGF8 and SHH substitute for anterior-posterior tissue interactions to induce limb regeneration.

    PubMed

    Nacu, Eugeniu; Gromberg, Elena; Oliveira, Catarina R; Drechsel, David; Tanaka, Elly M

    2016-04-27

    In salamanders, grafting of a left limb blastema onto a right limb stump yields regeneration of three limbs, the normal limb and two 'supernumerary' limbs. This experiment and other research have shown that the juxtaposition of anterior and posterior limb tissue plus innervation are necessary and sufficient to induce complete limb regeneration in salamanders. However, the cellular and molecular basis of the requirement for anterior-posterior tissue interactions were unknown. Here we have clarified the molecular basis of the requirement for both anterior and posterior tissue during limb regeneration and supernumerary limb formation in axolotls (Ambystoma mexicanum). We show that the two tissues provide complementary cross-inductive signals that are required for limb outgrowth. A blastema composed solely of anterior tissue normally regresses rather than forming a limb, but activation of hedgehog (HH) signalling was sufficient to drive regeneration of an anterior blastema to completion owing to its ability to maintain fibroblast growth factor (FGF) expression, the key signalling activity responsible for blastema outgrowth. In blastemas composed solely of posterior tissue, HH signalling was not sufficient to drive regeneration; however, ectopic expression of FGF8 together with endogenous HH signalling was sufficient. In axolotls, FGF8 is expressed only in the anterior mesenchyme and maintenance of its expression depends on sonic hedgehog (SHH) signalling from posterior tissue. Together, our findings identify key anteriorly and posteriorly localized signals that promote limb regeneration and show that these single factors are sufficient to drive non-regenerating blastemas to complete regeneration with full elaboration of skeletal elements.

  18. An extended signal control strategy for urban network traffic flow

    NASA Astrophysics Data System (ADS)

    Yan, Fei; Tian, Fuli; Shi, Zhongke

    2016-03-01

    Traffic flow patterns are in general repeated on a daily or weekly basis. To improve the traffic conditions by using the inherent repeatability of traffic flow, a novel signal control strategy for urban networks was developed via iterative learning control (ILC) approach. Rigorous analysis shows that the proposed learning control method can guarantee the asymptotic convergence. The impacts of the ILC-based signal control strategy on the macroscopic fundamental diagram (MFD) were analyzed by simulations on a test road network. The results show that the proposed ILC strategy can evenly distribute the accumulation in the network and improve the network mobility.

  19. Circulating Fibroblast Growth Factor 21 (Fgf21) as Diagnostic and Prognostic Biomarker in Renal Cancer

    PubMed Central

    Knott, ME; Minatta, JN; Roulet, L; Gueglio, G; Pasik, L; Ranuncolo, SM; Nuñez, M; Puricelli, L; De Lorenzo, MS

    2016-01-01

    Background The finding of new biomarkers is needed to have a better sub-classification of primary renal tumors (RCC) as well as more reliable predictors of outcome and therapy response. In this study, we evaluated the role of circulating FGF21, an endocrine factor, as a diagnostic and prognostic biomarker for ccRCC. Materials and Methods Serum samples from healthy controls (HC), clear cell and chromophobe RCC cancer patients were obtained from the serum biobank “Biobanco Público de Muestras Séricas Oncológicas” (BPMSO) of the “Instituto de Oncología “Ángel H. Roffo”. Serum FGF21 and leptin were measured by ELISA while other metabolic markers were measured following routinely clinical procedures. Results One of our major findings was that FGF21 levels were significantly increased in ccRCC patients compared with HC. Moreover, we showed an association between the increased serum FGF21 levels and the shorter disease free survival in a cohort of 98 ccRCC patients, after adjustment for other predictors of outcome. Conclusion Our results suggest that higher FGF21 serum level is an independent prognostic biomarker, associated with worse free-disease survival. PMID:27358750

  20. Chaos control applied to cardiac rhythms represented by ECG signals

    NASA Astrophysics Data System (ADS)

    Borem Ferreira, Bianca; Amorim Savi, Marcelo; Souza de Paula, Aline

    2014-10-01

    The control of irregular or chaotic heartbeats is a key issue in cardiology. In this regard, chaos control techniques represent a good alternative since they suggest treatments different from those traditionally used. This paper deals with the application of the extended time-delayed feedback control method to stabilize pathological chaotic heart rhythms. Electrocardiogram (ECG) signals are employed to represent the cardiovascular behavior. A mathematical model is employed to generate ECG signals using three modified Van der Pol oscillators connected with time delay couplings. This model provides results that qualitatively capture the general behavior of the heart. Controlled ECG signals show the ability of the strategy either to control or to suppress the chaotic heart dynamics generating less-critical behaviors.

  1. Effect of FGF-2 on collagen tissue regeneration by human vertebral bone marrow stem cells.

    PubMed

    Park, Dong-Soo; Park, Jung-Chul; Lee, Jung-Seok; Kim, Tae-Wan; Kim, Ki-Joon; Jung, Byung-Joo; Shim, Eun-Kyung; Choi, Eun-Young; Park, So-Yon; Cho, Kyoo-Sung; Kim, Chang-Sung

    2015-01-15

    The effects of fibroblast growth factor-2 (FGF-2) on collagen tissue regeneration by human bone marrow stem cells (hBMSCs) were investigated. hBMSCs were isolated from human vertebral body bone marrow during vertebral surgery and a population of hBMSCs with the characteristics of mesenchymal stem cells was observed. The FGF-2 treatment (5 ng/mL) affected on the colony-forming efficiency, proliferation, and in vitro differentiation of hBMSCs. Insoluble/soluble collagen and hydroxyproline synthesis was significantly enhanced in hBMSCs expanded with FGF-2 and the treatment of FGF-2 caused a reduction in the mRNA expression of collagen type I, but an increase of collagen types II and III along with lysyl oxidase family genes. Collagen formation was also examined using an in vivo assay model by transplanting hBMSCs into immunocompromised mice (n=4) and the histologic and immunohistochemical results revealed that significantly more collagen with a well-organized structure was formed by FGF-2-treated hBMSCs at 8 weeks posttransplantation (P<0.05). The DNA microarray assay demonstrated that genes related to extracellular matrix formation were significantly upregulated. To elucidate the underlying mechanism, chemical inhibitors against extracellular-signal-regulated kinase (ERK) and phosphoinositide 3-kinase (PI3K) were treated and following downstream expression was observed. Collectively, FGF-2 facilitated the collagen-producing potency of hBMSCs both in vitro and in vivo, rendering them more suitable for use in collagen regeneration in the clinical field.

  2. The biological effects of XTC-MIF: quantitative comparison with Xenopus bFGF.

    PubMed

    Green, J B; Howes, G; Symes, K; Cooke, J; Smith, J C

    1990-01-01

    Mesoderm in Xenopus and other amphibian embryos is induced by signals from the vegetal hemisphere acting on equatorial or animal hemisphere cells. These signals are diffusible and two classes of candidate signal molecule have been identified: the fibroblast growth factor (FGF) and transforming growth factor beta (TGF-beta) types. In this paper, we compare the effects of cloned Xenopus basic FGF (XbFGF) and electophoretically homogeneous XTC-MIF (a TGF-beta-like factor obtained from a Xenopus cell line) on animal pole explants. We find that they have a similar minimum active concentration (0.1-0.2 ng ml-1) but that, nonetheless, XTC-MIF is at least 40 times more active in inducing muscle. In general, we find that the two factors cause inductions of significantly different characters in terms of tissue type, morphology, gene expression and timing. At low concentrations (0.1-1.0 ng ml-1) both factors induce the differentiation of 'mesenchyme' and 'mesothelium' as well as blood-like cells. These latter cells do not, however, react with an antibody to Xenopus globin. This raised the possibility that the identification of red blood cells in other studies on mesoderm induction might have been mistaken, but combinations of animal pole regions with ventral vegetal pole regions confirmed that genuine erythrocytes are formed. The identity of the blood-like cells formed in response to the inducing factors remains unknown. At higher concentrations XTC-MIF induces neural tissue, notochord, pronephros and substantial and often segmented muscle. By contrast, XbFGF only induces significant amounts of muscle above 24 ng ml-1 and even then this is much less than that induced by XTC-MIF. For both factors an exposure of less than 30 min is effective. Competence of animal pole cells to respond to XbFGF is completely lost by the beginning of gastrulation (stage 10) while competence to XTC-MIF is detectable until somewhat later (stage 11). Since animal pole tissue is known to be able to

  3. Sprouty-2 Overexpression in C2C12 Cells Confers Myogenic Differentiation Properties in the Presence of FGF2D⃞

    PubMed Central

    de Alvaro, Cristina; Martinez, Natalia; Rojas, Jose M.; Lorenzo, Margarita

    2005-01-01

    Myoblast C2C12 cells cultured in the presence of FGF2 actively proliferate and showed a differentiation-defective phenotype compared with cells cultured in low serum or in the presence of insulin. These FGF2 effects are associated with sustained activation of p44/p42-MAPK and lack of activation of AKT. Here we demonstrate that Sprouty-2, a protein involved in the negative feedback of receptor tyrosine kinase signaling, when stably overexpressed in C2C12 cells and in the presence of FGF2 produces growth arrest (precluding the expression of PCNA and the phosphorylation of retinoblastoma and inducing the expression of p21CIP) and myogenesis (multinucleated myotubes formation, induction of creatine kinase and expression of myosin heavy chain protein). These events were accompanied by repression of p44/p42-MAPK and activation of AKT. When C2C12 cells were stably transfected with a Sprouty-2 (Y55F) mutant defective in inhibiting p44/p42-MAPK activation by FGF, myoblasts in the presence of FGF continue to grow and completely fail to form myotubes. This work is the first evidence of the contribution of sprouty genes to myogenic differentiation in the presence of FGF2. PMID:16000370

  4. Heparin-Based Coacervate of FGF2 Improves Dermal Regeneration by Asserting a Synergistic Role with Cell Proliferation and Endogenous Facilitated VEGF for Cutaneous Wound Healing.

    PubMed

    Wu, Jiang; Ye, Jingjing; Zhu, Jingjing; Xiao, Zecong; He, Chaochao; Shi, Hongxue; Wang, Yadong; Lin, Cai; Zhang, Hongyu; Zhao, Yingzheng; Fu, Xiaobing; Chen, Hong; Li, Xiaokun; Li, Lin; Zheng, Jie; Xiao, Jian

    2016-06-13

    Effective wound healing requires complicated, coordinated interactions and responses at protein, cellular, and tissue levels involving growth factor expression, cell proliferation, wound closure, granulation tissue formation, and vascularization. In this study, we develop a heparin-based coacervate consisting of poly(ethylene argininylaspartate digylceride) (PEAD) as a storage matrix, heparin as a bridge, and fibroblast growth factor-2 (FGF2) as a cargo (namely heparin-FGF2@PEAD) for wound healing. First, in vitro characterization demonstrates the loading efficiency and control release of FGF2 from the heparin-FGF2@PEAD coacervate. The following in vivo studies examine the wound healing efficiency of the heparin-FGF2@PEAD coacervate upon delivering FGF2 to full-thickness excisional skin wounds in vivo, in comparison with the other three control groups with saline, heparin@PEAD as vehicle, and free FGF2. Collective in vivo data show that controlled release of FGF2 to the wounds by the coacervate significantly accelerates the wound healing by promoting cell proliferation, stimulating the secretion of vascular endothelial growth factor (VEGF) for re-epithelization, collagen deposition, and granulation tissue formation, and enhancing the expression of platelet endothelial cell adhesion molecule (CD31) and alpha-smooth muscle actin (α-SMA) for blood vessel maturation. In parallel, no obvious wound healing effect is found for the control, vehicle, and free FGF2 groups, indicating the important role of the coavervate in the wound healing process. This work designs a suitable delivery system that can protect and release FGF2 in a sustained and controlled manner, which provides a promising therapeutic potential for topical treatment of wounds.

  5. FGF receptor antagonism does not affect adipose tissue development in nutritionally induced obesity.

    PubMed

    Scroyen, Ilse; Vranckx, Christine; Lijnen, Henri Roger

    2014-01-01

    The fibroblast growth factor (FGF)-FGF receptor (FGFR) system plays a role in angiogenesis and maintenance of vascular integrity, but its potential role in adipose tissue related angiogenesis and development is still unknown. Administration of SSR, a low molecular weight inhibitor of multiple FGFRs, did not significantly affect body weight nor weight of subcutaneous or gonadal (GON) fat, as compared with pair-fed control mice. Adipocyte hypertrophy and reduced adipocyte density were only observed in GON adipose tissues of treated mice. Adipose tissue angiogenesis was not affected by SSR treatment, as normalized blood vessel density was comparable in adipose tissues of both groups. Blocking the FGF-FGFR system in vivo does not markedly affect adipose tissue development in mice with nutritionally induced obesity.

  6. Relationships between digital signal processing and control and estimation theory

    NASA Technical Reports Server (NTRS)

    Willsky, A. S.

    1978-01-01

    Research directions in the fields of digital signal processing and modern control and estimation theory are discussed. Stability theory, linear prediction and parameter identification, system synthesis and implementation, two-dimensional filtering, decentralized control and estimation, and image processing are considered in order to uncover some of the basic similarities and differences in the goals, techniques, and philosophy of the disciplines.

  7. Signal generation and clarification: use of case-control data.

    PubMed

    Kaufman, D W; Rosenberg, L; Mitchell, A A

    2001-05-01

    Case-control surveillance systems are useful for 'signal' generation, i.e., signaling potential previously unidentified adverse effects of drugs. Two systems currently in operation, the Slone Epidemiology Unit's Case-Control Surveillance and the Birth Defects Study, have monitored drug effects since 1976. With extensive information on the diagnoses and covariates, the systems have the capacity to carry out in-depth analyses in which the outcome measure is more specifically defined and in which confounding is controlled, thus reducing the possibility of false alarms.

  8. Comparison of human dermal fibroblasts (HDFs) growth rate in culture media supplemented with or without basic fibroblast growth factor (bFGF).

    PubMed

    Abdian, Narges; Ghasemi-Dehkordi, Payam; Hashemzadeh-Chaleshtori, Morteza; Ganji-Arjenaki, Mahbobe; Doosti, Abbas; Amiri, Beheshteh

    2015-12-01

    Basic fibroblast growth factor (bFGF or FGF-2) is a member of the FGF family secreted by different kinds of cells like HDFs and it is an important nutritional factor for cell growth and differentiation. The HDFs release bFGF in culture media at very low. The present study aims to investigate the HDFs growth rate in culture media supplemented either with or without bFGF. In brief, HDFs were isolated from human foreskin sample and were cultured in vitro in media containing bFGF and lack of this factor. The cells growth rate was calculated by trypan blue. The karyotyping was performed using G-banding to investigate the chromosomal abnormality of HDFs in both groups. Total RNA of each groups were extracted and cDNA samples were synthesized then, real-time Q-PCR was used to measure the expression level of p27kip1 and cyclin D1 genes normalized to internal control gene (GAPDH). The karyotype analysis showed that HDFs cultured in media or without bFGF had normal karyotype (46 chromosomes, XY) and chromosomal abnormalities were not observed. The cell growth rates in both groups were normal with proliferated exponentially but the slope of growth curve in HDFs cultured in media containing bFGF was increased. Karyotyp test showed that bFGF does not affect on cytogenetic stability of cells. The survey of p27kip1 and cyclin D1 genes by real-time Q-PCR showed that the expression level of these genes were up-regulated when adding bFGF in culture media (p < 0.05). The findings of the present study demonstrate that appropriate supplementation of culture media with growth factor like bFGF could enhance the proliferation and differentiation capacity of cells and improve cells growth rate. Similarly, fibroblast growth factors did not induce any chromosomal abnormality in cells. Furthermore, in HDFs cultured in bFGF supplemented media, the p27kip1 and cyclin D1 genes were up-regulated and suggesting an important role for bFGF in cell-cycle regulation and progression and fibroblast

  9. Compound Deficiencies in Multiple Fibroblast Growth Factor Signalling Components Differentially Impact the Murine Gonadotrophin-Releasing Hormone System

    PubMed Central

    Chung, W. C. J.; Matthews, T. A.; Tata, B. K.; Tsai, P.-S.

    2011-01-01

    Gonadotrophin-releasing hormone (GnRH) neurones control the onset and maintenance of fertility. Aberrant development of the GnRH system underlies infertility in Kallmann syndrome [KS; idiopathic hypogonadotropic hypogonadism (IHH) and anosmia]. Some KS patients harbour mutations in the fibroblast growth factor receptor 1 (Fgfr1) and Fgf8 genes. The biological significance of these two genes in GnRH neuronal development was corroborated by the observation that GnRH neurones were severely reduced in newborn transgenic mice deficient in either gene. In the present study, we hypothesised that the compound deficiency of Fgf8 and its cognate receptors, Fgfr1 and Fgfr3, may lead to more deleterious effects on the GnRH system, thereby resulting in a more severe reproductive phenotype in patients harbouring these mutations. This hypothesis was tested by counting the number of GnRH neurones in adult transgenic mice with digenic heterozygous mutations in Fgfr1/Fgf8, Fgfr3/Fgf8 or Fgfr1/Fgfr3. Monogenic heterozygous mutations in Fgfr1, Fgf8 or Fgfr3 caused a 30–50% decrease in the total number of GnRH neurones. Interestingly, mice with digenic mutations in Fgfr1/Fgf8 showed a greater decrease in GnRH neurones compared to mice with a heterozygous defect in the Fgfr1 or Fgf8 alone. This compounding effect was not detected in mice with digenic heterozygous mutations in Fgfr3/Fgf8 or Fgfr1/Fgfr3. These results support the hypothesis that IHH/KS patients with digenic mutations in Fgfr1/Fgf8 may have a further reduction in the GnRH neuronal population compared to patients harbouring monogenic haploid mutations in Fgfr1 or Fgf8. Because only Fgfr1/Fgf8 compound deficiency leads to greater GnRH system defect, this also suggests that these fibroblast growth factor signalling components interact in a highly specific fashion to support GnRH neuronal development. PMID:20553372

  10. Therapeutic effects of complex rearing or bFGF after perinatal frontal lesions.

    PubMed

    Comeau, Wendy; Gibb, Robbin; Hastings, Erica; Cioe, Jan; Kolb, Bryan

    2008-03-01

    We investigated the effects of an enriched environment and/or basic fibroblast growth factor (bFGF) on recovery from neonatal frontal injury in rats. Rats received medial frontal lesions, or sham surgery, on postnatal day (P) 2/3. In the first set of experiments (Experiments 1 and 2), rats were housed in enriched environments that consisted of a large enclosure with multiple objects (or standard housing) for 90 days beginning at weaning (P22) or in adulthood (P110). In Experiment 3, the rats either received 7 days of subcutaneous bFGF beginning on the day after surgery or bFGF plus enriched housing beginning at weaning. After the 90-day housing period, the animals were tested on a spatial navigation task and a skilled reaching task. Early lesions of the medial frontal cortex caused severe impairments in spatial learning but this deficit was markedly reduced with enriched housing, bFGF, or a combination of both, with the latter being most effective. The housing effects varied with age, however: the earlier the experience began, the better the outcome. Enriched housing increased dendritic length in cortical pyramidal neurons, an effect that was greater in the lesion than the control animals, and enriched housing reversed the lesion-induced decrease in spine density. Enriched environment increased the thickness of the cortical mantle in both lesion and controls whereas bFGF had no effect. Experience thus can affect functional and anatomical outcome after early brain injury but the effects vary with age at experience and may be facilitated by treatment with bFGF. PMID:18286581

  11. Basic Fibroblast Growth Factor (bFGF, FGF-2) Potentiates Leukocyte Recruitment to Inflammation by Enhancing Endothelial Adhesion Molecule Expression

    PubMed Central

    Zittermann, Sandra I.; Issekutz, Andrew C.

    2006-01-01

    Basic fibroblast growth factor (bFGF, FGF-2) is a potent angiogenic factor and endothelial cell mitogen. Although bFGF levels are increased in chronically inflamed tissue, its role in inflammation is unclear. We investigated the effect of bFGF on acute dermal inflammation and the recruitment of monocytes, T cells, and neutrophils. Leukocyte recruitment to inflamed sites was quantified with radiolabeled leukocytes. Intradermal injection of bFGF in rats did not induce leukocyte recruitment or inflammation. However, the recruitment of leukocytes to inflammation induced by tumor necrosis factor-α, interferon-γ, C5a, or a delayed hypersensitivity reaction was enhanced by bFGF by 55 to 132% (P < 0.05). Either acute or prolonged bFGF treatment of dermal sites had this effect. The potentiating effect of bFGF on leukocyte recruitment was also seen in joints. There was no associated modulation of vascular permeability, blood flow, or angiogenesis in the sites by bFGF. However, the expression of the endothelial cell adhesion molecules (CAMs) for leukocytes, P-selectin, E-selectin, and ICAM-1, was significantly up-regulated in the inflamed tissue by bFGF, as quantified by radiolabeled anti-CAM antibody binding in vivo. Thus, although not directly proinflammatory, bFGF synergistically potentiates inflammatory mediator-induced leukocyte recruitment, at least in part, by enhancing CAM up-regulation on endothelium. PMID:16507899

  12. Autoregulation of glypican-1 by intronic microRNA-149 fine tunes the angiogenic response to FGF2 in human endothelial cells

    PubMed Central

    Chamorro-Jorganes, Aránzazu; Araldi, Elisa; Rotllan, Noemi; Cirera-Salinas, Daniel; Suárez, Yajaira

    2014-01-01

    ABSTRACT MicroRNA-149 (miR-149) is located within the first intron of the glypican-1 (GPC1) gene. GPC1 is a low affinity receptor for fibroblast growth factor (FGF2) that enhances FGF2 binding to its receptor (FGFR1), subsequently promoting FGF2–FGFR1 activation and signaling. Using bioinformatic approaches, both GPC1 and FGFR1 were identified and subsequently validated as targets for miR-149 (both the mature strand, miR-149, and the passenger strand, miR-149*) in endothelial cells (ECs). As a consequence of their targeting activity towards GPC1 and FGFR1, both miR-149 and miR-149* regulated FGF2 signaling and FGF2-induced responses in ECs, namely proliferation, migration and cord formation. Moreover, lentiviral overexpression of miR-149 reduced in vivo tumor-induced neovascularization. Importantly, FGF2 transcriptionally stimulated the expression of miR-149 independently of its host gene, therefore assuring the steady state of FGF2-induced responses through the regulation of the GPC1–FGFR1 binary complex in ECs. PMID:24463821

  13. Optogenetic pharmacology for control of native neuronal signaling proteins.

    PubMed

    Kramer, Richard H; Mourot, Alexandre; Adesnik, Hillel

    2013-07-01

    The optical neuroscience revolution is transforming how we study neural circuits. By providing a precise way to manipulate endogenous neuronal signaling proteins, it also has the potential to transform our understanding of molecular neuroscience. Recent advances in chemical biology have produced light-sensitive compounds that photoregulate a wide variety of proteins underlying signaling between and within neurons. Chemical tools for optopharmacology include caged agonists and antagonists and reversibly photoswitchable ligands. These reagents act on voltage-gated ion channels and neurotransmitter receptors, enabling control of neuronal signaling with a high degree of spatial and temporal precision. By covalently attaching photoswitch molecules to genetically tagged proteins, the newly emerging methodology of optogenetic pharmacology allows biochemically precise control in targeted subsets of neurons. Now that the tools for manipulating endogenous neuronal signaling proteins are available, they can be implemented in vivo to enhance our understanding of the molecular bases of brain function and dysfunctions. PMID:23799474

  14. Temporally precise in vivo control of intracellular signalling.

    PubMed

    Airan, Raag D; Thompson, Kimberly R; Fenno, Lief E; Bernstein, Hannah; Deisseroth, Karl

    2009-04-23

    In the study of complex mammalian behaviours, technological limitations have prevented spatiotemporally precise control over intracellular signalling processes. Here we report the development of a versatile family of genetically encoded optical tools ('optoXRs') that leverage common structure-function relationships among G-protein-coupled receptors (GPCRs) to recruit and control, with high spatiotemporal precision, receptor-initiated biochemical signalling pathways. In particular, we have developed and characterized two optoXRs that selectively recruit distinct, targeted signalling pathways in response to light. The two optoXRs exerted opposing effects on spike firing in nucleus accumbens in vivo, and precisely timed optoXR photostimulation in nucleus accumbens by itself sufficed to drive conditioned place preference in freely moving mice. The optoXR approach allows testing of hypotheses regarding the causal impact of biochemical signalling in behaving mammals, in a targetable and temporally precise manner.

  15. Coordinated signal control for arterial intersections using fuzzy logic

    NASA Astrophysics Data System (ADS)

    Kermanian, Davood; Zare, Assef; Balochian, Saeed

    2013-09-01

    Every day growth of the vehicles has become one of the biggest problems of urbanism especially in major cities. This can waste people's time, increase the fuel consumption, air pollution, and increase the density of cars and vehicles. Fuzzy controllers have been widely used in many consumer products and industrial applications with success over the past two decades. This article proposes a comprehensive model of urban traffic network using state space equations and then using Fuzzy Logic Tool Box and SIMULINK Program MATLAB a fuzzy controller in order to optimize and coordinate signal control at two intersections at an arterial road. The fuzzy controller decides to extend, early cut or terminate a signal phase and phase sequence to ensure smooth flow of traffic with minimal waiting time and length of queue. Results show that the performance of the proposed traffic controller at novel fuzzy model is better that of conventional controllers under normal and abnormal traffic conditions.

  16. Persistent Cellular Motion Control and Trapping Using Mechanotactic Signaling

    PubMed Central

    Zhu, Xiaoying; Bouffanais, Roland; Yue, Dick K. P.

    2014-01-01

    Chemotactic signaling and the associated directed cell migration have been extensively studied owing to their importance in emergent processes of cellular aggregation. In contrast, mechanotactic signaling has been relatively overlooked despite its potential for unique ways to artificially signal cells with the aim to effectively gain control over their motile behavior. The possibility of mimicking cellular mechanotactic signals offers a fascinating novel strategy to achieve targeted cell delivery for in vitro tissue growth if proven to be effective with mammalian cells. Using (i) optimal level of extracellular calcium ([Ca2+ ]ext mM) we found, (ii) controllable fluid shear stress of low magnitude (), and (iii) the ability to swiftly reverse flow direction (within one second), we are able to successfully signal Dictyostelium discoideum amoebae and trigger migratory responses with heretofore unreported control and precision. Specifically, we are able to systematically determine the mechanical input signal required to achieve any predetermined sequences of steps including straightforward motion, reversal and trapping. The mechanotactic cellular trapping is achieved for the first time and is associated with a stalling frequency of Hz for a reversing direction mechanostimulus, above which the cells are effectively trapped while maintaining a high level of directional sensing. The value of this frequency is very close to the stalling frequency recently reported for chemotactic cell trapping [Meier B, et al. (2011) Proc Natl Acad Sci USA 108:11417–11422], suggesting that the limiting factor may be the slowness of the internal chemically-based motility apparatus. PMID:25207940

  17. The control of specificity in guard cell signal transduction

    PubMed Central

    Hetherington, A. M.

    1998-01-01

    Stomatal guard cells have proven to be an attractive system for dissecting the mechanisms of stimulus-response coupling in plants. In this review we focus on the intracellular signal transduction pathways by which extracellular signals bring about closure and opening of the stomatal pore. It is proposed that guard cell signal transduction pathways may be organized into functional arrays or signalling cassettes that contain elements common to a number of converging signalling pathways. The purpose of these signalling cassettes may be to funnel extracellular signals down onto the ion transporters that control the fluxes of ions that underlie stomatal movements. Evidence is emerging that specificity in guard cell signalling may be, in part, encoded in complex spatio-temporal patterns of increases in the concentration of cytosolic-free calcium ([Ca2+]cyt). It is suggested that oscillations in [Ca2+]cyt may generate calcium signatures that encode information concerning the stimulus type and strength. New evidence is presented that suggests that these calcium signatures may integrate information when many stimuli are present.

  18. Physiological and Pharmacological Roles of FGF21 in Cardiovascular Diseases.

    PubMed

    Cheng, Peng; Zhang, Fangfang; Yu, Lechu; Lin, Xiufei; He, Luqing; Li, Xiaokun; Lu, Xuemian; Yan, Xiaoqing; Tan, Yi; Zhang, Chi

    2016-01-01

    Cardiovascular disease (CVD) is one of the most severe diseases in clinics. Fibroblast growth factor 21 (FGF21) is regarded as an important metabolic regulator playing a therapeutic role in diabetes and its complications. The heart is a key target as well as a source of FGF21 which is involved in heart development and also induces beneficial effects in CVDs. Our review is to clarify the roles of FGF21 in CVDs. Strong evidence showed that the development of CVDs including atherosclerosis, coronary heart disease, myocardial ischemia, cardiac hypertrophy, and diabetic cardiomyopathy is associated with serum FGF21 levels increase which was regarded as a compensatory response to induced cardiac protection. Furthermore, administration of FGF21 suppressed the above CVDs. Mechanistic studies revealed that FGF21 induced cardiac protection likely by preventing cardiac lipotoxicity and the associated oxidative stress, inflammation, and apoptosis. Normally, FGF21 induced therapeutic effects against CVDs via activation of the above kinases-mediated pathways by directly binding to the FGF receptors of the heart in the presence of β-klotho. However, recently, growing evidence showed that FGF21 induced beneficial effects on peripheral organs through an indirect way mediated by adiponectin. Therefore whether adiponectin is also involved in FGF21-induced cardiac protection still needs further investigation. PMID:27247947

  19. Physiological and Pharmacological Roles of FGF21 in Cardiovascular Diseases

    PubMed Central

    Cheng, Peng; Zhang, Fangfang; Yu, Lechu; Lin, Xiufei; He, Luqing; Li, Xiaokun; Lu, Xuemian; Yan, Xiaoqing; Tan, Yi; Zhang, Chi

    2016-01-01

    Cardiovascular disease (CVD) is one of the most severe diseases in clinics. Fibroblast growth factor 21 (FGF21) is regarded as an important metabolic regulator playing a therapeutic role in diabetes and its complications. The heart is a key target as well as a source of FGF21 which is involved in heart development and also induces beneficial effects in CVDs. Our review is to clarify the roles of FGF21 in CVDs. Strong evidence showed that the development of CVDs including atherosclerosis, coronary heart disease, myocardial ischemia, cardiac hypertrophy, and diabetic cardiomyopathy is associated with serum FGF21 levels increase which was regarded as a compensatory response to induced cardiac protection. Furthermore, administration of FGF21 suppressed the above CVDs. Mechanistic studies revealed that FGF21 induced cardiac protection likely by preventing cardiac lipotoxicity and the associated oxidative stress, inflammation, and apoptosis. Normally, FGF21 induced therapeutic effects against CVDs via activation of the above kinases-mediated pathways by directly binding to the FGF receptors of the heart in the presence of β-klotho. However, recently, growing evidence showed that FGF21 induced beneficial effects on peripheral organs through an indirect way mediated by adiponectin. Therefore whether adiponectin is also involved in FGF21-induced cardiac protection still needs further investigation. PMID:27247947

  20. Hybrid optical/electronic signal processor for laser radar signals in fire control systems

    NASA Astrophysics Data System (ADS)

    Findley, George B., Jr.; Anderson, Christopher S.; Townley, S. K.; Pascale, Michael J.; Watson, Lee V.; Jenkinson, Howard A.

    1992-07-01

    This paper reports on the development of a hybrid optical/electronic signal processor for laser radar signals in fire control applications. The breadboard system being developed consists of three subsystems: (1) a signal generator producing target-representative signals, (2) the signal processor consisting of a radiometric channel and a Doppler channel, and (3) a data acquisition, analysis, and display subsystem. The radiometric channel provides target ladar cross section (LCS) resolved in crossrange, while the Doppler channel provides target radial velocity, also resolved in crossrange. Data from the two channels is fused and processed within the data analysis subsystem. Results are to be displayed in near real-time. The breadboard system will be used to demonstrate the capabilities of hybrid signal processor technology and to investigate processing laser radar returns for noncooperative target recognition, target orientation determination, and target trajectory estimation functions. It is anticipated that these functions will enhance the effectiveness of advanced fire control systems in future helicopters and ground vehicles.

  1. Tunable Signal Processing through a Kinase Control Cycle: the IKK Signaling Node

    PubMed Central

    Behar, Marcelo; Hoffmann, Alexander

    2013-01-01

    The transcription factor NFκB, a key component of the immune system, shows intricate stimulus-specific temporal dynamics. Those dynamics are thought to play a role in controlling the physiological response to cytokines and pathogens. Biochemical evidence suggests that the NFκB inducing kinase, IKK, a signaling hub onto which many signaling pathways converge, is regulated via a regulatory cycle comprising a poised, an active, and an inactive state. We hypothesize that it operates as a modulator of signal dynamics, actively reshaping the signals generated at the receptor proximal level. Here we show that a regulatory cycle can function in at least three dynamical regimes, tunable by regulating a single kinetic parameter. In particular, the simplest three-state regulatory cycle can generate signals with two well-defined phases, each with distinct coding capabilities in terms of the information they can carry about the stimulus. We also demonstrate that such a kinase cycle can function as a signal categorizer classifying diverse incoming signals into outputs with a limited set of temporal activity profiles. Finally, we discuss the extension of the results to other regulatory motifs that could be understood in terms of the regimes of the three-state cycle. PMID:23823243

  2. Integration and Modulation of Intercellular Signaling Underlying Blood Flow Control

    PubMed Central

    Segal, Steven S.

    2015-01-01

    Vascular resistance networks control tissue blood flow in concert with regulating arterial perfusion pressure. In response to increased metabolic demand, vasodilation arising in arteriolar networks ascends to encompass proximal feed arteries. By reducing resistance upstream, ascending vasodilation (AVD) increases blood flow into the microcirculation. Once initiated [e.g., through local activation of K+ channels in endothelial cells (ECs)], hyperpolarization is conducted through gap junctions along the endothelium. Via EC projections through the internal elastic lamina, hyperpolarization spreads into the surrounding smooth muscle cells (SMCs) through myoendothelial gap junctions (MEGJs) to promote their relaxation. Intercellular signaling through electrical signal transmission (i.e., cell-to-cell conduction) can thereby coordinate vasodilation along and among the branches of microvascular resistance networks. Perivascular sympathetic nerve fibers course through the adventitia and release norepinephrine to stimulate SMCs via α-adrenoreceptors to produce contraction. In turn, SMCs can signal ECs through MEGJs to activate K+ channels and attenuate sympathetic vasoconstriction. Activation of K+ channels along the endothelium will dissipate electrical signal transmission and inhibit AVD, thereby restricting blood flow into the microcirculation while maintaining peripheral resistance and perfusion pressure. This review explores the origins and nature of intercellular signaling governing blood flow control in skeletal muscle with respect to the interplay between AVD and sympathetic innervation. Whereas these interactions are integral to physical daily activity and athletic performance, resolving the interplay between respective signaling events provides insight into how selective interventions can improve tissue perfusion and oxygen delivery during vascular disease. PMID:26368324

  3. Therapeutic effect of CNP on renal osteodystrophy by antagonizing the FGF-23/MAPK pathway.

    PubMed

    Hu, Peng; Huang, Bao Yu; Xia, Xun; Xuan, Qiang; Hu, Bo; Qin, Yuan Han

    2016-01-01

    Renal osteodystrophy (ROD) is highly prevalent in chronic kidney disease (CKD). Because most patients with ROD are asymptomatic in the early stage and bone biopsy remains not a routine procedure in many clinical settings; therefore, several biochemical parameters may help to identify the existence of ROD. C-type natriuretic peptide (CNP) is considered as a positive regulator of bone formation. Both urinary excretion and renal expression of CNP are markedly up-regulated in the early stages of CKD, whereas they are still progressively declined accompanied by CKD progression, which invites speculation that the progressive decline of CNP may contribute, in part, to the pathogenesis of ROD. In addition, fibroblast growth factor (FGF)-23 is a bone-derived endocrine regulator of phosphate homeostasis. The elevation of serum FGF-23 has been recognized as a common feature in CKD to maintain normophosphatemia at the expense of declining 1,25-dihydroxyvitamin D values. Since the effects of CNP and FGF-23 on bone formation appear to oppose each other, it is reasonable to propose a direct interaction of their signaling pathways during the progression of ROD. CNP and FGF-23 act through a close or reciprocal pathway and are in agreement with recent studies demonstrating a down-regulatory role of the mitogen-activated protein kinase activity by CNP. The specific node may act at the level of RAF-1 through the activation of cyclic guanosine monophosphate-dependent protein kinases II. PMID:26459742

  4. The Antitumor Effect of Gekko Sulfated Glycopeptide by Inhibiting bFGF-Induced Lymphangiogenesis

    PubMed Central

    Ding, Xiu-Li; Man, Ya-Nan; Hao, Jian; Zhu, Cui-Hong; Liu, Chang; Yang, Xue

    2016-01-01

    Objective. To study the antilymphangiogenesis effect of Gekko Sulfated Glycopeptide (GSPP) on human lymphatic endothelial cells (hLECs). Methods. MTS was conducted to confirm the antiproliferation effect of GSPP on hLECs; flow cytometry was employed to detect hLECs cycle distribution; the antimigration effect of GSPP on hLECs was investigated by wound healing experiment and transwell experiment; tube formation assay was used to examine its inhibitory effect on the lymphangiogenesis; western blotting was conducted to detect the expression of extracellular signal-regulated kinase1/2 (Erk1/2) and p-Erk1/2 after GSPP and basic fibroblast growth factor (bFGF) treatment. Nude mice models were established to investigate the antitumor effect of GSPP in vivo. Decreased lymphangiogenesis caused by GSPP in vivo was verified by immunohistochemical staining. Results. In vitro, GSPP (10 μg/mL, 100 μg/mL) significantly inhibited bFGF-induced hLECs proliferation, migration, and tube-like structure formation (P < 0.05) and antagonized the phosphorylation activation of Erk1/2 induced by bFGF. In vivo, GSPP treatment (200 mg/kg/d) not only inhibited the growth of colon carcinoma, but also inhibited the tumor lymphangiogenesis. Conclusion. GSPP possesses the antitumor ability by inhibiting bFGF-inducing lymphangiogenesis in vitro and in vivo, which may further inhibit tumor lymphatic metastasis. PMID:27190997

  5. The Antitumor Effect of Gekko Sulfated Glycopeptide by Inhibiting bFGF-Induced Lymphangiogenesis.

    PubMed

    Ding, Xiu-Li; Man, Ya-Nan; Hao, Jian; Zhu, Cui-Hong; Liu, Chang; Yang, Xue; Wu, Xiong-Zhi

    2016-01-01

    Objective. To study the antilymphangiogenesis effect of Gekko Sulfated Glycopeptide (GSPP) on human lymphatic endothelial cells (hLECs). Methods. MTS was conducted to confirm the antiproliferation effect of GSPP on hLECs; flow cytometry was employed to detect hLECs cycle distribution; the antimigration effect of GSPP on hLECs was investigated by wound healing experiment and transwell experiment; tube formation assay was used to examine its inhibitory effect on the lymphangiogenesis; western blotting was conducted to detect the expression of extracellular signal-regulated kinase1/2 (Erk1/2) and p-Erk1/2 after GSPP and basic fibroblast growth factor (bFGF) treatment. Nude mice models were established to investigate the antitumor effect of GSPP in vivo. Decreased lymphangiogenesis caused by GSPP in vivo was verified by immunohistochemical staining. Results. In vitro, GSPP (10 μg/mL, 100 μg/mL) significantly inhibited bFGF-induced hLECs proliferation, migration, and tube-like structure formation (P < 0.05) and antagonized the phosphorylation activation of Erk1/2 induced by bFGF. In vivo, GSPP treatment (200 mg/kg/d) not only inhibited the growth of colon carcinoma, but also inhibited the tumor lymphangiogenesis. Conclusion. GSPP possesses the antitumor ability by inhibiting bFGF-inducing lymphangiogenesis in vitro and in vivo, which may further inhibit tumor lymphatic metastasis. PMID:27190997

  6. Accelerated wound closure of pressure ulcers in aged mice by chitosan scaffolds with and without bFGF.

    PubMed

    Park, Chan J; Clark, Sherrie G; Lichtensteiger, Carol A; Jamison, Russell D; Johnson, Amy J Wagoner

    2009-07-01

    Pressure ulcers are a significant healthcare concern, especially for elderly populations. Our work served to ameliorate the chronicity of these ulcers by addressing ischemia-reperfusion injury mediated by neutrophils and the concomitant loss of vasculature in these wounds. To this end, chitosan scaffolds loaded with basic fibroblast growth factor (bFGF) contained in gelatin microparticles were developed and tested for clinical relevance in an aged mouse model. Pressure ulcers were induced in aged mice, and efficacy of treatment was assessed. On days 3 and 7, both chitosan and chitosan-bFGF scaffolds significantly accelerated wound closure compared to gauze control. By day 10, all wounds achieved similar closure. Delivery and angiogenic function of bFGF was verified through ELISA and histology. Elevated neutrophil levels were observed in chitosan and chitosan-bFGF groups. Since neutrophil elastase contributes to the proteolytic environments of pressure ulcers, the effect of chitosan on elastase was assessed. In vitro, chitosan inhibited elastase activity. In vivo, elastase protein levels in wounds were reduced with chitosan-bFGF scaffolds by day 10. These results suggest that chitosan is an effective material for growth factor delivery and can help to heal chronic ulcers. Collectively, our data show that chitosan-bFGF scaffolds are effective in accelerating wound closure of pressure ulcers in aged animals.

  7. Entrapment of basic fibroblast growth factor (bFGF) in a succinylated chitosan nanoparticle delivery system and release profile.

    PubMed

    Butko, Alison; Bonat Celli, Giovana; Paulson, Allan; Ghanem, Amyl

    2016-07-01

    Basic fibroblast growth factor (bFGF) helps to regulate the proliferation and migration of fibroblasts, the proliferation of endothelial cells, and aids the development of angiogenesis. Its in vivo half-life is on the order of minutes due to extensive degradation and inactivation, which could be potentially reduced by controlled release vehicles. In this study, bFGF was entrapped into chitosan (CS) and N-succinyl-chitosan (SC) nanoparticles, with and without heparin, at two levels of initial loading, followed by further characterization of the particles. Release studies were conducted using radiolabeled bFGF-loaded nanoparticles. Both types of nanoparticles loaded similar amounts of bFGF (60.2 and 68.6% for CS and SC, respectively). The release profile varied greatly among the samples, and a burst release was observed in most cases, with the release amount approaching its final value in the first 6 h. The final amount released varied from 1.5 to 18% of the amount of bFGF-entrapped. The concomitant encapsulation of heparin and the use of SC as a nanoparticle matrix contributed to the largest amount of bFGF release (18%) over the time investigated.

  8. Preface: cardiac control pathways: signaling and transport phenomena.

    PubMed

    Sideman, Samuel

    2008-03-01

    Signaling is part of a complex system of communication that governs basic cellular functions and coordinates cellular activity. Transfer of ions and signaling molecules and their interactions with appropriate receptors, transmembrane transport, and the consequent intracellular interactions and functional cellular response represent a complex system of interwoven phenomena of transport, signaling, conformational changes, chemical activation, and/or genetic expression. The well-being of the cell thus depends on a harmonic orchestration of all these events and the existence of control mechanisms that assure the normal behavior of the various parameters involved and their orderly expression. The ability of cells to sustain life by perceiving and responding correctly to their microenvironment is the basis for development, tissue repair, and immunity, as well as normal tissue homeostasis. Natural deviations, or human-induced interference in the signaling pathways and/or inter- and intracellular transport and information transfer, are responsible for the generation, modulation, and control of diseases. The present overview aims to highlight some major topics of the highly complex cellular information transfer processes and their control mechanisms. Our goal is to contribute to the understanding of the normal and pathophysiological phenomena associated with cardiac functions so that more efficient therapeutic modalities can be developed. Our objective in this volume is to identify and enhance the study of some basic passive and active physical and chemical transport phenomena, physiological signaling pathways, and their biological consequences.

  9. Stress-induced glucocorticoids suppress the antisense molecular regulation of FGF-2 expression.

    PubMed

    Frank, Matthew G; Der-Avakian, Andre; Bland, Sondra T; Watkins, Linda R; Maier, Steven F

    2007-05-01

    Psychological stress can upregulate basic fibroblast growth factor (FGF-2) expression. Because glucocorticoids can also upregulate FGF-2 expression, the present studies investigated whether stress-induced glucocorticoids mediate the effects of stress on FGF-2. FGF-2 is regulated by an FGF-2 antisense (AS) molecular mechanism and so the present experiments also, for the first time, assessed the effects of stress on FGF-2-AS mRNA, as well as the mediating role of glucocorticoids. The effects of either escapable shock (ES) or yoked-inescapable tail shock (IS) on FGF-2 and FGF-2-AS were determined. To test whether glucocorticoids mediate the effect of stress on FGF-2 and FGF-2-AS, animals were pretreated with temporary corticosterone (CORT) synthesis inhibitors and exposed to IS. To test whether glucocorticoids are sufficient to modulate FGF-2 and FGF-2-AS mRNA, animals were injected with CORT and mRNA measured. ES and IS similarly downregulated FGF-2-AS mRNA at 0 h post-stress and upregulated FGF-2 mRNA 2 h post-stress. Inhibition of CORT synthesis abrogated the effect of IS on both FGF-2-AS and FGF-2 mRNA. Exogenous CORT mimicked the effects of ES and IS on FGF-2, but not FGF-2-AS mRNA. The present study demonstrates that glucocorticoids mediate the effects of stress on FGF-2 and FGF-2-AS.

  10. Associations of Plasma FGF2 Levels and Polymorphisms in the FGF2 Gene with Obesity Phenotypes in Han Chinese Population

    PubMed Central

    Hao, Ruo-Han; Guo, Yan; Dong, Shan-Shan; Weng, Gai-Zhi; Yan, Han; Zhu, Dong-Li; Chen, Xiao-Feng; Chen, Jia-Bin; Yang, Tie-Lin

    2016-01-01

    Obesity is highly heritable, but the specific genes influencing obesity related traits are largely unknown. Fibroblast growth factor 2 (FGF2) could influence adipocyte differentiation. However, the association of FGF2 polymorphisms and obesity remains unclear. This study aimed to investigate the associations of both the plasma FGF2 levels and SNPs in FGF2 gene with obesity phenotypes in Han Chinese populations. Plasma FGF2 levels were measured and subjected to association analyses in 62 subjects. Eleven SNPs in FGF2 were genotyped and tested for associations in a discovery sample of 1,300 subjects. SNPs significantly associated with obesity were subjected to replication in another independent sample of 1,035 subjects. We found that plasma FGF2 levels were positively correlated with fat mass (P = 0.010). Association analyses in the discovery sample identified three SNPs (rs1449683, rs167428, rs308442) significantly associated with fat mass after multiple testing adjustments (P < 0.0045). Subsequent replication study successfully validated one SNP (rs167428) associated with fat mass (Pcombine = 3.46 × 10−5). eQTL analyses revealed that SNPs associated with obesity also affected FGF2 expression. Our findings suggested that high plasma FGF2 level correlated with increased risk of obesity, and FGF2 gene polymorphisms could affect individual variances of obesity in Han Chinese population. PMID:26879180

  11. Selection of a novel FGF23-binding peptide antagonizing the inhibitory effect of FGF23 on phosphate uptake.

    PubMed

    Huang, Tao; Lin, Xiaomian; Li, Quchou; Luo, Wu; Song, Li; Tan, Xiangpeng; Wang, Wenhui; Li, Xiaokun; Wu, Xiaoping

    2015-04-01

    Fibroblast growth factor 23 (FGF23) is a bone-derived endocrine regulator of phosphate homeostasis and has been considered as a potential therapeutic target for hypophosphatemic disorders. Herein, we isolated a novel FGF23-binding peptide by screening a phage display library with FGF23180-205, the minimal epitope of FGF23 binding to the binary fibroblast growth factor receptor (FGFR)-Klotho complex. The corresponding peptide (referred to as 23-b6) showed high homology to the immunoglobulin-like (Ig-like) domain III (D3) of FGFR1c, the predominant receptor mediating the phosphaturic activity of FGF23. The 23-b6 peptide and panning target FGF23180-205 carried opposite charges and shared similar hydrophilic profiles. Functional analysis indicated that synthetic 23-b6 peptide exhibited antagonistic effect on the inhibition of phosphate uptake by FGF23 in opossum kidney cells (OK cells). The mechanisms of 23-b6 peptide impairing the bioactivity of FGF23 involved blockade of the activation of Erk cascade and up-regulation of NaPi-2a and NaPi-2c expression in OK cells. Our results demonstrate that the 23-b6 peptide is a potent FGF23 antagonist with increased effect on phosphate uptake in kidney cells and might have therapeutic potentials in hypophosphatemic disorders characterized by an abnormally high level of FGF23. PMID:25515813

  12. Cellular metabolic and autophagic pathways: traffic control by redox signaling.

    PubMed

    Dodson, Matthew; Darley-Usmar, Victor; Zhang, Jianhua

    2013-10-01

    It has been established that the key metabolic pathways of glycolysis and oxidative phosphorylation are intimately related to redox biology through control of cell signaling. Under physiological conditions glucose metabolism is linked to control of the NADH/NAD redox couple, as well as providing the major reductant, NADPH, for thiol-dependent antioxidant defenses. Retrograde signaling from the mitochondrion to the nucleus or cytosol controls cell growth and differentiation. Under pathological conditions mitochondria are targets for reactive oxygen and nitrogen species and are critical in controlling apoptotic cell death. At the interface of these metabolic pathways, the autophagy-lysosomal pathway functions to maintain mitochondrial quality and generally serves an important cytoprotective function. In this review we will discuss the autophagic response to reactive oxygen and nitrogen species that are generated from perturbations of cellular glucose metabolism and bioenergetic function.

  13. Computational models of signalling networks for non-linear control.

    PubMed

    Fuente, Luis A; Lones, Michael A; Turner, Alexander P; Stepney, Susan; Caves, Leo S; Tyrrell, Andy M

    2013-05-01

    Artificial signalling networks (ASNs) are a computational approach inspired by the signalling processes inside cells that decode outside environmental information. Using evolutionary algorithms to induce complex behaviours, we show how chaotic dynamics in a conservative dynamical system can be controlled. Such dynamics are of particular interest as they mimic the inherent complexity of non-linear physical systems in the real world. Considering the main biological interpretations of cellular signalling, in which complex behaviours and robust cellular responses emerge from the interaction of multiple pathways, we introduce two ASN representations: a stand-alone ASN and a coupled ASN. In particular we note how sophisticated cellular communication mechanisms can lead to effective controllers, where complicated problems can be divided into smaller and independent tasks.

  14. Villification in the mouse: Bmp signals control intestinal villus patterning.

    PubMed

    Walton, Katherine D; Whidden, Mark; Kolterud, Åsa; Shoffner, Suzanne K; Czerwinski, Michael J; Kushwaha, Juhi; Parmar, Nishita; Chandhrasekhar, Deepa; Freddo, Andrew M; Schnell, Santiago; Gumucio, Deborah L

    2016-02-01

    In the intestine, finger-like villi provide abundant surface area for nutrient absorption. During murine villus development, epithelial Hedgehog (Hh) signals promote aggregation of subepithelial mesenchymal clusters that drive villus emergence. Clusters arise first dorsally and proximally and spread over the entire intestine within 24 h, but the mechanism driving this pattern in the murine intestine is unknown. In chick, the driver of cluster pattern is tensile force from developing smooth muscle, which generates deep longitudinal epithelial folds that locally concentrate the Hh signal, promoting localized expression of cluster genes. By contrast, we show that in mouse, muscle-induced epithelial folding does not occur and artificial deformation of the epithelium does not determine the pattern of clusters or villi. In intestinal explants, modulation of Bmp signaling alters the spatial distribution of clusters and changes the pattern of emerging villi. Increasing Bmp signaling abolishes cluster formation, whereas inhibiting Bmp signaling leads to merged clusters. These dynamic changes in cluster pattern are faithfully simulated by a mathematical model of a Turing field in which an inhibitor of Bmp signaling acts as the Turing activator. In vivo, genetic interruption of Bmp signal reception in either epithelium or mesenchyme reveals that Bmp signaling in Hh-responsive mesenchymal cells controls cluster pattern. Thus, unlike in chick, the murine villus patterning system is independent of muscle-induced epithelial deformation. Rather, a complex cocktail of Bmps and Bmp signal modulators secreted from mesenchymal clusters determines the pattern of villi in a manner that mimics the spread of a self-organizing Turing field. PMID:26721501

  15. Clinical Significance of FGF-23 in Patients with CKD

    PubMed Central

    Russo, Domenico; Battaglia, Yuri

    2011-01-01

    FGF23 is a bone-derived hormone that plays an important role in the regulation of phosphate and 1,25-dihydroxy vitamin D metabolism. FGF23 principally acts in the kidney to induce urinary phosphate excretion and suppress 1,25-dihydroxyvitamin D synthesis in the presence of FGF receptor 1 (FGFR1) and its coreceptor Klotho. In patients with chronic kidney disease (CKD), circulating FGF23 levels are progressively increased to compensate for persistent phosphate retention, but this results in reduced renal production of 1,25-dihydroxyvitamin D and leads to hypersecretion of parathyroid hormone. Furthermore, FGF23 is associated with vascular dysfunction, atherosclerosis, and left ventricular hypertrophy. This paper summarizes the role of FGF23 in the pathogenesis of mineral, bone, and cadiovascular disorders in CKD. PMID:21603159

  16. A molecular logical switching beacon controlled by thiolated DNA signals.

    PubMed

    Zhang, Cheng; Wu, Liuqing; Yang, Jing; Liu, Shi; Xu, Jin

    2013-12-14

    A logical switching MB is established, with an "ON/OFF" switching function. In this study, thiolated DNA can participate as a switching controller to regulate the fluorescent increments of other DNA input signals. Assisted by gold nanoparticles and DNA branch migration, one and two-switch systems have been achieved.

  17. Relationships between digital signal processing and control and estimation theory

    NASA Technical Reports Server (NTRS)

    Willsky, A. S.

    1978-01-01

    Research areas associated with digital signal processing and control and estimation theory are identified. Particular attention is given to image processing, system identification problems (parameter identification, linear prediction, least squares, Kalman filtering), stability analyses (the use of the Liapunov theory, frequency domain criteria, passivity), and multiparameter systems, distributed processes, and random fields.

  18. Molecular Signaling Pathways Controlling Vascular Tube Morphogenesis and Pericyte-Induced Tube Maturation in 3D Extracellular Matrices.

    PubMed

    Bowers, S L K; Norden, P R; Davis, G E

    2016-01-01

    During capillary network formation, ECs establish interconnecting tubes with defined lumens that reside within vascular guidance tunnels (physical spaces generated during EC tubulogenesis). Pericytes are recruited to EC tubes within these tunnels and capillary basement membrane deposition occurs to facilitate tube maturation. Here, we discuss molecular mechanisms controlling EC tubulogenesis demonstrating the involvement of integrins, MT1-MMP, extracellular matrix, Cdc42, Rac1, Rac2, k-Ras, Rap1b, and key downstream effectors including Pak2, Pak4, IQGAP1, MRCKβ, and Rasip1. These molecules activate kinase cascades controlling EC tube formation, in conjunction with growth factor receptor signaling, which involve PKCɛ, Src family, Raf, Mek, and Erk kinases. These molecules and signaling cascades stimulate EC lumen and tube formation by: regulating MT-MMP-dependent lumen expansion and vascular guidance tunnel formation; generation of intracellular vacuoles/vesicles to create EC apical membranes; and establishing cytoskeletal polarity with acetylated tubulin distributed subapically (and F-actin basally) to facilitate vacuole trafficking/fusion in a polarized, perinuclear region. Using defined serum-free models, we have demonstrated that human EC tubulogenesis and EC-pericyte tube coassembly requires five exogenously applied growth factors which are SCF, IL-3, SDF-1α, FGF-2, and insulin (Factors). Also, we have demonstrated that EC-derived PDGF-BB and HB-EGF are necessary for pericytes to proliferate, recruit to tubes, and induce basement membrane assembly. Finally, we have shown that VEGF fails to directly stimulate EC tubulogenesis. In contrast, it acts as an upstream EC primer of downstream "Factor"-induced tubulogenic and EC-pericyte tube coassembly by upregulating c-Kit, IL-3Rα, and CXCR4 as well as PDGF-BB and HB-EGF expression. PMID:27451100

  19. The activation of fibroblast growth factors (FGFs) by glycosaminoglycans: influence of the sulfation pattern on the biological activity of FGF-1.

    PubMed

    Angulo, Jesús; Ojeda, Rafael; de Paz, José-Luis; Lucas, Ricardo; Nieto, Pedro M; Lozano, Rosa M; Redondo-Horcajo, Mariano; Giménez-Gallego, Guillermo; Martín-Lomas, Manuel

    2004-01-01

    Six synthetic heparin-like oligosaccharides have been used to investigate the effect of the oligosaccharide sulfation pattern on the stimulation of acidic fibroblast growth factor (FGF-1) induced mitogenesis signaling and the biological significance of FGF-1 trans dimerization in the FGF-1 activation process. It has been found that some molecules with a sulfation pattern that does not contain the internal trisaccharide motif, which has been proposed for high affinity for FGF-1, stimulate FGF-1 more efficiently than those with the structure of the regular region of heparin. In contrast to regular region oligosaccharides, in which the sulfate groups are distributed on both sides of their helical three-dimensional structures, the molecules containing this particular sulfation pattern display the sulfate groups only on one side of the helix. These results and the fact that these oligosaccharides do not promote FGF-1 dimerization according to sedimentation-equilibrium analysis, confirm the importance of negative-charge distribution in the activation process and strongly suggest that FGF dimerization is not a general and absolute requirement for biological activity. PMID:14695513

  20. Inhibition of Endoplasmic Reticulum Stress is Involved in the Neuroprotective Effect of bFGF in the 6-OHDA-Induced Parkinson’s Disease Model

    PubMed Central

    Cai, Pingtao; Ye, Jingjing; Zhu, Jingjing; Liu, Dan; Chen, Daqing; Wei, Xiaojie; Johnson, Noah R.; Wang, Zhouguang; Zhang, Hongyu; Cao, Guodong; Xiao, Jian; Ye, Junming; Lin, Li

    2016-01-01

    Parkinson's disease (PD) is a progressive neurodegenerative disorder with complicated pathophysiologic mechanisms. Endoplasmic reticulum (ER) stress appears to play a critical role in the progression of PD. We demonstrated that basic fibroblast growth factor (bFGF), as a neurotropic factor, inhibited ER stress-induced neuronal cell apoptosis and that 6-hydroxydopamine (6-OHDA)-induced ER stress was involved in the progression of PD in rats. bFGF administration improved motor function recovery, increased tyrosine hydroxylase (TH)-positive neuron survival, and upregulated the levels of neurotransmitters in PD rats. The 6-OHDA-induced ER stress response proteins were inhibited by bFGF treatment. Meanwhile, bFGF also increased expression of TH. The administration of bFGF activated the downstream signals PI3K/Akt and Erk1/2 in vivo and in vitro. Inhibition of the PI3K/Akt and Erk1/2 pathways by specific inhibitors partially reduced the protective effect of bFGF. This study provides new insight towards bFGF translational drug development for PD involving the regulation of ER stress. PMID:27493838

  1. TGF-β1 and FGF2 stimulate the epithelial-mesenchymal transition of HERS cells through a MEK-dependent mechanism.

    PubMed

    Chen, Jie; Chen, Guoqing; Yan, Zhiling; Guo, Yongwen; Yu, Mei; Feng, Lian; Jiang, Zongting; Guo, Weihua; Tian, Weidong

    2014-11-01

    Hertwig's epithelial root sheath (HERS) cells participate in cementum formation through epithelial-mesenchymal transition (EMT). Previous studies have shown that transforming growth factor beta 1 (TGF-β1) and fibroblast growth factor 2 (FGF2) are involved in inducing EMT. However, their involvement in HERS cell transition remains elusive. In this study, we confirmed that HERS cells underwent EMT during the formation of acellular cementum. We found that both TGF-β1 and FGF2 stimulated the EMT of HERS cells. The TGF-β1 regulated the differentiation of HERS cells into periodontal ligament fibroblast-like cells, and FGF2 directed the differentiation of HERS cells into cementoblast-like cells. Treatment with TGF-β1 or FGF2 inhibitor could effectively suppress HERS cells differential transition. Combined stimulation with both TGF-β1 and FGF-2 did not synergistically accelerate the EMT of HERS. Moreover, TGF-β1/FGF2-mediated EMT of HERS cells was reversed by the MEK1/2 inhibitor U0126. These results suggest that TGF-β1 and FGF2 induce the EMT of HERS through a MAPK/ERK-dependent signaling pathway. They also exert their different tendency of cellular differentiation during tooth root formation. This study further expands our knowledge of tooth root morphogenesis and provides more evidence for the use of alternative cell sources in clinical treatment of periodontal diseases. PMID:24610459

  2. Inhibition of Endoplasmic Reticulum Stress is Involved in the Neuroprotective Effect of bFGF in the 6-OHDA-Induced Parkinson's Disease Model.

    PubMed

    Cai, Pingtao; Ye, Jingjing; Zhu, Jingjing; Liu, Dan; Chen, Daqing; Wei, Xiaojie; Johnson, Noah R; Wang, Zhouguang; Zhang, Hongyu; Cao, Guodong; Xiao, Jian; Ye, Junming; Lin, Li

    2016-08-01

    Parkinson's disease (PD) is a progressive neurodegenerative disorder with complicated pathophysiologic mechanisms. Endoplasmic reticulum (ER) stress appears to play a critical role in the progression of PD. We demonstrated that basic fibroblast growth factor (bFGF), as a neurotropic factor, inhibited ER stress-induced neuronal cell apoptosis and that 6-hydroxydopamine (6-OHDA)-induced ER stress was involved in the progression of PD in rats. bFGF administration improved motor function recovery, increased tyrosine hydroxylase (TH)-positive neuron survival, and upregulated the levels of neurotransmitters in PD rats. The 6-OHDA-induced ER stress response proteins were inhibited by bFGF treatment. Meanwhile, bFGF also increased expression of TH. The administration of bFGF activated the downstream signals PI3K/Akt and Erk1/2 in vivo and in vitro. Inhibition of the PI3K/Akt and Erk1/2 pathways by specific inhibitors partially reduced the protective effect of bFGF. This study provides new insight towards bFGF translational drug development for PD involving the regulation of ER stress.

  3. Detection of FGF15 in Plasma by Stable Isotope Standards and Capture by Anti-Peptide Antibodies (SISCAPA) and Targeted Mass Spectrometry

    PubMed Central

    Katafuchi, Takeshi; Esterházy, Daria; Lemoff, Andrew; Ding, Xunshan; Sondhi, Varun; Kliewer, Steven A.; Mirzaei, Hamid; Mangelsdorf, David J.

    2015-01-01

    SUMMARY Fibroblast growth factor 15 (FGF15) has been proposed as a postprandial hormone that signals from intestine to liver to regulate bile acid and carbohydrate homeostasis. However, detecting FGF15 in blood using conventional techniques has proven difficult. Here, we describe a stable isotope standards and capture by anti-peptide antibodies (SISCAPA) assay that combines immuno-enrichment with selected reaction monitoring (SRM) mass spectrometry to overcome this issue. Using this assay, we show that FGF15 circulates in plasma in an FXR and circadian rhythm-dependent manner at concentrations that activate its receptor. Consistent with the proposed endocrine role for FGF15 in liver, mice lacking hepatocyte expression of the obligate FGF15 co-receptor, β-Klotho, have increased bile acid synthesis and reduced glycogen storage despite having supraphysiological plasma FGF15 concentrations. Collectively, these data demonstrate that FGF15 functions as a hormone and highlight the utility of SISCAPA-SRM as a sensitive assay for detecting low abundance proteins in plasma. PMID:26039452

  4. The activation of fibroblast growth factors (FGFs) by glycosaminoglycans: influence of the sulfation pattern on the biological activity of FGF-1.

    PubMed

    Angulo, Jesús; Ojeda, Rafael; de Paz, José-Luis; Lucas, Ricardo; Nieto, Pedro M; Lozano, Rosa M; Redondo-Horcajo, Mariano; Giménez-Gallego, Guillermo; Martín-Lomas, Manuel

    2004-01-01

    Six synthetic heparin-like oligosaccharides have been used to investigate the effect of the oligosaccharide sulfation pattern on the stimulation of acidic fibroblast growth factor (FGF-1) induced mitogenesis signaling and the biological significance of FGF-1 trans dimerization in the FGF-1 activation process. It has been found that some molecules with a sulfation pattern that does not contain the internal trisaccharide motif, which has been proposed for high affinity for FGF-1, stimulate FGF-1 more efficiently than those with the structure of the regular region of heparin. In contrast to regular region oligosaccharides, in which the sulfate groups are distributed on both sides of their helical three-dimensional structures, the molecules containing this particular sulfation pattern display the sulfate groups only on one side of the helix. These results and the fact that these oligosaccharides do not promote FGF-1 dimerization according to sedimentation-equilibrium analysis, confirm the importance of negative-charge distribution in the activation process and strongly suggest that FGF dimerization is not a general and absolute requirement for biological activity.

  5. FGF-4 gene therapy GENERX--Collateral Therapeutics.

    PubMed

    2002-01-01

    Collateral Therapeutics and Schering AG in Germany are developing a gene therapy product, GENERX for coronary artery disease. Based on the terms of the agreement, Schering or its affliates will be responsible for conducting and financing phase II/III clinical trials which are currently underway in the US and Europe. In particular, Berlex Labs (the US subsidiary of Schering AG), is involved in developing the gene therapy in the US. GENERX is an angiogenic gene therapy which triggers the production of a protein that stimulates new blood vessel growth providing an alternative route for blood to bypass clogged and blocked arteries in the heart. GENERX involves a one-time, non-surgical delivery of an adenovirus vector containing the human fibroblast growth factor-4 (FGF-4) into coronary arteries via a standard catheter. The FGF-4 gene was licensed from New York University. Collateral Therapeutics has been granted a US patent for "gene transfer-mediated angiogenesis therapy" for the nonsurgical administration of angiogenic genes for coronary and peripheral vascular disease. The patented technology has been licensed from the University of California. Collateral and Berlex have initiated pivotal phase IIb/III trials with GENERX in the US and Europe. The US-based study will evaluate the safety and efficacy of GENERX in patients with stable exertional angina due to coronary artery disease. The European-based study will evaluate patients with advanced coronary artery disease who are not considered candidates for interventions such as angioplasty and bypass surgery and/or patients who are unlikely to have positive outcomes from such interventions. Both studies, of a multicentre, randomised, double-blind and placebo-controlled design, will evaluate 2 dose levels of GENERX which will be non-surgically administered to the heart via intracoronary infusion through a standard cardiac catheter. Collateral also plans to develop a non-surgical gene therapy product using the FGF-4 gene

  6. An essential role for maternal control of Nodal signaling

    PubMed Central

    Kumari, Pooja; Gilligan, Patrick C; Lim, Shimin; Tran, Long Duc; Winkler, Sylke; Philp, Robin; Sampath, Karuna

    2013-01-01

    Growth factor signaling is essential for pattern formation, growth, differentiation, and maintenance of stem cell pluripotency. Nodal-related signaling factors are required for axis formation and germ layer specification from sea urchins to mammals. Maternal transcripts of the zebrafish Nodal factor, Squint (Sqt), are localized to future embryonic dorsal. The mechanisms by which maternal sqt/nodal RNA is localized and regulated have been unclear. Here, we show that maternal control of Nodal signaling via the conserved Y box-binding protein 1 (Ybx1) is essential. We identified Ybx1 via a proteomic screen. Ybx1 recognizes the 3’ untranslated region (UTR) of sqt RNA and prevents premature translation and Sqt/Nodal signaling. Maternal-effect mutations in zebrafish ybx1 lead to deregulated Nodal signaling, gastrulation failure, and embryonic lethality. Implanted Nodal-coated beads phenocopy ybx1 mutant defects. Thus, Ybx1 prevents ectopic Nodal activity, revealing a new paradigm in the regulation of Nodal signaling, which is likely to be conserved. DOI: http://dx.doi.org/10.7554/eLife.00683.001 PMID:24040511

  7. Immunolocalization of FGF-2 and VEGF in rat periodontal ligament during experimental tooth movement

    PubMed Central

    Salomão, Milene Freitas Lima; Reis, Sílvia Regina de Almeida; Vale, Vera Lúcia Costa; Machado, Cintia de Vasconcellos; Meyer, Roberto; Nascimento, Ivana Lucia Oliveira

    2014-01-01

    Objective This article aimed at identifying the expression of fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factor (VEGF) in the tension and pressure areas of rat periodontal ligament, in different periods of experimental orthodontic tooth movement. Methods An orthodontic force of 0.5 N was applied to the upper right first molar of 18 male Wistar rats for periods of 3 (group I), 7 (group II) and 14 days (group III). The counter-side first molar was used as a control. The animals were euthanized at the aforementioned time periods, and their maxillary bone was removed and fixed. After demineralization, the specimens were histologically processed and embedded in paraffin. FGF-2 and VEGF expressions were studied through immunohistochemistry and morphological analysis. Results The experimental side showed a higher expression of both FGF-2 and VEGF in all groups, when compared with the control side (P < 0.05). Statistically significant differences were also found between the tension and pressure areas in the experimental side. Conclusion Both FGF-2 and VEGF are expressed in rat periodontal tissue. Additionally, these growth factors are upregulated when orthodontic forces are applied, thereby suggesting that they play an important role in changes that occur in periodontal tissue during orthodontic movement. PMID:25162568

  8. Calcium Deficiency Reduces Circulating Levels of FGF23

    PubMed Central

    Rodriguez-Ortiz, María E.; Lopez, Ignacio; Muñoz-Castañeda, Juan R.; Martinez-Moreno, Julio M.; Ramírez, Alan Peralta; Pineda, Carmen; Canalejo, Antonio; Jaeger, Philippe; Aguilera-Tejero, Escolastico; Felsenfeld, Arnold; Almaden, Yolanda

    2012-01-01

    Fibroblast growth factor (FGF) 23 inhibits calcitriol production, which could exacerbate calcium deficiency or hypocalcemia unless calcium itself modulates FGF23 in this setting. In Wistar rats with normal renal function fed a diet low in both calcium and vitamin D, the resulting hypocalcemia was associated with low FGF23 despite high parathyroid hormone (PTH) and high calcitriol levels. FGF23 correlated positively with calcium and negatively with PTH. Addition of high dietary phosphorus to this diet increased FGF23 except in rats with hypocalcemia despite high PTH levels. In parathyroidectomized rats, an increase in dietary calcium for 10 days increased serum calcium, with an associated increase in FGF23, decrease in calcitriol, and no change in phosphorus. Also in parathyroidectomized rats, FGF23 increased significantly 6 hours after administration of calcium gluconate. Taken together, these results suggest that hypocalcemia reduces the circulating concentrations of FGF23. This decrease in FGF23 could be a response to avoid a subsequent reduction in calcitriol, which could exacerbate hypocalcemia. PMID:22581996

  9. Intrinsic FGF2 and FGF5 promotes angiogenesis of human aortic endothelial cells in 3D microfluidic angiogenesis system

    PubMed Central

    Seo, Ha-Rim; Jeong, Hyo Eun; Joo, Hyung Joon; Choi, Seung-Cheol; Park, Chi-Yeon; Kim, Jong-Ho; Choi, Ji-Hyun; Cui, Long-Hui; Hong, Soon Jun; Chung, Seok; Lim, Do-Sun

    2016-01-01

    The human body contains different endothelial cell types and differences in their angiogenic potential are poorly understood. We compared the functional angiogenic ability of human aortic endothelial cells (HAECs) and human umbilical vein endothelial cells (HUVECs) using a three-dimensional (3D) microfluidic cell culture system. HAECs and HUVECs exhibited similar cellular characteristics in a 2D culture system; however, in the 3D microfluidic angiogenesis system, HAECs exhibited stronger angiogenic potential than HUVECs. Interestingly, the expression level of fibroblast growth factor (FGF)2 and FGF5 under vascular endothelial growth factor (VEGF)-A stimulation was significantly higher in HAECs than in HUVECs. Moreover, small interfering RNA-mediated knockdown of FGF2 and FGF5 more significantly attenuated vascular sprouting induced from HAECs than HUVECs. Our results suggest that HAECs have greater angiogenic potential through FGF2 and FGF5 upregulation and could be a compatible endothelial cell type to achieve robust angiogenesis. PMID:27357248

  10. In search of cellular control: signal transduction in context

    NASA Technical Reports Server (NTRS)

    Ingber, D.

    1998-01-01

    The field of molecular cell biology has experienced enormous advances over the last century by reducing the complexity of living cells into simpler molecular components and binding interactions that are amenable to rigorous biochemical analysis. However, as our tools become more powerful, there is a tendency to define mechanisms by what we can measure. The field is currently dominated by efforts to identify the key molecules and sequences that mediate the function of critical receptors, signal transducers, and molecular switches. Unfortunately, these conventional experimental approaches ignore the importance of supramolecular control mechanisms that play a critical role in cellular regulation. Thus, the significance of individual molecular constituents cannot be fully understood when studied in isolation because their function may vary depending on their context within the structural complexity of the living cell. These higher-order regulatory mechanisms are based on the cell's use of a form of solid-state biochemistry in which molecular components that mediate biochemical processing and signal transduction are immobilized on insoluble cytoskeletal scaffolds in the cytoplasm and nucleus. Key to the understanding of this form of cellular regulation is the realization that chemistry is structure and hence, recognition of the the importance of architecture and mechanics for signal integration and biochemical control. Recent work that has unified chemical and mechanical signaling pathways provides a glimpse of how this form of higher-order cellular control may function and where paths may lie in the future.

  11. Digital signal processor control of scanned probe microscopes

    NASA Astrophysics Data System (ADS)

    Baselt, David R.; Clark, Steven M.; Youngquist, Michael G.; Spence, Charles F.; Baldeschwieler, John D.

    1993-07-01

    Digital signal processors have made it possible to control scanned probe microscopes using straightforward software emulations of analog circuits. Using a system consisting of a commercially available digital signal processor board interfaced to analog I/O, we have developed algorithms for self-optimizing feedback, raster generation (with hysteresis correction, sample tilt compensation, and scan rotation), lock-in detection, and automatic tip-sample approach. We also discuss an instruction parser that takes advantage of the digital architecture to allow automatic operation for extended periods.

  12. Fgf20 governs formation of primary and secondary dermal condensations in developing hair follicles

    PubMed Central

    Huh, Sung-Ho; Närhi, Katja; Lindfors, Päivi H.; Häärä, Otso; Yang, Lu; Ornitz, David M.; Mikkola, Marja L.

    2013-01-01

    In hair follicle development, a placode-derived signal is believed to induce formation of the dermal condensation, an essential component of ectodermal organs. However, the identity of this signal is unknown. Furthermore, although induction and patterning of hair follicles are intimately linked, it is not known whether the mesenchymal condensation is necessary for inducing the initial epithelial pattern. Here, we show that fibroblast growth factor 20 (Fgf20) is expressed in hair placodes and is induced by and functions downstream from epithelial ectodysplasin (Eda)/Edar and Wnt/β-Catenin signaling to initiate formation of the underlying dermal condensation. Fgf20 governs formation of primary and secondary dermal condensations in developing hair follicles and subsequent formation of guard, awl, and auchene hairs. Although primary dermal condensations are absent in Fgf20 mutant mice, a regular array of hair placodes is formed, demonstrating that the epithelial patterning process is independent of known histological and molecular markers of underlying mesenchymal patterns during the initial stages of hair follicle development. PMID:23431057

  13. Control of Intracellular Calcium Signaling as a Neuroprotective Strategy

    PubMed Central

    Duncan, R. Scott; Goad, Daryl L.; Grillo, Michael A.; Kaja, Simon; Payne, Andrew J.; Koulen, Peter

    2010-01-01

    Both acute and chronic degenerative diseases of the nervous system reduce the viability and function of neurons through changes in intracellular calcium signaling. In particular, pathological increases in the intracellular calcium concentration promote such pathogenesis. Disease involvement of numerous regulators of intracellular calcium signaling located on the plasma membrane and intracellular organelles has been documented. Diverse groups of chemical compounds targeting ion channels, G-protein coupled receptors, pumps and enzymes have been identified as potential neuroprotectants. The present review summarizes the discovery, mechanisms and biological activity of neuroprotective molecules targeting proteins that control intracellular calcium signaling to preserve or restore structure and function of the nervous system. Disease relevance, clinical applications and new technologies for the identification of such molecules are being discussed. PMID:20335972

  14. Melatonin Signaling Controls Circadian Swimming Behavior in Marine Zooplankton

    PubMed Central

    Tosches, Maria Antonietta; Bucher, Daniel; Vopalensky, Pavel; Arendt, Detlev

    2014-01-01

    Summary Melatonin, the “hormone of darkness,” is a key regulator of vertebrate circadian physiology and behavior. Despite its ubiquitous presence in Metazoa, the function of melatonin signaling outside vertebrates is poorly understood. Here, we investigate the effect of melatonin signaling on circadian swimming behavior in a zooplankton model, the marine annelid Platynereis dumerilii. We find that melatonin is produced in brain photoreceptors with a vertebrate-type opsin-based phototransduction cascade and a light-entrained clock. Melatonin released at night induces rhythmic burst firing of cholinergic neurons that innervate locomotor-ciliated cells. This establishes a nocturnal behavioral state by modulating the length and the frequency of ciliary arrests. Based on our findings, we propose that melatonin signaling plays a role in the circadian control of ciliary swimming to adjust the vertical position of zooplankton in response to ambient light. PMID:25259919

  15. Stochastic Model of Traffic Jam and Traffic Signal Control

    NASA Astrophysics Data System (ADS)

    Shin, Ji-Sun; Cui, Cheng-You; Lee, Tae-Hong; Lee, Hee-Hyol

    Traffic signal control is an effective method to solve the traffic jam. and forecasting traffic density has been known as an important part of the Intelligent Transportation System (ITS). The several methods of the traffic signal control are known such as random walk method, Neuron Network method, Bayesian Network method, and so on. In this paper, we propose a new method of a traffic signal control using a predicted distribution of traffic jam based on a Dynamic Bayesian Network model. First, a forecasting model to predict a probabilistic distribution of the traffic jam during each period of traffic lights is built. As the forecasting model, the Dynamic Bayesian Network is used to predict the probabilistic distribution of a density of the traffic jam. According to measurement of two crossing points for each cycle, the inflow and outflow of each direction and the number of standing vehicles at former cycle are obtained. The number of standing vehicle at k-th cycle will be calculated synchronously. Next, the probabilistic distribution of the density of standing vehicle in each cycle will be predicted using the Dynamic Bayesian Network constructed for the traffic jam. And then a control rule to adjust the split and the cycle to increase the probability between a lower limit and ceiling of the standing vehicles is deduced. As the results of the simulation using the actual traffic data of Kitakyushu city, the effectiveness of the method is shown.

  16. Evidence that Fgf10 contributes to the skeletal and visceral defects of an Apert syndrome mouse model.

    PubMed

    Hajihosseini, Mohammad K; Duarte, Raquel; Pegrum, Jean; Donjacour, Anne; Lana-Elola, Eva; Rice, David P; Sharpe, James; Dickson, Clive

    2009-02-01

    Apert syndrome (AS) is a severe congenital disease caused by mutations in fibroblast growth factor receptor-2 (FGFR2), and characterised by craniofacial, limb, visceral, and neural abnormalities. AS-type FGFR2 molecules exert a gain-of-function effect in a ligand-dependent manner, but the causative FGFs and their relative contribution to each of the abnormalities observed in AS remains unknown. We have generated mice that harbour an AS mutation but are deficient in or heterozygous for Fgf10. The genetic knockdown of Fgf10 can rescue the skeletal as well as some of the visceral defects observed in this AS model, and restore a near normal level of FgfR2 signaling involving an apparent switch between ERK(p44/p42) and p38 phosphorylation. Surprisingly, it can also yield de novo cleft palate and blind colon in a subset of the compound mutants. These findings strongly suggest that Fgf10 contributes to AS-like pathologies and highlight a complexity of Fgf10 function in different tissues.

  17. Structural permeability of complex networks to control signals

    NASA Astrophysics Data System (ADS)

    Lo Iudice, Francesco; Garofalo, Franco; Sorrentino, Francesco

    2015-09-01

    Many biological, social and technological systems can be described as complex networks. The goal of affecting their behaviour has motivated recent work focusing on the relationship between the network structure and its propensity to be controlled. While this work has provided insight into several relevant problems, a comprehensive approach to address partial and complete controllability of networks is still lacking. Here, we bridge this gap by developing a framework to maximize the diffusion of the control signals through a network, while taking into account physical and economic constraints that inevitably arise in applications. This approach allows us to introduce the network permeability, a unified metric of the propensity of a network to be controllable. The analysis of the permeability of several synthetic and real networks enables us to extract some structural features that deepen our quantitative understanding of the ease with which specific controllability requirements can be met.

  18. Basic FGF or VEGF gene therapy corrects insufficiency in the intrinsic healing capacity of tendons

    PubMed Central

    Tang, Jin Bo; Wu, Ya Fang; Cao, Yi; Chen, Chuan Hao; Zhou, You Lang; Avanessian, Bella; Shimada, Masaru; Wang, Xiao Tian; Liu, Paul Y.

    2016-01-01

    Tendon injury during limb motion is common. Damaged tendons heal poorly and frequently undergo unpredictable ruptures or impaired motion due to insufficient innate healing capacity. By basic fibroblast growth factor (bFGF) or vascular endothelial growth factor (VEGF) gene therapy via adeno-associated viral type-2 (AAV2) vector to produce supernormal amount of bFGF or VEGF intrinsically in the tendon, we effectively corrected the insufficiency of the tendon healing capacity. This therapeutic approach (1) resulted in substantial amelioration of the low growth factor activity with significant increases in bFGF or VEGF from weeks 4 to 6 in the treated tendons (p < 0.05 or p < 0.01), (2) significantly promoted production of type I collagen and other extracellular molecules (p < 0.01) and accelerated cellular proliferation, and (3) significantly increased tendon strength by 68–91% from week 2 after AAV2-bFGF treatment and by 82–210% from week 3 after AAV2-VEGF compared with that of the controls (p < 0.05 or p < 0.01). Moreover, the transgene expression dissipated after healing was complete. These findings show that the gene transfers provide an optimistic solution to the insufficiencies of the intrinsic healing capacity of the tendon and offers an effective therapeutic possibility for patients with tendon disunion. PMID:26865366

  19. Changes in vitreous VEGF, bFGF and fibrosis in proliferative diabetic retinopathy after intravitreal bevacizumab

    PubMed Central

    Li, Jiu-Ke; Wei, Fang; Jin, Xiao-Hong; Dai, Yuan-Min; Cui, Hu-Shan; Li, Yu-Min

    2015-01-01

    AIM To evaluate the relationship between intravitreal bevacizumab (IVB) treatment and the levels of vitreous vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and vitreous-retina surface fibrosis in patients with proliferative diabetic retinopathy (PDR). METHODS This study was a prospective, open-label, controlled, randomized clinical trial. Sixty-eight eyes of PDR patients (n=53) and macular hole patients (n=15) were enrolled in this study. Thirty-four eyes of the PDR patients received IVB before vitrectomy. Twenty-three of the 34 PDR patients received IVB treatment 5d before vitrectomy (subgroup a), and 11 of the 34 PDR patients received IVB treatment greater than 2wk prior to vitrectomy (subgroup b). Nineteen of the PDR patients did not receive IVB treatment at any time prior to vitrectomy. The levels of bFGF and VEGF in vitreous samples were measured using enzyme-linked immunosorbent assay (ELISA) and the degree of vitreoretinal fibrosis was characterized using clinical data and data obtained intra-operatively. RESULTS In PDR patients, VEGF and bFGF levels were significantly increased compared to non-PDR (control) subject's eyes (P<0.01). In PDR patients, vitreous VEGF levels were significantly decreased following IVB treatment compared to PDR patients that did not receive IVB treatment (P<0.01). The degree of vitreoretinal fibrosis was significantly increased in subgroup b compared to subgroup a(P<0.05) and to patients that did not receive IVB (P<0.05). Vitreous bFGF levels were significantly greater in subgroup b than subgroup a (P<0.01) or in patients who did not receive IVB treatment (P<0.05). A Spearman's rank correlation test indicated that higher levels of vitreous bFGF, but not VEGF, correlated with the degree of vitreoretinal fibrosis. CONCLUSION We found that bFGF levels increase in PDR patient's vitreous after IVB treatment longer than two weeks prior to vitrectomy and correlated with the degree of fibrosis after IVB

  20. Signal pulses superimposed on power supply lines improve electrical control

    SciTech Connect

    1996-06-01

    To manipulate or monitor the operation of cranes and hoists, control engineers typically create control schemes that add numerous conductors, festoon systems, bulky dedicated conductor rails, radio and infrared controls. With modern power line communication equipment, power and intelligence can be combined to: add an unlimited number of control circuits without adding a single wire; have data communication without special cables; and eliminate bulky festoon systems and heavy cable track. Available from US Safety Trolley Corp., a SmartRail system superimposes data and control information on the power line to create a fully functional Local Area Network (LAN). The system network is based on the CEBus protocol EIA/IS-60 and uses a spread spectrum power line carrier technology. The heart of this system is the controller which manages all communication and control tasks. A power line coupling circuit couples the data signal from the controller to the a-c power conductors. These power conductors are often TRI-BAR/FOUR-BAR continuous conductor bar systems or existing conductor bar systems. The combination results in a secure data communications and control system for moving equipment.

  1. Alpaca fiber growth is mediated by microRNA let-7b via down-regulation of target gene FGF5.

    PubMed

    Wang, T; Zhang, Y; Wang, H D; Shen, Y; Liu, N; Cao, J; Yu, X J; Dong, C S; He, X Y

    2015-10-29

    MicroRNAs are very small endogenous RNA molecules that play a crucial role in an array of biological processes, including regulation of skin morphogenesis. The microRNA let-7b is thought to modulate animal hair growth, by binding target genes that encode growth factors. Fibroblast growth factor 5 (FGF5) has been previously reported to be involved in the initiation of the catagen phase of hair growth. In this study, we combined previous reports with bioinformatic analysis techniques to identify and validate FGF5 and, using lucerifase assay, confirmed targeted binding of let-7b to FGF5. To investigate the interaction between let-7b and FGF5, alpaca skin fibroblasts were transfected with let-7b over-expression vectors, and then mRNA and protein expression levels of FGF5 and the gene encoding its receptor, FGFR1, were evaluated. Levels of FGF5 mRNA and protein were remarkably lower in transfected groups, as compared to controls. In summary, this study confirmed that let-7b acts as a regulator of skin morphogenesis, by directly targeting FGF5 and down-regulating its expression. It provides the evidence of hair growth regulated by miRNAs in animals and may have important applications in wool production.

  2. FGF8 and SHH substitute for anterior-posterior tissue interactions to induce limb regeneration.

    PubMed

    Nacu, Eugeniu; Gromberg, Elena; Oliveira, Catarina R; Drechsel, David; Tanaka, Elly M

    2016-05-19

    In salamanders, grafting of a left limb blastema onto a right limb stump yields regeneration of three limbs, the normal limb and two 'supernumerary' limbs. This experiment and other research have shown that the juxtaposition of anterior and posterior limb tissue plus innervation are necessary and sufficient to induce complete limb regeneration in salamanders. However, the cellular and molecular basis of the requirement for anterior-posterior tissue interactions were unknown. Here we have clarified the molecular basis of the requirement for both anterior and posterior tissue during limb regeneration and supernumerary limb formation in axolotls (Ambystoma mexicanum). We show that the two tissues provide complementary cross-inductive signals that are required for limb outgrowth. A blastema composed solely of anterior tissue normally regresses rather than forming a limb, but activation of hedgehog (HH) signalling was sufficient to drive regeneration of an anterior blastema to completion owing to its ability to maintain fibroblast growth factor (FGF) expression, the key signalling activity responsible for blastema outgrowth. In blastemas composed solely of posterior tissue, HH signalling was not sufficient to drive regeneration; however, ectopic expression of FGF8 together with endogenous HH signalling was sufficient. In axolotls, FGF8 is expressed only in the anterior mesenchyme and maintenance of its expression depends on sonic hedgehog (SHH) signalling from posterior tissue. Together, our findings identify key anteriorly and posteriorly localized signals that promote limb regeneration and show that these single factors are sufficient to drive non-regenerating blastemas to complete regeneration with full elaboration of skeletal elements. PMID:27120163

  3. Hedonic and incentive signals for body weight control.

    PubMed

    Egecioglu, Emil; Skibicka, Karolina P; Hansson, Caroline; Alvarez-Crespo, Mayte; Friberg, P Anders; Jerlhag, Elisabet; Engel, Jörgen A; Dickson, Suzanne L

    2011-09-01

    Here we review the emerging neurobiological understanding of the role of the brain's reward system in the regulation of body weight in health and in disease. Common obesity is characterized by the over-consumption of palatable/rewarding foods, reflecting an imbalance in the relative importance of hedonic versus homeostatic signals. The popular 'incentive salience theory' of food reward recognises not only a hedonic/pleasure component ('liking') but also an incentive motivation component ('wanting' or 'reward-seeking'). Central to the neurobiology of the reward mechanism is the mesoaccumbal dopamine system that confers incentive motivation not only for natural rewards such as food but also by artificial rewards (eg. addictive drugs). Indeed, this mesoaccumbal dopamine system receives and integrates information about the incentive (rewarding) value of foods with information about metabolic status. Problematic over-eating likely reflects a changing balance in the control exerted by hypothalamic versus reward circuits and/or it could reflect an allostatic shift in the hedonic set point for food reward. Certainly, for obesity to prevail, metabolic satiety signals such as leptin and insulin fail to regain control of appetitive brain networks, including those involved in food reward. On the other hand, metabolic control could reflect increased signalling by the stomach-derived orexigenic hormone, ghrelin. We have shown that ghrelin activates the mesoaccumbal dopamine system and that central ghrelin signalling is required for reward from both chemical drugs (eg alcohol) and also from palatable food. Future therapies for problematic over-eating and obesity may include drugs that interfere with incentive motivation, such as ghrelin antagonists.

  4. The Wnt3a/β-catenin target gene Mesogenin1 controls the segmentation clock by activating a Notch signaling program

    PubMed Central

    Chalamalasetty, Ravindra B.; Dunty, William C.; Biris, Kristin K.; Ajima, Rieko; Iacovino, Michelina; Beisaw, Arica; Feigenbaum, Lionel; Chapman, Deborah L.; Yoon, Jeong Kyo; Kyba, Michael; Yamaguchi, Terry P.

    2013-01-01

    Summary Segmentation is an organizing principle of body plans. The segmentation clock, a molecular oscillator best illustrated by the cyclic expression of Notch signaling genes, controls the periodic cleavage of somites from unsegmented presomitic mesoderm (PSM) during vertebrate segmentation. Wnt3a controls the spatiotemporal expression of cyclic Notch genes, however the underlying mechanisms remain obscure. Transcriptional profiling of Wnt3a−/− embryos led to the identification of the bHLH transcription factor, Mesogenin1 (Msgn1), as a direct target gene of Wnt3a. To identify Msgn1 targets, we performed genome-wide studies of Msgn1 activity in embryonic stem cells. Here we show that Msgn1 is a major transcriptional activator of a Notch signaling program, synergizing with Notch to trigger clock gene expression. Msgn1 also indirectly regulates cyclic genes in the Fgf and Wnt pathways. Thus, Msgn1 is a central component of a transcriptional cascade that translates a spatial Wnt3a gradient into a temporal pattern of clock gene expression. PMID:21750544

  5. iNKT Cells Induce FGF21 for Thermogenesis and Are Required for Maximal Weight Loss in GLP1 Therapy.

    PubMed

    Lynch, Lydia; Hogan, Andrew E; Duquette, Danielle; Lester, Chantel; Banks, Alexander; LeClair, Katherine; Cohen, David E; Ghosh, Abhisek; Lu, Bing; Corrigan, Michelle; Stevanovic, Darko; Maratos-Flier, Eleftheria; Drucker, Daniel J; O'Shea, Donal; Brenner, Michael

    2016-09-13

    Adipose-resident invariant natural killer T (iNKT) cells are key players in metabolic regulation. iNKT cells are innate lipid sensors, and their activation, using their prototypic ligand α-galactosylceramide (αGalCer), induces weight loss and restores glycemic control in obesity. Here, iNKT activation induced fibroblast growth factor 21 (FGF21) production and thermogenic browning of white fat. Complete metabolic analysis revealed that iNKT cell activation induced increased body temperature, V02, VC02, and fatty acid oxidation, without affecting food intake or activity. FGF21 induction played a major role in iNKT cell-induced weight loss, as FGF21 null mice lost significantly less weight after αGalCer treatment. The glucagon-like peptide 1 (GLP-1) receptor agonist, liraglutide, also activated iNKT cells in humans and mice. In iNKT-deficient mice, liraglutide promoted satiety but failed to induce FGF21, resulting in less weight loss. These findings reveal an iNKT cell-FGF21 axis that defines a new immune-mediated pathway that could be targeted for glycemic control and weight regulation. PMID:27593966

  6. Prefrontal D1 dopamine signaling is required for temporal control.

    PubMed

    Narayanan, Nandakumar S; Land, Benjamin B; Solder, John E; Deisseroth, Karl; DiLeone, Ralph J

    2012-12-11

    Temporal control, or how organisms guide movements in time to achieve behavioral goals, depends on dopamine signaling. The medial prefrontal cortex controls many goal-directed behaviors and receives dopaminergic input primarily from the midbrain ventral tegmental area. However, this system has never been linked with temporal control. Here, we test the hypothesis that dopaminergic projections from the ventral tegmental area to the prefrontal cortex influence temporal control. Rodents were trained to perform a fixed-interval timing task with an interval of 20 s. We report several results: first, that decreasing dopaminergic neurotransmission using virally mediated RNA interference of tyrosine hydroxylase impaired temporal control, and second that pharmacological disruption of prefrontal D1 dopamine receptors, but not D2 dopamine receptors, impaired temporal control. We then used optogenetics to specifically and selectively manipulate prefrontal neurons expressing D1 dopamine receptors during fixed-interval timing performance. Selective inhibition of D1-expressing prefrontal neurons impaired fixed-interval timing, whereas stimulation made animals more efficient during task performance. These data provide evidence that ventral tegmental dopaminergic projections to the prefrontal cortex influence temporal control via D1 receptors. The results identify a critical circuit for temporal control of behavior that could serve as a target for the treatment of dopaminergic diseases.

  7. Epistatic interactions between Chd7 and Fgf8 during cerebellar development

    PubMed Central

    Basson, M Albert

    2014-01-01

    CHARGE syndrome is a rare, autosomal dominant condition caused by mutations in the CHD7 gene. Although central nervous system defects have been reported, the detailed description and analysis of these anomalies in CHARGE syndrome patients lag far behind the description of other, more easily observed defects. We recently described cerebellar abnormalities in CHARGE syndrome patients and used mouse models to identify the underlying causes. Our studies identified altered expression of the homeobox genes Otx2 and Gbx2 in the developing neural tube of Chd7−/− embryos. Furthermore, we showed that the expression of Fgf8 is sensitive to Chd7 gene dosage and demonstrated an epistatic relationship between these genes during cerebellar vermis development. These findings provided, for the first time, an example of cerebellar vermis hypoplasia in a human syndrome that can be linked to deregulated FGF signaling. I discuss some of these observations and their implications for CHARGE syndrome. PMID:25054096

  8. Multi-chromatic control of mammalian gene expression and signaling.

    PubMed

    Müller, Konrad; Engesser, Raphael; Schulz, Simon; Steinberg, Thorsten; Tomakidi, Pascal; Weber, Cornelia C; Ulm, Roman; Timmer, Jens; Zurbriggen, Matias D; Weber, Wilfried

    2013-07-01

    The emergence and future of mammalian synthetic biology depends on technologies for orchestrating and custom tailoring complementary gene expression and signaling processes in a predictable manner. Here, we demonstrate for the first time multi-chromatic expression control in mammalian cells by differentially inducing up to three genes in a single cell culture in response to light of different wavelengths. To this end, we developed an ultraviolet B (UVB)-inducible expression system by designing a UVB-responsive split transcription factor based on the Arabidopsis thaliana UVB receptor UVR8 and the WD40 domain of COP1. The system allowed high (up to 800-fold) UVB-induced gene expression in human, monkey, hamster and mouse cells. Based on a quantitative model, we determined critical system parameters. By combining this UVB-responsive system with blue and red light-inducible gene control technology, we demonstrate multi-chromatic multi-gene control by differentially expressing three genes in a single cell culture in mammalian cells, and we apply this system for the multi-chromatic control of angiogenic signaling processes. This portfolio of optogenetic tools enables the design and implementation of synthetic biological networks showing unmatched spatiotemporal precision for future research and biomedical applications.

  9. A Regulatory Loop Involving PAX6, MITF, and WNT Signaling Controls Retinal Pigment Epithelium Development

    PubMed Central

    Bharti, Kapil; Gasper, Melanie; Ou, Jingxing; Brucato, Martha; Clore-Gronenborn, Katharina; Pickel, James; Arnheiter, Heinz

    2012-01-01

    The separation of the optic neuroepithelium into future retina and retinal pigment epithelium (RPE) is a critical event in early eye development in vertebrates. Here we show in mice that the transcription factor PAX6, well-known for its retina-promoting activity, also plays a crucial role in early pigment epithelium development. This role is seen, however, only in a background genetically sensitized by mutations in the pigment cell transcription factor MITF. In fact, a reduction in Pax6 gene dose exacerbates the RPE-to-retina transdifferentiation seen in embryos homozygous for an Mitf null allele, and it induces such a transdifferentiation in embryos that are either heterozygous for the Mitf null allele or homozygous for an RPE–specific hypomorphic Mitf allele generated by targeted mutation. Conversely, an increase in Pax6 gene dose interferes with transdifferentiation even in homozygous Mitf null embryos. Gene expression analyses show that, together with MITF or its paralog TFEC, PAX6 suppresses the expression of Fgf15 and Dkk3. Explant culture experiments indicate that a combination of FGF and DKK3 promote retina formation by inhibiting canonical WNT signaling and stimulating the expression of retinogenic genes, including Six6 and Vsx2. Our results demonstrate that in conjunction with Mitf/Tfec Pax6 acts as an anti-retinogenic factor, whereas in conjunction with retinogenic genes it acts as a pro-retinogenic factor. The results suggest that careful manipulation of the Pax6 regulatory circuit may facilitate the generation of retinal and pigment epithelium cells from embryonic or induced pluripotent stem cells. PMID:22792072

  10. Basic FGF attenuates amyloid beta-peptide-induced oxidative stress, mitochondrial dysfunction, and impairment of Na+/K+-ATPase activity in hippocampal neurons.

    PubMed

    Mark, R J; Keller, J N; Kruman, I; Mattson, M P

    1997-05-01

    Basic fibroblast growth factor (bFGF) exhibits trophic activity for many populations of neurons in the brain, and can protect those neurons against excitotoxic, metabolic and oxidative insults. In Alzheimer's disease (AD), amyloid beta-peptide (A beta) fibrils accumulate in plaques which are associated with degenerating neurons. A beta can be neurotoxic by a mechanism that appears to involve induction of oxidative stress and disruption of calcium homeostasis. Plaques in AD brain contain high levels of bFGF suggesting a possible modulatory role for bFGF in the neurodegenerative process. We now report that bFGF can protect cultured hippocampal neurons against A beta25-35 toxicity by a mechanism that involves suppression of reactive oxygen species (ROS) accumulation and maintenance of Na+/K+-ATPase activity. A beta25-35 induced lipid peroxidation, accumulation of H2O2, mitochondrial ROS accumulation, and a decrease in mitochondrial transmembrane potential; each of these effects of A beta25-35 was abrogated in cultures pre-treated with bFGF. Na+/K+-ATPase activity was significantly reduced following exposure to A beta25-35 in control cultures, but not in cultures pre-treated with bFGF. bFGF did not protect neurons from death induced by ouabain (a specific inhibitor of the Na+/K+-ATPase) or 4-hydroxynonenal (an aldehydic product of lipid peroxidation) consistent with a site of action of bFGF prior to induction of oxidative stress and impairment of ion-motive ATPases. By suppressing accumulation of oxyradicals, bFGF may slow A beta-induced neurodegenerative cascades. PMID:9187334

  11. Effects of FGF10 on bovine oocyte meiosis progression, apoptosis, embryo development and relative abundance of developmentally important genes in vitro.

    PubMed

    Pomini Pinto, R F; Fontes, P K; Loureiro, B; Sousa Castilho, A C; Sousa Ticianelli, J; Montanari Razza, E; Satrapa, R A; Buratini, J; Moraes Barros, C

    2015-02-01

    Fibroblast growth factor (FGF10) acts at the cumulus oocyte complex, increasing the expression of cumulus cell expansion-related genes and oocyte competency genes. We tested the hypothesis that addition of FGF10 to the maturation medium improves oocyte maturation, decreases the percentage of apoptotic oocytes and increases development to the blastocyst stage while increasing the relative abundance of developmentally important genes (COX2, CDX2 and PLAC8). In all experiments, oocytes were matured for 22 h in TCM-199 supplemented with 0, 2.5, 10 or 50 ng/ml FGF10. In Experiment 1, after maturation, oocytes were stained with Hoechst to evaluate meiosis progression (metaphase I, intermediary phases and extrusion of the first polar body) and submitted to the TUNEL assay to evaluate apoptosis. In Experiment 2, oocytes were fertilized and cultured to the blastocyst stage. Blastocysts were frozen for analysis of COX2, CDX2 and PLAC8 relative abundance. In Experiment 1, 2.5 ng/ml FGF10 increased (p < 0.05) the percentage of oocytes with extrusion of the first polar body (35%) compared to 0, 10 and 50 ng/ml FGF10 (21, 14 and 12%, respectively) and FGF10 decreased the percentage of oocytes that were TUNEL positive in all doses studied. In Experiment 2, there was no difference in the percentage of oocytes becoming blastocysts between treatments and control. Real-time RT-PCR showed a tendency of 50 ng/ml FGF10 to increase the relative abundance of COX2 and PLAC8 and of 10 ng/ml FGF10 to increase CDX2. In conclusion, the addition of FGF10 to the oocyte maturation medium improves oocyte maturation in vitro, decreases the percentage of apoptotic oocytes and tends to increase the relative abundance of developmentally important genes. PMID:25495767

  12. Metabolic control of signalling pathways and metabolic auto-regulation.

    PubMed

    Lorendeau, Doriane; Christen, Stefan; Rinaldi, Gianmarco; Fendt, Sarah-Maria

    2015-08-01

    Metabolic alterations have emerged as an important hallmark in the development of various diseases. Thus, understanding the complex interplay of metabolism with other cellular processes such as cell signalling is critical to rationally control and modulate cellular physiology. Here, we review in the context of mammalian target of rapamycin, AMP-activated protein kinase and p53, the orchestrated interplay between metabolism and cellular signalling as well as transcriptional regulation. Moreover, we discuss recent discoveries in auto-regulation of metabolism (i.e. how metabolic parameters such as metabolite levels activate or inhibit enzymes and thus metabolic pathways). Finally, we review functional consequences of post-translational modification on metabolic enzyme abundance and/or activities.

  13. Phosphoinositide kinase signaling controls ER-PM cross-talk

    PubMed Central

    Omnus, Deike J.; Manford, Andrew G.; Bader, Jakob M.; Emr, Scott D.; Stefan, Christopher J.

    2016-01-01

    Membrane lipid dynamics must be precisely regulated for normal cellular function, and disruptions in lipid homeostasis are linked to the progression of several diseases. However, little is known about the sensory mechanisms for detecting membrane composition and how lipid metabolism is regulated in response to membrane stress. We find that phosphoinositide (PI) kinase signaling controls a conserved PDK-TORC2-Akt signaling cascade as part of a homeostasis network that allows the endoplasmic reticulum (ER) to modulate essential responses, including Ca2+-regulated lipid biogenesis, upon plasma membrane (PM) stress. Furthermore, loss of ER-PM junctions impairs this protective response, leading to PM integrity defects upon heat stress. Thus PI kinase–mediated ER-PM cross-talk comprises a regulatory system that ensures cellular integrity under membrane stress conditions. PMID:26864629

  14. Canonical Wnt signaling in differentiated osteoblasts controls osteoclast differentiation.

    PubMed

    Glass, Donald A; Bialek, Peter; Ahn, Jong Deok; Starbuck, Michael; Patel, Millan S; Clevers, Hans; Taketo, Mark M; Long, Fanxin; McMahon, Andrew P; Lang, Richard A; Karsenty, Gerard

    2005-05-01

    Inactivation of beta-catenin in mesenchymal progenitors prevents osteoblast differentiation; inactivation of Lrp5, a gene encoding a likely Wnt coreceptor, results in low bone mass (osteopenia) by decreasing bone formation. These observations indicate that Wnt signaling controls osteoblast differentiation and suggest that it may regulate bone formation in differentiated osteoblasts. Here, we study later events and find that stabilization of beta-catenin in differentiated osteoblasts results in high bone mass, while its deletion from differentiated osteoblasts leads to osteopenia. Surprisingly, histological analysis showed that these mutations primarily affect bone resorption rather than bone formation. Cellular and molecular studies showed that beta-catenin together with TCF proteins regulates osteoblast expression of Osteoprotegerin, a major inhibitor of osteoclast differentiation. These findings demonstrate that beta-catenin, and presumably Wnt signaling, promote the ability of differentiated osteoblasts to inhibit osteoclast differentiation; thus, they broaden our knowledge of the functions Wnt proteins have at various stages of skeletogenesis. PMID:15866165

  15. Segregating neural and mechanosensory fates in the developing ear: patterning, signaling, and transcriptional control.

    PubMed

    Raft, Steven; Groves, Andrew K

    2015-01-01

    The vertebrate inner ear is composed of multiple sensory receptor epithelia, each of which is specialized for detection of sound, gravity, or angular acceleration. Each receptor epithelium contains mechanosensitive hair cells, which are connected to the brainstem by bipolar sensory neurons. Hair cells and their associated neurons are derived from the embryonic rudiment of the inner ear epithelium, but the precise spatial and temporal patterns of their generation, as well as the signals that coordinate these events, have only recently begun to be understood. Gene expression, lineage tracing, and mutant analyses suggest that both neurons and hair cells are generated from a common domain of neural and sensory competence in the embryonic inner ear rudiment. Members of the Shh, Wnt, and FGF families, together with retinoic acid signals, regulate transcription factor genes within the inner ear rudiment to establish the axial identity of the ear and regionalize neurogenic activity. Close-range signaling, such as that of the Notch pathway, specifies the fate of sensory regions and individual cell types. We also describe positive and negative interactions between basic helix-loop-helix and SoxB family transcription factors that specify either neuronal or sensory fates in a context-dependent manner. Finally, we review recent work on inner ear development in zebrafish, which demonstrates that the relative timing of neurogenesis and sensory epithelial formation is not phylogenetically constrained.

  16. Evaluation of a new automated chemiluminescence immunoassay for FGF23.

    PubMed

    Shimizu, Yuichiro; Fukumoto, Seiji; Fujita, Toshiro

    2012-03-01

    Fibroblast growth factor 23 (FGF23) is a hormone regulating phosphate and vitamin D metabolism. We have previously established a sandwich enzyme-linked immunosorbent assay (ELISA) for FGF23 and reported that FGF23 values are useful for the differential diagnosis of chronic hypophosphatemia. However, this ELISA has a rather narrow assay range of 3-800 pg/ml, and it was pointed out that the assay performance is not satisfactory when automatic washing is used. Here we evaluated a new automated chemiluminescence immunoassay for FGF23. This assay uses 10 μl sera or plasma samples and requires 20 min to obtain the first result. The assay was linear up to about 15,000 pg/ml and had a detection limit of 1 pg/ml. In addition, this assay showed coefficients of variation of less than 5% using samples with average FGF23 levels of 43.2-2,454.0 pg/ml. When FGF23 levels in 210 samples from chronic hypophosphatemic patients were evaluated by both the previous ELISA and this new assay, there was a good correlation of R (2) = 0.96. However, FGF23 levels by the new assay showed lower values, especially in samples with high FGF23 levels. Given that the lowest FGF23 level in patients with FGF23-related hypophosphatemia was 30.8 pg/ml and that the highest FGF23 levels in patients with non-FGF23-related hypophosphatemia was 20.8 pg/ml by this novel assay, the sensitivity and specificity were 100% when the cutoff was set between 20.8 and 30.8 pg/ml. From the aspect of convenience and the coefficients of variation of this assay, we propose that the cutoff be 25 pg/ml. There results indicate that this new assay is ideal for both clinical use and clinical studies, especially when measuring many samples with high FGF23 levels.

  17. PII Signal Transduction Proteins, Pivotal Players in Microbial Nitrogen Control

    PubMed Central

    Arcondéguy, Tania; Jack, Rachael; Merrick, Mike

    2001-01-01

    The PII family of signal transduction proteins are among the most widely distributed signal proteins in the bacterial world. First identified in 1969 as a component of the glutamine synthetase regulatory apparatus, PII proteins have since been recognized as playing a pivotal role in control of prokaryotic nitrogen metabolism. More recently, members of the family have been found in higher plants, where they also potentially play a role in nitrogen control. The PII proteins can function in the regulation of both gene transcription, by modulating the activity of regulatory proteins, and the catalytic activity of enzymes involved in nitrogen metabolism. There is also emerging evidence that they may regulate the activity of proteins required for transport of nitrogen compounds into the cell. In this review we discuss the history of the PII proteins, their structures and biochemistry, and their distribution and functions in prokaryotes. We survey data emerging from bacterial genome sequences and consider other likely or potential targets for control by PII proteins. PMID:11238986

  18. Optogenetic Control of Nodal Signaling Reveals a Temporal Pattern of Nodal Signaling Regulating Cell Fate Specification during Gastrulation.

    PubMed

    Sako, Keisuke; Pradhan, Saurabh J; Barone, Vanessa; Inglés-Prieto, Álvaro; Müller, Patrick; Ruprecht, Verena; Čapek, Daniel; Galande, Sanjeev; Janovjak, Harald; Heisenberg, Carl-Philipp

    2016-07-19

    During metazoan development, the temporal pattern of morphogen signaling is critical for organizing cell fates in space and time. Yet, tools for temporally controlling morphogen signaling within the embryo are still scarce. Here, we developed a photoactivatable Nodal receptor to determine how the temporal pattern of Nodal signaling affects cell fate specification during zebrafish gastrulation. By using this receptor to manipulate the duration of Nodal signaling in vivo by light, we show that extended Nodal signaling within the organizer promotes prechordal plate specification and suppresses endoderm differentiation. Endoderm differentiation is suppressed by extended Nodal signaling inducing expression of the transcriptional repressor goosecoid (gsc) in prechordal plate progenitors, which in turn restrains Nodal signaling from upregulating the endoderm differentiation gene sox17 within these cells. Thus, optogenetic manipulation of Nodal signaling identifies a critical role of Nodal signaling duration for organizer cell fate specification during gastrulation. PMID:27396324

  19. Fibroblast growth factor signaling in skeletal development and disease

    PubMed Central

    Ornitz, David M.; Marie, Pierre J.

    2015-01-01

    Fibroblast growth factor (FGF) signaling pathways are essential regulators of vertebrate skeletal development. FGF signaling regulates development of the limb bud and formation of the mesenchymal condensation and has key roles in regulating chondrogenesis, osteogenesis, and bone and mineral homeostasis. This review updates our review on FGFs in skeletal development published in Genes & Development in 2002, examines progress made on understanding the functions of the FGF signaling pathway during critical stages of skeletogenesis, and explores the mechanisms by which mutations in FGF signaling molecules cause skeletal malformations in humans. Links between FGF signaling pathways and other interacting pathways that are critical for skeletal development and could be exploited to treat genetic diseases and repair bone are also explored. PMID:26220993

  20. An Fgf8 Mouse Mutant Phenocopies Human 22q11 Deletion Syndrome

    PubMed Central

    Frank, Deborah U.; Fotheringham, Lori K.; Brewer, Judson A.; Muglia, Louis J.; Tristani-Firouzi, Martin; Capecchi, Mario R.; Moon, Anne M.

    2006-01-01

    SUMMARY Deletion of chromosome 22q11, the most common microdeletion detected in humans, is associated with a life-threatening array of birth defects. Although 90% of affected individuals share the same three megabase deletion, their phenotype is highly variable and includes craniofacial and cardiovascular anomalies, hypoplasia or aplasia of the thymus with associated deficiency of T cells, hypocalcemia with hypoplasia or aplasia of the parathyroids, and a variety of central nervous system abnormalities. Because ablation of neural crest in chicks produces many features of the deletion 22q11 syndrome, it has been proposed that haploinsufficiency in this region impacts neural crest function during cardiac and pharyngeal arch development. Few factors required for migration, survival, proliferation and subsequent differentiation of pharyngeal arch neural crest and mesoderm-derived mesenchyme into their respective cardiovascular, musculoskeletal, and glandular derivatives have been identified. However, the importance of epithelial-mesenchymal interactions and pharyngeal endoderm function is becoming increasingly clear. Fibroblast growth factor 8 is a signaling molecule expressed in the ectoderm and endoderm of the developing pharyngeal arches and known to play an important role in survival and patterning of first arch tissues. We demonstrate a dosage-sensitive requirement for FGF8 during development of pharyngeal arch, pharyngeal pouch and neural crest-derived tissues. We show that FGF8 deficient embryos have lethal malformations of the cardiac outflow tract, great vessels and heart due, at least in part, to failure to form the fourth pharyngeal arch arteries, altered expression of Fgf10 in the pharyngeal mesenchyme, and abnormal apoptosis in pharyngeal and cardiac neural crest. The Fgf8 mutants described herein display the complete array of cardiovascular, glandular and craniofacial phenotypes seen in human deletion 22q11 syndromes. This represents the first single gene

  1. Retina regeneration in the chick embryo is not induced by spontaneous Mitf downregulation but requires FGF/FGFR/MEK/Erk dependent upregulation of Pax6

    PubMed Central

    Aycinena, Juan-Carlos

    2007-01-01

    Purpose To elucidate the early cellular events that take place during induction of retina regeneration in the embryonic chick, focusing on the relationship between fibroblast growth factor (FGF) signaling and the regulation of Pax6 and Mitf. Methods The retina of embryonic day 4 (E4) chicks was removed and a heparin coated bead soaked in fibroblast growth factor 2 (FGF2) was placed into the optic cup. The pharmacological inhibitor PD173074 was used to inhibit FGF receptors, PD98059 was used to inhibit MAP kinase-kinase/extracellular signal-regulated kinase (MEK/Erk) signaling. Retroviral constructs for paired box 6 (Pax6), MEK, and microphthalmia (Mitf) were also used in overexpression studies. Immunohistochemistry was used to examine pErk, Pax6, Mitf, and melanosomal matrix protein 115 (MMP115) immunoreactivity and bromodeoxyuridine (BrdU) incorporation at different time points after removing the retina. Results The embryonic chick has the ability to regenerate a new retina by the process of transdifferentiation of the retinal pigment epithelium (RPE). We observed that during the induction of transdifferentiation, downregulation of Mitf was not sufficient to induce transdifferentiation at E4 and that FGF2 was required to drive Pax6 protein expression and cell proliferation, both of which are necessary for transdifferentiation. Furthermore, we show that FGF2 works through the FGFR/MEK/Erk signaling cascade to increase Pax6 expression and proliferation. Ectopic Mitf expression was able to inhibit transdifferentiation by acting downstream of FGFR/MEK/Erk signaling, likely by inhibiting the increase in Pax6 protein in the RPE. Conclusions FGF2 stimulates Pax6 expression during induction of transdifferentiation of the RPE through FGFR/MEK/Erk signaling cascade. This Pax6 expression is accompanied by an increase in BrdU incorporation. In addition, we show that Mitf is spontaneously downregulated after removal of the retina even in the absence of FGF2. This Mitf

  2. Connexin 43 Is Necessary for Salivary Gland Branching Morphogenesis and FGF10-induced ERK1/2 Phosphorylation.

    PubMed

    Yamada, Aya; Futagi, Masaharu; Fukumoto, Emiko; Saito, Kan; Yoshizaki, Keigo; Ishikawa, Masaki; Arakaki, Makiko; Hino, Ryoko; Sugawara, Yu; Ishikawa, Momoko; Naruse, Masahiro; Miyazaki, Kanako; Nakamura, Takashi; Fukumoto, Satoshi

    2016-01-01

    Cell-cell interaction via the gap junction regulates cell growth and differentiation, leading to formation of organs of appropriate size and quality. To determine the role of connexin43 in salivary gland development, we analyzed its expression in developing submandibular glands (SMGs). Connexin43 (Cx43) was found to be expressed in salivary gland epithelium. In ex vivo organ cultures of SMGs, addition of the gap junctional inhibitors 18α-glycyrrhetinic acid (18α-GA) and oleamide inhibited SMG branching morphogenesis, suggesting that gap junctional communication contributes to salivary gland development. In Cx43(-/-) salivary glands, submandibular and sublingual gland size was reduced as compared with those from heterozygotes. The expression of Pdgfa, Pdgfb, Fgf7, and Fgf10, which induced branching of SMGs in Cx43(-/-) samples, were not changed as compared with those from heterozygotes. Furthermore, the blocking peptide for the hemichannel and gap junction channel showed inhibition of terminal bud branching. FGF10 induced branching morphogenesis, while it did not rescue the Cx43(-/-) phenotype, thus Cx43 may regulate FGF10 signaling during salivary gland development. FGF10 is expressed in salivary gland mesenchyme and regulates epithelial proliferation, and was shown to induce ERK1/2 phosphorylation in salivary epithelial cells, while ERK1/2 phosphorylation in HSY cells was dramatically inhibited by 18α-GA, a Cx43 peptide or siRNA. On the other hand, PDGF-AA and PDGF-BB separately induced ERK1/2 phosphorylation in primary cultured salivary mesenchymal cells regardless of the presence of 18α-GA. Together, our results suggest that Cx43 regulates FGF10-induced ERK1/2 phosphorylation in salivary epithelium but not in mesenchyme during the process of SMG branching morphogenesis.

  3. Effects of lifestyle modification and metformin on irisin and FGF21 among HIV-infected subjects with the metabolic syndrome

    PubMed Central

    Srinivasa, Suman; Wong, Kimberly; Fitch, Kathleen V.; Wei, Jeffrey; Petrow, Eva; Cypess, Aaron M.; Torriani, Martin; Grinspoon, Steven K.

    2015-01-01

    Summary Objective Few studies have investigated irisin and FGF21 to elucidate the role of these hormones to regulate ‘beiging’ in HIV-infected patients. Design Fifty HIV-infected subjects with the metabolic syndrome were previously recruited and randomized to receive lifestyle modification (LSM) and/or metformin over 12 months. In the current study, we assessed FGF21 and irisin at baseline and after intervention. In addition, we assessed circulating FGF21 and irisin in relationship to brown adipose tissue (BAT) gene expression in dorsocervical subcutaneous fat biopsies from 13 HIV-infected subjects. Results At baseline, prior to intervention, HIV-infected subjects demonstrated increased log FGF21 (2·13 ± 0·06 vs 1·98 ± 0·05 pg/ml, P = 0·05) and log irisin (0·33 ± 0·02 vs 0·17 ± 0·04 μg/ml, P = 0·003) compared with healthy controls well matched based on waist circumference. After 12 months, HIV-infected subjects randomized to LSM demonstrated a relative reduction in FGF21 compared with those not randomized to LSM (−10 [−35,22] vs 40 [0,94] %change, P = 0·01). Changes in FGF21 were inversely associated with improved parameters of energy homoeostasis, including increased REE (ρ = −0·34, P = 0·046) and max VO2 (ρ = −0·38, P = 0·02), and reduced RQ (ρ = 0·40, P = 0·02) among all HIV-infected subjects. Increased UCP-1 (r = 0·75, P = 0·003), DIO2 (r = 0·58, P = 0·04) and CideA (r = 0·73, P = 0·01) gene expression in dorsocervical fat was significantly associated with FGF21 in HIV-infected subjects. Conclusion HIV-infected subjects with metabolic complications demonstrate increases in FGF21 in relationship to BAT gene expression. Relative reductions in FGF21 in those receiving long-term LSM relate to overall improvements in energy expenditure parameters. In contrast, irisin levels are elevated in HIV-infected subjects, but are not influenced by LSM nor associated with BAT gene expression. PMID:25130061

  4. Dutch and arctic mutant peptides of β amyloid1–40 differentially affect the FGF-2 pathway in brain endothelium

    PubMed Central

    Solito, Raffaella; Corti, Federico; Fossati, Silvia; Mezhericher, Emiliya; Donnini, Sandra; Ghiso, Jorge; Giachetti, Antonio; Rostagno, Agueda; Ziche, Marina

    2009-01-01

    Single point mutations of the amyloid precursor protein generate Aβ variants bearing amino acid substitutions at positions 21–23. These mutants are associated with distinct hereditary phenotypes of cerebral amyloid angiopathy, manifesting varying degrees of tropism for brain vessels, and impaired microvessel remodeling and angiogenesis. We examined the differential effects of E22Q (Dutch), and E22G (Arctic) variants in comparison to WT Aβ on brain endothelial cell proliferation, angiogenic phenotype expression triggered by fibroblast growth factor (FGF-2), pseudo-capillary sprouting, and induction of apoptosis. E22Q exhibited a potent anti-angiogenic profile in contrast to E22G, which had a much weaker effect. Investigations on the FGF-2 signaling pathway revealed the greatest differences among the peptides: E22Q andWT peptides suppressed FGF-2 expression while E22G had barely any effect. Phosphorylation of the FGF-2 receptor, FGFR-1, and the survival signal Akt were abolished by E22Q and WT peptides, but not by E22G. The biological dissimilar effect of the mutant and WT peptides on cerebral EC cannot be assigned to a particular Aβ structure, suggesting that the toxic effect of the Aβ assemblies goes beyond mere multimerization. PMID:19061884

  5. FGF receptor genes and breast cancer susceptibility: results from the Breast Cancer Association Consortium

    PubMed Central

    Agarwal, D; Pineda, S; Michailidou, K; Herranz, J; Pita, G; Moreno, L T; Alonso, M R; Dennis, J; Wang, Q; Bolla, M K; Meyer, K B; Menéndez-Rodríguez, P; Hardisson, D; Mendiola, M; González-Neira, A; Lindblom, A; Margolin, S; Swerdlow, A; Ashworth, A; Orr, N; Jones, M; Matsuo, K; Ito, H; Iwata, H; Kondo, N; Hartman, M; Hui, M; Lim, W Y; T-C Iau, P; Sawyer, E; Tomlinson, I; Kerin, M; Miller, N; Kang, D; Choi, J-Y; Park, S K; Noh, D-Y; Hopper, J L; Schmidt, D F; Makalic, E; Southey, M C; Teo, S H; Yip, C H; Sivanandan, K; Tay, W-T; Brauch, H; Brüning, T; Hamann, U; Dunning, A M; Shah, M; Andrulis, I L; Knight, J A; Glendon, G; Tchatchou, S; Schmidt, M K; Broeks, A; Rosenberg, E H; van't Veer, L J; Fasching, P A; Renner, S P; Ekici, A B; Beckmann, M W; Shen, C-Y; Hsiung, C-N; Yu, J-C; Hou, M-F; Blot, W; Cai, Q; Wu, A H; Tseng, C-C; Van Den Berg, D; Stram, D O; Cox, A; Brock, I W; Reed, M W R; Muir, K; Lophatananon, A; Stewart-Brown, S; Siriwanarangsan, P; Zheng, W; Deming-Halverson, S; Shrubsole, M J; Long, J; Shu, X-O; Lu, W; Gao, Y-T; Zhang, B; Radice, P; Peterlongo, P; Manoukian, S; Mariette, F; Sangrajrang, S; McKay, J; Couch, F J; Toland, A E; Yannoukakos, D; Fletcher, O; Johnson, N; Silva, I dos Santos; Peto, J; Marme, F; Burwinkel, B; Guénel, P; Truong, T; Sanchez, M; Mulot, C; Bojesen, S E; Nordestgaard, B G; Flyer, H; Brenner, H; Dieffenbach, A K; Arndt, V; Stegmaier, C; Mannermaa, A; Kataja, V; Kosma, V-M; Hartikainen, J M; Lambrechts, D; Yesilyurt, B T; Floris, G; Leunen, K; Chang-Claude, J; Rudolph, A; Seibold, P; Flesch-Janys, D; Wang, X; Olson, J E; Vachon, C; Purrington, K; Giles, G G; Severi, G; Baglietto, L; Haiman, C A; Henderson, B E; Schumacher, F; Le Marchand, L; Simard, J; Dumont, M; Goldberg, M S; Labrèche, F; Winqvist, R; Pylkäs, K; Jukkola-Vuorinen, A; Grip, M; Devilee, P; Tollenaar, R A E M; Seynaeve, C; García-Closas, M; Chanock, S J; Lissowska, J; Figueroa, J D; Czene, K; Eriksson, M; Humphreys, K; Darabi, H; Hooning, M J; Kriege, M; Collée, J M; Tilanus-Linthorst, M; Li, J; Jakubowska, A; Lubinski, J; Jaworska-Bieniek, K; Durda, K; Nevanlinna, H; Muranen, T A; Aittomäki, K; Blomqvist, C; Bogdanova, N; Dörk, T; Hall, P; Chenevix-Trench, G; Easton, D F; Pharoah, P D P; Arias-Perez, J I; Zamora, P; Benítez, J; Milne, R L

    2014-01-01

    Background: Breast cancer is one of the most common malignancies in women. Genome-wide association studies have identified FGFR2 as a breast cancer susceptibility gene. Common variation in other fibroblast growth factor (FGF) receptors might also modify risk. We tested this hypothesis by studying genotyped single-nucleotide polymorphisms (SNPs) and imputed SNPs in FGFR1, FGFR3, FGFR4 and FGFRL1 in the Breast Cancer Association Consortium. Methods: Data were combined from 49 studies, including 53 835 cases and 50 156 controls, of which 89 050 (46 450 cases and 42 600 controls) were of European ancestry, 12 893 (6269 cases and 6624 controls) of Asian and 2048 (1116 cases and 932 controls) of African ancestry. Associations with risk of breast cancer, overall and by disease sub-type, were assessed using unconditional logistic regression. Results: Little evidence of association with breast cancer risk was observed for SNPs in the FGF receptor genes. The strongest evidence in European women was for rs743682 in FGFR3; the estimated per-allele odds ratio was 1.05 (95% confidence interval=1.02–1.09, P=0.0020), which is substantially lower than that observed for SNPs in FGFR2. Conclusion: Our results suggest that common variants in the other FGF receptors are not associated with risk of breast cancer to the degree observed for FGFR2. PMID:24548884

  6. Striatal microRNA controls cocaine intake through CREB signalling.

    PubMed

    Hollander, Jonathan A; Im, Heh-In; Amelio, Antonio L; Kocerha, Jannet; Bali, Purva; Lu, Qun; Willoughby, David; Wahlestedt, Claes; Conkright, Michael D; Kenny, Paul J

    2010-07-01

    Cocaine addiction is characterized by a gradual loss of control over drug use, but the molecular mechanisms regulating vulnerability to this process remain unclear. Here we report that microRNA-212 (miR-212) is upregulated in the dorsal striatum of rats with a history of extended access to cocaine. Striatal miR-212 decreases responsiveness to the motivational properties of cocaine by markedly amplifying the stimulatory effects of the drug on cAMP response element binding protein (CREB) signalling. This action occurs through miR-212-enhanced Raf1 activity, resulting in adenylyl cyclase sensitization and increased expression of the essential CREB co-activator TORC (transducer of regulated CREB; also known as CRTC). Our findings indicate that striatal miR-212 signalling has a key role in determining vulnerability to cocaine addiction, reveal new molecular regulators that control the complex actions of cocaine in brain reward circuitries and provide an entirely new direction for the development of anti-addiction therapeutics based on the modulation of noncoding RNAs.

  7. FGF-1 Triggers Pannexin-1 Hemichannel Opening in Spinal Astrocytes of Rodents and Promotes Inflammatory Responses in Acute Spinal Cord Slices

    PubMed Central

    Yang, Guang; Bukauskas, Feliksas F.

    2016-01-01

    We show here that the growth factor FGF-1 is proinflammatory in the spinal cord and explore the inflammatory mechanisms. FGF-1 applied to rat spinal astrocytes in culture initiates calcium signaling and induces secretion of ATP that within minutes increases membrane permeability to ethidium (Etd+) and Ca2+ by activating P2X7 receptors (P2X7Rs) that open pannexin hemichannels (Px1 HCs) that release further ATP; by 7 h treatment, connexin 43 hemichannels (Cx43 HCs) are also opened. In acute mouse spinal cord slices ex vivo, we found that FGF-1 treatment for 1 h increases the percentage of GFAP-positive astrocytes that show enhanced Px1 HC-mediated Etd+ uptake. This response to FGF-1 was not observed in astrocytes in slices of cerebral cortex. FGF-1-induced dye uptake by astrocytes is prevented by BAPTA-AM or a phospholipase C (PLC) inhibitor. Furthermore, in spinal cord slices, P2X7R antagonists (BBG and A740003) and Px1 HC blockers (10Panx1 and carbenoxolone) prevent the increase in Etd+ uptake by astrocytes, whereas Gap19, a selective Cx43 HC blocker, has no effect on dye uptake at this time. Microglia are not required for the increase in Etd+ uptake by astrocytes induced by FGF-1, although they are activated by FGF-1 treatment. The morphological signs of microglia activation are inhibited by P2X7R antagonists and 10Panx1 and are associated with elevated levels of proinflammatory cytokines in cord slices treated with FGF-1. The FGF-1 initiated cascade may play an important role in spinal cord inflammation in vivo. SIGNIFICANCE STATEMENT We find that FGF-1 elevates [Ca2+]i in spinal astrocytes, which causes vesicular release of ATP and activation of P2X7Rs to trigger opening of Px1 HCs, which release further ATP. This regenerative response occurs in astrocyte cultures and in acute spinal cord slices. In the latter, FGF-1 application promotes the activation of microglia and increases the production of proinflammatory cytokines through mechanisms depending on P2X7

  8. Signalling to the nucleus under the control of light and small molecules.

    PubMed

    Juillot, Samuel; Beyer, Hannes M; Madl, Josef; Weber, Wilfried; Zurbriggen, Matias D; Römer, Winfried

    2016-02-01

    One major regulatory mechanism in cell signalling is the spatio-temporal control of the localization of signalling molecules. We synthetically designed an entire cell signalling pathway, which allows controlling the transport of signalling molecules from the plasma membrane to the nucleus, by using light and small molecules.

  9. Scleroderma fibroblasts show increased responsiveness to endothelial cell-derived IL-1 and bFGF.

    PubMed

    Denton, C P; Xu, S; Black, C M; Pearson, J D

    1997-03-01

    Fibroblasts cultured from lesional skin in scleroderma (systemic sclerosis) demonstrate an activated phenotype that may be important in pathogenesis. Endothelial cell-derived cytokines can modulate fibroblast properties, and endothelial cell changes occur early in scleroderma. Thus, endothelial cell and fibroblast dysfunction may be linked through the paracrine activity of soluble endothelial cell products. We have explored endothelial cell-fibroblast interactions in vitro by investigating the modulation of scleroderma and control fibroblast properties by endothelial cell-conditioned medium (EC-CM). EC-CM caused a concentration-dependent stimulation of fibroblast DNA and protein synthesis and upregulation of cell surface ICAM-1 expression. Scleroderma fibroblasts showed consistently greater responses than control cells. Medium conditioned by mechanically wounded endothelial cells had a greater effect than that from resting endothelial cells. Pre-incubation of EC-CM with anti-bFGF significantly reduced the promotion of fibroblast thymidine incorporation but did not affect endothelial cell-induced leucine incorporation. Conversely, anti-IL-1 antibodies abrogated EC-CM-induced leucine incorporation and ICAM-1 expression but did not diminish thymidine incorporation. Recombinant bFGF or IL-1 modulated fibroblast properties similarly. These data demonstrate that endothelial cell-derived IL-1 and bFGF modulate fibroblast properties independently and that lesional scleroderma strains are more responsive than control fibroblasts to endothelial cell-induced modulation, which supports the hypothesis that altered endothelial cell-fibroblast communication may be involved in the pathogenesis of scleroderma.

  10. Structural basis by which alternative splicing modulates the organizer activity of FGF8 in the brain

    PubMed Central

    Olsen, Shaun K.; Li, James Y.H.; Bromleigh, Carrie; Eliseenkova, Anna V.; Ibrahimi, Omar A.; Lao, Zhimin; Zhang, Fuming; Linhardt, Robert J.; Joyner, Alexandra L.; Mohammadi, Moosa

    2006-01-01

    Two of the four human FGF8 splice isoforms, FGF8a and FGF8b, are expressed in the mid-hindbrain region during development. Although the only difference between these isoforms is the presence of an additional 11 amino acids at the N terminus of FGF8b, these isoforms possess remarkably different abilities to pattern the midbrain and anterior hindbrain. To reveal the structural basis by which alternative splicing modulates the organizing activity of FGF8, we solved the crystal structure of FGF8b in complex with the “c” splice isoform of FGF receptor 2 (FGFR2c). Using surface plasmon resonance (SPR), we also characterized the receptor-binding specificity of FGF8a and FGF8b, the “b” isoform of FGF17 (FGF17b), and FGF18. The FGF8b-FGFR2c structure shows that alternative splicing permits a single additional contact between phenylalanine 32 (F32) of FGF8b and a hydrophobic groove within Ig domain 3 of the receptor that is also present in FGFR1c, FGFR3c, and FGFR4. Consistent with the structure, mutation of F32 to alanine reduces the affinity of FGF8b toward all these receptors to levels characteristic of FGF8a. More importantly, analysis of the mid-hindbrain patterning ability of the FGF8bF32A mutant in chick embryos and murine midbrain explants shows that this mutation functionally converts FGF8b to FGF8a. Moreover, our data suggest that the intermediate receptor-binding affinities of FGF17b and FGF18, relative to FGF8a and FGF8b, also account for the distinct patterning abilities of these two ligands. We also show that the mode of FGF8 receptor-binding specificity is distinct from that of other FGFs and provide the first biochemical evidence for a physiological FGF8b-FGFR1c interaction during mid-hindbrain development. Consistent with the indispensable role of FGF8 in embryonic development, we show that the FGF8 mode of receptor binding appeared as early as in nematodes and has been preserved throughout evolution. PMID:16384934

  11. Structural Basis by Which Alternative Splicing Modulates the Organizer Activity of FGF8 in the Brain

    SciTech Connect

    Olsen,S.; Li, J.; Eliseenkova, A.; Ibrahimi, O.; Lao, Z.; Zhang, F.; Linhardt, R.; Joyner, A.; Mohammadi, M.

    2006-01-01

    Two of the four human FGF8 splice isoforms, FGF8a and FGF8b, are expressed in the mid-hindbrain region during development. Although the only difference between these isoforms is the presence of an additional 11 amino acids at the N terminus of FGF8b, these isoforms possess remarkably different abilities to pattern the midbrain and anterior hindbrain. To reveal the structural basis by which alternative splicing modulates the organizing activity of FGF8, we solved the crystal structure of FGF8b in complex with the 'c' splice isoform of FGF receptor 2 (FGFR2c). Using surface plasmon resonance (SPR), we also characterized the receptor-binding specificity of FGF8a and FGF8b, the 'b' isoform of FGF17 (FGF17b), and FGF18. The FGF8b-FGFR2c structure shows that alternative splicing permits a single additional contact between phenylalanine 32 (F32) of FGF8b and a hydrophobic groove within Ig domain 3 of the receptor that is also present in FGFR1c, FGFR3c, and FGFR4. Consistent with the structure, mutation of F32 to alanine reduces the affinity of FGF8b toward all these receptors to levels characteristic of FGF8a. More importantly, analysis of the mid-hindbrain patterning ability of the FGF8b{sup F32A} mutant in chick embryos and murine midbrain explants shows that this mutation functionally converts FGF8b to FGF8a. Moreover, our data suggest that the intermediate receptor-binding affinities of FGF17b and FGF18, relative to FGF8a and FGF8b, also account for the distinct patterning abilities of these two ligands. We also show that the mode of FGF8 receptor-binding specificity is distinct from that of other FGFs and provide the first biochemical evidence for a physiological FGF8b-FGFR1c interaction during mid-hindbrain development. Consistent with the indispensable role of FGF8 in embryonic development, we show that the FGF8 mode of receptor binding appeared as early as in nematodes and has been preserved throughout evolution.

  12. Phospholipase D Controls Dictyostelium Development By Regulating G Protein Signaling

    PubMed Central

    Ray, Sibnath; Chen, Yi; Ayoung, Joanna; Hanna, Rachel; Brazill, Derrick

    2010-01-01

    Dictyostelium discoideum cells normally exist as individual amoebae, but will enter a period of multicellular development upon starvation. The initial stages of development involve the aggregation of individual cells, using cAMP as a chemoattractant. Chemotaxis is initiated when cAMP binds to its receptor, cAR1, and activates the associated G protein, Gα2βγ. However, chemotaxis will not occur unless there is a high density of starving cells present, as measured by high levels of the secreted quorum sensing molecule, CMF. We previously demonstrated that cells lacking PldB bypass the need for CMF and can aggregate at low cell density, whereas cells overexpressing pldB do not aggregate even at high cell density. Here, we found that PldB controlled both cAMP chemotaxis and cell sorting. PldB was also required by CMF to regulate G protein signaling. Specifically, CMF used PldB, to regulate the dissociation of Gα2 from Gβγ. Using fluorescence resonance energy transfer (FRET), we found that along with cAMP, CMF increased the dissociation of the G protein. In fact, CMF augmented the dissociation induced by cAMP. This augmentation was lost in cells lacking PldB. PldB appears to mediate the CMF signal through the production of phosphatidic acid, as exogenously added phosphatidic acid phenocopies overexpression of pldB. These results suggest that phospholipase D activity is required for CMF to alter the kinetics of cAMP-induced G protein signaling. PMID:20950684

  13. Control of cancer-related signal transduction networks

    NASA Astrophysics Data System (ADS)

    Albert, Reka

    2013-03-01

    Intra-cellular signaling networks are crucial to the maintenance of cellular homeostasis and for cell behavior (growth, survival, apoptosis, movement). Mutations or alterations in the expression of elements of cellular signaling networks can lead to incorrect behavioral decisions that could result in tumor development and/or the promotion of cell migration and metastasis. Thus, mitigation of the cascading effects of such dysregulations is an important control objective. My group at Penn State is collaborating with wet-bench biologists to develop and validate predictive models of various biological systems. Over the years we found that discrete dynamic modeling is very useful in molding qualitative interaction information into a predictive model. We recently demonstrated the effectiveness of network-based targeted manipulations on mitigating the disease T cell large granular lymphocyte (T-LGL) leukemia. The root of this disease is the abnormal survival of T cells which, after successfully fighting an infection, should undergo programmed cell death. We synthesized the relevant network of within-T-cell interactions from the literature, integrated it with qualitative knowledge of the dysregulated (abnormal) states of several network components, and formulated a Boolean dynamic model. The model indicated that the system possesses a steady state corresponding to the normal cell death state and a T-LGL steady state corresponding to the abnormal survival state. For each node, we evaluated the restorative manipulation consisting of maintaining the node in the state that is the opposite of its T-LGL state, e.g. knocking it out if it is overexpressed in the T-LGL state. We found that such control of any of 15 nodes led to the disappearance of the T-LGL steady state, leaving cell death as the only potential outcome from any initial condition. In four additional cases the probability of reaching the T-LGL state decreased dramatically, thus these nodes are also possible control