FGF (Fibroblast Growth Factor)

Abstract

(Duh et al. 1994; Holthuis et al. 1994). The sequence analyses revealed that fascin proteins form a unique family of actin-bundling proteins, sharing no apparent homology with nonfascin actin-bundling proteins including alpha-actinin, villin, and fimbrin.Vertebrates have three fascin genes (fascin-1 through À3): fascin-1 shows widespread expression in a variety of tissues, whereas expression of fascin-2 is restricted to retina and hair cell stereocilia, whereas fascin-3 is restricted to testis. Fascin is absent in Dictyostelium discoideum, C. elegans, or yeasts. As expected from the actin-bundling activity, fascin is mainly localized in filopodia of mammalian cultured cells, microvilli of sea urchin eggs, and drosophila bristles. Consistent with highly motile structure of filopodia, fascin is shown to promote cell motility and metastasis of tumor cells. Intriguingly, a fascin homologue is found in microvilli and filopodia of choanoflagellates. Because this unicellular organism is considered as the last ancestor of multicellular animals, fascin1 is suggested to be an ancestral component for filopodial assembly machinery (Sebe-Pedros et al. 2013). Structure and Function of FascinX-ray structural analyses revealed that fascin has a b-trefoil structure (Sedeh et al. 2010), showing Fascin1 plays an important role in the formation of filopodia in mammalian cells. In vitro, fascin1 makes parallel actin bundles with uniform polarity, which is consistent with its localization in filopodia. Upregulation of fascin1 induces membrane protrusions and increases cell motility of epithelial cells, as well as colonic epithelial and carcinoma cells. Conversely, Fascin1 knock down has been reported to block filopodia assembly of B16F1 mouse melanoma cells, as well as colon carcinoma cells and mature antigen-presenting dendritic cells (DCs) (Ross et al. 1998).In addition to binding to actin filaments, fascin1 has been recently reported to bind directly to microtubules (Villari et al. 2015). Fascin1-microtubule binding occurred independently of fascin1-actin binding. The association was shown to increase the dynamics of focal adhesions, as well as that of microtubules, thereby controlling cell motility. This regulation of focal adhesion dynamics may be controlled via FAK because fascin1 was found to bind to FAK. Genetic AnalysesAnalyses of Drosophila singed mutations indicate that fascin1 is involved in female sterility, in addition to the gnarled bristle phenotype. In Drosophila oogenesis, each developing oocyte is surrounded by and connected to 15 nurse cells via intercellular bridges. Nurse cell cytoplasmic contents flow into the oocyte along actin filaments traversing these cytoplasmic bridges. A singed allele affects the microfilament structure required for this nurse cell cytoplasmic flow, resulting in female sterility (Cant et al. 1994). Interestingly, fascin1 is involved in prostaglandin-mediated actin remodeling (Groen et al. 2012). Prostaglandin is synthesized in Drosophila by peroxidase (Pxt), a cyclooxygenase (COX)-like...

Targeting Growth Factor and Cytokine Pathways to Treat Idiopathic Pulmonary Fibrosis

“…FGFs rely on heparan sulfate proteoglycan (HSPG) and Klotho-type coreceptors to improve their binding to FGFRs (Ornitz and Itoh, 2022). After FGF-FGFR binding, through the autophosphorylation of FGFRs, with the help of FGFR substrate 2 and PLCγ, signals are transferred to the RAS-ERK, PI3K/AKT, PKC, and JAK-STAT signaling cascades, which mediate the survival, proliferation, differentiation, or migration of cells (Inomata et al, 2015;Katoh, 2018).…”

Pulmonary Fibrosis: One Manifestation, Various Diseases

“…FGFs rely on heparan sulfate proteoglycan (HSPG) and Klotho-type coreceptors to improve their binding to FGFRs (Ornitz and Itoh, 2022). After FGF-FGFR binding, through the autophosphorylation of FGFRs, with the help of FGFR substrate 2 and PLCγ, signals are transferred to the RAS-ERK, PI3K/AKT, PKC, and JAK-STAT signaling cascades, which mediate the survival, proliferation, differentiation, or migration of cells (Inomata et al, 2015;Katoh, 2018).…”

Tumour-Induced Osteomalacia—A Long Way to the Diagnosis Facilitated by [68Ga]Ga-DOTATATE PET/CT

“…FGF23 is an endocrine hormone physiologically synthesized by osteocytes and osteoblasts and is involved in the regulation of serum phosphate concentration [ 3 ]. Similar to parathyroid hormone (PTH), FGF23 downregulates the reabsorption of phosphate from the proximal convoluted tubules in the kidneys [ 4 ]. Additionally, FGF23 inhibits PTH and 1.25-dihydroxyvitamin D (1.25(OH) 2 D) synthesis.…”