title: Cytoarchitecture of fibroblast growth factor receptor 2 (FGFR-2) immunoreactivity in astrocytes of neurogenic and non-neurogenic regions of the young adult and aged rat brain.
abstract: Fibroblast growth factors (FGFs) are polypeptides that exert diverse biological effects on many cell types and tissues during embryogenesis and adulthood. In the adult brain, FGF-2 is primarily expressed by astrocytes and select groups of neurons. It has been shown that FGF-2 is neuroprotective and can stimulate proliferation of NSCs in neurogenic regions of the adult mammalian brain. Cellular responses to FGFs are mediated through membrane-spanning tyrosine kinase receptors in conjunction with low affinity binding to heparin sulfate proteoglycans. Four FGF receptors (FGFR1-4) have been cloned and characterized to date. In this study, we describe the anatomical distribution of FGFR-2 in young and aged rat brains. We demonstrate that the olfactory bulb, hippocampus, and cerebellum display the most robust FGFR-2 expression and observed age-related decrease in FGFR-2 levels in some but not all brain regions. In addition, we identified astrocytes as the primary source of FGFR-2 expression using immunofluorescence confocal microscopy. The astrocyte populations in the neurogenic areas, the subventricular zone (SVZ) and the subgranular zone (SGZ) of the dentate gyrus, express high levels of FGFR-2 protein, which points to its possible involvement in neurogenesis. We also explored the role of FGFR-2 in response to perforant pathway lesion and observed enhanced FGFR-2 expression by astrocytes surrounding the lesion. Thus, FGF-2 biological effects on astrocytes appear to be mediated through FGFR-2-dependent mechanisms, and this may provide an indirect route by which FGF-2 acts on neuronal populations.
authors.affiliation: Neural Repair and Neurogenesis Laboratory, Department of Neuroscience, The Chicago Medical School at Rosalind Franklin University of Medicine and Science, Chicago, Illinois 60064, USA.
authors.forename: Tamuna
authors.initials: T
authors.lastname: Chadashvili
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Peterson
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000378:metabolism*; D001921:Brain / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation; D015536:Down-Regulation / Q000502:physiology; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism*; D007150:Immunohistochemistry; D009416:Nerve Regeneration / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology; D019580:Perforant Pathway / Q000293:injuries / Q000502:physiology; D051381:Rats; D011916:Rats, Inbred F344; D051497:Receptor, Fibroblast Growth Factor, Type 2 / Q000378:metabolism*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism; D015854:Up-Regulation / Q000502:physiology
chemical_list: D016222:Fibroblast Growth Factor 2; D051497:Receptor, Fibroblast Growth Factor, Type 2