title: Cellular analysis of S100Beta and fibroblast growth factor-2 in the dorsal root ganglia and sciatic nerve of rodents. focus on paracrine actions of activated satellite cells after axotomy.
abstract: The role of satellite cells, a type of peripheral glia, in the paracrine mechanisms related to neuronal maintenance and plasticity in the dorsal root ganglia (DRG) needs to be further investigated. This study employed immunohistochemistry and image analysis to investigate basic fibroblast growth factor (bFGF, FGF-2) and S100Beta immunoreactivities in the DRG and sciatic nerve of the rat and mouse. Well-characterized antibodies against bovine (residues 1-24) and rat (residues 1-23) FGF-2 were employed. Furthermore, the state of satellite cell reaction and changes in the FGF-2/S100Beta immunoreactivity were analyzed after axotomy of rat sciatic nerve. Scattered neurons and the majority of the satellite cells of the rat DRG and also Schwann cells of the rat sciatic nerve stained for S100Beta. In the mouse, strong S100Beta was encountered in the majority of sensory neurons and Schwann cells. Moderate FGF-2 (residues 1-24) immunoreactivity was found in scattered small size neurons of the rat DRG. A strong FGF-2 (residues 1-23) immunoreactivity was achieved in the satellite cells of rat DRG. Both FGF-2 antisera showed strong labeling in the mouse DRG sensory neurons. Activated satellite cells of the axotomized DRG possessed increased amount of FGF-2 and S100Beta immunoreactivity as demonstrated by quantitative image analysis. The proximal stump of the lesioned rat sciatic nerve showed increased FGF-2 (residues 1-24 and 1-23) in the Schwann cells, myelin sheaths, and neuronal fibers, without changes in the level of S100Beta immunoreactivity. Results suggested a possible interaction between FGF-2 and S100Beta in activated satellite cells of the DRG, which might trigger paracrine actions in the axotomized sensory neurons.
authors.affiliation: Neuroregeneration Center, Department of Neurology, University of São Paulo School of Medicine, São Paulo, Brazil.
authors.forename: Beatriz De Freitas Azevedo
authors.initials: Bde F
authors.lastname: Levy
authors.forename: Jinger Do Carmo
authors.initials: Jdo C
authors.lastname: Cunha
authors.forename: Gerson
authors.initials: G
authors.lastname: Chadi
mesh_terms: D000818:Animals; D019771:Axotomy; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism*; D005727:Ganglia, Spinal / Q000166:cytology / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009412:Nerve Fibers / Q000378:metabolism; D009414:Nerve Growth Factors / Q000378:metabolism*; D009475:Neurons, Afferent / Q000378:metabolism / Q000648:ultrastructure; D019899:Paracrine Communication / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000378:metabolism*; D027161:Satellite Cells, Perineuronal / Q000166:cytology / Q000378:metabolism*; D012583:Schwann Cells / Q000166:cytology / Q000378:metabolism; D012584:Sciatic Nerve / Q000166:cytology / Q000378:metabolism*; D013047:Specific Pathogen-Free Organisms
chemical_list: D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D016222:Fibroblast Growth Factor 2