Differential regulation of FGF-2 in neurons and reactive astrocytes of axotomized rat hypoglossal nucleus. A possible therapeutic target for neuroprotection in peripheral nerve pathology

Autor(es)

de Oliveira, Gabriela Pintar ^[1] ; Duobles, Tatiana ^[1] ; Castelucci, Patricia ^[2] ; Chadi, Gerson ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Med, Dept Neurobiol, Neuroregenerat Ctr, BR-01246903 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Inst Biomed Sci, Dept Anat, BR-01246903 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ACTA HISTOCHEMICA; v. 112, n. 6, p. 604-617, 2010.
• Citações Web of Science: 7

Resumo

Despite the favorable treatment of cranial nerve neuropathology in adulthood, some cases are resistant to therapy leading to permanent functional impairments In many cases, suitable treatment is problematic as the therapeutic target remains unknown Basic fibroblast growth factor (bFGF, FGF 2) is involved in neuronal maintenance and wound repair following nervous system lesions It is one of few neurotrophic molecules acting in autocrine, paracrine and intracrine fashions depending upon specific circumstances Peripheral cranial somatic motor neurons, i e hypoglossal (XII) neurons, may offer a unique opportunity to study cellular FGF 2 mechanisms as the molecule is present in the cytoplasm of neurons and in the nuclei of astrocytes of the central nervous system FGF-2 may trigger differential actions during development, maintenance and lesion of XII neurons because axotomy of those cells leads to cell death during neonatal ages, but not in adult life Moreover, the modulatory effects of astroglial FGF 2 and the Ca+2 binding protein S100 beta have been postulated in paracrine mechanisms after neuronal lesions In our study, adult Wistar rats received a unilateral crush or transection (with amputation of stumps) of XII nerve, and were sacrificed after 72 h or 11 days Brains were processed for immunohistochemical localization of neurofilaments (NF), with or without counterstaining for Nissl substance, ghat fibrillary acidic protein (GFAP, as a marker of astrocytes), S100 beta and FGF-2 The number of Nissl positive neurons of axotomized XII nucleus did not differ from controls The NF immunoreactivity increased in the perikarya and decreased in the neuropil of axotomized XII neurons 11 days after nerve crush or transection An astrocytic reaction was seen in the ipsilateral XII nucleus of the crushed or transected animals 72 h and 11 days after the surgery The nerve lesions did not change the number of FGF-2 neurons in the ipsilateral XII nucleus, however, the nerve transection increased the number of FGF-2 ghat profiles by 72 h and 11 days Microdensitometric image analysis revealed a short lasting decrease in the intensity of FGF 2 immunoreactivity in axotomized XII neurons by 72 h after nerve crush or transection and also an elevation of FGF-2 in the ipsilateral of ghat nuclei by 72h and 11 days after the two lesions S100 beta decreased in astrocytes of 11-day transected XII nucleus The two-color immunoperoxidase for the simultaneous detection of the GFAP/FGF-2 indicated FGF-2 upregulation in the nuclei of reactive astrocytes of the lesioned XII nucleus Astroglial FGF-2 may exert paracrine trophic actions in mature axotomized XII neurons and might represent a therapeutic target for neuroprotection in peripheral nerve pathology (C) 2009 Elsevier GmbH All rights reserved (AU)

• Processo FAPESP: 99/01319-1 - Análise da regeneração da medula espinhal após enxertos de nervos ou inoculação de células de Schwann em presença do fator neurotrófico derivado de células gliais (GDNF)
• Beneficiário: Gerson Chadi
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 98/13122-5 - Efeito da ativação neuronal pela atividade física nas respostas tróficas e plásticas neuronais e gliais do sistema nervoso central lesado ou não de ratos: estudo imunohistoquímico combinado às análises estereológica e microdensitométrica quantitativas
• Beneficiário: Gerson Chadi
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 07/00491-3 - Análise do potencial das células de Schwann cultivadas e tratadas com o PEDF favorecem o trofismo de neurônios medulares in vitro a induzirem a regeneração e a recuperação motora de ratos submetidos ao trauma contuso da medula espinal pelo Impactor
• Beneficiário: Gerson Chadi
• Modalidade de apoio: Auxílio à Pesquisa - Regular