Abstracts
The integrity of myelin sheaths is maintained by oligodendrocytes and Schwann cells respectively in the central nervous system (CNS) and in the peripheral nervous system. The process of demyelination consisting of the withdrawal of myelin sheaths from their axons is a characteristic feature of multiple sclerosis, the most common human demyelinating disease. Many experimental models have been designed to study the biology of demyelination and remyelination (repair of the lost myelin) in the CNS, due to the difficulties in studying human material. In the ethidium bromide (an intercalating gliotoxic drug) model of demyelination, CNS remyelination may be carried out by surviving oligodendrocytes and/or by cells differentiated from the primitive cell lines or either by Schwann cells that invade the CNS. However, some factors such as the age of the experimental animals, intensity and time of exposure to the intercalating chemical and the topography of the lesions have marked influence on the repair of the tissue.
toxic demyelination; remyelination; central nervous system; peripheral nervous system
A integridade da bainha de mielina é fornecida pelos oligodendrócitos e pelas células de Schwann, no sistema nervoso central (SNC) e no sistema nervoso periférico, respectivamente. O fenômeno de desmielinização refere-se à remoção das bainhas de mielina de axônios e este fato é característico na esclerose múltipla, a doença desmielinizante do SNC mais comum no homem. Muitos modelos experimentais têm sido utilizados para o estudo da biologia da desmielinização e remielinização no SNC, face à dificuldade de estudo de material humano. No modelo experimental da droga intercalate, gliotóxica, brometo de etídio, a remielinização do SNC pode ser efetuada por oligodendrócitos sobreviventes à lesão e/ou oriundos de diferenciação de linhagens celulares mais primitivas e por células de Schwann que invadem o SNC. No entanto, fatores como a idade dos animais, a intensidade, e o tempo de exposição ao agente intercalante e a topografia da lesão influenciam significativamente a reparação da lesão.
desmielinização tóxica; remielinização; sistema nervoso central; sistema nervoso periférico
Biology of the repair of central nervous system demyelinated lesions: an appraisal
Biologia da reparação de lesões desmielinizantes do sistema nervoso central: uma avaliação
L. A. V PeireiraI; M. A. Cruz-HöflingII; M. S. J. DertkigilIII; D. L. GraçaIV
IAssistant Professor DHE/IB/UNICAMP
IIAssociate Professor DHE/1B/UN1CAMP
IIIGraduate Student of Medical Sciences/UNICAMP
IVProfessor of Pathology DP/ CCS/UFSM
ABSTRACT
The integrity of myelin sheaths is maintained by oligodendrocytes and Schwann cells respectively in the central nervous system (CNS) and in the peripheral nervous system. The process of demyelination consisting of the withdrawal of myelin sheaths from their axons is a characteristic feature of multiple sclerosis, the most common human demyelinating disease. Many experimental models have been designed to study the biology of demyelination and remyelination (repair of the lost myelin) in the CNS, due to the difficulties in studying human material. In the ethidium bromide (an intercalating gliotoxic drug) model of demyelination, CNS remyelination may be carried out by surviving oligodendrocytes and/or by cells differentiated from the primitive cell lines or either by Schwann cells that invade the CNS. However, some factors such as the age of the experimental animals, intensity and time of exposure to the intercalating chemical and the topography of the lesions have marked influence on the repair of the tissue.
Key words: toxic demyelination, remyelination, central nervous system, peripheral nervous system.
RESUMO
A integridade da bainha de mielina é fornecida pelos oligodendrócitos e pelas células de Schwann, no sistema nervoso central (SNC) e no sistema nervoso periférico, respectivamente. O fenômeno de desmielinização refere-se à remoção das bainhas de mielina de axônios e este fato é característico na esclerose múltipla, a doença desmielinizante do SNC mais comum no homem. Muitos modelos experimentais têm sido utilizados para o estudo da biologia da desmielinização e remielinização no SNC, face à dificuldade de estudo de material humano. No modelo experimental da droga intercalate, gliotóxica, brometo de etídio, a remielinização do SNC pode ser efetuada por oligodendrócitos sobreviventes à lesão e/ou oriundos de diferenciação de linhagens celulares mais primitivas e por células de Schwann que invadem o SNC. No entanto, fatores como a idade dos animais, a intensidade, e o tempo de exposição ao agente intercalante e a topografia da lesão influenciam significativamente a reparação da lesão.
Palavras-chave: desmielinização tóxica, remielinização, sistema nervoso central, sistema nervoso periférico.
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Acknowledgements - This study was benefited in part by a Grant-in Aid for Scientific Research (project number 93/4994-5) from FAPESP (São Paulo, Brazil). The authors wish to thank Mrs. Adriane S.Sprogis, Antonia F. Lima (UNICAMP) and Iara E. Flores (UFSM) for the technical assistance.
33. Wolswijk G, Noble M. Cooperation between PDGF and FGF converts slowly dividing 0-2A"*"' progenitor cells to rapidly dividing cells with characteristics of 0-2A *«*»•»> progenitor cells. J Cell Biol 1992; 118:889-900.
Aceite:9-janeiro-1996.
Study carried out in the Department of Histology and Embryology (DHE), Institute of Biology (IB), State University of Campinas (UNICAMP) and Department of Pathology (DP), Health Science Center (CCS), Federal University of Santa Maria (UFSM)
Dr. Luís Antônio Violin Pereira - Department of Histology and Embryology, IB/UNICAMP - P.O.Box 6109 -13083-970 Campinas SP - Brazil. FAX 55 192 39 3124.
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Publication Dates
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Publication in this collection
06 Dec 2010 -
Date of issue
June 1996