Trauma raquimedular: avaliação do potencial neuroregenerador e neuroprotetor da fração proteica extraída do látex
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Data
2018-05-24
Autores
Rosa-Ballaben, Nátalie Massaro
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A lesão medular não é um evento incomum na medicina humana e veterinária e resulta em disfunções neurológicas de graus variados. Apesar dos esforços no tratamento, lesões medulares frequentemente causam sequelas permanentes, desde déficit proprioceptivo isolado até paralisia completa de membros. A membrana confeccionada à base de látex natural extraído da seringueira Hevea brasiliensis tem sido utilizada com sucesso para regeneração de tecidos, e seu potencial regenerador foi reconhecido como sendo de uma fração proteica conhecida como proteína P1. Este novo biomaterial foi eficaz em vários testes de regeneração em animais de experimentação e humanos, e, ainda que tenha mostrado potencial regenerador em teste de lesão de nervo periférico, a proteína ainda não foi testada em Sistema Nervoso Central. Objetivou-se avaliar o potencial regenerador da fração proteica extraída do látex natural (P1) na hemissecção da medula espinhal em ratos. Foram utilizados 18 ratos machos adultos submetidos à hemissecção medular no segmento medular T13 subdivididos em dois grupos: GHP (tratados com proteína P1 em gel de ácido hialurônico) e GHSP (tratado somente com ácido hialurônico). Foram realizadas análises neuroclínicas, bem como avaliação funcional da marcha em plataforma de acrílico. Após oito semanas os animais foram submetidos à eutanásia e os segmentos medulares envolvidos foram avaliados por histoquímica pela coloração Tricrômico de Masson e Luxol Fast Blue, além de avaliação da reação astroglial por imunoistoquímica. Não houve diferença significativa entre os dois grupos para as avaliações neuroclínicas, não sendo observado melhora clínica satisfatória para as variáveis analisadas, porém, em relação à análise histológica foi notada diferença importante entre os grupos, evidenciando menor reação cicatricial e degeneração do tecido medular restante, além de presença de hipercelularidade organizada e menor reação astroglial nos animais tratados com a fração protéica P1. Apesar da não evidência de melhora nos parâmetro neuroclínicos com o uso da proteína P1, houve alterações histológicas notórias e relevantes nos animais em que foi utilizada, além de ser benéfica como indutora de neuroproteção.
Spinal cord injury is not an uncommon event in human and veterinary medicine and results in neurological dysfunctions of varying degrees. Despite efforts in treatment, spinal cord injuries often cause permanent sequelae, ranging from isolated proprioceptive deficit to complete limb paralysis. The membrane made from natural latex extracted from the rubber tree Hevea brasiliensis has been successfully used for tissue regeneration and its regenerative potential has been recognized as being of a protein fraction known as P1 protein. This new biomaterial has been effective in several regeneration tests in experimental animals and humans, and although it has shown a potential regenerator in a peripheral nerve injury test, the protein has not yet been tested in the Central Nervous System. The objective of this study was to evaluate the regenerative potential of the protein fraction extracted from natural latex (P1) in the hemisection of the spinal cord in rats. Eighteen adult male rats submitted to medullary hemisection in the T13 medullary segment were subdivided into two groups: GHP (treated with protein P1 in hyaluronic acid gel) and GHSP (treated with hyaluronic acid only). Neuroclinical analyzes were performed as well as functional evaluation of gait on acrylic platform. After eight weeks the animals were submitted to euthanasia and the involved spinal segments were evaluated by histochemistry by Masson and Luxol Fast Blue Trichrome staining, as well as evaluation of the astroglial reaction by immunohistochemistry. There was no significant difference between the two groups for the neuroclinical evaluations, and no satisfactory clinical improvement was observed for the analyzed variables; however, in relation to the histological analysis, an important difference between the groups was observed, evidencing a smaller cicatricial reaction and degeneration of the remaining spinal cord tissue, besides the presence of organized hypercellularity and less astroglial reaction in the animals treated with the protein fraction P1. Although there was no evidence of improvement in the neuroclinical parameters with the use of the P1 protein, there were significant and relevant histological changes in the animals in which it was used, besides being beneficial as inducer of neuroprotection.
Spinal cord injury is not an uncommon event in human and veterinary medicine and results in neurological dysfunctions of varying degrees. Despite efforts in treatment, spinal cord injuries often cause permanent sequelae, ranging from isolated proprioceptive deficit to complete limb paralysis. The membrane made from natural latex extracted from the rubber tree Hevea brasiliensis has been successfully used for tissue regeneration and its regenerative potential has been recognized as being of a protein fraction known as P1 protein. This new biomaterial has been effective in several regeneration tests in experimental animals and humans, and although it has shown a potential regenerator in a peripheral nerve injury test, the protein has not yet been tested in the Central Nervous System. The objective of this study was to evaluate the regenerative potential of the protein fraction extracted from natural latex (P1) in the hemisection of the spinal cord in rats. Eighteen adult male rats submitted to medullary hemisection in the T13 medullary segment were subdivided into two groups: GHP (treated with protein P1 in hyaluronic acid gel) and GHSP (treated with hyaluronic acid only). Neuroclinical analyzes were performed as well as functional evaluation of gait on acrylic platform. After eight weeks the animals were submitted to euthanasia and the involved spinal segments were evaluated by histochemistry by Masson and Luxol Fast Blue Trichrome staining, as well as evaluation of the astroglial reaction by immunohistochemistry. There was no significant difference between the two groups for the neuroclinical evaluations, and no satisfactory clinical improvement was observed for the analyzed variables; however, in relation to the histological analysis, an important difference between the groups was observed, evidencing a smaller cicatricial reaction and degeneration of the remaining spinal cord tissue, besides the presence of organized hypercellularity and less astroglial reaction in the animals treated with the protein fraction P1. Although there was no evidence of improvement in the neuroclinical parameters with the use of the P1 protein, there were significant and relevant histological changes in the animals in which it was used, besides being beneficial as inducer of neuroprotection.
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Palavras-chave
Neurologia, Biomateriais, Medula espinhal, Regeneração tecidual