Efeito neuroprotetor do antagonismo do receptor P2X7 no Parkinsonismo experimental induzido por 6-OHDA

Detalhes bibliográficos
Autor(a) principal: Carmo, Marta Regina Santos do
Data de Publicação: 2015
Tipo de documento: Tese
Idioma: por
Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
Texto Completo: http://www.repositorio.ufc.br/handle/riufc/11458
Resumo: Parkinson’s disease (PD) is characterized by a progressive degeneration of dopaminergic neurons in the substantia nigra (SN) and a concomitant decrease of dopamine (DA) in the striatum, which can be modeled by 6-OHDA administration. Since ATP released from damaged cells can exert noxious effects on neurons, acting through its P2X7 receptors (P2X7R), the aim of the present study was to investigate the effects of a P2X7R antagonist, Brilliant Blue G (BBG) on 6-OHDA-induced neurotoxicity. Male Wistar rats received stereotaxic injections of 6-OHDA (18 µg/3µl) into the right striatum and were treated with BBG (45 mg/kg, i.p. 48/48 h) for two weeks. In an additional experiment, animals were treated with the selective antagonist A-438079 (10 µM i.c.v.) for two weeks. BBG decreased the number of contralateral rotations in the apomorphine test, an effect mimicked by the selective P2X7R antagonist A438079. BBG has also improved the animals’ performance in the passive avoidance test (short-term memory) and in the cued version of the Morris Water maze. The antagonism of P2X7R by BBG has also prevented the reduction of dopamine content in the striatum and SN as well as the loss of dopaminergic neurons, and microgliosis and astrogliosis in the striatum. BBG treatment also decreased the IL-1β levels in striatum, despite the observed effect not being statistically significant. To grasp the mechanism of action of BBG, we used in vitro models exploring synaptotoxicity (striatal synaptosomes) and neurotoxicity (dopamine-differentiated SH-SY5Y cells). Besides showing that P2X7R are present in striatal dopaminergic terminals, we observed that BBG 100 nM prevented the 6-OHDA-induced synaptosomal dysfunction. Furthermore, we have shown the presence of P2X7 receptors in SH-SY5Y cells, their co-localization with tyrosine hydroxilase, and that BBG attenuates the cell damage, evaluated through lactate dehydrogenase release. The present results suggests that P2X7R contribute to PD pathogenesis through a triple impact on synaptotoxicity, gliosis and neurotoxicity, highlighting the therapeutic potential of P2X7R antagonists in the disease.
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spelling Efeito neuroprotetor do antagonismo do receptor P2X7 no Parkinsonismo experimental induzido por 6-OHDANeuroprotective effect of p2x7 receptors on experimental 6-ohda-induced parkinsonismTrifosfato de AdenosinaReceptores Purinérgicos P2X7Doença de ParkinsonParkinson’s disease (PD) is characterized by a progressive degeneration of dopaminergic neurons in the substantia nigra (SN) and a concomitant decrease of dopamine (DA) in the striatum, which can be modeled by 6-OHDA administration. Since ATP released from damaged cells can exert noxious effects on neurons, acting through its P2X7 receptors (P2X7R), the aim of the present study was to investigate the effects of a P2X7R antagonist, Brilliant Blue G (BBG) on 6-OHDA-induced neurotoxicity. Male Wistar rats received stereotaxic injections of 6-OHDA (18 µg/3µl) into the right striatum and were treated with BBG (45 mg/kg, i.p. 48/48 h) for two weeks. In an additional experiment, animals were treated with the selective antagonist A-438079 (10 µM i.c.v.) for two weeks. BBG decreased the number of contralateral rotations in the apomorphine test, an effect mimicked by the selective P2X7R antagonist A438079. BBG has also improved the animals’ performance in the passive avoidance test (short-term memory) and in the cued version of the Morris Water maze. The antagonism of P2X7R by BBG has also prevented the reduction of dopamine content in the striatum and SN as well as the loss of dopaminergic neurons, and microgliosis and astrogliosis in the striatum. BBG treatment also decreased the IL-1β levels in striatum, despite the observed effect not being statistically significant. To grasp the mechanism of action of BBG, we used in vitro models exploring synaptotoxicity (striatal synaptosomes) and neurotoxicity (dopamine-differentiated SH-SY5Y cells). Besides showing that P2X7R are present in striatal dopaminergic terminals, we observed that BBG 100 nM prevented the 6-OHDA-induced synaptosomal dysfunction. Furthermore, we have shown the presence of P2X7 receptors in SH-SY5Y cells, their co-localization with tyrosine hydroxilase, and that BBG attenuates the cell damage, evaluated through lactate dehydrogenase release. The present results suggests that P2X7R contribute to PD pathogenesis through a triple impact on synaptotoxicity, gliosis and neurotoxicity, highlighting the therapeutic potential of P2X7R antagonists in the disease.A doença de Parkinson (DP) é caracterizada por uma degeneração progressiva dos neurônios da substância negra (SN) e uma concomitante diminuição do conteúdo de dopamina no estriado, que pode ser mimetizada pela administração de 6-OHDA. Visto que o ATP liberado das células danificadas exerce efeitos deletérios diretos sobre os neurônios, agindo através de receptores P2X7, o objetivo do presente trabalho foi estudar os efeitos do Brilliant Blue G (BBG), um antagonista dos receptores P2X7, sobre a neurotoxicidade induzida por 6-OHDA. Ratos Wistar machos receberam injeções estereotáxicas de 6-OHDA (18 µg/3µl) no estriado direito e foram tratados com BBG (45 mg/kg, i.p. 48/48hs) durante 14 dias. Em uma série adicional de experimentos, os animais receberam o antagonista seletivo A-438079 (10 µM i.c.v.) por 14 dias. O tratamento com BBG diminuiu o número de rotações contralaterais no teste da apomorfina, efeito que foi mimetizado pelo antagonista seletivo A-438079. O BBG também melhorou o desempenho dos animais no teste da esquiva passiva (memória de curta duração), assim como na versão com plataforma sinalizada do labirinto aquático. O antagonismo dos receptores P2X7 pelo BBG preveniu ainda a redução do conteúdo de dopamina no estriado e SN, assim como a perda de neurônios dopaminérgicos, a microgliose e astrogliose no estriado. O tratamento com BBG também diminuiu os níveis de IL-1β no estriado, apesar das diferenças observadas entre os grupos não serem estatisticamente diferentes. Com o objetivo de entender melhor o mecanismo de ação do BBG, foram utilizados modelos in vitro explorando a sinaptotoxicidade (sinaptossomas estriatais) e neurotoxicidade (células SH-SY5Y dopaminérgicas diferenciadas). Além da demonstração da presença dos receptores P2X7 nos terminais nervosos estriatais, foi observado que o BBG 100 nM preveniu a disfunção sinaptossomal. Também demonstramos a presença dos receptores P2X7 nas células SH-SY5Y, assim como sua co-localização com tirosina hidroxilase, onde o pré-tratamento com BBG 100 nM diminuiu o dano celular, avaliado através da liberação de lactato desidrogenase. Os resultados obtidos no presente estudo sugerem que os receptores P2X7 contribuem para a patogênese da DP através de um triplo mecanismo sobre a sinaptotoxicidade, gliose e neurotoxicidade, ressaltando o potencial terapêutico dos antagonistas desses receptores na doença.Andrade, Geanne Matos deCarmo, Marta Regina Santos do2015-04-17T13:14:18Z2015-04-17T13:14:18Z2015info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisapplication/pdfCARMO, M. R. S. do. Efeito neuroprotetor do antagonismo do receptor P2X7 no Parkinsonismo experimental induzido por 6-OHDA. 2015. 110 f. Tese (Doutorado em Farmacologia) - Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, 2015.http://www.repositorio.ufc.br/handle/riufc/11458porreponame:Repositório Institucional da Universidade Federal do Ceará (UFC)instname:Universidade Federal do Ceará (UFC)instacron:UFCinfo:eu-repo/semantics/openAccess2019-10-24T19:23:26Zoai:repositorio.ufc.br:riufc/11458Repositório InstitucionalPUBhttp://www.repositorio.ufc.br/ri-oai/requestbu@ufc.br || repositorio@ufc.bropendoar:2024-09-11T18:55:43.813717Repositório Institucional da Universidade Federal do Ceará (UFC) - Universidade Federal do Ceará (UFC)false
dc.title.none.fl_str_mv Efeito neuroprotetor do antagonismo do receptor P2X7 no Parkinsonismo experimental induzido por 6-OHDA
Neuroprotective effect of p2x7 receptors on experimental 6-ohda-induced parkinsonism
title Efeito neuroprotetor do antagonismo do receptor P2X7 no Parkinsonismo experimental induzido por 6-OHDA
spellingShingle Efeito neuroprotetor do antagonismo do receptor P2X7 no Parkinsonismo experimental induzido por 6-OHDA
Carmo, Marta Regina Santos do
Trifosfato de Adenosina
Receptores Purinérgicos P2X7
Doença de Parkinson
title_short Efeito neuroprotetor do antagonismo do receptor P2X7 no Parkinsonismo experimental induzido por 6-OHDA
title_full Efeito neuroprotetor do antagonismo do receptor P2X7 no Parkinsonismo experimental induzido por 6-OHDA
title_fullStr Efeito neuroprotetor do antagonismo do receptor P2X7 no Parkinsonismo experimental induzido por 6-OHDA
title_full_unstemmed Efeito neuroprotetor do antagonismo do receptor P2X7 no Parkinsonismo experimental induzido por 6-OHDA
title_sort Efeito neuroprotetor do antagonismo do receptor P2X7 no Parkinsonismo experimental induzido por 6-OHDA
author Carmo, Marta Regina Santos do
author_facet Carmo, Marta Regina Santos do
author_role author
dc.contributor.none.fl_str_mv Andrade, Geanne Matos de
dc.contributor.author.fl_str_mv Carmo, Marta Regina Santos do
dc.subject.por.fl_str_mv Trifosfato de Adenosina
Receptores Purinérgicos P2X7
Doença de Parkinson
topic Trifosfato de Adenosina
Receptores Purinérgicos P2X7
Doença de Parkinson
description Parkinson’s disease (PD) is characterized by a progressive degeneration of dopaminergic neurons in the substantia nigra (SN) and a concomitant decrease of dopamine (DA) in the striatum, which can be modeled by 6-OHDA administration. Since ATP released from damaged cells can exert noxious effects on neurons, acting through its P2X7 receptors (P2X7R), the aim of the present study was to investigate the effects of a P2X7R antagonist, Brilliant Blue G (BBG) on 6-OHDA-induced neurotoxicity. Male Wistar rats received stereotaxic injections of 6-OHDA (18 µg/3µl) into the right striatum and were treated with BBG (45 mg/kg, i.p. 48/48 h) for two weeks. In an additional experiment, animals were treated with the selective antagonist A-438079 (10 µM i.c.v.) for two weeks. BBG decreased the number of contralateral rotations in the apomorphine test, an effect mimicked by the selective P2X7R antagonist A438079. BBG has also improved the animals’ performance in the passive avoidance test (short-term memory) and in the cued version of the Morris Water maze. The antagonism of P2X7R by BBG has also prevented the reduction of dopamine content in the striatum and SN as well as the loss of dopaminergic neurons, and microgliosis and astrogliosis in the striatum. BBG treatment also decreased the IL-1β levels in striatum, despite the observed effect not being statistically significant. To grasp the mechanism of action of BBG, we used in vitro models exploring synaptotoxicity (striatal synaptosomes) and neurotoxicity (dopamine-differentiated SH-SY5Y cells). Besides showing that P2X7R are present in striatal dopaminergic terminals, we observed that BBG 100 nM prevented the 6-OHDA-induced synaptosomal dysfunction. Furthermore, we have shown the presence of P2X7 receptors in SH-SY5Y cells, their co-localization with tyrosine hydroxilase, and that BBG attenuates the cell damage, evaluated through lactate dehydrogenase release. The present results suggests that P2X7R contribute to PD pathogenesis through a triple impact on synaptotoxicity, gliosis and neurotoxicity, highlighting the therapeutic potential of P2X7R antagonists in the disease.
publishDate 2015
dc.date.none.fl_str_mv 2015-04-17T13:14:18Z
2015-04-17T13:14:18Z
2015
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/doctoralThesis
format doctoralThesis
status_str publishedVersion
dc.identifier.uri.fl_str_mv CARMO, M. R. S. do. Efeito neuroprotetor do antagonismo do receptor P2X7 no Parkinsonismo experimental induzido por 6-OHDA. 2015. 110 f. Tese (Doutorado em Farmacologia) - Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, 2015.
http://www.repositorio.ufc.br/handle/riufc/11458
identifier_str_mv CARMO, M. R. S. do. Efeito neuroprotetor do antagonismo do receptor P2X7 no Parkinsonismo experimental induzido por 6-OHDA. 2015. 110 f. Tese (Doutorado em Farmacologia) - Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, 2015.
url http://www.repositorio.ufc.br/handle/riufc/11458
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dc.source.none.fl_str_mv reponame:Repositório Institucional da Universidade Federal do Ceará (UFC)
instname:Universidade Federal do Ceará (UFC)
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instname_str Universidade Federal do Ceará (UFC)
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reponame_str Repositório Institucional da Universidade Federal do Ceará (UFC)
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