CXCL12(5-67) induz apoptose em precursores neurais adultos
Data
2015-11-25
Autores
Almeida, Taís Adelita Morais de 
Orientadores
Porcionatto, Marimelia Aparecida
Tipo
Tese de doutorado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Na zona subventricular (SVZ) de mamíferos adultos residem células precursoras neurais com alta capacidade em responder a moléculas que induzem sua amplificação e migração em direção a áreas lesionadas no sistema nervoso central. Esses fatores extracelulares são secretados por diversos componentes que interagem direta ou indiretamente com os precursores neurais, tais como sistema vascular, líquido cerebrospinal, micróglia, astrócitos e projeções de neurônios localizados em áreas adjacentes. Durante uma lesão, fatores solúveis como CXCL12 são liberados por astrócitos e micróglia no local da lesão. Esses fatores interagem com neurônios maduros na região, além de alcançarem a SVZ através dos vasos sanguíneos e espaço intersticial, criando um gradiente que permite aos neuroblastos alcançarem o local da lesão. Adicionalmente, metaloproteases de matrix 2 e 9 também são liberadas durante uma lesão, podendo clivar CXCL12 na porção N-terminal, gerando CXCL12(5-67). Os objetivos deste trabalho foram produzir CXCL12 e CXCL12(5-67) recombinantes, avaliar o efeito de CXCL12(5-67) na migração e viabilidade de precursores neurais e identificar o receptor pelo qual CXCL12(5-67) produz seus efeitos. Para alcançar esses objetivos, CXCL12 e CXCL12(5-67) recombinantes foram produzidos pela transfecção plasmidial de células HEK293T. As quimiocinas foram testadas em precursores neurais adultos murinos para avaliação da migração e sobrevivência dessas células. Nossos resultados mostram que, in vitro, CXCL12(5-67) não promove quimiotaxia e induz a morte celular de precursores neurais por apoptose. Nossos resultados sugerem que essa atividade ocorre pela ativação do receptor CXCR3. Os resultados aqui apresentados sugerem que CXCL12(5-67) e o receptor CXCR3 estão potencialmente envolvidos na falha da regeneração do sistema nervoso central de mamíferos adultos, sendo possíveis alvos terapêuticos no tratamento de lesões e doenças neurodegenerativas do cérebro.
The adult subventricular zone (SVZ) hosts full potential neural precursor cells, which are able to respond to extracellular signaling thus amplifying the niche and migrating towards an injury site on central nervous system. Extracellular cues that interact, direct or indirectly, with neural stem cells come from many components, such as the vascular system, cerebrospinal fluid, microglia, astrocytes and projections of neurons from adjoining regions. During an injury, soluble factors such as CXCL12 are released by astrocytes and microglia at the injury site. Those factors interact with adult neurons in the surround and reach the SVZ through blood vessels and interstitial space, creating a gradient that allows neuroblasts to find the injury site. Among those factors, matrix metalloproteinase 2 and 9 are also released during an injury, and can cleave CXCL12 at its N-terminus generating CXCL12(5-67). Our goals were to produce recombinant CXCL12 and CXCL12(5-67), assess CXCL12(5-67) effect on neural precursors migration and viability, and identify the receptor involved in CXCL12(5-67) activity. We produced recombinant CXCL12 and CXCL12(5-67) using HEK293T plasmidial transfection and tested their effects on migration and survival of mice adult neural precursor cells. Our results show that, in vitro, CXCL12(5-67) did not promote precursor cells chemotaxis but induced cell death by apoptosis. Additionally, our data suggest that CXCL12(5-67) acts through CXCR3. The results presented here suggest that CXCL12(5-67) and the receptor CXCR3 are potentially involved in adult brain regeneration failure, being a candidate target for traumatic brain and neurodegenerative disease treatment.
The adult subventricular zone (SVZ) hosts full potential neural precursor cells, which are able to respond to extracellular signaling thus amplifying the niche and migrating towards an injury site on central nervous system. Extracellular cues that interact, direct or indirectly, with neural stem cells come from many components, such as the vascular system, cerebrospinal fluid, microglia, astrocytes and projections of neurons from adjoining regions. During an injury, soluble factors such as CXCL12 are released by astrocytes and microglia at the injury site. Those factors interact with adult neurons in the surround and reach the SVZ through blood vessels and interstitial space, creating a gradient that allows neuroblasts to find the injury site. Among those factors, matrix metalloproteinase 2 and 9 are also released during an injury, and can cleave CXCL12 at its N-terminus generating CXCL12(5-67). Our goals were to produce recombinant CXCL12 and CXCL12(5-67), assess CXCL12(5-67) effect on neural precursors migration and viability, and identify the receptor involved in CXCL12(5-67) activity. We produced recombinant CXCL12 and CXCL12(5-67) using HEK293T plasmidial transfection and tested their effects on migration and survival of mice adult neural precursor cells. Our results show that, in vitro, CXCL12(5-67) did not promote precursor cells chemotaxis but induced cell death by apoptosis. Additionally, our data suggest that CXCL12(5-67) acts through CXCR3. The results presented here suggest that CXCL12(5-67) and the receptor CXCR3 are potentially involved in adult brain regeneration failure, being a candidate target for traumatic brain and neurodegenerative disease treatment.
Descrição
Citação
ALMEIDA, Tais Adelita Morais de. Cxcl12(5-67) induz apoptose em precursores neurais adultos. 2015. 93 f. Tese (Doutorado em Biologia Molecular) - Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, 2015.