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Abstract(s)
O plexo coroide (PC) é uma estrutura vascularizada localizada nos ventrículos cerebrais que desempenha um papel crucial na produção e regulação do líquido cefalorraquidiano (LCR). Essa função é essencial para a proteção do sistema nervoso central (SNC), regulação da homeostase cerebral e transmissão de sinais neuronais. O PC é composto por células epiteliais que formam a BCSFB, caracterizada por junções apertadas que controlam seletivamente o fluxo de moléculas e células entre o sangue e o LCR. Anatomicamente, o PC apresenta configurações distintas nos diferentes ventrículos cerebrais, estende-se ao longo do assoalho ventricular nos ventrículos laterais e forma aglomerados no teto do terceiro e quarto ventrículos. A estrutura básica do PC inclui vasos sanguíneos envolvidos por tecido estromal e uma camada epitelial rica em junções de oclusão, constituídas por ocludinas e claudinas, que desempenham um papel crucial na manutenção da integridade da BCSFB. Além das funções na produção de LCR e na BCSFB, o PC atua na proteção antioxidante do SNC contra o estresse oxidativo, utilizando enzimas como superóxido dismutase e glutationa peroxidase. Esses sistemas enzimáticos são fundamentais para neutralizar espécies reativas de oxigênio que podem ser prejudiciais ao cérebro. Em contextos patológicos, como o cancro cerebral, o PC pode desempenhar um papel importante na propagação de metástases cerebrais, embora esse processo ainda não esteja completamente compreendido. Há indícios de que células tumorais, como as de cancro de pulmão, mama e melanoma, possam utilizar a via do PC para entrar no SNC, atravessando a BCSFB. No entanto, a capacidade de invasão por meio desta via e as interações moleculares envolvidas, como aquelas mediadas por E-caderina e ICAM2 nas células endoteliais do PC, ainda carecem de estudos mais aprofundados. Por isso, investigar esse mecanismo é crucial para esclarecer o papel do PC na invasão de células tumorais no cérebro. Para a realização deste trabalho foram utilizadas linhas celulares HIBCPP (que mimetizam a BCSFB) e A549 de cancro do pulmão para modelar a BCSFB in vitro e estudar a transmigração celular. As células foram cultivadas em meio DMEM/F12 suplementado com soro fetal bovino e antibióticos, mantidas em condições de 37°C e 5% de CO2. Os inserts foram revestidos com colagénio para melhorar a adesão das células HIBCPP, cuja integridade da barreira foi avaliada pela medição da resistência elétrica transepitelial (TEER). Ensaios de transmigração com células A549 marcadas com CellTracker Green CMFDA foram feitos com o intuito de investigar os possíveis efeitos na função da BCSFB e poder contribuir para a compreensão das interações celulares em condições fisiológicas e patológicas do SNC.
The choroid plexus (CP) is a vascularized structure located in the brain's ventricles that plays a crucial role in the production and regulation of cerebrospinal fluid (CSF). This function is essential for protecting the central nervous system (CNS), regulating cerebral homeostasis, and transmitting neuronal signals. The CP is composed of epithelial cells that form the blood-CSF barrier (BCSFB), characterized by tight junctions that selectively control the flow of molecules and cells between the blood and the CSF. Anatomically, the choroid plexus (CP) has distinct configurations in the different brain ventricles, extending along the ventricular floor in the lateral ventricles and forming clusters in the roof of the third and fourth ventricles. The basic structure of the CP includes blood vessels surrounded by stromal tissue and an epithelial layer rich in tight junctions, composed of occludins and claudins, which play a crucial role in maintaining the integrity of the blood-CSF barrier (BCSFB). In addition to its functions in CSF production and the blood-CSF barrier, the CP contributes to the antioxidant protection of the CNS against oxidative stress, utilizing enzymes such as superoxide dismutase and glutathione peroxidase. These enzymatic systems are essential for neutralizing reactive oxygen species that can be harmful to the brain. In pathological contexts, such as brain cancer, the CP may play an important role in the spread of brain metastases, although this process is not yet fully understood. There is evidence that tumor cells, such as those from lung, breast, and melanoma cancers, may use the CP pathways to enter the CNS by crossing the BCSFB. However, the capacity for invasion through these pathways and the molecular interactions involved, such as those mediated by E-cadherin and ICAM2 in the CP endothelial cells, still require further study. Therefore, investigating this mechanism is crucial to clarifying the role of the CP in the invasion of tumor cells into the brain. For this study, HIBCPP cell lines (which mimic the BCSFB) and A549 lung cancer cells were used to model the BCSFB in vitro and study cell transmigration. The cells were cultured in DMEM/F12 medium supplemented with fetal bovine serum and antibiotics, maintained at 37°C and 5% CO2. The inserts were coated with collagen to improve the adhesion of HIBCPP cells, and the integrity of the barrier was assessed by measuring transepithelial electrical resistance (TEER). Transmigration assays using A549 cells labeled with CellTracker Green CMFDA were performed to investigate potential effects on BCSFB function and contribute to understanding cellular interactions in physiological and pathological conditions of the CNS.
The choroid plexus (CP) is a vascularized structure located in the brain's ventricles that plays a crucial role in the production and regulation of cerebrospinal fluid (CSF). This function is essential for protecting the central nervous system (CNS), regulating cerebral homeostasis, and transmitting neuronal signals. The CP is composed of epithelial cells that form the blood-CSF barrier (BCSFB), characterized by tight junctions that selectively control the flow of molecules and cells between the blood and the CSF. Anatomically, the choroid plexus (CP) has distinct configurations in the different brain ventricles, extending along the ventricular floor in the lateral ventricles and forming clusters in the roof of the third and fourth ventricles. The basic structure of the CP includes blood vessels surrounded by stromal tissue and an epithelial layer rich in tight junctions, composed of occludins and claudins, which play a crucial role in maintaining the integrity of the blood-CSF barrier (BCSFB). In addition to its functions in CSF production and the blood-CSF barrier, the CP contributes to the antioxidant protection of the CNS against oxidative stress, utilizing enzymes such as superoxide dismutase and glutathione peroxidase. These enzymatic systems are essential for neutralizing reactive oxygen species that can be harmful to the brain. In pathological contexts, such as brain cancer, the CP may play an important role in the spread of brain metastases, although this process is not yet fully understood. There is evidence that tumor cells, such as those from lung, breast, and melanoma cancers, may use the CP pathways to enter the CNS by crossing the BCSFB. However, the capacity for invasion through these pathways and the molecular interactions involved, such as those mediated by E-cadherin and ICAM2 in the CP endothelial cells, still require further study. Therefore, investigating this mechanism is crucial to clarifying the role of the CP in the invasion of tumor cells into the brain. For this study, HIBCPP cell lines (which mimic the BCSFB) and A549 lung cancer cells were used to model the BCSFB in vitro and study cell transmigration. The cells were cultured in DMEM/F12 medium supplemented with fetal bovine serum and antibiotics, maintained at 37°C and 5% CO2. The inserts were coated with collagen to improve the adhesion of HIBCPP cells, and the integrity of the barrier was assessed by measuring transepithelial electrical resistance (TEER). Transmigration assays using A549 cells labeled with CellTracker Green CMFDA were performed to investigate potential effects on BCSFB function and contribute to understanding cellular interactions in physiological and pathological conditions of the CNS.
Description
Keywords
Plexo Coroide Metástase Cerebral Barreira Sangue-Líquido Cefalorraquidiano (BCSFB) Líquido Cefalorraquidiano (LCR) Junções apertadas Migração Celular Choroid Plexus Brain Metastasis Blood-Cerebrospinal Fluid Barrier