RESUMO
The present study aims to identify transcription factors (TFs) contributing to angiogenesis, a mechanism involved in giving plasticity to the brain, as potential therapeutic targets after cerebral ischemia. The promoter sequences from candidate genes involved in angiogenesis were submitted to a comparative analysis by bioinformatics software. High-mobility group I-Y protein (HMGIY) TF characterization in a rat permanent focal cerebral ischemia model was performed by quantitative real time polymerase chain reaction and Western blot for the TF expression profile study. The TF functional study was carried out using a TF-TF interaction array and gene silencing by siRNA in rat brain microvascular endothelial cells. The results showed that the promoters shared a common TF binding site for HMGIY. The expression profile analysis in ischemic rat brain showed an increase in HMGIY mRNA in the acute phase and a progressive overexpression of protein over time post-ischemia. The interaction array analysis revealed that ischemia promotes the interaction of HMGIY with TFs involved in different cerebral plasticity processes. In vitro knockdown studies showed that angiopoietin 1 and vascular endothelial growth factor expression is controlled by HMGIY and that this TF is involved in cell survival in brain endothelial cells. These findings suggest that HMGIY is a potential therapeutic target that could promote brain repair functions after stroke.
Assuntos
Isquemia Encefálica/fisiopatologia , Encéfalo/fisiopatologia , Proteína HMGA1a/metabolismo , Doença Aguda , Angiopoietina-1/metabolismo , Animais , Encéfalo/irrigação sanguínea , Movimento Celular/fisiologia , Sobrevivência Celular/fisiologia , Células Cultivadas , Progressão da Doença , Células Endoteliais/fisiologia , Expressão Gênica/fisiologia , Masculino , Microvasos/fisiopatologia , Neurônios/fisiologia , RNA Mensageiro/metabolismo , Ratos Endogâmicos F344 , Fatores de Transcrição/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Leucine-rich repeat in Flightless-1 interaction protein 1 (Lrrfip1) is an up-regulated protein after cerebral ischemia whose precise role in the brain both in healthy and ischemic conditions is unclear. Different Lrrfip1 isoforms with distinct roles have been reported in human and mouse species. The present study aimed to analyze the Lrrfip1 transcriptional variants expressed in rat cortex, to characterize their expression patterns and subcellular location after ischemia, and to define their putative role in the brain. Five transcripts were identified and three of them (Lrrfip1, CRA_g and CRA_a' (Fli-I leucine-rich repeat associated protein 1 - Flap-1)) were analyzed by quantitative real-time polymerase chain reaction (qPCR). All the transcripts were up-regulated and showed differential expression patterns after in vivo and in vitro ischemia models. The main isoform, Lrrfip1, was found to be up-regulated from the acute to the late phases of ischemia in the cytoplasm of neurons and astrocytes of the peri-infarct area. This study demonstrates that Lrrfip1 activates ß-catenin, Akt, and mammalian target of rapamycin (mTOR) proteins in astrocytes and positively regulates the expression of the excitatory amino acid transporter subtype 2 (GLT-1). Our findings point to Lrrfip1 as a key brain protein that regulates pro-survival pathways and proteins and encourages further studies to elucidate its role in cerebral ischemia as a potential target to prevent brain damage and promote functional recovery after stroke.
Assuntos
Isquemia Encefálica/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas de Ligação a RNA/metabolismo , Serina-Treonina Quinases TOR/metabolismo , beta Catenina/metabolismo , Animais , Astrócitos/metabolismo , Encéfalo/metabolismo , Isquemia Encefálica/etiologia , Células Cultivadas , Citoplasma/metabolismo , Transportador 2 de Aminoácido Excitatório/metabolismo , Técnicas de Silenciamento de Genes , Ácido Glutâmico/metabolismo , Infarto da Artéria Cerebral Média/complicações , Infarto da Artéria Cerebral Média/metabolismo , Masculino , Neurônios/metabolismo , Isoformas de RNA/metabolismo , Proteínas de Ligação a RNA/genética , Ratos Endogâmicos F344 , Ratos Wistar , Transdução de Sinais , Regulação para CimaRESUMO
The foot propelled scooter is a popular toy preferred by girls and boys, but at the same time, these put the children at risk of some kind of injury. The literature had reported that the fractures at the upper extremities are the most frequent injury observed related to the use of a scooter. The purpose of our study was to describe the injuries related to the scooters use in a sample of injuries handled at the UPR Hospital at Carolina, Puerto Rico. A total of 62 patients who arrived to the ED and were evaluated for some kind of injury related to the use of scooters were included in our study. Fractures (32.3) constituted the most frequent injury observed in the sample, followed by the lacerations (29.0), and the abrasions (11.3). The parents, doctors and the healthcare workers should be made aware of the causes and prevention of injuries caused by the foot propelled scooters, because this situation is potentially preventable
