RESUMO
Yin-Yang 1 (YY1) has been identified as playing critical roles in multiple diseases. However, little is known regarding its roles and mechanisms in cerebral ischemia/reperfusion (I/R) injury. This study is aimed to explore the roles of YY1 in regulating neuronal apoptosis in cerebral I/R injury and its underlying mechanisms. Primary mouse cerebral cortical neurons were isolated and subjected to OGD/R to mimic cerebral I/R injury in vitro. The roles of YY1 on OGD/R-induced neuronal injury were investigated by performing western blotting, quantitative real-time polymerase chain reaction, TUNEL, RNA-binding protein immunoprecipitation, chromatin immunoprecipitation, chromatin isolation by RNA purification assay, glucose uptake assay, lactate production assay, and extracellular acidification rate assay. YY1-binding long non-coding RNAs (LncRNAs) in neurons subjected to OGD/R were identified by RIP and RNA sequencing. The roles of YY1 on cerebral I/R in vivo were detected by assessing neuronbehaviour, infarct size, and neuronal apoptosis. We found that YY1 expression is downregulated, and LncRNA GAS5 is upregulated in neurons subjected to OGD/R. OGD/R treatment promotes YY1 interacting with GAS5 in neurons, and YY1 negatively regulates GAS5 expression by binding to GAS5 promoter to repress its transcription. Besides, YY1 and GAS5 bind to the same region of PFKFB3 promoter to promote PFKFB3 expression and strengthen neuronal glycolysis, resulting in aggravating OGD/R-induced neuronal apoptosis. Knockdown of YY1 or GAS5 protects against I/R-induced ischemic brain damage and improves overall neurological functions in vivo. Overall, YY1 interacts with LncRNA GAS5 to promote PFKFB3 transcription to enhance neuronal glycolysis, resulting in aggravating cerebral I/R injury.
Assuntos
Isquemia Encefálica/genética , Glucose/metabolismo , Glicólise/genética , Neurônios/metabolismo , Fosfofrutoquinase-2/genética , RNA Longo não Codificante/genética , Traumatismo por Reperfusão/genética , Fator de Transcrição YY1/genética , Animais , Apoptose/genética , Isquemia Encefálica/metabolismo , Córtex Cerebral/citologia , Imunoprecipitação da Cromatina , Imunoprecipitação , Marcação In Situ das Extremidades Cortadas , Masculino , Camundongos , Cultura Primária de Células , RNA Longo não Codificante/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Traumatismo por Reperfusão/metabolismo , Regulação para Cima , Fator de Transcrição YY1/metabolismoRESUMO
Neuroinflammation plays a critical role in the process of neurodegenerative disorders, during which microglia, the principal resident immune cells in the central nervous system, are activated and produce proinflammatory mediators. Yin-Yang 1 (YY1), a multi-functional transcription factor, is widely expressed in cells of the immune system and participate in various cellular processes. However, whether YY1 is involved in the process of neuroinflammation is still unknown. In the present study, we found that YY1 was progressively up-regulated in BV2 microglial cells stimulated with lipopolysaccharide (LPS), which was dependent on the transactivation function of nuclear factor kappa B (NF-κB). Furthermore, YY1 knockdown notably inhibited LPS-induced the activation of NF-κB signaling and interleukin-6 (IL-6) expression in BV-2â¯cells, but not mitogen-activated protein kinase (MAPK) signaling. Moreover, YY1 strengthened p65 binding to IL-6 promoter by interacting with p65 but decreased H3K27ac modification on IL-6 promoter, eventually increasing IL-6 transcription. Taken together, these results for the first time uncover the regulatory mechanism of YY1 on IL-6 expression during neuroinflammation responses and provide new lights into neuroinflammation.