RESUMEN
FERM domain including Rho GEF (FIR) is one of the guanine nucleotide exchange factors for Rac1. FIR, expressed in hippocampal and cortical neurons in vitro, is suggested to be involved in neurite remodeling. We examine developmental regulation of FIR mRNA expression in the mouse brain using in situ hybridization to get insight into its function. FIR mRNA is expressed in the ventricular zone and the intermediate zone as well as the cortical plate and the preplate in the brain from mice during the embryonic stages 12.5 to 14.5. In the brain during the later embryonic stages and the postnatal stages, the expression was restricted to the cortical plate. These results suggest that FIR may play a role not only in neurogenesis, but also in the asymmetrical cell division and migration of neurons.
Asunto(s)
Encéfalo/metabolismo , Regulación del Desarrollo de la Expresión Génica , Factores de Intercambio de Guanina Nucleótido/metabolismo , Animales , Encéfalo/anatomía & histología , Encéfalo/embriología , Embrión de Mamíferos , Femenino , Factores de Intercambio de Guanina Nucleótido/genética , Humanos , Hibridación in Situ , Masculino , Ratones , Embarazo , ARN Mensajero/metabolismo , Factores de Intercambio de Guanina Nucleótido RhoRESUMEN
FERM domain including Rho GEF (FIR) belongs to Dbl family of guanine nucleotide exchange factors and specifically activates biochemical pathways specific for Rac1. FIR was shown to regulate neurite remodeling of the embryonic neurons. Here we report a distribution of FIR mRNA in adult rat brain using in situ hybridization. The expression was found all throughout the brain with the most intensive signals in hippocampus, piriform cortex, red nucleus and nuclei of cranial nerves. The signal was predominantly localized in the neuronal cells.
Asunto(s)
Envejecimiento/genética , Encéfalo/metabolismo , Factores de Intercambio de Guanina Nucleótido/genética , Neuronas/metabolismo , Proteína de Unión al GTP rac1/metabolismo , Animales , Encéfalo/citología , Estructura Terciaria de Proteína/genética , ARN Mensajero/metabolismo , Ratas , Factores de Intercambio de Guanina Nucleótido RhoRESUMEN
Characteristics of the cellular response to oxygen deprivation and subsequent reoxygenation (hypoxia/reoxygenation) include redirection of energy metabolism, increased glucose utilization and expression of oxygen-regulated proteins. Inhibition of protein synthesis during early reoxygenation period prevented effective astrocyte adaptation to hypoxia/reoxygenation, resulting in eventual cell death. To elucidate the role of astrocytes in the central nervous system in response to hypoxia/reoxygenation, we analyzed the cDNA library derived from the cultured rat astrocytes subjected to 24 h of hypoxia followed by reoxygenation by differential display, and isolated a cDNA corresponding to Na/K ATPase alpha1 subunit. The expression of Na/K ATPase alpha1 subunit mRNA as well as beta1subunit mRNA was transiently increased after reoxygenation, whereas hypoxia itself did not induce any gene expression change. Na/K ATPase alpha1 subunit protein was transiently increased, whereas the protein expression for Na/K ATPase beta1 subunit showed sustained induction after reoxygenation. Overexpression of beta1 subunit in HEK 293 cells subjected to hypoxia/reoxygenation promoted survival of the cells. These findings suggest that Na/K ATPases may contribute to maintain the cellular environment of astrocytes subjected to hypoxia/reoxygenation.
