RESUMO
Dysfunction of brain vascular endothelial cells may be associated with the pathogenesis of several diseases including cerebral amyloid angiopathy, hemorrhagic stroke and Alzheimer disease. New model systems are necessary to examine the contribution of brain endothelial cells in these disorders. The Von Willebrand factor gene promoter fragment that spans sequences -487 to +247 targets the expression of LacZ marker gene in transgenic mice specifically to brain vascular endothelial cells. Transgenic mice have been prepared that express human amyloid beta protein precursor protein (AbetaPP) isoforms 695 and 751 (wild-type and Dutch variant mutations) under the regulation of this VWF promoter sequence. These AbetaPP transgenes are specifically expressed in brain vascular endothelial cells. The VWF promoter is a valuable tool for targeting gene expression to brain vascular endothelial cells to provide a model to directly examine endothelial cell placement of genes and their contribution to cerebral vascular disease.
Assuntos
Precursor de Proteína beta-Amiloide/biossíntese , Encéfalo/fisiopatologia , Transtornos Cerebrovasculares/fisiopatologia , Endotélio Vascular/citologia , Fator de von Willebrand/genética , Animais , Endotélio Vascular/patologia , Humanos , Camundongos , Camundongos Transgênicos , Regiões Promotoras GenéticasRESUMO
The molecular mechanisms by which neurotrophins such as nerve growth factor (NGF) induce neurite outgrowth and differentiation remain unclear, although multiple intracellular signaling pathways are known to participate. Recent studies have shown that nuclear transcription factors play an important role in NGF-stimulated neuritic outgrowth in PC12 cells. We investigated whether FAC1, a novel transcriptional regulator that exhibits altered subcellular distribution during brain development, is responsive to NGF-induced neurite outgrowth of PC12 cells. Our studies demonstrate that NGF induces a rapid, transient increase in FACI mRNA that is dependent upon ERK activation, and that FAC1 protein exhibits altered subcellular distribution during neurite outgrowth. These findings suggest that FAC1 expression and subcellular localization are regulated by NGF signaling pathways during neurite outgrowth.