Subject(s)
Anaphylaxis/etiology , Food Hypersensitivity/epidemiology , Seasons , Adolescent , Adult , Aged , Aged, 80 and over , Boston/epidemiology , Child , Child, Preschool , Female , Food Hypersensitivity/complications , Humans , Infant , Male , Middle Aged , Risk Factors , Sunlight , Ultraviolet Rays , Vitamin D/blood , Young AdultABSTRACT
Vascular development requires the tightly coordinated expression of several growth factors and their receptors. Among these are the Tie1 and Tie2 receptors, which are almost exclusively endothelial cell-specific. The critical transcriptional regulators of vascular-specific gene expression remain largely unknown. The Ets factors are a family of evolutionarily conserved transcription factors that regulate genes involved in cellular growth and differentiation. We have recently shown that the Ets factor NERF is a strong transactivator of the Tie1 and Tie2 genes. To extend these studies, we have begun to identify the Ets factors that are expressed in developing blood vessels of the chicken chorioallantoic membrane (CAM), a highly vascular embryonic network. RNA was extracted from microdissected CAM blood vessels, and reverse transcriptase-polymerase chain reaction was performed using oligonucleotides encoding conserved amino acids within the Ets domain. One of the polymerase chain reaction fragments was subcloned and identified as the chicken homologue of the Ets factor ELF-1, cELF-1. ELF-1 is most closely related to the Ets factor NERF. In situ hybridization and immunohistochemistry demonstrate that cELF-1 is enriched in developing chicken blood vessels. cELF-1 is also a strong transactivator of the Tie1 and Tie2 genes and can bind to conserved Ets sites within the promoters of these genes. A complex of similar size forms when gel shifts are performed with cellular extracts derived from the CAM blood vessels, which is recognized by an antibody against cELF-1. In summary, ELF-1 belongs to a subset of Ets factors that regulate vascular-specific gene expression during blood vessel development.
Subject(s)
DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Gene Expression Regulation, Developmental/genetics , Receptor Protein-Tyrosine Kinases/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Allantois/blood supply , Allantois/embryology , Allantois/metabolism , Animals , Blood Vessels/cytology , Blood Vessels/embryology , Blood Vessels/metabolism , Blotting, Northern , Cell Line , Chick Embryo , Chickens , Chorion/blood supply , Chorion/embryology , Chorion/metabolism , Cloning, Molecular , Humans , Immunohistochemistry , In Situ Hybridization , Mice , Molecular Sequence Data , Nuclear Proteins , Organ Specificity , Promoter Regions, Genetic/genetics , Receptor Protein-Tyrosine Kinases/genetics , Receptor, TIE-1 , Receptor, TIE-2 , Receptors, Cell Surface/genetics , Receptors, Cell Surface/metabolism , Receptors, TIE , Regulatory Sequences, Nucleic Acid/genetics , Sequence Alignment , Sequence Homology, Amino AcidABSTRACT
Inflammation is a hallmark of several vascular diseases. The nuclear factor kappaB (NF-kappaB) transcription factors are dimeric proteins involved in the activation of a large number of genes in response to inflammatory stimuli. We report the involvement of a novel member of the ETS transcription factor, ESE-1, in mediating vascular inflammation. ESE-1 is induced in response to inflammatory cytokines and lipopolysaccharide in vascular smooth muscle cells, endothelial cells, and cells of the monocyte-macrophage lineage. This induction occurs within hours of stimulation and is mediated by NF-kappaB transactivation of the ESE-1 promoter. We have identified the inducible form of nitric-oxide synthase (NOS2) as a putative target for ESE-1. ESE-1 can bind to the p50 subunit of NF-kappaB, and cotransfection of ESE-1 with the p50 and p65 subunits of NF-kappaB synergistically enhances transactivation of the NOS2 promoter by ESE-1. An ESE-1-binding site within the NOS2 promoter has been identified, the site-directed mutagenesis of which completely abolishes the ability of ESE-1 to transactivate the NOS2 promoter. Finally, in a mouse model of endotoxemia, associated with acute vascular inflammation, ESE-1 is strongly expressed in vascular endothelium and smooth muscle cells. In summary, ESE-1 represents a novel mediator of vascular inflammation.
