Evidence of hypoxia-inducible factor-1 in vascular endothelial and smooth muscle cells.
The hypoxia-inducible element (HIE-1), a 50-bp region just 3' to the human erythropoietin gene, has been found to regulate transcription in cells that do not ordinarily synthesize erythropoietin. We hypothesized that the HIE-1 and associated protein factors may have a role in transcriptional regulation in hypoxic vascular tissues. Therefore, tissues of vascular origin were grown in culture and exposed to hypoxia (1% 02, 5% CO2, balance N2) or normoxia (21% O2, 5% CO2). Human microvascular endothelial cells (HMEC-1) studied with electrophoretic mobility shifting demonstrated that HIE-1 was bound to a protein induced by hypoxia in these cells. HMEC-1 and rat aortic smooth muscle cells (RASM) were transfected with the vector pGL2-HIE-1. HMEC-1 reporter gene expression was 3.7 +/- 0.5-fold increased at 12 hours and 3.7 +/- 1.3-fold increased at 24 hours by hypoxia. RASM reporter gene expression was 18.6 +/- 6.5-fold (SEM) increased at 12 hours and 2.0 +/- 0.7-fold increased at 24 hours by hypoxia. These findings provide indirect evidence of a hypoxia-inducible factor in vascular cellular transcriptional regulation.
Schmedtje
J F
JF
Department of Medicine, University of Texas Medical Branch, Galveston, 77555-1064, USA.
Liu
W L
WL
Ji
Y
Y
Thompson
T M
TM
Runge
M S
MS
D000332:Aerobiosis; D000818:Animals; D001011:Aorta; D015687:Cell Hypoxia; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007700:Kinetics; D008833:Microcirculation; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000378:metabolism*; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism*; D014162:Transfection
D004268:DNA-Binding Proteins; C497442:HIF1A protein, human; C497444:Hif1a protein, rat; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D009687:Nuclear Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors