Upcoming/Recent Graduate student presentations, proposals and defenses
Michelle Sykes - Ph.D. Defense, 10:30 AM, Thursday, May 22nd, 2008, Emory University, Woodruff Memorial Research Building, Room 317
Advisor: Hanjoong Jo, Ph.D. (Georgia Institute of Technology and Emory University)
Committee: Kathy K. Griendling, Ph.D. (Emory University), David G. Harrison, M.D. (Emory University), May Wang, Ph.D. (Georgia Institute of Technology) and Ajit P. Yoganathan PhD. (Georgia Institute of Technology)
TITLE: “Regulation of Endothelial Gene Transcription by Shear Stress in a Manner Dependent on p47phox-based NADPH Oxidases”
Atherosclerosis occurs preferentially at branches and curves in arteries exposed to disturbed flow while sparing straight portions of arteries exposed to undisturbed flow. In vivo and in vitro studies have implicated NADPH oxidases in atherosclerosis and hypertension. Shear stress can induce reactive oxygen species production in endothelial cells from a variety of sources, including NADPH oxidases. Here, we examined the hypothesis that unidirectional laminar shear (LS) and ocillatory shear (OS) would differentially regulate gene expression profiles in NADPH oxidase-dependent and -independent manners, and that these genes would provide novel molecular targets in understanding endothelial cell biology and vascular disease.
The p47phox subunit of the NADPH oxidase can be an important regulator of certain Nox isoforms, including Nox1 and Nox2 which may be responsible for shear-induced superoxide production. In order to isolate p47phox-dependent shear responses, we took advantage of the p47phox-/- transgenic mouse model which lacks a functional p47phox subunit. We developed a method to isolate murine aortic endothelial cells using an enzymatic digestion technique. These cells were characterized as expressing typical endothelial markers, including VE-cadherin, PECAM1, and eNOS, and aligning in the direction of flow. We successfully isolated primary murine aortic endothelial cells from both wild-type C57BL/6 mice (MAE-WT) and p47phox-/- mice (MAE-p47). Furthermore, we established an immortalized cell line from each of these cell types, iMAE-WT and iMAE-p47. We carried out microarray studies using Affymetrix Mouse Genome 430 2.0 Arrays (39,000+ transcripts) on MAE-WT and MAE-p47 that were exposed to atheroprotective LS or atherogenic OS for 24 hours. Changes in expression of several genes, including Kruppel-like factor 2, junctional adhesion molecule 2, and endothelial
Last revised on May 13th, 2008