Cigarette smoke effects on human vascular endothelial genes
Initial Award Abstract
Although both active smoking and exposure to environmental tobacco smoke are strongly associated with atherosclerosis, the mechanism of this process is incompletely understood. The genetic response of the arteries to major risk factors for atherosclerosis is extremely important since increased activity of certain genes promotes atherosclerosis. Our aim is to find out which genes in the arteries are activated in response to cigarette smoke exposure and, in this way, to deduce why cigarette smoking is responsible for an increased risk for atherosclerosis. Although some gene activation responding to atherogenesis has been found, we hypothesize that there are other genes activated by cigarette smoke exposure.
We will use a model system in which we will expose human endothelial cells to cigarette smoke condensate, which is the particulate portion of the smoke known to contain the cancer-causing polycyclic aromatic hydrocarbons, nitrosamines and phenolic compounds. We will use this condensate at a concentration previously shown to be effective in activating certain atherogenic genes. Since we are not sure of the molecular mechanism of this process, we are not sure how long of an exposure will be important, so we will use different timed exposures and pool all of these cells for our first evaluation. When an activated gene has been identified using this procedure, we will retest cells from each time point to determine which point has the maximum amount of the gene. We will use this maximum time point to examine the best concentration of cigarette smoke condensate. The next step will be to identify the genes that have changed in response to cigarette smoke exposure. To do this, we will compare the genes in cigarette-smoke-condensate-exposed cells and non-exposed cells. The genes that have changed will be identified by comparison to known gene sequences available in gene and protein databanks If we are successful in determining the full spectrum of gene changes in the arteries as a result of cigarette smoke exposure, we can begin to examine any patterns that appear such as whether these genes are activated in the same ways. Determining which genes in the arteries are activated by cigarette smoke should indicate the future direction of research regarding cigarette smoke exposure as a risk factor for atherosclerosis. |