P307	Using a cardiac canine model for gene expression profiling of angiogenesis.
C.Gregory, T.Masters, A.Fokin, F.Robicsek
Heineman Medical Research Laboratory/Carolinas Heart Institute, Charlotte, NC, US.

Coronary heart disease remains the leading cause of morbidity and mortality in the United States. Despite the advances in myocardial revascularization, a large group of patients is not candidates for current surgical and cardiological interventions to restore blood flow. Therapeutic neovascularization via angiogenesis becomes a possible treatment. Numerous studies have implicated various growth factors to be involved in this process. However, the precise sequence of gene expression involved in initiation and maintenance of angiogenesis has not been delineated for clinical application. Using a canine model of coronary artery ischemia, angiogenesis was amplified by an AV fistula from the distal occluded coronary artery to the adjacent cardiac vein. Tissue from collateral vessels was taken, on day 8 after the AV fistula, from 5 experimentals and 4 controls. Gene expression profiling was accomplished using the Affymetrix GeneChip® Canine Genome Array, which contains over 21,700 transcripts of Canis familiaris. Using ArrayAssist® and PathwayAssist®, ~3,900 probe sets were significantly up or down regulated in the experimental dogs. Further refinement found 168 probe sets that showed differential expression log scale of ≤-1 and 109 probe sets of ≥+1 and a p value ≤0.05. Preliminary annotation of the probe sets, revealed an array of upregulated candidate genes involved in cell proliferation, differentiation, motility, and regulation of signal transduction. Some of the genes included in this group are LECT2, APBA1, RAD52, ANGPT1, MBL1, IMPD2, UCK2 and KHDRB. Hierarchical cluster analysis showed 3 distinct groups of temporal patterns made up of 53, 23, and 8 probe sets respectively from the animals that demonstrated development of angiogenesis. The clusters of 23 and 8 probes revealed limited annotation of the probe sets. Of the cluster of 53 probes, 33 were unknown status and 20 were annotated. The 20 annotated genes of the cluster were found to be involved in various cell processes including cell proliferation, differentiation, and regulation of signal transduction. In conclusion, this study has provided a snapshot of gene expression patterns at day 8 in the process of angiogenesis. This data enables further refinement of the genes that will be critical to initiate and maintain neovascularization.

Copyright © 2005 S. Karger AG, Basel. Any further use of this abstract requires written permission from the publisher.