DNA Microarray Profiling to Identify Angiotensin-Responsive Genes in Vascular Smooth Muscle Cells: Potential Mediators of Vascular Disease

ABSTRACT—Angiotensin II (Ang II) induces changes in vessel structure by its capacity to activate genes that are coupled to signaling pathways such as extracellular signal–regulated kinase (ERK), p38, and phosphatidylinositol 3-kinase (PI3K). Using a DNA microarray containing 5088 genes and expressed sequence tags, we initially established a database of replicated experiments (n=4) to define the variances in mRNA expression in response to Ang II versus vehicle treatment. We observed a wide range of values for the coefficients of variation in a gene-specific manner. Guided by power calculations, we used statistical inference on a sufficient number of experimental replicates to minimize the number of false-negatives and define a subset of Ang II–responsive genes (P