Transcriptional profile of mechanically induced genes in human vascular smooth muscle cells

Vascular smooth muscle cells must monitor and respond to their mechanical e nvironment; however, the molecular response of these cells to mechanical st imuli remains incompletely defined. By applying a highly uniform biaxial cy clic strain to cultured cells, we used DNA microarray technology to describ e the transcriptional profile of mechanically induced genes in human aortic smooth muscle cells. We first identified vascular endothelial growth facto r (VEGF) as a mechanically induced gene in these cells; VEGF served as a po sitive control for these experiments, We then used a DNA microarray with 50 00 genes with putative functions to identify additional mechanically induce d genes, Surprisingly, relatively few genes are mechanically induced in hum an aortic smooth muscle cells. Only 3 transcripts of 5000 were induced >2.5 -fold: cyclooxygenase-1, tenascin-C, and plasminogen activator inhibitor-1. Downregulated transcripts included matrix metalloproteinase-1 and thrombom odulin, The transcriptional profile of mechanically induced genes in human aortic smooth muscle cells suggests a response of defense against excessive deformation, These data also demonstrate that in addition to identifying l arge clusters of genes that respond to a given stimulus, DNA microarray tec hnology may be used to identify a small subset of genes that comprise a hig hly specific molecular response.