Identification by differential display of eight known genes induced during in vivo intimal hyperplasia.

To achieve a better understanding of the mechanism of intimal thickening, we used a rabbit model in which aorta was denuded mechanically by a balloon catheter. Total RNA was prepared from each aorta 1, 2, 7, 14, 23, or 30 days after denudation, and from intact aorta of non-denuded control rabbits. Subsequently, using the differential display method, we identified eight genes that were expressed differently during the time course after injury. One of them, RESP18 (encoding regulated endocrine secretory protein 18), was suppressed during the acute reaction. The other seven showed increase in expression during the acute phase: the genes for hTAFII68 (human TATA-binding protein associated factor), NPAT (nuclear protein mapped to the AT locus), OSF2 (osteoblast-specific factor 2), Pyst1, casein kinase 1 alpha, integrin alpha 1, and XP-C complementing protein. Although hTAFII68, NPAT, OSF2, and Pyst1 are thought to be related to transcription, not all four are positive regulators. Considering that none of these genes had previously been reported as being implicated in intimal hyperplasia, we conclude that many known or unknown genes play roles in this process. We believe that differential display is an effective method for screening genes whose variations in expression can provide clues toward understanding the molecular mechanism of intimal hyperplasia.