Distinct molecular phenotypes in murine cardiac muscle development, growth, and hypertrophy

The onset of cardiac hypertrophy is associated with characteristic changes in myocardial gene expression that are thought to recapitulate a developmen tal gene program. We report here the first gene expression profile of the m urine myocardium, using a rapid method of quantitative expression analysis based an real-time analytical RT-PCR. This assay was used to measure expres sion levels of 29 genes in (1) late stage development as represented by day 1 neonatal ventricles, (2) normal cardiac growth in 3 and 18 month old mic e, and (3) cardiac hypertrophy following pressure overload by aortic constr iction. For males and females normal growth is not associated with differen tial expression although there is elevated expression of skeletal and smoot h muscle actin mRNA's in males compared to females. Using normal adult vent ricles as a reference, there are many qualitative and quantitative differen ces between the day 1 neonatal myocardium and experimental cardiac hypertro phy. These data suggest that the response to POL involves a subset of re-ex pressed developmental genes together with altered expression of genes not n ecessarily associated with cardiac development. (C) 1998 Academic Press.