Altering Cardiac Function via Transgenesis A Nuts and Bolts Approach.

Transgenesis provides a means to modify the mammalian genome. By directing expression of a engineered protein to the heart, one now is able to remodel effectively the cardiac protein profile and study the consequences of a single genetic manipulation at the molecular, biochemical, cytological, and physiologic levels. Often, a particular pathology or even a global remodeling process such as hypertrophy is accompanied by the upregulation or downregulation of a gene or set(s) of genes. What is not known is whether these changes represent a beneficial compensatory response or contribute to the continued degeneration of normal heart function. The ability to perform genetic manipulations on cardiac gene expression via transgenesis offers one a rapid and effective means of extending the correlations noted to the mechanistic level. Now, one can, in theory, express a candidate protein at a particular developmental time and determine the direct consequences of its appearance. Similarly, one can explore structure-function relationships, both between different forms of a protein family and in terms of active domains within a protein, by expressing a transgene that encodes a suitable mutation or ectopic protein isoform. This review explores the practical considerations of the transgenic approach in terms of what is important for a successful experiment from the necessary animal husbandry to designing constructs that will express at appropriate levels in the heart. (Trends Cardiovasc Med 1997;7:185-191). © 1997, Elsevier Science Inc.