Understanding the role that cellular hypoxia plays in normal heart development

点击翻译按钮获取中文摘要

Congenital heart defects (CHD) are the most common type of birth defects, being present in 6 out of every 1000 live births, and 10% of stillbirths. In addition to the danger of death during childhood, such heart defects also increase the risk of heart disease during adulthood. Our research project involves looking for the genetic causes of CHD. We are looking at two genes , called HIF1a and CITED2, for which we already have evidence that they are very important in allowing the heart to form normally within the embryo. Because the heart is the first organ to form in the embryo (during the first trimester), we cannot use humans to study this process. Instead we have two lines of mice which specifically lack either the HIF1a or CITED2 genes throughout the embryo. Both of these mouse lines have severe heart defects similar to some types of CHD seen in humans. However, removal of either of these genes also causes severe defects in other tissues, complicating our study. To overcome this problem, we will use a slightly different technique to remove either gene specifically in the entire developing heart of the embryo, while leaving the normal gene in the rest of the embryo. Thus we will be able for the first time to study the effects of these genes on the heart alone. We suspect that the defects in the hearts of such embryos will be of a particular sub-type of CHD. If this is true, in the future we hope to be able show that mutation of either of these genes will cause a specific type of human CHD. This will enable genetic screening of families with a history of CHD, assist in genetic counselling, and promote the development of therapies.