Cell Migration and Survival Pathways in Cardiac Development and Disease

Mammalian cardiac development is a complex process, rendering it susceptible to errors. As a result, congenital heart defects are the most common type of birth defect. Furthermore, heart disease in adults is the leading cause of mortality in the developed world. Given these statistics, gaining an understanding of cardiac development and disease is of paramount importance. Here, data are presented suggesting that the signaling molecules SDF-1, ephrin-B1, and ephrin-B2 play important roles in proper valve formation and maturation during cardiogenesis. Furthermore, another signaling molecule, thymosin ᴬ is implicated in promoting cell survival, potentially through an ILK-Akt pathway, as well as angiogenesis in the treatment of mice post-myocardial infarction. Finally, SDF-1 not only plays a role in cardiac development but, in a manner strikingly similar to the actions of thymosin ᴬ also appears to have therapeutic benefit post-myocardial infarction through the ILK-Akt pathway, reduced cell death, and increased angiogenesis. Together, these data and other information presented herein suggest new roles for signaling molecules in both cardiogenesis and cardiac therapy.