| Congenital heart defects (CHDs), the most common congenital anomaly, affects ∼1% of live births in the United States. Further, over 1 million survivors of CHDs require continual clinical care. Progress in our understanding of the genetic and molecular events that underlie cardiovascular development have been derived from the ex vivo heart and whole embryo culture models and fortuitous transgenic mice with cardiovascular phenotypes. After decades of work with these models, the pathways that govern mammalian cardiovascular morphogenesis, though slowly being unraveled, are poorly understood. Advancements in the field have been hindered by the lengthy process of creating and breeding transgenic mice and the paucity of technological approaches amenable to the ex vivo model systems. Utilization of the ex vivo model requires the a priori knowledge of the molecules of interest and the availability of appropriate reagents to study a given factor (i.e. recombinant factors, inhibitors, antibodies or tissues from transgenic mice). Embryonic structures contain small amounts of protein which limits its use in biochemical assays. Further there is a lack of readily available homogeneous cell lines derived from the embryonic heart and vasculature to perform in vitro studies. To circumvent these methodological limitations, in addition to utilizing the classical ex vivo models, a proteomic approach was employed to determine protein profiles during normal and abnormal cardiovascular development and uncover proteins previously unappreciated to have a role in the cardiovascular system. Using these approaches several proteins were found to have novel roles in cardiovascular development including nitric oxide, leptin, Wnt16, ADAM15, NOGO, laminin 1, TRPC5, ST14 and PTPN1. The data accrued through these studies highlight the importance of antioxidant, adhesion/migration, differentiation and insulin like growth factor pathways in cardiovascular development. The successful application of these proteins (MMP2, laminin 1, Wnt16, PC1/3 and SVCT) as biomarkers of congenital heart defects was confirmed in both murine and human amniotic fluid samples. Discovery of novel proteins and pathways involved in cardiovascular development will broaden our understanding of the global developmental pathways of cardiovascular morphogenesis and the pathogenic mechanisms that underlie congenital heart defects in order to diagnose, prevent and treat CHDs in the future. |
