How did your heart form? What triggered your first heartbeat? To this day, the mechanisms of human heart development remain elusive.
Traditionally, scientists have used animal and cell models to study heart development and disease. However, researchers haven't been able to produce a cure for congenital heart disease in part because these models are unable to capture the complexity of the human heart. Due to ethical limitations, using human embryos for these studies is out of the question.
We created our heart organoids using a type of cell called a pluripotent stem cell. Although using these cells in research used to be controversial because they were originally derived from human embryos, this is no longer a concern, as they can be produced from any adult. Pluripotent stem cells have the potential to become any type of cell in the body.
We can mimic these maternal environments and simulate how they influence fetal heart development with heart organoids. For example, we used heart organoids to show that diabetes, a very common condition, increases the risk of heart disease in embryos. Compared to heart organoids created in healthy conditions, mini hearts exposed to diabetic conditions developed heart abnormalities like those of human fetuses and newborns with diabetic cardiomyopathy.
Testing medications on human heart organoids allows researchers to better explore and predict potential harmful effects during pregnancy. One example is ondansetron , a drug commonly prescribed to prevent nausea and vomiting during pregnancy. Although it has been linked with an increased risk of congenital heart disease, whether it causes the disease hasn't been confirmed.