The heart undergoes major changes during the first weeks of life. Researchers at Karolinska Institutet have now shown that a previously unknown metabolic vulnerability in mitochondria can disrupt heart development. The study, published in Science Advances, could improve our understanding of rare mitochondrial diseases that affect the heart.

During fetal development, the body receives oxygen and nutrients through the placenta. After birth, conditions change rapidly as oxygen availability increases and nutrition comes from milk and later solid food. At the same time, the heart continues to grow and mature.

In the new study, the researchers investigated the role of the molecule S-adenosylmethionine (SAM) in this transition. SAM is best known for its role in chemical modifications of DNA, RNA and proteins. Within mitochondria, however, it is also required for the production of lipoic acid, a molecule that is essential for the function of several important metabolic enzymes.