Small Molecule Activators of Mitochondrial Fusion Prevent Congenital Heart Defects Induced by Maternal Diabetes

Most congenital heart defect (CHD) cases are attributed to nongenetic factors; however, the mechanisms underlying nongenetic factor–induced CHDs are elusive. Maternal diabetes is one of the nongenetic factors, and this study aimed to determine whether impaired mitochondrial fusion contributes to maternal diabetes–induced CHDs and if mitochondrial fusion activators, teriflunomide and echinacoside, could reduce CHD incidence in diabetic pregnancy. We demonstrated maternal diabetes-activated FoxO3a increases miR-140 and miR-195, which in turn represses Mfn1 and Mfn2, leading to mitochondrial fusion defects and CHDs. Two mitochondrial fusion activators are effective in preventing CHDs in diabetic pregnancy.