Aorta-on-a-chip reveals impaired mitochondrial dynamics as a therapeutic target for aortic aneurysm in bicuspid aortic valve disease

Bicuspid aortic valve (BAV) is the most common congenital cardiovascular disease in general population and is frequently associated with the development of thoracic aortic aneurysm (TAA). There is no effective strategy to intervene with TAA progression due to an incomplete understanding of the pathogenesis. In this study, protein analyses of human aortic tissues showed the insufficient expression of NOTCH1 and impaired mitochondrial dynamics in BAV-TAA. To verify it, we constructed aorta-on-a-chip to replicate the rhythmic tensile on human aorta, on which human aortic smooth muscle cells (HAoSMCs) endured a microenvironment of biomimetic strain unattainable in animal models. HAoSMCs with NOTCH1-knockdown exhibited reduced contractile phenotype and were accompanied by attenuated mitochondrial fusion. Furthermore, we identified that mitochondrial fusion activators (leflunomide and teriflunomide) or mitochondrial fission inhibitor (Mdivi-1) rescued the mitochondrial dysfunction in HAoSMCs from BAV-TAA patients. These findings suggest that impaired mitochondrial dynamics could be a potential therapeutic target for BAV-TAA.