1 Department of Vascular Surgery, Beijing Friendship Hospital, Capital Medical University;Beijing Center of Vascular Surgery, Beijing, 100050, China;
2 Department of Vascular Surgery, Peking University People's Hospital, Beijing, 100044, China;
3 Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China;
4 Department of Vascular Surgery, The Affiliated hospital of Qingdao University, Qingdao, 266000, Shandong, China;
5 School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China;
6 Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing, 100191, China;
7 The Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, 100191, China
Funds:
This work was supported by the National Natural Science Foundations of China (82000429 and 81470574), Young Elite Scientists Sponsorship Program by CAST (No.YESS20230395/2023QNRC001), Beijing Nova Program (No.20230484308), Youth Elite Program of Beijing Friendship Hospital (YYQCJH2022-9), Young Elite Scientists Sponsorship Program by BAST (No.BYESS2024045), Capital’s Funds for Health Improvement and Research (CFH2022-4-20217), and Chinese Institutes for Medical Research, Beijing (CIMR) Organized Research Project (No.CX23YQ07).
Thoracic aortic aneurysm (TAA) significantly endangers the lives of individuals with Marfan syndrome (MFS), yet the intricacies of their biomechanical origins remain elusive. Our investigation delves into the pivotal role of hemodynamic disturbance in the pathogenesis of TAA, with a particular emphasis on the mechanistic contributions of the mammalian target of rapamycin (mTOR) signaling cascade. We uncovered that activation of the mTOR complex 1 (mTORC1) within smooth muscle cells, instigated by the oscillatory wall shear stress (OSS) that stems from disturbed flow (DF), is a catalyst for TAA progression. This revelation was corroborated through both an MFS mouse model (Fbn1+/C1039G) and clinical MFS specimens. Crucially, our research demonstrates a direct linkage between the activation of the mTORC1 pathway and the intensity in OSS. Therapeutic administration of rapamycin suppresses mTORC1 activity, leading to the attenuation of aberrant SMC behavior, reduced inflammatory infiltration, and restoration of extracellular matrix integrity—collectively decelerating TAA advancement in our mouse model. These insights posit the mTORC1 axis as a strategic target for intervention, offering a novel approach to manage TAAs in MFS and potentially pave insights for current treatment paradigms.