Oltipraz, the activator of nuclear factor erythroid 2-related factor 2 (Nrf2), protects against the formation of BAPN-induced aneurysms and dissection of the thoracic aorta in mice by inhibiting activation of the ROS-mediated NLRP3 inflammasome.

BACKGROUND: Thoracic aortic aneurysm and dissection (TAAD) is caused by the apoptosis and phenotypic transformation of vascular smooth muscle cells (VSMCs). The dysfunction of VSMCs affects their secretion of chemokines such as monocyte chemoattractant protein-1 (MCP-1) to recruit the infiltration of macrophages which release proinflammatory cytokines and matrix metalloproteinases (MMPs) to accelerate the process of TAAD formation.

APPROACH AND RESULTS: We analyzed the expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) in aortic tissues of TAAD patients and the β-aminopropionitrile fumarate (BAPN)-induced mouse model, and the levels of Nrf2 were elevated in both aortic lesions. Treatment with the Nrf2 activator oltipraz protects against the formation of BAPN-induced aneurysm and dissection, as demonstrated by a higher survival rate, postponing the time of aortic rupture, and inhibiting aortic luminal dilation. In addition, the thoracic aortas of BAPN-treated mice inhibited the apoptosis and phenotypic transformation of VSMCs. When treated with oltipraz, they had reduced macrophage infiltration proinflammatory cytokines and MMPs. Furthermore, oltipraz treatment promoted the translocation of Nrf2 and downregulated the NLRP3 pathway.

CONCLUSION: Nrf2 plays a crucial role in protecting against TAAD development, and persistent activation of Nrf2 is a promising therapeutic strategy against the progression of TAAD.