Baicalein attenuates atherogenesis by suppressing endothelial pyroptosis via cylindromatosis-mediated tumor necrosis...

Endothelial pyroptosis is a critical contributor to the development of atherosclerosis. Baicalein (BAI) exhibits anti-atherosclerotic potential; however, whether it alleviates atherosclerosis by modulating endothelial pyroptosis and the underlying molecular mechanisms remain unclear.

This study aimed to elucidate the mechanism by which baicalein attenuates atherosclerosis, with a particular focus on Cylindromatosis (CYLD)-mediated deubiquitination of tumor necrosis factor receptor-associated factor 6 (TRAF6).

Atherosclerosis was induced in ApoE⁻/⁻ mice, and ox-LDL was used to trigger pyroptosis in HUVECs. Serum lipid levels were measured, and aortic pathological changes were evaluated by Oil Red O, H&E, and Masson's trichrome staining. Endothelial injury, inflammasome activation, Gasdermin D cleavage, and TRAF6 ubiquitination were assessed using immunofluorescence, immunohistochemistry, western blotting, and co-immunoprecipitation. Pyroptosis was quantified by flow cytometry. CYLD knockdown, molecular docking, microscale thermophoresis (MST), and cellular thermal shift assays (CETSA) were performed to verify the interaction between baicalein and CYLD.

Baicalein significantly alleviated dyslipidemia, reduced aortic lipid deposition and plaque formation, and increased collagen content in ApoE⁻/⁻ mice. Baicalein also attenuated endothelial injury and suppressed the elevated expression of NF-κB, NLRP3, Caspase-1, and Gasdermin D in aortic tissues. In vitro, baicalein improved ox-LDL-induced HUVEC injury and markedly inhibited pyroptosis. Mechanistically, baicalein reduced TRAF6 ubiquitination by targeting CYLD, thereby suppressing Caspase-1 activation and Gasdermin D cleavage. Molecular interaction analyses confirmed direct binding of baicalein to the CYLD protein.

This study demonstrates that baicalein attenuates atherosclerosis by inhibiting endothelial pyroptosis through the CYLD-TRAF6-Caspase-1/Gasdermin D signaling axis, highlighting CYLD as a potential therapeutic target for atherosclerosis.