METTL14/YTHDF1 axis-modified UCHL5 aggravates atherosclerosis by activating the NLRP3 inflammasome

Vascular smooth muscle cell (VSMC) phenotypic switching contributes to VSMC proliferation and migration in atherosclerosis (AS). Nevertheless, the regulatory mechanism of VSMC phenotypic switching during AS progression is unclear. Here, the role and regulatory mechanism of UCHL5 in VSMC phenotypic switching during AS progression were investigated.

ApoE^-/- mice were fed with high fat diet to establish AS model in vivo. VSMCs stimulated by ox-LDL were used as AS cellular model. VSMC proliferation and migration were examined by CCK8 assay and transwell assay, respectively. The levels of pro-inflammatory cytokines were assessed using ELISA. The interactions between METTL14/YTHDF1, UCHL5 and NLRP3 were analyzed using RIP and/or dual-luciferase reporter gene and/or Co-IP assays. NLRP3 ubiquitination was analyzed by ubiquitination analysis.

UCHL5 was significantly upregulated in AS patients and ox-LDL-treated VSMCs. UCHL5 silencing ameliorated plaque formation and vascular remodeling in vivo and suppressed ox-LDL-induced VSMC proliferation, migration, inflammation and phenotypic switching in vitro. Moreover, METTL14 could increase UCHL5 mRNA m⁶A level and promoted UCHL5 expression by recruiting YTHDF1. Moreover, UCHL5 overexpression enhanced protein stability by deubiquitinating NLRP3. Rescue studies revealed that NLRP3 overexpression abrogated UCHL5 silencing-mediated biological effects in ox-LDL-treated VSMCs.

UCHL5 modified by METTL14/YTHDF1 axis could facilitate the inflammation and vascular remodeling in atherosclerosis by activating the NLRP3 inflammasome.