GLS1 governs vascular smooth muscle cell phenotypic switching and aortic dissection via glutamate metabolism

To evaluate the roles of glutaminase 1 (GLS1) in vascular smooth muscle cells (VSMCs) phenotypic switching and aortic dissection (AD). Integrative transcriptomic analyses were performed to identify the candidate genes involved in VSMC phenotypic switching in AD. The expression of GLS1 in VSMCs was assessed by qRT-PCR, Western blot and immunofluorescence. RNA-sequencing analysis was performed to recapitulate possible changes in the transcriptome profile of GLS1 in VSMCs. We identified GLS1 as a potential regulator in AD. GLS1 expression was significantly downregulated in VSMCs from both human AD aortic tissues and mouse models. Mechanistically, down-regulation of GLS1 impaired glutamate metabolism, leading to reduced levels of glutathione and α-ketoglutarate, thereby promoting mitochondrial dysfunction and accumulation of reactive oxygen species, which activated the PI3K/AKT pathway and ultimately triggered VSMC phenotypic switching. These findings revealed a critical role of GLS1-mediated glutamate metabolism in VSMC phenotypic switching and suggest a promising therapeutic target for AD.