Cytoskeletal-related genes function as checkpoints for the maintenance of VSMC contractile phenotype and prevent pathological remodeling in arterial diseases.

Abstract

INTRODUCTION: Arterial pathological remodeling, central to arterial diseases including atherosclerosis and aortic aneurysms, is characterized by vascular smooth muscle cell (VSMC) phenotypic switching with concomitant loss of contractile markers. Uncovering the molecular changes initiating phenotypic transition may advance the understanding of vascular pathogenesis and provide new therapeutic strategies. OBJECTIVES: To construct a cross-species integrative model of VSMC transition in arterial diseases including atherosclerosis and aortic aneurysm, identify key genes regulating phenotypic switching in the trajectory from contractile to other phenotypes, and further validate their function in arterial remodeling models. METHODS: Public single-cell RNA-seq datasets were analyzed to map VSMC transcriptional dynamics and identify regulated gene expression patterns during transition. The changes were further checked using experimental animal aneurysm samples and PDGF-BB treated VSMCs. Functional validation included in vitro siRNA-mediated knockdown using primary VSMCs and in vivo gene-manipulated (AAv-shRNA/Adv-overexpression) wire-injury models. RESULTS: Dysregulation of cytoskeletal-related genes (Fblim1, Tns1, and Synpo2) may cause disarrangement of actin cytoskeleton, and were identified as checkpoint process before VSMCs transition initiation. Knockdown of target genes suppressed contractile markers, enhanced proliferation, migration, and disrupted cytoskeleton architecture in VSMCs. In animal models, gene down-regulation exacerbated pathological remodeling while over-expression partially reverted these effects. CONCLUSION: The findings highlight the critical role of cytoskeleton-related genes in arterial diseases that function as a critical checkpoint in preventing VSMC pathological phenotypic switching.