Abstract Body: Abstract
Introduction: Vesicle-mediated protein sorting is essential for the proper segregation and trafficking of intracellular proteins to distinct organelles. Vacuolar protein sorting 11 (VPS11), a core subunit of the CORVET and HOPS complexes, regulates vesicle tethering, SNARE-mediated membrane fusion, and the endolysosomal pathway. Genome-wide association studies (GWAS) have identified genetic variants at the VPS11 gene that are significantly associated with coronary artery disease. Endothelial cell (EC) dysfunction represents a hallmark of early-stage atherosclerosis. However, the role of VPS11 in maintaining vascular EC homeostasis remains poorly understood.
Hypothesis: We hypothesize that VPS11 promotes autophagy and inhibits inflammatory response in ECs, thereby limiting atherosclerosis development.
Methods: Human coronary artery endothelial cells (HCAECs) were used to examine VPS11 expression following TNF-α and IL-1β stimulation. Lentivirus-mediated stable overexpression of VPS11 was used to assess the role of VPS11 in endothelial inflammation and apoptosis. Leukocyte adhesion and transmigration were evaluated under flow using a 3D microfluidic system. Autophagic flux was analyzed, and RNA sequencing was performed to explore underlying mechanisms. TIR Domain-Containing Adapter Molecule 1 (TICAM1) was identified as a VPS11-interacting protein based on BioGRID data and further investigated for mechanistic insights.
Results: VPS11 expression was rapidly upregulated in response to TNF-α and IL-1β treatment in ECs. Stable overexpression of VPS11 significantly downregulated proinflammatory adhesion molecules (VCAM1, ICAM1, and E-selectin) and reduced apoptosis in HUVECs suggesting a protective role of VPS11 against inflammation-induced EC dysfunction. Using vascular inflammation-on-a-chip, VPS11 markedly inhibited leukocyte adhesion and transmigration on the endothelial layer under flow. VPS11 also enhanced autophagic flux in ECs. Gene set enrichment analysis of RNA sequencing data revealed inhibition of inflammatory response and apoptosis pathways in VPS11-overexpressing ECs. Mechanistically, TICAM1 knockdown attenuated the increase in proinflammatory adhesion molecules induced by VPS11 deficiency.
Conclusion: VPS11 confers protections against endothelial dysfunction by promoting autophagy and restraining inflammatory activation. These findings identify VPS11 as a potential molecular target for mitigating endothelial dysfunction and atherosclerosis.