Endothelial LRRC8A delays vascular ageing in natural and accelerated ageing mouse models

Abstract Aims Vascular ageing (VA), characterised by vascular endothelial dysfunction, is a major contributor to age-related chronic conditions. Leucine-rich repeat-containing protein 8A (LRRC8A) is vital in maintaining vascular endothelial function; however, the role of endothelial LRRC8A in VA is undefined. We aimed to investigate the role and mechanism of endothelial LRRC8A in VA. Methods and results We found that LRRC8A expression was clearly downregulated in the aged murine aortas. Further integrated analysis of single-cell and bulk RNA-seq and experimental verification revealed that endothelial LRRC8A governed VA by counteracting cell cycle, cellular senescence and oxidative stress. Additionally, endothelial LRRC8A deletion exacerbated the D-galactose (D-gal)-induced VA progression. Mechanistically, endothelial LRRC8A phosphorylated AMPK at T172 and subsequently facilitated SIRT1 nuclear translocation, ultimately counteracting the p53-dependent senescence pathway and activating the FOXO3-dependent antioxidant pathway. Therapeutically, pharmacological agonists of AMPK and SIRT1 effectively rescued endothelial cell senescence and VA in the context of endothelial LRRC8A deficiency. Additionally, endothelial-targeted adeno-associated virus (AAV)-LRRC8A gene therapy can effectively delay the progression of VA in naturally ageing mice. Conclusions Our findings provide the first evidence supporting endothelial LRRC8A as a novel modulator of the AMPK-SIRT1 axis and suggest that targeting LRRC8A represents a promising therapeutic strategy for VA and age-related chronic conditions.