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.

Keywords: LRRC8A; cellular senescence; endothelial cell; oxidative stress; vascular ageing.