Senolytics prevent caveolar Ca_V 3.2-RyR axis malfunction in old vascular smooth muscle.

Abstract

Aging is a major risk factor for cardiovascular diseases. Our previous studies demonstrate that aging impairs the caveolar T-type Ca_V 3.2-RyR axis for extracellular Ca²⁺ influx to trigger Ca²⁺ sparks in vascular smooth muscle cells (VSMCs). We hypothesize that the administration of senolytics, which can selectively clear senescent cells, could preserve the caveolar Ca_V 3.2-RyR axis in aging VSMCs. In this study, 10-month-old mice were administered the senolytics cocktail consisting of dasatinib (5 mg/kg) and quercetin (50 mg/kg) or vehicle bi-weekly for 4 months. Using VSMCs from mouse mesenteric arteries, we found that Ca²⁺ sparks were diminished after caveolae disruption by methyl-β-cyclodextrin (10 mM) in cells from D + Q treated but not vehicle-treated 14-month-old mice. D + Q treatment promoted the expression of Ca_V 3.2 in 14-month-old mesenteric arteries. Structural analysis using electron tomography and immunofluorescence staining revealed the remodeling of caveolae and co-localization of Ca_V 3.2-Cav-1 in D + Q treatment aged mesenteric arteries. In keeping with theoretical observations, Ca_v 3.2 channel inhibition by Ni²⁺ (50 μM) suppressed Ca²⁺ in VSMCs from the D + Q group, with no effect observed in vehicle-treated arteries. Our study provides evidence that age-related caveolar Ca_V 3.2-RyR axis malfunction can be alleviated by pharmaceutical intervention targeting cellular senescence. Our findings support the potential of senolytics for ameliorating age-associated cardiovascular disease.