Resveratrol Mitigates Age-Associated Cognitive Decline via Inhibition of cGAS-STING-Mediated Microglial Senescence.

Background

Aging-related cognitive decline is closely associated with microglial senescence and the resulting chronic neuroinflammation. Emerging evidence identifies the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway as a pivotal innate immune signaling pathway linking DNA damage to cellular senescence and the senescence-associated secretory phenotype (SASP), particularly in microglia. Targeting the formation or selective clearance of senescent cells thus emerges as a promising therapeutic approach to ameliorate cognitive dysfunction. Resveratrol has shown promise in modulating immune response and exerting anti-aging effects. However, the therapeutic potential and underlying mechanisms of resveratrol in mitigating age-associated microglial senescence and cognitive decline are not fully understood.

Methods

In the present study, we employed a well-established murine model of accelerated aging induced by chronic intraperitoneal injection of D-galactose (D-gal) to elicit pronounced senescence-associated phenotypes and neuroinflammation. Resveratrol was administered via oral gavage daily for three weeks following D-gal injections. Behavioral assays were conducted to assess cognitive performance. Immunohistochemistry, quantitative PCR, and Western blot analyses were used to evaluate markers of cellular senescence, microglial activation and pro-inflammatory cytokine expression. In addition, in vitro assays in cultured microglia coupled with RNA sequencing were used to investigate the downstream signaling events following resveratrol treatment.

Results

Chronic D-gal treatment induced significant cognitive impairment, enhanced microglial activation, elevated pro-inflammatory cytokine levels, and increased markers of cellular senescence in the brain. Resveratrol administration remarkably attenuated these effects, as evidenced by improved memory performance, reduced microglial senescence markers, and suppressed expression of Cxcl-10, Il-1β, and other SASP factors. Mechanistically, unbiased transcriptomic analysis revealed that the cGAS-STING signaling and neuroinflammation pathways were prominently dysregulated with double-stranded DNA-induced cellular senescence, which was effectively normalized by resveratrol in cultured microglia. Interestingly, resveratrol inhibited the translocation of STING from the endoplasmic reticulum to the Golgi apparatus and suppressed phosphorylation of TBK1, thereby blocking downstream STING signaling.

Conclusions

These findings demonstrate that resveratrol mitigates microglial senescence and neuroinflammation and preserves cognitive function in D-gal-induced aging mice, at least partly through modulation of the cGAS-STING signaling. Therefore, targeting this pathway may represent a promising therapeutic strategy for age-related neuroinflammatory and cognitive disorders.