Disturbance of cytoskeleton induced by ligustilide promotes hepatic stellate cell senescence and ameliorates liver fibrosis.

Background and aims: Inducing the senescence of activated hepatic stellate cells (HSCs) has emerged as a promising therapeutic strategy for liver fibrosis, with potential connections to the Yes-associated protein (YAP)-controlled cGAS-STING pathway. However, the regulatory role of cytoskeletal dynamics on HSC senescence and its potential as a target for natural products have remained poorly understood. Methods: We employed preclinical in vivo and in vitro transcriptome analyses, experimental systems, Tmem173^-/- mice and liver-specific STING knockdown mice to demonstrate the anti-fibrotic effects and mechanism of ligustilide (LIG). Results: LIG selectively bound to monomeric globular actin (G-actin), thereby preventing its polymerization into polymeric filamentous actin (F-actin), which disturbed its interaction with intermediate filament component lamin A/C and initially destroyed the nuclear membrane. Moreover, the disruption of nuclear membrane caused YAP leakage from nuclear, which in turn suppressed lamin A/C and created a deleterious feedback loop that exacerbated nuclear membrane destabilization. Consequently, nuclear double stranded DNA (dsDNA) leakage caused by the above damage cascade ultimately triggered the activation of the cGAS-STING signaling pathway, promoting senescence-associated secretory phenotypes (SASPs) release and inducing HSC senescence. Moreover, the induction of HSC senescence and anti-fibrotic effects of LIG were completely abrogated in both whole-body STING knockout and liver-specific STING knockdown mice. Conclusions: By interacting with G-actin, LIG disrupted the cytoskeleton to compromise nuclear integrity with the involvement of YAP and further stimulated the cGAS-STING pathway, leading to the release of SASPs and HSC senescence, which ultimately mitigated liver fibrosis.