Mechanistic study of ferulic acid in inhibiting fibrosis via promoting fibroblast apoptosis through Bcl-xL/caspase-3 signaling pathway.

Abstract

Fibrotic disorders have always been a clinical challenge. The common pathogenesis is the persistence of apoptosis-resistant fibroblasts. Keloids, as a typical model of cutaneous fibrosis, exemplify this mechanism through hyperactive fibroblasts that evade programmed cell death. Ferulic acid (FA), a dietary phenolic compound, emerged as a candidate to overcome fibroblast apoptosis resistance. This study aims to explore the mechanisms by which FA may treat keloid. Overlapping targets between FA and keloid were identified. Enrichment analyses were conducted to predict the associated functions and pathways. Following identification of hub targets, molecular docking and molecular dynamics simulations were employed to evaluate the binding affinity of FA. For in vitro validation, keloid-derived fibroblasts were treated with FA at 20, 40, and 60 µM. Cell viability was assessed by CCK-8 assay, apoptosis was measured by flow cytometry, and the expression of key targets Bcl-xL and caspase-3 was determined by Western blot analysis. Molecular docking and molecular dynamics simulations predicted that FA has stable binding with Bcl-xL and caspase-3. Experimentally, FA dose‑dependently downregulated Bcl‑xL expression and increased the cleaved caspase‑3 expression in keloid fibroblasts, accompanied by elevated apoptosis. The apoptotic rate plateaued beyond 40 µM FA despite continued caspase‑3 activation, indicating that the pro‑apoptotic effect reaches a maximum at this concentration. FA overcomes fibroblast apoptosis resistance by targeting the Bcl-xL/caspase-3 axis, with 40 µM identified as the concentration for maximal cell death. The discordance between upstream signaling and terminal apoptosis highlights a threshold-driven mechanism.