Irisin Attenuates Hepatic Stellate Cell Activation and Liver Fibrosis in Bile Duct Ligation Mice Model and Improves Mitochondrial Dysfunction

Irisin effectively attenuated HSC activation, ameliorated liver fibrosis in BDL mice, and improved associated mitochondrial dysfunction. These findings highlight the therapeutic potential of irisin for the treatment of liver fibrosis.

In vitro experiments utilized LX-2 cells, a human HSC line, stimulated with transforming growth factor-β1 (TGF-β1), a major regulator of HSC fibrosis, with or without irisin. Mitochondrial function was assessed using mitochondrial fission markers, transmission electron microscopy, mitochondrial membrane potential, and adenosine triphosphate (ATP) production. In vivo, liver fibrosis was induced in mice via BDL, followed by daily intraperitoneal injections of irisin (100 μg/kg/day) for 10 days.

In vitro, irisin mitigated HSC activation and reduced reactive oxygen species associated with the TGF-β1/Smad signaling pathway. Irisin restored TGF-β1-induced increases in fission markers (Fis1, p-DRP1) and reversed the decreased expression of TFAM and SIRT3. Additionally, irisin restored mitochondrial membrane potential and ATP production lowered by TGF-β1 treatment. In vivo, irisin ameliorated the elevated liver-to-body weight ratio induced by BDL and alleviated liver fibrosis, as evidenced by Masson's trichrome staining. Irisin also improved mitochondrial dysfunction induced by BDL surgery.