G22037, a novel oxadiazole-pyrazole derivative, attenuates liver fibrosis by targeting annexin A5 and inhibition of ER stress-dependent hepatic stellate cell activation.

Liver fibrosis is a critical pathological process in chronic liver disease and is strongly associated with poor prognosis. This study investigated the anti-fibrotic potential of G22037, a novel oxadiazole-pyrazole derivative whose pharmacological properties have not been previously characterized. In the human hepatic stellate cell line LX-2, G22037 significantly suppressed TGFβ1-induced overexpression of COL1A1 and α-SMA, indicating a direct inhibitory effect on hepatic stellate cells (HSCs) activation. The in vivo anti-fibrotic activity of G22037 was validated in two complementary mouse models: bile duct ligation (BDL)-induced cholestatic liver injury and CDAHFD-induced MASH. In both models, administration of G22037 markedly attenuated liver injury, collagen deposition, and fibrogenesis. Mechanistically, limited proteolysis-mass spectrometry (LiP-MS) and cellular thermal shift assay (CETSA) revealed that G22037 directly targets Annexin A5 (ANXA5). By binding to ANXA5, G22037 alleviates liver fibrosis through inhibition of calcium overload and its downstream consequences, including reactive oxygen species (ROS) accumulation and endoplasmic reticulum (ER) stress. Furthermore, G22037 modulated macrophage-driven inflammatory responses by suppressing NLRP3 inflammasome activation and subsequent IL-1β release, which indirectly contributed to the inhibition of HSCs activation. Collectively, our study demonstrates that G22037 exerts significant anti-fibrotic activity both in vitro and in vivo, and possesses dual pharmacological activities that inhibit HSCs activation and macrophage polarization, positioning it as a promising and safe candidate for the treatment of liver fibrosis.