Ticagrelor attenuates cholestasis-induced liver fibrosis by inhibiting S1PR2-dependent Akt/ERK signaling, NLRP3 inflammasome activation.

S1PR2 activation is a pivotal player in chronic liver disease (CLD) progression through bile acid (BA) and sphingosine-1-phosphate (S1P) signaling. This signaling promotes ductular reaction (DR), NLRP3 inflammasome-driven inflammation, and fibrosis progression, making S1PR2 antagonism a promising therapeutic approach. Using structure-based virtual screening, Ticagrelor (TG) was identified as a potential S1PR2 inhibitor, demonstrating a strong predicted binding affinity (-10.1 kcal/mol) and stable interactions with key residues Thr 21, Arg 33, Asn 89, and His 271. Based on docking results, TG's hepatoprotective effects were evaluated in a bile duct ligation (BDL) rat model and compared to ursodeoxycholic acid (UDCA). TG showed greater efficacy in reducing liver injury and improving BA metabolism parameters compared to UDCA. Histological analysis revealed that TG preserved liver architecture and reduced DR, with decreased expression of biliary proliferation markers CK19 and EpCAM. Additionally, TG exhibited antifibrotic effects by downregulating COL1A1 and α-SMA expression. Mechanistically, TG inhibited S1PR2 pathway activation, lowered total BA levels, and suppressed the S1P/SphK2 axis. These effects involved reducing pAKT and pERK1/2 expression and inhibiting NLRP3 inflammasome activity, leading to diminished inflammatory responses. Our findings indicate that TG is a promising candidate for repurposing as a treatment for CLD, with benefits exceeding those of UDCA. Its ability to target S1PR2-mediated inflammation, fibrosis, and cholestasis suggests potential for broader applications in S1PR2-related inflammatory and fibrotic diseases.