Prostaglandin E2 alleviates acetaminophen-induced liver injury through DDIT4-enhanced autophagy regulated by circLima1/miR- 486

Background Studies indicate that acetaminophen (APAP) overdose induces autophagy, thereby attenuating APAP-induced hepatocyte death. Prostaglandin E2 (PGE2) has been shown to reduce serum transaminase levels and prevent mortality in APAP-induced liver injury(AILI) in mice, and PGE2 downregulation reduces autophagy in skeletal muscle tissue of young mice. However, the hepatoprotective mechanisms of PGE2 have not been elucidated. Methods High-throughput sequencing profiled circRNA, miRNA, and mRNA expression. Differentially expressed mRNAs were analyzed via protein-protein interaction networks and integrated with single-cell sequencing data from GEO. A circRNA/miRNA/mRNA network was computationally predicted (miRanda) and validated through miRNA mimic transfection and dual-luciferase assays. The role of Autophagy in PGE2-mediated protection was assessed by dual-fluorescent LC3 tracking and mitochondrial flux analysis. Results In the PGE2 group, a marked upregulation of circLima1 expression was detected, concomitant with downregulation of miR-486a-3p and miR-486b-3p. Transcriptomic analysis revealed significant DDIT4 upregulation in both APAP versus CON and PGE2 versus APAP comparisons. miRNA mimic transfection and dual-luciferase reporter assays were applied to confirm the regulatory axis involving circLima1/miR-486/DDIT4. Furthermore, we demonstrated that APAP + PGE2 enhances autophagic activity in hepatocytes, as shown by biochemical autophagic flux assays and LC3 dual-fluorescent lentivirus tracking. Pharmacological inhibition of autophagy with 3-methyladenine abolished the protective effects of dmPGE2 in AILI mice. Conclusion These results elucidate the role of PGE2 in alleviating AILI by enhancing autophagy through the circLima1/miR-486/DDIT4 regulatory axis network and provide a preliminary understanding of the molecular mechanisms underlying the hepatoprotective effects of dmPGE2 in AILI mice.