Integrated transcriptomic and metabolomic analyses reveal the pathogenesis of 3,5-diethoxycarbonyl-1,4-dihydrocollidine-induced liver injury in mice.

The hepatotoxic compound 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) has been widely utilized to establish various liver disease models. However, the molecular networks and metabolic regulatory mechanisms underlying DDC-induced liver injury remain to be fully elucidated. In this study, an integrated transcriptomic and metabolomic approach was employed to investigate the mechanisms of DDC-induced hepatotoxicity. C57BL/6 J mice were administered a 0.1 % DDC-supplemented diet for two weeks to induce liver injury, followed by collection of serum and liver tissue samples for analysis. The results demonstrated that DDC treatment significantly elevated markers of liver injury, cholestasis, and fibrosis. Histopathological examination revealed hepatocyte damage, inflammatory cell infiltration, and increased collagen deposition in DDC-treated mice. Liver transcriptomic analysis identified 814 differentially expressed genes, while serum metabolomic profiling detected 958 differentially expressed metabolites. Integrated pathway analysis revealed co-enrichment of 14 pathways in both transcriptomic and metabolomic datasets, including steroid hormone biosynthesis, glycerophospholipid metabolism, retrograde endocannabinoid signaling, and primary bile acid biosynthesis. Validation experiments using qRT-PCR and UPLC-MS/MS demonstrated that DDC treatment upregulated hepatic mRNA levels of Cyp27a1, Mrp2, and Mrp3, while downregulating Cyp8b1, Hsd3b7, Scp2, and Hsd17b4. Serum analysis showed significant increases in the concentrations of CA, TCA, GCA, TCDCA, α-MCA, β-MCA, Tβ-MCA, TUDCA, CDCA, UDCA, ω-MCA, and HDCA, along with decreased LCA levels. These findings indicate that DDC-induced liver injury involves multiple pathways and mechanisms, with disruption of bile acid homeostasis representing a central pathological feature.