Transcriptomic analysis reveals the mechanism of sulfasalazine-induced liver injury in mice. (15th March 2020)

• Record Type: Journal Article
• Authors: Li, Yu-Cheng; Shen, Ji-Duo; Lu, Shuai-Fei; Zhu, Lei-Lei; Wang, Bao-Ying; Bai, Ming; Xu, Er-Ping
• Is Part Of: Toxicology letters. Volume 321(2020)
• Page Start: 12
• Page End: 20
• Publication Date: 2020-03-15
• Subjects: Drug-induced liver injury -- Sulfasalazine -- Transcriptomics -- RNA sequencing; Toxicology -- Periodicals; 363.179
• DOI: 10.1016/j.toxlet.2019.12.011
• Languages: English
• ISSNs: 0378-4274

Abstract

Highlights: Total 187 DEGs were found in SASP-treated group, of which 106 genes were up-regulated and 81 genes were down-regulated. These 187 DEGs were enriched in 123 GO terms and 30 pathways. Egfr has the highest score in PPI analysis and cyp2c55 has the largest fold change in qPCR. Abstract: Liver injury is one of the main toxic effect of sulfasalazine (SASP). However, the toxicological mechanism of SASP-induced liver injury remains unclear. In the present study, the liver injury was induced by orally treatment with SASP for 4 weeks in mice. The hepatic mRNA profiles were detected by RNA sequencing and the differentially expressed genes (DEGs) were analyzed by bioinformatics methods. The elevated serum levels of alanine aminotransferase (ALT), alkaline phosphatase (ALP) and total bilirubin (TBIL), combined with the hepatic histopathological features verified that liver injury was successfully caused by SASP. Transcriptomic results showed that 187 genes (fold change > 1.5 and P < 0.05) were differentially expressed, of which 106 genes were up-regulated and 81 genes were down-regulated in SASP-treated group. Moreover, the further analysis showed that these 187 differentially expressed genes (DEGs) were enriched in 123 GO terms, which mainly including oxidation-reduction process, oxidoreductase activity and epoxygenase P450 pathway. KEGG pathway analysis showed 30 pathways including chemical carcinogenesis, retinol metabolism, arachidonic acid metabolism, linoleic acid metabolism and glutathione metabolism. Among these 187 DEGs, the top 22 hub genes were screened from network of protein-protein interaction (PPI) and verified by qRT-PCR. The results showed that the mRNA levels of hepatic drug-metabolizing enzymes, including cyp2b50, cyp2c50, cyp2c39, cyp2c38, cyp2c29, cyp2c54, cyp2c55, cyp2a5, gsta1, gsta2, gstt2, gstm2 and ephx1, were significantly up-regulated, while egfr and egr1 were down-regulated in SASP-treated group. Moreover, the mRNA levels of egfr and cyp2c55 exhibited a dose-dependent changes in SASP groups. Western blotting verified that the changes of protein levels of EGFR and CYP2C55 were consistent with mRNA levels. Considering that egfr has the highest score in PPI degree and cyp2c55 has the largest fold change in qPCR analysis, our present results suggested that the toxicological mechanisms of SASP-induced liver injury might be related to multi-biological processes and pathways, and egfr and cyp2c55 may play important roles in SASP-induced liver injury. The present study would be helpful for better understanding the hepatotoxic mechanism of SASP. However, the precise mechanism still needs further research.