Mice deficient in Cyp4a14 have an increased number of goblet cells and attenuated dextran sulfate sodium-induced colitis

Abstract

Background/Aims: Cyp4a14 is a member of cytochrome P450 (Cyp450) enzyme superfamily that possesses NADPH monooxygenase activity, which catalyzes omega-hydroxylation of medium-chain fatty acids and arachidonic acid. Study suggests that down-regulation of Cyp4a14 has an anti-inflammatory response in intestine. The present study was to test the function of Cyp4a14 in dextran sulfate sodium (DSS)-induced colitis. Methods: Female Cyp4a14-knockout (KO) and wild-type (WT) mice were treated with DSS for 6 days to induce colitis. The colon of mice was histologically observed by hematoxylin and eosin (H&E) and periodic acid Schiff (PAS) staining. The serum malondialdehyde (MDA), an endogenous indicator of oxidative stress, was chemically measured. Proinflammatory and NADPH oxidase genes were examined by quantitative polymerase chain reaction (qPCR). Results: Cyp4a14-KO mice had a significantly higher number of goblet cells in the colon and were more resistant to DSS-induced colitis compared with the WT mice. The DSS-treated KO mice had lower levels of MDA. Consistent with the milder inflammatory pathological changes, DSS-treated KO mice had lower levels of IL-1β, IL-6 and TNF-α mRNA in the liver and the colon. Moreover, the colon of DSS-treated Cyp4a14-KO and WT mice had higher mRNA levels of two members of NADPH oxidases, Nox2 and Nox4, suggesting that both Nox2 and Nox4 are inflammatory markers. By contrast, DSS-treated WT and KO mice had drastically decreased epithelium-localized Nox1 and dual oxidase (Duox) 2 mRNA levels, coinciding with the erosion of the mucosa induced by DSS. Conclusion: These results suggests a hypothesis that the increased goblet cell in the colon of Cyp4a14-KO mice provides protection from mucosal injury and Cyp4a14-increased oxidative stress exacerbates DSS-induced colitis. Therefore, Cyp4a14 may represent a potential target for treating colitis.