Adropin deficiency worsens TNBS-induced colitis

The aim of this study was to describe the effects of adropin deficiency on the distribution, phenotype and pathological phenotype of macrophages in colonic and mesenteric tissues of AdrKO (Enho^-/-) mice, so as to explore the mechanism of adropin deficiency in spontaneous and experimental colitis. In this study, RNA-seq and metabonomics were used to screen the regulatory mechanism of adropin on the phenotypic transformation of macrophages. We found that adropin levels in active UC patients were significantly lower than those in normal subjects and remission UC patients, and at the same time, a large number of proinflammatory M1-type macrophages were infiltrated in the mesenteric tissue of colonic tissues from UC and CD patients. At the same time, spontaneous colitis occurred in Enho-/- (adropin-deficient)C57BL/6 mice, and there was an imbalance of M2 → M1 polarization of macrophages in colon and mesentery of Enho-/- mice. In vivo, it has showed that adropin deficiency could exacerbate the pathological phenotype of colitis induced by TNBS. In vitro, adropin was used to intervene RAW264.7 macrophages, and then combined analysis of RNA-seq and metabolomics demonstrated that adropin regulated lipid metabolism of macrophages through PPARγ, thus promoting the repolarization of macrophages from M1 to M2. Adropin deficiency led to an imbalance in the phenotypic distribution of macrophages infiltrating the colon and mesenteric tissues, namely, an increase in M1 type, which led to the occurrence and development of colitis.