Study on Role and Mechanism of Leptin and BDNF in DSS Induced Colitis in Mice / 胃肠病学

ABSTRACT

Background: Abnormal expression of leptin and brain⁃derived neurotrophic factor (BDNF) is an important link in the occurrence of ulcerative colitis (UC), but the mechanism of leptin and BDNF in UC is still unclear. Aims: To explore the effect and mechanism of leptin and BDNF in DSS induced colitis in mice. Methods: Thirty⁃six male 8⁃10 weeks healthy leptin⁃deficient ob mice and leptin⁃normal expressing wild type (WT) mice were selected and randomly divided into WT experimental group, ob experimental group, WT control group and ob control group. The mice in experimental groups were given 3% DSS solution for 7 days to induce colitis model, and the mice in control group were given distilled water. After modeling, disease activity index (DAI) score, colon length, behavior and visceral sensitivity were observed. The mRNA expressions of leptin and BDNF in colon and hippocampus were detected by real⁃time fluorescent quantitative PCR, and the protein expression of BDNF in colon was detected by Western blotting. Results: Compared with corresponding control groups, DAI score, visceral sensitivity in WT experimental group and ob experimental group were significantly increased (P< 0.05), mRNA and protein expressions of BDNF in colon were significantly increased (P<0.05). Compared with WT control group, anxiety and depression⁃like behavior were found in WT experimental group, mRNA expressions of leptin, BDNF in hippocampus were significantly decreased (P<0.05). Correlation analysis showed that anxiety was positively correlated with length of colon in WT experimental group (P<0.05), and negatively correlated with DAI score (P<0.05); depression, expression of BDNF mRNA in colon were negatively correlated with length of colon (P<0.05), and positively correlated with DAI score (P<0.05); leptin in hippocampus was positively correlated with anxiety (P<0.05), while was negatively correlated with depression (P<0.05); expression of BDNF mRNA in colon was negatively correlated visceral sensitivity (P<0.05). Conclusions: Colonic BDNF secretion is associated with leptin expression, and both may be involved in the DSS⁃induced colitis in mice by mediating anxiety, depression and visceral sensitivity.