Role and Mechanism of Intestinal NDRG2 Mediating Visceral Hypersensitivity Following Exposure to PTSD / 胃肠病学

Background: Visceral hypersensitivity is considered as a key pathophysiological mechanism involved in functional gastrointestinal disorders (FGIDs). Visceral nociception and hyperalgesia is existed extensively following exposure to post-traumatic stress disorder (PTSD), however, its molecular mechanism in intestinal tract is unclear. Aims: To explore the potential role of N-Myc downstream-regulated gene 2 (NDRG2) in intestinal tract for mediating visceral hypersensitivity following exposure to PTSD. Methods: PTSD model was established by single prolonged stress (SPS). SD rats were divided into normal control group, CTX group, PTSD group and PTSD+CTX group. Mice were divided into normal control group, PTSD group, NDRG2

Role and Mechanism of Colon Circadian Clock Gene Bmal1 Involved in Symptoms of Irritable Bowel Syndrome With Diarrhea / 胃肠病学

Background: Symptoms of irritable bowel syndrome with diarrhea (IBS-D) are known to be influenced by circadian oscillation; however, the pathophysiological mechanism is still unclear. Aims: To investigate the role and underlying mechanism of colon circadian clock gene Bmal1 involved in the occurrence of symptoms in IBS-D patients. Methods: Forty-six patients with IBS-D and 34 normal controls from Army Medical Center of PLA during September 2018 to February 2021 were recruited in this study. IBS-severity scoring system (IBS-SSS) was used to evaluate the severity of IBS-D symptoms. A colonoscopy was performed to obtain biopsy specimens from rectosigmoid colon. The concentration of 5-hydroxytryptamine (5-HT), and expressions of Bmal1 and chromogranin A (CgA), a biomarker of enterochromaffin cells (EC cells), in colonic mucosa were detected by ELISA and double-labeled immunofluorescence, respectively. Results: Both the 5-HT concentration and number of EC cells in colonic mucosa of IBS-D patients were significantly higher than those of the normal controls (all P< 0.05). Bmal1 was mainly expressed in intestinal epithelial cells and was highly expressed in EC cells. Co-expression of Bmal1 and CgA was observed. Compared with the normal control group biopsied at the same time point, expression of Bmal1 was significantly higher in specimens taken at 9 a.m., and expression of Bmal1 was significantly lower in specimens taken at 17 p.m. in IBS-D patients (all P< 0.05). Spearman correlation coefficient analysis showed that Bmal1 expression at 9 a.m. was positively correlated with the total score of IBS-SSS and subscore of abdominal pain and discomfort (r