ABSTRACT
Although the underlying mechanism of stress remains unknown, it has been associated with the pathophysiology of gastroesophageal reflux diseases, the development of which appear to be accelerated by oxidative stress and fibrosis. The aim of the current study was to investigate the effect of chronic restraint stress on esophageal oxidative stress and fibrosis, as well as the impact of oxidative stress in a murine model whereby 8-week old C57BL/6J male mice were subjected to intermittent chronic restraint stress for a two-week period. The current study demonstrated that chronic restraint stress significantly reduced the body weight of mice compared with the control group. Although chronic restraint stress did not significantly alter the levels of triglycerides or cholesterol, free fatty acid concentration was significantly increased compared with the control group. Furthermore, chronic restraint stress significantly upregulated the expression levels of several fibrotic biomarkers including collagen type I, transforming growth factor ß-1, α-smooth muscle actin and SMAD-3 compared with the control group. In addition, the expression levels of the reactive oxygen species (ROS) NADPH oxidase-4 and malondialdehyde were significantly increased, while the expression levels of nuclear factor erythroid 2-related factor 2 and heme oxygenase-1 were significantly decreased in esophageal tissue from mice in the chronic restraint stress group compared with the control group. In conclusion, chronic restraint stress may induce esophageal fibrosis by accumulating ROS and increasing fibrotic gene expression in a murine model.
ABSTRACT
Objective To investigate the expression of malondialdehyde ( MDA) in esophageal mu-cosa of different types of gastroesophageal reflux disease ( GERD) patients and its role in the esophageal in-flammation. Methods According to the inclusion and exclusion criteria, 42 patients hospitalized in the the Xinjiang Uygur Autonomous Region People's Hospital from December 2017 to October 2018 were selected as the research group. 8 healthy subjects completed physical examination were set up as healthy control group. GERD completed GERDQ score, 24 h pH monitoring, and taken 3 cm on the dentate line of the esophagus as a specimen. The study group was divided into non-erosive reflux disease (NERD) group (17 cases) and Ero-sive reflux disease [erosive esophagitis (RE)] group (25 cases). Then hematoxylin-eosin (HE) staining, immunohistochemistry, real-time polymerase chain reaction ( qPCR ) , enzyme-linked immunosorbent assay (ELISA) methods were used to detect inflammation, oxidative stress (MDA), antioxidant enzyme [manga-nese superoxide dismutase (Mn SOD), glutathione (GSH), catalase (CAT)], and proinflammatory cyto-kines [monocyte chemotactic protein-1 (MCP-1), interlukin-8 (IL-8), tumor necrosis factorα(TNF-α)]. Results There was no significant difference in body mass index ( BMI ) between the three groups ( P >0. 05). 24 h pH monitoring of esophagus showed that the indexes of weak acid reflux (4<pH<7), acid re-flux ( pH<4 ) , esophageal near end acid reflux (％) and DeMeester score in RE group were significantly higher than those in NERD group, with statistical significance between the groups (P<0. 05). There was no significant difference in esophageal pressure between high resolution groups (P>0. 05). In RE group , the infiltration of immune cells (neutrophils, eosinophils), nipple lengthening, edema and other inflammatory changes were found in the esophageal mucosa, and the inflammation score reached the peak, which was signif-icantly higher than that in NERD group, with statistical significant difference (P<0. 001). The positive ex-pression of MDA in the two groups ( NERD, RE) was higher than that in the control group, and the MDA ex-pression in the RE group was almost covered with the full layer esophagus. The serum MDA concentration in the NERD and RE groups was significantly higher than that in the control group (P<0. 001). Compared with the NERD group, the serum MDA in the RE group reached the peak (P<0. 01). The relative expression of mRNA ( Mn SOD, GSH and CAT) in NERD group and RE group was significantly decreased, and there was a significant difference between the three groups (P<0. 001). Compared with the NERD group, the mRNA expression level of Mn SOD and CAT in RE group was significantly decreased (P<0. 01). The relative ex-pression of mRNA (MCP-1, IL-8, TNF- α) increased significantly in the two groups (NERD, RE), and there was a statistically significant difference between the three groups ( P <0. 001 ) . Compared with the NERD group, the expression of its inflammatory factors in the RE group significantly increased (P<0. 01). Conclusions The expression level of MDA in different types of GERD is significantly higher, which may be closely related to esophageal inflammation induced by acid reflux.
