학술논문
Serotonin disrupts esophageal mucosal integrity: an investigation using a stratified squamous epithelial model
Original Article-Alimentary Tract
Original Article-Alimentary Tract
Document Type
Academic Journal
Author
Source
Journal of Gastroenterology. November 2016, Vol. 51 Issue 11, p1040, 10 p.
Subject
Language
English
ISSN
0944-1174
Abstract
Author(s): Liping Wu [sup.1] [sup.2], Tadayuki Oshima [sup.1], Toshihiko Tomita [sup.1], Yoshio Ohda [sup.1], Hirokazu Fukui [sup.1], Jiro Watari [sup.1], Hiroto Miwa [sup.1] Author Affiliations: (1) grid.272264.7, 000000009142153X, Division of [...]
Background Serotonin regulates gastrointestinal function, and mast cells are a potential nonneuronal source of serotonin in the esophagus. Tight junction (TJ) proteins in the esophageal epithelium contribute to the barrier function, and the serotonin signaling pathway may contribute to epithelial leakage in gastroesophageal reflux disease. Therefore, the aim of this study was to investigate the role of serotonin on barrier function, TJ proteins, and related signaling pathways. Methods Normal primary human esophageal epithelial cells were cultured with use of an air-liquid interface system. Serotonin was added to the basolateral compartment, and transepithelial electrical resistance (TEER) was measured. The expression of TJ proteins and serotonin receptor 7 (5-HT.sub.7) was assessed by Western blotting. The involvement of 5-HT.sub.7 was assessed with use of an antagonist and an agonist. The underlying cellular signaling pathways were examined with use of specific blockers. Results Serotonin decreased TEER and reduced the expression of TJ proteins ZO-1, occludin, and claudin 1, but not claudin 4. A 5-HT.sub.7 antagonist blocked the serotonin-induced decrease in TEER, and a 5-HT.sub.7 agonist decreased TEER. Inhibition of p38 mitogen-activated protein kinase (MAPK) reduced the serotonin-induced decrease in TEER. Inhibition of p38 MAPK blocked the decrease of ZO-1 levels, whereas extracellular-signal-regulated kinase (ERK) inhibition blocked the decrease in occludin levels. Cell signaling pathway inhibitors had no effect on serotonin-induced alterations in claudin 1 and claudin 4 levels. Serotonin induced phosphorylation of p38 MAPK and ERK, and a 5-HT.sub.7 antagonist partially blocked serotonin-induced phosphorylation of p38 MAPK but not that of ERK. Conclusions Serotonin disrupted esophageal squamous epithelial barrier function by modulating the levels of TJ proteins. Serotonin signaling pathways may mediate the pathogenesis of gastroesophageal reflux disease.
Background Serotonin regulates gastrointestinal function, and mast cells are a potential nonneuronal source of serotonin in the esophagus. Tight junction (TJ) proteins in the esophageal epithelium contribute to the barrier function, and the serotonin signaling pathway may contribute to epithelial leakage in gastroesophageal reflux disease. Therefore, the aim of this study was to investigate the role of serotonin on barrier function, TJ proteins, and related signaling pathways. Methods Normal primary human esophageal epithelial cells were cultured with use of an air-liquid interface system. Serotonin was added to the basolateral compartment, and transepithelial electrical resistance (TEER) was measured. The expression of TJ proteins and serotonin receptor 7 (5-HT.sub.7) was assessed by Western blotting. The involvement of 5-HT.sub.7 was assessed with use of an antagonist and an agonist. The underlying cellular signaling pathways were examined with use of specific blockers. Results Serotonin decreased TEER and reduced the expression of TJ proteins ZO-1, occludin, and claudin 1, but not claudin 4. A 5-HT.sub.7 antagonist blocked the serotonin-induced decrease in TEER, and a 5-HT.sub.7 agonist decreased TEER. Inhibition of p38 mitogen-activated protein kinase (MAPK) reduced the serotonin-induced decrease in TEER. Inhibition of p38 MAPK blocked the decrease of ZO-1 levels, whereas extracellular-signal-regulated kinase (ERK) inhibition blocked the decrease in occludin levels. Cell signaling pathway inhibitors had no effect on serotonin-induced alterations in claudin 1 and claudin 4 levels. Serotonin induced phosphorylation of p38 MAPK and ERK, and a 5-HT.sub.7 antagonist partially blocked serotonin-induced phosphorylation of p38 MAPK but not that of ERK. Conclusions Serotonin disrupted esophageal squamous epithelial barrier function by modulating the levels of TJ proteins. Serotonin signaling pathways may mediate the pathogenesis of gastroesophageal reflux disease.