Riitta Ylitalo1, Susan L Thibeault. 1. Department of Otolaryngology-Head and Neck Surgery, Karolinska Institute, Stockholm, Sweden.
Abstract
OBJECTIVES: Acid reflux is damaging to the laryngeal mucosa; however, the significance of the duration of reflux episodes has not been evaluated. The purpose of this study was to determine whether varying the exposure times at low pH with or without pepsin alters gene expression in laryngeal fibroblasts. METHODS: Human false vocal fold and postcricoidal cultures were exposed to pH 4 or pH 5 media with and without pepsin for 10, 30, 60, and 240 seconds. Using a real-time polymerase chain reaction, we determined the messenger RNA expression of TGFbeta-1, VEGF, FGF-2, EGR-1, ATF-3, CTGF, MMP-1, MMP-2, and decorin. RESULTS: Molecular responses were initiated at pH 5. Postcricoidal fibroblasts were more sensitive than false vocal fold fibroblasts to the presence of pepsin. Changes in transcript levels were dependent on acid exposure time, and the most significant changes were measured during the first 60 seconds after exposure. CONCLUSIONS: Time of exposure to acid and pepsin needs to be taken into consideration when determining limit of pathology in pharyngeal reflux. Genes are identified that are induced by low pH and that may be of potential importance in the pathogenesis of reflux laryngitis.
OBJECTIVES: Acid reflux is damaging to the laryngeal mucosa; however, the significance of the duration of reflux episodes has not been evaluated. The purpose of this study was to determine whether varying the exposure times at low pH with or without pepsin alters gene expression in laryngeal fibroblasts. METHODS:Human false vocal fold and postcricoidal cultures were exposed to pH 4 or pH 5 media with and without pepsin for 10, 30, 60, and 240 seconds. Using a real-time polymerase chain reaction, we determined the messenger RNA expression of TGFbeta-1, VEGF, FGF-2, EGR-1, ATF-3, CTGF, MMP-1, MMP-2, and decorin. RESULTS: Molecular responses were initiated at pH 5. Postcricoidal fibroblasts were more sensitive than false vocal fold fibroblasts to the presence of pepsin. Changes in transcript levels were dependent on acid exposure time, and the most significant changes were measured during the first 60 seconds after exposure. CONCLUSIONS: Time of exposure to acid and pepsin needs to be taken into consideration when determining limit of pathology in pharyngeal reflux. Genes are identified that are induced by low pH and that may be of potential importance in the pathogenesis of reflux laryngitis.
Authors: Winson Y Cheung; Rihong Zhai; Penny Bradbury; Jessica Hopkins; Matthew H Kulke; Rebecca S Heist; Kofi Asomaning; Clement Ma; Wei Xu; Zhaoxi Wang; Suzanne Hooshmand; Li Su; David C Christiani; Geoffrey Liu Journal: Int J Cancer Date: 2012-04-24 Impact factor: 7.396
Authors: Julia Sanchez; Desiree M Schumann; Meropi Karakioulaki; Eleni Papakonstantinou; Frank Rassouli; Matthias Frasnelli; Martin Brutsche; Michael Tamm; Daiana Stolz Journal: Respir Res Date: 2020-08-21