Abstract:ObjectiveTo study the roles of tight junction proteins (TJPs) in vocal mucosal barrier damage via probing their differential expressions in vocal mucosa of patients suffering from vocal leukoplakia accompanied with laryngopharyngeal reflux (LPR).Methods26 patients suffering from vocal leukoplakia were divided into two groups (i.e., groups with and without LPR) (13 cases in each group) according to the results of 24h esophageal pH monitoring. Mucosal specimens of vocal cord were collected from all the patients during operation. HE staining was used to score the pathological changes of the mucosa. Transmission electron microscope (TEM) was utilized to observe the morphology of mucosal tight junction, and Western blot to detect the expressions of Claudin1 and ZO1.ResultsCompared with the group without LPR, marked inflammatory cell infiltration and poor structural integrity of the epithelium were observed via HE staining, TEM demonstrated significant decrease of electron dense materials around the tight junction and obvious morphological changes of the tight junction, and Western blot showed decreased expressions of Claudin1 and ZO1 in the specimens from the group with LPR. Furthermore, immunofluorescence assay confirmed that expressions of Claudin1 and ZO1 were decreased within cytoplasm in those from the group with LPR.ConclusionRefluxed materials may cause structural damage of tight junction and abnormal expressions of TJPs, thus leading to structural damage of intercellular junction, intercellular spaces dilatation and enhancement of epithelial permeability, which may be an important mechanism of vocal mucosal barrier damage in vocal leukoplakia accompanied with LPR.