Morphology of the esophagus of ferrets and expression profile of molecular markers

Abstract

To examine the morphological characteristics and the expression profile of molecular markers of ferret esophagus and assess the feasibility of using ferrets as animal models for studying human esophageal diseases. Frozen sections and paraffin- embedded specimens of the esophageal tissues were obtained from adult ferrets (aged 6 to 8 months) and ferrets aged 1 day, 3 days, 5 days, 1 week and 2 weeks. HE staining and periodic acid-Schiff (PAS) staining were used for morphological analysis of the esophageal submucosal glands (SMGs) of adult ferrets, and the expressions of MUC5B and MUC5AC were tested using Mucin staining; The expressions of cytokeratins (CK4, CK5, CK7, CK8, CK14, CK17, CK18, CK19, and CK20) in adult ferret esophagus were examined using HE staining and immunofluorescence assay. The expressions of LEF1 in the esophageal epithelium and SMGs were detected with immunofluorescence assay. In adult ferrets, the esophageal SMGs were connective tissues below the muscularis mucosa of the esophagus with secretory functions. Cytokeratins were expressed differentially in different esophageal cells: CK4, CK8 and CK20 were expressed mainly in the mucous cells, ductal cells and epithelial cells, respectively, while the mucous cells expressed the largest variety of cytokeratins. Mucin staining showed positive MUC5B and MUC5AC expression in the cytoplasm and lumen of adult ferret esophageal glands. Lectin from DBA, ECL, GSLI, GSL Ⅱ, SBA, Tacalin bioylated, ULEX, WGA, GSL Ⅰ and GSL Ⅱ were expressed on ductal cell membrane, and ECL, PNA and WGA were detected on epithelial cell membrane. Lectin with ConA, PHA-E and PHA-L were expressed on serous cell membrane. Immunofluorescence assay showed that LEF1 in the developing glands were visible from 3 days to 1 week of age and then disappeared as the glands matured. The intensity of LEF1 expression in the esophageal glands differed significantly between ferrets aged 1 to 7 days and those aged two weeks. Ferrets and human share similar esophageal tissue structures and some common molecular markers, suggesting the possibility of using ferrets as animal models of human esophageal diseases.