Immunohistochemical distribution of galectin-1, galectin-3, and olfactory marker protein in human olfactory epithelium

The expression pattern of galectin-1 and galectin-3 in the human olfactory epithelium was investigated in relation to olfactory marker protein (OMP) u sing confocal laser immunofluorescence in human specimens and postmortem bi opsies. OMP expression was found in olfactory receptor neurons (ORNs) in th e olfactory mucosa and in fibers of the olfactory nerve crossing the submuc ous connective tissue. Galectin-1 was expressed in both the connective tiss ue of the nasal cavity and in the basal layer of the olfactory epithelium. In contrast, galectin-3 expression was limited to cells of the upper one-th ird of the olfactory epithelium. Expression of galectin-3 occurred in a sub set of OMP-positive cells. However, between areas of galectin-1 and galecti n-3 expression in the lower and upper portion of the epithelium, OMP-positi ve ORNs did not stain for both galectins. Considering the potential role of galectin-1 and galectin-3 in cell differentiation and maturation, the diff erential localization of galectins in the olfactory epithelium appears to b e consistent with a significant role of these molecules in the physiologica l turnover of ORNs.