Aging alterations of salivary gland mucins elucidated by supported molecular matrix electrophoresis

Xerostomia is a symptom growing in the elderly, and associated with reduced salivary flow and increased salivary viscosity.Salivary mucins are responsible for the viscous property of the saliva.This study introduces aging alterations of a salivary gland by using submandibular glands of mice as a model.Supported molecular matrix electrophoresis (SMME) is a membrane electrophoresis to characterize mucins.Using SMME, we revealed that submandibular glands of the aged mice produced unknown mucin-like molecule that was absent in the glands of young mice.O-Glycosylations of the unknown mucin-like molecule are characterized by high ratio of sialoglycans to neutral glycans.The increase of sialoglycan-content may be attributed to the increased expression of the sialyl transferase genes, ST6GalNAc I and ST6GalNAc II, in the submandibular gland in the aged mice.