Expression of podoplanin in the mouse salivary glands

Objective: Podoplanin is one of the most highly expressed lymphatic-specific genes. Here, we report the distribution of cells expressing podoplanin in mouse salivary glands. Design: We immunohistochemically investigated the distribution of cells expressing podoplanin in mouse major salivary glands by laser-scanning microscopy. The expression of endothelial cell marker PECAM-1 was tested to discriminate lymphatic endothelium from salivary gland cells, and myoepithelial cells were identified by an antibody for P-cadherin. Results: The podoplanin expression was rarely found in acini of the parotid gland but clearly found at the basal portion of acini in the submandibular and sublingual glands. The number of portion reacted with anti-podoplanin is greater in the sublingual gland than in the submandibular gland. The expression was also found at the basal portion of ducts in all major salivary glands. The P-cadherin expression was rarely found in acini of the parotid gland but found in acini of the sublingual gland and on ducts in parotid and sublingual glands, corresponding to the area of podoplanin expression. Conclusions: It was suggested that the acinar and myoepithelial cells in the salivary glands have the ability to express podoplanin, and that the expression may be concerned with the mucous saliva excretion.