Characterization of Angiogenesis and Lymphangiogenesis in Human Minor Salivary Glands with Sjögren's Syndrome.

Angiogenesis has been proposed to play a role in the inflammation observed in Sjögren's Syndrome (SS). However, no studies have validated the degree of angiogenesis in salivary glands with SS. Therefore, the goal of this study was to determine the presence and localization of angiogenesis and lymphangiogenesis in salivary glands with SS. We used frozen tissue sections from human minor salivary glands (hMSG) with and without SS in our analyses. To investigate signs of angiogenesis, hMSG tissue lysates were used to detect levels of the pro-angiogenic protein vascular endothelial growth factor (VEGF) by western blot analyses. Additionally, we labeled blood vessels using antibodies specific to platelet endothelial cell adhesion molecule-1 (PECAM-1) and von Willebrand Factor (vWF) to determine blood vessel organization and volume fraction using fluorescence microscopy. Lymphatic vessel organization and volume fraction were determined using antibodies specific to lymphatic vessel endothelial hyaluronan receptor (LYVE-1). Our results suggest that expression levels of VEGF are decreased in hMSG with SS as compared with controls. Interestingly, there were no significant differences in blood or lymphatic vessel organization or volume fraction between hMSG with and without SS, suggesting that angiogenesis and lymphangiogenesis have little impact on the progression of SS.