Effect of high-glucose conditions on human periodontal ligament endothelial cells: in vitro analysis

Endothelial cells participate in key aspects of vascular biology, such as maintenance of capillary permeability and regulation of inflammation. According to previous reports, endothelial cells have revealed highly specific characteristics depending on the organs and tissues. In particular, periodontal endothelial cells have a higher permeability than vascular endothelial cells of other types of tissue. Periodontal disease is not only a chronic disease in oral, but also affect the entire body. Diabetes and periodontal disease are closely related, with periodontal disease even been referred to as the sixth complication of disease. However, no reports have investigated the pathophysiology of microvascular in periodontal tissue once diabetes has developed. Therefore, the aim of the present study is to investigate changes in the properties of human periodontal endothelial cells (HPDLECs) that were cultured under high-glucose conditions. We isolated HPDLECs from human periodontal ligament cells. HPDLECs were cultured under high-glucose (5.5, 11.0, 22.0 mM) and investigated proliferation, apoptosis, tube formation and the expression of cell adhesion molecules. A 5.5 mM (100 mg/dl) control was used in this study. HPDLECs stimulated with high glucose concentration exhibited suppression of cell proliferation and an increased percentage of apoptosis-positive cells. This results suggested that apoptosis was caused by TNF-α expression. The expression levels cell adhesion molecules increased. These results suggest that when HPDLECs are stimulated with a high glucose concentrations, PKC in the intracellular cell substrate is activated, increasing the expression of intercellular and vascular adhesion molecules. Thus, the results of this study demonstrate that diabetes exacerbates periodontal disease.