Alteration of gene expression profile by melatonin in endothelial cells

Melatonin is secreted by the pineal gland and gastrointestinal tract and plays a role in circadian rhythm synchronization. Melatonin is also reported to have various physiological effects on endothelial cells. Endothelial cells are responsible for physiologic homeostasis and maintaining blood vessel permeability in vivo. In this study, using gene expression profiling, we confirmed about 151 up-regulation and 1,023 downregulation expression genes, with an expression level difference of > 1.5-fold, after exposure to 100 μM and 1 mM melatonin concentrations in endothelial cells. The genes were classified into 16 functional groups based on their functions, including cell adhesion, immune response, lipid metabolism, and response to stress. We analyzed the gene expression profiling data of melatonin-treated human umbilical vein endothelial cells (HUVECs), which indicated a broad spectrum of physiological functions, including anti-oxidative/anti-inflammatory effects and cell-to-cell junction maintenancerelated genes.