Objective: To investigate the protection effect of sirtuin 1 (SIRT1) agonist resveratrol (Res) against the apoptosis of human pulmonary alveolar epithelial cells (HPAECs) induced by hyperxia.
Methods: The HPAECs in vitro were randomly divided into three groups: control group, hyperxia group, Res group. After 24-hour culture, the expressions of caspase-9, X-linked inhibitor of apoptosis protein (XIAP), SIRT1 proteins were measured by SP immunohistochemistry. The changes of reactive oxygen species (ROS) marked with MitoSOX(TM) and membrane potential marked with JC-1 in mitochondrion were detected by laser scanning confocal microscopy. The expression of SIRT1 protein was determined by Western blotting, and the change of cell apoptosis rate was analyzed by flow cytometry combined with annexin V-FITC/PI staining.
Results: Compared with the control group, the expression of caspase-9, the generation of ROS in mitochondrion of HPAECs and the cell apoptosis rate increased obviously. The expressions of both XIAP and SIRT1 and membrane potential decreased evidently in the hyperxia group. Compared with the hyperxia group, the expression of caspase-9, the generation of ROS in mitochondrion of HPAECs and the cell apoptosis rate went down obviously. The expressions of XIAP and SIRT1, and the membrane potential went up evidently in the Res group.
Conclusion: By up-regulating the expression of SIRT1 in of HPAECs and depressing the generation of ROS, Res inhibits the apoptosis of HPAECs and maintains the cell membrane potential, thus effectively alleviating hyperxia-induced lung injury.