N-acetylcysteine resists high-glucose-induced injury of human umbilical vein endothelial cells by inhibiting the leptin/leptin receptor

Abstract

Background The present study aimed to investigate whether N-acetylcysteine (NAC) protects human umbilical vein endothelial cells (HUVECs) against high glucose (HG)-induced injury by inhibiting leptin/leptin receptor (LEPR).Methods HUVECs were treated with 40 mmol/L glucose for 24 h to establish a model of HG-induced endothelial cell injury; The cell viability was examined by cell counter kit-8 (CCK-8) assay; The expression levels of leptin, LEPR, cleaved caspase-3 and endothelial nitric oxide synthase (eNOS) were detected by western blot. The intracellular levels of reactive oxygen species (ROS) were tested by DCFH-DA staining followed by photofluorography. Tumor necrosis factor-α (TNF-α) nuclear factorkappa B (NF-κB) and intercellular adhesion molecule-1 (ICAM-1) were detected by enzyme-linked immunosorbent assay (ELISA). The number of apoptotic cells was observed by photofluorograph with Hoechst 33258 nuclear staining. Mitochondrial membrane potential (MMP) was obtained using JC-1. ResultsThe expression of leptin and LEPR began to significantly increase after exposure to 40 mmol/L HG for 24 h. Pretreatment of HUVECs with 7 mmol/L NAC or 50 ng/mL leptin antagonists (LA) for 30min inhibited the increased expression of leptin and LEPR induced by HG in HUVECs.Furthermore, pretreatment with 7 mmol/L NAC or 50 ng/mL LA for 30 min also inhibited HG-induced injury, by increasing the cell viability and eNOS expression, and decreasing the inflammatory response and cleaved caspase-3 expression, the apoptotic cells and generation of intracellular ROS and a loss of MMP.Conclusions NAC protects the HUVECs against HG-induced injury by inhibiting leptin/LEPR.