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Objective: To observe the impact of hydrogen sulfide (hydrogen sulfide, H2S) on endothelial cell apoptosis, and explore its role from the point of view of the antioxidant mechanism. Method: 1. Cultured human umbilical vein endothelial cells (human umbilical vein endothelial cells, HUVECs) were treated with different concentrations (25, 50, 100, 200 μmol / L) and different time (6,12,24 h) sodium hydrosulfide (sodium hydrosulfide, NaHS) were pre-incubated for 24h joined 100μg/ml oxidized low-density lipoprotein (oxidized LDL, oxLDL) processing 24h, 24h group as a control, Hoechst 33258 staining observed in nuclear morphology changes to the control group and 100μg/ml oxLDL treatment; iodide The aziridine (propidium iodide, PI) staining and flow cytometry (flow cytometry, FCM) to detect apoptosis; 2. were divided into four groups: (1) control group: RPMI-1640 medium containing 10% fetal bovine serum; ② NaHS oxLDL Group: 50μmol / L NaHS incubation the HUVECs 24h before adding the 100μg/ml oxLDL incubated for 24h; ③ of oxLDL treatment group the incubation HUVECs24h of: 100μg/ml oxLDL; ④ NAC of oxLDL group: 1 mmol / L N-acetyl cysteine ??(N-acetyl- L-cysteine, NAC, anti-oxidants) incubated HUVECs 24h after joining 100μg/ml oxLDL incubated for 24h. Dihydrotestosterone Rhodamine 123 (Dihydrohodamine 123, DHR123) staining, microscopy and FCM in HUVECs DHR123 fluorescence intensity was measured to to clear intracellular reactive oxygen species (reactive oxygen species, ROS) content changes; Rhodamine 123 (Rhodamine 123 , Rh123) staining, microscopy and FCM Rh123 fluorescence intensity was measured in HUVECs to understand the mitochondrial membrane potential (mitochondrial membrane potential, △ Ψm) changes; Western Blot cell Caspase-3 and Caspase-9 protein expression . Results: H2S anti-oxLDL-induced apoptosis of HUVECs ① Hoechst 33258 staining fluorescence microscope found that, compared with the normal control group, oxLDL (100μg/ml) in the treatment group HUVECs appear the pyknosis form a large number of nuclei were dense stain or form or granular granular fluorescence of apoptotic cells, and the NaHS different concentrations (25, 50, 100, 200 μmol / L) and different time (6,12,24 h) pretreatment of HUVECs in dense hyperchromatic nuclei were pyknotic The fluorescence of the cells was significantly reduced, most of the cell chromatin was diffuse uniformly low intensity fluorescent. The ② FCM results showed that, compared with the normal control group, oxLDL (100μg/ml) apoptosis rate of the treatment group increased significantly (p lt; 0.01), and different concentrations (25, 50, 100, 200 μmol / L) NaHS pretreated group oxLDL (100μg/ml) the treated cells apoptosis rates were reduced by 80%, 85%, 89%, 92% (both p lt; 0.01); different times (6,12,24 h) NaHS pretreated group than oxLDL ( 100μg/ml) treated with the apoptosis rates were reduced by 80%, 81%, and 84% (both p lt; 0.01), 50, 100, 200 μmol / L NaHS pretreatment 24h anti-apoptotic effect is most obvious. Of HUVECs apoptosis 2.H2S anti-oxLDL-induced mechanism ① the HUVECs were by DHR123 staining, fluorescence microscopy observation that, compared with the control group of oxLDL treated HUVECs DHR123 fluorescence intensity was significantly enhanced, 50μmol / L NaHS or 1 mmol / L NAC for 24h and the oxLDL 100μg/ml continued incubation a 24h the HUVECs DHR123 of fluorescence intensity than 100μg/ml of oxLDL treatment group was significantly weakened; FCM quantitative analysis results show that, compared with the control group of oxLDL treated HUVECs fluorescence intensity increased DHR123 on 2.3-fold (p lt; 0.05), 50μmol / L NaHS or 1 mmol / L NAC pretreatment HUVECs were 24h DHR123 average fluorescence intensity than 100μg/ml of oxLDL treatment group were reduced by 63% and 67% (both p lt; 0.05 ). That H2S inhibited oxLDL-induced intracellular ROS generation. ② HUVECs after Rh123 staining, fluorescence microscopy discovery of oxLDL treated HUVECs Rh123 fluorescence intensity was significantly reduced compared with the control group, 50 μmol / L NaHS or 1 mmol / L NAC for 24h, then add oxLDL 100μg/ml incubated for 24 h HUVECs Rh123 fluorescence intensity than 100μg/ml of oxLDL treatment group was significantly enhanced; FCM quantitative analysis results show that the mean fluorescence intensity of oxLDL treated HUVECs Rh123 were decreased by 56% (p LT; 0.05), 50μmol / L NaHS or 1 mmol / L NAC pretreatment HUVECs 24h the Rh123 average fluorescence intensity than 100μg/ml of oxLDL treatment group increased by 104% and 126% respectively (both p lt; 0.05). △ Ψm oxLDL reduce HUVECs showed that H2S inhibited. ③ Western Blot results show., 100μg/ml oxLDL incubated HUVECs 24h, compared with the normal control group, caspase-3 expression of Caspase-9 protein expression were increased by 29% and 24%; 50μmol / L NaHS or 1 mmol / L NAC pre- with oxLDL treatment group, the treatment group compared to HUVECs caspase-3, caspase-9 protein expression were reduced by 19%, 20% or 12%, 19% (both p lt; 0.05). oxLDL caused
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