Abstract：
Sulodexide (SDX), a purified glycosaminoglycan mixture used to treat vascular diseases, has been reported to exert endothelial protective effects against ischemic injury. However, the mechanisms underlying these effects remain to be fully elucidated. The emerging evidence indicated that a relatively high intracellular concentration of reduced glutathione (GSH) and a maintenance of the redox environment participate in the endothelial cell survival during ischemia. Therefore, the aim of the present study was to examine the hypothesis that SDX alleviates oxygen-glucose deprivation (OGD)-induced human umbilical endothelial cells\' (HUVECs) injury, which serves as the in vitro model of ischemia, by affecting the redox state of the GSH: glutathione disulfide (GSSG) pool. The cellular GSH, GSSG and total glutathione (tGSH) concentrations were measured by colorimetric method and the redox potential (ΔEh) of the GSSG/2GSH couple was calculated, using the Nernst equation. Furthermore, the levels of the glutamate-cysteine ligase catalytic subunit (GCLc) and the glutathione synthetase (GSS) proteins, a key enzyme for de novo GSH synthesis, were determined using enzyme-linked immunoassay (ELISA). We demonstrated that the SDX treatment in OGD conditions significantly elevated the intracellular GSH, enhanced the GSH:GSSG ratio, shifting the redox potential to a more pro-reducing status. Furthermore, SDX increased the levels of both GCLc and GSS. The results show that SDX protects the human endothelial cells against ischemic stress by affecting the GSH levels and cellular redox state. These changes suggest that the reduction in the ischemia-induced vascular endothelial cell injury through repressing apoptosis and oxidative stress associated with SDX treatment may be due to an increase in GSH synthesis and modulation of the GSH redox system.
摘要：
Sulodexide(SDX),一种用于治疗血管疾病的纯化的糖胺聚糖混合物，已经报道了对缺血性损伤发挥内皮保护作用。然而,这些影响的潜在机制仍有待充分阐明。新出现的证据表明，在缺血期间，相对较高的细胞内还原型谷胱甘肽（GSH）浓度和氧化还原环境的维持参与了内皮细胞的存活。因此,本研究的目的是检验SDX减轻氧葡萄糖剥夺（OGD）诱导的人脐内皮细胞（HUVECs）损伤的假设，作为缺血的体外模型，通过影响GSH的氧化还原状态：谷胱甘肽二硫化物（GSSG）池。细胞GSH，通过比色法测量GSSG和总谷胱甘肽（tGSH）浓度，并计算GSSG/2GSH对的氧化还原电位（ΔEh），使用能斯特方程。此外，谷氨酸-半胱氨酸连接酶催化亚基（GCLc）和谷胱甘肽合成酶（GSS）蛋白的水平，从头合成GSH的关键酶，使用酶联免疫测定(ELISA)进行测定。我们证明在OGD条件下的SDX处理显著提高了细胞内GSH,提高了GSH：GSSG比率，将氧化还原电位转变为更亲还原的状态。此外，SDX增加了GCLc和GSS的水平。结果表明，SDX通过影响GSH水平和细胞氧化还原状态来保护人内皮细胞免受缺血性应激。这些变化表明，通过抑制与SDX治疗相关的凋亡和氧化应激来减少缺血诱导的血管内皮细胞损伤可能是由于GSH合成和GSH氧化还原系统调节的增加。
