Sulodexide Increases Glutathione Synthesis and Causes Pro-Reducing Shift in Glutathione-Redox State in HUVECs Exposed to Oxygen-Glucose Deprivation: Implication for Protection of Endothelium against Ischemic Injury.

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.

Sulodexide increases mRNA expression of glutathione-related genes in human umbilical endothelial cells exposed to oxygen-glucose deprivation.

INTRODUCTION: Sulodexide (SDX), a heparinoid used to treat vascular diseases, exerts anti-ischemic properties. However, the underlying molecular mechanisms remain unclear. Induction of glutathione (GSH)-dependent genes protects against ischemia. Here, we investigated the effect of SDX on GSH-associated gene expression in human umbilical endothelial cells (HUVECs) using an in vitro ischemia model. METHODS: The transcriptional expression of GSH-related genes (GCLc, xCT, GS, GPx1 and GR) in HUVECs treated without/with SDX (0.5 LRU/ml) under oxygen-glucose deprivation (OGD) condition for 1-6 h was analyzed by real-time polymerase chain reaction. RESULTS: GCLc and xCT were strongly up-regulated by SDX in HUVECs in the first 2 h of OGD. GS and GPx1 mRNA expression levels were significantly increased during any time interval in ischemic HUVECs treated with SDX. Furthermore, incubation of HUVECs with SDX in OGD for 1-4 h resulted in enhanced expression of GR. CONCLUSIONS: Our studies provide the first evidence that SDX activates GSH-related genes in OGD-injured HUVECs.

Sulodexide up-regulates glutathione S-transferase P1 by enhancing Nrf2 expression and translocation in human umbilical vein endothelial cells injured by oxygen glucose deprivation.

INTRODUCTION: Sulodexide (SDX) is used for the treatment of many vascular disorders due to its anticoagulant, anti-inflammatory and anti-atherosclerotic properties. However, the detailed molecular mechanism of its endothelioprotective action is still not completely understood. There is increasing evidence suggesting that antioxidant enzymes play an important role in anti-ischemic properties of SDX. We postulate that up-regulation of glutathione-S-transferase P1 (GSTP1) mediated by the transcription factor Nrf2 could be associated with the antioxidant effect of SDX on vascular endothelial cells. MATERIAL AND METHODS: In the present study, we investigated whether SDX affects GSTP1 and Nrf2 in oxygen glucose deprivation (OGD) treated human umbilical vein endothelial cells (HUVECs). The cells treated with/without SDX (0.5 LRU/ml) were subjected to OGD for 1-6 h. To study the influence of SDX on the Nrf2 nucleus accumulation, the cells were incubated with 0.5 LRU/ml SDX in OGD for 1 h. RESULTS: We found that after short-term OGD (1-3 h), the drug increased the expression of both GSTP1 and Nrf2 mRNA/protein in HUVECs (p < 0.05), as determined by real-time PCR and enzyme-linked immunosorbent assay (ELISA). SDX treatment also enhanced the nuclear accumulation of Nrf2 in HUVECs after 1 h of OGD (p < 0.05). CONCLUSIONS: SDX induces a rapid onset of the antioxidant response by up-regulating the expression of GSTP1 and Nrf2 in endothelial cells subjected to in vitro simulated ischemia.