Oscillating glucose induces microRNA-185 and impairs an efficient antioxidant response in human endothelial cells

Abstract

BackgroundIntracellular antioxidant response to high glucose is mediated by Cu/Mn-superoxide dismutases (SOD-1/SOD-2), catalase (CAT) and glutathione peroxidases (GPx), particularly glutathione peroxidase-1 (GPx-1). Although oscillating glucose can induce a more deleterious effect than high glucose on endothelial cells, the mechanism by which oscillating glucose exerts its dangerous effects is incompletely understood; however, the involvement of oxidative damage has been generally accepted. In this study we sought to determine whether oscillating glucose differentially modulates antioxidant response, and to elucidate the potential regulatory mechanisms exerted by the microRNA-185 (miR-185).MethodsHuman endothelial cells were exposed for 1 week to constant and oscillating high glucose. SOD-1, SOD-2, CAT and GPx-1, as well as two markers of oxidative stress [8-hydroxy-2′-deoxyguanosine (8-OHdG) and the phosphorylated form of H2AX (γ-H2AX)] were measured at the end of the experiment. Intracellular miR-185 was measured and loss-of function assays were performed in HUVEC. Bioinformatic tool was used to predict the link between miR-185 on 3′UTR of GPx-1 gene. Luciferase assay was performed to confirm the binding on HUVEC.ResultsAfter exposure to constant high glucose SOD-1 and GPx-1 increased, while in oscillating glucose SOD-1 increased and GPx-1 did not. SOD-2 and CAT remained unchanged under both conditions. A critical involvement of oscillating glucose-induced miR-185 in the dysregulation of endogenous GPx-1 was found. Computational analyses predict GPx-1 as miR-185′s target. HUVEC cultures were used to confirm glucose’s causal role on the expression of miR-185, its target mRNA and protein and finally the activation of antioxidant response. In vitro luciferase assays confirmed computational predictions targeting of miR-185 on 3′-UTR of GPx-1 mRNA. Knockdown of miR-185, using anti-miR-185 inhibitor, was accompanied by a significant upregulation of GPx-1 in oscillating glucose. 8-OHdG and γ-H2AX increased more in oscillating glucose than in constant high glucose.ConclusionsGlucose oscillations may exert more deleterious effects on the endothelium than high glucose, likely due to an impaired response of GPx-1, coupled by the upregulation of miR-185.Electronic supplementary materialThe online version of this article (doi:10.1186/s12933-016-0390-9) contains supplementary material, which is available to authorized users.

MiR-21 protected against diabetic cardiomyopathy induced diastolic dysfunction by targeting gelsolin

“…But the roles of miRNAs in diabetes and its cardiovascular complications are not fully discovered [18–20]. It was reported that miR-195 increased ROS production via Sirt1 and Bcl-2, and inhibition of miR-195 may be a promising therapeutic strategy for lipotoxic cardiomyopathy [21].…”

Erythropoietin signal protected human umbilical vein endothelial cells from high glucose‐induced injury

“…Recent studies have revealed that oxidative stress derived from HG stimulation induces inflammation and results in cell damage . In the present study, we observed increased expression of the gene for reactive oxygen species modulator 1 (ROMO1) in vascular endothelial cells under HG stimulation (Fig.…”

“…With reference to vascular endothelial cell damage caused by HG stimulation, previous studies have noted the significance of inflammatory conditions accompanied by the expressions of various adhesion factors and inflammation‐related molecules . Recent studies have reported that oxidative stress is involved in the process in which HG signaling activates cells and elicits inflammation . In fact, we observed increased expression of the ROMO1 gene in the present study.…”

Administration of Traditional Chinese Blood Circulation Activating Drugs for Microvascular Complications in Patients with Type 2 Diabetes Mellitus

“…High glucose induces injury to vascular endothelial cells, which leads to progressive thickening of the basement membrane and obstruction of the involved microvascular, thus resulting in tissue hypoxia and increased lesions [61]. Patients with more vascular endothelial cells and a higher level of plasma endothelin have more incidences of getting microvascular diseases.…”