Hyperglycemia induces differential change in oxidative stress at gene expression and functional levels in HUVEC and HMVEC

Abstract

BackgroundEndothelial dysfunction precedes pathogenesis of vascular complications in diabetes. In recent years, the mechanisms of endothelial dysfunction were investigated to outline strategies for its treatment. However, the therapies for dysfunctional endothelium resulted in multiple clinical trial failures and remain elusive. There is a need for defining hyperglycemia-induced endothelial dysfunction with both generic and specific dysfunctional changes in endothelial cells (EC) using a systems approach. In this study, we investigated hyperglycemia-induced endothelial dysfunction in HUVEC and HMVEC. We investigated hyperglycemia-induced functional changes (superoxide (O2‾), and hydrogen peroxide (H2O2) production and mitochondrial membrane polarization) and gene expression fingerprints of related enzymes (nitric oxide synthase, NAD(P)H oxidase, and reactive oxygen species (ROS) neutralizing enzymes) in both ECs.MethodGene expression of NOS2, NOS3, NOX4, CYBA, UCP1, CAT, TXNRD1, TXNRD2, GPX1, NOX1, SOD1, SOD2, PRDX1, 18s, and RPLP0 were measured using real-time PCR. O2‾ production was measured with dihydroethidium (DHE) fluorescence measurement. H2O2 production was measured using Amplex Red assay. Mitochondrial membrane polarization was measured using JC-10 based fluorescence measurement.ResultsWe showed that the O2‾ levels increased similarly in both ECs with hyperglycemia. However, these endothelial cells showed significantly different underlying gene expression profile, H2O2 production and mitochondrial membrane polarization. In HUVEC, hyperglycemia increased H2O2 production, and hyperpolarized mitochondrial membrane. ROS neutralizing enzymes SOD2 and CAT gene expression were downregulated. In contrast, there was an upregulation of nitric oxide synthase and NAD(P)H oxidase and a depolarization of mitochondrial membrane in HMVEC. In addition, ROS neutralizing enzymes SOD1, GPX1, TXNRD1 and TXNRD2 gene expression were significantly upregulated in high glucose treated HMVEC.ConclusionOur findings highlighted a unique framework for hyperglycemia-induced endothelial dysfunction. We showed that multiple pathways are differentially affected in these endothelial cells in hyperglycemia. High occurrences of gene expression changes in HMVEC in this study supports the hypothesis that microvasculature precedes macrovasculature in epigenetic regulation forming vascular metabolic memory. Identifying genomic phenotype and corresponding functional changes in hyperglycemic endothelial dysfunction will provide a suitable systems biology approach for understanding underlying mechanisms and possible effective therapeutic intervention.

Comparative Study of Antidiabetic Activity and Oxidative Stress Induced by Zinc Oxide Nanoparticles and Zinc Sulfate in Diabetic Rats

“…This finding is consistent with a number of previous studies (31,39,44). It has been reported that hyperglycemia increases hydrogen peroxide production and downregulates CAT gene expression (55). A number of in vitro and in vivo studies have found varying responses of catalase to increased amount of ROS production induced by ZnO.…”

The novel NADPH oxidase 4 inhibitor GLX351322 counteracts glucose intolerance in high-fat diet-treated C57BL/6 mice

“…In this instance NOX activation in endothelial cells could be of importance. Patel et al [23] highlighted a unique framework for hyperglycemia-induced hydrogen peroxide production by NOX in endothelial cells and Hecker et al [24] found that an aberrant up-regulation of the isoenzyme NOX4 results in a sustained redox imbalance, which promotes persistent myofibroblast senescence and fibrosis. In this context it is of interest to note that pancreatic islets are among the most vascularized organs in the body with 1000-1500 capillaries per square millimeter, i.e.…”

VEGF Expression in Diabetic Rats Promotes Alveolar Bone Resorption by <i>Porphyromonas gingivalis</i> LPS

“…Hyperglycemia causes formation and accumulation of irreversible advanced glycation end products (AGEs) in the body 31) and induces expression of their primary receptor RAGE 32) . Interactions between the AGEs and RAGE result in the dysfunction of immune cells 6,7) and functional alterations of various cells 8,9) , causing cytokine imbalance associated with inflammatory cytokine increases 10,11) . Furthermore, hyperglycemia shifts the balance of the RANKL/OPG interaction in the direction of tissue destruction through AGEs/RAGE interaction 33,34) .…”

“…Thus far, numerous mechanisms have been reported to underlie exacerbation of periodontitis caused by diabetes mellitus. Among them, the main mechanisms involve immune dysfunction 6,7 ) , cellular stress 8,9 ) , and cytokine imbalance 10,11) caused by hyperglycemia, which enhances tissue destruction of periodontitis and impairs tissue repair. The mechanism of exacerbation of alveolar bone resorption due to cytokine imbalance is initiated when hyperglycemia increases the level of inflammatory cytokines, such as TNF- 10) , IL-1 11) , and IL-6 11) .…”