Oxidative stress and diabetic cardiovascular disorders: roles of mitochondria and NADPH oxidaseThis review is one of a selection of papers published in a Special Issue on Oxidative Stress in Health and Disease.

2010 ◽  
Vol 88 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Garry X. Shen

Cardiovascular diseases are the predominant cause of death in patients with diabetes mellitus. Underlying mechanism for the susceptibility of diabetic patients to cardiovascular diseases remains unclear. Elevated oxidative stress was detected in diabetic patients and in animal models of diabetes. Hyperglycemia, oxidatively modified atherogenic lipoproteins, and advanced glycation end products are linked to oxidative stress in diabetes. Mitochondria are one of major sources of reactive oxygen species (ROS) in cells. Mitochondrial dysfunction increases electron leak and the generation of ROS from the mitochondrial respiratory chain (MRC). High levels of glucose and lipids impair the activities of MRC complex enzymes. NADPH oxidase (NOX) generates superoxide from NADPH in cells. Increased NOX activity was detected in diabetic patients. Hyperglycemia and hyperlipidemia increased the expression of NOX in vascular endothelial cells. Accumulated lines of evidence indicate that oxidative stress induced by excessive ROS production is linked to many processes associated with diabetic cardiovascular complications. Overproduction of ROS resulting from mitochondrial dysfunction or NOX activation is associated with uncoupling of endothelial nitric oxide synthase, which leads to reduced production of nitric oxide and endothelial-dependent vasodilation. Gene silence or inhibitor of NOX reduced oxidized or glycated LDL-induced expression of plasminogen activator inhibitor-1 in endothelial cells. Statins, hypoglycemic agents, and exercise may reduce oxidative stress in diabetic patients through the reduction of NOX activity or the improvement of mitochondrial function, which may prevent or postpone the development of cardiovascular complications.

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Rosa Breton-Romero ◽  
Bihua Feng ◽  
Monika Holbrook ◽  
Melissa G Farb ◽  
Jessica L Fetterman ◽  
...  

Introduction: Diabetes mellitus type 2 is an increasingly public health problem and it is a major cause in the development of cardiovascular diseases. Endothelial dysfunction is a key mechanism that contributes to the pathogenesis of cardiovascular diseases and is a well-known feature of clinical diabetes. Prior studies have demonstrated an impaired nitric oxide bioavailability and a reduced endothelium-dependent vasodilation under diabetic conditions and in animal models, JNK activity has been widely described to be involved in systemic insulin resistance. Hypothesis: Our study aimed to evaluate the involvement of JNK in endothelial dysfunction, studying its potential role in altered eNOS activation and NO synthesis in diabetic patients. Methods: We measured endothelial function and JNK activity in freshly isolated endothelial cells from diabetic patients (n=38) and nondiabetic controls (n=40). Results: ECs from diabetic patients displayed impaired eNOS activation and reduced NO release after insulin and A23187 stimulation, consistent with the presence of endothelial dysfunction. JNK activation was higher in diabetic (**P=0.003), and was associated with lower flow-mediated dilation (r=-0.53, *P=0.02). In endothelial cells from diabetic patients, treatment with JNK chemical inhibitor (SP600125) restored eNOS activation and insulin response (***P<0.001). Nitric oxide bioactivity after A23187 stimuli with diabetes was also recovered in endothelial cells from patients with diabetes. Conclusions: In summary, our data suggest that JNK activation contributes to vascular insulin resistance and endothelial dysfunction in patients with type 2 diabetes and may represent a target in novel therapeutic opportunities.


2016 ◽  
Vol 22 (18) ◽  
pp. 2650-2656 ◽  
Author(s):  
Noelia Diaz-Morales ◽  
Susana Rovira-Llopis ◽  
Irene Escribano-Lopez ◽  
Celia Bañuls ◽  
Sandra Lopez-Domenech ◽  
...  

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Fujiao Nie ◽  
Jiazhao Yan ◽  
Yanjun Ling ◽  
Zhengrong Liu ◽  
Chaojun Fu ◽  
...  

Abstract Background Diabetic retinopathy (DR) has become a worldwide concern because of the rising prevalence rate of diabetes mellitus (DM). Despite much energy has been committed to DR research, it remains a difficulty for diabetic patients all over the world. Since apoptosis of retinal microvascular pericytes (RMPs) is the early characteristic of DR, this study aimed to reveal the mechanism of Shuangdan Mingmu (SDMM) capsule, a Chinese patent medicine, on oxidative stress-induced apoptosis of pericytes implicated with poly (ADP-ribose) polymerase (PARP) / glyceraldehyde 3-phosphate dehydrogenase (GAPDH) pathway. Methods Network pharmacology approach was performed to predict biofunction of components of SDMM capsule dissolved in plasma on DR. Both PARP1 and GAPDH were found involved in the hub network of protein-protein interaction (PPI) of potential targets and were found to take part in many bioprocesses, including responding to the regulation of reactive oxygen species (ROS) metabolic process, apoptotic signaling pathway, and response to oxygen levels through enrichment analysis. Therefore, in vitro research was carried out to validate the prediction. Human RMPs cultured with media containing 0.5 mM hydrogen oxide (H2O2) for 4 h was performed as an oxidative-damage model. Different concentrations of SDMM capsule, PARP1 inhibitor, PARP1 activation, and GAPDH inhibitor were used to intervene the oxidative-damage model with N-Acetyl-L-cysteine (NAC) as a contrast. Flow cytometry was performed to determine the apoptosis rate of cells and the expression of ROS. Cell counting kit 8 (CCK8) was used to determine the activity of pericytes. Moreover, nitric oxide (NO) concentration of cells supernatant and expression of endothelial nitric oxide synthase (eNOS), superoxide dismutase (SOD), B cell lymphoma 2 (BCL2), vascular endothelial growth factor (VEGF), endothelin 1 (ET1), PARP1, and GAPDH were tested through RT-qPCR, western blot (WB), or immunocytochemistry (ICC). Results Overproduction of ROS, high apoptotic rate, and attenuated activity of pericytes were observed after cells were incubated with media containing 0.5 mM H2O2. Moreover, downregulation of SOD, NO, BCL2, and GAPDH, and upregulation of VEGFA, ET1, and PARP1 were discovered after cells were exposed to 0.5 mM H2O2 in this study, which could be improved by PARP1 inhibitor and SDMM capsule in a dose-dependent way, whereas worsened by PARP1 activation and GAPDH inhibitor. Conclusions SDMM capsule may attenuate oxidative stress-induced apoptosis of pericytes through downregulating PARP expression and upregulating GAPDH expression.


2021 ◽  
Vol 22 (15) ◽  
pp. 8296
Author(s):  
Rüdiger Hardeland

Melatonin interacts in multiple ways with microglia, both directly and, via routes of crosstalk with astrocytes and neurons, indirectly. These effects of melatonin are of relevance in terms of antioxidative protection, not only concerning free-radical detoxification, but also in prevention of processes that cause, promote, or propagate oxidative stress and neurodegeneration, such as overexcitation, toxicological insults, viral and bacterial infections, and sterile inflammation of different grades. The immunological interplay in the CNS, with microglia playing a central role, is of high complexity and includes signaling toward endothelial cells and other leukocytes by cytokines, chemokines, nitric oxide, and eikosanoids. Melatonin interferes with these processes in multiple signaling routes and steps. In addition to canonical signal transduction by MT1 and MT2 melatonin receptors, secondary and tertiary signaling is of relevance and has to be considered, e.g., via the upregulation of sirtuins and the modulation of pro- and anti-inflammatory microRNAs. Many details concerning the modulation of macrophage functionality by melatonin are obviously also applicable to microglial cells. Of particular interest is the polarization toward M2 subtypes instead of M1, i.e., in favor of being anti-inflammatory at the expense of proinflammatory activities, which is well-documented in macrophages but also applies to microglia.


Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 86
Author(s):  
Yunok Oh ◽  
Chang-Bum Ahn ◽  
Jae-Young Je

Oxidative stress-induced endothelial dysfunction is strongly linked to the pathogenesis of cardiovascular diseases. A previous study revealed that seahorse hydrolysates ameliorated oxidative stress-mediated human umbilical vein endothelial cells (HUVECs) injury. However, the responsible compounds have not yet been identified. This study aimed to identify cytoprotective peptides and to investigate the molecular mechanism underlying the cytoprotective role in H2O2-induced HUVECs injury. After purification by gel filtration and HPLC, two peptides were sequenced by liquid chromatography-tandem mass spectrometry as HGSH (436.43 Da) and KGPSW (573.65 Da). The synthesized peptides and their combination (1:1 ratio) showed significant HUVECs protection effect at 100 μg/mL against H2O2-induced oxidative damage via significantly reducing intracellular reactive oxygen species (ROS). Two peptides and their combination treatment resulted in the increased heme oxygenase-1 (HO-1), a phase II detoxifying enzyme, through the activation of nuclear transcription factor-erythroid 2-related factor (Nrf2). Additionally, cell cycle and nuclear staining analysis revealed that two peptides and their combination significantly protected H2O2-induced cell death through antiapoptotic action. Two peptides and their combination treatment led to inhibit the expression of proapoptotic Bax, the release of cytochrome C into the cytosol, the activation of caspase 3 by H2O2 treatment in HUVECs, whereas antiapoptotic Bcl-2 expression was increased with concomitant downregulation of Bax/Bcl-2 ratio. Taken together, these results suggest that seahorse-derived peptides may be a promising agent for oxidative stress-related cardiovascular diseases.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Gabriela Gambato ◽  
Elisa Maria Pavão ◽  
Gabriela Chilanti ◽  
Roselei Claudete Fontana ◽  
Mirian Salvador ◽  
...  

Hyperglycaemia exacerbates the production of reactive oxygen species (ROS), contributing to the multiple complications associated with diabetes. Mitochondrial dysfunction is also known to be associated with diabetes. Therefore, the aim of this work was to study the effect of Pleurotus albidus extract on the mitochondrial dysfunction induced by hyperglycaemia in EA.hy926 endothelial cells. The results showed that P. albidus treatment prevented the increase in the activity of complex I of the electron transport chain and minimized the ROS production induced by hyperglycaemia. In addition, the extract minimized oxidative damage to lipids and proteins, caused an imbalance in the antioxidant enzyme activities of superoxide dismutase and catalase, and decreased the nitric oxide levels induced by hyperglycaemia. These data contribute to our understanding of the mitochondrial disorder induced by hyperglycaemia as well as establishing the conditions required to minimize these alterations.


Author(s):  
Sarah Basehore ◽  
Samantha Bohlman ◽  
Callie Weber ◽  
Swathi Swaminathan ◽  
Yuji Zhang ◽  
...  

Rationale: In diabetic animals as well as high glucose cell culture conditions, endothelial nitric oxide synthase (eNOS) is heavily O-GlcNAcylated, which inhibits its phosphorylation and nitric oxide (NO) production. It is unknown, however, whether varied blood flow conditions, which affect eNOS phosphorylation, modulate eNOS activity via O-GlcNAcylation-dependent mechanisms. Objective: The goal of this study was to test if steady laminar flow, but not oscillating disturbed flow, decreases eNOS O-GlcNAcylation, thereby elevating eNOS phosphorylation and NO production. Methods and Results: Human umbilical vein endothelial cells (HUVEC) were exposed to either laminar flow (20 dynes/cm2 shear stress) or oscillating disturbed flow (4{plus minus}6 dynes/cm2 shear stress) for 24 hours in a cone-and-plate device. eNOS O-GlcNAcylation was almost completely abolished in cells exposed to steady laminar but not oscillating disturbed flow. Interestingly, there was no change in protein level or activity of key O-GlcNAcylation enzymes (OGT, OGA, or GFAT). Instead, metabolomics data suggest that steady laminar flow decreases glycolysis and hexosamine biosynthetic pathway (HBP) activity, thereby reducing UDP-GlcNAc pool size and consequent O-GlcNAcylation. Inhibition of glycolysis via 2-deoxy-2-glucose (2-DG) in cells exposed to disturbed flow efficiently decreased eNOS O-GlcNAcylation, thereby increasing eNOS phosphorylation and NO production. Finally, we detected significantly higher O-GlcNAcylated proteins in endothelium of the inner aortic arch in mice, suggesting that disturbed flow increases protein O-GlcNAcylation in vivo. Conclusions: Our data demonstrate that steady laminar but not oscillating disturbed flow decreases eNOS O-GlcNAcylation by limiting glycolysis and UDP-GlcNAc substrate availability, thus enhancing eNOS phosphorylation and NO production. This research shows for the first time that O-GlcNAcylation is regulated by mechanical stimuli, relates flow-induced glycolytic reductions to macrovascular disease, and highlights targeting HBP metabolic enzymes in endothelial cells as a novel therapeutic strategy to restore eNOS activity and prevent EC dysfunction in cardiovascular disease.


2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Yanan Sun ◽  
Cao Ma ◽  
Hui Sun ◽  
Huan Wang ◽  
Wei Peng ◽  
...  

As a chronic metabolic disease, diabetes mellitus (DM) is broadly characterized by elevated levels of blood glucose. Novel epidemiological studies demonstrate that some diabetic patients have an increased risk of developing dementia compared with healthy individuals. Alzheimer’s disease (AD) is the most frequent cause of dementia and leads to major progressive deficits in memory and cognitive function. Multiple studies have identified an increased risk for AD in some diabetic populations, but it is still unclear which diabetic patients will develop dementia and which biological characteristics can predict cognitive decline. Although few mechanistic metabolic studies have shown clear pathophysiological links between DM and AD, there are several plausible ways this may occur. Since AD has many characteristics in common with impaired insulin signaling pathways, AD can be regarded as a metabolic disease. We conclude from the published literature that the body’s diabetic status under certain circumstances such as metabolic abnormalities can increase the incidence of AD by affecting glucose transport to the brain and reducing glucose metabolism. Furthermore, due to its plentiful lipid content and high energy requirement, the brain’s metabolism places great demands on mitochondria. Thus, the brain may be more susceptible to oxidative damage than the rest of the body. Emerging evidence suggests that both oxidative stress and mitochondrial dysfunction are related to amyloid-β (Aβ) pathology. Protein changes in the unfolded protein response or endoplasmic reticulum stress can regulate Aβ production and are closely associated with tau protein pathology. Altogether, metabolic disorders including glucose/lipid metabolism, oxidative stress, mitochondrial dysfunction, and protein changes caused by DM are associated with an impaired insulin signal pathway. These metabolic factors could increase the prevalence of AD in diabetic patients via the promotion of Aβ pathology.


Proceedings ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Parent ◽  
Zhou ◽  
Bonetti ◽  
Perrin-Sarrado ◽  
Lartaud ◽  
...  

Cardiovascular diseases are associated with oxidative stress and a reduced bioavailability of nitric oxide (NO). To counteract both processes, the administration of S-nitrosoglutathione (GSNO) can be envisaged. GSNO is able to induce protein S-nitrosation (Pr-SNO), which is a post-translational modification of proteins, participating in the storage of NO in tissues, and protect thiol functions from oxidation. However, GSNO antioxidant power is poorly studied, which is probably linked to its low stability. This low stability can be addressed by nanotechnologies that will increase GSNO protection and provide a sustained release of the drug.


2019 ◽  
Vol 8 (6) ◽  
pp. 918-927 ◽  
Author(s):  
Li Pang ◽  
Ping Deng ◽  
Yi-dan Liang ◽  
Jing-yu Qian ◽  
Li-Chuan Wu ◽  
...  

Abstract Paraquat (PQ) is a widely used herbicide in the agricultural field. The lack of an effective antidote is the significant cause of high mortality in PQ poisoning. Here, we investigate the antagonistic effects of alpha lipoic acid (α-LA), a naturally existing antioxidant, on PQ toxicity in human microvascular endothelial cells (HMEC-1). All the doses of 250, 500 and 1000 μM α-LA significantly inhibited 1000 μM PQ-induced cytotoxicity in HMEC-1 cells. α-LA pretreatment remarkably diminished the damage to cell migration ability, recovered the declined levels of the vasodilator factor nitric oxide (NO), elevated the expression level of endothelial nitric oxide synthases (eNOS), and inhibited the upregulated expression of vasoconstrictor factor endothelin-1 (ET-1). Moreover, α-LA pretreatment inhibited reactive oxygen species (ROS) generation, suppressed the damage to the mitochondrial membrane potential (ΔΨm) and mitigated the inhibition of adenosine triphosphate (ATP) production in HMEC-1 cells. These results suggested that α-LA could alleviate PQ-induced endothelial dysfunction by suppressing oxidative stress. In summary, our present study provides novel insight into the protective effects and pharmacological potential of α-LA against PQ toxicity in microvascular endothelial cells.


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