Magnolol attenuates hyperlipidemia-induced endothelial disorder by alleviating oxidative stress, inflammation, and mitochondrial dysfunction via p38 MAPK-FoxO1 axis.

Endothelial dysfunction is a characteristic of aging-related vascular disease and is worsened during diabetes. High glucose can impair endothelial cell (EC) function through cellular accumulation of reactive oxygen species, an insult that can also limit replicative lifespan. Nicotinamide phosphoribosyltransferase (Nampt), also known as PBEF and visfatin, is rate-limiting for NAD+ salvage from nicotinamide and confers resistance to oxidative stress via SIRT1. We therefore sought to determine if Nampt expression could resist the detrimental effects of high glucose and confer a survival advantage to human vascular EC in this pathologic environment. Human aortic EC were infected with retrovirus encoding eGFP or eGFP-Nampt, and FACS-selected to yield populations with similar, modest transgene expression. Using a chronic glucose exposure model we tracked EC populations to senescence, assessed cellular metabolism, and determined in vitro angiogenic function. Overexpression of Nampt increased proliferation and extended replicative lifespan, and did so preferentially during glucose overload. Nampt expression delayed markers of senescence and limited reactive oxygen species accumulation in high glucose through a modest increase in aerobic glycolysis. Furthermore, tube networks formed by Nampt-overexpressing EC were more extensive and glucose-resistant, in accordance with SIRT1-mediated repression of the anti-angiogenic transcription factor, FoxO1. We conclude that Nampt enables proliferating human EC to resist the oxidative stress of aging and of high glucose, and to productively use excess glucose to support replicative longevity and angiogenic activity. Enhancing endothelial Nampt activity may thus be beneficial in scenarios requiring EC-based vascular repair and regeneration during aging and hyperglycemia, such as atherosclerosis and diabetes-related vascular disease.

Approximately 65% of patients with T2DM die as a result of cardiovascular disease with hyperglycemia and hyperlipidemia being important risk factors for cardiovascular diseases. Both T2DM and atherosclerosis are considered to be inflammatory processes Human T-lymphocytes (T-cells) and aortic endothelial cells (HAEC) have been shown to be components of plaque formation in atherosclerosis. T cells and HAEC are unique in that in their naive state they have no insulin receptors responsive to insulin but become activated in vitro hyperglycemia and in vivo hyperglycemic conditions such as diabetic ketoacidosis and non-ketotic hyperglycemic conditions. Our studies show that T-cells and HAEC in the presence of high concentrations of glucose /and or the saturated fatty acid (SFA) palmitic acid become activated and express insulin receptors, reactive oxygen species (ROS), cytokine elevation, and lipid peroxidation in a time and concentration-dependent manner. Whereas, the unsaturated fatty acid α-linoleic, was not able to activate these cells and had a salutary effect on the activation by glucose and palmitic acid. We have demonstrated that unsaturated fatty acids (UFA) may provide a protective mechanism against the prooxidant effects of hyperglycemia and high SFA such as palmitic acid. Therefore, diet alternations may be beneficial for decreasing hyperglycemia and cardiovascular risks. Studies have shown that lifestyle changes of diet and exercise can reduce the risk of developing diabetes by 58%. Hyperglycemia and hyperlipidemia are important risk factors of developing diabetes and cardiovascular disease. Therefore, we studied the effects of a High Protein diet versus a High Carbohydrate diet in obese non-diabetic, prediabetic and diabetic subjects for effects on weight loss, blood sugar, lipid levels, inflammation, and oxidative stress.

Impaired angiogenesis and wound healing carry significant morbidity and mortality in diabetic patients. Metabolic stress from hyperglycemia and elevated free fatty acids have been shown to inhibit endothelial angiogenesis. However, the underlying mechanisms remain poorly understood. In this study, we show that dysregulation of the Hippo-Yes-associated protein (YAP) pathway, an important signaling mechanism in regulating tissue repair and regeneration, underlies palmitic acid (PA)-induced inhibition of endothelial angiogenesis. PA inhibited endothelial cell proliferation, migration, and tube formation, which were associated with increased expression of mammalian Ste20-like kinases 1 (MST1), YAP phosphorylation/inactivation, and nuclear exclusion. Overexpression of YAP or knockdown of MST1 prevented PA-induced inhibition of angiogenesis. When searching upstream signaling mechanisms, we found that PA dysregulated the Hippo-YAP pathway by inducing mitochondrial damage. PA treatment induced mitochondrial DNA (mtDNA) release to cytosol, and activated cytosolic DNA sensor cGAS-STING-IRF3 signaling. Activated IRF3 bound to the MST1 gene promoter and induced MST1 expression, leading to MST1 up-regulation, YAP inactivation, and angiogenesis inhibition. Thus, mitochondrial damage and cytosolic DNA sensor cGAS-STING-IRF3 signaling are critically involved in PA-induced Hippo-YAP dysregulation and angiogenesis suppression. This mechanism may have implication in impairment of angiogenesis and wound healing in diabetes.

Palmitic acid promotes endothelial-to-mesenchymal transition via activation of the cytosolic DNA-sensing cGAS-STING pathway

Ginsenoside Rg1 attenuates diabetic vascular endothelial dysfunction by inhibiting the calpain-1/ROS/PKC-β axis

Retinol binding protein 4 induces mitochondrial dysfunction and vascular oxidative damage

endothelial cells that line the inner wall of blood vessels secrete many vasoactive factors including nitric oxide (vasorelaxant) and endothelin-1 (vasoconstrictor) that contribute to the regulation of vascular tone and blood pressure ([21][1]). Endothelial cells respond to various humoral agents,

Free radicals and other oxygen- or nitrogen-derived reactive species formed during cellular metabolism and respiration, like superoxide (O2·−), hydrogen peroxide (H2O2), and nitric oxide (NO), are important second messengers and fundamental mediators in biological processes, redox signaling, and cellular growth. However, over the past 2 decades it has become clear that reactive oxygen species (ROS) in particular are also important participants in a number of pathological processes, including cardiovascular and kidney diseases. In fact, increased production of ROS has been proposed as a common pathomechanism by which cardiovascular risk factors affect the vessel wall to induce and amplify vessel and organ injury. See page 943 Several possible enzymatic sources of ROS have been identified in blood vessels and other tissues, such as nicotineamide adenine dinucleotide (phosphate) oxidase (NAD(P)H oxidase), xanthine oxidase (XO), and uncoupled nitric oxide synthase. NAD(P)H oxidase has long been considered one of the most important sources of ROS in the vessel wall. One of its most potent stimulants is angiotensin II. In turn, NAD(P)H oxidase mediates several downstream effects of angiotensin II like inflammation, endothelial dysfunction, collagen deposition, and vascular hypertrophy. Nevertheless, an important role in the pathogenesis of cardiovascular disease has also been ascribed to XO. This …

Atherosclerosis (AS) is a common vascular disease, and its main influencing factor is endothelial damage caused by oxidized low-density lipoprotein (ox-LDL). As one of the main active ingredients of ginseng, ginsenoside Rb3 has anti-inflammatory and anti-oxidative effects. However, the role of ginsenoside Rb3 in endothelial injury induced by ox-LDL is not clear. This study aimed to evaluate the effect and potential mechanism of ginsenoside Rb3 action on ox-LDL-treated human aortic endothelial cells (HAECs). The HAECs treated with ox-LDL were used to establish an in vitro AS model. The viability of the HAECs was analyzed with Cell Counting Kit-8 (CCK-8). Flow cytometry was performed to assess the apoptosis. Oxidative stress, inflammation and endothelial dysfunction were evaluated using enzyme-linked immunosorbent assay (ELISA) and western blotting. The levels of miR-513a-5p were assessed using quantitative real-time polymerase chain reaction (qPCR). A dual-luciferase assay was performed to analyze the relationship between miR-513a-5p and a zinc finger and BTB domain-containing protein (ZBTB20). Exposure of HAECs to ox-LDL (50 μg/mL) reduced cell viability, superoxide dismutase (SOD) activity and endothelial nitric oxide synthase (eNOS) expression, while increasing the levels of malondialdehyde (MDA), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), and soluble intercellular adhesion molecule-1 (sICAM-1). The pretreatment with Rb3 markedly enhanced cell viability and decreased ox-LDL-induced oxidative stress, inflammation and endothelial dysfunction in HAECs. The ox-LDL decreased the level of miR-513a-5p, which was reversed by Rb3 pretreatment. The ZBTB20 was a target of miR-513a-5p in HAECs, and ox-LDL upregulated ZBTB20 expression, which was reversed by Rb3 pretreatment. The protective effect of Rb3 on ox-LDL-induced HAECs was diminished by miR-513a-5p inhibition, which was reversed by ZBTB20 knockdown. Ginsenoside Rb3 reduces the effects of ox-LDL on HAECs by regulating the miR-513a-5p/ZBTB20 axis, which provides a theoretical basis for the treatment of AS.

Over the past 10 to 15 years, a vast collection of studies have provided evidence indicating that reactive oxygen species (ROS), particularly superoxide (O2·−) and hydrogen peroxide (H2O2), contribute to the pathogenesis of cardiovascular diseases, such as heart failure and hypertension. Griendling et al1 first demonstrated that NADPH oxidase present in the vasculature is a primary source of the elevated ROS levels. Since these initial studies, NADPH oxidase-derived ROS in the kidney,2 heart,3 and brain4 have been linked to the development and progression of numerous cardiovascular-related diseases. More recently, however, mitochondria have also been identified as important sources of ROS in controlling cardiovascular function. Considering that mitochondria are the primary source of ROS in most cells during normal respiration because of the leaking of electrons from the electron transport chain (ETC), perhaps it should not be all that surprising that mitochondrial-produced ROS are involved in pathophysiological conditions of the cardiovascular system. To date, most of the evidence linking mitochondrial dysfunction and mitochondrial-produced ROS to the pathogenesis of cardiovascular diseases comes from studies on the peripheral renin-angiotensin system.5 For example, using a model of cardiac ischemic reperfusion injury, Kimura et al6 reported that angiotensin II (Ang II)-induced preconditioning is mediated by mitochondrial-produced ROS. The authors further demonstrated that Ang II-induced NADPH oxidase-derived ROS lie upstream of mitochondrial-produced ROS, thus, implicating a ROS-induced ROS mechanism. Similarly, it was demonstrated recently that, in aortic endothelial cells, Ang II-induced NADPH oxidase activation leads to an increase in mitochondrial ROS production, as well as mitochondrial dysfunction, as determined by a decrease in mitochondrial membrane potential and mitochondrial respiration.7 Together, these studies and others (detailed elsewhere5) clearly illustrate a role for mitochondrial-produced ROS and mitochondrial dysfunction in peripheral tissues in the pathogenesis of …

metabolic syndrome is a cluster of conditions including insulin resistance, dyslipidemia, hypertension, and central obesity, and it results in an increased risk of type 2 diabetes mellitus and cardiovascular diseases such as atherosclerosis. These conditions are rising year to year and are a leading

Cytoprotective effects of berry anthocyanins against induced oxidative stress and inflammation in primary human diabetic aortic endothelial cells

As the most important natural antioxidants in plant extracts, polyphenols demonstrate versatile bioactivities and are susceptible to oxidation. The commonly used ultrasonic extraction often causes oxidation reactions involving the formation of free radicals. To minimize the oxidation effects during the ultrasonic extraction process, we designed a hydrogen (H2)-protected ultrasonic extraction method and used it in Chrysanthemum morifolium extraction. Hydrogen-protected extraction improved the total antioxidant capacity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and polyphenol content of Chrysanthemum morifolium water extract (CME) compared with air and nitrogen (N2) conditions. We further investigated the protective effects and mechanisms of CME on palmitate (PA)-induced endothelial dysfunction in human aorta endothelial cells (HAECs). We found that hydrogen-protected CME (H2-CME) best-prevented impairment in nitric oxide (NO) production, endothelial NO synthase (eNOS) protein level, oxidative stress, and mitochondrial dysfunction. In addition, H2-CME prevented PA-induced endothelial dysfunction by restoring mitofusin-2 (MFN2) levels and maintaining redox balance.

Background: Atherosclerosis is a metabolic disorder characterized by hyperlipidemia and chronic inflammation that is initiated by endothelial dysfunction and altered lipid homeostasis. Sigma1 receptor (Sigmar1) is a ubiquitously expressed chaperone protein known to have a role in lipid metabolism and ER-mitochondrial lipid transport. Although studies showed a correlation between Sigmar1 inhibition and induction of inflammation, the role of Sigmar1 in regulating vascular inflammation during atherosclerosis remained unknown. Hypothesis: Absence of Sigmar1 will accelerate the development and progression of atherosclerosis by inducing endothelial inflammation and mitochondrial dysfunction. Methods and Results: We used a hypercholesterolemia model induced by AAV8-PCSK9 injection followed by 12 weeks of western diet (WD) in wildtype (Wt) and global Sigmar1 knockout (Sigmar1 -/- ) mice to determine the role of Sigmar1 in diet-induced atherosclerosis. We also used human aortic endothelial cells (HAEC) and CRISPR-Cas9 mediated Sigmar1 knockout HAECs (HAEC hKO ) to delineate the molecular mechanisms in vitro . Sigmar1 protein level was notably decreased in the human and mouse atherosclerotic tissues and in HAECs treated with inflammatory trigger, LPS+IFNγ. We observed increased atherosclerotic plaque area in aorta by en face analysis in Sigmar1 -/- mice compared to Wt mice subjected to PCSK9/WD model. LPS+IFNγ treated HAEC hKO showed significant upregulation of EC adhesion molecules (VCAM1, ICAM1) and activated nuclear factor NFκB expressions than the control HAEC hWT . Since mitochondrial dysfunction and elevated reactive oxygen species (ROS) generation play a role in inflammation and diseases, and Sigmar1 is known to regulate mitochondrial function, we wanted to dissect the contribution of EC-Sigmar1 in vascular inflammation. Both lack of Sigmar1 and LPS+IFNγ stimuli significantly reduced mitochondrial respiration in HAEC hKO cells and induced ROS production along with the induction of inflammation. Conclusion: So, lack of Sigmar1 leads to increased atherosclerotic plaque area in mice in response to PCSK9/WD suggesting a novel protective role for Sigmar1 in the development and progression of atherosclerosis and vascular inflammation.

Metabolic syndrome (MetS) is a collection of metabolic risk factors associated with an increased risk of developing atherosclerosis. Reducing levels of modifiable atherogenic risk factors is an essential goal in the prevention of atherosclerosis. Since there is an established relationship between metabolic syndrome, oxidative stress, chronic inflammation and cardiovascular disease, the first study focused on demonstrating these links. Therefore, this research focuses on a sedentary population who work under conditions that predispose them to risk factors of metabolic syndrome and who are likely to develop atherosclerosis ultimately. Accordingly, a comprehensive evaluation of metabolic syndrome risk factors was conducted on 79 transport drivers. The clinical examination collected anthropometric data and blood biochemistry results. Daily step counts calculated by the Fitbit over seven days were also used to monitor their activity trends over time. Health assessments were conducted at the beginning of the study. The results showed that 68% (n = 51) of participants were recorded as having three or more risk factors which can contribute to MetS including obesity, hyperglycaemia, lipid profile abnormalities, blood pressure, hyperuricemia and markers of inflammation. This study also demonstrated that there are interconnections between oxidative stress and chronic inflammation with MetS components highlighting the role of oxidative stress and inflammation in metabolic syndrome and atherosclerosis. It could be suggested that the potential use of anthocyanins as antioxidants and with anti-inflammatory properties as an alternative approach for the prevention and management of atherosclerosis in MetS population. Initially, the use of an in vitro model of endothelial cells can offer valuable mechanistic insights into the development and progression of inflammatory conditions that provide an efficient platform for product screening before conducting a human intervention trial. Based on findings from the literature review, it is hypothesised that anthocyanin might exert protective effects on healthy human aortic endothelial cells against inflammation and oxidative stress in vitro. The second study aimed to examine and compare the abilities of healthy and diabetic human aortic endothelial cells to incorporate anthocyanins’ potential benefits against hydrogen peroxide (H2O2) as an oxidative stressor and lipopolysaccharide (LPS) to induce inflammation. Cultured Primary Human Aortic Endothelial Cells (HAEC) and Diseased-(type II diabetic) Aortic Endothelial Cells (D-HAEC) were exposed to oxidative stress by H2O2 (75 μM) and LPS (1μg/ml) and were treated with the anthocyanin (AC, 50 μl/ml). The results showed that anthocyanins might be responsible for protecting that aortic endothelial cells against inflammatory insult. These findings may have important implications for preserving endothelial cell function and preventing the initiation of endothelial cell damage that leads to platelets activation and coagulation associated with endothelial dysfunction. Finally, based on the in vitro finding, the last chapter aimed to investigate the antithrombotic effects of same berry-derived anthocyanin supplements on biomarkers of atherosclerosis, platelet function, and the expression of pro-atherogenic genes in a population with metabolic syndrome. A total of 55 participants in two groups of Normal and MetS (age 25-75y) were given 320 mg anthocyanin supplements twice daily for four weeks in a clinical trial. The effects of berry-derived supplementation were examined on features of metabolic syndrome, including fasting blood glucose, lipid profile, inflammatory markers, oxidative stress marker (uric acid), platelet surface markers, and the expression of pro-atherogenic genes. The results showed that anthocyanin consumption for four weeks significantly decreased the average fasting blood glucose (FBG) level by 13.3 % in the MetS group. Similarly, significant reductions were observed in triglyceride (24.9%) and low-density lipoprotein (LDL) (33.1%) levels in the MetS group compared with the Normal group (P ≤ 0.05). Anthocyanin supplementation also caused a reduction (18%) in high sensitivity C-reactive protein (hs-CRP), an inflammatory biomarker, with no significant difference in the Normal group. There was a positive correlation between decreased hs-CRP values and the levels of LDL-C and FBG in the MetS group (P ≤ 0.05). Anthocyanin supplements also decreased ADP-induced platelet activation configuration expressed as P-selectin by 40%. The data here revealed that anthocyanin intake showed an inhibitory effect on the gene expression of proinflammatory cytokines, including interleukin (IL)-1A, tumour necrosis factor-alpha (TNF-α) and interleukin (IL)-6, as well as endothelial cell adhesion molecule-1 (ECAM-1) and cyclooxygenase (COX)-2, with stimulatory effects on the expression of superoxide dismutase (SOD) and Peroxisome proliferator-activated receptor gamma (PPRAG). Thus, these findings suggest that short-term consumption of anthocyanin supplements may have atheroprotective effects through the inhibition of chronic inflammation and platelet activation and improvement of MetS components.