scholarly journals Berberine Protects against Palmitate-Induced Endothelial Dysfunction: Involvements of Upregulation of AMPK and eNOS and Downregulation of NOX4

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ming Zhang ◽  
Chun-Mei Wang ◽  
Jing Li ◽  
Zhao-Jie Meng ◽  
Sheng-Nan Wei ◽  
...  

Endothelial dysfunction is a critical factor during the initiation of cardiovascular complications in diabetes. Berberine can ameliorate endothelial dysfunction induced by diabetes. However, the underlying mechanisms remain unclear. The aim of this study was to investigate the protective effect and mechanism of berberine on palmitate-induced endothelial dysfunction in human umbilical vein endothelial cells (HUVECs). The cell viability of HUVECs was determined by MTT assays. Nitric oxide (NO) level and production of reactive oxygen species (ROS) were determined in supernatants or in the cultured HUVECs. The mRNA level of endothelial nitric oxide synthase (eNOS) was measured by RT-PCR, and the protein levels of eNOS, p-eNOS, Akt, p-Akt, AMPK, p-AMPK, and NADPH oxidase (NOX4) were analyzed. The results demonstrated that berberine significantly elevated NO levels and reduced the production of ROS. The expressions of eNOS were significantly increased, while NOX4 protein expression was decreased in berberine-treated HUVECs. Moreover, berberine upregulated the protein expression of AMPK and p-AMPK in palmitate-treated HUVECs, but had no effect on the levels of Akt. Therefore, berberine ameliorates palmitate-induced endothelial dysfunction by upregulating eNOS expression and downregulating expression of NOX4. This regulatory effect of berberine may be related to the activation of AMPK.

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Dafeng Yang ◽  
Shenglan Tan ◽  
Zhousheng Yang ◽  
Pei Jiang ◽  
Caie Qin ◽  
...  

Accumulating studies demonstrate that dihydromyricetin (DMY), a compound extracted from Chinese traditional herb, Ampelopsis grossedentata, attenuates atherosclerotic process by improvement of endothelial dysfunction. However, the underlying mechanism remains poorly understood. Thus, the aim of this study is to investigate the potential mechanism behind the attenuating effects of DMY on tumor necrosis factor alpha- (TNF-α-) induced endothelial dysfunction. In response to TNF-α, microRNA-21 (miR-21) expression was significantly increased in human umbilical vein endothelial cells (HUVECs), in line with impaired endothelial dysfunction as evidenced by decreased tube formation and migration, endothelial nitric oxide synthase (eNOS) (ser1177) phosphorylation, dimethylarginine dimethylaminohydrolases 1 (DDAH1) expression and metabolic activity, and nitric oxide (NO) concentration as well as increased asymmetric dimethylarginine (ADMA) levels. In contrast, DMY or blockade of miR-21 expression ameliorated endothelial dysfunction in HUVECs treated with TNF-α through downregulation of miR-21 expression, whereas these effects were abolished by overexpression of miR-21. In addition, using a nonspecific NOS inhibitor, L-NAME, also abrogated the attenuating effects of DMY on endothelial dysfunction. Taken together, these data demonstrated that miR-21-mediated DDAH1/ADMA/NO signal pathway plays an important role in TNF-α-induced endothelial dysfunction, and DMY attenuated endothelial dysfunction induced by TNF-α in a miR-21-dependent manner.


2005 ◽  
Vol 289 (4) ◽  
pp. H1752-H1757 ◽  
Author(s):  
Friedrich Mittermayer ◽  
Johannes Pleiner ◽  
Georg Schaller ◽  
Stefan Zorn ◽  
Khodadad Namiranian ◽  
...  

Acute inflammation causes endothelial dysfunction, which is partly mediated by oxidant stress and inactivation of nitric oxide. The contribution of depletion of tetrahydrobiopterin (BH4), the cofactor required for nitric oxide generation, is unclear. In this randomized, double-blind, three-way crossover study, forearm blood flow (FBF) responses to ACh and glyceryltrinitrate (GTN) were measured before and 3.5 h after infusion of Escherichia coli endotoxin (LPS, 20 IU/kg iv) in eight healthy men. The effect of intra-arterial BH4(500 μg/min), placebo, or vitamin C (24 mg/min) was studied on separate days 3.5 h after LPS infusion. In addition, human umbilical vein endothelial cells were incubated for 24 h with vitamin C and LPS. ACh and GTN caused dose-dependent forearm vasodilation. The FBF response to ACh, which was decreased by 23 ± 17% ( P < 0.05) by LPS infusion, was restored to baseline reactivity by BH4and vitamin C. FBF responses to GTN were not affected by BH4or vitamin C. LPS increased leukocyte count, high-sensitivity C-reactive protein, IL-6, IL-1β, IFN-γ, monocyte chemoattractant protein-1, pulse rate, and body temperature and decreased platelet count and vitamin C concentration. Vitamin C increased forearm plasma concentration of BH4by 32% ( P < 0.02). Incubation with LPS and vitamin C, but not LPS alone, increased intracellular BH4concentration in human umbilical vein endothelial cells. Impaired endothelial function during acute inflammation can be restored by BH4or vitamin C. Vitamin C may exert some of its salutary effects by increasing BH4concentration.


2018 ◽  
Vol 46 (3) ◽  
pp. 965-974 ◽  
Author(s):  
Xuhua Yu ◽  
Jiajun Xu ◽  
Wenwu Liu ◽  
Weigang Xu

Background/Aims: Intravascular bubbles can exert pleiotropic detrimental effects, partly by inducing endothelial microparticles (EMPs) production, which play critical roles in cell communication and vascular inflammation cascades. However, the underlying mechanisms remain unclear. This study aimed to delineate the possible mechanisms involving bubble-induced EMPs formation. Methods: Human umbilical vein endothelial cells (HUVECs) were contacted by bubbles and EMPs level in supernatant were quantified by flow cytometry. Cytoplasmic calcium (Ca2+) was measured by the Ca2+ binding dyes Fluo-3 AM and flippase activity was assessed by translocation rate of fluorescent phosphatidylserine (PS) analogue NBD-PS. Protein levels of phospho-myosin light chain (MLC, a Rho kinase substrate) and phospho-extracellular signal-regulated kinase 1 or 2 (ERK1/2) were determined by western blotting. The score of actin colocalization was assessed by phalloidin-FITC using an immunofluorescent microscopy. Results: EMPs level markedly increased after bubble stimulus. Cytoplasmic calcium (Ca2+) significantly elevated (P< 0.05), flippase activity decreased (P< 0.05), protein levels of phospho- MLC and phospho- ERK1/2 significantly increased (P< 0.05, P < 0.05), and the score of actin colocalization markedly reduced (P< 0.05) in bubble-stimulated HUVECs. All the above changes except the increase in phospho-ERK1/2 can be reversed by Ca2+ channel blocker LaCl3 (P< 0.05). Additionally, MLC phosphorylation was significantly inhibited and actin colocalization markedly increased by Rho kinase inhibitor pretreatment and more importantly, bubble-induced EMPs markedly decreased. Conclusions: These results demonstrate that bubble stimulates EMPs formation by cytoplasmic Ca2+ elevation and subsequently activating Rho kinase pathway and cytoskeleton reorganization. Simultaneously, cytoplasmic Ca2+ inhibits the flippase activity and subsequently increases phosphatidylserine exposure, which also contributes to EMPs formation.


2021 ◽  
Author(s):  
Suowen Xu ◽  
Sihui Luo ◽  
Xueying Zheng ◽  
Jianping Weng

AbstractCoronavirus disease 2019 (COVID-19) is regarded as an endothelial disease (endothelialitis) with its mechanism being incompletely understood. Emerging evidence has demonstrated that the endothelium represents the Achilles' heel in COVID-19 patients and that endothelial dysfunction precipitates COVID-19 and accompanying multi-organ injuries. Thus, pharmacotherapies targeting endothelial dysfunction have potential to ameliorate COVID-19 and its cardiovascular complications. Primary human umbilical vein endothelial cells (HUVECs) and human pulmonary microvascular endothelial cells (HPMECs) were treated with serum from control subjects or COVID-19 patients. Downstream monocyte adhesion and associated gene/protein expression was evaluated in endothelial cells exposed to COVID-19 patient serum in the presence of KLF2 activator (Atorvastatin) or KLF2 overexpression by an adenoviral vector. Here, we demonstrate that the expression of KLF2 was significantly reduced and monocyte adhesion was increased in endothelial cells treated with COVID-19 patient serum due to elevated levels of pro-adhesive molecules, ICAM1 and VCAM1. IL-1β and TNF-α, two cytokines observed in cytokine release syndrome in COVID-19 patients, decreased KLF2 gene expression. Next-generation RNA-sequencing data showed that atorvastatin treatment leads to a cardiovascular protective transcriptome associated with improved endothelial function (vasodilation, anti-inflammation, antioxidant status, anti-thrombosis/-coagulation, anti-fibrosis and reduced angiogenesis). Treatment of HPMECs with atorvastatin or KLF2 adenovirus ameliorate COVID-19 serum-induced increase in endothelial inflammation and monocyte adhesion by increasing KLF2 expression. Altogether, the present study demonstrates that genetic and pharmacological activation of KLF2 represses COVID-19 associated endothelial dysfunction, heralding a potentially new direction to treat endothelialitis accompanying COVID-19.


Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1782 ◽  
Author(s):  
Zhiqiang He ◽  
Xuanhong He ◽  
Menghan Liu ◽  
Lingyue Hua ◽  
Tian Wang ◽  
...  

Atherosclerosis is the pathological basis of cardiovascular disease, whilst endothelial dysfunction (ED) plays a primary role in the occurrence and development of atherosclerosis. Simvastatin has been shown to possess significant anti-atherosclerosis activity. In this study, we evaluated the protective effect of simvastatin on endothelial cells under oxidative stress and elucidated its underlying mechanisms. Simvastatin was found to attenuate H2O2-induced human umbilical vein endothelial cells (HUVECs) dysfunction and inhibit the Wnt/β-catenin pathway; however, when this pathway was activated by lithium chloride, endothelial dysfunction was clearly enhanced. Further investigation revealed that simvastatin did not alter the expression or phosphorylation of LRP6, but reduced intracellular cholesterol deposition and inhibited endoplasmic reticulum (ER) stress. Inducing ER stress with tunicamycin activated the Wnt/β-catenin pathway, whereas reducing ER stress with 4-phenylbutyric acid inhibited it. We hypothesize that simvastatin does not affect transmembrane signal transduction in the Wnt/β-catenin pathway, but inhibits ER stress by reducing intracellular cholesterol accumulation, which blocks intracellular signal transduction in the Wnt/β-catenin pathway and ameliorates endothelial dysfunction.


2016 ◽  
Vol 94 (11) ◽  
pp. 1132-1140 ◽  
Author(s):  
Chonghua Xu ◽  
Futian Tang ◽  
Meili Lu ◽  
Jing Yang ◽  
Ronghui Han ◽  
...  

Endothelial cell injury caused by reactive oxygen species (ROS) plays a critical role in the pathogenesis of cardiovascular disorders. Astragaloside IV (AsIV) possesses potent antioxidant properties against oxidative stress through undefined mechanism(s). We sought to investigate whether AsIV protects human umbilical vein endothelial cells (HUVECs) from hydrogen peroxide (H2O2) induced oxidative stress focusing on eNOS uncoupling and the NADPH oxidase – ROS – NF-κB pathway. Compared with HUVECs incubated with H2O2 alone, pretreatment with AsIV significantly increased the viability of HUVECs, which was accompanied with apparent increase in nitric oxide (NO) production and decrease in intracellular superoxide anion production. Furthermore, pretreatment with AsIV increased endothelial nitric oxide synthase (eNOS) dimer/monomer ratio and its critical cofactor tetrahydrobiopterin (BH4) content, decreased Nox4 protein expression (the most abundant Nox isoform in HUVECs), inhibited translocation of NF-κB p65 subunit into nuclear fraction while enhanced the protein expression of IκB-α (the inhibitor of NF-κB p65), reduced the levels of IL-1β, IL-6, and TNF-α in HUVECs medium, and decreased iNOS protein expression. These results suggest that AsIV may protect HUVECs from H2O2-induced oxidative stress via inhibiting NADPH oxidase – ROS – NF-κB pathway and eNOS uncoupling.


2017 ◽  
Vol 43 (1) ◽  
pp. 293-307 ◽  
Author(s):  
Qianqian Dong ◽  
Wenjuan Xing ◽  
Feifei Su ◽  
Xiangyan Liang ◽  
Fei Tian ◽  
...  

Aims: Obesity is a major risk for hypertension. Endothelial dysfunction contributes to increased peripheral vascular resistance and subsequent hypertension. Autophagy regulates endothelial function, however, whether autophagy is related to hypertension in obesity remains largely unclear. We wished to ascertain: (i) the role of autophagy in obesity-induced hypertension and the underlying mechanisms; (ii) if tetrahydroxystilbene glycoside (TSG) influences endothelial dysfunction and obesity-associated hypertension. Methods: (TSG-treated) male Zucker diabetic fatty (ZDF) rats and cultured human umbilical vein endothelial cells (HUVECs) were used. Blood pressure was measured non-invasively with a tail-cuff system. Westernblotting was performed to determine the expression of autophagy-associated proteins. Autophagy flux was assessed by transfection HUVECs with the Ad-mGFP–RFP–LC3. Results: Compared with their lean counterparts, obese ZDF rats exhibited hypertension and endothelial dysfunction, along with impaired Akt/mTOR signaling and upregulated expression of autophagy-associated proteins beclin1, microtubule-associated protein 1 light chain 3 II/I, autophagy protein (ATG)5 and ATG7. Two-week TSG administration restored blood pressure and endothelial function, reactivated Akt/mTOR pathway and decreased endothelial autophagy in ZDF rats. Rapamycin pretreatment blocked the hypotensive effect of TSG in ZDF rats. Suppression of Akt/mTOR expression with siRNA significantly blunted the anti-autophagic effect of TSG in HUVECs as evidenced by abnormal autophagic flux and increased expression of autophagy-associated proteins. Conclusion: Endothelial dysfunction in ZDF rats is partially attributable to excessive autophagy. TSG improves endothelial function and exerts hypotensive effects via regulation of endothelial autophagy.


Author(s):  
Hongru Lin ◽  
Xuehan Wu ◽  
Yaqin Yang ◽  
Ziwei Wang ◽  
Weilu Huang ◽  
...  

Inflammation-induced activation and dysfunction of endothelial cells play an important role in the pathology of multiple vascular diseases. Nicaraven, a potent hydroxyl radical scavenger, has recently been found to have anti-inflammatory roles. However, the mechanism of its action is not fully understood. Here we investigated the effects of Nicaraven on TNFα-induced inflammatory response in human umbilical vein endothelial cells (HUVECs) and explore the underlying mechanisms related to NF-κB signaling pathway. Our results showed that Nicaraven significantly reduced the reactive oxygen species production after TNFα stimulation. Nicaraven suppressed TNFα-induced mRNA expression of multiple adhesion molecules and pro-inflammatory cytokines, including VCAM-1, ICAM-1, E-selectin, MCP-1, TNFα, IL-1β, IL-6 and IL-8. In addition, Nicaraven inhibited monocyte adhesion and reduced the protein levels of VCAM-1 and ICAM-1. Mechanistically, Nicaraven prevented TNFα-induced activation of NF-κB signaling pathway by suppressing the phosphorylation of NF-κB p65, IκBα, and IKKα/β, stabilizing IκBα, and inhibiting the translocation of p65 from cytosol to nucleus. Finally, we showed that Nicaraven improved the functions of endothelial cells, seen as the up-regulation of endothelial nitric oxide synthase and increased nitric oxide levels. Our findings indicated that Nicaraven effectively inhibits TNFα-induced endothelial activation and inflammatory response at least partly through inhibiting NF-κB signaling pathway.


Author(s):  
Majid Shokri ◽  
Sajad Jeddi ◽  
Hassan Faridnouri ◽  
Vajiheh Khorasani ◽  
Khosrow Kashfi ◽  
...  

Background and Objective: Decreased nitric oxide (NO) bioavailability contributes to the pathophysiology of type 2 diabetes mellitus (T2DM). This study aims to determine the effects of nitrate (NO3–) on gene and protein expression of NO synthase (NOS) enzymes in the liver, soleus muscle (SM), and epididymal adipose tissue (eAT) of rats with T2DM. Methods: Twenty-eight male rats were divided into 4 groups: Control, diabetes, control+NO3–, and diabetes+NO3– (n = 7/each group). NO3– was administered for 6 months, and mRNA and protein levels of NOS enzymes were measured at the end of the study. Results: mRNA and protein levels of inducible NOS (iNOS) were higher in the liver (475% and 73%), SM (271% and 43%), and eAT (543% and 24%) of rats with T2DM. In the case of the endothelial NOS (eNOS), diabetic rats had lower mRNA and protein levels in the liver (26% and 24%) and SM (60% and 62%) and lower mRNA level (30%) in eAT. mRNA and protein levels of neural NOS (nNOS) were lower in SM (69% and 73%) and eAT (25% and 31%) of rats with T2DM. NO3– administration restored disrupted iNOS and eNOS expressions to their near normal values in all the studied tissues; NO3– also increased nNOS mRNA and protein levels in SM and eAT but decreased nNOS protein level in the liver. Conclusion: Long-term NO3– administration restored disrupted expression of NOS enzymes in the liver, SM, and eAT of rats with T2DM; these findings partly explain the beneficial metabolic effects of nitrate in T2DM.


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