Trimethylamine N-oxide aggravates vascular permeability and endothelial cell dysfunction under diabetic condition:in vitro and in vivo study

AIM:To provide the direct evidence for the crucial role of trimethylamine N-oxide(TMAO)in vascular permeability and endothelial cell dysfunction under diabetic condition.METHODS:The role of TMAO on the in vitro biological effect of human retinal microvascular endothelial cells(HRMEC)under high glucose conditions was tested by a cell counting kit,wound healing,a transwell and a tube formation assay.The inflammation-related gene expression affected by TMAO was tested by real-time polymerase chain reaction(RT-PCR).The expression of the cell junction was measured by Western blotting(WB)and immunofluorescence staining.In addition,two groups of rat models,diabetic and non-diabetic,were fed with normal or 0.1%TMAO for 16wk,and their plasma levels of TMAO,vascular endothelial growth factor(VEGF),interleukin(IL)-6 and tumor necrosis factor(TNF)-αwere tested.The vascular permeability of rat retinas was measured using FITC-Dextran,and the expression of zonula occludens(ZO)-1 and claudin-5 in rat retinas was detected by WB or immunofluorescence staining.RESULTS:TMAO administration significantly increased the cell proliferation,migration,and tube formation of primary HRMEC either in normal or high-glucose conditions.RT-PCR showed elevated inflammation-related gene expression of HRMEC under TMAO stimulation,while WB or immunofluorescence staining indicated decreased cell junction ZO-1 and occludin expression after high-glucose and TMAO treatment.Diabetic rats showed higher plasma levels of TMAO as well as retinal vascular leakage,which were even higher in TMAO-feeding diabetic rats.Furthermore,TMAO administration increased the rat plasma levels of VEGF,IL-6 and TNF-αwhile decreasing the retinal expression levels of ZO-1 and claudin-5.CONCLUSION:TMAO enhances the proliferation,migration,and tube formation of HRMEC,as well as destroys their vascular integrity and tight connection.It also regulates the expression of VEGF,IL-6,and TNF-α.

Endoplasmic Reticulum Stress-induced Endothelial Dysfunction Promotes Neointima Formation after Arteriovenous Grafts in Mice on High-fat Diet

Objective Endothelial dysfunction is one candidate for triggering neointima formation after arteriovenous grafts(AVGs),but the factors mediating this process are unclear.The purpose of this study was to investigate the role of endoplasmic reticulum stress(ERS)-induced endothelial dysfunction in neointima formation following AVGs in high-fat diet(HFD)mice.Methods CCAAT-enhancer-binding protein-homologous protein(CHOP)knockout(KO)mice were created.Mice were fed with HFD to produce HFD model.AVGs model were applied in the groups of WT ND,WT HFD,and CHOP KO HFD.Human umbilical vein endothelial cells(HUVECs)were cultured with oxidized low density lipoprotein(ox-LDL)(40 mg/L)for the indicated time lengths(0,6,12,24 h).ERS inhibitor tauroursodeoxycholic acid(TUDCA)was used to block ERS.Immunohistochemical staining was used to observe the changes of ICAM1.Changes of ERS were detected by real-time RT-PCR.Protein expression levels and ERS activation were detected by Western blotting.Endothellial cell function was determined by endothelial permeability assay and transendothelial migration assay.Results HFD increased neointima formation in AVGs associated with endothelial dysfunction.At the same time,ERS was increased in endothelial cells(ECs)after AVGs in mice consuming the HFD.In vitro,ox-LDL was found to stimulate ERS,increase the permeability of the EC monolayer,and cause endothelial dysfunction.Blocking ERS with TUDCA or CHOP siRNA reversed the EC dysfunction caused by ox-LDL.In vivo,knockout of CHOP(CHOP KO)protected the function of ECs and decreased neointima formation after AVGs in HFD mice.Conclusion Inhibiting ERS in ECs could improve the function of AVGs.

The emerging role of nitric oxide in the synaptic dysfunction of vascular dementia

With an increase in global aging,the number of people affected by cerebrovascular diseases is also increasing,and the incidence of vascular dementia-closely related to cerebrovascular risk-is increasing at an epidemic rate.However,few therapeutic options exist that can markedly improve the cognitive impairment and prognosis of vascular dementia patients.Similarly in Alzheimer’s disease and other neurological disorders,synaptic dysfunction is recognized as the main reason for cognitive decline.Nitric oxide is one of the ubiquitous gaseous cellular messengers involved in multiple physiological and pathological processes of the central nervous system.Recently,nitric oxide has been implicated in regulating synaptic plasticity and plays an important role in the pathogenesis of vascular dementia.This review introduces in detail the emerging role of nitric oxide in physiological and pathological states of vascular dementia and summarizes the diverse effects of nitric oxide on different aspects of synaptic dysfunction,neuroinflammation,oxidative stress,and blood-brain barrier dysfunction that underlie the progress of vascular dementia.Additionally,we propose that targeting the nitric oxide-sGC-cGMP pathway using certain specific approaches may provide a novel therapeutic strategy for vascular dementia.

Vascular endothelial dysfunction and pharmacological treatment

The endothelium exerts multiple actions involving regulation of vascular permeability and tone, coagulation and fibrinolysis, inflammatory and immunological reactions and cell growth. Alterations of one or more such actions may cause vascular endothelial dysfunction. Different risk factors such as hypercholesterolemia, homocystinemia, hyperglycemia, hypertension, smo-king, inflammation, and aging contribute to the development of endothelial dysfunction. Mechanisms underlying endothelial dysfunction are multiple, including impaired endothelium-derived vasodilators, enhanced endothelium-derived vasoconstrictors, over production of reactive oxygen species and reactive nitrogen species, activation of inflammatory and immune reactions, and imbalance of coagulation and fibrinolysis. Endothelial dysfunction occurs in many cardiovascular diseases, which involves different mechanisms, depending on specific risk factors affecting the disease. Among these mechanisms, a reduction in nitric oxide(NO) bioavailability plays a central role in the development of endothelial dysfunction because NO exerts diverse physiological actions, including vasodilation, anti-inflammation, antiplatelet, antiproliferation and antimigration. Experimental and clinical studies have demonstrated that a variety of currently used or investigational drugs, such as angiotensin-converting enzyme inhibitors, angiotensin AT1 receptors blockers, angiotensin-(1-7), antioxidants, beta-blockers, calcium channel blockers, endothelial NO synthase enhancers, phosphodiesterase 5 inhibitors, sphingosine-1-phosphate and statins, exert endothelial protective effects. Due to the difference in mechanisms of action, these drugs need to be used according to specific mechanisms underlying endothelial dysfunction of the disease.

Vascular dysfunction in diabetes: The endothelial progenitor cells as new therapeutic strategy

The vascular endothelium is a critical determinant of dia- betes-associated vascular complications, and improving endothelial function is an important target for therapy. Diabetes mellitus contributes to endothelial cell injury and dysfunction. Endothelial progenitor cells (EPCs) play a critical role in maintaining endothelial function and might affect the progression of vascular disease. EPCs are essential to blood vessel formation, can differentiate into mature endothelial cells, and promote the repair of damaged endothelium. In diabetes, the circulating EPC count is low and their functionality is impaired. The me- chanisms that underlie this reduced count and impaired functionality are poorly understood. Knowledge of the status of EPCs is critical for assessing the health of the vascular system, and interventions that increase the number of EPCs and restore their angiogenic activity in diabetes may prove to be particularly beneficial. The pre-sent review outlines current thinking on EPCs' therapeutic potential in endothelial dysfunction in diabetes, as well as evidence-based perspectives regarding their use for vascular regenerative medicine.

Relationship of Inflammation and Endothelial Dysfunction with Risks to Cardiovascular Disease among People in Inner Mongolia of China

Objective To explore the relationship of inflammation and endothelial dysfunction with risks to cardiovascular disease （CVD）. Methods Blood pressure, body weight, body height, waist circumference and lifestyle risk factors were measured and studied among 2589 participants in Inner Mongolia of China, and biomarkers of inflammation and endothelial dysfunction including high-sensitivity C-reactive protein （hsCRP）, soluble inter-cellular adhesion molecule-1 （slCAM-1）, soluble E-selectin （sE-selectin）, and angiotensin II were investigated. Results Subjects with metabolic risk factors for CVD had higher levels of hsCRP, sE-selectin and slCAM-1 than those without such risk factors （all P〈O.05）. Levels of all biomarkers positively and significantly increased with aggregation of the metabolic risk factors among the subjects （all P for trend 〈0.001）. Data from the multivariate analysis showed that participants with high levels of hsCRP [odds ratio （OR}： 1.96, 95% confidence interval （CI）： 1.52-2.53], sE-selectin （OR： 1.35, 95% Cl： 1.05-1.72）, and angiotensin II （OR： 1.81, 95% CI＂ 1.40-2.33） were more likely to develop hypertension; participants with high levels of hsCRP （OR： 2.33, 95% CI： 1.85-2.94）, sE-selectin （OR： 1.24, 95% CI： 1.00-1.54）, and slCAM-1 （OR： 1.70, 95% CI： 1.30-2.22） were more likely to develop dyslipidemia, and those with high levels of hsCRP （OR： 2.95, 95% CI： 2.27-3.83） and slCAM-I（OR： 2.80, 95% CI： 2.06-3.80） were more likely to develop hyperglycemia. Conclusion Biomarkers of inflammation and endothelial dysfunction were separately associated with relevant metabolic risk factors for CVD. And appropriate measures should be taken to control inflammation and improve endothelial function among individuals with different metabolic risk factors for CVD.

Endothelial dysfunction as a predictor of cardiovascular disease in type 1 diabetes

Macro and microvascular disease are the main cause of morbi-mortality in type 1 diabetes(T1DM).Although there is a clear association between endothelial dysfunction and atherosclerosis in type 2 diabetes,a cause-effect relationship is less clear in T1 DM.Although endothelial dysfunction(ED) precedes atherosclerosis,it is not clear weather,in recent onset T1 DM,it may progress to clinical macrovascular disease.Moreover,endothelial dysfunction may either be reversed spontaneously or in response to intensive glycemic control,long-term exercise training and use of statins.Acute,long-term and post-prandial hyperglycemia as well as duration of diabetes and microalbuminuria are all conditions associated with ED in T1 DM.The pathogenesis of endothelial dysfunction is closely related to oxidative-stress.NAD(P)H oxidase over activity induces excessive superoxide production inside the mitochondrial oxidative chain of endothelial cells,thus reducing nitric oxide bioavailability and resulting in peroxynitrite formation,a potent oxidant agent.Moreover,oxidative stress also uncouples endothelial nitric oxide synthase,which becomes dysfunctional,inducing formation of superoxide.Other important mechanisms are the activation of both the polyol and protein kinase C pathways as well as the presence of advanced glycation end-products.Future studies are needed to evaluate the potential clinical applicability of endothelial dysfunction as a marker for early vascular complications in T1 DM.

Mobilisation of endothelial progenitor cells： one of the possible mechanisms involved in the chronic administration of melatonin preventing erectile dysfunction in diabetic rats

Diabetes-induced oxidative stress plays a critical role in the mobilisation of endothelial progenitor cells （EPCs） from the bone marrow to the circulation. This study was designed to explore the effects of chronic melatonin administration on the promotion of the mobilisation of EPCs and on the preservation of erectile function in type I diabetic rats. Melatonin was administered to streptozotocin-induced type I diabetic rats. EPCs levels were determined using flow cytometry. Oxidative stress in the bone marrow was indicated by the levels of superoxide dismutase and malondialdehyde. Erectile function was evaluated by measuring the intracavernous pressure during an electrostimulation of the cavernous nerve. The density of the endothelium and the proportions of smooth muscle and collagen in the corpus cavernosum were determined by immunohistochemistry. The administration of melatonin increased the superoxide dismutase level and decreased the malondialdehyde level in the bone marrow. This effect was accompanied by an increased level of circulating EPCs in the diabetic rats. The intracavernous pressure to mean arterial pressure ratio of the rats in the treatment group was significantly greater, compared with diabetic control rats. The histological analysis demonstrated an increase in the endothelial density of the corpus cavernosum after the administration of melatonin. However, melatonin treatment did not change the proportions of smooth muscle and collagen in the corpus cavernosum of diabetic rats. Chronic administration of melatonin has a beneficial effect on preventing erectile dysfunction （ED） in type I diabetic rats. Promoting the mobilisation of EPCs is one of the possible mechanisms involved in the improvement of ED.

Role of microparticles in endothelial dysfunction and arterial hypertension

Microparticles are small cell vesicles that can be released by almost all eukaryotic cells during cellular stress and cell activation. Within the last 1-2 decades it has been shown that microparticles are useful blood surrogate markers for different pathological conditions, such as vascular inflammation, coagulation and tumour diseases. Several studies have investigated the abundance of microparticles of different cellular origins in multiple cardiovascular diseases. It thereby has been shown that microparticles released by platelets, leukocytes and endothelial cells can be found in conditions of endothelial dysfunction, acute and chronic vascular inflammation and hypercoagulation. In addition to their function as surrogate markers, several studies indicate that circulating microparticles can fuse with distinct target cells, such as endothelial cells or leukocyte, and thereby deliver cellular components of their parental cells to the target cells. Hence, microparticles are a novel entity of circulating, paracrine, biological vectors which can influence the phenotype, the function and presumably even the transcriptome of their target cells.This review article aims to give a brief overview about the microparticle biology with a focus on endothelial activation and arterial hypertension. More detailed information about the role of microparticles in pathophysiology and disease can be found in already published work.

Non-coding RNAs and other determinants of neuroinflammation and endothelial dysfunction:regulation of gene expression in the acute phase of ischemic stroke and possible therapeutic applications

Ischemic stroke occurs under a variety of clinical conditions and has different pathogeneses,resulting in necrosis of brain parenchyma.Stroke pathogenesis is characterized by neuroinflammation and endothelial dysfunction.Some of the main processes triggered in the early stages of ischemic damage are the rapid activation of resident inflammatory cells(microglia,astrocytes and endothelial cells),inflammatory cytokines,and translocation of intercellular nuclear factors.Inflammation in stroke includes all the processes mentioned above,and it consists of either protective or detrimental effects concerning the“polarization”of these processes.This polarization comes out from the interaction of all the molecular pathways that regulate genome expression:the epigenetic factors.In recent years,new regulation mechanisms have been cleared,and these include non-coding RNAs,adenosine receptors,and the activity of mesenchymal stem/stromal cells and microglia.We reviewed how long non-coding RNA and microRNA have emerged as an essential mediator of some neurological diseases.We also clarified that their roles in cerebral ischemic injury may provide novel targets for the treatment of ischemic stroke.To date,we do not have adequate tools to control pathophysiological processes associated with stroke.Our goal is to review the role of non-coding RNAs and innate immune cells(such as microglia and mesenchymal stem/stromal cells)and the possible therapeutic effects of their modulation in patients with acute ischemic stroke.A better understanding of the mechanisms that influence the“polarization”of the inflammatory response after the acute event seems to be the way to change the natural history of the disease.

Role of ferroptosis in the process of diabetes-induced endothelial dysfunction

BACKGROUND Endothelial dysfunction,a hallmark of diabetes,is a critical and initiating contributor to the pathogenesis of diabetic cardiovascular complications.However,the underlying mechanisms are still not fully understood.Ferroptosis is a newly defined regulated cell death driven by cellular metabolism and irondependent lipid peroxidation.Although the involvement of ferroptosis in disease pathogenesis has been shown in cancers and degenerative diseases,the participation of ferroptosis in the pathogenesis of diabetic endothelial dysfunction remains unclear.AIM To examine the role of ferroptosis in diabetes-induced endothelial dysfunction and the underlying mechanisms.METHODS Human umbilical vein endothelial cells(HUVECs)were treated with high glucose(HG),interleukin-1β(IL-1β),and ferroptosis inhibitor,and then the cell viability,reactive oxygen species(ROS),and ferroptosis-related marker protein were tested.To further determine whether the p53-xCT(the substrate-specific subunit of system Xc-)-glutathione(GSH)axis is involved in HG and IL-1βinduced ferroptosis,HUVECs were transiently transfected with p53 small interfering ribonucleic acid or NC small interfering ribonucleic acid and then treated with HG and IL-1β.Cell viability,ROS,and ferroptosis-related marker protein were then assessed.In addition,we detected the xCT and p53 expression in the aorta of db/db mice.RESULTS It was found that HG and IL-1βinduced ferroptosis in HUVECs,as evidenced by the protective effect of the ferroptosis inhibitors,Deferoxamine and ferrostatin-1,resulting in increased lipid ROS and decreased cell viability.Mechanistically,activation of the p53-xCT-GSH axis induced by HG and IL-1βenhanced ferroptosis in HUVECs.In addition,a decrease in xCT and the presence of deendothelialized areas were observed in the aortic endothelium of db/db mice.CONCLUSION Ferroptosis is involved in endothelial dysfunction and p53-xCT-GSH axis activation plays a crucial role in endothelial cell ferroptosis and endothelial dysfunction.

Intrahepatic vascular changes in non-alcoholic fatty liver disease: potential role of insulin-resistance and endothelial dysfunction

Metabolic syndrome is a cluster of several clinical conditions characterized by insulin-resistance and high cardiovascular risk. Non-alcoholic fatty liver disease is the liver expression of the metabolic syndrome, and insulin resistance can be a frequent comorbidity in several chronic liver diseases, in particular hepatitis C virus infection and/or cirrhosis. Several studies have demonstrated that insulin action is not only relevant for glucose control, but also for vascular homeostasis. Insulin regulates nitric oxide production, which mediates to a large degree the vasodilating, antiinflammatory and antithrombotic properties of a healthy endothelium, guaranteeing organ perfusion. The effects of insulin on the liver microvasculature and the effects of IR on sinusoidal endothelial cells have been studied in animal models of non-alcoholic fatty liver disease. The hypotheses derived from these studies and the potential translation of these results into humans are critically discussed in this review.

Prognostic value of endothelial dysfunction in type 1 diabetes mellitus

Patients with diabetes mellitus are at high risk of developing atherosclerosis, associated with higher rates of micro and macro vascular involvement such as coronary artery disease and renal disease. The role of hyperglycemia to induce synthesis of reactive oxygen species by the oxidation of glucose, leading to an increased production of advanced glycosylation end products, as well as inflammation and oxidative stress has been proposed as a possible mechanism in the pathogenesis of endothelial dysfunction(ED). The interaction between C-peptide- the connecting segment of pro-insulin-and nitric oxide in vasodilation is also discussed. Therefore, endothelial dysfunction has been identified as an early marker of vascular disorder in type 1 and type 2 diabetes mellitus. In some other diseases, ED has been considered an independent predictor of vascular disease, regardless of the method used. Studies have demonstrated the importance of endothelial dysfunction as an useful tool for identifying the risk of vascular complications in patients with type 1 diabetes mellitus, particularly as regards to renal impairment. The aim of this review is to clarify the prognostic value of endothelial dysfunction as a marker of vascular disease in these subjects.

Effects of Fuscoporia obliqua on Postprandial Glucose Excursion and Endothelial Dysfunction in Type 2 Diabetic Patients

Postprandial hyperglycemia has been reported to elicit endothelial dysfunction and provoke future cardiovascular complications. A reduction of postprandial blood glucose levels by the glucosidase inhibitor Fuscoporia obliqua was associated with a risk reduction of cardiovascular complications, but the effects of Fuscoporia obliqua on endothelial function have never been elucidated. This study is aimed to assess the efficacy of Fuscoporia obliqua on postprandial metabolic parameters and endothelial function in type 2 diabetic patients. Postprandial peak glucose (14.47±1.27 vs. 8.50±0.53 mmol/liter), plasma glucose excursion (PPGE), and change in the area under the curve (AUC) glucose after a single loading of test meal (total 450 kcal; protein 15.3%; fat 32.3%; carbohydrate 51.4%) were significantly higher in the diet-treated type 2 diabetic patients (n=14) than the age-and sex-matched controls (n=12). The peak forearm blood flow response and total reactive hyperemic flow (flow debt repayment) during reactive hyperemia, indices of resistance artery endothelial function on strain-gauge plethysmography, were unchanged before and after meal loading in the controls. But those of the diabetics were significantly decreased 120 and 240 min after the test meal. A prior administration of Fuscoporia obliqua decreased postprandial peak glucose, PPGE, and AUC glucose. The peak forearm blood flow and flow debt repayment were inversely well correlated with peak glucose, PPGE, and AUC glucose, but not with AUC insulin or the other lipid parameters. Even a single loading of the test meal was shown to impair the endothelial function in type 2 diabetic patients, and the postprandial endothelial dysfunction was improved by a prior use of Fuscoporia obliqua. Fuscoporia obliqua might reduce macrovascular complication by avoiding endothelial injury in postprandial hyperglycemic status.

Three-dimensional-arterial spin labeling perfusion correlation with diabetes-associated cognitive dysfunction and vascular endothelial growth factor in type 2 diabetes mellitus rat

BACKGROUND Type 2 diabetes mellitus(T2DM) has been strongly associated with an increased risk of developing cognitive dysfunction and dementia.The mechanisms of diabetes-associated cognitive dysfunction(DACD) have not been fully elucidated to date.Some studies proved lower cerebral blood flow(CBF) in the hippocampus was associated with poor executive function and memory in T2DM.Increasing evidence showed that diabetes leads to abnormal vascular endothelial growth factor(VEGF) expression and CBF changes in humans and animal models.In this study,we hypothesized that DACD was correlated with CBF alteration as measured by three-dimensional(3D) arterial spin labeling(3D-ASL) and VEGF expression in the hippocampus.AIM To assess the correlation between CBF(measured by 3D-ASL and VEGF expression) and DACD in a rat model of T2DM.METHODS Forty Sprague-Dawley male rats were divided into control and T2DM groups.The T2DM group was established by feeding rats a high-fat diet and glucose to induce impaired glucose tolerance and then injecting them with streptozotocin to induce T2DM.Cognitive function was assessed using the Morris water maze experiment.The CBF changes were measured by 3D-ASL magnetic resonance imaging.VEGF expression was determined using immunofluorescence.RESULTS The escape latency time significantly reduced 15 wk after streptozotocin injection in the T2DM group.The total distance traveled was longer in the T2DM group;also,the platform was crossed fewer times.The percentage of distance in the target zone significantly decreased.CBF decreased in the bilateral hippocampus in the T2DM group.No difference was found between the right CBF value and the left CBF value in the T2DM group.The VEGF expression level in the hippocampus was lower in the T2DM group and correlated with the CBF value.The escape latency negatively correlated with the CBF value.The number of rats crossing the platform positively correlated with the CBF value.CONCLUSION Low CBF in the hippocampus and decreased VEGF expression might be crucial in DACD.CBF measured by 3D-ASL might serve as a noninvasive imaging biomarker for cognitive impairment associated with T2DM.

Sang-Yod rice bran hydrolysates alleviate hypertension, endothelial dysfunction, vascular remodeling, and oxidative stress in nitric oxide deficient hypertensive rats

Objective:To evaluate the potential therapeutic effect of Sang-Yod rice bran hydrolysates(SRH)and in combination with lisinopril against hypertension,endothelial dysfunction,vascular remodeling,and oxidative stress in rats with nitric oxide deficiency-induced hypertension.Methods:Hypertension was induced in male Sprague-Dawley rats by administration of a nitric oxide synthase inhibitor,Nω-nitro-L-arginine methyl ester(L-NAME)in drinking water for 6 weeks.Hypertensive rats were administered daily with SRH(500 mg/kg/day),lisinopril(1 mg/kg/day),or the combination of SRH and lisinopril by gastric lavage for the last 3 weeks of L-NAME treatment.Hemodynamic status,vascular reactivity to vasoactive agents,and vascular remodeling were assessed.Blood and aortic tissues were collected for measurements of oxidative stress markers,plasma angiotensin-converting enzyme(ACE)activity,plasma angiotensinⅡ,and protein expression.Results:L-NAME induced remarkable hypertension and severe oxidative stress,and altered contents of smooth muscle cells,elastin,and collagen of the aortic wall.SRH or lisinopril alone reduced blood pressure,restored endothelial function,decreased plasma ACEs and angiotensinⅡlevels,alleviated oxidant markers and glutathione redox status,and restored the vascular structure.The effects were associated with increased expression of endothelial nitric oxide synthase and decreased expression of gp91phox and AT1R expression.The combination of SRH and lisinopril was more effective than monotherapy.Conclusions:SRH alone or in combination with lisinopril exert an antihypertensive effect and improve endothelial function and vascular remodeling through reducing oxidative stress and suppressing elevated renin-angiotensin system.

Association between body-constitution type and vascular endothelial dysfunction: A cross-sectional study in an adult obese/ overweight population

Objective:To measure vascular endothelial function (VED) in obese/overweight people grouped according to the constitutional theory of traditional Chinese medicine (TCM).We wished to predict the risk of VED and cardiovascular diseases in obese/overweight populations.Methods:This was a cross-sectional study.Eighty-six obese/overweight volunteers from Beijing Chao-Yang Hospital were enrolled and divided into four groups based on body-constitution type:phlegm dampness (PD);phlegm dampness with blood stasis (PDBS);qi-deficiency (QD);balance (BA).Height,weight,waist circumference and hip circumference were measured,and percent body fat and reactive hyperemia index (RHI) calculated.Levels of vascular endothelial growth factor (VEGF),von Willebrand factor (vWF) and plasma endothelial-1 (ET-1) were detected by immunohistochemistry.Results:The RHI and vWF levels in the PDBS group were significantly lower than those in the BA group and QD group (P <.05),but there was no significant difference compared with the PD group (P >.05).These two indicators displayed no significant differences among BA,QD,and PD groups (P >.05).There was no significant difference among the four groups in level of ET-1 or VEGF (P >.05).Conclusion:Of the four indicators selected,the RHI and vWF displayed significant differences between the PDBS group and BA group,and between the PDBS group and QD group.Hence,in an obese/overweight population with different constitutional types,compared with BA and QD groups,a relatively higher risk of suffering from VED was detected in the PDBS group.Meanwhile,this study provides the experimental basis for confirming the feasibility of constitutional classification in obese/overweight population.

Tadalafil treatment had a modest effect on endothelial cell damage and repair ability markers in men with erectile dysfunction and vascular risk

The number of the circulating angiogenic cells （CACs） and colony forming units （CFUs） derived from cultured circulating mononuclear cells （MNCs） represents a laboratory surrogate for endothelial cell repair ability. The serum of men with erectile dysfunction （ED） and vascular risk factors （VRFs） showed an increased level of endothelial cell damage/dysfunction markers and reduced the numbers of CACs and CFUs derived from the cells of healthy men. We analyzed whether treating men with ED and VRFs with the selective phosphodiesterase type 5 inhibitor tadalafil improved the endothelial cell repair ability and reduced the levels of the serum markers of endothelial cell damage/dysfunction. MNCs from healthy men were cultured with 20% serum from 36 ED patients to obtain CACs and CFUs. The ED patients were evaluated before and after 4weeks of treatment with tadalafil （20 mg every other day） or with a placebo. The tadalafil treatment improved erectile function （P = 0.0028）, but had no effect on the inhibitory effects of serum from ED patients on the CACs and CFUs derived from healthy men. The levels of endothelin-1 （P = 0.011） and tissue type plasminogen activator （P = 0.005） were reduced after treatment compared to baseline and those of the placebo group, whereas no changes were observed in the E-selectin levels. The tadalafil treatment in the ED patients with VRFs resulted in only a modest effect on the laboratory measures of the endothelial cell damage/dysfunction and repair ability. The proposed beneficial effect of phosphodiesterase type 5 inhibition on vascular homeostasis requires further analysis.

TMEM16A contributes to endothelial dysfunction through accelerating Nox2 NADPH oxidase-derived ROS generation in hypertension

OBJECTIVE The Ca2+-activated Cl-channel(Ca CC)plays a crucial role in various physiological functions.Recent evidences suggest TMEM16A encodes CaC C in various cells,including endothelial cells.However,the role of TMEM16A in the vascular endothelial dysfunction in hypertension is unclear.METHODS In the study,RT-PCR,Western blotting,co-immunopricipitation,confocal imaging,patch-clamp,and endothelial-specific TMEM16A transgenic and knockout mice were employed.RESULTS We found that TMEM16A was expressed abundantly and functioned as Ca CC in endothelial cells.AngiotensinⅡ(AngⅡ)induced endothelial dysfunction with an increase in TMEM16A expression,which was alleviated by TMEM16A inhibitor.Further studies revealed that TMEM16A endothelial-specific knockout significantly lowered the blood pressure and ameliorated endothelial dysfunction in AngⅡ-induced hypertension,whereas,TMEM16A endothelial-specific overexpression showed the opposite effects.These results were related to the increased reactive oxygen species(ROS)generation,NADPH oxidase activation,and Nox2,p22phox expression facilitated by TMEM16A upon AngⅡ-induced hypertensive challenges.Moreover,TMEM16A directly interacted with Nox2 monomer and reduced the degradation of Nox2 through the proteasome-dependent endoplasmic recticulum-associated degradation pathway.TMEM16A also potentiated the translocation of p47phox and p67phox from cytosol to cell membrane and the subsequent interaction with Nox2.CONCLUSION Our results demonstrated that TMEM16A,as Ca CC,is a positive regulator of ROS generation via upregulating the activation of Nox2 NADPH oxidase in the vascular endothelium,and therefore facilitates endothelial dysfunction and hypertension.Modification of TMEM16A may be a novel therapeutic strategy for endothelial dysfunction-associated cardiovascular diseases.

TNF-α Induces Endothelial Dysfunction via PKC-ζ-dependent NADPH Oxidase Activation

Endothelial dysfunction is implicated in a variety of cardiovascular diseases although the detailed mechanisms are not yet completely understood. A relationship has been suggested to exist between inflammation and endothelial dysfunction. TNF-α serves as one of the most important pro-inflammatory cytokines. The main objectives of the present study were to explore the effect of PKC-ζ on TNF-α-impaired endothelial function as well as the underlying mechanisms. Acetylcho-line-induced endothelium-dependent vasodilation of mouse thoracic aorta stimulated by TNF-α was initially determined. PKC-ζ deficient mice and the specific inhibitor of NADPH oxidase were respectively applied to elucidate their roles in TNF-α-induced endothelial dysfunction. In vitro superoxide generation in HAECs was detected by DHE staining after administration of TNF-α. Meanwhile, the regulatory p47phox subunit of NADPH oxidase was evaluated by Western blotting and RT-PCR. The results showed that TNF-α conspicuously impaired endothelium-dependent vasodilation and the impairment was attenuated by either depleting PKC-ζ or inhibiting NADPH oxidase. In vitro TNF-α increased superoxide production and p47phox expression in HAECs, and such increases could be ameliorated by the specific PKC-ζ inhibitor. Our findings suggest that superoxide over-production triggered by PKC-ζ-dependent NADPH oxidase activation contributes to TNF-α-induced endothelial dysfunction.