Endothelial progenitor cells, endothelial dysfunction, inflammation, and oxidative stress in hypertension

Therapeutic potential of natural flavonoids in pulmonary arterial hypertension: A review

BACKGROUND

Pulmonary arterial hypertension (PAH) is a fatal disease caused by pulmonary vascular remodeling, with a high incidence and mortality. At present, many clinical drugs for treating PAH mainly exert effects by relaxing the pulmonary artery, with limited therapeutic effects, so the search for viable therapeutic agents continues uninterrupted. In recent years, natural flavonoids have shown promising potential in the treatment of cardiovascular diseases. It is necessary to comprehensively elucidate the potential of natural flavonoids to combat PAH.

PURPOSE

To evaluate the potential of natural flavonoids to hinder or slow down the occurrence and development of PAH, and to identify promising drug discovery candidates.

METHODS

Literature was collected from PubMed, Science Direct, Web of science, CNKI databases and Google scholar. The search terms used included "pulmonary arterial hypertension", "pulmonary hypertension", "natural products", "natural flavonoids", "traditional chinese medicine", etc., and several combinations of these keywords.

RESULTS

The resources, structural characteristics, mechanisms, potential and prospect strategies of natural flavonoids for treating PAH were summarized. Natural flavonoids offer different solutions as possible treatments for PAH. These mechanisms may involve various pathways and molecular targets related to the pathogenesis of PAH, such as inflammation, oxidative stress, vascular remodeling, genetic, ion channels, cell proliferation and autophagy. In addition, prospect strategies of natural flavonoids for anti-PAH including structural modification and nanomaterial delivery systems have been explored. This review suggests that the potential of natural flavonoids as alternative therapeutic agents in the prevention and treatment of PAH holds promise for future research and clinical applications.

CONCLUSION

Despite displaying the enormous potential of flavonoids in PAH, some limitations need to be further explored. Firstly, using advanced drug discovery tools, including computer-aided design and high-throughput screening, to further investigate the safety, biological activity, and precise mechanism of action of flavonoids. Secondly, exploring the structural modifications of these compounds is expected to optimize their efficacy. Lastly, it is necessary to conduct well controlled clinical trials and a comprehensive evaluation of potential side effects to determine their effectiveness and safety.

Interacting and joint effects of triglyceride-glucose index and hypertension on stroke risk in middle-aged and older Chinese adults: a population-based prospective cohort study

Background

Triglyceride-glucose (TyG) index and hypertension were well-established risk factors for stroke. And TyG index was associated with hypertension. However, no prior study has investigated the interactive effects of the TyG index and hypertension on stroke. This study examined whether hypertension mediates associations of TyG index with incident stroke and the extent of interaction or joint relations of TyG index and hypertension with stroke in middle-aged and older Chinese adults.

Methods

The China Health and Retirement Longitudinal Study (CHARLS) is an ongoing nationally representative prospective cohort study initiated in 2011. This cohort study included 9,145 middle-aged and older Chinese adults without stroke at baseline. The eposures were TyG index and the logarithmized product of hypertension, as determined during the baseline health examination. The main outcome was self-reported physician-diagnosed stroke which followed up from June 1, 2011, to June 30, 2018.

Results

Of the 9,145 participants, 4,251 were men (46.5%); the mean (SD) age was 59.20 (9.33) years. During a median follow-up of 7.1 years, 637 (7.0%) participants developed stroke. In multivariable-adjusted models, the TyG index was significantly associated with the risk of hypertension [odds ratio (OR) per 1-SD increase, 1.29; 95% CI, 1.19-1.41] and stroke [hazard ratio (HR) per 1-SD increase, 1.16; 95% CI, 1.02-1.33]. Both multiplicative and additive interactions were observed between TyG index and hypertension on stroke (HR for multiplicative: 2.34, 95% CI, 1.57-3.48; Synergy index: 4.13, 95% CI, 2.73-6.25). Mediation analysis showed that 20.0% of the association between TyG index and stroke was mediated through hypertension.

Conclusions

This study suggests a synergistic effect of TyG index and hypertension on stroke, and a small proportion of the association between TyG index and stroke was mediated by hypertension, indicating the benefit of coordinated control strategies for both exposures.

Geographic disparities of dietary inflammatory index and its association with hypertension in middle-aged and elders in China: results from a nationwide cross-sectional study

Background

Geographic distribution of dietary inflammatory index (DII) in China has not been thoroughly evaluated and evidence on the association between DII and hypertension among Chinese middle-aged and older population was inadequate.

Objective

To investigate the geographic disparities of DII and its association with hypertension among Chinese middle-aged and elders.

Methods

Data was from the China Adults Chronic Diseases and Nutrition Surveillance (CACDNS 2015) for middle-aged and older participants. The DII for each participant was determined through a combination of 3 days 24 h dietary recall interviews and a food frequency questionnaire. Spatial analysis was employed to investigate the geographic distribution of DII in China. Restricted cubic spline models and binary logistic regression analysis were used to assess the relationship between DII and hypertension. The least absolute shrinkage and selection operator (LASSO) regression was applied for identifying key hypertension-related factors, which was then included in the establishment of a risk prediction nomogram model, with the receiver operating characteristic (ROC) curve and decision curve analysis (DCA) being built to evaluate its discriminatory power for hypertension.

Results

A total of 52,087 middle-aged and older participants were included in the study, among whom 36.6% had hypertension. it revealed that a clear spatial correlation in the national distribution of DII scores (Moran I: 0.252, p = 0.001), with higher DII scores concentrated in the northwest region and lower DII scores concentrated in the southeast region. Hypertensive participants had higher DII scores compared to those without hypertension (OR: 1.507 vs. 1.447, p = 0.003). Restricted cubic spline models and binary logistic regression analysis demonstrated a positive association between DII and hypertension after adjusting for potential confounding factors. There was a significant increasing trend in the proportion of hypertensive individuals as DII scores increase (p for trend = 0.004). The nomogram model, constructed using key factors identified through LASSO regression, demonstrated a robust discriminative capacity, with an area under the curve (AUC) of 73.2% (95% CI, 72.4-74.0%). Decision curve analysis confirmed the reliability and effectiveness of the nomogram model. Sensitivity analysis conducted within the subpopulation aged under 45 years yielded results consistent with the primary analysis.

Conclusion

In Chinese adults middle-aged and older, geographic disparities in dietary inflammatory potential are notable, with lower levels observed in the southeastern coastal regions of China and higher levels in the northwestern regions. Meanwhile, there is a positive association between the inflammatory potential of the diet and hypertension. Additional research is needed to investigate regional disparities in dietary inflammatory potential and pinpoint specific dietary patterns associated with lower inflammation.

Roles of Protein S-Nitrosylation in Endothelial Homeostasis and Dysfunction

Significance: Nitric oxide (NO) plays several distinct roles in endothelial homeostasis. Except for activating the guanylyl cyclase enzyme-dependent cyclic guanosine monophosphate signaling pathway, NO can bind reactive cysteine residues in target proteins, a process known as S-nitrosylation (SNO). SNO is proposed to explain the multiple biological functions of NO in the endothelium. Investigating the targets and mechanism of protein SNO in endothelial cells (ECs) can provide new strategies for treating endothelial dysfunction-related diseases. Recent Advances: In response to different environments, proteomics has identified multiple SNO targets in ECs. Functional studies confirm that SNO regulates NO bioavailability, inflammation, permeability, oxidative stress, mitochondrial function, and insulin sensitivity in ECs. It also influences EC proliferation, migration, apoptosis, and transdifferentiation. Critical Issues: Single-cell transcriptomic analysis of ECs isolated from different mouse tissues showed heterogeneous gene signatures. However, litter research focuses on the heterogeneous properties of SNO proteins in ECs derived from different tissues. Although metabolism reprogramming plays a vital role in endothelial functions, little is known about how protein SNO regulates metabolism reprogramming in ECs. Future Directions: Precisely deciphering the effects of protein SNO in ECs isolated from different tissues under different conditions is necessary to further characterize the relationship between protein SNO and endothelial dysfunction-related diseases. In addition, identifying SNO targets that can influence endothelial metabolic reprogramming and the underlying mechanism can offer new views on the crosstalk between metabolism and post-translational protein modification. Antioxid. Redox Signal. 40, 186-205.

Endocan as a marker of endothelial dysfunction in hypertension: a systematic review and meta-analysis

Hypertension is one of the foremost risk factors for cardiovascular disease and a significant cause of death worldwide. Importantly, endothelial dysfunction (ED) is one of the primary manifestations that may precede the development of hypertension. Endocan is a novel endothelial dysfunction and inflammation biomarker secreted from endothelial cells. Whether endocan may serve as a biomarker of hypertension is currently debated. This systematic review and meta-analysis aimed at linking endocan to ED in hypertensive patients. International databases, including PubMed, Scopus, Embase, and Web of Science, were systematically searched for studies investigating Endocan serum or plasma levels in hypertensive patients and healthy controls. Random effect meta-analysis was performed to calculate the standardized mean difference (SMD) and 95% confidence interval (CI). A total of 20 studies assessing the association between endocan levels and hypertension were included in which 3130 individuals with a mean age of 50.48 ± 8.45 years were assessed. Hypertensive patients presented with higher circulating endocan levels (SMD 0.91, 95% CI 0.44-1.38, p-value < 0.01) compared with healthy controls. Interestingly, our data demonstrated that removing three studies assessing endocan levels in hypertensive patients with different comorbidities or special populations resulted in the same statistically higher endocan levels (SMD 1.16, 95% CI 0.66-1.65, p-value < 0.01). Overall, this systematic review and meta-analysis indicated that in hypertensive patients circulating endocan levels are significantly elevated. Thus, suggesting endocan as an easy-to-use biomarker to detect ED in hypertension. Despite this, more research is warranted to address this potential ability specifically.

Endothelial dysfunction, platelet hyperactivity, hypertension, and the metabolic syndrome: molecular insights and combating strategies

Metabolic syndrome (MetS) is a multifaceted condition that increases the possibility of developing atherosclerotic cardiovascular disease. MetS includes obesity, hypertension, dyslipidemia, hyperglycemia, endothelial dysfunction, and platelet hyperactivity. There is a concerning rise in the occurrence and frequency of MetS globally. The rising incidence and severity of MetS need a proactive, multipronged strategy for identifying and treating those affected. For many MetS patients, achieving recommended goals for healthy fat intake, blood pressure control, and blood glucose management may require a combination of medicine therapy, lifestyles, nutraceuticals, and others. However, it is essential to note that lifestyle modification should be the first-line therapy for MetS. In addition, MetS requires pharmacological, nutraceutical, or other interventions. This review aimed to bring together the etiology, molecular mechanisms, and dietary strategies to combat hypertension, endothelial dysfunction, and platelet dysfunction in individuals with MetS.

Bifidobacterium longum CCFM752 prevented hypertension and aortic lesion, improved antioxidative ability, and regulated the gut microbiome in spontaneously hypertensive rats

Oxidative stress and gut dysbiosis are important risk factors for hypertension. In this study, the preventive effect of Bifidobacterium longum CCFM752 (CCFM752) on hypertension was evaluated. 5-week-old spontaneously hypertensive rats (SHR) were treated with vehicle or CCFM752 (1.0 × 10⁹ CFU day^-1) for 12 weeks. The increase in systolic blood pressure and diastolic blood pressure was significantly prevented by CCFM752 treatment. Simultaneously, CCFM752 prevented aortic fibrosis and hypertrophy and increased aortic endothelial nitric oxide synthase (eNOS) activity. CCFM752 presented an antioxidative effect by inhibiting aortic NADPH oxidase activation and increasing aortic and serum catalase activity, and reducing aortic reactive oxygen species (ROS). The gut dysbiosis of SHR, including the increased Firmicutes/Bacteroidetes ratio, decreased Actinobacteria as well as reduced α-diversity, were restored by CCFM752. CCFM752 also increased the prevalence of Bifidobacterium and Lactobacillus, while decreasing Turicibacter at the genus level. Furthermore, serum metabolomic analysis revealed that CCFM752 up-regulated serum proline and pyridoxamine 5'-phosphate, both of which were negatively correlated with blood pressure. In conclusion, the positive impact of CCFM752 on the gut microbiota may contribute to the antioxidative effect as well as its preventive effect on hypertension.

Levels of circulating endothelial progenitor cells inversely correlate with manic and positive symptom severity in patients with bipolar disorder

OBJECTIVES

Patients with bipolar disorder (BPD) are at high risk of cardiovascular diseases (CVDs) that are attributed to endothelial dysfunction. Circulating endothelial progenitor cells (cEPCs) are proposed as indicators of endothelial dysfunction. This study examined the relationship of cEPC numbers with BPD diagnosis and its clinical symptoms in patients with BPD.

METHODS

We recruited 48 patients with BPD and 50 healthy controls (HCs). All the patients had scores of <13 on the Young Mania Rating Scale (YMRS). In addition to the YMRS and Clinical Global Impression for BPD (CGI-BP), bipolar patients were assessed using relevant measurements for their depression, anxiety, general psychopathology, cognitive dysfunction and deficit, somatic symptoms, quality of life, and level of disability. cEPC counts were measured using flow cytometry.

RESULTS

The numbers of immature and mature cEPCs in the bipolar patients did not significantly differ from those in the HCs. After correction for multiple comparisons and controlling for body mass index and smokers, the number of immature cEPCs was observed to be inversely correlated with CGI-BP (corrected p [p_corr ] = .00018) and positive scores in the positive and negative syndrome scale (PANSS-P; p_corr  = .0049). The number of mature cEPCs was inversely correlated with YMRS (p_corr  = .014), CGI-BP (p_corr  = .00022), and PANSS-P (p_corr  = .0049) scores. In multivariate stepwise analysis, numbers of both types of cEPCs were associated with CGI-BP.

CONCLUSIONS

cEPC levels, an indicator of endothelial dysfunction and risk of CVDs, may be associated manic and positive symptom severities in patients with BPD.

Circulating MicroRNA-505 May Serve as a Prognostic Biomarker for Hypertension-Associated Endothelial Dysfunction and Inflammation

Our previous study has reported that the plasma microRNA-505 (miR-505) is elevated in hypertensive patients. However, the pathophysiological significance of miR-505 in hypertension remains to be elucidated. Hypertension is not only a vascular disorder, but also an inflammatory condition. The current study therefore aims to further investigate the pathophysiological implications of miR-505 in hypertension-associated vascular and inflammatory changes. In vivo experiments reveal that the plasma level of miR-505 is elevated in spontaneously hypertensive rats and angiotensin II-infused mice. In addition, miR-505 agomir treatment results in elevated blood pressure, endothelial dysfunction, increased vascular expression of inflammatory genes and renal inflammatory injuries as well as pre-activation of PBMCs in mice. In vitro experiments further demonstrate that miR-505 agomir increases the expression of IL1B and TNFA, whereas miR-505 antagomir attenuates TNF-α-induced upregulation of IL1B and TNFA in endothelial cells, HUVECs. In addition, miR-505 modulates the levels of endothelial activation markers VCAM1 and E-selectin in HUVECs as well as the adhesion of THP-1 monocytes to HUVECs. Lastly, the plasma level of miR-505 is positively correlated with systolic blood pressure and the level of C-reactive protein in human subjects. Our work links for the first time miR-505 to endothelial dysfunction and inflammation under hypertensive conditions, supporting the translational value of miR-505 in prognosticating hypertension-associated endothelial impairment and inflammatory injuries in target organs such as the vessels and kidneys.

Specialized Pro-Resolving Lipid Mediators: New Therapeutic Approaches for Vascular Remodeling

Vascular remodeling is a typical feature of vascular diseases, such as atherosclerosis, aneurysms or restenosis. Excessive inflammation is a key mechanism underlying vascular remodeling via the modulation of vascular fibrosis, phenotype and function. Recent evidence suggests that not only augmented inflammation but unresolved inflammation might also contribute to different aspects of vascular diseases. Resolution of inflammation is mediated by a family of specialized pro-resolving mediators (SPMs) that limit immune cell infiltration and initiate tissue repair mechanisms. SPMs (lipoxins, resolvins, protectins, maresins) are generated from essential polyunsaturated fatty acids. Synthases and receptors for SPMs were initially described in immune cells, but they are also present in endothelial cells (ECs) and vascular smooth muscle cells (VSMCs), where they regulate processes important for vascular physiology, such as EC activation and VSMC phenotype. Evidence from genetic models targeting SPM pathways and pharmacological supplementation with SPMs have demonstrated that these mediators may play a protective role against the development of vascular remodeling in atherosclerosis, aneurysms and restenosis. This review focuses on the latest advances in understanding the role of SPMs in vascular cells and their therapeutic effects in the vascular remodeling associated with different cardiovascular diseases.

Could the systemic immune-inflammation index be a predictor to estimate cerebrovascular events in hypertensive patients?

BACKGROUND AND OBJECTIVES

Hypertension is one of the most important risk factors for cardiovascular and cerebrovascular events. Inflammatory processes occupy an important place in the pathogenesis of hypertension. Many studies have studied inflammatory markers responsible for the onset of hypertension and organ damage. In this study, we investigated whether the systemic immune-inflammation index (SII) (platelet × neutrophil/lymphocyte), - one of the new inflammatory markers - can be used to predict cerebrovascular events in hypertensive patients.

METHODS

Ambulatory blood pressure monitoring results between January 2019 and June 2020 of approximately 379 patients followed up with hypertension were retrospectively analyzed. These patients were divided into two groups as with or without a previous cerebrovascular event in the analyzed database. In all patients, complete blood count and biochemistry test results just before the cerebrovascular event were found from the database. SII, atherogenic index, neutrophil-lymphocyte ratio were calculated from the complete blood count. Forty-nine patients with stroke (group 1: 12.9%; mean age: 64.3 ± 14.6) and 330 patients without stroke (group 2: 87.1%; mean age: 50.8 ± 14.4).

RESULTS

Ambulatory blood pressure measurements were lower in group 1. Lipid parameters were also lower in this group. Receiver operating characteristic curve analysis showed that SII had a sensitivity of 85.7% and specificity of 84.8 % for stroke in individuals who participated in the study when the cutoff value of SII was 633.26 × 103 (P = 0.0001) area under curve (95%); 0.898 (0.856-0.941). In multivariate logistic regression analysis, age and SII were significantly associated with a higher risk of stroke. Age, (hazard ratio:1.067; 95% CI, 1.021-1.115), SII (hazard ratio:1.009; 95% CI, 1.000-1.009), respectively.

CONCLUSIONS

In conclusion, SII is a simple, useful new inflammatory parameter for predicting stroke from hypertension. We found that the high SII levels increase the risk of stroke in hypertensive patients.

Endothelial Dysfunction and Endocan Levels in Patients with Gilbert Syndrome and Moderate Hyperbilirubinemia

In this study, we aim to evaluate the presence of endothelial dysfunction in Gilbert syndrome patients with left ventricular mass index (LVMI) and endocan levels. The study included 60 patients who diagnosed with Gilbert syndrome and 60 healthy controls who did not have any known diseases. Human endocan levels were measured using a sandwich ELISA method. The endocan and LVMI levels were lower in the Gilbert syndrome group than in the healthy controls. In the Gilbert syndrome group, total bilirubin level was negatively correlated with LVMI (r = -0246; P = .007) and endocan levels (r = -.270; P = .046). In the Gilbert syndrome group, increasing age (β ± SE = 20.78 ± 7.47; P = .006), was a positive independent predictor of LVMI, and increasing high-density lipoprotein cholesterol (HDL-C) (β ± SE = -.27 ± .09; P = .007), and total bilirubin levels (β ± SE = -6.09 ± 3.02; P = .046) were found to be a negative independent predictor. These results support that endothelial dysfunction is decreased in Gilbert Syndrome patients with mild hyperbilirubinemia compared with the healthy control group.

COVID-19, the Pandemic of the Century and Its Impact on Cardiovascular Diseases

COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection likely ranks among the deadliest diseases in human history. As with other coronaviruses, SARS-CoV-2 infection damages not only the lungs but also the heart and many other organs that express angiotensin-converting enzyme 2 (ACE2), a receptor for SARS-CoV-2. COVID-19 has upended lives worldwide. Dietary behaviors have been altered such that they favor metabolic and cardiovascular complications, while patients have avoided hospital visits because of limited resources and the fear of infection, thereby increasing out-hospital mortality due to delayed diagnosis and treatment. Clinical observations show that sex, age, and race all influence the risk for SARS-CoV-2 infection, as do hypertension, obesity, and pre-existing cardiovascular conditions. Many hospitalized COVID-19 patients suffer cardiac injury, acute coronary syndromes, or cardiac arrhythmia. SARS-CoV-2 infection may lead to cardiomyocyte apoptosis and necrosis, endothelial cell damage and dysfunction, oxidative stress and reactive oxygen species production, vasoconstriction, fibrotic and thrombotic protein expression, vascular permeability and microvascular dysfunction, heart inflammatory cell accumulation and activation, and a cytokine storm. Current data indicate that COVID-19 patients with cardiovascular diseases should not discontinue many existing cardiovascular therapies such as ACE inhibitors, angiotensin receptor blockers, steroids, aspirin, statins, and PCSK9 inhibitors. This review aims to furnish a framework relating to COVID-19 and cardiovascular pathophysiology.

Bioinspired therapeutic platform based on extracellular vesicles for prevention of arterial wall remodeling in hypertension

Arterial stiffness due to the vessel remodeling is closely linked to raised blood pressure, and its physiopathologic mechanism is still not fully understood. We here aimed to explore whether extracellular vesicle (EV) mediated intercellular communication between endothelium and smooth muscle cell contribute to the blood vessel remodeling under hypertension. We here revealed that the arterial endothelial cells robustly secreted EV, which in turn could be circulated and/or directly taken up by the subendothelial smooth muscle cells (SMC). Under hypertension, the EV secretion increased and the miRNA profile changed significantly mainly due to the raised mechanical force and subsequent enhanced reactive oxygen species generation. Among the miRNA cargos in the EV, miR-320d/423-5p were found increased most significantly. In vivo delivery of miR-320d/423-5p mimics via engineered EV increased their expression in arterial vessels, recapitulating the phenotype in hypertension. In contrast, therapeutic delivery of miR-320d/423-5p inhibitors via engineered EV alleviated the phenotype in spontaneous hypertension rat model. Together, we have found that the injured endothelium due to the raised mechanical force in hypertension contributes to the arterial wall remodeling via the secreted EV. Our study has not only provided novel insights on the mechanism of hypertension associated blood vessel wall remodeling, but also shed light on therapeutic intervention of hypertension associated vascular diseases.

Cognitive Impairment in Frail Hypertensive Elderly Patients: Role of Hyperglycemia

Endothelial dysfunction is a key hallmark of hypertension, which is a leading risk factor for cognitive decline in older adults with or without frailty. Similarly, hyperglycemia is known to impair endothelial function and is a predictor of severe cardiovascular outcomes, independent of the presence of diabetes. On these grounds, we designed a study to assess the effects of high-glucose and metformin on brain microvascular endothelial cells (ECs) and on cognitive impairment in frail hypertensive patients. We tested the effects of metformin on high-glucose-induced cell death, cell permeability, and generation of reactive oxygen species in vitro, in human brain microvascular ECs. To investigate the consequences of hyperglycemia and metformin in the clinical scenario, we recruited frail hypertensive patients and we evaluated their Montreal Cognitive Assessment (MoCA) scores, comparing them according to the glycemic status (normoglycemic vs. hyperglycemic) and the use of metformin. We enrolled 376 patients, of which 209 successfully completed the study. We observed a significant correlation between MoCA score and glycemia. We found that hyperglycemic patients treated with metformin had a significantly better MoCA score than hyperglycemic patients treated with insulin (18.32 ± 3.9 vs. 14.94 ± 3.8; p < 0.001). Our in vitro assays confirmed the beneficial effects of metformin on human brain microvascular ECs. To our knowledge, this is the first study correlating MoCA score and glycemia in frail and hypertensive older adults, showing that hyperglycemia aggravates cognitive impairment.

Pathological Bases and Clinical Application of Long Noncoding RNAs in Cardiovascular Diseases

Increasing evidence has suggested that noncoding RNAs (ncRNAs) have vital roles in cardiovascular tissue homeostasis and diseases. As a main subgroup of ncRNAs, long ncRNAs (lncRNAs) have been reported to play important roles in lipid metabolism, inflammation, vascular injury, and angiogenesis. They have also been implicated in many human diseases including atherosclerosis, arterial remodeling, hypertension, myocardial injury, cardiac remodeling, and heart failure. Importantly, it was reported that lncRNAs were dysregulated in the development and progression of cardiovascular diseases (CVDs). A variety of studies have demonstrated that lncRNAs could influence gene expression at transcription, post-transcription, translation, and post-translation level. Particularly, emerging evidence has confirmed that the crosstalk among lncRNAs, mRNA, and miRNAs is an important underlying regulatory mechanism of lncRNAs. Nevertheless, the biological functions and molecular mechanisms of lncRNAs in CVDs have not been fully explored yet. In this review, we will comprehensively summarize the main findings about lncRNAs and CVDs, highlighting the most recent discoveries in the field of lncRNAs and their pathophysiological functions in CVDs, with the aim of dissecting the intrinsic association between lncRNAs and common risk factors of CVDs including hypertension, high glucose, and high fat. Finally, the potential of lncRNAs functioning as the biomarkers, therapeutic targets, as well as specific diagnostic and prognostic indicators of CVDs will be discussed in this review.

Endothelial Progenitor Cells Dysfunctions and Cardiometabolic Disorders: From Mechanisms to Therapeutic Approaches

Metabolic syndrome (MetS) is a cluster of several disorders, such as hypertension, central obesity, dyslipidemia, hyperglycemia, insulin resistance and non-alcoholic fatty liver disease. Despite health policies based on the promotion of physical exercise, the reduction of calorie intake and the consumption of healthy food, there is still a global rise in the incidence and prevalence of MetS in the world. This phenomenon can partly be explained by the fact that adverse events in the perinatal period can increase the susceptibility to develop cardiometabolic diseases in adulthood. Individuals born after intrauterine growth restriction (IUGR) are particularly at risk of developing cardiovascular diseases (CVD) and metabolic disorders later in life. It has been shown that alterations in the structural and functional integrity of the endothelium can lead to the development of cardiometabolic diseases. The endothelial progenitor cells (EPCs) are circulating components of the endothelium playing a major role in vascular homeostasis. An association has been found between the maintenance of endothelial structure and function by EPCs and their ability to differentiate and repair damaged endothelial tissue. In this narrative review, we explore the alterations of EPCs observed in individuals with cardiometabolic disorders, describe some mechanisms related to such dysfunction and propose some therapeutical approaches to reverse the EPCs dysfunction.

The Inverse Relationship Between Endothelium-Dependent Vasodilation and Blood Pressure is Lost After Cardiopulmonary Bypass

Cardiopulmonary bypass (CPB) is required for the surgical correction of congenital heart defects and incites an acute inflammatory response that impairs endothelial function post-operatively. Therefore, we hypothesized that the pre-operative relationship between endothelial function and blood pressure would be impaired after CPB-mediated inflammation. Using laser Doppler perfusion monitoring coupled with iontophoresis, we found that while there was a significant inverse correlation between endothelium-dependent vascular reactivity to acetylcholine (ACh) stimulation and systolic blood pressure (SBP), this relationship was lost after CPB. No relationship was observed between endothelium-independent vascular reactivity using sodium nitroprusside (SNP) and SBP either pre-CPB or any point thereafter. Additionally, neither CPB time nor inflammatory cytokines correlated with the degree of responsiveness to ACh. These data suggest that the measurement of endothelium impairment after CPB may be more reflective of cardiovascular health than SBP alone.

Oxidative Stress in Ischemic Heart Disease

One of the novel interesting topics in the study of cardiovascular disease is the role of the oxidation system, since inflammation and oxidative stress are known to lead to cardiovascular diseases, their progression and complications. During decades of research, many complex interactions between agents of oxidative stress, oxidation, and antioxidant systems have been elucidated, and numerous important pathophysiological links to na number of disorders and diseases have been established. This review article will present the most relevant knowledge linking oxidative stress to vascular dysfunction and disease. The review will focus on the role of oxidative stress in endotheleial dysfunction, atherosclerosis, and other pathogenetic processes and mechanisms that contribute to the development of ischemic heart disease.

Acute renal denervation normalizes aortic function and decreases blood pressure in spontaneously hypertensive rats

Mechanisms involved in the acute responses to renal denervation (RDN) have yet to be fully understood. We assessed urinary volume, autonomic control and aorta vascular reactivity after acute RDN. Male normotensive Wistar rats and spontaneously hypertensive rats (SHR) were divided into normotensive + RDN (ND) or sham surgery (NS), and hypertensive + RDN (HD) or sham surgery (HS). Metabolic parameters and hemodynamic measurements were recorded 72h and 4 days after intervention, respectively. Aortic rings were studied 7 days post RDN in an isometric myograph. Concentration–response curves to phenylephrine, sodium nitroprusside and acetylcholine (10^–10–10⁻⁵ M) were performed. Two-way ANOVA was used for group comparisons and differences reported when p < 0.05. Results are presented as mean ± SEM. Urinary volume was 112% higher in HD vs. HS (HS = 14.94 ± 2.5 mL; HD = 31.69 ± 2.2 mL) and remained unchanged in normotensive rats. Systolic BP was lower in HD rats (HS = 201 ± 12 vs. HD = 172 ± 3 mmHg) without changes in normotensive group. HD group showed increased HF and LF modulation (HS = 5.8 ± 0.7 ms²vs. HD = 13.4 ± 1.4 ms²; HS = 3.5 ± 0.7 ms²vs. HD = 10.5 ± 1.7 ms², respectively). RDN normalized vascular reactivity in HD rats and increased phenylephrine response in ND rats. Acute fall in BP induced by RDN is associated with increased urinary volume, which in turn may also have contributed to functional changes of the aorta.

Biological Context Linking Hypertension and Higher Risk for COVID-19 Severity

The coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), represents a public health crisis of major proportions. Advanced age, male gender, and the presence of comorbidities have emerged as risk factors for severe illness or death from COVID-19 in observation studies. Hypertension is one of the most common comorbidities in patients with COVID-19. Indeed, hypertension has been shown to be associated with increased risk for mortality, acute respiratory distress syndrome, need for intensive care unit admission, and disease progression in COVID-19 patients. However, up to the present time, the precise mechanisms of how hypertension may lead to the more severe manifestations of disease in patients with COVID-19 remains unknown. This review aims to present the biological plausibility linking hypertension and higher risk for COVID-19 severity. Emphasis is given to the role of the renin-angiotensin system and its inhibitors, given the crucial role that this system plays in both viral transmissibility and the pathophysiology of arterial hypertension. We also describe the importance of the immune system, which is dysregulated in hypertension and SARS-CoV-2 infection, and the potential involvement of the multifunctional enzyme dipeptidyl peptidase 4 (DPP4), that, in addition to the angiotensin-converting enzyme 2 (ACE2), may contribute to the SARS-CoV-2 entrance into target cells. The role of hemodynamic changes in hypertension that might aggravate myocardial injury in the setting of COVID-19, including endothelial dysfunction, arterial stiffness, and left ventricle hypertrophy, are also discussed.

The Chemical Composition of Brazilian Green Propolis and Its Protective Effects on Mouse Aortic Endothelial Cells against Inflammatory Injury

Propolis has a very complex composition, with antibacterial, anti-inflammatory and other properties. To determine the composition of ethanol extracts of Brazilian green propolis (EEP-B) and their protective effect on mouse aortic endothelial cells (MAECs), the chemical composition of EEP-B was analysed by UPLC/Q-TOF-MS/MS, and the protective effect of EEP-B on the proliferation of lipopolysaccharide (LPS)-induced MAECs was determined by Cell Counting Kit-8 (CCK-8) assays. The protein levels of inflammatory cytokines tumour necrosis factor-α (TNF-α) and interleukin- 6 (IL-6) were measured by enzyme-linked immunosorbent assay (ELISA), and ICAM-1, VCAM-1 and MCP-1 expressions were analysed by western blotting. The results showed that a total of 24 compounds belonging to cinnamic acids and flavonoids, including 3,5-diisopentenyl-4-hydroxycinnamic acid (artepillin C), kaempferide, 3-isoprenyl p-coumaric acid, pinocembrin and 4′-methoxy pinobanksin, were identified in EEP-B. Among them, a new component, suggested to be 5-isoprenyl caffeic acid p-coumaric acid ester, was reported for the first time. The LPS-induced levels of TNF-α, IL-6, ICAM-1, VCAM-1 and MCP-1 were downregulated in response to 5, 10 and 20 μg/mL EEP-B. This study revealed that EEP-B could reduce LPS-induced inflammatory reactions, improve cell survival, and protect MAECs by regulating ICAM-1, VCAM-1 and MCP-1 expression. These findings could provide a theoretical basis for MAEC treatment using EEP-B.

Lifestyle interventions for the prevention and treatment of hypertension

Hypertension affects approximately one third of the world's adult population and is a major cause of premature death despite considerable advances in pharmacological treatments. Growing evidence supports the use of lifestyle interventions for the prevention and adjuvant treatment of hypertension. In this Review, we provide a summary of the epidemiological research supporting the preventive and antihypertensive effects of major lifestyle interventions (regular physical exercise, body weight management and healthy dietary patterns), as well as other less traditional recommendations such as stress management and the promotion of adequate sleep patterns coupled with circadian entrainment. We also discuss the physiological mechanisms underlying the beneficial effects of these lifestyle interventions on hypertension, which include not only the prevention of traditional risk factors (such as obesity and insulin resistance) and improvements in vascular health through an improved redox and inflammatory status, but also reduced sympathetic overactivation and non-traditional mechanisms such as increased secretion of myokines.

The Efficacy of Tai Chi and Qigong Exercises on Blood Pressure and Blood Levels of Nitric Oxide and Endothelin-1 in Patients with Essential Hypertension: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective

Tai Chi and Qigong are the two similar traditional Chinese wellness exercises. A strong body of published clinical randomized controlled trials (RCTs) has investigated the health benefits of Tai Chi and Qigong exercises (TCQE) in patients with essential hypertension (EH). This is the first meta-analysis to evaluate the efficacy of TCQE on blood pressure (BP) and blood levels of nitric oxide (NO) and endothelin-1 (ET-1) in EH patients and explore the potential antihypertensive mechanism of TCQE.

Methods

We conducted a literature retrieval for Chinese and English studies in seven databases from their respective inceptions until January 14, 2020. All RCTs examining clinical efficacy of TCQE for EH patients were considered. The major therapeutic outcomes of TCQE were changes in the blood levels of NO, ET-1, and BP in EH patients. Methodological quality of the included RCTs was detected via The Cochrane Risk of Bias tool. We evaluated the data reported and performed the meta-analysis by Review Manager 5.3 software.

Results

9 RCTs involving 516 EH patients were included. The intervention duration lasted from 1.5 months to 6 months. The results of comprehensive analysis showed that compared with control interventions, experimental interventions were more effective in reducing the systolic blood pressure and the diastolic blood pressure and contributed higher blood levels of NO and lower blood levels of ET-1.

Conclusions

TCQE could be an effective complementary and alternative therapy for EH. The lower BP in EH patients who practice TCQE may have some connection with exercise-related increased blood NO levels and decreased blood ET-1 levels. However, further research is needed to make clear the efficacy of TCQE in management of EH and the mechanism of lowering BP in TCQE.

Experimental and Clinical Evidence of Endothelial Dysfunction in Inflammatory Bowel Disease

The endothelium has a crucial role in proper hemodynamics. Inflammatory bowel disease (IBD) is mainly a chronic inflammatory condition of the gastrointestinal tract. However, considerable evidence points to high cardiovascular risk in patients with IBD. This review positions the basic mechanisms of endothelial dysfunction in the IBD setting (both clinical and experimental). Furthermore, we review the main effects of drugs used to treat IBD in endothelial (dys)function. Moreover, we leave challenging points for enlarging the therapeutic arsenal for IBD with new or repurposed drugs that target endothelial dysfunction besides inflammation.

Inhibition of Mitochondrial Oxidative Damage Improves Reendothelialization Capacity of Endothelial Progenitor Cells via SIRT3 (Sirtuin 3)-Enhanced SOD2 (Superoxide Dismutase 2) Deacetylation in Hypertension

OBJECTIVE

Dysfunction of endothelial progenitor cells (EPCs) leads to impaired endothelial repair capacity in patients with hypertension, but the mechanisms remain incompletely understood. Mitochondrial oxidative stress is involved in endothelial injury in hypertension. In this study, we aim to investigate the role of mitochondrial oxidative stress in the deficient endothelial reparative capacity of EPCs and identify enhanced SIRT3 (sirtuin 3)-mediated SOD2 (superoxide dismutase 2) deacetylation as a novel endothelial protective mechanism in hypertension. Approach and Results: Hypertension-EPCs displayed increased mitochondrial reactive oxygen species and mitochondrial damage, including loss of mitochondrial membrane potential, abnormal mitochondrial ultrastructure, and mtDNA oxidative injury, which was coincided with impaired in vitro function and in vivo reendothelialization capacity. The harmful effects of hypertension on mitochondrial function of EPCs were in vitro mimicked by angiotensin II coincubation. Scavenging of mitochondrial reactive oxygen species with mitoTEMPO attenuated mitochondrial oxidative damage and rescued reendothelialization capacity. Enzymatic activity and deacetylation level of SOD2 were significantly reduced in hypertension-EPCs, which was accompanied with decreased SIRT3 expression. Knockdown of SIRT3 in EPCs resulted in mitochondrial oxidative damage, hyperacetylation of SOD2, and suppression of reendothelialization capacity. SIRT3 physically interacted with SOD2 and eliminated excess mitochondrial reactive oxygen species, restored mitochondrial function through enhancing SOD2 activity by deacetylation of K68. Upregulation of SIRT3/SOD2 signaling improved reendothelialization capability of EPCs.

CONCLUSIONS

The present study demonstrated for the first time that mitochondrial oxidative damage because of deficient SIRT3/SOD2 signaling contributes to the decline in reendothelialization capacity of EPCs in hypertension. Maintenance of mitochondrial redox homeostasis in EPCs may be a novel therapeutic target for endothelial injury.

The dominant models of KCNJ11 E23K and KCNMB1 E65K are associated with essential hypertension (EH) in Asian: Evidence from a meta-analysis

BACKGROUND

The K channel, subfamily J, member-11 (KCNJ11) E23K and β1 subunit of large-conductance Ca-activated K channel (KCNMB1) E65K polymorphisms were shown to be associated with the risk of essential hypertension (EH). However, the results were inconclusive with relatively small sample size. Thus, we carried out a meta-analysis to investigate the genetic association between KCNJ11 E23K and KCNMB1 E65K polymorphisms and essential hypertension risk.

METHODS

Relative studies were collected using PubMed, Web of Science, the Cochrane Library databases, Chinese National Knowledge Infrastructure and Embase databases. Pooled odds ratios with 95% confidence intervals were used to assess the strength of associations.

RESULTS

The dominant models of KCNJ11 E23K (P = .006, OR [95%CI] = 0.45 [0.25, 0.79]) and KCNMB1 E65K (P = .04, OR [95%CI] = 0.91 [0.83, 1.00]) were significantly associated with essential hypertension risk. No significant association was detected between the allelic and recessive models of KCNJ11 E23K and KCNMB1 E65K and the susceptibility of EH. Subgroup analysis stratified by ethnicity showed that the dominant model of KCNMB1 E65K was associated with EH risk in Asian population (P = .003, OR [95%CI] = 0.83 [0.74, 0.94]), but not in Caucasian (P = .74, OR [95%CI] = 1.02 [0.89, 1.18]).

CONCLUSIONS

The dominant model of KCNJ11 E23K and KCNMB1 E65K might be susceptible factors for essential hypertension. To confirm this result, large-scale case-control studies with more subjects are necessary.

Inflammation markers and risk of developing hypertension: a meta-analysis of cohort studies

OBJECTIVE

To systematically assess the association of circulating inflammation markers with the future risk of hypertension.

METHODS

We did a systematic literature search of PubMed and Scopus, from database inception to July 10, 2018. Prospective and retrospective cohort studies evaluating the association of circulating C reactive protein (CRP), high-sensitive CRP (hs-CRP), interleukin 6 (IL-6) and IL-1β to the risk of developing hypertension in the general population were included. The relative risks (RRs) for the top versus bottom tertiles of circulating biomarkers were calculated using a fixed-effects/random-effects model. A potential non-linear dose-response association was tested.

RESULTS

Fourteen prospective cohort studies, two retrospective cohort studies and five nested case-control studies involving 142 640 participants and 20 676 cases were identified. The RR for the third versus first tertiles of circulating CRP was 1.23 (95% CI 1.11 to 1.35; I²=59%, n=12). The association remained unchanged after adjustment for body mass index. The RRs for other biomarkers were as follows: hs-CRP (RR 1.20, 95% CI 1.02 to 1.37; I²=74%, n=7), IL-6 (RR 1.51, 95% CI 1.30 to 1.71; I²=0%, n=5), and IL-1β (RR 1.22, 95% CI 0.92 to 1.51; I²=0%, n=3). A non-linear dose-response meta-analysis demonstrated that the risk of hypertension increased linearly with increasing circulating inflammation markers, even within the low-risk and intermediate-risk categories.

CONCLUSIONS

Higher levels of circulating CRP, hs-CRP and IL-6, but not IL-1β, were associated with the risk of developing hypertension. The association persisted in subgroups of studies defined by major sources of heterogeneity.

The prostaglandin H2 analog U-46619 improves the differentiation efficiency of human induced pluripotent stem cells into endothelial cells by activating both p38MAPK and ERK1/2 signaling pathways

Background

We have shown that the differentiation of human-induced pluripotent stem cells (hiPSCs) into endothelial cells (ECs) is more efficient when performed with a 3-dimensional (3D) scaffold of biomaterial than in monolayers. The current study aims to further increase hiPSC-EC differentiation efficiency by deciphering the signaling pathways in 3D scaffolds.

Methods and results

We modified our 3D protocol by using U-46619 to upregulate both p38 mitogen-activated protein kinase (p38MAPK) and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling, which increased the differentiation efficiency (as measured by CD31 expression) to as high as 89% in two established hiPSC lines. The differentiated cells expressed arteriovenous, but not lymphatic, markers; formed tubular structures and EC lumen in vitro; had significantly shorter population-doubling times than monolayer-differentiated hiPSC-ECs; and restored perfusion and vascularity in a murine hind limb ischemia model. The differentiation efficiency was also > 85% in three hiPSC lines that had been derived from patients with diseases or disease symptoms that have been linked to endothelial dysfunction.

Conclusions

These observations demonstrate that activating both p38MAPK and ERK1/2 signaling pathways with U-46619 improves the efficiency of arteriovenous hiPSC-EC differentiation and produces cells with greater proliferative capacity.

Electronic supplementary material

The online version of this article (10.1186/s13287-018-1061-4) contains supplementary material, which is available to authorized users.

Combined Aerobic and Resistance Exercise Training Improve Hypertension Associated With Menopause

The prevalence of hypertension sharply increases in menopausal women. Recent studies have demonstrated that aerobic or resistance training may help control hypertension. In this study, we report that combining aerobic and resistance training may provide an effective therapeutic approach for hypertension control, attenuating inflammation and oxidative stress in ovariectomized rats. Female Wistar and spontaneous hypertensive rats (SHR) were distributed into four groups: sedentary control (C), sedentary hypertensive (HR), sedentary hypertensive ovariectomized (HR-O), and combined trained hypertensive ovariectomized (T-HR-O). Combined exercise training was performed on a motor treadmill (aerobic training) and on a ladder adapted to rats (resistance training), in alternate days for 8 weeks. Direct arterial pressure was recorded and oxidative stress and inflammation were evaluated in cardiac and renal tissue. Ovariectomy increases increased mean arterial blood pressure, sympathetic modulation, and oxidative stress in SHR. Combining aerobic and resistance training reduced mean arterial blood pressure (12% vs. HR-O), heart rate (8% vs. HR-O), vascular sympathetic modulation (40% vs. HR-O), and improved baroreflex sensitivity. Combined training reduced cardiac inflammation (TNF and IL-6) and cardiac and renal lipoperoxidation (59% and 57%, respectively vs. HR-O). It also enhanced cardiac (71%) and renal (76%) total antioxidant capacity when compared to HR-O group. In conclusion, combining aerobic and resistance training improves mean arterial blood pressure, cardiovascular autonomic control, preventing cardiac and renal oxidative stress and inflammation in an experimental hypertension model with surgical menopause induced with ovariectomy.

Role of MicroRNA in Endothelial Dysfunction and Hypertension

Purpose of Review

Hypertension is either a cause or a consequence of the endothelial dysfunction and a major risk factor for cardiovascular disease (CVD). In vitro and in vivo studies established that microRNAs (miRNAs) are decisive for endothelial cell gene expression and function in various pathological conditions associated with CVD.

This review provides an overview of the miRNA role in controlling the key connections between endothelial dysfunction and hypertension.

Recent Findings

Herein we summarize the present understanding of mechanisms underlying hypertension and its associated endothelial dysfunction as well as the miRNA role in endothelial cells with accent on the modulation of renin-angiotensin-aldosterone-system, nitric oxide, oxidative stress and on the control of vascular inflammation and angiogenesis in relation to endothelial dysfunction in hypertension. In particular, latest insights in the identification of endothelial-specific microRNAs and their targets are added to the understanding of miRNA significance in hypertension.

Summary

This comprehensive knowledge of the role of miRNAs in endothelial dysfunction and hypertension and of molecular mechanisms proposed for miRNA actions may offer novel diagnostic biomarkers and therapeutic targets for controlling hypertension-associated endothelial dysfunction and other cardiovascular complications.

Monotropein promotes angiogenesis and inhibits oxidative stress-induced autophagy in endothelial progenitor cells to accelerate wound healing

Attenuating oxidative stress‐induced damage and promoting endothelial progenitor cell (EPC) differentiation are critical for ischaemic injuries. We suggested monotropein (Mtp), a bioactive constituent used in traditional Chinese medicine, can inhibit oxidative stress‐induced mitochondrial dysfunction and stimulate bone marrow‐derived EPC (BM‐EPC) differentiation. Results showed Mtp significantly elevated migration and tube formation of BM‐EPCs and prevented tert‐butyl hydroperoxide (TBHP)‐induced programmed cell death through apoptosis and autophagy by reducing intracellular reactive oxygen species release and restoring mitochondrial membrane potential, which may be mediated viamTOR/p70S6K/4EBP1 and AMPK phosphorylation. Moreover, Mtp accelerated wound healing in rats, as indicated by reduced healing times, decreased macrophage infiltration and increased blood vessel formation. In summary, Mtp promoted mobilization and differentiation of BM‐EPCs and protected against apoptosis and autophagy by suppressing the AMPK/mTOR pathway, improving wound healing in vivo. This study revealed that Mtp is a potential therapeutic for endothelial injury‐related wounds.

Chromogranins: from discovery to current times

The discovery in 1953 of the chromaffin granules as co-storage of catecholamines and ATP was soon followed by identification of a range of uniquely acidic proteins making up the isotonic vesicular storage complex within elements of the diffuse sympathoadrenal system. In the mid-1960s, the enzymatically inactive, major core protein, chromogranin A was shown to be exocytotically discharged from the stimulated adrenal gland in parallel with the co-stored catecholamines and ATP. A prohormone concept was introduced when one of the main storage proteins collectively named granins was identified as the insulin release inhibitory polypeptide pancreastatin. A wide range of granin-derived biologically active peptides have subsequently been identified. Both chromogranin A and chromogranin B give rise to antimicrobial peptides of relevance for combat of pathogens. While two of the chromogranin A-derived peptides, vasostatin-I and pancreastatin, are involved in modulation of calcium and glucose homeostasis, respectively, vasostatin-I and catestatin are important modulators of endothelial permeability, angiogenesis, myocardial contractility, and innate immunity. A physiological role is now evident for the full-length chromogranin A and vasostatin-I as circulating stabilizers of endothelial integrity and in protection against myocardial injury. The high circulating levels of chromogranin A and its fragments in patients suffering from various inflammatory diseases have emerged as challenges for future research and clinical applications.

Therapeutic Strategies for Oxidative Stress-Related Cardiovascular Diseases: Removal of Excess Reactive Oxygen Species in Adult Stem Cells

Accumulating evidence indicates that acute and chronic uncontrolled overproduction of oxidative stress-related factors including reactive oxygen species (ROS) causes cardiovascular diseases (CVDs), atherosclerosis, and diabetes. Moreover ROS mediate various signaling pathways underlying vascular inflammation in ischemic tissues. With respect to stem cell-based therapy, several studies clearly indicate that modulating antioxidant production at cellular levels enhances stem/progenitor cell functionalities, including proliferation, long-term survival in ischemic tissues, and complete differentiation of transplanted cells into mature vascular cells. Recently emerging therapeutic strategies involving adult stem cells, including endothelial progenitor cells (EPCs), for treating ischemic CVDs have highlighted the need to control intracellular ROS production, because it critically affects the replicative senescence of ex vivo expanded therapeutic cells. Better understanding of the complexity of cellular ROS in stem cell biology might improve cell survival in ischemic tissues and enhance the regenerative potentials of transplanted stem/progenitor cells. In this review, we will discuss the nature and sources of ROS, drug-based therapeutic strategies for scavenging ROS, and EPC based therapeutic strategies for treating oxidative stress-related CVDs. Furthermore, we will discuss whether primed EPCs pretreated with natural ROS-scavenging compounds are crucial and promising therapeutic strategies for vascular repair.

Nafamostat mesilate promotes endothelium-dependent vasorelaxation via the Akt-eNOS dependent pathway

Nafamostat mesilate (NM), a synthetic serine protease inhibitor, has anticoagulant and anti-inflammatory properties. The intracellular mediator and external anti-inflammatory external signal in the vascular wall have been reported to protect endothelial cells, in part due to nitric oxide (NO) production. This study was designed to examine whether NM exhibit endothelium dependent vascular relaxation through Akt/endothelial nitric oxide synthase (eNOS) activation and generation of NO. NM enhanced Akt/eNOS phosphorylation and NO production in a dose- and time-dependent manner in human umbilical vein endothelial cells (HUVECs) and aorta tissues obtained from rats treated with various concentrations of NM. NM concomitantly decreased arginase activity, which could increase the available arginine substrate for NO production. Moreover, we investigated whether NM increased NO bioavailability and decreased aortic relaxation response to an eNOS inhibitor in the aorta. These results suggest that NM increases NO generation via the Akt/eNOS signaling pathway, leading to endothelium-dependent vascular relaxation. Therefore, the vasorelaxing action of NM may contribute to the regulation of cardiovascular function.

Circulating Progenitor Cells is Linked to Cognitive Decline in Healthy Adults

OBJECTIVE

Cognitive and cardiovascular disorders share many risk factors. Higher bone-marrow derived progenitor cells (PC) in blood are associated with lower rates of cardiovascular events but the association of PC with cognitive function is unclear. The objective of this study was to assess the association between PC and cognition in a sample of healthy adults enrolled in a cohort study.

MATERIALS AND METHODS

A random sample of employees at Emory University and Georgia Institute of Technology were followed for 4 years and underwent yearly vascular and cognitive assessment (N = 430, mean age = 49.2 years, 70% women, and 27% African-American). Cognition was assessed using computerized versions of 15 cognitive tests and principal component analysis was used for deriving cognitive scores: executive function, memory and working memory. PC were defined as mononuclear cells with specific surface markers (7 phenotypes). Decreased cognition in a domain was defined as performing below the lowest quartile for the corresponding domain at baseline. Generalized estimating equations were used to investigate associations between PC and cognition.

RESULTS

Higher PC levels at baseline were associated with lower risk of cognitive decline in the executive and working memory domains during the follow-up period (P < 0.002 for all PC phenotypes). Further, the degree of decline in PC over the follow-up period was correlated with a corresponding decline in performances in all 3 cognitive domains over the same period (All P < 0.002).

CONCLUSION

Lower PC and greater yearly declines in PC are associated with greater cognitive decline. These findings suggest the role for PC in neurocognitive aging.

Rg3-enriched Korean Red Ginseng enhances blood pressure stability in spontaneously hypertensive rats

Background

Korean Red Ginseng (Panax ginseng) has been shown to exert antihypertensive effects. In particular, ginsenoside Rg3 is thought to be a potent modulator of vascular function. The present study was performed to examine the antihypertensive efficacy of Korean Red Ginseng (KRG) extract and Rg3-enriched KRG (REKRG) extract.

Methods

Spontaneously hypertensive rats (SHRs) and Wistar–Kyoto rats (WKYs) were divided into six groups (WKY control, WKY-KRG, WKY-REKRG, SHR control, SHR-KRG, and SHR-REKRG), and systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured at the carotid artery, followed by injection of 3 mg/kg KRG or 3 mg/kg REKRG.

Results

REKRG treatment significantly decreased SBP and DBP 3 hours post-treatment in the SHR group compared with SHR control group. However, SBP and DBP were not significantly different in KRG-treated SHRs compared with control SHRs. REKRG treatment did not significantly alter SBP or DBP 3 hours post-treatment in the WKY group compared with WKY control group. Similarly, there were no differences in SBP or DBP with KRG treatment in the WKY group and WKY control group. Both KRG and REKRG increased endothelial nitric oxide synthase phosphorylation levels in the aorta, and the increases in endothelial nitric oxide synthase phosphorylation levels by REKRG treatment were higher than those with KRG treatment. Similarly, nitric oxide production in plasma from WKYs and SHRs was also increased by both KRG and REKRG.

Conclusion

These results suggest that REKRG has a more beneficial effect on blood pressure control than KRG in SHRs.

Inhibition of Store-Operated Calcium Entry Protects Endothelial Progenitor Cells from H2O2-Induced Apoptosis

Store-operated calcium entry (SOCE), a major mode of extracellular calcium entry, plays roles in a variety of cell activities. Accumulating evidence indicates that the intracellular calcium ion concentration and calcium signaling are critical for the responses induced by oxidative stress. The present study was designed to investigate the potential effect of SOCE inhibition on H₂O₂-induced apoptosis in endothelial progenitor cells (EPCs), which are the predominant cells involved in endothelial repair. The results showed that H₂O₂-induced EPC apoptosis was reversed by SOCE inhibition induced either using the SOCE antagonist ML-9 or via silencing of stromal interaction molecule 1 (STIM1), a component of SOCE. Furthermore, SOCE inhibition repressed the increases in intracellular reactive oxygen species (ROS) levels and endoplasmic reticulum (ER) stress and ameliorated the mitochondrial dysfunction caused by H₂O₂. Our findings provide evidence that SOCE inhibition exerts a protective effect on EPCs in response to oxidative stress induced by H₂O₂ and may serve as a potential therapeutic strategy against vascular endothelial injury.

Tempol improves xanthine oxidoreductase-mediated vascular responses to nitrite in experimental renovascular hypertension

Upregulation of xanthine oxidoreductase (XOR) increases vascular reactive oxygen species (ROS) levels and contributes to nitroso-redox imbalance. However, XOR can generate nitric oxide (NO) from nitrite, and increased superoxide could inactivate NO formed from nitrite. This study tested the hypothesis that XOR contributes to the cardiovascular effects of nitrite in renovascular hypertension, and that treatment with the antioxidant tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl) improves XOR-mediated effects of nitrite. Blood pressure was assessed weekly in two-kidney one-clip (2K1C) and control rats. After six weeks of hypertension, the relaxing responses to nitrite were assessed in aortic rings in the presence of the XOR inhibitor oxypurinol (or vehicle), either in the absence or in the presence of tempol. Moreover, in vivo hypotensive responses to nitrite were also examined in the presence of oxypurinol (or vehicle) and tempol (or vehicle). Aortic XOR activity and expression were evaluated by fluorescence and Western blot, respectively. Vascular ROS production was assessed by the dihydroethidium assay. 2K1C hypertensive rats showed increased aortic XOR activity and vascular ROS production compared with control rats. Oxypurinol shifted the nitrite concentration–response curve to the right in aortic rings from 2K1C rats (but not in controls). Oxypurinol also attenuated the hypotensive responses to nitrite in 2K1C rats (but not in controls). These functional findings agree with increased aortic and plasma XOR activity found in 2K1C rats. Tempol treatment enhanced oxypurinol-induced shift of the nitrite concentration–response curve to the right. However, antioxidant treatment did not affect XOR-mediated hypotensive effects of nitrite. Our results show that XOR is important to the cardiovascular responses to nitrite in 2K1C hypertension, and XOR inhibitors commonly used by patients may cancel this effect. This finding suggests that nitrite treatment may not be effective in patients being treated with XOR inhibitors. Moreover, while tempol may improve the vascular responses to nitrite, antihypertensive responses are not affected.

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Upregulation of xanthine oxidoreductase (XOR) is usually found in hypertension.

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While XOR produces superoxide, it can also produce NO from nitrite.

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This study shows that XOR mediates vasorelaxing effects of nitrite in renovascular hypertension.

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XOR inhibition prevents against the antihypertensive effects of nitrite.

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Antioxidant treatment improves XOR-mediated vasorelaxing effects of nitrite.

Dietary proteins improve endothelial function under fasting conditions but not in the postprandial state, with no effects on markers of low-grade inflammation

Endothelial dysfunction (ED) and low-grade inflammation (LGI) have a role in the development of CVD. The two studies reported here explored the effects of dietary proteins and carbohydrates on markers of ED and LGI in overweight/obese individuals with untreated elevated blood pressure. In the first study, fifty-two participants consumed a protein mix or maltodextrin (3×20 g/d) for 4 weeks. Fasting levels and 12 h postprandial responses of markers of ED (soluble intercellular adhesion molecule 1 (sICAM), soluble vascular cell adhesion molecule 1 (sVCAM), soluble endothelial selectin and von Willebrand factor) and markers of LGI (serum amyloid A, C-reactive protein and sICAM) were evaluated before and after intervention. Biomarkers were also combined into mean Z-scores of ED and LGI. The second study compared 4 h postprandial responses of ED and LGI markers in forty-eight participants after ingestion of 0·6 g/kg pea protein, milk protein and egg-white protein. In addition, postprandial responses after maltodextrin intake were compared with a protein mix and sucrose. The first study showed significantly lower fasting ED Z-scores and sICAM after 4 weeks on the high-protein diet (P≤0·02). The postprandial studies found no clear differences of ED and LGI between test meals. However, postprandial sVCAM decreased more after the protein mix compared with maltodextrin in both studies (P≤0·04). In conclusion, dietary protein is beneficial for fasting ED, but not for fasting LGI, after 4 weeks of supplementation. On the basis of Z-scores, postprandial ED and LGI were not differentially affected by protein sources or carbohydrates.

Soluble epoxide hydrolase null mice exhibit female and male differences in regulation of vascular homeostasis

Increased CYP epoxygenase activity and consequently up regulation of epoxyeicosatrienoic acids (EETs) levels provides protection against metabolic syndrome and cardiovascular diseases. Conversion of arachidonic acid epoxides to diols by soluble epoxide hydrolase (sEH) diminishes the beneficial cardiovascular properties of these epoxyeicosanoids. We therefore examined the possible biochemical consequences of sEH deletion on vascular responses in male and female mice. Through the use of the sEH KO mouse, we provide evidence of differences in the compensatory response in the balance between nitric oxide (NO), carbon monoxide (CO), EETs and the vasoconstrictor 20-HETE in male and female KO mice. Serum levels of adiponectin, TNFα, IL-1b and MCP1 and protein expression in vascular tissue of p-AMPK, p-AKT and p-eNOS were measured. Deletion of sEH caused a significant (p<0.05) decrease in body weight, and an increase in adiponectin, pAMPK and pAKT levels in female KO mice compared to male KO mice. Gene deletion resulted in a higher production of renal EETs in female KO compared to male KO mice and, concomitantly, we observed an increase in renal 20-HETEs levels and superoxide anion production only in male KO mice. sEH deletion increased p-AKT and p-eNOS protein expression but decreased p-AMPK levels in female KO mice. Increased levels of p-eNOS at Thr-495 were observed only in KO male mice. While p-eNOS at 1177 were not significantly different between male and female. Nitric oxide production was unaltered in male KO mice. These results provide evidence of gender differences in the preservation of vascular homeostasis in response to sEH deletion which involves regulation of phosphorylation of eNOS at the 495 site.

The protective effect of lipoic acid on selected cardiovascular diseases caused by age-related oxidative stress

Oxidative stress is considered to be the primary cause of many cardiovascular diseases, including endothelial dysfunction in atherosclerosis and ischemic heart disease, hypertension, and heart failure. Oxidative stress increases during the aging process, resulting in either increased reactive oxygen species (ROS) production or decreased antioxidant defense. The increase in the incidence of cardiovascular disease is directly related to age. Aging is also associated with oxidative stress, which in turn leads to accelerated cellular senescence and organ dysfunction. Antioxidants may help lower the incidence of some pathologies of cardiovascular diseases and have antiaging properties. Lipoic acid (LA) is a natural antioxidant which is believed to have a beneficial effect on oxidative stress parameters in relation to diseases of the cardiovascular system.

Maternal hypertension after a low-birth-weight delivery differs by race/ethnicity: evidence from the National Health and Nutrition Examination Survey (NHANES) 1999-2006

Studies have suggested an increase in maternal morbidity and mortality due to cardiovascular diseases in women with a prior low-birth-weight (LBW, <2,500 grams) delivery. This study evaluated blood pressure and hypertension in women who reported a prior preterm or small-for-gestational-age (SGA) LBW delivery in the National Health and Nutrition Examination Survey 1999-2006 (n = 6,307). This study also aimed to explore if race/ethnicity, menopause status, and years since last pregnancy modified the above associations. A total of 3,239 white, 1,350 black, and 1,718 Hispanics were assessed. Linear regression models were used to evaluate blood pressure by birth characteristics (preterm-LBW, SGA-LBW, and birthweight ≥2,500). Logistic regression models estimated the odds ratios (OR) of hypertension among women who reported a preterm-LBW or SGA-LBW delivery compared with women who reported an infant with birthweight ≥2,500 at delivery. Overall, there was a positive association between a preterm-LBW delivery and hypertension (adjusted OR = 1.39, 95% confidence interval (CI) 1.02-1.90). Prior SGA-LBW also increased the odds of hypertension, but the estimate did not reach statistical significance (adjusted OR = 1.21, 95% CI 0.76-1.92). Race/ethnicity modified the above associations. Only black women had increased risk of hypertension following SGA-LBW delivery (adjusted OR = 2.09, 95% CI 1.12-3.90). Black women were at marginally increased risk of hypertension after delivery of a preterm-LBW (adjusted OR = 1.49, 95% CI 0.93-2.38). Whites and Hispanics had increased, but not statistically significant, risk of hypertension after a preterm-LBW (whites: adjusted OR = 1.39, 95% CI 0.92-2.10; Hispanics: adjusted OR = 1.22, 95% CI 0.62-2.38). Stratified analysis indicated that the associations were stronger among women who were premenopausal and whose last pregnancy were more recent. The current study suggests that in a representative United States population, women with a history of preterm- or SGA-LBW deliveries have increased odds of hypertension and this risk appears to be higher for black women and younger women.

Obstructive sleep apnea and endothelial progenitor cells

BACKGROUND

Obstructive sleep apnea (OSA) occurs in 4% of middle-aged men and 2% of middle-aged women in the general population, and the prevalence is even higher in specific patient groups. OSA is an independent risk factor for a variety of cardiovascular diseases. Endothelial injury could be the pivotal determinant in the development of cardiovascular pathology in OSA. Endothelial damage ultimately represents a dynamic balance between the magnitude of injury and the capacity for repair. Bone marrow-derived endothelial progenitor cells (EPCs) within adult peripheral blood present a possible means of vascular maintenance that could home to sites of injury and restore endothelial integrity and normal function.

METHODS

We summarized pathogenetic mechanisms of OSA and searched for available studies on numbers and functions of EPCs in patients with OSA to explore the potential links between the numbers and functions of EPCs and OSA. In particular, we tried to elucidate the molecular mechanisms of the effects of OSA on EPCs.

CONCLUSION

Intermittent hypoxia cycles and sleep fragmentation are major pathophysiologic characters of OSA. Intermittent hypoxia acts as a trigger of oxidative stress, systemic inflammation, and sympathetic activation. Sleep fragmentation is associated with a burst of sympathetic activation and systemic inflammation. In most studies, a reduction in circulating EPCs has emerged. The possible mechanisms underlying the decrease in the number or function of EPCs include prolonged inflammation response, oxidative stress, increased sympathetic activation, physiological adaptive responses of tissue to hypoxia, reduced EPC mobilization, EPC apoptosis, and functional impairment in untreated OSA. Continuous positive airway pressure (CPAP) therapy for OSA affects the mobilization, apoptosis, and function of EPCs through preventing intermittent hypoxia episodes, improving sleep quality, and reducing systemic inflammation, oxidative stress levels, and sympathetic overactivation. To improve CPAP adherence, the medical staff should pay attention to making the titration trial a comfortable first CPAP experience for the patients; for example, using the most appropriate ventilators or proper humidification. It is also important to give the patients education and support about CPAP use in the follow-up, especially in the early stage of the treatment.

Association of the level of heteroplasmy of the 15059G>A mutation in the MT-CYB mitochondrial gene with essential hypertension

AIM

To examine whether the heteroplasmy level for 15059G>A mutation in the mitochondrial genome might be associated with essential hypertension.

METHODS

This cross-sectional study involved 196 unrelated participants randomly selected from general population (90 males and 106 females) who underwent a regular medical check-up at the Institute for Atherosclerosis Research (Moscow, Russia). One hundred and twenty of them (61%) had essential hypertension, and 76 (39%) were apparently healthy normotensive persons. The level of heteroplasmy for 15059G>A mutation occurring in the coding region of cytochrome b gene (MT-CYB) of mtDNA isolated from the blood leukocytes, was quantified using DNA pyrosequencing method.

RESULTS

The 15059G>A heteroplasmy level ranged between 4% and 83%, with a median level of 31%. Between the upper and lower quartiles of 15059G>A heteroplasmy distribution, significant differences were observed for patients' age, systolic blood pressure, and triglyceride levels. 15059G>A heteroplasmy correlated both with age (r = 0.331, P < 0.001) and the presence of hypertension (r = 0.228, P = 0.002). Regression analysis revealed that the age explains 12% variability of 15059G>A heteroplasmy, and hypertension independently explains more 5% variability. The 15059G>A heteroplasmy exceeding 31% was found to be significantly associated with a higher risk of essential hypertension (odds ratio 2.76; P (Fisher) 0.019]. The study participants with high 15059G>A heteroplasmy level were found to have significantly higher age (P < 0.001) and the prevalence of essential hypertension (P = 0.033), as compared to those with low 15059G>A heteroplasmy level. These observations suggested a positive correlation between the level of 15059G>A heteroplasmy and essential hypertension.

CONCLUSION

This study provides the evidence of association of mtDNA 15059G>A mutation heteroplasmy with essential hypertension.

Endothelial progenitor cell dysfunction in cardiovascular diseases: role of reactive oxygen species and inflammation

Endothelial progenitor cells (EPCs) move towards injured endothelium or inflamed tissues and incorporate into foci of neovascularisation, thereby improving blood flow and tissue repair. Patients with cardiovascular diseases have been shown to exhibit reduced EPC number and function. It has become increasingly apparent that these changes may be effected in response to enhanced oxidative stress, possibly as a result of systemic and localised inflammatory responses. The interplay between inflammation and oxidative stress affects the initiation, progression, and complications of cardiovascular diseases. Recent studies suggest that inflammation and oxidative stress modulate EPC bioactivity. Clinical medications with anti-inflammatory and antioxidant properties, such as statins, thiazolidinediones, angiotensin II receptor 1 blockers, and angiotensin-converting enzyme inhibitors, are currently administered to patients with cardiovascular diseases. These medications appear to exert beneficial effects on EPC biology. This review focuses on EPC biology and explores the links between oxidative stress, inflammation, and development of cardiovascular diseases.