Endothelial Dysfunction and Hypertension

Non-alcoholic fatty liver disease and hypertension: coprevalent or correlated?

OBJECTIVE

To provide a comprehensive review summarizing the existing evidence on the association between nonalcoholic fatty liver disease (NAFLD) and hypertension (HT) independent of other components of metabolic syndrome.

METHODS

We searched the literature through Medline and the Cochrane Library for studies evaluating the relationship between hypertension and fatty liver disease.

RESULTS

Studies testing this association are limited, but agree that HT and fatty liver disease are inter-related independent of other components of the metabolic syndrome such as obesity and diabetes mellitus. Clinical evidence shows that NAFLD is associated with new-onset HT, whereas increased blood pressure is related to the development of fatty liver disease and the possible subsequent progression to liver fibrosis. Insulin resistance and activation of the renin-angiotensin-aldosterone system (RAAS) might provide potential pathophysiologic links between these clinical entities. Until further evidence is available, patients with HT should be meticulously evaluated and treated for fatty liver disease and vice versa. RAAS inhibitors have been tested in NAFLD, presenting a favorable profile by decreasing insulin resistance and fibrosis progression.

CONCLUSION

NAFLD and HT are associated independent of traditional cardiovascular risk factors. Insulin resistance appears to be the main linking mechanism. Although RAAS inhibitors are the most beneficial treatment option for HT in patients with NAFLD, randomized studies on the administration of these agents in HT patients with NAFDL are warranted to provide optimal treatment options in these high cardiovascular risk individuals.

20-MHz Ultrasound for Measurements of Flow-Mediated Dilation and Shear Rate in the Radial Artery

A high-frequency scanning system consisting of a 20-MHz linear array transducer combined with a 20-MHz pulsed Doppler probe was introduced to evaluate the degree of radial artery flow-mediated dilation (FMD [%]) in two groups of patients after 5 min of controlled forearm ischemia followed by reactive hyperemia. In group I, comprising 27 healthy volunteers, FMD (mean ± standard deviation) was 15.26 ± 4.90% (95% confidence interval [CI]: 13.32%-17.20%); in group II, comprising 17 patients with chronic coronary artery disease, FMD was significantly less at 4.53 ± 4.11% (95% CI: 2.42%-6.64%). Specifically, the ratio FMD/SR (mean ± standard deviation), was equal to 5.36 × 10^-4 ± 4.64 × 10^-4 (95% CI: 3.54 × 10^-4 to 7.18 × 10^-4) in group I and 1.38 × 10^-4 ± 0.89 × 10^-4 (95% CI: 0.70 × 10^-4 to 2.06 × 10^-4) in group II. Statistically significant differences between the two groups were confirmed by a Wilcoxon-Mann-Whitney test for both FMD and FMD/SR (p <0.01). Areas under receiver operating characteristic curves for FMD and FMD/SR were greater than 0.9. The results confirm the usefulness of the proposed measurements of radial artery FMD and SR in differentiation of normal patients from those with chronic coronary artery disease.

Biochemical markers of hypertension, prehypertension

OBJECTIVE

There are insufficient researches aimed at evaluating biochemical markers of mechanisms of formation of AH and lesion of target organs in hypertension and prehypertension. The aim of that research was to study the level of endothelial dysfunction markers and damage to the cardiovascular system in hypertension and prehypertension.

PATIENTS AND METHODS

A cross-sectional study was performed among 938 people aged 18 to 65 years. All respondents were surveyed, blood pressure measured, for glucose, cholesterol, interleukin-6, sFAS, LIGHT, hFABP, NT-ProBNP and an Endocan concentrations were tested. Depending on the level of blood pressure participants were splitted into groups with normotension, prehypertension and hypertension.

RESULTS

Comparing the markers of inflammation, apoptosis and target organ damage in the prehypertensive group, the level of the LIGHT protein was Me=265.2pg/ml (Q₂₅-Q₇₅: 197.7-444.3), in the control group - Me=251.1pg/ml (Q₂₅-Q₇₅: 176.6-376.6), the Endocan level was Me=660.6pg/ml (Q₂₅-Q₇₅: 419.6-867.4) and in the control group Me=587.5pg/ml (Q₂₅-Q₇₅: 401.9-838.1). In the AH group, the level of the LIGHT Me=273.1pg/ml (Q₂₅-Q₇₅: 195.1-455.2), Endocan Me=668.2pg/ml (Q₂₅-Q₇₅: 434.8-977.3), heart-type fatty-acid-binding protein Me=2233.1pg/ml (Q₂₅-Q₇₅: 1518.4-3391.1) exceeded the control group.

CONCLUSION

Thus, the development of prehypertension and hypertension is characterized by an increase in the activity of biochemical markers of endothelial dysfunction and damage to target organs, more expressed in the presence of hypertension.

Non-Coding RNA in the Pathogenesis, Progression and Treatment of Hypertension

Hypertension is a complex, multifactorial disease that involves the coexistence of multiple risk factors, environmental factors and physiological systems. The complexities extend to the treatment and management of hypertension, which are still the pursuit of many researchers. In the last two decades, various genes have emerged as possible biomarkers and have become the target for investigations of specialized drug design based on its risk factors and the primary cause. Owing to the growing technology of microarrays and next-generation sequencing, the non-protein-coding RNAs (ncRNAs) have increasingly gained attention, and their status of redundancy has flipped to importance in normal cellular processes, as well as in disease progression. The ncRNA molecules make up a significant portion of the human genome, and their role in diseases continues to be uncovered. Specifically, the cellular role of these ncRNAs has played a part in the pathogenesis of hypertension and its progression to heart failure. This review explores the function of the ncRNAs, their types and biology, the current update of their association with hypertension pathology and the potential new therapeutic regime for hypertension.

Predictors of oedema type in reversible posterior leukoencephalopathy syndrome with preeclampsia or eclampsia

OBJECTIVE

To explore the predictive factors of oedema types in reversible posterior leukoencephalopathy syndrome (RPLS) with preeclampsia (PE) and eclampsia, which is closely related to reversible lesions and clinical recovery.

METHOD

We collected data from 44 consecutive patients diagnosed with RPLS in PE or eclampsia between 2013 and 2017. All patients were classified into vasogenic oedema (n = 31) or cytotoxic oedema (n = 13) groups according to magnetic resonance imaging (MRI) results. General information, clinical data, biochemical indicators and imaging features were collected retrospectively to explore the differences between the groups. Furthermore, we analysed potential predictive factors by logistic regression.

RESULTS

The occurrence rates of immune disease and stillbirth, hospitalization time and the levels of serum albumin (ALB), lactate dehydrogenase (LDH), aspartate transaminase (AST) and alanine aminotransferase (ALT) were higher, while the values of systolic blood pressure (SBP), mean arterial pressure (MAP) and 24-h urine protein were lower in the cytotoxic oedema patients than those in the vasogenic oedema patients (p < .05). The ALB concentration was closely correlated with vasogenic oedema, while AST and ALT were closely correlated with cytotoxic oedema by logistic regression (p < .05).

CONCLUSION

The levels of ALB, AST and ALT are potential predictors for the development of oedema in RPLS. ALB is related to vasogenic oedema by a possible mechanism of decreased colloid osmotic pressure, while AST and ALT are related to cytotoxic oedema by a possible mechanism of endothelial dysfunction.

Free androgen index as a determinant of arterial stiffness in menopause: a mediation analysis

OBJECTIVE

Associations of endogenous androgens in menopause with blood pressure (BP) and indices of arterial stiffness are reported, but directional relationships are not clear. Structural equation modeling is a contemporary statistical method, which allows assessment of such relationships and improves pathway understanding.

METHODS

We recruited 411 consecutive apparently healthy postmenopausal women who underwent noninvasive vascular evaluation. This included pulse wave analysis (aortic pressures and arterial wave reflections [augmentation index]), measurement of aortic stiffness by pulse wave velocity (PWV), stiffness index (SI), and flow-mediated dilatation. A cumulative marker combining PWV and SI (combined local and aortic arterial stiffness [CAS]) was also assessed. Free androgen index (FAI) was calculated from circulating total testosterone and sex hormone-binding globulin.

RESULTS

FAI was an independent determinant of systolic BP (SBP) (P = 0.032), SI (P = 0.042), and PWV (P = 0.027). Under structural equation modeling analysis, FAI was a direct predictor for PWV (beta = 0.149, P = 0.014), SI (beta = 0.154, P = 0.022), and CAS (beta = 0.193, P = 0.02), whereas SBP was a parallel mediator of androgen's vascular effects on PWV (beta = 0.280, P < 0.001) and CAS (beta = 0.248, P = 0.004), but not SI (beta = 0.024, P = 0.404). FAI-induced increase in arterial stiffness via flow-mediated dilatation was not established. FAI was not a determinant of augmentation index.

CONCLUSIONS

In healthy postmenopausal women, FAI was directly associated with PWV, SI, and CAS. FAI also directly correlated with SBP, which in turn concurrently increased PWV and CAS. The directional correlations found herein, imply that endogenous androgens may be causally associated with indices of arterial stiffness both directly and indirectly. This hypothesis should be confirmed in further studies with causal design.

Anti-oxidants correct disturbance of redox enzymes in the hearts of rat fetuses with congenital diaphragmatic hernia

AIM

To evaluate if the redox system is unbalanced in the hearts of nitrofen-induced congenital diaphragmatic hernia  (CDH) animals and to study the possible preventive effects of two anti-oxidant treatments, apocynin and epigallocatechin-3-gallate (EGCG).

METHODS

Adult rats were divided into four groups. Group 1: rats received only vehicle on day E9.5. Group 2: rats received 100 mg nitrofen on day E9.5. Group 3: 1 month before mating rats received apocynin 1.5 mM and, when pregnant, 100 mg nitrofen on day E9.5. Group 4: same than group 3 but with EGCG 30 mg/kg. All fetuses were recovered at term and the hearts were processed. Nox activity and mRNA levels of Nox1, Nox2, Nox4, SOD1, SOD2, SOD3, catalase, and GPX1 were analyzed. Nox, SOD, and Catalase activity and H2O2 production were also evaluated.

RESULTS

Nox activity, H₂O₂ production and Nox1, Nox2, and Nox4 mRNA levels were increased in the hearts of fetuses with CDH. There were no changes in SOD1 levels, whereas those of SOD2, SOD3, catalase, and GPX1 mRNA were decreased. Apocynin and EGCG treatments attenuated the increment of Nox and SOD activities and H₂O₂ production was only decreased by apocynin.

CONCLUSION

These findings suggest a possible preventive effect on the abnormal redox metabolism of anti-oxidant treatments in the hearts from rat fetuses with CDH. If the same occurs in humans, it could represent a potential tool in future prenatal treatment.

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.

Endothelial transcriptomics reveals activation of fibrosis-related pathways in hypertension

Hypertension poses a significant challenge to vasculature homeostasis and stands as the most common cardiovascular disease in the world. Its effects are especially profound on endothelial cells that form the inner lining of the vasculature and are directly exposed to the effects of excess pressure. Here, we characterize the in vivo transcriptomic response of cardiac endothelial cells to hypertension by rapidly isolating these cells from the spontaneous hypertension mouse model BPH/2J and its normotensive BPN/3J control strain and performing and RNA sequencing on both. Comparison of transcriptional differences between these groups reveals statistically significant changes in cellular pathways consistent with cardiac fibrosis found in hypertensive animals. Importantly, many of the fibrosis-linked genes identified also differ significantly between juvenile prehypertensive and adult hypertensive BPH/2J mice, suggesting that these transcriptional differences are hypertension related. We examined the dynamic nature of these transcriptional changes by testing whether blood pressure normalization using either a calcium channel blocker (amlodipine) or a angiotensin II receptor blocker (losartan) is able to reverse these expression patterns associated with hypertension. We find that blood pressure reduction is capable of reversing some gene-expression patterns, while other transcripts are recalcitrant to therapeutic intervention. This illuminates the possibility that unmanaged hypertension may irreversibly alter some endothelial transcriptional patterns despite later intervention. This study quantifies how endothelial cells are remodeled at the molecular level in cardiovascular pathology and advances our understanding of the transcriptional events associated with endothelial response to hypertensive challenge.

Endothelial nitric oxide synthase modulates Toll-like receptor 4-mediated IL-6 production and permeability via nitric oxide-independent signaling

Endothelial dysfunction, characterized by changes in eNOS, is a common finding in chronic inflammatory vascular diseases. These states are associated with increased infectious complications. We hypothesized that alterations in eNOS would enhance the response to LPS-mediated TLR4 inflammation. Human microvascular endothelial cells were treated with sepiapterin or N-nitro-L-arginine methylester (L-NAME) to alter endogenous NO production, and small interfering RNA to knockdown eNOS. Alterations of endogenous NO by sepiapterin, and L-NAME provided no significant changes to LPS inflammation. In contrast, eNOS knockdown greatly enhanced endothelial IL-6 production and permeability in response to LPS. Knockdown of eNOS enhanced LPS-induced p38. Inhibition of p38 with SB203580 prevented IL-6 production, without altering permeability. Knockdown of p38 impaired NF-κB activation. Physical interaction between p38 and eNOS was demonstrated by immunoprecipitation, suggesting a novel, NO-independent mechanism for eNOS regulation of TLR4. In correlation, biopsy samples in patients with systemic lupus erythematous showed reduced eNOS expression with associated elevations in TLR4 and p38, suggesting an in vivo link. Thus, reduced expression of eNOS, as seen in chronic inflammatory disease, was associated with enhanced TLR4 signaling through p38. This may enhance the response to infection in patients with chronic inflammatory conditions.-Stark, R. J., Koch, S. R., Choi, H., Mace, E. H., Dikalov, S. I., Sherwood, E. R., Lamb, F. S. Endothelial nitric oxide synthase modulates Toll-like receptor 4-mediated IL-6 production and permeability via nitric oxide-independent signaling.

Aspirin for Evidence-Based Preeclampsia Prevention trial: effect of aspirin in prevention of preterm preeclampsia in subgroups of women according to their characteristics and medical and obstetrical history

BACKGROUND

The Combined Multimarker Screening and Randomized Patient Treatment with Aspirin for Evidence-Based Preeclampsia Prevention trial demonstrated that in women who were at high risk for preterm preeclampsia with delivery at <37 weeks' gestation identified by screening by means of an algorithm that combines maternal factors and biomarkers at 11-13 weeks' gestation, aspirin administration from 11 to 14 until 36 weeks' gestation was associated with a significant reduction in the incidence of preterm preeclampsia (odds ratio 0.38; 95% confidence interval, 0.20 to 0.74; P=0.004).

OBJECTIVE

We sought to examine whether there are differences in the effect of aspirin on the incidence of preterm preeclampsia in the Aspirin for Evidence-Based Preeclampsia Prevention trial in subgroups defined according to maternal characteristics and medical and obstetrical history.

STUDY DESIGN

This was a secondary analysis of data from the Aspirin for Evidence-Based Preeclampsia Prevention trial. Subgroup analysis was performed to assess evidence of differences in the effect of aspirin on incidence of preterm preeclampsia in subgroups defined by maternal age (<30 and ≥30 years), body mass index (<25 and ≥25 kg/m²), racial origin (Afro-Caribbean, Caucasian and other), method of conception (natural and assisted), cigarette smoking (smoker and non-smoker), family history of preterm preeclampsia (present and absent), obstetrical history (nulliparous, multiparous with previous preterm preeclampsia and multiparous without previous preterm preeclampsia), history of chronic hypertension (present and absent). Interaction tests were performed on the full data set of patients in the intention to treat population and on the data set of patients who took ≥ 90% of the prescribed medication. Results are presented as forest plot with P values for the interaction effects, group sizes, event counts and estimated odds ratios. We examined whether the test of interaction was significant at the 5% level with a Bonferroni adjustment for multiple comparisons.

RESULTS

There was no evidence of heterogeneity in the aspirin effect in subgroups defined according to maternal characteristics and obstetrical history. In participants with chronic hypertension preterm preeclampsia occurred in 10.2% (5/49) in the aspirin group and 8.2% (5/61) in the placebo group (adjusted odds ratio, 1.29; 95% confidence interval, 0.33-5.12). The respective values in those without chronic hypertension were 1.1% (8/749) in the aspirin group and 3.9% (30/761) in the placebo group (adjusted odds ratio, 0.27; 95% confidence interval, 0.12-0.60). In all participants with adherence of ≥90% the adjusted odds ratio in the aspirin group was 0.24 (95% confidence interval, 0.09-0.65); in the subgroup with chronic hypertension it was 2.06 (95% confidence interval, 0.40-10.71); and in those without chronic hypertension it was 0.05 (95% confidence interval, 0.01-0.41). For the complete data set the test of interaction was not significant at the 5% level (P = .055), but in those with adherence ≥90%, after adjustment for multiple comparisons, the interaction was significant at the 5% level (P = .0019).

CONCLUSION

The beneficial effect of aspirin in the prevention of preterm preeclampsia may not apply in pregnancies with chronic hypertension. There was no evidence of heterogeneity in the aspirin effect in subgroups defined according to maternal characteristics and obstetrical history.

Endocan Concentration in Patients With Primary Hypertension

Inflammation and endothelial dysfunction may play an important role in the multifactorial pathogenesis of hypertension. Endocan is also thought to play a role in cell adhesion and inflammatory disorders. The aim of the study was to compare endocan concentrations in patients with primary hypertension and healthy volunteers. There were 104 patients with hypertension (study group) and 21 healthy volunteers (control group). The correlation between endocan, catecholamines, and blood pressure control in patients with primary hypertension and the control group was analyzed. The median endocan concentration in the study group (2.03 ng/mL) was significantly higher than in the control group (1.09 ng/mL, P = .0001). Endocan concentration was correlated positively with renalase ( r = .2, P = .047) and norepinephrine ( r = .25, P = .02). Negative correlation was observed between endocan and body mass index ( r = −.25, P = .016) and leukocyte count ( r = −.36, P = .0004). The present study reports higher plasma endocan concentration in patients with treated, well-controlled primary hypertension compared with healthy volunteers. The higher endocan concentration in the study group may reflect endothelial dysfunction in this population.

Impaired placentation in women with chronic hypertension who develop pre-eclampsia

OBJECTIVE

To compare the degree of impaired placentation in women with and those without chronic hypertension (CH) who develop pre-eclampsia (PE) in pregnancy.

METHODS

Data were derived from prospective screening for adverse pregnancy outcomes in women with singleton pregnancy attending their first routine hospital visit at 11 + 0 to 13 + 6 weeks' gestation. This visit included recording of maternal characteristics and medical history and measurement of mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), serum placental growth factor (PlGF) and serum pregnancy-associated plasma protein-A (PAPP-A). The measured biomarkers were converted to multiples of the median (MoM) after adjustment for pregnancy characteristics. MoM values in women with CH who developed PE (n = 283) were compared to those of women without CH who developed PE (n = 2236).

RESULTS

In both groups with and without CH, measurements of MAP and UtA-PI were increased, whereas those of PlGF and PAPP-A were decreased and the deviation from normal in all biomarkers decreased with advancing gestational age at delivery with PE. There was no significant difference between women with and those without CH in the slope of the regression line of log₁₀ MoM biomarker values against gestational age at delivery with PE for any of the biomarkers. However, there was a significant difference in the intercepts and coefficients of biomarkers in the two groups; compared to those without CH, MAP MoM, PlGF MoM and PAPP-A MoM were higher and UtA-PI MoM was lower in the CH group (all P < 0.01).

CONCLUSION

In pregnancies that develop PE, the degree of impaired placentation, reflected in high UtA-PI and low PlGF and PAPP-A at 11-13 weeks' gestation, is less in women with CH than in those without CH. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Integrative Medicine for Cardiovascular Disease and Prevention

Cardiovascular disease (CVD) is traditionally treated through medications and lifestyle modifications, yet adherence to these treatments is often poor. The use of complementary therapies is increasing, and it is vital for physicians to be aware of the risks and benefits of these options. This article summarizes the current evidence base on integrative therapies for the prevention and treatment of CVD, including hypertension, hyperlipidemia, coronary artery disease, heart failure, and arrhythmias. Where applicable, recommendations are included for therapies that may be used as an adjunct to traditional medical care to improve cardiovascular health and quality of life.

Prognostic Value of the CHADS2 Score for Adverse Cardiovascular Events in Coronary Artery Disease Patients Without Atrial Fibrillation-A Multi-Center Observational Cohort Study

Background

The CHADS₂ score has mainly been used to predict the likelihood of cerebrovascular accidents in patients with atrial fibrillation. However, increasing attention is being paid to this scoring system for risk stratification of patients with coronary artery disease. We investigated the value of the CHADS₂ score in predicting cardiovascular/cerebrovascular events in coronary artery disease patients without atrial fibrillation.

Methods and Results

This was a multicenter, observational cohort study. The subjects had been admitted to one of the participating institutions with coronary artery disease requiring percutaneous coronary intervention. We calculated the CHADS₂ scores for 7082 patients (mean age, 69.7 years; males, 71.9%) without clinical evidence of atrial fibrillation. Subjects were subdivided into low‐ (0–1), intermediate‐ (2–3), and high‐score (4–6) groups and followed for 1 year. The end point was a composite of cardiovascular/cerebrovascular death, nonfatal myocardial infarction, and ischemic stroke at 1‐year follow‐up. Rates of triple‐vessel/left main trunk disease correlated positively with CHADS₂ score categories. CHADS₂ scores among single, double, and triple‐vessel/left main trunk groups were 2 (1–2), 2 (1–3), and 2 (2–3), respectively (P<0.001). A total of 194 patients (2.8%) had a cardiovascular/cerebrovascular event, and Kaplan–Meier analysis demonstrated a significantly higher probability of cardiovascular/cerebrovascular events in proportion to a higher CHADS₂ score (log‐rank test, P<0.001). Multivariate Cox hazard analysis identified CHADS₂ score (per 1 point) as an independent predictor of cardiovascular/cerebrovascular events (hazard ratio, 1.31; 95% CI, 1.17–1.47; P<0.001).

Conclusions

This large cohort study indicated that the CHADS₂ score is useful for the prediction of cardiovascular/cerebrovascular events in coronary artery disease patients without atrial fibrillation.

Effect of Intensive Periodontal Therapy on Blood Pressure and Endothelial Microparticles in Patients With Prehypertension and Periodontitis: A Randomized Controlled Trial

BACKGROUND

Although some studies show a positive association between periodontitis and blood pressure (BP) elevation, research on the effect of intensive periodontal treatment on decline in BP levels and endothelial microparticles (EMPs) without any antihypertensive management is lacking. Therefore, the present clinical trial explores whether intensive periodontal therapy would lower BP levels and EMPs of patients with prehypertension with periodontitis.

METHODS

From a total 107 patients, 95 underwent randomization (47 assigned to control-treatment [CT] group and 48 assigned to intensive-treatment [IT] group) and completed the trial. Patients received intervention for 4 consecutive weeks and were followed for 6 months. Levels of BP and EMPs were evaluated at baseline and 1, 3, and 6 months after intervention.

RESULTS

Periodontal conditions were significantly improved (P <0.05) 6 months after intensive periodontal treatment. In parallel, the primary outcomes including systolic and diastolic BP and EMPs were markedly reduced in the IT group compared with the CT group (absolute difference: 12.57 and 9.65 mm Hg and 581.59/μL, respectively; 95% confidence intervals: 10.45 to 14.69, 7.06 to 12.24, and 348.12 to 815.06, respectively; P <0.05). Reduction in BP levels and EMPs was related to improvement in probing depth (r = 0.358, 0.363, and 0.676, respectively, by the Pearson product-moment correlation; P = 0.009, 0.008, and P <0.001, respectively).

CONCLUSION

To the best knowledge of the authors, the present study demonstrates for the first time that intensive periodontal intervention without any antihypertensive medication therapy may be an effective means to lower levels of BP and EMPs in patients with prehypertension with periodontitis.

New insights into the non-hemostatic role of von Willebrand factor in endothelial protection

During exposure to ischemia-reperfusion (I/R) insult, angiotensin II (AngII)-induced endothelin-1 (ET-1) upregulation in endothelial cells progressively impairs nitric oxide (NO) bioavailability while increasing levels of superoxide anion (O₂^-) and leading to the onset of endothelial dysfunction. Moreover, the overexpression of ET-1 increases the endothelial and circulating levels of von Willebrand factor (vWF), a glycoprotein with a crucial role in arterial thrombus formation. Nowadays, the non-hemostatic role of endothelial vWF is emerging, although we do not yet know whether its increased expression is cause or consequence of endothelial dysfunction. Notably, the vWF blockade or depletion leads to endothelial protection in cultured cells, animal models of vascular injury, and patients as well. Despite the recent efforts to develop an effective pharmacological strategy, the onset of endothelial dysfunction is still difficult to prevent and remains closely related to adverse clinical outcome. Unraveling the non-hemostatic role of endothelial vWF in the onset of endothelial dysfunction could provide new avenues for protection against vascular injury mediated by AngII.

Blood Pressure Trajectories and the Risk of Intracerebral Hemorrhage and Cerebral Infarction: A Prospective Study

The association between long-term blood pressure (BP) patterns in community-dwelling adults and risk of intracerebral hemorrhage and cerebral infarction is not well characterized. This prospective study included 79 385 participants, free of stroke, myocardial infarction, and cancer in or before 2010 (baseline). Systolic BP trajectories were identified using latent mixture modeling with data from 2006, 2008, and 2010. Incident cases of intracerebral hemorrhage and cerebral infarction occurred during 2010 to 2014, confirmed by review of medical records, by 3 physicians. We identified 5 distinct systolic BP trajectories during 2006 to 2010. Each of the trajectories was labeled according to their BP range and pattern over time: normotensive-stable (n=26 740), prehypertension-stable (n=35 674), stage 1 hypertension-increasing (n=8215), stage 1 hypertension-decreasing (n=6422), and stage 2 hypertension-stable (n=2334). We documented 1034 incident cases of cerebral infarction and 187 cases of intracerebral hemorrhage. Although the prehypertension-stable trajectory exhibited systolic BP range within the normal range (120-140 mm Hg) during 2006 to 2010, this group had higher stroke risk relative to the normotensive-stable group (<120 mm Hg) (adjusted hazard ratio was 3.11 for intracerebral hemorrhage and 1.99 for cerebral infarction; P<0.001 for both), after adjusting for possible confounders. Individuals in the stage 2 hypertension-stable systolic BP trajectory (175-179 mm Hg) had the highest risk of intracerebral hemorrhage (adjusted hazard ratio was 12.4) and cerebral infarction (adjusted hazard ratio was 5.07), relative to the normotensive-stable group (P<0.001 for both). BP trajectories were associated with the risk of stroke and increasing BP trajectories within the currently designated normal range may still increase the risk for stroke.

MicroRNAs Modulate Oxidative Stress in Hypertension through PARP-1 Regulation

Oxidative stress is thought to contribute to aging and age-related diseases, such as cardiovascular and neurodegenerative diseases, and is a risk factor for systemic arterial hypertension. Previously, we reported differential mRNA and microRNA (miRNA) expression between African American (AA) and white women with hypertension. Here, we found that the poly-(ADP-ribose) polymerase 1 (PARP-1), a DNA damage sensor protein involved in DNA repair and other cellular processes, is upregulated in AA women with hypertension. To explore this mechanism, we identified two miRNAs, miR-103a-2-5p and miR-585-5p, that are differentially expressed with hypertension and were predicted to target PARP1. Through overexpression of each miRNA-downregulated PARP-1 mRNA and protein levels and using heterologous luciferase reporter assays, we demonstrate that miR-103a-2-5p and miR-585-5p regulate PARP1 through binding within the coding region. Given the important role of PARP-1 in DNA repair, we assessed whether overexpression of miR-103a-2-5p or miR-585-5p affected DNA damage and cell survival. Overexpression of these miRNAs enhanced DNA damage and decreased both cell survival and colony formation. These findings highlight the role for PARP-1 in regulating oxidative DNA damage in hypertension and identify important new miRNA regulators of PARP-1 expression. These insights may provide additional avenues to understand hypertension health disparities.

TRPV4: Molecular Conductor of a Diverse Orchestra

Transient receptor potential vanilloid type 4 (TRPV4) is a calcium-permeable nonselective cation channel, originally described in 2000 by research teams led by Schultz (Nat Cell Biol 2: 695-702, 2000) and Liedtke (Cell 103: 525-535, 2000). TRPV4 is now recognized as being a polymodal ionotropic receptor that is activated by a disparate array of stimuli, ranging from hypotonicity to heat and acidic pH. Importantly, this ion channel is constitutively expressed and capable of spontaneous activity in the absence of agonist stimulation, which suggests that it serves important physiological functions, as does its widespread dissemination throughout the body and its capacity to interact with other proteins. Not surprisingly, therefore, it has emerged more recently that TRPV4 fulfills a great number of important physiological roles and that various disease states are attributable to the absence, or abnormal functioning, of this ion channel. Here, we review the known characteristics of this ion channel's structure, localization and function, including its activators, and examine its functional importance in health and disease.

Prolactin as a predictor of endothelial dysfunction and arterial stiffness progression in menopause

Postmenopausal women are at increased risk for progression of arteriosclerosis and hypertension. Recent cross-sectional evidence suggests that high normal circulating prolactin levels may accelerate vascular ageing in menopause. Postmenopausal women (n=201) were consecutively recruited from a Menopause Clinic and re-evaluated in at least one follow-up visit within the next 3 years. Baseline circulating prolactin levels were measured while both baseline and follow-up vascular and biochemical measurements were performed. Endothelial function was assessed by flow-mediated dilation (FMD), aortic stiffness by pulse-wave velocity (PWV) and arterial wave reflections by applanation tonometry. Baseline prolactin significantly correlated with lower FMD at follow-up (P=0.005). After multivariable adjustment for age, follow-up time, blood pressure (BP), body mass index, smoking and medication, this correlation remained significant (P=0.003). In addition, baseline circulating prolactin levels were independently associated with changes in mean BP (β=0.131, P=0.021), peripheral diastolic BP (β=0.169, P=0.004) and new-onset hypertension (OR=1.235, P=0.001). Owing to significant interaction between baseline prolactin and age for changes in PWV over time (P=0.036), a subgroup analysis based on median age was performed. This analysis revealed that in women younger than 55 years, prolactin was an independent predictor of changes in PWV over time (P=0.008). In conclusion, high normal circulating prolactin levels predict changes in haemodynamic indices and worsening endothelial function in healthy postmenopausal women. Particularly in young postmenopausal women, prolactin predicts accelerated arterial stiffening.

Cardiac and renal complications of carfilzomib in patients with multiple myeloma

Clinical trials with carfilzomib have indicated a low but reproducible incidence of cardiovascular and renal toxicities. Among 60 consecutive myeloma patients treated with carfilzomib-based regimens who were thoroughly evaluated for cardiovascular risk factors, 12% (95% confidence interval, 3.8%-20%) experienced a reversible reduction of left ventricular ejection fraction (LVEF) by ≥20%, an objective measure of cardiac dysfunction. The incidence of LVEF reduction was 5% at 3 months, 8% at 6 months, 10% at 12 months, and 12% at 15 months, whereas the respective carfilzomib discontinuation rate unrelated to toxicity was 17%, 35%, 41%, and 49%. The presence of any previously known cardiovascular disease was associated with an increased incidence of cardiac events (23.5% vs 7%; P = .07), but there was no association with the dose of carfilzomib or the duration of infusion. Re-treatment with carfilzomib at lower doses was possible. Carfilzomib was commonly associated with a transient reduction of estimated glomerular filtration rate (eGFR) but also improved renal function in 55% of patients with baseline eGFR <60 mL/min/1.73 m². Further investigation is needed to elucidate the underlying mechanisms of carfilzomib-related cardiorenal toxicity.

The effect of candesartan on pentraxin-3 plasma levels as marker of endothelial dysfunction in patients with essential arterial hypertension

BACKGROUND

In the last decades, the studies performed on the field of endothelial dysfunction confirmed the fact that the starting point of this pathology is the inflammation. Several inflammatory biomarkers had been discovered and studied, ones showing systemic inflammation, and others being more specific biomarkers and showing the local inflammation. Pentraxin-3 (PTX3) is a new inflammatory biomarker, from the same family as high-selectivity C-reactive protein (hs-CRP), but it is a more specific biomarker, due to its local production: the endothelial cells and not the liver like in the case of hs-CRP.

AIMS

Several antihypertensive classes of drugs seem to have a positive impact on reducing the local endothelial inflammation, beyond their effect of lowering the blood pressure, so this study aims to analyze the effect of candesartan on the two inflammatory biomarkers: PTX3 and CRP, compared with other antihypertensive drugs, in hypertensive patients with endothelial dysfunction.

METHODS

A total of 365 patients were included in the study: 127 hypertensive patients were under treatment with candesartan, 134 patients were under treatment with other hypotensive medication (beta blockers, calcium channel blockers, and diuretics), both groups with controlled values of blood pressure, and 104 were normotensive persons. Classical methods of assessing the endothelial function were correlated with these biochemical markers.

RESULTS

The patients treated with candesartan had a significant lower value of PTX3 and hs-CRP, compared with those under treatment with other antihypertensive medication as follows: PTX3: 0.61 ± 0.49 vs 0.95 ± 1.04 ng/ml, P = 0.006 and hs-CRP: 0.19 ± 0.20 vs 0.20 ± 0.22 mg/dl, P = 0.54.

CONCLUSIONS

Candesartan decreases PTX3 and hs-CRP plasma levels more powerful than other classes of antihypertensive drugs (beta blockers, calcium channel blockers, and diuretics), so we may assume that candesartan has a more potent action in reversing endothelial dysfunction and that it offers a higher vascular protection than other classes of antihypertensive drugs. We are suggesting that this new biochemical marker, PTX3, might be better and more specific marker for endothelial dysfunction, than hs-CRP.

Effects of Aspirin on Endothelial Function and Hypertension

PURPOSE OF REVIEW

Endothelial dysfunction is intimately related to the development of various cardiovascular diseases, including hypertension, and is often used as a target for pharmacological treatment. The scope of this review is to assess effects of aspirin on endothelial function and their clinical implication in arterial hypertension.

RECENT FINDINGS

Emerging data indicate the role of platelets in the development of vascular inflammation due to the release of proinflammatory mediators, for example, triggered largely by thromboxane. Vascular inflammation further promotes oxidative stress, diminished synthesis of vasodilators, proaggregatory and procoagulant state. These changes translate into vasoconstriction, impaired circulation and thrombotic complications. Aspirin inhibits thromboxane synthesis, abolishes platelets activation and acetylates enzymes switching them to the synthesis of anti-inflammatory substances. Aspirin pleiotropic effects have not been fully elucidated yet. In secondary prevention studies, the decrease in cardiovascular events with aspirin outweighs bleeding risks, but this is not the case in primary prevention settings. Ongoing trials will provide more evidence on whether to expand the use of aspirin or stay within current recommendations.

Human Endothelial Cell-Specific Molecule-1 (Endocan) and Coronary Artery Disease and Microvascular Angina

Endothelial cell-specific molecule-1 (endocan) is an immunoinflammatory marker linked to endothelial activation and dysfunction. We investigated the relationship between obstructive coronary artery disease (CAD), microvascular angina (MVA), and plasma levels of endocan. We included 53 healthy individuals as controls, 40 MVA patients, and 120 patients with obstructive CAD. The severity of CAD was assessed by the Gensini and SYNergy between percutaneous coronary intervention with TAXUS and Cardiac Surgery (SYNTAX) scores. Endocan levels were 382.7 (313.8-470.2) pg/mL in patients with obstructive CAD; 324.3 (277.1-460.7) pg/mL in MVA group, and 268.0 (226.4-336.5) pg/mL ( P < .001) in controls. Endocan levels in obstructive CAD and MVA groups were similar but both were significantly higher than for the control group ( P < .001 and P = .002, respectively). In subgroup analysis, similar to the hypertensive subgroup results, endocan was still an independent predictor of presence of obstructive CAD in normotensives (odds ratio = 1.005, 95% confidence interval = 1.001-1.010, P = .024). There was also an independent positive correlation between endocan levels and SYNTAX score both in the hypertensives (β = 0.414, t = 3.21, P = .002) and in the normotensives (β = .301, t = 2.23, P = .031). In conclusion, endocan could be a common predictor of the endothelium-dependent inflammatory processes, rather than related with specific risk factors.

Association of Endothelial and Mild Renal Dysfunction With the Severity of Left Ventricular Hypertrophy in Hypertensive Patients

BACKGROUND

The association between impaired renal function and increase left ventricular mass was shown to be related to increase in arterial stiffness, which indicates that vascular homeostasis and remodeling may impact the left ventricular hypertrophy (LVH) in patients with renal dysfunction.

METHODS

We measured the peripheral arterial reactive hyperemia index (RHI) and estimated glomerular filtration rate (eGFR) in 317 hypertensive patients comprising 115 normal RHI (RHI > 1.67) and normal eGFR (eGFR ≥ 90ml/min per 1.73 m(2)), 136 low RHI (RHI ≤ 1.67), 27 low eGFR (60 ≤ eGFR < 90ml/min per 1.73 m(2)) and 39 low RHI combined with low eGFR.

RESULTS

Multivariate logistic regression analysis identified lg RHI (odds ratio (OR): 0.001, 95% confidence interval (CI): 10(-6) to 0.426, P = 0.024) and lg eGFR (OR: 0.009, 95% CI: 10(-4) to 0.414, P = 0.016) as independent factors correlated with LVH respectively in hypertensive patients. Compared with normal RHI and eGFR patients, the extent of LVH in patients with either low RHI (OR: 1.224 95% CI: 0.451 to 3.327, P = 0.691) or low eGFR (OR: 0.593 95% CI: 0.070 to 5.037, P = 0.632) did not significantly increase, while it increased significantly in patients with low RHI combined with low eGFR (OR: 4.629 95% CI: 1.592 to 13.458, P = 0.005).

CONCLUSIONS

The concurrence of endothelial and mild renal dysfunction was significantly associated with the severity of LVH in hypertensive patients.

Chronic depression symptoms and salivary NOx are associated with retinal vascular dysregulation: The SABPA study

BACKGROUND

Depression has been associated with impaired nitric oxide (NO)-mediated vasodilation and vascular dysregulation (VD). Whether depression and NO levels will disturb retinal haemodynamics is not clear.

OBJECTIVES AND METHODS

Associations between the retinal vasculature, diastolic ocular perfusion pressure (DOPP) as measure of hypoperfusion, NO metabolites (NOx) and depression symptoms were assessed. Chronic VD risk markers [depression symptoms (Patient Health Questionnaire/PHQ-9 ≥ 10) and 24 h pulse pressure] were determined in a bi-ethnic cohort (n = 313; 48.6 ± 9 years; 53.9% men). At 3 year follow-up, retinal vessel calibre and retinopathy signs were quantified from digital images. Salivary NOx was obtained pre- and post-flicker light-induced provocation (FLIP). DOPP was defined as diastolic blood pressure minus intraocular pressure.

RESULTS

Chronic VD risk was evident in Blacks opposed to acute risk in Whites (P < 0.05). At follow-up, retinopathy (Blacks 60.4%/Whites 39.6%), lower pre-FLIP (μM) and higher post-FLIP NOx (changes from baseline, %), arteriolar narrowing and wider venular calibre values were evident in Blacks compared to Whites, independent of confounders. A wider venular calibre, an index of stroke risk, was associated with chronic depression symptoms [cut point 248 MU: Area under the curve 0.61 (95% CI: 0.51, 0.72); 71% sensitivity; 55% specificity] as well as with hypoperfusion in the Blacks. In this group, arteriolar narrowing was associated with hypoperfusion; and attenuated arteriolar dilation with increased post-FLIP NOx responses.

CONCLUSIONS

Chronic depression symptoms may alter NO regulation and facilitate VD. NO-mediated vasoconstriction presumably impeded perfusion, retinal haemodynamics and -remodelling; potentiating stroke risk in Blacks.

Free androgen index as a predictor of blood pressure progression and accelerated vascular aging in menopause

BACKGROUND AND AIMS

We aimed to assess the prognostic value of free androgen index (FAI) and its change over time in arterial stiffness progression, endothelial function and hypertension in postmenopausal women.

METHODS

Postmenopausal women (n = 180) without clinically overt cardiovascular disease or diabetes were consecutively recruited and followed for a median of 29 months. The main outcome measures were changes over time in endothelial function (FMD), reflected waves, localized and systemic (PWV) arterial stiffness and hypertension.

RESULTS

Increased baseline FAI was significantly associated with new onset hypertension (OR for each SD, 2.71, 95% CI 1.14-6.41, p = 0.024), deterioration of pulse wave velocity (PWV) (0.414 m/s per SD), flow-mediated dilation (FMD) (-0.42% per SD), systolic (2.5 mmHg per SD) and pulse pressure progression (2.3 mmHg per SD, p < 0.05 for all). Baseline FAI remained an independent predictor of changes in PWV (p = 0.006), FMD (p = 0.02), peripheral pulse pressure (p = 0.028), transition to new onset hypertension (p = 0.001) and higher BP category (p = 0.012), after adjustment for age, changes in systolic blood pressure, traditional risk factors, vasoactive medication or total testosterone. Baseline FAI improved reclassification for the risk of transition into higher BP category (NRI = 47.5 ± 20.3%, p = 0.02) and abnormal PWV (NRI = 53.4 ± 23.2%, p = 0.021). Similarly, in a subgroup of patients with measured FAI at follow-up, its changes over time predicted changes in PWV, peripheral pulse pressure and hypertension status (p < 0.05 for all).

CONCLUSIONS

In apparently healthy postmenopausal women, FAI could be a novel biomarker superior to total testosterone for accelerated vascular aging and hypertension status.

Hypochlorite-Modified Albumin Upregulates ICAM-1 Expression via a MAPK-NF-κB Signaling Cascade: Protective Effects of Apocynin

Hypochlorite-modified albumin (HOCl-alb) has been linked to endothelial dysfunction, which plays an important role in the development of hypertension, diabetes, and chronic kidney disease. However, whether HOCl-alb induces endothelial dysfunction via vascular inflammation and whether a signaling pathway is involved are unknown and have not been investigated. HOCl-alb was found to upregulate ICAM-1 expression in human umbilical vein endothelial cells (HUVECs) in a time- and dose-dependent manner. HOCl-alb time-dependently phosphorylated ERK1/2 and p38(MAPK). HOCl-alb also activated NF-κB. ICAM-1 expression was dose-dependently inhibited by U0126 (a specific inhibitor of MEK1/2, a signal upstream from ERK1/2), SB203580 (a specific inhibitor of p38(MAPK)), and SN50 (a specific inhibitor of NF-κB). U0126 and SB203580 both counteracted the activation of NF-κB, whereas the phosphorylation of ERK1/2 and p38(MAPK) was not blocked by SN50. ERK1/2 phosphorylation was blocked by U0126 but not by SB203580, and p38(MAPK) activity was reduced by SB203580 but not by U0126. Apocynin, a specific NADPH oxidase (NOX) inhibitor, inhibited ICAM-1 expression and the activity of ERK1/2, p38(MAPK), and NF-κB. These results indicate that HOCl-alb-induced ICAM-1 expression is caused by the activation of a redox-sensitive intracellular signal cascade involving ERK1/2 and p38(MAPK), culminating in the activation of NF-κB and involving NOXs among the upstream signals.

Interplay between Superoxide Dismutase, Glutathione Peroxidase, and Peroxisome Proliferator Activated Receptor Gamma Polymorphisms on the Risk of End-Stage Renal Disease among Han Chinese Patients

Background. Single nucleotide polymorphisms (SNPs) of antioxidants, including superoxide dismutase 2 (SOD2) and glutathione peroxidase 1 (GPX1), play an important role in the risk for cancer and metabolic disorders. However, little is known regarding the effect of antioxidant SNPs on renal events. Methods. We prospectively enrolled multicenter patients with end-stage renal disease (ESRD) and those without chronic kidney disease (CKD) of Han Chinese origin, with SOD2 (Val16Ala), GPX1 (Pro197Leu), and PPAR-γ (Pro12Ala, C161T) genotyped. Multiple regression analyses were conducted to evaluate the significant risk determinants for ESRD. Results. Compared to ESRD patients, non-CKD subjects were more likely to have T allele at SOD2 Val16Ala (p = 0.036) and CC genotype at PPAR-γ Pro12Ala (p = 0.028). Regression analysis showed that TT genotype of SOD2 Val16Ala conferred significantly lower ESRD risk among patients without diabetes (odds ratio 0.699; p = 0.018). GPX1 SNP alone did not alter the risk. We detected significant interactions between SNPs including PPAR-γ Pro12Ala, C161T, and GPX1 regarding the risk of ESRD. Conclusion. This is the first and largest study on the association between adverse renal outcomes and antioxidant SNPs among Han Chinese population. Determination of SOD2 and PPAR-γ SNPs status might assist in ESRD risk estimation.

Featured Article: Differential regulation of endothelial nitric oxide synthase phosphorylation by protease-activated receptors in adult human endothelial cells

Protease-activated receptors have been shown to regulate endothelial nitric oxide synthase through the phosphorylation of specific sites on the enzyme. It has been established that PAR-2 activation phosphorylates eNOS-Ser-1177 and leads to the production of the potent vasodilator nitric oxide, while PAR-1 activation phosphorylates eNOS-Thr-495 and decreases nitric oxide production in human umbilical vein endothelial cells. In this study, we hypothesize a differential coupling of protease-activated receptors to the signaling pathways that regulates endothelial nitric oxide synthase and nitric oxide production in primary adult human coronary artery endothelial cells. Using Western Blot analysis, we showed that thrombin and the PAR-1 activating peptide, TFLLR, lead to the phosphorylation of eNOS-Ser-1177 in human coronary artery endothelial cells, which was blocked by SCH-79797 (SCH), a PAR-1 inhibitor. Using the nitrate/nitrite assay, we also demonstrated that the thrombin- and TFLLR-induced production of nitric oxide was inhibited by SCH and L-NAME, a NOS inhibitor. In addition, we observed that TFLLR, unlike thrombin, significantly phosphorylated eNOS-Thr-495, which may explain the observed delay in nitric oxide production in comparison to that of thrombin. Activation of PAR-2 by SLIGRL, a PAR-2 specific ligand, leads to dual phosphorylation of both catalytic sites but primarily regulated eNOS-Thr-495 phosphorylation with no change in nitric oxide production in human coronary artery endothelial cells. PAR-3, known as the non-signaling receptor, was activated by TFRGAP, a PAR-3 mimicking peptide, and significantly induced the phosphorylation of eNOS-Thr-495 with minimal phosphorylation of eNOS-Ser-1177 with no change in nitric oxide production. In addition, we confirmed that PAR-mediated eNOS-Ser-1177 phosphorylation was Ca(2+)-dependent using the Ca(2+) chelator, BAPTA, while eNOS-Thr-495 phosphorylation was mediated via Rho kinase using the ROCK inhibitor, Y-27632, suggesting protease-activated receptor coupling to Gq and G12/13, respectively. These data suggest a vascular bed specific differential coupling of protease-activated receptors to the signaling pathways that regulate endothelial nitric oxide synthase and nitric oxide production that may be responsible for endothelial dysfunction associated with cardiovascular disease.

Reversible Cerebral Vasoconstriction Syndrome and Posterior Reversible Encephalopathy Syndrome Presenting with Deep Intracerebral Hemorrhage in Young Women

Reversible cerebral vasoconstriction syndrome (RCVS) is a group of syndromes characterized by reversible segmental constriction of cerebral arteries. Posterior reversible encephalopathy syndrome (PRES) is another clinical-radiologic syndrome characterized by reversible, posterior-predominant brain edema. Although the exact causes of these reversible syndromes are poorly understood, these entities may share some common pathophysiologic elements leading to hemorrhagic strokes and rarely, deep intracerebral hemorrhage (ICH). Recent studies have suggested that endothelial dysfunction is a common pathophysiologic factor associated with these syndromes. We report on two young female patients who presented with deep ICH and were later diagnosed as RCVS and PRES. Both patients suffered from vasoconstriction and delayed ischemic stroke. Early detection of distinguishing clinical-radiologic features associated with these reversible syndromes and removing triggers would facilitate successful treatment with no complications.

Ghrelin restores nitric oxide availability in resistance circulation of essential hypertensive patients: role of NAD(P)H oxidase

AIMS

We assessed whether acute intra-arterial infusion of exogenous ghrelin can improve endothelial dysfunction by restoring nitric oxide (NO) availability in the forearm microcirculation of essential hypertensive patients. The effect of ghrelin on endothelial dysfunction (pressurized myograph), vascular oxidative stress generation (fluorescent dihydroethidium), and phosphorylation of p47phox (western blot), an index of NAD(P)H oxidase activation, in isolated small arteries taken from essential hypertensive patients (subcutaneous biopsy) were also investigated.

METHODS AND RESULTS

In 18 normotensive control subjects and 18 essential hypertensive patients, we studied the forearm blood flow (strain-gauge plethysmography) response to intra-arterial acetylcholine, repeated under NO synthase inhibitor N(G)-monomethyl-l-arginine (l-NMMA) or the antioxidant ascorbic acid. The protocol was repeated at the end of exogenous ghrelin intra-arterial infusion. In hypertensive patients, ghrelin normalized the blunted response to acetylcholine, restored the inhibiting effect of l-NMMA and abrogated the potentiating effect of ascorbic acid on acetylcholine. In controls, ghrelin failed to modify these vascular responses. In hypertensive patients, ghrelin decreased venous levels of malondialdehyde, lipoperoxide, and interleukin-6, and concomitantly increased endogenous antioxidant capacity. Small vessels from hypertensive patients showed an enhanced intravascular oxidative stress, which was strongly and similarly decreased by incubation with ghrelin, the NAD(P)H oxidase inhibitor gp91 ds-tat, or both. Ghrelin also normalized the overexpression of p47 phosphorylation and restored the NO availability in small vessels from hypertensive patients.

CONCLUSIONS

Exogenous ghrelin increases endothelial dysfunction by restoring NO availability in the forearm microcirculation of essential hypertensive patients, an effect ascribable to an antioxidant effect via inhibition of NAD(P)H oxidase activation.