Effects of BAFF Neutralization on Atherosclerosis Associated With Systemic Lupus Erythematosus

OBJECTIVE

Cardiovascular disease (CVD) is the leading cause of death in systemic lupus erythematosus (SLE). B cells play a key role in the pathogenesis of lupus, and anti-BAFF therapy has been approved for use in SLE. Since mature B cells also promote atherosclerosis, we undertook this study to evaluate, in a mouse model and in SLE patients, whether BAFF neutralization has an atheroprotective effect in SLE.

METHODS

The effect of BAFF on atherosclerosis associated with lupus was investigated in the atherosclerosis/lupus-prone apolipoprotein E-knockout D227K mouse model and in a cohort of SLE patients. Mice were treated with a blocking anti-BAFF monoclonal antibody (mAb), while fed a standard chow diet. Carotid plaque and carotid intima-media thickness were assessed by ultrasound at baseline and during follow-up in SLE patients who were asymptomatic for CVD.

RESULTS

Anti-BAFF mAb in ApoE^-/- D227K mice induced B cell depletion, efficiently treated lupus, and improved atherosclerosis lesions (21% decrease; P = 0.007) in mice with low plasma cholesterol levels but worsened the lesions (17% increase; P = 0.06) in mice with high cholesterol levels. The atheroprotective effect of the BAFF-BAFF receptor signaling inhibition on B cells was counterbalanced by the proatherogenic effect of the BAFF-TACI signaling inhibition on macrophages. In SLE patients, blood BAFF levels were associated with subclinical atherosclerosis (r = 0.26, P = 0.03). Anti-BAFF mAb treatment had a differential effect on the intima-media thickness progression in SLE patients depending on body mass index.

CONCLUSION

Depending on the balance between lipid-induced and B cell-induced proatherogenic conditions, anti-BAFF could be detrimental or beneficial, respectively, to atherosclerosis development in SLE.

Pulmonary haemodynamic effects of interatrial shunt in heart failure with preserved ejection fraction: a preclinical study

AIMS

The aim of this study was to evaluate the effect of the creation of a left-to-right interatrial shunt on pulmonary haemodynamics in rats with heart failure with preserved ejection fraction (HFPEF).

METHODS AND RESULTS

An interatrial communication (IAC) was created in 11 healthy rats (Lewis rats) and 11 rats which developed HFPEF (36-week-old spontaneously hypertensive rats [SHR]). Effects of the interatrial shunt were compared to 11 sham-operated Lewis and 11 sham-operated SHR. At 45 days post shunt, strain effect was observed in diastolic function (E/A ratio, p<0.001; isovolumetric relaxation time, p<0.001), left atrial volume (p=0.005) and pulmonary wall shear rate (WSR) (p=0.02) measured by Doppler echo. At sacrifice of the animals (60 days), a strain effect was also noted in elastin density (p=0.003) and eNOS protein expression (p=0.001). Interatrial shunt creation resulted in (i) an increase in pulmonary WSR (p=0.04) and a decrease in left atrial volume (p<0.001), (ii) an increase in elastin density (p<0.005), and (iii) an increase in eNOS protein expression (p=0.03).

CONCLUSIONS

Creation of a left-to-right atrial shunt in rats with HFPEF was effective in improving pulmonary haemodynamics. In addition, this study provides preliminary evidence of the potential risk of right volume overload and pulmonary hypertension due to atrial shunting.

AB0140 BAFF NEUTRALIZATION HAS JANUS-FACED EFFECT ON ATHEROSCLEROSIS ASSOCIATED WITH SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

Cardiovascular diseases (CVD) are the leading cause of death in systemic lupus erythematosus (SLE). B cells play a key role in the pathogenesis of lupus and anti-BAFF therapy has been approved in SLE. Since mature B cells also promote atherosclerosis, BAFF neutralization is expected to have an atheroprotective effect in SLE.

Objectives:

The aim of our study was to test this hypothesis using a new mouse model with a mix susceptibility to lupus and atherosclerosis that received or not an anti-BAFF treatment, and in a cohort of SLE patients in whom we monitored carotid plaques, the B cell compartment and BAFF levels.

Methods:

The effect of BAFF on atherosclerosis associated with lupus was investigated in the atherosclerosis- and lupus-proneApoe°D227Kmouse model and in a cohort of SLE patients. Mice were treated with a blocking anti-BAFF monoclonal antibody (Ab), while fed with a standard chow diet. Carotid plaque and carotid intima media thickness were assessed by ultrasound at baseline and during follow-up in SLE patients asymptomatic for CVD.

Results:

Anti-BAFF Ab inApoe°D227Kmice i/ induced a B cell depletion, ii/ efficiently treated lupus, iii/improved atherosclerosis lesions in mice that had low plasma cholesterol levels but worsened the lesions in mice with high cholesterol levels. In that case, the atheroprotective effect of the BAFF-BAFFR signaling inhibition on B cells was counterbalanced by the proatherogenic effect of the BAFF-TACI signaling inhibition on macrophages. In SLE patients, BAFF blood levels were associated with subclinical atherosclerosis. Anti-BAFF Ab treatment had a differential effect on the intima media thickness progression in SLE patients depending on the body mass index

Conclusion:

Depending on the balance between metabolic- and B cell-induced proatherogenic conditions, anti-BAFF could be respectively detrimental or beneficial on atherosclerosis development in SLE

Acknowledgments:

Guillaume Even, Yasmine Lamri, Anh-Thu Gaston,

Disclosure of Interests:

Fanny Saidoune Grant/research support from: supported by a research partnerships between the academic and GlaxoSmithKline France.

Anti-BAFF mAb (IgG1, clone 10F4B) in mice was provided by Glaxosmithkline, Nicolas Charles: None declared, Julie Chezel: None declared, Brigitte Escoubet: None declared, Thomas Papo: None declared, Antonino Nicoletti: None declared, karim sacre: None declared

Prokineticin Receptor-1 Signaling Inhibits Dose- and Time-Dependent Anthracycline-Induced Cardiovascular Toxicity Via Myocardial and Vascular Protection

Objectives

This study investigated how different concentrations of doxorubicin (DOX) can affect the function of cardiac cells. This study also examined whether activation of prokineticin receptor (PKR)-1 by a nonpeptide agonist, IS20, prevents DOX-induced cardiovascular toxicity in mouse models.

Background

High prevalence of heart failure during and following cancer treatments remains a subject of intense research and therapeutic interest.

Methods

This study used cultured cardiomyocytes, endothelial cells (ECs), and epicardium-derived progenitor cells (EDPCs) for in vitro assays, tumor-bearing models, and acute and chronic toxicity mouse models for in vivo assays.

Results

Brief exposure to cardiomyocytes with high-dose DOX increased the accumulation of reactive oxygen species (ROS) by inhibiting a detoxification mechanism via stabilization of cytoplasmic nuclear factor, erythroid 2. Prolonged exposure to medium-dose DOX induced apoptosis in cardiomyocytes, ECs, and EDPCs. However, low-dose DOX promoted functional defects without inducing apoptosis in EDPCs and ECs. IS20 alleviated detrimental effects of DOX in cardiac cells by activating the serin threonin protein kinase B (Akt) or mitogen-activated protein kinase pathways. Genetic or pharmacological inactivation of PKR1 subdues these effects of IS20. In a chronic mouse model of DOX cardiotoxicity, IS20 normalized an elevated serum marker of cardiotoxicity and vascular and EDPC deficits, attenuated apoptosis and fibrosis, and improved the survival rate and cardiac function. IS20 did not interfere with the cytotoxicity or antitumor effects of DOX in breast cancer lines or in a mouse model of breast cancer, but it did attenuate the decreases in left ventricular diastolic volume induced by acute DOX treatment.

Conclusions

This study identified the molecular and cellular signature of dose-dependent, DOX-mediated cardiotoxicity and provided evidence that PKR-1 is a promising target to combat cardiotoxicity of cancer treatments.

Soluble CD163 is a biomarker for accelerated atherosclerosis in systemic lupus erythematosus patients at apparent low risk for cardiovascular disease

Objective: This study aimed to determine whether sCD163, a soluble macrophage marker up-regulated in numerous inflammatory disorders, is predictive of accelerated atherosclerosis associated with systemic lupus erythematosus (SLE).Methods: Carotid ultrasound was prospectively performed, at baseline and during follow-up, in 63 consecutive SLE patients asymptomatic for cardiovascular disease (CVD) and 18 volunteer health workers. Serum sCD163 level was determined at baseline using enzyme-linked immunosorbent assay. The primary outcome was the presence of a carotid plaque. Factors associated with carotid plaques were identified through multivariate analysis.Results: Despite a low risk for cardiovascular events according to Framingham score in both groups (2.1 ± 3.8% in SLE vs 2.1 ± 2.9% in controls; p = 0.416), ultrasound at baseline showed a carotid plaque in 23 SLE patients (36.5%) and two controls (11.1%) (p = 0.039). Multivariate analysis showed that SLE status increased the risk for carotid plaque by a factor of 9 (p = 0.017). In SLE patients, sCD163 level was high (483.7 ± 260.8 ng/mL vs 282.1 ± 97.5 ng/mL in controls; p < 0.001) and independently associated with carotid plaques, as assessed by stratification based on sCD163 quartile values (p = 0.009), receiver operating characteristics (p = 0.001), and multivariate analysis (p = 0.015). sCD163 at baseline was associated with the onset of carotid plaque during follow-up (3 ± 1.4 years) in SLE patients who had no carotid plaque at the first evaluation (p = 0.041).Conclusion: sCD163 is associated with progressing carotid plaque in SLE and may be a useful biomarker for accelerated atherosclerosis in SLE patients at apparent low risk for CVD.

Risk of Ascending Aortic Aneurysm in Patients With Autosomal Dominant Polycystic Kidney Disease

In recent years, simple renal cysts have been associated with an increased risk of aortic aneurysms. There is little data regarding aortic dilation in patients with autosomal dominant polycystic kidney disease (ADPKD). The aim of this study was to compare Sinuses of Valsalva (SoV) and tubular ascending aorta diameters in ADPKD patients with matched controls. From 2008 to 2016, 61 consecutive ADPKD patients who had an echocardiogram performed in our institution were matched 1:1 with controls for sex, age, blood pressure, and β-blocker therapy use. SoV and tubular ascending aorta were measured at end-diastole, using the leading-edge to leading-edge convention. Paired t Tests were used for quantitative variables and McNemar-tests for qualitative variables. The mean age of patients was 56 ± 12 years, 54% were men, 38% received β-blockers, and mean systolic and diastolic BP were 137 ± 25 and 78 ± 19 mm Hg. SoV diameters were significantly larger in ADPKD patients than in controls (36.4 ± 4.1 vs 34.0 ± 3.7 mm, p <0.0001). The Z-scores (normalized for sex, age, and body surface area) were significantly higher in ADPKD patients, both for SoV and tubular ascending aorta. Moreover, aortic aneurysms, as defined by a Z score >2 standard deviations, were present in 27 ADPKD patients (44%) versus 9 controls (15%, p <0.001). In conclusion, there is an increased prevalence of aortic aneurysms in ADPKD patients as compared with controls matched for common confounding factors for aortic dilation.

Left Ventricular Torsion Associated With Aortic Stiffness in Hypertension

BACKGROUND

Left ventricular (LV) torsion plays a key role in cardiac efficiency. In hypertension, aortic stiffening augments cardiac afterload. However, little is known about the links between LV regional contraction and aortic stiffness. We, therefore, investigated these relationships and their contribution to LV diastolic function.

METHODS AND RESULTS

The study included normotensive and hypertensive individuals with normal LV ejection. Apical, basal, and global LV rotation rate and LV global longitudinal strain were measured (2-dimensional speckle tracking echocardiography). Aortic stiffness was calculated from carotid-femoral pulse wave velocity, and LV relaxation was calculated from early diastolic mitral annulus motion. The ratio of basal or apical untwist/twist rates was calculated to assess relationships between aortic stiffness and LV torsion parameters. LV twist and untwist rates were greater in hypertensive than normotensive individuals because of increased basal twist (P<0.001) and untwist (P<0.001) rates. LV relaxation was reduced (early diastolic mitral annulus motion=7.4±1.9 versus 10.4±2.3 cm/s; P<0.001). In the whole population, basal untwist rate increased with aortic stiffening (R=0.43; P<0.001) and LV relaxation (R=0.41; P=0.001). The ratio of basal untwist/twist rate was positively correlated with carotid-femoral pulse wave velocity, and in the hypertensive group, was greater than in the control group and positively correlated to carotid-femoral pulse wave velocity(P<0.001). Results were independent of age, treatment, mean blood pressure, and indexed LV mass.

CONCLUSIONS

In hypertensive individuals, greater basal LV torsion was associated with increased aortic stiffness and improved diastolic function. These changes may compensate for the deleterious effects of aortic stiffening on LV relaxation.

High-sensitivity cardiac troponin T is a biomarker for atherosclerosis in systemic lupus erythematous patients: a cross-sectional controlled study

Background

Cardiovascular disease (CVD) is the main cause of death in systemic lupus erythematous (SLE) patients. The Framingham score underestimates the risk for CVD in this population. Our study aimed to determine whether serum high-sensitivity cardiac troponin T (HS-cTnT) might help to identify SLE patients at risk for CVD.

Methods

The presence of carotid plaques was prospectively assessed by ultrasound in 63 consecutive SLE patients asymptomatic for CVD and 18 controls. Serum HS-cTnT concentration was measured using the electrochemiluminescence method. Factors associated with carotid plaques were identified and multivariate analysis was performed.

Results

Framingham score was low in both SLE patients (median 1 (range 1–18%)) and controls (1 (1–13%)). Nevertheless, 23 (36.5%) SLE patients, but only 2 (11.1%) controls (p = 0.039), had carotid plaque detected by vascular ultrasound. In the multivariate analysis, only age (p = 0.006) and SLE status (p = 0.017) were independently associated with carotid plaques. Serum HS-cTnT concentration was detectable (i.e. >3 ng/L) in 37 (58.7%) SLE patients and 6 (33.3%) controls (p = 0.057). Interestingly, 87% of SLE patients with carotid plaques, but only 42.5% of SLE patients without plaques (p < 0.001), had detectable HS-cTnT. Conversely, 54.5% of SLE patients with detectable HS-cTnT, but only 11.5% with undetectable HS-cTnT (p < 0.001), had a carotid plaque. In the multivariate analysis, only body mass index (p = 0.006) and HS-cTnT (p = 0.033) were statistically associated with carotid plaques in SLE patients. Overall, the risk of having a carotid plaque was increased by 9 (odds ratio 9.26, 95% confidence interval 1.55–90.07) in SLE patients in whom HS-cTnT was detectable in serum.

Conclusion

Serum HS-cTnT level is high and associated with carotid plaques in SLE patients who are at an apparently low risk for CVD according to the Framingham score. HS-cTnT may be a useful biomarker for SLE-associated atherosclerosis.

High mass (>18g) of late gadolinium enhancement on CMR imaging is associated with major cardiac events on long-term outcome in patients with biopsy-proven extracardiac sarcoidosis

BACKGROUND

Cardiac involvement is the most important cause of mortality in patients with systemic sarcoidosis. Late gadolinium enhancement (LGE) on cardiovascular magnetic resonance imaging (CMR) has been shown to be a predictor of major cardiovascular adverse events (MACE) in the setting of systemic sarcoidosis. We sought to evaluate the relationship between LGE mass and adverse long-term outcome in patients with biopsy-proven extracardiac sarcoidosis.

METHODS

Between 2001 and 2013, 197 consecutive patients with suspected cardiac sarcoidosis were identified in our institution database. Of them, 56 patients have had biopsy-proven extracardiac sarcoidosis and represented our studied population. Patients were divided into two groups based on LGE mass by a median value (mild LGE<18g, high LGE>18g) for comparison of MACE.

RESULTS

Twenty-eight patients had a high mass of LGE. Of them, 15 (54%) experienced MACE (OR=31.15, 95% CI 3.7-262). Except for 1 patient, no patient with mild LGE presented with any MACE during follow-up (median of 32months). Patients with high LGE had lower CMR-derived left (53.6±14.9 vs. 62.2±6.7, p<0.01) and right (49.1±11.5 vs. 56.4±9.2, p<0.05) ventricular ejection fractions. LGE mass of 18g discriminated patients with and without MACE (93% sensitivity, 88% specificity, AUC=0.972). LGE mass was the only independent predictor of MACE on multivariate Cox analysis adjusted (OR=1.7, 95% CI 1.06 to 2.72, p=0.03).

CONCLUSION

In biopsy-proven extracardiac sarcoidosis patients, a high mass of LGE >18g was associated with MACE.

Overweight Is a Major Contributor to Atherosclerosis in Systemic Lupus Erythematosus Patients at Apparent Low Risk for Cardiovascular Disease: A Cross-Sectional Controlled Study

Cardiovascular disease (CVD) is the main cause of death in systemic lupus erythematosus (SLE) patients. We aimed to determine whether overweight (defined as a body mass index [BMI] > 25 kg/m(2)) contributed to subclinical atherosclerosis in SLE patients at low risk for CVD according to traditional factors. Wall thickness of the internal carotid artery (ICWT) measured at the carotid bulb and carotid plaques were assessed in 49 SLE patients asymptomatic for CVD and 49 controls matched on Framingham score. Factors associated to ICWT were identified and multivariate analysis was performed.SLE patients and controls displayed a low 10-year risk for CVD according to Framingham score (mean 1.9 ± 3.5 in SLE vs 1.8 ± 3.2% in controls, P = 0.37). ICWT (P < 0.001) and number of patients with carotid plaques (P = 0.015) were, however, higher in SLE patients as compared to controls. In multivariable analysis, SLE was an independent risk for a carotid atherosclerosis (OR [95% confidence interval, CI]: 3.53 [1.36-9.14]; P = 0.009). Older age, higher BMI, and higher Framingham score were associated with atherosclerosis in SLE patients in univariate analysis. In multivariate analysis, only the association with overweight remained significant (OR [95% CI]: 4.13 [1.02-16.75]; P = 0.047). Overweight is a major contributor to atherosclerosis in SLE patients at apparent low risk for CVD.

CD4+CXCR3+ T cells and plasmacytoid dendritic cells drive accelerated atherosclerosis associated with systemic lupus erythematosus

Cardiovascular disease due to accelerated atherosclerosis is the leading cause of death in patients with systemic lupus erythematosus (SLE). Noteworthy, accelerated atherosclerosis in SLE patients appears to be independant of classical Framingham risk factors. This suggests that aggravated atherosclerosis in SLE patients may be a result of increased inflammation and altered immune responses. However, the mechanisms that mediate the acceleration of atherosclerosis in SLE remain elusive. Based on experimental data which includes both humans (SLE patients and control subjects) and rodents (ApoE-/- mice), we herein propose a multi-step model in which the immune dysfunction associated with SLE (i.e. high level of IFN-α production by TLR 9-stimulated pDCs) is associated with, first, an increased frequency of circulating pro inflammatory CD4+CXCR3+ T cells; second, an increased production of CXCR3 ligands by endothelial cells; third, an increased recruitment of pro-inflammatory CD4+CXCR3+ T cells into the arterial wall, and fourth, the development of atherosclerosis. In showing how SLE may promote accelerated atherosclerosis, our model also points to hypotheses for potential interventions, such as pDCs-targeted therapy, that might be studied in the future.

Activation of the hypothalamic-pituitary-adrenal axis in adults with mineralocorticoid receptor haploinsufficiency

CONTEXT

Mineralocorticoid receptors (MRs) contribute to the negative feedback of the hypothalamic-pituitary-adrenal (HPA) axis in rodents. Studies with MR antagonists suggest a similar role in humans.

OBJECTIVE

The objective of the study was to establish whether loss-of-function mutations in NR3C2, encoding MR, cause activation of the HPA axis.

DESIGN AND SETTING

This was a case-control study in members of pedigrees from the PHA1.NET cohort, comprising patients with pseudohypoaldosteronism type 1 (PHA1) who are heterozygous for loss-of-function mutations in NR3C2 and healthy controls who are unaffected family members.

PARTICIPANTS

Twelve adult patients with PHA1 (six men, six women) and 20 age-matched healthy controls (seven men, 13 women) participated in the study.

RESULTS

Patients with PHA1 had higher morning plasma cortisol (816 ± 85 vs 586 ± 50 nmol/L, P = .02) and increased 24-hour urinary excretion of cortisol metabolites (985 ± 150 vs 640 ± 46 μg/mmol creatinine, P = .03), independently of gender. After adjustment for gender, age, PHA1 diagnosis, and percentage body fat, higher plasma cortisol was associated with higher plasma renin, lower serum high-density lipoprotein-cholesterol, and higher waist circumference but not with blood pressure, carotid intima-media thickness, or echocardiographic parameters.

CONCLUSIONS

Haploinsufficiency of MR in PHA1 causes HPA axis activation, providing genetic evidence that MR contributes to negative feedback in the human HPA axis. With limited sample size, initial indications suggest the resulting hypercortisolemia is related to the severity of MR deficiency and has adverse effects mediated by glucocorticoid receptors on liver lipid metabolism and adipose tissue distribution but does not adversely affect cardiac and vascular remodeling in the absence of normal signaling through the MR.

Increased arterial stiffness in systemic lupus erythematosus (SLE) patients at low risk for cardiovascular disease: a cross-sectional controlled study

Cardiovascular disease (CVD) is a major cause of death in systemic lupus erythematosus (SLE) patients. Although the risk for cardiovascular events in patients with SLE is significant, the absolute number of events per year in any given cohort remains small. Thus, CVD risks stratification in patients with SLE focuses on surrogate markers for atherosclerosis at an early stage, such as reduced elasticity of arteries. Our study was designed to determine whether arterial stiffness is increased in SLE patients at low risk for CVD and analyze the role for traditional and non-traditional CVD risk factors on arterial stiffness in SLE. Carotid-femoral pulse wave velocity (PWV) was prospectively assessed as a measure of arterial stiffness in 41 SLE patients and 35 controls (CTL). Adjustment on age or Framingham score was performed using a logistic regression model. Factors associated with PWV were identified separately in SLE patients and in controls using Pearson's correlation coefficient for univariate analysis and multiple linear regression for multivariate analysis. SLE patients and controls displayed a low 10-year risk for CVD according to Framingham score (1.8±3.6% in SLE vs 1.6±2.8% in CTL, p = 0.46). Pulse wave velocity was, however, higher in SLE patients (7.1±1.6 m/s) as compared to controls (6.3±0.8 m/s; p = 0.01, after Framingham score adjustment) and correlated with internal carotid wall thickness (p = 0.0017). In multivariable analysis, only systolic blood pressure (p = 0.0005) and cumulative dose of glucocorticoids (p = 0.01) were associated with PWV in SLE patients. Interestingly, the link between systolic blood pressure (SBP) and arterial stiffness was also confirmed in SLE patients with normal systolic blood pressure. In conclusion, arterial stiffness is increased in SLE patients despite a low risk for CVD according to Framingham score and is associated with systolic blood pressure and glucocorticoid therapy.

Epac contributes to cardiac hypertrophy and amyloidosis induced by radiotherapy but not fibrosis

BACKGROUND

Cardiac toxicity is a side-effect of anti-cancer treatment including radiotherapy and this translational study was initiated to characterize radiation-induced cardiac side effects in a population of breast cancer patients and in experimental models in order to identify novel therapeutic target.

METHODS

The size of the heart was evaluated in CO-HO-RT patients by measuring the Cardiac-Contact-Distance before and after radiotherapy (48months of follow-up). In parallel, fibrogenic signals were studied in a severe case of human radiation-induced pericarditis. Lastly, radiation-induced cardiac damage was studied in mice and in rat neonatal cardiac cardiomyocytes.

RESULTS

In patients, time dependent enhancement of the CCD was measured suggesting occurrence of cardiac hypertrophy. In the case of human radiation-induced pericarditis, we measured the activation of fibrogenic (CTGF, RhoA) and remodeling (MMP2) signals. In irradiated mice, we documented decreased contractile function, enlargement of the ventricular cavity and long-term modification of the time constant of decay of Ca(2+) transients. Both hypertrophy and amyloid deposition were correlated with the induction of Epac-1; whereas radiation-induced fibrosis correlated with Rho/CTGF activation. Transactivation studies support Epac contribution in hypertrophy stimulation and showed that radiotherapy and Epac displayed specific and synergistic signals.

CONCLUSION

Epac-1 has been identified as a novel regulator of radiation-induced hypertrophy and amyloidosis but not fibrosis in the heart.

Potassium channel openers increase aortic elastic fiber formation and reverse the genetically determined elastin deficit in the BN rat

Hypertension is a cardiovascular disorder that appears in more than half of the patients with Williams-Beuren syndrome, hemizygous for the elastin gene among 26 to 28 other genes. It was shown that the antihypertensive drug minoxidil, an ATP-dependent potassium channel opener, enhances elastic fiber formation; however, no wide clinical application was developed because of its adverse side effects. The Brown Norway rat was used here as an arterial elastin-deficient model. We tested 3 different potassium channel openers, minoxidil, diazoxide, and pinacidil, and 1 potassium channel blocker, glibenclamide, on cultured smooth muscle cells from Brown Norway rat aorta. All tested potassium channel openers increased mRNAs encoding proteins and enzymes involved in elastic fiber formation, whereas glibenclamide had the opposite effect. The higher steady-state level of tropoelastin mRNA in minoxidil-treated cells was attributable to an increase in both transcription and mRNA stability. Treatment of Brown Norway rats for 10 weeks with minoxidil or diazoxide increased elastic fiber content and decreased cell number in the aortic media, without changing collagen content. The minoxidil-induced cardiac hypertrophy was reduced when animals simultaneously received irbesartan, an angiotensin II-receptor antagonist. This side effect of minoxidil was not observed in diazoxide-treated animals. In conclusion, diazoxide, causing less undesirable side effects than minoxidil, or coadministration of minoxidil and irbesartan, increases elastic fiber content, decreases cell number in the aorta and, thus, could be suitable for treating vascular pathologies characterized by diminished arterial elastin content and simultaneous hypertension.

Cardiovascular Effects of Aldosterone

Background—

High plasma aldosterone has deleterious cardiovascular effects that are independent of blood pressure, but the role of the mineralocorticoid receptor remains unclear. Renal pseudohypoaldosteronism type 1 is a rare autosomal-dominant disease caused by NR3C2 loss-of-function mutations, which is characterized by renal salt loss and compensatory high renin and aldo secretion. We aimed to assess the cardiovascular outcomes in adults carrying NR3C2 mutations.

Methods and Results—

In this case-control study, 39 NR3C2 mutation carriers were compared with sex- and age-paired noncarriers. Patients underwent cardiac and vascular ultrasound, cardiac MRI with gadolinium injection, measurement of pulse wave velocity, extracellular water, 24-hour ambulatory blood pressure, and autonomous nervous system activity. Mutation carriers showed increased aldo and renin plasma levels (4.5- and 1.6-fold, respectively; P <0.0001), together with increased salt appetite (1.8-fold; P =0.002), with normal extracellular water and blood pressure, and no autonomous nervous system activation. Cardiac and vascular parameters were not significantly different between mutation carriers and noncarriers (no left ventricular remodeling or fibrosis, normal left ventricular systolic function, and aorta stiffness). Tissue Doppler showed better diastolic left ventricular function in mutation carriers (e′, P =0.001; E/e′, P =0.003). Mutation carriers had significantly more frequent history of slow body weight recovery at birth, symptomatic hypotension, and miscarriage in women.

Conclusions—

Despite life-long increase in plasma aldosterone and renin levels, no adverse cardiovascular outcome occurred in pseudohypoaldosteronism type 1, but rather an improved diastolic left ventricular function. This suggests that the cardiovascular consequences of aldosterone excess require full mineralocorticoid receptor signaling.

Clinical Trial Registration—

http://www.clinicaltrials.gov ; unique identifier: NCT00646828.