Aldosterone inhibits antifibrotic factors in mouse hypertensive heart

Effect of spironolactone on pharmacological treatment of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) was recently renamed to metabolic (dysfunction)-associated fatty liver disease (MAFLD) to better characterize its pathogenic origin. NAFLD represents, at least in western societies, a potential epidemic with raising prevalence. Its multifactorial pathogenesis is partially unraveled and till now there is no approved pharmacotherapy for NAFLD. A plethora of various choices are investigated in clinical trials, targeting an arsenal of different pathways and molecules. Since the mineralocorticoid receptor (MR) and renin-angiotensin-aldosterone system (RAAS) appear to be implicated in NAFLD, within this concise review, we focus on a rather classical and inexpensive pharmacological agent, spironolactone. We present the current lines of evidence of MR and RAAS-related preclinical models and human trials reporting an association with NAFLD. In conclusion, evidence about spironolactone of RAAS is commented, as potential future pharmacological management of NAFLD.

Potential clinical biomarkers and perspectives in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a serious cardiovascular complication and the leading cause of death in diabetic patients. Patients typically do not experience any symptoms and have normal systolic and diastolic cardiac functions in the early stages of DCM. Because the majority of cardiac tissue has already been destroyed by the time DCM is detected, research must be conducted on biomarkers for early DCM, early diagnosis of DCM patients, and early symptomatic management to minimize mortality rates among DCM patients. Most of the existing implemented clinical markers are not very specific for DCM, especially in the early stages of DCM. Recent studies have shown that a number of new novel markers, such as galactin-3 (Gal-3), adiponectin (APN), and irisin, have significant changes in the clinical course of the various stages of DCM, suggesting that we may have a positive effect on the identification of DCM. As a summary of the current state of knowledge regarding DCM biomarkers, this review aims to inspire new ideas for identifying clinical markers and related pathophysiologic mechanisms that could be used in the early diagnosis and treatment of DCM.

Cardiovascular Disease in Obstructive Sleep Apnea: Putative Contributions of Mineralocorticoid Receptors

Obstructive sleep apnea (OSA) is a chronic and highly prevalent condition that is associated with oxidative stress, inflammation, and fibrosis, leading to endothelial dysfunction, arterial stiffness, and vascular insulin resistance, resulting in increased cardiovascular disease and overall mortality rates. To date, OSA remains vastly underdiagnosed and undertreated, with conventional treatments yielding relatively discouraging results for improving cardiovascular outcomes in OSA patients. As such, a better mechanistic understanding of OSA-associated cardiovascular disease (CVD) and the development of novel adjuvant therapeutic targets are critically needed. It is well-established that inappropriate mineralocorticoid receptor (MR) activation in cardiovascular tissues plays a causal role in a multitude of CVD states. Clinical studies and experimental models of OSA lead to increased secretion of the MR ligand aldosterone and excessive MR activation. Furthermore, MR activation has been associated with worsened OSA prognosis. Despite these documented relationships, there have been no studies exploring the causal involvement of MR signaling in OSA-associated CVD. Further, scarce clinical studies have exclusively assessed the beneficial role of MR antagonists for the treatment of systemic hypertension commonly associated with OSA. Here, we provide a comprehensive overview of overlapping mechanistic pathways recruited in the context of MR activation- and OSA-induced CVD and propose MR-targeted therapy as a potential avenue to abrogate the deleterious cardiovascular consequences of OSA.

Phosphorylation of CaMK and CREB-Mediated Cardiac Aldosterone Synthesis Induced by Arginine Vasopressin in Rats with Myocardial Infarction

Both aldosterone and arginine vasopressin (AVP) are produced in the heart and may participate in cardiac fibrosis. However, their relationship remains unknown. This study aims to demonstrate the regulation and role of AVP in aldosterone synthesis in the heart. Rats were subjected to a sham operation or myocardial infarction (MI) by ligating the coronary artery. Cardiac function and fibrosis were assessed using echocardiography and immunohistochemical staining, respectively. In addition, the effects of AVP stimulation on cardiac microvascular endothelial cells (CMECs) were studied using ELISA, real-time PCR, and Western blotting. Compared with the rats having undergone a sham operation, the MI rats had an increased LVMI, type I collagen composition, and concentrations of aldosterone and AVP in the heart but decreased cardiac function. As the MI rats aged, the LVMI, type I collagen, aldosterone, and AVP increased, while the LVMI decreased. Furthermore, AVP time-dependently induced aldosterone secretion and CYP11B2 mRNA expression in CMECs. The p-CREB levels were significantly increased by AVP. Nevertheless, these effects were completely blocked by SR49059 or partially inhibited by KN93. This study demonstrated that AVP could induce the secretion of local cardiac aldosterone, which may involve CaMK and CREB phosphorylation and CYP11B2 upregulation through V1 receptor activation.

Trend of Galectin-3 Levels in Patients with Non-ST-Elevation and ST-Elevation Myocardial Infarction

Background and Objectives: Given the fact that galectin-3 has a predictive significance on the development of myocardial dysfunction after acute myocardial infarction, the aim of our study was to examine potential factors that could be important for the dynamics of the concentration of this biomarker in the early postinfarction period. Materials and Methods: This study included 89 patients with a diagnosis of stable angina pectoris (SAP) or the first non-ST elevation (NSTEMI) or ST-elevation (STEMI) myocardial infarction, who underwent percutaneous coronary intervention (PCI). The study group included 23 patients with the first NSTEMI and 42 patients with STEMI, while the control group consisted of 24 patients with SAP hospitalized for elective PCI without a previous MI. All patients had preserved left ventricular ejection fraction. Galectin-3 levels were determined on days 1, 5, and 30 after PCI. The significance of various independent variables as predictors of galectin-3 concentration was analyzed after a series of univariate linear regression modeling in a multivariate linear regression model. Results: The average patients’ age was 63.99 ± 9.13 years. Statistically significantly higher values of C-reactive protein were established in STEMI compared to SAP (p < 0.01) or NSTEMI (p < 0.001), whereas WBC count was significantly lower in SAP than in STEMI (p < 0.001) and NSTEMI (p < 0.01) group. Although there were no statistically significant differences in measured galectin-3 concentrations between the examined groups on days 1, 5, and 30 after PCI, HTA, triglyceride level, LA size, treatment with trimetazidine and long-acting nitrates, as well as percentage of LM stenosis and E/A ratio were identified as independent predictors of galectin-3 concentration. Conclusions: In the post-MI period, very early values of galectin-3 correlate mostly with atherosclerosis factors, while on day 30 this biomarker correlates with diastolic dysfunction and “announces” left ventricular remodeling.

The Diagnostic and Therapeutic Potential of Galectin-3 in Cardiovascular Diseases

Galectin-3 plays a prominent role in chronic inflammation and has been implicated in the development of many disease conditions, including heart disease. Galectin-3, a regulatory protein, is elevated in both acute and chronic heart failure and is involved in the inflammatory pathway after injury leading to myocardial tissue remodelling. We discussed the potential utility of galectin-3 as a diagnostic and disease severity/prognostic biomarker in different cardio/cerebrovascular diseases, such as acute ischemic stroke, acute coronary syndromes, heart failure and arrhythmogenic cardiomyopathy. Over the last decade there has been a marked increase in the understanding the role of galectin-3 in myocardial fibrosis and inflammation and as a therapeutic target for the treatment of heart failure and myocardial infarction.

Mineralocorticoid receptor actions in cardiovascular development and disease

Mineralocorticoid receptors (MRs) are transcriptional regulators that mediate the diverse physiological and pathophysiological actions of corticosteroid hormones across many tissues. In the kidney aldosterone control of sodium/water resorption via DNA-binding actions of the MR is established. MRs also regulate tissues not involved in electrolyte homeostasis such as the heart, adipose tissue, brain, and inflammatory cells where the MRs can respond to both aldosterone and cortisol. The pathology of inappropriate MR activation in non-epithelial tissues are well-described, and steroidal antagonists of the MR have been clinically beneficial in the management of heart failure and blood pressure for decades. However, the role of cortisol-dependent MR activation in the physiological setting is less well defined. Like other steroid hormone receptors, the MR also regulates non-DNA-binding pathways including MAPK pathways and G protein coupled receptors to provide diversity to MR signaling. Whether nonDNA binding pathways are more relevant for MR activation in non-epithelial, versus epithelial, tissues remain unclear. This review will focus on molecular regulation of ligand-dependent MR activation and the physiology and pathophysiology of MR actions in the heart with a focus on the cardiomyocyte and provide a discussion of relevant genomic and non-genomic MR pathways and potential new transcriptional partners for the MR and their relevance for health and disease. Understanding MR actions in the heart will provide new insights into cell-selective mechanisms that underpin the therapeutic benefits of MRAs, and are a critical step towards developing next-generation tissue selective MR modulators with improved safety profiles.

Current and emerging drug targets in heart failure treatment

After initial strategies targeting inotropism and congestion, the neurohormonal interpretative model of heart failure (HF) pathophysiology has set the basis for current pharmacological management of HF, as most of guideline recommended drug classes, including beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and mineralocorticoid receptor antagonists, blunt the activation of detrimental neurohormonal axes, namely sympathetic and renin–angiotensin–aldosterone (RAAS) systems. More recently, sacubitril/valsartan, a first-in-class angiotensin receptor neprilysin inhibitor, combining inhibition of RAAS and potentiation of the counter-regulatory natriuretic peptide system, has been consistently demonstrated to reduce mortality and HF-related hospitalization. A number of novel pharmacological approaches have been tested during the latest years, leading to mixed results. Among them, drugs acting directly at a second messenger level, such as the soluble guanylate cyclase stimulator vericiguat, or other addressing myocardial energetics and mitochondrial function, such as elamipretide or omecamtiv-mecarbil, will likely change the therapeutic management of patients with HF. Sodium glucose cotransporter 2 inhibitors, initially designed for the management of type 2 diabetes mellitus, have been recently demonstrated to improve outcome in HF, although mechanisms of their action on cardiovascular system are yet to be elucidated. Most of these emerging approaches have shifted the therapeutic target from neurohormonal systems to the heart, by improving cardiac contractility, metabolism, fibrosis, inflammation, and remodeling. In the present paper, we review from a pathophysiological perspective current and novel therapeutic strategies in chronic HF.

Role of novel biomarkers in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is commonly defined as cardiomyopathy in patients with diabetes mellitus in the absence of coronary artery disease and hypertension. As DCM is now recognized as a cause of substantial morbidity and mortality among patients with diabetes mellitus and clinical diagnosis is still inappropriate, various expert groups struggled to identify a suitable biomarker that will help in the recognition and management of DCM, with little success so far. Hence, we thought it important to address the role of biomarkers that have shown potential in either human or animal studies and which could eventually result in mitigating the poor outcomes of DCM. Among the array of biomarkers we thoroughly analyzed, long noncoding ribonucleic acids, soluble form of suppression of tumorigenicity 2 and galectin-3 seem to be most beneficial for DCM detection, as their plasma/serum levels accurately correlate with the early stages of DCM. The combination of relatively inexpensive and accurate speckle tracking echocardiography with some of the highlighted biomarkers may be a promising screening method for newly diagnosed diabetes mellitus type 2 patients. The purpose of the screening test would be to direct affected patients to more specific confirmation tests. This perspective is in concordance with current guidelines that accentuate the importance of an interdisciplinary team-based approach.

Doxorubicin-induced and trastuzumab-induced cardiotoxicity in mice is not prevented by metoprolol

Aims

Our objectives were to validate a murine model of chronic cardiotoxicity induced by Doxorubicin (Dox) and Trastuzumab (Trast) and to test the potential cardio‐protective effect of metoprolol.

Methods and results

Male C57Bl6 mice were intraperitoneally injected during 2 weeks with Dox (24 mg/kg) or saline, and then with Trast (10 mg/kg) or saline for two more weeks. Half of the mice received metoprolol (100 mg/kg). Cardiotoxicity was defined by a decline in left ventricular ejection fraction (LVEF) ≥ 10 points. At Day 42, Dox + Trast‐treated mice exhibited a 13‐points decline in LVEF (74 ± 2.6% vs. 87 ± 0.8% for control mice, P < 0.001) and a severe cardiac atrophy (heart weight: 105 ± 2.7 mg vs. 119 ± 3.9 mg for control mice, P < 0.01). This cardiac atrophy resulted from an excess of cardiac necrosis (assessed by plasma cardiac troponin I level: 3.2 ± 0.4 ng/L vs. 1.3 ± 0.06 ng/L for control mice, P < 0.01), an increase in apoptosis (caspase 3 activity showing a six‐fold increase for Dox + Trast‐treated mice vs. controls, P < 0.001), and cardiomyocyte atrophy (myocyte size: 0.67 ± 0.08 μm² vs. 1.36 ± 0.10 μm² for control mice, P < 0.001). In addition, Dox + Trast‐treated mice were shown to have an increased cardiac oxidative stress (164 ± 14 dihydroethidine‐marked nuclei per area vs. 56 ± 9.5 for control mice, P < 0.01) and increased cardiac fibrosis (the semi‐quantitative fibrosis score was three‐fold higher for Dox + Trast‐treated mice as compared with controls, P < 0.01). Metoprolol was not able to prevent either the decrease in LVEF or the severe cardiac atrophy, the cardiac necrosis, and the cardiac remodelling induced by chemotherapies.

Conclusion

A murine model of chronic cardiotoxicity induced by Dox and Trast was characterized by a decrease in cardiac function, a cardiac apoptosis and necrosis leading to cardiomyocyte atrophy. Metoprolol did not prevent this cardiotoxicity.

sST2 adds to the prognostic value of Gal-3 and BNP in chronic heart failure

Background: The soluble form of the IL-33 receptor (sST2) and Galectin-3 (Gal-3) are fibrosis biomarkers with prognostic value in heart failure (HF). We investigated the prognostic capacity of sST2 when combined with Gal-3, and determined if the prognostic utility of sST2 is affected by mineralocorticoid receptor antagonist (MRA) therapy.Methods: sST-2 and Gal-3 were measured in 101 stable chronic HF (CHF) patients receiving MRA therapy and compared to 97 BNP and cardiovascular risk factor matched patients not treated with MRA. sST2 and Gal-3 levels were measured to determine the relationship with all-cause mortality at 6-year follow-up.Results: ROC curve cut-off points were defined as sST2 = 36.3 ng/mL, Gal-3 = 17.8 ng/mL, and BNP = 500 pg/mL, and had 6-year mortality hazard ratios (HR) of 7.3, 6.6 and 5.4, respectively. The combination of an elevated sST2 and Gal-3 had a HR = 4.4 [95% CI 1.9-8.9]. Combining sST2 and Gal-3 to a clinical model relevant for CHF prognosis allowed a significant reclassification of 1-year adverse outcome risk, even when BNP was included. Finally, prognostic prediction by sST2 was unaffected by MRA treatment.Conclusion: Simultaneous sST2 and Gal-3 elevation is associated with poorer prognosis compared to either alone, regardless of BNP levels, and the prognostic capacity of sST2 is independent of MRA therapy.

Plasma levels of the cardiovascular protective endogenous nucleoside adenosine are reduced in patients with primary aldosteronism without affecting ischaemia-reperfusion injury: A prospective case-control study

BACKGROUND

Patients with primary aldosteronism (PA) experience more cardiovascular events compared to patients with essential hypertension (EHT), independent from blood pressure levels. In animals, mineralocorticoid receptor antagonists limit ischaemia-reperfusion (IR) injury by increasing extracellular adenosine formation and adenosine receptor stimulation. Adenosine is an endogenous compound with profound cardiovascular protective effects. Firstly, we hypothesized that patients with PA have lower circulating adenosine levels which might contribute to the observed increased cardiovascular risk. Secondly, we hypothesized that by this mechanism, patients with PA are more susceptible to IR compared to patients with EHT.

DESIGN

In our prospective study in 20 patients with PA and 20 patients with EHT, circulating adenosine was measured using a pharmacological blocker solution that halts adenosine metabolism after blood drawing. Brachial artery flow-mediated dilation (FMD) before and after forearm IR was used as a well-established method to study IR injury.

RESULTS

Patients with PA had a 33% lower adenosine level compared to patients with EHT (15.3 [13.3-20.4] vs 22.7 [19.4-36.8] nmol/L, respectively, P < .01). The reduction in FMD after IR, however, did not differ between patients with PA and patients with EHT (-1.0 ± 2.9% vs -1.6 ± 1.6%, respectively, P = .52).

CONCLUSIONS

As adenosine receptor stimulation induces various powerful protective cardiovascular effects, its lower concentration in patients with PA might be an important novel mechanism that contributes to their increased cardiovascular risk. We suggest that modulation of the adenosine metabolism is an exciting novel pharmacological opportunity to limit cardiovascular risk in patients with PA that needs further exploration.

Acute Kidney Injury Induces Remote Cardiac Damage and Dysfunction Through the Galectin-3 Pathway

Acute kidney injury is associated with increased risk of heart failure and mortality. This study demonstrates that acute kidney injury induces remote cardiac dysfunction, damage, injury, and fibrosis via a galectin-3 (Gal-3) dependent pathway. Gal-3 originates from bone marrow-derived immune cells. Cardiac damage could be prevented by blocking this pathway.

Adrecizumab, a non-neutralizing anti-adrenomedullin antibody, improves haemodynamics and attenuates myocardial oxidative stress in septic rats

Background

Sepsis still represents a major health issue, with persistent high morbidity and mortality rates. Cardiovascular dysfunction occurs frequently during sepsis. Adrenomedullin has been identified as a key mediator in vascular tone regulation. A non-neutralizing anti-adrenomedullin antibody, Adrecizumab, may improve haemodynamic dysfunction during caecal ligation and puncture-induced septic shock in a murine model. Our objective was to determine the role of Adrecizumab on haemodynamics in a rat model of sepsis.

Methods

For the induction of sepsis, caecal ligation and puncture were performed in Wistar male rats. Single blinded administration of Adrecizumab (2 mg/kg) or placebo was injected i.v. 24 h after the surgery, and norepinephrine was infused as the standard of care. There were > 7 animals per group. Invasive blood pressure and cardiac function (by echocardiography) were assessed until 3 h after Adrecizumab injection.

Results

A single therapeutic injection of Adrecizumab in septic rats induced rapid haemodynamic benefits with an increase in systolic blood pressure in septic-Adrecizumab rats versus untreated-septic rats (p = 0.049). The shortening fraction did not differ between the untreated-septic and septic-Adrecizumab groups. However, cardiac output increased during the 3 h after a single dose of Adrecizumab compared to untreated septic rats (p = 0.006). A single dose of Adrecizumab resulted in similar haemodynamics to the continuous administration of norepinephrine.

Three hours after a single injection of Adrecizumab, there was no change in the inflammatory phenotype (TNFα, IL-10) in the hearts of the septic rats. By contrast, 3 h after a single Adrecizumab injection, free-radical production decreased in the hearts of septic-Adrecizumab vs untreated septic rats (p < 0.05).

Conclusions

In a rat model of sepsis, a single therapeutic injection of Adrecizumab rapidly restored haemodynamic parameters and blunted myocardial oxidative stress. Currently, a proof-of-concept and dose-finding phase II trial (Adrenoss-2) is ongoing in patients with septic shock and elevated concentrations of circulating bio-adrenomedullin.

Electronic supplementary material

The online version of this article (10.1186/s40635-019-0255-0) contains supplementary material, which is available to authorized users.

The renin-angiotensin-aldosterone system and its suppression

Chronic activation of the renin-angiotensin-aldosterone system (RAAS) promotes and perpetuates the syndromes of congestive heart failure, systemic hypertension, and chronic kidney disease. Excessive circulating and tissue angiotensin II (AngII) and aldosterone levels lead to a pro-fibrotic, -inflammatory, and -hypertrophic milieu that causes remodeling and dysfunction in cardiovascular and renal tissues. Understanding of the role of the RAAS in this abnormal pathologic remodeling has grown over the past few decades and numerous medical therapies aimed at suppressing the RAAS have been developed. Despite this, morbidity from these diseases remains high. Continued investigation into the complexities of the RAAS should help clinicians modulate (suppress or enhance) components of this system and improve quality of life and survival. This review focuses on updates in our understanding of the RAAS and the pathophysiology of AngII and aldosterone excess, reviewing what is known about its suppression in cardiovascular and renal diseases, especially in the cat and dog.

Echocardiographic diastolic function evolution in patients with an anterior Q-wave myocardial infarction: insights from the REVE-2 study

Aims

Myocardial fibrosis plays a key role in the development of adverse left ventricular remodelling after myocardial infarction (MI). This study aimed to determine whether the circulating levels of BNP, collagen peptides, and galectin‐3 are associated with diastolic function evolution (both deterioration and improvement) at 1 year after an anterior MI.

Methods and results

The REVE‐2 is a prospective multicentre study including 246 patients with a first anterior Q‐wave MI. Echocardiographic assessment was performed at hospital discharge and ±1 year after MI. BNP, galectin‐3, and collagen peptides were measured ±1 month after MI. Left ventricular diastolic dysfunction (DD) was defined according to the presence of at least two criteria of echocardiographic parameters: septal e′ < 8 cm/s, lateral e′ < 10 cm/s, and left atrial volume ≥ 34 mL/m². At baseline, 87 (35.4%) patients had normal diastolic function and 159 (64.6%) patients had DD. Follow‐up of 61 patients among the 87 patients with normal diastolic function at baseline showed that 22 patients (36%) developed DD at 1 year post‐MI. The circulating levels of amino‐terminal propeptide of type III procollagen > 6 mg/L [odds ratio (OR) = 5.29; 95% confidence interval (CI) = 1.05–26.66; P = 0.044], galectin‐3 > 13 μg/L (OR = 5.99; 95% CI = 1.18–30.45; P = 0.031), and BNP > 82 ng/L (OR = 10.25; 95% CI = 2.36–44.50; P = 0.002) quantified at 1 month post‐MI were independently associated with 1 year DD. Follow‐up of the 137 patients with DD at baseline among the 159 patients showed that 36 patients (26%) had a normalized diastolic function at 1 year post‐MI. Patients with a BNP > 82 ng/L were less likely to improve diastolic function (OR = 0.06; 95% CI = 0.01–0.28; P = 0.0003).

Conclusions

The present study suggests that circulating levels of amino‐terminal propeptide of type III procollagen, galectin‐3, and BNP may be independently associated with new‐onset DD in post‐MI patients.

Effects of hypoestrogenism and/or hyperaldosteronism on myocardial remodeling in female mice

We investigated the potential adverse effects of hyperaldosteronism and/or hypoestrogenism on cardiac phenotype, and examined their combined effects in female mice overexpressing cardiac aldosterone synthase (AS). We focused on some signaling cascades challenging defensive responses to adapt and/or to survive in the face of double deleterious stresses, such as Ca2+ -homeostasis, pro/anti-hypertrophic, endoplasmic reticulum stress (ER stress), pro- or anti-apoptotic effectors, and MAP kinase activation, and redox signaling. These protein expressions were assessed by immunoblotting at 9 weeks after surgery. Female wild type (FWT) and FAS mice were fed with phytoestrogen-free diet; underwent ovariectomy (Ovx) or sham-operation (Sham). Ovx increased gain weight and hypertrophy index. Transthoracic echocardiograghy was performed. Both Ovx-induced heart rate decrease and fractional shortening increase were associated with collagen type III shift. Cardiac estrogen receptor (ERα, ERβ) protein expression levels were downregulated in Ovx mice. Hypoestrogenism increased plasma aldosterone and MR protein expression in FAS mice. Both aldosterone and Ovx played as mirror effects on up and downstream signaling effectors of calcium/redox homeostasis, apoptosis, such as concomitant CaMKII activation and calcineurin down-regulation, MAP kinase inhibition (ERK1/2, p38 MAPK) and Akt activation. The ratio Bcl2/Bax is in favor to promote cell survivor. Finally, myocardium had dynamically orchestrated multiple signaling cascades to restore tolerance to hostile environment thereby contributing to a better maintenance of Ca2+ /redox homeostasis. Ovx-induced collagen type III isoform shift and its upregulation may be important for the biomechanical transduction of the heart and the recovery of cardiac function in FAS mice. OVX antagonized aldosterone signaling pathways.

Mineralocorticoid Receptor and Aldosterone-Related Biomarkers of End-Organ Damage in Cardiometabolic Disease

The mineralocorticoid receptor (MR) was first identified as a blood pressure regulator, modulating renal sodium handling in response to its principal ligand aldosterone. The mineralocorticoid receptor is also expressed in many tissues other than the kidney, such as adipose tissue, heart and vasculature. Recent studies have shown that MR plays a relevant role in the control of cardiovascular and metabolic function, as well as in adipogenesis. Dysregulation of aldosterone/MR signaling represents an important cause of disease as high plasma levels of aldosterone are associated with hypertension, obesity and increased cardiovascular risk. Aldosterone displays powerful vascular effects and acts as a potent pro-fibrotic agent in cardiovascular remodeling. Mineralocorticoid receptor activation regulates genes involved in vascular and cardiac fibrosis, calcification and inflammation. This review focuses on the role of novel potential biomarkers related to aldosterone/MR system that could help identify cardiovascular and metabolic detrimental conditions, as a result of altered MR activation. Specifically, we discuss: (1) how MR signaling regulates the number and function of different subpopulations of circulating and intra-tissue immune cells; (2) the role of aldosterone/MR system in mediating cardiometabolic diseases induced by obesity; and (3) the role of several MR downstream molecules as novel potential biomarkers of cardiometabolic diseases, end-organ damage and rehabilitation outcome.

Perivascular fibrosis and the microvasculature of the heart. Still hidden secrets of pathophysiology?

Perivascular fibrosis, the deposition of connective tissue around the vessels, has been demonstrated crucially involved in the development of cardiac dysfunction. Although cardiac fibrosis has been shown to be reversible under certain experimental conditions, effective anti-fibrotic therapies remain largely elusive. Therefore, perivascular fibrosis currently represents a major therapeutic target for cardiovascular diseases. The main topic of this review will be to address the mechanisms underlying perivascular fibrosis of the vasculature within the myocardium, with a special focus on perivascular fibrosis of small vessels, microvascular dysfunction and disease.

Plasma galectin-3 concentrations in patients with primary aldosteronism

BACKGROUND

The incidence of cardiovascular events is higher in patients with primary aldosteronism than in patients with essential hypertension (EHT), despite similar blood pressure levels. This suggests detrimental cardiovascular effects of aldosterone. Amongst others, it has been suggested that galectin-3 (Gal-3) is a key mediator in aldosterone-induced myocardial fibrosis.

OBJECTIVE

We studied whether patients with primary aldosteronism have higher plasma Gal-3 concentrations than patients with EHT and evaluated its reversibility after adrenalectomy.

METHODS

In a retrospective cohort from our tertiary referral centre, we measured plasma Gal-3 concentrations in 78 patients with primary aldosteronism, 39 cured primary aldosteronism patients after adrenalectomy and 56 patients with EHT. Paired samples were available in 11 patients (preadrenalectomy and postadrenalectomy). We compared plasma Gal-3 levels by univariate analysis of covariance with correction for cardiovascular risk factors, plasma creatinine concentration, plasma potassium levels and alcohol intake.

RESULTS

Adjusted plasma Gal-3 concentrations in patients with primary aldosteronism, patients after adrenalectomy and patients with EHT were 11.39 ± 0.60, 11.64 ± 0.81 and 11.41 ± 0.73 ng/ml, respectively (mean ± SD; P = 0.95). In 11 patients of whom paired samples were available, mean Gal-3 concentrations increased from 10.03 ± 1.67 ng/ml preadrenalectomy to 14.36 ± 2.07 ng/ml postadrenalectomy (P < 0.01).

CONCLUSION

In patients with primary aldosteronism, plasma Gal-3 concentrations are not elevated when compared with patients with EHT, and levels do not decrease after adrenalectomy. These results are in contrast to previous studies and do not support a pathophysiological role of plasma Gal-3 in the increased cardiovascular risk in patients with primary aldosteronism.

Preoperative plasma aldosterone and the risk of atrial fibrillation after coronary artery bypass surgery: a prospective cohort study

OBJECTIVE

Postoperative atrial fibrillation (POAF) is associated with poor outcomes after coronary artery bypass graft (CABG) surgery. We aimed to assess the additional value of preoperative plasma aldosterone levels, a biomarker promoting proarrhythmic and profibrotic pathways, for predicting POAF after CABG.

METHODS

We conducted a prospective cohort study involving consecutive patients with left ventricular ejection fraction (LVEF) more than 50% requiring elective CABG in our university hospital. Plasma aldosterone levels, two-dimensional echocardiography including left atrial strain analysis and galectin-3 (Gal-3) examination were assessed before cardiac surgery. The primary endpoint was the occurrence of POAF within 30 days after surgery.

RESULTS

POAF occurred in 34 (24.8%) out of the 137 included patients. Compared with controls, patients experiencing POAF were significantly older (73 years old ± 8 vs 65 ± 11, P < 0.001) and had higher preoperative plasma aldosterone levels [183 pmol/l (interquartile range 138-300) vs 143 pmol/l (interquartile range 96.5-216.5), P < 0.01]. Age [odds ratio (OR), 1.088; 95% confidence interval (CI) (1.038-1.140); P = 0.0004] and plasma aldosterone levels [OR, 1.007; 95% CI (1.003-1.012); P = 0.0013] were independently associated with POAF in multivariate analysis and could therefore be combined to predict the occurrence of POAF ['Aldoscore', OR, 2.7; 95% CI (1.7-4.3); P < 0.0001]. Reverse transcriptase PCR analysis performed on right atrial appendage and plasma examination revealed that Gal-3 was activated in POAF patients.

CONCLUSION

We developed the preoperative 'Aldoscore' for POAF risk stratification among patients with preserved LVEF requiring elective CABG. This new tool may be helpful to identify good responders to interventions targeting the proarrhythmic and profibrotic pathways of aldosterone.

Deoxycorticosterone/Salt-Mediated Cardiac Inflammation and Fibrosis Are Dependent on Functional CLOCK Signaling in Male Mice

Activation of the mineralocorticoid receptor (MR) promotes inflammation, fibrosis, and hypertension. Clinical and experimental studies show that MR antagonists have significant therapeutic benefit for all-cause heart failure; however, blockade of renal MRs limits their widespread use. Identification of key downstream signaling mechanisms for the MR in the cardiovascular system may enable development of targeted MR antagonists with selectivity for pathological MR signaling and lower impact on physiological renal electrolyte handling. One candidate pathway is the circadian clock, the dysregulation of which is associated with cardiovascular diseases. We have previously shown that the circadian gene Per2 is dysregulated in hearts with selective deletion of cardiomyocyte MR. We therefore investigated MR-mediated cardiac inflammation and fibrosis in mice that lack normal regulation and oscillation of the circadian clock in peripheral tissues, that is, CLOCKΔ19 mutant mice. The characteristic cardiac inflammatory/fibrotic response to a deoxycorticosterone (DOC)/salt for 8 weeks was significantly blunted in CLOCKΔ19 mice when compared with wild-type mice, despite a modest increase at "baseline" for fibrosis and macrophage number in CLOCKΔ19 mice. In contrast, cardiac hypertrophy in response to DOC/salt was significantly greater in CLOCKΔ19 vs wild-type mice. Markers for renal inflammation and fibrosis were similarly attenuated in the CLOCKΔ19 mice given DOC/salt. Moreover, increased CLOCK expression in H9c2 cardiac cells enhanced MR-mediated transactivation of Per1, suggesting cooperative signaling between these transcription factors. This study demonstrates that the full development of MR-mediated cardiac inflammation and fibrosis is dependent on intact signaling by the circadian protein CLOCK.

Polycystin 2-dependent cardio-protective mechanisms revealed by cardiac stress

Although autosomal dominant polycystic kidney disease (ADPKD) is characterized by the development of multiple kidney cysts, the most frequent cause of death in ADPKD patients is cardiovascular disease. ADPKD is linked to mutations in PKD1 or pkd2, the genes that encode for the proteins polycystin 1 and polycystin 2 (PC1 and PC2, respectively). The cardiovascular complications have been assumed to be a consequence of renal hypertension and activation of renin/angiotensin/aldosterone (RAAS) pathway. However, the expression of PC1 and PC2 in cardiac tissue suggests additional direct effects of these proteins on cardiac function. We previously reported that zebrafish lacking PC2 develop heart failure, and that heterozygous Pkd2^+/- mice are hypersensitive to acute β-adrenergic receptor (βAR) stimulation. Here, we investigate the effect of cardiac stress (prolonged continuous βAR stimulus) on Pkd2^+/- mice. After βAR stimulation for 7 days, wild-type (WT) mice had increased left ventricular mass and natriuretic peptide (ANP and BNP) mRNA levels. The WT mice also had upregulated levels of PC2 and chromogranin B (CGB, an upstream regulator of BNP). Conversely, Pkd2^+/- mice had increased left ventricular mass, but natriuretic peptide and CGB expression levels remained constant. Reversal of the increased cardiac mass was observed in WT mice 3 days after cessation of the βAR stimulation, but not in Pkd2^+/- mice. We suggest that cardiac stress leads to upregulation of the PC2-CGB-BNP signaling axis, and this pathway regulates the production of cardio-protective natriuretic peptides. The lack of a PC2-dependent cardio-protective function may contribute to the severity of cardiac dysfunction in Pkd2^+/- mice and in ADPKD patients.

Utility of galectin-3 in predicting post-infarct remodeling after acute myocardial infarction based on extracellular volume fraction mapping

AIMS

ST-segment elevation myocardial infarction (STEMI) triggers remote extracellular matrix expansion. Myocardial extracellular volume fraction (ECV), determined by cardiovascular magnetic resonance, permits quantification of interstitial space expansion. Our aim was to determine the relationship between early serum fibrosis biomarkers and 180-day post-infarct remote myocardium remodeling using ECV.

METHODS AND RESULTS

In 26 patients with STEMI, functional imaging, T1-mapping, and late-gadolinium-enhancement were performed on a 3-T CMR scanner at baseline (days 3 to 5) and 180days. Biomarkers were measured at days 1, 3, and 7 after STEMI. The mean initial and follow-up left ventricular ejection fraction (LVEF) were 48.3±18.1% and 52.6±12.3%, respectively. Initial infarct size was 11.6±16.8% of LV mass. ECV in the remote myocardium at 180days correlated with indexed end-systolic volume (r=0.4, p=0.045). A significant correlation was observed between galectin-3 at day 7 and ECV at 6months (r=0.428, p=0.037). A trend towards a direct correlation was found for BNP (r=0.380, p=0.059). Multivariate analysis revealed that BNP and galectin-3 were independent predictors of long-term changes in ECV and explained nearly 30% of the variance in this parameter (r²=0.34; p=0.01). A galectin-3 cutoff value of 10.15ng/mL was the most powerful predictor of high ECV values (≥28.5%) at follow-up. Galectin-3 at day 7 was an independent predictor of high ECV values at follow-up (OR=22.51; CI 95%: 2.1-240.72; p=0.01) with 0.76 AUC (CI: 0.574-0.964; p=0.03).

CONCLUSIONS

Galectin-3 measured acutely after STEMI is an independent predictor of increased ECV at 6-month follow-up that might be useful for long-term risk stratification.

Association between long-term prescription of aldosterone antagonist and the progression of heart failure with preserved ejection fraction in hypertensive patients

BACKGROUND

Hypertension complicated with left ventricular hypertrophy (LVH) and diastolic dysfunction is independently related to increasing risk of subsequent incident heart failure with preserved ejection fraction (HFpEF). This study was designed to evaluate the influences of long-term aldosterone antagonist prescription in these patients.

METHODS

Using a propensity score matching of 1:2 ratio, this retrospective claims database study compared spironolactone prescription (n=65) and non-spironolactone therapy (n=130) in hypertensive patients with LVH [left ventricular mass index (LVMI)>125g/m(2) for men and >110g/m(2) for women] and suspected diastolic dysfunction (E/E' ratio between 8 and 15) and without clinical signs or symptoms of heart failure.

RESULTS

With a median follow-up of 7.4years, the new-onset symptomatic HFpEF occurred in 3 of 65 patients in the spironolactone group and 21 of 130 patients in the non-spironolactone group (P=0.021). Spironolactone also generated more prominent improvement in diastolic function and LVH. And multivariate logistic regression model revealed that spironolactone prescription (OR 0.177, 95% CI: 0.045-0.687, P=0.012) was associated with a reduced risk of new onset of symptomatic HFpEF, and the elevation of LVMI (OR 1.053, 95% CI: 1.011-1.097, P=0.012) or E/E' (OR 1.280, 95% CI: 1.015-1.615, P=0.037) was associated with a high risk of new onset of symptomatic HFpEF.

CONCLUSIONS

Long-term aldosterone antagonist exposure was associated with protective effects in terms of the incidence of new-onset symptomatic HFpEF, LV diastolic dysfunction and LVH in hypertensive patients, which might be beneficial for the delay of HFpEF progression.

Aldosterone Induces Tissue Inhibitor of Metalloproteinases-1 Expression and Further Contributes to Collagen Accumulation

Aldosterone induces myocardial fibrosis. Tissue inhibitor of metalloproteinases-1 (TIMP-1) is a key factor of myocardial fibrosis. This study tested the hypothesis that aldosterone induces TIMP-1 expression and contributes to the fibrotic process. We prospectively enrolled 54 patients with primary aldosteronism, and measured plasma TIMP-1 and echocardiographic parameters. In the cell study, we investigated the possible molecular mechanism by which aldosterone induces TIMP-1 secretion and the effects on collagen accumulation. In the animal study, we measured serum TIMP-1 levels, cardiac TIMP-1 levels, and cardiac structure in an aldosterone infusion mouse model using implantation of aldosterone pellets. In patients with primary aldosteronism, plasma TIMP-1 was correlated with 24-hour urinary aldosterone, left ventricular mass, and impairment of left ventricular diastolic function. In human cardiac fibroblasts, TIMP-1 protein and mRNA expressions were significantly increased by aldosterone through the glucocorticoid receptor/PI3K/Akt/nuclear factor-κB pathway. TIMP-1 small-interfering RNA significantly reduced aldosterone-induced collagen accumulation, and aldosterone did not alter the levels of collagen1a1 or matrix metalloproteinase-1 mRNA. The aldosterone-induced TIMP-1 expression was inversely related to matrix metalloproteinase-1 activity. Furthermore, in the animal model, the serum and cardiac levels of TIMP-1 were significantly elevated in the mice that received aldosterone infusion. This elevation was blocked by RU-486 but not by eplerenone, suggesting that the effect was through glucocorticoid receptors. In a long-term aldosterone infusion model, serum TIMP-1 was associated with serum aldosterone level, cardiac structure, and fibrosis. In conclusion, aldosterone induced TIMP-1 expression in vivo and in vitro. This increased TIMP-1 expression resulted in enhanced collagen accumulation via the suppression of matrix metalloproteinase-1 activity.

The next generation of therapeutics for chronic kidney disease

Chronic kidney disease (CKD) represents a leading cause of death in the United States. There is no cure for this disease, with current treatment strategies relying on blood pressure control through blockade of the renin-angiotensin system. Such approaches only delay the development of end-stage kidney disease and can be associated with serious side effects. Recent identification of several novel mechanisms contributing to CKD development - including vascular changes, loss of podocytes and renal epithelial cells, matrix deposition, inflammation and metabolic dysregulation - has revealed new potential therapeutic approaches for CKD. This Review assesses emerging strategies and agents for CKD treatment, highlighting the associated challenges in their clinical development.

The relation among aldosterone, galectin-3, and myocardial fibrosis: a prospective clinical pilot follow-up study

Primary aldosteronism has been associated with myocardial fibrosis, and is the most common cause of secondary hypertension. We previously showed that aldosterone can induce the secretion of galectin-3. The aim of this study was to investigate the association between myocardial fibrosis and plasma galectin-3 level in patients with primary aldosteronism. We prospectively analyzed 11 patients with aldosterone-producing adenoma (APA) who received adrenalectomy from December 2006 to October 2008, and 17 patients with essential hypertension as controls. Levels of plasma galectin-3 were determined in both groups, and both groups underwent echocardiography with cyclic variations of integrated backscatter (CVIBS) to characterize tissue initially and 1 year after surgery in the APA group. Diastolic blood pressure, concentration of plasma aldosterone and aldosterone-renin ratio were significantly higher, and serum potassium level and plasma renin activity significantly lower in the APA group compared to the controls. In addition, left ventricular mass index was significantly higher and CVIBS significantly lower in the APA group (7.3±2.0 vs 9.2±1.7 dB, p=0.015). Furthermore, the concentration of plasma galectin-3 was significantly higher in the APA group (2.1±0.9 vs 1.1±0.6 ng/mL, p=0.005) compared to the controls. CVIBS was correlated to plasma galectin-3 level. In the APA group, CVIBS increased significantly (7.3±2.0 to 9.2±2.4 dB, p=0.032) and plasma galectin-3 decreased (2.1±0.9 to 1.2±0.6, p=0.049) 1 year postadrenalectomy. The patients with APA had increased myocardial fibrosis, and this was associated with a higher plasma galectin-3 level. Both increased myocardial fibrosis and plasma galectin-3 level recovered at least partially after adrenalectomy.

TRIAL REGISTRATION NUMBER

200611031R; Results.

The search for efficient diagnostic and prognostic biomarkers of heart failure

Several biomarkers have been tested for screening, diagnosis and prognosis purposes, as well as to guide treatment in heart failure, but only the assay of circulating B-type natriuretic peptides has widely recognized applications for clinical decision-making. Natriuretic peptides are sensitive in detecting the clinically overt or subclinical myocardial damage, but their plasma levels are increased following every generic insult to the cardiovascular system. Novel biomarkers are required to identify specific pathways of disease progression, such as diverse neurohormonal axes activation, inflammation and fibrogenesis, and to act as a tool for therapeutic tailoring. In this view, Gal-3 and ST-2 assays seem very promising, given their involvement in mechanisms of cardiac fibrosis and their prognostic value.

Interaction of Galectin-3 Concentrations with the Treatment Effects of β-Blockers and RAS Blockade in Patients with Systolic Heart Failure: A Derivation-Validation Study from TIME-CHF and GISSI-HF

BACKGROUND

Galectin-3 predicts prognosis in heart failure (HF) and may help to select HF patients in need of intensified therapy.

METHODS

This retrospective post hoc analysis included 219 patients from the Trial of Intensified versus Standard Medical Therapy in Elderly Patients with Congestive Heart Failure (TIME-HF) and 631 patients from Gruppo Italiano per lo Studio della Sopravvivenza nell'Insufficienza Cardiaca (GISSI-HF) with HF who had reduced ejection fraction and available galectin-3 plasma concentrations. The interaction between galectin-3, β-blockers, renin-angiotensin system (RAS) blockade, and spironolactone on outcome was evaluated in TIME-CHF and validated in GISSI-HF. End points were all-cause mortality and the composite of mortality with HF hospitalization or any hospitalization.

RESULTS

High galectin-3 concentrations were associated with adverse outcome in both cohorts and remained significantly associated with death after multivariate adjustment [hazard ratio 2.42 (95% CI 1.17-5.01), P = 0.02, in TIME-CHF; 1.47 (1.02-2.10), P = 0.04, in GISSI-HF). In TIME-CHF, patients with low galectin-3 plasma concentrations had a better prognosis when β-blockers were up-titrated, whereas patients with high galectin-3 plasma concentrations did not (interaction P < 0.05 for mortality and death with or without hospitalization). Opposite trends were seen for RAS blockade but were not statistically significant. Patients with high galectin-3 plasma concentrations had neutral prognosis when receiving spironolactone, whereas patients with low galectin-3 plasma concentrations had worse prognosis when receiving spironolactone (interaction P < 0.10 for death with or without hospitalization). In the GISSI-HF validation cohort, these interactions were confirmed for β-blockers (P < 0.05 for all end points) and consistent for RAS blockade (P < 0.10 for death with or without hospitalization), but inconsistent for spironolactone.

CONCLUSIONS

Galectin-3 is a mediocre prognostic marker, and galectin-3 concentrations interact with the treatment effect of β-blockers and possibly RAS blockade in patients with systolic HF.

Galectin-3 blockade inhibits cardiac inflammation and fibrosis in experimental hyperaldosteronism and hypertension

Hypertensive cardiac remodeling is accompanied by molecular inflammation and fibrosis, 2 mechanisms that finally affect cardiac function. At cardiac level, aldosterone promotes inflammation and fibrosis, although the precise mechanisms are still unclear. Galectin-3 (Gal-3), a β-galactoside-binding lectin, is associated with inflammation and fibrosis in the cardiovascular system. We herein investigated whether Gal-3 inhibition could block aldosterone-induced cardiac inflammation and fibrosis and its potential role in cardiac damage associated with hypertension. Aldosterone-salt-treated rats presented hypertension, cardiac inflammation, and fibrosis that were prevented by the pharmacological inhibition of Gal-3 with modified citrus pectin. Cardiac inflammation and fibrosis presented in spontaneously hypertensive rats were prevented by modified citrus pectin treatment, whereas Gal-3 blockade did not modify blood pressure levels. In the absence of blood pressure modifications, Gal-3 knockout mice were resistant to aldosterone-induced cardiac inflammation. In human cardiac fibroblasts, aldosterone increased Gal-3 expression via its mineralocorticoid receptor. Gal-3 and aldosterone enhanced proinflammatory and profibrotic markers, as well as metalloproteinase activities in human cardiac fibroblasts, effects that were not observed in Gal-3-silenced cells treated with aldosterone. In experimental hyperaldosteronism, the increase in Gal-3 expression was associated with cardiac inflammation and fibrosis, alterations that were prevented by Gal-3 blockade independently of blood pressure levels. These data suggest that Gal-3 could be a new molecular mechanism linking cardiac inflammation and fibrosis in situations with high-aldosterone levels, such as hypertension.

Blockade of brain angiotensin II type 1 receptor inhibits the development of atrial fibrillation in hypertensive rats

BACKGROUND

Hypertension is a powerful risk factor of atrial fibrillation (AF). The pathophysiology of AF with hypertension is associated with sympathoexcitation or the renin-angiotensin system; however, current therapies cannot sufficiently prevent its development. We previously revealed that brain angiotensin II type 1 receptor (AT1R) blockade causes a depressor response via sympathoinhibition. Herein, we evaluated whether brain AT1R contributes to AF development in hypertensive rats.

METHODS

We divided the stroke-prone spontaneously hypertensive rats (SHRSP) treated with intracerebroventricular (ICV) infusion of vehicle, ICV infusion of losartan (S-LOS), or oral administration of hydralazine (S-HYD); and Wistar Kyoto rats treated with ICV S-VEH.

RESULTS

Two weeks later, systolic blood pressure was significantly lower in the S-LOS group than in the S-VEH group and was even lower in the S-HYD group. Urinary norepinephrine excretion for 24h, an indirect marker of sympathoexcitation, significantly reduced in the S-LOS group but increased in the S-HYD group despite depressor response. AF was induced by transesophageal burst pacing. AF duration was significantly shorter in the S-LOS group than in the S-VEH group (5.0±0.4 vs. 15.2±3.7 s; n = 8 each; P < 0.05). However, it was significantly longer in the S-HYD group than in the S-VEH group. Interstitial atrial fibrosis and echocardiographic parameters did not differ between the SHRSP groups.

CONCLUSIONS

Brain AT1R blockade suppresses AF inducibility and maintenance independent of depressor response in hypertensive rats.

Novel biomarkers in heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFPEF) is a common subtype of heart failure with morbidity and mortality similar to that of heart failure with systolic dysfunction. This article discusses the numerous biomarkers that promise to play a substantial role in terms of our ability to understand the mechanisms of HFPEF and discern possible phenotypes that respond to targeted therapies: natriuretic peptides, high-sensitivity troponins, galectin-3, soluble ST2, neutrophil gelatinase-associated lipocalin, and cystatin C.

Galectin-3 and myocardial fibrosis in nonischemic dilated cardiomyopathy

BACKGROUND

Left ventricular (LV) fibrosis, assessed by late gadolinium enhancement (LGE) at cardiac magnetic resonance imaging (MRI), is a marker of LV remodeling, and holds prognostic value in nonischemic dilated cardiomyopathy (NICM). Galectin-3 has been shown to participate in tissue fibrogenesis and to be a prognosticator in heart failure. Our aim was to investigate the relationships between galectin-3 circulating level and myocardial fibrosis at MRI in patients with NICM.

METHODS AND RESULTS

One-hundred-fifty patients were enrolled (males 73%; age 58, SD 14 years), with a NICM diagnosis according to the World Health Organization criteria. All patients underwent a comprehensive clinical assessment and biohumoral characterization, including galectin-3 assay, and cardiac MRI, with LGE assessment of fibrosis. Median galectin-3 value was 14.4 ng/mL (IQR 11.7-19.0 ng/mL), and LGE was detected in 106 (71%) patients. Patients with LGE had higher galectin-3 than those without (15.4, 11.8-21.0, vs 13.1, 11.7-16.4 ng/mL, p=0.006). Among univariate predictors of LGE presence (galectin-3, male sex, disease duration, arterial hypertension, left and right ventricular ejection fraction, left ventricular stroke volume), galectin-3 maintained its predictive value at multivariate analysis, together with sex, hypertension, disease duration and right ventricular ejection fraction. At receiver operating characteristic analysis the optimal galectin-3 cut-off for LGE prediction was 14.6 ng/mL (AUC 0.651, sensitivity 57%, specificity 73%).

CONCLUSIONS

Galectin-3 is associated with LGE-assessed myocardial replacement fibrosis in patients with NICM. These results support the hypothesis that galectin-3 is involved in cardiac fibrosis and remodeling in NICM, and that its assay may help to select subgroups at higher risk.

Effects of biological sex on the pathophysiology of the heart

Cardiovascular diseases are the leading causes of death in men and women in industrialized countries. While the effects of biological sex on cardiovascular pathophysiology have long been known, the sex-specific mechanisms mediating these processes have been further elucidated over recent years. This review aims at analysing the sex-based differences in cardiac structure and function in adult mammals, and the sex-based differences in the main molecular mechanisms involved in the response of the heart to pathological situations. It emerged from this review that the sex-based difference is a variable that should be dealt with, not only in basic science or clinical research, but also with regards to therapeutic approaches.

Aldosterone induced galectin-3 secretion in vitro and in vivo: from cells to humans

Context

Patients with primary aldosteronism are associated with increased myocardial fibrosis. Galectin-3 is one of the most important mediators between macrophage activation and myocardial fibrosis.

Objective

To investigate whether aldosterone induces galectin-3 secretion in vitro and in vivo.

Methods and Results

We investigated the possible molecular mechanism of aldosterone-induced galectin-3 secretion in macrophage cell lines (THP-1 and RAW 264.7 cells). Aldosterone induced galectin-3 secretion through mineralocorticoid receptors via the PI3K/Akt and NF-κB transcription signaling pathways. In addition, aldosterone-induced galectin-3 expression enhanced fibrosis-related factor expression in fibroblasts. We observed that galectin-3 mRNA from peripheral blood mononuclear cells and serum galectin-3 levels were both significantly increased in mice implanted with aldosterone pellets on days 7 and 14. We then conducted a prospective preliminary clinical study to investigate the association between aldosterone and galectin-3. Patients with aldosterone-producing adenoma had a significantly higher plasma galectin-3 level than patients with essential hypertension. One year after adrenalectomy, the plasma galectin-3 level had decreased significantly in the patients with aldosterone-producing adenoma.

Conclusion

This study demonstrated that aldosterone could induce galectin-3 secretion in vitro and in vivo.

Featured article: induction of heme oxygenase with hemin improves pericardial adipocyte morphology and function in obese Zucker rats by enhancing proteins of regeneration

Oxidative stress and inflammation are implicated in tissue remodeling, hypertrophy, and organ malfunction. Since heme-oxygenase (HO) is a cytoprotective enzyme with effects against oxidative stress and inflammation, we investigated the effects of upregulating HO with hemin on adipocyte hypertrophy, proteins of repair/regeneration including beta-catenin, Oct3/4 and Pax2 as well as pro-fibrotic/remodeling proteins like osteopontin and transforming growth factor-beta (TGF-β) in pericardial adipose tissue from obese Zucker rats (ZRs). Treatment with hemin significantly reduced pericardial adipose tissue inflammation/oxidative stress, suppressed osteopontin and TGF-β, and attenuated pericardial adipocyte hypertrophy in obese ZRs. These were associated with enhanced expression of the stem/progenitor-cell marker cKit; the potentiation of several proteins of regeneration including beta-catenin, Oct3/4, Pax2; and improved pericardial adipocyte morphology. Interestingly, the amelioration of adipocyte hypertrophy in hemin-treated animals was accompanied by improved adipocyte function, evidenced by increased levels of pericardial adipose tissue adiponectin. Furthermore, hemin significantly reduced hypertriglyceridemia and hypercholesteromia in obese ZRs. The protective effects of hemin were accompanied by robust potentiation HO activity and the total antioxidant capacity, whereas the co-administration of hemin with the HO inhibitor, stannous mesoporphyrin abolished the effects of hemin. These data suggest that hemin improves pericardial adipocyte morphology and function by enhancing proteins of repair and regeneration, while concomitantly abating inflammatory/oxidative insults and suppressing extracellular-matrix/profibrotic and remodeling proteins. The reduction of hypertriglyceridemia, hypercholesteromia, pericardial adiposity, and pericardial adipocyte hypertrophy with corresponding improvement of adipocyte morphology/function in hemin-treated animals suggests that HO inducers may be explored for the design of novel remedies against cardiac complications arising from excessive adiposity.

The role of the renin-angiotensin-aldosterone system in the pathobiology of pulmonary arterial hypertension (2013 Grover Conference series)

Pulmonary arterial hypertension (PAH) is associated with aberrant pulmonary vascular remodeling that leads to increased pulmonary artery pressure, pulmonary vascular resistance, and right ventricular dysfunction. There is now accumulating evidence that the renin-angiotensin-aldosterone system is activated and contributes to cardiopulmonary remodeling that occurs in PAH. Increased plasma and lung tissue levels of angiotensin and aldosterone have been detected in experimental models of PAH and shown to correlate with cardiopulmonary hemodynamics and pulmonary vascular remodeling. These processes are abrogated by treatment with angiotensin receptor or mineralocorticoid receptor antagonists. At a cellular level, angiotensin and aldosterone activate oxidant stress signaling pathways that decrease levels of bioavailable nitric oxide, increase inflammation, and promote cell proliferation, migration, extracellular matrix remodeling, and fibrosis. Clinically, enhanced renin-angiotensin activity and elevated levels of aldosterone have been detected in patients with PAH, which suggests a role for angiotensin and mineralocorticoid receptor antagonists in the treatment of PAH. This review will examine the current evidence linking renin-angiotensin-aldosterone system activation to PAH with an emphasis on the cellular and molecular mechanisms that are modulated by aldosterone and may be of importance for the pathobiology of PAH.