New Mechanisms to Prevent Heart Failure with Preserved Ejection Fraction Using Glucagon-like Peptide-1 Receptor Agonism (GLP-1 RA) in Metabolic Syndrome and in Type 2 Diabetes: A Review.

This review examines the impact of obesity on the pathophysiology of heart failure with preserved ejection fraction (HFpEF) and focuses on novel mechanisms for HFpEF prevention using a glucagon-like peptide-1 receptor agonism (GLP-1 RA). Obesity can lead to HFpEF through various mechanisms, including low-grade systemic inflammation, adipocyte dysfunction, accumulation of visceral adipose tissue, and increased pericardial/epicardial adipose tissue (contributing to an increase in myocardial fat content and interstitial fibrosis). Glucagon-like peptide 1 (GLP-1) is an incretin hormone that is released from the enteroendocrine L-cells in the gut. GLP-1 reduces blood glucose levels by stimulating insulin synthesis, suppressing islet α-cell function, and promoting the proliferation and differentiation of ß-cells. GLP-1 regulates gastric emptying and appetite, and GLP-1 RA is currently indicated for treating type 2 diabetes (T2D), obesity, and metabolic syndrome (MS). Recent evidence indicates that GLP-1 RA may play a significant role in preventing HFpEF in patients with obesity, MS, or obese T2D. This effect may be due to activating cardioprotective mechanisms (the endogenous counter-regulatory renin angiotensin system and the AMPK/mTOR pathway) and by inhibiting deleterious remodeling mechanisms (the PKA/RhoA/ROCK pathway, aldosterone levels, and microinflammation). However, there is still a need for further research to validate the impact of these mechanisms on humans.

Rho-kinase pathway activation and apoptosis in circulating leucocytes in patients with heart failure with reduced ejection fraction.

BACKGROUND: Increased Rho-kinase activity in circulating leucocytes is observed in heart failure with reduced ejection fraction (HFrEF). However, there is little information in HFrEF regarding other Rho-kinase pathway components an on the relationship between Rho-kinase and apoptosis. Here, Rho-kinase activation levels and phosphorylation of major downstream molecules and apoptosis levels were measured for the first time both in HFrEF patients and healthy individuals. METHODS: Cross-sectional study comparing HFrEF patients (n = 20) and healthy controls (n = 19). Rho-kinase activity in circulating leucocytes (peripheral blood mononuclear cells, PBMCs) was determined by myosin light chain phosphatase 1 (MYPT1) and ezrin-radixin-moesin (ERM) phosphorylation. Rho-kinase cascade proteins phosphorylation p38-MAPK, myosin light chain-2, JAK and JNK were also analysed along with apoptosis. RESULTS: MYPT1 and ERM phosphorylation were significantly elevated in HFrEF patients, (3.9- and 4.8-fold higher than in controls, respectively). JAK phosphorylation was significantly increased by 300% over controls. Phosphorylation of downstream molecules p38-MAPK and myosin light chain-2 was significantly higher by 360% and 490%, respectively, while JNK phosphorylation was reduced by 60%. Catecholamine and angiotensin II levels were significantly higher in HFrEF patients, while angiotensin-(1-9) levels were lower. Apoptosis in circulating leucocytes was significantly increased in HFrEF patients by 2.8-fold compared with controls and significantly correlated with Rho-kinase activation. CONCLUSION: Rho-kinase pathway is activated in PMBCs from HFrEF patients despite optimal treatment, and it is closely associated with neurohormonal activation and with apoptosis. ROCK cascade inhibition might induce clinical benefits in HFrEF patients, and its assessment in PMBCs could be useful to evaluate reverse remodelling and disease regression.

Rho kinase cascade activation in circulating leukocytes in patients with diabetes mellitus type 2.

BACKGROUND: The intracellular ROCK signaling pathway is an important modulator of blood pressure and of cardiovascular and renal remodeling when Rho-kinase activity is increased. Besides, in preclinical models of diabetes, ROCK activation has also a role in abnormal glucose metabolism as well as in subsequent vascular and myocardial dysfunction. In humans, there are a few data assessing ROCK activation in patients with type 2 diabetes mellitus (T2D) and no studies assessing upstream/downstream components of the ROCK pathway. We assessed here levels of ROCK activation and some of the RhoA/ROCK cascade molecules in peripheral blood mononuclear cells (PBMCs) in T2D patients under current treatment. METHODS: Cross-sectional observational study comparing 28 T2D patients under current antidiabetic treatment with 31 consecutive healthy subjects, matched by age and gender. Circulating levels of malondialdehyde, angiotensin II and inflammatory cytokines IL-6 and IL-8 were determined in all subjects. ROCK activation in PMBCs, upstream and downstream cascade proteins, and levels of the proinflammatory molecules VCAM, ICAM-1 and IL-8 were determined in their PMBCs by Western blot. RESULTS: Compared to healthy controls, ROCK activation in T2D patients measured by 2 direct ROCK targets in PBMCs was increased by 420 and 570% (p < 0001) and it correlated significantly with serum glucose levels. p38 MAPK phosphorylation (downstream from ROCK) and JAK-2 (upstream from ROCK) were significantly higher in the T2D patients by 580% and 220%, respectively. In T2D patients, significantly increased PBMC levels of the proinflammatory molecules VCAM-1, ICAM-1 and IL-8 were observed compared to control subjects (by 180%, 360% and 260%, respectively). Circulating levels of Ang II and MDA were significantly higher in T2D patients by 29 and 63%, respectively. CONCLUSIONS: T2D patients under treatment with glucose-lowering drugs, antihypertensive treatment as well as with statins have significantly increased ROCK activation in their circulating leukocytes along with higher phosphorylation of downstream cascade proteins despite pharmacologic treatment, along with increased plasma angiotensin II and MDA levels. ROCK inhibition might have an additional role in the prevention and treatment of T2D.

Rho kinase activation in circulating leukocytes is related to hypertensive myocardial remodeling.

Rho-kinase has relevant functions in blood pressure modulation and cardiovascular remodeling. Rho-kinase activity is determined in circulating leukocytes measuring phosphorylation of its target myosin phosphatase target subunit 1 (MYPT1), but its relationship with Rho-kinase activity in the myocardium and in vasculature in hypertension has not been evaluated.The aim was to determine the degree of association between Rho-kinase cascade activation in circulating leukocytes with cardiac and aortic Rho-kinase pathway activation in a model of hypertension and to analyze it with a cause-effect perspective.Hypertensive deoxycorticosterone (DOCA)-salt rats received the Rho-kinase antagonist fasudil (DOCA-Fas, 100 mg/kg/day, 3 weeks). Results were compared with an untreated DOCA-salt and a sham group.Rho-kinase inhibition reduced significantly blood pressure, cardiac hypertrophy, myocardial collagen and macrophage infiltration, but not aortic wall hypertrophy. Fasudil decreased significantly Rho-kinase activity in peripheral blood mononucleated cells (PBMC), myocardium and aortic wall to similar levels as in the sham group. A significant correlation was found between PBMC Rho-kinase activity and cardiac remodeling, specifically with hypertrophy (r = 0.51, P≤0.01), myocardial collagen (r = 0.40, P≤0.05) and ED1 immunostaining (r = 0.48, P≤0.01). In the untreated hypertensive group, increased levels (P<0.05) of the proinflammatory molecules p65 NF-κB, vascular cell adhesion molecule 1 and interleukin-6 antibody in the myocardium, aortic wall and PBMC were observed and were reduced with fasudil (P<0.05).In conclusion, in this hypertension model, Rho-kinase and its pathway activation determined in circulating leukocytes reflect the activation of this pathway in the myocardium and in the aortic wall and are significantly related to myocardial remodeling (hypertrophy, fibrosis and inflammation).

Protection of the myocardium against ischemia/reperfusion injury by angiotensin-(1-9) through an AT2R and Akt-dependent mechanism.

Angiotensin-(19), a peptide of the non-classical renin angiotensin system, has been shown to prevent and revert hypertension and cardiac hypertrophy. We hypothetized that systemic delivery of angiotensin-(1-9) following myocardial infarction will also be protective and extend to provide protection during reperfusion of the ischemic heart. Adult Sprague Dawley rats were subjected to left anterior descending artery ligation and treated with angiotensin-(1-9) via osmotic mini-pump for 2 weeks in the presence or absence of Mas receptor or AT2R antagonists (A779 and PD123319, respectively). Myocardial death and left ventricular function were evaluated after infarction. Infarct size and functional parameters were determined in isolated rat hearts after global ischemia/reperfusion in the presence of angiotensin-(1-9) plus receptor antagonists or Akt inhibitor at reperfusion. in vitro, neonatal rat ventricular cardiomyocytes underwent simulated ischemia/reperfusion and angiotensin-(1-9) was co-incubated with A779, PD123319 or Akt inhibitor. Systemic delivery of angiotensin-(1-9) significantly decreased cell death and improved left ventricular recovery after in vivo myocardial infarction. Perfusion with the peptide reduced the infarct size and improved functional recovery after ex vivo ischemia/reperfusion. In vitro, angiotensin-(1-9) decreased cell death in isolated neonatal rat ventricular cardiomyocytes subjected to simulated ischemia/reperfusion. The cardioprotective effects of angiotensin-(1-9) were blocked by PD123319 and Akti VIII but not by A779. Angiotensin-(1-9) limits reperfusion-induced cell death by an AT2R- and Aktdependent mechanism. Angiotensin-(1-9) is a novel strategy to protect against cardiac ischemia/reperfusion injury.

Gaps and Resemblances in Current Heart Failure Guidelines: A Clinical Perspective.

The newly available clinical guidelines in heart failure (HF) from Europe (2012), the United States (2010 and 2013), and Canada (2015) were compared, focusing on the systems for grading the evidence and classifying the recommendations, HF definitions, pharmacologic treatment, and devices used in HF. Some gaps were evident in the methodology for assessing evidence or in HF definitions. Pharmacologic treatments and recommendations for cardiac resynchronization therapy and implantable cardioverter-defibrillators are similar but some differences need to be considered by the practicing clinician. Guideline recommendations regarding new emergent treatments are becoming available.

Effects of trimetazidine in nonischemic heart failure: a randomized study.

OBJECTIVES: Heart failure (HF) is associated with changes in myocardial metabolism that lead to impairment of contractile function. Trimetazidine (TMZ) modulates cardiac energetic efficiency and improves outcomes in ischemic heart disease. We evaluated the effects of TMZ on left ventricular ejection fraction (LVEF), cardiac metabolism, exercise capacity, O2 uptake, and quality of life in patients with nonischemic HF. METHODS AND RESULTS: Sixty patients with stable nonischemic HF under optimal medical therapy were included in this randomized double-blind study. Patients were randomized to TMZ (35 mg orally twice a day) or placebo for 6 months. LVEF, 6-minute walk test (6MWT), maximum O2 uptake in cardiopulmonary exercise test, different markers of metabolism, oxidative stress, and endothelial function, and quality of life were assessed at baseline and after TMZ treatment. Left ventricular peak glucose uptake was evaluated with the use of the maximum standardized uptake value (SUV) by 18-fluorodeoxyglucose positron emission tomography ((18)FDG-PET). Etiology was idiopathic in 85% and hypertensive in 15%. Both groups were similar in age, functional class, LVEF, and levels of N-terminal pro-B-type natriuretic peptide at baseline. After 6 months of TMZ treatment, no changes were observed in LVEF (31 ± 10% vs 34 ± 8%; P = .8), 6MWT (443 ± 25 m vs 506 ± 79 m; P = .03), maximum O2 uptake (19.1 ± 5.0 mL kg(-1) min(-1) vs 23.0 ± 7.2 mL kg(-1) min(-1); P = .11), functional class (percentages of patients in functional classes I/II/III/IV 10/3753/0 vs 7/40/50/3; P = .14), or quality of life (32 ± 26 points vs 24 ± 18 points; P = .25) in TMZ versus placebo, respectively. In the subgroup of patients evaluated with (18)FDG-PET, no significant differences were observed in SUV between both groups (7.0 ± 3.6 vs 8.2 ± 3.4 respectively; P = .47). CONCLUSIONS: In patients with nonischemic HF, the addition of TMZ to optimal medical treatment does not result in significant changes of LVEF, exercise capacity, O2 uptake, or quality of life.

Recent insights and therapeutic perspectives of angiotensin-(1-9) in the cardiovascular system.

Chronic RAS (renin-angiotensin system) activation by both AngII (angiotensin II) and aldosterone leads to hypertension and perpetuates a cascade of pro-hypertrophic, pro-inflammatory, pro-thrombotic and atherogenic effects associated with cardiovascular damage. In 2000, a new pathway consisting of ACE2 (angiotensin-converting enzyme2), Ang-(1-9) [angiotensin-(1-9)], Ang-(1-7) [angiotensin-(1-7)] and the Mas receptor was discovered. Activation of this novel pathway stimulates vasodilation, anti-hypertrophy and anti-hyperplasia. For some time, studies have focused mainly on ACE2, Ang-(1-7) and the Mas receptor, and their biological properties that counterbalance the ACE/AngII/AT1R (angiotensin type 1 receptor) axis. No previous information about Ang-(1-9) suggested that this peptide had biological properties. However, recent data suggest that Ang-(1-9) protects the heart and blood vessels (and possibly the kidney) from adverse cardiovascular remodelling in patients with hypertension and/or heart failure. These beneficial effects are not modified by the Mas receptor antagonist A779 [an Ang-(1-7) receptor blocker], but they are abolished by the AT2R (angiotensin type 2 receptor) antagonist PD123319. Current information suggests that the beneficial effects of Ang-(1-9) are mediated via the AT2R. In the present review, we summarize the biological effects of the novel vasoactive peptide Ang-(1-9), providing new evidence of its cardiovascular-protective activity. We also discuss the potential mechanism by which this peptide prevents and ameliorates the cardiovascular damage induced by RAS activation.

Markedly increased Rho-kinase activity in circulating leukocytes in patients with chronic heart failure.

BACKGROUND: The small guanosine triphosphatase Rho and its target Rho-kinase have significant roles in experimental remodeling and ventricular dysfunction, but no data are available on Rho-kinase activation in patients with heart failure (HF). We hypothesized that, in patients with chronic HF, Rho-kinase in circulating leukocytes is activated and related to left ventricular (LV) remodeling and dysfunction. METHODS: Accordingly, Rho-kinase activity, assessed by the levels of phosphorylated to total myosin light chain phosphatase 1 (MYPT1-P/T) in circulating leukocytes, and echocardiographic LV function data were compared between patients with HF New York Heart Association functional class II or III due to systolic dysfunction (n = 17), healthy controls (n = 17), and hypertensive patients without HF (n = 17). RESULTS: In the control subjects, mean MYPT1-P/T ratio was 1.2 ± 0.2 (it was similar in the hypertensive patients without HF), whereas in patients with HF, it was significantly increased by >100-fold (P < .001). Both MYPT1-P/T and log MYPT1-P/T ratios were inversely correlated with ejection fraction (r = -0.54, P < .03 and r = -0.86, P < .001, respectively). Furthermore, in patients with HF with LV end-diastolic diameter <60 mm, MYPT1-P/T ratio was 35.8 ± 18.1, whereas it was significantly higher in patients with LV diameter ≥60 mm (P < .05). CONCLUSIONS: Rho-Kinase activity is markedly increased in patients with stable chronic HF under optimal medical treatment, and it is associated with pathologic LV remodeling and systolic dysfunction. Mechanisms of Rho-kinase activation in patients with HF, its role in the progression of the disease, and the direct effect of Rho-kinase inhibition need further investigation.

Hydrochlorothiazide Reduces Cardiac Hypertrophy, Fibrosis and Rho-Kinase Activation in DOCA-Salt Induced Hypertension.

BACKGROUND: Thiazides are one of the most common antihypertensive drugs used for hypertension treatment and hydrochlorothiazide (HCTZ) is the most frequently used diuretic for hypertension treatment. The Rho/Rho-kinase (ROCK) path plays a key function in cardiovascular remodeling. We hypothesized that in preclinical hypertension HCTZ reduces myocardial ROCK activation and consequent myocardial remodeling. METHODS: The preclinical model of deoxycorticosterone (DOCA)-salt hypertension was used (Sprague-Dawley male rats). After 3 weeks, in 3 different groups: HCTZ, the ROCK inhibitor fasudil or spironolactone was added (3 weeks). After 6 weeks myocardial hypertrophy and fibrosis, cardiac levels of profibrotic proteins, mRNA levels (RT PCR) of pro remodeling and pro oxidative molecules and ROCK activity were determined. RESULTS: Blood pressure, myocardial hypertrophy and fibrosis were reduced significantly by HCTZ, fasudil and spironolactone. In the heart, increased levels of the pro-fibrotic proteins Col-I, Col-III and TGF-ß1 and gene expression of pro-remodeling molecules TGF-ß1, CTGF, MCP-1 and PAI-1 and the pro-oxidative molecules gp91phox and p22phox were significantly reduced by HCTZ, fasudil and spironolactone. ROCK activity in the myocardium was increased by 54% (P < 0.05) as related to the sham group and HCTZ, spironolactone and fasudil, reduced ROCK activation to control levels. CONCLUSIONS: HCTZ reduced pathologic LVH by controlling blood pressure, hypertrophy and myocardial fibrosis and by decreasing myocardial ROCK activation, expression of pro remodeling, pro fibrotic and pro oxidative genes. In hypertension, the observed effects of HCTZ on the myocardium might explain preventive outcomes of thiazides in hypertension, specifically on LVH regression and incident heart failure.

Left Cardiac Remodelling Assessed by Echocardiography Is Associated with Rho-Kinase Activation in Long-Distance Runners.

This single-blind and cross-sectional study evaluated the role of Rho-kinase (ROCK) as a biomarker of the cardiovascular remodelling process assessed by echocardiography in competitive long-distance runners (LDRs) during the training period before a marathon race. Thirty-six healthy male LDRs (37.0 ± 5.3 years; 174.0 ± 7.0 height; BMI: 23.8 ± 2.8; V˙ O2-peak: 56.5 ± 7.3 mL·kg-1·min-1) were separated into two groups according to previous training level: high-training (HT, n = 16) ≥ 100 km·week-1 and low-training (LT, n = 20) ≥ 70 and < 100 km·week-1. Also, twenty-one healthy nonactive subjects were included as a control group (CTR). A transthoracic echocardiography was performed and ROCK activity levels in circulating leukocytes were measured at rest (48 h without exercising) the week before the race. The HT group showed a higher left ventricular mass index (LVMi) and left atrial volume index (LAVi) than other groups (p < 0.05, for both); also, higher levels of ROCK activity were found in LDRs (HT = 6.17 ± 1.41 vs. CTR = 1.64 ± 0.66 (p < 0.01); vs. LT = 2.74 ± 0.84; (p < 0.05)). In LDRs a direct correlation between ROCK activity levels and LVMi (r = 0.83; p < 0.001), and LAVi (r = 0.70; p < 0.001) were found. In conclusion, in male competitive long-distance runners, the load of exercise implicated in marathon training is associated with ROCK activity levels and the left cardiac remodelling process assessed by echocardiography.

Circulating Vascular Cell Adhesion Molecule-1 (sVCAM-1) Is Associated With Left Atrial Remodeling in Long-Distance Runners.

Introduction: An increased risk of atrial fibrillation (AF) has been demonstrated in high-performance athletes. Soluble vascular adhesion molecule-1 (sVCAM-1), a biomarker involved in inflammation and cardiac remodeling, is associated with the development of AF in the general population. However, the relationship between sVCAM-1 and left atrial (LA) remodeling has been poorly investigated in long-distance runners (LDR). Aim: To determine the association between LA remodeling and sVCAM-1 levels in LDR during the training period before a marathon race. Methods: Thirty-six healthy male LDR (37.0 ± 5.3 years; 174.0 ± 7.0 height; BMI: 23.8 ± 2.8; V°O2-peak: 56.5 ± 7.3 mL·kg-1·min-1) were evaluated in this single-blind and cross-sectional study. The LDR were separated into two groups according to previous training levels: high-training (HT) (n = 18) ≥100 km·week-1 and low-training (LT) (n = 18) ≥70 and <100 km·week-1. Also, 18 healthy non-active subjects were included as a control group (CTR). In all participants, transthoracic echocardiography was performed. sVCAM-1 blood levels were measured baseline and immediately finished the marathon race in LDR. Results: HT showed increased basal levels of sVCAM-1 (651 ± 350 vs. 440 ± 98 ng·mL-1 CTR, p = 0.002; and vs. 533 ± 133 ng·mL-1 LT; p = 0.003) and a post-marathon increase (ΔsVCAM-1) (651 ± 350 to 905 ± 373 ng·mL-1; p = 0.002), that did not occur in LT (533 ± 133 to 651 ± 138 ng·mL-1; p = 0.117). In LDR was a moderate correlation between LA volume and sVCAM-1 level (rho = 0.510; p = 0.001). Conclusions: In male long-distance runners, sVCAM-1 levels are directly associated with LA remodeling. Also, the training level is associated with basal sVCAM-1 levels and changes after an intense and prolonged exercise (42.2 km). Whether sVCAM-1 levels predict the risk of AF in runners remains to be established.

Reverse Remodeling in Human Heart Failure after Cardiac Resynchronization Therapy Is Associated With Reduced RHO-Kinase Activation.

Background: Reverse remodeling is a clinically relevant endpoint in heart failure with reduced ejection fraction (HFrEF). Rho-kinase (ROCK) signaling cascade activation correlates with cardiac remodeling and left ventricular (LV) systolic dysfunction in HFrEF patients. Cardiac resynchronization therapy (CRT) is effective in HFrEF, especially when there is a left bundle block, as this treatment may stimulate reverse remodeling, thereby improving quality of life and prolonging survival for patients with this severe condition. Here, we evaluate the hypothesis that ROCK activation is reduced after effective CRT in HFrEF. Methods: ROCK activation in circulating leukocytes was evaluated in 28 HFrHF patients, using Western blot (myosin light chain phosphatase subunit 1 phosphorylation, MYPT1p/t), before and three months after initiation of CRT. LV systolic function and remodeling were assessed by echocardiography. Results: Three months after CRT, LV ejection fraction increased an average of 14.5% (p < 0.001) in 13 patients (responders), while no change was observed in 15 patients (non-responders). End-systolic diameter decreased 16% (p < 0.001) in responders, with no change in non-responders. ROCK activation in PBMCs decreased 66% in responders (p < 0.05) but increased 10% in non-responders (NS). LV end-diastolic diameter was also 5.2 mm larger in non-responders vs. responders (p = 0.058). LV ejection fraction, systolic diameter, and ROCK activation levels were similar in both groups at baseline. Conclusion: In HFrEF patients, 3 months of effective CRT induced reverse myocardial remodeling, and ROCK activation was significantly decreased in circulating leukocytes. Thus, decreased ROCK activation in circulating leukocytes may reflect reverse cardiac remodeling in patients with heart failure.

Effect of Early Normotension with Olmesartan on Rho-kinase Activity in Hypertensive Patients.

BACKGROUND: Angiotensin II is a potent activator of the Rho-kinase (ROCK) pathway, through which it exerts some of its adverse vasoconstrictor effects. Clinical evidence on the effects of blocking the angiotensin II receptor 1 on ROCK activity in hypertensive patients is scarce. OBJECTIVE: To demonstrate that ROCK activity in peripheral blood mononuclear cells (PMBCs) in patients with essential hypertension is reduced earlier than previously observed, along with blood pressure (BP) lowering on treatment with olmesartan. METHODS: Prospective pilot open study; 17 hypertensive patients were treated with progressive olmesartan doses starting with 20 mg qd. BP was measured at 3, 6 and 9 weeks after treatment initiation. If treatment failed to normalize BP after 3 weeks, olmesartan dose was increased to 40 mg qd, and if still hypertensive after 6 weeks, 12.5 mg of hydrochlorothiazide qd was added. ROCK activity was measured at baseline and 9 weeks after treatment as myosin phosphatase target subunit 1 phosphorylation (MYPT1-p/T ratio) in PBMC. RESULTS: Mean baseline BP was 162 ± 4.9/101 ± 2.4 mmHg. After 9 weeks of treatment, both systolic and diastolic BP were reduced by 41 and 22 mmHg, respectively (p<0.05). Mean pretreatment MYPT1- p/T ratio in PMBCs was significantly reduced by 80% after 9 weeks with olmesartan (p<0.01). CONCLUSION: Normotension achieved after 9 weeks in 82% of the patients treated with olmesartan was associated with a significant reduction of ROCK activity in PBMC.

Counter-regulatory renin-angiotensin system in cardiovascular disease.

The renin-angiotensin system is an important component of the cardiovascular system. Mounting evidence suggests that the metabolic products of angiotensin I and II - initially thought to be biologically inactive - have key roles in cardiovascular physiology and pathophysiology. This non-canonical axis of the renin-angiotensin system consists of angiotensin 1-7, angiotensin 1-9, angiotensin-converting enzyme 2, the type 2 angiotensin II receptor (AT2R), the proto-oncogene Mas receptor and the Mas-related G protein-coupled receptor member D. Each of these components has been shown to counteract the effects of the classical renin-angiotensin system. This counter-regulatory renin-angiotensin system has a central role in the pathogenesis and development of various cardiovascular diseases and, therefore, represents a potential therapeutic target. In this Review, we provide the latest insights into the complexity and interplay of the components of the non-canonical renin-angiotensin system, and discuss the function and therapeutic potential of targeting this system to treat cardiovascular disease.

Angiotensin-(1-9) prevents vascular remodeling by decreasing vascular smooth muscle cell dedifferentiation through a FoxO1-dependent mechanism.

The renin-angiotensin system, one of the main regulators of vascular function, controls vasoconstriction, inflammation and vascular remodeling. Antagonistic actions of the counter-regulatory renin-angiotensin system, which include vasodilation, anti-proliferative, anti-inflammatory and anti-remodeling effects, have also been described. However, little is known about the direct effects of angiotensin-(1-9), a peptide of the counter-regulatory renin-angiotensin system, on vascular smooth muscle cells. Here, we studied the anti-vascular remodeling effects of angiotensin-(1-9), with special focus on the control of vascular smooth muscle cell phenotype. Angiotensin-(1-9) decreased blood pressure and aorta media thickness in spontaneously hypertensive rats. Reduction of media thickness was associated with decreased vascular smooth muscle cell proliferation. In the A7r5 VSMC cell line and in primary cultures of rat aorta smooth muscle cells, angiotensin-(1-9) did not modify basal proliferation. However, angiotensin-(1-9) inhibited proliferation, migration and contractile protein decrease induced by platelet derived growth factor-BB. Moreover, angiotensin-(1-9) reduced Akt and FoxO1 phosphorylation at 30 min, followed by an increase of total FoxO1 protein content. Angiotensin-(1-9) effects were blocked by the AT2R antagonist PD123319, Akt-Myr overexpression and FoxO1 siRNA. These data suggest that angiotensin-(1-9) inhibits vascular smooth muscle cell dedifferentiation by an AT2R/Akt/FoxO1-dependent mechanism.

Elevated Systemic Inflammatory Burden and Cardiovascular Risk in Young Adults with Endodontic Apical Lesions.

INTRODUCTION: The aim of this study was to assess whether apical lesions are associated with inflammatory serum markers of cardiovascular risk, especially high-sensitivity C-reactive protein (hsCRP), in young adults. METHODS: In this cross-sectional study, otherwise healthy individuals with apical lesions of endodontic origin (ALEOs) and a clinical diagnosis of asymptomatic apical periodontitis and controls aged between 18 and 40 years were included. Patients' sociodemographic characteristics, medical history, and classic cardiovascular risk factors were recorded, and the pathobiological determinants of atherosclerosis in youth score was calculated. Oral clinical and radiographic examinations were performed. Blood samples were collected to determine the lipid profile, glycated hemoglobin, hsCRP, immunoglobulin G, interleukin (IL)-6, IL-10, IL-12p70, matrix metalloproteinase 8, soluble vascular cellular adhesion molecule-1, soluble intercellular adhesion molecule-1, and soluble E-selectin. Bivariate and multivariate analyses adjusting for oral and classic cardiovascular risk factors were performed. RESULTS: hsCRP levels were significantly higher in ALEO patients versus controls (median = 2.54 vs 0.78), whereas the pathobiological determinants of atherosclerosis in youth score was comparable among the groups. Also, the levels of IL-6, matrix metalloproteinase 8, and soluble E-selectin were significantly higher in ALEO patients. hsCRP, IL-6, and IL-12 correlated with soluble adhesion molecules. Bivariate analysis based on hsCRP serum concentrations ≥1 mg/L showed an odds ratio (OR) = 6.8, and the risk increased 3.3 times for an additional ALEO. In multivariate analysis, ALEO was significantly associated with hsCRP levels ≥1 mg/L (OR = 5.1-12.8) independently of the adjustment model. ALEO also associated with CRP levels >3 mg/L, which was significant after the adjustment for covariates (OR = 4.0). CONCLUSIONS: ALEO is associated with the systemic inflammatory burden and cardiovascular risk determined by hsCRP, supporting a mechanistic link for cardiovascular diseases in young adults.

Osmotically-induced genes are controlled by the transcription factor TonEBP in cultured cardiomyocytes.

Changes in cardiac osmolarity occur in myocardial infarction. Osmoregulatory mechanisms may, therefore, play a crucial role in cardiomyocyte survival. Tonicity-responsive enhancer binding protein (TonEBP) is a key transcription factor participating in the adaptation of cells to increases in tonicity. However, it is unknown whether cardiac TonEBP is activated by tonicity. Hypertonicity activated transcriptional activity of TonEBP, increased the amounts of both TonEBP mRNA and protein, and induced both the mRNA and protein of TonEBP target genes (aldose reductase and heat shock protein-70). Hypotonicity decreased the amount of TonEBP protein indicating bidirectional osmoregulation of this transcription factor. Adenoviral expression of a dominant negative TonEBP suppressed the hypertonicity-dependent increase of aldose reductase protein. These results indicated that TonEBP controls osmoregulatory mechanisms in cardiomyocytes.

Angiotensin-(1-9) reduces cardiovascular and renal inflammation in experimental renin-independent hypertension.

Hypertension-induced cardiovascular and renal damage can be mediated by activation of the renin-angiotensin-aldosterone system. There are different factors beyond renin-angiotensin-aldosterone system involved in hypertension and renal damage. Inflammation has emerged as an important mediator of hypertension and cardiovascular and kidney damage. Angiotensin-(1-9), a peptide of the renin-angiotensin system, counter-regulates both the physiological and pathological actions of angiotensin II. Recent data has shown that angiotensin-(1-9) protects the heart and blood vessels from adverse cardiovascular remodeling in experimental models of hypertension and/or heart failure and reduces cardiac fibrosis in stroke-prone, spontaneously hypertensive rats. These effects are mediated by the angiotensin II type 2 receptor (AT2R). However, it remains unknown whether angiotensin-(1-9) also has an anti-inflammatory effect. In the present study, we investigate whether angiotensin-(1-9) reduces inflammation and fibrosis in the heart, arteries, and kidney in a DOCA-salt hypertensive model and explore the mechanisms underlying the amelioration of end-organ damage. DOCA-salt hypertensive rats received: a) vehicle, b) angiotensin-(1-9), c) PD123319 (AT2R blocker), d) angiotensin-(1-9) plus A779 (a Mas receptor blocker) or e) angiotensin-(1-9) plus PD123319, and sham rats were used as a control. Our results showed that angiotensin-(1-9) decreased hypertension and increased vasodilation in DOCA-salt hypertensive rats. These actions were partially inhibited by PD123319. Moreover, angiotensin-(1-9) decreased diuresis, fibrosis, and inflammation. These beneficial effects were not mediated by Mas or AT2R blockers. We concluded that angiotensin-(1-9) protects against volume overload-induced hypertensive cardiovascular and kidney damage by decreasing inflammation in the heart, aortic wall, and kidney, through mechanisms independent of the Mas or AT2R.