Elena Cavarretta

microRNAs in Cardiovascular Diseases: Current Knowledge and the Road Ahead

Over the last few years, the field of microribonucleic acid (miRNA) in cardiovascular biology and disease has expanded at an incredible pace. miRNAs are themselves part of a larger family, that of non-coding RNAs, the importance of which for biological processes is starting to emerge. miRNAs are ~22-nucleotide-long RNA sequences that can legate messenger (m)RNAs at partially complementary binding sites, and hence regulate the rate of protein synthesis by altering the stability of the targeted mRNAs. In the cardiovascular system, miRNAs have been shown to be critical regulators of development and physiology. They control basic functions in virtually all cell types relevant to the cardiovascular system (such as endothelial cells, cardiac muscle, smooth muscle, inflammatory cells, and fibroblasts) and, thus, are directly involved in the pathophysiology of many cardiovascular diseases. As a result of their role in disease, they are being studied for exploitation in diagnostics, prognostics, and therapeutics. However, there are still significant obstacles that need to be overcome before they enter the clinical arena. We present here a review of the literature and outline the directions toward their use in the clinic.

Circulating miR-29a, Among Other Up-Regulated MicroRNAs, Is the Only Biomarker for Both Hypertrophy and Fibrosis in Patients With Hypertrophic Cardiomyopathy

OBJECTIVES The purpose of this paper was to determine whether microRNAs (miRNAs) involved in myocardial remodeling were differentially expressed in the blood of hypertrophic cardiomyopathy (HCM) patients, and whether circulating miRNAs correlated with the degree of left ventricular hypertrophy and fibrosis. BACKGROUND miRNAs-small, noncoding ribonucleic acids (RNAs) that regulate gene expression by inhibiting RNA translation-modulate cellular function. Myocardial miRNAs modulate processes such as cardiomyocyte (CM) hypertrophy, excitation-contraction coupling, and apoptosis; non-CM-specific miRNAs regulate myocardial vascularization and fibrosis. Recently, the possibility that circulating miRNAs may be biomarkers of cardiovascular disease has been raised. METHODS Forty-one HCM patients were characterized with conventional transthoracic echocardiography and cardiac magnetic resonance. Peripheral plasma levels of 21 miRNAs were assessed by quantitative real-time polymerase chain reaction and were compared with levels in a control group of 41 age- and sex-matched blood donors. RESULTS Twelve miRNAs (miR-27a, -199a-5p, -26a, -145, -133a, -143, -199a-3p, -126-3p, -29a, -155, -30a, and -21) were significantly increased in HCM plasma. However, only 3 miRNAs (miR-199a-5p, -27a, and -29a) correlated with hypertrophy; more importantly, only miR-29a correlated also with fibrosis. CONCLUSIONS Our data suggest that cardiac remodeling associated with HCM determines a significant release of miRNAs into the bloodstream: the circulating levels of both cardiac- and non-cardiac-specific miRNAs are significantly increased in the plasma of HCM patients. However, correlation with left ventricular hypertrophy parameters holds true for only a few miRNAs (i.e., miR-199a-5p, -27a, and -29a), whereas only miR-29a is significantly associated with both hypertrophy and fibrosis, identifying it as a potential biomarker for myocardial remodeling assessment in HCM.

A 20-year experience with mitral valve repair with artificial chordae in 608 patients

OBJECTIVE Mitral valve repair with artificial chordae for degenerative mitral regurgitation is widely adopted. We evaluated long-term results of mitral repair with expanded polytetrafluoroethylene sutures (GORE-TEX CV-5; W. L. Gore & Associates, Inc, Flagstaff, Ariz). METHODS Between November 1986 and November 2006, 608 consecutive patients underwent mitral repair with artificial neochordae. Mean age was 55 +/- 11 years (15-85 years); 433 (71.2%) were male. Valve disease was purely degenerative in 555 patients (91.3%). Prolapse of anterior, posterior, or both leaflets was present in 47 (7.7%), 308 (50.7%), and 253 (41.6%), respectively. Atrial fibrillation was associated in 117 (19.2%). In 125 cases (20.5%), additional surgical procedures were performed. Follow-up was complete at a median of 5.7 years (interquartile range 2.2-9.8 years, range 0-19.4 years). RESULTS In-hospital mortality was less than 1% (6 deaths). Overall and cardiac late mortalities were 6.6% and 3.9% (34 and 24 deaths). Kaplan-Meier survival at 15 years was 84% (95% confidence interval 75%-90%). Freedoms from endocarditis, thromboembolic events, reoperation, and recurrent mitral regurgitation at 15 years were 97% (95% confidence interval 93%-99%), 92% (87%-95%), 92% (88%-95%), and 85% (78%-91%), respectively. Sinus rhythm was restored in 75% (33 patients) after surgical atrial fibrillation correction. Calcification of GORE-TEX neochordae was never reported. CONCLUSION Mitral valve repair with GORE-TEX artificial chordae is effective, safe, and associated with low operative mortality and low rates of valve-related complications at long-term follow-up. Artificial chordae showed excellent biologic adaptation, retaining flexibility and tension with time.

Left ventricular remodelling index (LVRI) in various pathophysiological conditions: a real-time three-dimensional echocardiographic study

Background: Various studies have reported a close correlation between real-time three-dimensional echocardiography (RT3DE) and cine magnetic resonance imaging studies for the assessment of cardiac volumes and mass. Objective: The aim of our study was to evaluate changes in left ventricular volumes and mass in subjects with different pathophysiological conditions. A ratio between left ventricular mass and end-diastolic volume (LVRI), detected by RT3DE, was used to describe various patterns of left ventricular remodelling. Methods: RT3DE was performed to calculate left ventricular end-diastolic (LVEDV) and end-systolic volume (LVESV), ejection fraction (LVEF) and mass in 220 selected subjects. Of these, 152 were healthy volunteers, 19 top-level rowers, 23 patients with dilated cardiomyopathy and 26 patients with hypertrophic cardiomyopathy. Off-line analysis was performed by two independent operators by tracing manual endocardial and epicardial borders of the left ventricle through eight cutting planes. Inter- and intra-observer variability were calculated. Results: Despite the increase in LV volume and mass in the rowers, LVRI remained unchanged compared with control subjects (p = 0.455), while significantly lower values were found patients with dilated cardiomyopathy (p<0.001) and significantly higher values in patients with hypertrophic cardiomyopathy (p<0.001). There was inter- and intra-observer variability. Conclusion: The LVRI may serve as a simple and useful indicator of left ventricular adaptation to physiological and pathological conditions.

Remodelling of the left ventricle in athlete's heart: a three dimensional echocardiographic and magnetic resonance imaging study.

Intensive long term athletic training is associated with morphological cardiac changes, which have extensively been described as “athlete’s heart”. These changes are considered to be physiological adaptations to increased haemodynamic overload induced by chronic and intensive exercise.1,2 For many years, morphological assessment of athlete’s heart and its differentiation from pathological cardiac conditions have been based on two dimensional and M mode echocardiography. The formulas used with these methods are based on geometric assumptions and are possible causes of inaccuracy. The objective of our study was, therefore, to validate and assess the pattern of left ventricular (LV) remodelling in a population of highly trained athletes by using three different techniques—conventional two dimensional echocardiography, three dimensional echocardiography, and magnetic resonance imaging (MRI)—and to explore the potential advantages and limitations of these techniques. Thirty subjects were studied: 18 male top level athletes, who were members of the Italian Olympic rowing team (> 3 consecutive years’ long term exercise), and 12 untrained sedentary male subjects. All subjects signed an informed consent form. Each patient underwent two dimensional echocardiography (Sonos 5500; Philips). LV mass was calculated by the Devereux formula, and LV volumes and ejection fraction (EF) were calculated by the modified Simpson’s rule. Three dimensional echocardiography was performed with a Philips Sonos 7500 equipped with the X-Matrix probe (2–4 MHz). Images were acquired by the “full volume” technique, which consists of a wide angle three dimensional pyramid built on four smaller …

Pathological biominerals: Raman and infrared studies of bioapatite deposits in human heart valves

We studied pathological bioapatite from patients undergoing valvular replacement due to severe aortic and mitral stenosis. Three different types of mineralized human cardiac valves were analyzed. We used infrared and Raman spectroscopy to infer the presence of the carbonate group and evaluate the carbonate substitution in bioapatite structure. The Raman spectra showed that the pathological bioapatite is a B-type “carbonateapatite” (CO32- for PO43-) similar to the major mineralized products derived from normal biomineralization processes occurring in the human body. Fourier transform infrared spectra (FT-IR) confirmed the B-type carbonate substitution (CO32- for PO43-) and showed evidence for the partial replacement of [OH] by [CO3] (A-type substitution). The carbonate content of the samples inferred by the spectroscopic measurements is in good agreement with the range of values estimated for biological apatite. On the contrary, the crystal size of the pathological apatite estimated using the percentage area of the component at 1059 cm−1 of the infrared spectrum is in the nanometer range and it is significantly smaller than the crystal size of normal mineralized tissues.

miR-21 and cardiac fibrosis: another brick in the wall?

This editorial refers to ‘Osteopontin is indispensible for activator protein-1-mediated angiotensin II-related miR-21 transcription during cardiac fibrosis’, by J. Lorenzen et al ., on page doi:10.1093/eurheartj/ehv109. Organ fibrosis is a common final pathway of long-lasting and iterative tissue fibrosis, and is present in several pathologies, including ischaemic heart disease, diabetes mellitus, hypertension, and chronic kidney disease. Thus, it represents a widespread cause of morbidity and mortality. Tissue fibrosis is characterized by an excessive and uncontrolled deposition of extracellular matrix (ECM) elements. The development of fibrosis requires: (i) increased synthesis by matrix metalloproteinases (MMPs) and decreased degradation of ECM due to down-regulation of MMP inhibitors; (ii) the stimulation of profibrotic mediators, such as transforming growth factor-β (TGF-β), α-smooth muscle actin (α-SMA), platelet-derived growth factor (PDGF), and cytokines; (iii) the differentiation of fibroblasts into myofibroblasts, which express features of smooth muscle differentiation; and (iv) the recruitment of cells of an endothelial origin for endothelial to mesenchymal transition (EndMT), generating cells that still express endothelial markers while gaining fibroblast-like characteristics.1 In addition, innate and adaptive immune responses play an important role in development of fibrosis.2 Despite recent advances in the understanding of the mechanisms underlying its development, therapeutic strategies specifically …

New insights into the steen solution properties: Breakthrough in antioxidant effects via NOX2 downregulation

Ex vivo lung perfusion (EVLP) allows perfusion and reconditioning of retrieved lungs for organ transplantation. The Steen solution is specifically designed for this procedure but the mechanism through which it elicits its activity is still to be fully clarified. We speculated that Steen solution may encompass antioxidant properties allowing a reestablishment of pulmonary tissue homeostasis. Blood samples from 10 healthy volunteers were recruited. Platelets and white cells were incubated with Steen solution or buffer solution as control and stimulated with suitable agonists. Reactive oxidant species (ROS), soluble NOX2 (sNOX2-derived peptide), a marker of NADPH oxidase activation, p47phox translocation to cell membrane and isoprostanes production, as marker of oxidative stress, and nitric oxide (NO), a powerful vasodilator and antioxidant molecule, were measured upon cell stimulation. The Steen solution significantly inhibited p47phox translocation and NOX2 activation in platelets and white cells. Consistent with this finding was the reduction of oxidative stress as documented by a significantly lowered formation of ROS and isoprostanes by both platelets and white cells. Finally, cell incubation with Steen solution resulted in enhanced generation of NO. Herewith, we provide the first evidence that Steen solution possesses antioxidant properties via downregulation of NADPH oxidase activity and enhanced production of NO.

Β-blockers treatment of cardiac surgery patients enhances isolation and improves phenotype of cardiosphere-derived cells

Β-blockers (BB) are a primary treatment for chronic heart disease (CHD), resulting in prognostic and symptomatic benefits. Cardiac cell therapy represents a promising regenerative treatment and, for autologous cell therapy, the patients clinical history may correlate with the biology of resident progenitors and the quality of the final cell product. This study aimed at uncovering correlations between clinical records of biopsy-donor CHD patients undergoing cardiac surgery and the corresponding yield and phenotype of cardiospheres (CSs) and CS-derived cells (CDCs), which are a clinically relevant population for cell therapy, containing progenitors. We describe a statistically significant association between BB therapy and improved CSs yield and CDCs phenotype. We show that BB-CDCs have a reduced fibrotic-like CD90 + subpopulation, with reduced expression of collagen-I and increased expression of cardiac genes, compared to CDCs from non-BB donors. Moreover BB-CDCs had a distinctive microRNA expression profile, consistent with reduced fibrotic features (miR-21, miR-29a/b/c downregulation), and enhanced regenerative potential (miR-1, miR-133, miR-101 upregulation) compared to non-BB. In vitro adrenergic pharmacological treatments confirmed cytoprotective and anti-fibrotic effects of β1-blocker on CDCs. This study shows anti-fibrotic and pro-commitment effects of BB treatment on endogenous cardiac reparative cells, and suggests adjuvant roles of β-blockers in cell therapy applications.

Echocardiographic findings in 2261 peri-pubertal athletes with or without inverted T waves at electrocardiogram

Objective T wave inversion (TWI) has been associated with cardiomyopathies. The hypothesis of this study was that TWI has relevant clinical significance in peri-pubertal athletes. Methods Consecutive male soccer players, aged 8–18 years, undergoing preparticipation screening between January 2008 and March 2009 were enrolled. Medical and family histories were collected; physical examinations, 12-lead ECGs and transthoracic echocardiogram (TTE) were performed. TWI was categorised by ECG lead (anterior (V1–V3), extended anterior (V1–V4), inferior (DII–aVF) and infero-lateral (DII–aVF/V4–V6/DI-aVL)) and by age. Results Overall, 2261 (mean age 12.4 years, 100% Caucasian) athletes were enrolled. TWI in ≥2 consecutive ECG leads was found in 136 athletes (6.0%), mostly in anterior leads (126/136, 92.6%). TWI in anterior leads was associated with TTE abnormalities in 6/126 (4.8%) athletes. TWI in extended anterior (2/136, 1.5%) and inferior (3/136, 2.2%) leads was never associated with abnormal TTE. TWI in infero-lateral leads (5/136, 3.7%) was associated with significant TTE abnormalities (3/5, 60.0%), including one hypertrophic cardiomyopathy (HCM) and two LV hypertrophies. Athletes with normal T waves had TTE abnormalities in 4.4% of cases, including one HCM with deep Q waves in infero-lateral leads. Conclusions In this broad population of peri-pubertal male athletes, TWI in anterior leads was associated with mild cardiac disease in 4.8% of cases, while TWI in infero-lateral leads revealed HCM and LV hypertrophy in 60% of cases. ECG identified all cases of HCM.