miR-208b upregulation interferes with calcium handling in HL-1 atrial myocytes: Implications in human chronic atrial fibrillation

MicroRNAs (miR) have considerable potential as therapeutic tools in cardiac diseases. Alterations in atrial miR are involved in the development of atrial fibrillation (AF), but the molecular mechanism underlying their contribution to atrial remodeling in chronic atrial fibrillation (CAF) is only partially understood. Here we used miR array to analyze the miR profile of atrial biopsies from sinus rhythm (SR) and CAF patients. qRT-PCR identified a distinctive CAF-miR signature and described conserved miR-208b upregulation in human and ovine AF atrial tissue. We used bioinformatics analysis to predict genes and signaling pathways as putative miR-208b targets, which highlighted genes from the cardiac muscle gene program and from canonical WNT, gap-junction and Ca²⁺ signaling networks. Results from analysis of miR-208b-overexpressing HL-1 atrial myocytes and from myocytes isolated from CAF patients showed that aberrant miR-208b levels reduced the expression and function of L-type Ca²⁺ channel subunits (CACNA1C and CACNB2) as well as the sarcoplasmic reticulum-Ca²⁺ pump SERCA2. These findings clearly pointed to CAF-specific upregulated miR-208b as an important mediator in Ca²⁺ handling impairment during atrial remodeling.

Diagnostic yield and complications of extended lymphadenectomy versus limited lymphadenectomy combined with radical prostatectomy

BACKGROUND

Lymphadenectomy for prostate cancer (PC) is the most reliable procedure for detecting lymphatic metastases. The optimal extension of this procedure is still a topic of debate.

OBJECTIVE

To analyse the diagnostic performance and complications of extended lymphadenectomy (ELD) and limited lymphadenectomy (LLD) in a series of patients with high-risk PC who underwent radical prostatectomy (RP).

MATERIAL AND METHODS

A retrospective study was conducted on patients with high d'Amico risk who underwent RP with lymphadenectomy between 1999 and 2014. A comparative analysis was performed of the diagnostic capacity of lymphatic metastases of ELD and LLD and of postoperative complications at 90 days.

RESULTS

Ninety-three patients were analysed, 20 (21.5%) and 73 (78.5%) of whom underwent ELD and LLD, respectively. The mean age of the series was 65.26 years (SD, 5.51). The median follow-up was 1.51 (0.61-2.29) years in the ELD group and 5.94 (3.61-9.10) in the LLD group. The median number of nodes obtained was 13 (9-23) in the ELD group compared with 5 (2-8) in the LLD group (p <.001). The percentages of patients with positive nodes in the ELD and LLD groups were 35% and 5.47%, respectively (p <.001). The overall complication rate at 90 days was 35.5% (33 patients). In the ELD group, 12 patients (60%) had complications, compared with 21 patients (28.8%) in the LLD group (p=.016), with no significant differences in severity according to the Clavien scale (p=.73).

CONCLUSIONS

In our series, the detection of metastatic nodes was significantly greater with ELD. ELD increases the number of complications, with no differences compared with LLD in severity according to the modified Clavien scale.

Circulating Biomarkers of Myocardial Fibrosis: The Need for a Reappraisal

Myocardial fibrosis impairs cardiac function, in addition to facilitating arrhythmias and ischemia, and thus influences the evolution and outcome of cardiac diseases. Its assessment is therefore clinically relevant. Although tissue biopsy is the gold standard for the diagnosis of myocardial fibrosis, a number of circulating biomarkers have been proposed for the noninvasive assessment of this lesion. A review of the published clinical data available on these biomarkers shows that most of them lack proof that they actually reflect the myocardial accumulation of fibrous tissue. In this "call to action" article, we propose that this absence of proof may lead to misinterpretations when considering the incremental value provided by the biomarkers with respect to traditional diagnostic tools in the clinical handling of patients. We thus argue that strategies are needed to more strictly validate whether a given circulating biomarker actually reflects histologically proven myocardial fibrosis before it is applied clinically.

Association of low GLP-1 with oxidative stress is related to cardiac disease and outcome in patients with type 2 diabetes mellitus: a pilot study

Oxidative stress (OS) contributes to cardiovascular damage in type 2 diabetes mellitus (T2DM). The peptide glucagon-like peptide-1 (GLP-1) inhibits OS and exerts cardiovascular protective actions. Our aim was to investigate whether cardiac remodeling (CR) and cardiovascular events (CVE) are associated with circulating GLP-1 and biomarkers of OS in T2DM patients. We also studied GLP-1 antioxidant effects in a model of cardiomyocyte lipotoxicity. We examined 72 T2DM patients with no coronary or valve heart disease and 14 nondiabetic subjects. A median of 6 years follow-up information was obtained in 60 patients. Circulating GLP-1, dipeptidyl peptidase-4 activity, and biomarkers of OS were quantified. In T2DM patients, circulating GLP-1 decreased and OS biomarkers increased, compared with nondiabetics. Plasma GLP-1 was inversely correlated with serum 3-nitrotyrosine in T2DM patients. Patients showing high circulating 3-nitrotyrosine and low GLP-1 levels exhibited CR and higher risk for CVE, compared to the remaining patients. In palmitate-stimulated HL-1 cardiomyocytes, GLP-1 reduced cytosolic and mitochondrial oxidative stress, increased mitochondrial ATP synthase expression, partially restored mitochondrial membrane permeability and cytochrome c oxidase activity, blunted leakage of creatine to the extracellular medium, and inhibited oxidative damage in total and mitochondrial DNA. These results suggest that T2DM patients with reduced circulating GLP-1 and exacerbated OS may exhibit CR and be at higher risk for CVE. In addition, GLP-1 exerts antioxidant effects in HL-1 palmitate-overloaded cardiomyocytes. It is proposed that therapies aimed to increase GLP-1 may counteract OS, protect from CR, and prevent CVE in patients with T2DM.

Biomarkers of collagen type I metabolism are related to B-type natriuretic peptide, left ventricular size, and diastolic function in heart failure

AIMS

Myocardial collagen metabolism can be assessed indirectly by circulating biomarkers. We aimed to examine associations between myocardial collagen type I synthesis and degradation, and echocardiographic, clinical, and B-type natriuretic peptide (BNP) findings in heart failure.

METHODS

We studied 57 women and 75 men 60 years or older with systolic heart failure (New York Heart Association II-IV and an ejection fraction ≤ 45%). Mean age was 75 years, blood pressure 134/80  mmHg, ejection fraction 34%, and median BNP 210  ng/l. Analyses of the carboxy-terminal propeptide of procollagen type I (PICP, biomarker of collagen type I synthesis) and the serum carboxy-terminal telopeptide of collagen type I (CITP, biomarker of collagen type I degradation) were measured. Extensive echocardiographic examinations were performed, including variables of dyssynchrony.

RESULTS

Increased collagen synthesis (PICP) was independently related to increased BNP levels (r = 0.24, P = 0.018). Furthermore, independent associations were found between PICP and left ventricular size, isovolumic relaxation time, and relative wall thickness. Increased collagen degradation (CITP) was independently related to increased BNP levels (r = 0.35, P < 0.001). Also, univariable, but not multivariable, associations were found between CITP and E/E' septal and QRS duration.

CONCLUSION

Biomarkers of collagen type I synthesis and degradation are independently related to BNP and to indices of left ventricular size and diastolic function in systolic heart failure. It is proposed that BNP may contribute to alterations in collagen type I metabolism in systolic heart failure.

Diltiazem treatment for pre-clinical hypertrophic cardiomyopathy sarcomere mutation carriers: a pilot randomized trial to modify disease expression

OBJECTIVES

The study sought to assess the safety, feasibility, and effect of diltiazem as disease-modifying therapy for at-risk hypertrophic cardiomyopathy (HCM) mutation carriers.

BACKGROUND

HCM is caused by sarcomere mutations and characterized by left ventricular hypertrophy (LVH) with increased risk of heart failure and sudden death. HCM typically cannot be diagnosed early in life, although subtle phenotypes are present. Animal studies indicate that intracellular calcium handling is altered before LVH develops. Furthermore, early treatment with diltiazem appeared to attenuate disease emergence.

METHODS

In a pilot, double-blind trial, we randomly assigned 38 sarcomere mutation carriers without LVH (mean 15.8 years of age) to therapy with diltiazem 360 mg/day (or 5 mg/kg/day) or placebo. Treatment duration ranged from 12 to 42 months (median 25 months). Study procedures included electrocardiography, echocardiography, cardiac magnetic resonance imaging, and serum biomarker measurement.

RESULTS

Diltiazem was not associated with serious adverse events. Heart rate and blood pressure did not differ significantly between groups. However, mean left ventricular (LV) end-diastolic diameter improved toward normal in the diltiazem group but decreased further in controls (change in z-scores, +0.6 vs. -0.5; p < 0.001). Mean LV thickness-to-dimension ratio was stable in the diltiazem group but increased in controls (-0.02 vs. +0.15; p = 0.04). Among MYBPC3 mutation carriers, LV wall thickness and mass, diastolic filling, and cardiac troponin I levels improved in those taking diltiazem compared with controls. Four participants developed overt HCM, 2 in each treatment group.

CONCLUSIONS

Pre-clinical administration of diltiazem is safe and may improve early LV remodeling in HCM. This novel strategy merits further exploration. (Treatment of Preclinical Hypertrophic Cardiomyopathy With Diltiazem; NCT00319982).

[Characteristics of deep sedation in gastrointestinal endoscopic procedures performed by intensivists]

OBJECTIVE

To determine tolerance, pain intensity, percentage of tests completed successfully and complications of deep sedation controlled by intensivists during gastrointestinal endoscopic procedures.

DESIGN

A one-year, prospective observational study was carried out.

SETTING

Department of Intensive Care intervention in the Endoscopy Unit of Hospital Universitario del Tajo (Spain).

PATIENTS

Subjects over 15 years of age subjected to endoscopic procedures under deep sedation.

RESULTS

A total of 868 patients were sedated during the study period, with the conduction of 1010 endoscopic procedures. The degree of tolerance was considered adequate («Very good»/«Good») in 96.9% of the patients (95%CI: 95.7-98.1%), with a median score of 0 on the pain visual analog scale. A total of 988 endoscopic procedures were successfully completed (97.8%; 95%CI: 96.9-98.8%): 675 colonoscopies (97.1%) and 305 endoscopies (99.7%). Complications were recorded in 106 patients (12.2%; 95%CI: 10.0-14.5%). The most frequent being desaturation (6.1%), rhythm disturbances (5.1%) and hypotension (2.4%).

CONCLUSION

Gastrointestinal endoscopic procedures under sedation controlled by intensivists are well tolerated and satisfactory for the patient, and are successfully completed in a very large percentage of cases. The procedures are associated with frequent minor complications that are resolved successfully.

Atrial fibrillation and biomarkers of myocardial fibrosis in heart failure

OBJECTIVES

Alterations of collagen metabolism present in heart failure promote the fibrotic substrate for the development of atrial fibrillation (AF). Myocardial collagen I synthesis and degradation can be assessed indirectly by circulating biomarkers such as the carboxy terminal propeptide (PICP) and carboxy-terminal telopeptide (CITP), respectively.

DESIGN

We examined myocardial collagen type-I metabolism in 143 patients with systolic heart failure (New York Heart Association Class 2-4) in relation to coexisting AF.

RESULTS

Mean age was 75 years, blood pressure 134/80 mm Hg, ejection fraction 34%, serum PICP 81 μg/L and CITP 8.3 μg/L, and median plasma brain natriuretic peptide 215 pg/L; 77 were in AF. PICP and CITP were related to left atrial diameter (r = 0.22, P = 0.013, and r = 0.26, P = 0.003) and CITP to pulmonary capillary wedge pressure and C-reactive protein (r = 0.19, P = 0.044, and r = 0.29, P = 0.003). A logistic regression suggested that PICP (odds ratio per 1 μg/L change 1.01, P = 0.012) and left ventricular end-diastolic volume (odds ratio per 1 mL change 0.98, P < 0.001) were independently associated with coexisting AF.

CONCLUSION

Collagen type-I metabolism is associated to left atrial size. Heart failure patients with coexisting AF exhibit more altered collagen type-I metabolism than patients in sinus rhythm. This might represent more severe atrial and ventricular fibrosis.

Optimization of an early discharge program after laparoscopic radical prostatectomy

OBJECTIVE

To assess the safety of hospital discharge 24 hours after laparoscopic radical prostatectomy and to identify possible factors associated with longer hospital stays.

MATERIAL AND METHODS

Retrospective study of patients diagnosed with localized prostate cancer underwent to laparoscopic radical prostatectomy consecutively between May of 2007 and December of 2010. Those patients who met the following requirements were discharged in less than 24 hours: absence of complications, drainage debit minor than 50 cc, normal oral tolerance, no significant bladder haematuria and good functional recovery. Logistic regression analysis was conducted in order to assess the possible associated variables with longer hospital stays.

RESULTS

A total of 266 patients were analysed. The follow-up median was 34 months. Eighty patients (30.1%) were discharged in less than 24 hours. Average stay (SD) of all series was 2.9 days (3.08). Solely HTA, neurovascular bundles sparing and the development of lymphadenectomy were statistically significant between both groups in univariate analysis (discharge<24 hours vs. discharge>24 hours). In multivariate analysis, only HTA (OR=1.98 [CI 95%:1.13-3.47], P=.016) and lymphadenectomy performance (OR=2.56 [CI 95%:1.18-5.56] P=.017) were independent predictive variables of hospital stays longer than 24 hours.

CONCLUSIONS

Early hospital discharge of patients underwent to LRP is feasible and safe. In our series, the lymphadenectomy performance and the HTA were associated factors to longer hospital stay.

Association of cardiotrophin-1 with myocardial fibrosis in hypertensive patients with heart failure

Cardiotrophin-1 has been shown to be profibrogenic in experimental models. The aim of this study was to analyze whether cardiotrophin-1 is associated with left ventricular end-diastolic stress and myocardial fibrosis in hypertensive patients with heart failure. Endomyocardial biopsies from patients (n=31) and necropsies from 7 control subjects were studied. Myocardial cardiotrophin-1 protein and mRNA and the fraction of myocardial volume occupied by collagen were increased in patients compared with controls (P<0.001). Cardiotrophin-1 overexpression in patients was localized in cardiomyocytes. Cardiotrophin-1 protein was correlated with collagen type I and III mRNAs (r=0.653, P<0.001; r=0.541, P<0.01) and proteins (r=0.588, P<0.001; r=0.556, P<0.005) in all subjects and with left ventricular end-diastolic wall stress (r=0.450; P<0.05) in patients. Plasma cardiotrophin-1 and N-terminal pro-brain natriuretic peptide and serum biomarkers of myocardial fibrosis (carboxy-terminal propeptide of procollagen type I and amino-terminal propeptide of procollagen type III) were increased (P<0.001) in patients compared with controls. Plasma cardiotrophin-1 was correlated with N-terminal pro-brain natriuretic peptide (r=0.386; P<0.005), carboxy-terminal propeptide of procollagen type I (r=0.550; P<0.001), and amino-terminal propeptide of procollagen type III (r=0.267; P<0.05) in all subjects. In vitro, cardiotrophin-1 stimulated the differentiation of human cardiac fibroblast to myofibroblasts (P<0.05) and the expression of procollagen type I (P<0.05) and III (P<0.01) mRNAs. These findings show that an excess of cardiotrophin-1 is associated with increased collagen in the myocardium of hypertensive patients with heart failure. It is proposed that exaggerated cardiomyocyte production of cardiotrophin-1 in response to increased left ventricular end-diastolic stress may contribute to fibrosis through stimulation of fibroblasts in heart failure of hypertensive origin.

A synthetic peptide from transforming growth factor-β₁ type III receptor inhibits NADPH oxidase and prevents oxidative stress in the kidney of spontaneously hypertensive rats

AIMS

The NADPH oxidases constitute a major source of superoxide anion (·O2(-)) in hypertension. Several studies suggest an important role of NADPH oxidases in different effects mediated by transforming growth factor-β₁ (TGF-β₁). We investigated whether a chronic treatment with P144, a peptide synthesized from type III TGF-β₁ receptor, inhibited NADPH oxidases in the renal cortex of spontaneously hypertensive rats (SHR).

RESULTS

Here, we show that chronic administration of P144 significantly reduced the NADPH oxidase expression and activity as well as the oxidative stress observed in control vehicle-treated SHR (V-SHR). In addition, P144 was also able to reduce the significant increase in the renal fibrosis and in mRNA expression of different components of collagen metabolism, as well as in the levels of connective tissue growth factor observed in V-SHR. Finally, TGF-β₁-stimulated NRK52E exhibited a significant increase in NADPH oxidase expression and activity as well as a TGF-β₁-dependent intracellular pathway that were inhibited in the presence of P144.

INNOVATION

Our experimental evidence suggests that reversing oxidative stress may be therapeutically useful in preventing fibrosis-associated renal damage. We show here that (i) the TGF-β₁-NADPH oxidases axis is crucial in the development of fibrosis in an experimental hypertensive renal disease animal model, and (ii) the use of P144 reverses TGF-β₁-dependent NADPH oxidase activity; thus, P144 may be considered a novel therapeutic tool in kidney disease associated with hypertension.

CONCLUSION

We demonstrate that P144 inhibits NADPH oxidases and prevents oxidative stress in kidneys from hypertensive rats. Our data also suggest that these effects are associated with the renal antifibrotic effect of P144.

Epicardial delivery of collagen patches with adipose-derived stem cells in rat and minipig models of chronic myocardial infarction

Although transplantation of adipose-derived stem cells (ADSC) in chronic myocardial infarction (MI) models is associated with functional improvement, its therapeutic value is limited due to poor long-term cell engraftment and survival. Thus, the objective of this study was to examine whether transplantation of collagen patches seeded with ADSC could enhance cell engraftment and improve cardiac function in models of chronic MI. With that purpose, chronically infarcted Sprague-Dawley rats (n = 58) were divided into four groups and transplanted with media, collagen scaffold (CS), rat ADSC, or CS seeded with rat ADSC (CS-rADSC). Cell engraftment, histological changes, and cardiac function were assessed 4 months after transplantation. In addition, Göttingen minipigs (n = 18) were subjected to MI and then transplanted 2 months later with CS or CS seeded with autologous minipig ADSC (CS-pADSC). Functional and histological assessments were performed 3 months post-transplantation. Transplantation of CS-rADSC was associated with increased cell engraftment, significant improvement in cardiac function, myocardial remodeling, and revascularization. Moreover, transplantation of CS-pADSC in the pre-clinical swine model improved cardiac function and was associated with decreased fibrosis and increased vasculogenesis. In summary, transplantation of CS-ADSC resulted in enhanced cell engraftment and was associated with a significant improvement in cardiac function and myocardial remodeling.

The activity of circulating dipeptidyl peptidase-4 is associated with subclinical left ventricular dysfunction in patients with type 2 diabetes mellitus

Background

Patients with type 2 diabetes mellitus (T2DM) present subclinical left ventricular systolic and/or diastolic dysfunction (LVD). Dipeptidyl peptidase-4 (DPP4) inactivates peptides that possess cardioprotective actions. Our aim was to analyze whether the activity of circulating DPP4 is associated with echocardiographically defined LVD in asymptomatic patients with T2DM.

Methods

In this cross-sectional study, we examined 83 T2DM patients with no coronary or valve heart disease and 59 age and gender-matched non-diabetic subjects. Plasma DPP4 activity (DPP4a) was measured by enzymatic assay and serum amino-terminal pro-brain natriuretic peptide (NT-proBNP) was measured by enzyme-linked immunosorbent assay. LV function was assessed by two-dimensional echocardiographic imaging, targeted M-mode recordings and Doppler ultrasound measurements. Differences in means were assessed by t-tests and one-way ANOVA. Associations were assessed by adjusted multiple linear regression and logistic regression analyses.

Results

DPP4a was increased in T2DM patients as compared with non-diabetic subjects (5855 ± 1632 vs 5208 ± 957 pmol/min/mL, p < 0.05). Clinical characteristics and echocardiographic parameters assessing LV morphology were similar across DPP4a tertiles in T2DM patients. However, prevalence of LVD progressively increased across incremental DPP4a tertiles (13%, 39% and 71%, all p < 0.001). Multivariate regression analysis confirmed the independent associations of DPP4a with LVD in T2DM patients (p < 0.05). Similarly, multiple logistic regression analysis showed that an increase of 100 pmol/min/min plasma DPP4a was independently associated with an increased frequency of LVD with an adjusted odds ratio of 1.10 (95% CI, 1.04 to 1.15, p = 0.001).

Conclusions

An excessive activity of circulating DPP4 is independently associated with subclinical LVD in T2DM patients. Albeit descriptive, these findings suggest that DPP4 may be involved in the mechanisms of LVD in T2DM.

Myocardial titin hypophosphorylation importantly contributes to heart failure with preserved ejection fraction in a rat metabolic risk model

BACKGROUND

Obesity and diabetes mellitus are important metabolic risk factors and frequent comorbidities in heart failure with preserved ejection fraction. They contribute to myocardial diastolic dysfunction (DD) through collagen deposition or titin modification. The relative importance for myocardial DD of collagen deposition and titin modification was investigated in obese, diabetic ZSF1 rats after heart failure with preserved ejection fraction development at 20 weeks.

METHODS AND RESULTS

Four groups of rats (Wistar-Kyoto, n=11; lean ZSF1, n=11; obese ZSF1, n=11, and obese ZSF1 with high-fat diet, n=11) were followed up for 20 weeks with repeat metabolic, renal, and echocardiographic evaluations and hemodynamically assessed at euthanization. Myocardial collagen, collagen cross-linking, titin isoforms, and phosphorylation were also determined. Resting tension (Fpassive)-sarcomere length relations were obtained in small muscle strips before and after KCl-KI treatment, which unanchors titin and allows contributions of titin and extracellular matrix to Fpassive to be discerned. At 20 weeks, the lean ZSF1 group was hypertensive, whereas both obese ZSF1 groups were hypertensive and diabetic. Only the obese ZSF1 groups had developed heart failure with preserved ejection fraction, which was evident from increased lung weight, preserved left ventricular ejection fraction, and left ventricular DD. The underlying myocardial DD was obvious from high muscle strip stiffness, which was largely (±80%) attributable to titin hypophosphorylation. The latter occurred specifically at the S3991 site of the elastic N2Bus segment and at the S12884 site of the PEVK segment.

CONCLUSIONS

Obese ZSF1 rats developed heart failure with preserved ejection fraction during a 20-week time span. Titin hypophosphorylation importantly contributed to the underlying myocardial DD.

T1 measurements identify extracellular volume expansion in hypertrophic cardiomyopathy sarcomere mutation carriers with and without left ventricular hypertrophy

BACKGROUND

Myocardial fibrosis is a hallmark of hypertrophic cardiomyopathy (HCM) and a potential substrate for arrhythmias and heart failure. Sarcomere mutations seem to induce profibrotic changes before left ventricular hypertrophy (LVH) develops. To further evaluate these processes, we used cardiac magnetic resonance with T1 measurements on a genotyped HCM population to quantify myocardial extracellular volume (ECV).

METHODS AND RESULTS

Sarcomere mutation carriers with LVH (G+/LVH+, n=37) and without LVH (G+/LVH-, n=29), patients with HCM without mutations (sarcomere-negative HCM, n=11), and healthy controls (n=11) underwent contrast cardiac magnetic resonance, measuring T1 times pre- and postgadolinium infusion. Concurrent echocardiography and serum biomarkers of collagen synthesis, hemodynamic stress, and myocardial injury were also available in a subset. Compared with controls, ECV was increased in patients with overt HCM, as well as G+/LVH- mutation carriers (ECV=0.36±0.01, 0.33±0.01, 0.27±0.01 in G+/LVH+, G+/LVH-, controls, respectively; P≤0.001 for all comparisons). ECV correlated with N-terminal probrain natriuretic peptide levels (r=0.58; P<0.001) and global E' velocity (r=-0.48; P<0.001). Late gadolinium enhancement was present in >60% of overt patients with HCM but absent from G+/LVH- subjects. Both ECV and late gadolinium enhancement were more extensive in sarcomeric HCM than sarcomere-negative HCM.

CONCLUSIONS

Myocardial ECV is increased in HCM sarcomere mutation carriers even in the absence of LVH. These data provide additional support that fibrotic remodeling is triggered early in disease pathogenesis. Quantifying ECV may help characterize the development of myocardial fibrosis in HCM and ultimately assist in developing novel disease-modifying therapy, targeting interstitial fibrosis.

Effect of tempol on myocardial vascular remodeling in female spontaneously hypertensive rats

OBJECTIVE

The present study evaluated whether the treatment with the superoxide anion dismutase mimetic tempol prevents the worsening in hypertension and in myocardial vascular remodeling induced by ovariectomy in female spontaneously hypertensive rats (SHR).

METHODS

Experiments were performed in ten week old female SHRs randomly assigned to the groups: intact (INT: given vehicle; INT+T: treated with tempol, 90 mg/kg/day), ovariectomized (OVX: vehicle and OVX+T: tempol, respectively) and ovariectomized treated with 17β-estradiol (OVX+E2 and OVX+E2+T). Evolution of systolic blood pressure (SBP) was determined every other week in lightly restrained awake rats using a noninvasive computerized tail-cuff plethysmography system. At 18 weeks of age the heart was excised and structural changes in histopathological sections of coronary vessels were quantified on a computerized imaging system analyzer.

RESULTS

SBP was significantly lower in female SHRs treated with tempol compared to the values measured in untreated animals. In the vascular remodeling of myocardial arterioles, OVX+T rats had a lower media cross sectional area and media-to-lumen ratio than those observed in the OVX SHR. Interestingly, treatment with tempol in the presence of estradiol (in female INT and OVX+E2 SHR ) increased media cross sectional area and wall-to-lumen ratio of myocardial arterioles, despite the fact that it lowered arterial pressure in those groups.

CONCLUSIONS

These results indicate that tempol prevents arterial hypertension and blunts myocardial vascular remodeling in ovariectomized SHR. Paradoxically, when tempol is given in presence of estradiol it has a detrimental effect on myocardial arteriolar remodeling.

Cardiotrophin-1 in hypertensive heart disease

Hypertensive heart disease, here defined by the presence of pathologic left ventricular hypertrophy in the absence of a cause other than arterial hypertension, is characterized by complex changes in myocardial structure including enhanced cardiomyocyte growth and non-cardiomyocyte alterations that induce the remodeling of the myocardium, and ultimately, deteriorate left ventricular function and facilitate the development of heart failure. It is now accepted that a number of pathological processes mediated by mechanical, neurohormonal, and cytokine routes acting on the cardiomyocyte and the non-cardiomyocyte compartments are responsible for myocardial remodeling in the context of arterial hypertension. For instance, cardiotrophin-1 is a cytokine member of the interleukin-6 superfamily, produced by cardiomyocytes and non-cardiomyocytes in situations of biomechanical stress that once secreted interacts with its receptor, the heterodimer formed by gp130 and gp90 (also known as leukemia inhibitory factor receptor beta), activating different signaling pathways leading to cardiomyocyte hypertrophy, as well as myocardial fibrosis. Beyond its potential mechanistic contribution to the development of hypertensive heart disease, cardiotrophin-1 offers the opportunity for a new translational approach to this condition. In fact, recent evidence suggests that cardiotrophin-1 may serve as both a biomarker of left ventricular hypertrophy and dysfunction in hypertensive patients, and a potential target for therapies aimed to prevent and treat hypertensive heart disease beyond blood pressure control.

Collagen cross-linking but not collagen amount associates with elevated filling pressures in hypertensive patients with stage C heart failure: potential role of lysyl oxidase

We investigated whether the quality of myocardial collagen associates with elevated left-sided filling pressures in 38 hypertensive patients with stage C chronic heart failure. Filling pressures were assessed invasively measuring pulmonary capillary wedge pressure. Left ventricular chamber stiffness constant was calculated from the deceleration time of the early mitral filling wave. The fraction of myocardial volume occupied by total collagen tissue and collagen type I fibers was assessed histomorphologically. The degree of collagen cross-linking (CCL), which determines the formation of insoluble stiff collagen, was assessed by colorimetric and enzymatic procedures. The expression of lysyl oxidase (LOX), which regulates CCL, was assessed by Western blot. Compared with patients with normal pulmonary capillary wedge pressure (≤12 mm Hg; n=16), patients with elevated pulmonary capillary wedge pressure (>12 mm Hg; n=22) exhibited increases of left ventricular chamber stiffness constant, fraction of myocardial volume occupied by total collagen tissue, fraction of myocardial volume occupied by collagen type I fibers, CCL, insoluble stiff collagen, and LOX. Pulmonary capillary wedge pressure was correlated with left ventricular chamber stiffness constant (r=0.639; P<0.001), insoluble stiff collagen (r=0.474; P<0.005), CCL (r=0.625; P<0.001), and LOX (r=0.410; P<0.05) in all of the patients but not with fraction of myocardial volume occupied by total collagen tissue or fraction of myocardial volume occupied by collagen type I fibers. In addition, CCL was correlated with insoluble stiff collagen (r=0.612; P<0.005), LOX (r=0.538; P<0.01), left ventricular chamber stiffness constant (r=0.535; P<0.005), peak filling rate (r=-0.343; P<0.05), ejection fraction (r=-0.430; P<0.01), and amino-terminal propeptide of brain natriuretic peptide (r=0.421; P<0.05) in all of the patients. These associations were independent of confounding factors. These findings indicate that, in hypertensive patients with stage C heart failure, it is only the quality of collagen (ie, degree of cross-linking) that associates with elevated filling pressures. It is suggested that LOX-mediated excessive CCL facilitates the increase in left ventricular stiffness with the resulting elevation of filling pressures in these patients.

Analysis of genetic diversity of southern Spain fig tree (Ficus carica L.) and reference materials as a tool for breeding and conservation

The common fig tree (Ficus carica L.) is a Mediterranean crop with problematic cultivar identification. The recovery and conservation of possible local varieties for ecological production requires the previous genetic characterization of the available germplasm. In this context, 42 lines corresponding to 12 local varieties and two caprifigs, in addition to 15 reference samples have been fingerprinted using 21 SSR markers. A total of 77 alleles were revealed, detecting a useful level of genetic variability within the local germplasm pools. UPGMA clustering analysis has revealed the genetic structure and relationships among the local and reference germplasm. Eleven of the local varieties could be identified and defined as obtained clusters, showing that SSR analysis is an efficient method to evaluate the Andalusian fig tree diversity for on-farm conservation.

Prevalence of left ventricular diastolic dysfunction in European populations based on cross-validated diagnostic thresholds

Background

Different diagnostic criteria limit comparisons between populations in the prevalence of diastolic left ventricular (LV) dysfunction. We aimed to compare across populations age-specific echocardiographic criteria for diastolic LV dysfunction as well as their correlates and prevalence.

Methods

We measured the E and A peaks of transmitral blood flow by pulsed wave Doppler and the e' and a' peaks of mitral annular velocities by tissue Doppler imaging (TDI) in 2 cohorts randomly recruited in Belgium (n = 782; 51.4% women; mean age, 51.1 years) and in Italy, Poland and Russia (n = 476; 55.7%; 44.5 years).

Results

In stepwise regression, the multivariable-adjusted correlates of the transmitral and TDI diastolic indexes were similar in the 2 cohorts and included sex, age, body mass index, blood pressure and heart rate. Similarly, cut-off limits for the E/A ratio (2.5th percentile) and E/e' ratio (97.5th percentile) in 338 and 185 reference subjects free from cardiovascular risk factors respectively selected from both cohorts were consistent within 0.02 and 0.26 units (median across 5 age groups). The rounded 2.5th percentile of the E/A ratio decreased by ~0.10 per age decade in these apparently healthy subjects. The reference subsample provided age-specific cut-off limits for normal E/A and E/e' ratios. In the 2 cohorts combined, diastolic dysfunction groups 1 (impaired relaxation), 2 (possible elevated LV filling pressure) and 3 (elevated E/e' and abnormally low E/A) encompassed 114 (9.1%), 135 (10.7%), and 40 (3.2%) subjects, respectively.

Conclusions

The age-specific criteria for diastolic LV dysfunction were highly consistent across the study populations with an age-standardized prevalence of 22.4% vs. 25.1%.

Cardiovascular translational medicine (III). Genomics and proteomics in heart failure research

Heart failure is a complex syndrome and is one of the main causes of morbidity and mortality in developed countries. Despite considerable research effort in recent years, heart failure prevention and treatment strategies still suffer significant limitations. New theoretical and technical approaches are, therefore, required. It is in this context that the "omic" sciences have a role to play in heart failure. The incorporation of "omic" methodologies into the study of human disease has substantially changed biological approaches to disease and has given an enormous impetus to the search for new disease mechanisms, as well as for novel biomarkers and therapeutic targets. The application of genomics, proteomics and metabonomics to heart failure research could increase our understanding of the origin and development of the different processes contributing to this syndrome, thereby enabling the establishment of specific diagnostic profiles and therapeutic templates that could help improve the poor prognosis associated with heart failure. This brief review contains a short description of the fundamental principles of the "omic" sciences and an evaluation of how these new techniques are currently contributing to research into human heart failure. The focus is mainly on the analysis of gene expression microarrays in the field of genomics and on studies using two-dimensional electrophoresis with mass spectrometry in the area of proteomics.