Daniela Fraccarollo

Bio: Daniela Fraccarollo is an academic researcher from University of Würzburg. The author has contributed to research in topics: Heart failure & Myocardial infarction. The author has an hindex of 33, co-authored 59 publications receiving 3539 citations. Previous affiliations of Daniela Fraccarollo include Technische Universität München & Hannover Medical School.

Endothelial Nitric Oxide Synthase Uncoupling Impairs Endothelial Progenitor Cell Mobilization and Function in Diabetes

Abstract: Uncoupling of the endothelial nitric oxide synthase (eNOS) resulting in superoxide anion (O(2)(-)) formation instead of nitric oxide (NO) causes diabetic endothelial dysfunction. eNOS regulates mobilization and function of endothelial progenitor cells (EPCs), key regulators of vascular repair. We postulate a role of eNOS uncoupling for reduced number and function of EPC in diabetes. EPC levels in diabetic patients were significantly reduced compared with those of control subjects. EPCs from diabetic patients produced excessive O(2)(-) and showed impaired migratory capacity compared with nondiabetic control subjects. NOS inhibition with N(G)-nitro-l-arginine attenuated O(2)(-) production and normalized functional capacity of EPCs from diabetic patients. Glucose-mediated EPC dysfunction was protein kinase C dependent, associated with reduced intracellular BH(4) (tetrahydrobiopterin) concentrations, and reversible after exogenous BH(4) treatment. Activation of NADPH oxidases played an additional but minor role in glucose-mediated EPC dysfunction. In rats with streptozotocin-induced diabetes, circulating EPCs were reduced to 39 +/- 5% of controls and associated with uncoupled eNOS in bone marrow. Our results identify uncoupling of eNOS in diabetic bone marrow, glucose-treated EPCs, and EPCs from diabetic patients resulting in eNOS-mediated O(2)(-) production. Subsequent reduction of EPC levels and impairment of EPC function likely contributes to the pathogenesis of vascular disease in diabetes.

Improvement of Left Ventricular Remodeling and Function by Hydroxymethylglutaryl Coenzyme A Reductase Inhibition With Cerivastatin in Rats With Heart Failure After Myocardial Infarction

Abstract: Background Hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) attenuate angiotensin II-induced cellular signaling. Because angiotensin II is involved in left ventricular (LV) remodeling after myocardial infarction (MI), we examined the effects of statin treatment in an experimental model of chronic heart failure after MI. Methods and Results Rats with extensive MI were treated with placebo or cerivastatin (0.3 mg/kg per day) as a dietary supplement or via gavage for 11 weeks starting on the 7th postoperative day. Infarct size and cholesterol levels were similar among all groups. LV cavity area, an index of LV dilatation, was reduced in MI rats on cerivastatin compared with placebo. LV end-diastolic pressure was increased in MI rats on placebo (24.1±4.1 mm Hg versus sham: 5.1±0.3 mm Hg; P <0.01), and it was significantly reduced by cerivastatin treatment (13.7±2.7 mm Hg; P <0.05 versus placebo). Cerivastatin partially normalized LV dP/dtmax and dP/dtmin, indices of LV systolic and diastolic function, which were significantly reduced in MI rats on placebo. Improvement of LV function by cerivastatin was accompanied by a reduced expression of collagen type I and β-myosin heavy chain. LV endothelial nitric oxide synthase was increased, whereas the nitrotyrosine protein level was decreased in MI rats by cerivastatin treatment. Conclusions Cerivastatin improved LV remodeling and function in rats with heart failure. This effect was associated with an attenuated LV expression of fetal myosin heavy chain isoenzymes and collagen I. Statin treatment may retard the progression of chronic heart failure. Received June 1, 2001; revision received July 9, 2001; accepted July 10, 2001.

Gut Microbiota–Dependent Trimethylamine N-Oxide Predicts Risk of Cardiovascular Events in Patients With Stroke and Is Related to Proinflammatory Monocytes

Abstract: Objective- Gut microbiota-dependent metabolites, in particular trimethylamine N-oxide (TMAO), have recently been reported to promote atherosclerosis and thrombosis. Here, we examined for the first time the relation of TMAO and the risk of incident cardiovascular events in patients with recent first-ever ischemic stroke in 2 independent prospective cohorts. Moreover, the link between TMAO and proinflammatory monocytes as a potential contributing factor for cardiovascular risk in stroke patients was studied. Approach and Results- In a first study (n=78), higher TMAO plasma levels were linked with an increased risk of incident cardiovascular events including myocardial infarction, recurrent stroke, and cardiovascular death (fourth quartile versus first quartile; hazard ratio, 2.31; 95% CI, 1.25-4.23; P<0.01). In the second independent validation cohort (n=593), high TMAO levels again heralded marked increased risk of adverse cardiovascular events (fourth quartile versus first quartile; hazard ratio, 5.0; 95% CI, 1.7-14.8; P<0.01), and also after adjustments for cardiovascular risk factors including hypertension, diabetes mellitus, LDL (low-density lipoprotein) cholesterol, and estimated glomerular filtration rate (hazard ratio, 3.3; 95% CI, 1.2-10.9; P=0.04). A significant correlation was also found between TMAO levels and percentage of proinflammatory intermediate CD14++CD16+ monocytes ( r=0.70; P<0.01). Moreover, in mice fed a diet enriched with choline to increase TMAO synthesis, levels of proinflammatory murine Ly6Chigh monocytes were higher than in the chow-fed control group (choline: 9.2±0.5×103 per mL versus control: 6.5±0.5×103 per mL; P<0.01). This increase was abolished in mice with depleted gut microbiota (choline+antibiotics: 5.4±0.7×103 per mL; P<0.001 versus choline). Conclusions- The present study demonstrates for the first time a graded relation between TMAO levels and the risk of subsequent cardiovascular events in patients with recent prior ischemic stroke. Our data support the notion that TMAO-related increase of proinflammatory monocytes may add to elevated cardiovascular risk of patients with increased TMAO levels.

Deletion of Cardiomyocyte Mineralocorticoid Receptor Ameliorates Adverse Remodeling After Myocardial Infarction

Abstract: Background—Mineralocorticoid receptor (MR) blockade improves morbidity and mortality among patients with heart failure; however, the underlying mechanisms are still under investigation. We studied left ventricular remodeling after myocardial infarction in mice with cardiomyocyte-specific inactivation of the MR gene (MRMLCCre) that were generated with a conditional MR allele (MRflox) in combination with a transgene expressing Cre recombinase under control of the myosin light-chain (MLC2a) gene promoter. Methods and Results—Control (MRflox/flox, MRflox/wt) and MRMLCCre mice underwent coronary artery ligation. MR ablation had no detectable baseline effect on cardiac morphology and function. The progressive left ventricular chamber enlargement and functional deterioration in infarcted control mice, detected by echocardiography and conductance catheter analysis during the 8-week observation period, were substantially attenuated in MRMLCCre mice. Chronically infarcted MRMLCCre mice displayed attenuated pulmonar...

Eplerenone, a Selective Aldosterone Blocker, in Patients with Left Ventricular Dysfunction after Myocardial Infarction

Abstract: background Aldosterone blockade reduces mortality and morbidity among patients with severe heart failure. We conducted a double-blind, placebo-controlled study evaluating the effect of eplerenone, a selective aldosterone blocker, on morbidity and mortality among patients with acute myocardial infarction complicated by left ventricular dysfunction and heart failure. methods Patients were randomly assigned to eplerenone (25 mg per day initially, titrated to a maximum of 50 mg per day; 3313 patients) or placebo (3319 patients) in addition to optimal medical therapy. The study continued until 1012 deaths occurred. The primary end points were death from any cause and death from cardiovascular causes or hospitalization for heart failure, acute myocardial infarction, stroke, or ventricular arrhythmia. results During a mean follow-up of 16 months, there were 478 deaths in the eplerenone group and 554 deaths in the placebo group (relative risk, 0.85; 95 percent confidence interval, 0.75 to 0.96; P=0.008). Of these deaths, 407 in the eplerenone group and 483 in the placebo group were attributed to cardiovascular causes (relative risk, 0.83; 95 percent confidence interval, 0.72 to 0.94; P = 0.005). The rate of the other primary end point, death from cardiovascular causes or hospitalization for cardiovascular events, was reduced by eplerenone (relative risk, 0.87; 95 percent confidence interval, 0.79 to 0.95; P=0.002), as was the secondary end point of death from any cause or any hospitalization (relative risk, 0.92; 95 percent confidence interval, 0.86 to 0.98; P=0.02). There was also a reduction in the rate of sudden death from cardiac causes (relative risk, 0.79; 95 percent confidence interval, 0.64 to 0.97; P=0.03). The rate of serious hyperkalemia was 5.5 percent in the eplerenone group and 3.9 percent in the placebo group (P = 0.002), whereas the rate of hypokalemia was 8.4 percent in the eplerenone group and 13.1 percent in the placebo group (P<0.001). conclusions The addition of eplerenone to optimal medical therapy reduces morbidity and mortality among patients with acute myocardial infarction complicated by left ventricular dysfunction and heart failure.

Nitric oxide synthases: regulation and function.

Abstract: Nitric oxide (NO), the smallest signalling molecule known, is produced by three isoforms of NO synthase (NOS; EC 1.14.13.39). They all utilize l-arginine and molecular oxygen as substrates and require the cofactors reduced nicotinamide-adenine-dinucleotide phosphate (NADPH), flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN), and (6R-)5,6,7,8-tetrahydrobiopterin (BH(4)). All NOS bind calmodulin and contain haem. Neuronal NOS (nNOS, NOS I) is constitutively expressed in central and peripheral neurons and some other cell types. Its functions include synaptic plasticity in the central nervous system (CNS), central regulation of blood pressure, smooth muscle relaxation, and vasodilatation via peripheral nitrergic nerves. Nitrergic nerves are of particular importance in the relaxation of corpus cavernosum and penile erection. Phosphodiesterase 5 inhibitors (sildenafil, vardenafil, and tadalafil) require at least a residual nNOS activity for their action. Inducible NOS (NOS II) can be expressed in many cell types in response to lipopolysaccharide, cytokines, or other agents. Inducible NOS generates large amounts of NO that have cytostatic effects on parasitic target cells. Inducible NOS contributes to the pathophysiology of inflammatory diseases and septic shock. Endothelial NOS (eNOS, NOS III) is mostly expressed in endothelial cells. It keeps blood vessels dilated, controls blood pressure, and has numerous other vasoprotective and anti-atherosclerotic effects. Many cardiovascular risk factors lead to oxidative stress, eNOS uncoupling, and endothelial dysfunction in the vasculature. Pharmacologically, vascular oxidative stress can be reduced and eNOS functionality restored with renin- and angiotensin-converting enzyme-inhibitors, with angiotensin receptor blockers, and with statins.

Pleiotropic effects of statins

Abstract: ▪ Abstract Statins are potent inhibitors of cholesterol biosynthesis. In clinical trials, statins are beneficial in the primary and secondary prevention of coronary heart disease. However, the over...

Gut microbiota in human metabolic health and disease.

Abstract: Observational findings achieved during the past two decades suggest that the intestinal microbiota may contribute to the metabolic health of the human host and, when aberrant, to the pathogenesis of various common metabolic disorders including obesity, type 2 diabetes, non-alcoholic liver disease, cardio-metabolic diseases and malnutrition. However, to gain a mechanistic understanding of how the gut microbiota affects host metabolism, research is moving from descriptive microbiota census analyses to cause-and-effect studies. Joint analyses of high-throughput human multi-omics data, including metagenomics and metabolomics data, together with measures of host physiology and mechanistic experiments in humans, animals and cells hold potential as initial steps in the identification of potential molecular mechanisms behind reported associations. In this Review, we discuss the current knowledge on how gut microbiota and derived microbial compounds may link to metabolism of the healthy host or to the pathogenesis of common metabolic diseases. We highlight examples of microbiota-targeted interventions aiming to optimize metabolic health, and we provide perspectives for future basic and translational investigations within the nascent and promising research field. In this Review, Fan and Pedersen discuss how the gut microbiota and derived microbial compounds may contribute to human metabolic health and to the pathogenesis of common metabolic diseases, and highlight examples of microbiota-targeted interventions aiming to optimize metabolic health.