Pietro Francia

Deletion of p66shc Gene Protects Against Age-Related Endothelial Dysfunction

Background—Enhanced production of reactive oxygen species (ROS) has been recognized as the major determinant of age-related endothelial dysfunction. The p66shc protein controls cellular responses to oxidative stress. Mice lacking p66shc (p66shc−/−) have increased resistance to ROS and a 30% prolonged life span. The present study investigates age-dependent changes of endothelial function in this model. Methods and Results—Aortic rings from young and old p66shc−/− or wild-type (WT) mice were suspended for isometric tension recording. Nitric oxide (NO) release was measured by a porphyrinic microsensor. Expression of endothelial NO synthase (eNOS), inducible NOS (iNOS), superoxide dismutase, and nitrotyrosine-containing proteins was assessed by Western blotting. Nitrotyrosine residues were also identified by immunohistochemistry. Superoxide (O2−) production was determined by coelenterazine-enhanced chemiluminescence. Endothelium-dependent relaxation in response to acetylcholine was age-dependently impaired in WT mice but not in p66shc−/− mice. Accordingly, an age-related decline of NO release was found in WT but not in p66shc−/− mice. The expression of eNOS and manganese superoxide dismutase was not affected by aging either in WT or in p66shc−/− mice, whereas iNOS was upregulated only in old WT mice. It is interesting that old WT mice displayed a significant increase of O2− production as well as of nitrotyrosine expression compared with young animals. Such age-dependent changes were not found in p66shc−/− mice. Conclusions—We report that inactivation of the p66shc gene protects against age-dependent, ROS-mediated endothelial dysfunction. These findings suggest that the p66shc is part of a signal transduction pathway also relevant to endothelial integrity and may represent a novel target to prevent vascular aging.

Genetic deletion of p66Shc adaptor protein prevents hyperglycemia-induced endothelial dysfunction and oxidative stress

Increased production of reactive oxygen species (ROS) and loss of endothelial NO bioavailability are key features of vascular disease in diabetes mellitus. The p66Shc adaptor protein controls cellular responses to oxidative stress. Mice lacking p66Shc (p66Shc−/−) have increased resistance to ROS and prolonged life span. The present work was designed to investigate hyperglycemia-associated changes in endothelial function in a model of insulin-dependent diabetes mellitus p66Shc−/− mouse. p66Shc−/− and wild-type (WT) mice were injected with citrate buffer (control) or made diabetic by an i.p. injection of 200 mg of streptozotocin per kg of body weight. Streptozotocin-treated p66Shc−/− and WT mice showed a similar increase in blood glucose. However, significant differences arose with respect to endothelial dysfunction and oxidative stress. WT diabetic mice displayed marked impairment of endothelium-dependent relaxations, increased peroxynitrite (ONOO−) generation, nitrotyrosine expression, and lipid peroxidation as measured in the aortic tissue. In contrast, p66Shc−/− diabetic mice did not develop these high-glucose-mediated abnormalities. Furthermore, protein expression of the antioxidant enzyme heme oxygenase 1 and endothelial NO synthase were up-regulated in p66Shc−/− but not in WT mice. We report that p66Shc−/− mice are resistant to hyperglycemia-induced, ROS-dependent endothelial dysfunction. These data suggest that p66Shc adaptor protein is part of a signal transduction pathway relevant to hyperglycemia vascular damage and, hence, may represent a novel therapeutic target against diabetic vascular complications.

Final common molecular pathways of aging and cardiovascular disease: Role of the p66Shc protein

Oxidative stress affects the availability of key-regulators of vascular homeostasis and controls a number of signaling pathways relevant to myocardial and vascular disease. Reactive oxygen species are generated by different intracellular molecular pathways principally located in mitochondria. The notion that mice carrying a targeted mutation of the p66(Shc) gene display prolonged lifespan, reduced production of intracellular oxidants, and increased resistance to oxidative stress-induced apoptosis prompted a series of studies aimed at defining the biochemical function of p66(Shc) and its possible implication in cardiovascular diseases. Indeed, p66(Shc-/-) mice are protected against vascular, cardiac, and renal impairment attributable to hypercholesterolemia, aging, diabetes, and ischemia/reperfusion. The present review focuses on the biochemical and physiological function of the p66(Shc) adaptor protein as well as on the mechanisms linking p66(Shc)-associated generation of free radicals to the pathophysiology of aging and cardiovascular disease. On the whole, the evidence so far reported and here discussed supports the concept that pharmacological modulation of p66(Shc) expression and activity may be a novel and effective target for the treatment of atherosclerotic vascular disease as well as myocardial adaptation to hypertrophic, inflammatory and neuro-hormonal stimuli in the overloaded heart.

Cardiac resynchronization therapy increases plasma levels of the endogenous inotrope apelin.

Cardiac resynchronization therapy (CRT) has been introduced to treat drug refractory chronic heart failure (CHF). Apelin, the endogenous ligand of the APJ receptor, is under evaluation for its potential role in human CHF pathophysiology. This study aims to assess whether biventricular pacing affects plasma apelin levels in patients with severe CHF.

p66Shc protein, oxidative stress, and cardiovascular complications of diabetes: the missing link

Diabetes affects more than 150 million people worldwide, and it is estimated that this would increase to 299 million by the year 2025. The incidence of and mortality from cardiovascular disease are two- to eightfold higher in subjects with diabetes than in those without, coronary artery disease accounting for the large majority of deaths. Among the full spectrum of biochemical effects of high glucose, generation of oxygen-derived free radicals is one of the main pathophysiological mechanisms linking hyperglycemia to atherosclerosis, nephropathy, and cardiomyopathy. The adaptor protein p66Shc is implicated in mitochondrial reactive oxygen species (ROS) generation and translation of oxidative signals into apoptosis. Indeed, p66Shc−/− mice display prolonged lifespan, reduced production of intracellular oxidants, and increased resistance to oxidative stress-induced apoptosis. Accordingly, a series of studies defined the pathophysiological role of p66Shc in cardiovascular disease where ROS represent a substantial triggering component. As p66Shc modulates the production of cellular ROS, it represents a proximal node through which high glucose exerts its deleterious effects on different cell types; indeed, several studies tested the hypothesis that deletion of the p66Shc gene may confer protection against diabetes-related cardiovascular complications. The present review focuses on the reported evidence linking p66Shc signaling pathway to high glucose-associated endothelial dysfunction, atherogenesis, nephropathy, and cardiomyopathy.

Plasma osteopontin reveals left ventricular reverse remodelling following cardiac resynchronization therapy in heart failure

BACKGROUND Cardiac resynchronization therapy (CRT) promotes left ventricular (LV) reverse remodelling and affects myocardial collagen turnover in heart failure (HF) patients. Osteopontin (OPN) is a matrix glycoprotein required for the activation of fibroblasts upon TGF-β1 stimulation. In humans, plasma OPN and OPN-expressing lymphocytes correlate with the severity of HF. We sought to evaluate whether plasma OPN and TGF-β1 reflect LV reverse remodelling following CRT. METHODS Eighteen patients (12 men, mean age 65 ± 11 years) undergoing CRT were studied. Patients underwent baseline clinical and echocardiographic evaluation, and assessment of plasma OPN and TGF-β1. The evaluation was repeated 8.5 ± 4 months after device implantation. Eight healthy age- and sex-matched subjects served as controls. RESULTS In HF patients, baseline plasma OPN and TGF-β1 were higher as compared to control subjects (OPN: 99 ± 48 vs 59 ± 22 ng/ml; p<0.05; TGF-β1: 15.9 ± 8.0 vs 9.3 ± 5.6 ng/ml; p<0.05). At follow-up, 12 patients responded to CRT and showed LV reverse remodelling, whereas 6 did not. Plasma OPN decreased in CRT responders (108 ± 47 vs 84 ± 37 ng/ml; p=0.03) and increased in non-responders (79 ± 58 vs 115 ± 63 ng/ml; p<0.01). TGF-β1 showed a trend towards reduction in responders (17.5 ± 8.7 vs 10.2 ± 8.9 ng/ml; p=0.08) and was unchanged in non-responders. A significant correlation (r=-0.56; p=0.01) was found between relative changes of LVESV and plasma OPN. CONCLUSIONS CRT-induced LV reverse remodelling is reflected by changes in plasma OPN. Circulating OPN may represent a marker of LV dilation/impairment and an indicator of the response to HF therapies promoting LV reverse remodelling.

Prediction of long-term survival in chronic heart failure by multiple biomarker assessment: A 15-year prospective follow-up study

In chronic heart failure (CHF), several plasma biomarkers identify subjects at risk of death over the midterm. However, their long‐term predictive value in the context of other candidate predictors has never been assessed. This information may prove valuable in the management of a chronic disease with a long natural history, as CHF is today.

Anti-aging medicine: Molecular basis for endothelial cell-targeted strategies - A mini-review

Due to improvements in lifestyle and healthcare, the proportion of aged people is rising steadily, especially in developed countries. With aging, some physiological functions are altered and resemble those occurring in disease conditions such as hypertension, chronic coronary disease and diabetes. Thus, there is the urge to better understand molecular and cellular mechanisms underlying aging and aging-related diseases. In rodents and possibly primates, calorie restriction is an effective approach to extend lifespan by reducing free radical-induced damage. Increased production of oxygen-derived free radicals plays an important role in the process of aging. Reactive oxygen species are generated by different intracellular molecular pathways principally located in the cytoplasm and in the mitochondria. The mitochondrial protein p66Shc is considered a longevity assurance gene since its genetic deletion extends the lifespan of rodents and displays protective effects in several models of cardiovascular disease. Silent mating type information regulation 2 homolog 1 Saccharomyces cerevisiae (SIRT1) is a nicotinamide adenine dinucleotide (NAD+)-dependent histone deacetylase that may also be involved in aging and diseases. SIRT1 also deacetylates a number of nonhistone target proteins, including p53, endothelial nitric oxide synthase and forkhead box protein. This review focuses on the latest scientific advances in understanding aging as well as delineates the possible therapeutic implications of p66Shc and SIRT1 in this process.

Calcium channel blockers and hypertension.

Effective treatment of high blood pressure (BP) represents a key strategy for reducing the burden of hypertension-related cardiovascular and renal diseases. In spite of these well-established concepts, hypertension remains poorly controlled worldwide. In order to improve BP control in patients with hypertension, several interventions have been proposed, among which (1) preferred use of more effective, sustained, and well-tolerated antihypertensive drug aimed to ensure adherence to prescribed medications and (2) extensive use of rational, integrated, and synergistic combination therapies, even as first-line strategy, aimed to achieve the recommended BP targets. Within the possible antihypertensive drug classes currently available for the clinical management of hypertension, both in monotherapy and in combination therapy, drugs inhibiting the renin–angiotensin system and calcium channel blockers (CCBs) have demonstrated to be effective and safe in lowering BP levels and achieving the recommended BP targets with a good tolerability profile. In particular, CCBs have been one of the most widely used classes of antihypertensive agents in the last 20 years, based on their effectiveness in reducing BP levels, good tolerability, and abundant evidence on reducing cardiovascular and renal consequences of hypertension. This article provides an updated overview of the evidence supporting the use of CCBs-based antihypertensive regimen, both in monotherapy and in combination therapies with different classes of antihypertensive drugs.

Attitudes and preferences for the clinical management of hypertension and hypertension-related cardiac disease in general practice: results of the Italian Hypertension and Heart Survey

The aim of this study was to evaluate attitudes and preferences for the clinical management of hypertensive patients with cardiac organ disease, including left ventricular hypertrophy (LVH) and coronary artery disease (CAD), in Italy. A predefined 15-item questionnaire was anonymously administered to a large community sample of general practitioners (GPs) and specialised physicians between November 2012 and June 2013. Estimated prevalence of hypertension-related clinical conditions was stratified into four groups (10–20%, 20–40%, 40–50%, >50%); preferences were reported as percentage among valid answers to the survey questionnaire. A total of 1319 physicians (672 males, age 55.0±7.1 years, age of medical activity 27.1±7.6 years), among whom 1264 GPs and 55 specialised physicians, was included. LVH was reported to be the most frequent marker of organ damage by the majority of physicians (73.5%). LV diastolic dysfunction was reported to be relatively frequent (>40%) by more than half of the specialised physicians (58.2%) and less frequent (10–20%) by GPs (49.8%); LV systolic dysfunction, atrial fibrillation and CAD were considered to be less frequent (10–20%) by the majority of physicians (61.3, 71.6 and 53.3%, respectively). Echocardiography was the preferred diagnostic tool used to estimate LVH (76.6%). Tight blood pressure control (130/80 mm Hg) was considered to be the most appropriate by the majority of physicians, both in hypertensive patients with LVH and in those with CAD. With the well-known limitations of a cross-sectional survey, this study provides information on attitudes and preferences for the clinical management of outpatients with hypertension and high CV risk profile in general practice in Italy.