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Biomedical subjects

Filomena de Nigris

Publications and source records attributed to Filomena de Nigris.

At least 19 recordsLinked to original sources

Autologous bone marrow cell therapy and metabolic intervention in ischemia-induced angiogenesis in the diabetic mouse hindlimb.

Peripheral arterial disease (PAD) is a major health problem especially when associated to diabetes. Administration of autologous bone marrow cells (BMC) is emerging as a novel intervention to induce therapeutic angiogenesis in experimental ischemic limb models and in patients with PAD. Since tissue ischemia and diabetes are associated with an overwhelming generation of oxygen radicals and detrimental effects due to formation of glycosylation end-products, metabolic intervention with antioxidants and L-arginine can confer beneficial effects beyond those achieved by BMC alone. The effects of cotreatment with intravenous BMCs and metabolic vascular protection (1.0% vitamin E, 0.05% vitamin C, and 6% L-arginine) were examined in the ischemic hindlimb of diabetic and non diabetic mice. BMC therapy increased blood flow and capillary densities and Ki67 proliferative marker, and decreased interstitial fibrosis. This effect was amplified by metabolic cotreatment, an intervention inducing vascular protection, at least in part, through the nitric oxide pathway, reduction of systemic oxidative stress, and macrophage activation.

Animals↗

Expression of transcription factor Yin Yang 1 in human osteosarcomas.

The transcription factor Yin Yang 1 (YY1) is known to be present in some human cancer cell lines and its expression correlates with immune-mediated apoptosis. By using Western blot analysis, we have shown that the YY1 protein is strongly expressed in human osteosarcoma cells and localised mainly in the nucleus. Moreover, by using immunohistochemistry and RT-PCR techniques, we have analysed the expression of YY1 protein in biopsies from human osteosarcomas. The YY1 protein was not detectable by immunohistochemistry in osteoid tissue. However, its expression was restricted to osteosarcoma tissues. These data were confirmed by densitometric analysis of RT-PCR for YY1 expression. Thus, YY1 gene activation appears to be an early event in the process of osteoblastic transformation and its detection may represent, together with the analysis of other established markers, a useful diagnostic tool in human osteosarcomas.

Adolescent↗

Effects of a pomegranate fruit extract rich in punicalagin on oxidation-sensitive genes and eNOS activity at sites of perturbed shear stress and atherogenesis.

BACKGROUND: Atherosclerosis is enhanced in arterial segments exposed to disturbed flow. Perturbed shear stress increases the expression of oxidation-sensitive responsive genes (such as ELK-1 and p-CREB). Polyphenolic antioxidants contained in the juice derived from the pomegranate contribute to the reduction of oxidative stress and atherogenesis during disturbed shear stress. AIM OF THE STUDY: To evaluate the effects of intervention with the Pomegranate Fruit Extract (PFE) rich in polyphones (punicalagin, which is a potent antioxidant) on ELK-1, p-CREB, and endothelial nitric oxide synthase (eNOS) expression induced by high shear stress in vitro and in vivo. RESULTS: At the doses used in the study, both the PFE and the regular pomegranate juice concentrate reduced the activation of ELK-1 and p-CREB and increased eNOS expression (which was decreased by perturbed shear stress) in cultured human endothelial cells and in atherosclerosis-prone areas of hypercholesterolemic mice. PFE and pomegranate juice increased cyclic GMP levels while there was no significant effect of both compounds on the conversion of L-arginine to L-citrulline. Administration of these compounds to hypercholesterolemic mice significantly reduced the progression of atherosclerosis and isoprostane levels and increased nitrates. This protective effect was relevant with PFE. Vasomotor reactivity was improved and EC(25) values in response to Ach and NONOate were significantly increased in treated mice in comparison to controls. CONCLUSION: This study indicates that the proatherogenic effects induced by perturbed shear stress can be also reversed by chronic administration of PFE.

Analysis of Variance↗

Targeting c-Myc, Ras and IGF cascade to treat cancer and vascular disorders.

Cancer and vascular diseases remain the predominant causes of morbidity and mortality in industrialized countries worldwide. The course of atherosclerosis with initiation, progression, and complication parallels the three stages of carcinogenesis with induction, growth, and invasion of tissue and neoangiogenesis. Within this framework, the oncogene c-Myc and growth factors pathways are acquiring increasing importance. Insulin-like growth factor-1 (IGF-1) pathway emerges among them for its versatile pleiotropic actions. A number of genes that permit extensive communication between IGF-1-AKT, p53, and mammalian target of rapamycin (mTOR) pathways have been identified. In turn these pathways lead to p53 transcriptional program, the forkhead transcriptional programs, autophagy, and translational controls, which determine cell growth or arrest, cell survival or death. The increased understanding of the extensive communication and coordination between all these pathways may enable to targeting these events and to prevent neoplastic and vascular diseases. Great effort has been focused on the development of new agents designed to target various steps of c-Myc, Ras, and IGF cascade. However, what have we recently learned about their safety and effectiveness? Here, we review the very recent advances in the identification of novel inhibitors as well as antisense oligonuleotides (ASOs) and siRNA that are proving their usefulness in ongoing clinical trials both in terms of toxicity and specificity.

Animals↗

Therapeutic effects of concurrent autologous bone marrow cell infusion and metabolic intervention in ischemia-induced angiogenesis in the hypercholesterolemic mouse hindlimb.

Lower-limb ischemia is a major health problem especially when associated to hypercholesterolemia. Because of the absence of effective treatment in the advanced stages of the disease, amputation is undertaken to alleviate unbearable symptoms. Since tissue ischemia and hypercholesterolemia are associated with an overwhelming generation of oxygen radicals, metabolic intervention with antioxidants and l-arginine can induce beneficial effects beyond those achieved by a novel therapeutic approach represented by the use of autologous bone marrow cells (BMCs). The protective effect of BMCs and vascular protection by metabolic cotreatment (1.0% vitamin E added to the chow, 0.05% vitamin C and 6% l-arginine added to the drinking water) were examined in ischemia-induced angiogenesis in the hypercholesterolemic mouse hindlimb. Intravenous BMC therapy improved blood flow and increased capillary densities. This beneficial effect was amplified by metabolic cotreatment, an intervention inducing vascular protection, at least in part, through the nitric oxide pathway, reduction of systemic oxidative stress and macrophage activation.

Animals↗

Physical training and metabolic supplementation reduce spontaneous atherosclerotic plaque rupture and prolong survival in hypercholesterolemic mice.

Moderate physical exercise (PE) combined with metabolic treatment (MT) (antioxidants and l-arginine) are well known to reduce atherosclerotic lesion formation in hypercholesterolemic mice. However, the long-term beneficial effects on unstable atheroma remain poorly understood. We started early PE training in large groups of 6-week-old hypercholesterolemic mice (by graduated swimming) alone or in combination with nutritional supplementation (1.0% vitamin E added to the chow and 0.05% vitamin C and 6% l-arginine added to the drinking water). Inactive controls did not receive PE. The spontaneous development of atherosclerotic plaque rupture (associated with advanced atherosclerosis) and survival rates were evaluated. Moderate PE elicited an increase in plasma levels of nitric oxide. Early combined treatment with PE and MT in the hypercholesterolemic mice significantly reduced lesions (also detected noninvasively at 10 months) and spontaneous atherosclerotic plaque rupture and prolonged survival more effectively than each intervention alone. Thus, early concerted actions of MT and PE improve the natural history of atherosclerotic lesions and reduce the plaque instability in hypercholesterolemic mice.

Animals↗

Pomegranate juice protects nitric oxide against oxidative destruction and enhances the biological actions of nitric oxide.

Pomegranate juice (PJ), which is a rich source of potent flavonoid antioxidants, was tested for its capacity to protect nitric oxide (NO) against oxidative destruction and enhance the biological actions of NO. Employing chemiluminescence headspace analysis, PJ was found to be a potent inhibitor of superoxide anion-mediated disappearance of NO. PJ was much more potent than Concord grape juice, blueberry juice, red wine, ascorbic acid, and DL-alpha-tocopherol. As little as 3 microl of a 6-fold dilution of PJ, in a reaction volume of 5000 microl, produced a marked antioxidant effect, whereas 300 microl of undiluted blueberry juice or nearly 1000 microl of undiluted Concord grape juice were required to produce similar effects. PJ and other antioxidant-containing products were found to augment the anti-proliferative action of NO (DETA/NO) on vascular smooth muscle cell (rat aorta) proliferation. PJ was much more effective than the other products tested and elicited no effects when tested alone in the absence of added NO. Similarly, neither PJ nor the other products enhanced the anti-proliferative action of alpha-difluoromethylornithine, a stable substance that inhibits cell growth by NO-independent mechanisms. In order to determine whether PJ is capable of increasing the production of NO by vascular endothelial cells, PJ was tested for its capacity to upregulate and/or activate endothelial NO synthase (eNOS) in bovine pulmonary artery endothelial cells. PJ elicited no effects on eNOS protein expression or catalytic activity. Moreover, PJ did not enhance promoter activity in the eNOS gene (COS-7 cells transfected with eNOS). These observations indicate that PJ possesses potent antioxidant activity that results in marked protection of NO against oxidative destruction, thereby resulting in augmentation of the biological actions of NO.

Animals↗

Nitric oxide and atherosclerosis: an update.

Nitric oxide (NO) is a molecule that has gained recognition as a crucial modulator of vascular disease. NO has a number of intracellular effects that lead to vasorelaxation, endothelial regeneration, inhibition of leukocyte chemotaxis, and platelet adhesion. Endothelium damage induced by atherosclerosis leads to the reduction in bioactivity of endothelial NO synthase (eNOS) with subsequent impaired release of NO together with a local enhanced degradation of NO by increased generation of reactive oxygen species with subsequent cascade of oxidation-sensitive mechanisms in the arterial wall. Many commonly used vasculoprotective agents have their therapeutic actions through the production of NO. L-Arginine, the precursor of NO, has demonstrated beneficial effects in atherosclerosis and disturbed shear stress. Finally, eNOS gene polymorphism might be an additional risk factor that may contribute to predict cardiovascular events. However, further studies are needed to understand the possible clinical implications of these correlations.

Animals↗

Pomegranate juice reduces oxidized low-density lipoprotein downregulation of endothelial nitric oxide synthase in human coronary endothelial cells.

We examined the hypothesis that pomegranate juice (PJ) can revert the potent downregulation of the expression of endothelial nitric-oxide synthase (NOSIII) induced by oxidized low-density liporotein (oxLDL) in human coronary endothelial cells. Western blot and Northern blot analyses showed a significant decrease of NOSIII expression after a 24-h treatment with oxLDL. Accordingly, we observed a significant dose-dependent reduction in nitric oxide bioactivity represented by both basal and bradykinin-stimulated cellular cGMP accumulation. These phenomena were corrected significantly by the concomitant treatment with PJ. Our data suggest that PJ can exert beneficial effects on the evolution of clinical vascular complications, coronary heart disease, and atherogenesis in humans by enhancing the NOSIII bioactivity.

Beverages↗

Beneficial effects of concurrent autologous bone marrow cell therapy and metabolic intervention in ischemia-induced angiogenesis in the mouse hindlimb.

Lower-limb ischemia is a major health problem. Because of the absence of effective treatment in the advanced stages of the disease, amputation is undertaken to alleviate unbearable symptoms. Novel therapeutic approaches include the intramuscular use of autologous bone marrow cells (BMCs). Because tissue ischemia is associated with an overwhelming generation of oxygen radicals and negative effects due to perturbed shear-stress, metabolic intervention with antioxidants and l-arginine could potentially induce beneficial effects beyond those achieved by BMCs. The protective effect of autologous BMCs and vascular protection by metabolic cotreatment (1.0% vitamin E added to the chow and 0.05% vitamin C and 6% l-arginine added to the drinking water) were examined in ischemia-induced angiogenesis in the mouse hindlimb, a model of extensive acute peripheral arterial occlusion. i.v. BMC therapy improved blood flow and increased capillary densities and expression of Ki-67, a proliferation-associated protein. This beneficial effect was amplified by metabolic cotreatment, an intervention inducing vascular protection, at least in part, through the nitric oxide pathway, reduction of systemic oxidative stress, and macrophage activation. Therefore, although a cautious approach is mandatory when experimental findings are extended to human diseases, autologous BMCs together with metabolic intervention could be an effective clinical treatment for peripheral arterial disease.

Animals↗

Glycoxidation of low-density lipoprotein promotes multiple apoptotic pathways and NFkappaB activation in human coronary cells.

Apoptosis of arterial cells induced by oxidized low-density lipoprotein (oxLDL) is thought to contribute to the progression of vascular dysfunction and atherogenesis. It is well established that diabetes mellitus is accompanied by both glycosylation and oxidation LDL, but the biological effects of these modified lipoproteins are poorly understood. We demonstrate here that glycosylated oxLDL (glc-oxLDL) promotes apoptotic signaling in human coronary smooth muscle cells. This was associated by a decrease of the antiapoptotic protein Bcl-2, an increase of the pro-apoptotic protein Bax, and activation of caspase 3. Glc-oxLDL also activated NFK: B and decreased IK: B, these effects were more pronounced than those achieved with oxLDL. Our study shows that glc-oxLDL influences a broad cascade of signaling transduction pathways, which may not only result in apoptosis, but also could affect NFkappaB in human coronary cells. This cascade of events may influence the evolution of atherogenesis and vascular complications in diabetic patients.

Apoptosis↗

Beneficial effects of pomegranate juice on oxidation-sensitive genes and endothelial nitric oxide synthase activity at sites of perturbed shear stress.

Atherosclerosis is enhanced in arterial segments exposed to disturbed flow. Perturbed shear stress increases the expression of oxidation-sensitive responsive genes (such as ELK-1 and p-JUN) in the endothelium. Evidence suggests that polyphenolic antioxidants contained in the juice derived from the pomegranate can contribute to the reduction of oxidative stress and atherogenesis. The aim of the present study was to evaluate the effects of intervention with pomegranate juice (PJ) on oxidation-sensitive genes and endothelial NO synthase (eNOS) expression induced by high shear stress in vitro and in vivo. Cultured human coronary artery endothelial cells (EC) exposed to high shear stress in vitro and hypercholesterolemic mice were used in this study. PJ concentrate reduced the activation of redox-sensitive genes (ELK-1 and p-JUN) and increased eNOS expression (which was decreased by perturbed shear stress) in cultured EC and in atherosclerosis-prone areas of hypercholesterolemic mice. Moreover, oral administration of PJ to hypercholesterolemic mice at various stages of disease reduced significantly the progression of atherosclerosis. This experimental study indicates that the proatherogenic effects induced by perturbed shear stress can be reversed by chronic administration of PJ. This approach may have implications for the prevention or treatment of atherosclerosis and its clinical manifestations.

Analysis of Variance↗

New advances in microarrays: finding the genes causally involved in disease.

Much progress has been made in the technologies available to assess global alterations in mRNA levels in clinical research samples. Although such transcript profiling can provide a powerful research tool, the broad range of options can be bewildering for the inexperienced investigator, and more often than not the limitations and pitfalls of this approach are not fully appreciated. It is important to recognize that the major goal of transcript profiling experiments can be to identify novel therapeutic targets or delineate complex patterns of gene expression that provide a potentially pathognomonic phenotype. Microarrays are therefore potentially powerful tools to address the need for high-throughput analysis techniques, but a careful postanalysis follow-up and validation of microarray experiments will be needed soon (1). A projected decrease in cost and complexity may facilitate increased availability of this technology in the physician's office, and future applications may then allow tailoring of clinical diagnosis and targeted therapeutic strategies.

Arteriosclerosis↗

[Childhood infection and endothelial dysfunction: a potential synergistic link in atherosclerosis].

The prodromal stage of atherosclerotic lesions is already formed during human fetal development. The presence of infections during childhood may increase synergistically the progression of atherogenesis. After delivery, especially those children exposed to severe maternal hypercholesterolemia should be followed up for the onset and development of acute and chronic infections and be included in clinical and noninvasive examinations of vascular function.

Atherosclerosis↗

Deletion of the p66Shc longevity gene reduces systemic and tissue oxidative stress, vascular cell apoptosis, and early atherogenesis in mice fed a high-fat diet.

Several experimental and clinical studies have shown that oxidized low-density lipoprotein and oxidation-sensitive mechanisms are central in the pathogenesis of vascular dysfunction and atherogenesis. Here, we have used p66(Shc-/-) and WT mice to investigate the effects of high-fat diet on both systemic and tissue oxidative stress and the development of early vascular lesions. To date, the p66(Shc-/-) mouse is the unique genetic model of increased resistance to oxidative stress and prolonged life span in mammals. Computer-assisted image analysis revealed that chronic 21% high-fat treatment increased the aortic cumulative early lesion area by approximately 21% in WT mice and only by 3% in p66(Shc-/-) mice. Early lesions from p66(Shc-/-) mice had less content of macrophage-derived foam cells and apoptotic vascular cells, in comparison to the WT. Furthermore, in p66(Shc-/-) mice, but not WT mice, we found a significant reduction of systemic and tissue oxidative stress (assessed by isoprostanes, plasma low-density lipoprotein oxidizability, and the formation of arterial oxidation-specific epitopes). These results support the concept that p66(Shc-/-) may play a pivotal role in controlling systemic oxidative stress and vascular diseases. Therefore, p66(Shc) might represent a molecular target for therapies against vascular diseases.

Adaptor Proteins, Signal Transducing↗

Beneficial effects of antioxidants and L-arginine on oxidation-sensitive gene expression and endothelial NO synthase activity at sites of disturbed shear stress.

Atherogenesis is enhanced in arterial segments exposed to disturbed blood flow, indicating the active participation of the hemodynamic environment in lesion formation. Turbulent shear stress selectively regulates responsive genes in the endothelium and increases the damage induced by free radicals. The purpose of the present study was to evaluate the effects of intervention with antioxidants and l-arginine on endothelial NO synthase (eNOS) and oxidation-sensitive gene perturbation induced by disturbed flow in vitro and in vivo. Both human endothelial cells exposed to shear stress and high atherosclerosis-prone areas of hypercholesterolemic low-density lipoprotein receptor knockout (LDLR(-/-)) mice showed increased activities of redox-transcription factors (ELK-1, p-Jun, and p-CREB) and decreased expression of eNOS. Intervention with antioxidants and l-arginine reduced the activation of redox-transcription factors and increased eNOS expression in cells and in vivo. These results demonstrate that atherogenic effects induced by turbulent shear stress can be prevented by cotreatment with antioxidants and l-arginine. The therapeutic possibility to modulate shear stress-response genes may have important implications for the prevention of atherosclerosis and its clinical manifestations.

Animals↗

Oxidation-sensitive mechanisms, vascular apoptosis and atherosclerosis.

Increased generation of oxidants, resulting from disruption of aerobic metabolism and from respiratory burst, is an essential defense mechanism against pathogens and aberrant cells. However, oxidative stress can also trigger and enhance deregulated apoptosis or programmed cell death, characteristic of atherosclerotic lesions. Oxidation-sensitive mechanisms also modulate cellular signaling pathways that regulate vascular expression of cytokines and growth factors, and influence atherogenesis, in particular when increased levels of plasma lipoproteins provide ample substrate for lipid peroxidation and lead to increased formation of adducts with lipoprotein amino acids. In some cases, increased oxidation and apoptosis in a group of cells might be beneficial for survival and function of other groups of arterial cells. However, overall, oxidation and apoptosis appear to promote the progression of diseased arteries towards a lesion that is vulnerable to rupture, and to give rise to myocardial infarction and ischemic stroke. Recent rapid advances in our understanding of the interactions between oxidative stress, apoptosis and arterial gene regulation suggest that selective interventions targeting these biological functions have great therapeutic potential.

Apoptosis↗