| Name | Maria Luisa |
| Surname | Balestrieri |
| Institution | Università degli Studi della Campania Luigi Vanvitelli |
| marialuisa.balestrieri@unicampania.it | |
| Address | Department of Biochemistry, Biophysics and General Pathology, University of Campania "L. Vanvitelli", Via L. De Crecchio 7, 80138 Naples, Italy |
| Resume | Download |
Peripheral arterial disease (PAD) is a major health problem especially when associated to concomitant diabetes and hypercholesterolemia. Hyperglycemia with an overwhelming generation of oxygen radicals and formation of glycation end-products exacerbates oxidation-sensitive mechanisms activated by tissue ischemia. Administration of autologous bone marrow cells (BMC) is an increasing notable intervention to induce therapeutic angiogenesis, ameliorated by metabolic intervention (MT). Recently, hemangioblasts (HS) with functional properties were isolated.
Betulinic acid (BA) is a naturally occurring lupane-type triterpene which exhibits a variety of biological activities including potent cytotoxic properties. On the basis of the structural similarity to BA, two lupane derivatives namely lup-20(29)-ene-3beta,30-diol (1) and lup-20(29)-ene-3beta,28-diol (2), along with two friedelane derivatives, namely friedelan-3-one (3) and friedelan-3beta-ol (4), isolated from the Brazilian plant Maytenus rigida, have been evaluated for their anti-proliferative effect. Similarly to BA, compounds 1 and 3 at 1 microM concentration significantly inhibited the VEGF-induced Kaposi's sarcoma (KS) cell proliferation by 50%. In contrast, this effect was not found in control endothelial cells (EC). Moreover, compounds 1 and 3 showed a dose-dependent effect on the apoptotic cell death, as detected by FACS analysis and caspase-3 assay. Specifically, at 10 microM concentration, apoptosis was significantly induced (from 45% to 55% of hypodiploid cells vs control cells) and showed the same potency order observed for the anti-proliferative effect at 1 microM, i.e., compound 3>BA>compound 1. Taking into account the interest given rise by BA as anticancer agent, the comparable anti-proliferative activity shown by compounds 1 and 3 and BA, can give an impulse to further investigate lupane and friedelane derivatives as cytotoxic agents.
Short-term (within 6 weeks follow-up) clinical studies indicate that implantation of bone marrow cells (BMCs) into ischemic limbs may improve peripheral ischemia. Here, the long-term safety and feasibility of intraarterial autologous BMCs with oral treatment with antioxidants and L-arginine were investigated in patients with critical ischemia on account of advanced atherosclerotic peripheral arterial disease (PAD).
The custom microenvironment 'vascular niche' is a potential therapeutic target for several pathophysiological conditions. Osteoblasts regulate the hematopoietic stem cell niche, and activation of the parathyroid hormone (PTH) receptor can increase the number of cells mobilized into the bloodstream.
To date, there is no report on the effect of antioxidants on endothelial progenitor cells (EPCs). This study shows that in vitro incubation of EPCs with vitamin C and E reverted the already well documented lowering effect of TNF-alpha on EPC number and increased p-p38 expression levels. In order to document major changes of gene expression levels and gain insight into signalling pathways, microarray analysis was performed and a significant variation of the expression of 5389 genes in EPCs following antioxidant treatment was detected. Also in vivo evidence is provided about the positive effect of antioxidant vitamins on EPCs, since vitamin C and E supplementation potentiated the physical training-induced increase of EPC number and VEGF levels. Together, these data indicate that antioxidant treatment ameliorates EPC number and causes major changes of gene expression within these cells in vitro. Furthermore, concomitant antioxidant supplementation and physical training in vivo raised the levels of circulating EPCs and serum VEGF more than physical training alone.
Nitric oxide (NO) exerts a plethora of vascular beneficial effects. The NO-releasing beta-blocker nebivolol is a racemic mixture of D/L-enantiomers that displays negative inotropic as well as direct vasodilating activity. The in vivo antiatherogenic activity of therapeutic doses of the beta-blocker with antioxidant properties carvedilol (12.5mg/day) or nebivolol (5mg/day) was tested in cholesterol-fed rabbits. Animals received a 1% cholesterol-rich diet alone (controls) or mixed with drugs (treated animals) for 8 weeks. While it did not affect hyperlipidemia, nebivolol inhibited the development of atherosclerosis, expressed as computer-assisted imaging analysis of aortic area covered by lesions (23.3+/-4.1% in treated vs 38.2+/-6.4% in control animals, p<0.01). Differently, in our experimental condition of therapeutic drug doses, this antiatherogenic effect did not reach statistical significance in rabbits treated with carvedilol (32.5+/-5.1% aortic area covered by lesions, p=NS vs controls). Plasma nitrates increased in rabbits treated with nebivolol while both beta-blockers reduced LDL oxidation. Moreover, nebivolol induced a consistent increase of endothelial reactivity and aortic eNOS expression compared with control animals (p<0.05) and those receiving carvedilol (p<0.05). Since NO may exert beneficial effects in atherosclerosis, a NO-dependent mechanism could explain this data. These observations suggest that the NO-releasing beta-blocker, nebivolol, might represent an effective pharmacological approach for preventing atherosclerotic lesion progression.
Alteration of levels and functional activities of circulating endothelial progenitor cells (EPCs) induced by risk factors for coronary heart disease (CHD) profoundly influence their role in the regeneration of tissue ischemia and angiogenesis. Among antioxidant nutrients in the prevention of CHD, L-arginine is particularly effective in enhancing the protection afforded by moderate physical exercise. Here, we aimed to evaluate the effects of L-arginine on EPC levels in C57BL/6J mice subjected to moderate physical exercise. Results showed that supplementation with L-arginine potentiates the effects of moderate physical exercise by increasing significantly EPCs (P<0.001) and VEGF serum levels (P<0.001). Our report highlights the beneficial effect of l-arginine in the modulation of EPC levels and VEGF secretion.
Increasing evidence indicates that mammalian SIRT1 mediates calorie restriction and influences lifespan regulating a number of biological molecules such as FoxO1. SIRT1 controls the angiogenic activity of endothelial cells via deacetylation of FoxO1. Endothelial dysfunction and reduced new blood vessel growth in diabetes involve a decreased bioactivity of endothelial progenitor cells (EPCs) via repression of FoxO1 transcriptional activity. The relative contribution of SIRT1 with respect to the direct effects of high glucose on EPC number is poorly understood. We report that treatment of EPCs with high glucose for 3 days determined a consistent downregulation of EPC positive to DiLDL/lectin staining and, interestingly, this was associated with reduced SIRT1 expression levels and enzyme activity, and increased acetyl-FoxO1 expression levels. Moreover, EPCs responded to high glucose with major changes in the expression levels of cell metabolism-, cell cycle-, and oxidative stress-related genes or proteins. Proteomic analysis shows increased expression of nicotinamide phosphoribosyl transferase and mitochondrial superoxide dismutase whereas a glucose-related heat shock protein is reduced. These findings show that SIRT1 is a critical modulator of EPCs dysfunction during alteration of glucose metabolism.
Circulating endothelial progenitor cells (EPCs) play a significant role in regeneration of damaged blood vessels. Levels and functional activities of EPCs are noticeable altered by risk factors for coronary heart disease (CHD) and compounds that can prevent or ameliorate EPC dysfunction are currently of special clinical interest. Here, we evaluate the effects of red wine (RW) on EPCs in C57BL/6J mice subjected to physical exercise. FACS computed counting showed a significant increase of EPC number (P<0.05) in mice after short-term supplementation with RW. VEGF serum concentration was significantly increased by physical training in the presence or absence of RW supplementation (P<0.001). These in vivo observations support previous in vitro observation of the beneficial effect of RW in the modulation of EPC levels.
Chemokines, originally discovered as mediators of directional migration of immune cells to sites of inflammation and injury, have a function beyond their role in leukocyte chemotaxis. Indeed, they participate in organ development, angiogenesis, tumourigenesis and, more importantly, in the immune response. The chemokine family characterized by four highly conserved cysteine amino acid residues, with two cysteine residues (C) and a non-cysteine amino acid (X) between them (CXC), is known for its ability to promote trafficking of various leukocytes and to regulate angiogenesis and vascular remodelling. Intriguingly, the presence or absence of a structural-functional domain constituted by glutamic acid-leucine-arginine motif that precedes the first cysteine amino acid residue accounts for their unique property to induce or inhibit angiogenesis (angiogenic or angiostatic activity). The ability of CXC chemokine receptor 3 to promote Th1-dependent immunity and, at the same time, inhibit angiogenesis (immunoangiostasis) is of critical importance for inducing tumour regression. Agents that are able to inhibit angiogenic activities or promote angiostatic activities of CXC chemokines are future targets for research on cancer treatment. Here, we review insights on CXC chemokines in the context of immunoangiostasis and vascular damage.