The protective effect of bergamot oil extract on lecitine-like oxyLDL receptor-1 expression in balloon injury-related neointima formation.

Lectin-like oxyLDL receptor-1 (LOX-1) has recently been suggested to be involved in smooth muscle cell (SMC) proliferation and neointima formation in injured blood vessels. This study evaluates the effect of the nonvolatile fraction (NVF), the antioxidant component of bergamot essential oil (BEO), on LOX-1 expression and free radical generation in a model of rat angioplasty. Common carotid arteries injured by balloon angioplasty were removed after 14 days for histopathological, biochemical, and immunohistochemical studies. Balloon injury led to a significant restenosis with SMC proliferation and neointima formation, accompanied by increased expression of LOX-1 receptor, malondialdehyde and superoxide formation, and nitrotyrosine staining. Pretreatment of rats with BEO-NVF reduced the neointima proliferation together with free radical formation and LOX-1 expression in a dose-dependent manner. These results suggest that natural antioxidants may be relevant in the treatment of vascular disorders in which proliferation of SMCs and oxyLDL-related endothelial cell dysfunction are involved

Cholesterol as an Endogenous ERRα Agonist: A New Perspective to Cancer Treatment

The estrogen-related receptors (ERRs) are important members of nuclear receptors which contain three isoforms (α, β, and γ). ERRα is the best-characterized isoform expressed mainly in high-energy demanding tissues where it preferentially works in association with the peroxisome proliferator-activated receptor-γ co-activator 1α (PGC-1α) and PGC-1β. ERRα together with its cofactors modulates cellular metabolism, supports the growth of rapidly dividing cells, directs metabolic programs required for cell differentiation and maintains cellular energy homeostasis in differentiated cells. In cancer cells, the functional association between ERRα and PGC-1s is further influenced by oncogenic signals and induces metabolic programs favoring cell growth and proliferation as well as tumor progression. Recently, cholesterol has been identified as a natural ERRα ligand using a combined biochemical strategy. This new finding highlighted some important physiological aspects related to the use of cholesterol-lowering drugs such as statins and bisphosphonates. Even more meaningful is the link between increased cholesterol levels and certain cancer phenotypes characterized by an overexpressed ERRα such as mammary, prostatic, and colorectal cancers, where the metabolic adaptation affects many cancer processes. Moreover, high-energy demanding cancer-related processes are strictly related to the cross-talk between tumor cells and some key players of tumor microenvironment, such as tumor-associated macrophage that fuels cancer progression. Some evidence suggests that high cholesterol content and ERRα activity favor the inflammatory environment by the production of different cytokines. In this review, starting from the most recent observations on the physiological role of the new signaling activated by the natural ligand of ERRα, we propose a new hypothesis on the suitability to control cholesterol levels as a chance in modulating ERRα activity in those tumors in which its expression and activity are increased

Statins reduce intratumor cholesterol affecting adrenocortical cancer growth

Mitotane causes hypercholesterolemia in ACC patients. We suppose that cholesterol increases within the tumor and can be used to activate proliferative pathways. In this study, we used statins to decrease intratumor cholesterol and investigated the effects on ACC growth related to ER\u3b1 action at the nuclear and mitochondrial levels. We first used microarray to investigate mitotane effect on genes involved in cholesterol homeostasis and evaluated their relationship with patients' survival in ACC TCGA. We then blocked cholesterol synthesis with simvastatin and determined the effects on H295R cell proliferation, estradiol production and ER\u3b1 activity in vitro and in xenograft tumors. We found that mitotane increases intratumor cholesterol content and expression of genes involved in cholesterol homeostasis, among them INSIG, whose expression affects patients' survival. Treatment of H295R cells with simvastatin to block cholesterol synthesis decreased cellular cholesterol content and this affected cell viability. Simvastatin reduced estradiol production and decreased nuclear and mitochondrial ER\u3b1 function. A mitochondrial target of ER\u3b1, the respiratory complex IV (COX IV) was reduced after simvastatin treatment, which profoundly affected mitochondrial respiration activating apoptosis. In vivo experiments confirmed the ability of simvastatin to reduce tumor volume and weight of grafted H295R cells, intratumor cholesterol content, Ki-67 and ER\u3b1, COX IV expression and activity and increase TUNEL positive cells. Collectively these data demonstrate that a reduction in intratumor cholesterol content prevents estradiol production, inhibits mitochondrial respiratory chain inducing apoptosis in ACC cells. Inhibition of mitochondrial respiration by simvastatin represents a novel strategy to counteract ACC growth

Healing of surgical site after total hip and knee replacements show similar telethermographic patterns

BACKGROUND: Isolated reports indicate the efficacy of infrared thermography for monitoring wound healing and septic complications, but no long-term analysis has ever been performed on this, and there are no data on the telethermographic patterns of surgical site healing after uncomplicated total hip prosthesis and after knee prosthesis. MATERIALS AND METHODS: In this prospective, observational, nonrandomized cohort study, two groups with forty consecutive patients each, who were operated on respectively for total hip and for total knee replacements, underwent telethermographic examination of the operated and contralateral joints prior to and at fixed intervals for up to 1\ua0year after uncomplicated surgery. A digital, portable telethermocamera and dedicated software were used for data acquisition and processing. RESULTS: No thermographic difference was observed preoperatively between the affected side and the contralateral side in both groups. After the intervention, a steep increase in the temperature of the operated joint was recorded after total hip replacement and after knee replacement, with a peak mean differential temperature measured three days postoperatively between the operated and unoperated joint of 3.1\ua0\ub1\ua00.8\ub0C after total hip replacement, and 3.4\ua0\ub1\ua00.7\ub0C after total knee replacement. Thereafter, the mean differential temperature declined slowly to 0.7\ua0\ub1\ua01.1\ub0C and to 0.5\ua0\ub1\ua01.3\ub0C at 60\ua0days, and to 0.0\ua0\ub1\ua01.0\ub0C and -0.1\ua0\ub1\ua01.1\ub0C 90\ua0days post-operatively, respectively. No further changes were observed for up to 1\ua0year after surgery. Results were similar when comparing the average telethermographic values of an elliptical area where the main axis corresponded to the surgical wound. CONCLUSIONS: The surgical sites after uncomplicated total hip or total knee replacement show similar telethermographic patterns for up to 1\ua0year from surgery, and can easily be monitored using a portable, digital, telethermocamera

Effetti dello stress ossidativo sulla tolleranza ai nitroderivati

Nel secolo scorso, la nitroglicerina è stato il farmaco più comunemente usato come agente antiischemico ed antianginoso. La sua continua somministrazione, però, ne fa svanire piuttosto rapidamente l’efficacia terapeutica. L’attivazione neuroormonale dei segnali vasocostrittori e l’espansione del volume intravascolare costituiscono le iniziali risposte contro-regolatorie (pseudotelleranza), mentre il trattamento a lungo termine induce cambiamenti vascolari intrinseci, come per esempio la perdita delle risposte nitrovasodilatatorie (tolleranza vascolare). Tutto ciò è causato da un’incrementata produzione di anione superossido e da una ipersensibilità verso vasocostrittori secondari per una tonica attivazione della PKC. Come fonti di anione superossido sono state proposte la NADPH ossidasi e la eNOS disaccoppiata. Il superossido ed il nitrossido vascolare formano rapidamente perossinitrito, che aumenta la tolleranza promuovendo il disaccoppiamento della eNOS e l’inibizione della guanilato ciclasi solubile e della prostaciclina. Questo concetto di stress ossidtivo può spiegare perché gli scavangers dei radicali e le sostanze che riducono indirettamente lo stress ossidativo, sono capaci di attenuare la tolleranza e la disfunzione endoteliale. Un lavoro recente ha definito un nuovo meccanismo di tolleranza basato sull’inibizione dell’ALDH-2, l’enzima deputato alla bioconversione enzimatica del GTN in NO, ed ha identificato i mitocondri come una fonte addizionale di specie reattive dell’ossigeno (ROS). Le specie reattive indotte dal GTN inibiscono la 6 bioattivazione della nitroglicerina medinte l’ossidazione tiolica dell’ALDH-2. Sia l’increnmento dello stress ossidativo che l’alterazione della bioconversione del GTN in NO, possono fornire un nuovo concetto di tolleranza ai nitrati nonché di cross-tolerance. Nel presente lavoro abbiamo documentato che la somministrazione a lungo termine di IS-5-MN in vitro ed in vivo induce tolleranza al GTN (definita cross-tolerance). Si sono altresì studiati gli effetti di CPT, ENA e NAC sulle risposte in vivo al GTN dopo trattamento cronico dei ratti con IS-5-MN e sono stati paragonati gli effetti di CPT, ENA o glutatione con quelli della NAC sugli effetti antipiastrinici del GTN in assenza o in presenza di TSMCs e TECs e sulla produzione di perossinitrito da GTN in un Krebs buffer. Per finire, sono stati valutate le risposte emodinamiche al GTN in ratti tolleranti e non, in presenza ed in assenza di co-trattamento con MnTBAP (1, 20 mg/kg/die, i.p.). Il presente studio, nel tentativo di chiarire i meccanismi molecolari che sottendono alla tolleranza ai nitrati, ha incentrato l’attenzione sul ruolo, che in tale fenomeno hanno, enzimi essenziali, quali la SOD e l’ALDH-2, i quali risultano, rispettivamente, down-regulated ed inattivata dal fenomeno della tolleranza. Il MnTBAP, un SOD-mimic di ultima generazione, si è rivelato in grado di inibire lo sviluppo di tolleranza ai nitrati organici in maniera dose-dipendente, ripristinando l’effetto del GTN sulla pressione sanguigna e sull’ggregazione piastrinica, riducendo la formazione di perossinitrito, come dimostrato dallo staining della nitrotirosina ed antagonizzando l’inibizione dell’ALDH-2 indotta dallo stress ossidativo. La formazione di perossinitrito gioca un ruolo 7 cruciale durante lo sviluppo di tolleranza ai nitroderivati in quanto riduce la biodisponibilità di NO. Quindi, quanto riportato nel nostro studio potrebbe aprire una nuova frontiera nel management delle malattie cardiovascolari, consentendo l’uso a lungo termine dei nitrati organici, senza che si sviluppi tolleranza.During the last century, nitroglycerin has been the most commonly used antiischemic and antianginal agent. Unfortunately, after continuous application, its therapeutic efficacy rapidly vanishes. Neurohormonal activation of vasoconstrictor signals and intravascular volume expansion constitute early counter-regulatory responses (pseudotolerance), whereas long-term treatment induces intrinsic vascular changes, eg, a loss of nitrovasodilatorresponsiveness (vascular tolerance). This is caused by increased vascular superoxide production and a supersensitivity to vasoconstrictors secondary to a tonic activation of protein kinase C. NADPH oxidase(s) and uncoupled endothelial nitric oxide synthase have been proposed as superoxide sources. Superoxide and vascular NO rapidly form peroxynitrite, which aggravates tolerance by promoting NO synthase uncoupling and inhibition of soluble guanylyl cyclase and prostacyclin synthase. This oxidative stress concept may explain why radical scavengers and substances, which reduce oxidative stress indirectly, are able to relieve tolerance and endothelial dysfunction. Recent work has defined a new tolerance mechanism, ie, an inhibition of mitochondrial aldehyde dehydrogenase, the enzyme that accomplishes bioactivation of nitroglycerin, and has identified mitochondria as an additional source of reactive oxygen species. Nitroglycerin-induced reactive oxygen species inhibit the bioactivation of nitroglycerin by thiol oxidation of aldehyde dehydrogenase. Both mechanisms, increased oxidative 3 stress and impaired bioactivation of nitroglycerin, can be joined to provide a new concept for nitroglycerin tolerance and crosstolerance. In this work we have demonstrate that long-term administration of isosorbide-5-mononitrate in vitro ed in vivo induces tolerance to GTN (this is the so-called cross-tolerance). Here we have studied the effects of CPT, NAC or ENA on the in vivo responses to GTN after long-term treatment of rats with IS-5-MN. In addition, we have compared the effects of CPT, ENA or glutathione to those of NAC on the anti-platelet effects of GTN in the absence or presence of tolerant cultured SMCs or ECs and on production from GTN in Krebs buffer. Finally, we have valuated the haemodynamic responses to glyceryl trinitrate in non-tolerant rats and in tolerant rats with or without pharmacological co- treatment with MnTBAP (1-20 mg/kg, i.p.). The present study was designed to elucidate the mechanisms of nitrate tolerance by assessing the function of essential enzymes implicated in this phenomenon. We demonstrated that SOD and ALDH-2 are downregulated and inactivated, respectly, during nitrate-tolerance. MnTBAP, a new generation antioxidant, is able to inhibit the development of tolerance to organic nitrates in a dose dependent fashion restoring the GTN effect on blood pressure and on platelets aggregation and reducing the peroxynitrite formation as evaluated by the inhibition of the nitrotyrosine staining and antagonizing the ALDH-2 inhibition oxidative stress-induced. Peroxynitrite formation play a crucial role during the development of tolerance to organic nitrates most likely via reduction of nitric oxide bioavalaibility. The broader implications 4 of these findings may open a new frontier in the clinical management of cardiovascular disease, in particular allowing the use of long-term organic nitrates treatment without development of tolerance

Effetti dello stress ossidativo sulla tolleranza ai nitroderivati

Nel secolo scorso, la nitroglicerina è stato il farmaco più comunemente usato come agente antiischemico ed antianginoso. La sua continua somministrazione, però, ne fa svanire piuttosto rapidamente l’efficacia terapeutica. L’attivazione neuroormonale dei segnali vasocostrittori e l’espansione del volume intravascolare costituiscono le iniziali risposte contro-regolatorie (pseudotelleranza), mentre il trattamento a lungo termine induce cambiamenti vascolari intrinseci, come per esempio la perdita delle risposte nitrovasodilatatorie (tolleranza vascolare). Tutto ciò è causato da un’incrementata produzione di anione superossido e da una ipersensibilità verso vasocostrittori secondari per una tonica attivazione della PKC. Come fonti di anione superossido sono state proposte la NADPH ossidasi e la eNOS disaccoppiata. Il superossido ed il nitrossido vascolare formano rapidamente perossinitrito, che aumenta la tolleranza promuovendo il disaccoppiamento della eNOS e l’inibizione della guanilato ciclasi solubile e della prostaciclina. Questo concetto di stress ossidtivo può spiegare perché gli scavangers dei radicali e le sostanze che riducono indirettamente lo stress ossidativo, sono capaci di attenuare la tolleranza e la disfunzione endoteliale. Un lavoro recente ha definito un nuovo meccanismo di tolleranza basato sull’inibizione dell’ALDH-2, l’enzima deputato alla bioconversione enzimatica del GTN in NO, ed ha identificato i mitocondri come una fonte addizionale di specie reattive dell’ossigeno (ROS). Le specie reattive indotte dal GTN inibiscono la 6 bioattivazione della nitroglicerina medinte l’ossidazione tiolica dell’ALDH-2. Sia l’increnmento dello stress ossidativo che l’alterazione della bioconversione del GTN in NO, possono fornire un nuovo concetto di tolleranza ai nitrati nonché di cross-tolerance. Nel presente lavoro abbiamo documentato che la somministrazione a lungo termine di IS-5-MN in vitro ed in vivo induce tolleranza al GTN (definita cross-tolerance). Si sono altresì studiati gli effetti di CPT, ENA e NAC sulle risposte in vivo al GTN dopo trattamento cronico dei ratti con IS-5-MN e sono stati paragonati gli effetti di CPT, ENA o glutatione con quelli della NAC sugli effetti antipiastrinici del GTN in assenza o in presenza di TSMCs e TECs e sulla produzione di perossinitrito da GTN in un Krebs buffer. Per finire, sono stati valutate le risposte emodinamiche al GTN in ratti tolleranti e non, in presenza ed in assenza di co-trattamento con MnTBAP (1, 20 mg/kg/die, i.p.). Il presente studio, nel tentativo di chiarire i meccanismi molecolari che sottendono alla tolleranza ai nitrati, ha incentrato l’attenzione sul ruolo, che in tale fenomeno hanno, enzimi essenziali, quali la SOD e l’ALDH-2, i quali risultano, rispettivamente, down-regulated ed inattivata dal fenomeno della tolleranza. Il MnTBAP, un SOD-mimic di ultima generazione, si è rivelato in grado di inibire lo sviluppo di tolleranza ai nitrati organici in maniera dose-dipendente, ripristinando l’effetto del GTN sulla pressione sanguigna e sull’ggregazione piastrinica, riducendo la formazione di perossinitrito, come dimostrato dallo staining della nitrotirosina ed antagonizzando l’inibizione dell’ALDH-2 indotta dallo stress ossidativo. La formazione di perossinitrito gioca un ruolo 7 cruciale durante lo sviluppo di tolleranza ai nitroderivati in quanto riduce la biodisponibilità di NO. Quindi, quanto riportato nel nostro studio potrebbe aprire una nuova frontiera nel management delle malattie cardiovascolari, consentendo l’uso a lungo termine dei nitrati organici, senza che si sviluppi tolleranza.During the last century, nitroglycerin has been the most commonly used antiischemic and antianginal agent. Unfortunately, after continuous application, its therapeutic efficacy rapidly vanishes. Neurohormonal activation of vasoconstrictor signals and intravascular volume expansion constitute early counter-regulatory responses (pseudotolerance), whereas long-term treatment induces intrinsic vascular changes, eg, a loss of nitrovasodilatorresponsiveness (vascular tolerance). This is caused by increased vascular superoxide production and a supersensitivity to vasoconstrictors secondary to a tonic activation of protein kinase C. NADPH oxidase(s) and uncoupled endothelial nitric oxide synthase have been proposed as superoxide sources. Superoxide and vascular NO rapidly form peroxynitrite, which aggravates tolerance by promoting NO synthase uncoupling and inhibition of soluble guanylyl cyclase and prostacyclin synthase. This oxidative stress concept may explain why radical scavengers and substances, which reduce oxidative stress indirectly, are able to relieve tolerance and endothelial dysfunction. Recent work has defined a new tolerance mechanism, ie, an inhibition of mitochondrial aldehyde dehydrogenase, the enzyme that accomplishes bioactivation of nitroglycerin, and has identified mitochondria as an additional source of reactive oxygen species. Nitroglycerin-induced reactive oxygen species inhibit the bioactivation of nitroglycerin by thiol oxidation of aldehyde dehydrogenase. Both mechanisms, increased oxidative 3 stress and impaired bioactivation of nitroglycerin, can be joined to provide a new concept for nitroglycerin tolerance and crosstolerance. In this work we have demonstrate that long-term administration of isosorbide-5-mononitrate in vitro ed in vivo induces tolerance to GTN (this is the so-called cross-tolerance). Here we have studied the effects of CPT, NAC or ENA on the in vivo responses to GTN after long-term treatment of rats with IS-5-MN. In addition, we have compared the effects of CPT, ENA or glutathione to those of NAC on the anti-platelet effects of GTN in the absence or presence of tolerant cultured SMCs or ECs and on production from GTN in Krebs buffer. Finally, we have valuated the haemodynamic responses to glyceryl trinitrate in non-tolerant rats and in tolerant rats with or without pharmacological co- treatment with MnTBAP (1-20 mg/kg, i.p.). The present study was designed to elucidate the mechanisms of nitrate tolerance by assessing the function of essential enzymes implicated in this phenomenon. We demonstrated that SOD and ALDH-2 are downregulated and inactivated, respectly, during nitrate-tolerance. MnTBAP, a new generation antioxidant, is able to inhibit the development of tolerance to organic nitrates in a dose dependent fashion restoring the GTN effect on blood pressure and on platelets aggregation and reducing the peroxynitrite formation as evaluated by the inhibition of the nitrotyrosine staining and antagonizing the ALDH-2 inhibition oxidative stress-induced. Peroxynitrite formation play a crucial role during the development of tolerance to organic nitrates most likely via reduction of nitric oxide bioavalaibility. The broader implications 4 of these findings may open a new frontier in the clinical management of cardiovascular disease, in particular allowing the use of long-term organic nitrates treatment without development of tolerance

N-acetylcysteine prevents HIV gp 120-related damage of human cultured astrocytes: correlation with glutamine synthase dysfunction

<p>Abstract</p> <p>Background</p> <p>HIV envelope gp 120 glycoprotein is released during active HIV infection of brain macrophages thereby generating inflammation and oxidative stress which contribute to the development of the AIDS-Dementia Complex (ADC). Gp120 has also been found capable to generate excitotoxic effect on brain tissue via enhancement of glutamatergic neurotransmission, leading to neuronal and astroglial damage, though the mechanism is still to be better understood.</p> <p>Here we investigated on the effect of N-acetylcysteine (NAC), on gp120-induced damage in human cultured astroglial cells and the possible contribution of gp120-related reacting oxygen species (ROS) in the imbalanced activity of glutamine synthase (GS), the enzyme that metabolizes glutamate into glutamine within astroglial cells playing a neuroprotective role in brain disorders.</p> <p>Results</p> <p>Incubation of Lipari human cultured astroglial cells with gp 120 (0.1–10 nM) produced a significant reduction of astroglial cell viability and apoptosis as evaluated by TUNEL reaction and flow cytometric analysis (FACS). This effect was accompanied by lipid peroxidation as detected by means of malondialdehyde assay (MDA). In addition, gp 120 reduced both glutamine concentration in astroglial cell supernatants and GS expression as detected by immunocytochemistry and western blotting analysis. Pre-treatment of cells with NAC (0.5–5 mM), dose-dependently antagonised astroglial apoptotic cell death induced by gp 120, an effect accompanied by significant attenuation of MDA accumulation. Furthermore, both effects were closely associated with a significant recovery of glutamine levels in cell supernatants and by GS expression, thus suggesting that overproduction of free radicals might contribute in gp 120-related dysfunction of GS in astroglial cells.</p> <p>Conclusion</p> <p>In conclusion, the present experiments demonstrate that gp 120 is toxic to astroglial cells, an effect accompanied by lipid peroxidation and by altered glutamine release. All the effects of gp120 on astroglial cells were counteracted by NAC thus suggesting a novel and potentially useful approach in the treatment of glutammatergic disorders found in HAD patients.</p

Dietary Intervention during Weaning and Development of Food Allergy: What Is the State of the Art?

Food allergy (FA) affects approximately 6–8% of children worldwide causing a significant impact on the quality of life of children and their families. In past years, the possible role of weaning in the development of FA has been studied. According to recent studies, this is still controversial and influenced by several factors, such as the type of food, the age at food introduction and family history. In this narrative review, we aimed to collect the most recent evidence about weaning and its role in FA development, organizing the gathered data based on both the type of study and the food. As shown in most of the studies included in this review, early food introduction did not show a potential protective role against FA development, and we conclude that further evidence is needed from future clinical trials