Endothelial heme oxygenase-1 induction by hypoxia. Modulation by inducible nitric-oxide synthase and S-nitrosothiols.

The stress protein heme oxygenase-1 (HO-1) is induced in endothelial cells exposed to nitric oxide (NO)-releasing agents, and this process is finely modulated by thiols (Foresti, R., Clark, J. E., Green, C. J., and Motterlini R. (1997) J. Biol. Chem. 272, 18411–18417). Here, we report that up-regulation of HO-1 in aortic endothelial cells by severe hypoxic conditions (pO2 ≤ 2 mm Hg) is preceded by increased inducible NO synthase and NO synthase activity. This effect is accompanied by oxidation of intracellular glutathione and formation of S-nitrosothiols. Incubation of cells with a selective inhibitor of inducible NO synthase (S-(2-aminoethyl)-isothiourea) or a NO scavenger ([2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide]) significantly attenuated the increase in heme oxygenase activity caused by reduced oxygen availability. A series of antioxidant agents did not prevent the elevation in heme oxygenase activity by hypoxia; however, the precursor of glutathione synthesis and thiol donor,N-acetylcysteine, completely abolished HO-1 induction. We also found that the hypoxia-mediated increase in endothelial heme oxygenase activity was potentiated by the presence ofS-nitrosoglutathione. These results indicate that intracellular interaction of thiols with NO is an important determinant in the mechanism leading to HO-1 induction by reduced oxygen levels. We suggest that in addition to oxidative stress, HO-1 gene expression can be regulated by redox reactions involving NO andS-nitrosothiols (nitrosative stress), emphasizing a versatile role for the heme oxygenase pathway in the cellular adaptation to a variety of stressful conditions

Vasorelaxing effects and inhibition of nitric oxide in macrophages by new iron-containing carbon monoxide-releasing molecules (CO-RMs)

Carbon monoxide-releasing molecules (CO-RMs) are a class of organometallo carbonyl complexes capable of delivering controlled quantities of CO gas to cells and tissues thus exerting a broad spectrum of pharmacological effects. Here we report on the chemical synthesis, CO releasing properties, cytotoxicity profile and pharmacological activities of four novel structurally related iron-allyl carbonyls. The major difference among the new CO-RMs tested was that three compounds (CORM-307, CORM-308 and CORM-314) were soluble in dimethylsulfoxide (DMSO), whereas a fourth one (CORM-319) was rendered water-soluble by reacting the iron-carbonyl with hydrogen tetrafluoroborate. We found that despite the fact all compounds liberated CO, CO-RMs soluble in DMSO caused a more pronounced toxic effect both in vascular and inflammatory cells as well as in isolated vessels. More specifically, iron carbonyls

Susceptibility of corn to stink bug (\u3ci\u3eDichelops melacanthus\u3c/i\u3e) and its management through seed treatment

We determined the susceptibility of vegetative corn stages to Dichelops melacanthus damage, and how seed treatment can reduce damage and yield loss. Two field trials were carried out. In the first, corn plants were artificially infested with D. melacanthus male/female pairs at rate of 0.5 pair per plant at different vegetative stages and infestation periods lasting 7-28 days (V1-V3, V1-V5, V1-V7, V1-V9, V3-V5, V3-V7, V3-V9, V5-V7, V5-V9, and V7-V9), plus a control without infestation. In the second, corn plants were artificially infested at a rate of one male/female pair per plant at different vegetative stages and infestation periods (V1-V3, V1-V5, V1-V7, V3-V5, V3-V7 and V5-V7) and treated with two pesticide seed coatings: (i) fungicide [carbendazim + thiram (150 g i.a. per L and 350 g i.a. per L)] + insecticide [clothianidin (600 g i.a. per L)] or (ii) only fungicide (carbendazim + thiram), plus three controls without infestation and with only fungicide-treatment (V1-V7, V3-V7 and V5-V7). In both trials, plants were caged during the entire period in order to hold stink bugs in contact with plants and to avoid injury from other arthropods. The most stink bug susceptible corn growth periods were from V1-V5 and from V1-V7. Seed treatment with clothianidin at the rate of 3.5 mL per Kg during the most susceptible infestation periods increased yield gain of 37.8 to 61%. Treatment with clothianidin during V1-V5 and V1-V7 caused 40% to 50% D. melacanthus adult mortality, respectively

Differential antibacterial activity against Pseudomonas aeruginosa by carbon monoxide-releasing molecules.

International audienceAIMS: Carbon monoxide (CO) delivered in a controlled manner to cells and organisms mediates a variety of pharmacological effects to the extent that CO-releasing molecules (CO-RMs) are being developed for therapeutic purposes. Recently, ruthenium-based CO-RMs have been shown to posses important bactericidal activity. Here we assessed the effect of fast CO releasers containing ruthenium (Ru(CO)(3)Cl(glycinate) [CORM-3] and tricarbonyldichlororuthenium(II) dimer [CORM-2]) and a novel slow manganese-based CO releaser ([Me(4)N][Mn(CO)(4)(thioacetate)(2)] [CORM-371]) on O(2) consumption and growth of Pseudomonas aeruginosa (PAO1). We then compared these effects with the action elicited by sodium boranocarbonate (CORM-A1), which lacks a transition metal but liberates CO with a rate similar to CORM-371. RESULTS: CORM-2, CORM-3, and, to a lesser extent, CORM-371 exerted a significant bactericidal effect and decreased O(2) consumption in PAO1 in vitro. The effect appeared to be independent of reactive oxygen species production, but in the case of metal-containing compounds it was prevented by the thiol donor N-acetylcysteine. In contrast, CORM-A1 was bacteriostatic rather than bactericidal in vitro eliciting only a moderate and transient decrease in O(2) consumption. INNOVATION: None of the tested CO-RMs was toxic to murine macrophages or human fibroblasts at the concentration impairing PA01 growth but only ruthenium-containing CO-RMs showed potential therapeutic properties by increasing the survival of mice infected with PA01. CONCLUSION: CO carriers inhibit bacterial growth and O(2) consumption in vitro, but transition metal carbonyls appear more powerful than compounds spontaneously liberating CO. The nature of the metal in CO-RMs also modulates the anti-bacterial effect, with ruthenium-based CO-RMs being efficacious both in vitro and in vivo

Bioactive properties of iron-containing carbon monoxide-releasing molecules

Carbon monoxide-releasing molecules (CO-RMs) are compounds capable of delivering controlled amounts of CO within a cellular environment. Ruthenium-based carbonyls [tricarbonyldichloro ruthenium(II) dimer and tricarbonylchloro-(glycinato)ruthenium(II)] and boronacorbonates (sodium boranocarbonate) have been shown to promote vasodilatory, cardioprotective, and anti-inflammatory activities in a variety of experimental models. Here, we extend our previous studies by showing that η-4-(4-bromo-6-methyl-2-pyrone)tricarbonyl iron (0) (CORM-F3), an irontricarbonyl complex that contains a 2-pyrone motif, liberates CO in vitro and exerts pharmacological actions that are typical of CO gas. Specifically, CORM-F3 caused vasorelaxation in isolated aortic rings and inhibited the inflammatory response (e.g., nitrite production) of RAW264.7 macrophages stimulated with endotoxin in a dose-dependent fashion. By

BIOACTIVE PROPERTIES OF IRON-CONTAINING CARBON

Carbon monoxide-releasing molecules (CO-RMs) are compounds capable of delivering controlled amounts of CO within a cellular environment. Ruthenium-based carbonyls (CORM-2 and CORM-3) and boronacorbonates (CORM-A1) have been shown to promote vasodilatory, cardioprotective and anti-inflammatory activities in a variety of experimental models. Here we extend our previous studies by showing that CORM-F3, an irontricarbonyl complex which contains a 2-pyrone motif, liberates CO in vitro and exerts pharmacological actions that are typical of CO gas. Specifically, CORM-F3 caused vasorelaxation in isolated aortic rings and inhibited the inflammatory response (eg nitrite production) of RAW264. 7 macrophages stimulated with endotoxin in a dose-dependent fashion. By analyzing the rate of CO release, we found that when the bromide at the 4-position of the 2-pyrone in CORM-F3 is substituted with a chloride group (CORM-F8), the rate of CO release is significantly decreased (4.5 fold) and a further decrease is observed when the 4-and 6-positions are substituted with a methyl group (CORM-F11) or a hydrogen (CORM-F7), respectively. Interestingly, the compounds containing halogens at the 4-position and the methyl at the 6-position of the 2-pyrone ring (CORM-F3 and CORM-F8) were found to be less cytotoxic compared to other CO-RMs when tested in RAW246. 7 macrophages. Thus, iron-based carbonyls mediate pharmacological responses that are achieved through liberation of CO and the nature of the substituents in the organic ligand have a profound effect on both the rate of CO release and cytotoxicity

Anti-inflammatory and antioxidant activities of Nrf2/HO-1 activators: in vitro studies in microglia and retinal cells

Inflammation and oxidative stress play essential roles during the progression and resolution of disease states. It is now being recognized that persistent inflammation and oxidative stress underlie several chronic diseases of Western countries. This is relevant in the ageing population, where neurodegenerative diseases and diabetes, among others, are pathologies that require pharmacological interventions targeting multiple pathways involved in these diseases. Microglia cells, the macrophages of the brain, work under normal conditions to protect neurons from infectious agents and by removing dead cells to promote tissue repair. Similarly, retinal pigmented epithelial cells support the eye by protecting photoreceptors and mediating nutrient uptake for retinal tissue. Because of their anatomical position, both cell types participate in the pathophysiology of neurodegenerative diseases and retinal diabetes complications. A highly relevant cellular response to stress is mediated by the nuclear factor (erythroid-derived 2)-like 2 (Nrf2), a redox sensitive protein that promotes the up-regulation of cytoprotective enzymes. Among these genes is heme oxygenase-1 (HO-1), which converts heme into iron, carbon monoxide and biliverdin, subsequently reduced to bilirubin by biliverdin reductase. These products exhibit anti-inflammatory and antioxidant actions in models of disease characterized by redox stress and inflammation and lack of HO-1 exacerbates damage in experimental animal models and two human cases reported in the literature. The Nrf2/HO-1 axis is amenable to pharmacological manipulation and molecules that target these pathways are of high interest for the discovery of therapeutic approaches to counteract neuroinflammation and retinal diseases. The work presented herein focuses on characterizing anti-inflammatory and antioxidant activities of Nrf2/HO-1 activators. In the first instance I identified effective Nrf2/HO-1 inducers that modulate the inflammatory response in BV2 murine microglia cells. I searched the literature and selected 56 compounds that activate Nrf2 or HO-1 and analyzed them for HO-1 induction and cytotoxicity in vitro. Approximately 20 compounds increased HO-1 at concentrations of 5 to 20 µM, with carnosol, curcumin, cobalt protoporphyrin-IX and dimethyl fumarate (DMF) exhibiting the best induction/low cytotoxicity profile. HO-1 up-regulation by some compounds resulted in increased bilirubin which correlated with the potency of the inducers to reduce nitrite production after challenge with interferon-ã (INF-ã) or lipopolysaccharide (LPS). The compounds strongly down-regulated inflammation (TNF-á, PGE2 and nitrite) in cells stimulated with INF-ã and LPS; silencing HO-1 or Nrf2 with shRNA partially reversed this effect. I then chose the Nrf2 inducers DMF and carnosol and investigated their effect on antioxidant pathways, oxygen consumption and wound healing in human retinal pigment epithelial cells (ARPE-19) grown in medium containing normal (NG) or high (HG) glucose to mimic hyperglycemia. I found that Nrf2 activation and heme oxygenase increased in ARPE cells treated with DMF or carnosol irrespective of glucose levels. However, in HG retinal cells were more sensitive to regulators of glutathione synthesis and produced lower reactive oxygen species. Culture in HG decreased respiration, ATP levels and damaged mitochondria; treatment with DMF or carnosol did not restore oxygen consumption. Using the scratch assay in vitro I observed that wound closure was faster in HG than NG cells and was accelerated by carnosol. An inhibitor of heme oxygenase reversed this effect, supporting a pro-healing role of HO-1. In summary, Nrf2/HO-1 activators modulate microglia inflammation and exert pharmacological activities in retinal cells cultured under normal or hyperglycemic conditions. Thus, promising chemical scaffolds are identified for the synthesis of potent new derivatives to counteract neuroinflammation and retinal diseases

L\u2019immagine della destinazione turistica: il Trentino Alto Adige

L\u2019importanza dell\u2019immagine della destinazione turistica \ue8 universalmente riconosciuta e sempre pi\uf9 crescente \ue8 l\u2019attenzione da parte dei ricercatori del settore in quanto non solo permette di differenziare tra loro le localit\ue0 ma \ue8 parte integrante ed influente del processo di decisone e scelta della vacanza stessa. La ricerca, che ha come obiettivo l\u2019analisi dei messaggi pubblicitari del Trentino Alto Adige apparsi negli ultimi dieci anni, si configura come un\u2019esplorazione del mondo pubblicitario trentino con l\u2019intento di rinvenire informazioni relative alle scelte di immagine promosse dalla regione. Modello teorico di riferimento \ue8 la teoria \uabpush-pull\ubb del costrutto di immagine primaria elaborata da Chon (1989, 1991). Sono stati analizzati i messaggi pubblicitari del Trentino pubblicati dal 1995 al 2004, per un totale di 63 messaggi. I messaggi pubblicitari sono stati esaminati mediante un\u2019analisi del contenuto, effettuata con l\u2019ausilio del software Atlas.ti. L\u2019immagine viene maggiormente creata da elementi pull (la frequenza totale dei codici degli elementi pull \ue8 433). Il Trentino rappresenta la \uabmontanit\ue0\ubb, intesa come un ambiente naturale, unico, sorprendente, ricco di valori etici e spirituali, di grande qualit\ue0, dotato di strutture ricettive pi\uf9 che soddisfacenti. Il Trentino \ue8 presentato come terra dell\u2019intrattenimento e dello svago, con l\u2019offerta di eventi che coinvolgono il turista offrendo la possibilit\ue0 di divertimento, di gusto e di arricchimento conoscitivo. I fattori push (la frequenza totale dei codici degli elementi push \ue8 314) su cui punta maggiormente la pubblicit\ue0 e che vanno a completare l\u2019immagine sono i bisogni fisiologici e quelli di autorealizzazione. Nei dieci anni presi in considerazione la pubblicit\ue0 ha mantenuto invariato il tono dei suoi messaggi (ovviamente sono cambiati gli slogan e il tipo di immagine) che risulta amichevole, rassicurante, emotivo e coerente con l\u2019offerta. La comunicazione contribuisce al rafforzamento dell\u2019immagine e a consolidare la forte identit\ue0 del territorio

Susceptibility of corn to stink bug (\u3ci\u3eDichelops melacanthus\u3c/i\u3e) and its management through seed treatment

We determined the susceptibility of vegetative corn stages to Dichelops melacanthus damage, and how seed treatment can reduce damage and yield loss. Two field trials were carried out. In the first, corn plants were artificially infested with D. melacanthus male/female pairs at rate of 0.5 pair per plant at different vegetative stages and infestation periods lasting 7-28 days (V1-V3, V1-V5, V1-V7, V1-V9, V3-V5, V3-V7, V3-V9, V5-V7, V5-V9, and V7-V9), plus a control without infestation. In the second, corn plants were artificially infested at a rate of one male/female pair per plant at different vegetative stages and infestation periods (V1-V3, V1-V5, V1-V7, V3-V5, V3-V7 and V5-V7) and treated with two pesticide seed coatings: (i) fungicide [carbendazim + thiram (150 g i.a. per L and 350 g i.a. per L)] + insecticide [clothianidin (600 g i.a. per L)] or (ii) only fungicide (carbendazim + thiram), plus three controls without infestation and with only fungicide-treatment (V1-V7, V3-V7 and V5-V7). In both trials, plants were caged during the entire period in order to hold stink bugs in contact with plants and to avoid injury from other arthropods. The most stink bug susceptible corn growth periods were from V1-V5 and from V1-V7. Seed treatment with clothianidin at the rate of 3.5 mL per Kg during the most susceptible infestation periods increased yield gain of 37.8 to 61%. Treatment with clothianidin during V1-V5 and V1-V7 caused 40% to 50% D. melacanthus adult mortality, respectively

Emerging concepts on the anti-inflammatory actions of carbon monoxide-releasing molecules (CO-RMs).

International audienceABSTRACT: Carbon monoxide-releasing molecules (CO-RMs) are a class of organometallo compounds capable of delivering controlled quantities of CO gas to cells and tissues thus exerting a broad spectrum of pharmacological effects. CO-RMs containing transition metal carbonyls were initially implemented to mimic the function of heme oxygenase-1 (HMOX1), a stress inducible defensive protein that degrades heme to CO, biliverdin leading to anti-oxidant and anti-inflammatory actions. Ten years after their discovery, the research on the chemistry and biological activities of CO-RMs has greatly intensified indicating that their potential use as CO delivering agents for the treatment of several pathological conditions is feasible. Although CO-RMs are a class of compounds that structurally diverge from traditional organic-like pharmaceuticals, their behaviour in the biological environments is progressively being elucidated revealing interesting features of metal-carbonyl chemistry towards cellular targets. Specifically, the presence of carbonyl groups bound to transition metals such as ruthenium, iron or manganese appears to make CO-RMs unique in their ability to transfer CO intracellularly and amplify the mechanisms of signal transduction mediated by CO. In addition to their well-established vasodilatory activities and protective effects against organ ischemic damage, CO-RMs are emerging for their striking anti-inflammatory properties which may be the result of the multiple activities of metal carbonyls in the control of redox signaling, oxidative stress and cellular respiration. Here, we review evidence on the pharmacological effects of CO-RMs in models of acute and chronic inflammation elaborating on some emerging concepts that may help to explain the chemical reactivity and mechanism(s) of action of this distinctive class of compounds in biological systems