Journal articles on the topic 'Oxydes de manganèse – Synthèse'

L'origine et le mécanisme de l'augmentation de la concentration en manganèse dans l'eau de la nappe phréatique de Beaucaire ont été recherchés afin d'orienter le choix d'un procédé de démanganisation adapté aux conditions du site. L'aquifère est caractérisé par son déficit en oxygène et par la présence de dépôts d'oxyde de manganèse (Mn(IV)) sur les sédiments. Dans ces conditions la microflore utilise les oxydes de manganèse conne accepteur final d'électrons (démontré dans les expériences in vitro) et le manganèse réduit passe alors en solution. Lors des essais d'application du procédé Vyredox le potentiel d'oxydoréduction de la nappe augmente et la concentration en manganèse dissous diminue. Rien n'indique une précipitation du manganèse et donc un colmatage à la périphérie de la partie oxygénée de la nappe.

Amine oxides, 1, 5, 10, 15, 21, 23, when treated by lithium diisopropylamide undergo deprotonation. Monodeprotonation gives rise either to secondary amines and benzaldehyde resulting from the hydrolysis of an intermediate immonium (I) or to hydroxylamines via a Stevens-like rearrangement observed for the first time on an amine oxide. Double deprotonation gives an immonium ylid (Y) which, depending upon the structure of the initial tertiary amine yields either "head to head" piperazines (biradical-like behavior of (DD)) or aziridines. The immonium ylid (Y5) derived from trimethylamine oxide, whose formation and reactivity are reported for the first time, has the remarkable property of undergoing cycloaddition reactions with unactivated olefins, leading to a new and efficient synthesis of various pyrrolidines.

Une étude expérimentale concernant l'adsorption des métaux lourds Cu, Cd, Zn et Pb par des sédiments d'un cours d'eau pollué par des rejets industriels a été entreprise pour mettre en évidence l'importance de certains paramètres expérimentaux, notamment le pH, la masse de sédiments et la température. Elle a permis également d'analyser la nature des liens qui participent à la fixation des cations métalliques sur les différentes fractions sédimentaires déterminées selon la méthode de TESSIER et al. (1979) et d'interpréter les capacités d'adsorption relativement variables suivant la nature du métal. Les résultats confirment le rôle particulier des fractions réductible (oxydes de fer et de manganèse) et organique (substances humiques en particulier), dont les propriétés respectives d'échange d'ions et de complexation ont été souvent vérifiées. La capacité d'adsorption de ce sédiment a notamment pu être interprétée en termes d'isothermes d'adsorption en exploitant les modèles de Langmuir et de Freundlich et leurs équations linéarisées.

Abstract Nous avons examiné les possibilités de fixation des ions chromate sur une hydrotalcite de synthèse (Mg-Al-CO3) et son produit de calcination à 550ºC. Les différentes analyses physico-chimiques (diffraction des rayons X, analyse thermogravimétrique et composition chimique) ont permis d'une part d'établir la formule chimique du matériau de départ et d'autre part, de mettre en évidence sa propriété de pouvoir se régénérer après calcination ménagée et formation des oxydes mixtes. La sorption d'ions chromate par le matériau préparé et par son produit de calcination a été étudiée. Nos résultats montrent que la cinétique de sorption est rapide (l'équilibre est atteint au bout de 20 minutes de contact) et que le phénomène dépend du pH. Le traitement, par le matériau calciné, de solutions contenant de 15 à 300 mg/l de Cr(VI) a donné de bons résultats. En effet, la comparaison des capacités de sorption pour les ions Cr(VI) de l'hydrotalcite calcinée avec d'autres phases LDHMg, Al montre bien la supériorité des propriétés sorptives des hydrotalcites calcinées d'où l'utilité de ces matériaux dans le domaine du traitement des eaux usées.

La métallothionéine (MT) est un ligand protéinique intracellulaire important à cause de son implication dans les processus de régulation des métaux traces essentiels et non-essentiels. Bon nombre de travaux ont été conduits en laboratoire pour bien comprendre les mécanismes de synthèse de cette protéine, mais les études réalisées en milieu aquatique sont beaucoup plus rares, particulièrement dans les rivières (milieu lotique). Dans ce contexte, la présente étude avait deux objectifs principaux : (1) identifier en milieu lotique les métaux traces (argent "Ag", cadmium "Cd", cuivre "Cu", nickel "Ni", plomb "Pb" et zinc "Zn") susceptibles d'induire la synthèse de la MT chez trois espèces sentinelles, soit le mollusque bivalve Pyganodon grandis, la larve d'éphémère Hexagenia limbata et le grand brochet du nord Esox lucius ; (2) définir les variables physico-chimiques ou toxicologiques pouvant influencer la prise en charge des métaux traces et conséquemment les concentrations en MT chez le mollusque P. grandis et l'éphémère H. limbata. Deux rivières de la région de l'Abitibi ont été échantillonnées à l'été 2001 afin de récolter les espèces sentinelles à 21 stations. Les concentrations en métaux traces, ainsi qu'en métallothionéine, ont été mesurées dans les branchies des mollusques, dans le rein des brochets et dans le corps entier des éphémères. La métallothionéine a été mesurée à l'aide d'une technique de saturation au mercure. D'après nos résultats, le cadmium tissulaire semble être le meilleur prédicteur de la concentration de MT chez les trois espèces sentinelles. Cependant, l'implication d'autres métaux est également possible. Dans le cas de P. grandis, la concentration de manganèse (Mn) dans les sédiments pourrait influencer la prise en charge du Cd et la synthèse de MT.

La désodorisation physico-chimique en stations d'épuration s'effectue généralement par lavage basique oxydant pour piéger les espèces soufrées réduites telles que H2 S ou CH3 SH. L'utilisation du peroxyde d'hydrogène n'est pas encore répandue en comparaison de celle du chlore. Cette étude a été menée afin de déterminer le comportement de H2O2 en fonction de la composition de l'eau de lavage. L'influence des paramètres : concentration en métaux (fer, manganèse, cuivre et zinc), pH, [H2O2], [CO32-], [HS-] a été étudiée en utilisant un plan d'expériences. La décomposition de H2O2 et la concentration de radicaux libres ont été mesurées pour chaque expérience. En présence de métaux, un pH élevé et une forte concentration en peroxyde sont les deux paramètres principalement responsables d'une forte décomposition. Cette décomposition serait accompagnée d'une production de radicaux avec [HO°]max =10-13 M. Cette valeur mesurée de radicaux dans le milieu n'explique qu'une petite part de la décomposition de peroxyde observée. Par conséquent, la majorité de la décomposition est due à des réactions soit à la surface des oxydes, soit en solution avec les cations dissous. Le mélange de métaux et de carbonates à pH 10,5 présente un effet de synergie sur la décomposition de H2O2. Ces résultats démontrent que malgré le pouvoir oxydant des radicaux HO° formés, l'utilisation de H2O2 en désodorisation ne sera possible qu'avec l'ajout de stabilisant.

The products obtained from MnO2–V2O5 mixtures at the ambient oxygen pressure and temperatures up to 900 °C were studied by means of thermal analysis and x-ray diffraction methods. The following phases were found to exist in equilibrium, depending on the composition: (I) Mn2O3–Mn2V2O7, (II) Mn2V2O7–MnV2O6, and (III) V2O5–solid solution of VO2 in MnV2O6. A phase diagram was obtained for the composition region III. The data are instructive for syntheses of manganese vanadates by thermal methods.

In this review, free-base and metalloporphyrins, functionalized on meso-positions by quaternary pyridinium units, also referred to as cationic porphyrins, are presented. The article consists of five parts. In the first part free-base porphyrins are described, especially taking account on generation of singlet oxygen; next parts concern metalloporphyrins. The second and third parts deal with zinc and manganese porphyrins, respectively; in the fourth part copper, palladium, and platinum porphyrins are presented. In the fifth part, describing porphyrins with various metal ions an attention is paid to porphyrin metal-organic frameworks (MOFs) and metal-organic materials (MOMs) in which metalloporphyrins are immobilized; syntheses and characterization of obtained products are shown.

AMPK (AMP-activated protein kinase) is a key regulator of cellular energy because of its capacity to detect changes in the concentration of AMP. Recent evidence, however, indicates the existence of alternative mechanisms of activation of this protein. Mitochondrial ROS (reactive oxygen species), generated as a result of the interaction between nitric oxide and mitochondrial cytochrome c oxidase, activate AMPKα1 in HUVECs (human umbilical-vein endothelial cells) at a low oxygen concentration (i.e. 3%). This activation is independent of changes in AMP. In the present study we show, using HUVECs in which AMPKα1 has been silenced, that this protein is responsible for the expression of genes involved in antioxidant defence, such as manganese superoxide dismutase, catalase, γ-glutamylcysteine synthase and thioredoxin. Furthermore, peroxisome proliferator-activated-coactivator-1, cAMP-response-element-binding protein and Foxo3a (forkhead transcription factor 3a) are involved in this signalling pathway. In addition, we show that silencing AMPKα1 in cells results in a reduced mitochondrial and eNOS (endothelial NO synthase) content, reduced cell proliferation, increased accumulation of ROS and apoptosis. Thus AMPKα1 in HUVECs regulates both their mitochondrial content and their antioxidant defences. Pharmacological activation of AMPKα1 in the vascular endothelium may be beneficial in conditions such as metabolic syndrome, Type 2 diabetes and atherosclerosis, not only because of its bioenergetic effects but also because of its ability to counteract oxidative stress.

Diabetic encephalopathy, characterized by impaired cognitive functions and neurochemical and structural abnormalities, may involve direct neuronal damage caused by intracellular glucose. The study assesses the direct effect of chronic hyperglycemia on the function of brain mitochondria, the major site of reactive species production, in diabetic streptozotocin (STZ) rats. Oxidative stress plays a central role in diabetic tissue damage. Alongside enhanced reactive oxygen species (ROS) levels, both nitric oxide (NO) levels and mitochondrial nitric oxide synthase expression were found to be increased in mitochondria, whereas glutathione (GSH) peroxidase activity and manganese superoxide dismutase protein content were reduced. GSH was reduced and GSH disulfide (GSSG) was increased in STZ rats. Oxidative and nitrosative stress, by reducing the activity of complexes III, IV and V of the respiratory chain and decreasing ATP levels, might contribute to mitochondrial dysfunction. In summary, this study offers fresh evidence that, besides the vascular-dependent mechanisms of brain dysfunction, oxidative and nitrosative stress, by damaging brain mitochondria, may cause direct injury of neuronal cells.

Resveratrol is a polyphenol with pleiotropic effects against oxidative damage that has been widely implicated in lowering hypertension risk. The purpose of this study was to determine whether improve nitric oxide (NO) release in the brain, either through the activation of AMP-activated protein kinase (AMPK) or reduced Ras-related C3 botulinum toxin substrate 1 (Rac1)-induced reactive oxygen species (ROS) generation, thereby reducing blood pressure (BP) in rats with fructose-induced hypertension. The rats were fed with 10% fructose or Crestor (rosuvastatin; 1.5 mg·kg−1·day−1) and resveratrol (10 mg·kg−1·day−1) treatment for 1 wk, then the systolic blood pressure of the rats was measured by tail-cuff method. Endogenous in vivo superoxide radical production in the nucleus tractus solitarii (NTS) was determined with dihydroethidium. Immunoblotting analyses were used to quantify protein expression levels. Oral resveratrol treatment for 1 wk decreased BP and increased NO production in the NTS of fructose-fed rats but not in the control Wistar-Kyoto rats. The effect of Crestor is opposite that of resveratrol. Fructose induced hypertension by inactivating AMPK, which in turn enhanced the generation of ROS and reduced manganese superoxide dismutase by increasing the activity of Rac1-induced NADPH oxidase, abolishing the activity of the extracellular signal-regulated kinases 1 and 2 (ERK1/2) and ribosomal protein S6 kinase (RSK) and neuronal nitric oxide synthase (nNOS) phosphorylation signaling pathway in the brain. However, resveratrol had the opposite effect in the fructose-fed rats. Overall, we show that the resveratrol decreased BP better than Crestor, abolished ROS generation, and enhanced the ERK1/2-RSK-nNOS pathway by activating AMPK to downregulate Rac1-induced NADPH oxidase levels in the NTS during oxidative stress–associated hypertension. NEW & NOTEWORTHY 1) Evidence showed that the Ras-related C3 botulinum toxin substrate 1 (Rac1) augmented by Crestor (rosuvastatin) did not result in a significant change in blood pressure (BP) in fructose-induced hypertension. 2) Fructose induced hypertension by inactivating AMP-activated protein kinase (AMPK), which in turn enhanced the generation of reactive oxygen species (ROS) and reduced manganese superoxide dismutase in the brain. 3) Resveratrol decreased BP better than Crestor, abolished ROS generation, and enhanced the ERK1/2-ribosomal protein S6 kinase-neuronal nitric oxide synthase pathway by activating AMPK to negatively regulate Rac1-induced NADPH oxidase levels in the nucleus tractus solitarii during oxidative stress–associated hypertension.

Ischemic preconditioning by a single event of ischemia and reperfusion (SIRPC) dramatically protects renal function against ischemia and reperfusion (I/R) induced several weeks later. We recently reported that reactive oxygen species (ROS) and oxidative stress were sustained in a kidney that had functionally recovered from I/R injury, thus suggesting an association between SIRPC and ROS and oxidative stress. However, the role of ROS in SIRPC remains to be clearly elucidated. To assess the involvement of ROS in SIRPC, mice were subjected to SIRPC (30 min of bilateral renal ischemia and 8 days of reperfusion) and then exposed to I/R injury. Thirty minutes of bilateral renal ischemia in the non-SIRPC mice resulted in a marked increase in plasma creatinine levels 4 and 24 h after reperfusion, which was not observed in the I/R in the SIRPC mice. SIRPC resulted in increases in the levels of kidney superoxide. Administrations of manganese(III) tetrakis(1-methyl-4-pyridyl) porphyrin [MnTMPyP; a cell-permeable superoxide dismutase (SOD) mimetic] and N-acetylcysteine (NAc; a ROS scavenger) to SIRPC mice blocked the SIRPC-induced increase in superoxide levels and removed ∼48–64% of the functional protection of the SIRPC kidney. Additionally, these administrations significantly inhibited I/R-induced increases in superoxide formation, hydrogen peroxide production, and lipid peroxidation, along with the inhibition of I/R-induced reductions in the expression and activity of manganese SOD, copper-zinc SOD, and catalase. Furthermore, administrations of MnTMPyP or NAc inhibited the SIRPC-induced increase in inducible nitric oxide synthase expression but did not inhibit the SIRPC-induced increases in heat shock protein-25 expression. In conclusion, the renoprotection afforded by SIRPC was triggered by ROS generated by SIRPC.

The compounds MnCo(B2O5) (I) and MnMg(B2O5) (II) were prepared by using B2O3 flux techniques in an argon atmosphere. X-ray investigations on single crystals showed triclinic symmetry, space group Ci1 - P1̄, I: a = 320.94(10), b = 619.20(11), c = 939.0(2) pm, a = 104.38(2)°, β = 90.76(2)°, γ = 92.046(14)° and II: a = 318.97(7), b = 619.8(2), c = 936.7(2) pm, α = 104.47(2)°, β = 90.60(2)°, γ = 91.98(2)° Z = 2. Their structures are isotypic with Co2(B2O5). All metal ions are octahedrally coordinated by six oxygen atoms. The structures contain diborate anions B2O54-. Each boron atom is threefold coordinated by oxygen.

Amphibacillus xylanus grows at the same rate and with the same cell yield under aerobic and anaerobic conditions. Under aerobic conditions, it exhibits vigorous oxygen consumption in spite of lacking a respiratory system and haem catalase. To understand the adaptive response of A. xylanus to oxidative stresses, a genomic analysis of A. xylanus was conducted. The analysis showed that A. xylanus has the genes of four metabolic systems: two pyruvate metabolic pathways, a glycolytic metabolic pathway and an NADH oxidase (Nox)–AhpC (Prx) system. A transcriptional study confirmed that A. xylanus has these metabolic systems. Moreover, genomic analysis revealed the presence of two genes for NADH oxidase (nox1 and nox2), both of which were identified in the transcriptional analysis. The nox1 gene in A. xylanus was highly expressed under normal aerobic conditions but that of nox2 was not. A purification study of NADH oxidases indicated that the gene product of nox1 is a primary metabolic enzyme responsible for metabolism of both oxygen and reactive oxygen species. A. xylanus was successfully grown under forced oxidative stress conditions such as 0.1 mM H2O2, 0.3 mM paraquat and 80 % oxygen. Proteomic analysis revealed that manganese SOD, Prx, pyruvate dehydrogenase complex E1 and E3 components, and riboflavin synthase β-chain are induced under normal aerobic conditions, and the other proteins except the five aerobically induced proteins were not induced under forced oxidative stress conditions. Taken together, the present findings indicate that A. xylanus has a unique defence system against forced oxidative stress.

Les hétérocycles sont importants, aussi bien dans les domaines biologique, médicinal et thérapeutique (vitamines, hormones, antibiotiques, etc), que dans le secteur industriel et technologique (inhibiteurs de corrosion, colorants, agents stabilisants, pesticides, herbicides. Les chloroformiates ou chlorocarbonates sont les esters dérivés de l’acide chloroformique. La chimie des N-oxydes hétérocycliques (pyridine et N-oxydes) a connu un important développement au cours des dernières années. L’objectif principal du présent travail est l’étude de l’action du métoxycarbonylchloride sur la pyridine et certains de ses dérivés. Après avoir trouvé les conditions optimales, de nouveaux composés à base de pyridine ont été synthétisés. En remplaçant l’ion chlorure par d’autres ions, les produits synthétisés ont été cristallisés avec un bon rendement. La structure des produits a été caractérisée à l’aide de la spectroscopie infra rouge et la résonnance magnétique nucléaire. Spécifiquement, l’influence de la basicité du noyau hétérocyclique sur les enthalpies de formation des sels produits a été étudiée. En conclusion, la réaction chimique de formation est exothermique avec ΔH° < 0 pour tous les sels étudiés. En utilisant les constantes de Hammett sur le noyau de la pyridine, l’étude a monté que ces chaleurs de réaction dépendent de la basicité du noyau hétérocyclique. En perspective on peut envisager une étude de l’influence de la basicité des différents noyaux pyridiniques sur les effets de conjugaison polaire directe sur le groupe azoté dans les sels N-méthoxycarbonyl-(oxy)-pyridiniums.Mots clés: Pyridine N-Oxyde, chloroformiates, synthèse, constante de Hammett. English Title: Study of the influence of basicity on the enthalpy of reaction of N-methoxycarbonyl- (oxy) -pyridinium salts Heterocycles are important, as well in the biological, medicinal and therapeutic fields (vitamins, hormones, antibiotics, etc.), as in the industrial and technological sector (corrosion inhibitors, dyes, stabilizing agents, pesticides, herbicides). Chloroformates or chlorocarbonates are esters derived from chloroformic acid. The chemistry of heterocyclic N-oxides (pyridine and N-oxides) has experienced significant development in recent years. The main objective of this work is to study the action of metoxycarbonylchloride on pyridine and some of its derivatives. After finding the optimal conditions, new pyridine-based compounds were synthesized. By replacing the chloride ion with other ions, the synthesized products have been crystallized with good yield. Specifically, the influence of the basicity of the heterocyclic nucleus on the enthalpies of salt formation produced has been studied. The enthalpies formation of salt produced have been determined. In conclusion, the chemical reaction of formation is exothermic with ΔH ° < 0 for all the salts studied. Using Hammett's constants on the pyridine nucleus, the study has shown that these reaction heats depend on the basicity of the heterocyclic nucleus. In perspective, we can study the influence of the basicity of the different pyridine rings on the effects of direct polar conjugation on the nitrogen group in the N-methoxycarbonyl- (oxy) -pyridinium salts.Keywords: Pyridine N-Oxide, chloroformates, synthesis, Hammett constant.

Aging-associated cardiovascular diseases (CVDs) have some risk factors that are closely related to oxidative stress.Salvia miltiorrhiza(SM) has been used commonly to treat CVDs for hundreds of years in the Chinese community. We aimed to explore the effects of SM on oxidative stress in aging-associated CVDs. Through literature searches using Medicine, PubMed, EMBASE, Cochrane library, CINAHL, and Scopus databases, we found that SM not only possesses antioxidant, antiapoptotic, and anti-inflammatory effects but also exerts angiogenic and cardioprotective activities. SM may reduce the production of reactive oxygen species by inhibiting oxidases, reducing the production of superoxide, inhibiting the oxidative modification of low-density lipoproteins, and ameliorating mitochondrial oxidative stress. SM also increases the activities of catalase, manganese superoxide dismutase, glutathione peroxidase, and coupled endothelial nitric oxide synthase. In addition, SM reduces the impact of ischemia/reperfusion injury, prevents cardiac fibrosis after myocardial infarction, preserves cardiac function in coronary disease, maintains the integrity of the blood-brain barrier, and promotes self-renewal and proliferation of neural stem/progenitor cells in stroke. However, future clinical well-designed and randomized control trials will be necessary to confirm the efficacy of SM in aging-associated CVDs.

Exercise training is recognized to improve cardiac and skeletal muscle mitochondrial respiratory capacity; however, the impact of chronic exercise on vascular mitochondrial respiratory function is unknown. We hypothesized that exercise training concomitantly increases both vascular mitochondrial respiratory capacity and vascular function. Arteries from both sedentary (SED) and swim-trained (EX, 5 wk) mice were compared in terms of mitochondrial respiratory function, mitochondrial content, markers of mitochondrial biogenesis, redox balance, nitric oxide (NO) signaling, and vessel function. Mitochondrial complex I and complex I + II state 3 respiration and the respiratory control ratio (complex I + II state 3 respiration/complex I state 2 respiration) were greater in vessels from EX relative to SED mice, despite similar levels of arterial citrate synthase activity and mitochondrial DNA content. Furthermore, compared with the SED mice, arteries from EX mice displayed elevated transcript levels of peroxisome proliferative activated receptor-γ coactivator-1α and the downstream targets cytochrome c oxidase subunit IV isoform 1, isocitrate dehydrogenase ( Idh) 2, and Idh3a, increased manganese superoxide dismutase protein expression, increased endothelial NO synthase phosphorylation (Ser1177), and suppressed reactive oxygen species generation (all P < 0.05). Although there were no differences in EX and SED mice concerning endothelium-dependent and endothelium-independent vasorelaxation, phenylephrine-induced vasocontraction was blunted in vessels from EX compared with SED mice, and this effect was normalized by NOS inhibition. These training-induced increases in vascular mitochondrial respiratory capacity and evidence of improved redox balance, which may, at least in part, be attributable to elevated NO bioavailability, have the potential to protect against age- and disease-related challenges to arterial function.

We determined whether isoflurane can confer delayed cardioprotection in the adult rat by triggering increased production of reactive oxygen (ROS) and nitrogen species (RNS). Our objectives were to determine 1) the concentration of isoflurane that confers delayed cardioprotection in the adult rat, 2) the role of ROS and RNS in the induction of delayed cardioprotection, and 3) the cellular sources of ROS and RNS responsible for induction of delayed cardioprotection by isoflurane. Male Sprague-Dawley rats at 8 wk of age ( n = 8 rats/group) were exposed to 0.5%, 0.8%, 1%, and 2% (vol/vol) isoflurane-100% oxygen for 2 h. Isoflurane conferred delayed cardioprotection 24 h later at a concentration of 0.8% (vol/vol). Administration of manganese (III) tetrakis (4-benzoic acid)porphyrin chloride (MnTBAP), a superoxide scavenger (15 mg/kg ip), or NG-nitro-l-arginine methyl ester (l-NAME), a general nitric oxide synthase inhibitor (15 mg/kg ip), 15 min before isoflurane treatment abolished the delayed cardioprotective effects of isoflurane. MnTBAP and l-NAME had no effect on delayed cardioprotection in untreated hearts. Perfusion of isolated hearts with hydroethidine, a fluorescent probe for superoxide, after isoflurane treatment resulted in a twofold increase in ethidine staining of isoflurane-treated hearts compared with untreated controls, which was attenuated by myxothiazol, an inhibitor of the mitochondrial electron transport chain (0.2 mg/kg ip) and l-NAME (15 mg/kg ip). Nitrite and nitrate content in isoflurane-treated hearts was 1.5-fold higher than in untreated hearts, whereas myocardial reduced glutathione levels were decreased by 13% in 0.8% but not in 1.0% isoflurane-treated hearts. We conclude that isoflurane confers delayed cardioprotection in the adult rat, triggered by ROS and RNS.

Previously, we have shown that the selective mitochondrial ATP-sensitive potassium (mitoKATP) channel opener BMS-191095 (BMS) induces neuronal preconditioning (PC); however, the exact mechanism of BMS-induced neuroprotection remains unclear. In this study, we have identified key components of the cascade resulting in delayed neuronal PC with BMS using isolated rat brain mitochondria and primary cultures of rat cortical neurons. BMS depolarized isolated mitochondria without an increase in reactive oxygen species (ROS) generation and induced rapid phosphorylation of Akt and glycogen synthase kinase-3β. Long-term (3 days) treatment of neurons with BMS resulted in sustained mitochondrial depolarization, decreased basal ROS generation, and elevated ATP levels. This treatment also elicited almost complete protection against glutamate excitotoxicity, which could be abolished using the phosphoinositide 3-kinase (PI3K) inhibitor wortmannin, but not with the superoxide dismutase (SOD) mimetic M40401. Long-term BMS treatment induced a PI3K-dependent increase in the expression and activity of catalase without affecting manganese SOD and copper/zinc-dependent SOD. Finally, the catalase inhibitor 3-aminotriazole dose-dependently antagonized the neuroprotective effect of BMS-induced PC. In summary, BMS depolarizes mitochondria without ROS generation, activates the PI3K—Akt pathway, improves ATP content, and increases catalase expression. These mechanisms appear to play important roles in the neuroprotective effect of BMS.

Mitochondria support the energy-intensive functions of brain endothelium but also produce damaging-free radicals that lead to disease. Previously, we found that estrogen treatment protects cerebrovascular mitochondria, increasing capacity for ATP production while decreasing reactive oxygen species (ROS). To determine whether these effects occur specifically in endothelium in vivo and also explore underlying transcriptional mechanisms, we studied freshly isolated brain endothelial preparations from intact and ovariectomized female mice. This preparation reflects physiologic influences of circulating hormones, hemodynamic forces, and cell–cell interactions of the neurovascular unit. Loss of ovarian hormones affected endothelial expression of the key mitochondrial regulator family, peroxisome proliferator-activated receptor γ coactivator 1 (PGC-1), but in a unique way. Ovariectomy increased endothelial PGC-1α mRNA but decreased PGC-1β mRNA. The change in PGC-1β correlated with decreased mRNA for crucial downstream mitochondrial regulators, nuclear respiratory factor 1 and mitochondrial transcription factor A, as well as for ATP synthase and ROS protection enzymes, glutamate-cysteine ligase and manganese superoxide dismutase. Ovariectomy also decreased mitochondrial biogenesis (mitochondrial/nuclear DNA ratio). These results indicate ovarian hormones normally act through a distinctive regulatory pathway involving PGC-1β to support cerebral endothelial mitochondrial content and guide mitochondrial function to favor ATP coupling and ROS protection.

Cultured vascular endothelial cell (EC) exposure to steady laminar shear stress results in peroxynitrite (ONOO−) formation intramitochondrially and inactivation of the electron transport chain. We examined whether the “hyperoxic state” of 21% O2, compared with more physiological O2 tensions (Po2), increases the shear-induced nitric oxide (NO) synthesis and mitochondrial superoxide (O2·−) generation leading to ONOO− formation and suppression of respiration. Electron paramagnetic resonance oximetry was used to measure O2 consumption rates of bovine aortic ECs sheared (10 dyn/cm2, 30 min) at 5%, 10%, or 21% O2 or left static at 5% or 21% O2. Respiration was inhibited to a greater extent when ECs were sheared at 21% O2 than at lower Po2 or left static at different Po2. Flow in the presence of an endothelial NO synthase (eNOS) inhibitor or a ONOO− scavenger abolished the inhibitory effect. EC transfection with an adenovirus that expresses manganese superoxide dismutase in mitochondria, and not a control virus, blocked the inhibitory effect. Intracellular and mitochondrial O2·− production was higher in ECs sheared at 21% than at 5% O2, as determined by dihydroethidium and MitoSOX red fluorescence, respectively, and the latter was, at least in part, NO-dependent. Accumulation of NO metabolites in media of ECs sheared at 21% O2 was modestly increased compared with ECs sheared at lower Po2, suggesting that eNOS activity may be higher at 21% O2. Hence, the hyperoxia of in vitro EC flow studies, via increased NO and mitochondrial O2·− production, leads to enhanced ONOO− formation intramitochondrially and suppression of respiration.

MnO2 nanostructures were fabricated by plasma assisted-chemical vapor deposition (PA-CVD) using a fluorinated diketonate diamine manganese complex, acting as single-source precursor for both Mn and F. The syntheses were performed from Ar/O2 plasmas on MgAl2O4(100), YAlO3(010), and Y3Al5O12(100) single crystals at a growth temperature of 300 °C, in order to investigate the substrate influence on material chemico-physical properties. A detailed characterization through complementary analytical techniques highlighted the formation of highly pure and oriented F-doped systems, comprising the sole β-MnO2 polymorph and exhibiting an inherent oxygen deficiency. Optical absorption spectroscopy revealed the presence of an appreciable Vis-light harvesting, of interest in view of possible photocatalytic applications in pollutant degradation and hydrogen production. The used substrates directly affected the system structural features, as well as the resulting magnetic characteristics. In particular, magnetic force microscopy (MFM) measurements, sensitive to the out-of-plane magnetization component, highlighted the formation of spin domains and long-range magnetic ordering in the developed materials, with features dependent on the system morphology. These results open the door to future engineering of the present nanostructures as possible magnetic media for integration in data storage devices.

The mediators of acute exercise-induced preconditioning against ischemia-reperfusion injury are not understood. This study assesses the role of nitric oxide synthase (NOS), a reported mediator of other forms of preconditioning. Male Fischer 344 rats were divided into five groups ( n = 6–7): sedentary (Sed); exercised 2 days on a treadmill at 20 m/min, 6° grade, for 60 min (Run); sedentary, perfused with 100 μM Nω-nitro-l-arginine methyl ester hydrochloride (l-NAME) to inhibit NOS (Sed/L-N); exercised, perfused with l-NAME (Run/L-N); and exercised in a 4°C environment, perfused with l-NAME (CRun/L-N). Twenty-four hours following exercise, isolated, perfused working hearts were subjected to 22.5 min of global ischemia plus 30 min of normoxic reperfusion. Left ventricle contents of several putative preconditioning mediators were determined. Postischemic recovery of cardiac output times systolic pressure was better in Run than Sed (78.4 vs. 50.2% of preischemia, P < 0.05). Inhibition of NOS did not abrogate the improved recovery in the exercise groups or alter recovery in Sed. All exercise groups also displayed improved myocardial efficiency (cardiac output times systolic pressure/oxygen consumption) postischemia and less lactate dehydrogenase release ( P < 0.05). l-NAME appeared to lower lactate dehydrogenase release independent of exercise. The only change in antioxidant enzyme activity was a decrease in manganese superoxide dismutase in CRun/L-N ( P < 0.05). Heat shock protein 72 expression increased only in Run and Run/L-N and endothelial NOS only in CRun/L-N ( P < 0.05). Acute exercise-induced preconditioning of the Fischer 344 rat heart is not mediated by NOS and does not require increases in heat shock protein 72 or antioxidant enzymes.

We hypothesized that specific muscular transcript level adaptations participate in the improvement of endurance performances following intermittent hypoxia training in endurance-trained subjects. Fifteen male high-level, long-distance runners integrated a modified living low-training high program comprising two weekly controlled training sessions performed at the second ventilatory threshold for 6 wk into their normal training schedule. The athletes were randomly assigned to either a normoxic (Nor) (inspired O2 fraction = 20.9%, n = 6) or a hypoxic group exercising under normobaric hypoxia (Hyp) (inspired O2 fraction = 14.5%, n = 9). Oxygen uptake and speed at second ventilatory threshold, maximal oxygen uptake (V̇o2 max), and time to exhaustion (Tlim) at constant load at V̇o2 max velocity in normoxia and muscular levels of selected mRNAs in biopsies were determined before and after training. V̇o2 max (+5%) and Tlim (+35%) increased specifically in the Hyp group. At the molecular level, mRNA concentrations of the hypoxia-inducible factor 1α (+104%), glucose transporter-4 (+32%), phosphofructokinase (+32%), peroxisome proliferator-activated receptor gamma coactivator 1α (+60%), citrate synthase (+28%), cytochrome oxidase 1 (+74%) and 4 (+36%), carbonic anhydrase-3 (+74%), and manganese superoxide dismutase (+44%) were significantly augmented in muscle after exercise training in Hyp only. Significant correlations were noted between muscular mRNA levels of monocarboxylate transporter-1, carbonic anhydrase-3, glucose transporter-4, and Tlim only in the group of athletes who trained in hypoxia ( P < 0.05). Accordingly, the addition of short hypoxic stress to the regular endurance training protocol induces transcriptional adaptations in skeletal muscle of athletic subjects. Expressional adaptations involving redox regulation and glucose uptake are being recognized as a potential molecular pathway, resulting in improved endurance performance in hypoxia-trained subjects.

Sperm motility is one of the major determinants of male fertility. Since sperm need a great deal of energy to support their fast movement by active metabolism, they are thus extremely vulnerable to oxidative damage by the reactive oxygen species (ROS) and other free radicals generated as byproducts in the electron transport chain. The present study is aimed at understanding the impact of a mitochondrial oxidizing/reducing microenvironment in the etiopathology of male infertility. We detected the mitochondrial DNA (mtDNA) 4,977 bp deletion in human sperm. We examined the gene mutation of ATP synthase 6 (ATPase6 m.T8993G) in ATP generation, the gene polymorphisms of uncoupling protein 2 (UCP2, G-866A) in the uncoupling of oxidative phosphorylation, the role of genes such as manganese superoxide dismutase (MnSOD, C47T) and catalase (CAT, C-262T) in the scavenging system in neutralizing reactive oxygen species, and the role of human 8-oxoguanine DNA glycosylase (hOGG1, C1245G) in 8-hydroxy-2 ′ -deoxyguanosine (8-OHdG) repair. We found that the sperm with higher motility were found to have a higher mitochondrial membrane potential and mitochondrial bioenergetics. The genotype frequencies of UCP2 G-866A, MnSOD C47T, and CAT C-262T were found to be significantly different among the fertile subjects, the infertile subjects with more than 50% motility, and the infertile subjects with less than 50% motility. A higher prevalence of the mtDNA 4,977 bp deletion was found in the subjects with impaired sperm motility and fertility. Furthermore, we found that there were significant differences between the occurrences of the mtDNA 4,977 bp deletion and MnSOD (C47T) and hOGG1 (C1245G). In conclusion, the maintenance of the mitochondrial redox microenvironment and genome integrity is an important issue in sperm motility and fertility.

A mild heat shock (hyperthermia) protects cells from apoptotic and necrotic deaths by inducing overexpression of various heat shock proteins (Hsps). These proteins, in combination with the activation of the nitric oxide synthase (NOS) enzyme, play important roles in the protection of the myocardium against a variety of diseases. In the present work we report that the generation of potent reactive oxygen species (ROS), namely ·OH in cardiac H9c2 cells, is attenuated by heat shock treatment (2 h at 42°C). Western blot analyses showed that heat shock treatment induced overexpression of Hsp70, Hsp60, and Hsp25. The observed ·OH was found to be derived from the superoxide (O2−·) generated by the mitochondria. Whereas the manganese superoxide dismutase (MnSOD) activity was increased in the heat-shocked cells, the mitochondrial aconitase activity was reduced. The mechanism of O2−· conversion into ·OH in mitochondria is proposed as follows. The O2−· leaked from the electron transport chain, oxidatively damages the mitochondrial aconitase, releasing a free Fe2+. The aconitase-released Fe2+ combines with H2O2 to generate ·OH via a Fenton reaction and the oxidized Fe3+ recombines with the inactivated enzyme after being reduced to Fe2+ by other cellular reductants, turning it over to be active. However, in heat-shocked cells, because of higher MnSOD activity, the excess H2O2 causes irreversible damage to the mitochondrial aconitase enzyme, thus inhibiting its activity. In conclusion, we propose that attenuation of ·OH generation after heat shock treatment might play an important role in reducing the myocardial ischemic injury, observed in heat shock-treated animals.

We investigated the potential ability of quercetin to protect against lipopolysaccharide (LPS)-induced intestinal oxidative stress in broiler chickens and the potential role of the Nrf2 (nuclear factor erythroid 2-related factor 2) signaling pathway. One-day-old broiler chickens (n = 240) were randomized into four groups: saline-challenged broiler chickens fed a basal diet (Con), LPS-challenged broiler chickens on a basal diet (LPS), and LPS-treated broiler chickens on a basal diet containing either 200 or 500 mg/kg of quercetin (Que200+LPS or Que500+LPS). Quercetin (200 mg/kg) significantly alleviated LPS-induced decreased duodenal, jejunal, and illeal villus height and increased the crypt depth in these regions. Quercetin significantly inhibited LPS-induced jejunal oxidative stress, including downregulated reactive oxygen species (ROS), malondialdehyde (MDA), and 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels, and it upregulated superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels. Quercetin relieved LPS-induced jejunal mitochondria damage and upregulated mitochondrial DNA copy number-related gene expression, including cytochrome c oxidase subunit 1 (COX1), ATP synthase F0 subunit 6 (ATP6), and NADH dehydrogenase subunit 1 (ND1). Quercetin attenuated the LPS-induced inhibition of Nrf2 activation, translocation, and downstream gene expression, including heme oxygenase-1 (HO-1), NAD (P) H dehydrogenase quinone 1 (NQO1), and manganese superoxide dismutase (SOD2). Additionally, quercetin attenuated the LPS-inhibition of c-Jun N-terminal kinase (JNK), Extracellular Regulated protein Kinases (ERK), and p38MAPK (p38) phosphorylation in the MAPK pathway. Thus, quercetin attenuated LPS-induced oxidative stress in the intestines of broiler chickens via the MAPK/Nrf2 signaling pathway.

Single crystals of the compounds MnFe(BO3)O (I) and MnAl0.5Y0.5(BO3)O (II), were obtained by a B2O3 flux technique. I crystallizes with orthorhombic symmetry, space group D162h -Pnma (Nr.62), a = 939.92; b = 319.41; c = 939.11 pm; Z = 4 and II with monoclinic symmetry, space group C52h-P21/n (Nr. 14). a = 325.6; b = 955.1; c = 929.2 pm; β = 90.70° ; Z = 4. I is isotypic to the mineral Warwickite, while II is a distorded variant of this structure. All metal ions are octahedrally coordinated. Both structures contain isolated, trigonal planar BO3 units and oxygen atoms that are not coordinated to boron.

Mitochondria affect cerebrovascular tone by activation of mitochondrial ATP-sensitive K+ (KATP) channels and generation of reactive oxygen species (ROS). Insulin resistance accompanying obesity causes mitochondrial dysfunction, but the consequences on the cerebral circulation have not been fully identified. We evaluated the mitochondrial effects of diazoxide, a putative mitochondrial KATP channel activator, on cerebral arteries of Zucker obese (ZO) rats with insulin resistance and lean (ZL) controls. Diameter measurements showed diminished diazoxide-induced vasodilation in ZO compared with ZL rats. Maximal relaxation was 38 ± 3% in ZL vs. 21 ± 4% in ZO rats ( P < 0.05). Iberiotoxin, a Ca2+-activated K+ channel inhibitor, or manganese(III) tetrakis(4-benzoic acid)porphyrin chloride, an SOD mimetic, or endothelial denudation diminished vasodilation to diazoxide, implicating Ca2+-activated K+ channels, ROS, and endothelial factors in vasodilation. Inhibition of nitric oxide synthase (NOS) in ZL rats diminished diazoxide-induced vasodilation in intact arteries, but vasodilation was unaffected in endothelium-denuded arteries. In contrast, NOS inhibition in ZO rats enhanced vasodilation in endothelium-denuded arteries, but intact arteries were unaffected, suggesting that activity of endothelial NOS was abolished, whereas factors derived from nonendothelial NOS promoted vasoconstriction. Fluorescence microscopy showed decreased mitochondrial depolarization, ROS production, and nitric oxide generation in response to diazoxide in ZO arteries. Protein and mRNA measurements revealed increased expression of endothelial NOS and SODs in ZO arteries. Thus, cerebrovascular dilation to mitochondria-derived factors involves integration of endothelial and smooth muscle mechanisms. Furthermore, mitochondria-mediated vasodilation was diminished in ZO rats due to impaired mitochondrial KATP channel activation, diminished mitochondrial ROS generation, increased ROS scavenging, and abnormal NOS activity.

We have demonstrated recently [Callera, Touyz, Teixeira, Muscara, Carvalho, Fortes, Schiffrin and Tostes (2003) Hypertension 42, 811–817] that increased vascular oxidative stress in DOCA (deoxycorticosterone acetate)-salt rats is associated with activation of the ET (endothelin) system via ETA receptors. The exact source of ET-1-mediated oxidative stress remains unclear. The aim of the present study was to investigate whether ET-1 increases generation of ROS (reactive oxygen species) in DOCA-salt hypertension through NADPH-oxidase-dependent mechanisms. Xanthine oxidase, eNOS (endothelial nitric oxide synthase) and COX-2 (cyclo-oxygenase-2) were also examined as potential ET-1 sources of ROS as well as mitochondrial respiration. DOCA-salt and control UniNX (uninephrectomized) rats were treated with the ETA antagonist BMS182874 (40 mg·day−1·kg−1 of body weight) or vehicle. Plasma TBARS (thiobarbituric acid-reacting substances) were increased in DOCA-salt compared with UniNX rats. Activity of NADPH and xanthine oxidases in aorta, mesenteric arteries and heart was increased in DOCA-salt rats. BMS182874 decreased plasma TBARS levels without influencing NADPH and xanthine oxidase activities in DOCA-salt rats. Increased p22phox protein expression and increased p47phox membrane translocation in arteries from DOCA-salt by rats were not affected by BMS182874 treatment. Increased eNOS and COX-2 expression, also observed in aortas from DOCA-salt rats, was unaltered by BMS182874. Increased mitochondrial generation of ROS in DOCA-salt rats was normalized by BMS182874. ETA antagonism also increased the expression of mitochondrial MnSOD (manganese superoxide dismutase) in DOCA-salt rats. In conclusion, activation of NADPH oxidase does not seem to be the major source of oxidative stress induced by ET-1/ETA in DOCA-salt hypertension, which also appears to be independent of increased activation of xanthine oxidase or eNOS/COX-2 overexpression. Mitochondria may play a role in ET-1-driven oxidative stress, as evidenced by increased mitochondrial-derived ROS in this model of hypertension.

Abstract Manganese superoxide dismutase (SOD2) detoxifies superoxide anion radicals generated by mitochondrial respiration (Weisiger and Fridovich, J. Biol. Chem. 1973). While SOD2-deficiency is lethal, SOD2-deficient (SOD2−/−) hematopoietic stem cells can rescue lethally irradiated wild-type mice. SOD2−/− hematopoietic chimeras show a persistent hemolytic anemia similar to human sideroblastic anemia (Friedman et al. J. Exp. Med. 2001). SOD2−/− erythroid progenitor cells have increased mitochondrial mass, and reticulocytes show mitochondrial iron deposition. Mature RBC show abundant siderotic granules, evidence of a defect in iron incorporation into heme, and shortened lifespan. SOD2−/− progenitors and mature RBC show both enhanced reactive oxygen species production and protein oxidative damage (Friedman et al. Blood 2004; Martin et al. Submitted). To define early events in the pathogenesis of the SOD2-deficiency anemia and, in particular to identify genes involved in the response of erythroid progenitors to oxidative stress, we compared gene expression of sorted TER-119+ CD71+ erythroblasts from SOD2−/−versus wild-type hematopoietic stem cells recipients. Using cDNA microarrays and class comparison analysis, we identified 600 transcripts as significantly discriminant between genotypes. Analysis showed that eleven transcripts encoding different subunits of the mitochondrial oxidative phosphorylation, ATP synthase, and TCA cycle were down-regulated in SOD2−/− erythroblasts. Previous work showed similar results at the protein level in SOD2−/− RBC (Friedman et al. Blood 2004) and at the activity level in specific tissues of SOD2−/− neonates prior to death (Melov et al. PNAS 1999). One interpretation is that SOD2−/− erythroblasts show metabolic decline. Of interest, a single transcript involved in iron homeostasis, Trfr, was found to be expressed at twice the levels found in wild-type erythroblasts (p&lt;0.0007, parametric p value). Trfr encodes transferrin receptor 1; two-fold up-regulation of transferrin receptor 1 was also shown at the protein level by flow cytometry analysis of SOD2−/− erythroblasts (p&lt;0.0001, unpaired two-tailed t-test). Transferrin receptor 1 is the cellular gatekeeper for iron uptake whose genetic inactivation induces abnormal erythropoiesis and iron homeostasis (Levy et al. Nat. Genet. 1999). The stability of the Trfr transcript is highly regulated by iron regulatory proteins (IRPs), that are known to be controlled by numerous effectors including reactive oxygen species (Hentze et al. Cell 2004, for review). We focus our current work on investigating, in vitro and in vivo, the role that up-regulation of transferrin receptor 1, likely through oxidative stress-mediated IRPs activity regulation, plays in iron overload in our SOD2-deficiency model. Taken together, our findings raise the possibility that increased iron delivery may be sufficient to cause sideroblastic anemia or may contribute to a self-reinforcing cycle where oxidative stress favors increased iron, and increased iron results in enhanced oxidative damage.

Dairy cows usually experience negative energy balance coupled with an increased incidence of fatty liver during the periparturient period. The purpose of this study was to investigate the effect of hepatic steatosis on the expression of the sirtuin 1 (SIRT1), along with the target mRNA and protein expressions and activities related to lipid metabolism in liver tissue. Control cows (n = 6, parity 3.0 ± 2.0, milk production 28 ± 7 kg/d) and mild fatty liver cows (n = 6, parity 2.3 ± 1.5, milk production 20 ± 6 kg/d) were retrospectively selected based on liver triglycerides (TG) content (% wet liver). Compared with the control group, fatty liver cows had greater concentrations of cholesterol and TG along with the typically vacuolated appearance and greater lipid droplets in the liver. Furthermore, fatty liver cows had greater mRNA and protein abundance related to hepatic lipid synthesis proteins sterol regulatory element binding proteins (SREBP-1c), long-chain acyl-CoA synthetase (ACSL), acyl-CoA carbrolase (ACC) and fatty acid synthase (FAS) and lipid transport proteins Liver fatty acid binding protein (L-FABP), apolipoprotein E (ApoE), low density lipoprotein receptor (LDLR) and microsomal TG transfer protein (MTTP) (p < 0.05). However, they had lower mRNA and protein abundance associated with fatty acid β-oxidation proteins SIRT1, peroxisome proliferator-activated receptor co-activator-1 (PGC-1α), peroxisome proliferator–activated receptor-α (PPARα), retinoid X receptor (RXRα), acyl-CoA 1 (ACO), carnitine palmitoyltransferase 1 (CPT1), carnitine palmitoyltransferase 2 (CPT2) and long- and medium-chain 3-hydroxyacyl-CoA dehydrogenases (LCAD) (p < 0.05). Additionally, mRNA abundance and enzyme activity of enzymes copper/zinc superoxide dismutase (Cu/Zn SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and manganese superoxide dismutase (Mn SOD) decreased and mRNA and protein abundance of p45 nuclear factor-erythroid 2 (p45 NF-E2)-related factor 1 (Nrf1), mitochondrial transcription factor A (TFAM) decreased (p < 0.05). Lower enzyme activities of SIRT1, PGC-1α, Cu/Zn SOD, CAT, GSH-Px, SREBP-1c and Mn SOD (p < 0.05) and concentration of reactive oxygen species (ROS) were observed in dairy cows with fatty liver. These results demonstrate that decreased SIRT1 associated with hepatic steatosis promotes hepatic fatty acid synthesis and inhibits fatty acid β-oxidation. Hence, SIRT1 may represent a novel therapeutic target for the treatment of the fatty liver disease in dairy cows.

Green gram (Vigna radiata) is considered the chief legume in Pakistan. Thus, current study was conducted to examine the ameliorating effect of phytohormones pre-treatments under salt stress on proteome profile of green gram by sodium-dodecyl-sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The soluble green gram seedlings proteins were resolved on 4% stacking and 12% resolving gels. The SDS-PAGE resolved 24 polypeptide bands ranging from 200 to 17kDa. Among these, 12 out of 24 bands of proteins were essentials house-keeping or growth proteins of green grams. While, 120, 114.6, 51.8, 29.1, and 22.8 kDa bands were over-expressed under 50 to 350mM salt with phytohormones treatments. The others 104.5 kDa, 99.8 kDa, 95.3 kDa, 91.0 kDa, 55 kDa, 46 kDa, and 17kDa bands were related to the GAᴣ, IAA, and SA induced tolerance. Overall 120 kDa, 114.6 kDa, 104.5 kDa, 99.8, 95.3 kDa, 51.8 kDa, 29.1 kDa and 22.8kDa bands were first time identified in the current study. The information retrieved from NCBI protein database, the resolved peptides were principally belonging to 7S and 8S vicilin, 2S, 8S, 11S, and 16.5S globulins. It is determined that seed priming with SA enhanced tolerance in green gram by rapidly synthesizing stress alleviating peptides.Key word: Cluster analysis, dendrogram, mungbean, salt stress, SDS-PAGEINTRODUCTIONVarious world-wide health concerning organization recommended the use of high graded plant protein such as legumes to prevent the risk of metabolic disorder (Hou et al., 2019). Legumes are most important protein crop on the earth. Among the legumes, the green gram is the major pulses. Its seeds are rich in superior quality storage protein, which account 85% of the total protein while, another 15% have not been broadly studied (Yi-Shen et al., 2018). The soluble storage protein comprises of 60% globulins, 25% albumin and 15% prolamins. Globulins are further divided into 3.4% basic-type (7S), 7.6% legumin-type (11S), and 89% vicilin-type (8S) (Mendoza et al., 2001; Itoh et al., 2006). Other than proteins, the green gram seeds also contain starch, fiber, phenolic compound, saponins, vitamins, calcium zinc, potassium, folate, magnesium, manganese and very low in fat that made it meager man’s meat (Hou et al., 2019). It is also a good source of green manure and fodder (El-Kafafi et al., 2015). Its root has ability to fix 30 to 50 Kg/ha atmospheric nitrogen in the soil which is essential for maintaining soil fertility (Chadha, 2010). The green gram is the valuable and the major Rabi pulse crop of Pakistan. Its cultivation area in 2016-2017 was about 179,000 hectares with seed yield of 130,000 tones. In comparison during 2017-2018, it was cultivated on 161,800 hectares land with 118,800 tones seed yield (GOP, 2018). One of the reasons of this 9% decrease in both land and productivity is the shortage of irrigated land due to soil salinity. The salinity induce oxidative bust in the mungbean cells, caused by responsive oxygen species (ROS) such as hydrogen peroxide, singlet oxygen, hydroxyl radical and superoxide radical. The ROS create hindrance in various metabolic processes of plant via interacting with macromolecules like proteins (Alharby et al., 2016). However, phytohormones like gibberellic acid (GAᴣ), indole acetic acid (IAA), and salicylic acid (SA) take part in the biosynthesis of salt tolerance proteins under salinity. These salt tolerance proteins acclimate plants under salinity stress. Application of biotechnology plays a significant role in agriculture (Khan et al., 2017). Therefore, production of particular proteins under salt stress is a specific response of cell which can be analyzed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). SDS-PAGE is the simple, valid, and cost-effective biochemical marker (Mushtaq et al., 2018). This marker has been widely used to determine the extent of evolutionary variations in crops (El-Kafafi et al., 2015).OBJECTIVES The present study was directed first time with the aim to investigate the toxic effect of sodium chloride (0-350 mM) and stress acclimation by pre-treatment of GAᴣ, IAA, and SA on the proteome profile of NM-92 cultivar of a Pakistani green gram.MATERIALS AND METHODSThe present study was replicated thrice in the plant laboratory of Department of Genetics, Faculty of Science, and University of Karachi. The seeds of mung bean cultivar NM-92 were acquired from National Agricultural Research Centre (NARC), Islamabad. These freshly collected 15 seedsˉ1 treatment / replication were divided into two sets. The first was named as sodium chloride (SC) stress treatments were imbibed in sterile distilled water (DW) whereas, second set soaked in gibberellic acid (GAᴣ) (BDH Chemicals, England), indole acetic acid (IAA) (Fluka, Switzerland), and salicylic acid (SA) (J.T. Baker, Holland) in the separate beaker for 24 hours under dark condition. After 24 hours, given ample time to both the sets at room temperature. After recovery, all 20 treatments were sown in the 150 X 30 mm sized petri-dishes containing 0, 50, 150, 250, and 350 millimolar (mM) sodium chloride solution (Fisher Scientific, UK) for 72 hours.Protein extraction: Protein extraction was done by taking 0.3g of seedlings in an ice chilled mortar and crushed by adding 600µL 0.2 M Tris-HCl buffer having pH 7.5 contained 5% SDS (w/v) and 5% 2-mercaptoethanol (v/v). The homogenate was incubated at 0oC for 30 min., boiled in the water bath for 3 min. at 100oC. Samples were centrifuged in Heraeus Biofuge D-37520, Germany for 30 min. at 8000 rpm. The protein supernatant was saved at below 0°C for quantitative and qualitative determination with minor modifications. The total soluble protein content of the samples was estimated via “Bovine Serum Albumin (BSA) standard curve” and explicit in µg protein milligramˉ1 fresh weight of mung seedlings.Bovine serum albumin standard curve (2000 μg/mL): Total protein standard curve was made by dissolving 0.05g of Bovine Serum Albumin (BSA) in 25mL of distilled water. Ten serial dilutions were made from 0.1 mL to 1mL by BSA solution then performed Lowry. A standard curve of total proteins was plotted by taking BSA absorbance at Y-axis and 2000 μg BSA / mL at X-axisSample preparation for SDS-PAGE: For qualitative assessment of total proteins; the 35μL of saved protein supernatant was combined with 15μL of sample diluting buffer (SDB). The SDB was made up of 0.0625 M Tris-HCl pH 6.8 with 2% of SDS, 10% of glycerol, 0.003% of bromophenol blue dye and 5% of 2-mercaptoethanol. Boil the 50μL protein SDB supernatant at 100oC in water bath for 3 min., centrifuged at 6000 rpm for 4 min. The supernatant was loaded on SDS-PAGE gel with the given formulae. The SDS- PAGE: Total proteins were fractionated via SDS-PAGE with 4% stacking and 12% resolving gel. The resolving gel of 12% was made by taking 6mL solution A, 1.8 mL 3 M Tris 1 M HCl buffer pH 8.8, 144μL 10% SDS, 5.74 mL sterile distilled water, 720μL 1.5% ammonium persulphate (APS) in deionized water and 10μL TEMED. While, stacking was composed of 1.25mL of solution A, 2.5mL of 0.5M Tris 1M HCl buffer pH 6.8, 100μL 10% SDS, 1.8 mL of distilled water, 500μL 1.5% APS and 12μL TEMED. Solution A was prepared by conjoining 30% acrylamide and 0.8% N, N’-methylene-bisacrylamide in deionized water. To avoid polymerization in the beaker; the prepared solution was quickly poured into the 3 mm thick gel plates after adding TEMED. The stacking was lined over resolving gel, then combs were inserted between the gel plates of SCIE-PLAS TV-100 separation system, UK, and allowed to polymerize for ½ an hour. After polymerization gel was placed in the tank which were filled with Tris-Glycine buffer (electrode buffer) pH 8.4 then combs were removed. The electrode buffer contained 0.3% Tris, 1.41% Glycine and 0.1% SDS in 2000mL d/w. The gel was pre-run for 15 min. at 60 volts and 120 mA currents. The prepared SDS-PAGE samples were loaded in wells with BlueStepTM Broad Range Protein Marker, AMRESCO, USA as standard and run at 60 volts & 120 mA for about 45 min. When samples entered in resolving gel, and then gave 100 volts and 200 mA currents for around 2.5 hours. Furthermore, electrophoresis was carried out at a constant watt.The Gel was washed with 30% ethanol on Uni Thermo Shaker NTS-1300 EYELA, Japan at the constant shaking for 30 min. Then gels were placed in 10% glacial acetic acid in 50% methanol solution (Fixative) for 24 hours. SDS Gel was stained until protein bands were visible thereat placed as 5% of Methanol in 7.5% acetic acid glacial solution to destain the bands background. SDS-PAGE stain composed of 0.125% coomassie brilliant blue R-250 dissolved in 40% of Methanol and 7% acetic acid glacial solution. The stain was stirred on Magnetic stirrer & hot plate M6/1, Germany for 6-10 hours before used. Photographs were taken by Sanyo digital camera VPC-T1284BL and bands were scored through numbering pattern. Gels preserved in 10% acetic acid solution at 4°C.Interpretation of bands and data analysis: The total soluble protein bands relative mobility calculated by below formulae and Dendrogram was constructed via SPSS v. 20Where,F=(Migrated distance of protein band)/(Migrated distance of dye front)Slop=(Log MW of protein marker lower limit band–log〖MW of protein marker upper limit band )/(RF protein marker lower limit band –RF of protein marker upper limit band)RESULTS:The total soluble proteins extracted from green gram were perceived by SDS-PAGE Blue StepTm broad range biochemical markers. The protein-based marker was used to evaluate the toxic effect of sodium chloride along with pre-treatments of GAᴣ, IAA, and SA on proteome assay. In the current work, seedlings total soluble proteome resolved 24 polypeptide bands ranging from 200 to 17.1 kDa were recognized by using SDS-PAGE. The figure 1 showed Dendrogram assay, which classified the 20 treatments of SC, GAᴣ, IAA and SA into two major clusters where, the cluster I was the largest one (figure 1). Cluster I consisted of 15 treatments that further divided into I-A, and I-B. The pre-treatments of SC50+SA, SC150+SA, SC250+SA, and SC350+IAA were grouped together into C-1 of sub-cluster I-A. The C-2 of sub-cluster I-A, pre-treatment SC350+SA was most diverse among 20 treatments. The C-1 treatments showed 99% homology when compared with each other while, it was 97% similar with C-2. The sub-cluster I-B comprised another 10 treatments, SC0+GAᴣ, SC50+GAᴣ, SC150+GAᴣ, SC250+GAᴣ, SC350+GAᴣ, SC0+IAA, SC50+IAA, SC150+IAA, SC250+IAA, and SC0+SA that were also 99% similar for total proteins. Sub-cluster I-B pre-treatments was exhibiting 94% homology with the sub-cluster I-A. The second cluster was the smallest one that was divided into two sub-clusters, II-A and II-B. The II-A was comprised of SC50, SC150, and SC250 while, sub-cluster II-B consisted of SC0 and SC350. Within each sub-cluster, pre-treatments expressed 99% homology whereas, II-A was 97 different from II-B. Furthermore, cluster I showed 75% similarities with cluster II (figure 1). The seedlings storage proteome profile of green gram was shown in table 1.The results showed that 120kDa, 114.6 kDa, 51.8 kDa, 29.1 kDa and 22.8 kDa proteins bands were not induced at 0 mM SC, GAᴣ, IAA, and SA. The table 1 depicted the presence of 120 kDa and 114.6 kDa bands only at 350 mM SC level with all phytohormones treatments. Similarly, 51.8 kDa protein bands were appearing at 150SC, 250SC and 350SC stress with phytohormones. Based on the information collected from the NCBI protein database, this peptide was related to the 8S globulin alpha subunits. The two other, 7S globulins sub-units having 29.1kDa and 22.8 kDa molecular weights bands were synthesized under 50mM, 150mM, 250mM, 350mM SC stress with phytohormones. Concerning protein polypeptide of molecular weight 104.5 kDa, 99.8 kDa, 91.0 kDa, 55.0 kDa, and 46.0 kDa, those were induced by GAᴣ, IAA and SA at 0 to 350 mM SC. While, 17kDa protein band was appearing in SA, and IAA treated samples and 95.3kDa band was only present in SA treatment. Other 12 protein bands were present in all treatments proved as house-keeping proteins of green gram (table 1).DISCUSSIONThe SDS-PAGE profiling for proteome is the reliable and applied biochemical approach that has been used as biochemical marker in various crop differentiation, and characterization. In the current study, first time SDS-PAGE was utilized to investigate the impact of GAᴣ, IAA, and SA pre-soaking on green gram under salt toxicity. The salt toxicity adversely affects all seed, seedling, and plant metabolic process (Parveen et al., 2016). At salt toxicity, the endogenous GAᴣ, IAA, and SA levels markedly decrease (El-Khallal et al., 2009). In such condition, exogenous application of GAᴣ, IAA, and SA enhance seedlings survival rate by increasing synthesis of seed storage proteins. Likewise, our Dendrogram characterization based on 20 treatments showed significant diversity under 0 to 350 mM SC stress. The salicylic acid treatments were grouped together except SC0+SA treatment, exhibiting a close relationship, which proved its acclimating role under salt stress. These findings will help plant breeder toward enhancing food quality and quantity of green gram in future breeding programme on saline sodic land.The SDS-PAGE assay revealed 200. kDa, 109.4 kDa, 77 kDa, 68 kDa, 49 kDa, 38 kDa, 33 kDa, 26 kDa, 24 kDa, 22 kDa, 21 kDa and 19 kDa fractions as essential green gram proteins. Among these, 68 kDa, 49 kDa, 33 kDa, 26 kDa, 24 kDa and 21 kDa peptides were seed biotinylated isoform protein (Riascos et al., 2009), putative NADH-ubiquinone oxidoreductase subunit H (Gostinčar et al., 2019), heat shock protein 33 (Hamidian et al., 2015), globulin protein, seed coat / maturation protein (Dhaubhadel et al., 2005), and protein for dimerization. While, 22 kDa proteins belonged to the class of prolamin alpha zein Z1C1_2, Z1C1_4, and Z1C1_8 precursors, and 19kDa peptide was related with Z1A1_2, Z1A2_2, and Z1B_6 precursors (Miclaus et al., 2011). Further, the 91 kDa peptide is sucrose synthase SS1 protein, and 77kDa protein is the NADPH-cytochrome P450 reductase (Wang et al., 2004). Also, the phosphatase-associated two other proteins having 46 and 55 kDa molecular weight were reported earlier in Mucuna pruriens. Hameed et al. (2012) and Malviya et al. (2008) found 55 and 46kDa peptides as 7S vicilin small sub-units and 17kDa as 11S globulins sub-unit in the studied Vigna radiata. Some other molecular weight proteome such as 68 kDa and 49kDa are 7S vicilin, 33kDa is 8S vicilin, 38 and 26kDa 8S globulins, 24kDa 11S globulins, and 22kDa 16.5S globulins. These proteins required for germination and seed establishment of green gram plant (Hameed et al., 2012).The vast accumulation of 23kDa and 22kDa peptides under salt stress by salicylic acid, were reported previously in the mangrove Bruguiera parviffora and Zea mays (El-Khallal et al., 2009). Correspondingly, El-Kafafi et al. (2015) reported the presence of 115kDa, 23kDa, and 22kDa bands in the salt tolerant lines of green gram. These proteomes induced under salt stress may play a pivotal part in the stress acclimation and osmotic adjustment. Similarly, the induction of 104 kDa and 100kDa MW polypeptide by SC stress in the salt tolerant genotypes of green gram indicated the functional role of phytohormones in various metabolic and defense response El-Kafafi et al. (2015); Alharby et al. (2016), El-Khallal et al. (2009), Qados (2010). Ali et al. (2007), Alharby et al. (2016), and El-Kafafi et al. (2015) observed 17kDa, 26kDa, 33kDa and 77kDa bands involving in salt tolerance and can be considered as a positive biochemical marker for salt stress. Further, 26 kDa MW peptide also functions as osmotin under the salt stress that involved in enhancing the accumulation of glycine betaine and proline in the cells. Hence, proteome assay of green gram showed that GAᴣ, IAA, and SA could regulate the expression of salt stress proteins that are anticipated to play a crucial part in the salt tolerance mechanism. Likewise, the involvement of phytohormones in the induction of changes in the proteome profile pattern was attributed to their part in managing cell division by regulating some genes of apical meristems.CONCLUSIONFinally, the results revealed the presence of the ten new bands with MW of 200kDa, 120 kDa, 114.6 kDa, 109.4kDa, 104.5kDa, 99.8kDa, 95.3kDa, 51.8kDa, 29.1kDa and 22.8kDa have not reported previously under salt stress with phytohormones treatments in green gram. Furthermore, it was observed that phytohormones alleviate the negative impact of salt stress on green gram by enhancing synthesis of salt defense polypeptides. Hence, higher accumulation of proteins was observed in salicylic acid treated seedlings. Thus, present work recommended the pre-soaking of phytohormones to overcome the toxic impact of sodium chloride on green gram. 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AbstractThe iron and manganese complexes that activate oxygen atom play multiple role in technologically relevant reactions as well as in biological transformations, in which exist in different redox states. Among them, high-valent oxo intermediate seems to be the most important one. Iron, and/or manganese-based processes have found application in many areas, starting from catalysis and sustainable technologies, through DNA oxidative cleavage, to new substances useful in chemotherapeutic drugs. This review is not only the latest detailed list of uses of homogeneous N-pentadentate iron and manganese catalysts for syntheses of valuable molecules with huge applications in green technologies, but also a kind of "a cookbook", collecting "recipes" for the discussed complexes, in which the sources necessary to obtain a full characterization of the compounds are presented. Following the catalytic activity of metalloenzymes, and taking into account the ubiquity of iron and manganese salts, which in combination with properly designed ligands may show similarity to natural systems, the discussed complexes can find application as new anti-cancer drugs. Also, owing to ability of oxygen atom to exchange in reaction with H2O, they can be successfully applied in photodriven reactions of water oxidation, as well as in chemically regenerated fuel cells as a redox catalyst. Graphical abstract

Background: Oxidative stress is one of the most crucial factors that develop chronic heart failure (CHF), leading to cardiac apoptosis and fibrosis and vascular endothelial dysfunction. We have reported that Waon therapy, which is a form of thermal therapy using a far infrared-ray dry sauna at 60 degrees centigrade, improves cardiac and vascular endothelial functions and prognosis in patients with CHF. The aim of this study is to investigate whether Waon therapy reduces oxidative stress and prevents from developing cardiac dysfunction in CHF. Methods: Thirty-week old male TO-2 cardiomyopathic hamsters with CHF were divided into Waon therapy or control group. Waon therapy group underwent Waon therapy daily for 4 weeks. Control hamsters did not take any treatment. We examined the amounts of reactive oxygen species of serum, hearts and aortas using ELISA and immunohistochemistry. We measured left ventricular % fractional shortening (LV%FS), and performed TUNEL and Azan staining of hearts to assess cardiac function, apoptosis and fibrosis, respectively. Anti-oxidants and apoptotic and angiogenetic factors were assessed by Western blot. All examinations were performed after 4 weeks of treatment. Results: Four-week Waon therapy significantly decreased oxidative stress of serum, hearts and aortas compared to those of controls. Waon therapy significantly increased LV%FS and decreased cardiac apoptosis and fibrosis (LV%FS, Waon therapy: 23.3±4.3 vs. control: 16.5±4.2%, P<0.01, TUNEL positive nuclei, 22.0±2.6 vs. 49.3±7.2%, P<0.01, % fibrosis, 20.6±5.3 vs. 47.6±4.8%, P<0.01). Waon therapy significantly increased the expressions of manganese superoxide dismutase, heat shock protein 27 (HSP27) and HSP32 of hearts and aortas, which negatively modulate oxidative stress, compared to those of controls. Waon therapy significantly increased endothelial nitric oxide synthase and decreased plasminogen activator inhibitor-1 of aortas. In addition, Waon therapy significantly decreased Bax, cleaved caspase 3 and cytochrome c and increased Bcl-2 and hypoxia-inducible factor-1α of the failing hearts. Conclusions: Waon therapy reduces oxidative stress systemically and inhibits the progression of cardiac dysfuntion in TO-2 cardiomyopathic hamsters.