Impact of carvedilol on the mitochondrial damage induced by hypoxanthine and xantine oxidase: what role in myocardial ischemia and reperfusion?

OBJECTIVES: The cardioprotective effects of carvedilol (CV) may be explained in part by interactions with heart mitochondria. The objective of this work was to study the protection afforded by CV against oxidative stress induced in isolated heart mitochondria by hypoxanthine and xanthine oxidase (HX/XO), a well-known source of reactive oxygen species (ROS) in the cardiovascular system. METHODS: Mitochondria were isolated from Wistar rat hearts (n = 8) and incubated with HX/XO in the presence and in the absence of calcium. Several methods were used to assess the protection afforded by CV: evaluation of mitochondrial volume changes (by measuring changes in the optical density of the mitochondrial suspension), calcium uptake and release (with a fluorescent probe, Calcium Green 5-N) and mitochondrial respiration (with a Clark-type oxygen electrode). RESULTS: CV decreased mitochondrial damage associated with ROS production by HX and XO, as verified by the reduction of mitochondrial swelling and increase in mitochondrial calcium uptake. In the presence of HX and XO, CV also ameliorated mitochondrial respiration in the active phosphorylation state and prevented decrease in the respiratory control ratio (p < 0.05) and in mitochondrial phosphorylative efficiency (p < 0.001). CONCLUSIONS: The data indicate that CV partly protected heart mitochondria from oxidative damage induced by HX and XO, which may be useful during myocardial ischemia and reperfusion. It is also suggested that mitochondria may be a priority target for the protective action of some compounds

Clinical and quality-of-life assessment among women with temporomandibular disorder

OBJETIVOS: Este estudo teve como objetivo avaliar sintomas de dor, apertamento dos dentes, qualidade do sono e sensibilidade dolorosa nos principais músculos mastigatórios e estabilizadores cervicais e qualidade de vida de mulheres com Disfunção Temporomandibular (DTM). MÉTODOS: Foram avaliadas 45 mulheres, divididas em dois grupos. O grupo I, composto por 27 mulheres (30,1±5,8anos) com diagnóstico de DTM e o grupo II, controle, composto por 18 mulheres saudáveis (23,4±2,3 anos). A intensidade dos sintomas de dor, cefaleia, cervicalgia, de apertamento dos dentes e dificuldade de dormir foram avaliados por escala visual analógica (EVA), o limiar de dor dos músculos masseter, temporal anterior, trapézio superior e esternocleidomastoideo, com dolorímetro e a qualidade de vida, pelo SF-36. Foi realizada análise estatística e o nível de significância foi &#945;=0,05. RESULTADOS: Os resultados mostram que mulheres com DTM têm sintomas mais intensos de cefaleia (p<0,001), cervicalgia (p<0,001), intensidade de apertamento dos dentes (p<0,001) e dificuldade de dormir (p<0,001). Também apresentam limiar de dor mais baixo nos músculos masseter (p<0,001), temporal anterior (p<0,001), trapézio superior (p<0,001), esternocleidomastoideo (p<0,001) e pior qualidade de vida em todos os domínios avaliados (p<0,05), quando comparados com o grupo controle. CONCLUSÕES: Mulheres com DTM têm maior intensidade dos sintomas de dor, apertamento dos dentes, dificuldade de dormir, maior sensibilidade dolorosa em músculos mastigatórios e cervicais e pior qualidade de vida quando comparadas com mulheres sem DTM.OBJECTIVES: The aim of this study was to evaluate pain symptoms, teeth clenching, quality of sleep, sensitivity to pain in the main masticatory and stabilizer muscles, and quality of life among women with temporomandibular disorder (TMD). METHODS: Forty-five women were evaluated and divided into two groups. Group I included 27 women (mean age 30.1±5.8 years) with a diagnosis of TMD and Group II (control) included 18 healthy women (mean age 23.4±2.3 years). The intensity of pain symptoms (headache, neck pain), teeth clenching and trouble sleeping was evaluated using a visual analog scale (VAS). The pain thresholds of the masseter, anterior temporalis, upper trapezius and sternocleidomastoid muscles were evaluated using a dolorimeter. Quality of life was evaluated using SF-36. Statistical analysis was performed and the significance level was &#945;<0.05. RESULTS: The results showed that the women with TMD presented more intense headache (p<0.001), neck pain (p<0.001), teeth clenching (p<0.001) and trouble sleeping (p<0.001). They also presented lower pain threshold in the masseter (p<0.001), anterior temporalis (p<0.001), upper trapezius (p<0.001) and sternocleidomastoid (p<0.001) muscles and lower quality of life in all evaluated domains (p<0.05) when compared with the control group. CONCLUSIONS:Women with TMD had greater intensity of pain symptoms, teeth clenching, trouble sleeping, sensitivity to pain in the masticatory and neck muscles and lower quality of life, compared with women without TMD

Advantages in the use of carvedilol versus propranolol for the protection of cardiac mitochondrial function

BACKGROUND: Carvedilol is a neurohormonal antagonist of multiple action which is used in clinical practice for the treatment of congestive heart failure, mild to moderate hypertension and myocardial infarction. Previous results from our group have demonstrated that one of the main targets for the protective effect of carvedilol is the cardiac mitochondrial network. In-this work, we compare the effect of carvedilol with propranolol in different models of mitochondrial dysfunction and in the generation of transmembrane electric potential (EP). We further tested if carvedilol was able to inhibit the mitochondrial permeability transition (MPT) induced by doxorubicin and calcium-dependent cytochrome c release, a phenomenon frequently associated with apoptotic cell death. METHODS: Cardiac mitochondria were isolated by differential centrifugation. Oxygen consumption and mitochondrial EP were determined using an oxygen electrode and a tetraphenylphosphonium-sensitive electrode, respectively. Changes in mitochondrial volume and the release of cytochrome c were measured with spectrophotometric techniques. RESULTS: Propranolol, compared with carvedilol, had only a marginal effect, not only in protection against MPT induction, but also against oxygen consumption linked to the oxidation of external NADH, a process that is considered by several authors as key in the cardiotoxicity of doxorubicin. Regarding EP generation, propranolol had no effect, in contrast to carvedilol, which was confirmed to act as a protonophore. For the first time we also show that carvedilol inhibits the MPT induced by doxorubicin and calcium-dependent cytochrome c release. CONCLUSIONS: With this work, we further support the notion that carvedilol is effective in several models of mitochondrial dysfunction, particularly those involving oxidative stress. The results demonstrate that for some pathological conditions, carvedilol and propranolol have different mechanisms of action at the sub-cellular level, as propranolol seems to lack effectiveness in the protection of cardiac mitochondria

Histological changes and impairment of liver mitochondrial bioenergetics after long-term treatment with alpha-naphthyl-isothiocyanate (ANIT)

This study was designed to evaluate the effects of long-term treatment with alpha-naphthyl-isothiocyanate (ANIT) on liver histology and at the mitochondrial bioenergetic level. Since, ANIT has been used as a cholestatic agent and it has been pointed out that an impairment of mitochondrial function is a cause of hepatocyte dysfunction leading to cholestatic liver injury, serum markers of liver injury were measured and liver sections were analyzed in ANIT-treated rats (i.p. 80 mg/kg/week x 16 weeks). Mitochondrial parameters such as transmembrane potential, respiration, calcium capacity, alterations in permeability transition susceptibility and ATPase activity were monitored. Histologically, the most important features were the marked ductular proliferation, proliferation of mast cells and the presence of iron deposits in ANIT-treated liver. Mitochondria isolated from ANIT-treated rats showed no alterations in state 4 respiration, respiratory control ratio and ADP/O ratio, while state 3 respiration was significantly decreased. No changes were observed on transmembrane potential, but the repolarization rate was decreased in treated rats. Consistently with these data, there was a significant decrease in the ATPase activity of treated mitochondria. Associated with these parameters, mitochondria from treated animals exhibited increased susceptibility to mitochondrial permeability transition pore opening (lower calcium capacity). Since, human cholestatic liver disease progress slowly overtime, these data provide further insight into the role of mitochondrial dysfunction in the process

Brazilian Contemporary Art in the International Art Market

With changes in the art world, the Brazilian Contemporary art becomes an interesting subject to be analyzed in its relationship to the art market dynamics. The international art market has been growing since late 90s thanks to globalization. In this sense, the problematization of the research lies in an economical perspective of the art market to understand Brazilian Contemporary art internationalization through art fairs, biennials, art galleries and auction houses. With this analysis, the objective is to present an opinion about the panorama of Brazilian Contemporary art and its international market insertion

Molecular basis of FIR-mediated c-myc transcriptional control

The far upstream element (FUSE) regulatory system promotes a peak in the concentration of c-Myc during cell cycle. First, the FBP transcriptional activator binds to the FUSE DNA element upstream of the c-myc promoter. Then, FBP recruits its specific repressor (FIR), which acts as an on/off transcriptional switch. Here we describe the molecular basis of FIR recruitment, showing that the tandem RNA recognition motifs of FIR provide a platform for independent FUSE DNA and FBP protein binding and explaining the structural basis of the reversibility of the FBP-FIR interaction. We also show that the physical coupling between FBP and FIR is modulated by a flexible linker positioned sequentially to the recruiting element. Our data explain how the FUSE system precisely regulates c-myc transcription and suggest that a small change in FBP-FIR affinity leads to a substantial effect on c-Myc concentration.MRC Grant-in-aid U11757455

'Special K' and a loss of cell-to-cell adhesion in proximal tubule-derived epithelial cells: modulation of the adherens junction complex by ketamine

Ketamine, a mild hallucinogenic class C drug, is the fastest growing ‘party drug’ used by 16–24 year olds in the UK. As the recreational use of Ketamine increases we are beginning to see the signs of major renal and bladder complications. To date however, we know nothing of a role for Ketamine in modulating both structure and function of the human renal proximal tubule. In the current study we have used an established model cell line for human epithelial cells of the proximal tubule (HK2) to demonstrate that Ketamine evokes early changes in expression of proteins central to the adherens junction complex. Furthermore we use AFM single-cell force spectroscopy to assess if these changes functionally uncouple cells of the proximal tubule ahead of any overt loss in epithelial cell function. Our data suggests that Ketamine (24–48 hrs) produces gross changes in cell morphology and cytoskeletal architecture towards a fibrotic phenotype. These physical changes matched the concentration-dependent (0.1–1 mg/mL) cytotoxic effect of Ketamine and reflect a loss in expression of the key adherens junction proteins epithelial (E)- and neural (N)-cadherin and β-catenin. Down-regulation of protein expression does not involve the pro-fibrotic cytokine TGFβ, nor is it regulated by the usual increase in expression of Slug or Snail, the transcriptional regulators for E-cadherin. However, the loss in E-cadherin can be partially rescued pharmacologically by blocking p38 MAPK using SB203580. These data provide compelling evidence that Ketamine alters epithelial cell-to-cell adhesion and cell-coupling in the proximal kidney via a non-classical pro-fibrotic mechanism and the data provides the first indication that this illicit substance can have major implications on renal function. Understanding Ketamine-induced renal pathology may identify targets for future therapeutic intervention

Transcriptome profiling of grapevine seedless segregants during berry development reveals candidate genes associated with berry weight

Indexación: Web of Science; PubMedBackground Berry size is considered as one of the main selection criteria in table grape breeding programs. However, this is a quantitative and polygenic trait, and its genetic determination is still poorly understood. Considering its economic importance, it is relevant to determine its genetic architecture and elucidate the mechanisms involved in its expression. To approach this issue, an RNA-Seq experiment based on Illumina platform was performed (14 libraries), including seedless segregants with contrasting phenotypes for berry weight at fruit setting (FST) and 6–8 mm berries (B68) phenological stages. Results A group of 526 differentially expressed (DE) genes were identified, by comparing seedless segregants with contrasting phenotypes for berry weight: 101 genes from the FST stage and 463 from the B68 stage. Also, we integrated differential expression, principal components analysis (PCA), correlations and network co-expression analyses to characterize the transcriptome profiling observed in segregants with contrasting phenotypes for berry weight. After this, 68 DE genes were selected as candidate genes, and seven candidate genes were validated by real time-PCR, confirming their expression profiles. Conclusions We have carried out the first transcriptome analysis focused on table grape seedless segregants with contrasting phenotypes for berry weight. Our findings contributed to the understanding of the mechanisms involved in berry weight determination. Also, this comparative transcriptome profiling revealed candidate genes for berry weight which could be evaluated as selection tools in table grape breeding programs.http://bmcplantbiol.biomedcentral.com/articles/10.1186/s12870-016-0789-

Why and how might genetic and phylogenetic diversity be reflected in the identification of key biodiversity areas?

‘Key biodiversity areas' are defined as sites contributing significantly to the global persistence of biodiversity. The identification of these sites builds from existing approaches based on measures of species and ecosystem diversity and process. Here, we therefore build from the work of Sgró et al. (2011 Evol. Appl. 4, 326–337. (doi:10.1111/j.1752-4571.2010.00157.x)) to extend a framework for how components of genetic diversity might be considered in the identification of key biodiversity areas. We make three recommendations to inform the ongoing process of consolidating a key biodiversity areas standard: (i) thresholds for the threatened species criterion currently consider a site's share of a threatened species' population; expand these to include the proportion of the species' genetic diversity unique to a site; (ii) expand criterion for ‘threatened species' to consider ‘threatened taxa’ and (iii) expand the centre of endemism criterion to identify as key biodiversity areas those sites holding a threshold proportion of the compositional or phylogenetic diversity of species (within a taxonomic group) whose restricted ranges collectively define a centre of endemism. We also recommend consideration of occurrence of EDGE species (i.e. threatened phylogenetic diversity) in key biodiversity areas to prioritize species-specific conservation actions among sites

Scavenging activity of Magnéli phases as a function of Ti(4+)/Ti(3+) ratios

TiO2 is able to scavenge reactive oxygen and nitrogen species (ROS and RNS) in the absence of light. The scavenging mechanism has been related to the chemistry of defects (oxygen vacancy reduced oxidation states of Ti) but it is still unknown. This study describes the ROS scavenging activity of different titanium oxide phases and relates their scavenging activities with the Ti4+/Ti3+ molar ratio as well as the band gap value. The Ti5O9 phase, with a mixture of both oxidation states, presented a substantially higher percentage of 2,2-diphenyl-1-picrylhydracyl radicals (DPPH) eliminated per m2 of specific surface area in comparison to phases with predominant oxidation states Ti4+ or Ti3+ such as TiO2 and Ti2O3, respectively. The obtained results indicate that the DPPH scavenging mechanism corresponds to a catalytic process on the Ti5O9 surface which is facilitated by the presence of charges that can easily move through the material. The mobility of charges and electrons in the semiconductor surface, related to the presence of oxidation states Ti4+ and Ti3+ and a small band gap, could create an attractive surface for radical species such as DPPH. This puts forward Ti5O9 as a promising candidate coating for implantable biomedical devices, as an electrode, since it can cushion inflammatory processes which could lead to device encapsulation and, consequently, failure.The authors would like to thank the Fundación General CSIC and Obra Social “La Caixa” (Project BIOAMD) for providing financial support to this work. Dr Canillas acknowledges the financial support received from the CSIC for her PhD JAEpre grant and Dr Moreno is grateful to the Fondo Social Europeo and CSIC for her JAEDoc contract