996 resultados para Mitochondrial permeability transition
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BACKGROUND: Alterations in glucose metabolism and epithelial-mesenchymal transition (EMT) constitute two important characteristics of carcinoma progression toward invasive cancer. Despite an extensive characterization of each of them separately, the links between EMT and glucose metabolism of tumor cells remain elusive. Here we show that the neuronal glucose transporter GLUT3 contributes to glucose uptake and proliferation of lung tumor cells that have undergone an EMT. RESULTS: Using a panel of human non-small cell lung cancer (NSCLC) cell lines, we demonstrate that GLUT3 is strongly expressed in mesenchymal, but not epithelial cells, a finding corroborated in hepatoma cells. Furthermore, we identify that ZEB1 binds to the GLUT3 gene to activate transcription. Importantly, inhibiting GLUT3 expression reduces glucose import and the proliferation of mesenchymal lung tumor cells, whereas ectopic expression in epithelial cells sustains proliferation in low glucose. Using a large microarray data collection of human NSCLCs, we determine that GLUT3 expression correlates with EMT markers and is prognostic of poor overall survival. CONCLUSIONS: Altogether, our results reveal that GLUT3 is a transcriptional target of ZEB1 and that this glucose transporter plays an important role in lung cancer, when tumor cells loose their epithelial characteristics to become more invasive. Moreover, these findings emphasize the development of GLUT3 inhibitory drugs as a targeted therapy for the treatment of patients with poorly differentiated tumors.
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Echinococcus granulosus, the etiologic agent of cystic echinococcosis (CE) in humans and other animal species, is distributed worldwide. Ten intra-specific variants, or genotypes (G1-G10), have been defined based on genetic diversity. To determine the genotypes present in endemic areas of Peru, samples were collected from cattle (44), sheep (41) and humans (14) from Junín, Puno Huancavelica, Cusco, Arequipa and Ayacucho. DNA was extracted from protoscolex and/or germinal layers derived from 99 E. granulosus isolates and used as templates to amplify the mitochondrial cytochrome C oxidase subunit 1 gene. The resulting polymerase chain reaction products were sequenced and further examined by sequence analysis. All isolates, independent of the host, exhibited the G1 genotype. Phylogenetic analysis showed that three isolates from Ayacucho shared the same cluster with microvariant G1(4). The G1 genotype is considered the most widespread and infectious form of E. granulosusworldwide and our results confirm that the same patterns apply to this country. Therefore, these findings should be taken into consideration in developing prevention strategies and control programs for CE in Peru.
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Bien que la transition des soins pédiatriques aux soins adultes soit extrêmement importante pour les adolescents souffrant de maladies chroniques, celle-ci se limite le plus souvent à un simple transfert. L'objectif de cet article est de décrire les barrières au bon déroulement de la transition du point de vue du patient et de sa famille, des professionnels de la santé et du système de soins; de détailler les éléments clés pour que la transition soit la moins traumatique possible; et d'énoncer les différentes approches proposées dans la littérature. [Abstract] The transition from pediatric to adult care of chronically ill adolescents Even though the transition from pediatric to adult health care is extremely important for chronically ill adolescents, most of the times it is limited to a simple transfer The objective of this paper is to describe the barriers to a smooth transition from the point of view of the patient and his/her family, the health professionals and the health system, to review the key elements for a smooth transition, and to address the different approaches proposed in the literature.
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BACKGROUND It is known that mitochondria play an important role in certain cancers (prostate, renal, breast, or colorectal) and coronary disease. These organelles play an essential role in apoptosis and the production of reactive oxygen species; in addition, mtDNA also reveals the history of populations and ancient human migration. All these events and variations in the mitochondrial genome are thought to cause some cancers, including prostate cancer, and also help us to group individuals into common origin groups. The aim of the present study is to analyze the different haplogroups and variations in the sequence in the mitochondrial genome of a southern European population consisting of subjects affected (n = 239) and non-affected (n = 150) by sporadic prostate cancer. METHODOLOGY AND PRINCIPAL FINDINGS Using primer extension analysis and DNA sequencing, we identified the nine major European haplogroups and CR polymorphisms. The frequencies of the haplogroups did not differ between patients and control cohorts, whereas the CR polymorphism T16356C was significantly higher in patients with PC compared to the controls (p = 0.029). PSA, staging, and Gleason score were associated with none of the nine major European haplogroups. The CR polymorphisms G16129A (p = 0.007) and T16224C (p = 0.022) were significantly associated with Gleason score, whereas T16311C (p = 0.046) was linked with T-stage. CONCLUSIONS AND SIGNIFICANCE Our results do not suggest that mtDNA haplogroups could be involved in sporadic prostate cancer etiology and pathogenesis as previous studies performed in middle Europe population. Although some significant associations have been obtained in studying CR polymorphisms, further studies should be performed to validate these results.
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Starting from a cohort of 50 NADH-oxidoreductase (complex I) deficient patients, we carried out the systematic sequence analysis of all mitochondrially encoded complex I subunits (ND1 to ND6 and ND4L) in affected tissues. This approach yielded the unexpectedly high rate of 20% mutation identification in our series. Recurrent heteroplasmic mutations included two hitherto unreported (T10158C and T14487C) and three previously reported mutations (T10191C, T12706C and A13514G) in children with Leigh or Leigh-like encephalopathy. The recurrent mutations consistently involved T-->C transitions (p<10(-4)). This study supports the view that an efficient molecular screening should be based on an accurate identification of respiratory chain enzyme deficiency.
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Candida albicans is a common member of the human microbiota and may cause invasive disease in susceptible populations. Several risk factors have been proposed for candidaemia acquisition. Previous Candida multifocal colonisation among hospitalised patients may be crucial for the successful establishment of candidaemia. Nevertheless, it is still not clear whether the persistence or replacement of a single clone of C. albicans in multiple anatomical sites of the organism may represent an additional risk for candidaemia acquisition. Therefore, we prospectively evaluated the dynamics of the colonising strains of C. albicans for two groups of seven critically ill patients: group I included patients colonised by C. albicans in multiple sites who did not develop candidaemia and group II included patients who were colonised and who developed candidaemia. ABC and microsatellite genotyping of 51 strains of C. albicans revealed that patients who did not develop candidaemia were multiply colonised by at least two ABC genotypes of C. albicans, whereas candidaemic patients had highly related microsatellites and the same ABC genotype in colonising and bloodstream isolates that were probably present in different body sites before the onset of candidaemia.
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BACKGROUND: Obesity is a contemporary epidemic that does not affect all age groups and sections of society equally. OBJECTIVE: The objective was to examine socioeconomic differences in trajectories of body mass index (BMI; in kg/m(2)) and obesity between the ages of 45 and 65 y. DESIGN: A total of 13,297 men and 4532 women from the French GAZEL (Gaz de France Electricité de France) cohort study reported their height in 1990 and their weight annually over the subsequent 18 y. Changes in BMI and obesity between ages 45 and 49 y, 50 and 54 y, 55 and 59 y, and 60 and 65 y as a function of education and occupational position (at age 35 y) were modeled by using linear mixed models and generalized estimating equations. RESULTS: BMI and obesity rates increased between the ages of 45 and 65 y. In men, BMI was higher in unskilled workers than in managers at age 45 y; this difference in BMI increased from 0.82 (95% CI: 0.66, 0.99) at 45 y to 1.06 (95% CI: 0.85, 1.27) at 65 y. Men with a primary school education compared with those with a high school degree at age 45 y had a 0.75 (95% CI: 0.51, 1.00) higher BMI, and this difference increased to 1.32 (95% CI: 1.03,1.62) at age 65 y. Obesity rates were 3.35% and 7.68% at age 45 y and 9.52% and 18.10% at age 65 y in managers and unskilled workers, respectively; the difference in obesity increased by 4.25% (95% CI: 1.87, 6.52). A similar trend was observed in women. Conclusions: Weight continues to increase in the transition between midlife and old age; this increase is greater in lower socioeconomic groups.
The Mixture Transition Distribution Model for High-Order Markov Chains and Non-Gaussian Time Series.
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Résumé Cette thèse de doctorat se fixe comme objectif général de définir la spécificité d'un espace urbain situé en centre-ville à travers sa dynamique sociale et interethnique. Il s'agit de relever les différentes formes et manifestations ethniques, mais également de comprendre la manière dont est vécue cette socialité, tout en tenant compte du contexte urbain dans lequel elles se situent. La particularité de ce travail est le fait de proposer une démarche alliant deux disciplines à savoir la géographie et la sociologie, dans le but de proposer une recherche transdisciplinaire, avec comme conséquence la mise en oeuvre d'une démarche commune nourrie des deux disciplines. Les quartiers ethniques situés en centre-ville ne se présentent pas comme des espaces figés, puisque des changements fréquents sont observés aussi bien au niveau de leur population que de l'affectation des locaux commerciaux et des logements. Ils semblent davantage se caractériser comme des « espaces à l'avenir indéterminé » dans le sens où leur avenir aussi bien au niveau de leur structure urbaine que de leurs rapports sociaux ne peut être prévisible et qu'ils sont par ailleurs susceptibles d'être soumis à de nombreux changements, d'où l'idée également d' « espaces en mutations ». Pour aborder ces thématiques de recherche, nous avons opté pour une étude fondée sur le principe de la représentation et de l'une des formes essentielles à travers lesquelles elles se produisent et se manifestent, à savoir les images. Cette recherche privilégie ainsi une analyse dynamique du phénomène interethnique, l'inscrivant dans le courant constructiviste qui s'intéresse notamment à l'étude des pratiques des acteurs sociaux et leurs représentations, dans le sens qu'elles sont le fruit d'une construction sociale. Dans ce type de démarche analytique, il s'agit de prendre en considération à la fois l'analyse du chercheur et la réalité objective et subjective du vécu des acteurs urbains qui regroupent les riverains, les commerçants, les membres associatifs, les politiques et les médias. C'est justement l'association de ces deux approches qui permet de définir un quartier urbain. Abstract "The spatial and social stakes of an interethnic dynamics in transition in the downtown area. The construction of the various forms of representations in order to define an urban quarter in Nice" The general objective of this PHD is to define the specificity of an urban space located in the downtown area with social and interethnic dynamics. Specifically the diverse ethnic form and sign to include the understanding mariner where society has lived in a specific urban context. The particularity of this work is to advance an analytic method using two disciplines: geography and sociology, in order to bring up a transdisciplinarian research with a common method. The ethnic quarters in the inner-city area are not presented as fixed spaces, since frequent changes were observed in the population level and at the allotment level of the commercial premises and the lodgings. Defined as "undetermined future spaces" as their future in the urban structure or the social relations can not be foresee and are supposed to be subjective to many changes. Therefore speaking of "mutations spaces". The option of this type of thematic research is the study of the principle of representation and essential form which shows and produces the images. Research promotes a dynamic analyses of the interethnic phenomena, inside the constructivist which is focused the practices of social actors, their own representations, and products of a social construction. The production of analytical approach is necessary in order to consider the analyses of the research worker and the objective and subjective reality of the life of the urban actors. It gathers the residents, tradesmen, members of associations, politicians and the press. The association of these types of approach define a urban quarter.
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BACKGROUND Alternative macrophages (M2) express the cluster differentiation (CD) 206 (MCR1) at high levels. Decreased M2 in adipose tissue is known to be associated with obesity and inflammation-related metabolic disturbances. Here we aimed to investigate MCR1 relative to CD68 (total macrophages) gene expression in association with adipogenic and mitochondrial genes, which were measured in human visceral [VWAT, n = 147] and subcutaneous adipose tissue [SWAT, n = 76] and in rectus abdominis muscle (n = 23). The effects of surgery-induced weight loss were also longitudinally evaluated (n = 6). RESULTS MCR1 and CD68 gene expression levels were similar in VWAT and SWAT. A higher proportion of CD206 relative to total CD68 was present in subjects with less body fat and lower fasting glucose concentrations. The ratio MCR1/CD68was positively associated with IRS1gene expression and with the expression of lipogenic genes such as ACACA, FASN and THRSP, even after adjusting for BMI. The ratio MCR1/CD68 in SWAT increased significantly after the surgery-induced weight loss (+44.7%; p = 0.005) in parallel to the expression of adipogenic genes. In addition, SWAT MCR1/CD68ratio was significantly associated with muscle mitochondrial gene expression (PPARGC1A, TFAM and MT-CO3). AT CD206 was confirmed by immunohistochemistry to be specific of macrophages, especially abundant in crown-like structures. CONCLUSION A decreased ratio MCR1/CD68 is linked to adipose tissue and muscle mitochondrial dysfunction at least at the level of expression of adipogenic and mitochondrial genes.
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Leishmaniasis is a neglected tropical disease. According to the World Health Organization, there are approximately 1.5-two million new cases of cutaneous leishmaniasis each year worldwide. Chemotherapy against leishmaniasis is based on pentavalent antimonials, which were developed more than a century ago. The goals of this study were to investigate the antileishmanial activity of diterpene acids in copaiba oil, as well as some possible targets of their action against Leishmania amazonensis. Methyl copalate and agathic, hydroxycopalic, kaurenoic, pinifolic and polyaltic acids isolated from Copaifera officinales oleoresins were utilised. Ultrastructural changes and the specific organelle targets of diterpenes were investigated with electron microscopy and flow cytometry, respectively. All compounds had some level of activity against L. amazonensis. Hydroxycopalic acid and methyl copalate demonstrated the most activity against promastigotes and had 50% inhibitory concentration (IC50) values of 2.5 and 6.0 µg/mL, respectively. However, pinifolic and kaurenoic acid demonstrated the most activity against axenic amastigote and had IC50 values of 3.5 and 4.0 µg/mL, respectively. Agathic, kaurenoic and pinifolic acid caused significant increases in plasma membrane permeability and mitochondrial membrane depolarisation of the protozoan. In conclusion, copaiba oil and its diterpene acids should be explored for the development of new antileishmanial drugs.
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ABSTRACT: The execution of the apoptotic death program in metazoans is characterized by a sequence of morphological and biochemical changes that include cell shrinkage, presentation of phosphatidylserine at the cell surface, mitochondrial alterations, chromatin condensation, nuclear fragmentation, membrane blebbing and the formation of apoptotic bodies. Methodologies for measuring apoptosis are based on these markers. Except for membrane blebbing and formation of apoptotic bodies, all other events have been observed in most protozoan parasites undergoing cell death. However, while techniques exist to detect these markers, they are often optimised for metazoan cells and therefore may not pick up subtle differences between the events occurring in unicellular organisms and multi-cellular organisms.In this review we discuss the markers most frequently used to analyze cell death in protozoan parasites, paying special attention to changes in cell morphology, mitochondrial activity, chromatin structure and plasma membrane structure/permeability. Regarding classical regulators/executors of apoptosis, we have reviewed the present knowledge of caspase-like and nuclease activities.
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Résumé Les mécanismes qui coordonnent la progression du cycle cellulaire lors de la méiose avec les événements du développement embryonnaire précoce, y compris la formation des axes de polarité embryonnaire, sont peu compris. Dans le zygote du vers Caenorhabditis elegans, les premiers signes de polarité Antéro-Postérieur (A-P) embryonnaire apparaissent après que la méiose soit terminée. La nature des protéines et des mécanismes moléculaires qui cassent la symétrie du zygote n'est pas connue. Nous démontrons que zyg-11 et cul-2 promeuvent la transition métaphase - anaphase et la sortie de la phase M lors de la seconde division méiotique. Nos résultats indiquent que ZYG-11 agit comme unité recrutant le substrat d'une ligase E3 comprennant CUL-2. Nos résultats montrent aussi que le délai de sortie de la phase M dépend de l'accumulation de la Cyclin B, CYB-3. Nous démontrons que dans des embryons zyg-11(RNAi) ou cul-2(RNAi), une polarité inversée est établie lors du délai de méiosis II. Enfin nous montrons que les défauts de cycle cellulaire et ceux de polarité peuvent être séparés. De plus, nous faisons apparaitre que l'établissement d'une polarité inversée pendant le délai de méiose II des embryons zyg-11(RNAi), comme l'établissement de la A-P polarité des embryons sauvage ne semblent pas requérir les microtubules. Nous montrons également les premiers résultats d'un crible deux hybrides ainsi qu'un crible génomique qui vise à identifier des gènes dont l'inactivation augmente ou supprime les défauts de mutants pour le gène zyg-11, afin d'identifier les gènes qui intéragissent avec ZYG-11 pour assumer ses deux fonctions séparables. Par conséquent, nos trouvailles suggèrent un modèle selon lequel ZYG-11 est une sous-unité qui recrute les substrats d'une ligase E3 basée sur CUL-2 qui promeut la progression du cycle cellulaire et empêche l'établissement de la polarité pendant la méiose II, et où le centrosome agit comme la clé qui polarise l'embryon à la fin de la méiose. Summary The mechanisms that couple meiotic cell cycle progression to subsequent developmental events, including specification of embryonic axes, are poorly understood. In the one cell stage embryos of Caenorhabditis elegans, the first signs of Antero-Posterior (A-P) polarity appear after meiosis completion. A centrosome ¬derived component breaks symmetry of the embryo, but the molecular nature of this polarity signal is not known. We established that zyg-11 and cul-2 promote the metaphase to anaphase transition and M phase exit at meiosis II. Our results indicate that ZYG-11 acts as a substrate recruitment subunit of a CUL-2-based E3 ligase. Moreover, we find that the delayed meiosis II exit of embryos lacking zyg-11 is caused by accumulation of the B-type cyclin, CYB-3. We demonstrate that inverted A-P polarity is established during the meiosis II delay in zyg-11(RNAi) and cul¬2(RNAi) embryos. Importantly, we demonstrate that the polarity defects following zyg-11 or cul-2 inactivation can be uncoupled from the cell cycle defects. Furthermore, we found that microtubules appear dispensable for inverted polarity during the meiosis II delay in zyg-11(RNAi) embryos, as well as for A-P polarity during the first mitotic cell cycle in wild-type embryos. We also show the initial results from a comprehensive yeast two hybrid, as well as an RNAi-based functional genomic enhancer and suppressor screen, that may lead to identification of proteins that interact with zyg-11 to ensure the two functions. Our findings suggest a model in which ZYG-11 is a substrate recruitment subunit of an CUL-2-based E3 ligase that promotes cell cycle progression and prevents polarity establishment during meiosis II, and in which the centrosome acts as a cue to polarize the embryo along the AP axis after exit from the meiotic cell cycle.
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RésuméLa naissance du premier enfant est un événement normatif à l'origine de nombreux changements dans le parcours de vie des hommes et des femmes. La présente recherche s'intéresse à la transition à la parentalité en tant que moment à l'origine d'un processus de stratification sociale. Trois dimensions dépendantes sont étudiées du point de vue de leur changement: l'insertion professionnelle, le travail domestique et la qualité de la relation conjugale. Les concepts de divergence et de convergence interindividuelle, élaborés à partir de l'hypothèse des dés/avantages cumulatifs et de l'hypothèse alternative des effets compensatoires, sont utilisés pour opérationnaliser le changement qui se produit dans ces trois dimensions lors de la naissance du premier enfant.Les résultats montrent, dans un premier moment, la présence de divergences entre les hommes et les femmes dans chacune de ces trois dimensions. Ces divergences inter-sexe sont associées à des convergences entre les individus de même sexe. Les analyses se focalisent dans un deuxième moment, sur les divergences et convergences ultérieures qui se produisent entre individus du même sexe en fonction des ressources sociales, culturelles et économiques initiales. Quelles sont ainsi, par exemple, les mères qui ne diminuent pas leur taux d'occupation initial? Quels sont les pères qui réduisent moins que les autres leur investissement dans le travail domestique? Quels sont les parents qui connaissent une moindre diminution de la qualité de leur relation conjugale? Les réponses données à ces questions montrent comment le processus de stratification sociale au sein d'une cohorte doit être expliqué en relation avec le changement qui se produit lors d'une transition spécifique et non seulement en tant que résultat du simple passage du temps.AbstractThe birth of the first child is a normative event creating important changes in the life course of men and women. This research analyzes the transition to parenthood as a moment creating social stratification. Three dependent dimensions are studied in their change: the occupational career, the domestic labour and the conjugal relationship's quality. The concepts of interindividual divergences and convergence, conceived from the cumulative dis/advantage hypothesis and the alternative hypothesis of compensatory effects, are used to operationalize the change in these three dimensions after the birth of the first child.Results show that, firstly, divergences take place between men and women becoming parents in the three dependent dimensions. Inter-sex divergences are associated to convergence between same-sex individuals. Secondly, the analyses focus on further di/convergences taking place between same-sex individuals, in relation with the initial social, cultural and economical resources. Who are the mothers who will not reduce their initial occupational rates? Who are the fathers who will reduce less than the others their involvement in the domestic tasks? Who are the parents who will experience a less important reduction in their conjugal relationship's quality? The answers to these questions show how the process of social stratification within a cohort has to be explained in relation with the change taking place during a specific transition and not only as a result of the simple passage of time.
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Phospholipase is an important virulence factor for pathogenic fungi. In this study, we demonstrate the following: (i) the Paracoccidioides brasiliensis pld gene is preferentially expressed in mycelium cells, (ii) the plb1 gene is mostly up-regulated by infection after 6 h of co-infection of MH-S cells or during BALB/c mice lung infection, (iii) during lung infection, plb1, plc and pld gene expression are significantly increased 6-48 h post-infection compared to 56 days after infection, strongly suggesting that phospholipases play a role in the early events of infection, but not during the chronic stages of pulmonary infection by P. brasiliensis.