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1.
Microbiol Res ; 243: 126649, 2020 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-33285428

RESUMO

The unicellular, free-living, nonphotosynthetic chlorophycean alga Polytomella parva, closely related to Chlamydomonas reinhardtii and Volvox carteri, contains colorless, starch-storing plastids. The P. parva plastids lack all light-dependent processes but maintain crucial metabolic pathways. The colorless alga also lacks a plastid genome, meaning no transcription or translation should occur inside the organelle. Here, using an algal fraction enriched in plastids as well as publicly available transcriptome data, we provide a morphological and proteomic characterization of the P. parva plastid, ultimately identifying several plastid proteins, both by mass spectrometry and bioinformatic analyses. Data are available via ProteomeXchange with identifier PXD022051. Altogether these results led us to propose a plastid proteome for P. parva, i.e., a set of proteins that participate in carbohydrate metabolism; in the synthesis and degradation of starch, amino acids and lipids; in the biosynthesis of terpenoids and tetrapyrroles; in solute transport and protein translocation; and in redox homeostasis. This is the first detailed plastid proteome from a unicellular, free-living colorless alga.

2.
Salud ment ; 43(5): 227-233, Sep.-Oct. 2020. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1145104

RESUMO

Abstract Introduction Burnout syndrome (BOS) comprises emotional exhaustion, depersonalization, and reduced personal accomplishment in those affected. Instruments such as the Maslach Burnout Inventory (MBI) can help to identify those affected. Physicians in training have been described as an at-risk group for this syndrome. Objective Describe the association between BOS and medical training by specialty in first-year residents. Method This is a cross-sectional analytical study of specialty residents at the Hospital Civil de Guadalajara. Sociodemographic data were obtained and the MBI was administered to identify BOS. Samples were compared, and a comparative analysis performed to identify factors associated with BOS. Results Eighty-eight residents were included, with 21.6% (n = 19) presenting BOS, 53.4% displaying emotional exhaustion (n = 47), 53.7% showing depersonalization (n = 47), and 39.8% reduced personal accomplishment (n = 35). Presenting BOS was not associated with sociodemographic characteristics or type of specialty. Work hours (ro = .229, p = .032), and a higher number of on-call hours/week (ro = .34, p = .001) were associated with higher BOS. Discussion and conclusion The prevalence of BOS was lower than expected. Over half scored for emotional exhaustion and depersonalization, which could be explained by a self-reporting bias. There was no association between the group/type of specialty and BOS. This study creates new knowledge that works as an institutional situational diagnosis, helps to determine the scope of the problem, and encourages to consider the contributing factors to its origin and maintenance.


Resumen Introducción El síndrome de burnout (SBO) comprende el agotamiento emocional, la despersonalización y la reducción de la realización personal en aquellos a quienes afecta. Instrumentos como el Maslach Burnout Inventory (MBI) pueden ayudar a identificar a los afectados. Los médicos en formación se han descrito como un grupo de riesgo para presentar este síndrome. Objetivo Describir la asociación entre el síndrome de burnout y la formación médica por especialidad en residentes de primer año. Método Se trata de un estudio analítico transversal de residentes de especialidad del Hospital Civil de Guadalajara. Se obtuvieron datos sociodemográficos y se administró el MBI para identificar SBO. Se compararon las muestras y se realizó un análisis comparativo para identificar los factores asociados con SBO. Resultados Se incluyeron 88 residentes, con 21.6% (n = 19) presentando SBO; 53.4% mostrando agotamiento emocional (n = 47); 53.7% (n = 47) mostrando despersonalización; y 39.8% (n = 35) reducción de realización personal. La presentación de SBO no se asoció a características sociodemográficas ni al tipo de especialidad. Las horas de trabajo (ro = .229, p = .032) y un mayor número de horas de guardia/semana (ro = .34, p = .001) se asociaron con una mayor BOS. Discusión y conclusión La prevalencia de SBO fue menor de lo esperado. Más de la mitad puntuó por agotamiento emocional y despersonalización, lo que podría explicarse por un sesgo en la autoevaluación. No hubo asociación entre el grupo/tipo de especialidad y SBO. Este estudio genera nuevos conocimientos que funcionan como un diagnóstico situacional institucional, ayuda a determinar el alcance del problema y alienta a considerar los factores que contribuyen a su origen y mantenimiento.

4.
Ann Hepatol ; 2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32835861

RESUMO

Infected hepatic echinococcosis (IHE), defined as a cystic infection, and the development of a liver abscess may be a complication in the natural history of hepatic echinococcosis. The aim of this study was to review the evidence available related to clinical, therapeutic, and prognostic aspects of IHE. We conducted a systematic review. Trip Database, BIREME-BVS, SciELO, LILACS, IBECS, PAHO-WHO; WoS, EMBASE, SCOPUS and PubMed were consulted. Studies related to IHE in humans, without language restriction, published between 1966 and 2020 were considered. Variables studied were publication year, geographical origin of the samples, number of patients, therapeutic and prognosis aspects, and methodological quality (MQ) for each article. Descriptive statistics was applied. Subsequently, weighted averages (WA) of the MQ of each article were calculated for each variable of interest. 960 related articles were identified; 47 fulfilled selection criteria, including 486 patients with a median age of 48 years, 51.6% being male. The largest proportion of articles were from Spain, India, and Greece (36.1%). Mean cyst diameter was 14.1 cm, and main location was right liver lobe (74.0%). WA for morbidity, mortality, hospital stay, and follow-up were 28.5%, 7.4%, 8.5 days and 14.8 months, respectively. The most common causative microorganisms of superinfection isolated were Enterobacteriaceae. An association with cholangitis was reported in 13.4% of cases. Mean MQ of the 47 articles included was 7.6 points. We can conclude that the information related to IHE is scarce and scattered throughout articles of small casuistry and poor quality, and consequently does not provide strong evidence.

6.
Pediatr. aten. prim ; 22(86): 141-150, abr.-jun. 2020. tab
Artigo em Espanhol | IBECS-Express | IBECS | ID: ibc-ET1-6407

RESUMO

INTRODUCCIÓN: en España existe un elevado consumo de galletas en la población infantil. Son productos ultraprocesados de alto contenido energético y densidad calórica, en general con azúcar añadido y grasas poco saludables. MATERIAL Y MÉTODOS: estudio descriptivo transversal sobre características y composición nutricional de galletas disponibles en supermercados españoles y comparativo entre las dirigidas al público infantil y el resto. RESULTADOS: se analizaron 350 galletas: valor energético medio 471,86 ± 35,83 kcal/100 g. El 53,1% contenían grasas saturadas, aceite de palma el 47,1% y azúcar añadido el 90%. Mediana de azúcares 25 g/100 g (rango intercuartílico [RI]: 20-33). Mediana de fibra alimentaria 3,2 g/100 g (RI: 2,4-5,2); 86 galletas mostraban publicidad sobre fibra y 95,34% indicaban la cantidad, mediana de 5,45 g/100 g (RI: 4-7,9). Se analizaron 53 galletas (15,1%) dirigidas al público infantil. Valor energético medio 466,47 ± 19,31 kcal/100 g. El aceite de oliva/girasol alto oleico (GAO) fue la grasa principal en el 67,9%. Aceite de palma presente en el 37,7% y azúcar añadido en 98,1% (media 25,88 ± 6,82 g/100 g). Mediana de fibra alimentaria 2,9 g/100 g (RI: 2,27-3,42). El 75,5% mostraron publicidad de reclamo. Las galletas dirigidas al público infantil contenían azúcar añadido en mayor porcentaje (98,1 frente a 88,6%; p = 0,033), menos fibra (mediana 2,9 g/100 g frente a 3,5 g/100 g; p = 0,005), aceite de oliva/GAO en mayor porcentaje (67,9 frente a 36,7%; p <0,001) y más publicidad de reclamo (75,5 frente a 45,5%; p <0,001). CONCLUSIONES: las galletas dirigidas al público infantil contienen azúcar añadido, elevado contenido calórico, grasas saturadas en más del 37% y publicidad de reclamo en elevado porcentaje. Por otro lado, se observa el uso de grasas monoinsaturadas en más del 50%. La información de este estudio podría facilitar intervenciones de salud pública e incentivar a los fabricantes para reformular sus productos


INTRODUCTION: the consumption of biscuits is high in the Spanish paediatric population. Biscuits are ultra-processed products with a high energy content and energy density and generally contain added sugars and unhealthy fats. METHODS: we conducted a cross-sectional descriptive study on the characteristics and nutritional composition of biscuits available in Spanish supermarkets, and compared biscuits marketed to children to all other biscuits. RESULTS: we analysed a sample of 350 biscuits. The mean energy content was 471.86 ± 35.83 kcal/100 g. Saturated fats were used in 53.1%, palm oil in 47.1% and added sugars in 90% (median content, 25 g/100 g; IQR: 20-33). The median dietary fibre content was 3.2 g/100 g (IQR: 2.4-5.2). The packaging of 86 advertised that the product contained fibre, specifying the total fibre content in 95.34% of cases, with a median value of 5.45 g/100 g (IQR: 4-7.9). Of the total products, 53 (15.1%) were marketed to children, and their mean energy content was 466.47 ± 19.31 kcal/100 g. The main fat was olive oil or high oleic sunflower oil (HOSO) in 67.9%, and palm oil was present in 20 (37.7%). There were added sugars in 98.1% (mean sugar content, 25.88 ± 6.82 g/100 g). The median dietary fibre content was 2.9 g/100 g (IQR 2.27-3.42). The packaging of 75.5% featured some form of advertising. The comparative analysis showed that a greater percentage of biscuits specifically marketed to children had added sugars (98.1% vs 88.6%, p = 0.033) and that these biscuits had a lower fibre content (median, 2.9 g/100 g vs. 3.5 g/100 g, p = 0.005), that a greater percentage contained olive oil or HOSO (67.9% vs 36.7%, p <0.001), and a greater percentage featured promotional advertising in their packaging (75.5% vs 45.5%, p <0.001). CONCLUSIONS: biscuits marketed to the paediatric population had added sugars and a high energy content; more than 37% had saturated fats and a high proportion featured advertising in the packaging. On the other hand, we found that monounsaturated fats were used in more than 50% of these products. The findings of this study could serve as reference to guide the development of public health interventions or product reformulation by manufacturers

7.
J Inherit Metab Dis ; 43(6): 1382-1391, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32418222

RESUMO

Inherited cutis laxa, or inelastic, sagging skin is a genetic condition of premature and generalised connective tissue ageing, affecting various elastic components of the extracellular matrix. Several cutis laxa syndromes are inborn errors of metabolism and lead to severe neurological symptoms. In a patient with cutis laxa, a choreoathetoid movement disorder, dysmorphic features and intellectual disability we performed exome sequencing to elucidate the underlying genetic defect. We identified the amino acid substitution R275W in phosphatidylinositol 4-kinase type IIα, caused by a homozygous missense mutation in the PI4K2A gene. We used lipidomics, complexome profiling and functional studies to measure phosphatidylinositol 4-phosphate synthesis in the patient and evaluated PI4K2A deficient mice to define a novel metabolic disorder. The R275W residue, located on the surface of the protein, is involved in forming electrostatic interactions with the membrane. The catalytic activity of PI4K2A in patient fibroblasts was severely reduced and lipid mass spectrometry showed that particular acyl-chain pools of PI4P and PI(4,5)P2 were decreased. Phosphoinositide lipids play a major role in intracellular signalling and trafficking and regulate the balance between proliferation and apoptosis. Phosphatidylinositol 4-kinases such as PI4K2A mediate the first step in the main metabolic pathway that generates PI4P, PI(4,5)P2 and PI(3,4,5)P3 . Although neurologic involvement is common, cutis laxa has not been reported previously in metabolic defects affecting signalling. Here we describe a patient with a complex neurological phenotype, premature ageing and a mutation in PI4K2A, illustrating the importance of this enzyme in the generation of inositol lipids with particular acylation characteristics.

8.
Nat Commun ; 11(1): 1643, 2020 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-32242014

RESUMO

Regulation of the turnover of complex I (CI), the largest mitochondrial respiratory chain complex, remains enigmatic despite huge advancement in understanding its structure and the assembly. Here, we report that the NADH-oxidizing N-module of CI is turned over at a higher rate and largely independently of the rest of the complex by mitochondrial matrix protease ClpXP, which selectively removes and degrades damaged subunits. The observed mechanism seems to be a safeguard against the accumulation of dysfunctional CI arising from the inactivation of the N-module subunits due to attrition caused by its constant activity under physiological conditions. This CI salvage pathway maintains highly functional CI through a favorable mechanism that demands much lower energetic cost than de novo synthesis and reassembly of the entire CI. Our results also identify ClpXP activity as an unforeseen target for therapeutic interventions in the large group of mitochondrial diseases characterized by the CI instability.


Assuntos
Complexo I de Transporte de Elétrons/metabolismo , Animais , Complexo I de Transporte de Elétrons/genética , Endopeptidase Clp/genética , Endopeptidase Clp/metabolismo , Camundongos , Camundongos Knockout , Mitocôndrias/genética , Mitocôndrias/metabolismo , Mioblastos/metabolismo , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo
9.
Biochim Biophys Acta Bioenerg ; 1861(8): 148202, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32275929

RESUMO

Protein complexes from the oxidative phosphorylation (OXPHOS) system are assembled with the help of proteins called assembly factors. We here delineate the function of the inner mitochondrial membrane protein TMEM70, in which mutations have been linked to OXPHOS deficiencies, using a combination of BioID, complexome profiling and coevolution analyses. TMEM70 interacts with complex I and V and for both complexes the loss of TMEM70 results in the accumulation of an assembly intermediate followed by a reduction of the next assembly intermediate in the pathway. This indicates that TMEM70 has a role in the stability of membrane-bound subassemblies or in the membrane recruitment of subunits into the forming complex. Independent evidence for a role of TMEM70 in OXPHOS assembly comes from evolutionary analyses. The TMEM70/TMEM186/TMEM223 protein family, of which we show that TMEM186 and TMEM223 are mitochondrial in human as well, only occurs in species with OXPHOS complexes. Our results validate the use of combining complexome profiling with BioID and evolutionary analyses in elucidating congenital defects in protein complex assembly.


Assuntos
Complexo I de Transporte de Elétrons/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Mitocondriais/metabolismo , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Biotinilação , Evolução Molecular , Técnicas de Inativação de Genes , Células HEK293 , Humanos , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Proteínas Mitocondriais/deficiência , Proteínas Mitocondriais/genética , Fosforilação Oxidativa , Ligação Proteica
10.
Int. j. morphol ; 38(2): 406-414, abr. 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1056455

RESUMO

Although infrequent in the diagnostics areas, liver abscesses are of significant relevance, which is related to the high morbidity and mortality figures they can cause if they are not detected and treated in time. Although multiple operational classifications are described, the one most recognized for its usefulness is that related to its causative agent (pyogenic or bacterial infection, hydatid origin or secondary to infected hydatidosis, and amoebic or by invasive amebiasis). The objective of this article was to generate a study report regarding the morphological characteristics of liver abscesses, characterizing them according to their etiology, as well as describing their study and the latest recommended treatments.


Los abscesos hepáticos son entidades nosológicas de baja frecuencia, pero de significativa relevancia, la que se relacionada con las elevadas cifras de morbilidad y mortalidad que pueden causar si no son detectados y tratados a tiempo. Si bien se describen múltiples clasificaciones operacionales, aquella más reconocida por su utilidad es la relacionada a su agente causal (piógenos o bacterianos, hidatídicos o secundarios a hidatidosis infectada, y amebianos o por amebiasis invasora). El objetivo de este artículo fue generar un documento de estudio respecto de las características morfológicas de los abscesos hepáticos, caracterizándolos de acuerdo con su etiología, así como describir su estudio y tratamiento recomendado de acuerdo con el estado del arte.


Assuntos
Humanos , Equinococose Hepática/patologia , Abscesso Hepático/patologia , Abscesso Hepático Piogênico/patologia , Equinococose Hepática/etiologia , Abscesso Hepático/etiologia , Abscesso Hepático Amebiano/patologia
11.
Psicol. teor. prát ; 22(1): 41-63, Jan.-Apr. 2020. ilus, tab
Artigo em Inglês | LILACS-Express | LILACS, Index Psicologia - Periódicos técnico-científicos | ID: biblio-1098538

RESUMO

This study aimed to adapt to the Brazilian Portuguese the O*NET Interests Profiler - Short Form. The instrument evaluates vocational interests according to the RIASEC model, which includes six types (Realistic, Investigative, Artistic, Social, Enterprising, and Conventional). Validity evidence was obtained through Principal Components Analysis, Multidimensional Scaling, correlations between secondary concepts from the theoretical model, and contrasts between groups. PCA results, the contrasts between selected occupational groups and correlational results between secondary concepts followed the theoretical expectations. However, the MDS results did not fully confirm the hexagonal structure. Overall results suggest the adapted instrument has acceptable evidence of validity. Further studies are suggested to increase the suitability of the Brazilian version of the instrument.


O objetivo deste estudo foi adaptar o O*NET Interests Profiler - Short Form para o português brasileiro. O instrumento avalia interesses vocacionais de acordo com o modelo RIASEC, que inclui seis dimensões (Realista, Investigativo, Artístico, Social, Empreendedor e Convencional). As evidências de validade foram obtidas por meio da Análise de Componentes Principais, Escalonamento Multidimensional, correlações entre os conceitos secundários do modelo teórico e contrastes entre grupos ocupacionais. Os resultados da ACP, dos contrastes entre os grupos selecionados e dos resultados das correlações entre os conceitos secundários confirmaram as expectativas teóricas. No entanto, os resultados do EMD não confirmaram totalmente a estrutura hexagonal. Em geral, os resultados sugerem que o instrumento adaptado apressenta evidências aceitáveis de validade. Estudos adicionais são sugeridos para aumentar a adequação da versão brasileira do instrumento.


Este estudio tuvo como objetivo adaptar al portugués brasileño el O*NET Interests Profiler - Short Form. El instrumento evalúa los intereses vocacionales de acuerdo con el modelo RIASEC, que incluye seis dimensiones (Realista, Investigativo, Artístico, Social, Emprendedor y Convencional). Las evidencias de validez se obtuvieron mediante Análisis de Componentes Principales, Escalamiento Multidimensional, correlaciones entre los conceptos secundarios del modelo teórico y contrastes entre grupos ocupacionales. Los resultados del PCA, los contrastes entre los grupos seleccionados y los resultados de las correlaciones entre los conceptos secundarios confirmaron las expectativas teóricas. Sin embargo, los resultados del MDS solo confirmaron parcialmente la estructura hexagonal. Los resultados sugieren que el instrumento adaptado tiene evidencias aceptables de validez y confiabilidad. Se sugieren estudios adicionales para aumentar la idoneidad de la versión brasileña del instrumento.

12.
Cochrane Database Syst Rev ; 12: CD008661, 2019 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-31828767

RESUMO

BACKGROUND: People with schizophrenia have a range of different symptoms, including positive symptoms (hallucinations and delusions), negative symptoms (such as social withdrawal and lack of affect), and cognitive impairment. The standard medication for people with schizophrenia is antipsychotics. However, these medications may not be effective for all symptoms of schizophrenia, as cognitive and negative symptoms are usually hard to treat. Additional therapies or medications are available for the management of these symptoms. Modafinil, a wakefulness-promoting agent most frequently used in narcolepsy or shift work sleep disorder, is one intervention that is theorised to have an effect of these symptoms. OBJECTIVES: The primary objective of this review was to assess the effects of modafinil for people with schizophrenia or related disorders. SEARCH METHODS: On 27 April 2015, 24 May 2017, and 31 October 2019, we searched the Cochrane Schizophrenia Group's register of trials, which is based on regular searches of CENTRAL, MEDLINE, Embase, AMED, BIOSIS, CINAHL, PsycINFO, PubMed, and registries of clinical trials. There are no language, time, document type, or publication status limitations for the inclusion of records in the register. SELECTION CRITERIA: We selected all randomised controlled trials comparing modafinil with placebo or other treatments for people with schizophrenia or schizophrenia-spectrum disorders. DATA COLLECTION AND ANALYSIS: We independently extracted data from the included studies. We analysed dichotomous data using risk ratios (RR) and 95% confidence intervals (CI). We analysed continuous data using mean difference (MD) with a 95% CI. We used a random-effects model for the meta-analysis. We used GRADE to complete a 'Summary of findings' table and assessed risk of bias for the included studies. MAIN RESULTS: Eleven studies including a total of 422 participants contributed to data analyses. Most studies had a small population size (average 38 people per study) and were of short duration. We also detected a high risk of bias for selective outcome reporting in just under 50% of the trials. We therefore rated the overall methodological quality of the included studies as low. We considered seven main outcomes of interest: clinically important change in overall mental state, clinically important change in cognitive functioning, incidence of a clinically important adverse effect/event, clinically important change in global state, leaving the study early for any reason, clinically important change in quality of life, and hospital admission. All studies assessed the effects of adding modafinil to participants' usual antipsychotic treatment compared to adding placebo to usual antipsychotic treatment. Six studies found that adding modafinil to antipsychotic treatment may have little or no effect on overall mental state of people with schizophrenia, specifically the risk of worsening psychosis (RR 0.91, 95% CI 0.28 to 2.98; participants = 209; studies = 6, low-quality evidence). Regarding the effect of modafinil on cognitive function, the trials did not report clinically important change data, but one study reported endpoint scores on the MATRICS Consensus Cognitive Battery (MCCB): in this study we found no clear difference in scores between modafinil and placebo treatment groups (MD -3.10, 95% CI -10.9 to 4.7; participants = 48; studies = 1, very low-quality evidence). Only one study (N = 35) reported adverse effect/event data. In this study one serious adverse event occurred in each group (RR 0.84, 95% CI 0.06 to 12.42; participants = 35; studies = 1, very low-quality evidence). One study measured change in global state using the Clinical Global Impression - Improvement Scale. This study found that adding modafinil to antipsychotic treatment may have little or no effect on global state (RR 6.36, 95% CI 0.94 to 43.07, participants = 21; studies = 1, very low-quality evidence). Nine studies found that modafinil has no effect on numbers of participants leaving the study early (RR 1.26, 95% CI 0.63 to 2.52 participants = 357; studies = 9, moderate-quality evidence). None of the trials reported clinically important change in quality of life, but one study did report quality of life using endpoint scores on the Quality of Life Inventory, finding no clear difference between treatment groups (MD -0.2, 95% CI -1.18 to 0.78; participants = 20; studies = 1, very low-quality evidence). Finally, one study reported data for number of participants needing hospitalisation: one participant in each group was hospitalised (RR 0.84, 95% CI 0.06 to 12.42; participants = 35; studies = 1, very low-quality evidence). AUTHORS' CONCLUSIONS: Due to methodological issues, low sample size, and short duration of the clinical trials as well as high risk of bias for outcome reporting, most of the evidence available for this review is of very low or low quality. For results where quality is low or very low, we are uncertain or very uncertain if the effect estimates are true effects, limiting our conclusions. Specifically, we found that modafinil is no better or worse than placebo at preventing worsening of psychosis; however, we are uncertain about this result. We have more confidence that participants receiving modafinil are no more likely to leave a trial early than participants receiving placebo. However, we are very uncertain about the remaining equivocal results between modafinil and placebo for outcomes such as improvement in global state or cognitive function, incidence of adverse events, and changes in quality of life. More high-quality data are needed before firm conclusions regarding the effects of modafinil for people with schizophrenia or related disorders can be made.


Assuntos
Modafinila/uso terapêutico , Esquizofrenia/tratamento farmacológico , Promotores da Vigília/uso terapêutico , Antipsicóticos/uso terapêutico , Cognição/efeitos dos fármacos , Cognição/fisiologia , Humanos , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto
13.
Biochim Biophys Acta Bioenerg ; 1860(9): 734-744, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31376363

RESUMO

The atmospheric concentration of the potent greenhouse gases methane and nitrous oxide (N2O) has increased drastically during the last century. Methylomirabilis bacteria can play an important role in controlling the emission of these two gases from natural ecosystems, by oxidizing methane to CO2 and reducing nitrite to N2 without producing N2O. These bacteria have an anaerobic metabolism, but are proposed to possess an oxygen-dependent pathway for methane activation. Methylomirabilis bacteria reduce nitrite to NO, and are proposed to dismutate NO into O2 and N2 by a putative NO dismutase (NO-D). The O2 produced in the cell can then be used to activate methane by a particulate methane monooxygenase. So far, the metabolic model of Methylomirabilis bacteria was based mainly on (meta)genomics and physiological experiments. Here we applied a complexome profiling approach to determine which of the proposed enzymes are actually expressed in Methylomirabilis lanthanidiphila. To validate the proposed metabolic model, we focused on enzymes involved in respiration, as well as nitrogen and carbon transformation. All complexes suggested to be involved in nitrite-dependent methane oxidation, were identified in M. lanthanidiphila, including the putative NO-D. Furthermore, several complexes involved in nitrate reduction/nitrite oxidation and NO reduction were detected, which likely play a role in detoxification and redox homeostasis. In conclusion, complexome profiling validated the expression and composition of enzymes hypothesized to be involved in the energy, methane and nitrogen metabolism of M. lanthanidiphila, thereby further corroborating their unique metabolism involved in the environmentally relevant process of nitrite-dependent methane oxidation.


Assuntos
Bactérias Anaeróbias/enzimologia , Proteínas de Bactérias/metabolismo , Metano/química , Complexos Multienzimáticos/metabolismo , Nitratos/química , Óxido Nítrico/química , Metano/metabolismo , Nitratos/metabolismo , Óxido Nítrico/metabolismo , Oxirredução , Oxigenases/metabolismo
15.
Neurochem Res ; 44(2): 498-506, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30603981

RESUMO

Spinal cord injury (SCI) is a condition that puts the patient's life at risk in the acute phase and, during the chronic stage, results in permanent deficits in motor, sensory and autonomic functions. Isolated therapeutic strategies have not shown an effect on this condition. Therefore, this study aimed to evaluate the effects of electroacupuncture (EA) and curcumin, alone or combined, on the oxidative balance, motor function recovery and amount of preserved tissue following a traumatic SCI. Long-Evans rats were divided into five groups: SHAM, SCI, SCI + EA, SCI + Curcumin, and SCI + EA + Curcumin. Nitric oxide was significantly decreased in the Curcumin group; the EA, Curcumin and SCI + EA + Curcumin groups had significantly decreased hydroxyl radical and lipid peroxidation levels. Motor function recovery and the amount of preserved spinal cord tissue were significantly greater in the EA, Curcumin and EA + Curcumin groups. The results show that EA and Curcumin treatment alone or in combination decreased oxidative stress, improved functional motor recovery and increased the amount of preserved spinal cord tissue following a traumatic injury.


Assuntos
Eletroacupuntura , Estresse Oxidativo/efeitos dos fármacos , Recuperação de Função Fisiológica/efeitos dos fármacos , Traumatismos da Medula Espinal/terapia , Animais , Curcumina/farmacologia , Modelos Animais de Doenças , Eletroacupuntura/métodos , Feminino , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Ratos Long-Evans , Medula Espinal/efeitos dos fármacos , Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/tratamento farmacológico
16.
Bioinformatics ; 35(17): 3083-3091, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-30649188

RESUMO

MOTIVATION: Complexome profiling combines native gel electrophoresis with mass spectrometry to obtain the inventory, composition and abundance of multiprotein assemblies in an organelle. Applying complexome profiling to determine the effect of a mutation on protein complexes requires separating technical and biological variations from the variations caused by that mutation. RESULTS: We have developed the COmplexome Profiling ALignment (COPAL) tool that aligns multiple complexome profiles with each other. It includes the abundance profiles of all proteins on two gels, using a multi-dimensional implementation of the dynamic time warping algorithm to align the gels. Subsequent progressive alignment allows us to align multiple profiles with each other. We tested COPAL on complexome profiles from control mitochondria and from Barth syndrome (BTHS) mitochondria, which have a mutation in tafazzin gene that is involved in remodeling the inner mitochondrial membrane phospholipid cardiolipin. By comparing the variation between BTHS mitochondria and controls with the variation among either, we assessed the effects of BTHS on the abundance profiles of individual proteins. Combining those profiles with gene set enrichment analysis allows detecting significantly affected protein complexes. Most of the significantly affected protein complexes are located in the inner mitochondrial membrane (mitochondrial contact site and cristae organizing system, prohibitins), or are attached to it (the large ribosomal subunit). AVAILABILITY AND IMPLEMENTATION: COPAL is written in python and is available from http://github.com/cmbi/copal. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Síndrome de Barth , Humanos , Espectrometria de Massas , Mitocôndrias , Proteínas Mitocondriais , Mutação
17.
J Cereb Blood Flow Metab ; 39(9): 1790-1802, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-29629602

RESUMO

Mortality from perinatal hypoxic-ischemic (HI) brain injury reached 1.15 million worldwide in 2010 and is also a major factor for neurological disability in infants. HI directly influences the oxidative phosphorylation enzyme complexes in mitochondria, but the exact mechanism of HI-reoxygenation response in brain remains largely unresolved. After induction of HI-reoxygenation in postnatal day 10 rats, activities of mitochondrial respiratory chain enzymes were analysed and complexome profiling was performed. The effect of conformational state (active/deactive (A/D) transition) of mitochondrial complex I on H2O2 release was measured simultaneously with mitochondrial oxygen consumption. In contrast to cytochrome c oxidase and succinate dehydrogenase, HI-reoxygenation resulted in inhibition of mitochondrial complex I at 4 h after reoxygenation. Immediately after HI, we observed a robust increase in the content of deactive (D) form of complex I. The D-form is less active in reactive oxygen species (ROS) production via reversed electron transfer, indicating the key role of the deactivation of complex I in ischemia/reoxygenation. We describe a novel mechanism of mitochondrial response to ischemia in the immature brain. HI induced a deactivation of complex I in order to reduce ROS production following reoxygenation. Delayed activation of complex I represents a novel mitochondrial target for pathological-activated therapy.


Assuntos
Complexo I de Transporte de Elétrons/metabolismo , Hipóxia-Isquemia Encefálica/metabolismo , Mitocôndrias/metabolismo , Animais , Animais Recém-Nascidos , Encéfalo/metabolismo , Encéfalo/patologia , Células Cultivadas , Transporte de Elétrons , Feminino , Humanos , Peróxido de Hidrogênio/metabolismo , Hipóxia-Isquemia Encefálica/patologia , Masculino , Mitocôndrias/patologia , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo
18.
Nat Commun ; 9(1): 4500, 2018 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-30374105

RESUMO

Complex I (proton-pumping NADH:ubiquinone oxidoreductase) is the largest enzyme of the mitochondrial respiratory chain and a significant source of reactive oxygen species (ROS). We hypothesized that during energy conversion by complex I, electron transfer onto ubiquinone triggers the concerted rearrangement of three protein loops of subunits ND1, ND3, and 49-kDa thereby generating the power-stoke driving proton pumping. Here we show that fixing loop TMH1-2ND3 to the nearby subunit PSST via a disulfide bridge introduced by site-directed mutagenesis reversibly disengages proton pumping without impairing ubiquinone reduction, inhibitor binding or the Active/Deactive transition. The X-ray structure of mutant complex I indicates that the disulfide bridge immobilizes but does not displace the tip of loop TMH1-2ND3. We conclude that movement of loop TMH1-2ND3 located at the ubiquinone-binding pocket is required to drive proton pumping corroborating one of the central predictions of our model for the mechanism of energy conversion by complex I proposed earlier.


Assuntos
Complexo I de Transporte de Elétrons/química , Complexo I de Transporte de Elétrons/ultraestrutura , Bombas de Próton/química , Ubiquinona/química , Ubiquinona/ultraestrutura , Cristalografia por Raios X , Dissulfetos , Transporte de Elétrons , Complexo I de Transporte de Elétrons/genética , Ativação Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Cinética , Membranas Mitocondriais/enzimologia , Membranas Mitocondriais/metabolismo , Modelos Moleculares , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Conformação Proteica , Bombas de Próton/ultraestrutura , Espécies Reativas de Oxigênio/metabolismo , Yarrowia/genética , Yarrowia/metabolismo
19.
Molecules ; 23(10)2018 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-30241366

RESUMO

Scaffolds can be considered as one of the most promising treatments for bone tissue regeneration. Herein, blends of chitosan, poly(vinyl alcohol), and hydroxyapatite in different ratios were used to synthesize scaffolds via freeze-drying. Mechanical tests, FTIR, swelling and solubility degree, DSC, morphology, and cell viability were used as characterization techniques. Statistical significance of the experiments was determined using a two-way analysis of variance (ANOVA) with p < 0.05. Crosslinked and plasticized scaffolds absorbed five times more water than non-crosslinked and plasticized ones, which is an indicator of better hydrophilic features, as well as adequate resistance to water without detriment of the swelling potential. Indeed, the tested mechanical properties were notably higher for samples which were undergone to crosslinking and plasticized process. The presence of chitosan is determinant in pore formation and distribution which is an imperative for cell communication. Uniform pore size with diameters ranging from 142 to 519 µm were obtained, a range that has been described as optimal for bone tissue regeneration. Moreover, cytotoxicity was considered as negligible in the tested conditions, and viability indicates that the material might have potential as a bone regeneration system.


Assuntos
Desenvolvimento Ósseo/efeitos dos fármacos , Regeneração Óssea/efeitos dos fármacos , Engenharia Tecidual , Tecidos Suporte/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/uso terapêutico , Osso e Ossos/química , Proliferação de Células/efeitos dos fármacos , Quitosana/síntese química , Quitosana/química , Quitosana/uso terapêutico , Durapatita/síntese química , Durapatita/química , Durapatita/uso terapêutico , Humanos , Osteoblastos/efeitos dos fármacos , Álcool de Polivinil/síntese química , Álcool de Polivinil/química , Álcool de Polivinil/uso terapêutico
20.
Biochim Biophys Acta Mol Basis Dis ; 1864(11): 3650-3658, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30251684

RESUMO

Barth syndrome (BTHS) is a rare X-linked disorder that is characterized by cardiac and skeletal myopathy, neutropenia and growth abnormalities. The disease is caused by mutations in the tafazzin (TAZ) gene encoding an enzyme involved in the acyl chain remodeling of the mitochondrial phospholipid cardiolipin (CL). Biochemically, this leads to decreased levels of mature CL and accumulation of the intermediate monolysocardiolipin (MLCL). At a cellular level, this causes mitochondrial fragmentation and reduced stability of the respiratory chain supercomplexes. However, the exact mechanism through which tafazzin deficiency leads to disease development remains unclear. We therefore aimed to elucidate the pathways affected in BTHS cells by employing proteomic and metabolic profiling assays. Complexome profiling of patient skin fibroblasts revealed significant effects for about 200 different mitochondrial proteins. Prominently, we found a specific destabilization of higher order oxidative phosphorylation (OXPHOS) supercomplexes, as well as changes in complexes involved in cristae organization and CL trafficking. Moreover, the key metabolic complexes 2-oxoglutarate dehydrogenase (OGDH) and branched-chain ketoacid dehydrogenase (BCKD) were profoundly destabilized in BTHS patient samples. Surprisingly, metabolic flux distribution assays using stable isotope tracer-based metabolomics did not show reduced flux through the TCA cycle. Overall, insights from analyzing the impact of TAZ mutations on the mitochondrial complexome provided a better understanding of the resulting functional and structural consequences and thus the pathological mechanisms leading to Barth syndrome.


Assuntos
Síndrome de Barth/patologia , Redes e Vias Metabólicas/genética , Membranas Mitocondriais/patologia , Transdução de Sinais/genética , Fatores de Transcrição/genética , Síndrome de Barth/genética , Cardiolipinas/metabolismo , Estudos de Casos e Controles , Fibroblastos , Voluntários Saudáveis , Humanos , Metabolômica , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Membranas Mitocondriais/metabolismo , Mutação , Fosforilação Oxidativa , Cultura Primária de Células , Proteômica , Pele/citologia , Pele/patologia , Fatores de Transcrição/metabolismo
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