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1.
Cell ; 159(4): 956-956.e1, 2014 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-25417168

RESUMO

The mammalian sirtuins have emerged as critical regulators of cellular stress resistance, energy metabolism, and tumorigenesis. In some contexts, they delay the onset of age-related diseases and promote a healthy lifespan. The seven mammalian sirtuins, SIRT1-7, share a highly conserved NAD+-binding catalytic core domain although they exhibit distinct expression patterns, catalytic activities, and biological functions. This SnapShot provides an overview of these properties, with an emphasis on their relevance to aging.


Assuntos
Sirtuínas/metabolismo , Animais , Núcleo Celular/metabolismo , Humanos , Mamíferos/metabolismo , Mitocôndrias/metabolismo , Sirtuínas/análise , Sirtuínas/química
2.
BMC Public Health ; 24(1): 1187, 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38678202

RESUMO

BACKGROUND: Thriving from Work is a construct that has been highlighted as an important integrative positive worker well-being indicator that can be used in both research and practice. Recent public discourse emphasizes the important contributions that work should have on workers' lives in positive and meaningful ways and the importance of valid and reliable instruments to measure worker well-being. The Thriving from Work Questionnaire measures how workers' experiences of their work and conditions of work contributes in positive ways to their thriving both at and outside of work. METHODS: The purpose of this study was to translate the Thriving from Work Questionnaire from English to Spanish, and then validate the translated questionnaire in a sample of 8,795 finance workers in Peru and Mexico. We used item response theory models replicating methods that were used for the original validation studies. We conducted a differential item functioning analysis to evaluate any differences in the performance of models between Peru and Mexico. We evaluated criterion validity with organizational leadership, flourishing, vitality, community well-being, and worker's home location socio-economic position. RESULTS: The current study demonstrates that the Spanish (Peru/Mexico) questionnaire was found to be a reliable and valid measure of workers' thriving from work. One item was dropped from the long-form version of the original U.S. questionnaire. Both the long and short form versions of the questionnaire had similar psychometric properties. Empirical reliability was high. Criterion validity was established as hypothesized relationships between constructs was supported. There were no differences in the performance of the model between countries suggesting utility across Latin American countries. CONCLUSIONS: The current study demonstrated that the Spanish (Peru and Mexico) version of the questionnaire is both a reliable and valid measure of worker well-being in Latin America. Specific recommendations are made for the adaptation of the questionnaire and directions of future research.


Assuntos
Traduções , Humanos , Inquéritos e Questionários/normas , Masculino , México , Feminino , Adulto , Peru , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Satisfação no Emprego , Psicometria
3.
Am J Ind Med ; 67(7): 667-676, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38738969

RESUMO

BACKGROUND: Hospital patient-care workers have high occupational injury rates. While physical hazards within hospital work environments are established determinants of injury, social exposures may also contribute. This study examined how reports of unfair treatment at work, a dimension of work-related experiences of discrimination, were associated with injury among hospital-based patient-care workers. METHODS: We used data from the Boston Hospital Workers Health Study, a longitudinal cohort of nurses and nursing assistants at two Boston-area hospitals. In 2018, we conducted a worker survey asking about three types of unfair treatment at work and occupational injuries during the past year. We used mixed-effects logistic regression models to evaluate associations between specific types, total load, and high-frequency exposure of unfair treatment with injury, adjusting for age, gender, race and ethnicity, job title, and unit type. RESULTS: Among 1001 respondents, 21% reported being humiliated in front of others at work, 28% reported being watched more closely than other workers, and 47% reported having to work twice as hard as others for the same treatment. For each type of unfair treatment, we observed a monotonic relationship with occupational injury wherein increasing frequency of exposure was associated with increased odds of injury. We also observed monotonic relationships between total load and high-frequency exposure to unfair treatment and odds of injury. CONCLUSIONS: Work-related unfair treatment is associated with injury among hospital workers. Programs and policies that focus on preventing unfair treatment may lessen injury burden in hospital workers.


Assuntos
Traumatismos Ocupacionais , Humanos , Masculino , Feminino , Adulto , Traumatismos Ocupacionais/epidemiologia , Pessoa de Meia-Idade , Boston/epidemiologia , Estudos Longitudinais , Inquéritos e Questionários , Recursos Humanos de Enfermagem Hospitalar/estatística & dados numéricos , Recursos Humanos de Enfermagem Hospitalar/psicologia , Assistentes de Enfermagem/estatística & dados numéricos , Preconceito , Local de Trabalho/estatística & dados numéricos
4.
Am J Ind Med ; 66(4): 281-296, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36748853

RESUMO

INTRODUCTION: Thriving from Work is defined as the state of positive mental, physical, and social functioning in which workers' experiences of their work and working conditions enable them to thrive in their overall lives, contributing to their ability to achieve their full potential at work, at home, and in the community. The purpose of this study was to develop a psychometrically-sound questionnaire measuring the positive contribution that work can have on one's well-being both at, and outside of, their work. METHODS: We used both a qualitative and quantitative approach of item reduction, domain mapping dimensionality testing, development of "long-" and "short-" versions of the questionnaire, reliability, and construct and criterion validity testing. This was established in two independent online samples of US based workers (n = 1550, n = 500). RESULTS: We developed a bi-factor model 30-item long-form and a uni-factorial 8-item short-version. The long-form measures both the latent construct of Thriving from Work and six domains (psychological/emotional; work-life integration; social; experience of work; basic needs; health). Both long- and short- forms were found to have high empirical reliability (0.93  and 0.87 respectively). The short-form captures 94% of variance of the long-form. Construct and criterion validity were supported. Test-retest reliability was high. CONCLUSIONS: The Thriving from Work Questionnaire appears to be a valid and reliable measure of work-related well-being in United States workers. Further testing is needed to refine and test the instrument in specific industries, unique worker populations, and across geographic regions.


Assuntos
Qualidade de Vida , Humanos , Reprodutibilidade dos Testes , Psicometria , Inquéritos e Questionários , Qualidade de Vida/psicologia
5.
Am J Public Health ; 112(8): 1134-1137, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35709410

RESUMO

During fall 2020 in rural Pierce County, Washington, school districts and the county health department offered weekly rapid antigen screening to students and staff. Asymptomatic screening identified 42.5% of confirmed cases from the population. Parents reported it was a positive experience for their children. The program supported decisions to return to in-person learning, but screening ended because of resource and technical limitations. When planning in-school screening, stakeholder engagement and resource sustainability are important factors to consider. (Am J Public Health. 2022;112(8):1134-1137. https://doi.org/10.2105/AJPH.2022.306875).


Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , Criança , Humanos , Instituições Acadêmicas , Estudantes , Washington/epidemiologia
6.
Mol Cell ; 54(1): 5-16, 2014 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-24725594

RESUMO

Cellular proteins are decorated with a wide range of acetyl and other acyl modifications. Many studies have demonstrated regulation of site-specific acetylation by acetyltransferases and deacetylases. Acylation is emerging as a new type of lysine modification, but less is known about its overall regulatory role. Furthermore, the mechanisms of lysine acylation, its overlap with protein acetylation, and how it influences cellular function are major unanswered questions in the field. In this review, we discuss the known roles of acetyltransferases and deacetylases and the sirtuins as a conserved family of a nicotinamide adenine dinucleotide (NAD⁺)-dependent protein deacylases that are important for response to cellular stress and homeostasis. We also consider the evidence for an emerging idea of nonenzymatic protein acylation. Finally, we put forward the hypothesis that protein acylation is a form of protein "carbon stress" that the deacylases evolved to remove as a part of a global protein quality-control network.


Assuntos
Carbono/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas/metabolismo , Sirtuínas/metabolismo , Estresse Fisiológico , Acilação , Animais , Humanos , Lisina , Modelos Biológicos
7.
BMC Public Health ; 21(1): 1869, 2021 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-34656090

RESUMO

BACKGROUND: Many organizational interventions aim to improve working conditions to promote and protect worker safety, health, and well-being. The Workplace Organizational Health Study used process evaluation to examine factors influencing implementation of an organizational intervention. This paper examines the extent to which the intervention was implemented as planned, the dose of intervention implemented, and ways the organizational context hindered or facilitated the implementation of the intervention. METHODS: This proof-of-concept trial was conducted with a large, multinational company that provides food service through contractual arrangements with corporate clients. The 13-month intervention was launched in five intervention sites in October 2018. We report findings on intervention implementation based on process tracking and qualitative data. Qualitative data from 25 post-intervention interviews and 89 process tracking documents were coded and thematically analyzed. RESULTS: Over the 13-month intervention, research team representatives met with site managers monthly to provide consultation and technical assistance on safety and ergonomics, work intensity, and job enrichment. Approximately two-thirds of the planned in-person or phone contacts occurred. We tailored the intervention to each site as we learned more about context, work demands, and relationships. The research team additionally met regularly with senior leadership and district managers, who provided corporate resources and guidance. By assessing the context of the food service setting in which the intervention was situated, we explored factors hindering and facilitating the implementation of the intervention. The financial pressures, competing priorities and the fast-paced work environment placed constraints on site managers' availability and limited the full implementation of the intervention. CONCLUSIONS: Despite strong support from corporate senior leadership, we encountered barriers in the implementation of the planned intervention at the worksite and district levels. These included financial demands that drove work intensity; turnover of site and district managers disrupting continuity in the implementation of the intervention; and staffing constraints that further increased the work load and pace. Findings underscore the need for ongoing commitment and support from both the parent employer and the host client. TRIAL REGISTRATION: This study was retrospectively registered with the Clinical Trials. Gov Protocol and Results System on June 2, 2021 with assigned registration number NCT04913168 .


Assuntos
Serviços de Alimentação , Saúde Ocupacional , Ergonomia , Humanos , Estudo de Prova de Conceito , Salários e Benefícios , Local de Trabalho
8.
Biochemistry ; 58(49): 4983-4996, 2019 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-31702900

RESUMO

von Willebrand A domain-containing protein 8 (VWA8) is a poorly characterized, mitochondrial matrix-targeted protein with an AAA ATPase domain and ATPase activity that increases in livers of mice fed a high-fat diet. This study was undertaken to use CRISPR/Cas9 to delete VWA8 in cultured mouse hepatocytes and gain insight into its function. Unbiased omics techniques and bioinformatics were used to guide subsequent assays, including the assessment of oxidative stress and the determination of bioenergetic capacity. Metabolomics analysis showed VWA8 null cells had higher levels of oxidative stress and protein degradation; assays of hydrogen peroxide production revealed higher levels of production of reactive oxygen species (ROS). Proteomics and transcriptomics analyses showed VWA8 null cells had higher levels of expression of mitochondrial proteins (electron transport-chain Complex I, ATP synthase), peroxisomal proteins, and lipid transport proteins. The pattern of higher protein abundance in the VWA8 null cells could be explained by a higher level of hepatocyte nuclear factor 4 α (HNF4α) expression. Bioenergetic assays showed higher rates of carbohydrate oxidation and mitochondrial and nonmitochondrial lipid oxidation in intact and permeabilized cells. Inhibitor assays localized sites of ROS production to peroxisomes and NOX1/4. The rescue of VWA8 protein restored the wild-type phenotype, and treatment with antioxidants decreased the level of HNF4α expression. Thus, loss of VWA8 produces a mitochondrial defect that may be sensed by NOX4, leading to an increase in the level of ROS that results in a higher level of HNF4α. The compensatory HNF4α response results in a higher oxidative capacity and an even higher level of ROS production. We hypothesize that VWA8 is an AAA ATPase protein that plays a role in mitochondrial protein quality.


Assuntos
Adenosina Trifosfatases/genética , Fator 4 Nuclear de Hepatócito/metabolismo , Hepatócitos/metabolismo , Estresse Oxidativo , Adenosina Trifosfatases/metabolismo , Animais , Linhagem Celular , Deleção de Genes , Fator 4 Nuclear de Hepatócito/genética , Camundongos , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Espécies Reativas de Oxigênio/metabolismo
10.
BMC Public Health ; 19(1): 1712, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31856772

RESUMO

BACKGROUND: Increasing evidence suggests that psychological well-being (PWB) is associated with lower disease and mortality risk, and may be enhanced with relatively low-cost interventions. Yet, dissemination of these interventions remains limited, in part because insufficient attention has been paid to distinct PWB dimensions, which may impact physical health outcomes differently. METHODS: This essay first reviews the empirical evidence regarding differential relationships between all-cause mortality and multiple dimensions of PWB (e.g., life purpose, mastery, positive affect, life satisfaction, optimism). Then, individual-level positive psychology interventions aimed at increasing PWB and tested in randomized-controlled trials are reviewed as these allow for easy implementation and potentially broad outreach to improve population well-being, in concert with efforts targeting other established social determinants of health. RESULTS: Several PWB dimensions relate to mortality, with varying strength of evidence. Many of positive psychology trials indicate small-to-moderate improvements in PWB; rigorous institution-level interventions are comparatively few, but preliminary results suggest benefits as well. Examples of existing health policies geared towards the improvement of population well-being are also presented. Future avenues of well-being epidemiological and intervention research, as well as policy implications, are discussed. CONCLUSIONS: Although research in the fields of behavioral and psychosomatic medicine, as well as health psychology have substantially contributed to the science of PWB, this body of work has been somewhat overlooked by the public health community. Yet, the growing interest in documenting well-being, in addition to examining its determinants and consequences at a population level may provoke a shift in perspective. To cultivate optimal well-being-mental, physical, social, and spiritual-consideration of a broader set of well-being measures, rigorous studies, and interventions that can be disseminated is critically needed.


Assuntos
Saúde Mental , Saúde Pública , Promoção da Saúde , Humanos , Políticas , Ensaios Clínicos Controlados Aleatórios como Assunto
11.
Prev Med ; 111: 235-240, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29567439

RESUMO

Preventive medical care may reduce downstream medical costs and reduce population burden of disease. However, although social, demographic, and geographic determinants of preventive care have been studied, there is little information about how the workplace affects preventive care utilization. This study examines how four types of organizational policies and practices (OPPs) are associated with individual workers' preventive care utilization. We used data collected in 2012 from 838 hospital patient care workers, grouped in 84 patient care units at two hospitals in Boston. Via survey, we assessed individuals' perceptions of four types of OPPs on their work units. We linked the survey data to a database containing detailed information on medical expenditures. Using multilevel models, we tested whether individual-level perceptions, workgroup-average perceptions, and their combination were associated with individual workers' preventive care utilization (measured by number of preventive care encounters over a two-year period). Adjusting for worker characteristics, higher individual-level perceptions of workplace flexibility were associated with greater preventive care utilization. Higher average unit-level perceptions of people-oriented culture, ergonomic practices, and flexibility were associated with greater preventive care utilization. Overall, we find that workplace policies and practices supporting flexibility, ergonomics, and people-oriented culture are associated with positive preventive care-seeking behavior among workers, with some policies and practices operating at the individual level and some at the group level. Improving the work environment could impact employers' health-related expenditures and improve workers' health-related quality of life.


Assuntos
Política Organizacional , Aceitação pelo Paciente de Cuidados de Saúde , Percepção , Medicina Preventiva , Adulto , Boston , Feminino , Humanos , Pessoa de Meia-Idade , Cultura Organizacional , Psicologia , Qualidade de Vida , Inquéritos e Questionários , Local de Trabalho/psicologia
12.
Am J Ind Med ; 2018 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-29845635

RESUMO

OBJECTIVE: We examined relationships between organizational policies and practices (OPPs) (safety practices, ergonomic practices, and people-oriented culture) and work limitations in a sample of hospital workers. METHODS: We used the 6-item Work Limitations Questionnaire (WLQ) to assess workers' perceptions of health-related work limitations. Self-reported OPPs and the WLQ were collected from workers in Boston, Massachusetts (n = 1277). We conducted random-intercept multi-level logistic regression models for each OPP using stepwise selection of covariates. RESULTS: As the unit-average ergonomic practice score increased by one, the odds of a worker reporting work limitations decreased by approximately 39% (P-value = 0.018), adjusted for job title, age, and body mass index. A similar relationship existed for people-oriented culture (P-value = 0.038). The association between safety practices and work limitations was similar, but not statistically significant. CONCLUSIONS: This study demonstrated the importance of workplace OPPs. OPPs that promote positive and supportive environments and that foster improvements in ergonomics may help reduce work limitations.

14.
Am J Public Health ; 107(7): 1051-1057, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28520495

RESUMO

The true burden (morbidity, mortality, disability, cost, pain, distress) of occupational and work-related diseases and injuries is unknown, and what is reported as burden is significantly underestimated. This underestimation affects the way decision-makers view investments in research and worker protection, which in turn has a substantial impact on national welfare and public health. To better describe the societal and individual burdens of occupational and work-related diseases and injuries, we propose an approach to gauge what is known about burden and where new assessments may be made. This approach consists of 4 elements to consider in burden assessments: (1) utilizing multiple domains, including the individual worker, the worker's family, the community in which the workplace is located, the employer, and society as a whole; (2) taking a broader view of the work-relatedness of disease and injury; (3) assessing the impact of the entire working-life continuum; and (4) applying the comprehensive concept of "well-being" as an indicator in addressing contemporary changes in the nature of work, the workplace, and the workforce. Further research on burden and enhanced surveillance is needed to develop these elements.


Assuntos
Doenças Profissionais/economia , Traumatismos Ocupacionais/economia , Local de Trabalho/organização & administração , Pessoal Administrativo , Pessoas com Deficiência/psicologia , Humanos , Doenças Profissionais/mortalidade , Doenças Profissionais/prevenção & controle , Traumatismos Ocupacionais/mortalidade , Traumatismos Ocupacionais/prevenção & controle , Saúde Pública , Estresse Psicológico/psicologia , Local de Trabalho/psicologia
15.
Mol Cell Proteomics ; 14(6): 1489-500, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25795660

RESUMO

The availability of acyl-Coenzyme A (acyl-CoA) thioester compounds affects numerous cellular functions including autophagy, lipid oxidation and synthesis, and post-translational modifications. Consequently, the acyl-CoA level changes tend to be associated with other metabolic alterations that regulate these critical cellular functions. Despite their biological importance, this class of metabolites remains difficult to detect and quantify using current analytical methods. Here we show a universal method for metabolomics that allows for the detection of an expansive set of acyl-CoA compounds and hundreds of other cellular metabolites. We apply this method to profile the dynamics of acyl-CoA compounds and corresponding alterations in metabolism across the metabolic network in response to high fat feeding in mice. We identified targeted metabolites (>50) and untargeted features (>1000) with significant changes (FDR < 0.05) in response to diet. A substantial extent of this metabolic remodeling exhibited correlated changes in acyl-CoA metabolism with acyl-carnitine metabolism and other features of the metabolic network that together can lead to the discovery of biomarkers of acyl-CoA metabolism. These findings show a robust acyl-CoA profiling method and identify coordinated changes of acyl-CoA metabolism in response to nutritional stress.


Assuntos
Acil Coenzima A/metabolismo , Dieta Hiperlipídica , Animais , Células HCT116 , Humanos , Metabolômica , Camundongos Endogâmicos C57BL
16.
Prev Med ; 91: 188-196, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27527576

RESUMO

There is increasing recognition of the value added by integrating traditionally separate efforts to protect and promote worker safety and health. This paper presents an innovative conceptual model to guide research on determinants of worker safety and health and to inform the design, implementation and evaluation of integrated approaches to promoting and protecting worker health. This model is rooted in multiple theories and the premise that the conditions of work are important determinants of individual safety and health outcomes and behaviors, and outcomes important to enterprises such as absence and turnover. Integrated policies, programs and practices simultaneously address multiple conditions of work, including the physical work environment and the organization of work (e.g., psychosocial factors, job tasks and demands). Findings from two recent studies conducted in Boston and Minnesota (2009-2015) illustrate the application of this model to guide social epidemiological research. This paper focuses particular attention on the relationships of the conditions of work to worker health-related behaviors, musculoskeletal symptoms, and occupational injury; and to the design of integrated interventions in response to specific settings and conditions of work of small and medium size manufacturing businesses, based on a systematic assessment of priorities, needs, and resources within an organization. This model provides an organizing framework for both research and practice by specifying the causal pathways through which work may influence health outcomes, and for designing and testing interventions to improve worker safety and health that are meaningful for workers and employers, and responsive to that setting's conditions of work.


Assuntos
Promoção da Saúde/organização & administração , Saúde Ocupacional , Local de Trabalho/organização & administração , Humanos , Liderança , Doenças Profissionais/prevenção & controle , Serviços de Saúde do Trabalhador/organização & administração , Pesquisa/organização & administração , Estados Unidos , Local de Trabalho/psicologia
17.
Am J Ind Med ; 58(3): 282-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25308763

RESUMO

BACKGROUND: Patient-care workers are frequently exposed to sharps injuries, which can involve the risk of serious illness. Underreporting of these injuries can compromise prevention efforts. METHODS: We linked survey responses of 1,572 non-physician patient-care workers with the Occupational Health Services (OHS) database at two academic hospitals. We determined whether survey respondents who said they had sharps injuries indicated that they had reported them and whether reported injuries were recorded in the OHS database. RESULTS: Respondents said that they reported 62 of 78 sharps injuries occurring over a 12-month period. Only 28 appeared in the OHS data. Safety practices were positively associated with respondents' saying they reported sharps injuries but not with whether reported injuries appeared in the OHS data. CONCLUSIONS: Administrators should consider creating reporting mechanisms that are simpler and more direct. Administrators and researchers should attempt to understand how incidents might be lost before they are recorded.


Assuntos
Bases de Dados Factuais/estatística & dados numéricos , Hospitais Universitários/estatística & dados numéricos , Ferimentos Penetrantes Produzidos por Agulha/epidemiologia , Saúde Ocupacional/estatística & dados numéricos , Traumatismos Ocupacionais/epidemiologia , Gestão de Riscos/normas , Adulto , Segurança de Equipamentos/normas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recursos Humanos em Hospital/estatística & dados numéricos , Gestão de Riscos/métodos
19.
J Biol Chem ; 288(40): 29036-45, 2013 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-23946487

RESUMO

Alterations in mitochondrial protein acetylation are implicated in the pathophysiology of diabetes, the metabolic syndrome, mitochondrial disorders, and cancer. However, a viable mechanism responsible for the widespread acetylation in mitochondria remains unknown. Here, we demonstrate that the physiologic pH and acyl-CoA concentrations of the mitochondrial matrix are sufficient to cause dose- and time-dependent, but enzyme-independent acetylation and succinylation of mitochondrial and nonmitochondrial proteins in vitro. These data suggest that protein acylation in mitochondria may be a chemical event facilitated by the alkaline pH and high concentrations of reactive acyl-CoAs present in the mitochondrial matrix. Although these results do not exclude the possibility of enzyme-mediated protein acylation in mitochondria, they demonstrate that such a mechanism may not be required in its unique chemical environment. These findings may have implications for the evolutionary roles that the mitochondria-localized SIRT3 deacetylase and SIRT5 desuccinylase have in the maintenance of metabolic health.


Assuntos
Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Succinatos/metabolismo , Acetilação , Sequência de Aminoácidos , Animais , Catálise , Coenzima A/metabolismo , Biologia Computacional , Concentração de Íons de Hidrogênio , Hidróxidos/metabolismo , Cinética , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Mitocondriais/química , Dados de Sequência Molecular , Sirtuína 3/metabolismo
20.
Hum Mol Genet ; 21(12): 2688-97, 2012 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-22394676

RESUMO

Friedreich's ataxia (FRDA) is the most common inherited human ataxia and is caused by a deficiency in the mitochondrial protein frataxin. Clinically, patients suffer from progressive spinocerebellar degeneration, diabetes and a fatal cardiomyopathy, associated with mitochondrial respiratory chain defects. Recent findings have shown that lysine acetylation regulates mitochondrial function and intermediary metabolism. However, little is known about lysine acetylation in the setting of pathologic energy stress and mitochondrial dysfunction. We tested the hypothesis that the respiratory chain defects in frataxin deficiency alter mitochondrial protein acetylation. Using two conditional mouse models of FRDA, we demonstrate marked hyperacetylation of numerous cardiac mitochondrial proteins. Importantly, this biochemical phenotype develops concurrently with cardiac hypertrophy and is caused by inhibition of the NAD(+)-dependent SIRT3 deacetylase. This inhibition is caused by an 85-fold decrease in mitochondrial NAD(+)/NADH and direct carbonyl group modification of SIRT3, and is reversed with excess SIRT3 and NAD(+) in vitro. We further demonstrate that protein hyperacetylation may be a common feature of mitochondrial disorders caused by respiratory chain defects, notably, cytochrome oxidase I (COI) deficiency. These findings suggest that SIRT3 inhibition and consequent protein hyperacetylation represents a negative feedback mechanism limiting mitochondrial oxidative pathways when respiratory metabolism is compromised, and thus, may contribute to the lethal cardiomyopathy in FRDA.


Assuntos
Ataxia de Friedreich/metabolismo , Proteínas de Ligação ao Ferro/metabolismo , Mitocôndrias Cardíacas/metabolismo , Sirtuína 3/metabolismo , Acetilação , Animais , Western Blotting , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Retroalimentação Fisiológica , Feminino , Ataxia de Friedreich/genética , Ataxia de Friedreich/patologia , Humanos , Proteínas de Ligação ao Ferro/genética , Masculino , Camundongos , Camundongos Knockout , Proteínas Mitocondriais/metabolismo , Modelos Biológicos , Miocárdio/metabolismo , NAD/metabolismo , Estresse Oxidativo , Frataxina
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