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1.
Mol Cell ; 63(1): 7-20, 2016 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-27392145

RESUMO

In modern molecular biology, RNA has emerged as a versatile macromolecule capable of mediating an astonishing number of biological functions beyond its role as a transient messenger of genetic information. The recent discovery and functional analyses of new classes of noncoding RNAs (ncRNAs) have revealed their widespread use in many pathways, including several in the nucleus. This Review focuses on the mechanisms by which nuclear ncRNAs directly contribute to the maintenance of genome stability. We discuss how ncRNAs inhibit spurious recombination among repetitive DNA elements, repress mobilization of transposable elements (TEs), template or bridge DNA double-strand breaks (DSBs) during repair, and direct developmentally regulated genome rearrangements in some ciliates. These studies reveal an unexpected repertoire of mechanisms by which ncRNAs contribute to genome stability and even potentially fuel evolution by acting as templates for genome modification.


Assuntos
Núcleo Celular/metabolismo , Instabilidade Genômica , RNA não Traduzido/genética , Animais , Quebras de DNA de Cadeia Dupla , Reparo do DNA , Dosagem de Genes , Inativação Gênica , Heterocromatina/genética , Heterocromatina/metabolismo , Humanos , Conformação de Ácido Nucleico , RNA não Traduzido/química , RNA não Traduzido/classificação , RNA não Traduzido/metabolismo , Relação Estrutura-Atividade , Telômero/genética , Telômero/metabolismo
2.
Mol Cell ; 64(6): 1088-1101, 2016 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-27984744

RESUMO

Quiescence (G0) is a ubiquitous stress response through which cells enter reversible dormancy, acquiring distinct properties including reduced metabolism, resistance to stress, and long life. G0 entry involves dramatic changes to chromatin and transcription of cells, but the mechanisms coordinating these processes remain poorly understood. Using the fission yeast, here, we track G0-associated chromatin and transcriptional changes temporally and show that as cells enter G0, their survival and global gene expression programs become increasingly dependent on Clr4/SUV39H, the sole histone H3 lysine 9 (H3K9) methyltransferase, and RNAi proteins. Notably, G0 entry results in RNAi-dependent H3K9 methylation of several euchromatic pockets, prior to which Argonaute1-associated small RNAs from these regions emerge. Overall, our data reveal another function for constitutive heterochromatin proteins (the establishment of the global G0 transcriptional program) and suggest that stress-induced alterations in Argonaute-associated sRNAs can target the deployment of transcriptional regulatory proteins to specific sequences.


Assuntos
Proteínas Argonautas/genética , Proteínas de Ciclo Celular/genética , Eucromatina/metabolismo , Regulação Fúngica da Expressão Gênica , Metiltransferases/genética , RNA Interferente Pequeno/genética , Proteínas de Schizosaccharomyces pombe/genética , Schizosaccharomyces/genética , Proteínas Argonautas/metabolismo , Sítios de Ligação , Proteínas de Ciclo Celular/metabolismo , Eucromatina/ultraestrutura , Heterocromatina/metabolismo , Heterocromatina/ultraestrutura , Histona-Lisina N-Metiltransferase , Histonas/genética , Histonas/metabolismo , Metiltransferases/metabolismo , Ligação Proteica , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Fase de Repouso do Ciclo Celular/genética , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Transcrição Gênica
3.
Rev Panam Salud Publica ; 48: e14, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38464879

RESUMO

More than 8 million older people in Latin America depend on long-term care (LTC), accounting for 12% of people aged ≥ 60 years and almost 27% of those aged ≥ 80. It is crucial to develop sustainable strategies for providing LTC in the area, including institutional care. This special report aims to characterize institutional LTC in four countries (Brazil, Chile, Costa Rica and Mexico), using available information systems, and to identify the strategies adopted to support institutional care in these countries. This narrative review used nationwide, open-access, public data sources to gather demographic estimates and information about institutional LTC coverage and the availability of open-access data for the proportion of people with LTC needs, the number of LTC facilities and the number of residents living in them. These countries have a larger share of older people than the average in Latin America but fewer LTC facilities than required by the demand. National surveys lack standardization in defining disability, LTC and dependency on care. Information about institutional care is mainly fragmented and does not regularly include LTC facilities, their residents and workers. Data are crucial to inform evidence-based decisions to favor prioritization and to support advances in promoting policies around institutional LTC in Latin America. Although information about institutional care in the region is fragmented and insufficient, this paper profiles the four selected countries. It highlights the need for a better structure for data-driven LTC information systems. The lack of information emphasizes the urgency of the need to focus on and encourage research into this topic.


En América Latina, más de 8 millones de personas mayores dependen de los cuidados a largo plazo (CLP), lo que representa el 12% de las personas de 60 años o más y casi el 27% de las de 80 años o más Resulta crucial elaborar estrategias sostenibles para la prestación de CLP en la región, incluida la atención en centros de CLP. Este artículo especial tiene como finalidad determinar las características de la atención prestada en centros de CLP en cuatro países (Brasil, Chile, Costa Rica y México), utilizando los sistemas de información disponibles, así como determinar cuáles son las estrategias adoptadas en estos países para brindar apoyo a la atención en centros de CLP. En esta revisión descriptiva se utilizaron fuentes de datos públicas, de libre acceso y de ámbito nacional para recopilar estimaciones demográficas e información sobre la cobertura de la atención en centros de CLP, así como sobre la disponibilidad de datos de libre acceso acerca de la proporción de personas con necesidades de CLP, el número de centros de CLP y su correspondiente número de residentes. Estos países tienen una proporción de personas mayores superior a la media de América Latina, pero menos centros de CLP de los necesarios para cubrir la demanda. En las encuestas nacionales no hay una definición estandarizada de la discapacidad, los cuidados a largo plazo y la dependencia. La mayor parte de la información sobre la atención en centros de CLP está fragmentada y no incluye datos periódicos sobre los centros de CLP existentes, sus residentes o sus trabajadores. Estos datos son cruciales para fundamentar decisiones basadas en la evidencia destinadas a propiciar la priorización y brindar apoyo a los avances en la promoción de políticas en materia de centros de CLP en América Latina. Aunque la información sobre la atención en centros de CLP en la región es fragmentaria e insuficiente, en este artículo se presenta el perfil de los cuatro países seleccionados. Se resalta la necesidad de mejorar la estructura de los sistemas de información sobre CLP basados en datos. Esta falta de información pone de relieve la necesidad urgente de centrarse en este tema y fomentar la investigación al respecto.


Na América Latina, mais de 8 milhões de pessoas idosas dependem de cuidados de longa duração (CLD), o que representa 12% das pessoas com mais de 60 anos e quase 27% das pessoas com mais de 80 anos. É fundamental criar estratégias sustentáveis para oferecer CLD na região, inclusive cuidados institucionais. O objetivo deste relatório especial é caracterizar CLD institucionais em quatro países (Brasil, Chile, Costa Rica e México), usando os sistemas de informação disponíveis, e identificar as estratégias adotadas para apoiar os cuidados institucionais nesses países. Esta revisão narrativa usou dados públicos de acesso aberto de âmbito nacional para coletar estimativas demográficas e informações sobre a cobertura de CLD institucionais e a disponibilidade de dados de acesso aberto sobre a porcentagem de pessoas com necessidades de CLD, o número de instituições de CLD e o número de residentes nessas instituições. Esses países têm uma parcela maior de pessoas idosas do que a média da América Latina, mas menos instituições de CLD do que a demanda exige. Falta padronização na definição de incapacidade, CLD e dependência de cuidados nas pesquisas nacionais. Em sua maior parte, as informações sobre cuidados institucionais são fragmentadas e não incluem instituições de CLD, seus residentes e trabalhadores de maneira regular. É essencial usar dados para guiar decisões baseadas em evidências a fim de favorecer a priorização e apoiar avanços que promovam políticas para CLD institucionais na América Latina. Embora as informações sobre cuidados institucionais na região sejam fragmentadas e insuficientes, este documento traça o perfil dos quatro países selecionados, destacando a necessidade de uma estrutura melhor para sistemas de informações de CLD orientados por dados. A falta de informações ressalta a urgência de aumentar o foco no tópico e encorajar pesquisas sobre o assunto.

4.
Am J Respir Cell Mol Biol ; 64(4): 465-476, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33493092

RESUMO

Fibroblast activation includes differentiation to myofibroblasts and is a key feature of organ fibrosis. The Notch pathway has been involved in myofibroblast differentiation in several tissues, including the lung. Here, we identify a subset of collagen-expressing cells in the lung that exhibit Notch3 activity at homeostasis. After injury, this activation increases, being found in αSMA-expressing myofibroblasts in the mouse and human fibrotic lung. Although previous studies suggest a contribution of Notch3 in stromal activation, in vivo evidence of the role of Notch3 in lung fibrosis remains unknown. In this study, we examine the effects of Notch3 deletion in pulmonary fibrosis and demonstrate that Notch3-deficient lungs are protected from lung injury with significantly reduced collagen deposition after bleomycin administration. The induction of profibrotic genes is reduced in bleomycin-treated Notch3-knockout lungs that consistently present fewer αSMA-positive myofibroblasts. As a result, the volume of healthy lung tissue is higher and lung function is improved in the absence of Notch3. Using in vitro cultures of lung primary fibroblasts, we confirmed that Notch3 participates in their survival and differentiation. Thus, Notch3 deficiency mitigates the development of lung fibrosis because of its role in mediating fibroblast activation. Our findings reveal a previously unidentified mechanism underlying lung fibrogenesis and provide a potential novel therapeutic approach to target pulmonary fibrosis.


Assuntos
Colágeno/metabolismo , Pulmão/metabolismo , Miofibroblastos/metabolismo , Fibrose Pulmonar/metabolismo , Receptor Notch3/deficiência , Actinas/metabolismo , Animais , Bleomicina , Diferenciação Celular , Sobrevivência Celular , Células Cultivadas , Modelos Animais de Doenças , Progressão da Doença , Humanos , Pulmão/patologia , Pulmão/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miofibroblastos/patologia , Fenótipo , Fibrose Pulmonar/genética , Fibrose Pulmonar/patologia , Fibrose Pulmonar/fisiopatologia , Receptor Notch3/genética
5.
J Biol Chem ; 295(8): 2270-2284, 2020 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-31949046

RESUMO

Besides being regulated by G-protein-coupled receptors, the activity of heterotrimeric G proteins is modulated by many cytoplasmic proteins. GIV/Girdin and DAPLE (Dvl-associating protein with a high frequency of leucine) are the best-characterized members of a group of cytoplasmic regulators that contain a Gα-binding and -activating (GBA) motif and whose dysregulation underlies human diseases, including cancer and birth defects. GBA motif-containing proteins were originally reported to modulate G proteins by binding Gα subunits of the Gi/o family (Gαi) over other families (such as Gs, Gq/11, or G12/13), and promoting nucleotide exchange in vitro However, some evidence suggests that this is not always the case, as phosphorylation of the GBA motif of GIV promotes its binding to Gαs and inhibits nucleotide exchange. The G-protein specificity of DAPLE and how it might affect nucleotide exchange on G proteins besides Gαi remain to be investigated. Here, we show that DAPLE's GBA motif, in addition to Gαi, binds efficiently to members of the Gs and Gq/11 families (Gαs and Gαq, respectively), but not of the G12/13 family (Gα12) in the absence of post-translational phosphorylation. We pinpointed Met-1669 as the residue in the GBA motif of DAPLE that diverges from that in GIV and enables better binding to Gαs and Gαq Unlike the nucleotide-exchange acceleration observed for Gαi, DAPLE inhibited nucleotide exchange on Gαs and Gαq These findings indicate that GBA motifs have versatility in their G-protein-modulating effect, i.e. they can bind to Gα subunits of different classes and either stimulate or inhibit nucleotide exchange depending on the G-protein subtype.


Assuntos
Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/química , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas dos Microfilamentos/química , Proteínas dos Microfilamentos/metabolismo , Sequência de Aminoácidos , Animais , Bovinos , Células HEK293 , Humanos , Modelos Biológicos , Proteínas Mutantes/metabolismo , Peptídeos/metabolismo , Ligação Proteica
6.
Curr Issues Mol Biol ; 43(2): 637-649, 2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34287260

RESUMO

The serum fraction of platelet-rich fibrin (hyperacute serum) has been shown to improve cartilage cell proliferation in in vitro osteoarthritic knee joint models. We hypothesize that hyperacute serum may be a potential regenerative therapeutic for osteoarthritic knees. In this study, the cytokine milieu at the synovial fluid of osteoarthritic knee joints exposed to hyperacute serum intraarticular injections was investigated. Patients with knee osteoarthritis received three injections of autologous hyperacute serum; synovial fluid was harvested before each injection and clinical monitoring was followed-up for 6 months. Forty osteoarthritic-related cytokines, growth factors and structural proteins from synovial fluid were quantified and analysed by Multivariate Factor Analysis. Hyperacute serum provided symptomatic relief regarding pain and joint stability for OA patients. Both patients "with" and "without effusion knees" had improved VAS, KOOS and Lysholm-Tegner scores 6 months after of hyperacute serum treatment. Synovial fluid analysis revealed two main clusters of proteins reacting together as a group, showing strong and significant correlations with their fluctuation patterns after hyperacute serum treatment. In conclusion, hyperacute serum has a positive effect in alleviating symptoms of osteoarthritic knees. Moreover, identified protein clusters may allow the prediction of protein expression, reducing the number of investigated proteins in future studies.


Assuntos
Citocinas/metabolismo , Osteoartrite do Joelho/metabolismo , Osteoartrite do Joelho/terapia , Fibrina Rica em Plaquetas , Adulto , Biomarcadores , Citocinas/sangue , Gerenciamento Clínico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/diagnóstico , Osteoartrite do Joelho/etiologia , Mapeamento de Interação de Proteínas , Mapas de Interação de Proteínas , Resultado do Tratamento , Adulto Jovem
7.
Exp Cell Res ; 395(2): 112215, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32771524

RESUMO

Human naïve pluripotent stem cells (PSCs) represent an optimal homogenous starting point for molecular interventions and differentiation strategies. This is in contrast to the standard primed PSCs which fluctuate in identity and are transcriptionally heterogeneous. However, despite many efforts, the maintenance and expansion of human naïve PSCs remains a challenge. Here, we discuss our recent strategy for the stabilization of human PSC in the naïve state based on the use of a single chemical inhibitor of the related kinases CDK8 and CDK19. These kinases phosphorylate and negatively regulate the multiprotein Mediator complex, which is critical for enhancer-driven recruitment of RNA Pol II. The net effect of CDK8/19 inhibition is a global stimulation of enhancers, which in turn reinforces transcriptional programs including those related to cellular identity. In the case of pluripotent cells, the presence of CDK8/19i efficiently stabilizes the naïve state. Importantly, in contrast to previous chemical methods to induced the naïve state based on the inhibition of the FGF-MEK-ERK pathway, CDK8/19i-naïve human PSCs are chromosomally stable and retain developmental potential after long-term expansion. We suggest this could be related to the fact that CDK8/19 inhibition does not induce DNA demethylation. These principles may apply to other fate decisions.


Assuntos
Diferenciação Celular/fisiologia , Células-Tronco Embrionárias/metabolismo , Complexo Mediador/metabolismo , Células-Tronco Pluripotentes/metabolismo , Animais , Humanos , Sistema de Sinalização das MAP Quinases/fisiologia , Transdução de Sinais/fisiologia
8.
Int J Mol Sci ; 22(14)2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34299123

RESUMO

Hyperacute serum (HAS) is a blood derivative product that promotes the proliferation of various cell types and controls inflammation in vitro. The aim of this study is to investigate the regenerative potential of different formulations of HAS, including lyophilized and hyaluronic acid combined versions, to obtain a stable and standardized therapeutic in osteoarthritis (OA), which may be able to overcome the variability limitations of platelet-rich plasma (PRP). Primary human osteoarthritic chondrocytes were used for testing cellular viability and gene expression of OA-related genes. Moreover, a co-culture of human explants of cartilage, bone and synovium under inflammatory conditions was used for investigating the inflammatory control capacities of the different therapeutics. In this study, one formulation of lyophilized HAS achieved the high cell viability rates of liquid HAS and PRP. Gene expression analysis showed that HAS induced higher Col1a1 expression than PRP. Cytokine quantification from supernatant fluids revealed that HAS treatment of inflamed co-cultures significantly reduced levels of IL-5, IL-15, IL-2, TNFα, IL-7 and IL-12. To conclude, lyophilized HAS is a stable and standardized therapeutic with high potential in joint regeneration.


Assuntos
Condrócitos/citologia , Osteoartrite/terapia , Plasma Rico em Plaquetas/química , Regeneração , Medicina Regenerativa/normas , Soro/química , Adulto , Técnicas de Cocultura , Voluntários Saudáveis , Humanos , Pessoa de Meia-Idade
9.
Aging Clin Exp Res ; 32(2): 313-321, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30919261

RESUMO

BACKGROUND: In Latin America, knowledge about the demography and health status of adults aged 100 years and over is scarce. Insufficient studies of the elderly population in Costa Rica exist despite having a "Blue Zone" (geographical area with a high concentration of centenarians) in the Peninsula of Nicoya, with a high percentage of centenarians in the districts of Santa Cruz, Nicoya, Hojancha, Nandayure and Carrillo. AIMS: To describe the clinical, functional, mental and social profile of centenarians residing in the Blue Zone of the Peninsula of Nicoya, Costa Rica. METHODS: This is a cross-sectional study using a population base of 43 community-dwelling centenarians. A comprehensive geriatric assessment was performed, including sociodemographic information, health status, electrocardiogram and laboratory tests. RESULTS: The mean age of centenarians was 101.93 years, of whom 18 (42%) were men and 25 (58%) women. Two (4.6%) resided in nursing homes. Women had worse results than men in the evaluation of dependence on basic and instrumental activities of daily living, and the short physical performance battery performance test. A high prevalence of low Vitamin D levels (87.3%), atrial fibrillation (9.3%) and visual impairment (46.5%) was found. CONCLUSIONS: This is the first study describing the medical, functional, mental and social profile of centenarians in the Peninsula of Nicoya (Blue Zone) in Costa Rica. This population has a high prevalence of malnutrition and hypertension with dependence on the basic activities of daily living, and a low prevalence for diabetes, depression, ischemic heart disease, chronic obstructive pulmonary disease, and polypharmacy.


Assuntos
Transtornos Cognitivos/epidemiologia , Avaliação Geriátrica , Atividades Cotidianas , Idoso de 80 Anos ou mais , Costa Rica , Estudos Transversais , Depressão/epidemiologia , Feminino , Nível de Saúde , Humanos , Vida Independente , Masculino , Casas de Saúde , Polimedicação , Prevalência , Comportamento Social
10.
Oncologist ; 24(8): e784-e792, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30470691

RESUMO

BACKGROUND: Peripheral neuropathy is the dose-limiting toxicity of many oncology drugs, including paclitaxel. There is large interindividual variability in the neuropathy, and several risk factors have been proposed; however, many have not been replicated. Here we present a comprehensive study aimed at identifying treatment and physiopathology-related paclitaxel-induced neuropathy risk factors in a large cohort of well-characterized patients. PATIENTS AND METHODS: Analyses included 503 patients with breast or ovarian cancer who received paclitaxel treatment. Paclitaxel dose modifications caused by the neuropathy were extracted from medical records and patients self-reported neuropathy symptoms were collected. Multivariate logistic regression analyses were performed to identify concomitant medications and comorbidities associated with paclitaxel-induced neuropathy. RESULTS: Older patients had higher neuropathy: for each increase of 1 year of age, the risk of dose modifications and grade 3 neuropathy increased 4% and 5%, respectively. Cardiovascular drugs increased the risk of paclitaxel dose reductions (odds ratio [OR], 2.51; p = .006), with a stronger association for beta-adrenergic antagonists. The total number of concomitant medications also showed an association with dose modifications (OR, 1.25; p = .012 for each concomitant drug increase). A dose modification predictive model that included the new identified factors gave an area under the curve of 0.74 (p = 1.07 × 10-10). Preexisting nerve compression syndromes seemed to increase neuropathy risk. CONCLUSION: Baseline characteristics of the patients, including age and concomitant medications, could be used to identify individuals at high risk of neuropathy, personalizing chemotherapy treatment and reducing the risk of severe neuropathy. IMPLICATIONS FOR PRACTICE: Peripheral neuropathy is a common adverse effect of many cancer drugs, including chemotherapeutics, targeted therapies, and immune checkpoint inhibitors. About 40% of survivors of cancer have functional deficits caused by this toxicity, some of them irreversible. Currently, there are no effective treatments to prevent or treat this neuropathy. This study, performed in a large cohort of well-characterized patients homogenously treated with paclitaxel, identified concomitant medications, comorbidities, and demographic factors associated with peripheral neuropathy. These factors could serve to identify patients at high risk of severe neuropathy for whom alternative non-neurotoxic alternatives may be considered.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias da Mama/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Paclitaxel/administração & dosagem , Paclitaxel/efeitos adversos , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Fitogênicos/efeitos adversos , Antineoplásicos Fitogênicos/uso terapêutico , Neoplasias da Mama/epidemiologia , Interações Medicamentosas , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Ovarianas/epidemiologia , Doenças do Sistema Nervoso Periférico/epidemiologia , Prognóstico , Estudos Retrospectivos , Espanha/epidemiologia
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