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1.
Public Health Nutr ; : 1-11, 2022 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-35369893

RESUMO

OBJECTIVE: To quantify PUFA-associated improvement in linear growth among children aged 6-10 years. DESIGN: Serum fatty acids (FA), including essential FA (EFA) (linoleic acid (LA) and α-linolenic acid (ALA)) were quantified at baseline using GC-MS technology. FA totals by class (n-3, n-6, n-9, PUFA and SFA) and FA ratios were calculated. Height-for-age Z-score (HAZ) relative to WHO population reference values were calculated longitudinally at baseline, 6 and 12 months. Linear regression models estimated PUFA, HIV status and their interaction-associated standardised mean difference (SMD) and 95 % CI in HAZ over 12 months. SETTING: Community controls and children connected to community health centre in Kampala, Uganda, were enrolled. PARTICIPANTS: Children perinatally HIV-infected (CPHIV, n 82), or HIV-exposed but uninfected (CHEU, n 76) and community controls (n 78). RESULTS: Relative to highest FA levels, low SFA (SMD = 0·31, 95 % CI: 0·03, 0·60), low Mead acid (SMD = 0·38, 95 % CI: 0·02, 0·74), low total n-9 (SMD = 0·44, 95 % CI: 0·08, 0·80) and low triene-to-tetraene ratio (SMD = 0·42, 95 % CI: 0·07, 0·77) predicted superior growth over 12 months. Conversely, low LA (SMD = -0·47, 95 % CI: -0·82, -0·12) and low total PUFA (sum of total n-3, total n-6 and Mead acid) (SMD = -0·33 to -0·39, 95 % CI: -0·71, -0·01) predicted growth deficit over 12 months follow-up, regardless of HIV status. CONCLUSION: Low n-3 FA (ALA, EPA and n-3 index) predicted growth deficits among community controls. EFA sufficiency may improve stature in school-aged children regardless of HIV status. Evaluating efficacy of diets low in total SFA, sufficient in EFA and enriched in n-3 FA for improving child growth is warranted.

2.
Community Ment Health J ; 57(1): 57-63, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32681409

RESUMO

In March 2020, at the beginning of the COVID-19 pandemic, state-funded community mental health service programs (CMHSP) in Michigan, organized into 10 regions known as a "Prepaid Inpatient Health Plan" (PIHP), grappled with the task of developing a modified plan of operations, while complying with mitigation and social distancing guidelines. With the premise that psychiatric care is essential healthcare, a panel of physician and non-physician leaders representing Region 5, met and developed recommendations, and feedback iteratively, using an adaptive modified Delphi methodology. This facilitated the development of a service and patient prioritization document to triage and to deliver behavioral health services in 21 counties which comprised Region 5 PIHP. Our procedures were organized around the principles of mitigation and contingency management, like physical health service delivery paradigms. The purpose of this manuscript is to share region 5 PIHP's response; a process which has allowed continuity of care during these unprecedented times.


Assuntos
COVID-19/prevenção & controle , Centros Comunitários de Saúde Mental/organização & administração , Serviços Comunitários de Saúde Mental/métodos , Telemedicina , Triagem , Humanos , Saúde Mental , Michigan , Pandemias , SARS-CoV-2
3.
Phys Occup Ther Pediatr ; 40(6): 651-668, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32192403

RESUMO

AIMS: This study's purpose is to present facilitators and barriers for wakeful prone positioning or "tummy time" during infancy by exploring the personal perspectives of infant caregivers attempting to provide daily tummy time. METHODS: The study was qualitative in design, using thematic analysis to identify major and minor themes from semi-structured interviews. The Capability, Opportunity, Motivation - Behavior Model provided a conceptual framework for the interview guide and categorization of major themes. RESULTS: Within capability, opportunity, and motivation, the major themes of self-efficacy, scheduling, variations, siblings, committed adult help, social responses of acquaintances, and caregiver enjoyment could be barriers or facilitators, depending on the context. Optimized physical circumstances, caregiver interest, perceived benefits to the infant, pride and accomplishment, and obligation were identified as facilitators only. Barriers included negative infant affect. CONCLUSIONS: These results offer preliminary guidance in a knowledge gap: tummy time support that addresses the self-identified concerns of infant caregivers.


Assuntos
Cuidadores , Conhecimentos, Atitudes e Prática em Saúde , Saúde do Lactente , Pais , Decúbito Ventral , Adulto , Feminino , Humanos , Lactente , Masculino , Pesquisa Qualitativa , Adulto Jovem
4.
Adapt Phys Activ Q ; 37(2): 160-176, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32106078

RESUMO

This longitudinal study investigated monthly motor development and physical activity (PA) of infants with and without Down syndrome. Gross and fine motor skills (Bayley Scales of Infant Development-III) and PA (accelerometer) were assessed in 35 infants at eight time points during infancy. A multivariate mixed model identified time points when motor scores diverged between the groups. In infants with Down syndrome, bivariate correlations between monthly PA and motor changes were calculated, and multivariate analysis of variance probed the influence of early PA on motor-skill timing. Results indicate that differences in gross and fine motor skills first emerge at 2 and 4 months, respectively. In infants with Down syndrome, gross motor and PA changes between 4 and 6 months were positively correlated. Infants more active than the mean at 2 or 3 months achieved several prone and sitting skills earlier. These results highlight the adaptability of early infancy and the importance of early intervention.


Assuntos
Desenvolvimento Infantil/fisiologia , Síndrome de Down/fisiopatologia , Exercício Físico , Destreza Motora/fisiologia , Acelerometria , Adulto , Feminino , Humanos , Lactente , Masculino , Inquéritos e Questionários
5.
J Phys Act Health ; 20(3): 180-192, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36706762

RESUMO

BACKGROUND: This study investigated the effect of an adapted physical activity (APA) course on knowledge and perceptions of preservice trainees regarding physical activity (PA) and autism spectrum disorder in 3 areas: knowledge/perspectives, importance and ease of improving developmental domains, and importance and ease of improving motor skills. METHODS: Four hundred upper-level undergraduate students were recruited to participate in this survey-based study (251 APA students and 149 non-APA students participated). Survey data were analyzed using multivariate analyses of variance. RESULTS: Participants estimated that the moderate to vigorous PA recommendations are 39.34 minutes per day, that 46.65% of moderate to vigorous PA occurs during school, and that 61.03% of children have motor difficulties. Participants perceived activities of daily living, sleep habits, and heart health as the easiest domains to improve, and problem behaviors, social skills, and self-esteem as the most difficult domains to improve. Knowledge/perspectives regarding autism spectrum disorder and PA were different by APA exposure (F12,324 = 3.11, P < .001). Differences included self-efficacy in providing PA advice, knowledge of PA guidelines, and willingness to provide motor assessment referrals. Students differed by APA exposure in the importance of developmental domains (F8,381 = 4.37, P < .001) but not ease of improving those domains. CONCLUSION: Results suggest that APA education and contact with children with disabilities improves self-efficacy, perspectives, and knowledge of PA and motor concerns in children with autism spectrum disorder.


Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Criança , Humanos , Exercício Físico , Atividades Cotidianas , Estudantes
6.
Res Q Exerc Sport ; 92(4): 813-823, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32854599

RESUMO

Purpose: There is a relationship between motor and language skills in children with Autism Spectrum Disorder (ASD), but little work addresses the ramifications of this relationship for professionals who teach motor skills to this population. Within a motor skills intervention, this study probed the importance of language skills for motor intervention. We examined the relationship between motor and language skills at baseline, and then the relationship between baseline language skills and motor improvements resulting from the intervention. Method: Twenty children aged 4-6 years with ASD participated. Eleven children received 20 hr per week of motor intervention for 8 weeks. Nine children did not receive motor intervention. Language skills (Mullen Scales of Early Learning) and motor skills (Test of Gross Motor Development - 2) were assessed at baseline and post-intervention. Spearman correlations tested the associations between baseline language and baseline motor skills. This analysis was repeated in the intervention sample to test the association between baseline language level and response to intervention (motor skill changes from baseline to post-intervention). Results: Prior to intervention, locomotor skills are positively correlated (p < .001) with both receptive (rs = 0.827) and expressive (rs = 0.722) language skills. Similarly, object-control skills are positively correlated (rs < .001) with receptive (rs = 0.779) and expressive (rs = 0.729) language skills. However, those baseline language skills do not relate to motor change in the experimental group. Conclusion: These results suggest that motor programs may improve motor skills in children with ASD when language is supported, regardless of pre-program language ability.


Assuntos
Transtorno do Espectro Autista , Criança , Pré-Escolar , Exercício Físico , Humanos , Idioma , Destreza Motora
7.
Infant Behav Dev ; 58: 101392, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31778860

RESUMO

Sleep during early childhood is important for many developmental outcomes and shows promise as an important correlate of both obesity risk and physical activity behaviors. This was a cross-sectional study concerning the relationships between sleep and moderate- to - vigorous intensity physical activity and body fat percentage in a sample of 1- to 3-year-old children (N = 50; ages 27.512 ± 10.363 months). Sleep was measured with a caregiver questionnaire. Sedentary time, light, moderate, vigorous, and moderate- to - vigorous intensity physical activity were measured with Actigraph wT3x-BT accelerometers. Body fat was measured using Air Displacement Plethysmography with the BodPod Pediatric Option. Moderate- to - vigorous intensity physical activity and body fat percentage both associated with sleep duration, controlling for age and accelerometer wear time. These factors combined explained 54.3 % of the variance in sleep duration present in the sample. These results suggest the presence of relationships between sleep and physical activity and body composition constructs in this sample. Sleep may be an important variable in efforts to both promote early childhood physical activity and healthy body composition.


Assuntos
Tecido Adiposo/fisiologia , Composição Corporal/fisiologia , Exercício Físico/fisiologia , Sono/fisiologia , Fatores de Tempo , Acelerometria , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Lactente , Masculino , Pletismografia , Comportamento Sedentário , Inquéritos e Questionários
8.
Front Integr Neurosci ; 14: 24, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32477076

RESUMO

Background: The purpose of this study was to explore the question of the minimal amount of instructional time needed to still be effective by assessing the efficacy at mid-intervention of an early fundamental movement skill (FMS) intervention for preschoolers with Autism Spectrum Disorder (ASD). Method: Fourteen preschoolers participated in this randomized controlled trial daily over 10 weeks (10 h total at mid-intervention). A two-factor mixed MANOVA tested the significance of group*time interactions for two dependent variables: object control and locomotor raw scores on the Test of Gross Motor Development-III. Results: Group*time interactions approached significance with large effect sizes on the vector of both dependent variables and in a univariate fashion on object control scores, but not locomotor scores. Conclusions: These findings hold relevance for physical educators working with young children with ASD, indicating that 10 h of FMS instruction, at least in this form, is not adequate to improve FMS.

9.
Expert Rev Cardiovasc Ther ; 18(7): 381-394, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32538199

RESUMO

INTRODUCTION: Blood lipid screening recommendations begin at ages 9-11 years, despite poor adherence and evidence of fatty streaks in coronary arteries by 3 years of age. For cardiovascular disease (CVD) prevention, there may be value in earlier measurement of blood lipids. AREAS COVERED: The present systematic review examines evidence concerning total cholesterol, low-density lipoprotein, high-density lipoprotein, and triglycerides during the infant period. Included are studies examining the extent to which infant blood lipids predict later values in childhood and factors that influence their magnitude. A total of 38 articles (published from 1965 to 2013) met inclusion criteria and were examined in this review. EXPERT OPINION: Longitudinal data suggest correlative relationships in all lipid values around 6 months of age, except for TRG. Influential factors related to blood lipids in infancy include sex, race, family history, feeding, gestational length, birth weight, and maternal factors. Clinical measurement of infant lipids could perhaps provide an early marker of CVD and a target of early CVD prevention strategies. The identification of personal characteristics that associate with high or low values in each lipid could become important in the early identification of vulnerable populations and the promotion of personalized CVD prevention.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Lipídeos/sangue , Criança , Pré-Escolar , Colesterol/sangue , Humanos , Lactente , Fatores de Risco , Triglicerídeos/sangue
10.
Cell Syst ; 11(5): 536-546.e7, 2020 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-32910905

RESUMO

Transcriptional profiling of tumors has revealed a stress-like state among the cancer cells with the concerted expression of genes such as fos, jun, and heat-shock proteins, though this has been controversial given possible dissociation-effects associated with single-cell RNA sequencing. Here, we validate the existence of this state using a combination of zebrafish melanoma modeling, spatial transcriptomics, and human samples. We found that the stress-like subpopulation of cancer cells is present from the early stages of tumorigenesis. Comparing with previously reported single-cell RNA sequencing datasets from diverse cancer types, including triple-negative breast cancer, oligodendroglioma, and pancreatic adenocarcinoma, indicated the conservation of this state during tumorigenesis. We also provide evidence that this state has higher tumor-seeding capabilities and that its induction leads to increased growth under both MEK and BRAF inhibitors. Collectively, our study supports the stress-like cells as a cancer cell state expressing a coherent set of genes and exhibiting drug-resistance properties.


Assuntos
Carcinogênese/patologia , Melanoma/genética , Estresse Fisiológico/genética , Adenocarcinoma/genética , Animais , Carcinogênese/metabolismo , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Expressão Gênica/genética , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Melanoma/metabolismo , Melanoma/fisiopatologia , Inibidores de Proteínas Quinases/farmacologia , Análise de Sequência de RNA/métodos , Análise de Célula Única/métodos , Transcriptoma/genética , Peixe-Zebra
11.
Percept Mot Skills ; 126(5): 753-763, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31216236

RESUMO

Sedentary activity occupies a substantial amount of time during early childhood, with these habits influenced by changing trends in screen time for very young children. Among school-aged children, motor ability is inversely related to sedentary activity. However, the concept of sedentary activity is rarely investigated in toddlers, and thus little is known concerning its relationship with motor development during this rapidly changing and early period of life. Among two groups of toddlers, aged 18 months (N = 26) and aged 24 months (N = 16), this study investigated cross-sectional correlations of motor development (Bayley Scales of Infant Development-III) with daily sedentary activity (accelerometers). In both groups, gross motor ability, but not fine motor ability, was inversely correlated with time spent in sedentary activity. At 18 months, gross motor raw scores inversely correlated significantly with time in sedentary activity (r = -.533, p < .001) but fine motor raw scores did not (r = .182, p = .441). Also, at 24 months, gross motor raw scores inversely correlated with time in sedentary activity (r = -.563, p = .029), while fine motor raw scores did not (r = -.112, p = .425). These findings add important missing knowledge to the empirical literature regarding sedentary activity in toddlers and its relationship to emerging motor development. Future work might investigate best practices for measuring sedentary activity in this age-group and mechanisms behind its relationship with gross motor skills.


Assuntos
Desenvolvimento Infantil , Destreza Motora , Comportamento Sedentário , Acelerometria , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Lactente , Masculino , Fatores de Tempo
12.
Mol Biol Cell ; 29(3): 247-255, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29187578

RESUMO

The microtubule-associated protein Stu2 (XMAP215) has the remarkable ability to act either as a polymerase or as a destabilizer of the microtubule plus end. In budding yeast, it is required for the dynamicity of spindle microtubules and also for kinetochore force generation. To understand how Stu2 contributes to these distinct activities, we analyzed the contributions of its functional domains to its localization and function. We find that Stu2 colocalizes with kinetochores using its TOG domains, which bind GTP-tubulin, a coiled-coil homodimerization domain, and a domain that interacts with plus-end interacting proteins. Stu2 localization is also promoted by phosphorylation at a putative CDK1 phosphorylation site located within its microtubule-binding basic patch. Surprisingly, however, we find that kinetochore force generation is uncorrelated with the amount of kinetochore-colocalized Stu2. These and other data imply that Stu2 colocalizes with kinetochores by recognizing growing microtubule plus ends within yeast kinetochores. We propose that Stu2 destabilizes these plus ends to indirectly contribute to the "catch-bond" activity of the kinetochores.


Assuntos
Metáfase/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Microtúbulos/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Segregação de Cromossomos , Cinetocoros/metabolismo , Cinetocoros/fisiologia , Proteínas Associadas aos Microtúbulos/genética , Microtúbulos/fisiologia , Fosforilação , Ligação Proteica , Domínios Proteicos/fisiologia , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Fuso Acromático/metabolismo , Tubulina (Proteína)/metabolismo
13.
Infant Behav Dev ; 53: 18-24, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30388466

RESUMO

This study examined low-intensity physical activity (PA), sleep behavior (24-hour accelerometry), and growth in 22 6-month old infants. Relationships were assessed using bivariate correlations. Infants accumulating less 'total' sleep spent more time in low-intensity PA (r = -.524, p = .012). Those with less 'nighttime' sleep had greater nap frequency (r = -.460, p = .031), nap duration (r = -.529, p = .011) and weight-for-length z-scores (r = -.481, p = .024), but still accumulated less total sleep (r = .608, p = .003). These preliminary data highlight the importance of promoting healthy nighttime sleep behavior during infancy.


Assuntos
Desenvolvimento Infantil/fisiologia , Exercício Físico/fisiologia , Sono/fisiologia , Acelerometria/métodos , Antropometria , Feminino , Humanos , Lactente , Masculino , Comportamento Sedentário
14.
Dis Model Mech ; 11(9)2018 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-30061297

RESUMO

Transgenic animals are invaluable for modeling cancer genomics, but often require complex crosses of multiple germline alleles to obtain the desired combinations. Zebrafish models have advantages in that transgenes can be rapidly tested by mosaic expression, but typically lack spatial and temporal control of tumor onset, which limits their utility for the study of tumor progression and metastasis. To overcome these limitations, we have developed a method referred to as Transgene Electroporation in Adult Zebrafish (TEAZ). TEAZ can deliver DNA constructs with promoter elements of interest to drive fluorophores, oncogenes or CRISPR-Cas9-based mutagenic cassettes in specific cell types. Using TEAZ, we created a highly aggressive melanoma model via Cas9-mediated inactivation of Rb1 in the context of BRAFV600E in spatially constrained melanocytes. Unlike prior models that take ∼4 months to develop, we found that TEAZ leads to tumor onset in ∼7 weeks, and these tumors develop in fully immunocompetent animals. As the resulting tumors initiated at highly defined locations, we could track their progression via fluorescence, and documented deep invasion into tissues and metastatic deposits. TEAZ can be deployed to other tissues and cell types, such as the heart, with the use of suitable transgenic promoters. The versatility of TEAZ makes it widely accessible for rapid modeling of somatic gene alterations and cancer progression at a scale not achievable in other in vivo systems.


Assuntos
Envelhecimento/genética , Eletroporação , Transgenes , Peixe-Zebra/genética , Animais , Animais Geneticamente Modificados , Sistemas CRISPR-Cas/genética , Carcinogênese/genética , Carcinogênese/patologia , Modelos Animais de Doenças , Progressão da Doença , Embrião não Mamífero/metabolismo , Técnicas de Transferência de Genes , Melanoma/patologia , Plasmídeos/genética , Regiões Promotoras Genéticas , Peixe-Zebra/embriologia
15.
Cancer Discov ; 8(8): 1006-1025, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29903879

RESUMO

Advanced, metastatic melanomas frequently grow in subcutaneous tissues and portend a poor prognosis. Though subcutaneous tissues are largely composed of adipocytes, the mechanisms by which adipocytes influence melanoma are poorly understood. Using in vitro and in vivo models, we find that adipocytes increase proliferation and invasion of adjacent melanoma cells. Additionally, adipocytes directly transfer lipids to melanoma cells, which alters tumor cell metabolism. Adipocyte-derived lipids are transferred to melanoma cells through the FATP/SLC27A family of lipid transporters expressed on the tumor cell surface. Among the six FATP/SLC27A family members, melanomas significantly overexpress FATP1/SLC27A1. Melanocyte-specific FATP1 expression cooperates with BRAFV600E in transgenic zebrafish to accelerate melanoma development, an effect that is similarly seen in mouse xenograft studies. Pharmacologic blockade of FATPs with the small-molecule inhibitor Lipofermata abrogates lipid transport into melanoma cells and reduces melanoma growth and invasion. These data demonstrate that stromal adipocytes can drive melanoma progression through FATP lipid transporters and represent a new target aimed at interrupting adipocyte-melanoma cross-talk.Significance: We demonstrate that stromal adipocytes are donors of lipids that mediate melanoma progression. Adipocyte-derived lipids are taken up by FATP proteins that are aberrantly expressed in melanoma. Inhibition of FATPs decreases melanoma lipid uptake, invasion, and growth. We provide a mechanism for how stromal adipocytes drive tumor progression and demonstrate a novel microenvironmental therapeutic target. Cancer Discov; 8(8); 1006-25. ©2018 AACR.This article is highlighted in the In This Issue feature, p. 899.


Assuntos
Adipócitos/citologia , Proteínas de Transporte de Ácido Graxo/metabolismo , Ácidos Graxos/metabolismo , Melanoma/patologia , Proteínas Proto-Oncogênicas B-raf/genética , Células 3T3-L1 , Adipócitos/metabolismo , Animais , Animais Geneticamente Modificados , Transporte Biológico/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Técnicas de Cocultura , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Humanos , Melanoma/tratamento farmacológico , Melanoma/metabolismo , Camundongos , Mutação , Invasividade Neoplásica , Transplante de Neoplasias , Compostos de Espiro/administração & dosagem , Compostos de Espiro/farmacologia , Tiadiazóis/administração & dosagem , Tiadiazóis/farmacologia , Microambiente Tumoral , Regulação para Cima , Peixe-Zebra
16.
Nat Commun ; 8: 14343, 2017 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-28181494

RESUMO

Cellular plasticity is a state in which cancer cells exist along a reversible phenotypic spectrum, and underlies key traits such as drug resistance and metastasis. Melanoma plasticity is linked to phenotype switching, where the microenvironment induces switches between invasive/MITFLO versus proliferative/MITFHI states. Since MITF also induces pigmentation, we hypothesize that macrometastatic success should be favoured by microenvironments that induce a MITFHI/differentiated/proliferative state. Zebrafish imaging demonstrates that after extravasation, melanoma cells become pigmented and enact a gene expression program of melanocyte differentiation. We screened for microenvironmental factors leading to phenotype switching, and find that EDN3 induces a state that is both proliferative and differentiated. CRISPR-mediated inactivation of EDN3, or its synthetic enzyme ECE2, from the microenvironment abrogates phenotype switching and increases animal survival. These results demonstrate that after metastatic dissemination, the microenvironment provides signals to promote phenotype switching and provide proof that targeting tumour cell plasticity is a viable therapeutic opportunity.


Assuntos
Plasticidade Celular , Melanoma/patologia , Microambiente Tumoral , Animais , Sistemas CRISPR-Cas/genética , Diferenciação Celular/genética , Plasticidade Celular/genética , Proliferação de Células/genética , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Melanoma/genética , Modelos Biológicos , Metástase Neoplásica , Fenótipo , Microambiente Tumoral/genética , Peixe-Zebra , Proteínas de Peixe-Zebra/metabolismo
17.
Cancer Res ; 75(20): 4272-4282, 2015 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-26282170

RESUMO

Metastasis is the defining feature of advanced malignancy, yet remains challenging to study in laboratory environments. Here, we describe a high-throughput zebrafish system for comprehensive, in vivo assessment of metastatic biology. First, we generated several stable cell lines from melanomas of transgenic mitfa-BRAF(V600E);p53(-/-) fish. We then transplanted the melanoma cells into the transparent casper strain to enable highly quantitative measurement of the metastatic process at single-cell resolution. Using computational image analysis of the resulting metastases, we generated a metastasis score, µ, that can be applied to quantitative comparison of metastatic capacity between experimental conditions. Furthermore, image analysis also provided estimates of the frequency of metastasis-initiating cells (∼1/120,000 cells). Finally, we determined that the degree of pigmentation is a key feature defining cells with metastatic capability. The small size and rapid generation of progeny combined with superior imaging tools make zebrafish ideal for unbiased high-throughput investigations of cell-intrinsic or microenvironmental modifiers of metastasis. The approaches described here are readily applicable to other tumor types and thus serve to complement studies also employing murine and human cell culture systems.


Assuntos
Modelos Biológicos , Neoplasias/patologia , Peixe-Zebra , Algoritmos , Animais , Animais Geneticamente Modificados , Linhagem Celular Tumoral , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Melanoma/genética , Melanoma/metabolismo , Melanoma/patologia , Mutação , Metástase Neoplásica , Neoplasias/genética , Neoplasias/metabolismo , Transcriptoma
18.
Curr Biol ; 24(13): 1437-46, 2014 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-24930965

RESUMO

BACKGROUND: The kinetochore is a multiprotein machine that couples chromosome movement to microtubule (MT) polymerization and depolymerization. It uses numerous copies of at least three MT-binding proteins to generate bidirectional movement. The nanoscale organization of these proteins within the kinetochore plays an important role in shaping the mechanisms that drive persistent, bidirectional movement of the kinetochore. RESULTS: We used fluorescence resonance energy transfer (FRET) between genetically encoded fluorescent proteins fused to kinetochore subunits to reconstruct the nanoscale organization of the budding yeast kinetochore. We performed >60 FRET and high-resolution colocalization measurements involving the essential MT-binding kinetochore components: Ndc80, Dam1, Spc105, and Stu2. These measurements reveal that neighboring Ndc80 complexes within the kinetochore are narrowly distributed along the length of the MT. Dam1 complex molecules are concentrated near the MT-binding domains of Ndc80. Stu2 localizes in high abundance within a narrowly defined territory within the kinetochore centered ∼20 nm on the centromeric side of the Dam1 complex. CONCLUSIONS: Our data show that the MT attachment site of the budding yeast kinetochore is well organized. Ndc80, Dam1, and Stu2 are all narrowly distributed about their average positions along the kinetochore-MT axis. The relative organization of these components, their narrow distributions, and their known MT-binding properties together elucidate how their combined actions generate persistent, bidirectional kinetochore movement coupled to MT polymerization and depolymerization.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Cinetocoros/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Microtúbulos/metabolismo , Modelos Biológicos , Complexos Multiproteicos/metabolismo , Proteínas Nucleares/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomycetales/metabolismo , Transferência Ressonante de Energia de Fluorescência
19.
Curr Biol ; 23(9): 770-4, 2013 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-23623551

RESUMO

The centromere is defined by the incorporation of the centromere-specific histone H3 variant centromere protein A (CENP-A). Like histone H3, CENP-A can form CENP-A-H4 heterotetramers in vitro. However, the in vivo conformation of CENP-A chromatin has been proposed by different studies as hemisomes, canonical, or heterotypic nucleosomes. A clear understanding of the in vivo architecture of CENP-A chromatin is important, because it influences the molecular mechanisms of the assembly and maintenance of the centromere and its function in kinetochore nucleation. A key determinant of this architecture is the number of CENP-A molecules bound to the centromere. Accurate measurement of this number can limit possible centromere architectures. The genetically defined point centromere in the budding yeast Saccharomyces cerevisiae provides a unique opportunity to define this number accurately, as this 120-bp-long centromere can at the most form one nucleosome or hemisome. Using novel live-cell fluorescence microscopy assays, we demonstrate that the budding yeast centromere recruits two Cse4 (ScCENP-A) molecules. These molecules are deposited during S phase and they remain stably bound through late anaphase. Our studies suggest that the budding yeast centromere incorporates a Cse4-H4 tetramer.


Assuntos
Autoantígenos/metabolismo , Centrômero/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Cinetocoros/metabolismo , Nucleossomos/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiologia , Anáfase , Autoantígenos/química , Autoantígenos/genética , Proteína Centromérica A , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/química , Proteínas Cromossômicas não Histona/genética , Histonas/metabolismo , Cinetocoros/química , Microscopia de Fluorescência , Mitose , Nucleossomos/genética , Conformação Proteica , Fase S , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética
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