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1.
Cell ; 185(23): 4376-4393.e18, 2022 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-36318920

RESUMO

The function of biomolecular condensates is often restricted by condensate dissolution. Whether condensates can be suppressed without condensate dissolution is unclear. Here, we show that upstream regulators of the Hippo signaling pathway form functionally antagonizing condensates, and their coalescence into a common phase provides a mode of counteracting the function of biomolecular condensates without condensate dissolution. Specifically, the negative regulator SLMAP forms Hippo-inactivating condensates to facilitate pathway inhibition by the STRIPAK complex. In response to cell-cell contact or osmotic stress, the positive regulators AMOT and KIBRA form Hippo-activating condensates to facilitate pathway activation. The functionally antagonizing SLMAP and AMOT/KIBRA condensates further coalesce into a common phase to inhibit STRIPAK function. These findings provide a paradigm for restricting the activity of biomolecular condensates without condensate dissolution, shed light on the molecular principles of multiphase organization, and offer a conceptual framework for understanding upstream regulation of the Hippo signaling pathway.


Assuntos
Via de Sinalização Hippo , Proteínas Serina-Treonina Quinases , Transdução de Sinais
2.
Nat Rev Mol Cell Biol ; 24(1): 5, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36008600
3.
Annu Rev Genet ; 53: 67-91, 2019 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-31283358

RESUMO

Cell-cell fusion is indispensable for creating life and building syncytial tissues and organs. Ever since the discovery of cell-cell fusion, how cells join together to form zygotes and multinucleated syncytia has remained a fundamental question in cell and developmental biology. In the past two decades, Drosophila myoblast fusion has been used as a powerful genetic model to unravel mechanisms underlying cell-cell fusion in vivo. Many evolutionarily conserved fusion-promoting factors have been identified and so has a surprising and conserved cellular mechanism. In this review, we revisit key findings in Drosophila myoblast fusion and highlight the critical roles of cellular invasion and resistance in driving cell membrane fusion.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila/citologia , Mioblastos/citologia , Actinas/metabolismo , Actomiosina/metabolismo , Animais , Moléculas de Adesão Celular/metabolismo , Fusão Celular , Drosophila/embriologia , Drosophila/fisiologia , Proteínas de Drosophila/genética , Embrião não Mamífero/citologia , Bicamadas Lipídicas/metabolismo , Músculos/citologia , Músculos/embriologia , Mioblastos/fisiologia , Pupa/citologia
4.
Nature ; 592(7853): 272-276, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33508854

RESUMO

Cell competition involves a conserved fitness-sensing process during which fitter cells eliminate neighbouring less-fit but viable cells1. Cell competition has been proposed as a surveillance mechanism to ensure normal development and tissue homeostasis, and has also been suggested to act as a barrier to interspecies chimerism2. However, cell competition has not been studied in an interspecies context during early development owing to the lack of an in vitro model. Here we developed an interspecies pluripotent stem cell (PSC) co-culture strategy and uncovered a previously unknown mode of cell competition between species. Interspecies competition between PSCs occurred in primed but not naive pluripotent cells, and between evolutionarily distant species. By comparative transcriptome analysis, we found that genes related to the NF-κB signalling pathway, among others, were upregulated in less-fit 'loser' human cells. Genetic inactivation of a core component (P65, also known as RELA) and an upstream regulator (MYD88) of the NF-κB complex in human cells could overcome the competition between human and mouse PSCs, thereby improving the survival and chimerism of human cells in early mouse embryos. These insights into cell competition pave the way for the study of evolutionarily conserved mechanisms that underlie competitive cell interactions during early mammalian development. Suppression of interspecies PSC competition may facilitate the generation of human tissues in animals.


Assuntos
Competição entre as Células/fisiologia , Quimerismo , Técnicas de Cocultura/métodos , Embrião de Mamíferos/citologia , Células-Tronco Pluripotentes/citologia , Animais , Contagem de Células , Sobrevivência Celular , Feminino , Humanos , Masculino , Camundongos , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais , Especificidade da Espécie , Fator de Transcrição RelA/metabolismo
5.
Health Promot Int ; 39(2)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38501311

RESUMO

Research on social innovations in health has increased in recent years. However, little training is geared toward enhancing social innovation research capacity. Most health training for low- and middle-income countries (LMICs) is developed by individuals in high-income countries, disregarding LMIC researchers' wisdom and insights and the communities' needs. Our team organized a multi-phase investigation involving a series of surveys and co-creation group discussions to assess individuals' training needs that directly informed a subsequent co-created training workshop series. We conducted a Hennessy-Hicks Training Needs Assessment among the Social Innovation in Health Initiative (SIHI) network and formed a co-creation group comprising SIHI fellows to design related training workshops. We ran a final evaluation survey and analyzed the workshop series' strengths, weaknesses and threats. Descriptive and thematic analysis were employed to analyze survey data and open-ended responses. The final evaluation survey captured data from 165 learners in 35 countries, including 26 LMICs. Most participants (67.3%, 111/165) rated the training workshop series as excellent, and 30.3% (50/165) rated it as good on a five-point scale. The need for writing research grants and manuscripts was rated the highest priority. Learners were interested in community-engaged research and diversity, equity and inclusion. This workshop illustrated how co-creation could be an effective tool for developing training materials tailored for LMIC researchers. We also offer a template for conducting a needs assessment and subsequent training workshops for LMICs. The ground-up, locally developed courses may be more effective than externally developed training programs intended for LMICs.


Assuntos
Países em Desenvolvimento , Renda , Humanos , Avaliação das Necessidades , Inquéritos e Questionários , Pesquisadores
6.
Cell Mol Neurobiol ; 43(6): 2953-2962, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36988771

RESUMO

Alzheimer's disease (AD) is a progressive neuroinflammatory and neurodegenerative disorder that affects different regions of the brain. Its pathophysiology includes the accumulation of ß-amyloid protein, formation of neurofibrillary tangles, and inflammatory processes. Genetic factors are involved in the onset of AD, but they are not fully elucidated. Identification of gene expression in encephalic tissues of patients with AD may help elucidate its development. Our objectives were to characterize and compare the gene expression of CDK10, CDK11, FOXO1, and FOXO3 in encephalic tissue samples from AD patients and elderly controls, from the auditory cortex and cerebellum. RT-qPCR was used on samples from 82 individuals (45 with AD and 37 controls). We observed a statistically significant increase in CDK10 (p = 0.029*) and CDK11 (p = 0.048*) gene expression in the AD group compared to the control, which was most evident in the cerebellum. Furthermore, the Spearman test demonstrated the presence of a positive correlation of gene expression both in the auditory cortex in the AD group (r = 0.046/p = 0.004) and control group (r = 0.454/p = 0.005); and in the cerebellum in the AD group (r = 0.654 /p < 0.001). There was no statistically significant difference and correlation in the gene expression of FOXO1 and FOXO3 in the AD group and the control. In conclusion, CDK10 and CDK11 have high expression in AD patients compared to control, and they present a positive correlation of gene expression in the analyzed groups and tissues, which suggests that they play an important role in the pathogenesis of AD.


Assuntos
Doença de Alzheimer , Humanos , Idoso , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Emaranhados Neurofibrilares/metabolismo , Encéfalo/metabolismo , Expressão Gênica , Proteína Forkhead Box O1/genética , Proteína Forkhead Box O1/metabolismo , Proteína Forkhead Box O3/genética , Quinases Ciclina-Dependentes/genética , Quinases Ciclina-Dependentes/metabolismo
7.
J Pediatr Hematol Oncol ; 45(8): e1018-e1022, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37749779

RESUMO

Trisomy 18 is associated with several congenital malformations, including horseshoe kidney. It can be full, partial, or mosaic, and mosaicism is often associated with lesser severity and longer life expectancy, placing patients at greater risk of developing neoplasms or malignancies. One common tumor among children with Trisomy 18 is Wilms tumor, which is also associated with renal congenital abnormalities such as horseshoe kidney. We present a case describing the occurrence of these three characteristics: development of Wilms tumor in a patient with Trisomy 18 and a horseshoe kidney and discuss treatment with regards to these conditions.


Assuntos
Rim Fundido , Neoplasias Renais , Tumor de Wilms , Humanos , Criança , Neoplasias Renais/genética , Neoplasias Renais/patologia , Rim Fundido/complicações , Rim Fundido/genética , Síndrome da Trissomía do Cromossomo 18/complicações , Síndrome da Trissomía do Cromossomo 18/genética , Tumor de Wilms/complicações , Tumor de Wilms/genética , Tumor de Wilms/patologia , Rim/anormalidades , Rim/patologia , Trissomia/genética
8.
BMC Health Serv Res ; 23(1): 583, 2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37287022

RESUMO

BACKGROUND: Staff shortage is a long-standing issue in long term care facilities (LTCFs) that worsened with the COVID-19 outbreak. Different states in the US have employed various tools to alleviate this issue in LTCFs. We describe the actions taken by the Commonwealth of Massachusetts to assist LTCFs in addressing the staff shortage issue and their outcomes. Therefore, the main question of this study is how to create a central mechanism to allocate severely limited medical staff to healthcare centers during emergencies. METHODS: For the Commonwealth of Massachusetts, we developed a mathematical programming model to match severely limited available staff with LTCF demand requests submitted through a designed portal. To find feasible matches and prioritize facility needs, we incorporated restrictions and preferences for both sides. For staff, we considered maximum mileage they are willing to travel, available by date, and short- or long-term work preferences. For LTCFs, we considered their demand quantities for different positions and the level of urgency for their demand. As a secondary goal of this study, by using the feedback entries data received from the LTCFs on their matches, we developed statistical models to determine the most salient features that induced the LTCFs to submit feedback. RESULTS: We used the developed portal to complete about 150 matching sessions in 14 months to match staff to LTCFs in Massachusetts. LTCFs provided feedback for 2,542 matches including 2,064 intentions to hire the matched staff during this time. Further analysis indicated that nursing homes and facilities that entered higher levels of demand to the portal were more likely to provide feedback on the matches and facilities that were prioritized in the matching process due to whole facility testing or low staffing levels were less likely to do so. On the staffing side, matches that involved more experienced staff and staff who can work afternoons, evenings, and overnight were more likely to generate feedback from the facility that they were matched to. CONCLUSION: Developing a central matching framework to match medical staff to LTCFs at the time of a public health emergency could be an efficient tool for responding to staffing shortages. Such central approaches that help allocate a severely limited resource efficiently during a public emergency can be developed and used for different resource types, as well as provide crucial demand and supply information in different regions and/or demographics.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , Assistência de Longa Duração , Casas de Saúde , Surtos de Doenças , Corpo Clínico
9.
Prev Sci ; 24(Suppl 2): 174-184, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37351667

RESUMO

This paper describes a human-centered design approach to investigate unmet adolescent sexual health wants and needs among youth of color in low-income and rural communities in Texas, North Carolina, and Connecticut (n = 149). The approach involved gathering qualitative data through in-depth interviews and other human-centered design activities between April 2016 and August 2016. Data were analyzed using thematic content analysis after each round of data collection. Themes were triangulated across multiple data sources to identify key insights. Results highlighted several important unmet wants and needs. Participants shared that schools were not the preferred place to learn about sexual health and healthy relationships, due to uncomfortable and sometimes even hostile environments. When discussing the potential to use internet- and technology-based sexual health resources, participants expressed concerns over privacy, safety, and credibility of information available. Similarly, participants preferred mobile apps over websites due to the privacy of the experience. Most importantly, key emotions impacting adolescents' access to and use of sexual health resources were identified. Results indicated a preference for consuming story-based information in a text message format that described diverse experiences related to sexual health topics. Together, these findings led to the development of an innovative, mobile health intervention for adolescents, the Real Talk mobile app. This human-centered approach can support researchers and practitioners in strengthening intervention development efforts to improve the reach, adoption, and implementation of sexual health interventions.


Assuntos
Saúde Sexual , Telemedicina , Envio de Mensagens de Texto , Humanos , Adolescente , Comportamento Sexual/psicologia , Saúde do Adolescente , Telemedicina/métodos
10.
J Clin Psychol ; 79(11): 2542-2555, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37433045

RESUMO

INTRODUCTION: Unhoused individuals have high rates of suicidal ideation (SI) and suicidal behaviors (SB), but few have studied the relative timing of homelessness and SI/SB. Our study examines the potential to use state-wide electronic health record data from Rhode Island's health information exchange (HIE) to identify temporal relationships, service utilization, and associations of SI/SB among unhoused individuals. METHODS: We use timestamped HIE data for 5368 unhoused patients to analyze service utilization and the relative timing of homelessness versus SI/SB onset. Multivariable models identified associations of SI/SB, hospitalization, and repeat acute care utilization within 30 days from clinical features representing 10,000+ diagnoses captured within the HIE. RESULTS: The onset of SI typically precedes homelessness onset, while the onset of SB typically follows. Weekly rates of suicide-related service utilization increased over 25 times the baseline rate during the week before and after homelessness onset. Over 50% of encounters involving SI/SB result in hospitalization. Of those engaging in acute care for suicide-related reasons, we found high rates of repeat acute care encounters. CONCLUSION: HIEs are a particularly valuable resource for understudied populations. Our study demonstrates how longitudinal, multi-institutional data from an HIE can be used to characterize temporal associations, service utilization, and clinical associations of SI and behaviors among a vulnerable population at scale. Increasing access to services that address co-occurring SI/SB, mental health, and substance use is needed.


Assuntos
Troca de Informação em Saúde , Transtornos Relacionados ao Uso de Substâncias , Suicídio , Humanos , Ideação Suicida , Suicídio/psicologia , Saúde Mental , Fatores de Risco
11.
Health Promot Pract ; 24(1): 45-58, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36310429

RESUMO

Background. It is challenging for junior public health investigators who identify as Black, Indigenous, or People of Color (BIPOC) to secure funding for projects and research. We used a narrative inquiry approach to understand and present the funding cascade from the perspectives of female, junior BIPOC researchers and provide funders with actionable recommendations to advance their antiracist goals. Approach. We applied a Critical Race Theory (CRT) framework to guide our narrative inquiry approach. The participants were the four co-authors and we each drafted individual narratives around our experience with the funding cascade and subsequently the five stages of narrative analysis. Results. We created a visual representation of key activities for funders and applicants organized by our perceived magnitude of inequities in a journey map, an interpreter table that describes common phrases and barriers encountered, and a composite counternarrative presented as a group text message conversation, elevating common themes including feeling pressured to have our research agendas conform to funders' interests and receiving limited key information and support in the funding process. Discussion. We discussed how our findings represented manifestations of White supremacy characteristics like power hoarding and paternalism. Implications for practice. We offered specific antidotes for funding organizations to make their processes more antiracist and invited leaders of public health funding organizations to join us to further identify antidotes and share lessons learned in Fall 2023.


Assuntos
Antídotos , Saúde Pública , Feminino , Humanos , Brancos , Narração , Comunicação
12.
Acta Neuropsychiatr ; 35(6): 346-361, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37605989

RESUMO

OBJECTIVE: In Alzheimer's disease (AD), angiotensin II receptor blockers (ARBs) could reduce cerebrovascular dysfunction, while angiotensin-converting enzyme inhibitors (ACEis) might increase brain amyloid-ß by suppressing effects of the angiotensin-converting enzyme 1, an amyloid-ß-degrading enzyme. However, ACEis could benefit patients with AD by reducing the amyloidogenic processing of the amyloid precursor protein, by central cholinergic and anti-inflammatory mechanisms, and by peripheral modulation of glucose homeostasis. We aimed to investigate whether the ACE insertion/deletion polymorphism is associated with clinical changes in patients with AD, while considering apolipoprotein E (APOE)-ϵ4 carrier status and blood pressure response to angiotensin modulators. METHODS: Consecutive outpatients with late-onset AD were screened with cognitive tests and anthropometric measurements, while their caregivers were queried for functional and caregiver burden scores. Prospective pharmacogenetic associations were estimated for 1 year, taking APOE-ϵ4 carrier status and genotypes of the ACE insertion/deletion polymorphism into account, along with treatment with ACEis or ARBs. RESULTS: For 193 patients (67.4% women, 53.4% APOE-ϵ4 carriers), the ACE insertion/deletion polymorphism was in Hardy-Weinberg equilibrium (p = 0.281), while arterial hypertension was prevalent in 80.3% (n = 124 used an ACEi, n = 21 used an ARB). ARBs benefitted mostly APOE-ϵ4 carriers concerning caregiver burden variations, cognitive and functional decline. ACEis benefitted APOE-ϵ4 non-carriers concerning cognitive and functional decline due to improved blood pressure control in addition to possible central mechanisms. The ACE insertion/deletion polymorphism led to variable response to angiotensin modulators concerning neurological outcomes and blood pressure variations. CONCLUSION: Angiotensin modulators may be disease-modifiers in AD, while genetic stratification of samples is recommended in clinical studies.


Assuntos
Doença de Alzheimer , Humanos , Feminino , Masculino , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Doença de Alzheimer/complicações , Antagonistas de Receptores de Angiotensina/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Angiotensinas/genética , Angiotensinas/uso terapêutico , Farmacogenética , Alelos , Estudos Prospectivos , Apolipoproteínas E/genética , Apolipoproteínas E/uso terapêutico
13.
J Neurooncol ; 156(2): 257-267, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34982371

RESUMO

BACKGROUND: Levetiracetam (LEV) is an anti-epileptic drug (AED) that sensitizes glioblastoma (GBM) to temozolomide (TMZ) chemotherapy by inhibiting O6-methylguanine-DNA methyltransferase (MGMT) expression. Adding LEV to the standard of care (SOC) for GBM may improve TMZ efficacy. This study aimed to pool the existing evidence in the literature to quantify LEV's effect on GBM survival and characterize its safety profile to determine whether incorporating LEV into the SOC is warranted. METHOD: A search of CINAHL, Embase, PubMed, and Web of Science from inception to May 2021 was performed to identify relevant articles. Hazard ratios (HR), median overall survival, and adverse events were pooled using random-effect models. Meta-regression, funnel plots, and the Newcastle-Ottawa Scale were utilized to identify sources of heterogeneity, bias, and statistical influence. RESULTS: From 20 included studies, 5804 GBM patients underwent meta-analysis, of which 1923 (33%) were treated with LEV. Administration of LEV did not significantly improve survival in the entire patient population (HR 0.89, p = 0.094). Significant heterogeneity was observed during pooling of HRs (I2 = 75%, p < 0.01). Meta-regression determined that LEV treatment effect decreased with greater rates of MGMT methylation (RC = 0.03, p = 0.02) and increased with greater proportions of female patients (RC = - 0.05, p = 0.002). Concurrent LEV with the SOC for GBM did not increase odds of adverse events relative to other AEDs. CONCLUSIONS: Levetiracetam treatment may not be effective for all GBM patients. Instead, LEV may be better suited for treating specific molecular profiles of GBM. Further studies are necessary to identify optimal GBM candidates for LEV.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Levetiracetam , Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Humanos , Levetiracetam/uso terapêutico , Análise de Sobrevida , Resultado do Tratamento
14.
J Neuropsychiatry Clin Neurosci ; 34(4): 351-360, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35272493

RESUMO

OBJECTIVE: Neuropsychiatric syndromes have been associated with memory dysfunction and risk of and earlier onset of dementia, but how psychotropic drugs affect clinical changes in Alzheimer's disease is not entirely clear. This study aimed to assess the prospective effects of psychotropic drugs on cognitive and functional changes in Alzheimer's disease according to APOE ε4 carrier status. METHODS: The study included consecutive outpatients with late-onset Alzheimer's disease (N=193) and examined score variations at 1 year on the following tests: Clinical Dementia Rating sum of boxes, Mini-Mental State Examination, Severe Mini-Mental State Examination (SMMSE), Brazilian version of the Zarit Caregiver Burden Interview, Index of Independence in Activities of Daily Living, and Lawton's Instrumental Activities of Daily Living Scale. Analyses of score variations accounted for the use of psychotropic drugs or the number of different medications in use, as well as APOE ε4 carrier status, with significance at p<0.05. RESULTS: For APOE ε4 noncarriers (N=90), cholinesterase inhibitors were beneficial regarding caregiver burden (p=0.030) and basic functionality (p=0.046), memantine was harmful regarding SMMSE score changes (p=0.032), second-generation antipsychotics had nonsignificant harmful effects on SMMSE score changes (p=0.070), and antiepileptic therapy (p=0.001) and the number of different medications in use (p=0.006) were harmful in terms of basic functionality. APOE ε4 carriers (N=103) did not experience any effects of isolated psychotropic drugs on clinical changes, including antidepressants. CONCLUSIONS: Results support the harmful prospective effects of second-generation antipsychotics and antiepileptic drugs on cognitive and functional changes in Alzheimer's disease, particularly for APOE ε4 noncarriers, whereas antidepressants may be safer options for behavioral enhancement.


Assuntos
Doença de Alzheimer , Atividades Cotidianas , Doença de Alzheimer/complicações , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Anticonvulsivantes/uso terapêutico , Apolipoproteína E4/genética , Inibidores da Colinesterase/uso terapêutico , Humanos , Memantina/uso terapêutico , Testes Neuropsicológicos , Psicotrópicos/uso terapêutico
15.
PLoS Med ; 18(9): e1003788, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34516565

RESUMO

BACKGROUND: Social innovations in health are inclusive solutions to address the healthcare delivery gap that meet the needs of end users through a multi-stakeholder, community-engaged process. While social innovations for health have shown promise in closing the healthcare delivery gap, more research is needed to evaluate, scale up, and sustain social innovation. Research checklists can standardize and improve reporting of research findings, promote transparency, and increase replicability of study results and findings. METHODS AND FINDINGS: The research checklist was developed through a 3-step community-engaged process, including a global open call for ideas, a scoping review, and a 3-round modified Delphi process. The call for entries solicited checklists and related items and was open between November 27, 2019 and February 1, 2020. In addition to the open call submissions and scoping review findings, a 17-item Social Innovation For Health Research (SIFHR) Checklist was developed based on the Template for Intervention Description and Replication (TIDieR) Checklist. The checklist was then refined during 3 rounds of Delphi surveys conducted between May and June 2020. The resulting checklist will facilitate more complete and transparent reporting, increase end-user engagement, and help assess social innovation projects. A limitation of the open call was requiring internet access, which likely discouraged participation of some subgroups. CONCLUSIONS: The SIFHR Checklist will strengthen the reporting of social innovation for health research studies. More research is needed on social innovation for health.


Assuntos
Lista de Checagem , Pesquisa sobre Serviços de Saúde , Projetos de Pesquisa , Fatores Socioeconômicos , Técnica Delphi , Difusão de Inovações , Humanos , Determinantes Sociais da Saúde , Participação dos Interessados
16.
J Cell Sci ; 132(18)2019 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-31527149

RESUMO

Cell-cell fusion is a fundamental process underlying fertilization, development, regeneration and physiology of metazoans. It is a multi-step process involving cell recognition and adhesion, actin cytoskeletal rearrangements, fusogen engagement, lipid mixing and fusion pore formation, ultimately resulting in the integration of two fusion partners. Here, we focus on the asymmetric actin cytoskeletal rearrangements at the site of fusion, known as the fusogenic synapse, which was first discovered during myoblast fusion in Drosophila embryos and later also found in mammalian muscle and non-muscle cells. At the asymmetric fusogenic synapse, actin-propelled invasive membrane protrusions from an attacking fusion partner trigger actomyosin-based mechanosensory responses in the receiving cell. The interplay between the invasive and resisting forces generated by the two fusion partners puts the fusogenic synapse under high mechanical tension and brings the two cell membranes into close proximity, promoting the engagement of fusogens to initiate fusion pore formation. In this Cell Science at a Glance article and the accompanying poster, we highlight the molecular, cellular and biophysical events at the asymmetric fusogenic synapse using Drosophila myoblast fusion as a model.


Assuntos
Citoesqueleto de Actina/metabolismo , Proteínas de Drosophila/metabolismo , Mioblastos/citologia , Mioblastos/metabolismo , Citoesqueleto de Actina/genética , Animais , Fusão Celular , Drosophila , Proteínas de Drosophila/genética , Embrião não Mamífero/citologia , Embrião não Mamífero/metabolismo , Mecanotransdução Celular/genética , Mecanotransdução Celular/fisiologia
17.
EMBO J ; 35(21): 2270-2284, 2016 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-27670760

RESUMO

The large GTPase dynamin is the first protein shown to catalyze membrane fission. Dynamin and its related proteins are essential to many cell functions, from endocytosis to organelle division and fusion, and it plays a critical role in many physiological functions such as synaptic transmission and muscle contraction. Research of the past three decades has focused on understanding how dynamin works. In this review, we present the basis for an emerging consensus on how dynamin functions. Three properties of dynamin are strongly supported by experimental data: first, dynamin oligomerizes into a helical polymer; second, dynamin oligomer constricts in the presence of GTP; and third, dynamin catalyzes membrane fission upon GTP hydrolysis. We present the two current models for fission, essentially diverging in how GTP energy is spent. We further discuss how future research might solve the remaining open questions presently under discussion.


Assuntos
Membrana Celular/fisiologia , Dinaminas/fisiologia , Animais , Guanosina Trifosfato/fisiologia , Humanos
18.
J Vasc Interv Radiol ; 31(6): 1018-1024.e4, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32376173

RESUMO

PURPOSE: To demonstrate that random forest models trained on a large national sample can accurately predict relevant outcomes and may ultimately contribute to future clinical decision support tools in IR. MATERIALS AND METHODS: Patient data from years 2012-2014 of the National Inpatient Sample were used to develop random forest machine learning models to predict iatrogenic pneumothorax after computed tomography-guided transthoracic biopsy (TTB), in-hospital mortality after transjugular intrahepatic portosystemic shunt (TIPS), and length of stay > 3 days after uterine artery embolization (UAE). Model performance was evaluated with area under the receiver operating characteristic curve (AUROC) and maximum F1 score. The threshold for AUROC significance was set at 0.75. RESULTS: AUROC was 0.913 for the TTB model, 0.788 for the TIPS model, and 0.879 for the UAE model. Maximum F1 score was 0.532 for the TTB model, 0.357 for the TIPS model, and 0.700 for the UAE model. The TTB model had the highest AUROC, while the UAE model had the highest F1 score. All models met the criteria for AUROC significance. CONCLUSIONS: This study demonstrates that machine learning models may suitably predict a variety of different clinically relevant outcomes, including procedure-specific complications, mortality, and length of stay. Performance of these models will improve as more high-quality IR data become available.


Assuntos
Mineração de Dados/métodos , Aprendizado de Máquina , Radiografia Intervencionista/efeitos adversos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Bases de Dados Factuais , Feminino , Mortalidade Hospitalar , Humanos , Doença Iatrogênica , Biópsia Guiada por Imagem/efeitos adversos , Lactente , Recém-Nascido , Pacientes Internados , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Pneumotórax/etiologia , Derivação Portossistêmica Transjugular Intra-Hepática/efeitos adversos , Derivação Portossistêmica Transjugular Intra-Hepática/mortalidade , Radiografia Intervencionista/mortalidade , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Estados Unidos , Embolização da Artéria Uterina/efeitos adversos , Adulto Jovem
19.
Am J Emerg Med ; 38(7): 1377-1383, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31843326

RESUMO

OBJECTIVE: We sought to determine if the duration of pain or other features of the history predict major adverse cardiac events (MACE) in patients with chest pain in the emergency department (ED). METHODS: This was a prospective cohort study of patients presenting to a single ED with chest pain. Consenting patients filled out a survey about their symptoms. After 6 weeks, we assessed patients for MACE via chart review and direct contact. We used this data to calculate the likelihood ratios (LRs) of a number of historical features for acute myocardial infarction (MI) (primary endpoint) and MACE within 6 weeks (secondary endpoint). We planned a priori to analyze patients who reported chest pain for ≤1 min or continuously for ≥24 h. RESULTS: We enrolled 1002 patients, and 83.6% had successful 6-week follow up. Regarding chest pain lasting for ≤1 min, the positive LR was 0.95 (95% CI 0.24 to 3.80) for acute MI and 0.67 (95% CI 0.17 to 2.72) for MACE within 6 weeks. The positive LRs of continuous pain lasting ≥24 h for acute MI and MACE within 6 weeks were 0.15 (95% CI 0.04 to 0.58) and 0.36 (95% CI 0.18 to 0.74), respectively. Amongst other historical features assessed, radiation to the right arm was the strongest positive predictor of acute MI. CONCLUSION: Patients with continuous chest pain for ≥24 h are unlikely to have an acute MI. Chest pain lasting ≤1 min does not exclude acute MI.


Assuntos
Dor no Peito/fisiopatologia , Mortalidade , Infarto do Miocárdio/epidemiologia , Revascularização Miocárdica/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Ponte de Artéria Coronária/estatística & dados numéricos , Serviço Hospitalar de Emergência , Feminino , Seguimentos , Humanos , Funções Verossimilhança , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Intervenção Coronária Percutânea/estatística & dados numéricos , Fatores de Tempo , Estados Unidos/epidemiologia
20.
Proc Natl Acad Sci U S A ; 114(45): 11950-11955, 2017 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-29078404

RESUMO

Skeletal muscle formation requires fusion of mononucleated myoblasts to form multinucleated myofibers. The muscle-specific membrane proteins myomaker and myomixer cooperate to drive mammalian myoblast fusion. Whereas myomaker is highly conserved across diverse vertebrate species, myomixer is a micropeptide that shows relatively weak cross-species conservation. To explore the functional conservation of myomixer, we investigated the expression and function of the zebrafish myomixer ortholog. Here we show that myomixer expression during zebrafish embryogenesis coincides with myoblast fusion, and genetic deletion of myomixer using CRISPR/Cas9 mutagenesis abolishes myoblast fusion in vivo. We also identify myomixer orthologs in other species of fish and reptiles, which can cooperate with myomaker and substitute for the fusogenic activity of mammalian myomixer. Sequence comparison of these diverse myomixer orthologs reveals key amino acid residues and a minimal fusogenic peptide motif that is necessary for promoting cell-cell fusion with myomaker. Our findings highlight the evolutionary conservation of the myomaker-myomixer partnership and provide insights into the molecular basis of myoblast fusion.


Assuntos
Proteínas de Membrana/genética , Desenvolvimento Muscular/genética , Fibras Musculares Esqueléticas/citologia , Proteínas Musculares/genética , Mioblastos/metabolismo , Proteínas de Peixe-Zebra/genética , Sequência de Aminoácidos , Animais , Sistemas CRISPR-Cas/genética , Fusão Celular , Linhagem Celular , Elefantes/genética , Desenvolvimento Muscular/fisiologia , Tubarões/genética , Tartarugas/genética , Peixe-Zebra/embriologia , Peixe-Zebra/genética
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