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1.
Biochem Pharmacol ; 174: 113823, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31987856

RESUMO

Supressed levels of intracellular cAMP have been associated with malignancy. Thus, elevating cAMP through activation of adenylyl cyclase (AC) or by inhibition of phosphodiesterase (PDE) may be therapeutically beneficial. Here, we demonstrate that elevated cAMP levels suppress growth in C6 cells (a model of glioma) through treatment with forskolin, an AC activator, or a range of small molecule PDE inhibitors with differing selectivity profiles. Forskolin suppressed cell growth in a PKA-dependent manner by inducing a G2/M phase cell cycle arrest. In contrast, trequinsin (a non-selective PDE2/3/7 inhibitor), not only inhibited cell growth via PKA, but also stimulated (independent of PKA) caspase-3/-7 and induced an aneuploidy phenotype. Interestingly, a cocktail of individual PDE 2,3,7 inhibitors suppressed cell growth in a manner analogous to forskolin but not trequinsin. Finally, we demonstrate that concomitant targeting of both AC and PDEs synergistically elevated intracellular cAMP levels thereby potentiating their antiproliferative actions.

2.
Development ; 147(2)2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31932352

RESUMO

Evolution is replete with reuse of genes in different contexts, leading to multifunctional roles of signaling factors during development. Here, we explore osteoclast regulation during skeletal development through analysis of colony-stimulating factor 1 receptor (csf1r) function in the zebrafish. A primary role of Csf1r signaling is to regulate the proliferation, differentiation and function of myelomonocytic cells, including osteoclasts. We demonstrate the retention of two functional paralogues of csf1r in zebrafish. Mutant analysis indicates that the paralogues have shared, non-redundant roles in regulating osteoclast activity during the formation of the adult skeleton. csf1ra, however, has adopted unique roles in pigment cell patterning not seen in the second paralogue. We identify a unique noncoding element within csf1ra of fishes that is sufficient for controlling gene expression in pigment cells during development. As a role for Csf1r signaling in pigmentation is not observed in mammals or birds, it is likely that the overlapping roles of the two paralogues released functional constraints on csf1ra, allowing the signaling capacity of Csf1r to serve a novel function in the evolution of pigment pattern in fishes.

3.
Elife ; 92020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31985398

RESUMO

The use of genetics has been invaluable in defining the complex mechanisms of aging and longevity. Zebrafish, while a prominent model for vertebrate development, have not been used systematically to address questions of how and why we age. In a mutagenesis screen focusing on late developmental phenotypes, we identified a new mutant that displays aging phenotypes at young adult stages. We find that the phenotypes are due to loss-of-function in the non-classical cadherin celsr1a. The premature aging is not associated with increased cellular senescence or telomere length but is a result of a failure to maintain progenitor cell populations. We show that celsr1a is essential for maintenance of stem cell progenitors in late stages. Caloric restriction can ameliorate celsr1a aging phenotypes. These data suggest that celsr1a function helps to mediate stem cell maintenance during maturation and homeostasis of tissues and thus regulates the onset or expressivity of aging phenotypes.

4.
BMJ ; 368: m36, 2020 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-31924661
5.
Health Econ ; 2020 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-31943499

RESUMO

Unlike in the production of most goods, changes in capacity for labor-intensive services only affect outcomes of interest insofar as service providers change the way they allocate their time in response to those capacity changes. In this paper, we examine how public sector service providers respond to unexpected capacity constraints in the specific context of public health clinics. We exploit an exogenous reduction in public health clinic capacity to quantify the trade-off between patients treated and time spent with each patient, which we treat as a proxy for a quality versus quantity decision. We provide evidence that these small and generally insignificant effects on nurse time favor public sector employees prioritizing quality of each interaction over clearing the patient queue.

6.
J Orthop Res ; 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31773769

RESUMO

Advances in next-generation sequencing have transformed our ability to identify genetic variants associated with clinical disorders of the musculoskeletal system. However, the means to functionally validate and analyze the physiological repercussions of genetic variation have lagged behind the rate of genetic discovery. The zebrafish provides an efficient model to leverage genetic analysis in an in vivo context. Its utility for orthopedic research is becoming evident in regard to both candidate gene validation as well as therapeutic discovery in tissues such as bone, tendon, muscle, and cartilage. With the development of new genetic and analytical tools to better assay aspects of skeletal tissue morphology, mineralization, composition, and biomechanics, researchers are emboldened to systematically approach how the skeleton develops and to identify the root causes, and potential treatments, of skeletal disease. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J. Orthop. Res.

7.
Pract Neurol ; 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31757818

RESUMO

There are over 87 000 Deaf people in the UK with British Sign Language (BSL) as their first language.1 Few healthcare professionals receive training in Deaf awareness or in BSL, and missed diagnoses and inadequate treatment of Deaf patients are estimated to cost the National Health Service £30 million per year.2 Neurologists are likely to encounter Deaf BSL users in their practice, but without prior experience may find consultations challenging, especially within the time constraints and pressure of a standard clinic. In this article, we provide guidance on consulting with Deaf people in a neurology clinic, drawing on experience from our cognitive clinic for Deaf BSL users where effective communication is essential.

8.
Proc Natl Acad Sci U S A ; 116(48): 24093-24099, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31712427

RESUMO

Receptor-activity-modifying proteins (RAMPs) are single transmembrane-spanning proteins which serve as molecular chaperones and allosteric modulators of G-protein-coupled receptors (GPCRs) and their signaling pathways. Although RAMPs have been previously studied in the context of their effects on Family B GPCRs, the coevolution of RAMPs with many GPCR families suggests an expanded repertoire of potential interactions. Using bioluminescence resonance energy transfer-based and cell-surface expression approaches, we comprehensively screen for RAMP interactions within the chemokine receptor family and identify robust interactions between RAMPs and nearly all chemokine receptors. Most notably, we identify robust RAMP interaction with atypical chemokine receptors (ACKRs), which function to establish chemotactic gradients for directed cell migration. Specifically, RAMP3 association with atypical chemokine receptor 3 (ACKR3) diminishes adrenomedullin (AM) ligand availability without changing G-protein coupling. Instead, RAMP3 is required for the rapid recycling of ACKR3 to the plasma membrane through Rab4-positive vesicles following either AM or SDF-1/CXCL12 binding, thereby enabling formation of dynamic spatiotemporal chemotactic gradients. Consequently, genetic deletion of either ACKR3 or RAMP3 in mice abolishes directed cell migration of retinal angiogenesis. Thus, RAMP association with chemokine receptor family members represents a molecular interaction to control receptor signaling and trafficking properties.

11.
Biomolecules ; 9(9)2019 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-31540005

RESUMO

The dUTPase enzyme family plays an essential role in maintaining the genome integrity and are represented by two distinct classes of proteins; the ß-pleated homotrimeric and the all-α homodimeric dUTPases. Representatives of both trimeric and dimeric dUTPases are encoded by Staphylococcus aureus phage genomes and have been shown to interact with the Stl repressor protein of S. aureus pathogenicity island SaPIbov1. In the present work we set out to characterize the interactions between these proteins based on a range of biochemical and biophysical methods and shed light on the binding mechanism of the dimeric φNM1 phage dUTPase and Stl. Using hydrogen deuterium exchange mass spectrometry, we also characterize the protein regions involved in the dUTPase:Stl interactions. Based on these results we provide reasonable explanation for the enzyme inhibitory effect of Stl observed in both types of complexes. Our experiments reveal that Stl employs different peptide segments and stoichiometry for the two different phage dUTPases which allows us to propose a functional plasticity of Stl. The malleable character of Stl serves as a basis for the inhibition of both dimeric and trimeric dUTPases.

12.
Dev Biol ; 456(2): 164-178, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472116

RESUMO

The coordination of growth during development establishes proportionality within and among the different anatomic structures of organisms. Innate memory of this proportionality is preserved, as shown in the ability of regenerating structures to return to their original size. Although the regulation of this coordination is incompletely understood, mutant analyses of zebrafish with long-finned phenotypes have uncovered important roles for bioelectric signaling in modulating growth and size of the fins and barbs. To date, long-finned mutants identified are caused by hypermorphic mutations, leaving unresolved whether such signaling is required for normal development. We isolated a new zebrafish mutant, schleier, with proportional overgrowth phenotypes caused by a missense mutation and loss of function in the K+-Cl- cotransporter Kcc4a. Creation of dominant negative Kcc4a in wild-type fish leads to loss of growth restriction in fins and barbs, supporting a requirement for Kcc4a in regulation of proportion. Epistasis experiments suggest that Kcc4a and the two-pore potassium channel Kcnk5b both contribute to a common bioelectrical signaling response in the fin. These data suggest that an integrated bioelectric signaling pathway is required for the coordination of size and proportion during development.

13.
Fitoterapia ; 137: 104285, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31386897

RESUMO

Botanical-based natural products are an important resource for medicinal drug discovery and continue to provide diverse pharmacophores with therapeutic potential against cancer and other human diseases. A prototype Traditional Chinese Medicine (TCM) plant extract library has been established at the US National Cancer Institute, which contains both the organic and aqueous extracts of 132 authenticated medicinal plant species that collectively represent the potential therapeutic contents of most commonly used TCM herbal prescriptions. This library is publicly available in 96- and 384- well plates for high throughput screening across a broad array of biological targets, as well as in larger quantities for isolation of active chemical ingredients. Herein, we present the methodology used to generate the library and the preliminary assessment of the anti-proliferative activity of this crude extract library in NCI-60 human cancer cell lines screen. Particularly, we report the chemical profiling and metabolome comparison analysis of four commonly used TCM plants, namely Brucea javanica, Dioscorea nipponica, Cynanchum atratum, and Salvia miltiorrhiza. Bioassay-guided isolation resulted in the identification of the active compounds, and different extraction methods were compared for their abilities to extract cytotoxic compounds and to concentrate biologically active natural products.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Plantas Medicinais/química , Antineoplásicos Fitogênicos/isolamento & purificação , Brucea/química , Linhagem Celular Tumoral , China , Cynanchum/química , Dioscorea/química , Descoberta de Drogas , Humanos , Medicina Tradicional Chinesa , National Cancer Institute (U.S.) , Compostos Fitoquímicos/isolamento & purificação , Salvia miltiorrhiza/química , Estados Unidos
15.
FASEB J ; 33(11): 11735-11745, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31361156

RESUMO

Basal protein turnover, which largely relies on the degradation of ubiquitinated substrates, is instrumental for maintenance of muscle mass and function. However, the regulation of ubiquitinated protein degradation in healthy, nonatrophying skeletal muscle is still evolving, and potential tissue-specific modulators remain unknown. Using an unbiased expression analysis of 34 putative autophagy genes across mouse tissues, we identified unc-51 like autophagy activating kinase (Ulk)2, a homolog of the yeast autophagy related protein 1, as particularly enriched in skeletal muscle. Subsequent experiments revealed accumulations of insoluble ubiquitinated protein aggregates associated with the adaptors sequestosome 1 (SQSTM1, also known as p62) and next to breast cancer type 1 susceptibility protein gene 1 protein (NBR1) in adult muscles with ULK2 deficiency. ULK2 deficiency also led to impaired muscle force and caused myofiber atrophy and degeneration. These features were not observed in muscles with deficiency of the ULK2 paralog, ULK1. Furthermore, short-term ULK2 deficiency did not impair autophagy initiation, autophagosome to lysosome fusion, or protease activities of the lysosome and proteasome. Altogether, our results indicate that skeletal muscle ULK2 has a unique role in basal selective protein degradation by stimulating the recognition and proteolytic sequestration of insoluble ubiquitinated protein aggregates associated with p62 and NBR1. These findings have potential implications for conditions of poor protein homeostasis in muscles as observed in several myopathies and aging.-Fuqua, J. D., Mere, C. P., Kronemberger, A., Blomme, J., Bae, D., Turner, K. D., Harris, M. P., Scudese, E., Edwards, M., Ebert, S. M., de Sousa, L. G. O., Bodine, S. C., Yang, L., Adams, C. M., Lira, V. A. ULK2 is essential for degradation of ubiquitinated protein aggregates and homeostasis in skeletal muscle.

16.
Nat Ecol Evol ; 3(7): 1102-1109, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31182814

RESUMO

Adaptive radiation illustrates links between ecological opportunity, natural selection and the generation of biodiversity. Central to adaptive radiation is the association between a diversifying lineage and the evolution of phenotypic variation that facilitates the use of new environments or resources. However, is not clear whether adaptive evolution or historical contingency is more important for the origin of key phenotypic traits in adaptive radiation. Here we use targeted sequencing of >250,000 loci across 46 species to examine hypotheses concerning the origin and diversification of key traits in the adaptive radiation of Antarctic notothenioid fishes. Contrary to expectations of adaptive evolution, we show that notothenioids experienced a punctuated burst of genomic diversification and evolved key skeletal modifications before the onset of polar conditions in the Southern Ocean. We show that diversifying selection in pathways associated with human skeletal dysplasias facilitates ecologically important variation in buoyancy among Antarctic notothenioid species, and demonstrate the sufficiency of altered trip11, col1a2 and col1a1a function in zebrafish (Danio rerio) to phenocopy skeletal reduction in Antarctic notothenioids. Rather than adaptation being driven by the cooling of the Antarctic, our results highlight the role of historical contingency in shaping the adaptive radiation of notothenioids. Understanding the historical and environmental context for the origin of key traits in adaptive radiations extends beyond reconstructing events that result in evolutionary innovation, as it also provides a context in forecasting the effects of climate change on the stability and evolvability of natural populations.


Assuntos
Adaptação Fisiológica , Peixes , Animais , Regiões Antárticas , Biodiversidade , Humanos , Filogenia
17.
Ann Thorac Surg ; 108(2): 574-580, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30959013

RESUMO

BACKGROUND: Patients with single ventricle (SV) may often undergo aortic reconstruction that creates a stiff large vessel, increasing afterload and affecting exercise performance. The objective of this study was to determine the relationship of pulse wave velocity (PWV) and distensibility in reconstructed and normal aortic arches after Fontan with exercise variables. METHODS: PWV and distensibility of the descending aorta at the level of the diaphragm (DAo) were calculated with real-time exercise cardiac magnetic resonance in 48 patients with SV after Fontan (18 after aortic reconstruction; 30 without aortic reconstruction) and compared with metabolic exercise stress test variables. RESULTS: PWV was greater in the reconstructed group than in the non-reconstructed group (median 4.4 m/s [range: 2.3 to 9.8 m/s] versus 3.6 [range: 2.6 to 6.3 m/s], respectively, p = 0.003). Statistically significant inverse correlations were found between PWV and end-diastolic, end-systolic, and stroke volumes at rest and at exercise in the reconstructed group. In addition, inverse correlations also existed in the reconstructed group between distensibility of the DAo and the exercise variables such as peak oxygen pulse (R = 0.56, p = 0.02), peak oxygen consumption (R = 0.63, p = 0.008), oxygen consumption at ventilatory anaerobic threshold (R = 0.48, p = 0.04), and peak work (R = 0.54, p = 0.02). Similar correlations were not seen in patients with non-reconstructed aortas. CONCLUSIONS: Patients with SV with reconstructed aortas have increased aortic stiffness, increasing afterload on the ventricle. Native DAo stiffness distal to the reconstruction is inversely correlated with exercise performance, presumably to decrease impedance mismatch to maintain homogeneity of the aortic wall. This information suggests a possible mechanism for decreased exercise performance in patients with SV with aortic reconstructions.


Assuntos
Aorta Torácica/fisiopatologia , Velocidade do Fluxo Sanguíneo/fisiologia , Volume Cardíaco/fisiologia , Exercício/fisiologia , Cardiopatias Congênitas/fisiopatologia , Ventrículos do Coração/fisiopatologia , Rigidez Vascular/fisiologia , Adolescente , Adulto , Aorta Torácica/diagnóstico por imagem , Aorta Torácica/cirurgia , Procedimentos Cirúrgicos Cardíacos/métodos , Criança , Teste de Esforço , Feminino , Seguimentos , Cardiopatias Congênitas/diagnóstico , Cardiopatias Congênitas/cirurgia , Ventrículos do Coração/anormalidades , Ventrículos do Coração/diagnóstico por imagem , Humanos , Imagem Cinética por Ressonância Magnética , Masculino , Estudos Prospectivos , Procedimentos Cirúrgicos Reconstrutivos/métodos , Adulto Jovem
18.
Pediatr Emerg Care ; 2019 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-30973497

RESUMO

The profoundly hypoxemic child presents an interesting set of diagnostic and management challenges in the pediatric emergency department. While common pathologies including pneumonia, asthma, bronchiolitis, and pneumothoraces are managed using evidence-based algorithms, more enigmatic pathologies may present the treating physician with less diagnostic and therapeutic clarity. We present the case of a profoundly hypoxemic 16-year-old girl who presented in minimal distress, with oxyhemoglobin saturation of 63% on room air.

19.
Radiology ; 291(3): 774-780, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30938628

RESUMO

Background The Fontan operation is performed for surgical palliation of single ventricle physiology. This operation is usually preceded by a superior cavopulmonary connection (SCPC); lymphatic abnormalities after SCPC may be demonstrated at MRI and prior to the Fontan operation. Purpose To determine if the degree of neck and thoracic lymphatic abnormalities at T2-weighted MRI in patients after superior cavopulmonary connection (SCPC) correlated with surgical outcomes from the Fontan procedure. Materials and Methods Patients for whom SCPC was performed for palliation of single ventricle disease who underwent chest MRI between July 2012 and May 2015 at a single institution were retrospectively reviewed. T2-weighted images were scored as lymphatic type 1 (little or no T2 mediastinal and supraclavicular signal) to type 4 (T2 signal into both the mediastinum and the lung parenchyma). Fontan takedown, duration of post-Fontan hospitalization and pleural effusion, postoperative plastic bronchitis, need for transplant, and mortality were tabulated. The relationship between lymphatic type and clinical outcomes was evaluated by using analysis of variance (ANOVA), the Kruskal-Wallis H test, and the Fisher exact test. Results A total of 83 patients (mean age, 7.9 years ± 2.6) were evaluated. Among these 83 patients, 53 (64%) were classified with type 1 or 2 lymphatic abnormalities, 17 (20%) with type 3, and 12 (16%) with type 4. The rate of failure of Fontan completion was higher in patients with type 4 than in type 1 or 2 (54% vs 2%, respectively; P = .004). Need for cardiac transplant (one of 13 [8%]) and death (three of 13 [23%]) occurred only in type 4. Median postoperative length of stay was longer for patients with type 4 than for those with types 1 or 2 (29 days vs 9 days, respectively; P < .01). Conclusion Greater MRI-based severity of lymphatic abnormalities in patients prior to planned Fontan procedure was associated with failure of Fontan completion and longer postoperative stay. © RSNA, 2019 Online supplemental material is available for this article.


Assuntos
Técnica de Fontan , Anormalidades Linfáticas/diagnóstico por imagem , Complicações Pós-Operatórias/diagnóstico por imagem , Criança , Pré-Escolar , Técnica de Fontan/efeitos adversos , Técnica de Fontan/mortalidade , Técnica de Fontan/estatística & dados numéricos , Cardiopatias Congênitas/mortalidade , Cardiopatias Congênitas/cirurgia , Humanos , Tempo de Internação , Anormalidades Linfáticas/etiologia , Sistema Linfático/diagnóstico por imagem , Sistema Linfático/patologia , Imagem por Ressonância Magnética , Pescoço/diagnóstico por imagem , Pescoço/patologia , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Tórax/diagnóstico por imagem , Tórax/patologia , Resultado do Tratamento
20.
Biochim Biophys Acta Biomembr ; 1861(5): 997-1003, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30826286

RESUMO

Corticotrophin releasing factor (CRF) acts via two family B G-protein-coupled receptors, CRFR1 and CRFR2. Additional subtypes exist due to alternative splicing. CRFR1α is the most widely expressed subtype and lacks a 29-residue insert in the first intracellular loop that is present in CRFR1ß. It has been shown previously that co-expression of CRFR1ß with receptor activity modifying protein 2 (RAMP2) in HEK 293S cells increased the cell-surface expression of both proteins suggesting a physical interaction as seen with RAMPs and calcitonin receptor-like receptor (CLR). This study investigated the ability of CRFR1α, CRFR1ß and CRFR2ß to promote cell-surface expression of FLAG-tagged RAMP2. Four different cell-lines were utilised to investigate the effect of varying cellular context; COS-7, HEK 293T, HEK 293S and [ΔCTR]HEK 293 (which lacks endogenous calcitonin receptor). In all cell-lines, CRFR1α and CRFR1ß enhanced RAMP2 cell-surface expression. The magnitude of the effect on RAMP2 was dependent on the cell-line ([ΔCTR]HEK 293 > COS-7 > HEK 293T > HEK 293S). RT-PCR indicated this variation may relate to differences in endogenous RAMP expression between cell types. Furthermore, pre-treatment with CRF resulted in a loss of cell-surface FLAG-RAMP2 when it was co-expressed with CRFR1 subtypes. CRFR2ß co-expression had no effect on RAMP2 in any cell-line. Molecular modelling suggests that the potential contact interface between the extracellular domains of RAMP2 and CRF receptor subtypes is smaller than that of RAMP2 and CRL, the canonical receptor:RAMP pairing, assuming a physical interaction. Furthermore, a specific residue difference between CRFR1 subtypes (glutamate) and CRFR2ß (histidine) in this interface region may impair CRFR2ß:RAMP2 interaction by electrostatic repulsion.


Assuntos
Processamento Alternativo , Proteína 2 Modificadora da Atividade de Receptores/metabolismo , Receptores de Hormônio Liberador da Corticotropina/metabolismo , Processamento Alternativo/genética , Animais , Células COS , Células HEK293 , Humanos , Modelos Moleculares , Proteína 2 Modificadora da Atividade de Receptores/química , Proteína 2 Modificadora da Atividade de Receptores/genética , Receptores de Hormônio Liberador da Corticotropina/química , Receptores de Hormônio Liberador da Corticotropina/genética
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