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1.
Commun Biol ; 7(1): 426, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589567

RESUMO

Wilms tumor (WT) is the most common renal malignancy of childhood. Despite improvements in the overall survival, relapse occurs in ~15% of patients with favorable histology WT (FHWT). Half of these patients will succumb to their disease. Identifying novel targeted therapies remains challenging in part due to the lack of faithful preclinical in vitro models. Here we establish twelve patient-derived WT cell lines and demonstrate that these models faithfully recapitulate WT biology using genomic and transcriptomic techniques. We then perform loss-of-function screens to identify the nuclear export gene, XPO1, as a vulnerability. We find that the FDA approved XPO1 inhibitor, KPT-330, suppresses TRIP13 expression, which is required for survival. We further identify synergy between KPT-330 and doxorubicin, a chemotherapy used in high-risk FHWT. Taken together, we identify XPO1 inhibition with KPT-330 as a potential therapeutic option to treat FHWTs and in combination with doxorubicin, leads to durable remissions in vivo.


Assuntos
Hidrazinas , Neoplasias Renais , Triazóis , Tumor de Wilms , Humanos , 60611 , Transporte Ativo do Núcleo Celular , Carioferinas/genética , Carioferinas/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Linhagem Celular Tumoral , Apoptose , Recidiva Local de Neoplasia , Doxorrubicina/farmacologia , Tumor de Wilms/tratamento farmacológico , Tumor de Wilms/genética , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/genética , ATPases Associadas a Diversas Atividades Celulares/metabolismo , Proteínas de Ciclo Celular/metabolismo
2.
Oecologia ; 204(1): 147-159, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38151651

RESUMO

Functional trait ecology has the potential to provide generalizable and mechanistic predictions of ecosystem function from data of species distributions and traits. The traits that are selected should both respond to environmental factors and influence ecosystem functioning. Invertebrate mouthpart traits fulfill these criteria, but are seldom collected, lack standardized measurement protocols, and have infrequently been investigated in response to environmental factors. We surveyed isopod species that consume plant detritus, and tree communities in 58 plots across primary and secondary forests in Singapore. We measured body dimensions (body size traits), pereopod and antennae lengths (locomotory traits), dimensions of mandible structures (morphological mouthpart traits), and mechanical advantages generated by mandible shape (mechanical mouthpart traits) for six isopod species found in these plots and investigated if these traits respond to changes in tree community composition, tree diversity, and forest structure. Morphological mouthpart traits responded to a tree compositional gradient reflecting forest recovery degree. Mouthpart features associated with greater consumption of litter (broader but less serrated/rugose lacinia mobilis [an important cutting and chewing structure on the mandible]) were most prevalent in abandoned plantation and young secondary forests containing disturbance-associated tree species. Feeding strategies associated with fungi grazing (narrower and more serrated/rugose lacinia mobilis) were most prevalent in late secondary forests containing later successional tree species. Since morphological mouthpart traits likely also predict consumption and excretion rates of isopods, these traits advance our understanding of environment-trait-ecosystem functioning relationships across contrasting tropical forest plots that vary in composition, disturbance history, and post-disturbance recovery.


Assuntos
Ecossistema , Isópodes , Animais , Clima Tropical , Ecologia , Plantas
3.
Conserv Biol ; : e14162, 2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37551767

RESUMO

Trade in pangolins is illegal, and yet tons of their scales and products are seized at various ports. These large seizures are challenging to process and comprehensively genotype for upstream provenance tracing and species identification for prosecution. We implemented a scalable DNA barcoding pipeline in which rapid DNA extraction and MinION sequencing were used to genotype a substantial proportion of pangolin scales subsampled from 2 record shipments seized in Singapore in 2019 (37.5 t). We used reference sequences to match the scales to phylogeographical regions of origin. In total, we identified 2346 cytochrome b (cytb) barcodes of white-bellied (Phataginus tricuspis) (from 1091 scales), black-bellied (Phataginus tetradactyla) (227 scales), and giant (Smutsia gigantea) (1028 scales) pangolins. Haplotype diversity was higher for P. tricuspis scales (121 haplotypes, 66 novel) than that for P. tetradactyla (22 haplotypes, 15 novel) and S. gigantea (25 haplotypes, 21 novel) scales. Of the novel haplotypes, 74.2% were likely from western and west-central Africa, suggesting potential resurgence of poaching and newly exploited populations in these regions. Our results illustrate the utility of extensively subsampling large seizures and outline an efficient molecular approach for rapid genetic screening that should be accessible to most forensic laboratories and enforcement agencies.


Revelación de la magnitud de la caza furtiva del pangolín africano mediante el genotipo extenso de nanoporos de ADN de escamas incautadas Resumen Aunque el mercado de pangolines es ilegal, se incautan toneladas de sus escamas y productos derivados en varios puertos comerciales. Es un reto procesar estas magnas incautaciones y obtener el genotipo completo para usarlo en la trazabilidad logística ascendente e identificación de la especie y así imponer sanciones. Implementamos una canalización escalable del código de barras de ADN en el cual usamos la extracción rápida de ADN y la secuenciación MinION para obtener el genotipo de una proporción sustancial de las escamas de pangolín submuestreadas en dos cargamentos incautados en 2019 en Singapur (37.5 t). Usamos secuencias referenciales para emparejar las escamas con las regiones filogeográficas de origen. Identificamos en total 2,346 códigos de citocromo b (cytb) del pangolín de vientre blanco (Phataginus tricuspis) (de 1,091 escamas), de vientre negro (P. tetradactyla) (227 escamas) y del pangolín gigante (Smutsia gigantea) (1,028 escamas). La diversidad de haplotipos fue mayor en las escamas de P. tricuspis (121 haplotipos, 66 nuevos) que en las de P. tetradactyla (22 haplotipos, 15 nuevos) y S. gigantea (25 haplotipos, 21 nuevos). De los haplotipos nuevos, el 74.2% probablemente provenía del occidente y centro-occidente de África, lo que sugiere un resurgimiento potencial de la caza furtiva y poblaciones recién explotadas en estas regiones. Nuestros resultados demuestran la utilidad de submuestrear extensivamente las grandes incautaciones y esboza una estrategia molecular eficiente para un análisis genético rápido que debería ser accesible para la mayoría de los laboratorios forenses y las autoridades de aplicación.

4.
J Am Assoc Lab Anim Sci ; 61(4): 344-352, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35688608

RESUMO

Bats are known natural reservoirs of several highly pathogenic zoonotic viruses, including Hendra virus, Nipah virus, rabies virus, SARS-like coronaviruses, and suspected ancestral reservoirs of SARS-CoV-2 responsible for the ongoing COVID-19 pandemic. The capacity to survive infections of highly pathogenic agents without severe disease, together with many other unique features, makes bats an ideal animal model for studying the regulation of infection, cancer, and longevity, which is likely to translate into human health outcomes. A key factor that limits bat research is lack of breeding bat colonies. To address this need, a captive bat colony was established in Singapore from 19 wild-caught local cave nectar bats. The bats were screened for specific pathogens before the start of captive breeding. Custom-made cages and an optimized diet inclusive of Wombaroo dietary formula, liquid diet, and supplement of fruits enabled the bats to breed prolifically in our facility. Cages are washed daily and disinfected once every fortnight. Bats are observed daily to detect any sick bat or abnormal behavior. In addition, bats undergo a thorough health check once every 3 to 4 mo to check on their overall wellbeing, perform sampling, and document any potential pregnancy. The current colony houses over 80 bats that are successfully breeding, providing a valuable resource for research in Singapore and overseas.


Assuntos
COVID-19 , Quirópteros , Animais , Cruzamento , Reservatórios de Doenças , Humanos , Pandemias , Filogenia , Néctar de Plantas , SARS-CoV-2 , Singapura
5.
Int J Parasitol Parasites Wildl ; 15: 35-42, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33948432

RESUMO

Haemosporidians infect a wide diversity of bat genera and species, yet little is known about their transmission cycles or epidemiology. Though several recent studies have focused on the genus Hepatocystis, an Old World parasite primarily infecting bats, monkeys, and squirrels, this group is still understudied with little known about its transmission and molecular ecology. These parasites lack an asexual erythrocytic stage, making them unique from the Plasmodium vertebrate life cycle. In this study, we detected a prevalence of 31% of Hepatocystis in short-nosed fruit bats (Cynopterus brachyotis) in Singapore. Phylogenetic reconstruction with a partial cytochrome b sequence revealed a monophyletic group of Hepatocystis from C. brachyotis in Malaysia, Singapore, and Thailand. There was no relationship with infection and bat age, sex, location, body condition or monsoon season. The absence of this parasite in the five other bat species sampled in Singapore indicates this Hepatocystis species may be host restricted.

6.
Glob Chang Biol ; 27(17): 4139-4153, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34021965

RESUMO

An increasingly urbanized world is one of the most prominent examples of global environmental change. Across the globe, urban parks are designed and managed in a similar way, resulting in visually pleasing expansions of lawn interspersed with individually planted trees of varying appearances and functional traits. These large urban greenspaces have the capacity to provide various ecosystem services, including those associated with soil physicochemical properties. Our aim was to explore whether soil properties in urban parks diverge underneath vegetation producing labile or recalcitrant litter, and whether the impact is affected by climatic zone (from a boreal to temperate to tropical city). We also compared these properties to those in (semi)natural forests outside the cities to assess the influence of urbanization on plant-trait effects. We showed that vegetation type affected percentage soil organic matter (OM), total carbon (C) and total nitrogen (N), but inconsistently across climatic zones. Plant-trait effects were particularly weak in old parks in the boreal and temperate zones, whereas in young parks in these zones, soils underneath the two tree types accumulated significantly more OM, C and N compared to lawns. Within climatic zones, anthropogenic drivers dominated natural ones, with consistently lower values of organic-matter-related soil properties under trees producing labile or recalcitrant litter in parks compared to forests. The dominating effect of urbanization is also reflected in its ability to homogenize soil properties in parks across the three cities, especially in lawn soils and soils under trees irrespective of functional trait. Our study demonstrates that soil functions that relate to carbon and nitrogen dynamics-even in old urban greenspaces where plant-soil interactions have a long history-clearly diverged from those in natural ecosystems, implying a long-lasting influence of anthropogenic drivers on soil ecosystem services.


Assuntos
Ecossistema , Solo , Florestas , Árvores , Urbanização
7.
J Clin Endocrinol Metab ; 106(7): 2057-2076, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-33710344

RESUMO

CONTEXT: The early events regulating the remodeling program following skeletal muscle damage are poorly understood. OBJECTIVE: The objective of this study was to determine the association between myofibrillar protein synthesis (myoPS) and nuclear factor-kappa B (NF-κB) signaling by nutritionally accelerating the recovery of muscle function following damage. DESIGN, SETTING, PARTICIPANTS, AND INTERVENTIONS: Healthy males and females consumed daily postexercise and prebed protein-polyphenol (PP; n = 9; 4 females) or isocaloric maltodextrin placebo (PLA; n = 9; 3 females) drinks (parallel design) 6 days before and 3 days after 300 unilateral eccentric contractions of the quadriceps during complete dietary control. MAIN OUTCOME MEASURES: Muscle function was assessed daily, and skeletal muscle biopsies were taken after 24, 27, and 36 hours for measurements of myoPS rates using deuterated water, and gene ontology and NF-κB signaling analysis using a quantitative reverse transcription PCR (RT-qPCR) gene array. RESULTS: Eccentric contractions impaired muscle function for 48 hours in PLA intervention, but just for 24 hours in PP intervention (P = 0.047). Eccentric quadricep contractions increased myoPS compared with the control leg during postexercise (24-27 hours; 0.14 ± 0.01 vs 0.11 ± 0.01%·h-1, respectively; P = 0.075) and overnight periods (27-36 hours; 0.10 ± 0.01 vs 0.07 ± 0.01%·h-1, respectively; P = 0.020), but was not further increased by PP drinks (P > 0.05). Protein-polyphenol drinks decreased postexercise and overnight muscle IL1R1 (PLA = 2.8 ± 0.4, PP = 1.1 ± 0.4 and PLA = 1.9 ± 0.4, PP = 0.3 ± 0.4 log2 fold-change, respectively) and IL1RL1 (PLA = 4.9 ± 0.7, PP = 1.6 ± 0.8 and PLA = 3.7 ± 0.6, PP = 0.7 ± 0.7 log2 fold-change, respectively) messenger RNA expression (P < 0.05) and downstream NF-κB signaling compared with PLA. CONCLUSION: Protein-polyphenol drink ingestion likely accelerates recovery of muscle function by attenuating inflammatory NF-κB transcriptional signaling, possibly to reduce aberrant tissue degradation rather than increase myoPS rates.


Assuntos
Bebidas , Mialgia/dietoterapia , Recuperação de Função Fisiológica/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição Esportiva/efeitos dos fármacos , Proteínas na Dieta/administração & dosagem , Feminino , Voluntários Saudáveis , Humanos , Masculino , Contração Muscular/efeitos dos fármacos , Proteínas Musculares/efeitos dos fármacos , Músculo Esquelético/fisiopatologia , Mialgia/fisiopatologia , NF-kappa B/metabolismo , Polifenóis/administração & dosagem , Biossíntese de Proteínas/efeitos dos fármacos , Músculo Quadríceps/fisiopatologia , Treinamento de Força/efeitos adversos , Adulto Jovem
8.
Ticks Tick Borne Dis ; 12(1): 101574, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33074148

RESUMO

Though ticks pose a significant public health risk, until recently, little research had focused on the diversity of ticks and tick-borne diseases in Singapore. To date, only fourteen tick species in five genera have been recorded there. For the first time, Dermacentor auratus is recorded from Singapore from a range of hosts, including humans. DNA sequences are provided at 2 loci, for D. auratus, the cytochrome c oxidase I (COI) for DNA barcoding and the 16S large subunit ribosomal RNA (16S lsu rRNA). The health risk posed by D. auratus in Singapore is discussed.


Assuntos
Distribuição Animal , Dermacentor/fisiologia , Infestações por Carrapato/parasitologia , Animais , Criança , Código de Barras de DNA Taxonômico , DNA Mitocondrial/análise , Dermacentor/enzimologia , Dermacentor/genética , Complexo IV da Cadeia de Transporte de Elétrons/análise , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , RNA Ribossômico 16S/análise , Análise de Sequência de DNA , Singapura
9.
Am J Physiol Endocrinol Metab ; 320(2): E291-E305, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33284089

RESUMO

The contribution of myofibrillar protein synthesis (MyoPS) to recovery from skeletal muscle damage in humans is unknown. Recreationally active men and women consumed a daily protein-polyphenol beverage targeted at increasing amino acid availability and reducing inflammation (PPB; n = 9), both known to affect MyoPS, or an isocaloric placebo (PLA; n = 9) during 168 h of recovery from 300 maximal unilateral eccentric contractions (EE). Muscle function was assessed daily. Muscle biopsies were collected for 24, 27, 36, 72, and 168 h for MyoPS measurements using 2H2O and expression of 224 genes using RT-qPCR and pathway analysis. PPB improved recovery of muscle function, which was impaired for 5 days after EE in PLA (interaction P < 0.05). Acute postprandial MyoPS rates were unaffected by nutritional intervention (24-27 h). EE increased overnight (27-36 h) MyoPS versus the control leg (PLA: 33 ± 19%; PPB: 79 ± 25%; leg P < 0.01), and PPB tended to increase this further (interaction P = 0.06). Daily MyoPS rates were greater with PPB between 72 and 168 h after EE, albeit after function had recovered. Inflammatory and regenerative signaling pathways were dramatically upregulated and clustered after EE but were unaffected by nutritional intervention. These results suggest that accelerated recovery from EE is not explained by elevated MyoPS or suppression of inflammation.NEW & NOTEWORTHY The present study investigated the contribution of myofibrillar protein synthesis (MyoPS) and associated gene signaling to recovery from 300 muscle-damaging, eccentric contractions. Measured with 2H2O, MyoPS rates were elevated during recovery and observed alongside expression of inflammatory and regenerative signaling pathways. A nutritional intervention accelerated recovery; however, MyoPS and gene signaling were unchanged compared with placebo. These data indicate that MyoPS and associated signaling do not explain accelerated recovery from muscle damage.


Assuntos
Inflamação/genética , Músculo Esquelético/fisiologia , Doenças Musculares/reabilitação , Recuperação de Função Fisiológica/fisiologia , Regeneração/genética , Adulto , Traumatismos em Atletas/genética , Traumatismos em Atletas/metabolismo , Traumatismos em Atletas/fisiopatologia , Traumatismos em Atletas/reabilitação , Exercício Físico/fisiologia , Feminino , Expressão Gênica/fisiologia , Humanos , Inflamação/metabolismo , Inflamação/patologia , Masculino , Proteínas Musculares/biossíntese , Proteínas Musculares/genética , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Doenças Musculares/etiologia , Doenças Musculares/genética , Doenças Musculares/metabolismo , Miofibrilas/metabolismo , Miofibrilas/patologia , Biossíntese de Proteínas/genética , Treinamento de Força/efeitos adversos , Transdução de Sinais/genética , Adulto Jovem
10.
Evol Appl ; 13(9): 2300-2315, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33005225

RESUMO

The red junglefowl Gallus gallus is the ancestor of the domestic chicken and arguably the most important bird species on Earth. Continual gene flow between domestic and wild populations has compromised its gene pool, especially since the last century when human encroachment and habitat loss would have led to increased contact opportunities. We present the first combined genomic and morphological admixture assessment of a native population of red junglefowl, sampled from recolonized parts of its former range in Singapore, partly using whole genomes resequenced from dozens of individuals. Crucially, this population was genomically anchored to museum samples from adjacent Peninsular Malaysia collected ~110-150 years ago to infer the magnitude of modern domestic introgression across individuals. We detected a strong feral-wild genomic continuum with varying levels of domestic introgression in different subpopulations across Singapore. Using a trait scoring scheme, we determined morphological thresholds that can be used by conservation managers to successfully identify individuals with low levels of domestic introgression, and selected traits that were particularly useful for predicting domesticity in genomic profiles. Our study underscores the utility of combined genomic and morphological approaches in population management and suggests a way forward to safeguard the allelic integrity of wild red junglefowl in perpetuity.

11.
Int J Parasitol Parasites Wildl ; 12: 29-33, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32420022

RESUMO

Bat flies are highly-specialized, hematophagous arthropods that are globally ubiquitous. There is little published research on bat flies (Diptera: Nycteribiidae) in Singapore and understanding the diversity of nycteribiids, host association and infestation rates can provide insight into this host-ectoparasite relationship. Nycteribiids were collected from bats trapped in Singapore (2011-2016) and identified using morphological keys. Host-ectoparasite relationships were investigated with logistic regression and Bayesian poisson regression. Nycteribiids were found to be monoxenously associated with their host bat species and host age, sex, species, and BBCI appear to contribute to differences in prevalence and intensity. Differences in host specificity between bat fly species in Singapore and their conspecifics in less disturbed habitats with higher bat biodiversity, such as Malaysia, Philippines and Thailand, suggest that the high host specificity in Singapore derives from the paucity of suitable hosts and abundance of single species roosts and not from their coevolved restrictions to them.

12.
Phys Rev E ; 101(4-1): 042112, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32422830

RESUMO

We study a variation of the trapping reaction, A+B→A, in which both the traps (A) and the particles (B) undergo diffusion, and the traps upon meeting react according to A+A→0 or A. This two-species reaction-diffusion system is known to exhibit a nontrivial decay exponent for the B particles, and recently renormalization group methods have predicted an anomalous dimension in the BB correlation function. To test these predictions, we develop a computer simulation method, motivated by the technique of Mehra and Grassberger [Phys. Rev. E 65, 050101(R) (2002)1063-651X10.1103/PhysRevE.65.050101], that determines the complete probability distribution of the B particles for a given realization of the A-particle dynamics, thus providing a significant increase in the quality of statistics. Our numerical results indeed reveal the anomalous dimension predicted by the renormalization group, and compare well quantitatively to precisely known values in cases where the problem can be related to a four-walker problem.

13.
BMC Med Genomics ; 13(1): 64, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32312268

RESUMO

BACKGROUND: Circular RNAs are non-coding RNA molecules with gene regulatory potential that have been associated with several human diseases. They are stable and present in the circulation, making them excellent candidates for biomarkers of disease. Despite their promise as biomarkers or future therapeutic targets, information on their expression and functionality in human pancreatic islets is a relatively unexplored subject. METHODS: Here we aimed to produce an enriched circRNAome profile for human pancreatic islets by CircleSeq, and to explore the relationship between circRNA expression, diabetes status, genotype at T2D risk loci and measures of glycaemia (insulin secretory index; SI and HbA1c) in human islet preparations from healthy control donors and donors with type 2 diabetes using ANOVA or linear regression as appropriate. We also assessed the effect of elevated glucose, cytokine and lipid and hypoxia on circRNA expression in the human beta cell line EndoC-ßH1. RESULTS: We identified over 2600 circRNAs present in human islets. Of the five most abundant circRNAs in human islets, four (circCIRBP, circZKSCAN, circRPH3AL and circCAMSAP1) demonstrated marked associations with diabetes status. CircCIRBP demonstrated an association with insulin secretory index in isolated human islets and circCIRBP and circRPH3AL displayed altered expression with elevated fatty acid in treated EndoC-ßH1 cells. CircCAMSAP1 was also noted to be associated with T2D status in human peripheral blood. No associations between circRNA expression and genotype at T2D risk loci were identified in our samples. CONCLUSIONS: Our data suggest that circRNAs are abundantly expressed in human islets, and that some are differentially regulated in the islets of donors with type 2 diabetes. Some islet circRNAs are also expressed in peripheral blood and the expression of one, circCAMSAP1, correlates with diabetes status. These findings highlight the potential of circRNAs as biomarkers for T2D.


Assuntos
Diabetes Mellitus Tipo 2/patologia , Marcadores Genéticos , Intolerância à Glucose/patologia , Ilhotas Pancreáticas/patologia , RNA Circular/análise , RNA Circular/genética , Adulto , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/genética , Feminino , Intolerância à Glucose/sangue , Intolerância à Glucose/genética , Humanos , Secreção de Insulina , Ilhotas Pancreáticas/metabolismo , Masculino
14.
Am J Physiol Endocrinol Metab ; 318(2): E117-E130, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31743039

RESUMO

Short-term muscle disuse has been reported to lower both postabsorptive and postprandial myofibrillar protein synthesis rates. This study assessed the impact of disuse on daily myofibrillar protein synthesis rates following short-term (2 and 7 days) muscle disuse under free living conditions. Thirteen healthy young men (age: 20 ± 1 yr; BMI: 23 ± 1 kg/m-2) underwent 7 days of unilateral leg immobilization via a knee brace, with the nonimmobilized leg acting as a control. Four days before immobilization participants ingested 400 mL of 70% deuterated water, with 50-mL doses consumed daily thereafter. Upper leg bilateral MRI scans and muscle biopsies were collected before and after 2 and 7 days of immobilization to determine quadriceps volume and daily myofibrillar protein synthesis rates. Immobilization reduced quadriceps volume in the immobilized leg by 1.7 ± 0.3 and 6.7 ± 0.6% after 2 and 7 days, respectively, with no changes in the control leg. Over the 1-wk immobilization period, myofibrillar protein synthesis rates were 36 ± 4% lower in the immobilized (0.81 ± 0.04%/day) compared with the control (1.26 ± 0.04%/day) leg (P < 0.001). Myofibrillar protein synthesis rates in the control leg did not change over time (P = 0.775), but in the immobilized leg they were numerically lower during the 0- to 2-day period (16 ± 6%, 1.11 ± 0.09%/day, P = 0.153) and were significantly lower during the 2- to 7-day period (44 ± 5%, 0.70 ± 0.06%/day, P < 0.001) when compared with the control leg. We conclude that 1 wk of muscle disuse induces a rapid and sustained decline in daily myofibrillar protein synthesis rates in healthy young men.


Assuntos
Proteínas Musculares/biossíntese , Músculo Esquelético/metabolismo , Atrofia Muscular/metabolismo , Miofibrilas/metabolismo , Água Corporal/metabolismo , Dieta , Exercício Físico , Expressão Gênica , Voluntários Saudáveis , Humanos , Imobilização , Cinética , Perna (Membro) , Imageamento por Ressonância Magnética , Masculino , Proteínas Musculares/genética , Força Muscular , Músculo Esquelético/diagnóstico por imagem , Atrofia Muscular/diagnóstico por imagem , Músculo Quadríceps/diagnóstico por imagem , Músculo Quadríceps/metabolismo , Adulto Jovem
15.
Exp Gerontol ; 128: 110736, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31521722

RESUMO

Dietary restriction (DR) represents one of the most reproducible interventions to extend lifespan and improve health outcomes in a wide range of species, but substantial variability in DR response has been observed, both between and within species. The mechanisms underlying this variation in effect are still not well characterised. Splicing regulatory factors have been implicated in the pathways linked with DR-induced longevity in C. elegans and are associated with lifespan itself in mice and humans. We used qRT-PCR to measure the expression levels of a panel of 16 age- and lifespan-associated splicing regulatory factors in brain, heart and kidney derived from three recombinant inbred strains of mice with variable lifespan responses to short-term (2 months) or long-term (10 months) 40% DR to determine their relationship to DR-induced longevity. We identified 3 patterns of association; i) splicing factors associated with DR alone, ii) splicing factors associated with strain alone or iii) splicing factors associated with both DR and strain. Tissue specific variation was noted in response to short-term or long-term DR, with the majority of effects noted in brain following long-term DR in the positive responder strain TejJ89. Association in heart and kidney were less evident, and occurred following short-term DR. Splicing factors associated with both DR and strain may be mechanistically involved in strain-specific differences in response to DR. We provide here evidence concordant with a role for some splicing factors in the lifespan modulatory effects of DR across different mouse strains and in different tissues.


Assuntos
Processamento Alternativo/fisiologia , Restrição Calórica , Longevidade , Animais , Encéfalo/metabolismo , Rim/metabolismo , Camundongos , Miocárdio/metabolismo , Especificidade de Órgãos , Especificidade da Espécie
16.
Biogerontology ; 20(5): 649-663, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31292793

RESUMO

Dysregulation of splicing factor expression is emerging as a driver of human ageing; levels of transcripts encoding splicing regulators have previously been implicated in ageing and cellular senescence both in vitro and in vivo. We measured the expression levels of an a priori panel of 20 age- or senescence-associated splicing factors by qRT-PCR in peripheral blood samples from the InCHIANTI Study of Aging, and assessed longitudinal relationships with human ageing phenotypes (cognitive decline and physical ability) using multivariate linear regression. AKAP17A, HNRNPA0 and HNRNPM transcript levels were all predictively associated with severe decline in MMSE score (p = 0.007, 0.001 and 0.008 respectively). Further analyses also found expression of these genes was associated with a performance decline in two other cognitive measures; the Trail Making Test and the Purdue Pegboard Test. AKAP17A was nominally associated with a decline in mean hand-grip strength (p = 0.023), and further analyses found nominal associations with two other physical ability measures; the Epidemiologic Studies of the Elderly-Short Physical Performance Battery and calculated speed (m/s) during a timed 400 m fast walking test. These data add weight to the hypothesis that splicing dyregulation may contribute to the development of some ageing phenotypes in the human population.


Assuntos
Envelhecimento/fisiologia , Antígenos/genética , Disfunção Cognitiva , Força da Mão/fisiologia , Ribonucleoproteínas Nucleares Heterogêneas Grupo M/genética , Ribonucleoproteínas Nucleares Heterogêneas/genética , Glicoproteínas de Membrana/genética , Fatores de Processamento de RNA , Velocidade de Caminhada/genética , Idoso , Senescência Celular/fisiologia , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/genética , Correlação de Dados , Feminino , Humanos , Masculino , Testes de Estado Mental e Demência , Desempenho Físico Funcional , Valor Preditivo dos Testes , Fatores de Processamento de RNA/sangue , Fatores de Processamento de RNA/genética
17.
BMC Cancer ; 19(1): 86, 2019 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-30658617

RESUMO

BACKGROUND: Obesity increases breast cancer (BC) risk in post-menopausal women by mostly unknown molecular mechanisms which may partly be regulated by microRNAs (miRNAs). METHODS: We isolated RNA from paired benign and malignant biopsies from 83 BC patients and determined miRNA profiles in samples from 12 women at the extremes of the BMI distribution by RNA-seq. Candidates were validated in all samples. Associations between miR-10b expression and validated target transcript levels, and effects of targeted manipulation of miR-10b levels in a primary BC cell line on proliferation and invasion potential, were explored. RESULTS: Of the 148 miRNAs robustly expressed in breast tissues, the levels of miR-21, miR-10b, miR-451a, miR-30c, and miR-378d were significantly associated with presence of cancer. Of these, miR-10b showed a stronger down-regulation in the tumors of the obese subjects, as opposed to the lean. In ductal but not lobular tumors, significant inverse correlations were observed between the tumor levels of miR-10b and miR-30c and the mRNA levels of cancer-relevant target genes SRSF1, PIEZO1, MAPRE1, CDKN2A, TP-53 and TRA2B, as well as tumor grade. Suppression of miR-10b levels in BT-549 primary BC-derived cells increased cell proliferation and invasive capacity, while exogenous miR-10b mimic decreased invasion. Manipulation of miR-10b levels also inversely affected the mRNA levels of miR-10b targets BCL2L11, PIEZO1 and NCOR2. CONCLUSIONS: Our findings suggest that miR-10b may be a mediator between obesity and cancer in post-menopausal women, regulating several known cancer-relevant genes. MiR-10b expression may have diagnostic and therapeutic implications for the incidence and prognosis of BC in obese women.


Assuntos
Neoplasias da Mama/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Obesidade/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/patologia , Regulação para Baixo , Feminino , Perfilação da Expressão Gênica , Humanos , Pessoa de Meia-Idade , Prognóstico , Células Tumorais Cultivadas
18.
BMJ Open ; 8(2): e018742, 2018 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-29431133

RESUMO

OBJECTIVE: Bisphenol A (BPA) has been associated with adverse human health outcomes and exposure to this compound is near-ubiquitous in the Western world. We aimed to examine whether self-moderation of BPA exposure is possible by altering diet in a real-world setting. DESIGN: An Engaged Research dietary intervention study designed, implemented and analysed by healthy teenagers from six schools and undertaken in their own homes. PARTICIPANTS: A total of 94 students aged between 17 and 19 years from schools in the South West of the UK provided diet diaries and urine samples for analysis. INTERVENTION: Researcher participants designed a set of literature-informed guidelines for the reduction of dietary BPA to be followed for 7 days. MAIN OUTCOME MEASURES: Creatinine-adjusted urinary BPA levels were taken before and after the intervention. Information on packaging and food/drink ingested was used to calculate a BPA risk score for anticipated exposure. A qualitative analysis was carried out to identify themes addressing long-term sustainability of the diet. RESULTS: BPA was detected in urine of 86% of participants at baseline at a median value of 1.22 ng/mL (IQR 1.99). No effect of the intervention diet on BPA levels was identified overall (P=0.25), but there was a positive association in those participants who showed a drop in urinary BPA concentration postintervention and their initial BPA level (P=0.003). Qualitative analysis identified themes around feelings of lifestyle restriction and the inadequacy of current labelling practices. CONCLUSIONS: We found no evidence in this self-administered intervention study that it was possible to moderate BPA exposure by diet in a real-world setting. Furthermore, our study participants indicated that they would be unlikely to sustain such a diet long term, due to the difficulty in identifying BPA-free foods.


Assuntos
Compostos Benzidrílicos/urina , Exposição Dietética/análise , Estilo de Vida , Fenóis/urina , Adolescente , Feminino , Humanos , Modelos Lineares , Modelos Logísticos , Masculino , Medição de Risco , Estudantes , Reino Unido , Adulto Jovem
19.
Clin Sci (Lond) ; 132(3): 313-325, 2018 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-29330351

RESUMO

Coronary heart disease (CHD) is a leading cause of morbidity in people over 65 years of age; >40% of all deaths are due to this condition. The association between increasing age and CHD is well documented; the accumulation of senescent cells in cardiac and vascular tissues may represent one factor underpinning this observation. We aimed to identify senescence-related expression changes in primary human senescent cardiomyocytes and endothelial cells and to relate transcript expression in peripheral blood leucocytes to prevalent and incident CHD in the InCHIANTI study of aging. We quantified splicing factor expression and splicing patterns of candidate transcripts in proliferative and senescent later passage endothelial cells and cardiomyocytes using qRTPCR. Senescence-associated isoforms also expressed in peripheral blood leucocytes were then examined for associations with CHD status in 134 pairs of age, sex and BMI-matched CHD cases and controls. Splicing factor expression was dysregulated in senescent cardiomyocytes, as previously reported for endothelial cells, as was the expression of alternatively expressed cardiac and vascular candidate genes in both cell types. We found nominal associations between the expression of VEGFA156b and FNI-EIIIIA isoforms in peripheral blood mRNA and CHD status. Dysregulated splicing factor expression is a key feature of senescent cardiomyocytes and endothelial cells. Altered splicing of key cardiac or endothelial genes may contribute to the risk of CHD in the human population.


Assuntos
Doença das Coronárias/epidemiologia , Doença das Coronárias/genética , Células Endoteliais/citologia , Fator A de Crescimento do Endotélio Vascular/genética , Processamento Alternativo/genética , Células Cultivadas , Senescência Celular/genética , Endotélio Vascular , Humanos , Incidência , Isoformas de Proteínas/genética , RNA Interferente Pequeno/genética
20.
Emerg Infect Dis ; 24(1): 114-117, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29260678

RESUMO

To determine whether fruit bats in Singapore have been exposed to filoviruses, we screened 409 serum samples from bats of 3 species by using a multiplex assay that detects antibodies against filoviruses. Positive samples reacted with glycoproteins from Bundibugyo, Ebola, and Sudan viruses, indicating filovirus circulation among bats in Southeast Asia.


Assuntos
Quirópteros/sangue , Quirópteros/virologia , Ebolavirus , Marburgvirus , Proteínas do Envelope Viral/sangue , Animais , Glicoproteínas/sangue , Glicoproteínas/genética , Glicoproteínas/isolamento & purificação , Estudos Soroepidemiológicos , Singapura/epidemiologia
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