RESUMO
Time-limited eating is a dietary intervention whereby eating is limited to a specific window of time during the day. The usual eating windows of adults, and how these can be manipulated for dietary interventions, is well documented. However, there is a paucity of data on eating windows of young people, the manipulation of which may be a useful intervention for reducing obesity. This paper reviewed the existing literature on the eating windows of children and adolescents, aged 5-18 years, plus clock times of first and last intakes and variations by subgroup. Two databases (Medline and Embase) were searched for eligible papers published between February 2013 and February 2023, with forward searching of the citation network of included studies on Web of Science. Articles were screened, and data extracted, in duplicate by two independent reviewers. Ten studies were included, with both observational and experimental designs. Narrative synthesis showed large variations in eating windows with average values ranging from 9.7 h to 16.4 h. Meta-analysis, of five studies, showed a pooled mean daily eating window of 11.3 h (95% CI 11.0, 11.7). Large variations in eating windows exist across different study populations; however, the pooled data suggest that it may be possible to design time-limited eating interventions in paediatric populations aimed at reducing eating windows. Further high-quality research, investigating eating windows and subsequent associations with health outcomes, is needed.
Assuntos
Comportamento Alimentar , Humanos , Adolescente , Criança , Pré-Escolar , Fatores de Tempo , Feminino , Masculino , Ingestão de Alimentos/fisiologiaRESUMO
Prediction of RNA structure from sequence remains an unsolved problem, and progress has been slowed by a paucity of experimental data. Here, we present Ribonanza, a dataset of chemical mapping measurements on two million diverse RNA sequences collected through Eterna and other crowdsourced initiatives. Ribonanza measurements enabled solicitation, training, and prospective evaluation of diverse deep neural networks through a Kaggle challenge, followed by distillation into a single, self-contained model called RibonanzaNet. When fine tuned on auxiliary datasets, RibonanzaNet achieves state-of-the-art performance in modeling experimental sequence dropout, RNA hydrolytic degradation, and RNA secondary structure, with implications for modeling RNA tertiary structure.
RESUMO
The ribosome is a ribonucleoprotein complex found in all domains of life. Its role is to catalyze protein synthesis, the messenger RNA (mRNA)-templated formation of amide bonds between α-amino acid monomers. Amide bond formation occurs within a highly conserved region of the large ribosomal subunit known as the peptidyl transferase center (PTC). Here we describe the step-wise design and characterization of mini-PTC 1.1, a 284-nucleotide RNA that recapitulates many essential features of the Escherichia coli PTC. Mini-PTC 1.1 folds into a PTC-like structure under physiological conditions, even in the absence of r-proteins, and engages small molecule analogs of A- and P-site tRNAs. The sequence of mini-PTC 1.1 differs from the wild type E. coli ribosome at 12 nucleotides that were installed by a cohort of citizen scientists using the on-line video game Eterna. These base changes improve both the secondary structure and tertiary folding of mini-PTC 1.1 as well as its ability to bind small molecule substrate analogs. Here, the combined input from Eterna citizen-scientists and RNA structural analysis provides a robust workflow for the design of a minimal PTC that recapitulates many features of an intact ribosome.
Assuntos
Escherichia coli , Ribossomos , Humanos , Amidas , Escherichia coli/genética , Escherichia coli/metabolismo , Peptidil Transferases/genética , Peptidil Transferases/química , Ribossomos/metabolismo , RNA de Transferência/metabolismoRESUMO
Functional design of ribosomes with mutant ribosomal RNA (rRNA) can expand opportunities for understanding molecular translation, building cells from the bottom-up, and engineering ribosomes with altered capabilities. However, such efforts are hampered by cell viability constraints, an enormous combinatorial sequence space, and limitations on large-scale, 3D design of RNA structures and functions. To address these challenges, we develop an integrated community science and experimental screening approach for rational design of ribosomes. This approach couples Eterna, an online video game that crowdsources RNA sequence design to community scientists in the form of puzzles, with in vitro ribosome synthesis, assembly, and translation in multiple design-build-test-learn cycles. We apply our framework to discover mutant rRNA sequences that improve protein synthesis in vitro and cell growth in vivo, relative to wild type ribosomes, under diverse environmental conditions. This work provides insights into rRNA sequence-function relationships and has implications for synthetic biology.
Assuntos
RNA Ribossômico , Ribossomos , Ribossomos/metabolismo , RNA Ribossômico/metabolismo , Biologia Sintética , Fenótipo , Proteínas Ribossômicas/metabolismoRESUMO
INTRODUCTION: Bariatric surgery is an effective method of controlling glycaemia in patients with type 2 diabetes mellitus (T2DM) and obesity. Long-term studies suggest that although glycaemic control remains good, only 20%-40% of patients will maintain remission according to the American Diabetes Association criteria. PURPOSE: This trial aims to examine the safety and efficacy of combining Roux-en-Y gastric bypass or sleeve gastrectomy with goal-directed medical therapy to improve long-term glycaemic control of T2DM. METHODS AND ANALYSIS: This prospective, open-label multicentre randomised controlled trial (RCT) will recruit 150 patients with obesity and T2DM from tertiary care obesity centres. Patients will be randomised 1:1 to receive either bariatric surgery and standard medical care or bariatric surgery and intensive goal-directed medical therapy, titrated to specific targets for glycated haemoglobin (HbA1c), blood pressure (BP) and low-density lipoproteins (LDL) cholesterol. The primary endpoints are the proportion of patients in each arm with an HbA1c<6.5% (48 mmol/mol) at 1 year and the proportion of patients in each arm achieving the composite endpoint of HbA1c<6.5% (48 mmol/mol), BP<130/80 mm Hg and LDL<2.6 mmol/L at 5 years. ETHICS AND DISSEMINATION: The local institutional review board approved this study. This study represents the first RCT to examine the safety and efficacy of combining bariatric surgery with intensive medical therapy compared with bariatric surgery and usual care for long-term diabetes control. TRIAL REGISTRATION NUMBER: NCT04432025.
Assuntos
Cirurgia Bariátrica , Diabetes Mellitus Tipo 2 , Derivação Gástrica , Obesidade Mórbida , Cirurgia Bariátrica/métodos , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/cirurgia , Derivação Gástrica/métodos , Hemoglobinas Glicadas , Humanos , Obesidade/complicações , Obesidade/cirurgia , Obesidade Mórbida/cirurgia , Resultado do TratamentoRESUMO
The rapid spread of COVID-19 is motivating development of antivirals targeting conserved SARS-CoV-2 molecular machinery. The SARS-CoV-2 genome includes conserved RNA elements that offer potential small-molecule drug targets, but most of their 3D structures have not been experimentally characterized. Here, we provide a compilation of chemical mapping data from our and other labs, secondary structure models, and 3D model ensembles based on Rosetta's FARFAR2 algorithm for SARS-CoV-2 RNA regions including the individual stems SL1-8 in the extended 5' UTR; the reverse complement of the 5' UTR SL1-4; the frameshift stimulating element (FSE); and the extended pseudoknot, hypervariable region, and s2m of the 3' UTR. For eleven of these elements (the stems in SL1-8, reverse complement of SL1-4, FSE, s2m and 3' UTR pseudoknot), modeling convergence supports the accuracy of predicted low energy states; subsequent cryo-EM characterization of the FSE confirms modeling accuracy. To aid efforts to discover small molecule RNA binders guided by computational models, we provide a second set of similarly prepared models for RNA riboswitches that bind small molecules. Both datasets ('FARFAR2-SARS-CoV-2', https://github.com/DasLab/FARFAR2-SARS-CoV-2; and 'FARFAR2-Apo-Riboswitch', at https://github.com/DasLab/FARFAR2-Apo-Riboswitch') include up to 400 models for each RNA element, which may facilitate drug discovery approaches targeting dynamic ensembles of RNA molecules.
Assuntos
Consenso , Modelos Moleculares , Conformação de Ácido Nucleico , RNA Viral/química , SARS-CoV-2/genética , Regiões 3' não Traduzidas/genética , Regiões 5' não Traduzidas/genética , Algoritmos , Aptâmeros de Nucleotídeos/genética , Sequência de Bases , Sítios de Ligação , Microscopia Crioeletrônica , Conjuntos de Dados como Assunto , Avaliação Pré-Clínica de Medicamentos/métodos , Mudança da Fase de Leitura do Gene Ribossômico/genética , Genoma Viral/genética , Estabilidade de RNA , RNA Viral/genética , Reprodutibilidade dos Testes , Riboswitch/genética , Bibliotecas de Moléculas Pequenas/químicaRESUMO
Homopolymeric adenosine RNA plays numerous roles in both cells and noncellular genetic material. We report herein an unusual poly(A) signature in chemical mapping data generated by the Eterna Massive Open Laboratory. Poly(A) sequences of length seven or more show unexpected results in the selective 2'-hydroxyl acylation read out by primer extension (SHAPE) and dimethyl sulfate (DMS) chemical probing. This unusual signature first appears in poly(A) sequences of length seven and grows to its maximum strength at length â¼10. In a long poly(A) sequence, the substitution of a single A by any other nucleotide disrupts the signature, but only for the 6 or so nucleotides on the 5' side of the substitution.