RESUMO
Exon junction complexes (EJCs) are deposited on mRNAs during splicing and displaced by ribosomes during the pioneer round of translation. Nonsense-mediated mRNA decay (NMD) degrades EJC-bound mRNA, but the lack of suitable methodology has prevented the identification of other degradation pathways. Here, we show that the RNA degradomes of Arabidopsis (Arabidopsis thaliana), rice (Oryza sativa), worm (Caenorhabditis elegans), and human (Homo sapiens) cells exhibit an enrichment of 5' monophosphate (5'P) ends of degradation intermediates that map to the canonical EJC region. Inhibition of 5' to 3' exoribonuclease activity and overexpression of an EJC disassembly factor in Arabidopsis reduced the accumulation of these 5'P ends, supporting the notion that they are in vivo EJC footprints. Hundreds of Arabidopsis NMD targets possess evident EJC footprints, validating their degradation during the pioneer round of translation. In addition to premature termination codons, plant microRNAs can also direct the degradation of EJC-bound mRNAs. However, the production of EJC footprints from NMD but not microRNA targets requires the NMD factor SUPPRESSOR WITH MORPHOLOGICAL EFFECT ON GENITALIA PROTEIN7. Together, our results demonstrating in vivo EJC footprinting in Arabidopsis unravel the composition of the RNA degradome and provide a new avenue for studying NMD and other mechanisms targeting EJC-bound mRNAs for degradation before steady state translation.
Assuntos
Éxons/genética , Biossíntese de Proteínas/genética , Estabilidade de RNA/genética , Regiões 3' não Traduzidas/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Códon sem Sentido/genética , Exorribonucleases/metabolismo , Genes de Plantas , MicroRNAs/genética , MicroRNAs/metabolismo , Degradação do RNAm Mediada por Códon sem Sentido/genética , Oryza/genéticaRESUMO
High-throughput approaches for profiling the 5' ends of RNA degradation intermediates on a genome-wide scale are frequently applied to analyze and validate cleavage sites guided by microRNAs (miRNAs). However, the complexity of the RNA degradome other than miRNA targets is currently largely uncharacterized, and this limits the application of RNA degradome studies. We conducted a global analysis of 5'-truncated mRNA ends that mapped to coding sequences (CDSs) of Arabidopsis thaliana, rice (Oryza sativa), and soybean (Glycine max). Based on this analysis, we provide multiple lines of evidence to show that the plant RNA degradome contains in vivo ribosome-protected mRNA fragments. We observed a 3-nucleotide periodicity in the position of free 5' RNA ends and a bias toward the translational frame. By examining conserved peptide upstream open reading frames (uORFs) of Arabidopsis and rice, we found a predominance of 5' termini of RNA degradation intermediates that were separated by a length equal to a ribosome-protected mRNA fragment. Through the analysis of RNA degradome data, we discovered uORFs and CDS regions potentially associated with stacked ribosomes in Arabidopsis. Furthermore, our analysis of RNA degradome data suggested that the binding of Arabidopsis ARGONAUTE7 to a noncleavable target site of miR390 might directly hinder ribosome movement. This work demonstrates an alternative use of RNA degradome data in the study of ribosome stalling.
Assuntos
Oryza/genética , Oryza/metabolismo , RNA de Plantas/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , MicroRNAs/genética , Fases de Leitura Aberta/genética , Ribossomos/genética , Ribossomos/metabolismo , Análise de Sequência de RNA/métodos , Glycine max/genética , Glycine max/metabolismoRESUMO
BACKGROUND: Degradation is essential for RNA maturation, turnover, and quality control. RNA degradome sequencing that integrates a modified 5'-rapid amplification of cDNA ends protocol with next-generation sequencing technologies is a high-throughput approach for profiling the 5'-end of uncapped RNA fragments on a genome-wide scale. The primary application of degradome sequencing has been to identify the truncated transcripts that result from endonucleolytic cleavage guided by microRNAs or small interfering RNAs. As many pathways are involved in RNA degradation, degradome data should contain other RNA species besides the cleavage remnants of small RNA targets. Nevertheless, no systematic approaches have been established to explore the hidden complexity of plant degradome. RESULTS: Through analyzing Arabidopsis and rice RNA degradome data, we recovered 11 short motifs adjacent to predominant and abundant uncapped 5'-ends. Uncapped ends associated with several of these short motifs were more prevalent than those targeted by most miRNA families especially in the 3' untranslated region of transcripts. Through genome-wide analysis, five motifs showed preferential accumulation of uncapped 5'-ends at the same position in Arabidopsis and rice. Moreover, the association of uncapped 5'-ends with a CA-repeat motif and a motif recognized by Pumilio/Fem-3 mRNA binding factor (PUF) proteins was also found in non-plant species, suggesting that common mechanisms are present across species. Based on these motifs, potential sources of RNA ends that constitute degradome data were proposed and further examined. The 5'-end of small nucleolar RNAs could be precisely captured by degradome sequencing. Position-specific enrichment of uncapped 5'-ends was seen upstream of motifs recognized by several RNA binding proteins especially for the binding site of PUF proteins. False uncapped 5'-ends produced from capped transcripts through non-specific PCR amplification were common artifacts among degradome datasets. CONCLUSIONS: The complexity of plant RNA degradome data revealed in this study may contribute to the alternative applications of degradome in RNA research.
Assuntos
Arabidopsis/genética , Oryza/genética , Estabilidade de RNA , RNA de Plantas/metabolismo , Regiões 3' não Traduzidas , Regiões 5' não Traduzidas , Sequência de Bases , Sítios de Ligação , Genoma de Planta , MicroRNAs/química , MicroRNAs/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Clivagem do RNA , RNA de Plantas/química , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Análise de Sequência de RNARESUMO
Domestic rabbits (Oryctolagus cuniculus) are the fourth most common species admitted to the British Columbia Society for the Prevention of Cruelty to Animals (BC SPCA) shelter system. However, shelter data analysis has largely focused on cats and dogs and little is known about the population dynamics of rabbits in shelters. We analyzed five years of rabbit records (n = 1567) at the BC SPCA to identify trends in intake and predictors of length of stay (LOS) of rabbits. The majority of rabbits were surrendered by their owners (40.2%), with most rabbits being surrendered for human-related reasons (96.9%). Overall, rabbit intakes decreased over the study period. When analyzing by month of intake, rabbit intakes were found to be the highest in May. Most rabbits in our data were adults (46.7%), non-brachycephalic (66.7%), erect-eared (82.5%), short-furred (76.2%), and subsequently adopted (80.3%). The median LOS of rabbits was 29 days, highlighting the pressing need to improve their time to adoption. A linear model was constructed to identify predictors of LOS of adopted rabbits (n = 1203) and revealed that intake year, intake month, source of intake, age, cephalic type, and breed size significantly predicted time to adoption for rabbits (F(37, 1165) = 7.95, p < 2.2e-16, adjusted R2 = 0.18). These findings help characterize shelter population dynamics for rabbits, shed light on the challenges associated with unwanted rabbits, and offer a foundation for animal shelters to design programs and marketing strategies tailored to reduce LOS of rabbits with particular characteristics. Shelter rabbits represent an understudied population and our study highlights the importance of further research in companion rabbits.
Assuntos
Bem-Estar do Animal , Animais , Coelhos , Colúmbia Britânica , Masculino , Feminino , HumanosRESUMO
A safety evaluation was performed of Symbiota®, which is made by a proprietary anaerobic fermentation process of soybean with multistrains of probiotics and a yeast. The battery of genotoxicity studies showed that Symbiota® has no genotoxic effects. Safety and tolerability were further assessed by acute or repeated dose 28- and 90-day rodent studies, and no alterations in clinical observations, ophthalmological examination, blood chemistry, urinalysis, or hematology were observed between the control group and the different dosing groups (1.5, 5, and 15 mL/kg/day). There were no adverse effects on specific tissues or organs in terms of weight and histopathology. Importantly, the Symbiota® treatment did not perturb hormones and other endocrine-related endpoints. Of note, the No-Observed-Adverse-Effect-Level was determined to be 15 mL/kg/day in rats. Moreover, a randomized, double-blind, placebo-controlled clinical trial was recently conducted with healthy volunteers who consumed 8 mL/day of placebo or Symbiota® for 8 weeks. Only mild adverse events were reported in both groups, and the blood chemistry and blood cell profiles were also similar between the two groups. In summary, this study concluded that the oral consumption of Symbiota® at 8 mL/day by the general population does not pose any human health concerns.
RESUMO
Cancer immunotherapy has been regarded as a promising strategy for cancer therapy by blocking immune checkpoints and evoking immunity to fight cancer, but its efficacy seems to be heterogeneous among patients. Manipulating the gut microbiota is a potential strategy for enhancing the efficacy of immunotherapy. Here, we report that MS-20, also known as "Symbiota®", a postbiotic that comprises abundant microbial metabolites generated from a soybean-based medium fermented with multiple strains of probiotics and yeast, inhibited colon and lung cancer growth in combination with an anti-programmed cell death 1 (PD1) antibody in xenograft mouse models. Mechanistically, MS-20 remodeled the immunological tumor microenvironment by increasing effector CD8+ T cells and downregulating PD1 expression, which were mediated by the gut microbiota. Fecal microbiota transplantation (FMT) from mice receiving MS-20 treatment to recipient mice increased CD8+ T-cell infiltration into the tumor microenvironment and significantly improved antitumor activity when combined with anti-PD1 therapy. Notably, the abundance of Ruminococcus bromii, which increased following MS-20 treatment, was positively associated with a reduced tumor burden and CD8+ T-cell infiltration in vivo. Furthermore, an ex vivo study revealed that MS-20 could alter the composition of the microbiota in cancer patients, resulting in distinct metabolic pathways associated with favorable responses to immunotherapy. Overall, MS-20 could act as a promising adjuvant agent for enhancing the efficacy of immune checkpoint-mediated antitumor therapy.
Assuntos
Linfócitos T CD8-Positivos , Microbioma Gastrointestinal , Receptor de Morte Celular Programada 1 , Microambiente Tumoral , Animais , Camundongos , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Humanos , Microambiente Tumoral/imunologia , Linfócitos T CD8-Positivos/imunologia , Transplante de Microbiota Fecal , Linhagem Celular Tumoral , Probióticos/administração & dosagem , Probióticos/farmacologia , Imunoterapia , Feminino , Neoplasias do Colo/imunologia , Neoplasias do Colo/terapia , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/microbiologia , Inibidores de Checkpoint Imunológico/farmacologia , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/terapia , Camundongos Endogâmicos BALB C , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: The acronym COVID, which stands for coronavirus disease, has become one of the most infamous acronyms in the world since 2020. An analysis of acronyms in health and medical journals has previously found that acronyms have become more common in titles and abstracts over time (e.g., DNA and human immunodeficiency virus are the most common acronyms). However, the trends in acronyms related to COVID remain unclear. It is necessary to verify whether the dramatic rise in COVID-related research can be observed by visualizations. The purpose of this study was to display the acronym trends in comparison through the use of temporal graphs and to verify that the COVID acronym has a significant edge over the other 2 in terms of research dominance. METHODS: An analysis of the 30 most frequently used acronyms related to COVID in PubMed since 1950 was carried out using 4 graphs to conduct this bibliometric analysis, including line charts, temporal bar graphs (TBGs), temporal heatmaps (THM), and growth-share matrices (GSM). The absolute advantage coefficient (AAC) was used to measure the dominance strength for COVID acronym since 2020. COVID's AAC trend was expected to decline over time. RESULTS: This study found that COVID, DNA, and human immunodeficiency virus have been the most frequently observed research acronyms since 2020, followed by computed tomography and World Health Organization; although there is no ideal method for displaying acronym trends over time, researchers can utilize the GSM to complement traditional line charts, TBGs, and THMs, as shown in this study; and COVID has a significant edge over the other 2 in terms of research dominance by ACC (≥0.67), but COVID's AAC trend has declined (e.g., AACs 0.83, 0.80, and 0.69) since 2020. CONCLUSIONS: It is recommended that the GSM complement traditional line charts, TBGs, and THMs in trend analysis, rather than being restricted to acronyms in future research. This research provides readers with the AAC to understand how research dominates its counterparts, which will be useful for future bibliometric analyses.
Assuntos
COVID-19 , Nomes , Humanos , COVID-19/epidemiologia , PubMedAssuntos
Fístula Carótido-Cavernosa/complicações , Fístula Carótido-Cavernosa/diagnóstico , Angiografia Digital/métodos , Diplopia/complicações , Diplopia/diagnóstico , Feminino , Cefaleia/etiologia , Humanos , Pessoa de Meia-Idade , Hemorragia Subaracnóidea/complicações , Transtornos da Visão/etiologiaRESUMO
Whereas much research has been conducted on rats in their roles as pests and laboratory animal models, little is known about rats in their role as companion animals. However, rats have become the third most common companion animal admitted to the British Columbia Society for the Prevention of Cruelty to Animals (BC SPCA) shelter system after cats and dogs. This paper analyses 5 years of province-wide rat admission and outcome data (n = 3,392) at the BC SPCA. Most rats that entered BC SPCA shelters were white, sexually intact, and pups less than 6 months old. Rats were mostly relinquished by their owners, and the most common surrender reasons were due to owner-related issues and housing issues. Reasons for euthanasia were primarily poor health and neonatal age. A multiple linear regression model found that rats that were either senior, albino, unhealthy, seized by humane officers, or born onsite tended to stay longer in shelters (F[12, 1466] = 9.565, p < .001, adjusted R2 = .06). Time to adoption for albino rats was 79% longer than for white rats. These findings help us understand the preferences of rat adopters and why the rat-human relationship may fail. Results may also be useful to improve the quality of life for pet rats by identifying programs to reduce their length of stay in animal shelters. Finally, our study highlights new questions for welfare research in an understudied companion animal-the pet rat.