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1.
Am J Hum Genet ; 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39168119

RESUMO

The function of some genetic variants associated with brain-relevant traits has been explained through colocalization with expression quantitative trait loci (eQTL) conducted in bulk postmortem adult brain tissue. However, many brain-trait associated loci have unknown cellular or molecular function. These genetic variants may exert context-specific function on different molecular phenotypes including post-transcriptional changes. Here, we identified genetic regulation of RNA editing and alternative polyadenylation (APA) within a cell-type-specific population of human neural progenitors and neurons. More RNA editing and isoforms utilizing longer polyadenylation sequences were observed in neurons, likely due to higher expression of genes encoding the proteins mediating these post-transcriptional events. We also detected hundreds of cell-type-specific editing quantitative trait loci (edQTLs) and alternative polyadenylation QTLs (apaQTLs). We found colocalizations of a neuron edQTL in CCDC88A with educational attainment and a progenitor apaQTL in EP300 with schizophrenia, suggesting that genetically mediated post-transcriptional regulation during brain development leads to differences in brain function.

2.
Hum Mol Genet ; 32(21): 3053-3062, 2023 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-37540217

RESUMO

Pseudoexfoliation glaucoma (PEXG) is characterized by dysregulated extracellular matrix (ECM) homeostasis that disrupts conventional outflow function and increases intraocular pressure (IOP). Prolonged IOP elevation results in optic nerve head damage and vision loss. Uniquely, PEXG is a form of open angle glaucoma that has variable penetrance, is difficult to treat and does not respond well to common IOP-lowering pharmaceuticals. Therefore, understanding modulators of disease severity will aid in targeted therapies for PEXG. Genome-wide association studies have identified polymorphisms in the long non-coding RNA lysyl oxidase-like 1-antisense 1 (LOXL1-AS1) as a risk factor for PEXG. Risk alleles, oxidative stress and mechanical stretch all alter LOXL1-AS1 expression. As a long non-coding RNA, LOXL1-AS1 binds hnRNPL and regulates global gene expression. In this study, we focus on the role of LOXL1-AS1 in the ocular cells (trabecular meshwork and Schlemm's canal) that regulate IOP. We show that selective knockdown of LOXL1-AS1 leads to cell-type-specific changes in gene expression, ECM homeostasis, signaling and morphology. These results implicate LOXL1-AS1 as a modulator of cellular homeostasis, altering cell contractility and ECM turnover, both of which are well-known contributors to PEXG. These findings support LOXL1-AS1 as a key target for modifying the disease.


Assuntos
Síndrome de Exfoliação , Glaucoma de Ângulo Aberto , RNA Longo não Codificante , Humanos , Glaucoma de Ângulo Aberto/genética , RNA Longo não Codificante/genética , Proteína-Lisina 6-Oxidase/genética , Estudo de Associação Genômica Ampla , Síndrome de Exfoliação/genética , Síndrome de Exfoliação/metabolismo , Aminoácido Oxirredutases/genética
3.
Nucleic Acids Res ; 51(13): e73, 2023 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-37293974

RESUMO

Mitochondrial DNA (mtDNA) modifications play an emerging role in innate immunity and inflammatory diseases. Nonetheless, relatively little is known regarding the locations of mtDNA modifications. Such information is critically important for deciphering their roles in mtDNA instability, mtDNA-mediated immune and inflammatory responses, and mitochondrial disorders. The affinity probe-based enrichment of lesion-containing DNA represents a key strategy for sequencing DNA modifications. Existing methods are limited in the enrichment specificity of abasic (AP) sites, a prevalent DNA modification and repair intermediate. Herein, we devise a novel approach, termed dual chemical labeling-assisted sequencing (DCL-seq), for mapping AP sites. DCL-seq features two designer compounds for enriching and mapping AP sites specifically at single-nucleotide resolution. For proof of principle, we mapped AP sites in mtDNA from HeLa cells under different biological conditions. The resulting AP site maps coincide with mtDNA regions with low TFAM (mitochondrial transcription factor A) coverage and with potential G-quadruplex-forming sequences. In addition, we demonstrated the broader applicability of the method in sequencing other DNA modifications in mtDNA, such as N7-methyl-2'-deoxyguanosine and N3-methyl-2'-deoxyadenosine, when coupled with a lesion-specific repair enzyme. Together, DCL-seq holds the promise to sequence multiple DNA modifications in various biological samples.


Assuntos
DNA Mitocondrial , Humanos , Alquilação , Dano ao DNA , Reparo do DNA , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Células HeLa , Nucleotídeos , Análise de Sequência de DNA
4.
Proc Natl Acad Sci U S A ; 119(41): e2208415119, 2022 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-36191209

RESUMO

MicroRNAs (miRNAs) play an essential role in plant growth and development, and as such, their biogenesis is fine-tuned via regulation of the core microprocessor components. Here, we report that Arabidopsis AAR2, a homolog of a U5 snRNP assembly factor in yeast and humans, not only acts in splicing but also promotes miRNA biogenesis. AAR2 interacts with the microprocessor component hyponastic leaves 1 (HYL1) in the cytoplasm, nucleus, and dicing bodies. In aar2 mutants, abundance of nonphosphorylated HYL1, the active form of HYL1, and the number of HYL1-labeled dicing bodies are reduced. Primary miRNA (pri-miRNA) accumulation is compromised despite normal promoter activities of MIR genes in aar2 mutants. RNA decay assays show that the aar2-1 mutation leads to faster degradation of pri-miRNAs in a HYL1-dependent manner, which reveals a previously unknown and negative role of HYL1 in miRNA biogenesis. Taken together, our findings reveal a dual role of AAR2 in miRNA biogenesis and pre-messenger RNA splicing.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , MicroRNAs , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Eucariotos/genética , Regulação da Expressão Gênica de Plantas , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Processamento Pós-Transcricional do RNA , Fatores de Processamento de RNA/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Ribonucleoproteína Nuclear Pequena U5/genética
6.
Proc Natl Acad Sci U S A ; 118(6)2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33536344

RESUMO

An important question is what genes govern the differentiation of plant embryos into suspensor and embryo proper regions following fertilization and division of the zygote. We compared embryo proper and suspensor transcriptomes of four plants that vary in embryo morphology within the suspensor region. We determined that genes encoding enzymes in several metabolic pathways leading to the formation of hormones, such as gibberellic acid, and other metabolites are up-regulated in giant scarlet runner bean and common bean suspensors. Genes involved in transport and Golgi body organization are up-regulated within the suspensors of these plants as well, strengthening the view that giant specialized suspensors serve as a hormone factory and a conduit for transferring substances to the developing embryo proper. By contrast, genes controlling transcriptional regulation, development, and cell division are up-regulated primarily within the embryo proper. Transcriptomes from less specialized soybean and Arabidopsis suspensors demonstrated that fewer genes encoding metabolic enzymes and hormones are up-regulated. Genes active in the embryo proper, however, are functionally similar to those active in scarlet runner bean and common bean embryo proper regions. We uncovered a set of suspensor- and embryo proper-specific transcription factors (TFs) that are shared by all embryos irrespective of morphology, suggesting that they are involved in early differentiation processes common to all plants. Chromatin immunoprecipitation sequencing (ChIP-Seq) experiments with scarlet runner bean and soybean WOX9, an up-regulated suspensor TF, gained entry into a regulatory network important for suspensor development irrespective of morphology.


Assuntos
Desenvolvimento Vegetal/genética , Proteínas de Plantas/genética , Sementes/genética , Transcriptoma/genética , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Divisão Celular/genética , Regulação da Expressão Gênica de Plantas/genética , Giberelinas/metabolismo , Sementes/metabolismo , Glycine max/genética , Glycine max/crescimento & desenvolvimento
7.
J Child Psychol Psychiatry ; 64(3): 357-366, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36124731

RESUMO

BACKGROUND: Elevated levels of callous-unemotional (CU) traits have proven useful for identifying a distinct subgroup of children whose conduct problems (CP) are early emerging, severe, persistent, and underpinned by aberrant emotional processing. The early childhood emotional experiences and expressions of CP subtypes are poorly understood, despite their importance to understanding the problematic attachments and atypical social affiliation experienced by children with elevated CU traits. The current study aimed to test for differences in facial emotional reactions to mood-inducing film clips in children with CP and varying levels of CU traits. METHOD: We compared facial emotional reactions during a developmentally appropriate mood induction task in a mixed-sex sample of clinic-referred preschool children (Mage = 3.64 years, SD = 0.63, 66.9% male) classified as CP with elevated levels of CU traits (CP + CU; n = 25) versus low CU traits (CP-only; n = 47), and typically developing children (TD; n = 28). RESULTS: Relative to TD children, children with clinical CP showed less congruent and more incongruent facial emotional expressions to sad and happy film clips, controlling for child sex, age, and ethnicity. CONCLUSIONS: Consistent with older samples, young children with CP show atypical facial emotional expressions in response to positive and negative emotional stimuli. Findings have implications for developmental models of childhood antisocial behavior and can inform the development of targeted interventions.


Assuntos
Transtorno da Conduta , Comportamento Problema , Masculino , Humanos , Pré-Escolar , Feminino , Transtorno da Conduta/psicologia , Emoções/fisiologia , Comportamento Problema/psicologia , Transtorno da Personalidade Antissocial/psicologia , Empatia
8.
Proc Natl Acad Sci U S A ; 116(24): 12094-12102, 2019 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-31142655

RESUMO

As the most common RNA cap in eukaryotes, the 7-methylguanosine (m7G) cap impacts nearly all processes that a messenger RNA undergoes, such as splicing, polyadenylation, nuclear export, translation, and degradation. The metabolite and redox agent, nicotinamide adenine diphosphate (NAD+), can be used as an initiating nucleotide in RNA synthesis to result in NAD+-capped RNAs. Such RNAs have been identified in bacteria, yeast, and human cells, but it is not known whether they exist in plant transcriptomes. The functions of the NAD+ cap in RNA metabolism or translation are still poorly understood. Here, through NAD captureSeq, we show that NAD+-capped RNAs are widespread in Arabidopsis thaliana NAD+-capped RNAs are predominantly messenger RNAs encoded by the nuclear and mitochondrial genomes, but not the chloroplast genome. NAD+-capped transcripts from the nuclear genome appear to be spliced and polyadenylated. Furthermore, although NAD+-capped transcripts constitute a small proportion of the total transcript pool from any gene, they are enriched in the polysomal fraction and associate with translating ribosomes. Our findings implicate the existence of as yet unknown mechanisms whereby the RNA NAD+ cap interfaces with RNA metabolic processes as well as translation initiation. More importantly, our findings suggest that cellular metabolic and/or redox states may influence, or be regulated by, mRNA NAD+ capping.


Assuntos
Arabidopsis/genética , NAD/genética , Capuzes de RNA/genética , Transcriptoma/genética , Genoma de Cloroplastos/genética , Genoma Mitocondrial/genética , Guanosina/análogos & derivados , Guanosina/genética , Oxirredução , RNA Mensageiro/genética
9.
J ECT ; 38(2): e11-e19, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35613011

RESUMO

OBJECTIVES: Transcranial direct current stimulation (tDCS) is a noninvasive neurostimulation technique being translated clinically for the treatment of depression. There is limited research documenting the longer-term effectiveness and safety of tDCS treatment. This case series is the first report of remotely supervised, home-administered tDCS (HA-tDCS) for depression in a clinical setting. METHODS: We report clinical, cognitive, and safety outcomes from 16 depressed patients who received acute and/or maintenance HA-tDCS. We retrospectively examined clinical data from up to 2.5 years of treatment. Descriptive statistics are reported to document patient outcomes. RESULTS: Twelve patients received acute treatment for a current depressive episode and 4 commenced tDCS maintenance therapy after responding to ECT or repetitive transcranial magnetic stimulation (rTMS). The cohort was highly treatment-resistant wherein 15 of 16 patients failed 3 trials or more of antidepressant medication in the current episode, and 6 patients failed to gain significant benefit from prior ECT or rTMS. Five of 12 patients responded to acute tDCS within 6 weeks, and 9 patients who received tDCS for more than 12 weeks maintained improvements over several months. Cognitive tests showed no evidence of impairments in cognitive outcomes after up to 2 years of treatment. Two patients were withdrawn from treatment because of blurred vision or exacerbation of tinnitus. Transcranial direct current stimulation was otherwise safe and well tolerated. CONCLUSIONS: Transcranial direct current stimulation given for at least 6 weeks may be of clinical benefit even in treatment-resistant depression. Results provide support for long-term effectiveness, safety, and feasibility of remotely supervised HA-tDCS and suggest a role for maintenance tDCS after acute treatment with tDCS, rTMS, or ECT.


Assuntos
Transtorno Depressivo Resistente a Tratamento , Eletroconvulsoterapia , Estimulação Transcraniana por Corrente Contínua , Depressão , Transtorno Depressivo Resistente a Tratamento/etiologia , Transtorno Depressivo Resistente a Tratamento/terapia , Humanos , Estudos Retrospectivos , Estimulação Transcraniana por Corrente Contínua/métodos , Estimulação Magnética Transcraniana/efeitos adversos , Estimulação Magnética Transcraniana/métodos , Resultado do Tratamento
10.
J ECT ; 38(1): 45-51, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-34387286

RESUMO

OBJECTIVES: The coronavirus disease 2019 (COVID-19) pandemic has led to reported change in electroconvulsive therapy (ECT) services worldwide. However, minimal data have been published demonstrating tangible changes across multiple ECT centers. This article aimed to examine changes in ECT patients and ECT service delivery during the pandemic. METHODS: We retrospectively assessed data collected on ECT patients within the Clinical Alliance and Research in Electroconvulsive Therapy and Related Treatments (CARE) Network during a 3-month period starting at the first COVID-19 restrictions in 2020 and compared data with predicted values based on the corresponding 3-month period in 2019. Mixed-effects repeated-measures analyses examined differences in the predicted and actual number of acute ECT courses started and the total number of acute ECT treatments given in 2020. Sociodemographic, clinical, treatment factors, and ECT service delivery factors were compared for 2020 and 2019. RESULTS: Four Australian and 1 Singaporean site participated in the study. There were no significant differences between the predicted and actual number of acute ECT courses and total number of acute ECT treatments administered in 2020. During 2020, there were statistically significant increases in the proportion of patients requiring ECT under substitute consent and receiving ECT for urgent reasons compared with 2019. CONCLUSIONS: This multisite empirical study is among the first that supports anecdotal reports of changes in the triaging and delivery of ECT during COVID-19. Results suggest that ECT was prioritized for the most severely ill patients. Further data assessing the impacts of COVID-19 on ECT are needed.


Assuntos
COVID-19 , Eletroconvulsoterapia , Austrália , Eletroconvulsoterapia/métodos , Humanos , Estudos Retrospectivos , SARS-CoV-2 , Resultado do Tratamento
11.
PLoS Biol ; 15(2): e2001272, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28231321

RESUMO

The degradation of small RNAs in plants and animals is associated with small RNA 3' truncation and 3' uridylation and thus relies on exonucleases and nucleotidyl transferases. ARGONAUTE (AGO) proteins associate with small RNAs in vivo and are essential for not only the activities but also the stability of small RNAs. AGO1 is the microRNA (miRNA) effector in Arabidopsis, and its closest homolog, AGO10, maintains stem cell homeostasis in meristems by sequestration of miR165/6, a conserved miRNA acting through AGO1. Here, we show that SMALL RNA DEGRADING NUCLEASES (SDNs) initiate miRNA degradation by acting on AGO1-bound miRNAs to cause their 3' truncation, and the truncated species are uridylated and degraded. We report that AGO10 reduces miR165/6 accumulation by enhancing its degradation by SDN1 and SDN2 in vivo. In vitro, AGO10-bound miR165/6 is more susceptible to SDN1-mediated 3' truncation than AGO1-bound miR165/6. Thus, AGO10 promotes the degradation of miR165/6, which is contrary to the stabilizing effect of AGO1. Our work identifies a class of exonucleases responsible for miRNA 3' truncation in vivo and uncovers a mechanism of specificity determination in miRNA turnover. This work, together with previous studies on AGO10, suggests that spatially regulated miRNA degradation underlies stem cell maintenance in plants.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas Argonautas/metabolismo , Exorribonucleases/metabolismo , MicroRNAs/metabolismo , Estabilidade de RNA , Regulação da Expressão Gênica de Plantas , Metilação , MicroRNAs/genética , Mutação/genética , Plantas Geneticamente Modificadas , Ligação Proteica , Complexo de Inativação Induzido por RNA/metabolismo
12.
Proc Natl Acad Sci U S A ; 114(32): E6710-E6719, 2017 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-28739919

RESUMO

LEAFY COTYLEDON1 (LEC1), an atypical subunit of the nuclear transcription factor Y (NF-Y) CCAAT-binding transcription factor, is a central regulator that controls many aspects of seed development including the maturation phase during which seeds accumulate storage macromolecules and embryos acquire the ability to withstand desiccation. To define the gene networks and developmental processes controlled by LEC1, genes regulated directly by and downstream of LEC1 were identified. We compared the mRNA profiles of wild-type and lec1-null mutant seeds at several stages of development to define genes that are down-regulated or up-regulated by the lec1 mutation. We used ChIP and differential gene-expression analyses in Arabidopsis seedlings overexpressing LEC1 and in developing Arabidopsis and soybean seeds to identify globally the target genes that are transcriptionally regulated by LEC1 in planta Collectively, our results show that LEC1 controls distinct gene sets at different developmental stages, including those that mediate the temporal transition between photosynthesis and chloroplast biogenesis early in seed development and seed maturation late in development. Analyses of enriched DNA sequence motifs that may act as cis-regulatory elements in the promoters of LEC1 target genes suggest that LEC1 may interact with other transcription factors to regulate distinct gene sets at different stages of seed development. Moreover, our results demonstrate strong conservation in the developmental processes and gene networks regulated by LEC1 in two dicotyledonous plants that diverged ∼92 Mya.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Glycine max/metabolismo , Sementes/metabolismo , Transcrição Gênica/fisiologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas Estimuladoras de Ligação a CCAAT/genética , DNA de Plantas/genética , DNA de Plantas/metabolismo , Motivos de Nucleotídeos/fisiologia , Sementes/genética , Glycine max/genética
13.
Proc Natl Acad Sci U S A ; 114(45): E9730-E9739, 2017 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-29078418

RESUMO

We profiled soybean and Arabidopsis methylomes from the globular stage through dormancy and germination to understand the role of methylation in seed formation. CHH methylation increases significantly during development throughout the entire seed, targets primarily transposable elements (TEs), is maintained during endoreduplication, and drops precipitously within the germinating seedling. By contrast, no significant global changes in CG- and CHG-context methylation occur during the same developmental period. An Arabidopsis ddcc mutant lacking CHH and CHG methylation does not affect seed development, germination, or major patterns of gene expression, implying that CHH and CHG methylation does not play a significant role in seed development or in regulating seed gene activity. By contrast, over 100 TEs are transcriptionally de-repressed in ddcc seeds, suggesting that the increase in CHH-context methylation may be a failsafe mechanism to reinforce transposon silencing. Many genes encoding important classes of seed proteins, such as storage proteins, oil biosynthesis enzymes, and transcription factors, reside in genomic regions devoid of methylation at any stage of seed development. Many other genes in these classes have similar methylation patterns, whether the genes are active or repressed. Our results suggest that methylation does not play a significant role in regulating large numbers of genes important for programming seed development in both soybean and Arabidopsis. We conclude that understanding the mechanisms controlling seed development will require determining how cis-regulatory elements and their cognate transcription factors are organized in genetic regulatory networks.


Assuntos
Arabidopsis/genética , Metilação de DNA/fisiologia , DNA de Plantas/metabolismo , Glycine max/genética , Sementes/crescimento & desenvolvimento , Sementes/genética , Sequência de Bases , Metilação de DNA/genética , Elementos de DNA Transponíveis/genética , Elementos de DNA Transponíveis/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/genética , Redes Reguladoras de Genes , Inativação Gênica , Genes de Plantas/genética , Genoma de Planta/genética , Germinação/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA de Plantas/genética , RNA de Plantas/metabolismo , Plântula/genética , Plântula/metabolismo , Sementes/citologia
14.
Psychiatry Clin Neurosci ; 73(7): 357-369, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30864184

RESUMO

Imaging genetics aims to identify genetic variants associated with the structure and function of the human brain. Recently, collaborative consortia have been successful in this goal, identifying and replicating common genetic variants influencing gross human brain structure as measured through magnetic resonance imaging. In this review, we contextualize imaging genetic associations as one important link in understanding the causal chain from genetic variant to increased risk for neuropsychiatric disorders. We provide examples in other fields of how identifying genetic variant associations to disease and multiple phenotypes along the causal chain has revealed a mechanistic understanding of disease risk, with implications for how imaging genetics can be similarly applied. We discuss current findings in the imaging genetics research domain, including that common genetic variants can have a slightly larger effect on brain structure than on risk for disorders like schizophrenia, indicating a somewhat simpler genetic architecture. Also, gross brain structure measurements share a genetic basis with some, but not all, neuropsychiatric disorders, invalidating the previously held belief that they are broad endophenotypes, yet pinpointing brain regions likely involved in the pathology of specific disorders. Finally, we suggest that in order to build a more detailed mechanistic understanding of the effects of genetic variants on the brain, future directions in imaging genetics research will require observations of cellular and synaptic structure in specific brain regions beyond the resolution of magnetic resonance imaging. We expect that integrating genetic associations at biological levels from synapse to sulcus will reveal specific causal pathways impacting risk for neuropsychiatric disorders.


Assuntos
Encefalopatias , Genética , Estudo de Associação Genômica Ampla , Transtornos Mentais , Neuroimagem , Encefalopatias/diagnóstico por imagem , Encefalopatias/genética , Encefalopatias/patologia , Encefalopatias/fisiopatologia , Humanos , Transtornos Mentais/diagnóstico por imagem , Transtornos Mentais/genética , Transtornos Mentais/patologia , Transtornos Mentais/fisiopatologia
15.
EMBO Rep ; 17(12): 1799-1813, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27797852

RESUMO

Protein poly(ADP-ribosyl)ation (PARylation) primarily catalyzed by poly(ADP-ribose) polymerases (PARPs) plays a crucial role in controlling various cellular responses. However, PARylation targets and their functions remain largely elusive. Here, we deployed an Arabidopsis protein microarray coupled with in vitro PARylation assays to globally identify PARylation targets in plants. Consistent with the essential role of PARylation in plant immunity, the forkhead-associated (FHA) domain protein DAWDLE (DDL), one of PARP2 targets, positively regulates plant defense to both adapted and non-adapted pathogens. Arabidopsis PARP2 interacts with and PARylates DDL, which was enhanced upon treatment of bacterial flagellin. Mass spectrometry and mutagenesis analysis identified multiple PARylation sites of DDL by PARP2. Genetic complementation assays indicate that DDL PARylation is required for its function in plant immunity. In contrast, DDL PARylation appears to be dispensable for its previously reported function in plant development partially mediated by the regulation of microRNA biogenesis. Our study uncovers many previously unknown PARylation targets and points to the distinct functions of DDL in plant immunity and development mediated by protein PARylation and small RNA biogenesis, respectively.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/imunologia , Arabidopsis/metabolismo , Proteínas de Transporte/metabolismo , Imunidade Vegetal , Poli Adenosina Difosfato Ribose/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Transporte/genética , Flagelina/imunologia , Regulação da Expressão Gênica de Plantas , Teste de Complementação Genética , Análise em Microsséries , Transdução de Sinais
16.
PLoS Genet ; 10(7): e1004446, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24992598

RESUMO

RNA-directed DNA methylation (RdDM) and histone H3 lysine 9 dimethylation (H3K9me2) are related transcriptional silencing mechanisms that target transposable elements (TEs) and repeats to maintain genome stability in plants. RdDM is mediated by small and long noncoding RNAs produced by the plant-specific RNA polymerases Pol IV and Pol V, respectively. Through a chemical genetics screen with a luciferase-based DNA methylation reporter, LUCL, we found that camptothecin, a compound with anti-cancer properties that targets DNA topoisomerase 1α (TOP1α) was able to de-repress LUCL by reducing its DNA methylation and H3K9me2 levels. Further studies with Arabidopsis top1α mutants showed that TOP1α silences endogenous RdDM loci by facilitating the production of Pol V-dependent long non-coding RNAs, AGONAUTE4 recruitment and H3K9me2 deposition at TEs and repeats. This study assigned a new role in epigenetic silencing to an enzyme that affects DNA topology.


Assuntos
Metilação de DNA/genética , DNA Topoisomerases Tipo I/genética , Elementos de DNA Transponíveis/genética , Epigênese Genética , Transcrição Gênica , Arabidopsis/genética , DNA Topoisomerases Tipo I/metabolismo , Inativação Gênica , Histonas/genética , Lisina/genética , Mutação , RNA/genética , RNA Longo não Codificante/genética
17.
Plant Physiol ; 168(3): 1025-35, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25963149

RESUMO

We used an RNA interference screen to assay the function of 53 transcription factor messenger RNAs (mRNAs) that accumulate specifically within soybean (Glycine max) seed regions, subregions, and tissues during development. We show that basic helix-loop-helix (bHLH) transcription factor genes represented by Glyma04g41710 and its paralogs are required for the formation of stoma in leaves and stomatal precursor complexes in mature embryo cotyledons. Phylogenetic analysis indicates that these bHLH transcription factor genes are orthologous to Arabidopsis (Arabidopsis thaliana) SPEECHLESS (SPCH) that initiate asymmetric cell divisions in the leaf protoderm layer and establish stomatal cell lineages. Soybean SPCH (GmSPCH) mRNAs accumulate primarily in embryo, seedling, and leaf epidermal layers. Expression of Glyma04g41710 under the control of the SPCH promoter rescues the Arabidopsis spch mutant, indicating that Glyma04g41710 is a functional ortholog of SPCH. Developing soybean embryos do not form mature stoma, and stomatal differentiation is arrested at the guard mother cell stage. We analyzed the accumulation of GmSPCH mRNAs during soybean seed development and mRNAs orthologous to MUTE, FAMA, and inducer of C-repeat/dehydration responsive element-binding factor expression1/scream2 that are required for stoma formation in Arabidopsis. The mRNA accumulation patterns provide a potential explanation for guard mother cell dormancy in soybean embryos. Our results suggest that variation in the timing of bHLH transcription factor gene expression can explain the diversity of stomatal forms observed during plant development.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Linhagem da Célula/genética , Regulação para Baixo/genética , Genes de Plantas , Glycine max/embriologia , Glycine max/genética , Estômatos de Plantas/citologia , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Germinação/genética , Homozigoto , Desenvolvimento Vegetal/genética , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estômatos de Plantas/embriologia , Estômatos de Plantas/genética , Plantas Geneticamente Modificadas , Interferência de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sementes/embriologia , Sementes/genética
18.
Proc Natl Acad Sci U S A ; 110(5): E435-44, 2013 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-23319655

RESUMO

Seeds are complex structures that consist of the embryo, endosperm, and seed-coat regions that are of different ontogenetic origins, and each region can be further divided into morphologically distinct subregions. Despite the importance of seeds for food, fiber, and fuel globally, little is known of the cellular processes that characterize each subregion or how these processes are integrated to permit the coordinated development of the seed. We profiled gene activity genome-wide in every organ, tissue, and cell type of Arabidopsis seeds from fertilization through maturity. The resulting mRNA datasets offer the most comprehensive description of gene activity in seeds with high spatial and temporal resolution,providing unique insights into the function of understudied seed regions. Global comparisons of mRNA populations reveal unexpected overlaps in the functional identities of seed subregions. Analyses of coexpressed gene sets suggest that processes that regulate seed size and filling are coordinated across several subregions. Predictions of gene regulatory networks based on the association of transcription factors with enriched DNA sequence motifs upstream of coexpressed genes identify regulators of seed development. These studies emphasize the utility of these data sets as an essential resource for the study of seed biology.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Sementes/genética , Arabidopsis/anatomia & histologia , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/classificação , Análise por Conglomerados , Endosperma/anatomia & histologia , Endosperma/genética , Endosperma/crescimento & desenvolvimento , Genes de Plantas/genética , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Microscopia de Fluorescência , Análise de Sequência com Séries de Oligonucleotídeos , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sementes/anatomia & histologia , Sementes/crescimento & desenvolvimento
19.
Infect Dis Poverty ; 13(1): 16, 2024 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-38369483

RESUMO

BACKGROUND: Current soil-transmitted helminth (STH) control guidelines endorse the use of albendazole or mebendazole for school-based targeted preventive chemotherapy (PC), yet their reduced efficacy against Strongyloides stercoralis and Trichuris trichiura presents significant limitations. Emerging evidence indicates that community-wide PC [or mass drug administration (MDA)] using ivermectin, commonly used in other neglected tropical disease (NTD) control programs, may play an important role in controlling these parasites. We conducted a systematic review and meta-analysis to evaluate the effectiveness of ivermectin PC in reducing STH prevalence in endemic populations. METHODS: We searched Pubmed, EMBASE, and Web of Science on February 14, 2023, for studies that investigated the effectiveness of ivermectin PC, either alone or in combination with other anthelmintic drugs, on STH infections, and provided a measure of STH prevalence before and after PC. We calculated pooled prevalence reductions for each STH using random-effects meta-analyses. Our protocol is available on PROSPERO (registration number CRD42023401219). RESULTS: A total of 21 were eligible for the systematic review, of which 15 were eligible for meta-analysis. All studies delivered ivermectin through MDA. The pooled prevalence reduction of S. stercoralis following MDA with ivermectin alone was 84.49% (95% CI 54.96-94.66) across five studies and 81.37% (95% CI 61.62-90.96) across seven studies with or without albendazole. The prevalence reduction of T. trichiura was 49.93% (95% CI 18.23-69.34) across five studies with ivermectin alone, and 89.40% (95% CI 73.66-95.73) across three studies with the addition of albendazole. There was high heterogeneity for all syntheses (I2 > 65%). CONCLUSIONS: This study underscores the key role of ivermectin-based MDA in addressing limitations in current global STH guidelines in terms of limited efficacy against S. stercoralis and T. trichiura. Based on these findings, revising international STH guidelines to include ivermectin is a promising option to progress the control and eventual elimination of STHs and other NTDs.


Assuntos
Anti-Helmínticos , Helmintíase , Ivermectina , Administração Massiva de Medicamentos , Solo , Ivermectina/uso terapêutico , Ivermectina/administração & dosagem , Humanos , Helmintíase/epidemiologia , Helmintíase/prevenção & controle , Helmintíase/tratamento farmacológico , Solo/parasitologia , Anti-Helmínticos/uso terapêutico , Anti-Helmínticos/administração & dosagem , Doenças Endêmicas/prevenção & controle , Animais , Prevalência
20.
Chronobiol Int ; 41(2): 213-225, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38153128

RESUMO

Sleep regularity and chronotype can affect health, performance, and overall well-being. This observational study examines how sleep regularity and chronotype affect sleep quality and cardiorespiratory metrics. Data was collected from 1 January 2019 through 30 December 2019 from over 330 000 Sleep Number smart bed users across the United States who opted into this at-home study. A pressure signal from the smart bed reflected bed presence, movements, heart rate (HR), and breathing rate (BR). Participants (mean age: 55.69 years [SD: 14.0]; 51.2% female) were categorized by chronotype (16.8% early; 62.2% intermediate, 20.9% late) and regularity of sleep timing. Participants who were regular sleepers (66.1%) experienced higher percent restful sleep and lower mean HR and BR compared to the 4.8% categorized as irregular sleepers. Regular early-chronotype participants displayed better sleep and cardiorespiratory parameters compared to those with regular late-chronotypes. Significant variations were noted in sleep duration (Cohen's d = 1.54 and 0.88, respectively) and restful sleep (Cohen's d = 1.46 and 0.82, respectively) between early and late chronotypes, particularly within regular and irregular sleep patterns. This study highlights how sleep regularity and chronotype influence sleep quality and cardiorespiratory metrics. Irrespective of chronotype, sleep regularity demonstrated a substantial effect. Further research is necessary to confirm these findings.


Assuntos
Ritmo Circadiano , Transtornos do Sono-Vigília , Humanos , Feminino , Pessoa de Meia-Idade , Masculino , Ritmo Circadiano/fisiologia , Sono/fisiologia , Qualidade do Sono , Inquéritos e Questionários
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