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Aberrantly slow ribosomes incur collisions, a sentinel of stress that triggers quality control, signaling, and translation attenuation. Although each collision response has been studied in isolation, the net consequences of their collective actions in reshaping translation in cells is poorly understood. Here, we apply cryoelectron tomography to visualize the translation machinery in mammalian cells during persistent collision stress. We find that polysomes are compressed, with up to 30% of ribosomes in helical polysomes or collided disomes, some of which are bound to the stress effector GCN1. The native collision interface extends beyond the in vitro-characterized 40S and includes the L1 stalk and eEF2, possibly contributing to translocation inhibition. The accumulation of unresolved tRNA-bound 80S and 60S and aberrant 40S configurations identifies potentially limiting steps in collision responses. Our work provides a global view of the translation machinery in response to persistent collisions and a framework for quantitative analysis of translation dynamics in situ.
Assuntos
Biossíntese de Proteínas , Ribossomos , Animais , Ribossomos/genética , Ribossomos/metabolismo , Polirribossomos/genética , Polirribossomos/metabolismo , MamíferosRESUMO
Central memory CD8+ T cells (Tcm) control systemic secondary infections and can protect from chronic infection and cancer as a result of their stem-cell-like capacity to expand, differentiate, and self-renew. Central memory is generally thought to emerge following pathogen clearance and to form based on the de-differentiation of cytolytic effector cells. Here, we uncovered rare effector-phase CD8+ T cells expressing high amounts of the transcription factor Tcf7 (Tcf1) that showed no evidence of prior cytolytic differentiation and that displayed key hallmarks of Tcm cells. These effector-phase Tcf7hi cells quantitatively yielded Tcm cells based on lineage tracing. Mechanistically, Tcf1 counteracted the differentiation of Tcf7hi cells and sustained the expression of conserved adult stem-cell genes that were critical for CD8+ T cell stemness. The discovery of stem-cell-like CD8+ T cells during the effector response to acute infection provides an opportunity to optimize Tcm cell formation by vaccination.
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Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Diferenciação Celular/imunologia , Citotoxicidade Imunológica , Fator 1-alfa Nuclear de Hepatócito/metabolismo , Memória Imunológica , Fator 1 de Transcrição de Linfócitos T/metabolismo , Animais , Linfócitos T CD8-Positivos/citologia , Diferenciação Celular/genética , Montagem e Desmontagem da Cromatina , Citotoxicidade Imunológica/genética , Imunofluorescência , Expressão Gênica , Fator 1-alfa Nuclear de Hepatócito/química , Fator 1-alfa Nuclear de Hepatócito/genética , Humanos , Imunização , Memória Imunológica/genética , Imunofenotipagem , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Modelos Moleculares , Conformação Proteica , Baço/imunologia , Baço/metabolismo , Relação Estrutura-Atividade , Fator 1 de Transcrição de Linfócitos T/química , Fator 1 de Transcrição de Linfócitos T/genéticaRESUMO
Plasmodium falciparum malaria originated when Plasmodium praefalciparum, a gorilla malaria parasite transmitted by African sylvan anopheline mosquitoes, adapted to humans. Pfs47, a protein on the parasite surface mediates P. falciparum evasion of the mosquito immune system by interacting with a midgut receptor and is critical for Plasmodium adaptation to different anopheline species. Genetic analysis of 4,971 Pfs47 gene sequences from different continents revealed that Asia and Papua New Guinea harbor Pfs47 haplotypes more similar to its ortholog in P. praefalciparum at sites that determine vector compatibility, suggesting that ancestral P. falciparum readily adapted to Asian vectors. Consistent with this observation, Pfs47-receptor gene sequences from African sylvan malaria vectors, such as Anopheles moucheti and An. marshallii, were found to share greater similarity with those of Asian vectors than those of vectors of the African An. gambiae complex. Furthermore, experimental infections provide direct evidence that transformed P. falciparum parasites carrying Pfs47 orthologs of P. praefalciparum or P. reichenowi were more effective at evading the immune system of the Asian malaria vector An. dirus than An. gambiae. We propose that high compatibility of ancestral P. falciparum Pfs47 with the receptors of Asian vectors facilitated the early dispersal of human malaria to the Asian continent, without having to first adapt to sub-Saharan vectors of the An. gambiae complex.
Assuntos
Anopheles , Malária Falciparum , Malária , Plasmodium , Animais , Humanos , Plasmodium falciparum/genética , Anopheles/genética , Mosquitos Vetores/parasitologia , Malária Falciparum/parasitologia , Gorilla gorillaRESUMO
Controlled human malaria infections (CHMI) are a valuable tool to study parasite gene expression in vivo under defined conditions. In previous studies, virulence gene expression was analyzed in samples from volunteers infected with the Plasmodium falciparum (Pf) NF54 isolate, which is of African origin. Here, we provide an in-depth investigation of parasite virulence gene expression in malaria-naïve European volunteers undergoing CHMI with the genetically distinct Pf 7G8 clone, originating in Brazil. Differential expression of var genes, encoding major virulence factors of Pf, PfEMP1s, was assessed in ex vivo parasite samples as well as in parasites from the in vitro cell bank culture that was used to generate the sporozoites (SPZ) for CHMI (Sanaria PfSPZ Challenge (7G8)). We report broad activation of mainly B-type subtelomeric located var genes at the onset of a 7G8 blood stage infection in naïve volunteers, mirroring the NF54 expression study and suggesting that the expression of virulence-associated genes is generally reset during transmission from the mosquito to the human host. However, in 7G8 parasites, we additionally detected a continuously expressed single C-type variant, Pf7G8_040025600, that was most highly expressed in both pre-mosquito cell bank and volunteer samples, suggesting that 7G8, unlike NF54, maintains expression of some previously expressed var variants during transmission. This suggests that in a new host, the parasite may preferentially express the variants that previously allowed successful infection and transmission. Trial registration: ClinicalTrials.gov - NCT02704533; 2018-004523-36.
Assuntos
Culicidae , Malária Falciparum , Malária , Parasitos , Animais , Humanos , Culicidae/genética , Expressão Gênica , Malária Falciparum/genética , Malária Falciparum/parasitologia , Parasitos/genética , Plasmodium falciparum/genética , Esporozoítos , Virulência/genéticaRESUMO
Adult cytogenesis, the continuous generation of newly-born neurons (neurogenesis) and glial cells (gliogenesis) throughout life, is highly impaired in several neuropsychiatric disorders, such as Major Depressive Disorder (MDD), impacting negatively on cognitive and emotional domains. Despite playing a critical role in brain homeostasis, the importance of gliogenesis has been overlooked, both in healthy and diseased states. To examine the role of newly formed glia, we transplanted Glial Restricted Precursors (GRPs) into the adult hippocampal dentate gyrus (DG), or injected their secreted factors (secretome), into a previously validated transgenic GFAP-tk rat line, in which cytogenesis is transiently compromised. We explored the long-term effects of both treatments on physiological and behavioral outcomes. Grafted GRPs reversed anxiety-like deficits and demonstrated an antidepressant-like effect, while the secretome promoted recovery of only anxiety-like behavior. Furthermore, GRPs elicited a recovery of neurogenic and gliogenic levels in the ventral DG, highlighting the unique involvement of these cells in the regulation of brain cytogenesis. Both GRPs and their secretome induced significant alterations in the DG proteome, directly influencing proteins and pathways related to cytogenesis, regulation of neural plasticity and neuronal development. With this work, we demonstrate a valuable and specific contribution of glial progenitors to normalizing gliogenic levels, rescuing neurogenesis and, importantly, promoting recovery of emotional deficits characteristic of disorders such as MDD.
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DNA lesions caused by UV damage are thought to be repaired solely by the nucleotide excision repair (NER) pathway in human cells. Patients carrying mutations within genes functioning in this pathway display a range of pathologies, including an increased susceptibility to cancer, premature aging, and neurological defects. There are currently no curative therapies available. Here we performed a high-throughput chemical screen for agents that could alleviate the cellular sensitivity of NER-deficient cells to UV-induced DNA damage. This led to the identification of the clinically approved anti-diabetic drug acetohexamide, which promoted clearance of UV-induced DNA damage without the accumulation of chromosomal aberrations, hence promoting cellular survival. Acetohexamide exerted this protective function by antagonizing expression of the DNA glycosylase, MUTYH. Together, our data reveal the existence of an NER-independent mechanism to remove UV-induced DNA damage and prevent cell death.
Assuntos
Dano ao DNA , DNA Glicosilases/metabolismo , Reparo do DNA/efeitos da radiação , Raios Ultravioleta , Acetoexamida/farmacologia , Linhagem Celular Tumoral , DNA Glicosilases/biossíntese , DNA Glicosilases/genética , Reparo do DNA/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos da radiação , Humanos , MasculinoRESUMO
Cerebral malaria (CM) is a life-threatening form of Plasmodium falciparum infection caused by brain inflammation. Brain endothelium dysfunction is a hallmark of CM pathology, which is also associated with the activation of the type I interferon (IFN) inflammatory pathway. The molecular triggers and sensors eliciting brain type I IFN cellular responses during CM remain largely unknown. We herein identified the stimulator of interferon response cGAMP interactor 1 (STING1) as the key innate immune sensor that induces Ifnß1 transcription in the brain of mice infected with Plasmodium berghei ANKA (Pba). This STING1/IFNß-mediated response increases brain CXCL10 governing the extent of brain leukocyte infiltration and blood-brain barrier (BBB) breakdown, and determining CM lethality. The critical role of brain endothelial cells (BECs) in fueling type I IFN-driven brain inflammation was demonstrated in brain endothelial-specific IFNß-reporter and STING1-deficient Pba-infected mice, which were significantly protected from CM lethality. Moreover, extracellular particles (EPs) released from Pba-infected erythrocytes activated the STING1-dependent type I IFN response in BECs, a response requiring intracellular acidification. Fractionation of the EPs enabled us to identify a defined fraction carrying hemoglobin degradation remnants that activates STING1/IFNß in the brain endothelium, a process correlated with heme content. Notably, stimulation of STING1-deficient BECs with heme, docking experiments, and in vitro binding assays unveiled that heme is a putative STING1 ligand. This work shows that heme resultant from the parasite heterotrophic activity operates as an alarmin, triggering brain endothelial inflammatory responses via the STING1/IFNß/CXCL10 axis crucial to CM pathogenesis and lethality.
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Encéfalo , Heme , Interferon beta , Malária Cerebral , Proteínas de Membrana , Animais , Encéfalo/parasitologia , Células Endoteliais/imunologia , Células Endoteliais/metabolismo , Células Endoteliais/parasitologia , Endotélio/imunologia , Endotélio/parasitologia , Heme/metabolismo , Interferon beta/imunologia , Malária Cerebral/imunologia , Malária Cerebral/parasitologia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Plasmodium berghei/metabolismo , Ativação Transcricional/imunologiaRESUMO
CRISPR-Cas9-mediated genome editing holds great promise for the correction of pathogenic variants in humans. However, its therapeutic implementation is hampered due to unwanted editing outcomes. A better understanding of cell type- and tissue-specific DNA repair processes will ultimately enable precise control of editing outcomes for safer and effective therapies.
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Sistemas CRISPR-Cas , Edição de Genes , Sistemas CRISPR-Cas/genética , Reparo do DNA/genética , Humanos , Especificidade de Órgãos/genéticaRESUMO
Cell size varies between cell types but is tightly regulated by cell intrinsic and extrinsic mechanisms. Cell size control is important for cell function, and changes in cell size are frequently observed in cancer. Here, we uncover a role for SETD2 in regulating cell size. SETD2 is a lysine methyltransferase and a tumor suppressor protein involved in transcription, RNA processing and DNA repair. At the molecular level, SETD2 is best known for associating with RNA polymerase II through its Set2-Rbp1 interacting (SRI) domain and methylating histone H3 on lysine 36 (H3K36) during transcription. Using multiple independent perturbation strategies, we identify SETD2 as a negative regulator of global protein synthesis rates and cell size. We provide evidence that overexpression of the H3K36 demethylase KDM4A or the oncohistone H3.3K36M also increase cell size. In addition, ectopic overexpression of a decoy SRI domain increased cell size, suggesting that the relevant substrate is engaged by SETD2 via its SRI domain. These data add a central role of SETD2 in regulating cellular physiology and warrant further studies on separating the different functions of SETD2 in cancer development.
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Histonas , Neoplasias , Tamanho Celular , Histona Metiltransferases/metabolismo , Histonas/metabolismo , Humanos , Histona Desmetilases com o Domínio Jumonji/metabolismo , Lisina , Neoplasias/metabolismo , RNA Polimerase II/metabolismo , Proteínas Supressoras de Tumor/metabolismoRESUMO
This work reports the rational design and fabrication of magneto-active microfiber meshes with controlled hexagonal microstructures via melt electrowriting (MEW) of a magnetized polycaprolactone-based composite. In situ iron oxide nanoparticle deposition on oxidized graphene yields homogeneously dispersed magnetic particles with sizes above 0.5 µm and low aspect ratio, preventing cellular internalization and toxicity. With these fillers, homogeneous magnetic composites with high magnetic content (up to 20 weight %) are obtained and processed in a solvent-free manner for the first time. MEW of magnetic composites enabled the creation of skeletal muscle-inspired design of hexagonal scaffolds with tunable fiber diameter, reconfigurable modularity, and zonal distribution of magneto-active and nonactive material, with elastic tensile deformability. External magnetic fields below 300 mT are sufficient to trigger out-of-plane reversible deformation. In vitro culture of C2C12 myoblasts on three-dimensional (3D) Matrigel/collagen/MEW scaffolds showed that microfibers guided the formation of 3D myotube architectures, and the presence of magnetic particles does not significantly affect viability or differentiation rates after 8 days. Centimeter-sized skeletal muscle constructs allowed for reversible, continued, and dynamic magneto-mechanical stimulation. Overall, these innovative microfiber scaffolds provide magnetically deformable platforms suitable for dynamic culture of skeletal muscle, offering potential for in vitro disease modeling.
Assuntos
Engenharia Tecidual , Alicerces Teciduais , Alicerces Teciduais/química , Engenharia Tecidual/métodos , Músculo Esquelético , Impressão TridimensionalRESUMO
The successful translation of therapeutic nucleic acids (NAs) for the treatment of neurological disorders depends on their safe and efficient delivery to neural cells, in particular neurons. DNA nanostructures can be a promising NAs delivery vehicle. Nonetheless, the potential of DNA nanostructures for neuronal cell delivery of therapeutic NAs is unexplored. Here, tetrahedral DNA nanostructures (TDN) as siRNA delivery scaffolds to neuronal cells, exploring the influence of functionalization with two different reported neuronal targeting ligands: C4-3 RNA aptamer and Tet1 peptide are investigated. Nanostructures are characterized in vitro, as well as in silico using molecular dynamic simulations to better understand the overall TDN structural stability. Enhancement of neuronal cell uptake of TDN functionalized with the C4-3 Aptamer (TDN-Apt), not only in neuronal cell lines but also in primary neuronal cell cultures is demonstrated. Additionally, TDN and TDN-Apt nanostructures carrying siRNA are shown to promote silencing in a process aided by chloroquine-induced endosomal disruption. This work presents a thorough workflow for the structural and functional characterization of the proposed TDN as a nano-scaffold for neuronal delivery of therapeutic NAs and for targeting ligands evaluation, contributing to the future development of new neuronal drug delivery systems based on DNA nanostructures.
Assuntos
DNA , Nanoestruturas , Neurônios , RNA Interferente Pequeno , Nanoestruturas/química , Neurônios/metabolismo , DNA/química , DNA/metabolismo , Animais , Humanos , Aptâmeros de Nucleotídeos/química , Ácidos Nucleicos/química , Simulação de Dinâmica MolecularRESUMO
Naturally occurring peptides, such as rubiscolins derived from spinach leaves, have been shown to possess some interesting activities. They exerted central effects, such as antinociception, memory consolidation and anxiolytic-like activity. The fact that rubiscolins are potent even when given orally makes them very promising drug candidates. The present work tested whether rubiscolin-6 (R-6, Tyr-Pro-Leu-Asp-Leu-Phe) analogs have neuroprotective and anti-inflammatory effects. These hypotheses were tested in the 6-hydroxydopamine (6-OHDA) injury model of human neuroblastoma SH-SY5Y and lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The determination of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), Caspase-3 activity, lipid peroxidation and nitric oxide (NO) production allowed us to determine the effects of peptides on hallmarks related to Parkinson's Disease (PD) and inflammation. Additionally, we investigated the impact of R-6 analogs on serine-threonine kinase (also known as protein kinase B, AKT) and mammalian target of rapamycin (mTOR) activation. The treatment with analogs 3 (Tyr-Inp-Leu-Asp-Leu-Phe-OH), 5 (Dmt-Inp-Leu-Asp-Leu-Phe-OH) and 7 (Tyr-Inp-Leu-Asp-Leu-Phe-NH2) most effectively prevented neuronal death via attenuation of ROS, mitochondrial dysfunction and Caspase-3 activity. Peptides 5 and 7 significantly increased the protein expression of the phosphorylated-AKT (p-AKT) and phosphorylated-mTOR (p-mTOR). Additionally, selected analogs could also ameliorate LPS-mediated inflammation in macrophages via inhibition of intracellular generation of ROS and NO production. Our findings suggest that R-6 analogs exert protective effects, possibly related to an anti-oxidation mechanism in in vitro model of PD. The data shows that the most potent peptides can inhibit 6-OHDA injury by activating the PI3-K/AKT/mTOR pathway, thus playing a neuroprotective role and may provide a rational and robust approach in the design of new therapeutics or even functional foods.
Assuntos
Neuroblastoma , Fármacos Neuroprotetores , Doença de Parkinson , Fragmentos de Peptídeos , Ribulose-Bifosfato Carboxilase , Humanos , Apoptose , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Oxidopamina/toxicidade , Caspase 3/metabolismo , Lipopolissacarídeos/farmacologia , Linhagem Celular Tumoral , Neuroblastoma/metabolismo , Doença de Parkinson/tratamento farmacológico , Serina-Treonina Quinases TOR/metabolismo , Peptídeos/uso terapêutico , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Inflamação/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêuticoRESUMO
Polyglutamine diseases are a group of neurodegenerative disorders caused by an abnormal expansion of CAG repeat tracts in the codifying regions of nine, otherwise unrelated, genes. While the protein products of these genes are suggested to play diverse cellular roles, the pathogenic mutant proteins bearing an expanded polyglutamine sequence share a tendency to self-assemble, aggregate and engage in abnormal molecular interactions. Understanding the shared paths that link polyglutamine protein expansion to the nervous system dysfunction and the degeneration that takes place in these disorders is instrumental to the identification of targets for therapeutic intervention. Among polyglutamine diseases, spinocerebellar ataxias (SCAs) share many common aspects, including the fact that they involve dysfunction of the cerebellum, resulting in ataxia. Our work aimed at exploring a putative new therapeutic target for the two forms of SCA with higher worldwide prevalence, SCA type 2 (SCA2) and type 3 (SCA3), which are caused by expanded forms of ataxin-2 (ATXN2) and ataxin-3 (ATXN3), respectively. The pathophysiology of polyglutamine diseases has been described to involve an inability to properly respond to cell stress. We evaluated the ability of GTPase-activating protein-binding protein 1 (G3BP1), an RNA-binding protein involved in RNA metabolism regulation and stress responses, to counteract SCA2 and SCA3 pathology, using both in vitro and in vivo disease models. Our results indicate that G3BP1 overexpression in cell models leads to a reduction of ATXN2 and ATXN3 aggregation, associated with a decrease in protein expression. This protective effect of G3BP1 against polyglutamine protein aggregation was reinforced by the fact that silencing G3bp1 in the mouse brain increases human expanded ATXN2 and ATXN3 aggregation. Moreover, a decrease of G3BP1 levels was detected in cells derived from patients with SCA2 and SCA3, suggesting that G3BP1 function is compromised in the context of these diseases. In lentiviral mouse models of SCA2 and SCA3, G3BP1 overexpression not only decreased protein aggregation but also contributed to the preservation of neuronal cells. Finally, in an SCA3 transgenic mouse model with a severe ataxic phenotype, G3BP1 lentiviral delivery to the cerebellum led to amelioration of several motor behavioural deficits. Overall, our results indicate that a decrease in G3BP1 levels may be a contributing factor to SCA2 and SCA3 pathophysiology, and that administration of this protein through viral vector-mediated delivery may constitute a putative approach to therapy for these diseases, and possibly other polyglutamine disorders.
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Doença de Machado-Joseph , Ataxias Espinocerebelares , Humanos , Camundongos , Animais , DNA Helicases/metabolismo , Proteínas de Choque Térmico , Agregados Proteicos , Grânulos de Estresse , Proteínas de Ligação a Poli-ADP-Ribose/genética , RNA Helicases/genética , RNA Helicases/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/genética , Ataxias Espinocerebelares/genética , Ataxias Espinocerebelares/patologia , Ataxina-3/genética , Camundongos Transgênicos , Doença de Machado-Joseph/genéticaRESUMO
Modulation of brain olfactory (OR) and taste receptor (TASR) expression was recently reported in neurological diseases. However, there is still limited evidence of these genes' expression in the human brain and the transcriptional regulation mechanisms involved remain elusive. We explored the possible expression and regulation of selected OR and TASR in the human orbitofrontal cortex (OFC) of sporadic Alzheimer's disease (AD) and non-demented control specimens using quantitative real-time RT-PCR and ELISA. Global H3K9me3 amounts were measured on OFC total histone extracts, and H3K9me3 binding at each chemoreceptor locus was examined through native chromatin immunoprecipitation. To investigate the potential interactome of the repressive histone mark H3K9me3 in OFC specimens, native nuclear complex co-immunoprecipitation (Co-IP) was combined with reverse phase-liquid chromatography coupled to mass spectrometry analysis. Interaction between H3K9me3 and MeCP2 was validated by reciprocal Co-IP, and global MeCP2 levels were quantitated. We found that OR and TAS2R genes are expressed and markedly downregulated in OFC at early stages of sporadic AD, preceding the progressive reduction in their protein levels and the appearance of AD-associated neuropathology. The expression pattern did not follow disease progression suggesting transcriptional regulation through epigenetic mechanisms. We discovered an increase of OFC global H3K9me3 levels and a substantial enrichment of this repressive signature at ORs and TAS2Rs proximal promoter at early stages of AD, ultimately lost at advanced stages. We revealed the interaction between H3K9me3 and MeCP2 at early stages and found that MeCP2 protein is increased in sporadic AD. Findings suggest MeCP2 might be implicated in OR and TAS2R transcriptional regulation through interaction with H3K9me3, and as an early event, it may uncover a novel etiopathogenetic mechanism of sporadic AD.
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Doença de Alzheimer , Humanos , Doença de Alzheimer/metabolismo , Expressão Gênica , Epigênese Genética , Histonas/genética , Histonas/metabolismo , Córtex Pré-Frontal/metabolismoRESUMO
CMTR1 (cap methyltransferase 1) catalyses methylation of the first transcribed nucleotide of RNAPII transcripts (N1 2'-O-Me), creating part of the mammalian RNA cap structure. In addition to marking RNA as self, N1 2'-O-Me has ill-defined roles in RNA expression and translation. Here, we investigated the gene specificity of CMTR1 and its impact on RNA expression in embryonic stem cells. Using chromatin immunoprecipitation, CMTR1 was found to bind to transcription start sites (TSS) correlating with RNAPII levels, predominantly binding at histone genes and ribosomal protein (RP) genes. Repression of CMTR1 expression resulted in repression of RNAPII binding at the TSS and repression of RNA expression, particularly of histone and RP genes. In correlation with regulation of histones and RP genes, CMTR1 repression resulted in repression of translation and induction of DNA replication stress and damage. Indicating a direct role for CMTR1 in transcription, addition of recombinant CMTR1 to purified nuclei increased transcription of the histone and RP genes. CMTR1 was found to be upregulated during neural differentiation and there was an enhanced requirement for CMTR1 for gene expression and proliferation during this process. We highlight the distinct roles of the cap methyltransferases RNMT and CMTR1 in target gene expression and differentiation.
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Células-Tronco Embrionárias , Histonas , Metiltransferases , Proteínas Ribossômicas , Animais , Células-Tronco Embrionárias/metabolismo , Expressão Gênica , Histonas/genética , Histonas/metabolismo , Mamíferos/genética , Capuzes de RNA/genética , RNA Polimerase II/metabolismo , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Sítio de Iniciação de Transcrição , Transcrição GênicaRESUMO
Recent studies have revealed multiple mechanisms that can lead to heterogeneity in ribosomal composition. This heterogeneity can lead to preferential translation of specific panels of mRNAs, and is defined in large part by the ribosomal protein (RP) content, amongst other things. However, it is currently unknown to what extent ribosomal composition is heterogeneous across tissues, which is compounded by a lack of tools available to study it. Here we present dripARF, a method for detecting differential RP incorporation into the ribosome using Ribosome Profiling (Ribo-seq) data. We combine the 'waste' rRNA fragment data generated in Ribo-seq with the known 3D structure of the human ribosome to predict differences in the composition of ribosomes in the material being studied. We have validated this approach using publicly available data, and have revealed a potential role for eS25/RPS25 in development. Our results indicate that ribosome heterogeneity can be detected in Ribo-seq data, providing a new method to study this phenomenon. Furthermore, with dripARF, previously published Ribo-seq data provides a wealth of new information, allowing the identification of RPs of interest in many disease and normal contexts. dripARF is available as part of the ARF R package and can be accessed through https://github.com/fallerlab/ARF.
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Ribossomos/química , Humanos , RNA Mensageiro , RNA Ribossômico/análise , Proteínas Ribossômicas/análise , Ribossomos/genéticaRESUMO
Individuals acquire immunity to clinical malaria after repeated Plasmodium falciparum infections. Immunity to disease is thought to reflect the acquisition of a repertoire of responses to multiple alleles in diverse parasite antigens. In previous studies, we identified polymorphic sites within individual antigens that are associated with parasite immune evasion by examining antigen allele dynamics in individuals followed longitudinally. Here we expand this approach by analyzing genome-wide polymorphisms using whole genome sequence data from 140 parasite isolates representing malaria cases from a longitudinal study in Malawi and identify 25 genes that encode possible targets of naturally acquired immunity that should be validated immunologically and further characterized for their potential as vaccine candidates.
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Alelos , Genoma/genética , Malária Falciparum/imunologia , Malária Falciparum/parasitologia , Plasmodium falciparum/genética , Plasmodium falciparum/imunologia , Adolescente , Adulto , Envelhecimento/imunologia , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Malaui , Adulto JovemRESUMO
BACKGROUND: Motor performances of youth are related to growth and maturity status, among other factors. AIM: To estimate the contribution of skeletal maturity status per se to the motor performances of female athletes aged 10-15 years and the mediation effects of growth status on the relationships. SUBJECTS AND METHODS: Skeletal age (TW3 RUS SA), body size, proportions, estimated fat-free mass (FFM), motor performances, training history and participation motivation were assessed in 80 non-skeletally mature female participants in several sports. Hierarchical and regression-based statistical mediation analyses were used. RESULTS: SA per se explained a maximum of 1.8% and 5.8% of the variance in motor performances of athletes aged 10-12 and 13-15 years, respectively, over and above that explained by covariates. Body size, proportions, and hours per week of training and participation motivation explained, respectively, a maximum of 40.7%, 18.8%, and 22.6% of the variance in performances. Mediation analysis indicated specific indirect effects of SA through stature and body mass, alone or in conjunction with FFM on performances. CONCLUSION: SA per se accounted for small and non-significant amounts of variance in several motor performances of female youth athletes; rather, SA influenced performances indirectly through effects on stature, body mass and estimated FFM.
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Determinação da Idade pelo Esqueleto , Esportes , Adolescente , Feminino , Humanos , Criança , Tamanho Corporal , Atletas , EstaturaRESUMO
INTRODUCTION: Vulvodynia is defined as vulvar pain of at least 3 months' duration, without clear identifiable cause, which may have potential associated factors. It can have a significant impact on women's quality of life due to a combination of physical pain, emotional distress, and limited treatment options. Despite affecting a considerable number of women worldwide, the causes and underlying mechanisms of vulvodynia remain poorly understood. Given the recognized association of the vaginal microbiota with various gynecologic disorders, there has been growing interest in exploring the potential role of the vaginal microbiota in the etiology of vulvodynia. This systematic review aims to evaluate the current literature on the association between the vaginal microbiota and vulvodynia. MATERIAL AND METHODS: A systematic search of multiple databases, including PubMed, Scopus, Web of Science, Cochrane Library, and Ovid MEDLINE, was conducted to identify relevant peer-reviewed studies up to May 12, 2023. The following search terms were used across these databases: "vulvodynia," "vestibulodynia," "vulvar vestibulitis," "microbiome," "microbiota," and "flora." RESULTS: A total of 8 case-control studies were included, the quality of which was assessed using the Newcastle-Ottawa Scale. Data extraction and synthesis were performed using a standardized protocol. In most studies, no major differences were found between the vaginal bacterial composition of women with vulvodynia and that of controls. No specific bacterial taxa were consistently associated with vulvodynia. The relationship between vaginal microbiota diversity and vulvodynia remains to be fully understood. CONCLUSIONS: The role of vaginal microbiota in vulvodynia, if any, remains unclear. Because of the cross-sectional nature of the included studies, it is not possible to make any causal inferences. Further research, using larger and more diverse study populations and advanced sequencing techniques, is necessary to gain a better understanding of the potential relationship between the vaginal microbiota and vulvodynia.
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Microbiota , Vestibulite Vulvar , Vulvodinia , Feminino , Humanos , Vulvodinia/terapia , Qualidade de Vida , Estudos Transversais , Bactérias , DorRESUMO
For a minority of the bereaved, the loss of a significant other can trigger an overwhelming emotional reaction and impaired functioning across life domains, known as prolonged grief disorder (PGD). Hence, ongoing efforts have been made to refine existing treatments to increase their efficacy and to accommodate the idiosyncrasies of grief reactions. This study presents the results of an open clinical trial of the feasibility and effectiveness of the Meaning in Loss (MIL) protocol in an online format. The brief intervention of 12 to 16 sessions combines constructivist and narrative strategies to explore and work through impediments to meaning reconstruction in loss. The sample included 25 participants diagnosed with PGD who were treated by six therapists. Baseline and post-therapy comparisons showed a significant improvement in all clinical measures (grief symptomatology, depression and general distress) and an increase of meaning making regarding the loss. Meaning making was found to be a prospective mediator of symptomatic improvement in grief across the course of therapy. These findings suggest the effectiveness of the MIL protocol in decreasing grief specific and associated symptomatology and argue for the relevance of further controlled evaluations of its efficacy. Moreover, results confirm previous findings that meaning making is a relevant factor in the evolution of grief reactions, including in the context of psychotherapy.