RESUMO
mRNA translation is a fundamental process for life. Selection of the translation initiation site (TIS) is crucial, as it establishes the correct open reading frame for mRNA decoding. Studies in vertebrate mRNAs discovered that a purine at -3 and a G at +4 (where A of the AUG initiator codon is numbered + 1), promote TIS recognition. However, the TIS context in other eukaryotes has been poorly experimentally analyzed. We analyzed in vitro the influence of the -3, -2, -1 and + 4 positions of the TIS context in rabbit, Drosophila, wheat, and yeast. We observed that -3A conferred the best translational efficiency across these species. However, we found variability at the + 4 position for optimal translation. In addition, the Kozak motif that was defined from mammalian cells was only weakly predictive for wheat and essentially non-predictive for yeast. We discovered eight conserved sequences that significantly disfavored translation. Due to the big differences in translational efficiency observed among weak TIS context sequences, we define a novel category that we termed 'barren AUG context sequences (BACS)', which represent sequences disfavoring translation. Analysis of mRNA-ribosomal complexes structures provided insights into the function of BACS. The gene ontology of the BACS-containing mRNAs is presented.
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Códon de Iniciação , Sequência Conservada , Biossíntese de Proteínas , Animais , Coelhos , Códon de Iniciação/genética , Mamíferos/genética , Iniciação Traducional da Cadeia Peptídica , RNA Mensageiro/metabolismo , Leveduras , Eucariotos/genética , Eucariotos/metabolismoRESUMO
mRNA translation initiation plays a critical role in learning and memory. The eIF4F complex, composed of the cap-binding protein eIF4E, ATP-dependent RNA helicase eIF4A, and scaffolding protein eIF4G, is a pivotal factor in the mRNA translation initiation process. eIF4G1, the major paralogue of the three eIF4G family members, is indispensable for development, but its function in learning and memory is unknown. To study the role of eIF4G1 in cognition, we used an eIF4G1 haploinsufficient (eIF4G1-1D) mouse model. The axonal arborization of eIF4G1-1D primary hippocampal neurons was significantly disrupted, and the mice displayed impairment in hippocampus-dependent learning and memory. Translatome analysis showed that the translation of mRNAs encoding proteins of the mitochondrial oxidative phosphorylation (OXPHOS) system was decreased in the eIF4G1-1D brain, and OXPHOS was decreased in eIF4G1-silenced cells. Thus, eIF4G1-mediated mRNA translation is crucial for optimal cognitive function, which is dependent on OXPHOS and neuronal morphogenesis.
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Fator de Iniciação Eucariótico 4G , Fosforilação Oxidativa , Animais , Camundongos , RNA Mensageiro , Iniciação Traducional da Cadeia Peptídica , Morfogênese , DNA HelicasesRESUMO
Cells survive harsh environmental conditions by potently upregulating molecular chaperones such as heat shock proteins (HSPs), particularly the inducible members of the HSP70 family. The life cycle of HSP70 mRNA in the cytoplasm is unique-it is translated during stress when most cellular mRNA translation is repressed and rapidly degraded upon recovery. Contrary to its 5' untranslated region's role in maximizing translation, we discovered that the HSP70 coding sequence (CDS) suppresses its translation via the ribosome quality control (RQC) mechanism. The CDS of the most inducible Saccharomyces cerevisiae HSP70 gene, SSA4, is uniquely enriched with low-frequency codons that promote ribosome stalling during heat stress. Stalled ribosomes are recognized by the RQC components Asc1p and Hel2p and two novel RQC components, the ribosomal proteins Rps28Ap and Rps19Bp. Surprisingly, RQC does not signal SSA4 mRNA degradation via No-Go-Decay. Instead, Asc1p destabilizes SSA4 mRNA during recovery from heat stress by a mechanism independent of ribosome binding and SSA4 codon optimality. Therefore, Asc1p operates in two pathways that converge to regulate the SSA4 mRNA life cycle during stress and recovery. Our research identifies Asc1p as a critical regulator of the stress response and RQC as the mechanism tuning HSP70 synthesis.
Assuntos
Proteínas de Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ribossomos/genética , Ribossomos/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Códon/metabolismo , Biossíntese de ProteínasRESUMO
GCN2 (general control nonderepressible 2) is a serine/threonine-protein kinase that controls messenger RNA translation in response to amino acid availability and ribosome stalling. Here, we show that GCN2 controls erythrocyte clearance and iron recycling during stress. Our data highlight the importance of liver macrophages as the primary cell type mediating these effects. During different stress conditions, such as hemolysis, amino acid deficiency or hypoxia, GCN2 knockout (GCN2-/-) mice displayed resistance to anemia compared with wild-type (GCN2+/+) mice. GCN2-/- liver macrophages exhibited defective erythrophagocytosis and lysosome maturation. Molecular analysis of GCN2-/- cells demonstrated that the ATF4-NRF2 pathway is a critical downstream mediator of GCN2 in regulating red blood cell clearance and iron recycling.
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Aminoácidos , Eritrócitos , Ferro , Fígado , Macrófagos , Proteínas Serina-Treonina Quinases , Fator 4 Ativador da Transcrição/metabolismo , Aminoácidos/deficiência , Aminoácidos/metabolismo , Anemia/metabolismo , Animais , Citofagocitose , Eritrócitos/metabolismo , Deleção de Genes , Hemólise , Hipóxia/metabolismo , Ferro/metabolismo , Fígado/citologia , Lisossomos/metabolismo , Macrófagos/metabolismo , Camundongos , Camundongos Knockout , Fator 2 Relacionado a NF-E2/metabolismo , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Estresse FisiológicoRESUMO
Deregulation of mRNA translation engenders many human disorders, including obesity, neurodegenerative diseases, and cancer, and is associated with pathogen infections. The role of eIF4E-dependent translational control in macrophage inflammatory responses in vivo is largely unexplored. In this study, we investigated the involvement of the translation inhibitors eIF4E-binding proteins (4E-BPs) in the regulation of macrophage inflammatory responses in vitro and in vivo. We show that the lack of 4E-BPs exacerbates inflammatory polarization of bone marrow-derived macrophages and that 4E-BP-null adipose tissue macrophages display enhanced inflammatory gene expression following exposure to a high-fat diet (HFD). The exaggerated inflammatory response in HFD-fed 4E-BP-null mice coincides with significantly higher weight gain, higher Irf8 mRNA translation, and increased expression of IRF8 in adipose tissue compared with wild-type mice. Thus, 4E-BP-dependent translational control limits, in part, the proinflammatory response during HFD. These data underscore the activity of the 4E-BP-IRF8 axis as a paramount regulatory mechanism of proinflammatory responses in adipose tissue macrophages.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Tecido Adiposo/metabolismo , Inflamação/genética , Fatores Reguladores de Interferon/genética , Macrófagos/metabolismo , Biossíntese de Proteínas/genética , Animais , Medula Óssea/metabolismo , Dieta Hiperlipídica/métodos , Fator de Iniciação 4E em Eucariotos/genética , Expressão Gênica/genética , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
OBJECTIVE: Determine the prevalence of suicide attempts and the relationships between the different causes of attempts with sociodemographic and clinical characteristics among individuals in Iran. METHODS: A retrospective review of data about suicide attempts from poisoning care centers in Babol city between 2017 and 2021. Multinomial regression analysis (with mental illness being the reference variable) was used to determine the factors associated with the different causes of suicide attempts (addiction, romantic relationship problems, and economic problems). RESULTS: The overall prevalence of completed suicide in the population sampled was 10.8% (95% confidence interval 9.5-12.1) (244/2,263). Relative to mental disorder, given that other variables in the model are held constant the following were associated with suicide attempts. A previous history of suicide attempts was associated with increasing the relative risk ratio of attempting suicide while having no positive history of smoking was associated with reducing the relative risk ratio of a suicidal attempt. However, the use of multiple drugs to attempt suicide was associated with an increased relative risk ratio of attempting suicide with romantic relationship problems and addiction as causes of suicide attempts. The first year of data collection (2017) and the female gender were both associated with an increased relative risk ratio of having a suicide attempt due to romantic relationships and economic problems. A family history of suicide was associated with an increased relative risk ratio of suicide attempts due to romantic relationship problems. However, using Pesticides-aluminum phosphide and detergent and javel water to attempt reduced the relative risk ratio of attempting due to romantic relationship problems. Age, self-employment, middle income, and married were associated with an increased relative risk ratio of suicide attempts among individuals due to addiction. However, staying longer at the emergency department was associated with a reduced relative risk ratio of having had a suicide attempt due to addiction. CONCLUSIONS: This study highlights the interplay between romantic hardships, addiction, economic hardships as reasons for suicide attempts and various sociable variables in a population in Northern Iran. The most associated reason for suicide attempts was romantic relationship hardships. Therefore, interventions such as sessions on conflict resolution, boundary setting, and management of grieving would greatly benefit this society and reduce the rate of suicide, especially among individuals with a history of suicide attempts.
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Transtornos Mentais , Tentativa de Suicídio , Humanos , Feminino , Estudos Retrospectivos , Fatores de Risco , Prevalência , Ideação SuicidaRESUMO
Hippuristanol (Hipp) is a natural product that selectively inhibits protein synthesis by targeting eukaryotic initiation factor (eIF) 4A, a DEAD-box RNA helicase required for ribosome recruitment to mRNA templates. Hipp binds to the carboxyl-terminal domain of eIF4A, locks it in a closed conformation, and inhibits its RNA binding. The dependencies of mRNAs for eIF4A during initiation is contingent on the degree of secondary structure within their 5' leader region. Interest in targeting eIF4A therapeutically in cancer and viral-infected settings stems from the dependencies that certain cellular (e.g. pro-oncogenic, pro-survival) and viral mRNAs show towards eIF4A. Using a CRISPR/Cas9-based variomics screen, we identify functional EIF4A1 Hipp-resistant alleles, which in turn allowed us to link the translation-inhibitory and cytotoxic properties of Hipp to eIF4A1 target engagement. Genome-wide translational profiling in the absence or presence of Hipp were undertaken and our validation studies provided insight into the structure-activity relationships of eIF4A-dependent mRNAs. We find that mRNA 5' leader length, overall secondary structure and cytosine content are defining features of Hipp-dependent mRNAs.
Assuntos
Regiões 5' não Traduzidas , Resistencia a Medicamentos Antineoplásicos/genética , Fator de Iniciação 4A em Eucariotos/genética , Esteróis/farmacologia , Sistemas CRISPR-Cas , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Fator de Iniciação 4A em Eucariotos/antagonistas & inibidores , Fator de Iniciação 4A em Eucariotos/metabolismo , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Mutação , Ribossomos/genética , Ribossomos/metabolismoRESUMO
INTRODUCTION: Since hospitals play an important role in dealing with disaster victims, this study was conducted to audit the functional preparedness of the selected military hospital in response to incidents and disasters. MATERIALS AND METHODS: This applied action research was conducted in all wards of a military hospital from September 2020 to September 2021. The functional preparedness of the hospital was assessed using a functional preparedness checklist containing 17 domains and the weaknesses of the hospital were identified. Then, during the hospital audit cycle, a plan was developed to improve work processes and the functional preparedness of different wards of the hospital in response to incidents and disasters using the FOCUS-PDCA model. The functional preparedness of the hospital was compared before and after the intervention and analyzed using SPSS22. RESULTS: The relative mean score of hospital preparedness in response to disasters was 508 out of 900 (56.44%) before the intervention, which was moderate. The relative mean score of the hospital preparedness in response to disasters was 561 (63.63%) after the intervention, which was good. The highest preparedness was related to risk assessment (85%) and the lowest preparedness was related to victims' dead bodies (44%). CONCLUSION: Considering the effect of action research on improving the hospital's functional preparedness in response to disasters, other healthcare facilities are encouraged to incorporate auditing into their work plans.
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Planejamento em Desastres , Desastres , Lista de Checagem , Pesquisa sobre Serviços de Saúde , Hospitais Militares , Humanos , Inquéritos e Questionários , Estados UnidosRESUMO
Background: The International Convention on the Rights of Persons with Disabilities (CRPD) is the most important International Document for recognizing the rights of persons with disabilities, including the right to health and rehabilitation. Islamic Republic Iran acceded to the Convention in 2008, but still has a long way to go to achieve its desired status and in line with the objectives of the convention. This study aimed to identify the barriers to the implementation of articles 25 and 26 of the CRPD in Iran. Methods: This study was performed using conventional content analysis. Twenty-one individuals were recruited by purposive sampling with maximum variation and were continued until saturation. Data were gathered through in-depth, semi-structured interviews from June 2018 to May 2019. MAXQDA version 10 was used for analyzing data. Results: The resulting data analysis yielded 860 initial or open codes. The concepts were categorized into 27 subcategories and 7 categories. Main categories were included: "Structure inefficiency", "lack of comprehensive rehabilitation program", "inadequate awareness", "neglected economy of people with disabilities", "weak access to services", "cultural challenges" and "disregard for new technologies". Conclusion: The findings showed that the executive structures in the country have a lot of problems with health and rehabilitation programs for people with disabilities. It seems understanding the barriers to implementation of articles 25 and 26 of the international CRPD empowers officials in the field and improve services by providing a better view of the disabled. Nevertheless, it is recommended for policymakers to consider rehabilitation as a main element of the health system.
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BACKGROUND: Over-expression of cyclooxygenase (COX)-2 promotes breast cancer progression by multiple mechanisms, including induction of stem-like cells (SLC). Combined gene expression and microRNA microarray analyses of empty vector vs COX-2- transfected COX-2 low MCF7 breast cancer cell line identified two COX-2-upregulated microRNAs, miR-526b and miR-655, both found to be oncogenic and SLC-promoting. Cytoplasmic Polyadenylation Element-Binding Protein 2 (CPEB2) was the single common target of both microRNAs, the functions of which remain controversial. CPEB2 has multiple isoforms (A-F), and paradoxically, a high B/A ratio was reported to impart anoikis-resistance and metastatic phenotype in triple- negative breast cancer cells. We tested whether CPEB2 is a tumor suppressor in mammary epithelial cells. METHODS: We knocked-out CPEB2 in the non-tumorigenic mammary epithelial cell line MCF10A by CRISPR/Cas9-double nickase approach, and knocked-down CPEB2 with siRNAs in the poorly malignant MCF7 cell line, both lines being high CPEB2-expressing. The resultant phenotypes for oncogenity were tested in vitro for both lines and in vivo for CPEB2KO cells. Finally, CPEB2 expression was compared between human breast cancer and non-tumor breast tissues. RESULTS: CPEB2 (isoform A) expression was inversely correlated with COX-2 or the above microRNAs in COX-2-divergent breast cancer cell lines. CPEB2KO MCF10A cells exhibited oncogenic properties including increased proliferation, migration, invasion, EMT (decreased E-Cadherin, increased Vimentin, N-Cadherin, SNAI1, and ZEB1) and SLC phenotype (increased tumorsphere formation and SLC marker-expression). Tumor-suppressor p53 protein was shown to be a novel translationally-regulated target of CPEB2, validated with polysome profiling. CPEB2KO, but not wild-type cells produced lung colonies upon intravenous injection and subcutaneous tumors and spontaneous lung metastases upon implantation at mammary sites in NOD/SCID/IL2RÏ-null mice, identified with HLA immunostaining. Similarly, siRNA-mediated CPEB2 knockdown in MCF7 cells promoted oncogenic properties in vitro. Human breast cancer tissues (n = 105) revealed a lower mRNA expression for CPEB2 isoform A and also a lower A/B isoform ratio than in non-tumour breast tissues (n = 20), suggesting that CPEB2A accounts for the tumor-suppressor functions of CPEB2. CONCLUSIONS: CPEB2, presumably the isoform A, plays a key role in suppressing tumorigenesis in mammary epithelial cells by repressing EMT, migration, invasion, proliferation and SLC phenotype, via multiple targets, including a newly-identified translational target p53.
Assuntos
Neoplasias da Mama/patologia , Mama/citologia , Proteínas de Ligação a RNA/metabolismo , Animais , Sistemas CRISPR-Cas , Movimento Celular , Proliferação de Células , Ciclo-Oxigenase 2/metabolismo , Células Epiteliais/metabolismo , Transição Epitelial-Mesenquimal , Feminino , Técnicas de Inativação de Genes , Xenoenxertos , Humanos , Células MCF-7 , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , MicroRNAs/metabolismo , Isoformas de Proteínas , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
OBJECTIVE: This study attempted to evaluate the efficacy of ultra-low-dose intravenous (IV) naloxone combined with IV morphine, as compared to IV morphine alone, in terms of reducing pain and morphine-induced side effects in patients with renal colic. METHODS: In this double-blind clinical trial, 150 patients aged 34 to 60â¯years old who presented to the emergency department (ED) with renal colic were randomly allocated to either an intervention group that received ultra-low-dose IV naloxone combined with IV morphine or to a control group that received morphine plus a placebo. The severity of pain, sedation, and nausea were assessed and recorded for all patients at entrance to the ED (T1), then at 20 (T2), 40 (T3), 60 (T4), 120 (T5), and 180 (T6) minutes after starting treatment. The Numeric Rating Scale (NRS) was used for the assessment of pain and nausea intensities, and the Ramsay Sedation Scale (RSS) was used to assess sedation. RESULTS: A GEE model revealed that patients in the naloxone group had non-significantly reduced pain scores compared to those in the morphine group (coefficientâ¯=â¯-0.68; 95% CI: -1.24 to -0.11, Wald X2 (1)â¯=â¯5.41, pâ¯=â¯0.02). The sedation outcome demonstrated no statistically significant differences at T1 to T4 among patients with renal colic compared to the ones who only received morphine. At T5 and T6, 1.5% vs. 20% and 1.5% vs. 16.9% of subjects from the naloxone group versus the morphine group obtained RSS scores equal to 3, respectively (pâ¯=â¯0.001 and pâ¯=â¯0.004, respectively). CONCLUSIONS: Compared to patients who only received IV morphine, co-treatment of ultra-low-dose naloxone with morphine could not provide better analgesia and sedation/agitation states in renal colic patients.
Assuntos
Analgesia/normas , Morfina/administração & dosagem , Naloxona/administração & dosagem , Manejo da Dor/normas , Cólica Renal/complicações , Adulto , Analgesia/métodos , Analgesia/estatística & dados numéricos , Análise de Variância , Método Duplo-Cego , Quimioterapia Combinada/métodos , Quimioterapia Combinada/normas , Quimioterapia Combinada/estatística & dados numéricos , Serviço Hospitalar de Emergência/organização & administração , Serviço Hospitalar de Emergência/estatística & dados numéricos , Feminino , Humanos , Irã (Geográfico) , Masculino , Pessoa de Meia-Idade , Morfina/normas , Morfina/uso terapêutico , Naloxona/normas , Naloxona/uso terapêutico , Dor/tratamento farmacológico , Manejo da Dor/métodos , Manejo da Dor/estatística & dados numéricos , Medição da Dor/métodos , Cólica Renal/tratamento farmacológico , Estatísticas não ParamétricasRESUMO
BACKGROUND: Routine culture-based diagnosis of Pseudomonas aeruginosa lung infection in Cystic Fibrosis (CF) patients can be hampered by the phenotypic variability of the microorganism, including its transition to a Viable But Non-Culturable (VBNC) state. The aim of this study was to validate an ecfX-targeting qPCR protocol developed to detect all viable P. aeruginosa bacteria and to identify VBNC forms in CF sputum samples. METHODS: The study involved 115 P. aeruginosa strains of different origins and 10 non-P. aeruginosa strains and 88 CF sputum samples, 41 Culture-Positive (CP) and 47 Culture-Negative (CN). Spiking assays were performed using scalar dilutions of a mixture of live and dead P. aeruginosa ATCC 9027 and a pooled P. aeruginosa-free sputum batch. Total DNA from sputum samples was extracted by a commercial kit, whereas a crude extract was obtained from the broth cultures. Extracellular DNA (eDNA) interference was evaluated by comparing the qPCR counts obtained from DNase-treated and untreated aliquots of the same samples. The statistical significance of the results was assessed by the Wilcoxon test and Student's t test. RESULTS: The newly-developed qPCR protocol identified 96.6% of the P. aeruginosa isolates; no amplification was obtained with strains belonging to different species. Spiking assays supported protocol reliability, since counts always matched the amount of live bacteria, thus excluding the interference of dead cells and eDNA. The protocol sensitivity threshold was 70 cells/ml of the original sample. Moreover, qPCR detected P. aeruginosa in 9/47 CN samples and showed higher bacterial counts compared with the culture method in 10/41 CP samples. CONCLUSIONS: Our findings demonstrate the reliability of the newly-developed qPCR protocol and further highlight the need for harnessing a non-culture approach to achieve an accurate microbiological diagnosis of P. aeruginosa CF lung infection and a greater understanding of its evolution.
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Fibrose Cística/microbiologia , Viabilidade Microbiana , Técnicas Microbiológicas , Infecções por Pseudomonas/diagnóstico , Pseudomonas aeruginosa , Reação em Cadeia da Polimerase em Tempo Real/métodos , Fibrose Cística/complicações , Feminino , Humanos , Limite de Detecção , Pulmão/microbiologia , Masculino , Técnicas Microbiológicas/normas , Infecções por Pseudomonas/complicações , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/citologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/isolamento & purificação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Escarro/microbiologiaRESUMO
BACKGROUND: Hepatic steatosis is commonly observed in patients with chronic hepatitis C (CHC). Many studies indicate a relationship between steatosis and fibrosis progression. The aim of this study was to analyze the prevalence of hepatic steatosis and related factors in Iranian CHC patients. METHODS: One hundred and fifteen consecutive patients with CHC were enrolled which were treatment- naïve. The patients were divided into groups with and without steatosis according to the result of liver biopsy (58.3% and 41.7%, respectively). Demographic, histological, biochemical and virological factors were examined and compared in all patients. RESULTS: In terms of host factors, body mass index (BMI), triglyceride, fasting blood glucose (FBG), necroinflammatory activity and severity in fibrosis of CHC patients with steatosis was significantly higher than the patients without steatosis. Of viral factors, HCV viral load was not significantly altered in patients with steatosis. Moreover, HCV genotypes did not meet such association. Using multivariate regression analysis, parameters of BMI values, FBG level and stage of fibrosis were independently associated with steatosis. CONCLUSION: Our data indicate that CHC patients are more susceptible to development of hepatic steatosis. Based on our results, grade of steatosis appears to be associated with hepatic fibrosis progression rate in CHC patients.
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The integrated stress response (ISR) is critical for cell survival under stress. In response to diverse environmental cues, eIF2α becomes phosphorylated, engendering a dramatic change in mRNA translation. The activation of ISR plays a pivotal role in the early embryogenesis, but the eIF2-dependent translational landscape in pluripotent embryonic stem cells (ESCs) is largely unexplored. We employ a multi-omics approach consisting of ribosome profiling, proteomics, and metabolomics in wild-type (eIF2α+/+) and phosphorylation-deficient mutant eIF2α (eIF2αA/A) mouse ESCs (mESCs) to investigate phosphorylated (p)-eIF2α-dependent translational control of naive pluripotency. We show a transient increase in p-eIF2α in the naive epiblast layer of E4.5 embryos. Absence of eIF2α phosphorylation engenders an exit from naive pluripotency following 2i (two chemical inhibitors of MEK1/2 and GSK3α/ß) withdrawal. p-eIF2α controls translation of mRNAs encoding proteins that govern pluripotency, chromatin organization, and glutathione synthesis. Thus, p-eIF2α acts as a key regulator of the naive pluripotency gene regulatory network.
Assuntos
Células-Tronco Embrionárias Murinas , Células-Tronco Pluripotentes , Animais , Camundongos , Células-Tronco Embrionárias/metabolismo , Células-Tronco Embrionárias Murinas/metabolismo , Fosforilação , Células-Tronco Pluripotentes/metabolismo , RNA Mensageiro/metabolismo , Fator de Iniciação 2 em Eucariotos/metabolismoRESUMO
Sensitization of spinal nociceptive circuits plays a crucial role in neuropathic pain. This sensitization depends on new gene expression that is primarily regulated via transcriptional and translational control mechanisms. The relative roles of these mechanisms in regulating gene expression in the clinically relevant chronic phase of neuropathic pain are not well understood. Here, we show that changes in gene expression in the spinal cord during the chronic phase of neuropathic pain are substantially regulated at the translational level. Downregulating spinal translation at the chronic phase alleviated pain hypersensitivity. Cell-type-specific profiling revealed that spinal inhibitory neurons exhibited greater changes in translation after peripheral nerve injury compared to excitatory neurons. Notably, increasing translation selectively in all inhibitory neurons or parvalbumin-positive (PV+) interneurons, but not excitatory neurons, promoted mechanical pain hypersensitivity. Furthermore, increasing translation in PV+ neurons decreased their intrinsic excitability and spiking activity, whereas reducing translation in spinal PV+ neurons prevented the nerve injury-induced decrease in excitability. Thus, translational control mechanisms in the spinal cord, particularly in inhibitory neurons, play a role in mediating neuropathic pain hypersensitivity.
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AIM: This research aimed to examine the relationship between the intake of statins and the risk of post-stroke pneumonia in a systematic review and meta-analysis study. METHODS: An extensive search of published articles on March 21st , 2023, was done in several databases, like Web of Science (ISI), PubMed, Cochrane Library, Embase, Scopus, and Google Scholar. The Newcastle Ottawa Scale (NOS) checklist was employed to evaluate the quality of observational studies. Statistical tests (Chi-square test and I2 ) and graphical techniques (Forest plot) were used to determine whether heterogeneity existed in the meta-analysis studies. Funnel plots and Begg and Egger's tests were used to assess the publication bias. RESULTS: Seven studies (5 cohort and 2 case-control studies) were retrieved to examine the association between statins and post-stroke pneumonia. The sample size of the studies compiled in the meta-analysis was obtained to be 68,966 participants. Meta-analysis demonstrated that the overall odds of post-stroke pneumonia in the statin group was equal to 0.87 (95% CI: 0.67 - 1.13; p-value 0.458). Subgroup analysis indicated that the odds of post-stroke pneumonia in the statin group was equal to 0.93 (95% CI: 0.73-1.18; p-value=0.558) in the cohort studies, and equal to 0.92 (95% CI: 0.37-2.26; p-value=0.857) in the case-control studies. The examination of the association between the intake of statins and post-stroke pneumonia showed no evidence of publication bias (Begg's test, p-value = 0.368; Eggers test, p-value = 0.282). CONCLUSION: In this study, no relationship has been observed between receiving statins and the risk of post-stroke pneumonia.
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Translation initiation in eukaryotes is regulated at several steps, one of which involves the availability of the cap binding protein to participate in cap-dependent protein synthesis. Binding of eIF4E to translational repressors (eIF4E-binding proteins [4E-BPs]) suppresses translation and is used by cells to link extra- and intracellular cues to protein synthetic rates. The best studied of these interactions involves repression of translation by 4E-BP1 upon inhibition of the PI3K/mTOR signaling pathway. Herein, we characterize a novel 4E-BP, C8ORF88, whose expression is predominantly restricted to early spermatids. C8ORF88:eIF4E interaction is dependent on the canonical eIF4E binding motif (4E-BM) present in other 4E-BPs. Whereas 4E-BP1:eIF4E interaction is dependent on the phosphorylation of 4E-BP1, these sites are not conserved in C8ORF88 indicating a different mode of regulation.
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Proteínas de Transporte , Fator de Iniciação 4E em Eucariotos , Proteínas de Transporte/metabolismo , Fator de Iniciação 4E em Eucariotos/genética , Fator de Iniciação 4E em Eucariotos/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Ligação Proteica , FosforilaçãoRESUMO
BACKGROUND: Pancreatic cancer (PC) is a type of cancer with a high incidence and case-fatality rate. OBJECTIVE: This study aimed to evaluate the role of statins in preventing mortality following PC based on scientific evidence with systematic review and meta-analysis method. METHODS: This meta-analysis considered studies published from 1980 till the end of 2022 in ISI Web of Science, Scopus, PubMed, Cochrane, Science Direct, Google Scholar, and Embase databases. Funnel diagrams and Begg's and Egger's tests were used to assess the publication bias. RESULTS: In general, this meta-analysis has included 19 studies (13 cohort studies, 4 case-control, and 2 randomized clinical trials (RCTs)) and a total of 100,888 patients with PC. The risk of mortality of PC in statin users in total was 0.86 (95% CI: 0.80 - 0.92, P-value <0.001); in the case-control studies, it was equal to 0.53 (0.34-0.83); in the cohort studies, it was equal to 0.87 (0.82-0.92, P-value <0.001); in RCTs, it was equal to 1.19 (0.99-1.42, P-value <0.001); in studies with good quality score category, it was equal to 0.92 (0.86-0.99, P-value <0.001), and in articles of the moderate quality score category, it was equal to 0.73 (0.64-0.84, P-value <0.001). The results of statistical tests indicated the existence of publication bias (Begg's test (P-value = 0.002) and Egger's test (P-value = 0.004)). CONCLUSION: Statins reduce the risk of mortality in patients with PC. However, no significant relation has been observed in RCTs. Therefore, it is necessary to be cautious in interpreting the results.
Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases , Neoplasias Pancreáticas , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Incidência , Neoplasias Pancreáticas/tratamento farmacológico , Estudos de Casos e ControlesRESUMO
Objective: To investigate the use of prognostic markers such as C-reactive protein (CRP) and D-dimer for clinical outcomes in patients with mild traumatic brain injury (TBI). Methods: This cross-sectional study was conducted on patients with mild head trauma who were admitted to the Emergency Department of Imam Khomeini Hospital (Sari, Iran). Data were collected from 2018 to 2019. Age, sex, the time of injury hospitalization, length of hospitalization, length of unconsciousness, blood pressure, heart rate, respiratory rate, and concomitant symptoms were all recorded using a pre-designed checklist. The patient's Glasgow Coma Scale (GCS), CRP, and D-dimer were also measured. Moreover, all patients underwent CT scan. Results: This study included 74 patients with TBI. The mean age of the participants was 36.92±3.54. The mean CRP and D-dimer values were 5.69±0.77 and 0.58±0.11 in these patients, respectively. At the cut-off point of 11.50 for CRP, the sensitivity and specificity to detect the pathological lesions in CT scan were 75% and 95.50%, respectively (p<0.001). Additionally, with a D-dimer cut-off point of 0.90, the sensitivity and specificity for diagnosing pathological lesions in CT scan were 100% and 98.50%, respectively (p<0.001). Conclusion: In general, the CRP and D-dimer levels of patients with mild TBI (GCS≥13) can be assessed to protect against CT-induced radiation exposure and subsequent disorders; if they do not exhibit clinical signs to increase the risk of adverse brain damage, such as reduced level of consciousness, drowsiness, and prolonged periods of unconsciousness.
RESUMO
BACKGROUND: Carpal tunnel syndrome (CTS) is a debilitating neuropathy that accompanies pain and other physical limitations and disrupts the normal functioning of the victims' lives. OBJECTIVE: We aimed to investigate Vitamin D's preventive and therapeutic effects on the occurrence and remission of CTS symptoms. METHODS: In this systematic review the PRISMA statement has been designed primarily. An extensive search was undertaken in various databases, including PubMed, Cochrane library, Web of Science, EMBASE, and Scopus. After considering the inclusion and exclusion criteria of the study, finally, 19 articles were retrieved. The raw data were extracted and entered into an Excel form, and the study outcomes were investigated. RESULTS: The main symptoms and tests, including functional score, nerve conduction, and pain, were improved after Vitamin D supplementation in CTS patients. However, they revealed worse scores in people with low Vitamin D levels. In addition, the scores of mentioned indices were worsened in people with lower serum Vitamin D levels. Nevertheless, some studies did not find a significant relationship between low serum 25(OH)D and more significant pain scores in CTS patients. In addition, Vitamin D inserts its effects on CTS by regulating cell proliferation, nerve growth factor, suppression of oxidative stress and inflammatory cytokines, and improvement in cartilage and microvascular damage. CONCLUSION: Vitamin D supplementation can improve the symptoms in CTS patients, and low serum 25(OH)D can aggravate the symptoms of the disease and could be a risk factor for its occurrence. However, more observational studies and clinical trials are needed.