RESUMO
Alternative splicing (AS) plays important roles in embryonic stem cell (ESC) differentiation. In this study, we first identified transcripts that display specific AS patterns in pluripotent human ESCs (hESCs) relative to differentiated cells. One of these encodes T-cell factor 3 (TCF3), a transcription factor that plays important roles in ESC differentiation. AS creates two TCF3 isoforms, E12 and E47, and we identified two related splicing factors, heterogeneous nuclear ribonucleoproteins (hnRNPs) H1 and F (hnRNP H/F), that regulate TCF3 splicing. We found that hnRNP H/F levels are high in hESCs, leading to high E12 expression, but decrease during differentiation, switching splicing to produce elevated E47 levels. Importantly, hnRNP H/F knockdown not only recapitulated the switch in TCF3 AS but also destabilized hESC colonies and induced differentiation. Providing an explanation for this, we show that expression of known TCF3 target E-cadherin, critical for maintaining ESC pluripotency, is repressed by E47 but not by E12.
Assuntos
Processamento Alternativo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Caderinas/metabolismo , Células-Tronco Embrionárias/metabolismo , Ribonucleoproteínas Nucleares Heterogêneas Grupo F-H/metabolismo , Antígenos CD , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Caderinas/genética , Diferenciação Celular/genética , Linhagem Celular , Células-Tronco Embrionárias/citologia , Éxons , Regulação da Expressão Gênica , Humanos , Precursores de RNA/química , RNA Mensageiro/química , Sequências Reguladoras de Ácido RibonucleicoRESUMO
The RNA polymerase II largest subunit C-terminal domain consists of repeated YSPTSPS heptapeptides. The role of tyrosine-1 (Tyr1) remains incompletely understood, as, for example, mutating all Tyr1 residues to Phe (Y1F) is lethal in vertebrates but a related mutant has only a mild phenotype in S. pombe. Here we show that Y1F substitution in budding yeast resulted in a strong slow-growth phenotype. The Y1F strain was also hypersensitive to several different cellular stresses that involve MAP kinase signaling. These phenotypes were all linked to transcriptional changes, and we also identified genetic and biochemical interactions between Tyr1 and both transcription initiation and termination factors. Further studies uncovered defects related to MAP kinase I (Slt2) pathways, and we provide evidence that Slt2 phosphorylates Tyr1 in vitro and in vivo. Our study has thus identified Slt2 as a Tyr1 kinase, and in doing so provided links between stress response activation and Tyr1 phosphorylation.
Assuntos
Regulação Fúngica da Expressão Gênica , Proteínas Quinases Ativadas por Mitógeno/metabolismo , RNA Polimerase II/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimologia , Estresse Fisiológico , Quinase 8 Dependente de Ciclina/genética , Quinase 8 Dependente de Ciclina/metabolismo , Genótipo , Complexo Mediador/genética , Complexo Mediador/metabolismo , Proteínas Quinases Ativadas por Mitógeno/genética , Mutação , Fenótipo , Fosforilação , Domínios Proteicos , RNA Polimerase II/química , RNA Polimerase II/genética , RNA Fúngico/genética , RNA Fúngico/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Proteínas de Saccharomyces cerevisiae/genética , Transdução de Sinais , Fatores de Tempo , Transdução Genética , TirosinaRESUMO
We describe herein a facile method to access 2,3-epoxyesters with fluorine-containing substituents at their 3-position starting from the corresponding enoates by utilization of the low-costed and easy-to-handle reagent, NaOCl·5H2O. Because very little has been disclosed about the reactivity of such 2,3-epoxyesters, their epoxy ring opening by a variety of nucleophiles was carried out and we succeeded in clarifying these chemo- as well as regioselective processes proceeding via the SN2 mechanism to mainly afford 2-substituted 3-hydroxyesters usually in a highly anti selective manner.
RESUMO
The role of neuroinflammation in the pathophysiology of migraines is increasingly being recognized, and cytokines, which are important endogenous substances involved in immune and inflammatory responses, have also received attention. This review examines the current literature on neuroinflammation in the pathogenesis of migraine. Elevated TNF-α, IL-1ß, and IL-6 levels have been identified in non-invasive mouse models with cortical spreading depolarization (CSD). Various mouse models to induce migraine attack-like symptoms also demonstrated elevated inflammatory cytokines and findings suggesting differences between episodic and chronic migraines and between males and females. While studies on human blood during migraine attacks have reported no change in TNF-α levels and often inconsistent results for IL-1ß and IL-6 levels, serial analysis of cytokines in jugular venous blood during migraine attacks revealed consistently increased IL-1ß, IL-6, and TNF-α. In a study on the interictal period, researchers reported higher levels of TNF-α and IL-6 compared to controls and no change regarding IL-1ß levels. Saliva-based tests suggest that IL-1ß might be useful in discriminating against migraine. Patients with migraine may benefit from a cytokine perspective on the pathogenesis of migraine, as there have been several encouraging reports suggesting new therapeutic avenues.
Assuntos
Citocinas , Transtornos de Enxaqueca , Masculino , Camundongos , Feminino , Animais , Humanos , Fator de Necrose Tumoral alfa , Interleucina-6 , Doenças Neuroinflamatórias , Transtornos de Enxaqueca/etiologiaRESUMO
TCF3, also known as E2A, is a well-studied transcription factor that plays an important role in stem cell maintenance and hematopoietic development. The TCF3 gene encodes two related proteins, E12 and E47, which arise from mutually exclusive alternative splicing (MEAS). Since these two proteins have different DNA binding and dimerization domains, this AS event must be strictly regulated to ensure proper isoform ratios. Previously, we found that heterogeneous nuclear ribonucleoprotein (hnRNP) H1/F regulates TCF3 AS by binding to exonic splicing silencers (ESSs) in exon 18b. Here, we identify conserved intronic splicing silencers (ISSs) located between, and far from, the two mutually exclusive exons, and show that they are essential for MEAS. Further, we demonstrate that the hnRNP PTBP1 binds the ISS and is a regulator of TCF3 AS. We also demonstrate that hnRNP H1 and PTBP1 regulate TCF3 AS reciprocally, and that position-dependent interactions between these factors are essential for proper TCF3 MEAS. Our study provides a new model in which MEAS is regulated by cooperative actions of distinct hnRNPs bound to ISSs and ESSs.
Assuntos
Processamento Alternativo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Proteína de Ligação a Regiões Ricas em Polipirimidinas/metabolismo , RNA Helicases DEAD-box/metabolismo , Éxons , Células HeLa , Humanos , Íntrons , Ligação ProteicaRESUMO
Analysis of the skin mycobiome of an astronaut during a 1-year stay on the International Space Station (ISS) revealed an increased relative abundance of Malassezia restricta and level of Malassezia colonization, and the presence of Cyberlindnera jadinii and Candida boidinii, uncommon skin mycobiome taxa. Similar observations were made in astronauts during a 6-month stay on the ISS (Med Mycol. 2016; 54: 232-239). Future plans for extended space travel should consider the effect of high levels of Malassezia colonization over long periods on astronauts' skin, and the abnormal proliferation of uncommon microorganisms that may occur in closed environments such as the ISS.
Assuntos
Astronautas , Malassezia/isolamento & purificação , Microbiota , Saccharomycetales/isolamento & purificação , Pele/microbiologia , Voo Espacial , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estados UnidosRESUMO
1,6-Conjugate additions of in situ generated δ-CF3-δ-substituted p-quinone methides have been achieved with a variety of heteronucleophiles under mild conditions, which led to facile and practical construction of fully substituted carbon centers including a heteroatom and a CF3 group. In particular, it was revealed that some amines themselves worked for efficient cleavage of the TBS protective group, and addition of a catalytic amount of an appropriate Brønsted acid was found to sometimes improve the progress of the desired process.
RESUMO
As part of a series of studies regarding the microbiota in manned space environments, we isolated the fungal strains from nasal and pharyngeal smears and saliva of 21 astronauts preflight, in-flight, and postflight. On the ground, 120 strains from 43 genera of environmental fungi were isolated from the astronauts. The dominant fungal genera were Cladosporium, Penicillium, and Aspergillus. Only 18 strains from four genera were isolated from the astronauts inside the International Space Station. These fungi are currently thought to be harmless, but regular screening and cleaning are necessary to prevent fungus-related health disorders.
Assuntos
Voo Espacial , Astronautas , Fungos , Humanos , Microbiota , SalivaRESUMO
The International Space Station (ISS) is a closed facility that orbits the earth carrying not only its crew but also microorganisms. We have participated in microbiota analysis projects for the Japanese Experiment Module KIBO (ISS; operations nomenclature: Microbe-I, II, III, and IV) and were in charge of fungal screening. The interior of KIBO was sampled using swabs and microbe detection sheets (MDSs) for fungal detection. The dominant genera obtained by culture were Aspergillus and Penicillium. DNA analyses of the fungal biota using a clone library showed that KIBO was dominated by Malassezia, a fungal inhabitant of human skin. Three fungal species, Aspergillus sydowii, Penicillium palitans, and Rhodotorula mucilaginosa, which grew under microgravity in KIBO were observed under a field emission-scanning electron microscope on the ground. No novel phenotypic characteristics were noted. The results of antifungal susceptibility testing of all isolates did not differ significantly from previous reports of corresponding fungi. In Microbe-I (August 2009), MDSs were culture negative, while in the next stages the CFU of MDSs were 10 for Microbe-II (February 2011), 24 for Microbe-III (October 2012), and 151 for Microbe-IV (February 2015). These results indicated that fungi inside KIBO are increasing and expanding over time, and therefore continuous surveillance is crucial.
Assuntos
Fungos , Astronave , Aspergillus , Fungos/genética , Humanos , Japão , Penicillium , RhodotorulaRESUMO
PURPOSE: Surgical site infection (SSI) is one of the most devastating complications following spinal instrumented fusion surgeries because it may lead to a significant increase in morbidity, mortality, and poor clinical outcomes. Identifying the risk factors for SSI can help in developing strategies to reduce its occurrence. However, data on the risk factors for SSI in degenerative diseases are limited. This study aimed to identify risk factors for deep SSI following posterior instrumented fusion for degenerative diseases in the thoracic and/or lumbar spine in adult patients. METHODS: This was a multicenter, observational cohort study conducted at 10 study hospitals between July 2010 and June 2015. The subjects were consecutive adult patients who underwent posterior instrumented fusion surgery for degenerative diseases in the thoracic and/or lumbar spine and developed SSI. Detailed patient-specific and procedure-specific potential risk variables were prospectively recorded using a standardized data collection chart and retrospectively reviewed. RESULTS: Of the 2913 enrolled patients, 35 developed postoperative deep SSI (1.2%). Multivariable regression analysis identified three independent risk factors: male sex (P = 0.002) and American Society of Anesthesiologists (ASA) score of ≥ 3 (P = 0.003) as patient-specific risk factors, and operation including the thoracic spine (P = 0.018) as a procedure-specific risk factor. CONCLUSION: Thoracic spinal surgery, an ASA score of ≥ 3, and male sex were risk factors for deep SSI after routine thoracolumbar instrumented fusion surgeries for degenerative diseases. Awareness of these risk factors can enable surgeons to develop a more appropriate management plan and provide better patient counseling.
Assuntos
Fusão Vertebral , Infecção da Ferida Cirúrgica , Adulto , Estudos de Coortes , Humanos , Vértebras Lombares/cirurgia , Masculino , Estudos Retrospectivos , Fatores de Risco , Fusão Vertebral/efeitos adversos , Infecção da Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/etiologiaRESUMO
Febrile Infection-Related Epilepsy Syndrome (FIRES) is a unique catastrophic epilepsy syndrome, and the development of drug-resistant epilepsy (DRE) is inevitable. Recently, anakinra, an interleukin-1 receptor antagonist (IL-1RA), has been increasingly used to treat DRE due to its potent anticonvulsant activity. We here summarized its effects in 38 patients (32 patients with FIRES and six with DRE). Of the 22 patients with FIRES, 16 (73%) had at least short-term seizure control 1 week after starting anakinra, while the remaining six suspected anakinra-refractory cases were male and had poor prognoses. Due to the small sample size, an explanation for anakinra refractoriness was not evident. In all DRE patients, seizures disappeared or improved, and cognitive function improved in five of the six patients following treatment. Patients showed no serious side effects, although drug reactions with eosinophilia and systemic symptoms, cytopenia, and infections were observed. Thus, anakinra has led to a marked improvement in some cases, and functional deficiency of IL-1RA was indicated, supporting a direct mechanism for its therapeutic effect. This review first discusses the effectiveness of anakinra for intractable epileptic syndromes. Anakinra could become a new tool for intractable epilepsy treatment. However, it does not currently have a solid evidence base.
Assuntos
Encéfalo/patologia , Epilepsia Resistente a Medicamentos/tratamento farmacológico , Inflamação/tratamento farmacológico , Proteína Antagonista do Receptor de Interleucina 1/uso terapêutico , Humanos , Inflamação/patologia , Proteína Antagonista do Receptor de Interleucina 1/administração & dosagemRESUMO
Accumulating evidence has demonstrated that the pathogenesis of epilepsy is linked to neuroinflammation and cerebrovascular dysfunction. Peripheral immune cell invasion into the brain, along with these responses, is implicitly involved in epilepsy. This review explored the current literature on the association between the peripheral and central nervous systems in the pathogenesis of epilepsy, and highlights novel research directions for therapeutic interventions targeting these reactions. Previous experimental and human studies have demonstrated the activation of the innate and adaptive immune responses in the brain. The time required for monocytes (responsible for innate immunity) and T cells (involved in acquired immunity) to invade the central nervous system after a seizure varies. Moreover, the time between the leakage associated with blood-brain barrier (BBB) failure and the infiltration of these cells varies. This suggests that cell infiltration is not merely a secondary disruptive event associated with BBB failure, but also a non-disruptive event facilitated by various mediators produced by the neurovascular unit consisting of neurons, perivascular astrocytes, microglia, pericytes, and endothelial cells. Moreover, genetic manipulation has enabled the differentiation between peripheral monocytes and resident microglia, which was previously considered difficult. Thus, the evidence suggests that peripheral monocytes may contribute to the pathogenesis of seizures.
Assuntos
Astrócitos/patologia , Barreira Hematoencefálica/patologia , Encéfalo/patologia , Epilepsia/patologia , Leucócitos/patologia , Animais , Astrócitos/imunologia , Barreira Hematoencefálica/imunologia , Encéfalo/imunologia , Epilepsia/imunologia , Humanos , Leucócitos/imunologiaRESUMO
We have previously clarified that the strongly electron-withdrawing CF3 group nicely affected the base-mediated proton shift of CF3-containing propargylic or allylic alcohols to afford the corresponding α,ß-unsaturated or saturated ketones, respectively, which was applied this time to the Claisen rearrangement after O-allylation of the allylic alcohols with a CF3 group, followed by isomerization to the corresponding allyl vinyl ethers via the proton shift, enabling the desired rearrangement in a tandem fashion, or in a stepwise manner, the latter of which was proved to have attained an excellent diastereoselectivity with the aid of a palladium catalyst.
RESUMO
The concise preparation of 4,4,4-trifluorobut-2-yn-1-ones by the oxidation of the readily accessible corresponding propargylic alcohols as well as their utilization as Michael acceptors for the construction of aromatic and heteroaromatic compounds are reported.
RESUMO
New and successful results for the construction of new and structurally interesting compounds are reported via N-heterocyclic carbene (NHC)-catalyzed 1,6-conjugate additions of a variety of aldehydes to δ-CF3-δ-substituted p-quinone methides generated in situ, and the products are used for the 1,2-addition reactions of appropriate metal nucleophiles, enabling us to furnish highly diastereoselective products with a unique successive quaternary carbon-tertiary alcohol framework (up to dr = >99 : 1).
RESUMO
Burkitt lymphoma (BL) is an aggressive B-cell lymphoma characterized by translocation and deregulation of the proto-oncogene c-MYC. Transcription factor 3 (TCF3) has also been shown to be involved in BL pathogenesis. In BL, TCF3 is constitutively active, and/or expression of its transcriptional targets are altered as a result of BL-associated mutations. Here, we found that BL-related TCF3 mutations affect TCF3 alternative splicing, in part by reducing binding of the splicing regulator hnRNPH1 to exon 18b. This leads to greater exon 18b inclusion, thereby generating more of the mutated E47 isoform of TCF3. Interestingly, upregulation of E47 dysregulates the expression of TCF3 targets PTPN6, and perhaps CCND3, which are known to be involved in BL pathogenesis. Our findings thus reveal a mechanism by which TCF3 somatic mutations affect multilayered gene regulation underlying BL pathogenesis.
Assuntos
Processamento Alternativo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Linfoma de Burkitt/genética , Linfoma de Burkitt/metabolismo , Regulação Neoplásica da Expressão Gênica , Ribonucleoproteínas Nucleares Heterogêneas Grupo F-H/metabolismo , Mutação , Alelos , Sequência de Aminoácidos , Substituição de Aminoácidos , Sequência de Bases , Fatores de Transcrição Hélice-Alça-Hélice Básicos/química , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Biomarcadores Tumorais , Linfoma de Burkitt/patologia , Linhagem Celular Tumoral , Suscetibilidade a Doenças , Éxons , Humanos , Ligação Proteica , Proto-Oncogene MasRESUMO
It was reported for the first time that single-electron oxidants such as CAN or K2S2O8 affected facile ring opening of simple gem-difluorocyclopropanes to afford 1,3-dibromo-2,2-difluoropropanes in good yields by the action of KBr, and the appropriate choice of conditions allowed to incorporate not only second halogen atoms but also hydroxy or acetamido groups at the C1 position in the difluoropropane structures in a regiospecific fashion after initiation of the reaction by the introduction of the first bromine atom at the C3 position.
RESUMO
A 68-year-old woman underwent Miles' surgery with a diagnosis of a rectalgastrointestinalstromaltumor (GIST)in 2004. In 2005 and 2006, she developed liver metastases that were surgically removed, but once again in June 2006, she presented with liver metastasis, and imatinib therapy(400mg/day)was administered. In October 2016, she was diagnosed with progression of liver metastasis, and a tumor in the pancreatic body was identified on a CT scan. The patient was referred to our institution for treatment. We performed right hepatectomy and distalpancreatectomy in January 2017. Immunohistochemically, the recurrent tumor was positive for c-kit and CD34, and the diagnosis of GIST was confirmed. The pathological diagno- sis was a high-risk GIST showing 43mitoses per 50 high-power fields. Imatinib therapy(400mg/day)was administered after surgery. She is currently alive without recurrence.
Assuntos
Tumores do Estroma Gastrointestinal , Neoplasias Hepáticas , Neoplasias Pancreáticas , Idoso , Antineoplásicos/uso terapêutico , Feminino , Tumores do Estroma Gastrointestinal/patologia , Tumores do Estroma Gastrointestinal/terapia , Humanos , Mesilato de Imatinib/uso terapêutico , Neoplasias Hepáticas/secundário , Recidiva Local de Neoplasia , Neoplasias Pancreáticas/secundárioRESUMO
Ozonolysis of TMS-substituted olefins produces α-carbonyl TMS peroxides without cleavage of the C[double bond, length as m-dash]C bond. Herein, stereochemistry in the ozonolysis was studied using silyl derivatives of (E)- and (Z)-(1-TMS)alk-1-en-3-ols. The (E)-isomers afforded the anti-3-siloxy-2-(TMS-oxy)aldehydes as the major stereoisomer (anti/syn = 3-9 : 1) after reductive work-up with Ph3P. In contrast, Z-olefins selectively gave the syn isomers with syn/anti ratios of 4-19 : 1. Facial selection was speculated based on the Cieplak effect. This ozonolysis was successfully applied for the synthesis of 14R,15S- and 14S,15S-diHETEs (anti and syn isomers, respectively) in enantioenriched forms.