Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 239
Filtrar
1.
Cell ; 164(1-2): 279-292, 2016 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-26771496

RESUMO

Mammalian interspecific hybrids provide unique advantages for mechanistic studies of speciation, gene expression regulation, and X chromosome inactivation (XCI) but are constrained by their limited natural resources. Previous artificially generated mammalian interspecific hybrid cells are usually tetraploids with unstable genomes and limited developmental abilities. Here, we report the generation of mouse-rat allodiploid embryonic stem cells (AdESCs) by fusing haploid ESCs of the two species. The AdESCs have a stable allodiploid genome and are capable of differentiating into all three germ layers and early-stage germ cells. Both the mouse and rat alleles have comparable contributions to the expression of most genes. We have proven AdESCs as a powerful tool to study the mechanisms regulating X chromosome inactivation and to identify X inactivation-escaping genes, as well as to efficiently identify genes regulating phenotypic differences between species. A similar method could be used to create hybrid AdESCs of other distantly related species.


Assuntos
Fusão Celular/métodos , Quimera/genética , Células-Tronco Embrionárias/citologia , Células Híbridas , Camundongos , Ratos , Animais , Diferenciação Celular , Corpos Embrioides , Células-Tronco Embrionárias/metabolismo , Feminino , Haploidia , Masculino , Camundongos Endogâmicos , Ratos Endogâmicos F344 , Especificidade da Espécie , Inativação do Cromossomo X
2.
Brief Bioinform ; 23(2)2022 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-35048116

RESUMO

Accurate cell classification is the groundwork for downstream analysis of single-cell sequencing data, yet how to identify true marker genes for different cell types still remains a big challenge. Here, we report COSine similarity-based marker Gene identification (COSG) as a cosine similarity-based method for more accurate and scalable marker gene identification. COSG is applicable to single-cell RNA sequencing data, single-cell ATAC sequencing data and spatially resolved transcriptome data. COSG is fast and scalable for ultra-large datasets of million-scale cells. Application on both simulated and real experimental datasets showed that the marker genes or genomic regions identified by COSG have greater cell-type specificity, demonstrating the superior performance of COSG in terms of both accuracy and efficiency as compared with other available methods.


Assuntos
Análise de Célula Única , Transcriptoma , Perfilação da Expressão Gênica , Análise de Sequência de RNA , Análise de Célula Única/métodos , Sequenciamento do Exoma
3.
Plant Physiol ; 192(1): 648-665, 2023 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-36760172

RESUMO

Cold stress is a key environmental constraint that dramatically affects the growth, productivity, and quality of tomato (Solanum lycopersicum); however, the underlying molecular mechanisms of cold tolerance remain poorly understood. In this study, we identified REDUCED CHLOROPLAST COVERAGE 2 (SlREC2) encoding a tetratricopeptide repeat protein that positively regulates tomato cold tolerance. Disruption of SlREC2 largely reduced abscisic acid (ABA) levels, photoprotection, and the expression of C-REPEAT BINDING FACTOR (CBF)-pathway genes in tomato plants under cold stress. ABA deficiency in the notabilis (not) mutant, which carries a mutation in 9-CIS-EPOXYCAROTENOID DIOXYGENASE 1 (SlNCED1), strongly inhibited the cold tolerance of SlREC2-silenced plants and empty vector control plants and resulted in a similar phenotype. In addition, foliar application of ABA rescued the cold tolerance of SlREC2-silenced plants, which confirms that SlNCED1-mediated ABA accumulation is required for SlREC2-regulated cold tolerance. Strikingly, SlREC2 physically interacted with ß-RING CAROTENE HYDROXYLASE 1b (SlBCH1b), a key regulatory enzyme in the xanthophyll cycle. Disruption of SlBCH1b severely impaired photoprotection, ABA accumulation, and CBF-pathway gene expression in tomato plants under cold stress. Taken together, this study reveals that SlREC2 interacts with SlBCH1b to enhance cold tolerance in tomato via integration of SlNCED1-mediated ABA accumulation, photoprotection, and the CBF-pathway, thus providing further genetic knowledge for breeding cold-resistant tomato varieties.


Assuntos
Solanum lycopersicum , Solanum lycopersicum/genética , Repetições de Tetratricopeptídeos , Melhoramento Vegetal , Ácido Abscísico/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Mutação/genética , Regulação da Expressão Gênica de Plantas , Temperatura Baixa
4.
Acc Chem Res ; 56(21): 2992-2999, 2023 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-37847868

RESUMO

The development of various chemical methods has enabled scientists to decipher the distribution features and biological functions of RNA modifications in the past decade. In addition to modifying noncoding RNAs such as tRNAs and rRNAs, N6-methyladenosine (m6A) has been proven to be the most abundant internal chemical modification on mRNAs in eukaryotic cells and is also the most widely studied mRNA modification to date. Extensive studies have repeatedly demonstrated the important functions of m6A in various biological conditions, ranging from embryonic organ development to adult organ function and pathogenesis. Unlike DNA methylation which is relatively stable, the reversible m6A modification on mRNA is highly dynamic and easily influenced by various internal or external factors, such as cell type, developmental stage, nutrient supply, circadian rhythm, and environmental stresses.In this Account, we review our previous findings on the site selectivity mechanisms regulating m6A formation, as well as the physiological roles of m6A modification in cerebellum development and long-term memory consolidation. In our initial efforts to profile m6A in various types of mouse and human cells, we surprisingly found that the sequence motifs surrounding m6A sites were often complementary with the seed sequences of miRNAs. By manipulating the abundance of the miRNA biogenesis enzyme Dicer or individual miRNAs or mutating miRNA sequences, we were able to reveal a new role of nucleus localized miRNAs, which is to guide the m6A methyltransferase METTL3 to bind to mRNAs and to promote m6A formation. As a result, we partially answered the question of why only a small proportion of m6A motifs within an mRNA could have m6A modification at a certain time point. We further explored the functions of m6A modification in regulating brain development and brain functions. We found that cerebellum had the most severe defects when Mettl3 was knocked out in developing mouse embryonic brain and revealed that the underlying mechanisms could be attributed to aberrant mRNA splicing and enhanced cell apoptosis under m6A deficit conditions. On the other hand, knocking out Mettl3 in postnatal hippocampus did not cause morphological defects in the mouse brain but impaired the efficacy of long-term memory consolidation. Under learning stimuli, formation of m6A modifications could be detected on transcripts encoding proteins related to dendrite growth, synapse formation, and other memory related functions. Loss of m6A modifications on these transcripts would result in translation deficiency and reduced protein production, particularly in the translation of early response genes, and therefore would compromise the efficacy of long-term memory consolidation. Interestingly, excessive training sessions or increased training intensity could overcome such m6A deficiency related memory defects, which is likely due to the longer turnover cycle and the cumulative abundance of proteins throughout the training process. In addition to revealing the roles of m6A modification in regulating long-term memory formation, our work also demonstrated an effective method for studying memory formation efficacy. As the lack of an appropriate model for studying memory formation efficacy has been a long-lasting problem in the field of neural science, our hippocampus-specific postnatal m6A knockout model could also be utilized to study other questions related to memory formation efficacy.


Assuntos
Metiltransferases , MicroRNAs , Animais , Humanos , Camundongos , Adenosina/metabolismo , Metilação , Metiltransferases/metabolismo , MicroRNAs/metabolismo , RNA Mensageiro/metabolismo
5.
Mol Cell ; 61(4): 507-519, 2016 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-26876937

RESUMO

The regulatory role of N(6)-methyladenosine (m(6)A) and its nuclear binding protein YTHDC1 in pre-mRNA splicing remains an enigma. Here we show that YTHDC1 promotes exon inclusion in targeted mRNAs through recruiting pre-mRNA splicing factor SRSF3 (SRp20) while blocking SRSF10 (SRp38) mRNA binding. Transcriptome assay with PAR-CLIP-seq analysis revealed that YTHDC1-regulated exon-inclusion patterns were similar to those of SRSF3 but opposite of SRSF10. In vitro pull-down assay illustrated a competitive binding of SRSF3 and SRSF10 to YTHDC1. Moreover, YTHDC1 facilitates SRSF3 but represses SRSF10 in their nuclear speckle localization, RNA-binding affinity, and associated splicing events, dysregulation of which, as the result of YTHDC1 depletion, can be restored by reconstitution with wild-type, but not m(6)A-binding-defective, YTHDC1. Our findings provide the direct evidence that m(6)A reader YTHDC1 regulates mRNA splicing through recruiting and modulating pre-mRNA splicing factors for their access to the binding regions of targeted mRNAs.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Splicing de RNA , Proteínas de Ligação a RNA/metabolismo , Proteínas Repressoras/metabolismo , Adenosina/análogos & derivados , Adenosina/metabolismo , Sítios de Ligação , Éxons , Células HeLa , Humanos , Fatores de Processamento de RNA , RNA Mensageiro/metabolismo , Fatores de Processamento de Serina-Arginina
6.
Stroke ; 54(7): 1770-1776, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37264909

RESUMO

BACKGROUND: CYP2B6 (cytochrome P450 subfamily IIB polypeptide 6), encoded by the CYP2B6 gene, is a critical enzyme involved in clopidogrel metabolism. However, the association between CYP2B6 polymorphisms and the efficacy of clopidogrel in minor stroke or transient ischemic attack for secondary stroke prevention remains unclear. METHODS: Based on CHANCE (Clopidogrel in High-Risk Patients With Acute Nondisabling Cerebrovascular Events) randomized clinical trial of aspirin plus clopidogrel versus aspirin alone, we investigated the role of CYP2B6 polymorphisms and the efficacy of clopidogrel in patients with minor stroke or transient ischemic attack in China from October 2009 to July 2012. A total of 2853 patients were successfully genotyped for CYP2B6-516G>T, rs3745274 and CYP2B6-1456 T>C, rs2054675. The primary efficacy and safety outcomes were new stroke and any bleeding within 90 days. RESULTS: Among the 2853 patients, 32.8% were identified as the carriers of the CYP2B6-516 GT/TT or -1456 TC/CC genotype. The incidences of 90-day new stroke in aspirin plus clopidogrel and aspirin alone groups were 7.1% versus 11.3% among noncarriers, respectively; and 9.7% versus 12.2% among carriers, respectively. The efficacy of aspirin plus clopidogrel versus aspirin alone was not significantly different (P interaction=0.29) in noncarriers (adjusted hazard ratio, 0.61 [95% CI, 0.45-0.83]) compared to carriers (adjusted hazard ratio, 0.80 [95% CI, 0.54-1.18]). The incidence (n=51) of 90-day any bleeding in aspirin plus clopidogrel and aspirin alone groups were 2.2% (21 bleeds) versus 1.9% (18 bleeds) among noncarriers (adjusted hazard ratio, 1.11 [95% CI, 0.59-2.09]) and 1.9% (9 bleeds) versus 0.7% (3 bleeds) among carriers (adjusted hazard ratio, 3.23 [95% CI, 0.86-12.12]). Similar findings were observed during the 1-year follow-up. CONCLUSIONS: In this post hoc analysis of the CHANCE trial, we did not observe a significant difference in the efficacy of aspirin plus clopidogrel compared with aspirin in carriers versus noncarriers of CYP2B6-516 GT/TT or -1456 TC/CC genotype. Our results suggest that both carriers and noncarriers suffering from a minor stroke are likely to benefit from aspirin plus clopidogrel treatment over aspirin monotherapy for secondary prevention. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT00979589.


Assuntos
Aspirina , Clopidogrel , Citocromo P-450 CYP2B6 , Inibidores da Agregação Plaquetária , Acidente Vascular Cerebral , Clopidogrel/administração & dosagem , Humanos , Pessoa de Meia-Idade , Aspirina/administração & dosagem , Citocromo P-450 CYP2B6/genética , Inibidores da Agregação Plaquetária/administração & dosagem , Masculino , Feminino , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/prevenção & controle , Recidiva
7.
Environ Res ; 235: 116686, 2023 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-37467943

RESUMO

During the mining of rare earth minerals, the application of neodymium-containing manures, and the treatment of spent neodymium iron boron magnet, the generation of ammonia wastewater containing neodymium is increasing. Thus, the effects of neodymium (Nd(III)) on anaerobic ammonium oxidation (Anammox) were investigated from the aspects of performance, kinetics, statistics, microbial community and sludge morphology, and the recovery strategy of EDTA-2Na wash was discussed. The nitrogen removal efficiency of the Anammox reactor decreased significantly and eventually collapsed at the Nd(III) dosing levels of 20 and 40 mg L-1, respectively. And the toxicity of Nd(III) to AnAOB was determined by the amount internalized into the cells. The EDTA-2Na wash successfully increased the total nitrogen removal rate (TNRR) of Nd(III)-inhibited Anammox to 41.60% of its initial value within 30 days, and the modified Boltzmann model accurately simulated this recovery process. The transient and extended effects of Nd(III), self-recovery, and EDTA-2Na wash on Anammox were effectively assessed using a one-sample t-test. 16S rRNA gene sequencing indicated that Nd(III) remarkably decreased the relative abundance of Planctomycetes and Candidatus Brocadia. The scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) revealed crystal-like neodymium particles on the surface of Anammox sludge. The above-mentioned results demonstrate that the concentration of Nd(III) should be below the toxicity threshold (20 mg L-1) when treating ammonia wastewater containing neodymium by Anammox, and also emphasize the importance of an appropriate recovery strategy.


Assuntos
Compostos de Amônio , Metais Terras Raras , Esgotos , Águas Residuárias , Amônia , Neodímio , RNA Ribossômico 16S , Oxidação Anaeróbia da Amônia , Ácido Edético , Anaerobiose , Reatores Biológicos , Oxirredução , Nitrogênio , Compostos de Amônio/química
8.
Nucleic Acids Res ; 49(5): 2522-2536, 2021 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-33561291

RESUMO

Simultaneous dysregulation of multiple microRNAs (miRs) affects various pathological pathways related to cardiac failure. In addition to being potential cardiac disease-specific markers, miR-23b/27b/24-1 were reported to be responsible for conferring cardiac pathophysiological processes. In this study, we identified a conserved guanine-rich RNA motif within the miR-23b/27b/24-1 cluster that can form an RNA G-quadruplex (rG4) in vitro and in cells. Disruption of this intragenic rG4 significantly increased the production of all three miRs. Conversely, a G4-binding ligand tetrandrine (TET) stabilized the rG4 and suppressed miRs production in human and rodent cardiomyocytes. Our further study showed that the rG4 prevented Drosha-DGCR8 binding and processing of the pri-miR, suppressing the biogenesis of all three miRs. Moreover, CRISPR/Cas9-mediated G4 deletion in the rat genome aberrantly elevated all three miRs in the heart in vivo, leading to cardiac contractile dysfunction. Importantly, loss of the G4 resulted in reduced targets for the aforementioned miRs critical for normal heart function and defects in the L-type Ca2+ channel-ryanodine receptor (LCC-RyR) coupling in cardiomyocytes. Our results reveal a novel mechanism for G4-dependent regulation of miR biogenesis, which is essential for maintaining normal heart function.


Assuntos
Quadruplex G , MicroRNAs/química , MicroRNAs/metabolismo , Contração Miocárdica/genética , Miócitos Cardíacos/metabolismo , Animais , Benzilisoquinolinas/farmacologia , Sistemas CRISPR-Cas , Células Cultivadas , Quadruplex G/efeitos dos fármacos , Regulação da Expressão Gênica , Miocárdio/metabolismo , Miócitos Cardíacos/fisiologia , Processamento Pós-Transcricional do RNA , Proteínas de Ligação a RNA/metabolismo , Ratos , Ratos Sprague-Dawley , Ribonuclease III/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo
9.
Acta Cardiol Sin ; 39(2): 309-318, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36911543

RESUMO

Background: Hyperhomocysteinemia (HHcy) is an independent risk factor for atherosclerosis. Effective interventions to reduce HHcy-accelerated atherosclerosis are required. Objectives: This study aimed to investigate the effects of aerobic exercise (AE) and folate (FA) supplementation on plasma homocysteine (Hcy) level and atherosclerosis development in a mouse model. Methods: Six-week-old female apoE-/- mice were grouped into five groups (N = 6-8): HHcy (1.8 g/L DL-homocysteine (DL-Hcy) in drinking water), HHcy + AE (1.8 g/L DL-Hcy and aerobic exercise training on a treadmill), HHcy + FA (1.8 g/L DL-Hcy and 0.006% folate in diet), HHcy + AE + FA (1.8 g/L DL-Hcy, 0.006% folate, and aerobic exercise training on a treadmill), and a control group (regular water and diet). All treatment was sustained for 8 weeks. Triglyceride, cholesterol, lipoprotein, and Hcy levels were determined enzymatically. Plaque and monocyte chemoattractant protein-1 (MCP-1) expression levels in mouse aortic roots were evaluated by immunohistochemistry. Results: Compared to the HHcy group (18.88 ± 6.13 µmol/L), plasma Hcy concentration was significantly reduced in the HHcy + AE (14.79 ± 3.05 µmol/L, p = 0.04), HHcy + FA (9.4 ± 3.85 µmol/L, p < 0.001), and HHcy + AE + FA (9.33 ± 2.21 µmol/L, p < 0.001) groups. Significantly decreased aortic root plaque area and plaque burden were found in the HHcy + AE and HHcy + AE + FA groups compared to those in the HHcy group (both p < 0.05). Plasma MCP-1 level and MCP-1 expression in atherosclerotic lesions were significantly decreased in the HHcy + AE and HHcy + AE + FA groups compared to the HHcy group (all p < 0.05). Conclusions: AE reduced atherosclerosis development in HHcy apoE-/- mice independently of reducing Hcy levels. FA supplementation decreased plasma Hcy levels without attenuating HHcy-accelerated atherosclerosis. AE and FA supplementation have distinct mechanisms in benefiting atherosclerosis.

10.
New Phytol ; 233(5): 2127-2143, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34936108

RESUMO

Plants have evolved sophisticated regulatory networks to cope with dynamically changing light and temperature environments during day-night and seasonal cycles. However, the integration mechanisms of light and low temperature remain largely unclear. Here, we show that low red : far-red ratio (LR : FR) induces FAR-RED ELONGATED HYPOCOTYL3 (SlFHY3) transcription under cold stress in tomato (Solanum lycopersicum). Reverse genetic approaches revealed that knocking out SlFHY3 decreases myo-inositol accumulation and increases cold susceptibility, whereas overexpressing SlFHY3 induces myo-inositol accumulation and enhances cold tolerance in tomato plants. SlFHY3 physically interacts with ELONGATED HYPOCOTYL5 (SlHY5) to promote the transcriptional activity of SlHY5 on MYO-INOSITOL-1-PHOSPHATE SYNTHASE 3 (SlMIPS3) and induce myo-inositol accumulation in tomato plants under cold stress. Disruption of SlHY5 and SlMIPS3 largely suppresses the cold tolerance of SlFHY3-overexpressing plants and myo-inositol accumulation in tomato. Furthermore, silencing of SlMIPS3 drastically reduces myo-inositol accumulation and compromises LR : FR-induced cold tolerance in tomato. Together, our results reveal a crucial role of SlFHY3 in LR : FR-induced cold tolerance in tomato and unravel a novel regulatory mechanism whereby plants integrate dynamic environmental light signals and internal cues (inositol biosynthesis) to induce and control cold tolerance in tomato plants.


Assuntos
Solanum lycopersicum , Temperatura Baixa , Regulação da Expressão Gênica de Plantas , Inositol , Transdução de Sinal Luminoso , Solanum lycopersicum/genética
11.
Int J Mol Sci ; 23(21)2022 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-36361595

RESUMO

As powerful tools for local gene delivery, adeno-associated viruses (AAVs) are widely used for neural circuit studies and therapeutical purposes. However, most of them have the characteristics of large diffusion range and retrograde labeling, which may result in off-target transduction during in vivo application. Here, in order to achieve precise gene delivery, we screened AAV serotypes that have not been commonly used as gene vectors and found that AAV13 can precisely transduce local neurons in the brain, with a smaller diffusion range than AAV2 and rigorous anterograde labeling. Then, AAV13-based single-viral and dual-viral strategies for sparse labeling of local neurons in the brains of C57BL/6 or Cre transgenic mice were developed. Additionally, through the neurobehavioral test in the ventral tegmental area, we demonstrated that AAV13 was validated for functional monitoring by means of carrying Cre recombinase to drive the expression of Cre-dependent calcium-sensitive indicator. In summary, our study provides AAV13-based toolkits for precise local gene delivery, which can be used for in situ small nuclei targeting, sparse labeling and functional monitoring.


Assuntos
Dependovirus , Vetores Genéticos , Animais , Camundongos , Camundongos Endogâmicos C57BL , Dependovirus/metabolismo , Vetores Genéticos/genética , Técnicas de Transferência de Genes , Camundongos Transgênicos , Transdução Genética
12.
PLoS Biol ; 16(6): e2004880, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29879109

RESUMO

N6-methyladenosine (m6A) RNA methylation is the most abundant modification on mRNAs and plays important roles in various biological processes. The formation of m6A is catalyzed by a methyltransferase complex including methyltransferase-like 3 (METTL3) as a key factor. However, the in vivo functions of METTL3 and m6A modification in mammalian development remain unclear. Here, we show that specific inactivation of Mettl3 in mouse nervous system causes severe developmental defects in the brain. Mettl3 conditional knockout (cKO) mice manifest cerebellar hypoplasia caused by drastically enhanced apoptosis of newborn cerebellar granule cells (CGCs) in the external granular layer (EGL). METTL3 depletion-induced loss of m6A modification causes extended RNA half-lives and aberrant splicing events, consequently leading to dysregulation of transcriptome-wide gene expression and premature CGC death. Our findings reveal a critical role of METTL3-mediated m6A in regulating the development of mammalian cerebellum.


Assuntos
Adenosina/análogos & derivados , Cerebelo/embriologia , Metiltransferases/metabolismo , RNA Mensageiro/genética , Adenosina/metabolismo , Processamento Alternativo/genética , Animais , Apoptose/genética , Células Cultivadas , Cerebelo/anormalidades , Cerebelo/patologia , Deficiências do Desenvolvimento/genética , Deficiências do Desenvolvimento/patologia , Regulação da Expressão Gênica/genética , Metilação , Metiltransferases/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Malformações do Sistema Nervoso/genética , Malformações do Sistema Nervoso/patologia , Estabilidade de RNA/genética , RNA Mensageiro/metabolismo
13.
RNA Biol ; 18(6): 875-887, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32991228

RESUMO

The pluripotency of embryonic stem cells (ESCs) is controlled by a multilayer regulatory network, of which the key factors include core pluripotency genes Oct4, Sox2 and Nanog, and multiple microRNAs (miRNAs). Recently, long noncoding RNAs (lncRNAs) have been discovered as a class of new regulators for ESCs, and some lncRNAs could function as competing endogenous RNAs (ceRNAs) to regulate mRNAs by competitively binding to miRNAs. Here, we identify mmu-miR-139-5p as a new regulator for Nanog by targeting Nanog 3' untranslated region (UTR) to repress Nanog expression in mouse ESCs and embryos. Such regulation could be released by an ESC-specifically expressed ceRNA named lnc-NAP. The expression of lnc-NAP is activated by OCT4, SOX2, as well as NANOG through promoter binding. Downregulation of lnc-NAP reduces Nanog abundance, which leads to decreased pluripotency of mouse ESCs and embryonic lethality. These results reveal lnc-NAP as a new regulator for Nanog in mouse ESCs, and uncover a feed-forward regulatory loop of Nanog through the participation of lnc-NAP.


Assuntos
Embrião de Mamíferos/metabolismo , Células-Tronco Embrionárias/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , MicroRNAs/genética , Proteína Homeobox Nanog/genética , RNA Longo não Codificante/genética , Regiões 3' não Traduzidas/genética , Animais , Diferenciação Celular/genética , Embrião de Mamíferos/citologia , Embrião de Mamíferos/embriologia , Células-Tronco Embrionárias/citologia , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Endogâmicos NOD , Camundongos SCID , Proteína Homeobox Nanog/metabolismo , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Regiões Promotoras Genéticas/genética , Ligação Proteica , RNA-Seq/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo
14.
Mol Cell ; 49(1): 18-29, 2013 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-23177736

RESUMO

N(6)-methyladenosine (m(6)A) is the most prevalent internal modification of messenger RNA (mRNA) in higher eukaryotes. Here we report ALKBH5 as another mammalian demethylase that oxidatively reverses m(6)A in mRNA in vitro and in vivo. This demethylation activity of ALKBH5 significantly affects mRNA export and RNA metabolism as well as the assembly of mRNA processing factors in nuclear speckles. Alkbh5-deficient male mice have increased m(6)A in mRNA and are characterized by impaired fertility resulting from apoptosis that affects meiotic metaphase-stage spermatocytes. In accordance with this defect, we have identified in mouse testes 1,551 differentially expressed genes that cover broad functional categories and include spermatogenesis-related mRNAs involved in the p53 functional interaction network. The discovery of this RNA demethylase strongly suggests that the reversible m(6)A modification has fundamental and broad functions in mammalian cells.


Assuntos
Dioxigenases/metabolismo , Proteínas de Membrana/metabolismo , Oxirredutases N-Desmetilantes/metabolismo , Processamento Pós-Transcricional do RNA , RNA Mensageiro/metabolismo , Homólogo AlkB 5 da RNA Desmetilase , Animais , Sequência de Bases , Núcleo Celular/metabolismo , Dioxigenases/química , Dioxigenases/genética , Técnicas de Silenciamento de Genes , Células HeLa , Humanos , Infertilidade Masculina/enzimologia , Masculino , Proteínas de Membrana/química , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Tamanho do Órgão , Oxirredutases N-Desmetilantes/química , Oxirredutases N-Desmetilantes/genética , Proteínas Serina-Treonina Quinases/metabolismo , Transporte Proteico , Interferência de RNA , RNA Mensageiro/química , Espermatogênese/genética , Testículo/enzimologia , Testículo/patologia , Transcriptoma
15.
Nucleic Acids Res ; 47(D1): D976-D982, 2019 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-30365030

RESUMO

Traditional Chinese medicine (TCM) is not only an effective solution for primary health care, but also a great resource for drug innovation and discovery. To meet the increasing needs for TCM-related data resources, we developed ETCM, an Encyclopedia of Traditional Chinese Medicine. ETCM includes comprehensive and standardized information for the commonly used herbs and formulas of TCM, as well as their ingredients. The herb basic property and quality control standard, formula composition, ingredient drug-likeness, as well as many other information provided by ETCM can serve as a convenient resource for users to obtain thorough information about a herb or a formula. To facilitate functional and mechanistic studies of TCM, ETCM provides predicted target genes of TCM ingredients, herbs, and formulas, according to the chemical fingerprint similarity between TCM ingredients and known drugs. A systematic analysis function is also developed in ETCM, which allows users to explore the relationships or build networks among TCM herbs, formulas,ingredients, gene targets, and related pathways or diseases. ETCM is freely accessible at http://www.nrc.ac.cn:9090/ETCM/. We expect ETCM to develop into a major data warehouse for TCM and to promote TCM related researches and drug development in the future.


Assuntos
Bases de Dados de Produtos Farmacêuticos , Medicamentos de Ervas Chinesas , Medicina Tradicional Chinesa , Doença/genética , Descoberta de Drogas , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/normas , Humanos , Interface Usuário-Computador
16.
Phytother Res ; 35(7): 4007-4021, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34038010

RESUMO

Pituitary adenoma (PA) is a benign intracranial neoplasm originated from pituitary gland. Surgery is the first-line therapy for most of PAs, but lead to unsatisfactory prognosis in some cases. Tetrandrine (Tet) has anticancer effect on some cancers. However, growth inhibition effect on PA is unknown. To elucidate the inhibitory effect of Tet on the growth of PA and its potential mechanisms, we validated the in vitro and in vivo anti-PA effect of Tet and illustrated the cellular and molecular alterations by confocal microscopy observation, flow cytometry, and RNA interference. Tet inhibited PA cell growth in vitro and tumor progression in vivo. Tet induced autophagy and apoptosis in a dose-dependent manner. Low dosage (1.25 µM) of Tet induced PA cell autophagy by down-regulation of MAPK/STAT3 signal. While, higher dosage (5.0 µM) of Tet partially induced PA cell death through caspase-dependent apoptosis. Autophagy inhibitors enhanced Tet-induced caspase activity and apoptotic cell death. These findings demonstrated that Tet has anti-PA effect by inducing autophagy and apoptosis through MAPK/STAT3 signaling pathway attenuation and autophagy inhibition might enhance its anti-PA effect, indicating that Tet (or combined with autophagy inhibitor) is a potential therapeutic regimen for PAs.


Assuntos
Antineoplásicos Fitogênicos , Benzilisoquinolinas , Neoplasias Hipofisárias , Animais , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Benzilisoquinolinas/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Hipofisárias/tratamento farmacológico , Ratos
17.
Sheng Li Xue Bao ; 73(4): 584-596, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34405215

RESUMO

Heart failure (HF), a clinical syndrome with high morbidity and mortality, is becoming a growing public health problem. Dilated cardiomyopathy (DCM) is one of the major causes of HF, yet the molecular mechanisms underlying DCM-mediated HF are not completely understood. Previous studies have shown that dysregulation of arachidonic acid (AA) metabolism could contribute to the development of HF. To explore the roles of microRNAs (miRNAs) in regulating AA metabolism in HF, we used two public datasets to analyze the expression changes of miRNAs in the patients of DCM-mediated HF. A total of 101 and 88 miRNAs with significant abundance alterations in the two dataset were obtained, respectively. Around 1/3 of these miRNAs were predicted to target AA metabolic pathway genes. We also investigated the distribution of known single nucleotide polymorphisms (SNPs) within the sequences of miRNAs dysregulated in DCM-mediated HF patients, and identified miRNAs harboring high number of SNPs in either the seed regions or the entire sequences. These information could provide clues for further functional studies of miRNAs in the pathogeny of DCM-mediated HF.


Assuntos
Cardiomiopatia Dilatada , Insuficiência Cardíaca , MicroRNAs , Ácido Araquidônico , Cardiomiopatia Dilatada/genética , Insuficiência Cardíaca/genética , Humanos , MicroRNAs/genética
18.
Sheng Li Xue Bao ; 73(5): 781-794, 2021 Oct 25.
Artigo em Zh | MEDLINE | ID: mdl-34708235

RESUMO

The balance of glucose and lipid metabolism is a coordinated result of multiple factors and organs, and is one of the fundamental requirements for the maintenance of human health. As the most important organ for human metabolism, liver plays a key role in regulating glucose and lipid metabolism. With the advances of researches, the number of publications related to hepatic glucose and lipid metabolism has increased rapidly, which posed a challenge for grasping the hot research topics and developmental trends of hepatic glucose and lipid metabolism in a short time. To solve such problem, we developed an information analysis method, which systematically analyzes the research status, research techniques, and hot research topics of the hepatic glucose and lipid metabolism research field through Medical Subject Headings (MeSH) of related papers and high-throughput experimental data. The results showed that the number of publications related to hepatic glucose and lipid metabolism, especially publications by Chinese scholars, has increased dramatically in this century, along with the remarkable increment of the numbers of authors and affiliations per paper. Such increment is in part positively correlated with the impact of publications. Nowadays, various types of high-throughput experimental techniques have become the main research methods for genetic studies of hepatic glucose and lipid metabolism. Transcription factors, such as peroxisome proliferator-activated receptors (PPARs), sterol regulatory element binding proteins (SREBPs), and NF-E2-related factor 2 (Nrf2), have become the new research hotspots. These results systematically showed the current focuses and developmental trends of hepatic glucose and lipid metabolism research, and the data analysis method developed in this work can also be applied to other research fields.


Assuntos
Glucose , Metabolismo dos Lipídeos , Glucose/metabolismo , Humanos , Fígado
19.
Cent Eur J Immunol ; 46(3): 314-324, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34764803

RESUMO

Circular RNAs (circRNAs) are involved in the progression of various diseases, including lupus nephritis. Hsa_circ_0010957 is reported to be dysregulated in lupus nephritis, but the exact function of this circRNA is unknown. This research aims to study the function and mechanism of circRNA hsa_circ_0010957 in a lipopolysaccharide (LPS)-induced cellular model of lupus nephritis. Human renal proximal tubular cell line HK2 cells were challenged by LPS. Hsa_circ_0010957, microRNA-1224-5p (miR-1224-5p), and interleukin-1 receptor-associated kinase 1 (IRAK1) abundances were examined by quantitative reverse transcription polymerase chain reaction or western blot. LPS-induced damage was evaluated via cell viability, apoptosis, inflammatory response and oxidative injury. The target interaction was analyzed by dual-luciferase reporter analysis and RNA immunoprecipitation. Hsa_circ_0010957 abundance was enhanced in LPS-challenged HK2 cells. Hsa_circ_0010957 knockdown alleviated LPS-induced apoptosis, the inflammatory response and oxidative injury in HK2 cells. MiR-1224-5p was targeted by hsa_circ_0010957, and miR-1224-5p knockdown reversed the influence of hsa_circ_0010957 silence on LPS-induced injury. IRAK1 was targeted via miR-1224-5p, and hsa_circ_0010957 could regulate IRAK1 by miR-1224-5p. MiR-1224-5p overexpression could mitigate LPS-induced apoptosis, the inflammatory response and oxidative injury, and this effect was abolished by IRAK1. Hsa_circ_0010957 silence weakened LPS-induced HK2 cell apoptosis, the inflammatory response and oxidative injury via regulating the miR-1224-5p/IRAK1 axis.

20.
Cell Mol Neurobiol ; 40(5): 767-784, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31853695

RESUMO

Exosomes contain plenty of bioactive information, playing an important role in intercellular communication by transfer their bioactive molecular contents to recipient cells. Glioblastoma stem cells (GSCs) and non-GSC glioma cells coexist in GBM microenvironment; GSC-released exosomes contain intracellular signaling molecules, which may affect the biological phenotypes of recipient cells. However, whether GSC exosomes could affect the biological phenotype of non-GSC glioma cells has not yet been defined. To explore whether GSC exosomes could reprogramme non-GSC glioma cells into GSCs and its possible mechanism involved, non-GSC glioma cells were treated with GSCs released exosomes; the potential mechanisms of action were studied with RNA interference, Notch inhibitors and Western blot analysis. The proliferation, neurosphere formation, invasive capacities, and tumorigenicity of non-GSC glioma cells were increased significantly after GSC exosome treatment; Notch1 signaling pathway was activated in GSCs; Notch1 protein was highly enriched in GSC exosomes; Notch1 signaling pathway and stemness-related protein expressions were increased in GSC exosome treated non-GSC glioma cells and these cell generated tumor tissues; Notch1 protein expression in GSCs and their exosomes, and the neurosphere formation of GSCs were decreased by Notch1 RNA interference; Notch1 signaling pathway protein and stemness protein expressions were decreased in GSC exosome treated non-GSC glioma cells by Notch1 RNA interference and Notch inhibitors. The findings in this study indicated that GSC exosomes act as information carriers, mediated non-GSC glioma cell dedifferentiation into GSCs by delivering Notch1 protein through Notch1 signaling activation, and enhanced stemness and tumorigenicity of non-GSC glioma cells.


Assuntos
Neoplasias Encefálicas/patologia , Carcinogênese , Exossomos/metabolismo , Glioblastoma/patologia , Células-Tronco Neoplásicas/patologia , Receptor Notch1/metabolismo , Animais , Testes de Carcinogenicidade , Linhagem Celular Tumoral , Proliferação de Células , Reprogramação Celular , Exossomos/genética , Exossomos/transplante , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Interferência de RNA , Receptor Notch1/genética , Transdução de Sinais , Microambiente Tumoral
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA