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1.
Proc Natl Acad Sci U S A ; 121(12): e2318176121, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38483994

RESUMO

Endogenous retroviruses (ERVs) are frequently reactivated in mammalian placenta. It has been proposed that ERVs contribute to shaping the gene regulatory network of mammalian trophoblasts, dominantly acting as species- and placental-specific enhancers. However, whether and how ERVs control human trophoblast development through alternative pathways remains poorly understood. Besides the well-recognized function of human endogenous retrovirus-H (HERVH) in maintaining pluripotency of early human epiblast, here we present a unique role of HERVH on trophoblast lineage development. We found that the LTR7C/HERVH subfamily exhibits an accessible chromatin state in the human trophoblast lineage. Particularly, the LTR7C/HERVH-derived Urothelial Cancer Associated 1 (UCA1), a primate-specific long non-coding RNA (lncRNA), is transcribed in human trophoblasts and promotes the proliferation of human trophoblast stem cells (hTSCs), whereas its ectopic expression compromises human trophoblast syncytialization coinciding with increased interferon signaling pathway. Importantly, UCA1 upregulation is detectable in placental samples from early-onset preeclampsia (EO-PE) patients and the transcriptome of EO-PE placenta exhibits considerable similarities to that of the syncytiotrophoblasts differentiated from UCA1-overexpressing hTSCs, supporting up-regulated UCA1 as a potential biomarker of this disease. Altogether, our data shed light on the versatile regulatory role of HERVH in early human development and provide a unique mechanism whereby ERVs exert a function in human placentation and placental syndromes.


Assuntos
Retrovirus Endógenos , RNA Longo não Codificante , Animais , Humanos , Gravidez , Feminino , Retrovirus Endógenos/genética , Retrovirus Endógenos/metabolismo , Placenta/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Trofoblastos/metabolismo , Placentação , Primatas/genética , Mamíferos/genética
2.
PLoS Biol ; 21(6): e3002162, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37339119

RESUMO

There remains much that we do not understand about the earliest stages of human development. On a gross level, there is evidence for apoptosis, but the nature of the affected cell types is unknown. Perhaps most importantly, the inner cell mass (ICM), from which the foetus is derived and hence of interest in reproductive health and regenerative medicine, has proven hard to define. Here, we provide a multi-method analysis of the early human embryo to resolve these issues. Single-cell analysis (on multiple independent datasets), supported by embryo visualisation, uncovers a common previously uncharacterised class of cells lacking commitment markers that segregates after embryonic gene activation (EGA) and shortly after undergo apoptosis. The discovery of this cell type allows us to clearly define their viable ontogenetic sisters, these being the cells of the ICM. While ICM is characterised by the activity of an Old non-transposing endogenous retrovirus (HERVH) that acts to suppress Young transposable elements, the new cell type, by contrast, expresses transpositionally competent Young elements and DNA-damage response genes. As the Young elements are RetroElements and the cells are excluded from the developmental process, we dub these REject cells. With these and ICM being characterised by differential mobile element activities, the human embryo may be a "selection arena" in which one group of cells selectively die, while other less damaged cells persist.


Assuntos
Blastocisto , Elementos de DNA Transponíveis , Humanos , Elementos de DNA Transponíveis/genética , Blastocisto/metabolismo , Embrião de Mamíferos
3.
PLoS Genet ; 19(10): e1011006, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37851698

RESUMO

RNA-RNA interactions play a crucial role in regulating gene expression and various biological processes, but identifying these interactions on a transcriptomic scale remains a challenge. To address this, we have developed a new biochemical technique called pCp-biotin labelled RNA hybrid and ultraviolet crosslinking and immunoprecipitation (lhCLIP) that enables the transcriptome-wide identification of intra- and intermolecular RNA-RNA interactions mediated by a specific RNA-binding protein (RBP). Using lhCLIP, we have uncovered a diverse landscape of intermolecular RNA interactions recognized by hnRNPK in human cells, involving all major classes of noncoding RNAs (ncRNAs) and mRNA. Notably, hnRNPK selectively binds with snRNA U4, U11, and U12, and shapes the secondary structure of these snRNAs, which may impact RNA splicing. Our study demonstrates the potential of lhCLIP as a user-friendly and widely applicable method for discovering RNA-RNA interactions mediated by a particular protein of interest and provides a valuable tool for further investigating the role of RBPs in gene expression and biological processes.


Assuntos
RNA Nuclear Pequeno , RNA , Humanos , RNA/genética , RNA/metabolismo , RNA Nuclear Pequeno/genética , RNA Nuclear Pequeno/metabolismo , Splicing de RNA/genética , RNA não Traduzido/genética , RNA Mensageiro/metabolismo
4.
Small ; 20(6): e2304124, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37749960

RESUMO

Sodium-ion batteries are a promising substitute for lithium batteries due to the abundant resources and low cost of sodium. Herein, honeycomb-shaped MoSe2 /reduced graphene oxide (rGO) composite materials are synthesized from graphene oxide (GO) and MoSe2 through a one-step solvothermal process. Experiments show that the 3D honeycomb structure provides excellent electrolyte penetration while alleviating the volume change during electrochemical cycling. An anode prepared with MoSe2 /rGO composites exhibits significantly improved sodium-ion storage properties, where a large reversible capacity of 215 mAh g-1 is obtained after 2700 cycles at the current density of 30.0 A g-1 or after 5900 cycles at 8.0 A g-1 . When such an anode is paired with Na3 V2 (PO4 )3 to form a full cell, a reversible specific capacity of 107.5 mAh g-1 can be retained after 1000 cycles at the current of 1.0 A g-1 . Transmission electron microscopy, X-ray photoelectron spectroscopy and in situ X-ray diffraction (XRD) characterization reveal the reversible storage reaction of Na ions in the MoSe2 /rGO composites. The significantly enhanced sodium storage capacity is attributed to the unique honeycomb microstructure and the use of ether-based electrolytes. This study illustrates that combining rGO with ether-based electrolytes has tremendous potential in constructing high-performance sodium-ion batteries.

5.
Angew Chem Int Ed Engl ; 63(18): e202401924, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38366134

RESUMO

Nitrate electroreduction reaction (eNO3 -RR) to ammonia (NH3) provides a promising strategy for nitrogen utilization, while achieving high selectivity and durability at an industrial scale has remained challenging. Herein, we demonstrated that the performance of eNO3 -RR could be significantly boosted by introducing two-dimensional Cu plates as electrocatalysts and eliminating the general carrier gas to construct a steady fluid field. The developed eNO3 -RR setup provided superior NH3 Faradaic efficiency (FE) of 99 %, exceptional long-term electrolysis for 120 h at 200 mA cm-2, and a record-high yield rate of 3.14 mmol cm-2 h-1. Furthermore, the proposed strategy was successfully extended to the Zn-nitrate battery system, providing a power density of 12.09 mW cm-2 and NH3 FE of 85.4 %, outperforming the state-of-the-art eNO3 -RR catalysts. Coupled with the COMSOL multiphysics simulations and in situ infrared spectroscopy, the main contributor for the high-efficiency NH3 production could be the steady fluid field to timely rejuvenate the electrocatalyst surface during the electrocatalysis.

6.
J Cell Physiol ; 238(7): 1580-1591, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37305966

RESUMO

Poly(ADP-ribosyl)ation (PARylation) is an important post-translational modification of proteins that involves the transfer of ADP-ribose moieties, and plays important roles in many biological processes including DNA repair, gene expression, RNA processing, ribosome biogenesis, and protein translation. Though it is accepted that PARylation is crucial for oocyte maturation, little is known about how Mono(ADP-ribosyl)ation (MARylation) regulates this process. Here, we report that Parp12, a mon(ADP-ribosyl) transferase of poly(ADP-ribosyl) polymerase (PARP) family, was highly expressed at all stages of oocytes during meiotic maturation. At germinal vesicle (GV) stage, PARP12 was mainly distributed in cytoplasm. Interestingly, PARP12 formed granular aggregation near to spindle poles during metaphase I (MI) and metaphase II (MII). PARP12 depletion results in abnormal spindle organization and chromosome misalignment in mouse oocytes. Chromosome aneuploidy frequency in PARP12 knockdown oocytes was significantly increased. Importantly, PARP12 knockdown triggers activation of spindle assembly checkpoint as shown by active BUBR1 in PARP12-KD MI oocytes. Besides, F actin was significantly attenuated in PARP12-KD MI oocytes which may affect the asymmetric division process. Transcriptomic analysis demonstrated that PARP12 depletion disrupts transcriptome homeostasis. Collectively, our results showed that the maternally expressed mono(ADPribosyl) transferases PARP12 was essential for oocyte meiotic maturation in mouse.


Assuntos
Meiose , Oócitos , Animais , Camundongos , Cromossomos , Pontos de Checagem da Fase M do Ciclo Celular , Metáfase , Oócitos/metabolismo , Fuso Acromático/genética , Fuso Acromático/metabolismo
7.
Int J Mol Sci ; 24(8)2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-37108449

RESUMO

Transposons are parasitic genetic elements that frequently hijack vital cellular processes of their host. HMGXB4 is a known Wnt signaling-regulating HMG-box protein, previously identified as a host-encoded factor of Sleeping Beauty (SB) transposition. Here, we show that HMGXB4 is predominantly maternally expressed, and marks both germinal progenitor and somatic stem cells. SB piggybacks HMGXB4 to activate transposase expression and target transposition to germinal stem cells, thereby potentiating heritable transposon insertions. The HMGXB4 promoter is located within an active chromatin domain, offering multiple looping possibilities with neighboring genomic regions. HMGXB4 is activated by ERK2/MAPK1, ELK1 transcription factors, coordinating pluripotency and self-renewal pathways, but suppressed by the KRAB-ZNF/TRIM28 epigenetic repression machinery, also known to regulate transposable elements. At the post-translational level, SUMOylation regulates HMGXB4, which modulates binding affinity to its protein interaction partners and controls its transcriptional activator function via nucleolar compartmentalization. When expressed, HMGXB4 can participate in nuclear-remodeling protein complexes and transactivate target gene expression in vertebrates. Our study highlights HMGXB4 as an evolutionarily conserved host-encoded factor that assists Tc1/Mariner transposons to target the germline, which was necessary for their fixation and may explain their abundance in vertebrate genomes.


Assuntos
Cromossomos , Elementos de DNA Transponíveis , Animais , Elementos de DNA Transponíveis/genética , Células-Tronco , Proteína HMGB2/metabolismo
8.
Electrophoresis ; 43(21-22): 2217-2226, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36084168

RESUMO

Separation of microparticle in viscoelastic fluid is highly required in the field of biology and clinical medicine. For instance, the separation of the target cell from blood is an important prerequisite step for the drug screening and design. The microfluidic device is an efficient way to achieve the separation of the microparticle in the viscoelastic fluid. However, the existing microfluidic methods often have some limitations, including the requirement of the long channel length, the labeling process, and the low throughput. In this work, based on the elastic-inertial effect in the viscoelastic fluid, a new separation method is proposed where a gradually contracted microchannel is designed to efficiently adjust the forces exerted on the particle, eventually achieving the high-efficiency separation of different sized particles in a short channel length and at a high throughput. In addition, the separation of WBCs and RBCs is also validated in the present device. The effect of the flow rate, the fluid property, and the channel geometry on the particle separation is systematically investigated by the experiment. With the advantage of small footprint, simple structure, high throughput, and high efficiency, the present microfluidic device could be utilized in the biological and clinical fields, such as the cell analysis and disease diagnosis.


Assuntos
Micropartículas Derivadas de Células , Técnicas Analíticas Microfluídicas , Tamanho da Partícula , Microfluídica , Dispositivos Lab-On-A-Chip , Separação Celular/métodos
9.
Ann Vasc Surg ; 81: 240-248, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34748950

RESUMO

OBJECTIVE: To determine the risk for pulmonary embolism (PE) and explore the relationship between the site of thrombosis and PE in patients with acute lower extremity deep vein thrombosis (DVT). METHODS: A total of 1585 hospitalized patients first diagnosed with acute lower extremity DVT were investigated retrospectively. The patients were divided into two groups: the non-PE group (Group 1) and the PE group (Group 2). Then, Group 2 was divided into two subgroups: asymptomatic pulmonary embolism (asPE, Group 2a) and symptomatic pulmonary embolism (sPE, Group 2b). Kaplan-Meier curves and logistic regression analysis were used to explore the relevant risk factors for PE. RESULTS: Among 1585 patients, 458 patients suffered from PE, accounting for 28.9%. 102 (22.3%) of them had the typical clinical manifestations of PE and were defined as sPE, and the remaining 356 (77.7%) patients were classified as asPE. Patients with proximal lower extremity DVT were significantly more predominant in the PE group than in the non-PE group (92.8% vs. 86.2%, P<0.001). Moreover, in Group 2, patients with typical PE manifestations showed a higher proportion of patients with right lower extremity DVT than left lower extremity DVT (26.7% vs. 17.7%, P = 0.035), and bilateral lower extremity DVT than unilateral DVT (44.1% vs. 20.5%, P<0.001). By multivariate analysis, alcohol consumption (OR, 1.824; 95% CI, 1.194-2.787; P = 0.005), heart failure (OR, 2.345; 95% CI, 1.560-3.526; P<0.001), proximal DVT (OR, 2.096; 95% CI,1.407-3.123; P<0.001) were independent risk factors for PE. CONCLUSIONS: Patients with proximal acute lower extremity DVT were more likely to suffer from PE than those with distal DVT. Patients with right acute lower extremity DVT had a higher risk of sPE than patients with left acute lower extremity DVT. Alcohol consumption and heart failure were associated with the occurrence of PE in patients with acute lower extremity DVT.


Assuntos
Embolia Pulmonar , Trombose Venosa , Humanos , Extremidade Inferior/irrigação sanguínea , Embolia Pulmonar/complicações , Embolia Pulmonar/diagnóstico , Embolia Pulmonar/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento , Trombose Venosa/complicações , Trombose Venosa/epidemiologia
10.
Nucleic Acids Res ; 48(15): 8782-8795, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32633758

RESUMO

The stability and processing of cellular RNA transcripts are efficiently controlled via non-templated addition of single or multiple nucleotides, which is catalyzed by various nucleotidyltransferases including poly(A) polymerases (PAPs). Germline development defective 2 (GLD-2) is among the first reported cytoplasmic non-canonical PAPs that promotes the translation of germline-specific mRNAs by extending their short poly(A) tails in metazoan, such as Caenorhabditis elegans and Xenopus. On the other hand, the function of mammalian GLD-2 seems more diverse, which includes monoadenylation of certain microRNAs. To understand the structural basis that underlies the difference between mammalian and non-mammalian GLD-2 proteins, we determine crystal structures of two rodent GLD-2s. Different from C. elegans GLD-2, mammalian GLD-2 is an intrinsically robust PAP with an extensively positively charged surface. Rodent and C. elegans GLD-2s have a topological difference in the ß-sheet region of the central domain. Whereas C. elegans GLD-2 prefers adenosine-rich RNA substrates, mammalian GLD-2 can work on RNA oligos with various sequences. Coincident with its activity on microRNAs, mammalian GLD-2 structurally resembles the mRNA and miRNA processor terminal uridylyltransferase 7 (TUT7). Our study reveals how GLD-2 structurally evolves to a more versatile nucleotidyltransferase, and provides important clues in understanding its biological function in mammals.


Assuntos
Proteínas de Caenorhabditis elegans/genética , MicroRNAs/genética , Nucleotidiltransferases/genética , Polinucleotídeo Adenililtransferase/genética , Estabilidade de RNA/genética , RNA Mensageiro/genética , Proteínas de Xenopus/genética , Animais , Caenorhabditis elegans/genética , Citoplasma/genética , Células Germinativas/crescimento & desenvolvimento , Mamíferos , Poli A/genética , Interferência de RNA
11.
Nucleic Acids Res ; 48(5): 2733-2748, 2020 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-32009146

RESUMO

Family with sequence similarity (FAM46) proteins are newly identified metazoan-specific poly(A) polymerases (PAPs). Although predicted as Gld-2-like eukaryotic non-canonical PAPs, the detailed architecture of FAM46 proteins is still unclear. Exact biological functions for most of FAM46 proteins also remain largely unknown. Here, we report the first crystal structure of a FAM46 protein, FAM46B. FAM46B is composed of a prominently larger N-terminal catalytic domain as compared to known eukaryotic PAPs, and a C-terminal helical domain. FAM46B resembles prokaryotic PAP/CCA-adding enzymes in overall folding as well as certain inter-domain connections, which distinguishes FAM46B from other eukaryotic non-canonical PAPs. Biochemical analysis reveals that FAM46B is an active PAP, and prefers adenosine-rich substrate RNAs. FAM46B is uniquely and highly expressed in human pre-implantation embryos and pluripotent stem cells, but sharply down-regulated following differentiation. FAM46B is localized to both cell nucleus and cytosol, and is indispensable for the viability of human embryonic stem cells. Knock-out of FAM46B is lethal. Knock-down of FAM46B induces apoptosis and restricts protein synthesis. The identification of the bacterial-like FAM46B, as a pluripotent stem cell-specific PAP involved in the maintenance of translational efficiency, provides important clues for further functional studies of this PAP in the early embryonic development of high eukaryotes.


Assuntos
Células-Tronco Embrionárias Humanas/metabolismo , Nucleotidiltransferases/metabolismo , Polinucleotídeo Adenililtransferase/metabolismo , Células Procarióticas/metabolismo , Animais , Biocatálise , Linhagem Celular , Sobrevivência Celular , Desenvolvimento Embrionário , Humanos , Modelos Moleculares , Nucleotidiltransferases/química , Nucleotidiltransferases/genética , Polinucleotídeo Adenililtransferase/química , Ligação Proteica , Domínios Proteicos , RNA/metabolismo , Especificidade por Substrato , Xenopus
13.
Chaos ; 32(7): 073111, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35907722

RESUMO

This research investigated responses of the Belousov-Zhabotinsky (BZ) reaction to the presence of a chemically inert Pt wire in solution. Experiments showed that connecting the Pt wire to a neutral ground caused a spontaneous drastic shift in the redox potential and might even induce complex behavior. Characterizations using an unstirred ferriin solution demonstrated the formation of a red colored propagating front at the grounded Pt wire, suggesting the reduction of ferriin to ferroin. Measurements with different combinations of electrodes in both stirred and reaction-diffusion media further confirmed the reduction of BZ metal catalysts at the Pt wire and the accompanying oxidation reaction at the reference electrode. The observed drastic change in redox potential and oscillation waveform can be understood based on the passive reduction reaction at the indicator electrode that is connected to the reference electrode through a potential meter. The obtained influence can be further manipulated by adding a resistor between the Pt wire and the neutral ground, making this convenient perturbation method attractive for the study of redox chemical reaction dynamics.

14.
Phys Chem Chem Phys ; 23(32): 17502-17511, 2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34359072

RESUMO

The electronic structures and optical properties of a novel class of hybrid binary Janus materials derived from IV-V groups were investigated using first principles calculations. The computational results demonstrated that, except for Ge2NAs, all the other five structures of M2XY monolayers (M = Si, Ge; X, Y = N, P, As; X ≠ Y) have excellent thermal and dynamical stabilities. Janus Si2NP, Si2NAs, Si2PAs and Ge2NP are semiconductors with direct band gaps spanning the range between 0.82 and 2.49 eV. Notably, the hybrid M2XY materials exhibit highly efficient absorption within the visible light region, which are greatly higher than their pristine MX structures. Janus Si2PAs and Ge2PAs possess appropriate band edge alignments that straddle the water redox potentials in the pH range from 0 to 14, making them promising photocatalysts for water splitting under visible light. Our calculations further demonstrate that the catalytic selectivity for the water splitting reaction could be achieved through the hybrid Janus M2XY, where, for instance, Ge2NP appears to facilitate only the oxidation, but not the reduction of water under certain conditions. This outcome provides a new route for the design of novel photocatalysts with improved efficiency and selectivity.

15.
Gerontology ; 67(2): 144-151, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33582668

RESUMO

INTRODUCTION: This study aimed to examine whether intraplaque neovascularization (IPN) of carotid plaques, as characterized by contrast-enhanced ultrasound (CEUS), is associated with ischemic stroke recurrence in patients with carotid atherosclerosis. METHODS: We conducted a prospective study of consecutive patients with a recent stroke and at least one atherosclerotic plaque in the carotid artery on the side consistent with symptoms. All patients underwent CEUS after their first admission. IPN was graded on the basis of the presence and location of microbubbles within each plaque. RESULTS: We eventually included 155 patients, all of whom underwent IPN analysis. After a follow-up of 24 months, we recorded 25 (16.1%) stroke recurrences in the whole population. All the recurrences occurred in patients presenting IPN. There was significant difference in the IPN between the 2 groups (p = 0.002). In the final Cox proportional-hazards multivariable models, IPN of grade 2 was independently associated with the risk of stroke recurrence (HR = 4.535; 95% CI: 1.892-10.870; p = 0.001). This association remained after adjusting for the degree of carotid stenosis (HR = 3.491; 95% CI: 1.410-8.646; p = 0.007). CONCLUSIONS: IPN was an independent predictor of stroke recurrence in patients with a recent ischemic stroke and carotid atherosclerosis. In predicting stroke recurrence, IPN may be an earlier indicator than carotid stenosis and may help stratify the risk of stroke recurrence.


Assuntos
Isquemia Encefálica , Doenças das Artérias Carótidas , AVC Isquêmico , Acidente Vascular Cerebral , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/epidemiologia , Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/diagnóstico , Doenças das Artérias Carótidas/diagnóstico por imagem , Meios de Contraste , Humanos , Estudos Prospectivos , Recidiva , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/epidemiologia
16.
J Cell Biochem ; 121(3): 2139-2149, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31595560

RESUMO

Matrine, a natural product extracted from the root of Sophora flavescens Ait, was the main chemical ingredient of compounds of Kushen injection, which has been widely used for its remarkable anticancer effects for years. The underlying mechanisms for Matrine regulations of human breast cancer stem cells (BrCSCs) are barely known. LIN28, a well-characterized suppressor of Let-7 microRNA biogenesis, playing vital roles in regulations of stem cells' renewal and tumorigenesis. Here we show that the compounds of Kushen injection derived Matrine could suppress the BrCSCs differentiation and self-renewal through downregulating the expression of Lin28A, resulting in the inactivation of Wnt pathway through a Let-7b-dependent way. In opposite to Matrine, Cisplatin treatment increases the ability of tumorsphere formation and the expression of BrCSCs markers, which was partially blocked by either Let-7b overexpression or CCND1 inhibition. Furthermore, Matrine sensitized BrCSCs to cisplatin's suppression of cancer expansion in vitro and in vivo. Our study uncovers the role of the LIN28A/Let-7 in BrCSCs renewal, and more importantly, elucidated a novel mechanism by which Matrine induces breast cancer involution.


Assuntos
Alcaloides/farmacologia , Neoplasias da Mama/tratamento farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Pulmonares/tratamento farmacológico , MicroRNAs/genética , Células-Tronco Neoplásicas/efeitos dos fármacos , Quinolizinas/farmacologia , Animais , Apoptose , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proliferação de Células , Autorrenovação Celular , Feminino , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/secundário , Camundongos , Camundongos SCID , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto , Matrinas
17.
Small ; 16(17): e1906584, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32240573

RESUMO

Heteroatom-doped carbon materials are intensively studied in supercapacitors and fuel cells, because of their great potential for sustainably bearing on the energy crisis and environmental pollution. Although enormous efforts are put in material perfection with a hierarchically porous microstructure, the simultaneous optimization of both porous structures and surface functionalities is hard to achieve due to inevitable concurrent dopant leaching effect and structural collapse under required high pyrolysis temperature. In this study, an in situ dehalogenation polymerization and activation protocol is introduced to synthesize nitrogen- and sulfur-codoped carbon materials (NS-PCMs) with hierarchical pore distribution and abundant surface doping, which endows them with good conductivity, abundant accessible active sites, and efficient mass transport. As a result, the as-prepared carbon materials (NS-a-PCM-1000) show an excellent mass specific capacitance of 461.5 F g-1 at a current density of 0.1 A g-1 , long cycle life (>23 k, 10 A g-1 ), and high device energy and power density (17.3 Wh kg-1 , 250 W kg-1 ). Significantly, NS-a-PCM-1000 also exhibits one of the highest oxygen reduction reaction activities (onset potential of 1.0 V vs reversible hydrogen electrode) in alkaline media among all reported metal-free catalysts.

18.
Small ; 16(11): e1907141, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32083792

RESUMO

The high theoretical capacity of red phosphorus (RP) makes it a promising anode material for lithium-ion batteries. However, the large volume change of RP during charging/discharging imposes an adverse effect on the cyclability and the rate performance suffers from its low conductivity. Herein, a facile solution-based strategy is exploited to incorporate phosphorus into the pores of zeolitic imidazole framework (ZIF-8) derived carbon hosts under a mild temperature. With this method, the blocky RP is etched into the form of polyphosphides anions (PP, mainly P5 - ) so that it can easily diffuse into the pores of porous carbon hosts. Especially, the indelible crystalline surface phosphorus can be effectively avoided, which usually generates in the conventional vapor-condensation encapsulation method. Moreover, highly-conductive ZIF-8 derived carbon hosts with any pore smaller than 3 nm are efficient for loading PP and these pores can alleviate the volume change well. Finally, the composite of phosphorus encapsulated into ZIF-8 derived porous carbon exhibits a significantly improved electrochemical performance as lithium-ion battery anode with a high capacity of 786 mAh g-1 after 100 cycles at 0.1 A g-1 , a good stability within 700 cycles at 1 A g-1 , and an excellent rate performance.

19.
Nature ; 516(7531): 405-9, 2014 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-25317556

RESUMO

Naive embryonic stem cells hold great promise for research and therapeutics as they have broad and robust developmental potential. While such cells are readily derived from mouse blastocysts it has not been possible to isolate human equivalents easily, although human naive-like cells have been artificially generated (rather than extracted) by coercion of human primed embryonic stem cells by modifying culture conditions or through transgenic modification. Here we show that a sub-population within cultures of human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) manifests key properties of naive state cells. These naive-like cells can be genetically tagged, and are associated with elevated transcription of HERVH, a primate-specific endogenous retrovirus. HERVH elements provide functional binding sites for a combination of naive pluripotency transcription factors, including LBP9, recently recognized as relevant to naivety in mice. LBP9-HERVH drives hESC-specific alternative and chimaeric transcripts, including pluripotency-modulating long non-coding RNAs. Disruption of LBP9, HERVH and HERVH-derived transcripts compromises self-renewal. These observations define HERVH expression as a hallmark of naive-like hESCs, and establish novel primate-specific transcriptional circuitry regulating pluripotency.


Assuntos
Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Retrovirus Endógenos/metabolismo , Células-Tronco Pluripotentes Induzidas/fisiologia , Células Cultivadas , Elementos de DNA Transponíveis , Retrovirus Endógenos/genética , Perfilação da Expressão Gênica , Marcadores Genéticos , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/virologia , RNA Longo não Codificante/metabolismo , Fatores de Transcrição/metabolismo
20.
Nutr Metab Cardiovasc Dis ; 30(9): 1492-1499, 2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32620336

RESUMO

BACKGROUND AND AIMS: This study aimed to examine whether intraplaque neovascularization (IPN) of carotid plaques, as characterized by contrast-enhanced ultrasound (CEUS), is associated with atherosclerotic renal artery stenosis (ARAS) in patients with normal kidney function. METHODS AND RESULTS: We investigated carotid IPN using CEUS in 198 consecutive patients with normal kidney function with and without ARAS. IPN was graded on the basis of the presence and location of microbubbles within each plaque (0, no visible microbubbles in the plaque; 1, moderate microbubbles confined to the shoulder and/or adventitial side of the plaque; and 2, extensive microbubbles throughout the plaque). The grades of each plaque were averaged to obtain an overall score per patient. ARAS was determined angiographically. We found that a higher CEUS-assessed carotid IPN score was associated with ARAS (Odd Ratio, OR: 7.281; 95% Confidence Interval, 95% CI: 3.246-16.336; P < 0.001). Furthermore, an IPN score >1.75 predicted severe stenosis with a sensitivity of 81% and specificity of 58%. Compared with using the IPN score alone, the addition of the homocysteine (HCY) cutoff value (>22.5 mmol/L) resulted in a stronger predictive value (Area Under Curve, AUC: 0.893 vs 0.834; P < 0.001) for severe ARAS. CONCLUSION: Carotid plaque neovascularization combined with HCY levels is predictive of severe ARAS in patients with normal kidney function. CEUS-assessed carotid IPN is clinically useful for stratification of ARAS in patients with normal kidney function.


Assuntos
Artérias Carótidas/diagnóstico por imagem , Estenose das Carótidas/diagnóstico por imagem , Neovascularização Patológica , Placa Aterosclerótica , Obstrução da Artéria Renal/diagnóstico por imagem , Artéria Renal/diagnóstico por imagem , Ultrassonografia , Idoso , Biomarcadores/sangue , Estenose das Carótidas/sangue , Estenose das Carótidas/epidemiologia , Estenose das Carótidas/terapia , China/epidemiologia , Meios de Contraste/administração & dosagem , Feminino , Homocisteína/sangue , Humanos , Masculino , Microbolhas , Pessoa de Meia-Idade , Admissão do Paciente , Valor Preditivo dos Testes , Prevalência , Obstrução da Artéria Renal/sangue , Obstrução da Artéria Renal/epidemiologia , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença
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