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1.
Mol Cell ; 77(6): 1265-1278.e7, 2020 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-31959557

RESUMO

Diverse accessory subunits are involved in the recruitment of polycomb repressive complex 2 (PRC2) to CpG island (CGI) chromatin. Here we report the crystal structure of a SUZ12-RBBP4 complex bound to fragments of the accessory subunits PHF19 and JARID2. Unexpectedly, this complex adopts a dimeric structural architecture, accounting for PRC2 self-association that has long been implicated. The intrinsic PRC2 dimer is formed via domain swapping involving RBBP4 and the unique C2 domain of SUZ12. MTF2 and PHF19 associate with PRC2 at around the dimer interface and stabilize the dimer. Conversely, AEBP2 binding results in a drastic movement of the C2 domain, disrupting the intrinsic PRC2 dimer. PRC2 dimerization enhances CGI DNA binding by PCLs in pairs in vitro, reminiscent of the widespread phenomenon of transcription factor dimerization in active transcription. Loss of PRC2 dimerization impairs histone H3K27 trimethylation (H3K27me3) on chromatin at developmental gene loci in mouse embryonic stem cells.


Assuntos
Cromatina/metabolismo , Ilhas de CpG , Metilação de DNA , Histonas/metabolismo , Complexo Repressor Polycomb 2/química , Multimerização Proteica , Animais , Diferenciação Celular , Cromatina/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Histonas/genética , Humanos , Camundongos , Camundongos Knockout , Células-Tronco Embrionárias Murinas/citologia , Células-Tronco Embrionárias Murinas/metabolismo , Proteínas de Neoplasias , Complexo Repressor Polycomb 2/genética , Complexo Repressor Polycomb 2/metabolismo , Complexo Repressor Polycomb 2/fisiologia , Conformação Proteica , Proteína 4 de Ligação ao Retinoblastoma/genética , Proteína 4 de Ligação ao Retinoblastoma/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
2.
Mol Cell ; 69(5): 840-852.e5, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29499137

RESUMO

Developmentally regulated accessory subunits dictate PRC2 function. Here, we report the crystal structures of a 120 kDa heterotetrameric complex consisting of Suz12, Rbbp4, Jarid2, and Aebp2 fragments that is minimally active in nucleosome binding and of an inactive binary complex of Suz12 and Rbbp4. Suz12 contains two unique structural platforms that define distinct classes of PRC2 holo complexes for chromatin binding. Aebp2 and Phf19 compete for binding of a non-canonical C2 domain of Suz12; Jarid2 and EPOP occupy an overlapped Suz12 surface required for chromatin association of PRC2. Suz12 and Aebp2 progressively block histone H3K4 binding to Rbbp4, suggesting that Rbbp4 may not be directly involved in PRC2 inhibition by the active H3K4me3 histone mark. Nucleosome binding enabled by Jarid2 and Aebp2 is in part accounted for by the structures, which also reveal that disruption of the Jarid2-Suz12 interaction may underlie the disease mechanism of an oncogenic chromosomal translocation of Suz12.


Assuntos
Complexo Repressor Polycomb 2/química , Humanos , Proteínas de Neoplasias , Nucleossomos/química , Nucleossomos/genética , Nucleossomos/metabolismo , Complexo Repressor Polycomb 2/genética , Complexo Repressor Polycomb 2/metabolismo , Domínios Proteicos , Estrutura Quaternária de Proteína , Proteínas Repressoras/química , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Proteína 4 de Ligação ao Retinoblastoma/química , Proteína 4 de Ligação ao Retinoblastoma/genética , Proteína 4 de Ligação ao Retinoblastoma/metabolismo , Fatores de Transcrição
3.
Stem Cells ; 42(5): 460-474, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38381592

RESUMO

Cell therapy based on mesenchymal stem cells (MSCs) alleviate muscle atrophy caused by diabetes and aging; however, the impact of human umbilical cord mesenchymal stem cells on muscle atrophy following nerve injury and the underlying mechanisms remain unclear. In this study, we evaluated the therapeutic efficacy of human umbilical cord MSCs (hucMSCs) and hucMSC-derived exosomes (hucMSC-EXOs) for muscle atrophy following nerve injury and identified the underlying molecular mechanisms. Sciatic nerve crush injury in rats and the induction of myotubes in L6 cells were used to determine the ameliorating effect of hucMSCs and hucMSC-EXOs on muscle atrophy. Q-PCR and Western blot analyses were used to measure the expression of muscle-specific ubiquitin ligases Fbxo32 (Atrogin1, MAFbx) and Trim63 (MuRF-1). Dual-luciferase reporter gene experiments were conducted to validate the direct binding of miRNAs to their target genes. Local injection of hucMSCs and hucMSC-EXOs mitigated atrophy in the rat gastrocnemius muscle following sciatic nerve crush injury. In vitro, hucMSC-EXOs alleviated atrophy in L6 myotubes. Mechanistic analysis indicated the upregulation of miR-23b-3p levels in L6 myotubes following hucMSC-EXOs treatment. MiR-23b-3p significantly inhibited the expression of its target genes, Fbxo32 and Trim63, and suppressed myotube atrophy. Notably, an miR-23b-3p inhibitor reversed the inhibitory effect of miR-23b-3p on myotube atrophy in vitro. These results suggest that hucMSCs and their exosomes alleviate muscle atrophy following nerve injury. MiR-23b-3p in exosomes secreted by hucMSCs contributes to this mechanism by inhibiting the muscle-specific ubiquitination ligases Fbxo32 and Trim63.


Assuntos
Exossomos , Células-Tronco Mesenquimais , Atrofia Muscular , Traumatismos dos Nervos Periféricos , Ubiquitina-Proteína Ligases , Exossomos/metabolismo , Animais , Atrofia Muscular/patologia , Atrofia Muscular/metabolismo , Atrofia Muscular/terapia , Atrofia Muscular/genética , Humanos , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Células-Tronco Mesenquimais/metabolismo , Ratos , Traumatismos dos Nervos Periféricos/metabolismo , Traumatismos dos Nervos Periféricos/patologia , Traumatismos dos Nervos Periféricos/terapia , Ratos Sprague-Dawley , Proteínas Ligases SKP Culina F-Box/metabolismo , Proteínas Ligases SKP Culina F-Box/genética , Cordão Umbilical/citologia , Músculo Esquelético/patologia , Músculo Esquelético/metabolismo , Masculino , Proteínas com Motivo Tripartido/metabolismo , Proteínas com Motivo Tripartido/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas Musculares/metabolismo , Proteínas Musculares/genética , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia
4.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 46(3): 307-315, 2024 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-38548389

RESUMO

Objective To investigate the effects of platelet-rich plasma-derived exosomes (PRP-Exos) on the proliferation and migration of tendon stem/progenitor cell (TSPC).Methods PRP-Exos were extracted through the combination of polymer-based precipitation and ultracentrifugation.The morphology,concentration,and particle size of PRP-Exos were identified by transmission electron microscopy and nanoparticle tracking analysis.The expression levels of surface marker proteins on PRP-Exos and platelet membrane glycoproteins were determined by Western blot analysis.Rat TSPC was extracted and cultured,and the expression of surface marker molecules on TSPC was detected using flow cytometry and immunofluorescence staining.The proliferation of TSPC influenced by PRP-Exos was evaluated using CCK-8 assay and EdU assay.The effect of PRP-Exos on the migration of TSPC was evaluated by cell scratch assay and Transwell assay.Results The extracted PRP-Exos exhibit typical saucer-like structures,with a concentration of 4.9×1011 particles/mL,an average particle size of (132.2±56.8) nm,and surface expression of CD9,CD63 and CD41.The extracted TSPC expressed the CD44 protein.PRP-Exos can be taken up by TSPC,and after co-cultured for 48 h,concentrations of 50 and 100 µg/mL of PRP-Exos significantly promoted the proliferation of TSPC (both P<0.001),with no statistical difference between the two concentrations (P=0.283).Additionally,after co-cultured for 24 h,50 µg/mL of PRP-Exos significantly promoted the migration of TSPC (P<0.001).Conclusion Under in vitro culture conditions,PRP-Exos significantly promote the proliferation and migration of rat TSPC.


Assuntos
Movimento Celular , Proliferação de Células , Exossomos , Plasma Rico em Plaquetas , Células-Tronco , Tendões , Exossomos/metabolismo , Plasma Rico em Plaquetas/metabolismo , Ratos , Células-Tronco/citologia , Células-Tronco/metabolismo , Animais , Tendões/citologia , Tendões/metabolismo , Células Cultivadas , Ratos Sprague-Dawley , Masculino
5.
Small ; 19(2): e2205219, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36404124

RESUMO

Lightweight and impact-resistant materials with self-monitoring capability are highly desired for protective applications, but are challenging to be artificially fabricated. Herein, a scalable-manufactured aramid nanofiber (ANF)-based composite combining these key properties is presented. Inspired by the strengthening and toughening mechanisms relying on recoverable interfaces commonly existing in biological composites, mechanically weak but dense hydrogen bonds are introduced into the ANF interfaces to achieve simultaneously enhanced tensile strength (300 MPa), toughness (55 MJ m-3 ), and impact resistance of the nanofibrous composite. The achieved mechanical property combination displays attractive advantages compared with that of most of previously reported nanocomposites. Additionally, the nanofibrous composite is designed with a capability for real-time self-monitoring of its structural safety during both quasi-static tensile and dynamic impact processes, based on the strain/damage-induced resistance variations of a conductive nanowire network inside it. These comprehensive properties enable the present nanofibrous composite with promising potential for protective applications.


Assuntos
Nanofibras , Nanofibras/química , Resistência à Tração
6.
Acc Chem Res ; 55(11): 1480-1491, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-35578915

RESUMO

Natural biomaterials often show ordered nanowire structures (ONWS) which display unique structural color or superior mechanical performance. Meanwhile, plenty of modern nanodevices with ONWS have flourished with activities focused on both basic and applied research. Manipulating synthetic nanowire (NW) from a disordered state to a hierarchically ordered structure via various assembly strategies brings about intriguing and exotic chemical/physical properties. In the past decades, many methods have been developed to assemble NWs and fabricate organized architectures, such as Langmuir-Blodgett interfacial assembly, spin-coating assembly, fluid-flow-induced assembly, and ice-template assembly. Nevertheless, for practical applications, large-scale and high-efficiency assembly strategies toward precise controlled architectures are largely limited by the lack understanding of assembly mechanisms. Especially, the manipulation principles and driving forces behind the state-of-art assembly strategies are still unclear. Besides, the lesser research attention on dynamic kinetics also impedes the revelation of the NW self-assembly mechanism. With the emergence of advanced in situ techniques, such as synchrotron-based X-ray techniques and in situ transmission electron microscopy (TEM), the dynamic monitoring of NW behavior in many practical environments becomes possible. In addition, the alignment direction and the stacking manner of NW film are of significance to the final performance. There is a lack of connection between the properties of one-dimensional nanoscale building blocks and the functionalities of the macro-assembly structures. To this end, dynamic monitoring is highly desired, which enables the precision modulation of NW assembly structure, leading to the discovery or prediction of new structures, novel properties, and performance optimization.In this Account, we aim to uncover the underlying kinetics of NW assembly or local reaction and mass transportation processes, as well as to build a solid connection from individual NWs to NW assembly structures with enhanced properties and eventually to macroscopic materials application. We first review the recent progress in state-of-art NW assembly strategies for diverse aligned structures according to the manipulation principle and the driving forces. To systematically review the NW self-assembly strategies, we categorize these strategies into three states: NWs on the liquid interface via surface tension, NW assembly in liquid via solution-shearing flow field, and NW assembly at the solid interval via physical repulsive force. Then, we introduce the existing advanced characterization techniques, including synchrotron-based X-ray scattering and in situ TEM, to dynamically monitor the intermediate states of the NW assembly and transport processes. The comprehensive understanding of this thermodynamic and kinetic mechanism facilitates the rational design, large scale, and high-efficiency fabrication of NW assemblies, thus promoting their applications in tailored optical-electrical electronics, smart electrochromic devices, electrocatalysis, structural materials, and chiral photonic crystals.


Assuntos
Nanofios , Eletricidade , Eletrônica , Microscopia Eletrônica de Transmissão , Nanofios/química , Óptica e Fotônica
7.
Opt Express ; 31(11): 18147-18158, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37381531

RESUMO

Semiconductor mode-locked optical frequency comb (ML-OFC) sources with extremely high repetition rates are central to many high-frequency applications, such as dense wavelength-division multiplexing. Dealing with distortion-free amplification of ultra-fast pulse trains from such ML-OFC sources in high-speed data transmission networks requires the deployment of semiconductor optical amplifiers (SOAs) with ultrafast gain recovery dynamics. Quantum dot (QD) technology now lies at the heart of many photonic devices/systems owing to their unique properties at the O-band, including low alpha factor, broad gain spectrum, ultrafast gain dynamics, and pattern-effect free amplification. In this swork, we report on ultrafast and pattern-free amplification of ∼100 GHz pulsed trains from a passively ML-OFC and up to 80 Gbaud/s non-return-to-zero (NRZ) data transmission using an SOA. Most significantly, both key photonic devices presented in this work are fabricated from identical InAs/GaAs QD materials operating at O-band, which paves the way for future advanced photonic chips, where ML-OFCs could be monolithically integrated with SOAs and other photonic components, all originated from the same QD-based epi-wafer.

8.
Opt Lett ; 48(7): 1702-1705, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37221745

RESUMO

Optical resonant cavities with high quality factor (Q-factor) are widely used in science and technology for their capabilities of strong confinement of light and enhanced light-matter interaction. The 2D photonic crystal structure with bound states in the continuum (BICs) is a novel concept for resonators with ultra-compact device size, which can be used to generate surface emitting vortex beams based on symmetry-protected BICs at the Γ point. Here, to the best of our knowledge, we demonstrate the first photonic crystal surface emitter with a vortex beam by using BICs monolithically grown on CMOS-compatible silicon substrate. The fabricated quantum-dot BICs-based surface emitter operates at 1.3 µm under room temperature (RT) with a low continuous wave (CW) optically pumped condition. We also reveal the BIC's amplified spontaneous emission with the property of a polarization vortex beam, which is promising to provide a novel degree of freedom in classical and quantum realms.

9.
Theor Appl Genet ; 136(5): 117, 2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-37093272

RESUMO

KEY MESSAGE: Mapping of QTLs for dorsal aleurone thickness (DAT) was performed using chromosome segment substitution lines in rice. Three QTLs, qDAT3.1, qDAT3.2, and qDAT7.1, were detected in multiple environments. As a specified endosperm cell type, the aleurone has an abundance of various nutrients. Increasing the number of aleurone layers is a practicable way of developing highly nutritious cereals. Identifying genes that can increase aleurone thickness is useful for the breeding of aleurone traits to improve the nutritional and health values of rice. Here, we found that iodine staining could efficiently distinguish the aleurone layers, which revealed great variation of the aleurone thickness in rice, especially at the dorsal side of the seed. Therefore, we used a population of chromosome segmental substitution lines (CSSLs) derived from Koshihikari and Nona Bokra for quantitative trait locus (QTL) analysis of the dorsal aleurone thickness (DAT). Three QTLs, qDAT3.1, qDAT3.2, and qDAT7.1, were detected in multiple seasons. Among these, qDAT3.2 colocalizes with Hd6 and Hd16, two QTLs previously identified to regulate the heading date of Koshihikari, explaining the negative correlation between the DAT and days to heading (DTH) in rice. We also provide evidence that early-heading ensures the filling of rice seed under a relatively high temperature to promote aleurone thickening. qDAT7.1, the most stable QTL expressed in different environments, functions independently from heading date. Although Nona Bokra has a lower DAT, its qDAT7.1 allele significantly increased DAT in rice, which was further validated using two near-isogenic lines (NILs). These findings pave the way for further gene cloning of aleurone-related QTLs and may aid the development of highly nutritious rice.


Assuntos
Oryza , Locos de Características Quantitativas , Oryza/genética , Cromossomos de Plantas , Melhoramento Vegetal
10.
Eur Radiol ; 2023 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-37855852

RESUMO

OBJECTIVES: In this study, ultrasound (US) contrast arthrography and subacromial-subdeltoid bursography with the contrast agent of SonoVue were performed to evaluate their value for detecting and differentiating the rotator cuff tear (RCT) subtypes in patients with the uncertain RCT. METHODS: A total of 102 patients with the clinically suspected RCTs in the orthopedic clinic were prospectively recruited and underwent conventional high-frequency US for the category of undoubted full-thickness RCT, uncertain RCT, and intact rotator cuff. Among these patients, the patients with uncertain RCT underwent the subsequent US contrast arthrography and subacromial-subdeltoid bursography. The arthroscopic findings were used as the gold standard in this study. RESULTS: After the conventional US screening, 62 patients with uncertain RCT underwent the subsequent US contrast arthrography and subacromial-subdeltoid bursography. All the US contrast arthrography and subacromial-subdeltoid bursography were successfully performed and no severe side effects were observed in all the patients. For full-thickness tears, the sensitivity and specificity of the combined US contrast arthrography and subacromial-subdeltoid bursography were 94.7% (CI: 0.72-1.0) and 81.4% (CI: 0.66-0.91), respectively, and for articular-side tears 100% (CI: 0.51-1) and 100% (CI: 0.92-1), respectively, and for the bursal-side tears 84.6% (CI: 0.54-0.97) and 97.9% (CI: 0.88-1.0), respectively. The main inconsistency between the contrast-enhanced US and arthroscopy was that 7 patients with arthroscopic proved concurrent articular- and bursal-side tears were indicated as full-thickness RCTs on contrast-enhanced US. CONCLUSIONS: Combined US contrast arthrography and subacromial-subdeltoid bursography are useful for detecting the RCT subtypes in patients with the uncertain RCTs. CLINICAL RELEVANCE STATEMENT: When conventional high-frequency US has some difficulty in differentiating the full-thickness from partial-thickness RCTs, combined US contrast arthrography and subacromial-subdeltoid bursography could be used to improve the detection accuracy of RCT subtypes. KEY POINTS: • This is the first study by injection of the US contrast agent SonoVue into the shoulder joint cavity and subacromial-subdeltoid bursa for the detection and differentiation of the RCT subtypes among the people with the uncertain RCT by conventional US screening. • The SonoVue was injected into the glenohumeral joint cavity under US guidance to differentiate the full-thickness RCTs from partial-thickness RCTs. • Combined US contrast arthrography and subacromial-subdeltoid bursography are useful for detecting the RCT subtypes in patients with the uncertain RCTs.

11.
Environ Sci Technol ; 57(4): 1807-1818, 2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36598371

RESUMO

Vanadium(V) is a redox-sensitive heavy-metal contaminant whose environmental mobility is strongly influenced by pyrrhotite, a widely distributed iron sulfide mineral. However, relatively little is known about microbially mediated vanadate [V(V)] reduction characteristics driven by pyrrhotite and concomitant mineral dynamics in this process. This study demonstrated efficient V(V) bioreduction during 210 d of operation, with a lifespan about 10 times longer than abiotic control, especially in a stable period when the V(V) removal efficiency reached 44.1 ± 13.8%. Pyrrhotite oxidation coupled to V(V) reduction could be achieved by an enriched single autotroph (e.g., Thiobacillus and Thermomonas) independently. Autotrophs (e.g., Sulfurifustis) gained energy from pyrrhotite oxidation to synthesize organic intermediates, which were utilized by the heterotrophic V(V) reducing bacteria such as Anaerolinea, Bacillus, and Pseudomonas to sustain V(V) reduction. V(V) was reduced to insoluble tetravalent V, while pyrrhotite oxidation mainly produced Fe(III) and SO42-. Secondary minerals including mackinawite (FeS) and greigite (Fe3S4) were produced synchronously, resulting from further transformations of Fe(III) and SO42- by sulfate reducing bacteria (e.g., Desulfatiglans) and magnetotactic bacteria (e.g., Nitrospira). This study provides new insights into the biogeochemical behavior of V under pyrrhotite effects and reveals the previously overlooked mineralogical dynamics in V(V) reduction bioprocesses driven by Fe(II)-bearing minerals.


Assuntos
Compostos Férricos , Vanadatos , Minerais , Ferro , Oxirredução , Bactérias
12.
Proc Natl Acad Sci U S A ; 117(29): 16992-17002, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32631994

RESUMO

Enhancer of Zeste Homolog 2 (EZH2) is the catalytic subunit of Polycomb Repressive Complex 2 (PRC2), which minimally requires two other subunits, EED and SUZ12, for enzymatic activity. EZH2 has been traditionally known to mediate histone H3K27 trimethylation, a hallmark of silent chromatin. Emerging evidence indicates that EZH2 also activates gene expression in cancer cells in a context distinct from canonical PRC2. The molecular mechanism underlying the functional conversion of EZH2 from a gene repressor to an activator is unclear. Here, we show that EZH2 harbors a hidden, partially disordered transactivation domain (TAD) capable of interacting with components of active transcription machinery, mimicking archetypal acidic activators. The EZH2 TAD comprises the SRM (Stimulation-Responsive Motif) and SANT1 (SWI3, ADA2, N-CoR, and TFIIIB 1) regions that are normally involved in H3K27 methylation. The crystal structure of an EZH2-EED binary complex indicates that the EZH2 TAD mediates protein oligomerization in a noncanonical PRC2 context and is entirely sequestered. The EZH2 TAD can be unlocked by cancer-specific EZH2 phosphorylation events to undergo structural transitions that may enable subsequent transcriptional coactivator binding. The EZH2 TAD directly interacts with the transcriptional coactivator and histone acetyltransferase p300 and activates gene expression in a p300-dependent manner in cells. The corresponding TAD may also account for the gene activation function of EZH1, the paralog of EZH2. Distinct kinase signaling pathways that are known to abnormally convert EZH2 into a gene activator in cancer cells can now be understood in a common structural context of the EZH2 TAD.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Fatores de Transcrição de p300-CBP/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/química , Células HEK293 , Células HeLa , Humanos , Proteínas Intrinsicamente Desordenadas/química , Fosforilação , Ligação Proteica , Domínios Proteicos
13.
J Environ Manage ; 336: 117615, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-36893541

RESUMO

The bioleaching process is widely used in the treatment of ores or solid wastes, but little is known about its application in the treatment of vanadium-bearing smelting ash. This study investigated bioleaching of smelting ash with Acidithiobacillus ferrooxidans. The vanadium-bearing smelting ash was first treated with 0.1 M acetate buffer and then leached in the culture of Acidithiobacillus ferrooxidans. Comparison between one-step and two-step leaching process indicated that microbial metabolites could contribute to the bioleaching. The Acidithiobacillus ferrooxidans demonstrated a high vanadium leaching potential, solubilizing 41.9% of vanadium from the smelting ash. The optimal leaching condition was determined, which was 1% pulp density, 10% inoculum volume, an initial pH of 1.8, and 3 Fe2+g/L. The compositional analysis showed that the fraction of reducible, oxidizable, and acid-soluble was transferred into the leaching liquor. Therefore, as the alternative to the chemical/physical process, an efficient bioleaching process was proposed to enhance the recovery of vanadium from the vanadium-bearing smelting ash.


Assuntos
Acidithiobacillus , Vanádio , Acidithiobacillus/metabolismo
14.
Angew Chem Int Ed Engl ; 62(22): e202303656, 2023 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-37016511

RESUMO

Stable isotope chemical labeling methods have been widely used for high-throughput mass spectrometry (MS)-based quantitative proteomics in biological and clinical applications. However, the existing methods are far from meeting the requirements for high sensitivity detection. In the present study, a novel isobaric stable isotope N-phosphorylation labeling (iSIPL) strategy was developed for quantitative proteome analysis. The tryptic peptides were selectively labeled with iSIPL tag to generate the novel reporter ions containing phosphoramidate P-N bond with high intensities under lower collision energies. iSIPL strategy are suitable for peptide sequencing and quantitative analysis with high sensitivity and accuracy even for samples of limited quantity. Furthermore, iSIPL coupled with affinity purification and mass spectrometry was applied to measure the dynamics of cyclin dependent kinase 9 (CDK9) interactomes during transactivation of the HIV-1 provirus. The interaction of CDK9 with PARP13 was found to significantly decrease during Tat-induced activation of HIV-1 gene transcription, suggesting the effectiveness of iSIPL strategy in dynamic analysis of protein-protein interaction in vivo. More than that, the proposed iSIPL strategy would facilitate large-scale accurate quantitative proteomics by increasing multiplexing capability.


Assuntos
Proteoma , Espectrometria de Massas em Tandem , Proteoma/análise , Espectrometria de Massas em Tandem/métodos , Fosforilação , Peptídeos/química , Marcação por Isótopo/métodos , Isótopos
15.
Small ; 18(44): e2202659, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36059245

RESUMO

As a typical perovskite-type crystal, polyhedral strontium titanate (SrTiO3 ) has shown anisotropic charge transport behavior in recent studies, however, the carrier transportation and transition of which has not been explained very clearly. This work present the existence of Sr and O divacancies in the novel rhombicuboctahedron SrTiO3 micro/nano particles (Sr1- x TiO3- x /TiO2- x ) with exposing (100), (110) and (111) facets and the diameter of 300-700 nm synthesized via hydrothermal synthesis, and also summarizes the dissociation mechanism of self-trapped excitons (STEs) caused by the divacancy and facet effect. In addition, most importantly, the metastable STEs with ultra-low binding energy (Eb  < 3 meV) under illumination are discovered. Combining the model of S-scheme heterojunction, a conversion mechanism of photoinduced carriers is proposed. The photocatalytic reaction of Co2+ is used as the probe reaction, and the unique Sr1- x TiO3- x /TiO2- x possesses a high photooxidation efficiency of Co2+ , by which 70.3% of Co2+ is oxidized to Co3+ (CoOOH) in 5 min. This finding may provide a guideline for an optimal design of the photocatalytic materials for the recovery and extraction of metal ions based on SrTiO3 .

16.
BMC Neurol ; 22(1): 16, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-34996389

RESUMO

BACKGROUND: Progressive haemorrhagic injury after surgery in patients with traumatic brain injury often results in poor patient outcomes. This study aimed to develop and validate a practical predictive tool that can reliably estimate the risk of postoperative progressive haemorrhagic injury (PHI) in patients with traumatic brain injury (TBI). METHODS: Data from 645 patients who underwent surgery for TBI between March 2018 and December 2020 were collected. The outcome was postoperative intracranial PHI, which was assessed on postoperative computed tomography. The least absolute shrinkage and selection operator (LASSO) regression model, univariate analysis, and Delphi method were applied to select the most relevant prognostic predictors. We combined conventional coagulation test (CCT) data, thromboelastography (TEG) variables, and several predictors to develop a predictive model using binary logistic regression and then presented the results as a nomogram. The predictive performance of the model was assessed with calibration and discrimination. Internal validation was assessed. RESULTS: The signature, which consisted of 11 selected features, was significantly associated with intracranial PHI (p < 0.05, for both primary and validation cohorts). Predictors in the prediction nomogram included age, S-pressure, D-pressure, pulse, temperature, reaction time, PLT, prothrombin time, activated partial thromboplastin time, FIB, and kinetics values. The model showed good discrimination, with an area under the curve of 0.8694 (95% CI, 0.8083-0.9304), and good calibration. CONCLUSION: This model is based on a nomogram incorporating CCT and TEG variables, which can be conveniently derived at hospital admission. It allows determination of this individual risk for postoperative intracranial PHI and will facilitate a timely intervention to improve outcomes.


Assuntos
Lesões Encefálicas Traumáticas , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/diagnóstico por imagem , Humanos , Hemorragias Intracranianas , Modelos Logísticos , Nomogramas , Prognóstico
17.
Mol Biol Rep ; 49(3): 1669-1678, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34851478

RESUMO

BACKGROUND: Skin aging involves genetic, environmental and hormonal factors. Facial wrinkles also depend on muscular activity. Gene expression investigation may be useful for new anti-aging products. METHODS AND RESULTS: To evaluate structure and gene expression differences among exposed and unexposed skin in menopausal women. Cross-sectional study, including 15 menopausal women, 55-65 years, phototype III; photo-exposed, periorbital wrinkles (A1), preauricular, not wrinkled (A2), and unexposed gluteal (A3) areas were described and compared by non-invasive measures, histology, immunohistochemistry and gene expression (RNASeq); participants mean age was 61yo, presenting moderate periorbital wrinkles and light facial photodamage. Higher roughness, wrinkles number and echogenicity were observed in A1 and A2 versus A3. Decreased epidermal thickness and dermal collagen IV were demonstrated in A1 versus A2 and A3. Exposed areas impacted different pathways compared to unexposed. Exposed wrinkled skin (A1) showed impact on cell movement with decreased inflammatory activation state. Pathways related to lipid and aminoacids metabolism were modulated in non-wrinkled exposed (A2) compared to unexposed (A3) skin. CONCLUSIONS: Expected histological findings and gene expression differences among areas were observed. Photoaging in menopausal women may modulate lipid and aminoacids metabolism and decrease inflammatory and keratinization pathways, cellular homeostasis, immune response, fibrogenesis and filament formation. These findings may help development of new therapies for skin health and aging control.


Assuntos
Envelhecimento da Pele , Envelhecimento/patologia , Estudos Transversais , Feminino , Humanos , Pessoa de Meia-Idade , Pele/patologia , Envelhecimento da Pele/genética , Transcriptoma
18.
J Environ Manage ; 324: 116298, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36179473

RESUMO

This study investigated groundwater hexavalent chromium (Cr(VI)) decontamination by a biological permeable reactive barrier (bio-PRB), where a woodchip-elemental sulfur [S(0)] based mixotrophic process was established. 89.0 ± 0.27% of Cr(VI) was removed from the synthetic groundwater after 72 h at a concentration of 50 mg/L during the preliminary batch experiment. The impact of geochemical and hydrodynamic conditions Cr(VI) removal was investigated in the bio-PRB over 225 days. Although elevated Cr(VI) (i.e., 75 mg/L), addition of nitrate and short hydraulic retention time reduced the Cr(VI) removal, 87.2 ± 2.09% of Cr(VI) removal was accomplished. Characterization of the solids indicated that the soluble Cr(VI) was converted and immobilized as the insoluble trivalent chromium [Cr(III)]. 16S rRNA gene based sequencing results suggested that micromolecules produced by woodchip cellulose hydrolyzing- and sulfur oxidizing bacteria were further used by functional Cr(VI) removal bacteria (e.g., Geobacteraceae and Pseudomonas). The extracellular protein and humic-like substances in extracellular polymeric substances (EPS) can bind toxic Cr(VI) through carboxyl and hydroxyl groups, and reduce Cr(VI) in an enzymatic manner. The preliminary finding of this study provided a potential way to utilize agricultural waste for in-situ Cr(VI) contaminated-groundwater remediation.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , RNA Ribossômico 16S , Poluentes Químicos da Água/análise , Água Subterrânea/química , Cromo/análise , Enxofre , Biotecnologia
19.
Cancer Cell Int ; 21(1): 119, 2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33602230

RESUMO

BACKGROUND: High immunogenicity is an important feature of ccRCC, but its underlying immune-related molecular mechanisms remain unclear. This study aimed to investigate the effect of immune-related gene TEK on ccRCC and its prognostic value. METHODS: The immune-related differentially expressed genes (DEGs) and transcription factors (TFs) in ccRCC were screened based on The Cancer Genome Atlas (TCGA) database, and a regulatory network of TF was constructed. Prognostic-related immune genes were screened by univariate Cox regression analysis and functional annotation was performed. Univariate and multivariate Cox regression analyses were performed to construct the immune gene risk model and identify the hub gene TEK that independently affected the prognosis of ccRCC. The effectiveness of the TEK was verified by external microarray datasets. The relationship between TEK and immune cells in ccRCC was evaluated based on Tumor Immune Estimation Resource (TIMER). The expression of TEK in clinical specimens was verified by qRT-PCR and immunohistochemical (IHC) staining. MTT and cloning formation assay were used to evaluate cell proliferation. Transwell assays were used to assess cell migration. Apoptosis was assessed by flow cytometry, and the expression of related proteins was detected by Western blot and immunofluorescence. RESULTS: We constructed a prognostic model consisting of 12 hub genes and performed risk scores to determine the relationship between these scores and prognosis. Through Cox regression analysis and survival analysis, TEK, an immune marker highly related to survival prognosis, was obtained and validated. In vitro experiments showed that knockdown of TEK promoted the proliferation and migration of ccRCC cells, and we found that TEK promoted apoptosis by regulating the phosphorylation of AKT, thereby inhibiting cell proliferation. CONCLUSIONS: TEK plays an important role in risk assessment and survival prediction for ccRCC patients as a new immune gene and maybe an emerging target for immunotherapy for ccRCC patients.

20.
Cancer Cell Int ; 21(1): 461, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34461908

RESUMO

BACKGROUND: New effective drugs for prostate cancer (PCa) treatment are urgently needed. Avasimibe was recently identified as a promising drug for anticancer therapies. The main purpose of this study was to explore the effects and the underlying mechanisms of avasimibe in prostate cancer. METHODS: In this study, MTT and clonogenic survival assays were performed to detect cell proliferation after avasimibe treatment. The effect of avasimibe on cell migration was measured by wound healing and transwell migration assays. Cell cycle distribution and apoptosis were detected by flow cytometry. Immunofluorescence staining and western blot analysis were used to detect the expression of cell cycle-related proteins and epithelial-mesenchymal transition (EMT)-related proteins. In vivo, the antitumour effects of avasimibe were evaluated using a xenograft model and pulmonary metastasis model. RESULTS: The study found that avasimibe suppresses tumour growth and triggers G1 phase arrest. Moreover, the expression of the cell cycle-related proteins CDK2/4/6, Cyclin D1 and Cyclin A1 + A2 was significantly increased and p21 expression was decreased after avasimibe treatment. The migration of PCa cells was attenuated after treatment with avasimibe, followed by the downregulation of the expression of the EMT-related proteins N-cadherin, ß-catenin, vimentin, Snail and MMP9 and upregulation of E-cadherin expression. Moreover, E2F-1 was elevated after treatment with avasimibe. After knockdown of E2F-1 expression, the inhibition of cell proliferation and migration caused by avasimibe was significantly recovered. The results of the xenograft model showed that avasimibe suppressed tumour growth in vivo. Immunofluorescence staining revealed lower levels of Ki67 and higher levels of E2F-1 in tumour tissues of the avasimibe group than those of the control group. A pulmonary metastasis model also confirmed the inhibition of PCa metastasis by avasimibe. The number of lung metastatic foci in the avasimibe group was significantly decreased compared with that in the control group. CONCLUSIONS: Our results suggest that avasimibe can suppress tumour proliferation and metastasis via the E2F-1 signalling pathway. These findings demonstrate the potential of avasimibe as a new effective drug for PCa treatment.

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