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1.
Proc Natl Acad Sci U S A ; 121(18): e2314541121, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38657049

RESUMO

Recent evidence has demonstrated that the transsynaptic nanoscale organization of synaptic proteins plays a crucial role in regulating synaptic strength in excitatory synapses. However, the molecular mechanism underlying this transsynaptic nanostructure in inhibitory synapses still remains unclear and its impact on synapse function in physiological or pathological contexts has not been demonstrated. In this study, we utilized an engineered proteolysis technique to investigate the effects of acute cleavage of neuroligin-2 (NL2) on synaptic transmission. Our results show that the rapid cleavage of NL2 led to impaired synaptic transmission by reducing both neurotransmitter release probability and quantum size. These changes were attributed to the dispersion of RIM1/2 and GABAA receptors and a weakened spatial alignment between them at the subsynaptic scale, as observed through superresolution imaging and model simulations. Importantly, we found that endogenous NL2 undergoes rapid MMP9-dependent cleavage during epileptic activities, which further exacerbates the decrease in inhibitory transmission. Overall, our study demonstrates the significant impact of nanoscale structural reorganization on inhibitory transmission and unveils ongoing modulation of mature GABAergic synapses through active cleavage of NL2 in response to hyperactivity.


Assuntos
Moléculas de Adesão Celular Neuronais , Proteínas do Tecido Nervoso , Sinapses , Transmissão Sináptica , Animais , Camundongos , Moléculas de Adesão Celular Neuronais/metabolismo , Epilepsia/metabolismo , Epilepsia/fisiopatologia , Epilepsia/patologia , Hipocampo/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas do Tecido Nervoso/genética , Proteólise , Receptores de GABA-A/metabolismo , Sinapses/metabolismo , Transmissão Sináptica/fisiologia
2.
Br J Haematol ; 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38685577

RESUMO

Multiple myeloma (MM) is an incurable plasma cell cancer in the bone marrow. Immunomodulatory drugs, such as lenalidomide (LEN) and pomalidomide, are backbone agents in MM treatment, and LEN resistance is commonly seen in the MM clinic. In this study, we presented that heterogeneous nuclear ribonucleoprotein U (hnRNPU) affected MM resistance to LEN via the regulation of target mRNA translation. hnRNPULow MM cells exhibited upregulated CRBN and IKZF1 proteins, stringent IKZF1/3 protein degradation upon LEN addition and increased sensitivity to LEN. RNA pulldown assays and RNA electrophoretic mobility shift assays revealed that hnRNPU bound to the 3'-untranslated region of CRBN and IKZF1 mRNA. A sucrose gradient assay suggested that hnRNPU specifically regulated CRBN and IKZF1 mRNA translation. The competition of hnRNPU binding to its target mRNAs by small RNAs with hnRNPU-binding sites restored MM sensitivity to LEN. hnRNPU function in vivo was confirmed in an immunocompetent MM mouse model constructed by the inoculation of Crbn-humanized murine 5TGM1 cells into CrbnI391V/+ mice. Overall, this study suggests a novel mechanism of LEN sensitivity in which hnRNPU represses CRBN and IKZF1 mRNA translation.

3.
J Gene Med ; 26(7): e3712, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38949072

RESUMO

Aggrephagy, a type of autophagy, degrades the aggregation of misfolded protein in cells. However, the role of aggrephagy in multiple myeloma (MM) has not been fully demonstrated. In this study, we first investigated the correlation between aggrephagy signaling, MM immune microenvironment composition and disease prognosis. Single-cell RNA-seq data, including the expression profiles of 12,187 single cells from seven MM bone marrow (BM) and seven healthy BM samples, were analyzed by non-negative matrix factorization for 44 aggrephagy-related genes. Bulk RNA-seq cohorts from the Gene Expression Omnibus database were used to evaluate the prognostic value of aggrephagy-related immune cell subtypes and predict immune checkpoint blockade immunotherapeutic response in MM. Compared with healthy BM, MM BM exhibited different patterns of aggrephagy-related gene expression. In MM BM, macrophages, CD8+ T cells, B cells and natural killer cells could be grouped into four to nine aggrephagy-related subclusters. The signature of aggrephagy signaling molecule expression in the immune cells correlates with the patient's prognosis. Our investigation provides a novel view of aggrephagy signaling in MM tumor microenvironment cells, which might be a prognostic indicator and potential target for MM treatment.


Assuntos
Mieloma Múltiplo , Transdução de Sinais , Análise de Célula Única , Microambiente Tumoral , Mieloma Múltiplo/genética , Mieloma Múltiplo/imunologia , Humanos , Microambiente Tumoral/imunologia , Microambiente Tumoral/genética , Análise de Célula Única/métodos , Prognóstico , Regulação Neoplásica da Expressão Gênica , Autofagia/genética , Autofagia/imunologia , Perfilação da Expressão Gênica/métodos , Biomarcadores Tumorais/genética , Transcriptoma
4.
Small ; : e2403322, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38898720

RESUMO

Mineralized bio-tissues achieve exceptional mechanical properties through the assembly of rigid inorganic minerals and soft organic matrices, providing abundant inspiration for synthetic materials. Hydrogels, serving as an ideal candidate to mimic the organic matrix in bio-tissues, can be strengthened by the direct introduction of minerals. However, this enhancement often comes at the expense of toughness due to interfacial mismatch. This study reveals that extreme toughening of hydrogels can be realized through simultaneous in situ mineralization and salting-out, without the need for special chemical modification or additional reinforcements. The key to this strategy lies in harnessing the kosmotropic and precipitation behavior of specific anions as they penetrate a hydrogel system containing both anion-sensitive polymers and multivalent cations. The resulting mineralized hydrogels demonstrate significant improvements in fracture stress, fracture energy, and fatigue threshold due to a multiscale energy dissipation mechanism, with optimal values reaching 12 MPa, 49 kJ m-2, and 2.98 kJ m-2. This simple strategy also proves to be generalizable to other anions, resulting in tough hydrogels with osteoconductivity for promoting in vitro mineralization of human adipose-derived mesenchymal stem cells. This work introduces a universal route to toughen hydrogels without compromising other parameters, holding promise for biological applications demanding integrated mechanical properties.

5.
Inorg Chem ; 63(28): 13110-13116, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38940642

RESUMO

Chemical equilibrium stands as a fundamental principle governing the dynamics of chemical systems. However, it may become intricate when it refers to nanomaterials because of their unique properties. Here, we invesitigated concave gold nanocubes (CGNs) subjected to an akaline Au3+/H2O2 solution, which exhibit both etching and growth in a monotonic solution. When CGNs were subjected to an increasingly alkaline Au3+/H2O2 solution, their dimensions increased from 107 to 199 nm and then decreased to 125 nm. Transmission electron microscopy (TEM) demonstrated that their morphology undergoes intricate alternations from concave to mutibranch and finally to concave again. Real-time ultraviolet-visible spectroscopy and time-dependent TEM also demonstrated reduction first and then oxidation in one solution. Among the nanomaterials, the obtained carpenterworm-like gold nanoparticles revealed the best catalytic performance in p-nitrophenol reduction by NaBH4, with a chemical rate that continues to increase until the reaction reaches completion. Growth leading to atomic dislocation, distortion, and exposure on nanoparticles and the redox of H2O2 plausibly account for the further etching due to the Ostwald ripening effect. Our study may spur more interest in the tuning of the properties, engineering, investigation, and design of new kinds of nanomaterials.

6.
Nucleic Acids Res ; 50(18): 10733-10755, 2022 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-36200826

RESUMO

Long noncoding RNAs (lncRNAs) play important roles in the spatial and temporal regulation of muscle development and regeneration. Nevertheless, the determination of their biological functions and mechanisms underlying muscle regeneration remains challenging. Here, we identified a lncRNA named lncMREF (lncRNA muscle regeneration enhancement factor) as a conserved positive regulator of muscle regeneration among mice, pigs and humans. Functional studies demonstrated that lncMREF, which is mainly expressed in differentiated muscle satellite cells, promotes myogenic differentiation and muscle regeneration. Mechanistically, lncMREF interacts with Smarca5 to promote chromatin accessibility when muscle satellite cells are activated and start to differentiate, thereby facilitating genomic binding of p300/CBP/H3K27ac to upregulate the expression of myogenic regulators, such as MyoD and cell differentiation. Our results unravel a novel temporal-specific epigenetic regulation during muscle regeneration and reveal that lncMREF/Smarca5-mediated epigenetic programming is responsible for muscle cell differentiation, which provides new insights into the regulatory mechanism of muscle regeneration.


Assuntos
RNA Longo não Codificante , Adenosina Trifosfatases , Animais , Diferenciação Celular , Linhagem Celular , Cromatina/genética , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Epigênese Genética , Humanos , Camundongos , Desenvolvimento Muscular , Músculo Esquelético/metabolismo , Proteína MyoD/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Regeneração , Suínos
7.
Chemistry ; 29(52): e202301469, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37385953

RESUMO

In this work, an organic-inorganic hybrid crystal, violet-crystal (VC), was used to etch the nickel foam (NF) to fabricate a self-standing electrode for the water oxidation reaction. The efficacy of VC-assisted etching manifests the promising electrochemical performance towards the oxygen evolution reaction (OER), requiring only ~356 and ~376 mV overpotentials to reach 50 and 100 mA cm-2 , respectively. The OER activity improvement is attributed to the collectively exhaustive effects arising from the incorporation of various elements in the NF, and the enhancement of active site density. Furthermore, the self-standing electrode is robust, exhibiting a stable OER activity after 4,000 cyclic voltammetry cycles, and ~50 h. The anodic transfer coefficients (αa ) show that the first electron transfer step is the rate-determining step on the surface of NF-VCs-1.0 (NF etched by 1 g of VCs) electrode, while the chemical step involving dissociation following the first electron transfer step is identified as the rate-limiting step in other electrodes. The lowest Tafel slope value observed in the NF-VCs-1.0 electrode indicates the high surface coverage of oxygen intermediates and more favorable OER reaction kinetics, as confirmed by high interfacial chemical capacitance and low charge transport/interfacial resistance. This work demonstrates the importance of VCs-assisted etching of NF to activate the OER, and the ability to predict reaction kinetics and rate-limiting step based on αa values, which will open new avenues to identify advanced electrocatalysts for the water oxidation reaction.

8.
Langmuir ; 39(15): 5495-5504, 2023 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-37018471

RESUMO

Superhydrophobic coatings have garnered significant research interest due to their potential applications in areas such as ant-icing and windows. This study focuses on the development of superhydrophobic coatings using air-assisted electrospray and the effect of different carbon additives as templates in the coating. Carbon templates, with their unique topological varieties, offer a cost-effective alternative to other patterning technologies such as photolithography. By introducing dispersed carbon black, carbon nanotubes, and graphene additives in TEOS solution, silica is given the ability of localized secondary growth on or around the carbon surfaces as well as the building structure to provide adequate roughness on the substrate surface. The templated silica formations provide a thin coating with nano-scale roughness for heightened water resistance. As compared with the template-free coating that has small silica particles, a surface roughness of 135 nm, and a water contact angle (WCA) of 101.6° (non-superhydrophobic), the carbon templating effect allowed for increased silica particle size, a surface roughness as high as 845 nm, a WCA above 160°, and the ability to maintain superhydrophobicity over 30 abrasion cycles. The morphological characteristics that resulted from the templating effect correlate directly with heightened performance of the coatings. Herein, the carbon additives have been found to serve as cheap and effective templates for silica formation in thin TEOS-derived superhydrophobic coatings.

9.
Small ; 18(30): e2201953, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35768285

RESUMO

Porous electrodes that conduct electrons, protons, and oxygen ions with dramatically expanded catalytic active sites can replace conventional electrodes with sluggish kinetics in protonic ceramic electrochemical cells. In this work, a strategy is utilized to promote triple conduction by facilitating proton conduction in praseodymium cobaltite perovskite through engineering non-equivalent B-site Ni/Co occupancy. Surface infrared spectroscopy is used to study the dehydration behavior, which proves the existence of protons in the perovskite lattice. The proton mobility and proton stability are investigated by hydrogen/deuterium (H/D) isotope exchange and temperature-programmed desorption. It is observed that the increased nickel replacement on the B-site has a positive impact on proton defect stability, catalytic activity, and electrochemical performance. This doping strategy is demonstrated to be a promising pathway to increase catalytic activity toward the oxygen reduction and water splitting reactions. The chosen PrNi0.7 Co0.3 O3- δ oxygen electrode demonstrates excellent full-cell performance with high electrolysis current density of -1.48 A cm-2 at 1.3 V and a peak fuel-cell power density of 0.95 W cm-2 at 600 °C and also enables lower-temperature operations down to 350 °C, and superior long-term durability.

10.
Plant Biotechnol J ; 20(7): 1257-1273, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35244328

RESUMO

Plants of the Elaeagnaceae family are widely used to treat various health disorders owing to their natural phytochemicals. Seabuckthorn (Hippophae rhamnoides L.) is an economically and ecologically important species within the family with richness of biologically and pharmacologically active substances. Here, we present a chromosome-level genome assembly of seabuckthorn (http://hipp.shengxin.ren/), the first genome sequence of Elaeagnaceae, which has a total length of 849.04 Mb with scaffold N50 of 69.52 Mb and 30 864 annotated genes. Two sequential tetraploidizations with one occurring ~36-41 million years ago (Mya) and the last ~24-27 Mya were inferred, resulting in expansion of genes related to ascorbate and aldarate metabolism, lipid biosynthesis, and fatty acid elongation. Comparative genomic analysis reconstructed the evolutionary trajectories of the seabuckthorn genome with the predicted ancestral genome of 14 proto-chromosomes. Comparative transcriptomic and metabonomic analyses identified some key genes contributing to high content of polyunsaturated fatty acids and ascorbic acid (AsA). Additionally, we generated and analysed 55 whole-genome sequences of diverse accessions, and identified 9.80 million genetic variants in the seabuckthorn germplasms. Intriguingly, genes in selective sweep regions identified through population genomic analysis appeared to contribute to the richness of AsA and fatty acid in seabuckthorn fruits, among which GalLDH, GMPase and ACC, TER were the potentially major-effect causative genes controlling AsA and fatty acid content of the fruit, respectively. Our research offers novel insights into the molecular basis underlying phytochemical innovation of seabuckthorn, and provides valuable resources for exploring the evolution of the Elaeagnaceae family and molecular breeding.


Assuntos
Hippophae , Ácido Ascórbico , Cromossomos , Ácidos Graxos , Hippophae/genética , Metagenômica , Compostos Fitoquímicos
11.
Anal Biochem ; 642: 114562, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35093411

RESUMO

We propose a sensitive, selective, and rapid fluorescent assay for detecting resorcinol (RC) based on its specific chemical reaction with dopamine. Under alkaline condition, RC would react with dopamine to yield fluorescent azamonardine, which emits strong blue fluorescence and has a superior excitation wavelength at 416 nm and an emission wavelength at 461 nm. The azamonardine with a molecular weight of 258.1 confirmed by ICP-MS has a quantum yield of 71.3%. The reaction is completed within 1 min showing great potential for point-of-care testing. This assay showed high sensitivity and had a good relationship between fluorescent intensity at 461 nm and RC concentration (I461 = 106.4 + 93.6*CRC; R2 = 0.9904) over the range of 0-40 µM. More importantly, the assay showed a prominent anti-interference from various substances and even can distinguish RC from its isomers, o-dihydroxybenzene and p-dihydroxybenzene. Finally, our assay successfully quantified RC contents in wheat powder and hair dyes with high accuracy.


Assuntos
Compostos Aza/química , Dopamina/química , Corantes Fluorescentes/química , Resorcinóis/análise , Tinturas para Cabelo/química , Pós/química , Triticum/química
12.
Ecotoxicol Environ Saf ; 242: 113849, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35809394

RESUMO

Groundwater may contain radioactive substances which can be dangerous to human health. Concentrations of natural radionuclides polonium (Po), thorium (Th), uranium (U), and radium (Ra) isotopes were measured in groundwater samples collected from different locations in the vicinity of the Waste Isolation Pilot Plant (WIPP) site in Carlsbad, New Mexico. The average values of gross activity concentrations of 210Po, 228Th, 238U, 234U, 226Ra and 228 Ra isotopes were determined to be 1.62 Bq L-1 in shallow groundwater and 5.88 Bq L-1 in deep groundwater, respectively. The total radioactivity in deep groundwater was higher than that in shallow groundwater, and most of the radioactivity in the water is from 226Ra. Furthermore, the effective doses for ingestion of natural radionuclides were about 0.333 mSv y-1 for shallow groundwater and about 1.338 mSv y-1 for deep groundwater samples, which are higher than the World Health Organization (WHO, 2017) guideline level (0.1 mSv y-1) for drinking water. Ra dominated the total ingestion dose, contributing 93.06 % and 75.40 % of the total effective doses to the deep and shallow groundwater, respectively. The ingrowth and decay of natural radionuclides suggested that 228Ra/226Ra ratio can be a useful indicator of the source of radioactive contamination. The radioactivity data obtained from the investigated groundwater samples can be used to establish a baseline for radioactivity levels in groundwater around the WIPP site.


Assuntos
Água Subterrânea , Polônio , Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Urânio , Poluentes Radioativos da Água , Humanos , Polônio/análise , Radioisótopos/análise , Rádio (Elemento)/análise , Tório/análise , Urânio/análise , Poluentes Radioativos da Água/análise
13.
BMC Genomics ; 22(1): 315, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33933003

RESUMO

BACKGROUND: ATP-binding cassette (ABC) transporters have been found to play important roles in metabolic transport in plant cells, influencing subcellular compartmentalisation and tissue distribution of these metabolic compounds. Salvia miltiorrhiza Bunge, known as Danshen in traditional Chinese medicine, is a highly valued medicinal plant used to treat cardiovascular and cerebrovascular diseases. The dry roots and rhizomes of S. miltiorrhiza contain biologically active secondary metabolites of tanshinone and salvianolic acid. Given an assembled and annotated genome and a set of transcriptome data of S. miltiorrhiza, we analysed and identified the candidate genes that likely involved in the bioactive metabolite transportation of this medicinal plant, starting with the members of the ABC transporter family. RESULTS: A total of 114 genes encoding ABC transporters were identified in the genome of S. miltiorrhiza. All of these ABC genes were divided into eight subfamilies: 3ABCA, 31ABCB, 14ABCC, 2ABCD, 1ABCE, 7ABCF, 46ABCG, and 10 ABCI. Gene expression analysis revealed tissue-specific expression profiles of these ABC transporters. In particular, we found 18 highly expressed transporters in the roots of S. miltiorrhiza, which might be involved in transporting the bioactive compounds of this medicinal plant. We further investigated the co-expression profiling of these 18 genes with key enzyme genes involved in tanshinone and salvianolic acid biosynthetic pathways using quantitative reverse transcription polymerase chain reaction (RT-qPCR). From this RT-qPCR validation, we found that three ABC genes (SmABCG46, SmABCG40, and SmABCG4) and another gene (SmABCC1) co-expressed with the key biosynthetic enzymes of these two compounds, respectively, and thus might be involved in tanshinone and salvianolic acid transport in root cells. In addition, we predicted the biological functions of S. miltiorrhiza ABC transporters using phylogenetic relationships and analysis of the transcriptome to find biological functions. CONCLUSIONS: Here, we present the first systematic analysis of ABC transporters in S. miltiorrhiza and predict candidate transporters involved in bioactive compound transportation in this important medicinal plant. Using genome-wide identification, transcriptome profile analysis, and phylogenetic relationships, this research provides a new perspective on the critical functions of ABC transporters in S. miltiorrhiza.


Assuntos
Salvia miltiorrhiza , Transportadores de Cassetes de Ligação de ATP/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Filogenia , Raízes de Plantas/genética , Salvia miltiorrhiza/genética
14.
Ann Hematol ; 100(1): 135-141, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33083863

RESUMO

The aim of this study was to investigate the effect of low-dose ruxolitinib (daily dose ≤ 10 mg) for the treatment of myelofibrosis (MF). A retrospective analysis was performed on a total of 88 patients with myeloproliferative neoplasm-associated MF (MPN-MF) who were diagnosed and treated in West China Hospital, Sichuan University, China. A total of 44 MPN-MF patients received a low dose of ruxolitinib (daily dose ≤ 10 mg), while another 44 patients received 10-25 mg twice daily. Low-dose ruxolitinib treatment resulted in slow, but gradual spleen response. Compared with baseline, the mean changes in palpable spleen length in the low- and high-dose groups were -26.9 and -49.0% after 12 weeks of treatment, respectively, and -46.7 and -64.1% after 48 weeks of treatment, respectively. In the low dose group, the median myeloproliferative neoplasm symptom assessment form (MPN-SAF) total symptom score (TSS) decreased by 37.8 and 35.9% at the 12 weeks and 48 weeks after treatment, respectively. No statistical difference was observed in MPN-SAF TSS among different dose groups. After 48 weeks of treatment, bone marrow (BM) fibrosis improved in 43.3% (13/30) of evaluated patients and was stable in 56.7% (17/30) patients. In the low-dose treated group, BM fibrosis improved in 50% patients and was stable in remaining 50%. Low-dose ruxolitinib is effective in treating MF.


Assuntos
Inibidores de Janus Quinases/administração & dosagem , Mielofibrose Primária/tratamento farmacológico , Pirazóis/administração & dosagem , Baço/efeitos dos fármacos , Adulto , Idoso , Idoso de 80 Anos ou mais , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nitrilas , Mielofibrose Primária/patologia , Pirimidinas , Estudos Retrospectivos , Baço/patologia , Resultado do Tratamento
15.
BMC Med Educ ; 21(1): 582, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34789228

RESUMO

OBJECTIVE/BACKGROUND: In mainland China, most universities offer general rehabilitation curricula rather than specialized curricula. The purpose of the current study is to investigate senior students' academic motivation for rehabilitation and examine whether it varies among different curriculum structures, students' gender, specific interests, and parental average education level. METHODS: This cross-sectional study recruited both senior students in general and those who specialized in rehabilitation curricula using an online survey. The Academic Motivation Scale (AMS) was used to measure academic motivation. RESULTS: The response rate was 74.68%, and 59 senior students in total (male: 34.48%; female: 65.52%) were analyzed. Twenty-nine (50.00%) students were from a general rehabilitation curriculum at Guangxi Medical University, and the rest (n = 29, 50.00%) were from a specialized curriculum at West China Medical School of Sichuan University. The overall average academic motivation score was 30.96 ± 5.92. Students in the specialized rehabilitation curriculum (32.85 ± 6.26) showed a significantly higher academic motivation score than those in the general rehabilitation curriculum (29.10 ± 5.00, p<0.05). Male (31.13 ± 5.67) and female (30.88 ± 6.12) students had equally high scores (p = 0.88). Students who had specific interests (29.81 ± 4.73) and those who did not (24.69 ± 4.92) shared the same academic motivation (t = 2.00, p = 0.06). CONCLUSIONS: Senior rehabilitation science students in specialized curricula have higher levels of academic motivation than those in general curricula. There was no significant difference in academic motivation scores based on students' gender, specific interests, or parental average education levels.


Assuntos
Motivação , Estudantes de Medicina , China , Estudos Transversais , Currículo , Feminino , Humanos , Masculino , Estudantes , Inquéritos e Questionários
16.
Plant Physiol ; 180(4): 1988-2003, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31221734

RESUMO

Carotenoids exert multifaceted roles to plants and are critically important to humans. Phytoene synthase (PSY) is a major rate-limiting enzyme in the carotenoid biosynthetic pathway. PSY in plants is normally found as a small enzyme family with up to three members. However, knowledge of PSY isoforms in relation to their respective enzyme activities and amino acid residues that are important for PSY activity is limited. In this study, we focused on two tomato (Solanum lycopersicum) PSY isoforms, PSY1 and PSY2, and investigated their abilities to catalyze carotenogenesis via heterologous expression in transgenic Arabidopsis (Arabidopsis thaliana) and bacterial systems. We found that the fruit-specific PSY1 was less effective in promoting carotenoid biosynthesis than the green tissue-specific PSY2. Examination of the PSY proteins by site-directed mutagenesis analysis and three-dimensional structure modeling revealed two key amino acid residues responsible for this activity difference and identified a neighboring aromatic-aromatic combination in one of the PSY core structures as being crucial for high PSY activity. Remarkably, this neighboring aromatic-aromatic combination is evolutionarily conserved among land plant PSYs except PSY1 of tomato and potato (Solanum tuberosum). Strong transcription of tomato PSY1 likely evolved as compensation for its weak enzyme activity to allow for the massive carotenoid biosynthesis in ripe fruit. This study provides insights into the functional divergence of PSY isoforms and highlights the potential to rationally design PSY for the effective development of carotenoid-enriched crops.


Assuntos
Frutas/metabolismo , Geranil-Geranildifosfato Geranil-Geraniltransferase/metabolismo , Proteínas de Plantas/metabolismo , Solanum lycopersicum/metabolismo , Solanum tuberosum/metabolismo , Frutas/enzimologia , Frutas/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Geranil-Geranildifosfato Geranil-Geraniltransferase/genética , Solanum lycopersicum/enzimologia , Proteínas de Plantas/genética , Solanum tuberosum/enzimologia , Solanum tuberosum/genética
17.
Dev Biol ; 438(2): 124-137, 2018 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-29654745

RESUMO

Outflow tract (OFT) anomalies account for about 30% of human congenital heart defects detected at birth. The second heart field (SHF) progenitors contribute to OFT and right ventricle (RV) development, but the process largely remains unknown. WDR1 (WD-repeat domain 1) is a major co-factor of actin depolymerizing factor (ADF)/cofilin that actively disassembles ADF/cofilin-bound actin filaments. Its function in embryonic heart development has been unknown. Using Wdr1 floxed mice and Nkx2.5-Cre, we deleted Wdr1 in embryonic heart (Wdr1F/F;Nkx2.5-Cre) and found that these mice exhibited embryonic lethality, and hypoplasia of OFT and RV. To investigate the role of WDR1 in OFT and RV development, we generated SHF progenitors-specific Wdr1 deletion mice (shfKO). shfKO mice began to die at embryonic day 11.5 (E11.5), and displayed decreased size of the proximal OFT and RV at E10.5. In shfKO embryos, neither the number of SHF cells deployment to OFT nor cell proliferation and the cell number were changed, whereas the cellular organization and myofibrillar assembly of cardiomyocytes were severely disrupted. In the proximal OFT and RV of both shfKO and Wdr1F/F;Nkx2.5-Cre embryos, cardiomyocytes were dissociated from the outer compact myocardial layer and loosely and disorderly arranged into multilayered myocardium. Our results demonstrate that WDR1 is indispensable for normal OFT and RV development, and suggest that WDR1-mediated actin dynamics functions in controlling the size of OFT and RV, which might through regulating the spatial arrangement of cardiomyocytes.


Assuntos
Ventrículos do Coração/embriologia , Proteínas dos Microfilamentos/fisiologia , Actinas/genética , Actinas/metabolismo , Animais , Embrião de Mamíferos/embriologia , Desenvolvimento Embrionário/genética , Desenvolvimento Embrionário/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/genética , Coração/embriologia , Cardiopatias Congênitas/genética , Camundongos , Camundongos Knockout , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Miocárdio , Miócitos Cardíacos , Organogênese , Transdução de Sinais , Obstrução do Fluxo Ventricular Externo
18.
Plant Mol Biol ; 100(1-2): 83-93, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30847712

RESUMO

KEY MESSAGE: The novel AP2/ERF transcription factor SmERF128 positively regulates diterpenoid tanshinone biosynthesis by activating the expression of SmCPS1, SmKSL1, and SmCYP76AH1 in Salvia miltiorrhiza. Certain members of the APETALA2/ethylene-responsive factor (AP2/ERF) family regulate plant secondary metabolism. Although it is clearly documented that AP2/ERF transcription factors (TFs) are involved in sesquiterpenoid biosynthesis, the regulation of diterpenoid biosynthesis by AP2/ERF TFs remains elusive. Here, we report that the novel AP2/ERF TF SmERF128 positively regulates diterpenoid tanshinone biosynthesis in Salvia miltiorrhiza. Overexpression of SmERF128 increased the expression levels of copalyl diphosphate synthase 1 (SmCPS1), kaurene synthase-like 1 (SmKSL1) and cytochrome P450 monooxygenase 76AH1 (SmCYP76AH1), whereas their expression levels were decreased when SmERF128 was silenced. Accordingly, the content of tanshinone was reduced in SmERF128 RNA interference (RNAi) hairy roots and dramatically increased in SmERF128 overexpression hairy roots, as demonstrated through Ultra Performance Liquid Chromatography (UPLC) and Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) analysis. Furthermore, SmERF128 activated the expression of SmCPS1, SmKSL1, and SmCYP76AH1 by binding to the GCC box, and to the CRTDREHVCBF2 (CBF2) and RAV1AAT (RAA) motifs within their promoters during in vivo and in vitro assays. Our findings not only reveal the molecular basis of how the AP2/ERF transcription factor SmERF128 regulates diterpenoid biosynthesis, but also provide useful information for improving tanshinone production through genetic engineering.


Assuntos
Diterpenos/metabolismo , Proteínas de Plantas/metabolismo , Salvia miltiorrhiza/metabolismo , Fatores de Transcrição/metabolismo , Abietanos/biossíntese , Diterpenos/isolamento & purificação , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Genes de Plantas , Motivos de Nucleotídeos/genética , Proteínas de Plantas/genética , Raízes de Plantas/genética , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética , Ligação Proteica , Transporte Proteico , Interferência de RNA , Salvia miltiorrhiza/genética , Fatores de Transcrição/isolamento & purificação
19.
Retina ; 39(7): 1353-1360, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29547454

RESUMO

PURPOSE: In this study, we aimed to evaluate the efficacy and safety of intravitreal conbercept in patients with treatment-naive neovascular age-related macular degeneration in real-life setting. METHODS: Three consecutive intravitreal injections of conbercept following a pro re nata protocol. The main outcomes were the changes of Early Treatment Diabetic Retinopathy Study best-corrected visual acuity and central retinal thickness between the baseline and the 12th month. RESULTS: Mean best-corrected visual acuity was improved from 39.39 ± 24.91 letters at the baseline to 44.26 ± 22.89 letters at the final follow-up (P < 0.001). At the 12th month, the proportion of optimal response was 43.48% compared with 36.96% of poor response and 19.56% of nonresponse. A mean central retinal thickness of 480.94 ± 178.47 µm at the baseline was significantly reduced to 366.33 ± 173.52 µm at the 12th month. Patients received a median of 5.32 intravitreal injections. At the 12th month, the mean change in best-corrected visual acuity of eyes with intraretinal cystoid fluid from the baseline was markedly lower than that of eyes without intraretinal cystoid fluid. No adverse events were attributed to conbercept. CONCLUSION: With 12-month follow-up, conbercept was proved to be an effective and safety treatment for patients with treatment-naive neovascular age-related macular degeneration in real-life setting.


Assuntos
Macula Lutea/patologia , Proteínas Recombinantes de Fusão/administração & dosagem , Acuidade Visual , Degeneração Macular Exsudativa/tratamento farmacológico , Idoso , China , Progressão da Doença , Relação Dose-Resposta a Droga , Feminino , Angiofluoresceinografia/métodos , Seguimentos , Fundo de Olho , Humanos , Injeções Intravítreas , Masculino , Estudos Retrospectivos , Tomografia de Coerência Óptica/métodos , Resultado do Tratamento , Degeneração Macular Exsudativa/diagnóstico
20.
J Am Chem Soc ; 139(19): 6644-6653, 2017 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-28431206

RESUMO

The use of semiconductor nanocrystal quantum dots (QDs) in optoelectronic devices typically requires postsynthetic chemical surface treatments to enhance electronic coupling between QDs and allow for efficient charge transport in QD films. Despite their importance in solar cells and infrared (IR) light-emitting diodes and photodetectors, advances in these chemical treatments for lead chalcogenide (PbE; E = S, Se, Te) QDs have lagged behind those of, for instance, II-VI semiconductor QDs. Here, we introduce a method for fast and effective ligand exchange for PbE QDs in solution, resulting in QDs completely passivated by a wide range of small anionic ligands. Due to electrostatic stabilization, these QDs are readily dispersible in polar solvents, in which they form highly concentrated solutions that remain stable for months. QDs of all three Pb chalcogenides retain their photoluminescence, allowing for a detailed study of the effect of the surface ionic double layer on electronic passivation of QD surfaces, which we find can be explained using the hard/soft acid-base theory. Importantly, we prepare highly conductive films of PbS, PbSe, and PbTe QDs by directly casting from solution without further chemical treatment, as determined by field-effect transistor measurements. This method allows for precise control over the surface chemistry, and therefore the transport properties of deposited films. It also permits single-step deposition of films of unprecedented thickness via continuous processing techniques, as we demonstrate by preparing a dense, smooth, 5.3-µm-thick PbSe QD film via doctor-blading. As such, it offers important advantages over laborious layer-by-layer methods for solar cells and photodetectors, while opening the door to new possibilities in ionizing-radiation detectors.

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