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RNA tailing, or the addition of non-templated nucleotides to the 3' end of RNA, is the most frequent and conserved type of RNA modification. The addition of tails and their composition reflect RNA maturation stages and have important roles in determining the fate of the modified RNAs. Apart from canonical poly(A) polymerases, which add poly(A) tails to mRNAs in a transcription-coupled manner, a family of terminal nucleotidyltransferases (TENTs), including terminal uridylyltransferases (TUTs), modify RNAs post-transcriptionally to control RNA stability and activity. The human genome encodes 11 different TENTs with distinct substrate specificity, intracellular localization and tissue distribution. In this Review, we discuss recent advances in our understanding of non-canonical RNA tails, with a focus on the functions of human TENTs, which include uridylation, mixed tailing and post-transcriptional polyadenylation of mRNAs, microRNAs and other types of non-coding RNA.
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Regulação da Expressão Gênica/fisiologia , Processamento Pós-Transcricional do RNA/fisiologia , RNA/genética , Regiões 3' não Traduzidas/genética , Regiões 3' não Traduzidas/fisiologia , Animais , Regulação da Expressão Gênica/genética , Humanos , MicroRNAs/genética , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Poliadenilação , RNA/metabolismo , Processamento Pós-Transcricional do RNA/genética , Estabilidade de RNA/genética , RNA Mensageiro/genéticaRESUMO
Strand selection is a critical step in microRNA (miRNA) biogenesis. Although the dominant strand may change depending on cellular contexts, the molecular mechanism and physiological significance of such alternative strand selection (or "arm switching") remain elusive. Here we find miR-324 to be one of the strongly regulated miRNAs by arm switching and identify the terminal uridylyl transferases TUT4 and TUT7 to be the key regulators. Uridylation of pre-miR-324 by TUT4/7 re-positions DICER on the pre-miRNA and shifts the cleavage site. This alternative processing produces a duplex with a different terminus from which the 3' strand (3p) is selected instead of the 5' strand (5p). In glioblastoma, the TUT4/7 and 3p levels are upregulated, whereas the 5p level is reduced. Manipulation of the strand ratio is sufficient to impair glioblastoma cell proliferation. This study uncovers a role of uridylation as a molecular switch in alternative strand selection and implicates its therapeutic potential.
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MicroRNAs/metabolismo , UDPglucose-Hexose-1-Fosfato Uridiltransferase/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células , RNA Helicases DEAD-box/metabolismo , Proteínas de Ligação a DNA/metabolismo , Feminino , Humanos , Camundongos , MicroRNAs/genética , Cultura Primária de Células , RNA Nucleotidiltransferases/metabolismo , Ribonuclease III/metabolismoRESUMO
BACKGROUND: Autosomal recessive deafness 9, caused by mutations of the OTOF gene, is characterised by congenital or prelingual, severe-to-complete, bilateral hearing loss. However, no pharmacological treatment is currently available for congenital deafness. In this Article, we report the safety and efficacy of gene therapy with an adeno-associated virus (AAV) serotype 1 carrying a human OTOF transgene (AAV1-hOTOF) as a treatment for children with autosomal recessive deafness 9. METHODS: This single-arm, single-centre trial enrolled children (aged 1-18 years) with severe-to-complete hearing loss and confirmed mutations in both alleles of OTOF, and without bilateral cochlear implants. A single injection of AAV1-hOTOF was administered into the cochlea through the round window. The primary endpoint was dose-limiting toxicity at 6 weeks after injection. Auditory function and speech were assessed by appropriate auditory perception evaluation tools. All analyses were done according to the intention-to-treat principle. This trial is registered with Chinese Clinical Trial Registry, ChiCTR2200063181, and is ongoing. FINDINGS: Between Oct 19, 2022, and June 9, 2023, we screened 425 participants for eligibility and enrolled six children for AAV1-hOTOF gene therapy (one received a dose of 9 × 1011 vector genomes [vg] and five received 1·5 × 1012 vg). All participants completed follow-up visits up to week 26. No dose-limiting toxicity or serious adverse events occurred. In total, 48 adverse events were observed; 46 (96%) were grade 1-2 and two (4%) were grade 3 (decreased neutrophil count in one participant). Five children had hearing recovery, shown by a 40-57 dB reduction in the average auditory brainstem response (ABR) thresholds at 0·5-4·0 kHz. In the participant who received the 9 × 1011 vg dose, the average ABR threshold was improved from greater than 95 dB at baseline to 68 dB at 4 weeks, 53 dB at 13 weeks, and 45 dB at 26 weeks. In those who received 1·5 × 1012 AAV1-hOTOF, the average ABR thresholds changed from greater than 95 dB at baseline to 48 dB, 38 dB, 40 dB, and 55 dB in four children with hearing recovery at 26 weeks. Speech perception was improved in participants who had hearing recovery. INTERPRETATION: AAV1-hOTOF gene therapy is safe and efficacious as a novel treatment for children with autosomal recessive deafness 9. FUNDING: National Natural Science Foundation of China, National Key R&D Program of China, Science and Technology Commission of Shanghai Municipality, and Shanghai Refreshgene Therapeutics.
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Dependovirus , Terapia Genética , Humanos , Terapia Genética/métodos , Dependovirus/genética , Criança , Masculino , Pré-Escolar , Feminino , Adolescente , Lactente , Vetores Genéticos , Resultado do Tratamento , Surdez/genética , Surdez/terapia , Mutação , Proteínas de MembranaRESUMO
Gold nanoparticles (AuNPs), universally regarded as colorimetric signal reporters, are widely employed in lateral flow immunoassays (LFIAs). However, it is difficult for AuNPs-LFIA to achieve a wide range and sensitive detection. Herein, novel coral-like hollow gold nanospheres (CHGNPs) are synthesized. The growth of gold nanospheres can be regulated to obtain a multibranched and hollow construction. The obtained CHGNPs possess intense broadband absorption across the visible to near-infrared region, exhibiting a high molar extinction coefficient of 14.65 × 1011 M-1 cm-1 and a photothermal conversion efficiency of 79.75%. Thus, the photothermal/colorimetric dual-readout LFIA is developed based on CHGNPs (CHGNPs-PT-LFIA and CHGNPs-CM-LFIA) to effectively improve the detection sensitivity and broaden the detection range in regard to sulfonamides (SAs). The limits of detection of the CHGNPs-PT-LFIA and CHGNPs-CM-LFIA reached 1.9 and 2.8 pg mL-1 for the quantitative detection of sulfaquinoxaline, respectively, which are 6.3-fold and 4.3-fold lower than that of the AuNPs-LFIA. Meanwhile, the CHGNPs-PT-LFIA broadened the detection range to three orders of magnitude, which ranged from 2.5 to 5000 pg mL-1. The synthesized photothermal CHGNPs have been proven effective in improving the performance of the LFIA and provide a potential option for the construction of sensing platforms.
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Ouro , Nanopartículas Metálicas , Nanosferas , Sulfonamidas , Ouro/química , Nanopartículas Metálicas/química , Sulfonamidas/química , Nanosferas/química , Colorimetria/métodos , Animais , Antozoários/química , Imunoensaio/métodosRESUMO
Plants delicately regulate endogenous auxin levels through the coordination of transport, biosynthesis, and inactivation, which is crucial for growth and development. While it is well-established that the actin cytoskeleton can regulate auxin levels by affecting polar transport, its potential role in auxin biosynthesis has remained largely unexplored. Using LC-MS/MS-based methods combined with fluorescent auxin marker detection, we observed a significant increase in root auxin levels upon deletion of the actin bundling proteins AtFIM4 and AtFIM5. Fluorescent observation, immunoblotting analysis, and biochemical approaches revealed that AtFIM4 and AtFIM5 affect the protein abundance of the key auxin synthesis enzyme YUC8 in roots. AtFIM4 and AtFIM5 regulate the auxin synthesis enzyme YUC8 at the protein level, with its degradation mediated by the 26S proteasome. This regulation modulates auxin synthesis and endogenous auxin levels in roots, consequently impacting root development. Based on these findings, we propose a molecular pathway centered on the 'actin cytoskeleton-26S proteasome-YUC8-auxin' axis that controls auxin levels. Our findings shed light on a new pathway through which plants regulate auxin synthesis. Moreover, this study illuminates a newfound role of the actin cytoskeleton in regulating plant growth and development, particularly through its involvement in maintaining protein homeostasis via the 26S proteasome.
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In the pursuit of carbon neutrality, China's 2060 targets have been largely anchored in reducing greenhouse gas emissions, with less emphasis on the consequential benefits for air quality and public health. This study pivots to this critical nexus, exploring how China's carbon neutrality aligns with the World Health Organization's air quality guidelines (WHO AQG) regarding fine particulate matter (PM2.5) exposure. Coupling a technology-rich integrated assessment model, an emission-concentration response surface model, and exposure and health assessment, we find that decarbonization reduces sulfur dioxide (SO2), nitrogen oxides (NOx), and PM2.5 emissions by more than 90%; reduces nonmethane volatile organic compounds (NMVOCs) by more than 50%; and simultaneously reduces the disparities across regions. Critically, our analysis reveals that further targeted reductions in air pollutants, notably NH3 and non-energy-related NMVOCs, could bring most Chinese cities into attainment of WHO AQG for PM2.5 5 to 10 years earlier than the pathway focused solely on carbon neutrality. Thus, the integration of air pollution control measures into carbon neutrality strategies will present a significant opportunity for China to attain health and environmental equality.
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Zearalenone (ZEN), produced by Fusarium species, is a potential risk to human health. Traditional enzyme-linked immunosorbent assay (ELISA) is restricted due to low sensitivity for the detection of ZEN. Herein, enzyme nanocomposites (ALP-SA-Bio-ssDNA, ASBD) were prepared with the self-assembly strategy based on streptavidin-labeled alkaline phosphatase (SA-ALP) and dual-biotinylated ssDNA (B2-ssDNA). The enzyme nanocomposites improved the loading amount of ALP and catalyzed more ascorbic acid 2-phosphate to generate ascorbic acid (AA). Subsequently, Cu2+ could be reduced to copper nanoclusters (CuNCs) having strong fluorescence signal by AA with poly T. Benefiting from the high enzyme load of nanocomposites and the strong signal of CuNCs, the fluorescence ELISA was successfully established for the detection of ZEN. The proposed method exhibited lower limit of detection (0.26 ng mL-1) than traditional ELISA (1.55 ng mL-1). The recovery rates ranged from 92.00% to 108.38% (coefficient of variation < 9.50%) for the detection of zearalenone in corn and wheat samples. In addition, the proposed method exhibited no cross reaction with four other mycotoxins. This proposed method could be used in trace detection for food safety.
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Nanocompostos , Zearalenona , Humanos , Zearalenona/análise , Cobre/análise , Contaminação de Alimentos/análise , Ensaio de Imunoadsorção Enzimática/métodos , DNA de Cadeia Simples , Limite de DetecçãoRESUMO
What determines the rate at which a multicellular organism matures is a fundamental question in biology. In plants, the decline of miR156 with age serves as an intrinsic, evolutionarily conserved timer for the juvenile-to-adult phase transition. However, the way in which age regulates miR156 abundance is poorly understood. Here, we show that the rate of decline in miR156 is correlated with developmental age rather than chronological age. Mechanistically, we found that cell division in the apical meristem is a trigger for miR156 decline. The transcriptional activity of MIR156 genes is gradually attenuated by the deposition of the repressive histone mark H3K27me3 along with cell division. Our findings thus provide a plausible explanation of why the maturation program of a multicellular organism is unidirectional and irreversible under normal growth conditions and suggest that cell quiescence is the fountain of youth in plants.
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Proteínas de Arabidopsis/genética , Arabidopsis/genética , Divisão Celular/genética , Meristema/genética , MicroRNAs/genética , Brotos de Planta/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Regulação da Expressão Gênica de Plantas/genética , Folhas de Planta/genética , Plantas Geneticamente Modificadas/genética , Fatores de Transcrição/genéticaRESUMO
Credible and on-site detection of organophosphorus pesticides (OPs) in complex matrixes is significant for food security and environmental monitoring. Herein, a novel COF/methylene blue@MnO2 (COF/MB@MnO2) composite featured abundant signal loading, a specific recognition unit, and robust oxidase-like activity was successfully prepared through facile assembly processes. The multifunctional composite acted as a homogeneous electrochemical and photothermal dual-mode sensing platform for OPs detection through stimuli-responsive regulation. Without the presence of OPs, the surface MnO2 coating could recognize thiocholine (TCh), originating from acetylcholinesterase (AChE)-catalyzed hydrolysis of acetylthiocholine (ATCh), and exhibited a distinctly amplified diffusion current due to the release of plentiful MB; while the residual MnO2 nanosheets could only catalyze less TMB into oxidized TMB (oxTMB) with a typical near-infrared (NIR) absorption, enabling NIR-driven photothermal assay with a low temperature using a portable thermometer. Based on the inhibitory effect of OPs on AChE activity and OP-regulated generation of TCh, chlorpyrifos as a model target can be accurately detected with a low limit of detection of 0.0632 and 0.108 ng/mL by complementary electrochemical and photothermal measurements, respectively. The present dual-mode sensor was demonstrated to be excellent for application to the reliable detection of OPs in complex environmental and food samples. This work can not only provide a complementary dual-mode method for convenient and on-site detection of OPs in different scenarios but also expand the application scope of the COF-based multifunctional composite in multimodal sensors.
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Técnicas Biossensoriais , Praguicidas , Compostos Organofosforados , Acetilcolinesterase , Azul de Metileno , Compostos de Manganês , Óxidos , Técnicas Biossensoriais/métodosRESUMO
BACKGROUND: Special AT-rich sequence-binding protein 2 is essential for the development of cerebral cortex and key molecular node for the establishment of proper neural circuitry and function. Mutations in the SATB2 gene lead to SATB2-associated syndrome, which is characterized by abnormal development of skeleton and central nervous systems. METHODS: We generated Satb2 knockout mouse model through CRISPR-Cas9 technology and performed RNA-seq and ChIP-seq of embryonic cerebral cortex. We conducted RT-qPCR, western blot, immunofluorescence staining, luciferase reporter assay and behavioral analysis for experimental verification. RESULTS: We identified 1363 downstream effector genes of Satb2 and correlation analysis of Satb2-targeted genes and neurological disease genes showed that Satb2 contribute to cognitive and mental disorders from the early developmental stage. We found that Satb2 directly regulate the expression of Ntng1, Cdh13, Kitl, genes important for axon guidance, synaptic formation, neuron migration, and Satb2 directly activates the expression of Mef2c. We also showed that Satb2 heterozygous knockout mice showed impaired spatial learning and memory. CONCLUSIONS: Taken together, our study supportsroles of Satb2 in the regulation of axonogenesis and synaptic formation at the early developmental stage and provides new insights into the complicated regulatory mechanism of Satb2 and new evidence to elucidate the pathogen of SATB2-associated syndrome. IMPACT: 1363 downstream effector genes of Satb2 were classified into 5 clusters with different temporal expression patterns. We identified Plxnd1, Ntng1, Efnb2, Ephb1, Plxna2, Epha3, Plxna4, Unc5c, and Flrt2 as axon guidance molecules to regulate axonogenesis. 168 targeted genes of Satb2 were found to regulate synaptic formation in the early development of the cerebral cortex. Transcription factor Mef2c is positively regulated by Satb2, and 28 Mef2c-targeted genes can be directly regulated by Satb2. In the Morris water maze test, Satb2+/- mice showed impaired spatial learning and memory, further strengthening that Satb2 can regulate synaptic functions.
Assuntos
Proteínas de Ligação à Região de Interação com a Matriz , Animais , Camundongos , Córtex Cerebral/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Ligação à Região de Interação com a Matriz/genética , Proteínas de Ligação à Região de Interação com a Matriz/metabolismo , Glicoproteínas de Membrana/metabolismo , Camundongos Knockout , Proteínas do Tecido Nervoso/metabolismo , Plasticidade Neuronal , Receptores de Superfície Celular/metabolismo , Sinapses/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Three-component alkene 1,2-difunctionalizations have emerged as a powerful strategy for rapid buildup of diverse and complex alkylpyridines, but the distal functionalized alkyl radicals for the alkene 1,2-alkylpyridylations were still rare. Herein, we report an example of regioselective three-component 1,2-cyanoalkylpyridylation of feedstock styrenes with accessible nonredox-active cyclic oximes through visible-light photoredox catalysis, providing a series of structurally diverse ß-cyanoalkylated alkylpyridines. This protocol proceeds through a radical relay pathway including the generation of iminyl radicals enabled by phosphoranyl radical-mediated ß-scission, radical transposition through C-C bond cleavage, highly selective radical addition, and precise radical-radical cross-coupling sequence, thus facilitating the regioselective formation of two distinct C-C single bonds in a single-pot operation. This synthetic strategy features mild conditions, broad compatibility of functional groups and substrate scope, diverse product derivatization, and late-stage modification.
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The chemical industry is a major and growing source of CO2 emissions. Here, we extend the principal U.S.-based integrated assessment model, GCAM, to include a representation of steam cracking, the dominant process in the organic chemical industry today, and a suite of emerging decarbonization strategies, including catalytic cracking, lower-carbon process heat, and feedstock switching. We find that emerging catalytic production technologies only have a small impact on midcentury emissions mitigation. In contrast, process heat generation could achieve strong mitigation, reducing associated CO2 emissions by â¼76% by 2050. Process heat generation is diversified to include carbon capture and storage (CCS), hydrogen, and electrification. A sensitivity analysis reveals that our results for future net CO2 emissions are most sensitive to the amount of CCS deployed globally. The system as defined cannot reach net-zero emissions if the share of incineration increases as projected without coupling incineration with CCS. Less organic chemicals are produced in a net-zero CO2 future than those in a no-policy scenario. Mitigation of feedstock emissions relies heavily on biogenic carbon used as an alternative feedstock and waste treatment of plastics. The only scenario that delivers net-negative CO2 emissions from the organic chemical sector (by 2070) combines greater use of biogenic feedstocks with a continued reliance on landfilling of waste plastic, versus recycling or incineration, which has trade-offs.
Assuntos
Dióxido de Carbono , Incineração , Dióxido de Carbono/análise , Incineração/métodos , Indústrias , Compostos Orgânicos , Carbono , PlásticosRESUMO
China is challenged with the simultaneous goals of improving air quality and mitigating climate change. The "Beautiful China" strategy, launched by the Chinese government in 2020, requires that all cities in China attain 35 µg/m3 or below for annual mean concentration of PM2.5 (particulate matter with aerodynamic diameter less than 2.5 µm) by 2035. Meanwhile, China adopts a portfolio of low-carbon policies to meet its Nationally Determined Contribution (NDC) pledged in the Paris Agreement. Previous studies demonstrated the cobenefits to air pollution reduction from implementing low-carbon energy policies. Pathways for China to achieve dual targets of both air quality and CO2 mitigation, however, have not been comprehensively explored. Here, we couple an integrated assessment model and an air quality model to evaluate air quality in China through 2035 under the NDC scenario and an alternative scenario (Co-Benefit Energy [CBE]) with enhanced low-carbon policies. Results indicate that some Chinese cities cannot meet the PM2.5 target under the NDC scenario by 2035, even with the strictest end-of-pipe controls. Achieving the air quality target would require further reduction in emissions of multiple air pollutants by 6 to 32%, driving additional 22% reduction in CO2 emissions relative to the NDC scenario. Results show that the incremental health benefit from improved air quality of CBE exceeds 8 times the additional costs of CO2 mitigation, attributed particularly to the cost-effective reduction in household PM2.5 exposure. The additional low-carbon energy polices required for China's air quality targets would lay an important foundation for its deep decarbonization aligned with the 2 °C global temperature target.
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Poluição do Ar/análise , Dióxido de Carbono/química , Poluentes Atmosféricos/efeitos adversos , Carbono/química , China , Cidades , Mudança Climática , Monitoramento Ambiental/métodos , Humanos , Paris , Material Particulado/químicaRESUMO
Specific and sensitive microRNAs (miRNAs) detection is essential to early cancer diagnosis. The development of these technologies including functional nuclease-mediated target amplification and DNA nanotechnology possesses tremendous potential for the high-performance detection of miRNAs in the accurate diagnosis of disease. In this study, we have established an ultrasensitive electrochemical biosensor by combining nicking endonuclease-assisted primer exchange reaction (PER) cascade amplification with a DNA nanosphere (DNS)-mediated electrochemical signal-enhanced system for the detection of miRNA-21 (miR-21). The cascade amplification is initiated by a nicking endonuclease that can cleave specific DNA substrates and highly amplify translation of the target to single-stranded DNA fragments (sDNA). Then, the PER cascade is powered by strand-displacing polymerase and generates a large amount of nascent single-stranded connector DNA (cDNA) via sDNA triggering of the dumbbell probe (DP), thus achieving the cascade amplification of the target. Finally, the DNS loaded with plenty of electroactive substances can be captured on the electrode via cDNA for further enhancing the electrochemical signal and highly sensitive detection of miR-21. The proposed electrochemical biosensor exhibits a wide detection range of 1 aM to 0.1 nM and a low detection limit of 0.58 aM. The excellent selectivity allows the biosensor to discriminate miR-21 from other miRNAs, even the one base-mismatched sequence. Moreover, the practicability of the biosensor is investigated by analyzing miR-21 in human serum and cancer cell lysate. Therefore, our proposed nicking endonuclease-assisted PER cascade amplification strategy provides a powerful platform for the early detection of miRNA-related disease and molecular diagnosis.
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Técnicas Biossensoriais , MicroRNAs , Nanosferas , DNA/genética , DNA Complementar , DNA de Cadeia Simples , Técnicas Eletroquímicas , Endonucleases/química , Humanos , Limite de Detecção , MicroRNAs/genética , Técnicas de Amplificação de Ácido NucleicoRESUMO
Stimuli-responsive therapy of cancer with spatial and temporal control is crucial in improving the treatment efficacy and minimizing the side effects. MicroRNA (miRNA) as an important biomarker has become one of the most promising endogenous stimuli for cancer therapy. However, the therapy efficacy is often impeded by the low expression amount of miRNA. Herein, the upconversion nanoparticle@Au (UCNP@Au) core-satellite nanostructures are rationally fabricated for isothermal amplification detection and in situ imaging of microRNA-21 (miR-21) in living cells based on the toehold-mediated strand displacement (TMSD) reaction, which is further applied to miRNA-responsive combined photothermal and photodynamic therapy of breast cancer. The UCNP@Au are constructed by linking AuNPs to photosensitizers Rose Bengal (RB)-loaded UCNPs through DNA hybridization. The upconversion luminescence (UCL) is quenched by AuNPs, resulting in the attenuation of singlet oxygen generation of RB. Once UCNP@Au are internalized into MCF-7 cells, the overexpressed intracellular miR-21 trigger the cyclic disassembly of UCNP@Au through cascade TMSD reactions, which facilitate the restoration of UCL for in situ imaging of miR-21 with signal amplification. Moreover, the released AuNPs are aggregated for photothermal therapy (PTT), while the singlet oxygen generated by RB is enhanced for photodynamic therapy (PDT). Compared with single-mode therapy, the miRNA-activated combinational phototherapy has demonstrated a greatly improved therapeutic efficacy for breast cancer. Therefore, our proposed core-satellite nanostructures cannot only achieve in situ amplified imaging of endogenous miRNA but also provide an effective nanoplatform for stimuli-responsive combinational phototherapy, which hold great prospects in early diagnosis and treatment of cancers.
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Neoplasias da Mama , Nanopartículas Metálicas , MicroRNAs , Nanopartículas , Fotoquimioterapia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/terapia , Feminino , Ouro/química , Humanos , Nanopartículas Metálicas/química , MicroRNAs/química , MicroRNAs/genética , Nanopartículas/química , Fototerapia , Oxigênio SingleteRESUMO
The growth relationship between exosomes (EXOs) and the host cells is highly desired for tumor evaluations, which puts forward high demand on the accurate and convenient acquisition of their individual quantitative information. However, the tedious and destructive separation process and the requirement of dual-channel detection make it become an extremely challenging task. Herein, we integrated an enzymatic biofuel cell (EBFC)-powered biosensor with a flow cell-supported membrane separation device (FMSC) to develop a continuous separation and detection platform for EXOs and host cancer cells in human serum. The FMSC equipped with an aluminum oxide membrane served as a size-dependent sorting unit to nondestructively extract EXOs from human serum within 5 min, representing a 99.3% reduction in isolating time compared to ultracentrifugation. The EBFC-powered biosensors modified with different aptamers on anodes and cathodes were used as a dual-channel sensing unit. By regulating the controlling valves of different fluid passages, the extracted EXOs and residual host cells could be successively inputted into EBFC-powered biosensors, which generated a segmental degradation in output performance due to the EXO-and host cell-caused increase in the steric hindrance of anodes and cathodes, respectively. Based on these degradations, we obtained the quantitative information of EXOs and host cells with a record-breaking sensitivity (EXOs: 5.59 × 103 particles/mL and host cells: 25 cells/mL). Moreover, the growth relationship between EXOs and host cells was also built, which would be beneficial for the disclosure of the growth state or even more detailed biology information of tumor.
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Fontes de Energia Bioelétrica , Técnicas Biossensoriais , Exossomos , Biocombustíveis , Exossomos/metabolismo , Humanos , UltracentrifugaçãoRESUMO
To realize excellent selectivity of CH4 in CO2 photoreduction (CO2 PR) is highly desirable, yet which is challenging due to the limited active sites for CH4 generation and severe electron-hole recombination on photocatalysts. Herein, based on the theoretically calculated effects of vanadium incorporation into the laminate of layered double hydroxides (LDHs), V into NiAl-LDH to synthesize a series of LDHs with various V contents is introduced. NiV-LDH is revealed to afford a high CH4 selectivity (78.9%), and extremely low H2 selectivity (only 0.4%) under λ > 400 nm irradiation. By further tuning the molar ratio of Ni to V, a CH4 selectivity of as high as 90.1% is achieved on Ni4 V-LDH, and H2 is completely prohibited on Ni2 V-LDH. Fine structural characterizations and comprehensive optical and electrochemical studies uncover V incorporation creates the lower-valence Ni species as active sites for generating CH4 , and enhances the generation, separation, and transfer of photogenerated carriers.
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MicroRNA (miRNA)-mediated cleavage is involved in numerous essential cellular pathways. miRNAs recognize target RNAs via sequence complementarity. In addition to complementarity, in vitro and in silico studies have suggested that RNA structure may influence the accessibility of mRNAs to miRNA-induced silencing complexes (miRISCs), thereby affecting RNA silencing. However, the regulatory mechanism of mRNA structure in miRNA cleavage remains elusive. We investigated the role of in vivo RNA secondary structure in miRNA cleavage by developing the new CAP-STRUCTURE-seq method to capture the intact mRNA structurome in Arabidopsis thaliana. This approach revealed that miRNA target sites were not structurally accessible for miRISC binding prior to cleavage in vivo. Instead, we found that the unfolding of the target site structure plays a key role in miRISC activity in vivo. We found that the single-strandedness of the two nucleotides immediately downstream of the target site, named Target Adjacent nucleotide Motif, can promote miRNA cleavage but not miRNA binding, thus decoupling target site binding from cleavage. Our findings demonstrate that mRNA structure in vivo can modulate miRNA cleavage, providing evidence of mRNA structure-dependent regulation of biological processes.
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MicroRNAs/ultraestrutura , Conformação de Ácido Nucleico , Interferência de RNA , RNA/ultraestrutura , Arabidopsis/genética , Sítios de Ligação/genética , MicroRNAs/genética , RNA/genética , Proteínas com Motivo de Reconhecimento de RNA/genética , RNA Mensageiro/genética , Complexo de Inativação Induzido por RNA/genéticaRESUMO
Thiazolidinedione (TZD) is an oral anti-diabetic drug that exhibits some side effects on the male reproductive system by interfering with the steroidogenesis and androgenic activity and also shows anti-proliferative effect on several cell types. This study investigated the effect of TZD on immature chicken Sertoli cell (SC) proliferation and the potential mechanism by which 17ß-estradiol regulated this process. Chicken SC viability was investigated under different treatment concentration and time of TZD. 17ß-estradiol (0.001 µM, 24 h) was added to analyze its effects on TZD-mediated cell viability, cell metabolic activity, cell growth, cell cycle progression, reactive oxygen species (ROS) level, antioxidant enzyme activity, mitochondria activity, oxygen consumption rate, adenosine triphosphate (ATP) level, and mitochondrial respiratory chain enzyme activity, adiponectin expression and several cell proliferation-related genes mRNA and protein levels. We performed the microRNA (miRNA) array to find TZD-induced differentially expressed miRNAs and validated whether miR-1577 can target on adiponectin via the dual luciferase reporter assay, as well as verified the effect of adiponectin addition with different concentrations on the SC viability. Further, SCs were transfected with miR-1577 agomir (a double-stranded synthetic miRNA mimic) in the presence or absence of TZD and antagomir (a single-stranded synthetic miRNA inhibitor) in the presence or absence of 17ß-estradiol to analyze whether miR-1577 was involved in TZD-mediated SC proliferation and whether 17ß-estradiol regulated this process. Results showed that TZD significantly inhibited SC viability, cell metabolic activity, cell growth, and cell cycle progression, while increased adiponectin level and ROS generation. TZD-treated SCs presented decreases of antioxidant enzyme activity, mitochondria activity, basal and maximal respiration, ATP production and level, mitochondrial respiratory chain enzyme activity, and mRNA and protein expressions of several cell proliferation-related genes, as well as the significant alteration of miRNA expressions (a total number of 55 miRNAs were up-regulated whereas 53 miRNAs down-regulated). Whereas, 17ß-estradiol played a positive role in chicken SC proliferation and rescued the damage of TZD on SC proliferation by up-regulating miR-1577 expression whose target gene was validated to be the adiponectin. In addition, exogenous adiponectin (more than 1 µg/ml) treatment exhibited a significant inhibition on the SC viability. Transfection of miR-1577 agomir promoted the SC proliferation via down-expressed adiponectin, and increased the mitochondrial function and cell proliferation-related gene expression, while TZD weakened the positive effect of miR-1577 agomir on SCs. On the other hand, transfection of miR-1577 antagomir inhibited SC proliferation by producing the opposite effects on above parameters, while 17ß-estradiol attenuated the negative effect of miR-1577 antagomir on SCs. These findings suggest down-expressed miR-1577 is involved in the regulation of TZD-inhibited SC proliferation through increasing adiponectin level, and this damage of TZD on the immature chicken SC proliferation can be ameliorated by appropriate dose of exogenous 17ß-estradiol treatment. This study provides an insight into the cytoprotective effect of 17ß-estradiol on TZD-damaged SC proliferation and may suggest a potential strategy for reducing the risk of SC dysfunction caused by the abuse of TZD.
Assuntos
Galinhas , Tiazolidinedionas , Adiponectina/genética , Animais , Proliferação de Células , Galinhas/metabolismo , Estradiol/metabolismo , Masculino , Células de Sertoli/metabolismo , Tiazolidinedionas/metabolismo , Tiazolidinedionas/farmacologiaRESUMO
Nardosinone, a sesquiterpene peroxide, is one of the main active constituents of the ethnomedicine Nardostachyos Radix et Rhizoma, and it has many bioactivities, such as antiarrhythmia and cardioprotection. To elucidate its in vivo existence forms, its metabolism is first studied using mice. All urine and feces are collected during the six days of oral dosing of nardosinone, and blood is collected at one hour after the last dose. Besides, to validate some metabolites, a fast experiment is performed, in which nardosinone was orally administered and the subsequent one-hour urine is collected and immediately analyzed by UHPLC-Q-TOF-MS. In total, 76 new metabolites are identified in this study, including 39, 51, and 12 metabolites in urine, plasma, and feces, respectively. Nardosinone can be converted into nardosinone acid or its isomers. The metabolic reactions of nardosinone included hydroxylation, hydrogenation, dehydration, glucuronidation, sulfation, demethylation, and carboxylation. There are 56 and 20 metabolites with the structural skeleton of nardosinone and nardosinone acid, respectively. In total, 77 in vivo existence forms of nardosinone are found in mice. Nardosinone is mainly excreted in urine and is not detected in the feces. These findings will lay the foundation for further research of the in vivo effective forms of nardosinone and Nardostachyos Radix et Rhizoma.