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The subtle differences in the chemical structures of double-stranded (ds) RNA and DNA lead to significant variations in their biological roles and medical implications, largely due to their distinct biophysical properties, such as bending stiffness. Although it is well known that A-form dsRNA is stiffer than B-form dsDNA under physiological salt conditions, the underlying cause of this difference remains unclear. In this study, we employ high-precision magnetic-tweezer experiments along with molecular dynamics simulations and reveal that the relative bending stiffness between dsRNA and dsDNA is primarily determined by the structure- and salt-concentration-dependent ion distribution around their helical structures. At near-physiological salt conditions, dsRNA shows a sparser ion distribution surrounding its phosphate groups compared to dsDNA, causing its greater stiffness. However, at very high monovalent salt concentrations, phosphate groups in both dsRNA and dsDNA become fully neutralized by excess ions, resulting in a similar intrinsic bending persistence length of approximately 39 nm. This similarity in intrinsic bending stiffness of dsRNA and dsDNA is coupled to the analogous fluctuations in their total groove widths and further coupled to the similar fluctuation of base-pair inclination, despite their distinct A-form and B-form helical structures.
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DNA , RNA de Cadeia Dupla , Pareamento de Bases , DNA/química , Conformação de Ácido Nucleico , Fosfatos , RNA de Cadeia Dupla/química , Biologia Molecular/métodos , Simulação de Dinâmica MolecularRESUMO
Nucleic acid deformations play important roles in many biological processes. The physical understanding of nucleic acid deformation by environmental stimuli is limited due to the challenge in the precise measurement of RNA and DNA deformations and the complexity of interactions in RNA and DNA. Magnetic tweezers experiments provide an excellent opportunity to precisely measure DNA and RNA twist changes induced by environmental stimuli. In this work, we applied magnetic tweezers to measure double-stranded RNA twist changes induced by salt and temperature changes. We observed RNA unwinds when lowering salt concentration, or increasing temperature. Our molecular dynamics simulations revealed the mechanism: lowering salt concentration or increasing temperature enlarges RNA major groove width, which causes twist decrease through twist-groove coupling. Combining these results with previous results, we found some universality in RNA and DNA deformations induced by three different stimuli: salt change, temperature, and stretching force. For RNA, these stimuli first modify the major groove width, which is transduced into twist change through twist-groove coupling. For DNA, these stimuli first modify diameter, which is transduced into twist change through twist-diameter coupling. Twist-groove coupling and twist-diameter coupling appear to be utilized by protein binding to reduce DNA and RNA deformation energy cost upon protein binding.
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DNA , RNA de Cadeia Dupla , Conformação de Ácido Nucleico , Ligação Proteica , Temperatura , DNA/química , Cloreto de Sódio , Cloreto de Sódio na DietaRESUMO
Zero-knowledge proof (ZKP) is a fundamental cryptographic primitive that allows a prover to convince a verifier of the validity of a statement without leaking any further information. As an efficient variant of ZKP, noninteractive zero-knowledge proof (NIZKP) adopting the Fiat-Shamir heuristic is essential to a wide spectrum of applications, such as federated learning, blockchain, and social networks. However, the heuristic is typically built upon the random oracle model that makes ideal assumptions about hash functions, which does not hold in reality and thus undermines the security of the protocol. Here, we present a quantum solution to the problem. Instead of resorting to a random oracle model, we implement a quantum randomness service. This service generates random numbers certified by the loophole-free Bell test and delivers them with postquantum cryptography (PQC) authentication. By employing this service, we conceive and implement NIZKP of the three-coloring problem. By bridging together three prominent research themes, quantum nonlocality, PQC, and ZKP, we anticipate this work to inspire more innovative applications that combine quantum information science and the cryptography field.
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A high-performance 5-junction cascade quantum dot (QD) vertical cavity surface-emitting laser (VCSEL) with 1.3â µm wavelength was designed. The characteristics of the QD as active regions and tunnel junctions are combined to effectively increase output power. The photoelectric characteristics of single-junction, 3-junction cascade, and 5-junction cascade QD VCSELs are compared at continuous-wave conditions. Results indicate that the threshold current gradually decreases, and the output power and slope efficiency exponential increase with the increase of the number of active regions. The peak power conversion efficiency of 58.4% is achieved for the 5-junction cascade individual QD VCSEL emitter with 10â µm oxide aperture. The maximum slope efficiency of the device is 6.27â W/A, which is approximately six times than that of the single-junction QD VCSEL. The output power of the 5-junction cascade QD VCSEL reaches 188.13â mW at injection current 30â mA. High-performance multi-junction cascade 1.3-µm QD VCSEL provides data and theoretical support for the preparation of epitaxial materials.
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Bell's theorem states that the quantum mechanical description of physical quantities cannot be fully explained by local realistic theories, laying a solid basis for various quantum information applications. Hardy's paradox is celebrated as the simplest form of Bell's theorem concerning its "All versus Nothing" approach to test local realism. However, due to experimental imperfections, existing tests of Hardy's paradox require additional assumptions of the experimental systems, and these assumptions constitute potential loopholes for faithfully testing local realistic theories. Here, we experimentally demonstrate Hardy's nonlocality through a photonic entanglement source. By achieving a detection efficiency of 82.2%, a quantum state fidelity of 99.10%, and applying high-speed quantum random number generators for the measurement setting switching, the experiment is implemented in a loophole-free manner. During 6 h of running, a strong violation of P_{Hardy}=4.646×10^{-4} up to 5 standard deviations is observed with 4.32×10^{9} trials. A null hypothesis test shows that the results can be explained by local realistic theories with an upper bound probability of 10^{-16348}. These testing results provide affirmative evidence against local realism, and establish an advancing benchmark for quantum information applications based on Hardy's paradox.
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In this study, we systematically investigated the regioselective glycosylation of 2,4-OH mannoside and galactoside acceptors since regioselective protection of their 3- and 6-OHs is readily achieved. By altering the protecting groups at 1-, 3-, and 6-positions of such acceptors, we finally screened p-methoxyphenyl 3-OBn, 6-OTBDPS, α-mannoside, and ß-galactoside acceptors whose 2-OHs exhibited excellent selectivity for glycosylation with various glycosyl donors, leading to 1,2-linked products in 70-82% yields. By utilizing such acceptors, a series of 2,4-linked trisaccharide products (53-65% yields over two steps) have been highly efficiently synthesized without the need for complex protection/deprotection operations at the 2- and 4-positions of these acceptors.
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BACKGROUND: Reverse transcription quantitative polymerase chain reaction (RT-qPCR) can accurately detect relative gene expression levels in biological samples. However, widely used reference genes exhibit unstable expression under certain conditions. METHODS AND RESULTS: Here, we compared the expression stability of eight reference genes (RPLP0, RPS18, RPL13, EEF1A1, ß-actin, GAPDH, HPRT1, and TUBB) commonly used in liproxstatin-1 (Lip-1)-treated K562 cells using RNA-sequencing and RT-qPCR. The expression of EEF1A1, ACTB, GAPDH, HPRT1, and TUBB was considerably lower in cells treated with 20 µM Lip-1 than in the control, and GAPDH also showed significant downregulation in the 10 µM Lip-1 group. Meanwhile, when we used geNorm, NormFinder, and BestKeeper to compare expression stability, we found that GAPDH and HPRT1 were the most unstable reference genes among all those tested. Stability analysis yielded very similar results when geNorm or BestKeeper was used but not when NormFinder was used. Specifically, geNorm and BestKeeper identified RPL13 and RPLP0 as the most stable genes under 20 µM Lip-1 treatment, whereas RPL13, EEF1A1, and TUBB were the most stable under 10 µM Lip-1 treatment. TUBB and EEF1A1 were the most stable genes in both treatment groups according to the results obtained using NormFinder. An assumed most stable gene was incorporated into each software to validate the accuracy. The results suggest that NormFinder is not an appropriate algorithm for this study. CONCLUSIONS: Stable reference genes were recognized using geNorm and BestKeeper but not NormFinder. Overall, RPL13 and RPLP0 were the most stable reference genes under 20 µM Lip-1 treatment, whereas RPL13, EEF1A1, and TUBB were the most stable genes under 10 µM Lip-1 treatment.
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Actinas , Leucemia , Humanos , Células K562 , Sequência de Bases , Análise de Sequência de RNA , Hipoxantina Fosforribosiltransferase , Proteínas de Neoplasias , Proteínas RibossômicasRESUMO
Carbon nanosol (CNS) is a carbon-based nanomaterial capable of promoting plant growth while the underlying mechanism involved in this process remains unknown. This study demonstrates that CNS promotes rice seedling growth under restricted concentrations. Macroelement transporter mutants were investigated to further investigate the CNS-mediated promotion of rice seedling growth. The genetic and physiological findings revealed that nitrate transporter 1.1B (NRT1.1B) and ammonium transporter 1 (AMT1) mutants inhibited the CNS-induced growth development of rice seedlings, whereas potassium transporter (AKT1) and phosphate transporter 8 (PT8) did not exhibit any inhibitory effects. Further investigations demonstrated the inhibition of CNS-mediated growth promotion via glutamine synthetase 1;1 (gs1;1) mutants. Additionally, the administration of CNS resulted in enhanced accumulation of chlorophyll in plants, and the promotion of CNS-induced growth was inhibited by yellow-green leaf 8 (YGL8) mutants and the chlorophyll biosynthetic gene divinyl reductase (DVR) mutants. According to these findings, the CNS promotes plant growth by stimulating chlorophyll biosynthesis. Furthermore, the presence of CNS enhanced the ability of rice to withstand blast, sheath blight (ShB), and bacterial blight. The nrt1.1b, amt1, dvr, and ygl8 mutants did not exhibit a broad spectrum effect. The positive regulation of broad-spectrum resistance in rice by GS1;1 suggests the requirement of N assimilation for CNS-mediated broad-spectrum resistance. In addition, an in vitro assay demonstrated that CNS inhibits the growth of pathogens responsible for blast, ShB, and bacterial blight, namely Magnaporthe oryzae, Rhizoctonia solani AG1-IA, and Xanthomonas oryzae pv. Oryzae, respectively. CNS application may also induce broad-spectrum resistance against bacterial and fungal pathogens, indicating that in addition to its antifungal and antibacterial properties, CNS application may also stimulate N assimilation. Collectively, the results indicate that CNS may be a potential nano-therapeutic agent for improved plant growth promotion while also providing broad-spectrum resistance.
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Carbono , Oryza , Oryza/microbiologia , Oryza/crescimento & desenvolvimento , Oryza/efeitos dos fármacos , Oryza/genética , Carbono/metabolismo , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Clorofila/metabolismo , Plântula/crescimento & desenvolvimento , Plântula/efeitos dos fármacos , Plântula/microbiologia , Resistência à Doença/efeitos dos fármacosRESUMO
The deep-sea environment is an extremely difficult habitat for microorganisms to survive in due to its intense hydrostatic pressure. However, the mechanisms by which these organisms adapt to such extreme conditions remain poorly understood. In this study, we investigated the metabolic adaptations of Microbacterium sediminis YLB-01, a cold and stress-tolerant microorganism isolated from deep-sea sediments, in response to high-pressure conditions. YLB-01 cells were cultured at normal atmospheric pressure and 28 â until they reached the stationary growth phase. Subsequently, the cells were exposed to either normal pressure or high pressure (30 MPa) at 4 â for 7 days. Using NMR-based metabolomic and proteomic analyses of YLB-01 cells exposed to high-pressure conditions, we observed significant metabolic changes in several metabolic pathways, including amino acid, carbohydrate, and lipid metabolism. In particular, the high-pressure treatment stimulates cell division and triggers the accumulation of UDP-glucose, a critical factor in cell wall formation. This finding highlights the adaptive strategies used by YLB-01 cells to survive in the challenging high-pressure environments of the deep sea. Specifically, we discovered that YLB-01 cells regulate amino acid metabolism, promote carbohydrate metabolism, enhance cell wall synthesis, and improve cell membrane fluidity in response to high pressure. These adaptive mechanisms play essential roles in supporting the survival and growth of YLB-01 in high-pressure conditions. Our study offers valuable insights into the molecular mechanisms underlying the metabolic adaptation of deep-sea microorganisms to high-pressure environments. KEY POINTS: ⢠NMR-based metabolomic and proteomic analyses were conducted on Microbacterium sediminis YLB-01 to investigate the significant alterations in several metabolic pathways in response to high-pressure treatment. ⢠YLB-01 cells used adaptive strategies (such as regulated amino acid metabolism, promoted carbohydrate metabolism, enhanced cell wall synthesis, and improved cell membrane fluidity) to survive in the challenging high-pressure environment of the deep sea. ⢠High-pressure treatment stimulated cell division and triggered the accumulation of UDP-glucose, a critical factor in cell wall formation, in Microbacterium sediminis YLB-01 cells.
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Actinomycetales , Proteômica , Aminoácidos , Glucose , Difosfato de Uridina , MicrobacteriumRESUMO
The elasticities of double-stranded (ds) DNA and RNA, which are critical to their biological functions and applications in materials science, can be significantly modulated by solution conditions such as ions and temperature. However, there is still a lack of a comprehensive understanding of the role of solvents in the elasticities of dsRNA and dsDNA in a comparative way. In this work, we explored the effect of ethanol solvent on the elasticities of dsRNA and dsDNA by magnetic tweezers and all-atom molecular dynamics simulations. We found that the bending persistence lengths and contour lengths of dsRNA and dsDNA decrease monotonically with the increase in ethanol concentration. Furthermore, the addition of ethanol weakens the positive twist-stretch coupling of dsRNA, while promotes the negative twist-stretch coupling of dsDNA. Counter-intuitively, the lower dielectric environment of ethanol causes a significant re-distribution of counterions and enhanced ion neutralization, which overwhelms the enhanced repulsion along dsRNA/dsDNA, ultimately leading to the softening in bending for dsRNA and dsDNA. Moreover, for dsRNA, ethanol causes slight ion-clamping across the major groove, which weakens the major groove-mediated twist-stretch coupling, while for dsDNA, ethanol promotes the stretch-radius correlation due to enhanced ion binding and consequently enhances the helical radius-mediated twist-stretch coupling.
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DNA , Etanol , Simulação de Dinâmica Molecular , RNA de Cadeia Dupla , Etanol/química , DNA/química , RNA de Cadeia Dupla/química , Elasticidade , Conformação de Ácido NucleicoRESUMO
5-Methyl-cytosine (5mC) is one of the most important DNA modifications and plays versatile biological roles. It is well known that 5mC stabilizes DNA duplexes. However, it remains unclear how 5mC affects the kinetics of DNA melting and hybridization. Here, we studied the kinetics of unzipping and rezipping using a 502-bp DNA hairpin by single-molecule magnetic tweezers. Under constant loading rates, 5mC increases the unzipping force but counterintuitively decreases the rezipping force at various salt and temperature conditions. Under constant forces, the non-methylated DNA hops between metastable states during unzipping and rezipping, which implies low energy barriers. Surprisingly, the 5mC DNA can't rezip after fully unzipping unless much lower forces are applied, where it rezips stochastically in a one-step manner, which implies 5mC kinetically hinders DNA hybridization and high energy barriers in DNA hybridization. All-atom molecular dynamics simulations reveal that the 5mC kinetically hinders DNA hybridization due to steric effects rather than electrostatic effects caused by the additional methyl groups of cytosines. Considering the possible high speed of DNA unzipping and zipping during replication and transcription, our findings provide new insights into the biological roles of 5mC.
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5-Metilcitosina , DNA , Citosina , DNA/química , Fenômenos Magnéticos , Conformação de Ácido Nucleico , Hibridização de Ácido NucleicoRESUMO
BACKGROUND: Sleeping late has been a common phenomenon and brought harmful effects to our health. The purpose of this study was to investigate the association between sleep timing and major adverse cardiovascular events (MACEs) in patients with percutaneous coronary intervention (PCI). METHODS: Sleep onset time which was acquired by the way of sleep factors questionnaire in 426 inpatients was divided into before 22:00, 22:00 to 22:59, 23:00 to 23:59 and 24:00 and after. The median follow-up time was 35 months. The endpoints included angina pectoris (AP), new myocardial infarction (MI) or unplanned repeat revascularization, hospitalization for heart failure, cardiac death, nonfatal stroke, all-cause death and the composite endpoint of all events mentioned above. Cox proportional hazards regression was applied to analyze the relationship between sleep timing and endpoint events. RESULTS: A total of 64 composite endpoint events (CEEs) were reported, including 36 AP, 15 new MI or unplanned repeat revascularization, 6 hospitalization for heart failure, 2 nonfatal stroke and 5 all-cause death. Compared with sleeping time at 22:00-22:59, there was a higher incidence of AP in the bedtime ≥ 24:00 group (adjusted HR: 5.089; 95% CI: 1.278-20.260; P = 0.021). In addition, bedtime ≥ 24:00 was also associated with an increased risk of CEEs in univariate Cox regression (unadjusted HR: 2.893; 95% CI: 1.452-5.767; P = 0.003). After multivariable adjustments, bedtime ≥ 24:00 increased the risk of CEEs (adjusted HR: 3.156; 95% CI: 1.164-8.557; P = 0.024). CONCLUSION: Late sleeping increased the risk of MACEs and indicated a poor prognosis. It is imperative to instruct patients with PCI to form early bedtime habits.
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Intervenção Coronária Percutânea , Sono , Humanos , Masculino , Intervenção Coronária Percutânea/efeitos adversos , Feminino , Pessoa de Meia-Idade , Idoso , Fatores de Tempo , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/mortalidade , Fatores de Risco , Modelos de Riscos Proporcionais , Seguimentos , Inquéritos e QuestionáriosRESUMO
Two new triterpenoids (1-2), along with six known analogues (3-8) were obtained from the dried whole plant of Leptopus clarkei. Compound 1 is a 3,4-seco-lupane-type triterpenoid, and compound 2 is a phenylpropanoid-conjugated pentacyclic triterpenoid possessing trans-p-coumaroyl unit attached to oleanane-type skeleton. This is the first report on chemical investigation of the L. clarkei, and the triterpenoid derivatives were found in this plant for the first time. The structures of the new compounds were unequivocally elucidated by HRESIMS and 1D/2D NMR data. Additionally, the isolated compounds were evaluated for theircytotoxicities against four cancer cell lines including HepG2, MCF-7, A549 and HeLa. Notably, compound 2 exhibited the most significant antiproliferative activity with IC50 less than 20â µM for four cancer lines.
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Antineoplásicos Fitogênicos , Neoplasias , Triterpenos , Humanos , Triterpenos/farmacologia , Triterpenos/química , Espectroscopia de Ressonância Magnética , Extratos Vegetais/química , Células HeLa , Estrutura Molecular , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/química , Neoplasias/tratamento farmacológicoRESUMO
BACKGROUND: Visceral adipose tissue (VAT) has been linked to the severe acute pancreatitis (SAP) prognosis, although the underlying mechanism remains unclear. It has been reported that pyroptosis worsens SAP. The present study aimed to verify whether mesenteric adipose tissue (MAT, a component of VAT) can cause secondary intestinal injury through the pyroptotic pathway. METHODS: Thirty-six male Sprague Dawley (SD) rats were divided into six different groups. Twelve rats were randomly divided into the SAP and control groups. We monitored the changes of MAT and B lymphocytes infiltration in MAT of SAP rats. Twelve SAP rats were injected with MAT B lymphocytes or phosphate buffer solution (PBS). The remaining twelve SAP rats were first injected with MAT B lymphocytes, and then with MCC950 (NLRP3 inhibitor) or PBS. We collected blood and tissue samples from pancreas, gut and MAT for analysis. RESULTS: Compared to the control rats, the SAP group showed inflammation in MAT, including higher expression of tumor necrosis factor (TNF-α) and interleukin-6 (IL-6), lower expression of IL-10, and histological changes. Flow cytometry analysis revealed B lymphocytes infiltration in MAT but not T lymphocytes and macrophages. The SAP rats also exhibited intestinal injury, characterized by lower expression of zonula occludens-1 (ZO-1) and occludin, higher levels of lipopolysaccharide and diamine oxidase, and pathological changes. The expression of NLRP3 and n-GSDMD, which are responsible for pyroptosis, was increased in the intestine of SAP rats. The injection of MAT B lymphocytes into SAP rats exacerbated the inflammation in MAT. The upregulation of pyroptosis reduced tight junction in the intestine, which contributed to the SAP progression, including higher inflammatory indicators and worse histological changes. The administration of MCC950 to SAP + MAT B rats downregulated pyroptosis, which subsequently improved the intestinal barrier and ameliorated inflammatory response of SAP. CONCLUSIONS: In SAP, MAT B lymphocytes aggravated local inflammation, and promoted the injury to the intestine through the enteric pyroptotic pathway.
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Pancreatite , Ratos , Masculino , Animais , Pancreatite/induzido quimicamente , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Ratos Sprague-Dawley , Mucosa Intestinal , Piroptose , Doença Aguda , Inflamação/metabolismo , Fator de Necrose Tumoral alfa , Tecido Adiposo/metabolismo , Tecido Adiposo/patologia , Linfócitos B/metabolismo , Linfócitos B/patologiaRESUMO
Achieving single-atom catalysts (SACs) with high metal content and outstanding performance as well as robust stability is critically needed for clean and sustainable energy. However, most of the synthesized SACs are undesired on the loading content of the metal due to the anchored metals and the supports as well as the synthesizing methods. Herein, a Rh-SAC with high accessibility by loading it on the metal nodes of metal-porphyrin-based PCN MOFs (PCN-224) as supporting material is reported. Significantly, the PCN-Rh15.9 /KB catalyst with a high Rh content of 15.9 wt% exhibits excellent hydrogen evolution activity with a low overpotential of 25 mV at a current density of 10 mA cm-2 and a mass activity of 7.7 A mg-1 Rh at overpotential of 150 mV, which is much better than that of the commercial Rh/C. Various characterizations reveal the Rh species is stabilized by the metal nodes bearing -O/OHx in MOFs, which is of importance for the high loading amount and the good activity. This work establishes an efficient approach to synthesize high content SACs on the nodes of MOFs for wide catalyst design.
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Phytochrome (Phy)-regulated light signalling plays important roles in plant growth, development, and stress responses. However, its function in rice defence against sheath blight disease (ShB) remains unclear. Here, we found that PhyB mutation or shade treatment promoted rice resistance to ShB, while resistance was reduced by PhyB overexpression. Further analysis showed that PhyB interacts with phytochrome-interacting factor-like 15 (PIL15), brassinazole resistant 1 (BZR1), and vascular plant one-zinc-finger 2 (VOZ2). Plants overexpressing PIL15 were more susceptible to ShB in contrast to bzr1-D-overexpressing plants compared with the wild-type, suggesting that PhyB may inhibit BZR1 to negatively regulate rice resistance to ShB. Although BZR1 is known to regulate brassinosteroid (BR) signalling, the observation that BR signalling negatively regulated resistance to ShB indicated an independent role for BZR1 in controlling rice resistance. It was also found that the BZR1 ligand NAC028 positively regulated resistance to ShB. RNA sequencing showed that cinnamyl alcohol dehydrogenase 8B (CAD8B), involved in lignin biosynthesis was upregulated in both bzr1-D- and NAC028-overexpressing plants compared with the wild-type. Yeast-one hybrid, ChIP, and transactivation assays demonstrated that BZR1 and NAC028 activate CAD8B directly. Taken together, the analyses demonstrated that PhyB-mediated light signalling inhibits the BZR1-NAC028-CAD8B pathway to regulate rice resistance to ShB.
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Oryza , Fitocromo , Fitocromo B/metabolismo , Oryza/genética , Fitocromo/metabolismo , Brassinosteroides/metabolismo , Regulação da Expressão Gênica de PlantasRESUMO
Systemic lupus erythematosus (SLE) is an inflammatory disease caused by autoantibodies, with high morbidity and mortality. It involves multiple systems, particularly the renal, which can lead to lupus nephritis (LN); its multi-system effects have a significant impact on the physical and mental health of patients. Exosomes are vesicles that are secreted during cell activity and carry a variety of nucleic acids, proteins, and lipids. They are distributed through body fluids for cellular communication. MicroRNAs (miRNAs) are nucleic acids that are packaged within the exosome that are taken up and released in response to changes in plasma membrane structure. MiRNAs are potential participants in immune and inflammatory responses, which are transported to target cells and can inhibit gene expression in receptor cells. It has been suggested that exosomal miRNA can regulate the pathogenesis of SLE and, as such, they are of value in diagnosis and treatment. In this paper, we focus on the research progress into exosomal miRNA in SLE and inspire new directions for SLE related research.
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Exossomos , Lúpus Eritematoso Sistêmico , Nefrite Lúpica , MicroRNAs , Humanos , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/terapia , MicroRNAs/genética , Exossomos/genética , Exossomos/patologia , Nefrite Lúpica/diagnóstico , Nefrite Lúpica/genética , Nefrite Lúpica/terapia , Rim/patologiaRESUMO
In this study, we have successfully applied a visible-light-promoted desulfurization method to the synthesis of deoxysugars, especially 1-deoxyglycose, 2,4-deoxyglycosides, and 2-deoxyglycosides with exclusive α-configuration. Compared to the reported desulfurization under UV light (500 W mercury lamp), this desulfurization under visible light (20 W blue LED) is easy to operate since it does not require a dedicated photochemical reactor, occurs under very mild conditions, and is able to avoid many of the side reactions that often occur during the UV-induced desulfurization.
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Sulfetos , Sulfetos/química , Luz , Oxirredução , Glicosídeos/químicaRESUMO
Significant variations in leaf colours, pigment contents, and main taste compounds in young shoots from albino tea plants (Camellia sinensis) influence tea flavour. However, the seasonal metabolic pattern and molecular regulatory mechanism of these metabolites remain largely elusive. Herein, we conducted morphological, biochemical, metabolomic and transcriptomic analyses between an albino tea cultivar 'Zhonghuang 3' ('ZH3') and a green strain 'Tai cha 15' ('TC15') at four-time points (April 12, May 31, July 14, and August 17) to elucidate dynamic changes in these compounds and predict the relationships among transcription factors (TFs), target genes (TGs), and metabolite abundance. Generally, leaf colours and pigment contents were significantly lighter and lower, respectively, in 'ZH3' than in 'TC15' from spring to summer, but were subsequently similar. Compared to 'TC15', 'ZH3' had a lower and broader phenol/ammonia ratio as well as stable caffeine content and showed more significantly different metabolites and differentially expressed genes. The relationship between pigments, main taste compounds, and their biosynthetic genes, as well as TFs and their TGs, had genetic specificity. These results suggested that the biosynthesis of these compounds was probably both season- and variety-dependent. In total, 12 models of the TF-TG-metabolite regulatory network were proposed to uncover the biosynthetic and regulatory mechanisms of these metabolites in tea plants. A high correlation was observed between some structural genes and TFs with the accumulation of these metabolites. These findings provide novel insights into the regulatory mechanisms underlying accumulation of pigments and main taste compounds in tea plants.
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Camellia sinensis , Transcriptoma , Paladar , Camellia sinensis/genética , Camellia sinensis/metabolismo , Perfilação da Expressão Gênica , Folhas de Planta/metabolismo , Chá/química , Chá/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismoRESUMO
Nitric oxide (NO) is an important signaling molecule that is involved in a wide range of physiological and pathological events in biology. Metal coordination chemistry, especially with iron, is at the heart of many biological transformations involving NO. A series of heme proteins, nitric oxide synthases (NOS), soluble guanylate cyclase (sGC), and nitrophorins, are responsible for the biosynthesis, sensing, and transport of NO. Alternatively, NO can be generated from nitrite by heme- and copper-containing nitrite reductases (NIRs). The NO-bearing small molecules such as nitrosothiols and dinitrosyl iron complexes (DNICs) can serve as an alternative vehicle for NO storage and transport. Once NO is formed, the rich reaction chemistry of NO leads to a wide variety of biological activities including reduction of NO by heme or non-heme iron-containing NO reductases and protein post-translational modifications by DNICs. Much of our understanding of the reactivity of metal sites in biology with NO and the mechanisms of these transformations has come from the elucidation of the geometric and electronic structures and chemical reactivity of synthetic model systems, in synergy with biochemical and biophysical studies on the relevant proteins themselves. This review focuses on recent advancements from studies on proteins and model complexes that not only have improved our understanding of the biological roles of NO but also have provided foundations for biomedical research and for bio-inspired catalyst design in energy science.