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1.
Gene ; 736: 144410, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32007581

RESUMO

Magnoliaceae is a primitive taxon in the angiosperms, comprising approximately 240 species in 2-17 genera. Many of them have been widely cultivated due to their horticultural and medicinal value. However, there are uncertainties and controversies about the delimitation of the genera except Liriodendron L. in this family. The Yulania taxa is also the focus of dispute at the genus and section levels. In this study, we compared ten Yulania plastomes, including the newly sequenced M. polytepala. The plastome-wide comparative analysis demonstrated that 1) Yulania cp genomes were highly conserved, and the majority differences existed in IR regions with the loss/retention of trnV-GAC or ycf15 gene, 2) mutational hotspots with high levels of nucleotide diversity (Pi > 0.02) existed in both coding (rpoA, and ycf1) and no-coding (ccsA-ndhD, ndhE-ndhG, ndhF-rpl32, petA-psbJ, rpl32-trnL, rps3-rps19, and trnH-psbA) regions among the genus Yulania. Combined with other data from Magnoliaceae plastomes, our reconstructed molecular phylogenetic tree revealed that Yulania is monophyletic, separated from the genus Magnolia L. (=Magnolia subg. Magnolia L.), but seems a sister of Michelia L. Moreover, M. polytepala which belongs to the genus Yulania is most closely related to M. liliiflora. All these results indicated that plastome data may contribute to investigating taxonomy, population genetics and phylogeny of Yulania.


Assuntos
Cloroplastos/genética , Genoma de Cloroplastos/genética , Genoma de Planta/genética , Magnolia/genética , Magnoliaceae/genética , Genética Populacional/métodos , Genômica/métodos , Magnoliopsida/genética , Filogenia
2.
Chem Rev ; 120(1): 310-433, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31869214

RESUMO

Precise control over molecular movement is of fundamental and practical importance in physics, biology, and chemistry. At nanoscale, the peculiar functioning principles and the synthesis of individual molecular actuators and machines has been the subject of intense investigations and debates over the past 60 years. In this review, we focus on the design of collective motions that are achieved by integrating, in space and time, several or many of these individual mechanical units together. In particular, we provide an in-depth look at the intermolecular couplings used to physically connect a number of artificial mechanically active molecular units such as photochromic molecular switches, nanomachines based on mechanical bonds, molecular rotors, and light-powered rotary motors. We highlight the various functioning principles that can lead to their collective motion at various length scales. We also emphasize how their synchronized, or desynchronized, mechanical behavior can lead to emerging functional properties and to their implementation into new active devices and materials.

3.
Biochem Biophys Res Commun ; 514(3): 919-925, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31084926

RESUMO

Staphylococcal nuclease and tudor domain containing 1 (SND1) has multiple functions in a variety of cellular processes. Here, we assessed the effects of SND1 in cellular DNA damage after ionizing radiation (IR). Knocking down SND1 in the mouse-derived photoreceptor 661 W cell line markedly inhibited cell proliferation and increased apoptosis after IR treatment. After DNA damage, SND1 induced Ataxia telangiectasia mutated kinase (ATM) signaling to launch DNA repair. Defects of SND1 were associated with missing response to DNA damage signal to cell cycle checkpoints or DNA repair. The current findings reveal SND1 as a new regulatory factor in DNA damage response.

4.
RNA Biol ; 15(10): 1364-1375, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30321081

RESUMO

Multifunctional SND1 (staphylococcal nuclease and tudor domain containing 1) protein is reportedly associated with different types of RNA molecules, including mRNA, miRNA, pre-miRNA, and dsRNA. SND1 has been implicated in a number of biological processes in eukaryotic cells, including cell cycle, DNA damage repair, proliferation, and apoptosis. However, the specific molecular mechanism regarding the anti-apoptotic role of SND1 in mammalian cells remains largely elusive. In this study, the analysis of the online HPA (human protein atlas) and TCGA (the cancer genome atlas) databases showed the significantly high expression of SND1 in liver cancer patients. We found that the downregulation or complete depletion of SND1 enhanced the apoptosis levels of HepG2 and SMMC-7721 cells upon stimulation with 5-Fu (5-fluorouracil), a chemotherapeutic drug for HCC (hepatocellular carcinoma). SND1 affected the 5-Fu-induced apoptosis levels of HCC cells by modulating the expression of UCA1 (urothelial cancer associated 1), which is a lncRNA (long non-coding RNA). Moreover, MYB (MYB proto-oncogene, transcription factor) may be involved in the regulation of SND1 in UCA1 expression. In summary, our study identified SND1 as an anti-apoptotic factor in hepatocellular carcinoma cells via the modulation of lncRNA UCA1, which sheds new light on the relationship between SND1 protein and lncRNA.


Assuntos
Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Proteínas Nucleares/genética , RNA Longo não Codificante/genética , Apoptose/genética , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/patologia , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Endonucleases , Fluoruracila/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , MicroRNAs/genética , RNA Mensageiro/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
5.
Curr Eye Res ; 43(11): 1342-1350, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29966450

RESUMO

PURPOSE: We performed nailfold capillary microscopy to explore microvasculature abnormalities in uveitis overall and uveitis stratified in various ways. METHODS: This was a cross-sectional, case-control, observational study. One hundred and seven uveitis patients and 130 control subjects were included. We used a JH-1004 capillaroscope to perform nailfold capillary video microscopy on the fourth and fifth digits of each subject's nondominant hand. Videos were evaluated for hemorrhages, dilated capillary loops > 25 µm, and avascular zones > 200 µm. Univariate analyses were used for the assessment of case-control morphological differences and multivariate analyses were performed to assess the relation between nailfold capillaroscopic findings and uveitis subgroups. RESULTS: In univariate analysis, uveitis patients were more likely to have higher tortuosity ratings and reduced capillary density compared to controls (p < 0.001 for both); furthermore, dilated capillary loops, avascular zone and hemorrhages were more frequent in uveitis versus control subjects (p < 0.001 for all). Among cases, every unit increase in capillary density (vessels/mm) was associated with active uveitis (n = 72 cases) versus inactive disease (n = 35 cases; odds ratio (OR) = 1.7; (95% confidence interval (CI), 1.2-2.5) in multivariate analysis. Furthermore, the presence of any nailfold hemorrhage versus the absence of hemorrhage was more likely to be associated with posterior and panuveitis (n = 41 cases combined) compared to anterior and intermediate uveitis (n = 66 cases combined; OR = 5.8; 95% CI, 2.3-14.2). Moreover, we found a positive correlation between peripheral retinal leakage and nailfold capillaries dilation (r = 0.33; p = 0.015) that was not strictly significant based on the number of comparisons made. CONCLUSIONS: Our study provides support for non-ocular capillary bed abnormalities in uveitis, with interesting correlations based on disease stage and anatomical classification.


Assuntos
Capilares/diagnóstico por imagem , Microcirculação/fisiologia , Unhas/irrigação sanguínea , Uveíte/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Estudos Transversais , Feminino , Seguimentos , Humanos , Masculino , Angioscopia Microscópica , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Índice de Gravidade de Doença , Uveíte/fisiopatologia , Adulto Jovem
6.
Chin Med J (Engl) ; 131(15): 1819-1826, 2018 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-30058579

RESUMO

Background: Currently, spectral-domain optical coherence tomography (SD-OCT) appears to be a new type of glaucoma diagnostic tool. Thus, this study aimed to evaluate the effectiveness of glaucoma diagnostic parameters from SD-OCT of patients with different severities of myopia. Methods: This was a cross-sectional study. A total of 248 participants (248 eyes) were enrolled, including 51 cases in the early primary open-angle glaucoma group, 79 cases in the control group (0.50 D to -0.50 D, excluding -0.50 D), 47 cases in the low-myopic group (-0.50 to -3.00 D, excluding -3.00 D), 43 cases in the moderate-myopic group (-3.00 to -6.00 D, excluding -6.00 D), and 28 cases in the high-myopic group (≤-6.00 D). All participants were examined using the Humphrey visual field test and SD-OCT. The SD-OCT parameters of the retinal nerve fiber layer (RNFL) and ganglion cell complex were analyzed statistically using the receiver operating characteristic curve and area under the curve (AUC). Results: The AUC showed that the best parameters for the control and low-myopic groups were the inferior and inferior temporal RNFL thicknesses (AUC >0.94), respectively; for the moderate- and high-myopic groups, the best parameter was the temporal low RNFL thickness (AUC, 0.926 and 0.896, respectively). The AUC of the inferior parameters of the moderate-myopic group (0.864) was lower, ranked 15th among all RNFL parameters. When the sensitivity was fixed at 85%, the specificity of the inferior, superior, inferior temporal, and superior temporal quadrants was higher (>80%) in the control and low-myopic groups, while they were lower (20-60%) for the moderate- and high-myopia groups. The green color based on the OCT database was also less for the high-myopic group compared with that of other groups (P < 0.05). Conclusions: Glaucoma diagnostic parameters from SD-OCT were not clinically effective for the moderate- and high-myopic groups. The specificities were low. The moderate- and high-myopic groups require comprehensive analyses for the diagnoses of glaucoma. The SD-OCT database should be improved to better indicate the level of myopia based on the corresponding diopter readings.


Assuntos
Glaucoma/diagnóstico por imagem , Tomografia de Coerência Óptica , Idoso , Estudos de Casos e Controles , Estudos Transversais , Feminino , Glaucoma de Ângulo Aberto , Humanos , Masculino , Pessoa de Meia-Idade , Fibras Nervosas , Disco Óptico , Curva ROC , Células Ganglionares da Retina , Campos Visuais
7.
Adv Mater ; 30(3)2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29210216

RESUMO

Because of the rapid rise of the efficiency, perovskite solar cells are currently considered as the most promising next-generation photovoltaic technology. Much effort has been made to improve the efficiency and stability of perovskite solar cells. Here, it is demonstrated that the addition of a novel organic cation of 2-(6-bromo-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)ethan-1-ammonium iodide (2-NAM), which has strong Lewis acid and base interaction (between CO and Pb) with perovskite, can effectively increase crystalline grain size and reduce charge carrier recombination of the double cation FA0.83 MA0.17 PbI2.51 Br0.49 perovskite film, thus boosting the efficiency from 17.1 ± 0.8% to 18.6 ± 0.9% for the 0.1 cm2 cell and from 15.5 ± 0.5% to 16.5 ± 0.6% for the 1.0 cm2 cell. The champion cell shows efficiencies of 20.0% and 17.6% with active areas of 0.1 and 1.0 cm2 , respectively. Moreover, the hysteresis behavior is suppressed and the stability is improved. The result provides a promising route to further elevate efficiency and stability of perovskite solar cells by the fine tuning of triple organic cations.

8.
Chem Sci ; 7(7): 4582-4588, 2016 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30155105

RESUMO

A novel bistable molecular shuttle, composed of a Pt(ii) porphyrin-containing dibenzo[24]crown-8 macrocycle threaded onto two different recognition sites (secondary dialkylammonium (NH2+) and 4,4'-bipyridinium (Bpym2+) units), and the anthracene (Anth) moiety as one terminal stopper, was synthesized by click chemistry. Its acid-base switchable shuttling could be addressed by both the room temperature phosphorescence (RTP) emission signals of the Pt(ii) porphyrin moiety and the fluorescence emission of the Anth unit, as well as their lifetime changes. When the macrocycle was switched to be located on the NH2+ site close to Anth, the Pt(ii) porphyrin moiety exhibited strong RTP emission, excited in the Anth band at 370 nm. This was due to the distance-dependent efficient singlet energy transfer between the Anth unit and the porphyrin moiety, followed by intersystem crossing from a singlet to a triplet state in Pt(ii) porphyrin, while its RTP emission dramatically decreased when located on the Bpym2+ site far from the Anth unit. When excited in the porphyrin band at 402 nm, the RTP emission lifetimes changed obviously. This is the first rotaxane-type molecular shuttle whose shuttling has been encoded by RTP signals.

9.
Langmuir ; 31(51): 13647-54, 2015 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-26639514

RESUMO

An unexpected lower critical solution temperature (LCST) phenomenon is observed in a bis-p-sulfonatocalix[4]arene-based supramolecular amphiphile system, and the mechanism of this intriguing phenomenon is studied. The unusual macroscopic thermoresponsive behavior is based on the switch of the system from water-soluble assemblies to insoluble netlike cross-linked nanoparticles under temperature stimulus, which is regulated by multiple weak interactions, including hydrophilic and hydrophobic interactions, π-π stacking, and host-guest recognition. By using the LCST solution as the dispersion medium, a hydrogel with LCST behavior can be fabricated. This work contributes toward better understanding about calixarene-induced aggregation (CIA) and thermoresponsive self-assembled systems. It will also help to enrich the designing of complexed supramolecular amphiphile systems and develop their potential applications in hydrogels.

10.
Chem Asian J ; 10(11): 2352-5, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26211904

RESUMO

A hybrid supramolecular polymeric hydrogel is conveniently constructed via host-guest interaction of a host cyclodextrin polymer (poly-CD) with a guest α-bromonaphthalene polymer (poly-BrNp) and mixing with 6-thio-ß-cyclodextrin (ß-SH-CD) modified gold nanoparticles (GPCDs) in aqueous solution. According to the dynamic oscillatory data, the hydrogel exhibits markedly enhanced stiffness compared with the GPCD-free one (both G' and G" values are almost twice as high as those of the original GPCD-free hydrogel) due to the introduction of the inorganic gold nanoparticles. This hybrid supramolecular polymeric hydrogel has a rapid and excellent self-healing property (only about 1 min, and the G' and G" of the self-healed hydrogel almost turned back to their original levels after 1 hour) in air (without adding any solvent or additive).

11.
Chem Commun (Camb) ; 51(14): 2890-2, 2015 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-25582698

RESUMO

A new host was prepared for the first time from propanediurea-formaldehyde condensation. is soluble in both water and common organic solvents, and binds protonated amines in a 1 : 2 stoichiometry in H2O with the K1 and K2 values on the order of 10(3) M(-1). The self-assembly of with 1,4-xylylene diamine dihydrochloride results in the formation of a linear supramolecular polymer.

12.
Chem Commun (Camb) ; 51(7): 1202-5, 2015 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-25407997

RESUMO

The self-assembly process from a 1 : 1 to a 1 : 2 complex, facilitated by para-sulfonatocalix[6]arenes (SC6) as host and methyl viologen (MV(2+)) as guest, was analyzed at the single-molecule level through an α-hemolysin nanopore. Especially, the assembled complex structures were discriminated in real time in the mixture of SC6 and MV(2+).


Assuntos
Calixarenos/química , Paraquat/química , Proteínas de Escherichia coli/química , Proteínas Hemolisinas/química , Nanoporos
13.
Chem Commun (Camb) ; 50(54): 7166-8, 2014 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-24853232

RESUMO

A photochromic supramolecular polymer based on bis-p-sulfonatocalix[4]arene recognition with a dithienylethene derivative in aqueous solution was fabricated. The resultant polymer showed good photochromic behaviour with obvious colour switching and a morphology change under alternative UV/Vis light stimuli.

14.
Chem Commun (Camb) ; 50(13): 1567-9, 2014 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-24382583

RESUMO

The multistate micro-morphology of aggregates in aqueous solution can be manipulated by host-guest interactions between bis-sulfonatocalix[4]arene, γ-CD and a ditopic guest possessing viologen and coumarin moieties.


Assuntos
Calixarenos/química , Fenóis/química , gama-Ciclodextrinas/química , Cumarínicos/química , Modelos Moleculares , Transição de Fase , Viologênios/química , Água/química
15.
Sci Rep ; 3: 1662, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23588705

RESUMO

The open-close states of the ion channels in a living system are regulated by multiple stimuli such as ligand, pH, potential and light. Functionalizing natural channels by using synthetic chemistry would provide biological nanopores with novel properties and applications. Here we use para-sulfonato-calix[4]arene-based host-guest supramolecular system to develop artificial gating mechanisms aiming at regulating wild-type α-HL commanded by both ligand and light stimuli. Using the gating property of α-hemolysin, we studied the host-guest interactions between para-sulfonato-calix[4]arene and 4, 4'-dipyridinium-azobenzene at the single-molecule level. Subsequently, we have extended the application of this gating system to the real-time study of light-induced molecular shuttle based on para-sulfonato-calix[4]arene and 4, 4'-dipyridinium-azobenzene at the single-molecule level. These experiments provide a more efficient method to develop a general tool to analyze the individual motions of supramolecular systems by using commercially available α-HL nanopores.


Assuntos
Nanopartículas/química , Nanopartículas/efeitos da radiação , Estimulação Luminosa/métodos , Luz , Teste de Materiais , Porosidade/efeitos da radiação
16.
FEBS Lett ; 584(16): 3525-32, 2010 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-20643132

RESUMO

SGs are mRNA containing cytoplasmic structures that are assembled in response to stress. Tudor-SN protein is a ubiquitously expressed protein. Here, Tudor-SN protein was found to physiologically interact with G3BP, which is the marker and effector of SG. The kinetics of the assembly of SGs in the living cells demonstrated that Tudor-SN co-localizes with G3BP and is recruited to the same SGs in response to different stress stimuli. Knockdown of endogenous Tudor-SN did not inhibit the formation of SGs, but retarded the aggregation of small SGs into large SGs. Thus Tudor-SN may not be an initiator as essential as G3BP for the formation of SGs, but affects the aggregation of SGs. These findings identify Tudor-SN as a novel component of SGs.


Assuntos
Proteínas de Transporte/metabolismo , Grânulos Citoplasmáticos/metabolismo , Proteínas Nucleares/metabolismo , Animais , Células COS , Proteínas de Transporte/genética , DNA Helicases , Endonucleases , Técnicas de Silenciamento de Genes , Células HeLa , Humanos , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Proteínas de Ligação a Poli-ADP-Ribose , Mapeamento de Interação de Proteínas , RNA Helicases , Proteínas com Motivo de Reconhecimento de RNA , RNA Interferente Pequeno/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Estresse Fisiológico
17.
Anat Rec (Hoboken) ; 293(6): 1010-6, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20225206

RESUMO

The family of STAT proteins consists of seven members that mediate highly specific functions in cytokine signaling. STAT6 is a critical regulator of transcription for interleukin-4 (IL-4)-induced genes. Activation of gene expression involves recruitment of coactivator proteins that function as bridging factors connecting sequence-specific transcription factors to the basal transcription machinery, and as chromatin-modifying enzymes. In this report, we show that the coacitivator p100 protein can interact with STAT6 through its SN domain both in vivo and in vitro, resulting in enhancement of STAT6-mediated gene transcriptional acitivation. Consistent with our previous reports, we identified intracellular localization of p100 and STAT-6 by confocal microscopy examined in response to IL-4. Moreover, in consideration of STAT molecules sharing significant homology in structure and function, we detected whether p100 can associate with STAT-1. In conclusion, this study found no evidence that p100 functions as a transcriptional coactivator for STAT1-dependent gene regulation.


Assuntos
Proteínas Nucleares/metabolismo , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT6/genética , Transcrição Genética/genética , Ativação Transcricional/genética , Animais , Células COS , Endonucleases , Células HeLa , Humanos , Interleucina-4/metabolismo , Interleucina-4/farmacologia , Microscopia Confocal , Proteínas Nucleares/química , Proteínas Nucleares/genética , Estrutura Terciária de Proteína/genética , Fator de Transcrição STAT1/metabolismo , Fator de Transcrição STAT6/metabolismo , Transdução de Sinais/genética
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