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1.
Nucleic Acids Res ; 51(2): 619-630, 2023 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-36546827

RESUMO

Jasmonic acid (JA) signaling plays a pivotal role in plant development and defense. MYC2 is a master transcription factor in JA signaling, and was found to be phosphorylated and negatively regulated by MAP kinase and receptor-like kinase. However, the kinases that positively regulate MYC2 through phosphorylation and promote MYC2-mediated activation of JA response have not been identified. Here, we identified CK2 as a kinase that phosphorylates MYC2 and thus regulates the JA signaling. CK2 holoenzyme can interact with MYC2 using its regulatory subunits and phosphorylate MYC2 at multiple sites with its catalytic subunits. Inhibition of CK2 activity in a dominant-negative plant line, CK2mut, repressed JA response. On the other hand, increasing CK2 activity by overexpression of CKB4, a regulatory subunit gene of CK2, enhanced JA response in a MYC2-dependent manner. Substitution of the Ser and Thr residues at phosphorylation sites of MYC2 by CK2 with Ala impaired MYC2 function in activating JA response. Further investigations evidenced that CK2 facilitated the JA-induced increase of MYC2 binding to the promoters of JA-responsive genes in vivo. Our study demonstrated that CK2 plays a positive role in JA signaling, and reveals a previously undiscovered mechanism that regulates MYC2 function.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Caseína Quinase II , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Ciclopentanos/metabolismo , Regulação da Expressão Gênica de Plantas , Fosfotransferases/genética , Caseína Quinase II/metabolismo
2.
Plant Cell Rep ; 41(4): 833-852, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34773487

RESUMO

The 14-3-3 proteins widely exist in almost all plant species. They specifically recognize and interact with phosphorylated target proteins, including protein kinases, phosphatases, transcription factors and functional proteins, offering an array of opportunities for 14-3-3s to participate in the signal transduction processes. 14-3-3s are multigene families and can form homo- and heterodimers, which confer functional specificity of 14-3-3 proteins. They are widely involved in regulating biochemical and cellular processes and plant growth and development, including cell elongation and division, seed germination, vegetative and reproductive growth, and seed dormancy. They mediate plant response to environmental stresses such as salt, alkaline, osmotic, drought, cold and other abiotic stresses, partially via hormone-related signalling pathways. Although many studies have reviewed the function of 14-3-3 proteins, recent research on plant 14-3-3s has achieved significant advances. Here, we provide a comprehensive overview of the fundamental properties of 14-3-3 proteins and systematically summarize and dissect the emerging advances in understanding the roles of 14-3-3s in plant growth and development and abiotic stress responses. Some ambiguous questions about the roles of 14-3-3s under environmental stresses are reviewed. Interesting questions related to plant 14-3-3 functions that remain to be elucidated are also discussed.


Assuntos
Proteínas 14-3-3 , Estresse Fisiológico , Proteínas 14-3-3/genética , Proteínas 14-3-3/metabolismo , Secas , Regulação da Expressão Gênica de Plantas , Desenvolvimento Vegetal , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas/genética , Plantas/metabolismo
3.
Int J Mol Sci ; 23(18)2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36142587

RESUMO

Cynomorium songaricum is a perennial parasitic herb, and its stem is widely used as a traditional Chinese medicine, which largely relies on bioactive compounds (e.g., polysaccharides, flavonoids, and triterpenes). To date, although the optimum harvest time of stems has been demonstrated at the unearthed stage (namely the early flowering stage, EFS), the accumulation mechanism of polysaccharides and flavonoids during growth stages is still limited. In this study, the physiological characteristics (stem fresh weight, contents of soluble sugar and flavonoids, and antioxidant capacity) at four different growth stages (germination stage (GS), vegetative growth stage (VGS), EFS, and flowering stage (FS)) were determined, transcriptomics were analyzed by illumina sequencing, and expression levels of key genes were validated by qRT-PCR at the GS, VGS, and EFS. The results show that the stem biomass, soluble sugar and total flavonoids contents, and antioxidant capacity peaked at EFS compared with GS, VGS, and FS. A total of 6098 and 13,023 differentially expressed genes (DEGs) were observed at VGS and EFS vs. GS, respectively, with 367 genes co-expressed. Based on their biological functions, 109 genes were directly involved in polysaccharide and flavonoid biosynthesis as well as growth and development. The expression levels of key genes involved in polysaccharides (e.g., GLCs, XTHs and PMEs), flavonoids (e.g., 4CLLs, CYPs and UGTs), growth and development (e.g., AC58, TCPs and AP1), hormones biosynthesis and signaling (e.g., YUC8, AIPT and ACO1), and transcription factors (e.g., MYBs, bHLHs and WRKYs) were in accordance with changes of physiological characteristics. The combinational analysis of metabolites with transcriptomics provides insight into the mechanism of polysaccharide and flavonoid biosynthesis in C. songaricum during growth stages.


Assuntos
Cynomorium , Triterpenos , Antioxidantes/metabolismo , Cynomorium/genética , Cynomorium/metabolismo , Flavonoides , Hormônios , Polissacarídeos , Açúcares , Fatores de Transcrição , Transcriptoma
4.
Molecules ; 26(23)2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34885931

RESUMO

G-quadruplexes can bind with hemin to form peroxidase-like DNAzymes that are widely used in the design of biosensors. However, the catalytic activity of G-quadruplex/hemin DNAzyme is relatively low compared with natural peroxidase, which hampers its sensitivity and, thus, its application in the detection of nucleic acids. In this study, we developed a high-sensitivity biosensor targeting norovirus nucleic acids through rationally introducing a dimeric G-quadruplex structure into the DNAzyme. In this strategy, two separate molecular beacons each having a G-quadruplex-forming sequence embedded in the stem structure are brought together through hybridization with a target DNA strand, and thus forms a three-way junction architecture and allows a dimeric G-quadruplex to form, which, upon binding with hemin, has a synergistic enhancement of catalytic activities. This provides a high-sensitivity colorimetric readout by the catalyzing H2O2-mediated oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline -6-sulfonic acid) diammonium salt (ABTS). Up to 10 nM of target DNA can be detected through colorimetric observation with the naked eye using our strategy. Hence, our approach provides a non-amplifying, non-labeling, simple-operating, cost-effective colorimetric biosensing method for target nucleic acids, such as norovirus-conserved sequence detection, and highlights the further implication of higher-order multimerized G-quadruplex structures in the design of high-sensitivity biosensors.


Assuntos
Técnicas Biossensoriais/instrumentação , DNA Catalítico/química , Quadruplex G , Hemina/química , Norovirus/isolamento & purificação , Infecções por Caliciviridae/virologia , Colorimetria/instrumentação , Desenho de Equipamento , Humanos
5.
Molecules ; 27(1)2021 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-35011276

RESUMO

Cynomorium songaricum is a root holoparasitic herb that is mainly hosted in the roots of Nitraria roborowskii and Nitraria sibirica distributed in the arid desert and saline-alkaline regions. The stem of C. songaricum is widely used as a traditional Chinese medicine and applied in anti-viral, anti-obesity and anti-diabetes, which largely rely on the bioactive components including: polysaccharides, flavonoids and triterpenes. Although the differences in growth characteristics of C. songaricum between N. roborowskii and N. sibirica have been reported, the difference of the two hosts on growth and polysaccharides biosynthesis in C. songaricum as well as regulation mechanism are not limited. Here, the physiological characteristics and transcriptome of C. songaricum host in N. roborowskii (CR) and N. sibirica (CS) were conducted. The results showed that the fresh weight, soluble sugar content and antioxidant capacity on a per stem basis exhibited a 3.3-, 3.0- and 2.1-fold increase in CR compared to CS. A total of 16,921 differentially expressed genes (DEGs) were observed in CR versus CS, with 2573 characterized genes, 1725 up-regulated and 848 down-regulated. Based on biological functions, 50 DEGs were associated with polysaccharides and starch metabolism as well as their transport. The expression levels of the selected 37 genes were validated by qRT-PCR and almost consistent with their Reads Per kb per Million values. These findings would provide useful references for improving the yield and quality of C. songaricum.


Assuntos
Cynomorium/fisiologia , Polissacarídeos/biossíntese , Transcriptoma , Antioxidantes/metabolismo , Transporte Biológico , Metabolismo dos Carboidratos , Perfilação da Expressão Gênica , Amido/metabolismo , Açúcares/metabolismo
6.
Molecules ; 22(11)2017 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-29149016

RESUMO

Five new oleanane-type saponins, named ligushicosides A-E, and three known oleanane-type saponins were isolated from the roots of Ligulariopsis shichuana. Their structures were established by a combination of spectroscopic techniques, including 1D and 2D NMR and high resolution electrospray ionization mass spectroscopy (HR-ESI-MS). Furthermore, all isolates were evaluated for their yeast α-glucosidase inhibitory effects and exhibited potent inhibition against α-glucosidase, while compounds 1 and 2 showed excellent inhibitory activities. The 3-O-glycoside moiety in oleanane-type saponin is important for the α-glucosidase inhibitory effects.


Assuntos
Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Raízes de Plantas/química , Saponinas/química , Saponinas/farmacologia , Ativação Enzimática/efeitos dos fármacos , Hidrólise , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Relação Estrutura-Atividade , alfa-Glucosidases/química
7.
Tumour Biol ; 37(7): 9483-91, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26790436

RESUMO

MicroRNA (miR)-92 expression is often aberrant in human cancers. However, its expression in gastric carcinoma and its relation to clinicopathological features and prognosis are unclear.Tissue microarrays were constructed from 180 patients with gastric cancer (GC), who were undergoing radical resection. MiR-92a expression was detected using miRNA-locked nucleic acid in situ hybridization, and its correlation with clinicopathological features and overall survival was analyzed. MiR-92a expression was decreased in 13.9 % (25/180) of GC, increased in 81.1 % (146/180), and unchanged in 5.0 % (9/180), compared with paracancerous normal tissue (P < 0.001). Univariate analysis showed that high miR-92a expression, tumor stage, tumor status, node status, and tumor size were significant negative prognostic predictors for overall survival in patients with GC (P < 0.001, P < 0.001, P = 0.008, P < 0.001, and P = 0.001, respectively). High miR-92a expression still remained a significant predictor of shorter survival in stage II (n = 56, P = 0.001) and stage III (n = 92, P = 0.009) GC. Multivariate regression analysis demonstrated that tumor status (hazard ratio [HR], 3.10; 95 % confidence interval [CI], 1.51-6.37; P = 0.002), stage (HR, 3.54; 95 % CI, 1.65-7.63; P = 0.000), lymph node metastasis (HR, 2.83; 95 % CI, 1.88-4.28; P = 0.000), high expression of miR-92a (HR, 2.94; 95 % CI, 2.01-4.31; P = 0.000), and tumor size (HR, 2.34; 95 % CI, 1.45-3.79; P = 0.002) predicted shorter OS.High expression of miR-92a compared with adjacent normal tissues was associated with shorter OS. MiR-92a may thus be useful for evaluating prognosis and may provide a novel treatment target in patients with GC.


Assuntos
Adenocarcinoma/secundário , Biomarcadores Tumorais/genética , MicroRNAs/genética , Neoplasias Gástricas/patologia , Adenocarcinoma/genética , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Hibridização In Situ , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Oligonucleotídeos , Prognóstico , Estudos Retrospectivos , Neoplasias Gástricas/genética , Taxa de Sobrevida
8.
Plant Cell Rep ; 35(5): 1071-80, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26883224

RESUMO

KEY MESSAGE: Arabidopsis CK2 α4 subunit regulates the primary root and hypocotyl elongation, lateral root formation, cotyledon expansion, rosette leaf initiation and growth, flowering, and anthocyanin biosynthesis. Casein kinase 2 (CK2) is a conserved tetrameric kinase composed of two α and two ß subunits. The inhibition of CK2 activity usually results in severe developmental deficiency. Four genes (CKA1-CKA4) encode CK2 α subunit in Arabidopsis. Single mutations of CKA1, CKA2, and CKA3 do not affect the normal growth of Arabidopsis, while the cka1 cka2 cka3 triple mutants are defective in cotyledon and hypocotyl growth, lateral root development, and flowering. The inhibition of CKA4 expression in cka1 cka2 cka3 background further reduces the number of lateral roots and delays the flowering time. Here, we report the characterization of a novel knockout mutant of CKA4, which exhibits various developmental defects including reduced primary root and hypocotyl elongation, increased lateral root density, delayed cotyledon expansion, retarded rosette leaf initiation and growth, and late flowering. The examination of the cellular basis for abnormal root development of this mutant revealed reduced root meristem cells with enhanced RETINOBLASTOMA-RELATED (RBR) expression that promotes cell differentiation in root meristem. Moreover, this cka4-2 mutant accumulates higher anthocyanin in the aerial part and shows an increased expression of anthocyanin biosynthetic genes, suggesting a novel role of CK2 in modulating anthocyanin biosynthesis. In addition, the complementation test using primary root elongation assay as a sample confirms that the changed phenotypes of this cka4-2 mutant are due to the lack of CKA4. Taken together, this study reveals an essential role of CK2 α4 subunit in multiple developmental processes in Arabidopsis.


Assuntos
Antocianinas/metabolismo , Arabidopsis/enzimologia , Caseína Quinase II/metabolismo , Regulação da Expressão Gênica de Plantas , Arabidopsis/citologia , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Caseína Quinase II/genética , Cotilédone/citologia , Cotilédone/enzimologia , Cotilédone/genética , Cotilédone/crescimento & desenvolvimento , Flores/citologia , Flores/enzimologia , Flores/genética , Flores/crescimento & desenvolvimento , Genes Reporter , Hipocótilo/citologia , Hipocótilo/enzimologia , Hipocótilo/genética , Hipocótilo/crescimento & desenvolvimento , Mutação , Fenótipo , Folhas de Planta/citologia , Folhas de Planta/enzimologia , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Raízes de Plantas/citologia , Raízes de Plantas/enzimologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Plântula/citologia , Plântula/enzimologia , Plântula/genética , Plântula/crescimento & desenvolvimento , Alinhamento de Sequência
9.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(3): 896-902, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27400545

RESUMO

Human telomeric G-quadruplex is a four-stranded structure folded by guanines (G) via Hoogsteen hydrogen bonding. The ligands which stabilize the G-quadruplex are often telomerase inhibitors and may become antitumor agents. Here, the interaction between a lignan derivative liliflorin A and human telomeric sequence dGGG (TTAGGG)3G-quadruplex HTG21 were examined by CD, FRET, and NMR spectroscopic methods. In addition, Molecular Docking was used to study the binding of liliflorin A to dTAGGG (TTAGGG)3 G-quadruplex HTG23. The CD data showed that liliflorin A enhanced HTG21 T(m). The T(m) value of G-quadruplex was enhanced 3.2 degrees C by 4.0 µmol x L(-1) liliflorin A in FRET. The NMR spectra of HTG21 showed vivid alteration after reacting with liliflorin A in 3 hours. Molecular Docking suggested liliflorin A bound to the wide groove of HTG23 at G9, G10, G16 and G17. Liliflorin A was the first lignan derivative that could stabilize HTG21 selectively and provided a new candidate for antitumor drug design targeting on human telomeric G-quadruplex.


Assuntos
Quadruplex G , Lignanas/química , Análise Espectral , Telômero/química , Antineoplásicos , Inibidores Enzimáticos , Guanina , Humanos , Ligação de Hidrogênio , Ligantes , Simulação de Acoplamento Molecular
10.
Plant Cell Physiol ; 56(4): 727-36, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25552473

RESUMO

Plants exhibit reduced root growth when exposed to low temperature; however, how low temperature modulates root growth remains to be understood. Our study demonstrated that low temperature reduces both meristem size and cell number, repressing the division potential of meristematic cells by reducing auxin accumulation, possibly through the repressed expression of PIN1/3/7 and auxin biosynthesis-related genes, although the experiments with exogenous auxin application also suggest the involvement of other factor(s). In addition, we verified that ARABIDOPSIS RESPONSE REGULATOR 1 (ARR1) and ARR12 are involved in low temperature-mediated inhibition of root growth by showing that the roots of arr1-3 arr12-1 seedlings were less sensitive than wild-type roots to low temperature, in terms of changes in root length and meristem cell number. Furthermore, low temperature reduced the levels of PIN1/3 transcripts and the auxin level to a lesser extent in arr1-3 arr12-1 roots than in wild-type roots, suggesting that cytokinin signaling is involved in the low-temperature-mediated reduction of auxin accumulation. Taken together, our data suggest that low temperature inhibits root growth by reducing auxin accumulation via ARR1/12.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Temperatura Baixa , Proteínas de Ligação a DNA/metabolismo , Ácidos Indolacéticos/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis/citologia , Proteínas de Arabidopsis/genética , Contagem de Células , Divisão Celular , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica de Plantas , Meristema/citologia , Meristema/crescimento & desenvolvimento , Meristema/metabolismo , Raízes de Plantas/citologia , Estresse Fisiológico , Fatores de Transcrição/genética
11.
Zhongguo Zhong Yao Za Zhi ; 40(16): 3229-32, 2015 Aug.
Artigo em Zh | MEDLINE | ID: mdl-26790298

RESUMO

Chemical constituents from the acetone extract of twigs of Manglietia hookeri were isolated and purified by various column chromatographic methods over silica gel and sephadex LH-20, and preparative TLC. The structures of these compounds were identified on the basis of physicochemical properties and spectral analysis, including NMR and MS spectra. Six eudesmane sesquiterpenes were obtained and their structures were identified as trans-eudesmane-4, 11-diol(1), ß-eudesmol(2), (-) -10-epi-5ß-hydroxy-ß-eudesmol (3), epi-carrisone (4), 6-hydroxy-eudesm-4(14) -ene(5) and gynurenol(6). All the compounds were isolated from this plant for the first time. Furthermore, the 13C-NMR data of compound 3 were reported for the first time.


Assuntos
Medicamentos de Ervas Chinesas/química , Magnolia/química , Sesquiterpenos de Eudesmano/química , Medicamentos de Ervas Chinesas/isolamento & purificação , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Caules de Planta/química , Sesquiterpenos de Eudesmano/isolamento & purificação , Espectrometria de Massas por Ionização por Electrospray
12.
Cardiology ; 128(2): 88-91, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24662733

RESUMO

OBJECTIVE: We have evaluated 106 pediatric cases of infective endocarditis (IE) to elucidate clinical manifestations and pathogenic microorganism profiling of IE in China. METHODS: Clinical features, complications, pathogenic microorganisms, diagnosis and treatment of pediatric IE were reviewed in two groups of patients with IE from the different periods of time (group A, 34 cases obtained in the period from 2000 to 2011 and group B, 72 cases obtained in the period from 1964 to 1999). RESULTS: A total of 106 pediatric patients with a definite diagnosis of IE based on the modified Duke criteria were enrolled and evaluated in this study. By comparing two groups of patients from different time periods, we found that the incidence of rheumatic heart disease was significantly reduced (from 19.4 to 5.9%), whereas congenital heart disease-associated IE had a tendency to increase (from 55.6 to 79.4%). Staphylococcus aureus was detected as the most common pathogenic microorganism, and its involvement tended to increase (from 32.0 to 58.5%), whereas the percentage of infections caused by Streptococcus viridans (8.0%) had not changed. It was interesting to note that the rate of vegetations detected was increased from 50.0 to 67.6% and the incidence of right-sided IE was also increased (from 35.0 to 60.9%). The most common valves involved in recent cases were tricuspid valves (increase from 30.0 to 47.8%), while mitral valve infection was reduced (from 60.0 to 39.1%). Penicillin was still the most commonly used antibiotic for the treatment of IE; the combination of penicillin plus cephalosporin has been recommended more and more recently. CONCLUSIONS: Comparing pediatric IE patients during the past 40 years, we found that the role of rheumatic heart disease as a predisposing factor is diminishing. Pediatric IE is still predominantly caused by staphylococci. The most commonly involved valves are tricuspid valves instead of mitral valves. Gram-positive bacteria showed an increased resistance to penicillin when used alone, and the use of combination treatment with antibiotics is increasing in the area.


Assuntos
Endocardite Bacteriana/epidemiologia , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Positivas/epidemiologia , Adolescente , Criança , Pré-Escolar , China/epidemiologia , Endocardite Bacteriana/complicações , Feminino , Infecções por Bactérias Gram-Negativas/complicações , Infecções por Bactérias Gram-Positivas/complicações , Humanos , Lactente , Masculino , Prognóstico , Estudos Retrospectivos , Cardiopatia Reumática/complicações , Cardiopatia Reumática/epidemiologia
13.
Elife ; 132024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39255019

RESUMO

Stem cell niche is critical for regulating the behavior of stem cells. Drosophila neural stem cells (Neuroblasts, NBs) are encased by glial niche cells closely, but it still remains unclear whether glial niche cells can regulate the self-renewal and differentiation of NBs. Here, we show that ferritin produced by glia, cooperates with Zip13 to transport iron into NBs for the energy production, which is essential to the self-renewal and proliferation of NBs. The knockdown of glial ferritin encoding genes causes energy shortage in NBs via downregulating aconitase activity and NAD+ level, which leads to the low proliferation and premature differentiation of NBs mediated by Prospero entering nuclei. More importantly, ferritin is a potential target for tumor suppression. In addition, the level of glial ferritin production is affected by the status of NBs, establishing a bicellular iron homeostasis. In this study, we demonstrate that glial cells are indispensable to maintain the self-renewal of NBs, unveiling a novel role of the NB glial niche during brain development.


Iron is an essential nutrient for almost all living organisms. For example, iron contributes to the replication of DNA, the generation of energy inside cells, and the transport of oxygen around the body. Iron deficiency is the most common of all nutrient deficiencies, affecting over 40% of children worldwide. This can lead to anemia and also impair how the brain and nervous system develop, potentially resulting in long-lasting cognitive damage, even after the deficiency has been treated. It is poorly understood how iron contributes to the development of the brain and nervous system. In particular, whether and how it supports nerve stem cells (or NSCs for short) which give rise to the various neural types in the mature brain. To investigate, Ma et al. experimentally reduced the levels of ferritin (a protein which stores iron) in the developing brains of fruit fly larvae. This reduction in ferritin led to lower numbers of NSCs and a smaller brain. Unexpectedly, this effect was largest when ferritin levels were reduced in glial cells which support and send signals to NSCs, rather than in the stem cells themselves. Ma et al. then used fluorescence microscopy to confirm that glial cells make and contain a lot of ferritin which can be transported to NSCs. Adding iron supplements to the diet of flies lacking ferritin did not lead to normal numbers of stem cells in the brains of the developing fruit flies, whereas adding compounds that reduce the amount of iron led to lower numbers of stem cells. Together, this suggests that ferritin transports iron from glial cells to the NSCs. Without ferritin and iron, the NSCs could not produce enough energy to divide and make new stem cells. This caused the NSCs to lose the characteristics of stem cells and prematurely turn into other types of neurons or glial cells. Together, these findings show that when iron cannot move from glial cells to NSCs this leads to defects in brain development. Future experiments will have to test whether a similar transport of iron from supporting cells to NSCs also occurs in the developing brains of mammals, and whether this mechanism applies to stem cells in other parts of the body.


Assuntos
Proteínas de Drosophila , Ferritinas , Ferro , Células-Tronco Neurais , Neuroglia , Animais , Células-Tronco Neurais/metabolismo , Neuroglia/metabolismo , Ferro/metabolismo , Ferritinas/metabolismo , Ferritinas/genética , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Drosophila/metabolismo , Proliferação de Células , Diferenciação Celular , Drosophila melanogaster/metabolismo , Drosophila melanogaster/genética , Autorrenovação Celular
14.
Int J Biol Macromol ; 256(Pt 2): 128233, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38040166

RESUMO

In this work, we report an environmentally friendly renewable nanocomposite magnetic lignin-based palladium nanoparticles (Fe3O4-lignin@Pd-NPs) for efficient wastewater treatment by decorating palladium nanoparticles without using any toxic reducing agents on the magnetic lignin abstracted from Poplar. The structure of composite Fe3O4-lignin@Pd-NPs was unambiguously confirmed by XRD, SEM, TEM, EDS, FTIR, and Zeta potential. After systematic evaluation of the use and efficiency of the composite to remove toxic organic dyes in wastewater, some promising results were observed as follows: Fe3O4-lignin@Pd-NPs exhibits highly active and efficient performance in the removal of toxic methylene blue (MB) (up to 99.8 %) wastewater in 2 min at different concentrations of MB and different pH values. Moreover, except for toxic MB, the other organic dyes including Rhodamine B (RhB), Rhodamine 6G (Rh6G), and Methyl Orange (MO) can also be removed efficiently by the composite. Finally, the easily recovered composite Fe3O4-lignin@Pd-NPs exhibits well stability and reusability, and catalytic efficiency is maintained well after ten cycles. In conclusion, the lignin-based magnetism Pd composite exhibits powerful potential practical application in industrial wastewater treatment.


Assuntos
Nanopartículas Metálicas , Nanocompostos , Purificação da Água , Lignina , Nanopartículas Metálicas/química , Paládio/química , Águas Residuárias , Corantes
15.
J Int Med Res ; 51(1): 3000605221148410, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36624979

RESUMO

POEMS syndrome is a rare, serious, multisystem disorder and its diagnosis is frequently missed due to its varied clinical presentation. We report here, a 69-year-old woman with initial complaints of distended abdomen, who was misdiagnosed with tuberculosis but failed anti-tuberculosis treatment. Further examinations showed peripheral neuropathy, monoclonal plasma cell disease, sclerotic bone lesions, an elevated serum vascular endothelial growth factor (VEGF) concentration, lymph node hyperplasia, endocrine abnormalities, and skin hyperpigmentation. A diagnosis of POEMS syndrome was made and the patient responded to lenalidomide-based chemotherapy.


Assuntos
Síndrome POEMS , Humanos , Idoso , Síndrome POEMS/complicações , Síndrome POEMS/diagnóstico , Síndrome POEMS/patologia , Fator A de Crescimento do Endotélio Vascular , Diagnóstico Diferencial , Abdome/diagnóstico por imagem , Abdome/patologia
16.
J Hazard Mater ; 456: 131689, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37245372

RESUMO

In this study, Fe2O3 nanoparticles (Fe2O3 NPs) and CaO NPs were loaded on the zeolite sphere carrier to create nano Fe-Ca bimetallic oxide (Fe-Ca-NBMO) modified substrate, which was introduced into constructed wetland (CW) to remove Cu(II) and Ni(II) via constructing "substrate-microorganism" system. Adsorption experiments showed that the equilibrium adsorption capacities of Fe-Ca-NBMO modified substrate for Cu(II) and Ni(II) were respectively 706.48 and 410.59 mg/kg at an initial concentration of 20 mg/L, 2.45 and 2.39 times of gravel. The Cu(II) and Ni(II) removal efficiencies in CW with Fe-Ca-NBMO modified substrate respectively reached 99.7% and 99.9% at an influent concentration of 100 mg/L, significantly higher than those in gravel-based CW (47.0% and 34.3%). Fe-Ca-NBMO modified substrate could promote Cu(II) and Ni(II) removal by increasing electrostatic adsorption, chemical precipitation, as well as the abundances of resistant microorganisms (Geobacter, Desulfuromonas, Zoogloea, Dechloromonas, and Desulfobacter) and functional genes (copA, cusABC, ABC.CD.P, gshB, and exbB). This study provided an effective method to enhance Cu(II) and Ni(II) removal of electroplating wastewater by CW with Fe-Ca-NBMO modified substrate.

17.
Planta Med ; 78(2): 141-7, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22025343

RESUMO

Six new lignans, 1- 6, along with six known compounds were obtained from the flower buds of Magnolia liliflora Desr. The new lignans were elucidated as (1 S*,2 R*,5 S*,6 S*)-2-(3,5-dimethoxyphenyl)-6-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (1), (1 R*,2 R*,5 R*,6 S*)-2-(3,5-dimethoxyphenyl)-6-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (2), (1 R*, 2 R*,5 R*,6 S*)-2,6-bis (3,5-dimethoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (3), (1 R*,2 S*,5 R*,6 R*)-2-(3,4-methylenedioxyphenyl)-6-(3,5-dimethoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane ( 4), (7' S*,8 R*,8' R*)-3,5'-dimethoxy-3',4,9'-trihydroxy-7',9-epoxy-8,8'-lignan (5), and (7' R*,8' S*)-3,3',4,5'-tetramethoxy-7-en-7',9-epoxy-8,8'-lignan (6), by the analysis of 1D and 2D-NMR as well as HRESIMS data. The capacity of compound 1 to protect against damages to the DNA of rat lymphocyte cells induced by UV irradiation was assessed by the comet assay. It showed stronger antigenotoxicity than ascorbic acid from 6×10(-3) mmol·L(-1) to 6×10(-6) mmol·L(-1).


Assuntos
Dano ao DNA , Flores/química , Lignanas/farmacologia , Linfócitos/efeitos dos fármacos , Magnolia/química , Extratos Vegetais/farmacologia , Animais , Lignanas/isolamento & purificação , Linfócitos/efeitos da radiação , Extratos Vegetais/química , Ratos
18.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 11): o3251, 2012 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23284548

RESUMO

The title compound, C(15)H(20)O(4), is a eudesmanolide isolated from the Chinese medicinal plant Carpesium tris-te Maxim. The mol-ecule contains three rings, viz. two fused six-membered rings in chair conformations and a five-membered ring in a flattened envelope conformation. In the crystal, two hy-droxy groups are involved in the formation of intra- and inter-molecular O-H⋯O hydrogen bonds. The H atoms in these groups are split, with site-occupation factors of 0.5. The inter-molecular hydrogen bonds link mol-ecules into chains propagating in [010].

19.
Artigo em Inglês | MEDLINE | ID: mdl-36231283

RESUMO

The entrepreneurship of college students is an important issue related to the harmony and sustainable development of society as a whole. At present, the existing research in the industry pays less attention to the influence mechanism of non-cognitive ability and social support perception on college students' entrepreneurial intention. Using 450 survey data, this paper examines the relationship between non-cognitive ability and college students' entrepreneurial intention in terms of five dimensions: openness, conscientiousness, extraversion, agreeableness, and emotional stability. At the same time, it focuses on the role of social environmental factors, namely, social support perception in the relationship between the non-cognitive ability and entrepreneurial intention, and explores the influence path. The results show that openness, conscientiousness, extroversion, and emotional stability have significant positive effects on entrepreneurial intention; agreeableness has no significant effect on entrepreneurial intention; openness, conscientiousness, extraversion, agreeableness, and emotional stability have significant positive effects on social support perception. The mediating effect of social support perception is as follows-it is part of the intermediary effect between openness, conscientiousness, extraversion, and emotional stability on entrepreneurial intention; within the influence of agreeableness on entrepreneurial intention, it plays a complete intermediary role. This paper enriches the research results on the impact of non-cognitive ability on entrepreneurial intention, reveals the intermediary effect of social support perception on the impact of non-cognitive ability on college students' entrepreneurial intention, and broadens the field of vision for the study of college students' entrepreneurial intention. The research results can provide a decision-making reference for the promotion of the entrepreneurial intention of college students, alleviating the employment pressure of college graduates in China and promoting sustainable economic development.


Assuntos
Intenção , Estudantes , Empreendedorismo , Humanos , Percepção Social , Apoio Social , Estudantes/psicologia
20.
Org Lett ; 24(45): 8283-8288, 2022 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-36331137

RESUMO

In this work, we successfully explored an unexpected dehydrogenation triggered by Pd/Cu-catalyzed C(sp3)-H arylation and intramolecular C-N coupling of amides to synthesize the bioactive 1,2-dihydroquinoline scaffold with good regioselectivity and good compatibility of functional groups. This strategy provides an alternative route to realize molecular complexity and diversity from simple and readily available molecules via multiple C-H bond activation. Preliminary mechanistic studies demonstrated that ß,γ-dehydrogenation is triggered by the arylation of the C(sp3)-H bond and the intramolecular C-N coupling.


Assuntos
Amidas , Paládio , Amidas/química , Paládio/química , Catálise , Estrutura Molecular
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