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1.
Mol Cell ; 69(1): 100-112.e6, 2018 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-29290610

RESUMO

As sessile organisms, plants must adapt to variations in the environment. Environmental stress triggers various responses, including growth inhibition, mediated by the plant hormone abscisic acid (ABA). The mechanisms that integrate stress responses with growth are poorly understood. Here, we discovered that the Target of Rapamycin (TOR) kinase phosphorylates PYL ABA receptors at a conserved serine residue to prevent activation of the stress response in unstressed plants. This phosphorylation disrupts PYL association with ABA and with PP2C phosphatase effectors, leading to inactivation of SnRK2 kinases. Under stress, ABA-activated SnRK2s phosphorylate Raptor, a component of the TOR complex, triggering TOR complex dissociation and inhibition. Thus, TOR signaling represses ABA signaling and stress responses in unstressed conditions, whereas ABA signaling represses TOR signaling and growth during times of stress. Plants utilize this conserved phospho-regulatory feedback mechanism to optimize the balance of growth and stress responses.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Receptores de Superfície Celular/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases/metabolismo , Proteína Regulatória Associada a mTOR/metabolismo , Transdução de Sinais , Estresse Fisiológico
2.
Mol Cell Proteomics ; : 100804, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38901673

RESUMO

Osmotic stress significantly hampers plant growth and crop yields, emphasizing the need for a thorough comprehension of the underlying molecular responses. Previous research has demonstrated that osmotic stress rapidly induces calcium influx and signaling, along with the activation of a specific subset of protein kinases, notably the Raf-SnRK2 kinase cascades within minutes. However, the intricate interplay between calcium signaling and the activation of RAF-SnRK2 kinase cascades remains elusive. Here in this study, we discovered that Raf-like protein (RAF) kinases undergo hyperphosphorylation in response to osmotic shocks. Intriguingly, treatment with the calcium chelator EGTA robustly activates RAF-SnRK2 cascades, mirroring the effects of osmotic treatment. Utilizing high-throughput DIA-based phosphoproteomics, we unveiled the global impact of EGTA on protein phosphorylation. Beyond the activation of RAFs and sucrose non-fermenting-1-related protein kinase 2s (SnRK2s), EGTA treatment also activates mitogen-activated protein kinase (MAPKs) cascades, Calcium-dependent protein kinases (CDPKs), and receptor-like protein kinases, etc. Through overlapping assays, we identified potential roles of mitogen-activated protein kinase kinase kinase kinases (MAP4Ks) and receptor-like protein kinases in the osmotic-stress-induced activation of RAF-SnRK2 cascades. Our findings illuminate the regulation of phosphorylation and cellular events by Ca2+ signaling, offering insights into the (exocellular) Ca2+ deprivation during early hyperosmolality sensing and signaling.

3.
Mol Cell Proteomics ; 21(12): 100441, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36379402

RESUMO

Hyperphosphorylation of the microtubule-associated protein Tau is a major hallmark of Alzheimer's disease and other tauopathies. Understanding the protein kinases that phosphorylate Tau is critical for the development of new drugs that target Tau phosphorylation. At present, the repertoire of the Tau kinases remains incomplete, and methods to uncover novel upstream protein kinases are still limited. Here, we apply our newly developed proteomic strategy, fluorescence complementation mass spectrometry, to identify novel kinase candidates of Tau. By constructing Tau- and kinase-fluorescent fragment library, we detected 59 Tau-associated kinases, including 23 known kinases of Tau and 36 novel candidate kinases. In the validation phase using in vitro phosphorylation, among 15 candidate kinases we attempted to purify and test, four candidate kinases, OXSR1 (oxidative-stress responsive gene 1), DAPK2 (death-associated protein kinase 2), CSK (C-terminal SRC kinase), and ZAP70 (zeta chain of T-cell receptor-associated protein kinase 70), displayed the ability to phosphorylate Tau in time-course experiments. Furthermore, coexpression of these four kinases along with Tau increased the phosphorylation of Tau in human neuroglioma H4 cells. We demonstrate that fluorescence complementation mass spectrometry is a powerful proteomic strategy to systematically identify potential kinases that can phosphorylate Tau in cells. Our discovery of new candidate kinases of Tau can present new opportunities for developing Alzheimer's disease therapeutic strategies.


Assuntos
Doença de Alzheimer , Humanos , Doença de Alzheimer/metabolismo , Proteômica , Proteínas tau/genética , Fosforilação , Espectrometria de Massas , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo
4.
J Biol Chem ; 298(3): 101644, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35093383

RESUMO

Endocrine-therapy-resistant estrogen receptor-positive (ER+) breast cancer cells often exhibit an augmented capacity to maintain endoplasmic reticulum (EnR) homeostasis under adverse conditions. Oncoprotein hepatitis B X-interacting protein (HBXIP) is a known transcriptional coactivator that promotes cancer development. However, it is unclear whether HBXIP participates in maintaining EnR homeostasis and promoting drug resistance in ER+ breast cancer. Here, we report that tamoxifen-resistant (TmaR) breast cancer cells exhibit increased expression of HBXIP, which acts as an inactivator of the unfolded protein response (UPR) to diminish tamoxifen-induced EnR stress. We show that HBXIP deficiency promotes EnR-associated degradation, enhances UPR-element reporter activity and cellular oxidative stress, and ultimately attenuates the growth of TmaR cells in vitro and in vivo. Mechanistically, we demonstrate that HBXIP acts as a chaperone of UPR transducer inositol-requiring enzyme 1a and diminishes production of reactive oxygen species (ROS) in TamR breast cancer cells. Upon loss of HBXIP expression, tamoxifen treatment hyperactivates IRE1α and its downstream proapoptotic pathways and simultaneously induces accumulation of intracellular ROS. This elevated ROS programmatically activates the other two branches of the UPR, mediated by PKR-like ER kinase and activating transcription factor 6α. Clinical investigations and Kaplan-Meier plotter analysis revealed that HBXIP is highly expressed in TamR breast cancer tissues. Furthermore, reinforced HBXIP expression is associated with a high recurrence and poor relapse-free survival rates in tamoxifen monotherapy ER+ breast cancer patients. These findings indicate that HBXIP is a regulator of EnR homeostasis and a potential target for TamR breast cancer therapy.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Neoplasias da Mama , Tamoxifeno , Resposta a Proteínas não Dobradas , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Resistencia a Medicamentos Antineoplásicos , Retículo Endoplasmático , Endorribonucleases/metabolismo , Feminino , Humanos , Recidiva Local de Neoplasia , Proteínas Serina-Treonina Quinases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptores de Estrogênio/metabolismo , Tamoxifeno/farmacologia
5.
J Cardiovasc Pharmacol ; 82(5): 407-418, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37657070

RESUMO

ABSTRACT: Chronic alcohol intake contributes to high mortality rates due to ethanol-induced cardiac hypertrophy and contractile dysfunction, which are accompanied by increased oxidative stress and disrupted mitophagy. Alpha-lipoic acid (α-LA), a well-known antioxidant, has been shown to protect against cardiac hypertrophy and inflammation. However, little is known about its role and mechanism in the treatment of alcoholic cardiomyopathy. Here, we evaluated the role of α-LA in alcohol-induced cardiac damage by feeding mice a 4.8% (v/v) alcohol diet with or without α-LA for 6 w. Our results suggested that chronic alcohol consumption increased mortality, blood alcohol concentrations, and serum aldehyde levels, but a-LA attenuated the elevations in mortality and aldehydes. Chronic alcohol intake also induced cardiac dysfunction, including enlarged left ventricles, reduced left ventricular ejection fraction, enhanced cardiomyocyte size, and increased serum levels of brain natriuretic peptide, lactate dehydrogenase, and creatine kinase myocardial isoenzyme. Moreover, alcohol intake led to the accumulation of collagen fiber and mitochondrial dysfunction, the effects of which were alleviated by α-LA. In addition, α-LA intake also prevented the increase in reactive oxygen species production and the decrease in mitochondrial number that were observed after alcohol consumption. Chronic alcohol exposure activated PINK1/Parkin-mediated mitophagy. These effects were diminished by α-LA intake by the activation of aldehyde dehydrogenase 2. Our data indicated that α-LA helps protect cardiac cells against the effects of chronic alcohol intake, likely by inhibiting PINK1/Parkin-related mitophagy through the activation of aldehyde dehydrogenase 2.


Assuntos
Alcoolismo , Ácido Tióctico , Camundongos , Animais , Ácido Tióctico/farmacologia , Aldeído-Desidrogenase Mitocondrial/metabolismo , Alcoolismo/metabolismo , Volume Sistólico , Função Ventricular Esquerda , Miócitos Cardíacos , Etanol/toxicidade , Consumo de Bebidas Alcoólicas/efeitos adversos , Consumo de Bebidas Alcoólicas/metabolismo , Aldeídos/metabolismo , Aldeídos/farmacologia , Proteínas Quinases/metabolismo , Cardiomegalia/metabolismo , Aldeído Desidrogenase/metabolismo , Aldeído Desidrogenase/farmacologia
6.
Proc Natl Acad Sci U S A ; 117(6): 3270-3280, 2020 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-31992638

RESUMO

Protein kinases are major regulatory components in almost all cellular processes in eukaryotic cells. By adding phosphate groups, protein kinases regulate the activity, localization, protein-protein interactions, and other features of their target proteins. It is known that protein kinases are central components in plant responses to environmental stresses such as drought, high salinity, cold, and pathogen attack. However, only a few targets of these protein kinases have been identified. Moreover, how these protein kinases regulate downstream biological processes and mediate stress responses is still largely unknown. In this study, we introduce a strategy based on isotope-labeled in vitro phosphorylation reactions using in vivo phosphorylated peptides as substrate pools and apply this strategy to identify putative substrates of nine protein kinases that function in plant abiotic and biotic stress responses. As a result, we identified more than 5,000 putative target sites of osmotic stress-activated SnRK2.4 and SnRK2.6, abscisic acid-activated protein kinases SnRK2.6 and casein kinase 1-like 2 (CKL2), elicitor-activated protein kinase CDPK11 and MPK6, cold-activated protein kinase MPK6, H2O2-activated protein kinase OXI1 and MPK6, and salt-induced protein kinase SOS1 and MPK6, as well as the low-potassium-activated protein kinase CIPK23. These results provide comprehensive information on the role of these protein kinases in the control of cellular activities and could be a valuable resource for further studies on the mechanisms underlying plant responses to environmental stresses.


Assuntos
Proteínas de Arabidopsis/metabolismo , Mapas de Interação de Proteínas/fisiologia , Proteínas Quinases/metabolismo , Proteoma/metabolismo , Estresse Fisiológico/fisiologia , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Fosforilação , Mapeamento de Interação de Proteínas
7.
Zhongguo Dang Dai Er Ke Za Zhi ; 24(12): 1340-1344, 2022 Dec 15.
Artigo em Chinês | MEDLINE | ID: mdl-36544416

RESUMO

OBJECTIVES: To study the clinical and gastroscopic features of children with cyclic vomiting syndrome. METHODS: A retrospective analysis was performed on the medical data of 63 children with cyclic vomiting syndrome who were hospitalized and followed up in Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University from August 2019 to March 2022. RESULTS: Among the 63 children, there were 30 boys and 33 girls, with a mean age of 6.11 years, a mean course of disease of 2.57 years, and a mean vomiting period of 4.04 days. The most common accompanying symptom was listlessness or somnolence (55/63, 87%), followed by anorexia (45/63, 71%), abdominal pain or abdominal discomfort (40/63, 63%), constipation (19/63, 30%), salivation (12/63, 19%), nausea (11/63, 17%), headache (11/63, 17%), fever (6/63, 10%), and rash (1/63, 2%). All 63 children underwent gastroscopy, among whom 3 had no marked abnormalities, 22 (35%) had chronic superficial gastritis or chronic non-atrophic gastritis alone, and 38 (60%) had other abnormal changes aside from chronic gastritis (16 children with reflux esophagitis, 12 with bile reflux gastritis, 13 with duodenitis, 10 with erosive gastritis, and 5 with gastric or duodenal ulcer). Among the 63 children, 42 underwent pathological examinations of gastric mucosa, among whom 5 had no marked abnormalities, 34 had mild chronic gastritis, 2 had moderate chronic gastritis, and 1 had severe chronic gastritis. Among the 63 children, 15 received 24-hour dynamic esophageal pH monitoring during the interictal period, among whom 9 children were found to have pathological acid reflux. CONCLUSIONS: In addition to recurrent vomiting, most children with cyclic vomiting syndrome also have the symptoms such as somnolence or listlessness, anorexia, and abdominal pain. The main manifestation on gastroscopy is chronic gastritis, and most children may also have reflux esophagitis, bile reflux gastritis, and erosive gastritis. Mild chronic gastritis is the main pathological change of gastric mucosa.


Assuntos
Refluxo Biliar , Esofagite Péptica , Gastrite , Masculino , Feminino , Humanos , Criança , Gastroscopia , Esofagite Péptica/patologia , Refluxo Biliar/patologia , Anorexia/patologia , Estudos Retrospectivos , Sonolência , Gastrite/diagnóstico , Gastrite/patologia , Mucosa Gástrica/patologia , Vômito/etiologia , Vômito/patologia , Dor Abdominal
8.
BMC Evol Biol ; 20(1): 151, 2020 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-33183225

RESUMO

BACKGROUND: The northeastern part of the Qinghai-Tibet Plateau (QTP) presents a high number of plateau loach species. As one of the three major groups of fishes distributed on the QTP, plateau loach has high ecological value. However, the taxonomy and systematics of these fish are still controversial, and a large number of new species have been reported. The reason for this phenomenon is that the degree of morphological variation is low, the phylogenetic information provided by morphological and anatomical features used for species identification is relatively poor, and many cryptic species are observed. Based on the high-density sampling points from the biodiversity hotspots surveyed, this study aims to evaluate the biodiversity of plateau loach in the northeastern part of the QTP and reveal the hidden diversity by comparing morphological species with molecular operational taxonomic units (MOTUs). RESULTS: After careful identification and comparison of the morphology and DNA barcoding of 1630 specimens, 22 species were identified, with 20 considered valid local species and two identified as new species that had not been previously described. Based on the combination of morphological and molecular methods, a total of 24 native species were found, two of which were cryptic species: Triplophysa robusta sp1 and Triplophysa minxianensis sp1. Fourteen of the 24 species form clusters of barcodes that allow them to be reliably identified. The remaining cases involved 10 closely related species, including rapidly differentiated species and species that seemed to have experienced incomplete lineage sorting or showed introgressions. CONCLUSIONS: The results highlight the need to combine traditional taxonomies with molecular methods to correctly identify species, especially closely related species, such as the plateau loach. This study provides a basis for protecting the biodiversity of plateau loach.


Assuntos
Cipriniformes , Código de Barras de DNA Taxonômico , Filogenia , Animais , Cipriniformes/genética , DNA , Tibet
9.
Biomacromolecules ; 21(2): 803-814, 2020 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-31995366

RESUMO

Nucleoside analogue drugs are widely used in cancer therapy and antiviral therapy, while fast metabolism, drug resistance, and severe side effects significantly limit their clinical applications. To address these issues, a variety of ester- and amide-linked prodrugs and their nanoparticulate formulations have been devised. However, most of these prodrugs suffer from inefficient transformation to native drugs in tumor. Here, we report an approach to conjugate gemcitabine, a kind of anticancer nucleoside drug and widely used to treat cancers, to polyketal backbone via pH-sensitive ketal linkage, and prepared gemcitabine-containing polyketal prodrug nanoparticles with minimal drug release under physiological conditions and acid-triggerable release of native gemcitabine. Intracellular and intratumoral degradation of the pH-sensitive gemcitabine-containing polyketal prodrug and incorporation of gemcitabine into DNA were confirmed by confocal microscopy using EdU, an analogue of gemcitabine. One single intravenous injection of these gemcitabine-containing polyketal prodrug nanoparticles demonstrated notable anticancer efficacy in the A2780 ovarian xenograft tumor model with increased survival rate and good safety. Our approach can be adopted for other diol nucleoside analogues to synthesize pH-sensitive nucleoside-polyketal prodrugs for developing anticancer and antiviral formulations.


Assuntos
Antimetabólitos Antineoplásicos/metabolismo , Desoxicitidina/análogos & derivados , Liberação Controlada de Fármacos/fisiologia , Nanopartículas/metabolismo , Pró-Fármacos/metabolismo , Animais , Antimetabólitos Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Desoxicitidina/metabolismo , Desoxicitidina/farmacologia , Relação Dose-Resposta a Droga , Liberação Controlada de Fármacos/efeitos dos fármacos , Feminino , Humanos , Concentração de Íons de Hidrogênio , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Nanopartículas/administração & dosagem , Pró-Fármacos/farmacologia , Coelhos , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , Gencitabina
10.
J Nanobiotechnology ; 18(1): 144, 2020 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-33069258

RESUMO

BACKGROUND: During the course of gene transfection, the interaction kinetics between liposomes and DNA is speculated to play very important role for blood stability, cellular uptake, DNA release and finally transfection efficiency. RESULTS: As cationic peptide liposomes exhibited great gene transfer activities both in vitro and in vivo, two peptide lipids, containing a tri-ornithine head (LOrn3) and a mono-ornithine head (LOrn1), were chosen to further clarify the process of liposome-mediated gene delivery in this study. The results show that the electrostatically-driven binding between DNA and liposomes reached nearly 100% at equilibrium, and high affinity of LOrn3 to DNA led to fast binding rate between them. The binding process between LOrn3 and DNA conformed to the kinetics equation: y = 1.663631 × exp (- 0.003427x) + 6.278163. Compared to liposome LOrn1, the liposome LOrn3/DNA lipoplex exhibited a faster and more uniform uptake in HeLa cells, as LOrn3 with a tri-ornithine peptide headgroup had a stronger interaction with the negatively charged cell membrane than LOrn1. The efficient endosomal escape of DNA from LOrn3 lipoplex was facilitated by the acidity in late endosomes, resulting in broken carbamate bonds, as well as the "proton sponge effect" of the lipid. CONCLUSIONS: The interaction kinetics is a key factor for DNA transfection efficiency. This work provided insights into peptide lipid-mediated DNA delivery that could guide the development of the next generation of delivery systems for gene therapeutics.


Assuntos
Terapia Genética/métodos , Lipídeos/química , Lipossomos/química , Peptídeos/química , Cátions/química , Membrana Celular , DNA/química , Endossomos , Técnicas de Transferência de Genes , Células HeLa , Humanos , Cinética , Lipossomos/metabolismo , Transfecção
11.
Bioorg Med Chem ; 26(12): 3535-3540, 2018 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-29801966

RESUMO

In this paper, two novel carbamate-linked quaternary ammonium lipids (MU18: a lipid with a mono-ammonium head; GU18: a lipid with a Gemini-ammonium head) containing unsaturated hydrophobic chains were designed and synthesized. The chemical structures of the synthetic lipids were characterized by infrared spectrum, ESI-MS, 1H NMR, 13C NMR, and HPLC. For investigating the effect of unsaturation on gene delivery, the previous reported saturated cationic liposomes (MS18 and GS18) were used as comparison. Cationic liposomes were prepared by using these cationic lipids and neutral lipid DOPE at the molar ratio of 1:1. Particle sizes and zeta potentials of the cationic liposomes were studied to show that they were suitable for gene transfection. The binding abilities of the cationic liposomes were investigated by gel electrophoresis at various N/P ratios from 0.5/1 to 8/1. The results indicated that the binding ability of GU18 was much better than MU18 and the saturated cationic liposomes (MS18 and GS18). DNA transfection of these liposomes comparable to commercially available reagent (DOTAP) was achieved in vitro against Hela, HepG-2 and NCI-H460 cell lines. GU18 showed higher transfection at the N/P ratio of 3/1 than other cationic liposomes and the positive control, DOTAP. All of the liposomes presented a relatively low cytotoxicity, which was measured by MTT. Therefore, the synthetic lipids bearing unsaturated hydrophobic chains and Gemini-head could be promising candidates for gene delivery.


Assuntos
Carbamatos/química , Lipídeos/química , Lipossomos/química , Compostos de Amônio Quaternário/química , Transfecção , Cátions/química , Linhagem Celular Tumoral , Células HeLa , Células Hep G2 , Humanos , Interações Hidrofóbicas e Hidrofílicas , Lipossomos/metabolismo , Microscopia Eletrônica de Transmissão , Tamanho da Partícula
12.
Proc Natl Acad Sci U S A ; 112(2): 613-8, 2015 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-25550508

RESUMO

The phytohormone abscisic acid (ABA) plays important roles in plant development and adaptation to environmental stress. ABA induces the production of nitric oxide (NO) in guard cells, but how NO regulates ABA signaling is not understood. Here, we show that NO negatively regulates ABA signaling in guard cells by inhibiting open stomata 1 (OST1)/sucrose nonfermenting 1 (SNF1)-related protein kinase 2.6 (SnRK2.6) through S-nitrosylation. We found that SnRK2.6 is S-nitrosylated at cysteine 137, a residue adjacent to the kinase catalytic site. Dysfunction in the S-nitrosoglutathione (GSNO) reductase (GSNOR) gene in the gsnor1-3 mutant causes NO overaccumulation in guard cells, constitutive S-nitrosylation of SnRK2.6, and impairment of ABA-induced stomatal closure. Introduction of the Cys137 to Ser mutated SnRK2.6 into the gsnor1-3/ost1-3 double-mutant partially suppressed the effect of gsnor1-3 on ABA-induced stomatal closure. A cysteine residue corresponding to Cys137 of SnRK2.6 is present in several yeast and human protein kinases and can be S-nitrosylated, suggesting that the S-nitrosylation may be an evolutionarily conserved mechanism for protein kinase regulation.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Óxido Nítrico/metabolismo , Proteínas Quinases/metabolismo , Sequência de Aminoácidos , Substituição de Aminoácidos , Arabidopsis/citologia , Arabidopsis/genética , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Domínio Catalítico/genética , Sequência Conservada , Cisteína/química , Glutationa Redutase/genética , Glutationa Redutase/metabolismo , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Doadores de Óxido Nítrico/farmacologia , Fenótipo , Estômatos de Plantas/citologia , Estômatos de Plantas/metabolismo , Conformação Proteica , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases/química , Proteínas Quinases/genética , S-Nitrosoglutationa/farmacologia , Homologia de Sequência de Aminoácidos , Transdução de Sinais
13.
J Nanosci Nanotechnol ; 17(4): 2515-519, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29652118

RESUMO

A facile In Situ growth method was presented here for the preparation of graphitic carbon nitride (g-C3N4)/graphene composites, in which the direct growth and deposition of g-C3N4 nanosheets from organic N and C sources on the graphene surfaces was achieved to form the 3D contacted structure. The resulting 3D architecture possessed multilevel porous structure and efficient g-C3N4/graphene interfaces, which facilitated the fast electron transfer at the interfaces. Photoluminescence spectra showed that the recombination of photogenerated electrons and holes in the g-C3N4/graphene composites was greatly inhibited by the introduction of graphene, indicating the more efficient separation of electrons and hole in the g-C3N4/graphene composites than in pure g-C3N4. The catalytic activity of g-C3N4/graphene composite photocatalyst was enhanced by over two fold compared to pure g-C3N4 for removal of Rhodamine B under simulated sun light irradiation. This work indicates that the metal-free g-C3N4/graphene composite photocatalyst is a promising nanomaterial for further applications in water treatment.

14.
J Gastroenterol Hepatol ; 31(2): 384-93, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26414725

RESUMO

OBJECTIVE: This study determined the expression of microRNA-1 in esophageal squamous cell carcinoma (ESCC) tissue and cell lines to evaluate its effects on clinicopathological parameters and its target genes LASP1 and TAGLN2. METHODS: The expression of miR-1, lasp1, and tagln2 was detected in 55 ESCC tissues and adjacent normal tissues by reverse transcription-polymerase chain reaction (RT-PCR). The association between miR-1, lasp1, and tagln2 expression and clinicopathological characteristics was observed. MicroRNA-1 (mimics-miR-1) and its inhibitor (Inhibitor-miR-1) were transfected into esophageal cancer cells KYSE 510 and Eca 109; cell proliferation, migration, and invasion assays were carried out. Plasmid construction and dual-luciferase reporter assay were also carried out to indicate whether LASP1 and TAGLN2 were miR-1 target genes. The expression of LASP1 and TAGLN2 was detected with Western blot methods in cell lines, by immunohistochemistry in ESCC tissue. RESULTS: The gene expression level of microRNA-1 in cancer tissues was significantly lower than that in adjacent normal tissues (P < 0.01). The expression of miR-1 in ESCC was correlated with involvement of lymph nodes (P = 0.002), histologic classification (P = 0.000), and vessel invasion (P = 0.022). The expression of lasp1 and tagln2 increased in cancer tissues compared with in adjacent normal tissues (P < 0.05). MiR-1 suppresses the cell growth, migration, and invasion in vitro. The expression of LASP1 and TAGLN2 decreased in mimics-miR-1 transfected cells, and increased in inhibitor-miR-1 transfected cells. Luciferase reporter assay confirmed that LASP1 and TAGLN2 mRNA actually had the target sites of miR-1. CONCLUSIONS: miR-1 suppresses cell proliferation, invasiveness, metastasis, and progression of ESCC by binding its targeted genes LASP1 and TAGLN2.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Carcinoma de Células Escamosas/genética , Proteínas do Citoesqueleto/genética , Neoplasias Esofágicas/genética , Proteínas com Domínio LIM/genética , MicroRNAs/genética , MicroRNAs/fisiologia , Proteínas dos Microfilamentos/genética , Proteínas Musculares/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Idoso , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Proteínas do Citoesqueleto/metabolismo , Progressão da Doença , Neoplasias Esofágicas/patologia , Feminino , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Marcação de Genes , Humanos , Proteínas com Domínio LIM/metabolismo , Masculino , MicroRNAs/antagonistas & inibidores , MicroRNAs/metabolismo , Proteínas dos Microfilamentos/metabolismo , Pessoa de Meia-Idade , Proteínas Musculares/metabolismo , Invasividade Neoplásica/genética , Metástase Neoplásica/genética , Ligação Proteica , RNA Mensageiro , Reação em Cadeia da Polimerase Via Transcriptase Reversa
15.
Zhongguo Dang Dai Er Ke Za Zhi ; 18(12): 1217-1221, 2016 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-27974110

RESUMO

OBJECTIVE: To investigate the clinical features and outcomes of neuroblastoma (NB) children aged above 5 years, and to provide a theoretical basis for improving prognosis. METHODS: A retrospective analysis was performed for the clinical data of 54 previously untreated NB children, and their clinical features and outcome were analyzed. The Kaplan-Meier method was used for survival analysis. RESULTS: Among the 54 children, there were 36 boys and 18 girls, and all of them had stage 3 or 4 NB. Of all the children, 41 (41/54, 76%) had retroperitoneal space-occupying lesions, 10 (10/54, 18%) had mediastinal space-occupying lesions, 2 (2/54, 4%) had intraspinal space-occupying lesions, and 1 (1/54, 2%) had pelvic space-occupying lesions. At the end of the follow-up, 30 children (30/54, 56%) survived, among whom 23 (77%) achieved disease-free survival (9 achieved complete remission after chemotherapy for recurrence), 6 (20%) achieved partial remission of tumor (all of them received chemotherapy again due to recurrence), and 1 (3%) experienced progression (with progression after chemotherapy again due to recurrence); 24 children (44%) died, among whom 22 died after chemotherapy again due to recurrence and 2 died of multiple organ failure during the first treatment. According to the Kaplan-Meier survival analysis, the mean survival time was 53.8 months, and the children with stage 3 NB had a significantly higher overall survival rate than those with stage 4 NB (80% vs 53%; p<0.01). The children with recurrence had a significantly lower mean survival time than those without recurrence (51.68 months vs 62.57 months; p<0.01). CONCLUSIONS: Older children often have late-stage NB, but standard treatment can improve their outcomes.


Assuntos
Neuroblastoma/terapia , Adolescente , Criança , Pré-Escolar , Terapia Combinada , Feminino , Humanos , Masculino , Neuroblastoma/mortalidade , Estudos Retrospectivos
16.
Langmuir ; 31(27): 7644-51, 2015 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-26075681

RESUMO

Transition-metal-/metal-oxide-loaded mesoporous carbon materials with hollow structures are thought to have great potential as catalysts, especially in the areas of sustainable chemistry and energy conversion. However, it is hard to load transition metals/metal oxides onto carbon materials while keeping the carbon materials unchanged through traditional after-treatment processes, thus making it difficult to determine the true roles of the transition metal/metal oxide and carbon in the reactions. Here, Co-coordinated hollow mesoporous carbon cubes (CoMHMCCs) were prepared by a microwave-assisted approach in the presence of ethylene glycol and hollow mesoporous carbon cubes (HMCCs). The synthesized CoMHMCCs inherited most advantages of the HMCCs, such as large surface area and pore volume, uniform pore size distribution, and hollow mesoporous structure, and the Co species was found to coordinate with the N atoms in the N-doped hollow mesoporous carbon cubes. The synthesized CoMHMCCs exhibited a much enhanced oxygen electroreduction reaction activity (∼50 mV deviation from Pt/C), a high selectivity (number of electrons transferred = 3.7-3.9), and excellent electrochemical stability (as low as 12 mV negative shift of half-wave potential after 5000 potential cycles) as a result of a synergetic catalytic effect.

17.
Plant Physiol ; 161(3): 1392-408, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23300166

RESUMO

Reactive oxygen species (ROS) have been characterized as both important signaling molecules and universal stressors that mediate many developmental and physiological responses. So far, details of the transcriptional mechanism of ROS-responsive genes are largely unknown. In the study reported here, we identified seven potential ROS-responsive cis-acting elements (ROSEs) from the promoters of genes up-regulated by ROS in Arabidopsis (Arabidopsis thaliana). We also found that the APETALA2/ethylene-responsive element binding factor6 (ERF6) could bind specifically to the ROSE7/GCC box. Coexpression of ERF6 enhanced luciferase activity driven by ROSE7. The deficient mutants of ERF6 showed growth retardation and higher sensitivity to photodamage. ERF6 interacted physically with mitogen-activated protein kinase6 (MPK6) and also served as a substrate of MPK6. MPK6-mediated ERF6 phosphorylation at both serine-266 and serine-269 affected the dynamic alternation of the ERF6 protein, which resulted in changes in ROS-responsive gene transcription. These data might provide new insight into the mechanisms that regulate ROS-responsive gene transcription via a complex of MPK6, ERF6, and the ROSE7/GCC box under oxidative stress or a fluctuating light environment.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Arabidopsis/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Elementos de Resposta/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica , Sequência de Aminoácidos , Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Sequência de Bases , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas/genética , Peróxido de Hidrogênio/farmacologia , Dados de Sequência Molecular , Mutação/genética , Motivos de Nucleotídeos/genética , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Fenótipo , Fosforilação/efeitos dos fármacos , Fosfosserina/metabolismo , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/genética , Especificidade por Substrato/efeitos dos fármacos , Especificidade por Substrato/genética , Fatores de Transcrição/química , Fatores de Transcrição/genética , Transcrição Gênica/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/genética
18.
Cell Biol Int ; 38(4): 488-96, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24375547

RESUMO

Activated PI3K/Akt signalling exerts a protective effect after myocardial ischemia by phosphorylating various substrates; however, the precise mechanism by which this occurs remains to be elucidated. We have constructed the recombinant lentiviral vector pLVX-Akt1-EGFP- 3FLAG (LV-Akt1) to determine the efficiency of LV-Akt1 infection, explore the protective role of Akt1, and investigate the possible mechanism by which Akt1 signalling acts during anoxia/reoxygenation (A/R) of cardiomyocytes in primary culture. Akt1 gene transfection increased cardiomyocyte pulsation, reduced cell mortality, and decreased the concentration of lactate dehydrogenase (LDH) in myocardial cells supernatants. Akt1 transfection increased the levels of intracellular p-Akt, enhanced the expression of the anti-apoptosis protein Bcl-2, and reduced that of the apoptosis protein Bax (thereby increasing the Bcl-2/Bax ratio), and caused some increase in hypoxia-inducible factor1α (HIF-1α) and vascular endothelial growth factor (VEGF) expression after A/R. The protective role of Akt1 was partly suppressed by adding a phosphoinositide 3-kinase/Akt inhibitor (LY294002). In conclusion, LV-Akt1 was successfully constructed and neonatal rat cardiomyocytes were transfected efficiently. Akt1 overexpression significantly reduced A/R injury in cardiomyocytes, and this could be related to its effects on various targets of the PI3K/Akt signalling pathway, such as Bcl-2, Bax, HIF-1α and VEGF.


Assuntos
Miócitos Cardíacos/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Hipóxia Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cromonas/farmacologia , Vetores Genéticos/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Lentivirus/genética , Morfolinas/farmacologia , Miócitos Cardíacos/citologia , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/metabolismo , Proteína X Associada a bcl-2/metabolismo
19.
Mitochondrial DNA B Resour ; 9(2): 300-303, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38406670

RESUMO

Gobio huanghensis, a member of the eponymous genus within the Cyprinidae, family of the Cypriniformes order, is an endemic fish species found exclusively in the upper reaches of the Yellow River, spanning from Yinchuan to Lanzhou. This study presents the first comprehensive report of the complete mitochondrial genome sequence of G. huanghensis, encompassing 16,604 base pairs (bp) with a nucleotide composition of 26.3% cytosine (C), 17.6% guanine (G), 29.4% adenine (A), and 26.7% thymine (T). In congruence with other species in the Gobio genus, its mitochondrial genome comprises 37 genes, including two ribosomal RNA genes, 13 protein-coding genes (PCGs), and 22 transfer RNA genes. Notably, COX1 initiates with the start codon GTG, distinct from the typical ATG start codon of other PCGs. The mitogenome exhibits four types of stop codons: TAA, TAG, TA-, and T--. Phylogenetic analyses, grounded in complete mitochondrial sequences, position G. huanghensis at the forefront of one of two major clusters within the genus Gobio, corroborating existing morphological classifications. These findings offer valuable theoretical insights for the taxonomic classification, conservation, and population genetics of G. huanghensis.

20.
Zhen Ci Yan Jiu ; 49(3): 289-295, 2024 Mar 25.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-38500326

RESUMO

OBJECTIVES: To investigate the effects of the elongated needling at the points of hand and foot yang meridians and the Governor Vessel combined with the routine acupuncture therapy on pain, balance function and muscle strength of the patients with post-stroke hemiplegia and central post-stroke pain (CPSP), and to investigate whether its therapeutic mechanism is related to antioxidant damage. METHODS: Ninety-four patients with post-stroke hemiplegia and CPSP admitted from March 2020 to September 2021 were divided into a trial group (47 cases, 1 cases dropped out) and a control group (47 cases 3 cases dropped out). In the control group, the rehabilitation exercise combined with routine acupuncture therapy was used, and in the trial group, on the base of the treatment as the control group, the elongated needling at the points of hand and foot yang meridians and the Governor Vessel was supplemented. In the two groups, the treatment was given once daily, and 1 course of treatment was composed of 14 days, a total of 6 courses were required in the trial. Separately, before treatment, and 1, 2 and 3 months after treatment, between two groups, the score of visual analogue scale (VAS) and that of Berg balance scale (BBS), as well as muscle strength were compared;the neural function was evaluated using the national institutes of health stroke scale (NIHSS) and the serum contents of nitricoxide synthase (NOS), superoxide dismutase (SOD) and malondialdehyde (MDA) were detected by ELISA in the patients. RESULTS: Compared with those before treatment, VAS score and NIHSS score were all decreased (P<0.05) in the trial and the control group after 1 month, 2 months and 3 months of treatment, and BBS score was increased (P<0.05);and the case proportion of muscle strength grade 4 and 5 was higher (P<0.05) in the trial group. In the control group, the proportion of grade 4 increased after treatment for 2 months (P<0.05), and that of grade 4 and 5 increased after treatment for 3 months (P<0.05). The serum contents of NOS and SOD were increased (P<0.05), and MDA was decreased (P<0.05) after 3 months of treatment in the two groups. In comparison with the control group at the same time point, VAS score and NIHSS score were lower (P<0.05), BBS score higher (P<0.05) and the muscle strength grade was improved (P<0.05, P<0.01) after 1, 2 and 3 months of treatment, respectively;and the serum contents of NOS and SOD increased (P<0.05), and MDA decreased (P<0.05) after 3 months of treatment in the trial group. CONCLUSIONS: The elongated needling at the points of hand and foot yang meridians and the Governor Vessel, combined with the routine acupuncture therapy alleviates CPSP, improves balance and muscle strength and promotes the recovery of neural function in the patients with post-stroke hemiplegia, the mechanism may be related to antioxidant damage.


Assuntos
Terapia por Acupuntura , Neuralgia , Humanos , Hemiplegia/etiologia , Hemiplegia/terapia , Antioxidantes , Indução Percutânea de Colágeno , Resultado do Tratamento , Superóxido Dismutase , Pontos de Acupuntura
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