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1.
Microbiol Res ; 286: 127829, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39018940

RESUMO

The impact of climate warming on soil microbes has been well documented, with studies revealing its effects on diversity, community structure and network dynamics. However, the consistency of soil microbial community assembly, particularly in response to diverse plant root exudates under varying temperature conditions, remains an unresolved issue. To address this issue, we employed a growth chamber to integrate temperature and root exudates in a controlled experiment to examine the response of soil bacteria, fungi, and protists. Our findings revealed that temperature independently regulated microbial diversity, with distinct patterns observed among bacteria, fungi, and protists. Both root exudates and temperature significantly influenced microbial community composition, yet interpretations of these factors varied among prokaryotes and eukaryotes. In addition to phototrophic bacteria and protists, as well as protistan consumers, root exudates determined to varying degrees the enrichment of other microbial functional guilds at specific temperatures. The effects of temperature and root exudates on microbial co-occurrence patterns were interdependent; root exudates primarily simplified the network at low and high temperatures, while responses to temperature varied between single and mixed exudate treatments. Moreover, temperature altered the composition of keystone species within the microbial network, while root exudates led to a decrease in their number. These results emphasize the substantial impact of plant root exudates on soil microbial community responses to temperature, underscoring the necessity for future climate change research to incorporate additional environmental variables.


Assuntos
Bactérias , Fungos , Raízes de Plantas , Microbiologia do Solo , Temperatura , Raízes de Plantas/microbiologia , Fungos/classificação , Fungos/metabolismo , Bactérias/classificação , Bactérias/metabolismo , Microbiota , Mudança Climática , Eucariotos/crescimento & desenvolvimento , Biodiversidade , Exsudatos de Plantas/metabolismo , Exsudatos de Plantas/química , Solo/química
2.
Leukemia ; 37(6): 1204-1215, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37095208

RESUMO

Mismatch repair (MMR) deficiency has been linked to thiopurine resistance and hypermutation in relapsed acute lymphoblastic leukemia (ALL). However, the repair mechanism of thiopurine-induced DNA damage in the absence of MMR remains unclear. Here, we provide evidence that DNA polymerase ß (POLB) of base excision repair (BER) pathway plays a critical role in the survival and thiopurine resistance of MMR-deficient ALL cells. In these aggressive resistant ALL cells, POLB depletion and its inhibitor oleanolic acid (OA) treatment result in synthetic lethality with MMR deficiency through increased cellular apurinic/apyrimidinic (AP) sites, DNA strand breaks and apoptosis. POLB depletion increases thiopurine sensitivities of resistant cells, and OA synergizes with thiopurine to kill these cells in ALL cell lines, patient-derived xenograft (PDX) cells and xenograft mouse models. Our findings suggest BER and POLB's roles in the process of repairing thiopurine-induced DNA damage in MMR-deficient ALL cells, and implicate their potentials as therapeutic targets against aggressive ALL progression.


Assuntos
DNA Polimerase beta , Leucemia-Linfoma Linfoblástico de Células Precursoras , Animais , Humanos , Camundongos , Dano ao DNA , DNA Polimerase beta/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Mutações Sintéticas Letais , Reparo de Erro de Pareamento de DNA/genética
3.
Zhongguo Zhong Yao Za Zhi ; 43(12): 2556-2562, 2018 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-29950075

RESUMO

Two new polypeptides were isolated and purified from the extract of deer bone (constitutive part of Cucumis and Cervus polypeptide injection) by various column chromatography including C4 300Å and Sephadex G-50, as well as semipreparative HPLC. Their N-terminal amino acid sequences were identified by De Novo sequencing on the basis of MALDI-TOF-MS data and Explorer™ software. The N-terminal amino acid sequences of polypeptides were identified as NH2-Gly-Pro-Val-Gly-Pro-Thr-Gly-Pro-Val-Gly-Ala-Ala-Gly-Pro-Ser-Gly-Pro-Asp (Mei18 peptide, 1) and NH2-Ala-Gly-Pro-Ala-Gly-Pro-Leu-Gly-Pro-Leu-Gly-Pro-Leu-Gly-Pro-Leu-Gly-Pro-Pro-Asp-Ser-Try-Asp (Mei23 peptide, 2), respectively. Mei18 and Mei 23 peptides are new polypeptides.


Assuntos
Osso e Ossos/química , Cervos , Materia Medica/química , Peptídeos/química , Sequência de Aminoácidos , Animais , Espectrometria de Massas
4.
Chem Commun (Camb) ; 54(5): 527-530, 2018 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-29265135

RESUMO

A high quantum yield (4.3%) hybrid nanogel system based on engineered polypeptides and Ag2S quantum dots has been developed as a multifunctional diagnostic and therapeutic agent for targeted second near-infrared fluorescence, photoacoustic imaging, and photothermal therapy.


Assuntos
Géis/química , Nanoestruturas/química , Imagem Óptica , Peptídeos/química , Técnicas Fotoacústicas , Engenharia de Proteínas , Pontos Quânticos , Compostos de Prata/química , Fluorescência , Células HeLa , Humanos , Células MCF-7 , Tamanho da Partícula , Fototerapia , Teoria Quântica , Propriedades de Superfície
5.
Photochem Photobiol Sci ; 15(2): 181-6, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26787048

RESUMO

A facile method for in situ fabrication of three-dimensional gold nanoparticle micropatterns in a cell-resistant polyethylene glycol hydrogel has been developed by combining photochemical synthesis of gold nanoparticles with photolithography technology. The gold nanoparticle micropatterns were further bio-modified with cell integrated polypeptide NcysBRGD based on a gold-thiol bond to improve cell behaviors. Primary cell tests showed that NcysBRGD can enhance cell adhesion very well on the surface of gold nanoparticle micropatterns.


Assuntos
Ouro/química , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Nanopartículas Metálicas/química , Peptídeos/química , Sequência de Aminoácidos , Materiais Biocompatíveis/química , Adesão Celular , Desenho de Equipamento , Células HeLa , Humanos , Nanopartículas Metálicas/ultraestrutura , Microtecnologia , Dados de Sequência Molecular , Compostos de Sulfidrila/química , Análise Serial de Tecidos/instrumentação
6.
Nanotechnology ; 26(49): 495102, 2015 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-26567721

RESUMO

Quantum dot (QD)-polypeptide probes have been developed through the specific metal-affinity interaction between polypeptides appended with N-terminal polyhistidine sequences and CdSe/ZnS core-shell QDs. The size and charge of a QD-polypeptide can be tuned by using different coiled-coil polypeptides. Compared to glutathione-capped QDs (QD-GSH), QD-polypeptide probes showed an approximately two- to three-fold luminescence increase, and the luminescence increase was not obviously related to the charge of the polypeptide. QD-polypeptide probes with different charge have a great effect on nonspecific cellular uptake. QD-polypeptide probes with negative charge exhibited lower nonspecific cellular uptake in comparison to the QD-GSH, while positively charged QD-polypeptide probes presented higher cellular uptake than the QD-GSH. A targeted QD-ARGD probe can obviously increase targeted cellular uptake in α v ß 3 overexpressing HeLa cells compared to QD-A. In addition, QD-polypeptide probes showed lower in vitro cytotoxicity compared to the original QDs. These results demonstrate that these QD-polypeptide probes with high specific cellular uptake, high fluorescence intensity and low background noise are expected to have great potential applications in targeted cell imaging.


Assuntos
Técnicas Citológicas/métodos , Imagem Óptica/métodos , Peptídeos/química , Pontos Quânticos/química , Células HeLa , Humanos , Células MCF-7
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