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1.
Bioorg Med Chem ; 106: 117752, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38749341

RESUMO

Bromodomain protein 4 (BRD4) is a member of the BET family, and its overexpression is closely associated with the development of many tumors. Inhibition of BRD4 shows great therapeutic potential in anti-tumor, and pan-BRD4 inhibitors show adverse effects of dose limiting toxicity and thrombocytopenia in clinical trials. To improve clinical effects and reduce side effects, more efforts have focused on seeking selective inhibitors of BD1 or BD2. Herein, a series of indole-2-one derivatives were designed and synthesized through docking-guided optimization to find BRD4-BD1 selective inhibitors, and their BRD4 inhibitory and antiproliferation activities were evaluated. Among them, compound 21r had potent BRD4 inhibitory activity (the IC50 values of 41 nM and 313 nM in BD1 and BD2 domain), excellent anti-proliferation (the IC50 values of 4.64 ± 0.30 µM, 0.78 ± 0.03 µM, 5.57 ± 1.03 µM against HL-60, MV-4-11 and HT-29 cells), and displayed low toxicity against normal cell GES-1 cells. Further studies revealed that 21r inhibited proliferation by decreasing the expression of proto-oncogene c-Myc, blocking cell cycle in G0/G1 phase, and inducing apoptosis in MV-4-11 cells in a dose-dependent manner. All the results showed that compound 21r was a potent BRD4 inhibitor with BD1 selectivity, which had potential in treatment of leukemia.


Assuntos
Antineoplásicos , Proteínas de Ciclo Celular , Proliferação de Células , Ensaios de Seleção de Medicamentos Antitumorais , Indóis , Fatores de Transcrição , Humanos , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/metabolismo , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/metabolismo , Indóis/química , Indóis/farmacologia , Indóis/síntese química , Proliferação de Células/efeitos dos fármacos , Relação Estrutura-Atividade , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Estrutura Molecular , Descoberta de Drogas , Relação Dose-Resposta a Droga , Proto-Oncogene Mas , Apoptose/efeitos dos fármacos , Simulação de Acoplamento Molecular , Linhagem Celular Tumoral , Proteínas que Contêm Bromodomínio
2.
Int J Mol Sci ; 25(10)2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38791295

RESUMO

To achieve the environmentally friendly and rapid green synthesis of efficient and stable AgNPs for drug-resistant bacterial infection, this study optimized the green synthesis process of silver nanoparticles (AgNPs) using Dihydromyricetin (DMY). Then, we assessed the impact of AgNPs on zebrafish embryo development, as well as their therapeutic efficacy on zebrafish infected with Methicillin-resistant Staphylococcus aureus (MRSA). Transmission electron microscopy (TEM) and dynamic light-scattering (DLS) analyses revealed that AgNPs possessed an average size of 23.6 nm, a polymer dispersity index (PDI) of 0.197 ± 0.0196, and a zeta potential of -18.1 ± 1.18 mV. Compared to other published green synthesis products, the optimized DMY-AgNPs exhibited smaller sizes, narrower size distributions, and enhanced stability. Furthermore, the minimum concentration of DMY-AgNPs required to affect zebrafish hatching and survival was determined to be 25.0 µg/mL, indicating the low toxicity of DMY-AgNPs. Following a 5-day feeding regimen with DMY-AgNP-containing food, significant improvements were observed in the recovery of the gills, intestines, and livers in MRSA-infected zebrafish. These results suggested that optimized DMY-AgNPs hold promise for application in aquacultures and offer potential for further clinical use against drug-resistant bacteria.


Assuntos
Antibacterianos , Flavonóis , Química Verde , Nanopartículas Metálicas , Staphylococcus aureus Resistente à Meticilina , Prata , Peixe-Zebra , Animais , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Nanopartículas Metálicas/química , Prata/química , Prata/farmacologia , Flavonóis/farmacologia , Flavonóis/química , Química Verde/métodos , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Infecções Estafilocócicas/tratamento farmacológico , Testes de Sensibilidade Microbiana
3.
Sheng Li Xue Bao ; 76(3): 365-375, 2024 Jun 25.
Artigo em Zh | MEDLINE | ID: mdl-38939931

RESUMO

The purpose of the study was to investigate the mechanism of TFEB activator 1 (TA1) improving the autophagic degradation of oligomeric amyloid-ß (oAß) in microglia, and to explore the therapeutic effect of TA1 on an in vitro model of microglia in Alzheimer's disease (AD). Primary microglia were exposed to 1 µmol/L oAß for 0, 3, 12, and 24 h respectively to construct the in vitro model of microglia in AD. In order to explore the therapeutic effect of TA1, primary microglia were co-treated with 1 µmol/L oAß and 1 µmol/L TA1 for 12 h. To determine the autophagy flux, the above cells were further treated with 100 nmol/L Bafilomycin A1 for 1 h before fixation. Fluorescent probes were used to detect the endocytosis or degradation of oAß1-42 by microglia. The autophagic flux was determined by infection of lentivirus mCherry-EGFP-LC3. The nuclear TFEB intensity, the autophagosomes number, and the colocalization ratio of oAß1-42 with lysosome-associated membrane protein 1 (LAMP1) or microtubule-associated protein light chain 3 (LC3), were detected by immunofluorescence assay. Expressions of autophagy-related-genes, including Lamp1, Atg5, and Map1lc3b, were detected by qRT-PCR. Results showed that prolonged oAß exposure inhibited the endocytosis and degradation of oAß by microglia. Meanwhile, the number of autophagosomes and autophagy flux in microglia decreased after 12 h of oAß treatment. We further found that the nuclear expression of autophagy regulator TFEB decreased after 12 h of oAß exposure, resulting in the decrease of autophagy genes, thus leading to the damage of autophagic degradation of oAß. Therefore, long-term oAß exposure was considered to construct the in vitro model of microglia in AD. After TA1 treatment, the nuclear expression of TFEB in cells was obviously upregulated. TA1 treatment upregulated the expressions of autophagy-related genes, leading to the recovery of autophagy flux. TA1 also recovered the endocytosis and degradation of oAß by microglia. In conclusion, TA1 could improve oAß clearance by microglia in AD by upregulating microglial TFEB-mediated autophagy, suggesting TA1 as a potential therapeutic drug for AD.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Autofagia , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Microglia , Microglia/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Doença de Alzheimer/metabolismo , Células Cultivadas , Camundongos
4.
Angew Chem Int Ed Engl ; : e202410414, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38924578

RESUMO

A series of TADF-active compounds: 0D chiral Ln-Ag(I) clusters L-/D-Ln2Ag28-0D (Ln = Eu/Gd) and 2D chiral Ln-Ag(I) cluster-based frameworks L-/D-Ln2Ag28-2D (Ln = Gd) has been synthesized. Atomic-level structural analysis showed that the chiral Ag(I) cluster units {Ag14S12} in L-/D-Ln2Ag28-0D and L-/D-Ln2Ag28-2D exhibited similar configurations, linked by varying numbers of [Ln(H2O)x]3+ (x = 6 for 0D, x = 3 for 2D) to form the final target compounds. Temperature-dependent emission spectra and decay lifetimes measurement demonstrated the presence of TADF in L-Ln2Ag28-0D (Ln = Eu/Gd) and L-Gd2Ag28-2D. Experimentally, the remarkable TADF properties primarily originated from {Ag14S12} moieties in these compounds. Notably, {Ag14S12} in L-Eu2Ag28-0D and L-Gd2Ag28-2D displayed higher promote fluorescence rate and shorter TADF decay times than L-Gd2Ag28-0D. Combined with theoretical calculations, it was determined that the TADF behaviors of {Ag14S12} cluster units were induced by 4f perturbation of Ln3+ ions. Specially, while maintaining ΔE(S1-T1) small enough, it can significantly increase k(S1→S0) and reduce TADF decay time by adjusting the type or number of Ln3+ ions, thus achieving the purpose of improving TADF for cluster-based luminescent materials.

5.
Biomacromolecules ; 24(1): 1-18, 2023 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-36507729

RESUMO

Amyloid protein cross-seeding is a peculiar phenomenon of cross-spreading among different diseases. Unlike traditional infectious ones, diseases caused by amyloid protein cross-seeding are spread by misfolded proteins instead of pathogens. As a consequence of the interactions among misfolded heterologous proteins or polypeptides, amyloid protein cross-seeding is considered to be the crucial cause of overlapping pathological transmission between various protein misfolding disorders (PMDs) in multiple tissues and cells. Here, we briefly review the phenomenon of cross-seeding among amyloid proteins. As an interesting example worth mentioning, the potential links between the novel coronavirus pneumonia (COVID-19) and some neurodegenerative diseases might be related to the amyloid protein cross-seeding, thus may cause an undesirable trend in the incidence of PMDs around the world. We then summarize the theoretical models as well as the experimental techniques for studying amyloid protein cross-seeding. Finally, we conclude with an outlook on the challenges and opportunities for basic research in this field. Cross-seeding of amyloid opens up a new perspective in our understanding of the process of amyloidogenesis, which is crucial for the development of new treatments for diseases. It is therefore valuable but still challenging to explore the cross-seeding system of amyloid protein as well as to reveal the structural basis and the intricate processes.


Assuntos
COVID-19 , Doenças Neurodegenerativas , Humanos , Proteínas Amiloidogênicas , Peptídeos beta-Amiloides/química , Amiloide/metabolismo
6.
Bioorg Med Chem ; 78: 117152, 2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-36599264

RESUMO

The bromodomain-containing protein 4 (BRD4) has gained growing interest as an effective drug target for the treatment of hepatocellular carcinoma (HCC). Herein, we designed and synthesized a series of quinoxalinone derivatives as BRD4 inhibitors via scaffold hopping. The representative compound X9 showed potent BRD4 inhibitory activity (with IC50 = 82.3 nM), and preferable antiproliferative activity against HepG2 cells (with IC50 = 1.13 ± 0.07 µM), as well as less toxicity against GES-1 cells (with IC50 = 57.24 ± 5.46 µM). Furthermore, compound X9 dose-dependently inhibited colony formation and blocked the migration of HepG2 cells by down-regulating the expression of Snail and MMP-9 while up-regulating the E-cadherin and Occludin. Besides, compound X9 efficiently down-regulated the expression of c-Myc in HepG2 cells, induced apoptosis, and arrested at G0/G1 phase. In total, quinoxalinone was a potential core as BRD4 inhibitor and compound X9 might be effective for liver cancer therapy.


Assuntos
Antineoplásicos , Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Proteínas Nucleares/metabolismo , Relação Estrutura-Atividade , Carcinoma Hepatocelular/tratamento farmacológico , Desenho de Fármacos , Neoplasias Hepáticas/tratamento farmacológico , Fatores de Transcrição , Proliferação de Células , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Proteínas de Ciclo Celular/metabolismo
7.
Bioorg Chem ; 133: 106412, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36773456

RESUMO

The PI3K/AKT/mTOR signaling pathway is one of the most common abnormal activation pathways in tumor cells, and has associated with multiple functions such as tumor cell growth, proliferation, migration, invasion, and tumor angiogenesis. Here, a series of 3-amino-1H-indazole derivatives were synthesized, and their antiproliferative activities against HT-29, MCF-7, A-549, HepG2 and HGC-27 cells were evaluated. Among them, W24 exhibited the broad-spectrum antiproliferative activity against four cancer cells with IC50 values of 0.43-3.88 µM. Mechanism studies revealed that W24 inhibited proliferation by affecting the DNA synthesis, induced G2/M cell cycle arrest and apoptosis by regulating Cyclin B1, BAD and Bcl-xL, meanwhile induced the change of intracellular ROS and mitochondrial membrane potential in HGC-27 cells. Moreover, W24 inhibited the migration and invasion of HGC-27 cells by decreasing EMT pathway related proteins and reducing the mRNA expression levels of Snail, Slug and HIF-1α. Furthermore, W24 displayed low tissue toxicity profile and good pharmacokinetic properties in vivo. Therefore, 3-amino-1H-indazole derivatives might serve as a new scaffold for the development of PI3K/AKT/mTOR inhibitor and anti-gastric cancer reagent.


Assuntos
Indazóis , Neoplasias , Humanos , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias/tratamento farmacológico , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Indazóis/química , Indazóis/farmacologia
8.
Sheng Li Xue Bao ; 74(3): 401-410, 2022 Jun 25.
Artigo em Zh | MEDLINE | ID: mdl-35770638

RESUMO

The purpose of this paper was to study the transcriptional regulation of nuclear respiratory factor 1 (NRF1) on nuclear factor kappa B (NF-κB), a key molecule in lipopolysaccharide (LPS)-induced lung epithelial inflammation, and to clarify the mechanism of NRF1-mediated inflammatory response in lung epithelial cells. In vivo, male BALB/c mice were treated with NRF1 siRNA, followed with LPS (4 mg/kg) or 0.9% saline through respiratory tract, and sacrificed 48 h later. Expression levels of NRF1, NF-κB p65 and its target genes were detected by Western blot and real-time PCR. Nuclear translocation of NRF1 or p65 was measured by immunofluorescent technique. In vitro, L132 cells were transfected with NRF1 siRNA or treated with BAY 11-7082 (5 µmol/L) for 24 h, followed with treatment of 1 mg/L LPS for 6 h. Cells were lysed for detections of NRF1, NF-κB p65 and its target genes as well as the binding sites of NRF1 on RELA (encoding NF-κB p65) promoter by chromatin immunoprecipitation assay (ChIP). Results showed that LPS stimulated NRF1 and NF-κB p65. Pro-inflammatory factors including interleukin-1ß (IL-1ß) and IL-6 were significantly increased both in vivo and in vitro. Obvious nuclear translocations of NRF1 and p65 were observed in LPS-stimulated lung tissue. Silencing NRF1 resulted in a decrease of p65 and its target genes both in vivo and in vitro. In addition, BAY 11-7082, an inhibitor of NF-κB, significantly repressed the inflammatory responses induced by LPS without affecting NRF1 expression. Furthermore, it was proved that NRF1 had three binding sites on RELA promoter region. In summary, NRF1 is involved in LPS-mediated acute lung injury through the transcriptional regulation on NF-κB p65.


Assuntos
Lesão Pulmonar Aguda , NF-kappa B , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/genética , Animais , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , NF-kappa B/metabolismo , Fator 1 Nuclear Respiratório/genética , RNA Interferente Pequeno , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/metabolismo
9.
Mikrochim Acta ; 188(7): 234, 2021 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-34160693

RESUMO

Coral-like Ag-Mo2C/C-I and blocky Ag-Mo2C/C-II composites were obtained from one-step in situ calcination of [Ag(HL)3(Mo8O26)]n·nH2O [L: N-(pyridin-3-ylmethyl) pyridine-2-amine] under N2/H2 and N2 atmospheres, respectively. The coral-like morphology of Ag-Mo2C/C-I is composed of interwoven nanorods embedded with small particles, and the nano-aggregate of Ag-Mo2C/C-II is formed by cross-linkage of irregular nanoparticles. The above composites are decorated on glassy carbon electrode (GCE) drop by drop to generate two enzyme-free electrochemical sensors (Ag-Mo2C/C/GCE) for amperometric detection of H2O2. In particular, the coral-like Ag-Mo2C/C-I/GCE sensor possesses rapid response (1.2 s), high sensitivity (466.2 µA·mM-1·cm-2), and low detection limit (25 nM) towards trace H2O2 and has wide linear range (0.08 µM~4.67 mM) and good stability. All these sensing performances are superior to Ag-Mo2C/C-II/GCE, indicating that the calcining atmosphere has an important influence on microstructure and electrochemical properties. The excellent electrochemical H2O2 sensing performance of Ag-Mo2C/C-I/GCE sensor is mainly attributed to the synergism of unique microstructure, platinum-like electron structure of Mo2C, strong interaction between Mo and Ag, as well as the increased active sites and conductivity caused by co-doped Ag and carbon. Furthermore, this sensor has been successfully applied to the detection of H2O2 in human serum sample, contact lens solution, and commercial disinfector, demonstrating the potential in related fields of environment and biology. Graphical abstract.

10.
BMC Anesthesiol ; 20(1): 22, 2020 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-31973700

RESUMO

BACKGROUND: Splenectomy performed with a curved incision results in severe postoperative pain. The aim of this study was to evaluate the effect of transversus abdominis plane block and rectus sheath block on postoperative pain relief and recovery. METHODS: A total of 150 patients were randomized into the control (C), levobupivacaine (L) and levobupivacaine/morphine (LM) groups. The patients in the C group received only patient-controlled analgesia. The patients in the L and LM groups received transversus abdominis plane block and rectus sheath block with levobupivacaine or levobupivacaine plus morphine. The intraoperative opioid consumption; postoperative pain score; time to first analgesic use; postoperative recovery data, including the times of first exhaust, defecation, oral intake and off-bed activity; the incidence of postoperative nausea and vomiting and antiemetics use; and the satisfaction score were recorded. RESULTS: Transversus abdominis plane block and rectus sheath block reduced intraoperative opioid consumption. The patients in the LM group showed lower postoperative pain scores, opioid consumption, postoperative nausea and vomiting incidence and antiemetic use and presented shorter recovery times and higher satisfaction scores. CONCLUSIONS: The combination of transversus abdominis plane block and rectus sheath block with levobupivacaine and morphine can improve postoperative pain relief, reduce the consumption of analgesics, and partly accelerate postoperative recovery. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR 1,800,015,141, 10 March 2018.


Assuntos
Músculos Abdominais/efeitos dos fármacos , Levobupivacaína , Morfina , Bloqueio Nervoso/métodos , Dor Pós-Operatória/tratamento farmacológico , Esplenectomia/efeitos adversos , Músculos Abdominais/diagnóstico por imagem , Analgésicos Opioides , Anestésicos Locais , China , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor Pós-Operatória/etiologia , Estudos Prospectivos , Reto do Abdome/diagnóstico por imagem , Reto do Abdome/efeitos dos fármacos , Ultrassonografia de Intervenção/métodos
11.
Mediators Inflamm ; 2020: 3649613, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32908448

RESUMO

BACKGROUND: Brain injury is the leading cause of death following cardiac arrest (CA) and cardiopulmonary resuscitation (CPR). Ac2-26 and endothelial nitric oxide synthase (eNOS) have been shown to reduce neuroinflammation. This study is aimed at determining the mechanism by which Ac2-26 protects against inflammation during brain injury following CA and CPR. METHODS: Sixty-four rats were randomized into sham, saline, Ac2-26, and Ac2-26+L-NIO (endothelial nitric oxide synthase (eNOS) inhibitor) groups. Rats received Ac2-26, Ac2-26+L-NIO, or saline after CPR. Neurologic function was assessed at baseline, 24, and 72 hours after CPR. At 72 hours after resuscitation, serum and brain tissues were collected. RESULTS: Blood-brain barrier (BBB) permeability increased, and the number of surviving neurons and neurological function decreased in the saline group compared to the sham group. Anti-inflammatory and proinflammatory factors, neuron-specific enolase (NSE) levels, and the expression of eNOS, phosphorylated (p)-eNOS, inducible nitric oxide synthase (iNOS), and oxidative stress-related factors in the three CA groups significantly increased (P < 0.05). BBB permeability decreased, and the number of surviving neurons and neurological function increased in the Ac2-26 group compared to the saline group (P < 0.05). Ac2-26 increased anti-inflammatory and reduced proinflammatory markers, raised NSE levels, increased the expression of eNOS and p-eNOS, and reduced the expression of iNOS and oxidative stress-related factors compared to the saline group (P < 0.05). The effect of Ac2-26 on brain injury was reversed by L-NIO (P < 0.05). CONCLUSIONS: Ac2-26 reduced brain injury after CPR by inhibiting oxidative stress and neuroinflammation and protecting the BBB. The therapeutic effect of Ac2-26 on brain injury was largely dependent on the eNOS pathway.


Assuntos
Anexina A1/metabolismo , Lesões Encefálicas/metabolismo , Reanimação Cardiopulmonar/métodos , Parada Cardíaca/terapia , Óxido Nítrico Sintase Tipo III/metabolismo , Peptídeos/metabolismo , Animais , Anti-Inflamatórios , Barreira Hematoencefálica , Inflamação , Masculino , Neurônios/metabolismo , Ornitina/análogos & derivados , Ornitina/farmacologia , Estresse Oxidativo , Permeabilidade , Ratos , Ratos Sprague-Dawley
12.
Biochem Biophys Res Commun ; 507(1-4): 128-135, 2018 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-30415773

RESUMO

BACKGROUND INFORMATION: Divalent metal transporter 1 (DMT1) and transferrin receptor (TfR1) are vital proteins for cellular iron uptake. These proteins have hypoxia-responsive elements (HREs) in their 5'-regulatory region, and they are regulated by hypoxia-inducible factor 1α (HIF-1α) transcriptionally under hypoxic condition. Besides, iron regulatory protein 1 (IRP1) regulates DMT1 and TfR1 by binding to iron-responsive elements (IREs) present in their mRNAs to control cellular iron homeostasis. RESULTS: Here, we explored the effect of acute hypoxia on iron uptake. Ferrous iron uptake was elevated by DMT1(+IRE) and TfR1 under acute hypoxia. The luciferase activity analysis revealed that the functional HREs of DMT1 and TfR1 were increased. However, their IREs-dependent luciferase activities were reduced simultaneously. The mRNA stability of TfR1 and DMT1(+IRE) was suppressed under acute hypoxia. The mRNA levels of TfR1 and DMT1(+IRE) were restrain by silencing IRP1. In sharp contrast, HIF-1α overexpression enhanced the mRNA levels of TfR1 and DMT1(+IRE), which reversed the inhibition of IRP1 on both. HIF-1α konckdown suppressed the hypoxia-induced increase expression of TfR1 and DMT1(+IRE), whereas both proteins had little change when further decreased the IRP1 expression under hypoxia. Hypoxia upregulated the protein expression of Ferrtin-L in a time-dependent manner, yet there was no different when IRP1 silencing or overexperssion under hypoxia. The lactate dehydrogenase (LDH) release induced by hypoxia was increased by TfR1 siRNA silence. CONCLUSIONS: We propose that HIF-1/HRE system might play a principal part in hypoxia induced iron uptake.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Proteína 1 Reguladora do Ferro/metabolismo , Ferro/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Hipóxia Celular/genética , Ferritinas/metabolismo , Células Hep G2 , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Proteína 1 Reguladora do Ferro/genética , Receptores da Transferrina/metabolismo , Elementos de Resposta/genética
13.
J Basic Microbiol ; 55(8): 1029-39, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25727311

RESUMO

A yeast producing a cold-adapted phytase was isolated from Antarctic deep-sea sediment and identified as a Rhodotorula mucilaginosa strain JMUY14 of basidiomycetous yeasts. It was cultured in fermentation optimized by a response surface methodology based on the Box-Behnken design. The maximum activity of phytase reached 205.447 U ml(-1), which was close to the predicted value of 201.948 U ml(-1) and approximately 3.4 times higher than its initial activity. The extracellular phytase was purified by 15.2-fold to homogeneity with a specific activity of 31,635 U mg(-1) by (NH4 )2 SO4 precipitation, and a combination of DEAE Sepharose Fast Flow, SP Sepharose Fast Flow, and Sephadex G-100. The molecular weight of the purified enzyme was estimated to be 63 kDa and its pI was 4.33. Its optimal temperature and pH were 50 °C and 5.0, respectively. Its activity was 85% at 37 °C, and showed good stability at pH 3.0 ∼ 7.0. When compared with mesophilic counterparts, the phytase not only exhibited a higher activity during 20 ∼ 30 °C but also had a low Km (247 µM) and high kcat (1394 s(-1)). The phytase activity was slightly stimulated in the presence of Mg(2+), Fe(2+), Fe(3+), K(+), Na(+), Ca(2+), EDTA, and EGTA and moderately inhibited by Cu(2+), Zn(2+), Mn(2+), Ag(+), PMSF, SDS, and phenylgloxal hydrate. It was resistant to both pepsin and trypsin. Since the phytase produced by the R. mucilaginosa JMUY14 showed a high specific activity, good pH stability, strong protease resistance, and high activity at low temperature, it has great potential for feed applications, especially in aquaculture.


Assuntos
6-Fitase/isolamento & purificação , 6-Fitase/metabolismo , Adaptação Fisiológica , Temperatura Baixa , Sedimentos Geológicos/microbiologia , Rhodotorula/enzimologia , 6-Fitase/antagonistas & inibidores , 6-Fitase/química , Sequência de Aminoácidos , Regiões Antárticas , Aquicultura , Estabilidade Enzimática , Fermentação , Concentração de Íons de Hidrogênio , Cinética , Peso Molecular , Pepsina A/metabolismo , Filogenia , Rhodotorula/isolamento & purificação , Rhodotorula/fisiologia , Especificidade por Substrato , Tripsina/metabolismo
14.
Int J Biol Macromol ; 273(Pt 2): 132685, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38823749

RESUMO

To overcome the trade-off challenge encountered in the engineering of alginate lyase AlyG2 from Seonamhaeicola algicola Gy8T and to expand its potential industrial applications, we devised a two-step strategy encompassing activity enhancement followed by thermal stability engineering. To enhance the specific activity of efficient AlyG2, we strategically substituted residues with bulky steric hindrance proximal to the active pocket with glycine or alanine. This led to the generation of three promising positive mutants, with particular emphasis on the T91S mutant, exhibiting a 1.91-fold specific activity compared to the wild type. To mitigate the poor thermal stability of T91S, mutants with negative ΔΔG values in the thermal flexibility region were screened out. Notably, the S72Ya mutant not only displayed 17.96 % further increase in specific activity but also exhibited improved stability compared to T91S, manifesting as a remarkable 30.97 % increase in relative activity following a 1-hour incubation at 42 °C. Furthermore, enhanced kinetic stability was observed. To gain deeper insights into the mechanism underlying the enhanced thermostability of the S72Ya mutant, we conducted molecular dynamics simulations, principal component analysis (PCA), dynamic cross-correlation map (DCCM), and free energy landscape (FEL) analysis. The results unveiled a reduction in the flexibility of the surface loop, a stronger correlation dynamic and a narrower motion subspace in S72Ya system, along with the formation of more stable hydrogen bonds. Collectively, our findings suggest amino acids substitutions resulting in smaller side chains proximate to the active site can positively impact enzyme activity, while reducing the flexibility of surface loops emerges as a pivotal factor in conferring thermal stability. These insights offer valuable guidance and a framework for the engineering of other enzyme types.


Assuntos
Estabilidade Enzimática , Simulação de Dinâmica Molecular , Polissacarídeo-Liases , Polissacarídeo-Liases/química , Polissacarídeo-Liases/genética , Polissacarídeo-Liases/metabolismo , Cinética , Temperatura , Engenharia de Proteínas/métodos , Mutação , Substituição de Aminoácidos , Mutagênese Sítio-Dirigida
15.
Sci Total Environ ; 931: 172466, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38626826

RESUMO

The burgeoning issue of plasmid-mediated resistance genes (ARGs) dissemination poses a significant threat to environmental integrity. However, the prediction of ARGs prevalence is overlooked, especially for emerging ARGs that are potentially evolving gene exchange hotspot. Here, we explored to classify plasmid or chromosome sequences and detect resistance gene prevalence by using DNABERT. Initially, the DNABERT fine-tuned in plasmid and chromosome sequences followed by multilayer perceptron (MLP) classifier could achieve 0.764 AUC (Area under curve) on external datasets across 23 genera, outperforming 0.02 AUC than traditional statistic-based model. Furthermore, Escherichia, Pseudomonas single genera based model were also be trained to explore its predict performance to ARGs prevalence detection. By integrating K-mer frequency attributes, our model could boost the performance to predict the prevalence of ARGs in an external dataset in Escherichia with 0.0281-0.0615 AUC and Pseudomonas with 0.0196-0.0928 AUC. Finally, we established a random forest model aimed at forecasting the relative conjugation transfer rate of plasmids with 0.7956 AUC, drawing on data from existing literature. It identifies the plasmid's repression status, cellular density, and temperature as the most important factors influencing transfer frequency. With these two models combined, they provide useful reference for quick and low-cost integrated evaluation of resistance gene transfer, accelerating the process of computer-assisted quantitative risk assessment of ARGs transfer in environmental field.


Assuntos
Transferência Genética Horizontal , Plasmídeos , Plasmídeos/genética , Conjugação Genética , Farmacorresistência Bacteriana/genética , Pseudomonas/genética
16.
ACS Appl Mater Interfaces ; 15(43): 49931-49942, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37856675

RESUMO

The skin secretion of Andrias davidianus (SSAD) is a novel biological adhesive raw material under development. This material exhibits robust adhesion while maintaining the flexibility of the wound. It also has the potential for large-scale production, making it promising for practical application explore. Hence, in-depth research on methods to fine-tune SSAD properties is of great importance to promote its practical applications. Herein, we aim to enhance the adhesive and healing properties of SSAD by incorporating functional components. To achieve this goal, we selected 3,4-dihydroxy-l-phenylalanine and vaccarin as the functional components and mixed them with SSAD, resulting in a new bioadhesive, namely, a formulation termed "enhanced SSAD" (ESSAD). We found that the ESSAD exhibited superior adhesive properties, and its adhesive strength was improved compared with the SSAD. Moreover, ESSAD demonstrated a remarkable ability to promote wound healing. This study presents an SSAD-based bioadhesive formulation with enhanced properties, affirming the feasibility of developing SSAD-based adhesive materials with excellent performance and providing new evidence for the application of SSAD. This study also aims to show that SSAD can be mixed with other substances, and addition of effective components to SSAD can be studied to further adjust or improve its performance.


Assuntos
Adesivos Teciduais , Cicatrização , Humanos , Adesivos/farmacologia , Pele , Adesivos Teciduais/farmacologia , Aderências Teciduais , Muco , Hidrogéis
17.
Bioresour Technol ; 364: 128003, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36155810

RESUMO

Anaerobic digestion (AD) is a potential bioprocess for waste biomass utilization and energy conservation. Various iron/carbon-based CMs (e.g., magnetite, biochar, granular activated carbon (GAC), graphite and zero valent iron (ZVI)) have been supplemented in anaerobic digestors to improve AD performance. Generally, the supplementation of CMs has shown to improve methane production, shorten lag phase and alleviate environmental stress because they could serve as electron conduits and promote direct interspecies electron transfer (DIET). However, the CMs dosage varied greatly in previous studies and CMs wash out remains a challenge for its application in full-scale plants. Future work is recommended to standardize the CMs dosage and recover/reuse the CMs. Moreover, additional evidence is required to verify the electrotrophs involved in DIET.


Assuntos
Elétrons , Metano , Anaerobiose , Ferro , Transporte de Elétrons , Reatores Biológicos , Esgotos
18.
ACS Macro Lett ; 11(6): 805-812, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35666550

RESUMO

A versatile hydrophilic and antifouling coating was designed and prepared based on catechol-modified four-arm polyethylene glycol. The dopamine (DA) molecules were grafted onto the end of the four-arm polyethylene glycol carboxyl (4A-PEG-COOH) through the amidation reaction, which was proven by 1H NMR and FTIR analysis, assisting the strong adhesion of PEG on the surface of various types of materials, including metallic, inorganic, and polymeric materials. The reduction of the water contact angle and the bacteria-repellent and protein-repellent effects indicated that the coating had good hydrophilicity and antifouling performance. Raman spectroscopy analysis demonstrated the affinity between the polymeric surface and water, which further confirmed the hydrophilicity of the coating. Finally, in vitro cytotoxicity assay demonstrated good biocompatibility of the coating layer.


Assuntos
Incrustação Biológica , Polietilenoglicóis , Incrustação Biológica/prevenção & controle , Dopamina , Interações Hidrofóbicas e Hidrofílicas , Polietilenoglicóis/farmacologia , Água
19.
Bioresour Technol ; 346: 126641, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34973405

RESUMO

Hybrid microbial electrolysis cells-anaerobic digestion (MEC-AD) was proved to increase methane productivity and methane yield of waste activated sludge (WAS) by establishing direct interspecies electron transfer method and enriching functional microorganisms. This review first summarized the pretreatment methods of WAS for MEC-AD and then reviewed the reactor configurations, operation parameters, and the economic benefit of MEC-AD. Furthermore, the enhancement mechanisms of MEC-AD were reviewed based on the analysis of thermodynamics and microbial community. It was found that the decrease of hydrogen partial pressure due to the hydrogenotrophic methanogens enriched in cathodic biofilm and direct interspecies electron transfer between exoelectrogens and anode were the core mechanisms for improving acidogenesis, acetogenesis, and methanogenesis. Finally, the potentially technological issues that need to be addressed to increase energy efficiency in large-scale MEC-AD processes were discussed.


Assuntos
Reatores Biológicos , Esgotos , Anaerobiose , Eletrólise , Metano
20.
Eur J Med Chem ; 244: 114821, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36242985

RESUMO

VEGFR-2 is an attractive therapeutic target for antitumor drug research by blocking tumor angiogenesis and PROTAC provides a new technology for targeted protein knockout. Herein, a library of novel VEGFR-2-PROTAC degraders were rationally designed and synthesized based on the Lys residue region on the surface of VEGFR-2 protein using protein structure-based drug design strategy. Among them, P7 exhibited preferable antitumor activity against HGC-27 cells and less toxic to human normal HUVEC, HEK293T and GES-1 cells in vitro, as well as the potent degradation activity of VEGFR-2 protein in HGC-27 cells (DC50: 0.084 ± 0.04 µM, Dmax: 73.7%) and HUVEC cells (DC50: 0.51 ± 0.10 µM, Dmax: 76.6%). Additionally, P7 degraded VEGFR-2 protein by the formation of ternary complex and the ubiquitin proteasome pathway in HGC-27 cells. Furthermore, P7 shortened the half-life of VEGFR-2 protein synthesis and had no inhibitory effect on the expression of VEGFR-2 mRNA in HGC-27 cells. Moreover, P7 inhibited the colony formation, migration and invasion of HGC-27 cells in a time- and dose-dependent manner, and meanwhile induced G2/M phase cycle arrest and apoptosis. All the results demonstrated that P7 could be as a promising VEGFR-2-PROTAC degrader for gastric cancer therapy.


Assuntos
Antineoplásicos , Neoplasias Gástricas , Humanos , Receptor 2 de Fatores de Crescimento do Endotélio Vascular , Lisina/farmacologia , Neoplasias Gástricas/tratamento farmacológico , Células HEK293 , Proteólise , Proliferação de Células , Antineoplásicos/farmacologia , Antineoplásicos/química , Proteína Supressora de Tumor Von Hippel-Lindau
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