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1.
Proc Natl Acad Sci U S A ; 121(18): e2314541121, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38657049

RESUMO

Recent evidence has demonstrated that the transsynaptic nanoscale organization of synaptic proteins plays a crucial role in regulating synaptic strength in excitatory synapses. However, the molecular mechanism underlying this transsynaptic nanostructure in inhibitory synapses still remains unclear and its impact on synapse function in physiological or pathological contexts has not been demonstrated. In this study, we utilized an engineered proteolysis technique to investigate the effects of acute cleavage of neuroligin-2 (NL2) on synaptic transmission. Our results show that the rapid cleavage of NL2 led to impaired synaptic transmission by reducing both neurotransmitter release probability and quantum size. These changes were attributed to the dispersion of RIM1/2 and GABAA receptors and a weakened spatial alignment between them at the subsynaptic scale, as observed through superresolution imaging and model simulations. Importantly, we found that endogenous NL2 undergoes rapid MMP9-dependent cleavage during epileptic activities, which further exacerbates the decrease in inhibitory transmission. Overall, our study demonstrates the significant impact of nanoscale structural reorganization on inhibitory transmission and unveils ongoing modulation of mature GABAergic synapses through active cleavage of NL2 in response to hyperactivity.


Assuntos
Moléculas de Adesão Celular Neuronais , Proteínas do Tecido Nervoso , Sinapses , Transmissão Sináptica , Animais , Camundongos , Moléculas de Adesão Celular Neuronais/metabolismo , Epilepsia/metabolismo , Epilepsia/fisiopatologia , Epilepsia/patologia , Hipocampo/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas do Tecido Nervoso/genética , Proteólise , Receptores de GABA-A/metabolismo , Sinapses/metabolismo , Transmissão Sináptica/fisiologia
2.
Mol Cell ; 72(3): 457-468.e5, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30344099

RESUMO

Successful regeneration of severed peripheral nerves requires the breakdown and subsequent clearance of myelin, tightly packed membrane sheaths of Schwann cells that protect nerve fibers and harbor nerve growth-inhibitory proteins. How Schwann cells initiate myelin breakdown in response to injury is still largely unknown. Here we report that, following sciatic nerve injury, MLKL, a pseudokinase known to rupture cell membranes during necroptotic cell death, is induced and targets the myelin sheath membrane of Schwann cells to promote myelin breakdown. The function of MLKL in disrupting myelin sheaths requires injury-induced phosphorylation of serine 441, an activation signal distinct from the necroptosis-inducing phosphorylation by RIP3 kinase. Mice with Mlkl specifically knocked out in Schwann cells showed delayed myelin sheath breakdown. Lack of MLKL reduced nerve regeneration following injury, whereas overexpression of MLKL accelerated myelin breakdown and promoted the regeneration of axons.


Assuntos
Traumatismos dos Nervos Periféricos/metabolismo , Proteínas Quinases/fisiologia , Células de Schwann/fisiologia , Animais , Apoptose , Membrana Celular , Células HEK293 , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Bainha de Mielina/metabolismo , Necrose , Regeneração Nervosa/fisiologia , Traumatismos dos Nervos Periféricos/fisiopatologia , Fosforilação , Proteínas Quinases/genética , Proteínas Quinases/metabolismo
3.
J Comput Assist Tomogr ; 47(6): 924-933, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37948368

RESUMO

OBJECTIVE: We evaluated the feasibility of using multiregional radiomics to identify brain metastasis (BM) originating from lung adenocarcinoma (LA) and breast cancer (BC) and assess the epidermal growth factor receptor (EGFR) mutation and human epidermal growth factor receptor 2 (HER2) status. METHODS: Our experiment included 160 patients with BM originating from LA (n = 70), BC (n = 67), and other tumor types (n = 23), between November 2017 and December 2021. All patients underwent contrast-enhanced T1- and T2-weighted magnetic resonance imaging (MRI) scans. A total of 1967 quantitative MRI features were calculated from the tumoral active area and peritumoral edema area and selected using least absolute shrinkage and selection operator regression with 5-fold cross-validation. We constructed radiomic signatures (RSs) based on the most predictive features for preoperative assessment of the metastatic origins, EGFR mutation, and HER2 status. Prediction performance of the constructed RSs was evaluated based on the receiver operating characteristic curve analysis. RESULTS: The developed multiregion RSs generated good area under the receiver operating characteristic curve (AUC) for identifying the LA and BC origin in the training (AUCs, RS-LA vs RS-BC, 0.767 vs 0.898) and validation (AUCs, RS-LA vs RS-BC, 0.778 and 0.843) cohort and for predicting the EGFR and HER2 status in the training (AUCs, RS-EGFR vs RS-HER2, 0.837 vs 0.894) and validation (AUCs, RS-EGFR vs RS-HER2, 0.729 vs 0.784) cohorts. CONCLUSIONS: Our results revealed associations between brain MRI-based radiomics and their metastatic origins, EGFR mutations, and HER2 status. The developed multiregion combined RSs may be considered noninvasive predictive markers for planning early treatment for BM patients.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Encefálicas , Neoplasias da Mama , Neoplasias Pulmonares , Humanos , Feminino , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/genética , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/genética , Receptor ErbB-2/genética , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/genética , Estudos Retrospectivos , Imageamento por Ressonância Magnética
4.
Ecotoxicol Environ Saf ; 254: 114699, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36889212

RESUMO

Exposure to particulate matters with diameters below 2.5 µm (PM2.5) is considered a major risk factor for cardiovascular diseases (CVDs). The closest associations between PM2.5 and CVDs have been observed in hyperbetalipoproteinemia cases, although the detailed underpinning mechanism remains undefined. In this work, hyperlipidemic mice and H9C2 cells were used to examine the effects of PM2.5 on myocardial injury and their underlying mechanisms. The results revealed that PM2.5 exposure caused severe myocardial damage in the high-fat mouse model. Oxidative stress and pyroptosis were also observed along with myocardial injury. After inhibiting pyroptosis with disulfiram (DSF), the level of pyroptosis was effectively reduced as well as myocardial injury, suggesting that PM2.5 induced the pyroptosis pathway and further caused myocardial injury and cell death. Afterwards, by suppressing PM2.5-induced oxidative stress with N-acetyl-L-cysteine (NAC), myocardial injury was markedly ameliorated, and the upregulation of pyroptosis markers was reversed, which indicated that PM2.5-pyroptosis was also improved. Taken together, this study revealed that PM2.5 induce myocardial injury through the ROS-pyroptosis signaling pathway in hyperlipidemia mice models, providing a potential approach for clinical interventions.


Assuntos
Piroptose , Transdução de Sinais , Camundongos , Animais , Espécies Reativas de Oxigênio/metabolismo , Estresse Oxidativo , Material Particulado/toxicidade
5.
J Transl Med ; 20(1): 74, 2022 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-35123506

RESUMO

BACKGROUND: Free circular RNAs(circRNAs) escaping from primary lesion of cancer to brain are strictly regulated by blood-brain barrier and therefore cerebrospinal fluid (CSF) circRNAs have potential advantage in exploring biomarkers and mechanism of brain metastasis in lung cancer. METHODS: We collected paired cerebrospinal fluid, plasma and tumor tissues from 21 lung adenocarcinoma (ADC) patients with brain metastases (BM) and performed RNA sequencing. RESULTS: Compared to tumor tissue and plasma, circRNAs in CSF were characterized by lower number of spieces but higher abundance. Notably, CSF-circRNAs displayed high heterogeneity among different BM lung ADC patients. A total of 60 CSF-circRNAs was identified and associated with shorten overall survival. The circRNA-miRNA-mRNA network analysis revealed that the 60 CSF-circRNAs involved in cancer-associated pathways, and five of them showed strong association with WNT signaling pathway. Validation by RT-PCR of CSF and in vitro experiments of the five candidate circRNAs support their potential roles in cell proliferation and invasion. CONCLUSIONS: In summary, our results depicted the heterogenous CSF-circRNAs profiles among BM lung ADC and implied that CSF-circRNAs may be promising prognosis-related biomarkers.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Encefálicas , Neoplasias Pulmonares , MicroRNAs , Adenocarcinoma de Pulmão/genética , Neoplasias Encefálicas/genética , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , MicroRNAs/genética , RNA Circular/genética
6.
Support Care Cancer ; 30(9): 1-12, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35501513

RESUMO

BACKGROUND: A growing number of articles had reported the beneficial effects of physical exercise on reduced risks of cancer recurrence and mortality. However, the associations between physical exercise and laboratory biomarkers still had controversy. As we knew, this meta-analysis of randomized controlled trials (RCTs) was the first time for us to comprehensively clarify their relationships in cancer patients. METHODS: We comprehensively searched the PubMed, Cochrane Central, EMBASE, Web of Science, and SportDiscus online databases to identify eligible articles, up to June 1, 2021. Pooled standardized mean differences (SMDs) with 95% confidence intervals (CIs) were utilized to clarify their associations. Sensitivity analysis was performed to assess the impact of the individual on overall and Begg's/Egger's plot was utilized to evaluate potential publication bias. RESULTS: Finally, 35 randomized controlled trials (RCTs) were finally enrolled in this meta-analysis. Our results indicated that physical exercise could significantly reduce BMI (pooled SMD = -0.32 - 0.56 to -0.09)), body weight (pooled SMD = -0.31 (-0.54 to -0.08)), body fat (pooled SMD = -0.44 (-0.70 to -0.18)), waist circumference (pooled SMD = -0.50 (-0.76 to -0.23)), hip circumference (pooled SMD = -0.54 (-0.80 to -0.28)), triglyceride (pooled SMD = -0.35 (-0.69 to -0.02)), fasting insulin (pooled SMD = -0.38 (-0.54 to -0.22)), glucose (pooled SMD = -0.56 (-0.84 to -0.28)), insulin resistance (pooled SMD = -0.40 (-0.72 to -0.07)), CRP (pooled SMD = -0.97 (-1.48 to -0.46)), IGF-1 levels (pooled SMD = -0.56 (-0.83 to -0.29)) and remarkably increase IGFBP-3 levels (pooled SMD = 0.81 (0.45 to 1.17)). Further sensitivity analysis and Begg's or Egger's test suggested that our results were robust with no significant publication bias. CONCLUSIONS: Our results shed light on the beneficial effects of physical exercise on cancer patients by means of BMI/weight change and various biomarkers alteration (insulin-glucose pathways or inflammatory biomarkers). Our results were anticipated for clinical application to improve cancer patients' prognosis.


Assuntos
Exercício Físico , Neoplasias , Tecido Adiposo , Biomarcadores , Glucose , Humanos , Insulina , Neoplasias/terapia , Ensaios Clínicos Controlados Aleatórios como Assunto
7.
BMC Pulm Med ; 22(1): 463, 2022 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-36471379

RESUMO

BACKGROUND: To comprehensively analyze the stemness characteristics related to prognosis and the immune microenvironment in lung adenocarcinoma (LUAD). METHODS: The OCLR machine learning method was used to calculate the stemness index (mRNAsi) of the LUAD samples. DEGs common between the low mRNAsi, normal, and high mRNAsi groups were screened and the immune-stemness genes were obtained. Then the PPI network was created and enrichment analyses were performed. Moreover, different subtypes based on immune-stemness genes associated with prognosis were identified, and the relationships between LUAD stemness and TIME variables were systematically analyzed, followed by TMB analysis. RESULTS: Patients in the high mRNAsi groups with poor prognosis were screened along with 144 immune-stemness genes. IL-6, FPR2, and RLN3 showed a higher degree in the PPI network. A total of 26 immune-stemness genes associated with prognosis were screened. Two clusters were obtained (cluster 1 and cluster 2). Survival analysis revealed that patients in cluster 2 had a poor prognosis. A total of 12 immune cell subpopulations exhibited significant differences between cluster 1 and cluster 2 (P < 0.05). A total of 10 immune checkpoint genes exhibited significantly higher expression in cluster 1 (P < 0.05) than in cluster 2. Further, the TMB value in cluster 2 was higher than that in cluster 1 (P < 0.05). CONCLUSION: Immune-stemness genes, including L-6, FPR2, and RLN3, might play significant roles in LUAD development via cytokine-cytokine receptor interaction, neuroactive ligand‒receptor interaction, and the JAK‒STAT pathway. Immune-stemness genes were related to tumor-infiltrating immune cells, TMB, and expression of immune checkpoint gene.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Humanos , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/imunologia , Regulação Neoplásica da Expressão Gênica , Janus Quinases/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/imunologia , Prognóstico , Relaxina/genética , Transdução de Sinais , Fatores de Transcrição STAT/genética , Microambiente Tumoral
8.
Proc Natl Acad Sci U S A ; 116(46): 23332-23338, 2019 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-31653761

RESUMO

Apoptosis activation by cytochrome c release from mitochondria to cytosol is a normal cellular response to mitochondrial damage. Using cellular apoptosis assay, we have found small-molecule apoptosis inhibitors that protect cells from mitochondrial damage. Previously, we reported the discovery of a small molecule, Compound A, which blocks dopaminergic neuron death in a rat model of Parkinson's disease through targeting succinate dehydrogenase subunit B (SDHB) of complex II to protect the integrity of the mitochondrial respiratory chain. Here, we report a small molecule, Compound R6, which saves cells from apoptosis via mammalian target of rapamycin (mTOR)-mediated induction of autophagy. Additionally, we show that Compound R6 protects mitochondrial integrity and respiration after induction of the intrinsic apoptosis pathway. Encouragingly, and supporting the potential further application of Compound R6 as a tool for basic and medicinal research, a pharmacokinetics (PK) profiling study showed that Compound R6 is metabolically stable and can pass the blood-brain barrier. Moreover, Compound R6 accumulates in the brain of test animals via intravenous and intraperitoneal administration. Finally, we found that Compound R6 confers significant neuroprotective effects on a rat cerebral ischemia/reperfusion model, demonstrating its potential as a promising drug candidate for neurodegenerative diseases.


Assuntos
Apoptose/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Animais , Autofagia/efeitos dos fármacos , Proteína 11 Semelhante a Bcl-2/metabolismo , Avaliação Pré-Clínica de Medicamentos , Masculino , Mitocôndrias/efeitos dos fármacos , Doenças Neurodegenerativas/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Ratos Sprague-Dawley
9.
Sensors (Basel) ; 22(23)2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36502054

RESUMO

The fatigue life of orthotropic steel decks (OSDs) is significantly affected by vehicle loads, and the local stress response of OSDs is sensitive to the transverse position of vehicle loads. However, the presence of autonomous vehicles is likely to change the transverse distribution of vehicles within the lane, thereby affecting vehicle-induced fatigue damage to OSDs. Therefore, it is necessary to evaluate the potential effect of autonomous vehicles on the fatigue life of OSDs so that appropriate strategies can be implemented to control the transverse positions of autonomous vehicles passing the bridge deck. To this end, fatigue damages of several typical fatigue details in a conventional OSD (COSD) and a lightweight composite OSD (LWCD) induced by vehicle loads were calculated based on finite element analysis, and their fatigue lives were evaluated based on Miner's Rule, in which different transverse distribution patterns of autonomous vehicles and their proportions in the mixed traffic flow were considered. The results indicate that fatigue lives of both the COSD and the LWCD can be negatively affected by autonomous vehicles traveling across the bridge without any constraints on the transverse distribution, especially when their proportion in the mixed traffic flow exceeds 30%. Compared to the scenario without autonomous vehicles, the fatigue damage of most fatigue details in OSDs may increase by 51% to 210% in the most unfavorable case due to the presence of autonomous vehicles. Nevertheless, it is feasible to extend the fatigue life of OSDs by optimizing the transverse distribution of autonomous vehicles. Specifically, the fatigue life of most fatigue details in the COSD could be extended by more than 86% in the most favorable case when a bimodal Gaussian distribution is adopted as the transverse distribution pattern of autonomous vehicles. Moreover, both the negative and positive effects of autonomous vehicles on the fatigue life of the COSD are more significant than those of the LWCD in most cases. The results can provide references for the maintenance of OSDs under the action of autonomous vehicles.


Assuntos
Acidentes de Trânsito , Aço
10.
J Am Chem Soc ; 143(26): 9893-9900, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34160219

RESUMO

Organophosphorus nerve agents, a class of extremely toxic chemical warfare agents (CWAs), have remained a threat to humanity because of their continued use against civilian populations. To date, Zr(IV)-based metal organic framework (MOFs) are the most prevalent nerve agent hydrolysis catalysts, and relatively few reports disclose MOFs containing nodes with other Lewis acidic transition metals. In this work, we leveraged this synthetic tunability to explore how the identity of the transition metal node in the M-MFU-4l series of MOFs (M = Zn, Cu, Ni, Co) influences the catalytic performance toward the hydrolysis of the nerve agent simulant dimethyl (4-nitrophenyl)phosphate (DMNP). Experimental studies reveal that Cu-MFU-4l exhibits the best performance in this series with a half-life for hydrolysis of ∼2 min under these conditions. In contrast, both Ni- and Co-MFU-4l demonstrate significantly slower reactivity toward DMNP, as they both fail to surpass 30% conversion of DMNP after 1 h under analogous conditions. Further modification of the active site within Cu-MFU-4l is possible, and we found that although the identity of the anion coordinated to the Cu(II)-X (X = Cl-, HCOO-, ClO4-, NO3-) active site has little influence on the catalytic performance, reduction of the Cu(II) sites yields nodes that contain Cu(I) ions in a trigonal geometry with open metal sites, leading to remarkable catalytic activity with a half-life for hydrolysis less than 2 min. Computational studies indicate the Cu(I) sites exhibit stronger binding affinities than Cu(II) to both water and DMNP, which corroborates the experimental results.

11.
J Am Chem Soc ; 143(11): 4302-4310, 2021 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-33706512

RESUMO

The understanding of structure-activity relationships at the atomic level has played a profound role in heterogeneous catalysis, providing valuable insights into designing suitable heterogeneous catalysts. However, uncovering the detailed roles of how such active species' structures affect their catalytic performance remains a challenge owing to the lack of direct structural information on a specific active species. Herein, we deposited molybdenum(VI), an active species in oxidation reactions, on the Zr6 node of a mesoporous zirconium-based metal-organic framework (MOF) NU-1200, using solvothermal deposition in MOFs (SIM). Due to the high crystallinity of the NU-1200 support, the precise structure of the resulting molybdenum catalyst, Mo-NU-1200, was characterized through single-crystal X-ray diffraction (SCXRD). Two distinct anchoring modes of the molybdenum species were observed: one mode (Mo1), displaying an octahedral geometry, coordinated to the node through one terminal oxygen atom and the other mode (Mo2) coordinated to two adjacent Zr6 node oxygen atoms in a tetrahedral geometry. To investigate the role of base in the catalytic activity of these Mo centers, we assessed the activity of Mo-NU-1200 for the aerobic oxidation of 4-methoxybenzyl alcohol as a model reaction. The results revealed that Mo-NU-1200 exhibited remarkably higher catalytic reactivity under base-free conditions, while the presence of base inhibited the catalytic reactivity of this species. SCXRD studies revealed that the molybdenum binding motifs (structures of the supported metal on the Zr6 node in the MOF) changed over the course of the reactions. Following the oxidation without base, both pristine coordination modes (Mo1 and Mo2) evolved into a new coordination mode (Mo3), in which the molybdenum atom coordinated to two adjacent oxygen atoms from the Zr6 node in an octahedral geometry, while in the presence of base, the pristine Mo1 coordination mode evolved entirely into the pristine Mo2. This study demonstrates the direct observation of an active species' structural evolution from metal installation to subsequent catalytic reaction. As a result, these subtle structural changes in catalyst binding motifs led to distinct differences in catalytic activities, providing a compelling strategy for elucidating structure-activity relationships.

12.
J Am Chem Soc ; 143(40): 16777-16785, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34590851

RESUMO

The most recent global health crisis caused by the SARS-CoV-2 outbreak and the alarming use of chemical warfare agents highlight the necessity to produce efficient protective clothing and masks against biohazard and chemical threats. However, the development of a multifunctional protective textile is still behind to supply adequate protection for the public. To tackle this challenge, we designed multifunctional and regenerable N-chlorine based biocidal and detoxifying textiles using a robust zirconium metal-organic framework (MOF), UiO-66-NH2, as a chlorine carrier which can be easily coated on textile fibers. A chlorine bleaching converted the amine groups located on the MOF linker to active N-chlorine structures. The fibrous composite exhibited rapid biocidal activity against both Gram-negative bacteria (E. coli) and Gram-positive bacteria (S. aureus) with up to a 7 log reduction within 5 min for each strain as well as a 5 log reduction of SARS-CoV-2 within 15 min. Moreover, the active chlorine loaded MOF/fiber composite selectively and rapidly degraded sulfur mustard and its chemical simulant 2-chloroethyl ethyl sulfide (CEES) with half-lives less than 3 minutes. The versatile MOF-based fibrous composite designed here has the potential to serve as protective cloth against both biological and chemical threats.


Assuntos
Antibacterianos/farmacologia , Antivirais/farmacologia , Substâncias para a Guerra Química/química , Cloro/farmacologia , Estruturas Metalorgânicas/farmacologia , Roupa de Proteção , Animais , Antibacterianos/síntese química , Antivirais/síntese química , Linhagem Celular , Cloro/química , Escherichia coli/efeitos dos fármacos , Halogenação , Humanos , Estruturas Metalorgânicas/síntese química , Testes de Sensibilidade Microbiana , Gás de Mostarda/análogos & derivados , Gás de Mostarda/química , Oxirredução , SARS-CoV-2/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Têxteis , Zircônio/química
13.
J Am Chem Soc ; 142(51): 21428-21438, 2020 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-33290083

RESUMO

While linkers with various conformations pose challenges in the design and prediction of metal-organic framework (MOF) structures, they ultimately provide great opportunities for the discovery of novel structures thereby enriching structural diversity. Tetratopic carboxylate linkers, for example, have been widely used in the formation of Zr-based MOFs due to the ability to target diverse topologies, providing a promising platform to explore their mechanisms of formation. However, it remains a challenge to control the resulting structures when considering the complex assembly of linkers with unpredicted conformations and diverse Zr6 node connectivities. Herein, we systematically explore how solvents and modulators employed during synthesis influence the resulting topologies of Zr-MOFs, choosing H4TCPB-Br2 (1,4-dibromo-2,3,5,6-tetrakis(4-carboxyphenyl)benzene) as a representative tetratopic carboxylate linker. By modulating the reaction conditions, the conformations of the linker and the connectivities of the Zr6 node can be simultaneously tuned, resulting in four types of structures: a new topology (NU-500), she (NU-600), scu (NU-906), and csq (NU-1008). Importantly, we have synthesized the first 5-connected Zr6 node to date with the (4,4,4,5)-connected framework, NU-500. We subsequently performed detailed structural analyses to uncover the relationship between the structures and topologies of these MOFs and demonstrated the crucial role that the flexible linker played to access varied structures by different degrees of linker deformation. Due to a variety of pore structures ranging from micropores to hierarchical micropores and mesopores, the resulting MOFs show drastically different behaviors for the adsorption of n-hexane and dynamic adsorption of 2-chloroethyl ethyl sulfide (CEES) under dry and humid conditions.


Assuntos
Poluentes Ambientais/química , Poluentes Ambientais/isolamento & purificação , Estruturas Metalorgânicas/química , Zircônio/química , Adsorção , Benzeno/química , Cinética , Gás de Mostarda/análogos & derivados , Gás de Mostarda/química , Gás de Mostarda/isolamento & purificação , Porosidade
14.
Glycoconj J ; 37(6): 767-775, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32926333

RESUMO

ß1,4-GalT1 is a type II membrane glycosyltransferase. It catalyzes the production of lactose in the lactating mammary gland and is supposedly also involved in the galactosylation of terminal GlcNAc of complex-type N-glycans. In-vitro studies of the bovine ß4Gal-T1 homolog showed that replacing a single residue of tyrosine with leucine at position 289 alters the donor substrate specificity from UDP-Gal to UDP-N-acetyl-galactosamine (UDP-GalNAc). The effect of this peculiar change in ß1,4GalT1 specificity was investigated in-vivo, by generating biallelic Tyr286Leu ß1,4GalT1 mice using CRISPR/Cas9 and crossbreeding. Mice bearing this mutation showed no appreciable defects when compared to wild-type mice, with the exception of biallelic female B4GALT1 mutant mice, which were unable to produce milk. The detailed comparison of wild-type and mutant mice derived from liver, kidney, spleen, and intestinal tissues showed only small differences in their N-glycan pattern. Comparable N-glycosylation was also observed in HEK 293 wild-type and knock-out B4GALT1 cells. Remarkably and in contrast to the other analyzed tissue samples, sialylation and galactosylation of serum N-glycans of biallelic Tyr286Leu GalT1 mice almost disappeared completely. These results suggest that ß1,4GalT1 plays a special role in the synthesis of serum N-glycans. The herein described Tyr286Leu ß1,4GalT1 mutant mouse model may, therefore, prove useful in the investigation of the mechanism which regulates tissue-dependent galactosylation.


Assuntos
Galactose/metabolismo , Galactosiltransferases/genética , Polissacarídeos/sangue , Animais , Bovinos , Feminino , Galactosiltransferases/metabolismo , Glicosilação , Células HEK293 , Humanos , Lactação/genética , Camundongos , Polimorfismo de Nucleotídeo Único/genética , Polissacarídeos/genética , Especificidade por Substrato
15.
J Acoust Soc Am ; 145(6): EL567, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31255125

RESUMO

A passive broadband source localization approach in the deep ocean is proposed based on the coherent matched-field processing combined with a Riemannian distance. The spatial coherence between hydrophones over frequency bandwidth is utilized for eliminating the unknown source spectrum. Three Riemannian distances are introduced for the measurement of the similarity between the data and replica matrices. The experimental results indicate that the proposed processors with a short array can effectively suppress the sidelobe and improve the localization performance. The source localization influenced by the factors such as the aperture, number of hydrophones, and desired bandwidth is also demonstrated.

16.
Sensors (Basel) ; 19(17)2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31484441

RESUMO

Passive multiple sound source localization is a challenging problem in underwater acoustics, especially for a short hydrophone array in the deep ocean. Several attempts have been made to solve this problem by applying compressive sensing (CS) techniques. In this study, one greedy algorithm in CS theory combined with a spatial filter was developed and applied to a two-source localization scenario in the deep ocean. This method facilitates localization by utilizing the greedy algorithm with a spatial filter at several iterative loops. The simulated and experimental data suggest that the proposed method provides a certain localization performance improvement over the use of the Bartlett processor and the greedy algorithm without a spatial filter. Additionally, the effects on the source localization caused by factors such as the array aperture, number of hydrophones or snapshots, and signal-to-noise ratio (SNR) are demonstrated.

17.
J Cell Mol Med ; 22(6): 3259-3263, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29575613

RESUMO

Single-chain variable fragment (scFv) antibodies are the smallest immunoglobulins with high antigen-binding affinity. We have previously reported that fibroblast growth factor 1 played pivotal roles in cancer development and generated a mouse scFv (mscFv1C9) could effectively prohibit cancer cell proliferation in vitro and in vivo. Here, we further humanized this scFv (hscFv1C9) using a structure-guided complementarity determining region grafting strategy. The purified hscFv1C9 maintained similar antigen-binding affinity and specificity as mscFv1C9, and it was capable of inhibiting growth of different tumours in vitro and in vivo. These data strongly suggested that hscFv1C9 has antitumour potentials.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Fator 1 de Crescimento de Fibroblastos/antagonistas & inibidores , Glioma/tratamento farmacológico , Anticorpos de Cadeia Única/farmacologia , Sequência de Aminoácidos/genética , Animais , Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Monoclonais Humanizados/farmacologia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Feminino , Fator 1 de Crescimento de Fibroblastos/química , Fator 1 de Crescimento de Fibroblastos/genética , Fator 1 de Crescimento de Fibroblastos/imunologia , Glioma/genética , Glioma/patologia , Xenoenxertos , Humanos , Camundongos , Anticorpos de Cadeia Única/imunologia
18.
Org Biomol Chem ; 16(17): 3189-3202, 2018 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-29648554

RESUMO

Novel quinazoline-2,4(1H,3H)-dione derivatives bearing a 3-amino pyrrolidine moiety were designed and synthesized as PARP-1/2 inhibitors. Structure-activity relationships were examined which revealed a number of potent PARP-1/2 inhibitors with moderate selectivity toward PARP-1 over PARP-2. These compounds had IC50 values against PARP-1 at the 10-9 M level and against PARP-2 at the 10-8 M level. Among all the synthesized compounds, compounds 10 and 11 displayed strong cytotoxicities which are either used as a single agent or in combination with temozolomide (TMZ) in MX-1 cells (10, IC50 < 3.12 µM, PF50 > 10; 11, IC50 = 3.02 µM, PF50 ≈ 10). In vivo tumor growth inhibition was investigated using compound 11 in combination with TMZ, and it was demonstrated that compound 11 could strongly potentiate the cytotoxicity of TMZ in a MX-1 xenograft tumor model. The co-crystal structure of compound 11 complexed with PARP-1 was achieved and demonstrated a unique binding mode.


Assuntos
Antineoplásicos/química , Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Inibidores de Poli(ADP-Ribose) Polimerases/química , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Quinazolinas/química , Quinazolinas/uso terapêutico , Animais , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Desenho de Fármacos , Feminino , Humanos , Camundongos , Simulação de Acoplamento Molecular , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Poli(ADP-Ribose) Polimerase-1/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/síntese química , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Poli(ADP-Ribose) Polimerases/metabolismo , Quinazolinas/síntese química , Quinazolinas/farmacologia , Relação Estrutura-Atividade
19.
Bioorg Med Chem ; 26(8): 2186-2197, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29576270

RESUMO

Pin1 (Protein interacting with NIMA1) is a cis-trans isomerase and promotes the amide bond rotation of phosphoSer/Thr-Pro motifs in its substrates. Inhibition of Pin1 might be a novel strategy for developing anticancer agents. Herein, a series of pyrimidine derivatives were synthesized and their Pin1 inhibitory activities were evaluated. Among them, four compounds (2a, 2f, 2h and 2l) displayed potent inhibitory activities against Pin1 with IC50 values lower than 3 µM. This series of pyrimidine-based inhibitors presented time-dependent inhibition against Pin1. The structure-activity relationships on the 2-, 4- and 5-positions of the pyrimidine ring were analyzed in details, which would facilitate further exploration of new Pin1 inhibitors.


Assuntos
Inibidores Enzimáticos/síntese química , Peptidilprolil Isomerase de Interação com NIMA/antagonistas & inibidores , Pirimidinas/química , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/metabolismo , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Humanos , Peptidilprolil Isomerase de Interação com NIMA/genética , Peptidilprolil Isomerase de Interação com NIMA/metabolismo , Ligação Proteica , Pirimidinas/síntese química , Pirimidinas/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Relação Estrutura-Atividade
20.
Sensors (Basel) ; 18(2)2018 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-29360793

RESUMO

Wind-driven and distant shipping noise sources contribute to the total noise field in the deep ocean direct-arrival zones. Wind-driven and distant shipping noise sources may significantly and simultaneously affect the spatial characteristics of the total noise field to some extent. In this work, a ray approach and parabolic equation solution method were jointly utilized to model the low-frequency ambient noise field in a range-dependent deep ocean environment by considering their calculation accuracy and efficiency in near-field wind-driven and far-field distant shipping noise fields. The reanalysis databases of National Center of Environment Prediction (NCEP) and Volunteer Observation System (VOS) were used to model the ambient noise source intensity and distribution. Spatial vertical directionality and correlation were analyzed in three scenarios that correspond to three wind speed conditions. The noise field was dominated by distant shipping noise sources when the wind speed was less than 3 m/s, and then the spatial vertical directionality and vertical correlation of the total noise field were nearly consistent with those of distant shipping noise field. The total noise field was completely dominated by near field wind generated noise sources when the wind speed was greater than 12 m/s at 150 Hz, and then the spatial vertical correlation coefficient and directionality pattern of the total noise field was approximately consistent with that of the wind-driven noise field. The spatial characteristics of the total noise field for wind speeds between 3 m/s and 12 m/s were the weighted results of wind-driven and distant shipping noise fields. Furthermore, the spatial characteristics of low-frequency ambient noise field were compared with the classical Cron/Sherman deep water noise field coherence function. Simulation results with the described modeling method showed good agreement with the experimental measurement results based on the vertical line array deployed near the bottom in deep ocean direct-arrival zones.

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