RESUMO
The uncontrollable dendritic growth of metallic lithium during repeated cycling in carbonate electrolytes is a crucial obstacle hindering the practical use of Li-metal batteries (LMBs). Among numerous approaches proposed to mitigate the intrinsic constraints of Li metal, the design of a functional separator is an attractive approach to effectively suppress the growth of Li dendrites because direct contact with both the Li metal surface and the electrolyte is maintained. Here, a newly designed all-in-one separator containing bifunctional CaCO3 nanoparticles (CPP separator) is proposed to achieve the flattening of Li deposits on the Li electrode. Strong interactions between the highly polar CaCO3 nanoparticles and the polar solvent reduces the ionic radius of the Li+ -solvent complex, thus increasing the Li+ transference number and leading to a reduced concentration overpotential in the electrolyte-filled separator. Furthermore, the integration of CaCO3 nanoparticles into the separator induces the spontaneous formation of mechanically-strong and lithiophilic CaLi2 at the Li/separator interface, which effectively decreases the nucleation overpotential toward Li plating. As a result, the Li deposits exhibit dendrite-free planar morphologies, thus enabling excellent cycling performance in LMBs configured with a high-Ni cathode in a carbonate electrolyte under practical operating conditions.
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Sphingosine-1-phosphate-1 (S1P1) receptor agonists are well-known drugs for treating multiple sclerosis (MS) caused by autoreactive lymphocytes that attack the myelin sheath. Therefore, an effective therapeutic strategy is to reduce the lymphocytes in the blood by inducing S1P1 receptor internalization. We synthesized serinolamide A, a natural product of the sea, and performed S1P1 receptor internalization assay to evaluate functionally antagonistic S1P1 receptor agonist activity. In order to synthesize derivatives with better efficacy than serinolamide A and B, new derivatives were synthesized by introducing the phenyl ring moiety of fingolimod. Among them, compounds 19 and 21 had superior S1P1 agonistic effects to serinolamide. We also confirmed that compound 19 effectively inhibited lymphocyte outflow in peripheral lymphocyte count (PLC) assay.
Assuntos
Receptores de Lisoesfingolipídeo , Esfingosina , Cloridrato de Fingolimode/farmacologia , Linfócitos , Lisofosfolipídeos/farmacologia , Esfingosina/análogos & derivados , Esfingosina/farmacologiaRESUMO
OBJECTIVE: The study aimed to examine the relationship on attitudes toward suicide, frustrated interpersonal needs, and non-suicidal self-injury (NSSI) of the university students. METHODS: The participants included 175 university students. Data were analyzed using the SPSS PROCESS macro (Model 4). RESULTS: Depression showed a fully mediating effect on the relationship between one's attitude toward suicide and NSSI behaviors. Furthermore, depression showed a full mediating impact on the relationship between frustrated interpersonal needs and NSSI behaviors. CONCLUSIONS: These findings indicate that suicidal attitudes and frustrated interpersonal needs should be considered significant factors for developing NSSI preventions and intervention among university students.
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COVID-19 , Comportamento Autodestrutivo , Suicídio , Atitude , Depressão , Humanos , Pandemias , Estudantes , Tentativa de Suicídio , UniversidadesRESUMO
We propose a high efficiency flip chip-based ultraviolet (UV) emitter with aluminum (Al) reflector that includes indium tin oxide (ITO) nano grains for current injection between the Al and p-AlGaN layer. Al has attracted attention as a reflector for high efficiency UV emitters because of its high reflectance in the UV region. To improve the efficiency of UV emitter, we generated periodic microhole arrays on the p-AlGaN layer, which serve as a scattering center in the flip chip structure and enhance the light extraction efficiency. The light output power of the fabricated flip chip-based UV emitter with ITO nano grains/Al reflector and microhole arrays on the p-AlGaN layer is significantly improved by 72% and 45% at an injection current of 20 mA, compared to that of UV emitter with only Al reflector and ITO nano grains/Al reflector.
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We investigated the optical and electrical properties of a ß-Ga2O3/Ag/ß-Ga2O3 multilayer transparent conductive electrode deposited on an α-Al2O3 (0001) substrate. For the deposition of a continuous Ag layer, we preliminarily performed anultraviolet-ozone pretreatment of the Ga2O3 bottom layer. To obtain a stable ß-phase of Ga2O3, the ß-Ga2O3/Ag/ß-Ga2O3 multilayer was annealed at 700 °C under N2 atmosphere. The transmittance and sheet resistance of the ß-Ga2O3/Ag/ß-Ga2O3 multilayer were critically affected by the surface morphology and thickness of the Ag interlayer. The multilayer with optimized thicknesses (ß-Ga2O3 top layer: 30 nm; Ag interlayer: 12 nm; ß-Ga2O3 bottom layer: 60 nm) exhibited a resistance of 8.48 Ωsq-1, an average optical transmittance of 87.16% in the ultraviolet wavelength range from 300 to 350 nm, and a figure of merit of 29.81 × 10-3 Ω-1.
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Benzyloxyphenyl moiety is a common structure of highly potent, selective and reversible inhibitors of monoamine oxidase B (MAO-B), safinamide and sembragiline. We synthesized 4-(benzyloxy)phenyl and biphenyl-4-yl derivatives including halogen substituents on the terminal aryl unit. In addition, we modified the carbon linker between amine group and the biaryl linked unit. Among synthesized compounds, 12c exhibited the most potent and selective MAO-B inhibitory effect (hMAO-B IC50: 8.9â¯nM; >10,000-fold selectivity over MAO-A) as a competitive inhibitor. In addition, 12c showed greater MAO-B inhibitory activity and selectivity compared to well-known MAO-B inhibitors such as selegiline, safinamide and sembragiline. In the MPTP-induced mouse model of Parkinson's disease (PD), 12c significantly protected the tyrosine hydroxylase (TH)-immunopositive DAergic neurons and attenuated the PD-associated behavioral deficits. This study suggests characteristic structures as a MAO-B inhibitor that may provide a good insight for the development of therapeutic agents for PD.
Assuntos
Derivados de Benzeno/farmacologia , Inibidores da Monoaminoxidase/farmacologia , Monoaminoxidase/metabolismo , Doença de Parkinson/tratamento farmacológico , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/administração & dosagem , Animais , Derivados de Benzeno/síntese química , Derivados de Benzeno/química , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estrutura Molecular , Inibidores da Monoaminoxidase/síntese química , Inibidores da Monoaminoxidase/química , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Relação Estrutura-AtividadeRESUMO
We investigated the effect of the Ag interlayer thickness on the structural, electrical and optical properties of FTO/Ag/FTO structures designed for use in wide bandgap transparent conducting electrodes. The top and bottom FTO layers were deposited on α-Al2O3 (0001) substrates via RF magnetron sputtering at 300 °C and Ag interlayers were deposited using an e-beam evaporator system. We optimized the figure of merit by changing the thickness of the inserted Ag interlayer from 10 nm to 14 nm, achieving a maximum value of 2.46 × 10-3 Ω-1 and a resistivity of 6.4 × 10-4 Ω · cm using an FTO (70 nm)/Ag (14 nm)/FTO (40 nm) structure. Furthermore, the average optical transmittance in the deep UV range (300 to 330 nm) was 82.8%.
RESUMO
Proton nuclear magnetic resonance (1H-NMR) spectroscopy was used to study the response of zebrafish (Danio rerio) to increasing concentrations of bisphenol A (4,4'-(propane-2,2-diyl)diphenol, BPA). Orthogonal partial least squares discriminant analysis (OPLS-DA) was applied to detect aberrant metabolomic profiles after 72 h of BPA exposure at all levels tested (0.01, 0.1, and 1.0 mg/L). The OPLS-DA score plots showed that BPA exposure caused significant alterations in the metabolome. The metabolomic changes in response to BPA exposure generally exhibited nonlinear patterns, with the exception of reduced levels of several metabolites, including glutamine, inosine, lactate, and succinate. As the level of BPA exposure increased, individual metabolite patterns indicated that the zebrafish metabolome was subjected to severe oxidative stress. Interestingly, ATP levels increased significantly at all levels of BPA exposure. In the present study, we demonstrated the applicability of 1H-NMR-based metabolomics to identify the discrete nature of metabolic changes.
Assuntos
Compostos Benzidrílicos/toxicidade , Espectroscopia de Ressonância Magnética/métodos , Metabolômica/métodos , Fenóis/toxicidade , Peixe-Zebra/metabolismo , Animais , Análise dos Mínimos Quadrados , Metaboloma/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Testes de Toxicidade/métodosRESUMO
A 1H-nuclear magnetic resonance (NMR) spectroscopy with multivariate analysis was applied to detect the toxicity of antiacetylcholinesterase insecticides, methomyl (methyl (1E)-N-(methylcarbamoyloxy)ethanimidothioate) and methidathion (3-(dimethoxyphosphinothioyl sulfanylmethyl)-5-methoxy-1,3,4-thiadiazol-2-one), using zebrafish (Danio rerio) and Chinese bleak (Aphyocypris chinensis). Generally, methomyl and methidathion have been believed not to highly accumulate in fish tissues. However, these pesticides showed their toxicity by altering patterns of whole-body metabolites in neurotransmitter balance, energy metabolism, oxidative stress, and muscle maintenance in low concentrations. We used Pearson correlation analysis to contextualize the metabolic markers in pesticide treated groups. We observed that the positive correlations of choline with acetate and betaine in untreated control were shifted to null correlations showing acetylcholinesterase specific toxicity. This research demonstrated the applicability and potential of NMR metabolomics in detecting toxic effects of insecticide with a modicum of concentrations in aquatic environment.
Assuntos
Cyprinidae/metabolismo , Inseticidas/toxicidade , Metomil/toxicidade , Compostos Organotiofosforados/toxicidade , Peixe-Zebra/metabolismo , Animais , Comportamento Animal/efeitos dos fármacos , Feminino , Masculino , Metabolômica/métodos , Análise Multivariada , Estresse Oxidativo/efeitos dos fármacos , Praguicidas/metabolismo , Espectroscopia de Prótons por Ressonância Magnética , Testes de Toxicidade , Poluentes Químicos da Água/toxicidadeRESUMO
Drug-induced liver injury (DILI) is currently an increasingly relevant health issue. However, available biomarkers do not reliably detect or quantify DILI risk. Therefore, the purpose of this study was to comparatively evaluate plasma and urinary biomarkers obtained from humans treated with acetaminophen (APAP) using a metabolomics approach and a proton nuclear magnetic resonance (NMR) platform. APAP (3 g/day, two 500 mg tablets every 8 h) was administered to 20 healthy Korean males (age, 20-29 years) for 7 days. Urine was collected daily before and during dosing and 6 days after the final dose. NMR spectra of these urine samples were analyzed using principal component analysis (PCA) and partial least-squares-discrimination analysis. Although the activities of aspartate aminotransferase and lactate dehydrogenase were significantly increased 7 days post-APAP treatment, serum biochemical parameters of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total bilirubin, γ-glutamyl transpeptidase, and lactate dehydrogenase were within normal range of hepatic function. However, urine and plasma (1)H NMR spectroscopy revealed different clustering between predosing and after APAP treatment for global metabolomic profiling through PCA. Urinary endogenous metabolites of trimethylamine-N-oxide, citrate, 3-chlorotyrosine, phenylalanine, glycine, hippurate, and glutarate as well as plasma endogenous metabolites such as lactate, glucose, 3-hydroxyisovalerate, isoleucine, acetylglycine, acetone, acetate, glutamine, ethanol, and isobutyrate responded significantly to APAP dosing in humans. Urinary and plasma endogenous metabolites were more sensitive than serum biochemical parameters. These results might be applied to predict or screen potential hepatotoxicity caused by other drugs using urinary and plasma (1)H NMR analyses.
Assuntos
Acetaminofen/sangue , Acetaminofen/urina , Doença Hepática Induzida por Substâncias e Drogas/sangue , Doença Hepática Induzida por Substâncias e Drogas/urina , Espectroscopia de Ressonância Magnética/métodos , Metabolômica/métodos , Acetaminofen/efeitos adversos , Adulto , Biomarcadores/sangue , Biomarcadores/urina , Doença Hepática Induzida por Substâncias e Drogas/epidemiologia , Humanos , Hidrogênio , Masculino , Pessoa de Meia-Idade , Reconhecimento Automatizado de Padrão/métodos , República da Coreia/epidemiologia , Adulto JovemRESUMO
Microscopic visualization of DNA molecules is a simple, intuitive, and powerful method. Nonetheless, DNA-molecule quantification methods that employ microscopic visualization have not been reported so far. In this study, a new quantitative approach is presented that enables the counting of individual DNA molecules that have been rendered visible by fluorescence microscopy. Toward this, a microfluidic device was employed that directed DNA molecules into microchannels and deposited the molecules onto a positively charged surface. This microfluidic device had a vertically tapered channel inlet structure that prevented the accumulation of excess DNA molecules in the channel inlet while creating a tapering flow, thereby ensuring the even distribution of the DNA molecules in the microchannels. The channel heights and the density of positive charges on the surface were optimized for analysis. The linearity of this method with respect to the determination of the concentration of DNA in solutions was subsequently determined. The limit of detection was 0.48 fg/µL, which corresponds to 64 molecules of 7.25 kbp DNA in 1 µL of sample. This quantitative approach was finally used to count two types of plasmids co-transformed in an E. coli cell; a measurement that is typically considered challenging with gel electrophoresis.
Assuntos
Técnicas Analíticas Microfluídicas , Escherichia coli/genética , DNA/genética , DNA/análise , Microscopia de Fluorescência , PlasmídeosRESUMO
Learning classifiers with imbalanced data can be strongly biased toward the majority class. To address this issue, several methods have been proposed using generative adversarial networks (GANs). Existing GAN-based methods, however, do not effectively utilize the relationship between a classifier and a generator. This article proposes a novel three-player structure consisting of a discriminator, a generator, and a classifier, along with decision boundary regularization. Our method is distinctive in which the generator is trained in cooperation with the classifier to provide minority samples that gradually expand the minority decision region, improving performance for imbalanced data classification. The proposed method outperforms the existing methods on real data sets as well as synthetic imbalanced data sets.
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Neuropathic pain is a chronic and sometimes intractable condition caused by lesions or diseases of the somatosensory nervous system. Many drugs are available but unfortunately do not provide satisfactory effects in patients, producing limited analgesia and undesirable side effects. Thus, there is an urgent need to develop new pharmaceutical agents to treat neuropathic pain. To date, highly specific agents that modulate a single target, such as receptors or ion channels, never progress to the clinic, which may reflect the diverse etiologies of neuropathic pain seen in the human patient population. Therefore, the development of multifunctional compounds exhibiting two or more pharmacological activities is an attractive strategy for addressing unmet medical needs for the treatment of neuropathic pain. To develop novel multifunctional compounds, key pharmacophores of currently used clinical pain drugs, including pregabalin, fluoxetine and serotonin analogs, were hybridized to the side chain of tianeptine, which has been used as an antidepressant. The biological activities of the hybrid analogs were evaluated at the human transporters of neurotransmitters, including serotonin (hSERT), norepinephrine (hNET) and dopamine (hDAT), as well as mu (µ) and kappa (κ) opioid receptors. The most advanced hybrid of these multifunctional compounds, 17, exhibited multiple transporter inhibitory activities for the uptake of neurotransmitters with IC50 values of 70 nM, 154 nM and 2.01 µM at hSERT, hNET and hDAT, respectively. Additionally, compound 17 showed partial agonism (EC50 = 384 nM) at the µ-opioid receptor with no influence at the κ-opioid receptor. In in vivo pain animal experiments, the multifunctional compound 17 showed significantly reduced allodynia in a spinal nerve ligation (SNL) model by intrathecal administration, indicating that multitargeted strategies in single therapy could considerably benefit patients with multifactorial diseases, such as pain.
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The sphingosine-1-phosphate-1 (S1P1) receptor agonists have great potential for the treatment of multiple sclerosis (MS) because they can inhibit lymphocyte egress through receptor internalization. We designed and synthesized triazole and isoxazoline derivatives to discover a novel S1P1 agonist for MS treatment. Of the two scaffolds, the isoxazoline derivative was determined to have excellent in vitro efficacy and drug-like properties. Among them, compound 21l was found to have superior drug-like properties as well as excellent in vitro efficacies (EC50 = 7.03 nM in ß-arrestin recruitment and EC50 = 11.8 nM in internalization). We also confirmed that 21l effectively inhibited lymphocyte egress in the peripheral lymphocyte count test and significantly improved the clinical score in the experimental autoimmune encephalitis MS mouse model.
Assuntos
Esclerose Múltipla/tratamento farmacológico , Receptores de Esfingosina-1-Fosfato/antagonistas & inibidores , Animais , Cães , Desenho de Fármacos , Encefalomielite Autoimune Experimental/tratamento farmacológico , Frequência Cardíaca/efeitos dos fármacos , Humanos , Isoxazóis/síntese química , Isoxazóis/farmacocinética , Isoxazóis/farmacologia , Contagem de Linfócitos , Linfócitos/efeitos dos fármacos , Masculino , Camundongos , Ratos , Relação Estrutura-Atividade , Triazóis/síntese química , Triazóis/farmacocinética , Triazóis/farmacologia , beta-Arrestinas/efeitos dos fármacosRESUMO
The Kelch-like ECH-associated protein 1 (Keap1)-Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway plays a pivotal role in the cellular defense system against oxidative stress by inducing antioxidant and anti-inflammatory effects. We previously developed Nrf2 activators that potentially protect the death of dopaminergic (DAergic) neuronal cells against oxidative stress in Parkinson's disease (PD). In this study, we designed and synthesized a class of halogenated vinyl sulfones by inserting halogens and pyridine to maximize Nrf2 activation efficacy. Among the synthesized compounds, (E)-3-chloro-2-(2-((2-chlorophenyl)sulfonyl)vinyl)pyridine (9d) significantly exhibited potent Nrf2 activating efficacy (9d: EC50 = 26 nM) at least 10-fold compared with the previous developed compounds (1 and 2). Furthermore, treating with 9d remarkably increased Nrf2 nuclear translocation and Nrf2 protein levels in microglial BV-2 cells. 9d was shown to induce the expression of antioxidant response genes HO-1, GCLC, GCLM, and SOD-1 at both the mRNA and protein levels and suppress proinflammatory cytokines and enzymes. Also, 9d remarkably protected DAergic neurons and restored the PD-associated motor dysfunction in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model.
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Desenvolvimento de Medicamentos , Fator 2 Relacionado a NF-E2/metabolismo , Doença de Parkinson/tratamento farmacológico , Sulfonas/farmacologia , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Halogenação , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estrutura Molecular , Doença de Parkinson/metabolismo , Relação Estrutura-Atividade , Sulfonas/síntese química , Sulfonas/químicaRESUMO
Monoamine oxidase-B (MAO-B) is a well-established therapeutic target for Parkinson's disease (PD); however, previous clinical studies on currently available irreversible MAO-B inhibitors have yielded disappointing neuroprotective effects. Here, we tested the therapeutic potential of KDS2010, a recently synthesized potent, selective, and reversible MAO-B inhibitor in multiple animal models of PD. We designed and synthesized a series of α-aminoamide derivatives and found that derivative KDS2010 exhibited the highest potency, specificity, reversibility, and bioavailability (> 100%). In addition, KDS2010 demonstrated significant neuroprotective and anti-neuroinflammatory efficacy against nigrostriatal pathway destruction in the mouse MPTP model of parkinsonism. Treatment with KDS2010 also alleviated parkinsonian motor dysfunction in 6-hydroxydopamine-induced and A53T mutant α-synuclein overexpression rat models of PD. Moreover, KDS2010 showed virtually no toxicity or side effects in non-human primates. KDS2010 could be a next-generation therapeutic candidate for PD.
Assuntos
Desenvolvimento de Medicamentos/métodos , Inibidores da Monoaminoxidase/uso terapêutico , Monoaminoxidase/metabolismo , Transtornos Parkinsonianos/tratamento farmacológico , Animais , Relação Dose-Resposta a Droga , Feminino , Macaca fascicularis , Masculino , Camundongos , Inibidores da Monoaminoxidase/química , Transtornos Parkinsonianos/induzido quimicamente , Transtornos Parkinsonianos/enzimologia , Transtornos Parkinsonianos/patologia , Ratos , Resultado do TratamentoRESUMO
Due to the increased morbidity and mortality by fungal infections and the emergence of severe antifungal resistance, there is an urgent need for new antifungal agents. Here, we screened for antifungal activity in our in-house library through the minimum inhibitory concentration test and derived two hit compounds with moderate antifungal activities. The hit compounds' antifungal activities and drug-like properties were optimized by substituting various aryl ring, alkyl chain, and methyl groups. Among the optimized compounds, 22h was the most promising candidate with good drug-like properties and exhibited potent fast-acting fungicidal antifungal effects against various fungal pathogens and synergistic antifungal activities with some known antifungal drugs. Additionally, 22h was further confirmed to disturb fungal cell wall integrity by activating multiple cell wall integrity pathways. Furthermore, 22h exerted significant antifungal efficacy in both the subcutaneous infection mouse model and ex vivo human nail infection model.
Assuntos
Antifúngicos/uso terapêutico , Fungos/efeitos dos fármacos , Micoses/tratamento farmacológico , Animais , Antifúngicos/farmacocinética , Antifúngicos/farmacologia , Antifúngicos/toxicidade , Parede Celular/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Sinergismo Farmacológico , Feminino , Humanos , Masculino , Camundongos , Testes de Sensibilidade Microbiana , Micoses/microbiologia , Ratos Sprague-DawleyRESUMO
Parkinson's disease (PD) is a neurodegenerative disorder characterized by abnormal movement, including slowed movements, shuffling gait, lack of balance, and tremor. Oxidative stress has been shown to play a decisive role in dopaminergic neuronal cell death in PD. The nuclear factor E2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) signaling pathway provides the main defense system against oxidative stress by inducing the expression of antioxidant enzyme genes. Direct interference in the Keap1-Nrf2 protein-protein interaction (PPI) has emerged as an effective strategy for Nrf2 activation. Therefore, we searched for novel Nrf2 activators that can disrupt Nrf2-Keap1 interaction by using a virtual screening approach and identified a potent Nrf2 activator, KKPA4026. KKPA4026 was confirmed to induce the expression of the Nrf2-dependent antioxidant enzymes heme oxygenase-1, glutamate-cysteine ligase catalytic subunit, glutamate-cysteine ligase regulatory subunit, and NAD(P)H:quinone oxidoreductase 1 in BV-2 cells. Furthermore, KKPA4026 showed anti-inflammatory effects in an Nrf2-dependent manner. In a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD, KKPA4026 effectively attenuated PD-associated behavioral deficits and protected dopaminergic neurons. In summary, we identified KKPA4026 as a novel Nrf2 activator and suggested that Nrf2 activation through interference with the Nrf2-Keap1 interaction may be effective for PD treatment.
Assuntos
Anti-Inflamatórios/uso terapêutico , Antioxidantes/uso terapêutico , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Transtornos Parkinsonianos/metabolismo , Fragmentos de Peptídeos/uso terapêutico , Sequência de Aminoácidos , Animais , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/antagonistas & inibidores , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Simulação de Acoplamento Molecular/métodos , Fator 2 Relacionado a NF-E2/agonistas , Transtornos Parkinsonianos/tratamento farmacológico , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/farmacologia , Ligação Proteica/fisiologiaRESUMO
Heat shock factor 1 (HSF1) primarily regulates various cellular stress responses. The role of alpha-helix1 (H1) in its DNA-binding domain (DBD) during HSF1 activation remains unknown. Here, HSF1 lacking H1 loses its heat-induced activity, suggesting the importance of the latter. Furthermore, the CD spectra and AMBER prediction show that this H1 deficiency does not change the structure of HSF1 monomer, but does impact its heat-induced trimerization. Point mutation showed that Phe18 in H1 interacts with Tyr60, and that Trp23 interacts with Phe104 by an aromatic-aromatic interaction. Thus, the presence of H1 stabilizes the DBD structure, which facilitates the heat-induced trimerization and DNA-binding of HSF1.
Assuntos
Proteínas de Ligação a DNA/metabolismo , DNA/metabolismo , Resposta ao Choque Térmico , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Fatores de Transcrição de Choque Térmico , Temperatura Alta , Humanos , Dados de Sequência Molecular , Mutação Puntual , Ligação Proteica , Multimerização Proteica , Estabilidade Proteica , Estrutura Secundária de Proteína/genética , Estrutura Terciária de Proteína/genética , Deleção de Sequência , Fatores de Transcrição/química , Fatores de Transcrição/genéticaRESUMO
Cisplatin (CP) is an anti-cancer drug used for treatment of solid tumors, but the major adverse effect is drug-induced nephrotoxicity. The current study aimed to determine biomarkers that might predict nephrotoxicity induced by CP using serum or urinary proton nuclear magnetic resonance (1H NMR) spectral data in male Sprague-Dawley (S-D) rats. CP (0, 0.5 or 5 mg/kg) was intraperitoneally (i.p.) administered for single dose. Animals were sacrificed 2 days (D2) or 8 days (D8) after administration of CP in order to perform analysis of serum biochemistries and histopathologic examination. Urine samples were collected every 24 hr from pre-treatment to sacrifice. Serum and urinary 1H NMR spectral data revealed apparent differential clustering between control and CP-treated groups as evidenced by principal component analysis (PCA) and orthogonal projections to latent structures-discriminant analysis (OPLS-DA) in global and targeted profiling. The concentrations of endogenous serum metabolites, alanine, betaine, glucose, glutamine, lactate, and leucine were significantly increased on D2. Urinary concentrations of alanine, glucose, glycine, guanidinoacetate, acetate, and lactate were significantly elevated on D2 or D8, whereas concentrations of urinary metabolites, citrate and hippurate were significantly decreased on D2 or D8. The correlation of serum and urinary 1H NMR OPLS-DA with serum biochemistry and renal histopathologic changes suggests that 1H NMR urinalysis may be used to reliably predict or screen CP-induced nephrotoxicity. Data suggest that these altered endogenous metabolites might serve as specific biomarkers for CP-induced nephrotoxicity.