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1.
Environ Toxicol ; 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38808594

RESUMO

Decabrominated diphenyl ether (BDE-209) is a typical persistent organic pollutant that can cross the placental barrier, increasing the exposure risk for offspring. Norepinephrine (NE) from nerve terminals and acetylcholine (Ach) can bind to specific receptors on immune cells, inhibit the immune function of the body then cause immunotoxicity. However, whether maternal exposure to BDE-209 could lead to immunotoxicity in the offspring by acting on the sympathetic and parasympathetic nervous systems remains unclear. In view of this, the pregnancy and lactation rat BDE-209 exposure model was established and the results demonstrated that pregnancy and lactation BDE-209 exposure could induce immunotoxicity to female offspring via affecting immunopathology (hematological and biochemical parameters, organ indices, and spleen histopathological), decreasing humoral immunity (serum hemolysin, immunoglobulins, and cytokine productions), damaging cellular immunity (splenic lymphocytes and spleen cytokine productions), and restraining nonspecific immunity. Moreover, a dramatically significant correlation was observed between spleen nerve indices and immunity indices. Additionally, the mechanism revealed that maternal BDE-209 exposure caused offspring immunotoxicity through (1) activating MHC/PKCθ/NF-κB pathway; (2) promoting sympathetic nervous pathway, by upregulating the expression of ß2AR protein, which in turn elevating cAMP, following activate PKA and phosphorylate CREB, ultimately leading to immunotoxicity;(3) activating parasympathetic nerve pathway by reducing the binding with Ach and α7nAchR, upregulating the expression of JAK2 and phosphorylating STAT3, induced immunotoxicity of female offspring.

2.
Phys Chem Chem Phys ; 25(42): 29341-29349, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37877223

RESUMO

In this work, WO3 nanorod-based aggregates and WO3 nano-shuttles were constructed by a facile hydrothermal route. The structure, morphology, element composition and valence state of the formed WO3 samples were characterized using different testing instruments. As the active anode for lithium-ion batteries, the WO3 nano-shuttle electrode can deliver a reversible specific capacity of 614.7 mA h g-1 after 300 cycles at a current density of 500 mA g-1. The excellent electrochemical properties indicate that WO3 nano-shuttles are a prospective anode candidate for high performance lithium-ion batteries.

3.
Lancet Oncol ; 23(3): 353-361, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35085506

RESUMO

BACKGROUND: Patients with HER2-positive metastatic breast cancer have a high risk of developing brain metastases. Efficacious treatment options are scarce. We investigated the activity and safety of pyrotinib plus capecitabine in patients with HER2-positive metastatic breast cancer and brain metastases. METHODS: We did a multicentre, single-arm, two-cohort, phase 2 trial in eight tertiary hospitals in China. Patients aged 18 years or older who had radiotherapy-naive HER2-positive brain metastases (cohort A) or progressive disease after radiotherapy (cohort B), with an Eastern Cooperative Oncology Group performance status of 0-2, received pyrotinib 400 mg orally once daily, and capecitabine 1000 mg/m2 orally twice daily for 14 days, followed by 7 days off every 3 weeks until disease progression or unacceptable toxicity. The primary endpoint was confirmed intracranial objective response rate by investigator assessment according to the Response Evaluation Criteria In Solid Tumours (version 1.1). Activity and safety were analysed in patients with at least one dose of study drug. The study is ongoing, but recruitment is complete. The study is registered with ClinicalTrials.gov, NCT03691051. FINDINGS: Between Jan 29, 2019, and July 10, 2020, we enrolled 78 women: 51 (86%) of 59 patients in cohort A and 18 (95%) of 19 patients in cohort B had previous exposure to trastuzumab. Median follow-up duration was 15·7 months (IQR 9·7-19·0). The intracranial objective response rate was 74·6% (95% CI 61·6-85·0; 44 of 59 patients) in cohort A and 42·1% (20·3-66·5; eight of 19 patients) in cohort B. The most common grade 3 or worse treatment-emergent adverse event was diarrhoea (14 [24%] in cohort A and four [21%] in cohort B). Two (3%) patients in cohort A and three (16%) in cohort B had treatment-related serious adverse events. No treatment-related deaths occurred. INTERPRETATION: To our knowledge, this is the first prospective study showing the activity and safety of pyrotinib plus capecitabine in patients with HER2-positive breast cancer and brain metastases, especially in radiotherapy-naive population. This combination deserves further validation in a randomised, controlled trial. FUNDING: National Cancer Centre Climbing Foundation Key Project of China, Jiangsu Hengrui Pharmaceuticals. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.


Assuntos
Neoplasias Encefálicas , Neoplasias da Mama , Acrilamidas , Aminoquinolinas , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias Encefálicas/secundário , Neoplasias da Mama/patologia , Capecitabina , Feminino , Humanos , Masculino , Estudos Prospectivos , Receptor ErbB-2/metabolismo
4.
Soft Matter ; 18(41): 7975-7980, 2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36218035

RESUMO

A synthetic strategy for fabricating colloidal particles with spatially segregated amine-functionalized lobes enables regioselective coating with gold to afford metallodielectric particles with a variety of shapes and lobe sizes. This approach can produce either dissymmetric dumbbell-shaped two-lobed Au-TPM particles (Au-T) or dissymmetric or symmetric three-lobed particles with gold coating on one (Au-T-T and T-Au-T) or two lobes (Au-T-Au). Dielectrophoretic (DEP) forces exerted by an AC field confined between two opposing electrodes generate aggregates ranging from 1D chains to 2D close-packed lattices, depending on the particle shape and lobe arrangement. The aggregate structures reflect the lowest energy configurations resulting from the induced dipole moments created in particle lobes within the confined electric field.

5.
Chem Rev ; 120(23): 12903-12993, 2020 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-33050699

RESUMO

Bioelectrocatalysis is an interdisciplinary research field combining biocatalysis and electrocatalysis via the utilization of materials derived from biological systems as catalysts to catalyze the redox reactions occurring at an electrode. Bioelectrocatalysis synergistically couples the merits of both biocatalysis and electrocatalysis. The advantages of biocatalysis include high activity, high selectivity, wide substrate scope, and mild reaction conditions. The advantages of electrocatalysis include the possible utilization of renewable electricity as an electron source and high energy conversion efficiency. These properties are integrated to achieve selective biosensing, efficient energy conversion, and the production of diverse products. This review seeks to systematically and comprehensively detail the fundamentals, analyze the existing problems, summarize the development status and applications, and look toward the future development directions of bioelectrocatalysis. First, the structure, function, and modification of bioelectrocatalysts are discussed. Second, the essentials of bioelectrocatalytic systems, including electron transfer mechanisms, electrode materials, and reaction medium, are described. Third, the application of bioelectrocatalysis in the fields of biosensors, fuel cells, solar cells, catalytic mechanism studies, and bioelectrosyntheses of high-value chemicals are systematically summarized. Finally, future developments and a perspective on bioelectrocatalysis are suggested.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Catálise , Eletrodos , Oxirredução
6.
Exp Cell Res ; 405(2): 112689, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34107274

RESUMO

Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent chronic liver disease globally. Elderly individuals are at a higher risk of developing NAFLD with severe clinical outcomes. Although NAFLD is closely related to liver aging, the role of hepatocyte senescence in the progression of NAFLD, especially in the development of fibrosis, is still unclear. The early stage of NAFLD is mainly characterized by lipid accumulation in hepatocytes, which could lead to severe oxidative stress, causing cellular senescence. In the present study, hepatocytes cultured in the presence of free fatty acids to induce lipid deposition were used as a hepatocyte senescence model in vitro. Senescent hepatocytes significantly increased the activation of co-cultured primary hepatic stellate cells (HSCs) and the expression of pro-fibrosis molecules. Moreover, the antioxidant regulator nuclear factor erythroid 2-related factor 2 (Nrf2) that was upregulated in senescent hepatocytes was found to be related to the activation of co-cultured HSCs. The Nrf2 agonist sulforaphane, which upregulated the transcriptional activity of the Nrf2-antioxidant response element (ARE) pathway, remarkably inhibited hepatocyte senescence and its activation effect on HSCs. However, the liver tissue obtained from non-alcoholic steatohepatitis (NASH) mice with Nrf2 knockdown showed decreased antioxidation and significant liver senescence and fibrosis. In conclusion, this study confirmed that lipid accumulation induces hepatocyte senescence, which leads to HSC activation and development of hepatic fibrosis. Increasing the activity of the Nrf2-ARE antioxidant pathway in senescent hepatocytes elicited the opposite effect, suggesting that targeting Nrf2 may prevent or delay the progression of aging-related liver fibrosis in NASH.


Assuntos
Elementos de Resposta Antioxidante/fisiologia , Hepatócitos/citologia , Metabolismo dos Lipídeos/fisiologia , Fator 2 Relacionado a NF-E2/metabolismo , Animais , Fígado/metabolismo , Cirrose Hepática/patologia , Masculino , Camundongos Endogâmicos C57BL , Estresse Oxidativo/efeitos dos fármacos
7.
Cytokine ; 142: 155474, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33647584

RESUMO

BACKGROUND: The key characteristics in the pathogenesis of nonalcoholic steatohepatitis (NASH) are hepatic lipotoxicity, inflammatory cell infiltration (activated macrophages, in part), and varying degrees of fibrosis. The fatty acid palmitate (PA) can cause hepatocyte cellular dysfunction, but whether and how this process contributes to macrophage-associated inflammation is not well understood. This study aimed to explore whether lipid-injured hepatocytes result in the secretion of osteopontin (sOPN), and how sOPN induces macrophage migration to steatosis hepatocytes. METHODS: Human hepatocellular carcinoma HepG2 cells were incubated with PA to establish the lipotoxicity in hepatocytes model in vitro. The released sOPN was isolated, characterized, and applied to macrophage-like cells differentiated from the human monocytic cell line THP-1 cells. C57BL/6 mice were fed either chow or a diet high in fructose-fat-glucose (FFG) to induce NASH in vivo. Some NASH model mice were also given siSPP1 for two weeks to inhibit the expression of OPN. Related tissues were collected and analyzed by histology, immunofluorescence, ELISA, qRT-PCR, and western blotting. RESULTS: PA upregulated OPN expression and release in human hepatocytes, which drove the migration of macrophages. Incubation of HepG2 cells with palmitate increased mRNA expression and secretion of OPN in cell culture supernatants. Compared with the BSA and siSPP1 groups, treatment with the supernatant derived from PA-treated hepatocytes promoted macrophage migration and activation. The sOPN induction of macrophage migration occurred via CD44 engagement and activation of the pFak-NFκB signaling pathway. Likewise, administration of siSPP1 to NASH mice inhibited the expression and release of OPN, which was associated with decreased liver dysfunction, inflammatory cell infiltration, and even fibrosis. CONCLUSIONS: sOPN, which is released from lipid-injured hepatocytes, emerges as a cytokine driving the migration of macrophages, contributing to an inflammatory response in NASH.


Assuntos
Movimento Celular , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Hepatócitos/patologia , Receptores de Hialuronatos/metabolismo , Lipídeos/toxicidade , Macrófagos/metabolismo , NF-kappa B/metabolismo , Osteopontina/metabolismo , Animais , Movimento Celular/efeitos dos fármacos , Modelos Animais de Doenças , Células Hep G2 , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Macrófagos/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Modelos Biológicos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Fosforilação , Transdução de Sinais , Células THP-1 , Regulação para Cima/efeitos dos fármacos
8.
FASEB J ; 34(3): 3943-3955, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31944405

RESUMO

Mangrove-derived actinobacteria strains are well-known for producing novel secondary metabolites. The polycyclic tetramate macrolactam (PTM), ikarugamycin (IKA) isolated from Streptomyces xiamenensis 318, exhibits antiproliferative activities against pancreatic ductal adenocarcinoma (PDAC) in vitro. However, the protein target for bioactive IKA is unclear. In this study, whole transcriptome-based profiling revealed that the glycolysis pathway is significantly affected by IKA. Metabolomic studies demonstrated that IKA treatment induces a significant drop in glucose-6-phosphate and a slight increase in intracellular glucose level. Analysis of glucose consumption, lactate production, and the extracellular acidification rate confirmed the inhibitory role of IKA on the glycolytic flux in PDAC cells. Surface plasmon resonance (SPR) experiments and docking studies identified the key enzyme of glycolysis, hexokinase 2 (HK2), as a molecular target of IKA. Moreover, IKA reduced tumor size without overt cytotoxicity in mice with PDAC xenografts and increased chemotherapy response to gemcitabine in PDAC cells in vitro. Taken together, IKA can block glycolysis in pancreatic cancer by targeting HK2, which may be a potential drug candidate for PDAC treatment.


Assuntos
Hexoquinase/metabolismo , Lactamas/farmacologia , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Glucose/metabolismo , Glicólise/efeitos dos fármacos , Humanos , Imuno-Histoquímica , Ácido Láctico/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Reação em Cadeia da Polimerase em Tempo Real , Ressonância de Plasmônio de Superfície
9.
BMC Endocr Disord ; 21(1): 68, 2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33849490

RESUMO

BACKGROUND: Primary thyroid lymphoma (PTL) is a rare thyroid malignancy, there are few large sample studies on PTL and no standardized treatment regimen has been established due to the rarity. The aims of this study were to explore the incidence and prognostic factors of PTL and construct visual prognostic prediction models for post-chemotherapy and postoperative patients. METHODS: The incidence of PTL in 1975-2017 was extracted from the US Surveillance, Epidemiology, and End Results (SEER) database, then assessed using joinpoint regression software. A total of 1616 eligible PTL patients diagnosed in 1998-2016 were brought into prognostic analysis. Multivariate Cox regression analyses were carried out to reveal independent prognostic elements for overall survival (OS) and cancer-specific survival (CSS). RESULTS: PTL incidence showed a relatively steady increase in 1975-1994, which annual percent change (APC) was 4.0%, and steady decreasing in 1994-2017(APC - 2.4%). Age, marital status, lymphoma Ann Arbor stage, histological subtypes, surgery, chemotherapy, and radiation were significantly correlated to OS and CSS. Nomograms were constructed to predict OS and CSS in post-chemotherapy and postoperative PTL patients separately, and were verified to have good reliability. CONCLUSIONS: The incidence of PTL increased and subsequently decreased. We revealed the prognostic implications and constructed reliable nomograms for post-chemotherapy and postoperative PTL patients.


Assuntos
Antineoplásicos/administração & dosagem , Linfoma/epidemiologia , Nomogramas , Vigilância da População/métodos , Cuidados Pós-Operatórios/métodos , Neoplasias da Glândula Tireoide/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Linfoma/diagnóstico , Linfoma/terapia , Masculino , Pessoa de Meia-Idade , Prognóstico , Programa de SEER , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/terapia , Adulto Jovem
10.
J Am Chem Soc ; 142(39): 16528-16532, 2020 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-32931280

RESUMO

This contribution describes a synthetic strategy for the fabrication of multicomponent colloidal "molecules" with controllable complex morphologies and compositionally distinct lobes. Using 3-(trimethoxysilyl)propyl methacrylate (TPM) as the building block, the methodology enables a scalable bulk synthesis of customized chiral colloidal particles with geometric and compositional chirality by a sequential seeded growth method. The synthetic protocol presents a versatile platform for constructing colloidal molecules with multiple components having customized shapes and functionalities, with the potential to impact the design of chromatic patchy particles, colloidal swimmers, and chiral optical materials, as well as informing programmable assembly.

11.
J Am Chem Soc ; 142(8): 4028-4036, 2020 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-32017556

RESUMO

Enzymatic electrosynthesis is a promising approach to produce useful chemicals with the requirement of external electrical energy input. Enzymatic fuel cells (EFCs) are devices to convert chemical energy to electrical energy via the oxidation of fuel at the anode and usually the reduction of oxygen or peroxide at the cathode. The integration of enzymatic electrosynthesis with EFC architectures can simultaneously result in self-powered enzymatic electrosynthesis with more valuable usage of electrons to produce high-value-added chemicals. In this study, a H2/α-keto acid EFC was developed for the conversion from chemically inert nitrogen gas to chiral amino acids, powered by H2 oxidation. A highly efficient cathodic reaction cascade was first designed and constructed. Powered by an applied voltage, the cathode supplied enough reducing equivalents to support the NH3 production and NADH recycling catalyzed by nitrogenase and diaphorase. The produced NH3 and NADH were reacted in situ with leucine dehydrogenase (LeuDH) to generate l-norleucine with 2-ketohexanoic acid as the NH3 acceptor. A 92% NH3 conversion ratio and 87.1% Faradaic efficiency were achieved. On this basis, a H2-powered fuel cell with hyper-thermostable hydrogenase (SHI) as the anodic catalyst was combined with the cathodic reaction cascade to form the H2/α-keto acid EFC. After 10 h of reaction, the concentration of l-norleucine achieved 0.36 mM with >99% enantiomeric excess and 82% Faradaic efficiency. From the broad substrate scope and the high enzymatic enantioselectivity of LeuDH, the H2/α-keto acid EFC is an energy-efficient alternative to electrochemically produce chiral amino acids for biotechnology applications.


Assuntos
Aminoácidos/química , Técnicas Eletroquímicas/métodos , Hidrogênio/química , Cetoácidos/química , Nitrogênio/química , Biocatálise
12.
J Am Chem Soc ; 142(18): 8374-8382, 2020 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-32286819

RESUMO

Two obstacles limit the application of oxidoreductase-based asymmetric synthesis. One is the consumption of high stoichiometric amounts of reduced cofactor. The other is the low solubility of organic substrates, intermediates, and products in the aqueous phase. In order to address these two obstacles to oxidoreductase-based asymmetric synthesis, a biphasic bioelectrocatalytic system was constructed and applied. In this study, the preparation of chiral ß-hydroxy nitriles catalyzed by alcohol dehydrogenase (AdhS) and halohydrin dehalogenase (HHDH) was investigated as a model bioelectrosynthesis, since they are high-value intermediates in statin synthesis. Diaphorase (DH) was immobilized by a cobaltocene-modified poly(allylamine) redox polymer on the electrode surface (DH/Cc-PAA bioelectrode) to achieve effective bioelectrocatalytic NADH regeneration. Since AdhS is a NAD-dependent dehydrogenase, the diaphorase-modified biocathode was used to regenerate NADH to support the conversion from ethyl 4-chloroacetoacetate (COBE) to ethyl (S)-4-chloro-3-hydroxybutanoate ((S)-CHBE) catalyzed by AdhS. The addition of methyl tert-butyl ether (MTBE) as an organic phase not only increased the uploading of COBE but also prevented the spontaneous hydrolysis of COBE, extended the lifetime of DH/Cc-PAA bioelectrode, and increased the Faradaic efficiency and the concentration of generated (R)-ethyl-4-cyano-3-hydroxybutyrate ((R)-CHCN). After 10 h of reaction, the highest concentration of (R)-CHCN in the biphasic bioelectrocatalytic system was 25.5 mM with 81.2% enantiomeric excess (eep). The conversion ratio of COBE achieved 85%, which was 8.8 times higher than that achieved with the single-phase system. Besides COBE, two other substrates with aromatic ring structures were also used in this biphasic bioelectrocatalytic system to prepare the corresponding chiral ß-hydroxy nitriles. The results indicate that the biphasic bioelectrocatalytic system has the potential to produce a variety of ß-hydroxy nitriles with different structures.


Assuntos
Álcool Desidrogenase/metabolismo , Hidrolases/metabolismo , Nitrilas/metabolismo , Álcool Desidrogenase/química , Biocatálise , Técnicas Eletroquímicas , Hidrolases/química , Estrutura Molecular , Nitrilas/química
13.
Exp Appl Acarol ; 80(4): 521-530, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32162137

RESUMO

In this study, we de novo sequenced and analyzed the circular mitochondrial genome (mitogenome) of Tyrophagus putrescentiae. It was 14,156 bp long and contained a complete set of 37 genes, contrary to the initial published sequences; it included 22 tRNA sequences and the largest non-coding region. The mtDNA gene order of T. putrescentiae was found to be identical to that of Aleuroglyphus ovatus, Caloglyphus berlesei, and Rhizoglyphus robini (all Acaroidea). Most tRNAs of T. putrescentiae lack at least a D-arm or T-arm. Tyrophagus putrescentiae tRNAs also shared considerable structural and sequence similarity with the tRNAs of other reported Acaroidea species that have the full set of tRNAs. The largest non-coding region was located between trnF and trnS1, and it contained a microsatellite-like (AT)n sequence, short palindromic sequences, and several hairpin loops, as observed in other reported Acaroidea species (excepting Tyrophagus longior).


Assuntos
Acaridae/genética , Genoma Mitocondrial , Animais , DNA Mitocondrial/genética , Ordem dos Genes , RNA de Transferência/genética
14.
Gut ; 68(11): 1994-2006, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30826748

RESUMO

BACKGROUND AND AIMS: Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer-related death worldwide. Neurotransmitter-initiated signalling pathway is profoundly implicated in tumour initiation and progression. Here, we investigated whether dysregulated neurotransmitter receptors play a role during pancreatic tumourigenesis. METHODS: The Cancer Genome Atlas and Gene Expression Omnibus datasets were used to identify differentially expressed neurotransmitter receptors. The expression pattern of gamma-aminobutyric acid type A receptor pi subunit (GABRP) in human and mouse PDAC tissues and cells was studied by immunohistochemistry and western blot analysis. The in vivo implications of GABRP in PDAC were tested by subcutaneous xenograft model and lung metastasis model. Bioinformatics analysis, transwell experiment and orthotopic xenograft model were used to identify the in vitro and in vivo effects of GABRP on macrophages in PDAC. ELISA, co-immunoprecipitation, proximity ligation assay, electrophysiology, promoter luciferase activity and quantitative real-time PCR analyses were used to identify molecular mechanism. RESULTS: GABRP expression was remarkably increased in PDAC tissues and associated with poor prognosis, contributed to tumour growth and metastasis. GABRP was correlated with macrophage infiltration in PDAC and pharmacological deletion of macrophages largely abrogated the oncogenic functions of GABRP in PDAC. Mechanistically, GABRP interacted with KCNN4 to induce Ca2+ entry, which leads to activation of nuclear factor κB signalling and ultimately facilitates macrophage infiltration by inducing CXCL5 and CCL20 expression. CONCLUSIONS: Overexpressed GABRP exhibits an immunomodulatory role in PDAC in a neurotransmitter-independent manner. Targeting GABRP or its interaction partner KCNN4 may be an effective therapeutic strategy for PDAC.


Assuntos
Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Receptores de GABA-A/metabolismo , Ácido gama-Aminobutírico/metabolismo , Animais , Quimiocinas/metabolismo , Modelos Animais de Doenças , Humanos , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/metabolismo , Macrófagos/fisiologia , Camundongos , Transdução de Sinais/fisiologia
15.
J Am Chem Soc ; 141(12): 4963-4971, 2019 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-30835461

RESUMO

Enantiomerically pure chiral amines are of increasing value in the preparation of bioactive compounds, pharmaceuticals, and agrochemicals. ω-Transaminase (ω-TA) is an ideal catalyst for asymmetric amination because of its excellent enantioselectivity and wide substrate scope. To shift the equilibrium of reactions catalyzed by ω-TA to the side of the amine product, an upgraded N2 fixation system based on bioelectrocatalysis was developed to realize the conversion from N2 to chiral amine intermediates. The produced NH3 was in situ reacted with l-alanine dehydrogenase to generate alanine with NADH as a coenzyme. ω-TA transferred the amino group from alanine to ketone substrates and finally produced the desired chiral amine intermediates. The cathode of the upgraded N2 fixation system supplied enough reducing power to synchronously realize the regeneration of reduced methyl viologen (MV•+) and NADH for the nitrogenase and l-alanine dehydrogenase. The coproduct, pyruvate, was consumed by l-alanine dehydrogenase to regenerate alanine and push the equilibrium to the side of amine. After 10 h of reaction, the concentration of 1-methyl-3-phenylpropylamine achieved 0.54 mM with the 27.6% highest faradaic efficiency and >99% enantiomeric excess (eep). Because of the wide substrate scope and excellent enantioselectivity of ω-TA, the upgraded N2 fixation system has great potential to produce a variety of chiral amine intermediates for pharmaceuticals and other applications.


Assuntos
Aminas/química , Aminas/metabolismo , Fixação de Nitrogênio , Biocatálise , Eletroquímica , Modelos Moleculares , NAD/metabolismo , Oxirredutases/química , Oxirredutases/metabolismo , Conformação Proteica
16.
J Am Chem Soc ; 141(22): 8943-8950, 2019 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-31088049

RESUMO

Noninvasive control over the reversible generation of singlet oxygen (1O2) has found the practical significance in benefiting photodynamic therapy. In this study, we developed a new dual-stage metallacycle (M) by using a photosensitizer and photochromic switch as the functional building blocks, which enables the noninvasive "off-on" switching of 1O2 generation through the efficient intramolecular energy transfer. Due to the proximal placement of the functional entities within the well-defined metallacyclic scaffold, 1O2 generation in the ring-closed form state of the photochromic switch (C-M) is quenched by photoinduced energy transfer, whereas the generation of 1O2 in the ring-open form state (O-M) is activated upon light irradiation. More interestingly, the metallacycle-loaded nanoparticles with relatively high stability and water solubility were prepared, which allow for the delivery of metallacycles to cancer cells via endocytosis. Their theranostic potential has been systematically investigated both in vitro and in vivo. Under the light irradiation, the designed ring-open form nanoparticles (O-NPs) show remarkable higher cytotoxicity against cancer cells compared to the ring-closed form nanoparticles (C-NPs). In vivo experiments also revealed that tumors can be very efficiently eliminated by the designed nanoparticles under light irradiation with the ability to regulate in vivo generation of singlet oxygen. All these results demonstrated that the supramolecular coordination complexes with a dual-stage state provide a highly efficient nanoplatform for noninvasive control over the reversible generation of 1O2, thus allowing for their promising applications in tumor treatment and beyond.


Assuntos
Luz , Metais/química , Fármacos Fotossensibilizantes/química , Oxigênio Singlete/química , Células HeLa , Humanos , Modelos Moleculares , Conformação Molecular , Fotoquimioterapia , Fármacos Fotossensibilizantes/uso terapêutico , Oxigênio Singlete/uso terapêutico
17.
Gastroenterology ; 153(1): 277-291.e19, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28315323

RESUMO

BACKGROUND & AIMS: Desmoplasia and poor vascularity cause severe metabolic stress in pancreatic ductal adenocarcinomas (PDACs). Serotonin (5-HT) is a neuromodulator with neurotransmitter and neuroendocrine functions that contributes to tumorigenesis. We investigated the role of 5-HT signaling in the growth of pancreatic tumors. METHODS: We measured the levels of proteins that regulate 5-HT synthesis, packaging, and degradation in pancreata from KrasG12D/+/Trp53R172H/+/Pdx1-Cre (KPC) mice, which develop pancreatic tumors, as well as in PDAC cell lines and a tissue microarray containing 81 human PDAC samples. We also analyzed expression levels of proteins involved in 5-HT synthesis and degradation by immunohistochemical analysis of a tissue microarray containing 311 PDAC specimens, and associated expression levels with patient survival times. 5-HT level in 14 matched PDAC tumor and non-tumor tissues were analyzed by ELISA. PDAC cell lines were incubated with 5-HT and cell survival and apoptosis were measured. We analyzed expression of the 5-HT receptor HTR2B in PDAC cells and effects of receptor agonists and antagonists, as well as HTR2B knockdown with small hairpin RNAs. We determined the effects of 5-HT stimulation on gene expression profiles of BxPC-3 cells. Regulation of glycolysis by 5-HT signaling via HTR2B was assessed by immunofluorescence and immunoprecipitation analyses, as well as by determination of the extracellular acid ratio, glucose consumption, and lactate production. Primary PDACs, with or without exposure to SB204741 (a selective antagonist of HTR2B), were grown as xenograft tumors in mice, and SB204741 was administered to tumor-bearing KPC mice; tumor growth and metabolism were measured by imaging analyses. RESULTS: In immunohistochemical analysis of a tissue microarray of PDAC specimens, increased levels of TPH1 and decreased level of MAOA, which regulate 5-HT synthesis and degradation, correlated with stage and size of PDACs and shorter patient survival time. We found levels of 5-HT to be increased in human PDAC tissues compared with non-tumor pancreatic tissues, and PDAC cell lines compared with non-transformed pancreatic cells. Incubation of PDAC cell lines with 5-HT increased proliferation and prevented apoptosis. Agonists of HTR2B, but not other 5-HT receptors, promoted proliferation and prevented apoptosis of PDAC cells. Knockdown of HTR2B in PDAC cells, or incubation of cells with HTR2B inhibitors, reduced their growth as xenograft tumors in mice. We observed a correlation between 5-HT and glycolytic flux in PDAC cells; levels of metabolic enzymes involved in glycolysis, the phosphate pentose pathway, and hexosamine biosynthesis pathway increased significantly in PDAC cells following 5-HT stimulation. 5-HT stimulation led to formation of the HTR2B-LYN-p85 complex, which increased PI3K-Akt-mTOR signaling and the Warburg effect by increasing protein levels of MYC and HIF1A. Administration of SB204741 to KPC mice slowed growth and metabolism of established pancreatic tumors and prolonged survival of the mice. CONCLUSIONS: Human PDACs have increased levels of 5-HT, and PDAC cells increase expression of its receptor, HTR2B. These increases allow for tumor glycolysis under metabolic stress and promote growth of pancreatic tumors and PDAC xenograft tumors in mice.


Assuntos
Carcinoma Ductal Pancreático/metabolismo , Neoplasias Pancreáticas/metabolismo , Receptor 5-HT2B de Serotonina/metabolismo , Serotonina/metabolismo , Idoso , Animais , Apoptose/efeitos dos fármacos , Carcinoma Ductal Pancreático/química , Carcinoma Ductal Pancreático/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Inativação Gênica , Glucose/metabolismo , Glicólise/efeitos dos fármacos , Humanos , Indóis/uso terapêutico , Ácido Láctico/biossíntese , Masculino , Camundongos , Pessoa de Meia-Idade , Monoaminoxidase/análise , Transplante de Neoplasias , Pâncreas/química , Neoplasias Pancreáticas/química , Neoplasias Pancreáticas/tratamento farmacológico , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Receptor 5-HT2B de Serotonina/genética , Serotonina/análise , Serotonina/farmacologia , Agonistas do Receptor 5-HT2 de Serotonina/farmacologia , Antagonistas do Receptor 5-HT2 de Serotonina/farmacologia , Antagonistas do Receptor 5-HT2 de Serotonina/uso terapêutico , Transdução de Sinais , Estresse Fisiológico , Serina-Treonina Quinases TOR/metabolismo , Análise Serial de Tecidos , Transcriptoma , Triptofano Hidroxilase/análise , Ureia/análogos & derivados , Ureia/uso terapêutico , Quinases da Família src/metabolismo
18.
Anal Chem ; 88(24): 12294-12302, 2016 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-28193035

RESUMO

Intracellular pH undertakes critical functions in the formation of a proton gradient and electrochemical potential that drives the adenosine triphosphate synthesis. It is also involved in various metabolic processes occurring in mitochondria, such as the generation of reactive oxygen species, calcium regulation, as well as the triggering of cell proliferation and apoptosis. Meanwhile, the aberrant accumulation of O2•- within mitochondria is frequently intertwined with mitochondrial dysfunction and disease development. To disentangle the complicated inter-relationship between pH and O2•- in the signal transduction and homeostasis in mitochondria, herein we developed a mitochondria-targeted single fluorescent probe for simultaneous sensing and imaging of pH and O2•- in mitochondria. CdSe/ZnS quantum dots encapsulated in silica shell was designed as an inner reference element for providing a built-in correction, as well as employed as a carrier to assemble the responsive elements for O2•- and pH, together with mitochondria-targeted molecule. The developed nanosensor demonstrated high accuracy and selectivity for pH and O2•- sensing, against other ROS, metal ions, and amino acids. The remarkable analytical performance of the present nanosensor, as well as good biocompatibility, established an accurate and selective approach for real-time imaging and biosensing of O2•- and pH in mitochondria of live cells.


Assuntos
Compostos de Cádmio/química , Corantes Fluorescentes/química , Mitocôndrias/química , Imagem Óptica/métodos , Pontos Quânticos/química , Espécies Reativas de Oxigênio/análise , Compostos de Selênio/química , Sulfetos/química , Compostos de Zinco/química , Animais , Apoptose , Técnicas Biossensoriais/métodos , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Camundongos , Células RAW 264.7 , Dióxido de Silício/química , Espectrometria de Fluorescência/métodos
19.
Arch Virol ; 161(8): 2117-32, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27169600

RESUMO

There were three epidemic waves of human infection with avian influenza A (H7N9) virus in 2013-2014. While many analyses of the genomic origin, evolution, and molecular characteristics of the influenza A (H7N9) virus have been performed using sequences from the first epidemic wave, genomic characterization of the virus from the second epidemic wave has been comparatively less reported. In this study, an in-depth analysis was performed with respect to the genomic characteristics of 11 H7N9 virus strains isolated from confirmed cases and four H7N9 virus strains isolated from environmental samples in Shenzhen during the second epidemic wave. Phylogenetic analysis demonstrated that six internal segments of the influenza A (H7N9) virus isolated from confirmed cases and environmental samples in Shenzhen were clustered into two different clades and that the origin of the influenza A (H7N9) virus isolated from confirmed cases in Shenzhen was different from that of viruses isolated during the first wave. In addition, H9N2 viruses, which were prevalent in southern China, played an important role in the reassortment of the influenza A (H7N9) virus isolated in Shenzhen. HA-R47K and -T122A, PB2-V139I, PB1-I397M, and NS1-T216P were the signature amino acids of the influenza A (H7N9) virus isolated from confirmed cases in Shenzhen. We found that the HA, NA, M, and PA genes of the A(H7N9) viruses underwent positive selection in the human population. Therefore, enhanced surveillance should be carried out to determine the origin and mode of transmission of the novel influenza A (H7N9) virus and to facilitate the formulation of effective policies for prevention and containment of a human infection epidemics.


Assuntos
Subtipo H7N9 do Vírus da Influenza A/genética , Subtipo H7N9 do Vírus da Influenza A/isolamento & purificação , Influenza Aviária/virologia , Influenza Humana/virologia , Doenças das Aves Domésticas/virologia , Animais , Galinhas , China/epidemiologia , Genoma Viral , Genômica , Humanos , Subtipo H7N9 do Vírus da Influenza A/classificação , Influenza Aviária/epidemiologia , Influenza Humana/epidemiologia , Filogenia , Doenças das Aves Domésticas/epidemiologia , Proteínas Virais/genética
20.
Appl Microbiol Biotechnol ; 100(2): 825-35, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26496918

RESUMO

Alzheimer's disease (AD) is an age-related neurodegenerative disorder in which amyloid ß (Aß) peptide accumulates in the brain. The receptor for advanced glycation end product (RAGE) is a cellular binding site for Aß peptide and mediates amyloid ß-induced perturbations in cerebral vessels, neurons, and microglia in AD. Here, we identified a specific high-affinity RAGE inhibitor (APDTKTQ named RP-1) from a phage display library. RP-1 bound to RAGE and inhibited Aß peptide-induced cellular stress in human neuroblastoma SH-SYSY cells in vitro. Three amino acids in RP-1 are identical to those in the Aß peptide. RP-1 shows high homology to the 16-23 (KLVFFAED) regions in Aß peptide and high-affinity RAGE. Functional analyses indicated that RP-1 significantly reduced the level of reactive oxygen species (ROS) and ROS products and that it enhanced catalase and glutathione peroxidase (GPx) activity. Furthermore, it inactivated caspase3 and caspase9 and inhibited the upregulation of RAGE, nuclear factor-κB (NF-κB), and beta-site amyloid precursor protein-cleaving enzyme 1 (BACE1) protein expression. In addition, RP-1 activated the PI3K/AKT signaling pathway, inhibiting the interaction between Bax and Bcl-2. Our data suggest that RP-1 is a potent RAGE blocker that effectively controls the progression of Aß peptide-mediated brain disorders and that it may have potential as a disease-modifying agent for AD.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Biblioteca de Peptídeos , Receptor para Produtos Finais de Glicação Avançada/antagonistas & inibidores , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/química , Ácido Aspártico Endopeptidases/genética , Ácido Aspártico Endopeptidases/metabolismo , Bacteriófagos/metabolismo , Sítios de Ligação , Encéfalo/fisiologia , Caspases/genética , Caspases/metabolismo , Catalase/genética , Linhagem Celular Tumoral , Glutationa Peroxidase/metabolismo , Humanos , NF-kappa B/genética , Neurônios/fisiologia , Oligopeptídeos/isolamento & purificação , Oligopeptídeos/metabolismo , Fragmentos de Peptídeos/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptor para Produtos Finais de Glicação Avançada/genética , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Transdução de Sinais
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