Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 78
Filtrar
Mais filtros

País/Região como assunto
Intervalo de ano de publicação
1.
Nature ; 603(7901): 464-469, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35264793

RESUMO

The brain generates complex sequences of movements that can be flexibly configured based on behavioural context or real-time sensory feedback1, but how this occurs is not fully understood. Here we developed a 'sequence licking' task in which mice directed their tongue to a target that moved through a series of locations. Mice could rapidly branch the sequence online based on tactile feedback. Closed-loop optogenetics and electrophysiology revealed that the tongue and jaw regions of the primary somatosensory (S1TJ) and motor (M1TJ) cortices2 encoded and controlled tongue kinematics at the level of individual licks. By contrast, the tongue 'premotor' (anterolateral motor) cortex3-10 encoded latent variables including intended lick angle, sequence identity and progress towards the reward that marked successful sequence execution. Movement-nonspecific sequence branching signals occurred in the anterolateral motor cortex and M1TJ. Our results reveal a set of key cortical areas for flexible and context-informed sequence generation.


Assuntos
Córtex Motor , Movimento , Animais , Camundongos , Córtex Motor/fisiologia , Movimento/fisiologia , Optogenética , Córtex Somatossensorial/fisiologia , Língua/fisiologia , Tato
2.
Appl Opt ; 63(10): 2587-2593, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38568540

RESUMO

A novel approach, to the best of our knowledge, is presented for assessing silicon wafer surface profiles using an interferometer and vertically rotatable wafer holder. This approach significantly enhances precision and reduces costs, and outperforms traditional techniques in measurement consistency and accuracy. It effectively reduces sample distortion and positional shifts owing to the removal and reinstallation of the wafers. Using this method, a global backsurface-referenced ideal range of 0.385 µm, warp of 0.193 µm, and other parameters were obtained, demonstrating its practicality in efficiently capturing key surface profile metrics for silicon wafers. This innovation promises substantial improvements in high-volume wafer surface profile testing, overcoming prevalent technological challenges in this industry.

3.
J Org Chem ; 88(5): 2908-2920, 2023 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-36799936

RESUMO

Enol esters and conjugated enynes are valuable structural motifs for synthetic chemistry and material sciences. Herein, the synthesis of tetra-substituted enol ester 2-iodobenzoate derivatives was achieved in good yields at room temperature through a gold-catalyzed acyloxyalkynylation of sensitive ynol ethers with ethynylbenziodoxolones (EBXs), the latter acting as bifunctional reactants. The conversion is highly regioselective with a broad substrate scope. Mechanistically, an Au(III) species is the key intermediate of an Au(I)/Au(III) redox cycle. The reaction is synthetically useful and can easily be scaled up to gram scale.

4.
Proc Natl Acad Sci U S A ; 116(11): 5126-5134, 2019 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-30804200

RESUMO

Sensory neurons perceive environmental cues and are important of organismal survival. Peripheral sensory neurons interact intimately with glial cells. While the function of axonal ensheathment by glia is well studied, less is known about the functional significance of glial interaction with the somatodendritic compartment of neurons. Herein, we show that three distinct glia cell types differentially wrap around the axonal and somatodendritic surface of the polymodal dendritic arborization (da) neuron of the Drosophila peripheral nervous system for detection of thermal, mechanical, and light stimuli. We find that glial cell-specific loss of the chromatin modifier gene dATRX in the subperineurial glial layer leads to selective elimination of somatodendritic glial ensheathment, thus allowing us to investigate the function of such ensheathment. We find that somatodendritic glial ensheathment regulates the morphology of the dendritic arbor, as well as the activity of the sensory neuron, in response to sensory stimuli. Additionally, glial ensheathment of the neuronal soma influences dendritic regeneration after injury.


Assuntos
Dendritos/metabolismo , Drosophila melanogaster/metabolismo , Neuroglia/metabolismo , Células Receptoras Sensoriais/citologia , Células Receptoras Sensoriais/metabolismo , Animais , Axônios/metabolismo , Axônios/efeitos da radiação , Caspases/metabolismo , DNA Helicases/metabolismo , Dendritos/efeitos da radiação , Proteínas de Drosophila/metabolismo , Ativação Enzimática/efeitos da radiação , Luz , Neuroglia/efeitos da radiação , Células Receptoras Sensoriais/efeitos da radiação
5.
Int J Mol Sci ; 23(2)2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-35054790

RESUMO

Intestinal homeostasis is a dynamic balance involving the interaction between the host intestinal mucosa, immune barrier, intestinal microecology, nutrients, and metabolites. Once homeostasis is out of balance, it will increase the risk of intestinal diseases and is also closely associated with some systemic diseases. Probiotics (Escherichia coli Nissle 1917, Akkermansia muciniphila, Clostridium butyricum, lactic acid bacteria and Bifidobacterium spp.), maintaining the gut homeostasis through direct interaction with the intestine, can also exist as a specific agent to prevent, alleviate, or cure intestinal-related diseases. With genetic engineering technology advancing, probiotics can also show targeted therapeutic properties. The aims of this review are to summarize the roles of potential native and engineered probiotics in oncology, inflammatory bowel disease, and obesity, discussing the therapeutic applications of these probiotics.


Assuntos
Diabetes Mellitus/microbiologia , Enteropatias/microbiologia , Mucosa Intestinal/fisiologia , Obesidade/microbiologia , Probióticos/uso terapêutico , Akkermansia , Animais , Bifidobacterium , Clostridium butyricum , Diabetes Mellitus/terapia , Escherichia coli , Homeostase , Humanos , Doenças Inflamatórias Intestinais/microbiologia , Doenças Inflamatórias Intestinais/terapia , Enteropatias/terapia , Mucosa Intestinal/microbiologia , Lactobacillales , Obesidade/terapia
6.
Int J Mol Sci ; 23(19)2022 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-36232768

RESUMO

Antibiotics are broadly restricted in modern husbandry farming, necessitating the need for efficient and low-cost immunomodulatory preparations in antibiotic-free and healthful farming. As is known to all, CpG oligonucleotides (CpG-ODNs, an effective innate immunostimulatory agent) recognized by TLR9 in mammals (while TLR21 in avians) could collaborate with some united agent to induce stronger immune responses, but the cost is prohibitively expensive for farmers. Here, considering the coordination between TLR2 and TLR9/TLR21, we firstly proposed the idea that the well-fermented Lactococcus lactis could be utilized as a CpG-plasmid carrier (LACpG10) to enhance the host's innate immunity against pathogenic invasion. In the present study, after obtaining LACpG10-HL from homogenized and lyophilized recombinant strain LACpG10, we treated primary chicken lymphocytes, two cell lines (HD11 and IPEC-J2), and chickens with LACpG10-HL, CpG plasmids (pNZ8148-CpG10), and other stimulants, and respectively confirmed the effects by conducting qRT-PCR, bacterial infection assays, and a zoological experiment. Our data showed that LACpG10-HL could induce excellent innate immunity by regulating autophagy reactions, cytokine expression, and motivating PRRs. Interestingly, despite having no direct antiseptic effect, LACpG10-HL improved the antibacterial capacities of lymphocytes and enterocytes at the first line of defense. Most importantly, water-supplied LACpG10-HL treatment reduced the average adverse event rates, demonstrating that LACpG10-HL maintained its excellent immunostimulatory and protective properties under farming conditions. Our research not only contributes to revealing the satisfactory effects of LACpG10-HL but also sheds new light on a cost-effective solution with optimal immune effects in green, antibiotic-free, and healthful husbandry farming.


Assuntos
Anti-Infecciosos Locais , Receptor Toll-Like 9 , Adjuvantes Imunológicos/farmacologia , Animais , Antibacterianos/farmacologia , Anti-Infecciosos Locais/farmacologia , Galinhas/metabolismo , Citocinas/farmacologia , Imunidade Inata , Mamíferos/metabolismo , Oligodesoxirribonucleotídeos/farmacologia , Receptor 2 Toll-Like , Receptor Toll-Like 9/metabolismo , Água/farmacologia
7.
Fish Shellfish Immunol ; 118: 72-84, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34474150

RESUMO

Misgurnus anguillicaudatus (M. anguillicaudatus) is a widely cultivated fish. However, in M. anguillicaudatus breeding, the frequent cold stress during daily breeding could induce immune suppression and increase the risk of infection, causing serious economic loss. Based on existing findings, CpG Oligonucleotides (CpG-ODNs) may be an ideal protective agent for low temperature fish breeding, performing anti-infective when faced with cold stress with cold shock proteins Y box binding proteins (YBX). Although YBX has pleiotropic functions, its roles in CpG-ODNs-mediated immunity (especially under cold situations) remain largely unexplored. To clarify the relationship among them, we identified the YBX1/YBX2 in M. anguillicaudatus and analyzed using a series of bioinformatics methods. After that, we immunized the fish with 3 types of CpG-ODNs and challenged with Aeromonas hydrophila (A. hydrophila). Here we showed that the best anti-bacterial effect of CpG-B was accompanied by the significant upregulation of YBX1. And the detection of the YBX1 downstream effectors confirmed that CpG-B induced the YBX1-mediated Th1 oriented responses to A. hydrophila by regulation of the NLRP3 (Caspase-A/-B), IL-1ß, IL-12 and IFN-γ. Afterwards, we found that under cold stress, CpG-B can activate the NLRP3 and NF-κB pathways through YBX1, a key mediator of anti-A. hydrophila in CpG-B immunization. In this study, we demonstrated CpG-B protection against infection in low temperature, and its interaction with YBX1, expanded the research of CpG-ODN under cold stress, and provided a new CpG-ODN application for low temperature fish farming.


Assuntos
Infecções Bacterianas , Cipriniformes , Adjuvantes Imunológicos , Animais , Resposta ao Choque Frio , Proteína 3 que Contém Domínio de Pirina da Família NLR , Oligodesoxirribonucleotídeos
8.
Appl Microbiol Biotechnol ; 105(14-15): 5973-5991, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34396488

RESUMO

Clostridium butyricum (C. butyricum) is a probiotic that could promote animal growth and protect gut health. So far, current studies mainly keep up with the basic biological functions of C. butyricum, missing the effective strategy to further improve its protective efficiency. A recent report about C. butyricum alleviating intestinal injury through epidermal growth factor receptor (EGFR) inspired us to bridge this gap by porcine epidermal growth factor (EGF) overexpression. Lacking a secretory overexpression system, we constructed the recombinant strains overexpressing pEGF in C. butyricum for the first time and obtained 4 recombinant strains for highly efficient secretion of pEGF (BC/pPD1, BC/pSPP, BC/pGHF, and BC/pDBD). Compared to the wild-type strain, we confirmed that the expression level ranges of the intestinal development-related genes (Claudin-1, GLUT-2, SUC, GLP2R, and EGFR) and anti-inflammation-related gene (IL-10) in IPECs were upregulated under recombinant strain stimulation, and the growth of Staphylococcus aureus and Salmonella typhimurium was significantly inhibited as well. Furthermore, a particular inhibitor (stattic) was used to block STAT3 tyrosine phosphorylation, resulting in the downregulation on antibacterial effect of recombinant strains. This study demonstrated that the secretory overexpression of pEGF in C. butyricum could upregulate the expression level of EGFR, consequently improving the intestinal protective functions of C. butyricum partly following STAT3 signal activation in IPECs and making it a positive loop. These findings on the overexpression strains pointed out a new direction for further development and utilization of C. butyricum. KEY POINTS: • By 12 signal peptide screening in silico, 4 pEGF overexpression strains of C. butyricum/pMTL82151-pEGF for highly efficient secretion of pEGF were generated for the first time. • The secretory overexpression of pEGF promoted the intestinal development, antimicrobial action, and anti-inflammatory function of C. butyricum. • The overexpressed pEGF upregulated the expression level of EGFR and further magnified the gut protective function of recombinant strains which in turn partly depended on STAT3 signal pathway in IPECs.


Assuntos
Clostridium butyricum , Probióticos , Animais , Fator de Crescimento Epidérmico , Sinais Direcionadores de Proteínas , Transdução de Sinais , Suínos
9.
Microb Cell Fact ; 19(1): 35, 2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-32070347

RESUMO

Porcine growth hormone (pGH) is a class of peptide hormones secreted from the pituitary gland, which can significantly improve growth and feed utilization of pigs. However, it is unstable and volatile in vitro. It needs to be encapsulated in liposomes when feeding livestock, whose high cost greatly limits its application in pig industry. Therefore we attempted to express pGH as intracellular soluble protein in Pichia pastoris and feed these yeasts with partial wall-breaking for swine, which could release directly pGH in intestine tract in case of being degraded in intestinal tract with low cost. In order to improve the intracellular soluble expression of pGH protein in Pichia pastoris and stability in vitro, we optimized the pGH gene, and screened molecular chaperones from E. coli and Pichia pastoris respectively for co-expressing with pGH. In addition, we had also explored conditions of mechanical crushing and fermentation. The results showed that the expression of intracellular soluble pGH protein was significantly increased after gene optimized and co-expressed with Ssa1-Sis1 chaperone from Pichia pastoris. Meanwhile, the optimal conditions of partial wall-breaking and fermentation of Pichia pastoris were confirmed, the data showed that the intracellular expression of the optimized pGH protein co-expressed with Ssa1-Sis1 could reach 340 mg/L with optimal conditions of partial wall-breaking and fermentation. Animal experiments verified that the optimized pGH protein co-expression with Ssa1-Sis1 had the best promoting effects on the growth of piglets. Our study demonstrated that Ssa1-Sis1 could enhance the intracellular soluble expression of pGH protein in Pichia pastoris and that partial wall-breaking of yeast could prevent pGH from degradation in vitro, release targetedly in the intestine and play its biological function effectively. Our study could provide a new idea to cut the cost effectively, establishing a theoretical basis for the clinic application of unstable substances in vitro.


Assuntos
Proteínas Fúngicas/metabolismo , Hormônio do Crescimento/biossíntese , Chaperonas Moleculares/metabolismo , Pichia/metabolismo , Suínos/crescimento & desenvolvimento , Animais , Clonagem Molecular , Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Fermentação , Pichia/genética , Proteínas Recombinantes/biossíntese
10.
Fish Shellfish Immunol ; 99: 609-630, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32088284

RESUMO

Up to now, many previous reports have emphasized that Annexins (ANX) family played an important role in immune responses. Aeromonas hydrophila (A. hydrophila), the most common zoonotic pathogenic bacteria of yellow catfish (Pelteobagrus fulvidraco), can cause serious economic loss, especially to yellow catfish with high economic value. In our previous work, we demonstrated that synthetic oligodeoxynucleotides containing CpG motifs (CpG ODN) owned powerful immunostimulatory activity. However, the relationship among Pelteobagrus fulvidraco Annexins (Pf_ANX), CpG ODN and A. hydrophila is unknown. Therefore, we cloned Pf_ANX1-6 genes and analyzed its sequences, structures, genetic evolution, post-translation modifications (PTMs), Ca2+ ion binding sites and tissue distribution to reveal the relevance. In addition, we investigated the responses of ANXA1-6 and cytokines in intestine and spleen as well as morbidity/survival rate of fish post CpG ODN immunization and/or A. hydrophila infection. The results showed that compared with challenge alone (challenge-CK) group, the CpG immunization following challenge (CpG-challenge) group displayed relatively flat IL-1ß level throughout in both organs. Meanwhile, the expression of IFN-γ and morbidity/survival rate of fish in CpG-challenge group showed a great improvement compared with the challenge-CK group. Our results indicated that CpG ODN could improve morbidity/survival by up-regulating Pf_ANXA 1, 2 and 5 in the intestine and spleen to ameliorate inflammatory responses and promote anti-infective responses. Our findings offer some important insights into ANX related to the immunity of fish infection and lay a theoretical basis for the prevention and treatment of fish infections.


Assuntos
Anexinas/genética , Infecções Bacterianas/veterinária , Peixes-Gato/genética , Peixes-Gato/imunologia , Regulação da Expressão Gênica/imunologia , Oligodesoxirribonucleotídeos/imunologia , Aeromonas hydrophila , Animais , Infecções Bacterianas/imunologia , Infecções Bacterianas/prevenção & controle , Clonagem Molecular , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Doenças dos Peixes/prevenção & controle , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Imunidade Inata/genética , Interferon gama/genética , Interferon gama/imunologia , Oligodesoxirribonucleotídeos/administração & dosagem
11.
Fish Shellfish Immunol ; 100: 476-488, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32209398

RESUMO

Retinol-binding protein 4 (RBP4) is known as a highly conserved adipokine for immune activation. Aeromonas hydrophila (A. hydrophila) is the most common zoonotic pathogen in aquaculture, which causes serious economic losses to aquaculture, especially to bighead carp (Hypophthalmichthys nobilis, H. nobilis) and silver carp (Hypophthalmichthys molitrix, H. molitrix). Recent studies along with our previous findings have shown that synthetic oligodeoxynucleotides containing CpG motifs (CpG ODN) can play a good role in aquatic animals against infection. In order to clarify the relationship between CpG ODN and RBP4 under A. hydrophila infection, firstly, full-length RBP4 cDNAs from H. nobilis and H. molitrix were cloned. And characteristics of RBP4, including sequence and structure, tissue distribution and genetic evolution were analyzed. In addition, mRNA expression levels of RBP4, cytokine, toll-like receptors (TLRs), morbidity and survival rates of H. nobilis and H. molitrix were observed post CpG ODN immunization or following challenge. The results indicated that hn/hm_RBP4 (RBP4 genes obtained from H. nobilis and H. molitrix) had the highest homology with Megalobrama amblycephala. Distribution data showed that the expression level of hn_RBP4 mRNA was higher than that of hm_RBP4. After CpG ODN immunization followed by A.hydrophila challenge, significantly higher survival was observed in both carps, together with up-regulated RBP4 expression. Meanwhile, hn/hm_IL-1ß level was relatively flat (and decreased), hn/hm_IFN-γ, hn/hm_TLR4 and hn/hm_TLR9 levels increased significantly, but hn/hm_STRA6 showed no significant change, compared with control. Moreover, CpG ODN immunization could induce stronger immune protective responses (higher IFN-γ/gentle IL-1ß level and lower morbidity/higher survival rate) against A. hydrophila in H. nobilis, along with higher RBP4 level, when compared with that in H. molitrix. These results demonstrated that RBP4 was well involved in the immune protection of CpG ODN. Based on the results, we speculated that in the case of A. hydrophila infection, TLR9 signaling pathway was activated by CpG ODN. Subsequently, CpG ODN up-regulated RBP4, and RBP4 activated TLR4 signaling pathway. Then TLR4 and TLR9 synergistically improved the anti-infection responses. Our findings have good significance for improving resistance to pathogen infection in freshwater fish.


Assuntos
Carpas/genética , Carpas/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Imunização/veterinária , Oligodesoxirribonucleotídeos/administração & dosagem , Proteínas Celulares de Ligação ao Retinol/genética , Aeromonas hydrophila/patogenicidade , Animais , Carpas/imunologia , DNA Complementar , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/prevenção & controle , Oligodesoxirribonucleotídeos/imunologia , Proteínas Celulares de Ligação ao Retinol/química , Proteínas Celulares de Ligação ao Retinol/imunologia , Regulação para Cima
12.
Appl Microbiol Biotechnol ; 104(21): 9343-9361, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32965561

RESUMO

The human body is almost always facing the oxidative stress caused by foodborne aldehydes such as glyoxal (GO) and methylglyoxal (MGO), 4-hydroxyhexenal (HHE), and 4-hydroxynonenal (HNE). When these aldehydes build up, they can cause a range of harm. However, a probiotic, Clostridium butyricum, can increase nuclear factor erythroid-2 related factor 2 (Nrf2) and may have the potential to relieve oxidative stress. If C. butyricum is indeed resistant to aldehydes, the advantages (accessibility, convenience, and safety) will be of great significance compared with drugs. Unfortunately, whether C. butyricum can play a role in alleviating toxic effects of foodborne aldehydes in the intestine (the first line of defense against food-derived toxin) was unclear. To investigate these, we measured the viability, ROS, autophagy, and inflammatory cytokine expression of Caco-2 which were co-cultured with C. butyricum and stimulated by the four aldehydes via Nrf2 pathway (Staphylococcus aureus and Enterococcus faecium as controls). Then, we explored the link among C. butyricum, NLRP6, and Nrf2 signaling pathways when facing the stimuli. In the present study, we demonstrated that Clostridium butyricum relieved the oxidative stress induced by the aldehydes in Caco-2. Most interestingly, we found a "complementary" relationship between NLRP6 and Nrf2 in C. butyricum treatment under aldehyde stress. Our research not only makes a contribution to the popularization of C. butyricum as a probiotic-rich food instead of medicines but also sheds new light on the application of subsequent microecological formulation of C. butyricum. KEY POINTS: • The adverse effects are caused in a dose-dependent manner by foodborne aldehydes. • Clostridium butyricum can significantly ameliorate oxidative stress. • There is a "complementary" relationship between the NLRP6 and Nrf2 signaling pathways. • Using Clostridium butyricum foods to alleviate oxidative stress shows great prospects.


Assuntos
Clostridium butyricum , Aldeídos/toxicidade , Células CACO-2 , Manipulação de Alimentos , Humanos , Lipídeos , Estresse Oxidativo
13.
J Pharmacol Exp Ther ; 371(1): 75-86, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31289113

RESUMO

Tamoxifen, raloxifene, and nafoxidine are selective estrogen receptor modulators (SERMs) reported to inhibit the catalytic activity of human aldehyde oxidase 1 (AOX1). How these drugs interact with AOX1 and whether other SERMs inhibit this drug-metabolizing enzyme are not known. Therefore, a detailed in vitro and in silico study involving parent drugs and their analogs was conducted to investigate the effect of specific SERMs, particularly acolbifene, bazedoxifene, and lasofoxifene on AOX1 catalytic activity, as assessed by carbazeran 4-oxidation, an AOX1-selective catalytic marker. The rank order in the potency (based on IC50 values) of AOX1 inhibition by SERMs was raloxifene > bazedoxifene ∼ lasofoxifene > tamoxifen > acolbifene. Inhibition of liver cytosolic AOX1 by bazedoxifene, lasofoxifene, and tamoxifen was competitive, whereas that by raloxifene was noncompetitive. Loss of 1-azepanylethyl group increased the inhibitory potency of bazedoxifene, whereas the N-oxide group decreased it. The 7-hydroxy group and the substituted pyrrolidine ring attached to the tetrahydronaphthalene structure contributed to AOX1 inhibition by lasofoxifene. These results are supported by molecular-docking simulations in terms of predicted binding modes, encompassing binding orientation and efficiency, and analysis of key interactions, particularly hydrogen bonds. The extent of AOX1 inhibition by bazedoxifene was increased by estrone sulfate and estrone. In summary, SERMs differentially inhibited human AOX1 catalytic activity. Structural features of bazedoxifene and lasofoxifene contributed to AOX1 inhibition, whereas those of acolbifene rendered it considerably less susceptible to AOX1 inhibition. Overall, our novel biochemical findings and molecular-docking analyses provide new insights into the interaction between SERMs and AOX1. SIGNIFICANCE STATEMENT: Aldehyde oxidase (AOX1) is a molybdo-flavoprotein and has emerged as a drug-metabolizing enzyme of potential therapeutic importance because drugs have been identified as AOX1 substrates. Selective estrogen receptor modulators (SERM), which are drugs used to treat and prevent various conditions, differentially inhibit AOX1 catalytic activity. Structural features of bazedoxifene and lasofoxifene contribute to AOX1 inhibition, whereas those of acolbifene render it considerably less susceptible to AOX1 inhibition. Our novel biochemical findings, together with molecular- docking analyses, provide new insights into the differential inhibitory effect of SERMs on the catalytic activity of human AOX1, how SERMs bind to AOX1, and increase our understanding of the AOX1 pharmacophore in the inhibition of AOX1 by drugs and other chemicals.


Assuntos
Aldeído Oxidase/antagonistas & inibidores , Indóis/farmacologia , Simulação de Acoplamento Molecular , Pirrolidinas/farmacologia , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Tetra-Hidronaftalenos/farmacologia , Aldeído Oxidase/química , Aldeído Oxidase/metabolismo , Sítios de Ligação , Feminino , Humanos , Fígado/enzimologia , Masculino , Ligação Proteica
14.
Drug Metab Dispos ; 47(1): 26-37, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30337443

RESUMO

The present study investigated the contribution of microsomal cytochrome P450 and cytosolic aldehyde oxidase-1 (AOX-1) to carbazeran 4-oxidation and O 6-benzylguanine 8-oxidation in human liver microsomal, cytosolic, and S9 fractions. Incubations containing carbazeran and human liver microsomes with or without exogenously added NADPH yielded comparable levels of 4-oxo-carbazeran. O 6-Benzylguanine 8-oxidation occurred in microsomal incubations, and the extent was increased by NADPH. Human recombinant CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A4, and CYP3A5 did not catalyze carbazeran 4-oxidation, whereas CYP1A2 was highly active in O 6-benzylguanine 8-oxidation. 1-Aminobenzotriazole, a pan-cytochrome P450 inhibitor, decreased O 6-benzylguanine 8-oxidation, but not carbazeran 4-oxidation, in microsomal incubations, whereas 1-aminobenzotriazole and furafylline (a CYP1A2-selective inhibitor) did not inhibit carbazeran 4-oxidation or O 6-benzylguanine 8-oxidation in human liver S9 fraction. Carbazeran 4-oxidation in incubations containing human liver microsomes (from multiple donors and commercial suppliers) was attributed to microsomal preparations contaminated with AOX-1, as suggested by liver microsomal experiments indicating a decrease in carbazeran 4-oxidation by an AOX-1 inhibitor (hydralazine), and to detection of AOX-1 protein (at one-third the level of that in liver cytosol). Cytosolic contamination of liver microsomes was further demonstrated by the formation of dehydroepiandrosterone sulfate (catalyzed by cytosolic sulfotransferases) in liver microsomal incubations containing dehydroepiandrosterone. In conclusion, carbazeran 4-oxidation and O 6-benzylguanine 8-oxidation are enzyme-selective catalytic markers of human AOX-1, as shown in human liver S9 fraction expressing cytochrome P450 and AOX-1. This study highlights the negative impact of cytosolic contamination of liver microsomes on the interpretation of reaction phenotyping data collected in an in vitro study performed in microsomal fractions.


Assuntos
Aldeído Oxidase/metabolismo , Carbamatos/análise , Citosol/metabolismo , Guanina/análogos & derivados , Microssomos Hepáticos/metabolismo , Biocatálise , Biomarcadores/análise , Biomarcadores/metabolismo , Calibragem , Carbamatos/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Desenvolvimento de Medicamentos/instrumentação , Desenvolvimento de Medicamentos/normas , Guanina/análise , Guanina/metabolismo , Humanos , Oxirredução , Padrões de Referência
15.
Org Biomol Chem ; 17(38): 8706-8710, 2019 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-31549126

RESUMO

In this paper, a novel and sustainable synthesis of the hitherto unreported 5H-benzo[c]imidazo[1,2-a]azepine-6-carboxylic acids via the cascade reactions of 2-arylimidazoles (1) with methylene-oxetanones (2) is presented. Mechanistically, the formation of the title compounds is triggered by a Rh(iii)-catalyzed C(sp2)-H alkenylation of 1 with 2 followed by an intramolecular N-nucleophilic substitution. With this method, a series of hybrid compounds combining the biologically promising imidazole and benzoazepine moieties decorated with a synthetically versatile carboxyl group were prepared in moderate to good efficiency. In addition, the utility of the products thus obtained was remarkably showcased by their efficient transformations into some otherwise difficult-to-obtain pentacyclic compounds.

16.
Genet Mol Biol ; 40(3): 591-596, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28863211

RESUMO

X-linked intellectual disability (XLID) has been associated with various genes. Diagnosis of XLID, especially for non-syndromic ones (NS-XLID), is often hampered by the heterogeneity of this disease. Here we report the case of a Chinese family in which three males suffer from intellectual disability (ID). The three patients shared the same phenotype: no typical clinical manifestation other than IQ score ≤ 70. For a genetic diagnosis for this family we carried out whole exome sequencing on the proband, and validated 16 variants of interest in the genomic DNA of all the family members. A missense mutation (c.710G > T), which mapped to exon 6 of the Rab GDP-Dissociation Inhibitor 1 (GDI1) gene, was found segregating with the ID phenotype, and this mutation changes the 237th position in the guanosine diphosphate dissociation inhibitor (GDI) protein from glycine to valine (p. Gly237Val). Through molecular dynamics simulations we found that this substitution results in a conformational change of GDI, possibly affecting the Rab-binding capacity of this protein. In conclusion, our study identified a novel GDI1 mutation that is possibly NS-XLID causative, and showed that whole exome sequencing provides advantages for detecting novel ID-associated variants and can greatly facilitate the genetic diagnosis of the disease.

17.
Appl Microbiol Biotechnol ; 100(12): 5453-65, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26883349

RESUMO

Mammalian peptidoglycan recognition proteins (PGLYRPs) are highly conserved pattern-recognition molecules of the innate immune system with considerable bactericidal activity, which manifest their potential values for the application to food and pharmaceutical industry. However, the effective expression of porcine PGLYRP-1 in Pichia pastoris has not been reported so far. In this study, expression in P. pastoris was explored as an efficient way to produce functional porcine PGLYRP-1. Cooperation of chaperones co-expression and gene dosage (including protein disulfide isomerase (PDI)/binding protein (BiP) and pglyrp-1) were used to enhance functional expression of antimicrobial protein in P. pastoris. Overexpression of PDI was certainly able to increase secretion level of PGLYRP-1 protein because the increase in secreted PGLYRP-1 secretion was correlated with the copy numbers of PDI in high copy pglyrp-1 clones. However, co-expression of BiP was proved to be detrimental to PGLYRP-1 secretion. In addition, we also found that excessive expression of PDI and/or BiP could decrease the mRNA expression of pglyrp-1 gene. This showed that PDI and BiP as the target genes of unfolded protein response (UPR) might regulate the transcription of the target protein. These data demonstrated for the first time that the combination of chaperones and gene dosages could improve the yield of PGLYRP-1, which could facilitate the application to food and pharmaceutical industry.


Assuntos
Proteínas de Transporte/genética , Dosagem de Genes , Expressão Gênica , Chaperonas Moleculares/metabolismo , Pichia/genética , Animais , Antibacterianos/farmacologia , Proteínas de Transporte/biossíntese , Proteínas de Transporte/química , Proteínas de Transporte/farmacologia , Escherichia coli/efeitos dos fármacos , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Chaperonas Moleculares/genética , Pichia/química , Pichia/metabolismo , Isomerases de Dissulfetos de Proteínas/genética , Isomerases de Dissulfetos de Proteínas/metabolismo , Dobramento de Proteína , Proteínas Recombinantes/biossíntese , Staphylococcus aureus/efeitos dos fármacos , Suínos , Transformação Genética , Resposta a Proteínas não Dobradas
18.
Virol J ; 12: 211, 2015 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-26646953

RESUMO

BACKGROUND: Rice dwarf virus (RDV), a plant reovirus, is mainly transmitted by the green rice leafhopper, Nephotettix cincticeps, in a persistent-propagative manner. Plant reoviruses are thought to replicate and assemble within cytoplasmic structures called viroplasms. Nonstructural protein Pns4 of RDV, a phosphoprotein, is localized around the viroplasm matrix and forms minitubules in insect vector cells. However, the functional role of Pns4 minitubules during viral infection in insect vector is still unknown yet. METHODS: RNA interference (RNAi) system targeting Pns4 gene of RDV was conducted. Double-stranded RNA (dsRNA) specific for Pns4 gene was synthesized in vitro, and introduced into cultured leafhopper cells by transfection or into insect body by microinjection. The effects of the knockdown of Pns4 expression due to RNAi induced by synthesized dsRNA from Pns4 gene on viral replication and spread in cultured cells and insect vector were analyzed using immunofluorescence, western blotting or RT-PCR assays. RESULTS: In cultured leafhopper cells, the knockdown of Pns4 expression due to RNAi induced by synthesized dsRNA from Pns4 gene strongly inhibited the formation of minitubules, preventing the accumulation of viroplasms and efficient viral infection in insect vector cells. RNAi induced by microinjection of dsRNA from Pns4 gene significantly reduced the viruliferous rate of N. cincticeps. Furthermore, it also strongly inhibited the formation of minitubules and viroplasms, preventing efficient viral spread from the initially infected site in the filter chamber of intact insect vector. CONCLUSIONS: Pns4 of RDV is essential for viral infection and replication in insect vector. It may directly participate in the functional role of viroplasm for viral replication and assembly of progeny virions during viral infection in leafhopper vector.


Assuntos
Hemípteros/virologia , Insetos Vetores/virologia , Reoviridae/fisiologia , Proteínas não Estruturais Virais/metabolismo , Replicação Viral , Animais , Células Cultivadas , Técnicas de Silenciamento de Genes , Reoviridae/genética , Proteínas não Estruturais Virais/genética
19.
Br J Haematol ; 160(4): 487-502, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23252516

RESUMO

Durable responses with lenalidomide monotherapy have been reported in patients with non-Hodgkin lymphoma. In relapsed/refractory diffuse large B-cell lymphoma (DLBCL), higher responses were observed in the activated B-cell-like (ABC) subtype than in the germinal centre B-cell-like subtype. Herein, the molecular mechanisms involved in the differential efficacy of lenalidomide in DLBCL subtypes were investigated. Using DLBCL cell lines, lenalidomide treatment was found to preferentially suppress proliferation of ABC-DLBCL cells in vitro and delay tumour growth in a human tumour xenograft model, with minimal effect on non-ABC-DLBCL cells. This tumouricidal effect was associated with downregulation of interferon regulatory factor 4 (IRF4), a hallmark of ABC-DLBCL cells. IRF4 inhibition by lenalidomide induced downregulation of B-cell receptor (BCR)-dependent NF-κB. Whereas IRF4-specific small, interfering RNA mimicked the effects of lenalidomide reducing NF-κB activation, IRF4 overexpression enhanced NF-κB activation and conferred resistance to lenalidomide. These findings indicate the crucial role of IRF4 inhibition in lenalidomide efficacy in ABC cells. Furthermore, lenalidomide-induced IRF4 downregulation required the expression of cereblon, a molecular target of lenalidomide. Taken together, these findings suggest that lenalidomide has direct antitumour activity against DLBCL cells, preferentially ABC-DLBCL cells, by blocking IRF4 expression and the BCR-NF-κB signalling pathway in a cereblon-dependent manner.


Assuntos
Antineoplásicos/farmacologia , Fatores Reguladores de Interferon/metabolismo , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Peptídeo Hidrolases/metabolismo , Talidomida/análogos & derivados , Proteínas Adaptadoras de Transdução de Sinal/efeitos dos fármacos , Animais , Proteína 10 de Linfoma CCL de Células B , Proteínas Adaptadoras de Sinalização CARD/efeitos dos fármacos , Proteínas Adaptadoras de Sinalização CARD/genética , Caspases/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Guanilato Ciclase/efeitos dos fármacos , Guanilato Ciclase/genética , Humanos , Quinases Associadas a Receptores de Interleucina-1/efeitos dos fármacos , Lenalidomida , Linfoma Difuso de Grandes Células B/metabolismo , Camundongos , Camundongos SCID , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa , Mutação , Fator 88 de Diferenciação Mieloide/efeitos dos fármacos , NF-kappa B/efeitos dos fármacos , Proteínas de Neoplasias/efeitos dos fármacos , Proteínas de Neoplasias/metabolismo , Transplante de Neoplasias/métodos , Talidomida/farmacologia , Transplante Heterólogo , Ubiquitina-Proteína Ligases
20.
Appl Opt ; 52(28): 6948-55, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-24085209

RESUMO

High-quality ultrasmooth surface is needed in modern optics, while the existing ultrasmooth surface processing methods are difficult to meet the requirement of the surface figure. In order to solve this problem, the active feed polishing (AFP) is taken as the research object, and the dual-rotor tool path is put forward for this technology. This tool path is generated based on the motion synthesis principle, which realizes smooth connection between different sections. At the same time, the eccentricity, the speed ratio, the velocity, and other parameters can be modified easily, avoiding using the complicated dual-rotor polishing mechanism. In order to further analyze the removal error, the removal amount calculation method for the dual-rotor path is researched and proposed. The simulation analysis results show that the greatest influence factor for the removal error is the sampling interval, the influence of the eccentricity and the speed ratio is less, and the velocity has little impact on it. In addition, the removal error can be controlled within acceptable range by reasonable selection of process parameters. Finally, through a processing experiment of a 100 mm plane lens, the feasibility and effectiveness of this path is verified. This experimental result shows that the AFP technology using the dual-rotor tool path can effectively correct the surface shape while reducing the surface roughness.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA