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1.
Molecules ; 27(16)2022 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-36014582

RESUMO

The Broussonetia genus (Moraceae), recognized for its value in many Chinese traditional herbs, mainly includes Broussonetia papyrifera (L.) L'Hér. ex Vent. (BP), Broussonetia kazinoki Siebold (BK), and Broussonetia luzonica (Blanco) Bureau (BL). Hitherto, researchers have found 338 compounds isolated from BP, BK, and BL, which included flavonoids, polyphenols, phenylpropanoids, alkaloids, terpenoids, steroids, and others. Moreover, its active compounds and extracts have exhibited a variety of pharmacological effects such as antitumor, antioxidant, anti-inflammatory, antidiabetic, anti-obesity, antibacterial, and antiviral properties, and its use against skin wrinkles. In this review, the phytochemistry and pharmacology of Broussonetia are updated systematically, after its applications are first summarized. In addition, this review also discusses the limitations of investigations and the potential direction of Broussonetia. This review can help to further understand the phytochemistry, pharmacology, and other applications of Broussonetia, which paves the way for future research.


Assuntos
Alcaloides , Broussonetia , Moraceae , Broussonetia/química , Etnofarmacologia , Flavonoides/farmacologia , Compostos Fitoquímicos/química , Extratos Vegetais/química
2.
Nature ; 520(7547): 317-21, 2015 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-25822790

RESUMO

In response to adenosine 5'-diphosphate, the P2Y1 receptor (P2Y1R) facilitates platelet aggregation, and thus serves as an important antithrombotic drug target. Here we report the crystal structures of the human P2Y1R in complex with a nucleotide antagonist MRS2500 at 2.7 Å resolution, and with a non-nucleotide antagonist BPTU at 2.2 Å resolution. The structures reveal two distinct ligand-binding sites, providing atomic details of P2Y1R's unique ligand-binding modes. MRS2500 recognizes a binding site within the seven transmembrane bundle of P2Y1R, which is different in shape and location from the nucleotide binding site in the previously determined structure of P2Y12R, representative of another P2YR subfamily. BPTU binds to an allosteric pocket on the external receptor interface with the lipid bilayer, making it the first structurally characterized selective G-protein-coupled receptor (GPCR) ligand located entirely outside of the helical bundle. These high-resolution insights into P2Y1R should enable discovery of new orthosteric and allosteric antithrombotic drugs with reduced adverse effects.


Assuntos
Nucleotídeos de Desoxiadenina/química , Nucleotídeos de Desoxiadenina/metabolismo , Antagonistas do Receptor Purinérgico P2Y/química , Receptores Purinérgicos P2Y1/química , Receptores Purinérgicos P2Y1/metabolismo , Uracila/análogos & derivados , Difosfato de Adenosina/análogos & derivados , Difosfato de Adenosina/química , Difosfato de Adenosina/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Nucleotídeos de Desoxiadenina/farmacologia , Humanos , Ligantes , Modelos Moleculares , Conformação Molecular , Antagonistas do Receptor Purinérgico P2Y/metabolismo , Antagonistas do Receptor Purinérgico P2Y/farmacologia , Tionucleotídeos/química , Tionucleotídeos/metabolismo , Uracila/química , Uracila/metabolismo , Uracila/farmacologia
3.
Nature ; 509(7498): 115-8, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24670650

RESUMO

P2Y receptors (P2YRs), a family of purinergic G-protein-coupled receptors (GPCRs), are activated by extracellular nucleotides. There are a total of eight distinct functional P2YRs expressed in human, which are subdivided into P2Y1-like receptors and P2Y12-like receptors. Their ligands are generally charged molecules with relatively low bioavailability and stability in vivo, which limits our understanding of this receptor family. P2Y12R regulates platelet activation and thrombus formation, and several antithrombotic drugs targeting P2Y12R--including the prodrugs clopidogrel (Plavix) and prasugrel (Effient) that are metabolized and bind covalently, and the nucleoside analogue ticagrelor (Brilinta) that acts directly on the receptor--have been approved for the prevention of stroke and myocardial infarction. However, limitations of these drugs (for example, a very long half-life of clopidogrel action and a characteristic adverse effect profile of ticagrelor) suggest that there is an unfulfilled medical need for developing a new generation of P2Y12R inhibitors. Here we report the 2.6 Å resolution crystal structure of human P2Y12R in complex with a non-nucleotide reversible antagonist, AZD1283. The structure reveals a distinct straight conformation of helix V, which sets P2Y12R apart from all other known class A GPCR structures. With AZD1283 bound, the highly conserved disulphide bridge in GPCRs between helix III and extracellular loop 2 is not observed and appears to be dynamic. Along with the details of the AZD1283-binding site, analysis of the extracellular interface reveals an adjacent ligand-binding region and suggests that both pockets could be required for dinucleotide binding. The structure provides essential insights for the development of improved P2Y12R ligands and allosteric modulators as drug candidates.


Assuntos
Fibrinolíticos/química , Niacina/análogos & derivados , Receptores Purinérgicos P2Y12/química , Sulfonamidas/química , Sítios de Ligação , Cristalografia por Raios X , Dissulfetos/metabolismo , Humanos , Ligantes , Modelos Moleculares , Simulação de Acoplamento Molecular , Niacina/química , Niacina/metabolismo , Conformação Proteica , Antagonistas do Receptor Purinérgico P2Y/química , Antagonistas do Receptor Purinérgico P2Y/metabolismo , Receptores Purinérgicos P2Y12/metabolismo , Sulfonamidas/metabolismo
4.
Nature ; 509(7498): 119-22, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24784220

RESUMO

The P2Y12 receptor (P2Y12R), one of eight members of the P2YR family expressed in humans, is one of the most prominent clinical drug targets for inhibition of platelet aggregation. Although mutagenesis and modelling studies of the P2Y12R provided useful insights into ligand binding, the agonist and antagonist recognition and function at the P2Y12R remain poorly understood at the molecular level. Here we report the structures of the human P2Y12R in complex with the full agonist 2-methylthio-adenosine-5'-diphosphate (2MeSADP, a close analogue of endogenous agonist ADP) at 2.5 Šresolution, and the corresponding ATP derivative 2-methylthio-adenosine-5'-triphosphate (2MeSATP) at 3.1 Šresolution. These structures, together with the structure of the P2Y12R with antagonist ethyl 6-(4-((benzylsulfonyl)carbamoyl)piperidin-1-yl)-5-cyano-2-methylnicotinate (AZD1283), reveal striking conformational changes between nucleotide and non-nucleotide ligand complexes in the extracellular regions. Further analysis of these changes provides insight into a distinct ligand binding landscape in the δ-group of class A G-protein-coupled receptors (GPCRs). Agonist and non-nucleotide antagonist adopt different orientations in the P2Y12R, with only partially overlapped binding pockets. The agonist-bound P2Y12R structure answers long-standing questions surrounding P2Y12R-agonist recognition, and reveals interactions with several residues that had not been reported to be involved in agonist binding. As a first example, to our knowledge, of a GPCR in which agonist access to the binding pocket requires large-scale rearrangements in the highly malleable extracellular region, the structural and docking studies will therefore provide invaluable insight into the pharmacology and mechanisms of action of agonists and different classes of antagonists for the P2Y12R and potentially for other closely related P2YRs.


Assuntos
Difosfato de Adenosina/análogos & derivados , Trifosfato de Adenosina/análogos & derivados , Agonistas do Receptor Purinérgico P2Y/química , Receptores Purinérgicos P2Y12/química , Tionucleotídeos/química , Difosfato de Adenosina/química , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/química , Trifosfato de Adenosina/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Humanos , Ligantes , Modelos Moleculares , Niacina/análogos & derivados , Niacina/química , Niacina/metabolismo , Conformação Proteica , Agonistas do Receptor Purinérgico P2Y/metabolismo , Antagonistas do Receptor Purinérgico P2Y/química , Antagonistas do Receptor Purinérgico P2Y/metabolismo , Receptores Purinérgicos P2Y12/metabolismo , Especificidade por Substrato , Sulfonamidas/química , Sulfonamidas/metabolismo , Tionucleotídeos/metabolismo
5.
J Neurochem ; 133(1): 125-33, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25640170

RESUMO

Compelling evidence indicates that type 2 diabetes mellitus, insulin resistance (IR), and metabolic syndrome are often accompanied by cognitive impairment. However, the mechanistic link between these metabolic abnormalities and CNS dysfunction requires further investigations. Here, we evaluated whether adipose tissue IR and related metabolic alterations resulted in CNS changes by studying synapse lipid composition and function in the adipocyte-specific ecto-nucleotide pyrophosphate phosphodiesterase over-expressing transgenic (AtENPP1-Tg) mouse, a model characterized by white adipocyte IR, systemic IR, and ectopic fat deposition. When fed a high-fat diet, AtENPP1-Tg mice recapitulate essential features of the human metabolic syndrome, making them an ideal model to characterize peripherally induced CNS deficits. Using a combination of gas chromatography and western blot analysis, we found evidence of altered lipid composition, including decreased phospholipids and increased triglycerides (TG) and free fatty acid in hippocampal synaptosomes isolated from high-fat diet-fed AtENPP1-Tg mice. These changes were associated with impaired basal synaptic transmission at the Schaffer collaterals to hippocampal cornu ammonis 1 (CA1) synapses, decreased phosphorylation of the GluN1 glutamate receptor subunit, down-regulation of insulin receptor expression, and up-regulation of the free fatty acid receptor 1.


Assuntos
Tecido Adiposo/metabolismo , Hipocampo/metabolismo , Hipocampo/fisiologia , Resistência à Insulina/fisiologia , Metabolismo dos Lipídeos/fisiologia , Sinapses/metabolismo , Sinapses/fisiologia , Animais , Química Encefálica/efeitos dos fármacos , Hipoglicemiantes/farmacologia , Insulina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptor de Insulina/metabolismo , Sinaptossomos/metabolismo
6.
J Biol Chem ; 288(6): 3739-52, 2013 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-23271738

RESUMO

Staphylococcus epidermidis is a notorious human pathogen that is the major cause of infections related to implanted medical devices. Although redox regulation involving reactive oxygen species is now recognized as a critical component of bacterial signaling and regulation, the mechanism by which S. epidermidis senses and responds to oxidative stress remains largely unknown. Here, we report a new oxidation-sensing regulator, AbfR (aggregation and biofilm formation regulator) in S. epidermidis. An environment of oxidative stress mediated by H(2)O(2) or cumene hydroperoxide markedly up-regulates the expression of abfR gene. Similar to Pseudomonas aeruginosa OspR, AbfR is negatively autoregulated and dissociates from promoter DNA in the presence of oxidants. In vivo and in vitro analyses indicate that Cys-13 and Cys-116 are the key functional residues to form an intersubunit disulfide bond upon oxidation in AbfR. We further show that deletion of abfR leads to a significant induction in H(2)O(2) or cumene hydroperoxide resistance, enhanced bacterial aggregation, and reduced biofilm formation. These effects are mediated by derepression of SERP2195 and gpxA-2 that lie immediately downstream of the abfR gene in the same operon. Thus, oxidative stress likely acts as a signal to modulate S. epidermidis key virulence properties through AbfR.


Assuntos
Proteínas de Bactérias/metabolismo , Biofilmes , Estresse Oxidativo/fisiologia , Staphylococcus epidermidis/fisiologia , Fatores de Transcrição/metabolismo , Proteínas de Bactérias/genética , Dissulfetos/metabolismo , Humanos , Peróxido de Hidrogênio/farmacologia , Oxidantes/farmacologia , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Fatores de Transcrição/genética
7.
Biomed Pharmacother ; 177: 116930, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38878638

RESUMO

The tumor microenvironment (TME) is a combination of tumor cells and indigenous host stroma, which consists of tumor-infiltrating immune cells, endothelial cells, fibroblasts, pericytes, and non-cellular elements. Tumor-associated macrophages (TAMs) represent the major tumor-infiltrating immune cell type and are generally polarized into two functionally contradictory subtypes, namely classical activated M1 macrophages and alternatively activated M2 macrophages. Macrophage polarization refers to how macrophages are activated at a given time and space. The interplay between the TME and macrophage polarization can influence tumor initiation and progression, making TAM a potential target for cancer therapy. Here, we review the latest investigations on factors orchestrating macrophage polarization in the TME, how macrophage polarization affects tumor progression, and the perspectives in modulating macrophage polarization for cancer immunotherapy.

8.
J Neurosci Methods ; 396: 109920, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37459899

RESUMO

BACKGROUND: Synapses are highly specialized sites characterized by intricate networks of protein-protein interactions (PPIs) important to maintain healthy synapses. Therefore, mapping these networks could address unsolved questions about human cognition, synaptic plasticity, learning, and memory in physiological and pathological conditions. The limitation of analyzing synaptic interactions in living humans has led to the development of methods to isolate synaptic terminals (synaptosomes) from cryopreserved human brains. NEW METHOD: Here, we established a method to detect synaptic PPIs by applying flow cytometric proximity ligation assay (FlowPLA) to synaptosomes isolated from frozen human frontal cortex (FC) and hippocampus (HP) (Syn-FlowPLA). RESULTS: Applying this method in synaptosomes, we were able to detect the known post-synaptic interactions between distinct subtypes of N-methyl-D-aspartate glutamate receptors (NMDARs) and their anchoring postsynaptic density 95 protein (PSD95). Moreover, we detected the known pre-synaptic interactions between the SNARE complex proteins synaptosomal-associated protein of 25 kDa (SNAP25), synaptobrevin (VAMP2), and syntaxin 1a (STX1A). As a negative control, we analyzed the interaction between mitochondrial superoxide dismutase 2 (SOD2) and PSD95, which are not expected to be physically associated. COMPARISON WITH EXISTING METHODS: PPIs have been studied in vitro primarily by co-immunoprecipitation, affinity chromatography, protein-fragment complementation assays (PCAs), and flow cytometry. All these are valid approaches; however, they require more steps or combination with other techniques. PLA technology identifies PPIs with high specificity and sensitivity. CONCLUSIONS: The Syn-FlowPLA described here allows rapid analyses of PPIs, specifically within the synaptic compartment isolated from frozen autopsy specimens, achieving greater target sensitivity. Syn-FlowPLA, as presented here, is therefore a useful method to study human synaptic PPI in physiological and pathological conditions.


Assuntos
Sinapses , Sinaptossomos , Humanos , Citometria de Fluxo , Sinapses/metabolismo , Sinaptossomos/metabolismo , Terminações Pré-Sinápticas , Plasticidade Neuronal
9.
J Pharm Pharmacol ; 75(3): 328-362, 2023 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-36632823

RESUMO

OBJECTIVES: Solanum lyratum Thunb (SLT) is a perennial plant of the Solanaceae family, and is extensively used in the clinical practice of traditional Chinese medicine. Malaria, oedema, gonorrhoea, cancer, wind and fever, jaundiced hepatitis, cholecystitis and rheumatoid arthritis are among the diseases that it is used to treat. To offer a foundation for further development and usage of SLT, the pieces of literature about the chemical composition and pharmacological action of SLT were reviewed and analysed. KEY FINDINGS: The chemical constituents of SLT mainly included steroids, alkaloids, flavonoids, terpenoids, anthraquinones, phenylpropanoids and others. Pharmacological action mainly contains anti-tumour, antibacterial, anti-inflammatory, anti-oxidation and other pharmacological actions, among them, the anti-tumour effect is particularly outstanding. SUMMARY: At present, studies on the pharmacological effects of SLT mainly focus on alkaloids and steroidal saponins. In the follow-up studies, studies on the pharmacological activities of other chemical components in SLT, such as flavonoids and terpenoids, should be strengthened. It has the potential to pave the way for more research and development of novel SLT medicines.


Assuntos
Medicamentos de Ervas Chinesas , Neoplasias , Solanum , Humanos , Solanum/química , Extratos Vegetais/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Neoplasias/tratamento farmacológico , Flavonoides/uso terapêutico , Terpenos/uso terapêutico
10.
Protein Cell ; 14(1): 17-27, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36726755

RESUMO

The global COVID-19 coronavirus pandemic has infected over 109 million people, leading to over 2 million deaths up to date and still lacking of effective drugs for patient treatment. Here, we screened about 1.8 million small molecules against the main protease (Mpro) and papain like protease (PLpro), two major proteases in severe acute respiratory syndrome-coronavirus 2 genome, and identified 1851Mpro inhibitors and 205 PLpro inhibitors with low nmol/l activity of the best hits. Among these inhibitors, eight small molecules showed dual inhibition effects on both Mpro and PLpro, exhibiting potential as better candidates for COVID-19 treatment. The best inhibitors of each protease were tested in antiviral assay, with over 40% of Mpro inhibitors and over 20% of PLpro inhibitors showing high potency in viral inhibition with low cytotoxicity. The X-ray crystal structure of SARS-CoV-2 Mpro in complex with its potent inhibitor 4a was determined at 1.8 Å resolution. Together with docking assays, our results provide a comprehensive resource for future research on anti-SARS-CoV-2 drug development.


Assuntos
Antivirais , COVID-19 , Inibidores de Proteases , SARS-CoV-2 , Humanos , Antivirais/farmacologia , Antivirais/química , Tratamento Farmacológico da COVID-19 , Ensaios de Triagem em Larga Escala , Simulação de Acoplamento Molecular , Inibidores de Proteases/farmacologia , Inibidores de Proteases/química , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/enzimologia , Proteínas não Estruturais Virais
11.
J Neurochem ; 120(3): 440-52, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22060133

RESUMO

Intracellular deposition of fibrillar aggregates of α-synuclein (αSyn) characterizes neurodegenerative diseases such as Parkinson's disease (PD) and dementia with Lewy bodies. However, recent evidence indicates that small αSyn oligomeric aggregates that precede fibril formation may be the most neurotoxic species and can be found extracellularly. This new evidence has changed the view of pathological αSyn aggregation from a self-contained cellular phenomenon to an extracellular event and prompted investigation of the putative effects of extracellular αSyn oligomers. In this study, we report that extracellular application of αSyn oligomers detrimentally impacts neuronal welfare and memory function. We found that oligomeric αSyn increased intracellular Ca(2+) levels, induced calcineurin (CaN) activity, decreased cAMP response element-binding protein (CREB) transcriptional activity and resulted in calcineurin-dependent death of human neuroblastoma cells. Similarly, CaN induction and CREB inhibition were observed when αSyn oligomers were applied to organotypic brain slices, which opposed hippocampal long-term potentiation. Furthermore, αSyn oligomers induced CaN, inhibited CREB and evoked memory impairments in mice that received acute intracerebroventricular injections. Notably, all these events were reversed by pharmacological inhibition of CaN. Moreover, we found decreased active CaN and reduced levels of phosphorylated CREB in autopsy brain tissue from patients affected by dementia with Lewy bodies, which is characterized by deposition of αSyn aggregates and progressive cognitive decline. These results indicate that exogenously applied αSyn oligomers impact neuronal function and produce memory deficits through mechanisms that involve CaN activation.


Assuntos
Calcineurina/metabolismo , Potenciação de Longa Duração/efeitos dos fármacos , Transtornos da Memória/induzido quimicamente , Doenças Neurodegenerativas/metabolismo , alfa-Sinucleína , Idoso , Idoso de 80 Anos ou mais , Fosfatase Alcalina/genética , Fosfatase Alcalina/metabolismo , Análise de Variância , Animais , Biofísica , Cálcio/metabolismo , Linhagem Celular Tumoral , Condicionamento Psicológico/efeitos dos fármacos , Condicionamento Psicológico/fisiologia , Modelos Animais de Doenças , Vias de Administração de Medicamentos , Estimulação Elétrica , Medo/efeitos dos fármacos , Feminino , Hipocampo/citologia , Humanos , Técnicas In Vitro , L-Lactato Desidrogenase/metabolismo , Potenciação de Longa Duração/fisiologia , Masculino , Transtornos da Memória/patologia , Camundongos , Camundongos Endogâmicos C57BL , Neuroblastoma/patologia , Doenças Neurodegenerativas/patologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Técnicas de Patch-Clamp , Ratos , Ratos Sprague-Dawley , Transfecção , alfa-Sinucleína/química , alfa-Sinucleína/metabolismo , alfa-Sinucleína/farmacologia
12.
EMBO Rep ; 11(9): 685-90, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20616806

RESUMO

MexR functions as the primary regulator of the mexAB-oprM multidrug efflux expression in Pseudomonas aeruginosa. It has been shown that MexR senses oxidative stress by interprotomer disulphide bond formation between redox-active cysteines. This oxidation induces MexR to dissociate from the promoter DNA, thus activating the transcriptional expression of efflux pump genes. In this study, we present the crystal structure of MexR in its oxidized form at a resolution of 2.1 A. This crystal structure reveals the mechanism by which oxidative signal allosterically derepresses the MexR-controlled transcription activation.


Assuntos
Proteínas de Bactérias/química , Resistência Microbiana a Medicamentos , Oxirredução , Estrutura Quaternária de Proteína , Estrutura Terciária de Proteína , Pseudomonas aeruginosa/metabolismo , Proteínas Repressoras/química , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cristalografia por Raios X , Dissulfetos/química , Regulação Bacteriana da Expressão Gênica , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Dobramento de Proteína , Multimerização Proteica , Pseudomonas aeruginosa/genética , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Ativação Transcricional
13.
J Ethnopharmacol ; 296: 115462, 2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-35714877

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Tapinanthus species are hemiparasites that grow on diverse hosts in African regions. Tapinanthus species are locally known as "all purpose herbs" as they are traditionally used to treat various diseases such as diabetes, hypertension, cancer, inflammation, malaria, anemia, anxiety, itching, and so on. AIM OF THE STUDY: A comprehensive review on research outcomes and future perspectives of Tapinanthus species are presented to provide a reference for relevant researchers. MATERIALS AND METHODS: The references regarding Tapinanthus species were retrieved from Google Scholar, Web of Science, Sci-finder, PubMed, Elsevier, Wiley, China National Knowledge Infrastructure, Open Access Library, and SpringerLink between 1963 and 2022. Scientific plant names were provided by "The Plant List" (www.theplantlist.org) and "The world Flora Online" (www.worldfloraonline.org). RESULTS: Even though Tapinanthus species are regarded as notorious pests that can undermine various hosts, they are, as omnipotent herbs in folklore, meaningful for the development of potential phytomedicine sources. Phytochemistry screening has revealed the presence of glycosides, triterpenoids, flavonoids, alkaloids, tannins, steroids, anthraquinones. Among them, the chemical structures of 40 compounds have been elucidated by phytochemical methods without alkaloids and anthraquinones. These secondary metabolites might be responsible for ethnomedical uses and bioactivities of Tapinanthus species. Current research has provided scientific evidence for traditional uses of Tapinanthus species, especially unraveling hypoglycemic, hepatoprotective, antioxidant, antibacterial, anti-anxiety, anti-depression, anti-inflammatory, and other pharmacological properties. Given the fact that ethnomedical uses served as a valuable reference for pharmacology, however, some records to treat arthritis, fever, itching, dysentery, stomach pain, and anemia, have not been confirmed in current research. Furthermore, the toxic effects of Tapinanthus species were susceptible to the dosages, with relative safety across a wide range. CONCLUSIONS: To reasonably yield Tapinanthus species, artificial culture might be a promising method to develop in the future. The discrepancies between phytochemistry screening and structure elucidation, as well as between ethnomedical uses and current pharmacology, need to be further clarified. The identification of bioactive compounds in crude extracts and fractions, the illustration of the underlying mechanisms of pharmacology, along with the addition of cytotoxicity, genotoxicity, and clinical trials of toxic tests, should be carried out in depth. This review highlights that Tapinanthus species can be considered promising phytomedicine sources as long as we adhere to digging more deeply into their potential role.


Assuntos
Botânica , Loranthaceae , Antraquinonas , Etnobotânica , Etnofarmacologia , Compostos Fitoquímicos/uso terapêutico , Compostos Fitoquímicos/toxicidade , Fitoterapia , Extratos Vegetais/uso terapêutico , Extratos Vegetais/toxicidade , Prurido/tratamento farmacológico
14.
Nat Commun ; 13(1): 7955, 2022 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-36575163

RESUMO

Neuromedin U receptor 2 (NMU2), an emerging attractive target for treating obesity, has shown the capability in reducing food intake and regulating energy metabolism when activated. However, drug development of NMU2 was deferred partially due to the lack of structural information. Here, we present the cryo-electron microscopy (cryo-EM) structure of NMU2 bound to the endogenous agonist NmU-25 and Gi1 at 3.3 Å resolution. Combined with functional and computational data, the structure reveals the key factors that govern the recognition and selectivity of peptide agonist as well as non-peptide antagonist, providing the structural basis for design of novel and highly selective drugs targeting NMU2. In addition, a 25-degree rotation of Gi protein in reference to NMU2 is also observed compared in other structures of class A GPCR-Gi complexes, suggesting heterogeneity in the processes of G protein-coupled receptors (GPCRs) activation and G protein coupling.


Assuntos
Receptores Acoplados a Proteínas G , Receptores de Neurotransmissores , Ligantes , Microscopia Crioeletrônica , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Neurotransmissores/metabolismo , Proteínas de Ligação ao GTP/metabolismo
15.
Cell Res ; 32(8): 761-772, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35739238

RESUMO

Somatostatin receptors (SSTRs) play versatile roles in inhibiting the secretion of multiple hormones such as growth hormone and thyroid-stimulating hormone, and thus are considered as targets for treating multiple tumors. Despite great progress made in therapeutic development against this diverse receptor family, drugs that target SSTRs still show limited efficacy with preferential binding affinity and conspicuous side-effects. Here, we report five structures of SSTR2 and SSTR4 in different states, including two crystal structures of SSTR2 in complex with a selective peptide antagonist and a non-peptide agonist, respectively, a cryo-electron microscopy (cryo-EM) structure of Gi1-bound SSTR2 in the presence of the endogenous ligand SST-14, as well as two cryo-EM structures of Gi1-bound SSTR4 in complex with SST-14 and a small-molecule agonist J-2156, respectively. By comparison of the SSTR structures in different states, molecular mechanisms of agonism and antagonism were illustrated. Together with computational and functional analyses, the key determinants responsible for ligand recognition and selectivity of different SSTR subtypes and multiform binding modes of peptide and non-peptide ligands were identified. Insights gained in this study will help uncover ligand selectivity of various SSTRs and accelerate the development of new molecules with better efficacy by targeting SSTRs.


Assuntos
Neoplasias , Receptores de Somatostatina , Microscopia Crioeletrônica , Humanos , Ligantes , Neoplasias/metabolismo , Receptores de Somatostatina/agonistas , Receptores de Somatostatina/metabolismo , Somatostatina/metabolismo , Somatostatina/farmacologia , Somatostatina/uso terapêutico
16.
Med Princ Pract ; 20(1): 47-50, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21160214

RESUMO

OBJECTIVE: To investigate the safety and efficacy of percutaneous endoscopic gastrostomy/jejunostomy (PEG/PEJ) combined with percutaneous transhepatic biliary drainage (PTCD) in treating malignant biliary obstruction. SUBJECTS AND METHODS: Nine patients (6 males and 3 females, average age 71.3 ± 5.5 years) with complete obstruction of the biliary tract were treated with PEG/PEJ after PTCD. The PEG/PEJ and PTCD tubes were linked outside of the abdominal wall to direct the externally drained bile back to the jejunum through the PEG/PEJ intestinal tube. Clinical symptoms and liver function were assessed following the treatment. RESULTS: The operations were successfully completed in the 9 patients within 40 min (average 35 ± 2.9 min). Clinical symptoms such as jaundice, abdominal distension, stomachache and diarrhea appeared but improved within 7 days of the operation. Serum levels of bilirubin, aspartate aminotransferase and alanine aminotransferase were reduced (p < 0.01) 4 weeks following the treatment. There were no procedural complications. CONCLUSIONS: Combined PEG/PEJ and PTCD appeared to be safe and effective in the management of malignant biliary obstruction. Further, larger-scale studies will be needed to verify findings of this report.


Assuntos
Ductos Biliares Intra-Hepáticos/cirurgia , Neoplasias do Sistema Biliar/cirurgia , Colangiocarcinoma/cirurgia , Colestase/cirurgia , Gastrostomia/métodos , Jejunostomia/métodos , Idoso , Idoso de 80 Anos ou mais , Ductos Biliares Intra-Hepáticos/patologia , Bilirrubina/sangue , China , Drenagem , Endoscopia Gastrointestinal , Feminino , Humanos , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
17.
J Neurosci Res ; 88(13): 2923-32, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20544830

RESUMO

Soluble oligomeric aggregates of the amyloid-beta (A beta) peptide are believed to be the most neurotoxic A beta species affecting the brain in Alzheimer disease (AD), a terminal neurodegenerative disorder involving severe cognitive decline underscored by initial synaptic dysfunction and later extensive neuronal death in the CNS. Recent evidence indicates that A beta oligomers are recruited at the synapse, oppose expression of long-term potentiation (LTP), perturb intracellular calcium balance, disrupt dendritic spines, and induce memory deficits. However, the molecular mechanisms behind these outcomes are only partially understood; achieving such insight is necessary for the comprehension of A beta-mediated neuronal dysfunction. We have investigated the role of the phosphatase calcineurin (CaN) in these pathological processes of AD. CaN is especially abundant in the CNS, where it is involved in synaptic activity, LTP, and memory function. Here, we describe how oligomeric A beta treatment causes memory deficits and depresses LTP expression in a CaN-dependent fashion. Mice given a single intracerebroventricular injection of A beta oligomers exhibited increased CaN activity and decreased pCREB, a transcription factor involved in proper synaptic function, accompanied by decreased memory in a fear conditioning task. These effects were reversed by treatment with the CaN inhibitor FK506. We further found that expression of hippocampal LTP in acutely cultured rodent brain slices was opposed by A beta oligomers and that this effect was also reversed by FK506. Collectively, these results indicate that CaN activation may play a central role in mediating synaptic and memory disruption induced by acute oligomeric A beta treatment in mice.


Assuntos
Proteínas Amiloidogênicas/toxicidade , Calcineurina/metabolismo , Condicionamento Psicológico/efeitos dos fármacos , Medo/psicologia , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/fisiopatologia , Animais , Comportamento Animal/efeitos dos fármacos , Proteína de Ligação a CREB/metabolismo , Modelos Animais de Doenças , Interações Medicamentosas , Feminino , Imunossupressores/farmacologia , Técnicas In Vitro , Injeções Intra-Articulares/métodos , Potenciação de Longa Duração/efeitos dos fármacos , Masculino , Potenciais da Membrana/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Técnicas de Patch-Clamp/métodos , Monoéster Fosfórico Hidrolases/metabolismo , Ratos , Ratos Sprague-Dawley , Sirolimo/farmacologia , Tacrolimo/farmacologia
18.
Am J Physiol Regul Integr Comp Physiol ; 298(3): R584-98, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20007519

RESUMO

Human primary and clonal synovial cells were incubated with glutamate receptor agonists to assess their modulating influence on glutamate receptors N-methyl-d-aspartate (NMDA) NR1 and NR2 and inflammatory cytokines to determine potential for paracrine or autocrine (neurocrine) upregulation of glutamate receptors, as has been shown for bone and chondrocytes. Clonal SW982 synoviocytes constitutively express vimentin, smooth muscle actin (SMA), and NMDA NR1 and NR2. Coincubation (6 h) with glutamate agonists NMDA (5 microM), and the NMDA NR1 glycine site activator (+/-)1-aminocyclopentane-cis-1,3-dicarboxylic acid (5 muM), significantly increases cellular mRNA and protein levels of glutamate receptors, as well as increasing vimentin, SMA, tumor necrosis factor-alpha, and RANTES (regulated on activation, normal T-cell expressed and secreted), assessed qualitatively and quantitatively with nucleotide amplification, image analysis of immunocytochemical staining, fluorescein-activated cell sorting, Western blotting, and immunoassays. Human primary synovial cells harvested from patients with arthritic conditions also constitutively expressed NMDA NR1 with increases after agonist treatment. Glutamate receptor agonist-induced increases were blocked by the noncompetitive glutamate antagonist MK-801 (8 microg/ml) and NR1 blocking antibody. Coincubation with glutamate agonists and phorbol 12-myristate 13-acetate, a protein kinase C activator, significantly enhanced mean levels of TNF-alpha and RANTES in SW982 cell supernatants compared with incubation with either agent alone. Increases were diminished with protein kinase inhibitor and NR1 blocking antibody. The functional activation of glutamate receptors on human synoviocytes establishes a neurogenic cell signaling link between neurotransmitter glutamate released from nerve terminals and target cells in the joint capsule. The influence of glutamate on subsequent release of cellular proinflammatory mediators in non-neural tissue for activation of downstream immune events supports a peripheral neuroimmune link in arthritis.


Assuntos
Quimiocina CCL5/metabolismo , Inflamação Neurogênica/fisiopatologia , Receptores de N-Metil-D-Aspartato/genética , Sinovite/fisiopatologia , Fator de Necrose Tumoral alfa/metabolismo , Vimentina/metabolismo , Animais , Artrite/metabolismo , Artrite/fisiopatologia , Antígeno CD11b/metabolismo , Linhagem Celular Tumoral , Cicloleucina/análogos & derivados , Cicloleucina/farmacologia , Maleato de Dizocilpina/farmacologia , Agonistas de Aminoácidos Excitatórios/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Humanos , N-Metilaspartato/farmacologia , Inflamação Neurogênica/metabolismo , Neuroimunomodulação/fisiologia , Proteína Quinase C/metabolismo , RNA Mensageiro/metabolismo , Ratos , Receptores de Complemento 3d/metabolismo , Receptores de Glutamato/metabolismo , Receptores de N-Metil-D-Aspartato/agonistas , Receptores de N-Metil-D-Aspartato/metabolismo , Sarcoma Sinovial , Membrana Sinovial/citologia , Membrana Sinovial/fisiologia , Sinovite/metabolismo , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/fisiologia , Vimentina/genética
19.
J Environ Sci (China) ; 22(4): 533-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20617729

RESUMO

The pollutants in urban storm runoff, which lead to an non-point source contamination of water environment around cities, are of great concerns. The distributions of typical contaminants and the variations of their species in short term storm runoff from different land surfaces in Xiamen City were investigated. The concentrations of various contaminants, including organic matter, nutrients (i.e., N and P) and heavy metals, were significantly higher in parking lot and road runoff than those in roof and lawn runoff. The early runoff samples from traffic road and parking lot contained much high total nitrogen (TN 6-19 mg/L) and total phosphorus (TP 1-3 mg/L). A large proportion (around 60%) of TN existed as total dissolved nitrogen (TDN) species in most runoff. The percentage of TDN and the percentage of total dissolved phosphorus remained relatively stable during the rain events and did not decrease as dramatically as TN and TP. In addition, only parking lot and road runoff were contaminated by heavy metals, and both Pb (25-120 microg/L) and Zn (0.1-1.2 mg/L) were major heavy metals contaminating both runoff. Soluble Pb and Zn were predominantly existed as labile complex species (50%-99%), which may be adsorbed onto the surfaces of suspended particles and could be easily released out when pH decreased. This would have the great impact to the environment.


Assuntos
Chuva , Movimentos da Água , Poluentes Químicos da Água/química , Água/química , China , Monitoramento Ambiental , Metais Pesados/química , Nitrogênio/química , Fósforo/química
20.
Front Physiol ; 11: 440, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32536874

RESUMO

In the lumbar spinal cord dorsal horn, release of afferent nerve glutamate activates the neurons that relay information about injury pain. Here, we examined the effects of protein tyrosine kinase (PTK) inhibition on NMDA receptor NR1 subunit protein expression and subcellular localization in an acute experimental arthritis model. PTK inhibitors genistein and lavendustin A reduced cellular histological translocation of NMDA NR1 in the spinal cord occurring after the inflammatory insult and the nociceptive behavioral responses to heat. The PTK inhibitors were administered into lumbar spinal cord by microdialysis, and secondary heat hyperalgesia was determined using the Hargreaves test. NMDA NR1 cellular protein expression and nuclear translocation were determined by immunocytochemical localization with light and electron microscopy, as well as with Western blot analysis utilizing both C- and N-terminal antibodies. Genistein and lavendustin A (but not inactive lavendustin B or diadzein) effectively reduced (i) pain related behavior, (ii) NMDA NR1 subunit expression increases in spinal cord, and (iii) the shift of NR1 from a cell membrane to a nuclear localization. Genistein pre-treatment reduced these events that occur in vivo within 4 h after inflammatory insult to the knee joint with kaolin and carrageenan (k/c). Cycloheximide reduced glutamate activated upregulation of NR1 content confirming synthesis of new protein in response to the inflammatory insult. In addition to this in vivo data, genistein or staurosporin inhibited upregulation of NMDA NR1 protein and nuclear translocation in vitro after treatment of human neuroblastoma clonal cell cultures (SH-SY5Y) with glutamate or NMDA (4 h). These studies provide evidence that inflammatory activation of peripheral nerves initiates increase in NMDA NR1 in the spinal cord coincident with development of pain related behaviors through glutamate non-receptor, PTK dependent cascades.

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