RESUMO
The aim of this study was to screen sixteen meso-1 semi-synthetic derivatives bearing ether, esther, carbamate, phosphate or aminoether functional groups against five cancer cell lines: MCF-7 (breast), A549 (lung), HepG2 (liver), HeLa (cervix), and DU145 (prostate) at 25â µM using the MTT assay. Results from the screening showed that two derivatives had the lowest percentage of cell viability at 25â µM, the aminoether derivative meso-11 and the esther derivative meso-20 against A549 (44.15±0.78 %) and MCF-7 (41.60±0.92 %), respectively. Then, it was determined the IC50 value of each compound against their most sensitive cancer cell line. Results showed that aminoether derivative meso-11 showed potent cytotoxicity against A549 (IC50 =17.11±2.11â µM), whereas it resulted more cytotoxic against the LL-47 lung normal cell line (IC50 =9.49±1.19â µM) having a Selective Index (SI) of 0.55. On the other hand, the esther derivative meso-20 exhibited potent activity against MCF-7 (IC50 =18.20±1.98â µM), whereas it displayed moderate cytotoxicity against the MCF-10 breast normal cell line (IC50 =41.22±2.17â µM) with a SI of 2.2. Finally, studies on the mechanism of action of meso-20 indicated disruption of MCF-7 plasma membrane inâ vitro and the AMPK activation in silico.
Assuntos
Antineoplásicos , Guaiacol/análogos & derivados , Lignanas , Masculino , Humanos , Relação Estrutura-Atividade , Ensaios de Seleção de Medicamentos Antitumorais , Antineoplásicos/farmacologia , Lignanas/farmacologia , Proliferação de Células , Estrutura Molecular , Simulação de Acoplamento Molecular , Linhagem Celular Tumoral , Células MCF-7RESUMO
Cordycepin, or 3'-deoxyadenosine, is an adenosine analog with a broad spectrum of biological activity. The key structural difference between cordycepin and adenosine lies in the absence of a hydroxyl group at the 3' position of the ribose ring. Upon administration, cordycepin can undergo an enzymatic transformation in specific tissues, forming cordycepin triphosphate. In this study, we conducted a comprehensive analysis of the structural features of cordycepin and its derivatives, contrasting them with endogenous purine-based metabolites using chemoinformatics and bioinformatics tools in addition to molecular dynamics simulations. We tested the hypothesis that cordycepin triphosphate could bind to the active site of the adenylate cyclase enzyme. The outcomes of our molecular dynamics simulations revealed scores that are comparable to, and superior to, those of adenosine triphosphate (ATP), the endogenous ligand. This interaction could reduce the production of cyclic adenosine monophosphate (cAMP) by acting as a pseudo-ATP that lacks a hydroxyl group at the 3' position, essential to carry out nucleotide cyclization. We discuss the implications in the context of the plasticity of cancer and other cells within the tumor microenvironment, such as cancer-associated fibroblast, endothelial, and immune cells. This interaction could awaken antitumor immunity by preventing phenotypic changes in the immune cells driven by sustained cAMP signaling. The last could be an unreported molecular mechanism that helps to explain more details about cordycepin's mechanism of action.
Assuntos
AMP Cíclico , Desoxiadenosinas , Simulação de Dinâmica Molecular , Neoplasias , Desoxiadenosinas/metabolismo , Desoxiadenosinas/farmacologia , Desoxiadenosinas/química , Humanos , Neoplasias/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/patologia , AMP Cíclico/metabolismo , Trifosfato de Adenosina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Simulação por Computador , Adenilil Ciclases/metabolismoRESUMO
The developing of antibacterial resistance is becoming in crisis. In this sense, natural products play a fundamental role in the discovery of antibacterial agents with diverse mechanisms of action. Phytochemical investigation of Cissus incisa leaves led to isolation and characterization of the ceramides mixture (1): (8E)-2-(tritriacont-9-enoyl amino)-1,3,4-octadecanetriol-8-ene (1-I); (8E)-2-(2',3'-dihydroxyoctacosanoyl amino)-1,3,4-octadecanetriol-8-ene (1-II); (8E)-2-(2'-hydroxyheptacosanoyl amino)-1,3,4-octadecanetriol-8-ene (1-III); and (8E)-2-(-2'-hydroxynonacosanoyl amino)-1,3,4-octadecanetriol-8-ene (1-IV). Until now, this is the first report of the ceramides (1-I), (1-II), and (1-IV). The structures were elucidated using NMR and mass spectrometry analyses. Antibacterial activity of ceramides (1) and acetylated derivates (2) was evaluated against nine multidrug-resistant bacteria by Microdilution method. (1) showed the best results against Gram-negatives, mainly against carbapenems-resistant Acinetobacter baumannii with MIC = 50 µg/mL. Structure-activity analysis and molecular docking revealed interactions between plant ceramides with membrane proteins, and enzymes associated with biological membranes of Gram-negative bacteria, through hydrogen bonding of functional groups. Vesicular contents release assay showed the capacity of (1) to disturb membrane permeability detected by an increase of fluorescence probe over time. The membrane disruption is not caused for ceramides lytic action on cell membranes, according in vitro hemolyticactivity results. Combining SAR analysis, bioinformatics and biophysical techniques, and also experimental tests, it was possible to explain the antibacterial action of these natural ceramides.
Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/farmacologia , Ceramidas/farmacologia , Cissus/química , Simulação de Acoplamento Molecular , Antibacterianos/química , Antibacterianos/isolamento & purificação , Ceramidas/química , Ceramidas/isolamento & purificação , Relação Dose-Resposta a Droga , Farmacorresistência Bacteriana/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
Leishmaniasis is a disease caused by parasites of the Leishmania genus that affects 98 countries worldwide, 2 million of new cases occur each year and more than 350 million people are at risk. The use of the actual treatments is limited due to toxicity concerns and the apparition of resistance strains. Therefore, there is an urgent necessity to find new drugs for the treatment of this disease. In this context, enzymes from the polyamine biosynthesis pathway, such as arginase, have been considered a good target. In the present work, a chemical library of benzimidazole derivatives was studied performing computational, enzyme kinetics, biological activity, and cytotoxic effect characterization, as well as in silico ADME-Tox predictions, to find new inhibitors for arginase from Leishmania mexicana (LmARG). The results show that the two most potent inhibitors (compounds 1 and 2) have an I50 values of 52 µM and 82 µM, respectively. Moreover, assays with human arginase 1 (HsARG) show that both compounds are selective for LmARG. According to molecular dynamics simulation studies these inhibitors interact with important residues for enzyme catalysis. Biological activity assays demonstrate that both compounds have activity against promastigote and amastigote, and low cytotoxic effect in murine macrophages. Finally, in silico prediction of their ADME-Tox properties suggest that these inhibitors support the characteristics to be considered drug candidates. Altogether, the results reported in our study suggest that the benzimidazole derivatives are an excellent starting point for design new drugs against leishmanisis.
Assuntos
Antiprotozoários/farmacologia , Arginase/antagonistas & inibidores , Benzimidazóis/farmacologia , Leishmania mexicana/efeitos dos fármacos , Proteínas de Protozoários/antagonistas & inibidores , Animais , Antiprotozoários/química , Arginase/metabolismo , Benzimidazóis/química , Linhagem Celular , Descoberta de Drogas , Humanos , Leishmania mexicana/enzimologia , Leishmania mexicana/fisiologia , Leishmaniose Cutânea/tratamento farmacológico , Camundongos , Modelos Moleculares , Proteínas de Protozoários/metabolismoRESUMO
Multidrug resistance protein-4 (MRP4) belongs to the ABC transporter superfamily and promotes the transport of xenobiotics including drugs. A non-synonymous single nucleotide polymorphisms (nsSNPs) in the ABCC4 gene can promote changes in the structure and function of MRP4. In this work, the interaction of certain endogen substrates, drug substrates, and inhibitors with wild type-MRP4 (WT-MRP4) and its variants G187W and Y556C were studied to determine differences in the intermolecular interactions and affinity related to SNPs using protein threading modeling, molecular docking, all-atom, coarse grained, and umbrella sampling molecular dynamics simulations (AA-MDS and CG-MDS, respectively). The results showed that the three MRP4 structures had significantly different conformations at given sites, leading to differences in the docking scores (DS) and binding sites of three different groups of molecules. Folic acid (FA) had the highest variation in DS on G187W concerning WT-MRP4. WT-MRP4, G187W, Y556C, and FA had different conformations through 25 ns AA-MD. Umbrella sampling simulations indicated that the Y556C-FA complex was the most stable one with or without ATP. In Y556C, the cyclic adenosine monophosphate (cAMP) and ceefourin-1 binding sites are located out of the entrance of the inner cavity, which suggests that both cAMP and ceefourin-1 may not be transported. The binding site for cAMP and ceefourin-1 is quite similar and the affinity (binding energy) of ceefourin-1 to WT-MRP4, G187W, and Y556C is greater than the affinity of cAMP, which may suggest that ceefourin-1 works as a competitive inhibitor. In conclusion, the nsSNPs G187W and Y556C lead to changes in protein conformation, which modifies the ligand binding site, DS, and binding energy.
Assuntos
Conformação Molecular , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Proteínas Associadas à Resistência a Múltiplos Medicamentos/antagonistas & inibidores , Proteínas Associadas à Resistência a Múltiplos Medicamentos/química , Proteínas Mutantes/química , Trifosfato de Adenosina/química , Trifosfato de Adenosina/metabolismo , Benzotiazóis/química , Benzotiazóis/metabolismo , Sítios de Ligação , AMP Cíclico/química , AMP Cíclico/metabolismo , Ácido Fólico/química , Ácido Fólico/metabolismo , Ligantes , Domínios Proteicos , Homologia Estrutural de Proteína , Termodinâmica , Triazóis/química , Triazóis/metabolismoRESUMO
Preliminary bioassay-guided fractionation was performed to identify cytotoxic compounds from Hechtia glomerata, a plant that is used in Mexican ethnomedicine. Organic and aqueous extracts were prepared from H. glomerata's leaves and evaluated against two cancer cell lines. The CHCl3/MeOH (1:1) active extract was fractionated, and the resulting fractions were assayed against prostate adenocarcinoma PC3 and breast adenocarcinoma MCF7 cell lines. Active fraction 4 was further analyzed by high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry analysis to identify its active constituents. Among the compounds that were responsible for the cytotoxic effects of this fraction were flavonoids, phenolic acids, and aromatic compounds, of which p-coumaric acid (p-CA) and its derivatives were abundant. To understand the mechanisms that underlie p-CA cytotoxicity, a microarray assay was performed on PC3 cells that were treated or not with this compound. The results showed that mitogen-activated protein kinases (MAPKs) that regulate many cancer-related pathways were targeted by p-CA, which could be related to the reported effects of reactive oxygen species (ROS). A molecular docking study of p-CA showed that this phenolic acid targeted these protein active sites (MAPK8 and Serine/Threonine protein kinase 3) at the same binding site as their inhibitors. Thus, we hypothesize that p-CA produces ROS, directly affects the MAPK signaling pathway, and consequently causes apoptosis, among other effects. Additionally, p-CA could be used as a platform for the design of new MAPK inhibitors and re-sensitizing agents for resistant cancers.
Assuntos
Bromeliaceae/química , Ácidos Cumáricos/farmacologia , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Extratos Vegetais/química , Inibidores de Proteínas Quinases/farmacologia , Bioensaio , Morte Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Ácidos Cumáricos/química , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Humanos , Células MCF-7 , Proteínas Quinases Ativadas por Mitógeno/química , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Células PC-3 , Fenóis/farmacologia , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genéticaRESUMO
Vitiligo is a hypopigmentary skin pathology resulting from the death of melanocytes due to the activity of CD8+ cytotoxic lymphocytes and overexpression of chemokines. These include CXCL9, CXCL10, and CXCL11 and its receptor CXCR3, both in peripheral cells of the immune system and in the skin of patients diagnosed with vitiligo. The three-dimensional structure of CXCR3 and CXCL9 has not been reported experimentally; thus, homology modeling and molecular dynamics could be useful for the study of this chemotaxis-promoter axis. In this work, a homology model of CXCR3 and CXCL9 and the structure of the CXCR3/Gαi/0ßγ complex with post-translational modifications of CXCR3 are reported for the study of the interaction of chemokines with CXCR3 through all-atom (AA-MD) and coarse-grained molecular dynamics (CG-MD) simulations. AA-MD and CG-MD simulations showed the first activation step of the CXCR3 receptor with all chemokines and the second activation step in the CXCR3-CXCL10 complex through a decrease in the distance between the chemokine and the transmembrane region of CXCR3 and the separation of the ßγ complex from the α subunit in the G-protein. Additionally, a general protein-ligand interaction model was calculated, based on known antagonists binding to CXCR3. These results contribute to understanding the activation mechanism of CXCR3 and the design of new molecules that inhibit chemokine binding or antagonize the receptor, provoking a decrease of chemotaxis caused by the CXCR3/chemokines axis.
Assuntos
Quimiocina CXCL10/química , Quimiocina CXCL11/química , Quimiocina CXCL9/química , Desenho de Fármacos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Receptores CXCR3 , Vitiligo/tratamento farmacológico , Humanos , Receptores CXCR3/agonistas , Receptores CXCR3/antagonistas & inibidores , Receptores CXCR3/química , Vitiligo/metabolismoRESUMO
Recently, our research group demonstrated that uvaol and ursolic acid increase NO and H2S production in aortic tissue. Molecular docking studies showed that both compounds bind with high affinity to endothelial NO synthase (eNOS) and cystathionine gamma-lyase (CSE). The aim of this study was to identify hits with high binding affinity for the triterpene binding-allosteric sites of eNOS and CSE and to evaluate their vasodilator effect. Additionally, the mechanism of action of the most potent compound was explored. A high-throughput virtual screening (HTVS) of 107,373 compounds, obtained from four ZINC database libraries, was performed employing the crystallographic structures of eNOS and CSE. Among the nine top-scoring ligands, isoxsuprine showed the most potent vasodilator effect. Pharmacological evaluation, employing the rat aorta model, indicated that the vasodilation produced by this compound involved activation of the NO/cGMP and H2S/KATP signaling pathways and blockade of α1-adrenoceptors and L-type voltage-dependent Ca2+ channels. Incubation of aorta homogenates in the presence of isoxsuprine caused 2-fold greater levels of H2S, which supported our preliminary in silico data. This study provides evidence to propose that the vasodilator effect of isoxsuprine involves various mechanisms, which highlights its potential to treat a wide variety of cardiovascular diseases.
Assuntos
Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Isoxsuprina/química , Isoxsuprina/farmacologia , Redes e Vias Metabólicas/efeitos dos fármacos , Relação Quantitativa Estrutura-Atividade , Vasodilatadores/química , Vasodilatadores/farmacologia , Trifosfato de Adenosina/metabolismo , Antagonistas de Receptores Adrenérgicos alfa 1/química , Bloqueadores dos Canais de Cálcio/química , GMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Ensaios de Triagem em Larga Escala , Humanos , Sulfeto de Hidrogênio/metabolismo , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Óxido Nítrico/metabolismo , Bibliotecas de Moléculas Pequenas , Fluxo de TrabalhoRESUMO
Thirty-three meso-dihydroguaiaretic acid (meso-DGA) derivatives bearing esters, ethers, and amino-ethers were synthesized. All derivatives were tested against twelve drug-resistant clinical isolates of Gram-positive and Gram-negative bacteria, including sensitive (H37Rv) and multidrug-resistant Mycobacterium tuberculosis strains. Among the tested compounds, four esters (7, 11, 13, and 17), one ether (23), and three amino-ethers (30, 31, and 33) exhibited moderate activity against methicillin-resistant Staphylococcus aureus, whereas 30 and 31 showed better results than levofloxacin against vancomycin-resistant Enterococcus faecium. Additionally, nineteen meso-DGA derivatives displayed moderate to potent activity against M. tuberculosis H37Rv with minimum inhibitory concentration (MIC) values ranging from 3.125 to 50µg/mL. Seven meso-DGA derivatives bearing amino-ethers (26-31 and 33) exhibited the lowest MICs against M. tuberculosis H37Rv and G122 strains, with 31 being as potent as ethambutol (MICs of 3.125 and 6.25µg/mL). The presence of positively charged group precursors possessing steric and hydrophobic features (e.g. N-ethylpiperidine moieties in meso-31) resulted essential to significantly increase the antimycobacterial properties of parent meso-DGA as supported by the R-group pharmacophoric and field-based QSAR analyses. To investigate the safety profile of the antimycobacterial compounds, cytotoxicity on Vero cells was determined. The amino-ether 31 exhibited a selectivity index value of 23, which indicate it was more toxic to M. tuberculosis than to mammalian cells. Therefore, 31 can be considered as a promising antitubercular agent for further studies.
Assuntos
Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Guaiacol/análogos & derivados , Lignanas/farmacologia , Animais , Antibacterianos/síntese química , Antibacterianos/química , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Guaiacol/síntese química , Guaiacol/química , Guaiacol/farmacologia , Lignanas/síntese química , Lignanas/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Quantitativa Estrutura-Atividade , Células VeroRESUMO
The present research aimed to isolate the non-polar secondary metabolites that produce the vasodilator effects induced by the dichloromethane extract of Prunus serotina (P. serotina) fruits and to determine whether the NO/cGMP and the H2S/KATP channel pathways are involved in their mechanism of action. A bioactivity-directed fractionation of the dichloromethane extract of P. serotina fruits led to the isolation of ursolic acid and uvaol as the main non-polar vasodilator compounds. These compounds showed significant relaxant effect on rat aortic rings in an endothelium- and concentration-dependent manner, which was inhibited by NG-nitro-L-arginine methyl ester (L-NAME), DL-propargylglycine (PAG) and glibenclamide (Gli). Additionally, both triterpenes increased NO and H2S production in aortic tissue. Molecular docking studies showed that ursolic acid and uvaol are able to bind to endothelial NOS and CSE with high affinity for residues that form the oligomeric interface of both enzymes. These results suggest that the vasodilator effect produced by ursolic acid and uvaol contained in P. serotina fruits, involves activation of the NO/cGMP and H2S/KATP channel pathways, possibly through direct activation of NOS and CSE.
Assuntos
Sulfeto de Hidrogênio/agonistas , Óxido Nítrico/agonistas , Prunus avium/química , Triterpenos/farmacologia , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia , Alcinos/antagonistas & inibidores , Alcinos/farmacologia , Animais , Aorta/citologia , Aorta/efeitos dos fármacos , Aorta/metabolismo , GMP Cíclico/metabolismo , Cistationina gama-Liase/química , Cistationina gama-Liase/metabolismo , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Frutas/química , Glibureto/antagonistas & inibidores , Glibureto/farmacologia , Glicina/análogos & derivados , Glicina/antagonistas & inibidores , Glicina/farmacologia , Sulfeto de Hidrogênio/metabolismo , Canais KATP/agonistas , Canais KATP/metabolismo , Masculino , Simulação de Acoplamento Molecular , NG-Nitroarginina Metil Éster/antagonistas & inibidores , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase Tipo III/química , Óxido Nítrico Sintase Tipo III/metabolismo , Extratos Vegetais/química , Ligação Proteica , Ratos , Triterpenos/isolamento & purificação , Vasodilatadores/isolamento & purificação , Ácido UrsólicoRESUMO
BACKGROUND: Nitroaromatic compounds are important scaffolds used for the syn-thesis of a variety of compounds, such as explosives, herbicides, dyes, perfumes and phar-maceuticals. Bismuth nitrate pentahydrate is a widely used reagent in organic synthesis; how-ever, its utility as a nitrating agent for anilines is underexplored. OBJECTIVE: The aim of this work is to propose and find the proper reaction conditions of an alternative nitrating agent constituted by a mixture of bismuth nitrate / acetic anhydride in DCM with a series of substituted anilines under mild reflux. METHODS: Several anilines having both activating and deactivating substituents in the ortho, meta and para positions were the substrate for the nitration reaction. Experimental conditions were performed in "one-pot" conditions before product purification. RESULTS: Bi(NO3)3â¢5H2O demonstrated to be effective and somehow regioselective when it came to the nitration of anilines in the ortho position. Although other products were also identified under these conditions, in most cases, the ortho derivative was the major or even the only product obtained with moderate to high yields in the range of 50% - 96%. CONCLUSION: Bi(NO3)3â¢5H2O is an efficient and safe nitrating agent since the use of concen-trated and corrosive acids like sulfuric and nitric is avoided; furthermore, bismuth nitrate is low-priced and no special care nor equipment is required.
RESUMO
Epilepsy is a neurological disorder in which it has been shown that the presence of oxidative stress (OS) is implicated in epileptogenesis. The literature has shown that some antiseizure drugs (ASD) have neuroprotective properties. Levetiracetam (LEV) is a drug commonly used as an ASD, and in some studies, it has been found to possess antioxidant properties. Because the antioxidant effects of LEV have not been demonstrated in the chronic phase of epilepsy, the objective of this study was to evaluate, for the first time, the effects of LEV on the oxidant-antioxidant status in the hippocampus of rats with temporal lobe epilepsy (TLE). The in vitro scavenging capacity of LEV was evaluated. LEV administration in rats with TLE significantly increased superoxide dismutase (SOD) activity, increased catalase (CAT) activity, but did not change glutathione peroxidase (GPx) activity, and significantly decreased glutathione reductase (GR) activity in comparison with epileptic rats. LEV administration in rats with TLE significantly reduced hydrogen peroxide (H2O2) levels but did not change lipoperoxidation and carbonylated protein levels in comparison with epileptic rats. In addition, LEV showed in vitro scavenging activity against hydroxyl radical (HOâ¢). LEV showed significant antioxidant effects in relation to restoring the redox balance in the hippocampus of rats with TLE. In vitro, LEV demonstrated direct antioxidant activity against HOâ¢.
RESUMO
We report synthesis, characterization, biological evaluation, and molecular-docking studies of 18 thieno[2,3-b]pyridines with a phenylacetamide moiety at position 2, which is disubstituted with F, Cl, Br, or I at position 4, and with electron-withdrawing and electron-donating groups (-CN, -NO2, -CF3, and -CH3) at position 2, to study how the electronic properties of the substituents affected the FOXM1-inhibitory activity. Among compounds 1-18, only those bearing a -CN (regardless of the halogen) decreased FOXM1 expression in a triple-negative breast cancer cell line (MDA-MB-231), as shown by Western blotting. However, only compounds 6 and 16 decreased the relative expression of FOXM1 to a level lower than 50%, and hence, we determined their anti-proliferative activity (IC50) in MDA-MB-231 cells using the MTT assay, which was comparable to that observed with FDI-6, in contrast to compound 1, which was inactive according to both Western blot and MTT assays. We employed molecular docking to calculate the binding interactions of compounds 1-18 in the FOXM1 DNA-binding site. The results suggest a key role for residues Val296 and Leu289 in this binding. Furthermore, we used molecular electrostatic potential maps showing the effects of different substituents on the overall electron density.
RESUMO
Leukemia is the most common childhood malignancy in Mexico, representing more than 50% of all childhood cancers. Although treatment leads to a survival of up to 90% in developing countries, in our country, it is less than 65%. Additionally, ~30% of patients relapse with poor prognosis. Alternative splicing plays an important role in transcriptome diversity and cellular biology. This mechanism promotes an increase in the assortment of proteins with potentially distinct functions from a single gene. The proliferating cell nuclear antigen (PCNA) gene encodes two transcripts for the same protein of 261 amino acids, which is associated with several important cellular processes and with several types of cancer. However, the diversity of the transcript variants expressed in this condition is not clear. Then, we used microarray gene expression to identify changes in the exon expression level of PCNA. The data were validated using RT-PCR and Sanger sequencing, and three additional transcripts (PCNA_V3, PCNA_V4, and PCNA_V5) were identified. Computational analyses were used to determine the potential proteins resulting, their structure, and interactions with PCNA native protein and themselves. Additionally, the PCNA transcript variants were inhibited using specific siRNA, determining that their inhibition contributes to the malignant characteristics in vitro. Finally, we quantified the PCNA transcript variants in acute lymphoblastic leukemia samples and identified their expression in this disease. Based on the clinical characteristics, we determined that PCNA_V2 and PCNA_V4 are expressed at significantly low levels in relapsed B-ALL patients. We conclude that the low expression of PCNA_V2 and PCNA_V4 could be a potential molecular marker of relapse in acute lymphoblastic leukemia patients.
Assuntos
Linfoma de Burkitt , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Criança , Antígeno Nuclear de Célula em Proliferação/genética , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteínas Nucleares/metabolismo , RNA Interferente Pequeno , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Recidiva , Biomarcadores , Doença Aguda , AminoácidosRESUMO
Epilepsy is a chronic disease that affects millions of people worldwide. Antiepileptic drugs (AEDs) are used to control seizures. Even though parts of their mechanisms of action are known, there are still components that need to be studied. Therefore, the search for novel drugs, new molecular targets, and a better understanding of the mechanisms of action of existing drugs is still crucial. Levetiracetam (LEV) is an AED that has been shown to be effective in seizure control and is well-tolerable, with a novel mechanism of action through an interaction with the synaptic vesicle protein 2A (SV2A). Moreover, LEV has other molecular targets that involve calcium homeostasis, the GABAergic system, and AMPA receptors among others, that might be integrated into a single mechanism of action that could explain the antiepileptogenic, anti-inflammatory, neuroprotective, and antioxidant properties of LEV. This puts it as a possible multitarget drug with clinical applications other than for epilepsy. According to the above, the objective of this work was to carry out a comprehensive and integrative review of LEV in relation to its clinical uses, structural properties, therapeutical targets, and different molecular, genetic, and systemic action mechanisms in order to consider LEV as a candidate for drug repurposing.
RESUMO
Parasitic diseases are still a major health problem in developing countries. In our effort to find new antiparasitic agents, in this Letter we report the in vitro antiprotozoal activity of omeprazole, lansoprazole, rabeprazole and pantoprazole against Trichomonas vaginalis, Giardia intestinalis and Entamoeba histolytica. Molecular modeling studies were an important tool to highlight the potential antiprotozoal activity of these drugs. Experimental evaluations revealed a strong activity for all compounds tested. Rabeprazole and pantoprazole were the most active compounds, having IC(50) values in the nanomolar range, which were even better than metronidazole, the drug of choice for these parasites.
Assuntos
Antiprotozoários/química , Inibidores da Bomba de Prótons/química , 2-Piridinilmetilsulfinilbenzimidazóis/química , 2-Piridinilmetilsulfinilbenzimidazóis/farmacologia , Antiprotozoários/farmacologia , Desenho de Fármacos , Entamoeba histolytica/efeitos dos fármacos , Giardia lamblia/efeitos dos fármacos , Humanos , Lansoprazol , Omeprazol/química , Omeprazol/farmacologia , Pantoprazol , Doenças Parasitárias/tratamento farmacológico , Inibidores da Bomba de Prótons/farmacologia , Rabeprazol , Trichomonas vaginalis/efeitos dos fármacosRESUMO
The CXCR6âCXCL16 axis is involved in several pathological processes, and its overexpression has been detected in different types of cancer, such as prostate, breast, ovary, and lung cancer, along with schwannomas, in which it promotes invasion and metastasis. Moreover, this axis is involved in atherosclerosis, type 1 diabetes, primary immune thrombocytopenia, vitiligo, and other autoimmune diseases, in which it is responsible for the infiltration of different immune system cells. The 3D structure of CXCR6 and CXCL16 has not been experimentally resolved; therefore, homology modeling and molecular dynamics simulations could be useful for the study of this signaling axis. In this work, a homology model of CXCR6 and a soluble form of CXCL16 (CXCR6âCXCL16s) are reported to study the interactions between CXCR6 and CXCL16s through coarse-grained molecular dynamics (CG-MD) simulations. CG-MD simulations showed the two activation steps of CXCR6 through a decrease in the distance between the chemokine and the transmembrane region (TM) of CXCR6 and transmembrane rotational changes and polar interactions between transmembrane segments. The polar interactions between TM3, TM5, and TM6 are fundamental to functional conformation and the meta-active state of CXCR6. The interactions between D77-R280 and T243-TM7 could be related to the functional conformation of CXCR6; alternatively, the interaction between Q195-Q244 and N248 could be related to an inactive state due to the loss of this interaction, and an arginine cage broken in the presence of CXCL16s allows the meta-active state of CXCR6. A general proteinâligand interaction supports the relevance of TM3âTM5âTM6 interactions, presenting three relevant pharmacophoric features: HAc (H-bond acceptor), HDn (H-bond donator), and Hph (hydrophobic), distributed around the space between extracellular loops (ECLs) and TMs. The HDn feature is close to TM3 and TM6; likewise, the HAc and Hph features are close to ECL1 and ECL2 and could block the rotation and interactions between TM3âTM6 and the interactions of CXCL16s with the ECLs. Tridimensional quantitative structure-activity relationships (3D-QSAR) models show that the positive steric (VdW) and electrostatic fields coincide with the steric and positive electrostatic region of the exo-azabicyclo[3.3.1]nonane scaffold in the best pIC50 ligands. This substructure is close to the E274 residue and therefore relevant to the activity of CXCR6. These data could help with the design of new molecules that inhibit chemokine binding or antagonize the receptor based on the activation mechanism of CXCR6 and provoke a decrease in chemotaxis caused by the CXCR6âCXCL16 axis.
RESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that leads to coronavirus disease (COVID-19) has put public health at risk in 2020. The spike protein (SP) in SARS-CoV-2 is primarily responsible for the attachment and entry of the virus into the cell, which binds to the angiotensin-converting enzyme 2 (ACE2). Owing to the lack of an effective therapy, drug repositioning is an opportunity to search for molecules with pharmacological potential for the treatment of COVID-19. In this study, three candidates with the potential to destabilize the SP-ACE2 complex are reported. Through molecular docking, 147 drugs were evaluated and their possible binding sites in the interface region of the SP-ACE2 complex and the SP of SARS-CoV-2 were identified. The five best candidate molecules were selected for molecular dynamics studies to observe changes in interactions between SP-ACE2 and ligands with the SP-ACE2 complex. Using umbrella sampling molecular dynamics simulations, the binding energy of SP with ACE2 (-29.58 kcal/mol) without ligands, and in complex with amprenavir (-20.13 kcal/mol), enalaprilat (-23.84 kcal/mol), and plerixafor (-19.72 kcal/mol) were calculated. These drugs are potential candidates for the treatment of COVID-19 as they destabilize the SP-ACE2 complex; the binding energy of SP is decreased in the presence of these drugs and may prevent the virus from entering the cell. Plerixafor is the drug with the greatest potential to destabilize the SP-ACE2 complex, followed by amprenavir and enalaprilat; thus, these three drugs are proposed for future in vitro and in vivo evaluations.
RESUMO
Affinin is mainly recognized by its antinociceptive effect. Recently, our research group demonstrated that this compound produces vasodilation via activation of the gasotransmitters signaling pathways. However, the molecular targets of affinin were not identified. Considering the structural similarity of this alkamide with anandamide, we hypothesized that affinin-induced vasodilation could involve participation of TRP channels and cannabinoid receptors. In this work, by using the isolated rat aorta assay, we assessed involvement of TRP channels, the cannabinoid system, and the HNO-CGRP-TRPA1 pathway on the mechanism of action of affinin. Additionally, we measured NO and H2S levels elicited by affinin on rat aorta homogenates and carried out computer simulations of molecular interactions between affinin and the TRPA1 and TRPV1 channels and the CB1 receptor. Our results indicated that affinin induces an increase in aortic NO and H2S levels. We found evidence that the vasodilator effect induced by affinin involves activation of TRPA1 and TRPV1 channels and the CB1 and eCB receptors. In silico analyses showed that affinin is able to bind with high affinity to these molecular targets. Moreover, we also proved that affinin-induced vasodilation is partly mediated via activation of the HNO-TRPA1-CGRP pathway. Based on these results we propose a novel mechanism of action to explain the vasodilatory effect of affinin, which could be developed as an alternative drug to treat cardiovascular diseases.
Assuntos
Alcamidas Poli-Insaturadas/farmacologia , Receptores de Canabinoides/metabolismo , Canais de Cátion TRPV/metabolismo , Vasodilatação/efeitos dos fármacos , Animais , Aorta/efeitos dos fármacos , Sulfeto de Hidrogênio , Técnicas In Vitro , Masculino , Simulação de Acoplamento Molecular , Óxido Nítrico , Ratos , Ratos WistarRESUMO
Parkinson´s disease is the most important neuromotor pathology due to the prominent loss of dopaminergic neurons in the substantia nigra pars compacta. There is an inherent deficiency of dopamine in Parkinson´s disease, which is aggravated when neuroinflammatory processes are present. Several biomolecules are interesting candidates for the regulation of inflammation and possible neuroprotection, such as valerenic acid, one of the main components of Valeriana officinalis. A 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP)-induced mouse model of Parkinson's disease was developed to evaluate the motor effects of valerenic acid. The evaluation was carried out with four tests (an invert screen test for muscle strength, cross beam test, open field mobility test and lifting on hind legs test). Subsequently, the neuroinflammatory process was evaluated through ELISA of pro-inflammatory cytokines (IL-1ß, IL-6, TNF-α and IFN-γ). The decreases in the inflammatory and neurodegenerative processes were evaluated by Western blot and immunohistochemistry analyses of the tissues, which included an evaluation of the tyrosine hydroxylase and GFAP proteins. Finally, the predicted mechanism of action of valerenic acid was supported by molecular docking calculations with the 5-HT5A receptor. The results indicate that the use of valerenic acid as a co-treatment decreases the neuroinflammation in Parkinson's disease induced by MPTP and provides evidence of a decrease in the evaluated pro-inflammatory cytokines and in the amount of GFAP in the mesencephalic area. Valerenic acid prevents neuroinflammation in a Parkinson's disease mouse model, which might reflect the neuroprotection of dopaminergic neurons with the recovery of motor ability.