RESUMO
This study investigated an association between the cytochrome P450 (CYP) 2C8*3 polymorphism with asthma symptom control in children and changes in lipid metabolism and pro-inflammatory signaling by human bronchial epithelial cells (HBECs) treated with cigarette smoke condensate (CSC). CYP genes are inherently variable in sequence, and while such variations are known to produce clinically relevant effects on drug pharmacokinetics and pharmacodynamics, the effects on endogenous substrate metabolism and associated physiologic processes are less understood. In this study, CYP2C8*3 was associated with improved asthma symptom control among children: Mean asthma control scores were 3.68 (n = 207) for patients with one or more copies of the CYP2C8*3 allele versus 4.42 (n = 965) for CYP2C8*1/*1 (P = 0.0133). In vitro, CYP2C8*3 was associated with an increase in montelukast 36-hydroxylation and a decrease in linoleic acid metabolism despite lower mRNA and protein expression. Additionally, CYP2C8*3 was associated with reduced mRNA expression of interleukin-6 (IL-6) and C-X-C motif chemokine ligand 8 (CXCL-8) by HBECs in response to CSC, which was replicated using the soluble epoxide hydrolase inhibitor, 12-[[(tricyclo[3.3.1.13,7]dec-1-ylamino)carbonyl]amino]-dodecanoic acid. Interestingly, 9(10)- and 12(13)- dihydroxyoctadecenoic acid, the hydrolyzed metabolites of 9(10)- and 12(13)- epoxyoctadecenoic acid, increased the expression of IL-6 and CXCL-8 mRNA by HBECs. This study reveals previously undocumented effects of the CYP2C8*3 variant on the response of HBECs to exogenous stimuli. SIGNIFICANCE STATEMENT: These findings suggest a role for CYP2C8 in regulating the epoxyoctadecenoic acid:dihydroxyoctadecenoic acid ratio leading to a change in cellular inflammatory responses elicited by environmental stimuli that exacerbate asthma.
Assuntos
Asma , Brônquios , Citocromo P-450 CYP2C8 , Células Epiteliais , Humanos , Asma/tratamento farmacológico , Asma/genética , Asma/metabolismo , Citocromo P-450 CYP2C8/genética , Citocromo P-450 CYP2C8/metabolismo , Criança , Masculino , Feminino , Brônquios/efeitos dos fármacos , Brônquios/metabolismo , Brônquios/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Adolescente , Metabolismo dos Lipídeos/efeitos dos fármacos , Metabolismo dos Lipídeos/genética , Inflamação/genética , Inflamação/metabolismo , Células Cultivadas , Quinolinas/farmacologia , Polimorfismo de Nucleotídeo Único , Acetatos , Ciclopropanos , SulfetosRESUMO
Genetic variation among inhaled corticosteroid (ICS)-metabolizing enzymes may affect asthma control, but evidence is limited. This study tested the hypothesis that single-nucleotide polymorphisms (SNPs) in Cytochrome P450 3A5 (CYP3A5) would affect asthma outcomes. Patients aged 2-18 years with persistent asthma were recruited to use the electronic AsthmaTracker (e-AT), a self-monitoring tool that records weekly asthma control, medication use, and asthma outcomes. A subset of patients provided saliva samples for SNP analysis and participated in a pharmacokinetic study. Multivariable regression analysis adjusted for age, sex, race, and ethnicity was used to evaluate the impact of CYP3A5 SNPs on asthma outcomes, including asthma control (measured using the asthma symptom tracker, a modified version of the asthma control test or ACT), exacerbations, and hospital admissions. Plasma corticosteroid and cortisol concentrations post-ICS dosing were also assayed using liquid chromatography-tandem mass spectrometry. Of the 751 patients using the e-AT, 166 (22.1%) provided saliva samples and 16 completed the PK study. The e-AT cohort was 65.1% male, and 89.6% White, 6.0% Native Hawaiian, 1.2% Black, 1.2% Native American, 1.8% of unknown race, and 15.7% Hispanic/Latino; the median age was 8.35 (IQR: 5.51-11.3) years. CYP3A5*3/*3 frequency was 75.8% in White subjects, 50% in Native Hawaiians and 76.9% in Hispanic/Latino subjects. Compared with CYP3A5*3/*3, the CYP3A5*1/*x genotype was associated with reduced weekly asthma control (OR: 0.98; 95% CI: 0.97-0.98; p < 0.001), increased exacerbations (OR: 6.43; 95% CI: 4.56-9.07; p < 0.001), and increased asthma hospitalizations (OR: 1.66; 95% CI: 1.43-1.93; p < 0.001); analysis of 3/*3, *1/*1 and *1/*3 separately showed an allelic copy effect. Finally, PK analysis post-ICS dosing suggested muted changes in cortisol concentrations for patients with the CYP3A5*3/*3 genotype, as opposed to an effect on ICS PK. Detection of CYP3A5*3/3, CYPA35*1/*3, and CYP3A5*1/*1 could impact inhaled steroid treatment strategies for asthma in the future.
Assuntos
Corticosteroides , Asma , Citocromo P-450 CYP3A , Polimorfismo de Nucleotídeo Único , Humanos , Asma/tratamento farmacológico , Asma/genética , Criança , Masculino , Feminino , Citocromo P-450 CYP3A/genética , Citocromo P-450 CYP3A/metabolismo , Adolescente , Pré-Escolar , Corticosteroides/uso terapêutico , Corticosteroides/farmacocinética , Corticosteroides/administração & dosagem , Genótipo , Hidrocortisona/sangue , Saliva/metabolismo , Resultado do TratamentoRESUMO
Prior studies revealed increased expression of the transient receptor potential vanilloid-3 (TRPV3) ion channel after wood smoke particulate matter (WSPM) treatment of human bronchial epithelial cells (HBECs). TRPV3 attenuated pathologic endoplasmic reticulum stress and cytotoxicity mediated by transient receptor potential ankyrin-1. Here, the basis for how TRPV3 expression is regulated by cell injury and the effects this has on HBEC physiology and WSPM-induced airway remodeling in mice was investigated. TRPV3 mRNA was rapidly increased in HBECs treated with WSPM and after monolayer damage caused by tryptic disruption, scratch wounding, and cell passaging. TRPV3 mRNA abundance varied with time, and stimulated expression occurred independent of new protein synthesis. Overexpression of TRPV3 in HBECs reduced cell migration and wound repair while enhancing cell adhesion. This phenotype correlated with disrupted mRNA expression of ligands of the epidermal growth factor, tumor growth factor-ß, and frizzled receptors. Accordingly, delayed wound repair by TRPV3 overexpressing cells was reversed by growth factor supplementation. In normal HBECs, TRPV3 upregulation was triggered by exogenous growth factor supplementation and was attenuated by inhibitors of growth factor receptor signaling. In mice, subacute oropharyngeal instillation with WSPM also promoted TRPV3 mRNA expression and epithelial remodeling, which was attenuated by TRPV3 antagonist pre- and cotreatment. This latter effect may be the consequence of antagonist-induced TRPV3 expression. These findings provide insights into the roles of TRPV3 in lung epithelial cells under basal and dynamic states, as well as highlight potential roles for TRPV3 ligands in modulating epithelial damage/repair. SIGNIFICANCE STATEMENT: Coordinated epithelial repair is essential for the maintenance of the airways, with deficiencies and exaggerated repair associated with adverse consequences to respiratory health. This study shows that TRPV3, an ion channel, is involved in coordinating repair through integrated repair signaling pathways, wherein TRPV3 expression is upregulated immediately after injury and returns to basal levels as cells complete the repair process. TRPV3 may be a novel target for understanding and/or treating conditions in which airway/lung epithelial repair is not properly orchestrated.
Assuntos
Células Epiteliais/metabolismo , Lesão Pulmonar/metabolismo , Material Particulado/efeitos adversos , Transdução de Sinais , Fumaça/efeitos adversos , Canais de Cátion TRPV/metabolismo , Remodelação das Vias Aéreas/genética , Animais , Brônquios/lesões , Brônquios/metabolismo , Brônquios/patologia , Adesão Celular/genética , Linhagem Celular , Movimento Celular/genética , Células Epiteliais/patologia , Receptores ErbB/antagonistas & inibidores , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Lesão Pulmonar/etiologia , Masculino , Camundongos Endogâmicos C57BL , Canais de Cátion TRPV/antagonistas & inibidores , Canais de Cátion TRPV/genética , Transcriptoma , Fator de Crescimento Transformador beta/antagonistas & inibidores , Proteínas Wnt/antagonistas & inibidores , Madeira , Cicatrização/fisiologiaRESUMO
To better understand how adverse health effects are caused by exposure to particulate materials, and to develop preventative measures, it is important to identify the properties of particles and molecular targets that link exposure with specific biologic outcomes. Coal fly ash (CFA) is a by-product of coal combustion that can affect human health. We report that human transient receptor potential melastatin-8 (TRPM8) and an N-terminally truncated TRPM8 variant (TRPM8-Δ801) are activated by CFA and calcium-rich nanoparticles and/or soluble salts within CFA. TRPM8 activation by CFA was potentiated by cold temperature involving the phosphatidylinositol 4,5-bisphosphate binding residue (L1008), but was independent of the icilin and menthol binding site residue Y745 and, essentially, the N-terminal amino acids 1-800. CFA, calcium nanoparticles, and calcium salts also activated transient receptor potential vanilloid-1 (TRPV1) and transient receptor potential ankyrin-1 (TRPA1), but not TRPV4. CFA treatment induced CXCL1 and interleukin-8 mRNA in BEAS-2B and primary human bronchial epithelial cells through activation of both TRPM8 and TRPV1. However, neither mouse nor rat TRPM8 was activated by these materials, and Trpm8 knockout had no effect on cytokine induction in the lungs of CFA-instilled mice. Amino acids S921 and S927 in mouse Trpm8 were identified as important for the lack of response to CFA. These results imply that TRPM8, in conjunction with TRPV1 and TRPA1, might sense selected forms of inhaled particulate materials in human airways, shaping cellular responses to these materials, and improving our understanding of how and why certain particulate materials elicit different responses in biologic systems, affecting human health.
Assuntos
Brônquios/efeitos dos fármacos , Compostos de Cálcio/toxicidade , Fosfatos de Cálcio/toxicidade , Cinza de Carvão/toxicidade , Óxidos/toxicidade , Material Particulado/toxicidade , Mucosa Respiratória/efeitos dos fármacos , Canais de Cátion TRPM/metabolismo , Animais , Brônquios/citologia , Brônquios/metabolismo , Cálcio/metabolismo , Linhagem Celular , Cinza de Carvão/química , Citocinas/genética , Citocinas/metabolismo , Humanos , Inflamação/genética , Inflamação/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ratos , Mucosa Respiratória/citologia , Mucosa Respiratória/metabolismo , Especificidade da Espécie , Canais de Cátion TRPM/antagonistas & inibidores , Canais de Cátion TRPM/genéticaRESUMO
Seven cyclic depsipeptides were isolated from Hapsidospora irregularis and structurally characterized as the calcium channel blocker leualacin and six new analogues based on the NMR and HRESIMS data. These new compounds were named leualacins B-G. The absolute configurations of the amino acids and 2-hydroxyisocaproic acids were determined by recording the optical rotation values. Biological studies showed that calcium influx elicited by leualacin F in primary human lobar bronchial epithelial cells involves the TRPA1 channel. Through genome sequencing and targeted gene disruption, a noniterative nonribosomal peptide synthetase was found to be involved in the biosynthesis of leualacin. A comparison of the structures of leualacin and its analogues indicated that the A2 and A4 domains of the leualacin synthetase are substrate specific, while A1, A3, and A5 can accept alternative precursors to yield new molecules.
Assuntos
Depsipeptídeos/isolamento & purificação , Hypocreales/química , Peptídeo Sintases/metabolismo , Aminoácidos/química , Bloqueadores dos Canais de Cálcio/química , Depsipeptídeos/química , Depsipeptídeos/farmacologia , Humanos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Peptídeos CíclicosRESUMO
Background: Climatological shifts and human activities have decimated lakes worldwide. Water in the Great Salt Lake, Utah, USA is at near record lows which has increased risks for exposure to windblown dust from dried lakebed sediments. Formal studies evaluating the health effects of inhaled Great Salt Lake dust (GSLD) have not been performed despite the belief that the dust is harmful. The objectives of this study were to illustrate windblown dust events, assess the impact of inhaled dust on the lungs, and to identify mechanisms that could contribute to the effects of GSLD in the lungs. Results: An animation, hourly particle and meteorological data, and images illustrate the impact of dust events on the Salt Lake Valley/Wasatch front airshed. Great Salt Lake sediment and PM2.5 contained metals, lipopolysaccharides, natural and anthropogenic chemicals, and bacteria. Inhalation and oropharyngeal delivery of PM2.5 triggered neutrophilia and the expression of mRNA for Il6, Cxcl1, Cxcl2, and Muc5ac in mouse lungs, was more potent than coal fly ash (CFA) PM2.5, and more cytotoxic to human airway epithelial cells (HBEC3-KT) in vitro. Induction of IL6 and IL8 was replicated in vitro using HBEC3-KT and THP-1 cells. For HBEC3-KT cells, IL6 induction was variably attenuated by EGTA/ruthenium red, the TLR4 inhibitor TAK-242, and deferoxamine, while IL8 was attenuated by EGTA/ruthenium red. Inhibition of mRNA induction by EGTA/ruthenium red suggested roles for transition metals, calcium, and calcium channels as mediators of the responses. Like CFA, GSLD and a similar dust from the Salton Sea in California, activated human TRPA1, M8, and V1. However, only inhibition of TRPV1, TRPV3, and a combination of both channels impacted cytokine mRNA induction in HBEC3-KT cells. Responses of THP1 cells were partially mediated by TLR4 as opposed to TRP channels and mice expressing a "humanized" form of TRPV1 exhibited greater neutrophilia when exposed to GSLD via inhalation. Conclusions: This study suggests that windblown dust from Great Salt Lake and similar lake sediments could pose a risk to humans via mechanisms including the activation of TRPV1/V3, TLR4, and possibly oxidative stress.
RESUMO
Pain is often debilitating, and current treatments are neither universally efficacious nor without risks. Transient receptor potential (TRP) ion channels offer alternative targets for pain relief, but little is known about the regulation or identities of endogenous TRP ligands that affect inflammation and pain. Here, transcriptomic and targeted lipidomic analysis of damaged tissue from the mouse spinal nerve ligation (SNL)-induced chronic pain model revealed a time-dependent increase in Cyp1b1 mRNA and a concurrent accumulation of 8,9-epoxyeicosatrienoic acid (EET) and 19,20-EpDPA post injury. Production of 8,9-EET and 19,20-EpDPA by human/mouse CYP1B1 was confirmed in vitro, and 8,9-EET and 19,20-EpDPA selectively and dose-dependently sensitized and activated TRPA1 in overexpressing HEK-293 cells and Trpa1-expressing/AITC-responsive cultured mouse peptidergic dorsal root ganglia (DRG) neurons. TRPA1 activation by 8,9-EET and 19,20-EpDPA was attenuated by the antagonist A967079, and mouse TRPA1 was more responsive to 8,9-EET and 19,20-EpDPA than human TRPA1. This latter effect mapped to residues Y933, G939, and S921 of TRPA1. Intra-plantar injection of 19,20-EpDPA induced acute mechanical, but not thermal hypersensitivity in mice, which was also blocked by A967079. Similarly, Cyp1b1-knockout mice displayed a reduced chronic pain phenotype following SNL injury. These data suggest that manipulation of the CYP1B1-oxylipin-TRPA1 axis might have therapeutic benefit.
RESUMO
Seizure activity can alter GABA transporter and osmoprotective gene expression, which may be involved in the pathogenesis of epilepsy. However, the response of the betaine/GABA transporter (BGT1) is unknown. The goal of the present study was to compare the expression of BGT1 mRNA to that of other osmoprotective genes and GABA transporters following status epilepticus (SE). The possible contributory role of dehydration and inflammation was also investigated because both have been shown to be involved in the regulation of GABA transporter and/or osmoprotective gene expression. BGT1 mRNA was increased 24 h post-SE, as were osmoprotective genes. BGT1 was decreased 72 h and 4 weeks post-SE, as were the GABA transporter mRNAs. The mRNA values for osmoprotective genes following 24-h water withdrawal were significantly lower than the values obtained 24 h post-SE despite similarities in their plasma osmolality values. BGT1 mRNA was not altered by lipopolysaccharide-induced inflammation while the transcription factor tonicity-responsive enhancer binding protein and the GABA transporters 1 and 3 were. These results suggest that neither plasma osmolality nor inflammation fully account for the changes seen in BGT1 mRNA expression post-SE. However, it is evident that BGT1 mRNA expression is altered by SE and displays a temporal pattern with similarities to both GABA and osmolyte transporters. Further investigation of BGT1 regulation in the brain is warranted.
Assuntos
Betaína/metabolismo , Proteínas de Transporte/biossíntese , Proteínas de Transporte/genética , Desidratação/genética , Regulação da Expressão Gênica , Mediadores da Inflamação/fisiologia , RNA Mensageiro/biossíntese , Estado Epiléptico/metabolismo , Animais , Desidratação/etiologia , Desidratação/metabolismo , Proteínas da Membrana Plasmática de Transporte de GABA/biossíntese , Hipocampo/metabolismo , Hipocampo/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estado Epiléptico/complicações , Estado Epiléptico/genéticaRESUMO
Nanosilver particles are present in consumer and health care products. Their effects on human microsomal cytochrome P450 (P450) activities and induction in luciferase reporter-engineered Caco-2 (MDR1.C) and HepG2 (DPX2 and 1A2DRE) cells have been investigated. The LD(50) values were â¼ 4 µg silver/ml for HepG2 and 5 µg/ml for Caco-2 cells. At silver concentrations that showed no decreased cell viability (<1 µg silver/ml), the pregnane X receptor (PXR)-driven 4.5-fold induction response of MDR1.C cells to 50 µM omeprazole was unaffected. In DPX2 cells, the PXR-driven 5.5- and 6.5-fold induction responses to omeprazole and 10 µM rifampicin were attenuated to 4- and 3.5-fold, respectively. Nanosilver particles alone showed no induction. In 1A2DRE cells, the aryl hydrocarbon receptor-driven 5.5-fold induction response to omeprazole was attenuated to 4-fold. In 1A2DRE cells, nanosilver alone elicited slight induction at 1 µg/ml. The inhibition of human P450-selective activities by nanosilver particles in vitro was proportional to the silver/microsomal protein ratio. At a fixed (0.5 mg/ml) protein concentration, P450-selective activities differed in sensitivity (IC(50) value). Coumarin 7-hydroxylation and 7-ethoxy-4-trifluoromethylcoumarin O-deethylation exhibited the highest IC(50) values (33.5 and 31.9 µM, respectively) and S-mephenytoin 4-hydroxylation exhibited the lowest (6.4 µM). Other IC(50) values were, in ascending order, 8.0 to 9.3 µM (testosterone 6ß-hydroxylation, 7-benzyloxyquinoline debenzylation, and diclofenac 4-hydroxylation), 16.0 µM (chlorzoxazone 6-hydroxylation), 21.2 µM [7-methoxy-4-(aminomethyl)-coumarin O-demethylation], and 24.4 µM (7-methoxyresorufin O-demethylation). An investigation of 70 µM nanosilver particles showed that microsomal NADPH cytochrome c reductase activities were inhibited <12%. From our in vitro observations, we extrapolated that nanosilver particles reaching the liver may be a potential source of drug-drug interactions.
Assuntos
Nanopartículas , Preparações Farmacêuticas/metabolismo , Prata/farmacologia , Células CACO-2 , Células Hep G2 , Humanos , Receptor de Pregnano X , Receptores de Esteroides/efeitos dos fármacosRESUMO
3-Methylindole (3MI) is a preferential pneumotoxicant found in cigarette smoke. A number of lung-expressed human cytochrome P450 enzymes, including 1A1, 2F1, and 2A13, catalyze the metabolism of 3MI to reactive intermediates that fragment DNA, measured with the Comet assay to assess DNA damage, in a cytochrome P450-dependent manner in primary normal human lung cells in culture, but the mutagenesis of 3MI has been controversial. In the present study, the mutagenic potential of 3MI was compared to the prototypical cigarette smoke carcinogens benzo(a)pyrene (B(a)P) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). 3MI, B(a)P, and NNK were incubated with the Salmonella typhimurium strain TA98, which is known to detect the most common subtype of cigarette smoke-induced mutagenicity, frameshift mutations in DNA, and with Salmonella typhimurium strain TA100, which detects base pair substitution mutants, with five sources of P450-mediated bioactivation: rat liver S9, human lung microsomes, recombinant CYP2A13, purified CYP2F3, and recombinant CYP1A1. Only B(a)P was mutagenic in TA100, and it was bioactivated by human lung microsomes and rat liver S9 sources of P450s. However, with the TA98 strain, CYP1A1, CYP2A13, CYP2F3, and human lung microsomes bioactivated 3MI to highly mutagenic intermediates, whereas neither human nor rat liver S9 subcellular fractions formed mutagenic intermediates from 3MI. Quantitative Western blot analysis verified that all three respiratory enzymes were present in human lung microsomes in widely varying amounts. These results indicate that metabolism of 3MI by human lung-expressed cytochrome P450 enzymes but not hepatic P450s elicits equivalent or higher mutagenicity than the prototype cigarette smoke mutagens B(a)P and NNK and indicates that 3MI is a likely human pulmonary carcinogen.
Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Pulmão/enzimologia , Mutagênicos/toxicidade , Escatol/toxicidade , Animais , Hidrocarboneto de Aril Hidroxilases/metabolismo , Benzo(a)pireno/química , Benzo(a)pireno/toxicidade , Células Cultivadas , Sistema Enzimático do Citocromo P-450/genética , Dano ao DNA , Humanos , Fígado/metabolismo , Microssomos/enzimologia , Microssomos/metabolismo , Testes de Mutagenicidade , Mutagênicos/química , Nitrosaminas/química , Nitrosaminas/toxicidade , Ratos , Proteína S9 Ribossômica , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Salmonella typhimurium/efeitos dos fármacos , Escatol/química , FumarRESUMO
N-methoxy-2,2,3,3-tetramethylcyclopropane carboxamide (OM-TMCD) is a methoxyamide derivative of a cyclopropyl analogue of valproic acid (VPA). The structural considerations used in the design of OM-TMCD were aimed to enhance OM-TMCD anticonvulsant potency (compared to VPA) and to prevent VPA's two life-threatening side effects, i.e., induction of neural tube defects (NTDs) and hepatotoxicity. Following i.p. administration to rats OM-TMCD demonstrated a broad spectrum of anticonvulsant activity and showed better potency than VPA in the maximal electroshock seizure and subcutaneous pentylenetetrazole tests as well as in the hippocampal kindling model. OM-TMCD was inactive in the mouse 6-Hz test at 100 mg/kg dose. Teratogenicity studies performed in a SWV/Fnn-mouse model for VPA-induced-exencephaly showed that on the equimolar basis OM-TMCD possesses the same fetal toxicity and ability to induce NTDs as VPA, but since OM-TMCD is a much more potent anticonvulsant its activity/exencephaly formation ratio appears to be much more beneficial than that of VPA. OM-TMCD was found to be non-mutagenic and non-pro-mutagenic in the Ames test. It showed a beneficial pharmacokinetic profile in rats, having a high oral bioavailability of 75% and satisfactory values of clearance and volume of distribution. These results support further studies to fully characterize the therapeutic potential of OM-TMCD.
Assuntos
Anticonvulsivantes/farmacologia , Ciclopropanos/farmacologia , Mutagênese/efeitos dos fármacos , Convulsões/prevenção & controle , Ácido Valproico/análogos & derivados , Anormalidades Induzidas por Medicamentos/etiologia , Animais , Anticonvulsivantes/efeitos adversos , Anticonvulsivantes/farmacocinética , Ciclopropanos/efeitos adversos , Ciclopropanos/farmacocinética , Feminino , Masculino , Camundongos , Defeitos do Tubo Neural/induzido quimicamente , Alcamidas Poli-Insaturadas/efeitos adversos , Alcamidas Poli-Insaturadas/farmacocinética , Alcamidas Poli-Insaturadas/farmacologia , Ratos , Ratos Sprague-DawleyRESUMO
Murine (Hepa1c1c7) hepatoma cells are a suitable in vitro system for investigating the regulation of chemoprotective enzymes by selenazolidines, novel l-selenocysteine prodrugs developed as potential chemopreventive agents. They are less sensitive to the cytotoxic effects of both selenite and the less toxic selenazolidines than rat hepatoma (H4IIE) cells. All four selenazolidine 4-carboxylic acid (SCA) derivatives examined elevated thioredoxin reductase (Txnrd1), alpha-class glutathione transferases (Gsta), and UDP-glucuronosyltransferase (Ugt)1a6 mRNAs. NAD(P)H-quinone oxidoreductase (Nqo1) was induced by the three 2-alkyl derivatives (2-cyclohexylSCA, 2-butylSCA, and 2-methylSCA) but not SCA itself. Transcripts of mu- and pi-class glutathione transferases were induced only by 2-cyclohexylSCA and 2-butylSCA. Only Gsta and Txnrd1 transcripts were elevated by l-selenomethionine, l-selenocystine, or Se-methyl-l-selenocysteine. Txnrd1, Gsta, Nqo1, and Gstp responses to selenazolidines were all abolished by actinomycin D while Ugt1a6 responses were not. Induction responses to the selenazolidines were also eliminated (most) or reduced (Txnrd1 by 2-methylSCA) by cycloheximide, with the exception of Ugt1a6. The Ugt1a6 mRNA levels in the presence of SCAs and cycloheximide were similar to those with cycloheximide alone, and were almost double those of vehicle-treated cells. Thus, Hepa1c1c7 cells appear to provide a viable platform for the study of protective enzyme regulation by selenocompounds, and with the exception of Ugt1a6, the mRNA elevations from selenazolidines are transcriptionally dependent.
Assuntos
Indução Enzimática/efeitos dos fármacos , Enzimas/biossíntese , Enzimas/genética , Neoplasias Hepáticas Experimentais/enzimologia , Compostos Organosselênicos/farmacologia , Animais , Linhagem Celular Tumoral , Cicloeximida/farmacologia , Dactinomicina/farmacologia , Camundongos , Biossíntese de Proteínas/efeitos dos fármacos , Inibidores da Síntese de Proteínas/farmacologia , RNA Mensageiro/análise , RNA Mensageiro/biossíntese , RatosRESUMO
BACKGROUND: The aims of this study were to assess the safety and tolerability of nanoparticle albumin bound paclitaxel (nab-paclitaxel), doxorubicin, and cyclophosphamide as combination therapy for breast cancer patients in the neoadjuvant setting and to assess the overall clinical response and pathologic complete response (pCR). PATIENTS AND METHODS: Twenty-six women with newly diagnosed stage II to III histologically or cytologically proven adenocarcinoma of the breast with negative HER2 status were enrolled. Patients were treated with nab-paclitaxel 100 mg/m2, doxorubicin 50 mg/m2, and cyclophosphamide 500 mg/m2 on day 1 and nab-paclitaxel 100 mg/m2 on day 8 in a 21-day cycle for 6 cycles total. RESULTS: Most adverse events attributed to treatment were decreased white blood cell count, neutropenia, anemia, thrombocytopenia, and lymphopenia with a median duration of 8 days. Fifteen of 23 (65.2%; 95% confidence interval [CI], 45.7%-84.6%) had a complete clinical response and 8 of 23 (34.7%; 95% CI, 15.2%-54.1%) had a partial clinical response for an overall clinical response rate of 100%. Thirteen of 23 patients (56.5%; 95% CI, 36.2%-76.7%) had a pCR. All 10 triple-negative breast cancer (TNBC) patients (100%) achieved a pCR. CONCLUSION: The regimen of nab-paclitaxel, doxorubicin, and cyclophosphamide chemotherapy was well tolerated and resulted in high clinical as well as pathologic responses, particularly in TNBC.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Terapia Neoadjuvante , Adulto , Idoso , Albuminas/administração & dosagem , Neoplasias da Mama/patologia , Ciclofosfamida/administração & dosagem , Doxorrubicina/administração & dosagem , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Paclitaxel/administração & dosagem , PrognósticoRESUMO
PURPOSE: The anticancer activity of valproic acid (VPA) is attributed to the inhibition of histone deacetylase. We previously published the genomically derived sensitivity signature for VPA (GDSS-VPA), a gene expression biomarker that predicts breast cancer sensitivity to VPA in vitro and in vivo. We conducted a window-of-opportunity study that examined the tolerability of VPA and the ability of the GDSS-VPA to predict biologic changes in breast tumors after treatment with VPA. PATIENTS AND METHODS: Eligible women had untreated breast cancer with breast tumors larger than 1.5 cm. After a biopsy, women were given VPA for 7 to 12 days, increasing from 30 mg/kg/d orally divided into two doses per day to a maximum of 50 mg/kg/d. After VPA treatment, serum VPA level was measured and then breast surgery or biopsy was performed. Tumor proliferation was assessed by using Ki-67 immunohistochemistry. Histone acetylation of peripheral blood mononuclear cells was assessed by Western blot. Dynamic contrast-enhanced magnetic resonance imaging scans were performed before and after VPA treatment. RESULTS: Thirty women were evaluable. The median age was 54 years (range, 31-73 years). Fifty-two percent of women tolerated VPA at 50 mg/kg/d, but 10% missed more than two doses as a result of adverse events. Grade 3 adverse events included vomiting and diarrhea (one patient) and fatigue (one patient). The end serum VPA level correlated with a change in histone acetylation of peripheral blood mononuclear cells (ρ = 0.451; P = .024). Fifty percent of women (three of six) with triple-negative breast cancer had a Ki-67 reduction of at least 10% compared with 17% of other women. Women whose tumors had higher GDSS-VPA were more likely to have a Ki-67 decrease of at least 10% (area under the curve, 0.66). CONCLUSION: VPA was well tolerated and there was a significant correlation between serum VPA levels and histone acetylation. VPA treatment caused a decrease in proliferation of breast tumors. The genomic biomarker correlated with decreased proliferation. Inhibition of histone deacetylase is a valid strategy for drug development in triple-negative breast cancer using gene expression biomarkers.
RESUMO
2,2,3,3-Tetramethylcyclopropanecarbonylurea (TMCU) is an amide derivative of a tetramethylcyclopropyl analogue of valproic acid (VPA), one of the leading antiepileptic drugs. Structural considerations used in the design of TMCU aimed to enhance the anticonvulsant potency of VPA and to prevent its two life-threatening side effects; i.e., teratogenicity and hepatotoxicity. The anticonvulsant activity of TMCU was evaluated in the MES, scMet, 6-Hz, scBic and scPic tests, and also in the hippocampal kindling model of partial seizures and lamotrigine-resistant amygdala kindling model of therapy-resistant seizures. Minimal motor impairment was determined using the rotorod test in mice and the positional sense test, muscle tone test, and gait and stance test in rats. The antinociceptive effect of TMCU was evaluated in the mouse formalin model of acute-tonic pain. The molecular mechanisms of action of TMCU were investigated in electrophysiological studies using the whole-cell patch-clamp technique. Teratogenicity studies were performed in a SWV/Fnn-mouse model of VPA-induced teratogenicity. TMCU hepatotoxicity was evaluated following 1-week intraperitoneal and oral administration of 50, 250 and 500 mg/kg doses to rats. In the hepatotoxicity study the blood levels of TMCU were evaluated at day 1 and day 7 of the treatment. TMCU mutagenicity was evaluated in the Ames test.
Assuntos
Anticonvulsivantes/farmacologia , Ciclopropanos/farmacologia , Avaliação Pré-Clínica de Medicamentos , Excitação Neurológica/efeitos dos fármacos , Ureia/análogos & derivados , Análise de Variância , Animais , Anticonvulsivantes/sangue , Anticonvulsivantes/química , Comportamento Animal , Peso Corporal/efeitos dos fármacos , Células Cultivadas , Córtex Cerebral/citologia , Ciclopropanos/sangue , Ciclopropanos/química , Relação Dose-Resposta a Droga , Interações Medicamentosas , Humanos , Masculino , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Potenciais da Membrana/efeitos da radiação , Camundongos , Modelos Animais , Atividade Motora/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Tamanho do Órgão/efeitos dos fármacos , Técnicas de Patch-Clamp/métodos , Ratos , Ratos Sprague-Dawley , Teste de Desempenho do Rota-Rod/métodos , Convulsões/tratamento farmacológico , Convulsões/etiologia , Convulsões/fisiopatologia , Ureia/sangue , Ureia/química , Ureia/farmacologia , Ácido Valproico/farmacologiaRESUMO
Selenite and organoselenium compounds have been examined at supranutritional levels for their ability to influence the activity and mRNA levels of chemoprotective enzymes in the livers of selenium-sufficient mice and the changes compared to those elicited by oltipraz. Compounds investigated included novel selenocysteine prodrugs that have previously been evaluated for their ability to reduce the tumorigenicity of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in mice. Following seven daily doses (i.g.), all compounds except 2-methylselenazolidine-4(R)-carboxylic acid (MSCA) increased thioredoxin reductase activity (43-92%) but only for 2-oxoselenazolidine-4(R)-carboxylic acid (OSCA) was there an accompanying increase in mRNA. No compound enhanced glutathione peroxidase activity, although sodium selenite significantly elevated the mRNA of this enzyme. Oltipraz was an efficacious inducer of both thioredoxin reductase and glutathione peroxidase mRNAs. Sodium selenite, selenazolidine-4(R)-carboxylic acid (SCA), and OSCA elevated NAD(P)H-quinone oxidoreductase mRNA but only for OSCA was the elevation in mRNA accompanied by an increase in enzyme activity. L-Selenocystine significantly increased this activity without increasing mRNA levels. Sodium selenite, L-selenocystine, L-selenomethionine, and Se-methyl-L-selenocysteine all enhanced glutathione S-transferase activity. The increased activity with sodium selenite was accompanied by increases in mRNAs of Gst alpha, Gst mu and Gst pi classes, while for L-selenocystine and Se-methyl-L-selenocysteine, only an elevation in the mRNA for the Gst alpha class was observed. Gst alpha and Gst mu class mRNAs were elevated by OSCA without a significant elevation in enzyme activity. SCA and MSCA both elevated a Gst pi mRNA and MSCA elevated Gst mu in addition. By comparison, oltipraz only significantly elevated the mRNA of Gst mu, adding to the conclusion that across the entire study, no selenium compound appears to be acting purely through the antioxidant response typified by oltipraz. Despite their chemical similarity, the three cysteine prodrugs, SCA, MSCA, and OSCA, each produced its own unique pattern of effects on protective enzymes and none was identical to the pattern elicited by sodium selenite, L-selenocystine, L-selenomethionine, and Se-methyl-L-selenocysteine. The study also shows that after 7 days of administration, there was only occasional concordance between elevations in mRNA and enzyme activity for any selenium compound and for any protective enzyme, there was no response in common for all selenium compounds.
Assuntos
Fígado/enzimologia , Pró-Fármacos/toxicidade , Compostos de Selênio/toxicidade , Animais , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos , NAD(P)H Desidrogenase (Quinona)/genética , NAD(P)H Desidrogenase (Quinona)/metabolismo , RNA Mensageiro/metabolismo , Tiorredoxina Dissulfeto Redutase/genética , Tiorredoxina Dissulfeto Redutase/metabolismoRESUMO
Novel selenazolidines, designed as l-selenocysteine prodrugs and potential cancer chemopreventive agents, were examined for their ability to affect the transcription of murine hepatic chemoprotective enzymes. Compounds investigated were selenazolidine-4(R)-carboxylic acid (SCA) and six 2-substituted derivatives that cover a C log P range of -0.512 to -3.062. Their biological effects were compared with those of L-selenocystine. Gene transcripts were examined 24 h after a single dose, administered i.p. and i.g., and covered a range of chemoprotective enzymes; alpha, mu and pi class glutathione transferases (Gsts), UDP-glucuronosyltransferases (Ugts) 1a1, 1a6, 1a9, and 2b5, glutathione peroxidase 1 (Gpx), thioredoxin reductase (Tr), NAD(P)H-quinone oxidoreductase 1 (Nqo), and microsomal epoxide hydrolase (Meh). When given i.g., 2-butyl SCA (BSCA) resulted in elevations in alpha, mu and pi class Gsts, Ugt1a6, Tr, and Gpx, and 2-phenyl SCA (PhSCA) elevated GstP, Ugt1a9, Tr, Gpx (3 kb), and Meh. Other derivatives with C log P values both lower [2-(2'-hydroxy)phenyl SCA (PhOHSCA) and 2-methyl SCA (MSCA)] and higher [2-cyclohexyl SCA (ChSCA) and 2-oxo SCA (OSCA)] than BSCA and PhSCA elevated far fewer transcripts; PhOHSCA (Ugt1a1, Gpx), MSCA (Ugt1a1, Meh), ChSCA (Ugt1a1, Ugt1a9), and OSCA (Ugt1a6, Ugt1a9, GstM). When given i.p., the most pervasive transcript changes were parallel increases in Nqo and Tr transcripts which occurred with BSCA, PhSCA, MSCA, and OSCA. PhSCA also increased GstP, and PhOHSCA increased Ugt1a1 and Ugt1a6 levels. Unique among the compounds, PhSCA reduced the transcript levels of GstA, and the 1.6 kb transcript of Gpx although only when given i.p. Neither l-selenocystine nor SCA affected the level of any transcript and no compound altered the amount of Ugt2b5 mRNA. Despite chemical similarity and common ability to potentially serve as a source of l-selenocysteine, each selenazolidine compound appeared to elicit a unique pattern of mRNA responses and by either route of administration, there was no correlation between the magnitude of response of any gene and the calculated C log P values of the organoselenium compounds.
Assuntos
Citoproteção/efeitos dos fármacos , Enzimas/genética , Enzimas/metabolismo , Selenocisteína/farmacologia , Alanina Transaminase/metabolismo , Animais , Biomarcadores , Epóxido Hidrolases/genética , Glucuronosiltransferase/genética , Glutationa Peroxidase/genética , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Camundongos , Pró-Fármacos/farmacologia , RNA Mensageiro/genética , Fatores de TempoRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: A substantial proportion of the population in Papua New Guinea (PNG) lives with human immunodeficiency virus (HIV). Treatment requires lifelong use of antiretroviral therapy (ART). The majority of people in PNG use traditional medicines (TM) derived from plants for all types of health promotions. Consequently, there is a concern that herb-drug interactions may impact the efficacy of ART. Herb-drug, or drug-drug, interactions occur at the level of metabolism through two major mechanisms: enzyme induction or enzyme inhibition. In this study, extracts of commonly-used medicinal plants from PNG were screened for herb-drug interactions related to cytochrome P450s (CYPs). MATERIALS AND METHODS: Sixty nine methanol extracts of TM plants were screened for their ability to induce CYPs by human aryl hydrocarbon receptor- (hAhR-) and human pregnane X receptor- (hPXR-) dependent mechanisms, utilizing a commercially available cell-based luciferase reporter system. Inhibition of three major CYPs, CYP1A2, CYP3A4, and CYP2D6, was determined using human liver microsomes and enzyme-selective model substrates. RESULTS: Almost one third of the TM plant extracts induced the hAhR-dependent expression of CYP1A2, the hPXR-dependent expression of CYP3A4, or both. Almost two thirds inhibited CYP1A2, CYP3A4, or CYP2D6, or combinations thereof. Many plant extracts exhibited both induction and inhibition properties. CONCLUSIONS: We demonstrated that the potent and selective ability of extracts from PNG medicinal plants to affect drug metabolizing enzymes through induction and/or inhibition is a common phenomenon. Use of traditional medicines concomitantly with ART could dramatically alter the concentrations of antiretroviral drugs in the body; and their efficacy. PNG healthcare providers should counsel HIV patients because of this consequence.
Assuntos
Inibidores das Enzimas do Citocromo P-450/farmacologia , Sistema Enzimático do Citocromo P-450/biossíntese , Interações Ervas-Drogas , Extratos Vegetais/farmacologia , Plantas Medicinais , Antirretrovirais , Indução Enzimática/efeitos dos fármacos , Humanos , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Papua Nova Guiné , Receptor de Pregnano X , Receptores de Hidrocarboneto Arílico/metabolismo , Receptores de Esteroides/metabolismoRESUMO
Bisphenol A (BPA) and diethylstilbestrol (DES) are endocrine-disrupting chemicals that interact with the human pregnane X receptor (PXR). CYP3A4 enzyme is essential in the hydroxylation of steroid hormones and is regulated by PXR. In the present study, human and rat hepatoma cell lines were exposed to BPA and DES. Both BPA and DES (10-50µM) caused a significant activation of the CYP3A4 promoter via the PXR in the DPX2 human hepatoma cell line. No activation of rat PXR was seen. BPA and DES treated DPX2 cells demonstrated increased expression of CYP3A4 mRNA, and increased enzyme activity. In summary, BPA, in concentrations relevant to current safety levels of human exposure, activates the human PXR and demonstrates an increase in CYP3A4 mRNA expression and enzyme activity. BPA actions in this model system occur to a greater extent than DES. This study raises concerns regarding our current toxicity testing paradigms and species utilization.
Assuntos
Compostos Benzidrílicos/toxicidade , Citocromo P-450 CYP3A/biossíntese , Sistema Enzimático do Citocromo P-450/biossíntese , Dietilestilbestrol/toxicidade , Disruptores Endócrinos/toxicidade , Fenóis/toxicidade , Animais , Linhagem Celular Tumoral , Citocromo P-450 CYP3A/genética , Sistema Enzimático do Citocromo P-450/genética , Indução Enzimática , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Receptor de Pregnano X , Ratos , Receptores de Esteroides/metabolismo , Testes de ToxicidadeRESUMO
BACKGROUND: Epidemiological studies suggest that mushroom intake is inversely correlated with gastric, gastrointestinal and breast cancers. We have recently demonstrated anticancer and anti-inflammatory activity of triterpene extract isolated from mushroom Ganoderma lucidum (GLT). The aim of the present study was to evaluate whether GLT prevents colitis-associated carcinogenesis in mice. METHODS/PRINCIPAL FINDINGS: Colon carcinogenesis was induced by the food-borne carcinogen (2-Amino-1-methyl-6-phenylimidazol[4,5-b]pyridine [PhIP]) and inflammation (dextran sodium sulfate [DSS]) in mice. Mice were treated with 0, 100, 300 and 500 mg GLT/kg of body weight 3 times per week for 4 months. Cell proliferation, expression of cyclin D1 and COX-2 and macrophage infiltration was assessed by immunohistochemistry. The effect of GLT on XRE/AhR, PXR and rPXR was evaluated by the reporter gene assays. Expression of metabolizing enzymes CYP1A2, CYP3A1 and CYP3A4 in colon tissue was determined by immunohistochemistry. GLT treatment significantly suppressed focal hyperplasia, aberrant crypt foci (ACF) formation and tumor formation in mice exposed to PhIP/DSS. The anti-proliferative effects of GLT were further confirmed by the decreased staining with Ki-67 in colon tissues. PhIP/DSS-induced colon inflammation was demonstrated by the significant shortening of the large intestine and macrophage infiltrations, whereas GLT treatment prevented the shortening of colon lengths, and reduced infiltration of macrophages in colon tissue. GLT treatment also significantly down-regulated PhIP/DSS-dependent expression of cyclin D1, COX-2, CYP1A2 and CYP3A4 in colon tissue. CONCLUSIONS: Our data suggest that GLT could be considered as an alternative dietary approach for the prevention of colitis-associated cancer.