RESUMO
Alveolar epithelium, besides exerting a key role in gas exchange and surfactant production, plays important functions in host defense and inflammation. Pathological conditions associated to alveolar dysfunction include Acute Respiratory Distress Syndrome (ARDS), asthma, chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). The use of predictive in vitro models of human alveolar epithelium is nowadays required for the study of disease mechanisms, as well as of pharmacokinetic parameters of pulmonary drugs delivery. Here, we employed a novel 3D model of human alveoli, namely EpiAlveolar™, consisting of primary alveolar epithelial cells, pulmonary endothelial cells and fibroblasts, that reflects properly the in vivo-like conditions. In EpiAlveolar™ we performed a characterization of Organic Cation Transporters (OCTs and OCTNs) expression and activity and we found that OCTN2, OCT1 and OCT3 are expressed on the basolateral membrane; instead, ATB0,+ transporter for cationic and neutral amino acids, which shares with OCTN2 the affinity for carnitine as substrate, is readily detectable and functional at the apical side. We also show that these transporters differentially interact with anticholinergic drugs. Overall, our findings reveal close similarities of EpiAlveolar™ with the tracheal/bronchial epithelium (EpiAirway™ model) and entrust this alveolar tissue as a potential tool for the screening of biopharmaceuticals molecules.
Assuntos
Células Epiteliais Alveolares/metabolismo , Células Endoteliais/metabolismo , Fibroblastos/metabolismo , Pulmão/citologia , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Técnicas de Cocultura , Humanos , Pulmão/metabolismo , Cultura Primária de CélulasRESUMO
The targeting of both the muscarinic and ß-adrenergic pathways is a well validated therapeutic approach for the treatment of chronic obstructive pulmonary disease (COPD). In this communication we report our effort to incorporate two pharmacologies into a single chemical entity, whose characteristic must be suitable for a once daily inhaled administration. Contextually, we aimed at a locally acting therapy with limited systemic absorption to minimize side effects. Our lung-tailored design of bifunctional compounds that combine the muscarinic and ß-adrenergic pharmacologies by the elaboration of the muscarinic inhibitor 7, successfully led to the potent, pharmacologically balanced muscarinic antagonist and ß2 agonist (MABA) 13.
Assuntos
Agonistas de Receptores Adrenérgicos beta 2/farmacologia , Broncodilatadores/farmacologia , Descoberta de Drogas , Antagonistas Muscarínicos/farmacologia , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Administração por Inalação , Agonistas de Receptores Adrenérgicos beta 2/administração & dosagem , Broncodilatadores/administração & dosagem , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Antagonistas Muscarínicos/administração & dosagem , Doença Pulmonar Obstrutiva Crônica/metabolismo , Receptor Muscarínico M3/antagonistas & inibidores , Receptor Muscarínico M3/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , Relação Estrutura-AtividadeRESUMO
The ATP-binding cassette (ABC) transporters P-glycoprotein (MDR1/ABCB1), multidrug resistance-associated protein 1 (MRP1/ABCC1), and breast cancer resistance protein (BCRP/ABCG2) play a crucial role in the translocation of a broad range of drugs; data about their expression and activity in lung tissue are controversial. Here, we address their expression, localization and function in EpiAirway™, a three-dimensional (3D)-model of human airways; Calu-3 cells, a representative in vitro model of bronchial epithelium, are used for comparison. Transporter expression has been evaluated with RT-qPCR and Western blot, the localization with immunocytochemistry, and the activity by measuring the apical-to-basolateral and basolateral-to-apical fluxes of specific substrates in the presence of inhibitors. EpiAirway™ and Calu-3 cells express high levels of MRP1 on the basolateral membrane, while they profoundly differ in terms of BCRP and MDR1: BCRP is detected in EpiAirway™, but not in Calu-3 cells, while MDR1 is expressed and functional only in fully-differentiated Calu-3; in EpiAirway™, MDR1 expression and activity are undetectable, consistently with the absence of the protein in specimens from human healthy bronchi. In summary, EpiAirway™ appears to be a promising tool to study the mechanisms of drug delivery in the bronchial epithelium and to clarify the role of ABC transporters in the modulation of the bioavailability of administered drugs.
Assuntos
Brônquios/metabolismo , Epitélio/metabolismo , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Western Blotting , Linhagem Celular Tumoral , Humanos , Imuno-Histoquímica , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Mucosa Respiratória/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Carnitine plays a physiologically important role in the ß-oxidation of fatty acids, facilitating the transport of long-chain fatty acids across the inner mitochondrial membrane. Distribution of carnitine within the body tissues is mainly performed by novel organic cation transporter (OCTN) family, including the isoforms OCTN1 (SLC22A4) and OCTN2 (SLC22A5) expressed in human. We performed here a characterization of carnitine transport in human airway epithelial cells A549, Calu-3, NCl-H441, and BEAS-2B, by means of an integrated approach combining data of mRNA/protein expression with the kinetic and inhibition analyses of L-[(3)H]carnitine transport. Carnitine uptake was strictly Na(+)-dependent in all cell models. In A549 and BEAS-2B cells, carnitine uptake was mediated by one high-affinity component (Km<2 µM) identifiable with OCTN2. In both these cell models, indeed, carnitine uptake was maximally inhibited by betaine and strongly reduced by SLC22A5/OCTN2 silencing. Conversely, Calu-3 and NCl-H441 exhibited both a high (Km~20 µM) and a low affinity (Km>1 mM) transport component. While the high affinity component is identifiable with OCTN2, the low affinity uptake is mediated by ATB(0,+), a Na(+), and Cl(-)-coupled transport system for neutral and cationic amino acids, as demonstrated by the inhibition by leucine and arginine, as well as by SLC6A14/ATB(0,+) silencing. The presence of this transporter leads to a massive accumulation of carnitine inside the cells and may be of peculiar relevance in pathologic conditions of carnitine deficiency, such as those associated to OCTN2 defects.
Assuntos
Carnitina/metabolismo , Células Epiteliais/metabolismo , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Mucosa Respiratória/metabolismo , Sistemas de Transporte de Aminoácidos , Sistemas de Transporte de Aminoácidos Neutros/genética , Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Transporte Biológico Ativo/fisiologia , Carnitina/genética , Linhagem Celular Tumoral , Células Epiteliais/citologia , Regulação da Expressão Gênica/fisiologia , Humanos , Proteínas de Transporte de Cátions Orgânicos/genética , Mucosa Respiratória/citologia , Membro 5 da Família 22 de Carreadores de Soluto , SimportadoresRESUMO
Organic cation transporters (OCT1-3) mediate the transport of organic cations including inhaled drugs across the cell membrane, although their role in lung epithelium hasn't been well understood yet. We address here the expression and functional activity of OCT1-3 in human airway epithelial cells A549, Calu-3 and NCl-H441. Kinetic and inhibition analyses, employing [(3)H]1-methyl-4-phenylpyridinium (MPP+) as substrate, and the compounds quinidine, prostaglandine E2 (PGE2) and corticosterone as preferential inhibitors of OCT1, OCT2, and OCT3, respectively, have been performed. A549 cells present a robust MPP+ uptake mediated by one high-affinity component (Km~50µM) which is identifiable with OCT3. Corticosterone, indeed, completely inhibits MPP+ transport, while quinidine and PGE2 are inactive and SLC22A3/OCT3 silencing with siRNA markedly lowers MPP+ uptake. Conversely, Calu-3 exhibits both a high (Km<20µM) and a low affinity (Km>0.6mM) transport components, referable to OCT3 and OCT1, respectively, as demonstrated by the inhibition analysis performed at proper substrate concentrations and confirmed by the use of specific siRNA. These transporters are active also when cells are grown under air-liquid interface (ALI) conditions. Only a very modest saturable MPP+ uptake is measurable in NCl-H441 cells and the inhibitory effect of quinidine points to OCT1 as the subtype functionally involved in this model. Finally, the characterization of MPP+ transport in human bronchial BEAS-2B cells suggests that OCT1 and OCT3 are operative. These findings could help to identify in vitro models to be employed for studies concerning the specific involvement of each transporter in drug transportation.
Assuntos
Células Epiteliais/metabolismo , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Transportador 1 de Cátions Orgânicos/metabolismo , 1-Metil-4-fenilpiridínio/metabolismo , 1-Metil-4-fenilpiridínio/farmacocinética , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/genética , Linhagem Celular , Linhagem Celular Tumoral , Corticosterona/farmacologia , Dinoprostona/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Cinética , Pulmão/citologia , Proteínas de Transporte de Cátions Orgânicos/genética , Transportador 1 de Cátions Orgânicos/genética , Transportador 2 de Cátion Orgânico , Quinidina/farmacologia , Interferência de RNA , Fatores de TempoRESUMO
1. The metabolism of CHF 6001, a novel PDE4 inhibitor, was determined in vitro in mouse, rat, dog, monkey and human microsomes and hepatocytes and in vivo in plasma, urine, feces and bile of rats after intravenous and intratracheal administration. 2. The behavior of CHF 6001 in microsomes and hepatocytes changed across species. CYP3A4/5 isoenzymes were identified to be the primary enzymes responsible for the metabolism of CHF 6001 in human liver microsomes. 3. In the rat, CHF 6001 was found extensively metabolized in urine, feces and bile, but not in plasma, where CHF 6001 was the main compound present. The metabolite profiles were different in the four biological matrices from both qualitative and quantitative point of view. 4. CHF 6001 was metabolized through hydrolysis with the formation of the alcohol CHF 5956, loss of a chlorine atom, loss of the N-oxide, hydroxylation, loss of the cyclopropylmethyl group in the alcohol moiety, conjugation with glucuronic acid, glutathione and cysteine-glycine. 5. The major metabolite present in the bile was isolated and characterized by nuclear magnetic resonance analysis. It derived from CHF 6001 through contraction of the pyridine-N-oxide ring to N-hydroxy pyrrole and conjugation with glucuronic acid.
Assuntos
Bile/metabolismo , Hepatócitos/metabolismo , Microssomos Hepáticos/metabolismo , Inibidores da Fosfodiesterase 4/metabolismo , Diester Fosfórico Hidrolases/metabolismo , Pirróis/metabolismo , Administração Intravenosa , Animais , Cromatografia Líquida de Alta Pressão , Cães , Fezes/química , Haplorrinos , Humanos , Masculino , Camundongos , Inibidores da Fosfodiesterase 4/administração & dosagem , Inibidores da Fosfodiesterase 4/sangue , Inibidores da Fosfodiesterase 4/urina , Ratos , Especificidade da Espécie , Espectrometria de Massas em TandemRESUMO
Clinical guidelines for COPD and asthma recommend inhaled ß-adrenergic agonists, muscarinic antagonists, and, for frequent exacerbators, inhaled corticosteroids, with the challenge of combining them into a single device. The MABA (muscarinic antagonist and ß2 agonist) concept has the potential to simplify this complexity while increasing the efficacy of both pharmacologies. In this article, we report the outcome of our solid-state driven back-up program that led to the discovery of the MABA compound CHF-6550. A soft drug approach was applied, aiming at high plasma protein binding and high hepatic clearance, concurrently with an early stage assessment of crystallinity through a dedicated experimental workflow. A new chemotype was identified, the diphenyl hydroxyacetic esters, able to generate crystalline material. Among this class, CHF-6550 demonstrated in vivo efficacy, suitability for dry powder inhaler development, favorable pharmacokinetics, and safety in preclinical settings and was selected as a back-up candidate, fulfilling the desired pharmacological and solid-state profile.
Assuntos
Agonistas de Receptores Adrenérgicos beta 2 , Antagonistas Muscarínicos , Antagonistas Muscarínicos/farmacocinética , Antagonistas Muscarínicos/farmacologia , Antagonistas Muscarínicos/química , Antagonistas Muscarínicos/síntese química , Antagonistas Muscarínicos/uso terapêutico , Antagonistas Muscarínicos/administração & dosagem , Animais , Humanos , Agonistas de Receptores Adrenérgicos beta 2/farmacocinética , Agonistas de Receptores Adrenérgicos beta 2/farmacologia , Agonistas de Receptores Adrenérgicos beta 2/química , Agonistas de Receptores Adrenérgicos beta 2/administração & dosagem , Administração por Inalação , Ratos , Descoberta de Drogas , Relação Estrutura-Atividade , Masculino , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológicoRESUMO
Mass spectrometry (MS)-based proteomics has recently attracted the attention from forensic pathologists. This work is the first report of the development of a shotgun bottom-up proteomic approach based on rapid protein extraction and nano-liquid chromatography/high-resolution mass spectrometry applied to full-thickness human skin for the differential analysis of normal and ecchymotic tissues to identify new biomarkers for bruise characterization and dating. We identified around 2000 proteins from each pooled extract. The method showed excellent precision on independent replicates, with Pearson correlation coefficients always higher than 95%. Glycophorin A, a known biomarker of vital wounds from immunochemical studies, was identified only in ecchymotic tissues, as confirmed by Western blotting analysis. This finding suggests that this protein can be used as a MS-detectable biomarker of wound vitality. By focusing on skin samples from individuals with known wound dating, besides Glycophorin A, other proteins differentially expressed in ecchymotic samples and dependant on wound age were identified, although further analysis on larger datasets are needed to validate these findings. This study paves the way for an in-depth investigation of the potential of MS-based techniques for wound examination in forensic pathology, overcoming the limitations of immunochemical assays.
Assuntos
Glicoforinas , Espectrometria de Massas em Tandem , Humanos , Espectrometria de Massas em Tandem/métodos , Proteômica/métodos , Patologia Legal , Proteínas/metabolismo , BiomarcadoresRESUMO
ATP-binding cassette (ABC) transporters are a large superfamily of membrane transporters that facilitate the translocation of different substrates. While ABC transporters are clearly expressed in various tumor cells where they can play a role in drug extrusion, the presence of these transporters in normal lung tissues is still controversial. Here, we performed an analysis of ABC transporters in EpiAlveolarTM, a recently developed model of human alveoli, by defining the expression and activity of MDR1, BCRP, and MRPs. Immortalized primary epithelial cells hAELVi (human alveolar epithelial lentivirus-immortalized cells) were employed for comparison. Our data underline a close homology between these two models, where none of the ABC transporters here studied are expressed on the apical membrane and only MRP1 is clearly detectable and functional at the basolateral side. According to these findings, we can conclude that other thus-far-unidentified transporter/s involved in drug efflux from alveolar epithelium deserve investigations.
Assuntos
Transportadores de Cassetes de Ligação de ATP , Células Epiteliais Alveolares , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Trifosfato de Adenosina , Células Epiteliais Alveolares/metabolismo , Humanos , Proteínas de Membrana Transportadoras , Proteínas de Neoplasias/metabolismoRESUMO
The development of molecules embedding two distinct pharmacophores acting as muscarinic antagonists and ß2 agonists (MABAs) promises to be an excellent opportunity to reduce formulation issues and boost efficacy through cross-talk and allosteric interactions. Herein, we report the results of our drug discovery campaign aimed at improving the therapeutic index of a previous MABA series by exploiting the super soft-drug concept. The incorporation of a metabolic liability, stable at the site of administration but undergoing rapid systemic metabolism, to generate poorly active and quickly eliminated fragments was pursued. Our SAR studies yielded MABA 29, which demonstrated a balanced in vivo profile up to 24 h, high instability in plasma and the liver, as well as sustained exposure in the lung. In vitro safety and non-GLP toxicity studies supported the nomination of 29 (CHF-6366) as a clinical candidate, attesting to the successful development of a novel super-soft MABA compound.
Assuntos
Antagonistas Muscarínicos , Doença Pulmonar Obstrutiva Crônica , Administração por Inalação , Agonistas de Receptores Adrenérgicos beta 2/farmacologia , Agonistas de Receptores Adrenérgicos beta 2/uso terapêutico , Broncodilatadores/uso terapêutico , Descoberta de Drogas , Humanos , Pulmão , Antagonistas Muscarínicos/farmacologia , Antagonistas Muscarínicos/uso terapêutico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológicoRESUMO
Organic cation transporters (OCTs) and novel organic cation transporters (OCTNs) are responsible for drug delivery in the intestine and kidney; in the lung, OCTs mediate inhaled drugs' transport, although their physiological role in airways remains poorly understood. The studies addressing OCTs/OCTNs in human airways were mostly performed in immortal or transformed cell lines; here, we studied OCTs in EpiAirway™, a recently developed in vitro model of normal bronchial epithelium. Calu-3 monolayers were used for comparison. The activity of OCTs was evaluated by measuring the uptake of 1-methyl-4-phenylpyridinium (MPP+) at the apical and basolateral side of monolayers and protein expression through Western Blot analysis. OCTs and OCTNs expression, along with that of Amino acid Transporter B0,+ (ATB0,+)transporter, was determined by measuring the number of mRNA molecules through quantitative Polymerase Chain Reaction (qPCR). The interaction of the transporters with bronchodilators was also assessed. Results highlight significant differences between Calu-3 cells and EpiAirway™, since, in the latter, OCTs are active only on the basolateral membrane where they interact with the bronchodilator ipratropium. No activity of OCTs is detectable at the apical side; there, the most abundant carrier is, instead, SLC6A14/ATB0,+, that can thus be potentially listed among organic cation transporters responsible for drug delivery in the lung.
RESUMO
SCOPE: Urolithin A and B are gut metabolites of ellagic acid and ellagitannins associated with many beneficial effects. Evidence in vitro pointed to their potential as estrogenic modulators. However, both molecular mechanisms and biological targets involved in such activity are still poorly characterized, preventing a comprehensive understanding of their bioactivity in living organisms. This study aimed at rationally identifying novel biological targets underlying the estrogenic-modulatory activity of urolithins. METHODS AND RESULTS: The work relies on an in silico/in vitro target fishing study coupling molecular modeling with biochemical and cell-based assays. Estrogen sulfotransferase and 17ß-hydroxysteroid dehydrogenase are identified as potentially subject to inhibition by the investigated urolithins. The inhibition of the latter undergoes experimental confirmation either in a cell-free or cell-based assay, validating computational outcomes. CONCLUSIONS: The work describes target fishing as an effective tool to identify unexpected targets of food bioactives detailing the interaction at a molecular level. Specifically, it described, for the first time, 17ß-hydroxysteroid dehydrogenase as a target of urolithins and highlighted the need of further investigations to widen the understanding of urolithins as estrogen modulators in living organisms.
Assuntos
Cumarínicos/farmacologia , Inibidores Enzimáticos/farmacologia , Estradiol Desidrogenases/antagonistas & inibidores , Proteínas/metabolismo , 17-Hidroxiesteroide Desidrogenases/química , 17-Hidroxiesteroide Desidrogenases/metabolismo , Sistema Livre de Células , Simulação por Computador , Cumarínicos/química , Cumarínicos/metabolismo , Humanos , Ligantes , Células MCF-7 , Modelos Moleculares , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Proteínas/química , Sulfotransferases/química , Sulfotransferases/metabolismoRESUMO
[This corrects the article DOI: 10.1371/journal.pone.0228568.].
RESUMO
In human, OCTN2 (SLC22A5) and ATB0,+ (SLC6A14) transporters mediate the uptake of L-carnitine, essential for the transport of fatty acids into mitochondria and the subsequent degradation by ß-oxidation. Aim of the present study was to characterize L-carnitine transport in EpiAirway™, a 3D organotypic in vitro model of primary human tracheal-bronchial epithelial cells that form a fully differentiated, pseudostratified columnar epithelium at air-liquid interface (ALI) condition. In parallel, Calu-3 monolayers grown at ALI for different times (8d or 21d of culture) were used as comparison. OCTN2 transporter was equally expressed in both models and functional at the basolateral side. ATB0,+ was, instead, highly expressed and active on the apical membrane of EpiAirway™ and only in early-cultures of Calu-3 (8d but not 21d ALI). In both cell models, L-carnitine uptake on the apical side was significantly inhibited by the bronchodilators glycopyrrolate and tiotropium, that hence can be considered substrates of ATB0,+; ipratropium was instead effective on the basolateral side, indicating its interaction with OCTN2. Inflammatory stimuli, such as LPS or TNFα, caused an induction of SLC6A14/ATB0,+ expression in Calu-3 cells, along with a 2-fold increase of L-carnitine uptake only at the apical side; on the contrary SLC22A5/OCTN2 was not affected. As both OCTN2 and ATB0,+, beyond transporting L-carnitine, have a significant potential as delivery systems for drugs, the identification of these transporters in EpiAirway™ can open new fields of investigation in the study of drug inhalation and pulmonary delivery.
Assuntos
Sistema ASC de Transporte de Aminoácidos/fisiologia , Carnitina/metabolismo , Células Epiteliais/química , Sistema Respiratório/citologia , Membro 5 da Família 22 de Carreadores de Soluto/fisiologia , Sistema ASC de Transporte de Aminoácidos/análise , Transporte Biológico/efeitos dos fármacos , Broncodilatadores/farmacologia , Técnicas de Cultura de Células/métodos , Polaridade Celular , Glicopirrolato/farmacologia , Humanos , Membro 5 da Família 22 de Carreadores de Soluto/análise , Brometo de Tiotrópio/farmacologiaRESUMO
Recently, mesenchymal stromal stem cells (MSCs) have been proposed as therapeutic agents because of their promising preclinical features and good safety profile. However, their introduction into clinical practice has been associated with a suboptimal therapeutic profile. In this review, we address the biodistribution of MSCs in preclinical studies with a focus on the current understanding of the pharmacodynamics (PD) and pharmacokinetics (PK) of MSCs as key aspects to overcome unsatisfactory clinical benefits of MSC application. Beginning with evidence of MSC biodistribution and highlighting PK and PD factors, a new PK-PD model is also proposed. According to this theory, MSCs and their released factors are key players in PK, and the efficacy biomarkers are considered relevant for PD in more predictive preclinical investigations. Accounting for the PK-PD relationship in MSC translational research and proposing new models combined with better biodistribution studies could allow realization of the promise of more robust MSC clinical translation.
RESUMO
Lysinuric protein intolerance (LPI) is a recessively inherited aminoaciduria caused by mutations of SLC7A7, the gene encoding y+LAT1 light chain of system y+L for cationic amino acid transport. The pathogenesis of LPI is still unknown. In this study, we have utilized a gene silencing approach in macrophages and airway epithelial cells to investigate whether complications affecting lung and immune system are directly ascribable to the lack of SLC7A7 or, rather, mediated by an abnormal accumulation of arginine in mutated cells. When SLC7A7/y+LAT1 was silenced in human THP-1 macrophages and A549 airway epithelial cells by means of short interference RNA (siRNA), a significant induction of the expression and release of the inflammatory mediators IL1ß and TNFα was observed, no matter the intracellular arginine availability. This effect was mainly regulated at transcriptional level through the activation of NFκB signaling pathway. Moreover, since respiratory epithelial cells are the important sources of chemokines in response to pro-inflammatory stimuli, the effect of IL1ß has been addressed on SLC7A7 silenced A549 cells. Results obtained indicated that the downregulation of SLC7A7/y+LAT1 markedly strengthened the stimulatory effect of the cytokine on CCL5/RANTES expression and release without affecting the levels of CXCL8/IL8. Consistently, also the conditioned medium of silenced THP-1 macrophages activated airway epithelial cells in terms of CCL5/RANTES expression due to the presence of elevated amount of proinflammatory cytokines. In conclusion, our results point to a novel thus far unknown function of SLC7A7/y+LAT1, that, under physiological conditions, besides transporting arginine, may act as a brake to restrain inflammation.
Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/imunologia , Cadeias Leves da Proteína-1 Reguladora de Fusão/metabolismo , Inflamação/imunologia , Macrófagos/imunologia , Aminoacidúrias Renais/imunologia , Mucosa Respiratória/imunologia , Células A549 , Erros Inatos do Metabolismo dos Aminoácidos/genética , Sistema y+L de Transporte de Aminoácidos , Quimiocina CCL5/metabolismo , Cadeias Leves da Proteína-1 Reguladora de Fusão/genética , Inativação Gênica , Humanos , Inflamação/genética , Interleucina-1beta/metabolismo , Mutação/genética , NF-kappa B/metabolismo , Fenótipo , RNA Interferente Pequeno/genética , Aminoacidúrias Renais/genética , Células THP-1 , Fator de Necrose Tumoral alfa/metabolismoRESUMO
l-Carnitine, in addition to playing a fundamental role in the ß-oxidation of fatty acids, has been recently identified as a modulator of immune function, although the mechanisms that underlie this role remain to be clarified. In this study, we addressed the modulation of l-carnitine transport and expression of related transporters during differentiation of human monocytes to macrophages. Whereas monocytes display a modest uptake of l-carnitine, GM-CSF-induced differentiation massively increased the saturable Na+-dependent uptake of l-carnitine. Kinetic and inhibition analyses demonstrate that in macrophage l-carnitine transport is mediated by a high-affinity component (Km â¼4 µM) that is identifiable with the operation of OCTN2 transporter and a low-affinity component (Km > 10 mM) that is identifiable with system A for neutral amino acids. Consistently, both SLC22A5/OCTN2 and SLC38A2/SNAT2 are induced during the differentiation of monocytes to macrophages at gene and protein levels. Elucidation of GM-CSF signaling demonstrates that the cytokine causes the activation of mTOR kinase, leading to the phosphorylation and activation of STAT3, which, in turn, is responsible for OCTN2 transcription. SLC22A5/OCTN2 therefore emerges as a novel member of the set of genes markers of macrophage differentiation.
Assuntos
Carnitina/metabolismo , Diferenciação Celular , Macrófagos/citologia , Macrófagos/metabolismo , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Transporte Biológico , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Humanos , Cinética , Modelos Biológicos , Monócitos/citologia , Proteínas de Transporte de Cátions Orgânicos/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Membro 5 da Família 22 de Carreadores de Soluto , Fatores de TempoRESUMO
Flurbiprofen, a nonsteroidal antiinflammatory drug (NSAID), has been recently described to selectively inhibit beta-amyloid(1)(-)(42) (Abeta42) secretion, the most toxic component of the senile plaques present in the brain of Alzheimer patients. The use of this NSAID in Alzheimer's disease (AD) is hampered by a significant gastrointestinal toxicity associated with cyclooxygenase (COX) inhibition. New flurbiprofen analogues were synthesized, with the aim of increasing Abeta42 inhibitory potency while removing anti-COX activity. In vitro ADME developability parameters were taken into account in order to identify optimized compounds at an early stage of the project. Appropriate substitution patterns at the alpha position of flurbiprofen allowed for the complete removal of anti-COX activity, while modifications at the terminal phenyl ring resulted in increased inhibitory potency on Abeta42 secretion. In rats, some of the compounds appeared to be well absorbed after oral administration and to penetrate into the central nervous system. Studies in a transgenic mice model of AD showed that selected compounds significantly decreased plasma Abeta42 concentrations. These new flurbiprofen analogues represent potential drug candidates to be developed for the treatment of AD.
Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Anti-Inflamatórios não Esteroides/síntese química , Flurbiprofeno/análogos & derivados , Flurbiprofeno/síntese química , Fragmentos de Peptídeos/antagonistas & inibidores , Administração Oral , Doença de Alzheimer/sangue , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/sangue , Peptídeos beta-Amiloides/metabolismo , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Barreira Hematoencefálica/metabolismo , Células CACO-2 , Linhagem Celular Tumoral , Permeabilidade da Membrana Celular , Inibidores de Ciclo-Oxigenase/farmacologia , Flurbiprofeno/farmacologia , Glioma , Humanos , Imunoensaio , Técnicas In Vitro , Injeções Intravenosas , Camundongos , Camundongos Transgênicos , Fragmentos de Peptídeos/sangue , Fragmentos de Peptídeos/metabolismo , Ratos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
A cell-based assay using homogeneous time-resolved fluorescence has been developed for high throughput screening of putative beta-amyloid (Abeta)production inhibitors. In this assay, total Abeta is detected by simply adding two commercially available antibody complexes. The first was a biotinylated monoclonal antibody (4G8), specifically recognizing an epitope comprising the residues 17-24 of the Abetapeptide, complexed with europium cryptate-streptavidin conjugate. The second was a polyclonal antibody (BioS-N), raised against the N-terminus of the Abeta peptide, complexed with an allophycocyanin-anti rabbit antibody conjugate. Binding of the two complexes to the Abeta peptide brought europium cryptate (fluorescence donor) and allophycocyanin (fluorescence acceptor) into close proximity, consequently a fluorescent resonance energy transfer signal was produced upon excitation at 337 nm. The resulting fluorescence signal (665 nm) was then detected using a Discovery or a ViewLux reader. Detection of Abeta by the proposed method is possible at concentrations of approximately 1 nM. The method was employed for the detection of Abeta secreted from a stable transfected human neuroglioma cell line (H4) overexpressing a mutated form of the human amyloid precursor protein (APP695NL) and developed for robotic automation. At optimized conditions, signal-to-background ratios exceeding 5 and Z' factors around 0.7 were achieved in a 384-well format. High throughput screening of 56,913 potential Abeta production inhibitors led to identification of new non-cytotoxic and cell permeable compounds with potencies in the submicromolar range.
Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Peptídeos beta-Amiloides/metabolismo , Anticorpos Monoclonais , Células Cultivadas , Cromatografia Líquida , Avaliação Pré-Clínica de Medicamentos , Ensaio de Imunoadsorção Enzimática , Corantes Fluorescentes , Humanos , Imunoensaio , Espectrometria de MassasRESUMO
Long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) may delay or prevent the onset of Alzheimer's disease (AD). A subset of NSAIDs, including flurbiprofen, has been shown to selectively inhibit the production of beta-amyloid(1-42) (Abeta42), independently from their cyclooxygenase (COX) inhibiting activity. We evaluated the in vitro and in vivo profiles of CHF5022 and CHF5074, two flurbiprofen analogues. The in vitro Abeta inhibiting activity was evaluated in a human neuroglioma cell line (H4) carrying the double Swedish mutation (K595N/M596L) of the human amyloid precursor protein (APPsw). The in vitro anti-COX activity was evaluated using human recombinant enzymes isolated from transfected Sf-9 cells. The in vivo pharmacokinetic and pharmacodynamic profiles of the two compounds were evaluated in young APPsw transgenic mice (Tg2576) after oral gavage (100 or 300mgkg(-1) day(-1) for 4-5 days) and after medicated diet (375ppm for 4 weeks). R-Flurbiprofen was used as comparator. In vitro, CHF5022 and CHF5074 were found to be 3- and 7-fold more potent than R-flurbiprofen in inhibiting Abeta42 secretion (IC(50)s of 92, 40 and 268microM, respectively). Differently from R-flurbiprofen, CHF5022 and CHF5074 did not affect COX-1 (at 100microM) and COX-2 (at 300microM) activity. Similarly to R-flurbiprofen, no significant alteration in the expression profile of a subset of Notch intracellular domain-responsive genes was observed with either CHF5022 or CHF5074. In Tg2576 mice, CHF5022 was well tolerated when administered by oral gavage (100mgkg(-1) day(-1) for 5 days) or by medicated diet (56mg kg(-1) day(-1) for 4 weeks). R-Flurbiprofen was poorly tolerated in the diet (32mgkg(-1) day(-1)) with 55% of the animals dying during the first week of treatment. After 4-5 days of oral gavage, CHF5022 and CHF5074 plasma and brain levels at 3h were found to increase with the dose, leading to brain concentrations of about 10% and 5% of the corresponding plasma concentrations, respectively. In animals fed for 4 weeks with compound-supplemented diet, mean plasma (580microM) and brain (20microM) Cyrillic) concentrations of CHF5022 were 8 and 15 times higher than those of R-flurbiprofen. Plasma Abeta42 concentration was dose-dependently decreased by CHF5022 and CHF5074. Brain Abeta levels (formic acid-extractable) were not significantly affected by either compound, although Abeta42 levels tended to inversely correlate (P=0.105) with CHF5022 concentration in the brain. CHF5022 and CHF5074 thus appear to have a promising in vitro and in vivo profile. This warrants further evaluation of their long-term effects on Abeta brain pathology.