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1.
Bioorg Med Chem Lett ; 27(23): 5344-5348, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29110986

RESUMO

New synthetic methods were developed for the preparation of 2,3,6-trisubstituted 1-oxo-1,2-dihydroisoquinolines as CRTh2 antagonists. The isoquinolinone core could be constructed before the introduction of substitution groups or synthesized through a catalytic intramolecular cyclization reaction with desired substitution groups properly installed. These synthetic strategies have helped to accelerate the SAR development of this series, and potent lead compounds were identified in both the CRTh2 receptor binding assay and the CD11b biomarker assay.


Assuntos
Isoquinolinas/farmacologia , Receptores Imunológicos/antagonistas & inibidores , Receptores de Prostaglandina/antagonistas & inibidores , Relação Dose-Resposta a Droga , Humanos , Isoquinolinas/síntese química , Isoquinolinas/química , Estrutura Molecular , Relação Estrutura-Atividade
2.
Bioorg Med Chem Lett ; 24(6): 1615-20, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24556380

RESUMO

Isoxazoles are frequently used amide isosteres, as shown in the context of discovery of CRTh2 antagonists from amide 1 to isoxazole 2. However, persistent agonism and poor solubility in isoxazole series presented challenges to its further development. Based on the concept of quality by design (QbD), 5,5-disubstituted isoxazolines 3 were introduced. The chirality at 5 position of isoxazolines controlled the switch between two modes of actions, which led to a novel series of pure antagonists. This non-planar motif also conferred a change of shape of these molecules, which avoided flat structures and improved their physical properties.


Assuntos
Amidas/química , Desenho de Fármacos , Isoxazóis/química , Quinazolinonas/química , Receptores Imunológicos/antagonistas & inibidores , Receptores de Prostaglandina/antagonistas & inibidores , Animais , Cães , Meia-Vida , Haplorrinos , Humanos , Isoxazóis/síntese química , Isoxazóis/farmacocinética , Quinazolinonas/síntese química , Quinazolinonas/farmacocinética , Ratos , Ratos Wistar , Receptores Imunológicos/metabolismo , Receptores de Prostaglandina/metabolismo , Solubilidade , Relação Estrutura-Atividade
3.
Pulm Pharmacol Ther ; 26(6): 677-84, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23523662

RESUMO

Late phase airflow obstruction and reduction in forced vital capacity are characteristic features of human asthma. Airway microvascular leakage and lung edema are also present in the inflammatory phase of asthma, but the impact of this vascular response on lung functions has not been precisely defined. This study was designed to evaluate the role of increased lung microvascular leakage and edema on the late phase changes in forced vital capacity (FVC) and peak expiratory flow (PEF) in allergen-challenged Brown Norway rats using pharmacological inhibitors of the allergic inflammatory response. Rats were sensitized and challenged with ovalbumin aerosol and forced expiratory lung functions (FVC, PEF) and wet and dry lung weights were measured 48 h after antigen challenge. Ovalbumin challenge reduced FVC (63% reduction) and PEF (33% reduction) and increased wet (65% increase) and dry (51% increase) lung weights. The antigen-induced reduction in FVC and PEF was completely inhibited by oral treatment with betamethasone and partially attenuated by inhibitors of arachidonic acid metabolism including indomethacin (cyclooxygenase inhibitor), 7-TM and MK-7246 (CRTH2 antagonists) and montelukast (CysLT1 receptor antagonist). Antagonists of histamine H1 receptors (mepyramine) and 5-HT receptors (methysergide) had no significant effects indicating that these pre-formed mast cell mediators were not involved. There was a highly significant (P < 0.005) correlation for the inhibition of FVC reduction and increase in wet and dry lung weights by these pharmacological agents. These results strongly support the hypothesis that lung microvascular leakage and the associated lung edema contribute to the reduction in forced expiratory lung functions in antigen-challenged Brown Norway rats and identify an important role for the cyclooxygenase and lipoxygenase products of arachidonic acid metabolism in these responses.


Assuntos
Ácido Araquidônico/metabolismo , Inflamação/fisiopatologia , Microvasos/patologia , Edema Pulmonar/fisiopatologia , Alérgenos/imunologia , Animais , Asma/fisiopatologia , Betametasona/farmacologia , Permeabilidade Capilar/efeitos dos fármacos , Permeabilidade Capilar/fisiologia , Modelos Animais de Doenças , Inflamação/imunologia , Lipoxigenase/metabolismo , Masculino , Microvasos/imunologia , Ovalbumina/imunologia , Pico do Fluxo Expiratório , Prostaglandina-Endoperóxido Sintases/metabolismo , Edema Pulmonar/imunologia , Ratos , Ratos Endogâmicos BN , Capacidade Vital
6.
ACS Med Chem Lett ; 11(2): 114-119, 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32071676

RESUMO

The clinical success of anti-IL-17 monoclonal antibodies (i.e., Cosentyx and Taltz) has validated Th17 pathway modulation for the treatment of autoimmune diseases. The nuclear hormone receptor RORγt is a master regulator of Th17 cells and affects the production of a host of cytokines, including IL-17A, IL-17F, IL-22, IL-26, and GM-CSF. Substantial interest has been spurred across both academia and industry to seek small molecules suitable for RORγt inhibition. A variety of RORγt inhibitors have been reported in the past few years, the majority of which are orthosteric binders. Here we disclose the discovery and optimization of a class of inhibitors, which bind differently to an allosteric binding pocket. Starting from a weakly active hit 1, a tool compound 14 was quickly identified that demonstrated superior potency, selectivity, and off-target profile. Further optimization focused on improving metabolic stability. Replacing the benzoic acid moiety with piperidinyl carboxylate, modifying the 4-aza-indazole core in 14 to 4-F-indazole, and incorporating a key hydroxyl group led to the discovery of 25, which possesses exquisite potency and selectivity, as well as an improved pharmacokinetic profile suitable for oral dosing.

7.
Bioorg Med Chem Lett ; 19(3): 783-7, 2009 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-19114307

RESUMO

A series of spiro-piperidine azetidinone were synthesized and evaluated as potential TRPV1 antagonists. An important issue of plasma stability was investigated and resolved. Further focused SAR study lead to the discovery of a potent antagonist with good oral pharmacokinetic profile in rat.


Assuntos
Azetidinas/síntese química , Azetidinas/farmacocinética , Química Farmacêutica/métodos , Compostos de Espiro/síntese química , Compostos de Espiro/farmacologia , Canais de Cátion TRPV/antagonistas & inibidores , Administração Oral , Animais , Desenho de Fármacos , Concentração de Íons de Hidrogênio , Concentração Inibidora 50 , Modelos Químicos , Ratos , Estereoisomerismo , Relação Estrutura-Atividade
8.
ACS Med Chem Lett ; 9(7): 679-684, 2018 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-30034600

RESUMO

A novel series of tricyclic tetrahydroquinolines were identified as potent and selective CRTh2 receptor antagonists. The agonism and antagonism switch was achieved through structure-based drug design (SBDD) using a CRTh2 receptor homologue model. The challenge of very low exposures in pharmacokinetic studies was overcome by exhaustive medicinal chemistry lead optimization through focused SAR studies on the tricyclic core. Further optimization resulted in the identification of the preclinical candidate 4-(cyclopropyl((3aS,9R,9aR)-7-fluoro-4-(4-(trifluoromethoxy)benzoyl)-2,3,3a,4,9,9a-hexahydro-1H-cyclopenta[b]quinolin-9-yl)amino)-4-oxobutanoic acid (15c, MK-8318) with potent and selective CRTh2 antagonist activity and a favorable PK profile suitable for once daily oral dosing for potential treatment of asthma.

9.
Eur J Pharmacol ; 536(1-2): 28-37, 2006 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-16581066

RESUMO

The molecular and pharmacological properties of adenosine receptors in the T24 human bladder epithelial carcinoma cell line were assessed by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR), Ca2+ Flux, cAMP production and interleukin-8 measurements. RT-PCR experiments detected the presence of transcripts for the adenosine A1, A2A and A2B receptors but not for the adenosine A3 subtype. Application of specific adenosine receptor ligands resulted in concentration-dependent increases in intracellular calcium ([Ca2+]i) with the following order of potency and EC50 values: 5'-N-Ethylcarboxamidoadenosine (NECA) (1153+/-214)>5'-(N-Cyclopropyl)carboxamidoadenosine (CPCA) (1436+/-186)>adenosine (4823+/-932). This rank order of potency is typical of adenosine A2B receptors. In addition, select adenosine receptor antagonists N-(4-acetylphenyl)-2-[4-(2,3,6,7-tetrahydro-2,6 dioxo-1,3-dipropyl-1H-purin-8-yl)phenoxy]acetamide (MRS 1706), 8-[4-[((4-Cyano[2,6-]-phenyl)carbamoylmethyl)oxy]phenyl]-1,3-di(n-propyl)-xanthine (MRS 1754), 1,3-Diethyl-8-phenylxanthine (DPCPX), 1,3-Diethyl-8-phenylxanthine (DPX), Alloxazine, 8-(3-Chlorostyryl)caffeine (CSC), and Theophylline blocked the NECA-induced calcium responses. Additionally, NECA, CPCA, and adenosine stimulated cAMP formation with a rank order of potency characteristic of adenosine A2B receptors. The select adenosine A2A antagonist, 5-amino-7-(phenylethyl)-2-(2-furyl)-pyrazolo[4,3-e]-1,2,4-triazolo[1,5-c] pyrimidine (SCH 58261) failed to antagonize the NECA response, whereas the potent and highly selective adenosine A2B antagonists MRS 1754 and MRS 1706 inhibited NECA-stimulated cAMP production. Lastly, NECA-induced interleukin-8 secretion was inhibited by MRS 1754. Taken together, these data indicate that [Ca2+]i accumulation and cAMP production as well as interleukin-8 secretion is mediated through the adenosine A2B receptor in the T24 cell line.


Assuntos
Receptores Purinérgicos P1/fisiologia , Neoplasias da Bexiga Urinária/metabolismo , Adenosina/análogos & derivados , Adenosina/farmacologia , Adenosina-5'-(N-etilcarboxamida)/farmacologia , Cálcio/metabolismo , Linhagem Celular Tumoral , AMP Cíclico/biossíntese , Relação Dose-Resposta a Droga , Regulação Neoplásica da Expressão Gênica , Humanos , Interleucina-8/biossíntese , Líquido Intracelular/efeitos dos fármacos , Líquido Intracelular/metabolismo , Isoformas de Proteínas/agonistas , Isoformas de Proteínas/antagonistas & inibidores , Purinas/farmacologia , RNA Neoplásico/genética , RNA Neoplásico/metabolismo , Receptores Purinérgicos P1/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia , Xantinas/farmacologia
10.
Cell Rep ; 17(12): 3206-3218, 2016 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-28009290

RESUMO

Recent studies have elucidated the molecular mechanism of RORγT transcriptional regulation of Th17 differentiation and function. RORγT was initially identified as a transcription factor required for thymopoiesis by maintaining survival of CD4+CD8+ (DP) thymocytes. While RORγ antagonists are currently being developed to treat autoimmunity, it remains unclear how RORγT inhibition may impact thymocyte development. In this study, we show that in addition to regulating DP thymocytes survival, RORγT also controls genes that regulate thymocyte migration, proliferation, and T cell receptor (TCR)α selection. Strikingly, pharmacological inhibition of RORγ skews TCRα gene rearrangement, limits T cell repertoire diversity, and inhibits development of autoimmune encephalomyelitis. Thus, targeting RORγT not only inhibits Th17 cell development and function but also fundamentally alters thymic-emigrant recognition of self and foreign antigens. The analysis of RORγ inhibitors has allowed us to gain a broader perspective of the diverse function of RORγT and its impact on T cell biology.


Assuntos
Encefalomielite Autoimune Experimental/imunologia , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Timócitos/imunologia , Animais , Antígenos/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/genética , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/terapia , Regulação da Expressão Gênica/imunologia , Rearranjo Gênico/genética , Humanos , Camundongos , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/antagonistas & inibidores , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Células Th17/efeitos dos fármacos , Células Th17/imunologia
11.
Eur J Pharmacol ; 513(1-2): 57-66, 2005 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-15878709

RESUMO

Transient receptor potential vanilloid receptor-1 (TRPV1) is a sensory neuron-specific cation channel capable of integrating various noxious chemical and physical stimuli. The dog orthologue of TRPV1 was cloned using cDNA from nodose ganglia and heterologously expressed in HEK293(OFF) cells. At the amino acid level, dTRPV1 displays 85-89% sequence identity to other TRPV1 orthologues. Molecular pharmacological characterization of HEK293(OFF) cells expressing TRPV1 was assessed using a fluorescence imaging plate reader (FLIPR)-based calcium imaging assay. Dog TRPV1 was activated by various known TRPV1 agonists in a concentration-dependent manner: Ag23 = resiniferatoxin > olvanil approximately arvanil > capsaicin > phorbol 12-phenylacetate 13-acetate 20-homovanillate (PPAHV) > N-oleoyldopamine (OLDA). In addition, select TRPV1 antagonists (capsazepine, I-resiniferatoxin and N-(-4-tertiarybutylphenyl)-4-(3-cholorpyridin-2-yl)tetrahydropyrazine-1(2H)-carbox-amide (BCTC)) were able to block the response of dTRPV1 to capsaicin. Furthermore, the dog TRPV1 lacked a conserved protein kinase A (PKA) phosphorylation site (117) found in other cloned orthologues, which may have physiological consequences on dog TRPV1 function. Taken together, these data constitute the first study of the cloning, expression and pharmacological characterization of dog TRPV1.


Assuntos
Capsaicina/análogos & derivados , Cães/genética , Dopamina/análogos & derivados , Receptores de Droga/genética , Sequência de Aminoácidos , Animais , Transporte Biológico/efeitos dos fármacos , Cálcio/metabolismo , Cálcio/farmacocinética , Capsaicina/farmacologia , Linhagem Celular , Clonagem Molecular , DNA Complementar/química , DNA Complementar/genética , Diterpenos/farmacologia , Dopamina/farmacologia , Relação Dose-Resposta a Droga , Fluorometria/métodos , Vetores Genéticos/genética , Genótipo , Humanos , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Ésteres de Forbol/farmacologia , Filogenia , Pirazinas/farmacologia , Piridinas/farmacologia , Receptores de Droga/fisiologia , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Transfecção
12.
Nat Commun ; 6: 8833, 2015 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-26640126

RESUMO

RORγt is critical for the differentiation and proliferation of Th17 cells associated with several chronic autoimmune diseases. We report the discovery of a novel allosteric binding site on the nuclear receptor RORγt. Co-crystallization of the ligand binding domain (LBD) of RORγt with a series of small-molecule antagonists demonstrates occupancy of a previously unreported allosteric binding pocket. Binding at this non-canonical site induces an unprecedented conformational reorientation of helix 12 in the RORγt LBD, which blocks cofactor binding. The functional consequence of this allosteric ligand-mediated conformation is inhibition of function as evidenced by both biochemical and cellular studies. RORγt function is thus antagonized in a manner molecularly distinct from that of previously described orthosteric RORγt ligands. This brings forward an approach to target RORγt for the treatment of Th17-mediated autoimmune diseases. The elucidation of an unprecedented modality of pharmacological antagonism establishes a mechanism for modulation of nuclear receptors.


Assuntos
Interleucina-17/metabolismo , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/química , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Sítio Alostérico , Animais , Diferenciação Celular , Humanos , Interleucina-17/química , Ligantes , Camundongos , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Estrutura Terciária de Proteína , Células Th17/química , Células Th17/metabolismo
13.
Neurosci Lett ; 370(1): 55-60, 2004 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-15489017

RESUMO

The Transient Receptor Potential cation channel V1 (TRPV1) is expressed in peripheral nociceptive neurons and is subject to polymodal activation via various agents including capsaicin, noxious heat, low extracellular pH, and direct phosphorylation by protein kinase C (PKC). We have cloned and heterologously expressed mouse TRPV1 (mTRPV1) and characterized its function utilizing FLIPR-based calcium imaging to measure functional responses to various small molecule agonists, low pH and direct phosphorylation via PKC. The various TRPV1 agonists activated mTRPV1 with a rank order of agonist potency of (resiniferatoxin (RTX) = arvanil > capsaicin = olvanil > OLDA > PPAHV) (EC50 values of 0.15+/-0.04 nM, 0.27+/-0.07 nM, 9.1+/-1.2 nM, 3.7+/-0.3 nM, 258+/-105 nM, and 667+/-151 nM, respectively). Additionally, mTRPV1 was activated by either low pH or with addition of the PKC activator phorbol 12-myristate 13-acetate (PMA). The TRPV1 antagonists iodinated-resiniferatoxin (I-RTX) or BCTC were both able to block capsaicin, pH and PKC-induced responses of mTRPV1 (IC50 (I-RTX) = 0.35+/-0.12 nM, 1.9+/-0.7 nM, and 0.80+/-0.68 nM, IC50 (BCTC) = 1.3+/-0.36 nM, 0.59+/-0.16 nM, and 0.37+/-0.15 nM, respectively). However, the antagonist capsazepine was only able to inhibit a capsaicin-evoked response of mTRPV1 with an IC50 of 1426+/-316 nM. Comparable results were achieved with rat TRPV1, while capsazepine blocked all modes of human TRPV1 activation. Thus, the mTRPV1 cation channel has a molecular pharmacological profile more akin to rat TRPV1 than either human or guinea pig TRPV1 and the molecular pharmacology suggests that capsazepine may be an ineffective TRPV1 antagonist for in vivo models of inflammatory pain in the mouse.


Assuntos
Canais Iônicos/genética , Receptores de Droga/fisiologia , Sequência de Aminoácidos , Animais , Cálcio/metabolismo , Capsaicina/agonistas , Capsaicina/farmacologia , Linhagem Celular , Clonagem Molecular , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Diterpenos/farmacologia , Ativação Enzimática/efeitos dos fármacos , Cobaias , Humanos , Concentração de Íons de Hidrogênio , Concentração Inibidora 50 , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Canais Iônicos/fisiologia , Camundongos , Ésteres de Forbol/farmacologia , Fosforilação/efeitos dos fármacos , RNA Mensageiro/biossíntese , Coelhos , Ratos , Receptores de Droga/agonistas , Receptores de Droga/antagonistas & inibidores , Receptores de Droga/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Canais de Cátion TRPV , Transfecção/métodos
14.
J Med Chem ; 57(16): 6887-96, 2014 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-24697360

RESUMO

Seven transmembrane receptors (7TMRs), also known as G-protein-coupled receptors (GPCRs), have proven to be valuable targets for the development of therapeutics. The expansion of our understanding of 7TMR downstream signaling pathways beyond G-proteins has broadened our appreciation of the versatility of these cell surface receptors. In particular, the increased awareness of 7TMR engagement of ß-arrestin signaling has opened up additional avenues for drug discovery. 7TMRs can adopt different conformations and in response to various ligands can lead to a bias in downstream signaling mechanisms when comparing the overall efficacy between G-protein and ß-arrestin dependent pathways. In 2012, we organized a session at the Spring National Meeting of the American Chemical Society on biased signaling in 7TMRs.1-4 Building on that experience, we provide in this Miniperspective some examples that exemplify developments in the area of biased 7TMR signaling and highlight some cautionary notes as well as some of the exciting opportunities for drug discovery.


Assuntos
Descoberta de Drogas/métodos , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/metabolismo , Animais , Arrestinas/metabolismo , Humanos , Ligantes , Conformação Proteica , Receptores Adrenérgicos beta 1/química , Receptores Adrenérgicos beta 1/metabolismo , Receptores Adrenérgicos beta 2/química , Receptores Adrenérgicos beta 2/metabolismo , Receptores de Dopamina D2/agonistas , Receptores de Dopamina D2/química , Receptores de Dopamina D2/metabolismo , Receptores Nicotínicos/química , Receptores Nicotínicos/metabolismo , Receptores Opioides mu/química , Receptores Opioides mu/metabolismo , Transdução de Sinais , beta-Arrestinas
15.
Eur J Pharmacol ; 743: 106-16, 2014 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-25261040

RESUMO

Alternaria alternata is a fungal allergen linked to the development of severe asthma in humans. In view of the clinical relationship between A. alternata and asthma, we sought to investigate the allergic activity of this antigen after direct application to the lungs of Brown Norway rats. Here we demonstrate that a single intratracheal instillation of A. alternata induces dose and time dependent eosinophil influx, edema and Type 2 helper cell cytokine production in the lungs of BN rats. We established the temporal profile of eosinophilic infiltration and cytokine production, such as Interleukin-5 and Interleukin-13, following A. alternata challenge. These responses were comparable to Ovalbumin induced models of asthma and resulted in peak inflammatory responses 48h following a single challenge, eliminating the need for multiple sensitizations and challenges. The initial perivascular and peribronchiolar inflammation preceded alveolar inflammation, progressing to a more sub-acute inflammatory response with notable epithelial cell hypertrophy. To limit the effects of an A. alternata inflammatory response, MK-7246 was utilized as it is an antagonist for Chemoattractant Receptor-homologous molecule expressed in Th2 cells. In a dose-dependent manner, MK-7246 decreased eosinophil influx and Th2 cytokine production following the A. alternata challenge. Furthermore, therapeutic administration of corticosteroids resulted in a dose-dependent decrease in eosinophil influx and Th2 cytokine production. Reproducible asthma-related outcomes and amenability to pharmacological intervention by mechanisms relevant to asthma demonstrate that an A. alternata induced pulmonary inflammation in BN rats is a valuable preclinical pharmacodynamic in vivo model for evaluating the pharmacological inhibitors of allergic pulmonary inflammation.


Assuntos
Alternaria/efeitos dos fármacos , Anti-Inflamatórios/farmacologia , Carbolinas/farmacologia , Pneumonia/tratamento farmacológico , Receptores de Formil Peptídeo/metabolismo , Células Th2/efeitos dos fármacos , Alérgenos/imunologia , Alternaria/imunologia , Animais , Asma/tratamento farmacológico , Asma/imunologia , Asma/metabolismo , Citocinas/imunologia , Citocinas/metabolismo , Eosinófilos/efeitos dos fármacos , Eosinófilos/imunologia , Eosinófilos/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Interleucina-13/imunologia , Interleucina-13/metabolismo , Interleucina-5/imunologia , Interleucina-5/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/metabolismo , Masculino , Ovalbumina/imunologia , Ovalbumina/farmacologia , Pneumonia/imunologia , Pneumonia/metabolismo , Ratos , Ratos Endogâmicos BN , Receptores de Formil Peptídeo/imunologia , Células Th2/imunologia
16.
Lung ; 186 Suppl 1: S59-65, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17926096

RESUMO

Cough is an important defensive pulmonary reflex that removes irritants, fluids, or foreign materials from the airways. However, when cough is exceptionally intense or when it is chronic and/or nonproductive it may require pharmacologic suppression. For many patients, antitussive therapies consist of OTC products with inconsequential efficacies. On the other hand, the prescription antitussive market is dominated by older opioid drugs such as codeine. Unfortunately, "codeine-like" drugs suppress cough at equivalent doses that also often produce significant ancillary liabilities such as GI constipation, sedation, and respiratory depression. Thus, the discovery of a novel and effective antitussive drug with an improved side effect profile relative to codeine would fulfill an unmet clinical need in the treatment of cough. Afferent pulmonary nerves are endowed with a multitude of potential receptor targets, including TRPV1, that could act to attenuate cough. The evidence linking TRPV1 to cough is convincing. TRPV1 receptors are found on sensory respiratory nerves that are important in the generation of the cough reflex. Isolated pulmonary vagal afferent nerves are responsive to TRPV1 stimulation. In vivo, TRPV1 agonists such as capsaicin elicit cough when aerosolized and delivered to the lungs. Pertinent to the debate on the potential use of TRPV1 antagonist as antitussive agents are the observations that airway afferent nerves become hypersensitive in diseased and inflamed lungs. For example, the sensitivity of capsaicin-induced cough responses following upper respiratory tract infection and in airway inflammatory diseases such as asthma and COPD is increased relative to that of control responses. Indeed, we have demonstrated that TRPV1 antagonism can attenuate antigen-induced cough in the allergic guinea pig. However, it remains to be determined if the emerging pharmacologic profile of TRPV1 antagonists will translate into a novel human antitussive drug. Current efforts in clinical validation of TRPV1 antagonists revolve around various pain indications; therefore, clinical evaluation of TRPV1 antagonists as antitussive agents will have to await those outcomes.


Assuntos
Antitussígenos/uso terapêutico , Tosse/tratamento farmacológico , Fármacos do Sistema Sensorial/uso terapêutico , Canais de Cátion TRPV/antagonistas & inibidores , Animais , Capsaicina/uso terapêutico , Tosse/metabolismo , Tosse/fisiopatologia , Humanos , Pulmão/metabolismo , Pulmão/fisiopatologia , Reflexo/efeitos dos fármacos , Reflexo/fisiologia , Canais de Cátion TRPV/metabolismo , Resultado do Tratamento
17.
Cough ; 2: 10, 2006 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-17173683

RESUMO

We examined the molecular pharmacology and in vivo effects of a TRPV1 receptor antagonist, N-(4-Tertiarybutylphenyl)-4(3-cholorphyridin-2-yl)-tetrahydro-pyrazine1(2H) - carboxamide (BCTC) on the guinea pig TRPV1 cation channel. BCTC antagonized capsaicin-induced activation and PMA-mediated activation of guinea pig TRPV1 with IC50 values of 12.2 +/- 5.2 nM, and 0.85 +/- 0.10 nM, respectively. In addition, BCTC (100 nM) completely blocked the ability of heterologously expressed gpTRPV1 to respond to decreases in pH. Thus, BCTC is able to block polymodal activation of gpTRPV1. Furthermore, in nodose ganglia cells, capsaicin induced Ca2+ influx through TRPV1 channel was inhibited via BCTC in a concentration dependent manner. In in vivo studies capsaicin (10 - 300 muM) delivered by aerosol to the pulmonary system of non-sensitized guinea pigs produced an increase in cough frequency. In these studies, the tussigenic effects of capsaicin (300 muM) were blocked in a dose dependent fashion when BCTC (0.01-3.0 mg/kg, i.p.) was administered 30 minutes before challenge. The high dose of BCTC (3.0 mg/kg, i.p) produced a maximum inhibition of capsaicin-induced cough of 65%. We also studied the effects of BCTC (0.03 and 3.0) when administered 60 minutes before capsaicin. Under these conditions, BCTC (3.0 mg/kg, i.p) produced a maximum decrease in capsaicin-induced cough of 31%. In ovalbumin passively sensitized guinea pigs, we found that BCTC (1 and 3 mg/kg, i.p.) attenuated antigen ovalbumin (0.3%) cough responses by 27% and 60%, respectively. We conclude that TRPV1 channel activation may play role in cough mediated by antigen in sensitized guinea pigs. Our results supports increasing evidence that TRPV1 may play a role in the generation of the cough response.

18.
Am J Physiol Lung Cell Mol Physiol ; 287(2): L272-8, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15075247

RESUMO

Hypotonic stimulation induces airway constriction in normal and asthmatic airways. However, the osmolarity sensor in the airway has not been characterized. TRPV4 (also known as VR-OAC, VRL-2, TRP12, OTRPC4), an osmotic-sensitive cation channel in the transient receptor potential (TRP) channel family, was recently cloned. In the present study, we show that TRPV4 mRNA was expressed in cultured human airway smooth muscle cells as analyzed by RT-PCR. Hypotonic stimulation induced Ca(2+) influx in human airway smooth muscle cells in an osmolarity-dependent manner, consistent with the reported biological activity of TRPV4 in transfected cells. In cultured muscle cells, 4alpha-phorbol 12,13-didecanoate (4-alphaPDD), a TRPV4 ligand, increased intracellular Ca(2+) level only when Ca(2+) was present in the extracellular solution. The 4-alphaPDD-induced Ca(2+) response was inhibited by ruthenium red (1 microM), a known TRPV4 inhibitor, but not by capsazepine (1 microM), a TRPV1 antagonist, indicating that 4-alphaPDD-induced Ca(2+) response is mediated by TRPV4. Verapamil (10 microM), an L-type voltage-gated Ca(2+) channel inhibitor, had no effect on the 4-alphaPDD-induced Ca(2+) response, excluding the involvement of L-type Ca(2+) channels. Furthermore, hypotonic stimulation elicited smooth muscle contraction through a mechanism dependent on membrane Ca(2+) channels in both isolated human and guinea pig airways. Hypotonicity-induced airway contraction was not inhibited by the L-type Ca(2+) channel inhibitor nifedipine (1 microM) or by the TRPV1 inhibitor capsazepine (1 microM). We conclude that functional TRPV4 is expressed in human airway smooth muscle cells and may act as an osmolarity sensor in the airway.


Assuntos
Brônquios/citologia , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Canais Iônicos/genética , Canais Iônicos/metabolismo , Miócitos de Músculo Liso/fisiologia , Animais , Cálcio/metabolismo , Células Cultivadas , Expressão Gênica , Cobaias , Humanos , Soluções Hipotônicas/farmacologia , Contração Muscular/efeitos dos fármacos , Miócitos de Músculo Liso/citologia , Canais de Cátion TRPV , Traqueia/citologia , Traqueia/fisiologia , Equilíbrio Hidroeletrolítico/fisiologia
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