RESUMO
A novel set of compounds containing a 4,5-dihydro-5-methylisoxazoline have been successfully designed as VLA-4 receptor antagonists. Compound (14p) had a high receptor binding affinity of 4 nM and also found to be metabolically stable in vitro.
Assuntos
Integrina alfa4beta1/antagonistas & inibidores , Isoxazóis/química , Isoxazóis/farmacologia , Amidas/síntese química , Amidas/química , Amidas/farmacologia , Estabilidade de Medicamentos , Humanos , Integrina alfa4beta1/química , Isoxazóis/síntese química , Ligação Proteica , Relação Estrutura-Atividade , Células U937RESUMO
OBJECTIVE AND METHODS: Leukotrienes (LTs) including cysteinyl leukotrienes (CysLTs) and LTB4 are the most potent inflammatory lipid mediators and play a central role in the pathophysiology of asthma and other inflammatory diseases. These biological molecules mediate a plethora of contractile and inflammatory responses through specific interaction with distinct G protein-coupled receptors (GPCRs). The main objective of this review is to present an overview of the biological effects of CysLTs and their receptors, along with the current knowledge of mechanisms and role of LTs in the pathogenesis of asthma. RESULTS: CysLTs including LTC4, LTD4 and LTE4 are ligands for CysLT1 and CysLT2 receptors, and LTB4 is the agonist for BLT1 and BLT2 receptors. The role of CysLT1 receptor is well established, and most of the pathophysiological effects of CysLTs in asthma are mediated by CysLT1 receptor. Several CysLT1 antagonists have been developed to date and are currently in clinical practice. Most common among them are classical CysLT1 receptor antagonists such as montelukast, zafirlukast, pranlukast, pobilukast, iralukast, cinalukast and MK571. The pharmacological role of CysLT2 receptor, however, is less defined and there is no specific antagonist available so far. The recent demonstration that mice lacking both known CysLT receptors exhibit full/augmented response to CysLT points to the existence of additional subtypes of CysLT receptors. LTB4, on the other hand, is another potent inflammatory leukotriene, which acts as a strong chemoattractant for neutrophils, but weaker for eosinophils. LTB4 is known to play an important role in the development of airway hyper-responsiveness in severe asthma. However there is no LTB4 antagonist available in clinic to date. CONCLUSION: This review gives a recent update on the LTs including their biosynthesis, biological effects and the role of anti-LTs in the treatment of asthma. It also discusses about the possible existence of additional subtypes of CysLT receptors.
Assuntos
Asma/imunologia , Antagonistas de Leucotrienos/uso terapêutico , Leucotrienos/imunologia , Receptores de Leucotrienos/imunologia , Animais , Asma/tratamento farmacológico , HumanosRESUMO
A novel set of compounds with a 1,3-dioxolane ring which acts as a proline bioisostere have been successfully designed as VLA-4 receptor antagonists. Compounds (18e), (28j), and (35g) were shown to have high receptor affinities.
Assuntos
Dioxolanos/química , Dioxolanos/farmacologia , Integrina alfa4beta1/antagonistas & inibidores , Integrina alfa4beta1/metabolismo , Linhagem Celular , Dioxolanos/síntese química , Humanos , Modelos Moleculares , Ligação Proteica/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
Phosphodiesterases (PDE) are enzymes that catalyze the hydrolysis of cAMP/cGMP to 5'-AMP/GMP. In vitro assays have routinely assayed cAMP/cGMP levels as a direct indicator of PDE activity. Earlier PDE assays depended on radiometric detection of radiolabeled cAMP. Of late, nonradiometric cAMP detection systems have been developed that are cheaper and more amenable to high-throughput screening. Two such assays, namely the enzyme fragment complementation technology and homogeneous time-resolved fluorescence assays, are currently used for monitoring cAMP as a correlate for G-protein-coupled-receptor-induced cellular signaling events. Here, we have compared and validated both of these assays for the measurement of PDE4 enzyme activity in cell-free systems.
Assuntos
AMP Cíclico/metabolismo , Ensaios Enzimáticos/métodos , Diester Fosfórico Hidrolases/metabolismo , Sistema Livre de Células , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Técnica de Imunoensaio Enzimático de Multiplicação , Fluorimunoensaio , Cinética , Limite de Detecção , Substâncias Luminescentes , Concentração Osmolar , Reprodutibilidade dos Testes , Transdução de Sinais , Fatores de TempoRESUMO
Urotensin II (U-II) has been found to be one of the most potent vasoconstrictor (Ames et al., 1999; Bohm et al., 2002) reported till date. U-II exerts its response via activation of a G-protein coupled receptor, Urotensin II receptor(UT). Binding of U-II to UT leads to an instant increase in the inositol phosphate turnover and intracellular Ca2+. Such an instant Ca2+ release and potent vasoconstriction exerted by U-II is expected to have an important role in the progression of cardiac diseases. We have previously shown that UT antagonist DS37001789 prevents U-II induced blood pressure elevation in mice (Nishi et al., 2019) in a dose dependent manner, with potent efficacy at 30 and 100 mg/kg. Further to this, we have also shown that DS37001789 ameliorates mortality in pressure-overload mice with heart failure (Nishi et al., 2020). We therefore conducted an extensive structure-activity relationship studies to identify molecules with superior efficacy. In the present manuscript, we report the identification of two potent, non-peptide small molecule antagonists of Urotensin II receptor (UT), RCI-0879 and RCI-0298 which blocked the action of U-II, both in vitro and in vivo. These molecules were found to be very potent in in vitro Ca2+ and radioligand binding assays using human and mouse UT over-expressing CHO cells. RCI-0879 and RCI-0298 also exhibited superior efficacy in in vivo mouse pressor response model using C57BL/6 mice, compared to our initial molecules (Nishi et al., 2019) and demonstrated ED50 values of 3.2 mg/kg and 6.8 mg/kg respectively. Our findings reported herewith, further strengthen our concept and belief in UT antagonization as a potential therapeutic approach for the management of chronic heart failure.
Assuntos
Anti-Hipertensivos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Urotensinas/antagonistas & inibidores , Animais , Células CHO , Cálcio/metabolismo , Cricetinae , Cricetulus , Relação Dose-Resposta a Droga , Insuficiência Cardíaca/tratamento farmacológico , Humanos , Hipertensão/induzido quimicamente , Hipertensão/mortalidade , Camundongos , Camundongos Endogâmicos C57BL , Bibliotecas de Moléculas Pequenas , Relação Estrutura-AtividadeRESUMO
In modern drug discovery, numerous assay formats are available to screen and quantitate receptor-ligand interactions. Radioactive assays are "gold standard" because they are fast, easy, and reproducible; however, they are hazardous, produce radioactive waste, require special lab conditions, and are expensive on a large scale. Thus, it provides a lot of importance to the "mix & measure" assays that have an optical readout. Fluorescence techniques are likely to be among the most important detection approaches used for high throughput screening due to their high sensitivity and amenability to automation. The aim of the present study was to determine the functional antagonistic affinities of standard muscarinic antagonists in CHO cells over expressing m1, m3, and m5 receptors and to compare them with the respective binding affinities. This study was further extended to elucidate that Ca+2 measurement assays can serve as a functional screening tool for GPCRs. For this purpose, standard muscarinic receptor antagonists, namely, tolterodine, oxybutynin, and atropine were used. We determined and compared the IC50 values of these three standard inhibitors in fura 2 AM loaded m1, m3, and m5 overexpressing CHO cells and in radioligand binding assay. Both the assays exhibited comparable rank order potencies of the standard inhibitors. This study suggests that Ca+2 mobilization assays can be an alternate to radioligand binding assays.
Assuntos
Cálcio/análise , Fluorometria/métodos , Antagonistas Muscarínicos/farmacologia , Receptor Muscarínico M1/antagonistas & inibidores , Receptor Muscarínico M3/antagonistas & inibidores , Receptor Muscarínico M5/antagonistas & inibidores , Animais , Atropina/farmacologia , Compostos Benzidrílicos/farmacologia , Células CHO , Cresóis/farmacologia , Cricetinae , Cricetulus , Fluorescência , Corantes Fluorescentes/farmacologia , Fluorometria/instrumentação , Fura-2/análogos & derivados , Fura-2/farmacologia , Humanos , Ácidos Mandélicos/farmacologia , Fenilpropanolamina/farmacologia , Ensaio Radioligante , Receptor Muscarínico M1/metabolismo , Receptor Muscarínico M3/metabolismo , Receptor Muscarínico M5/metabolismo , Derivados da Escopolamina/antagonistas & inibidores , Derivados da Escopolamina/metabolismo , Tartarato de Tolterodina , TransfecçãoRESUMO
BACKGROUND: Intracellular cyclic adenosine monophosphate (cAMP) in inflammatory cells and airway smooth muscle is critical to the modulation of inflammatory response generation. Phosphodiesterase 4 (PDE4), an enzyme that catalyzes cAMP degradation, is therefore being actively explored as a molecular target for the treatment of airway inflammation, particularly asthma and chronic obstructive pulmonary disease. The field has undergone major advances in optimizing generation of compounds with a safe therapeutic margin; however, most PDE4 inhibitors tested so far have unacceptable side effects, particularly nausea and vomiting. METHODS: We evaluated NIS-62949 in a wide range of in vitro and ex vivo cell-based assays to ascertain its anti-inflammatory potential. The compound was evaluated in murine models of lipopolysaccharide-induced endotoxemia and pulmonary neutrophilia. Parameters of airway inflammation, airway hyperreactivity and bronchoconstriction were evaluated in a guinea pig model of antigen-induced allergy. In order to assess the emetic potential, the compound was evaluated biochemically for binding to high-affinity rolipram-binding site. Subsequently, the compound was tested in a surrogate model for emesis, and the results obtained were correlated directly to tests conducted in a Beagle dog model. RESULTS: NIS-62949 is a potent, highly selective PDE4 inhibitor. The compound demonstrated potent ability to inhibit tumor necrosis factor-alpha release from human peripheral blood mononuclear cells, lymphocyte proliferation and cytokine production. The in vitro profile of NIS-62949 prompted further evaluation of the compound in vivo and the compound was found to be comparable to roflumilast in several experimental models of pulmonary inflammation. Importantly, NIS-62949 displayed a safer profile compared to roflumilast. CONCLUSIONS: Our results report the development of a promising, novel PDE4 inhibitor, NIS-62949, with a wider therapeutic window as compared to second-generation PDE4 inhibitors such as roflumilast.
Assuntos
Inflamação/tratamento farmacológico , Inibidores da Fosfodiesterase 4 , Inibidores de Fosfodiesterase/farmacologia , Animais , Ácidos Carboxílicos/farmacologia , Linhagem Celular Transformada , AMP Cíclico/metabolismo , Ácidos Cicloexanocarboxílicos , Modelos Animais de Doenças , Cães , Feminino , Cobaias , Humanos , Ativação Linfocitária/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Nitrilas/farmacologia , Ratos , Ratos Wistar , Rolipram/metabolismo , Rolipram/farmacologia , Fator de Necrose Tumoral alfa/sangue , Fator de Necrose Tumoral alfa/metabolismo , Vômito/tratamento farmacológicoRESUMO
Nuclear factor kappa B (NF-kappaB) plays a significant role in immunity and inflammation and represents a first choice as pharmacological target for anti-inflammatory therapy. However, research in this field has been hampered by the fact that no convenient assay suitable for large-scale screening procedures is available. The present study provides a cell death-based assay method for screening of nuclear factor-kappaB inhibitors. In this study, we observed that four distinct pharmacologic inhibitors of NF-kappaB, pyrrolidine dithiocarbamate (PDTC), N-tosyl-L-lysyl chloromethyl ketone (TPCK), genistein and BAY11-7082, resulted in the cell death of murine macrophages, J774A.1. DNA-binding experiments showed that lethal doses were consistent with those required for NF-kappaB inhibition. DNA fragmentation analysis showed that cell death is apoptotic in nature. Further studies suggested that NF-kappaB inhibitors induced apoptosis is independent of the involvement of other markers of cell death such as caspases and p38 MAP (Mitogen activated protein) kinase. From this study, we conclude that NF-kappaB activation may represent an important survival mechanism in macrophages. This study also provides a new cell-based screening method, as any compound that will inhibit NF-kappaB activity will result in the death of macrophages.
Assuntos
Anti-Inflamatórios/farmacologia , Apoptose/efeitos dos fármacos , Bioensaio , Avaliação Pré-Clínica de Medicamentos/métodos , Macrófagos/efeitos dos fármacos , NF-kappa B/antagonistas & inibidores , Animais , Caspases/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Fragmentação do DNA , Ensaio de Imunoadsorção Enzimática , Genisteína/farmacologia , Macrófagos/enzimologia , Macrófagos/metabolismo , Camundongos , Nitrilas/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pirrolidinas/farmacologia , Sulfonas/farmacologia , Tiocarbamatos/farmacologia , Tosilfenilalanil Clorometil Cetona/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
During the past few years, high-throughput screening (HTS) has provided a useful resource to researchers involved in the development of kinase inhibitors as a novel therapeutic modality. However, with all the choices among kinase assays, there is not yet a one-size-fits-all assay. Therefore, selection of a specific kinase assay is a daunting task. HTS assays should be homogeneous, cost effective, use nonradioactive reagents, generic and not time consuming. Here, we report an improved method of assaying protein kinase activity using a zinc cocktail in a fluorescence polarization-(FP) based format. Assay conditions were standardized manually and validated in a HTS format using a liquid handler. We validated this assay for both serine/threonine and tyrosine (receptor/nonreceptor) kinases. The results obtained in the HTS assay system were comparable to the commercially available fluorescence-based assay. We suggest that the reported assay is a cost-effective alternative to the IMAP-based generic kinase assay.
Assuntos
Cloretos/química , Cloretos/metabolismo , Avaliação Pré-Clínica de Medicamentos/métodos , Polarização de Fluorescência/métodos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases/metabolismo , Compostos de Zinco/química , Compostos de Zinco/metabolismo , Sequência de Aminoácidos , Animais , Bovinos , Concentração Inibidora 50 , Dados de Sequência Molecular , Proteínas Quinases/químicaRESUMO
Intracellular levels of cyclic nuclec tides are closely regulated by distinct families of PD Es, which are responsible for the breakdown and degradation of cyclic nucleotides within cells. Type 4 PDEs have the potency to modulate the release of inflammatory mediators through cAMP-dependent and -independent mechanisms. Selective targeting of PDE4 is currently being investigated as a novel therapeutic approach in the treatment of inflammation-associated respiratory diseases such as asthma and COPD. The development of several PDE4 inhibitors, including roflumilast and cilomilast, reflects the success of this approach. In principle, therapeutic intervention of an inflammatory response by PDE4 inhibitors may be extended to other chronic inflammatory disease states such as psoriasis, rheumatoid arthritis and inflammatory bowel diseases (e.g., Crohns disease and ulcerative colitis). This retiiew explores the feasibility of PDE4 inhibitors as a promising alternative for therapeutic intervention in systemic inflammation and inflammation-based disease.
Assuntos
3',5'-AMP Cíclico Fosfodiesterases/antagonistas & inibidores , Anti-Inflamatórios/uso terapêutico , Drogas em Investigação/uso terapêutico , Inflamação/tratamento farmacológico , Inibidores de Fosfodiesterase/uso terapêutico , 3',5'-AMP Cíclico Fosfodiesterases/metabolismo , Administração Oral , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/efeitos adversos , Artrite/tratamento farmacológico , Asma/tratamento farmacológico , AMP Cíclico/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4 , Dermatite Atópica/tratamento farmacológico , Drogas em Investigação/administração & dosagem , Drogas em Investigação/efeitos adversos , Humanos , Inflamação/enzimologia , Doenças Inflamatórias Intestinais/tratamento farmacológico , Inibidores de Fosfodiesterase/administração & dosagem , Inibidores de Fosfodiesterase/efeitos adversos , Psoríase/tratamento farmacológico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacosRESUMO
The p38/MK2 pathway regulates a wide range of biological functions, and thus has most been explored as a therapeutic target for inhibition of severe and chronic inflammatory diseases. Till date, several p38 inhibitors with potent anti-inflammatory effects in pre-clinical models have been discovered, but most of them have failed in clinics due to serious systemic toxicity issues. MK2 is a serine-threonine kinase downstream to p38 and is activated directly through phosphorylation of p38 under stress and inflammatory stimulus. MK2 has been shown to be a direct and essential component in regulating the biosynthesis of pro-inflammatory cytokines. Disruption of MK2 signaling leads to a significant reduction in the level of several pro-inflammatory cytokine production. For these reasons, MK2 has been identified as an alternate molecular target in order to block the pathway with an assumption that this approach would show similar efficacy as that of p38 inhibitors with lesser toxicity concerns. This review briefly summarizes the molecular structure of MK2 and major biological functions in context with its pharmacological modulation to address various inflammatory diseases. It also discusses the points of advantages over p38 inhibition along with recent update in the development of small molecule MK2 inhibitors.
Assuntos
Regulação Enzimológica da Expressão Gênica/fisiologia , Inflamação/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas Serina-Treonina Quinases/genéticaRESUMO
Aurora kinases (AKs) represent a family of serine/threonine protein kinases that regulate mitotic processes during cell division. They are primarily involved in regulating the multiple steps of mitosis, including centrosome duplication, formation of bipolar mitotic spindle, chromosome alignment on the mitotic spindle, establishment and maintenance of the spindle checkpoint and cytokinesis. As AKs are key regulators of mitosis, several studies have indicated that they have a strong association with cancer and are overexpressed in numerous cancerous cell lines as well as human malignancies. Thus, AKs represent a promising therapeutic target for anticancer drug development. In this review, the role of AKs in cancer, and the current status and therapeutic potential of AK inhibitors is discussed.
Assuntos
Antineoplásicos/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Neoplasias/tratamento farmacológico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Animais , Aurora Quinases , Humanos , Neoplasias/enzimologia , Neoplasias/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/fisiologiaRESUMO
INTRODUCTION: Idiopathic pulmonary fibrosis (IPF) is a devastating and relentlessly progressive lung disorder. Previously, it was thought to be a chronic inflammatory disease; however, it is now considered to be an epithelial-fibroblastic disease. In accordance with this paradigm change, efforts toward the development of novel therapeutic targets for IPF have acquired a new direction. Currently available therapies are largely ineffective in reversing the lung damage, and lung transplantation is the only effective treatment for end-stage disease. Limitations in advancement of IPF therapeutics are due to a poor understanding of its pathogenesis, unavailability of reliable animal models and slow disease progression. Recent research on IPF has resulted in the identification of a plethora of novel targets that are in various stages of development and offers hope that in the near future that there will be better therapeutic options available for the treatment of IPF. AREAS COVERED: This review discusses existing therapies and highlights some of the recent, novel therapeutics being explored in the current clinical landscape for the treatment of this chronic, disabling disorder. The review also discusses the pathogenic rationale behind current therapies. EXPERT OPINION: Targeting one fibrotic signaling pathway at a time may not have any significant effect on the control of IPF. It is therefore recommended that future IPF management focuses on targeting multiple pro-fibrotic pathways associated with its complex pathogenesis.
Assuntos
Fibrose Pulmonar Idiopática/tratamento farmacológico , Animais , Humanos , Fibrose Pulmonar Idiopática/metabolismo , Fibrose Pulmonar Idiopática/patologia , Transdução de SinaisRESUMO
INTRODUCTION: Pulmonary fibrosis (PF) is a progressive fatal disorder and is characterized by alveolar epithelial injury, myofibroblast proliferation, and extracellular matrix remodeling, resulting in irreversible distortion of lung's architecture. Available therapies are associated with side effects and show restricted efficacy. Therefore, there is an urgent need to find a therapeutic solution to PF. Therapeutic strategies interfering myofibroblast expansion, apoptosis of epithelial and endothelial cells might be beneficial for treatment of PF. Hepatocyte growth factor (HGF), a pleiotropic growth factor, plays an important role in lung development, inflammation, repair, and regeneration. In animal model of PF, administration of recombinant HGF protein or ectopic HGF expression ameliorates fibrosis. AREAS COVERED: The focus of this review is to highlight HGF as a promising therapeutic approach for the treatment of PF. The review discusses the currently available treatment option for PF as well as highlights the possible beneficial effect of HGF as a drug target. EXPERT OPINION: HGF with its anti-fibrotic effect provides a promising new therapeutic approach by protecting lung from fibrotic remodeling and also promoting normal regeneration of lung. The development of HGF mimetics may provide a potential attractive therapy for treatment of this devastating and complex disease.
Assuntos
Fator de Crescimento de Hepatócito/metabolismo , Fibrose Pulmonar/metabolismo , Animais , Humanos , Fibrose Pulmonar/tratamento farmacológicoRESUMO
Pharmacological intervention of epidermal growth factor receptor (EGFR) family members by antibodies or small molecule inhibitors has been one of the most successful approaches for anticancer therapy. However this therapy has its own limitations due to the development of resistance, over a period of time. One of the possible causes of the development of resistance to the therapy with EGFR inhibitors could be the simultaneous activation of parallel pathways. Both EGFR and insulin like growth factor-1 receptor (IGF-1R) pathways are reported to act reciprocal to each other and converge into the mitogen activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K) pathways. Inhibiting one pathway alone may therefore not be sufficient and could be a cause of development of resistance. The other cause could be mutations of EGFR which would be less sensitive to the inhibitors. We, therefore, suggest that co-targeting IGF-1R and EGFR kinases by dual inhibitors can lead to improved efficacy and address the problems of resistance. In the present manuscript, we report the identification of a novel, small molecule dual EGFR/IGF-1R inhibitor, RBx10080307 which displayed in vitro activity at the molecular level and oral efficacy in mouse xenograft model. The compound also showed in vitro activity in an EGFR mutant cell line and may thus have the potential to show activity in resistant conditions. Additional efficacy studies are needed in EGFR resistant mouse cancer model and if found efficacious, this can be a major advantage over standalone erlotinib and other existing therapies.
Assuntos
Antineoplásicos/farmacologia , Receptores ErbB/antagonistas & inibidores , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , Receptor IGF Tipo 1/antagonistas & inibidores , Animais , Antineoplásicos/metabolismo , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Estabilidade de Medicamentos , Receptores ErbB/genética , Receptores ErbB/metabolismo , Cloridrato de Erlotinib , Feminino , Células HT29 , Humanos , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Microssomos Hepáticos/metabolismo , Mutação , Fosforilação/efeitos dos fármacos , Piperazina , Piperazinas/metabolismo , Inibidores de Proteínas Quinases/metabolismo , Pirazóis/metabolismo , Pirimidinas/metabolismo , Quinazolinas/farmacologia , Receptor IGF Tipo 1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
INTRODUCTION: The cyclooxygenase (COX) enzyme, which is responsible for the production of prostaglandins (PGs), key mediators of inflammation, may have the potential to become an attractive target for anti-inflammatory therapy. COX catalyzes the conversion of arachidonic acid (AA) into PGs, which play a significant role in disease. PGs are lipid mediators of central importance in the regulation of inflammation and smooth muscle tone. Airway-resident inflammatory cells release PGs: PGD2 and PDF2a amplify smooth muscle contraction and airway inflammation. Following its conversion from membrane phospholipids by phospholipase, AA enters the prostanoid pathway via COX, which catalyzes the conversion of AA to PGH2. PGH2 is then converted to biologically active PGs by cell-specific PG synthases. As COX is the rate limiting step in the PG pathway, the regulation of this enzyme is of critical importance in PG production. AREAS COVERED: This review addresses the opportunities and challenges of COX inhibitors as therapeutic targets in airway inflammation. The review covers literature from the past 20 years. EXPERT OPINION: Current literature favors COX inhibitors as potential targets for airway diseases. However, from the information available, it is not clear whether the COX enzyme by itself can serve as a target in drug development for asthma and COPD. Therefore, additional research is required to elucidate the mechanisms of action of COX metabolites before it can be considered as a target.
Assuntos
Inibidores de Ciclo-Oxigenase/uso terapêutico , Pneumonia/tratamento farmacológico , Animais , Ciclo-Oxigenase 1/metabolismo , Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase/farmacologia , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Pneumonia/enzimologiaRESUMO
A series of 3,5-disubstituted-1,2,4-oxadiazoles has been prepared and evaluated for phosphodiesterase inhibition (PDE4B2). Among the prepared 3,5-disubstituted-1,2,4-oxadiazoles, compound 9a is the most potent inhibitor (PDE4B2 IC(50) = 5.28 µm). Structure-activity relationship studies of 3,5-disubstituted-1,2,4-oxadiazoles revealed that substituents 3-cyclopentyloxy-4-methoxyphenyl group at 3-position and cyclic ring bearing heteroatoms at 5-position are important for activity. Molecular modeling study of the 3,5-disubstituted-1,2,4-oxadiazoles with PDE4B has shown similar interactions of 3-cyclopentyloxy-4-methoxyphenyl group; however, heteroatom ring is slightly deviating when compared to Piclamilast. 3-(3-Cyclopentyloxy-4-methoxyphenyl)-5-(piperidin-4-yl)-1,2,4-oxadiazole (9a) exhibited good analgesic and antiinflammatory activities in formalin-induced pain in mice and carrageenan-induced paw edema model in rat.
Assuntos
Analgésicos/química , Anti-Inflamatórios/química , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Edema/tratamento farmacológico , Oxidiazóis/química , Dor/tratamento farmacológico , Inibidores da Fosfodiesterase 4/química , Analgésicos/síntese química , Analgésicos/farmacologia , Analgésicos/uso terapêutico , Animais , Anti-Inflamatórios/síntese química , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/química , Desenho de Fármacos , Edema/induzido quimicamente , Feminino , Humanos , Masculino , Camundongos , Modelos Moleculares , Oxidiazóis/síntese química , Oxidiazóis/farmacologia , Oxidiazóis/uso terapêutico , Dor/induzido quimicamente , Inibidores da Fosfodiesterase 4/síntese química , Inibidores da Fosfodiesterase 4/farmacologia , Inibidores da Fosfodiesterase 4/uso terapêutico , Ratos , Ratos WistarRESUMO
Small molecule inhibitors of epidermal growth factor receptors (EGFR) have been found to show a good initial response in cancer patients but during the course of treatment, patients develop resistance after a few weeks of time. Development of secondary mutations or over-activation of insulin like growth factor (IGF-1R) pathway are a few of the several mechanisms proposed to explain the resistance. To study the effect of dual inhibition of EGFR and IGF-1R in overcoming the resistance, three strategies were envisaged and are reported in this manuscript: 1) a virtual predictive tumor model, 2) in vitro experimental data using a combination of EGFR and IGF-1R inhibitors and 3) in vitro experimental data using in house dual inhibitors. Findings reported in this manuscript suggest that simultaneous inhibition of IGF-1R and EGFR either by combination of two inhibitors or by dual kinase inhibitors is more efficacious compared to single agents. In vitro cell based experiments conducted using epidermoid cancer cell line, A431 and an EGFR mutant cell line, H1975 along with virtual predictions reported here suggests that dual inhibition of EGFR and IGF-1R is a viable approach to overcome EGFR resistance.
Assuntos
Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Receptores ErbB/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Receptor IGF Tipo 1/antagonistas & inibidores , Sequência de Aminoácidos , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Biologia Computacional , Ciclina D1/metabolismo , Sinergismo Farmacológico , Receptores ErbB/genética , Receptores ErbB/metabolismo , Cloridrato de Erlotinib , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Mutação , Fosforilação/efeitos dos fármacos , Pirimidinas/química , Pirimidinas/farmacologia , Quinazolinas/farmacologia , Receptor IGF Tipo 1/química , Receptor IGF Tipo 1/metabolismoRESUMO
RBx 343E48F0 is a novel, potent, selective and long acting muscarinic receptor antagonist with a potential for use in the treatment of Chronic Obstructive Pulmonary Disease (COPD). The aim of the present study was to describe the in vitro and in vivo profile of RBx 343E48F0 and to compare the results with the present day benchmark therapy, tiotropium. Radioligand binding and isolated tissue based functional assays were used to evaluate the affinity, potency and receptor subtype selectivity of RBx 343E48F0. Inhibition of carbachol-induced bronchoconstriction in the anaesthetized rat and acetylcholine-induced bronchoconstriction in the conscious rat were used to assess the extent and duration of the bronchospasmolytic activity of RBx 343E48F0. In vitro and in vivo pharmacokinetic studies were conducted to evaluate the pharmacokinetic and lung retention properties of the compound. In vitro radioligand binding studies using human recombinant muscarinic receptors showed that RBx 343E48F0 had a pKi of 9.6 at the M(3) receptor and a 60-fold selectivity for the M(3) receptor over the M(2) receptor. In isolated tissue bioassays, it exhibited surmountable antagonism at the guinea pig trachea with a pK(B) of 9.5. Intratracheal administration to anaesthetized rats demonstrated a dose-dependent inhibition of carbachol-induced bronchoconstriction with an ED(50) value of 110 ng/kg. RBx 343E48F0 also exhibited a fast onset of action and long duration of action of greater 24h.
Assuntos
Imidazóis/farmacologia , Imidazóis/farmacocinética , Antagonistas Muscarínicos/farmacologia , Antagonistas Muscarínicos/farmacocinética , Receptores Muscarínicos/metabolismo , Acetilcolina/farmacologia , Animais , Broncoconstrição/efeitos dos fármacos , Feminino , Cobaias , Humanos , Imidazóis/administração & dosagem , Imidazóis/metabolismo , Cloreto de Metacolina/farmacologia , Antagonistas Muscarínicos/administração & dosagem , Antagonistas Muscarínicos/metabolismo , Ratos , Respiração Artificial , Especificidade por SubstratoRESUMO
IMPORTANCE OF THE FIELD: The Polo-like kinase (Plk) family has emerged as an important regulator in cell cycle progression. Plks belong to a family of serine/threonine kinases and exist in four isoforms Plk1- 4. However, only one of these isoforms, Plk1, is shown to be involved in the activation of Cdc2, chromosome segregation, centrosome maturation, bipolar spindle formation and execution of cytokinesis. The activity of Plk1 is elevated in tissues and cells with a high mitotic index. In patients, Plk1 is overexpressed in tumors including those derived from lung, breast, colon, pancreas, prostate and ovary. Plk1 depletion is associated with the decrease in cell viability and induction of apoptosis in various cancerous cells. Several Plk1 inhibitors are in different phases of clinical development for anticancer therapy. AREAS COVERED IN THIS REVIEW: The focus of present review is to highlight Plk1 as a promising therapeutic approach for the treatment of cancer. The review discusses the role of Plk1 in cancer and the current status of Plk1 inhibitors, as well as highlighting the possible beneficial effect of inhibition of Plk1 as compared to other mitotic targets. WHAT THE READER WILL GAIN: Readers will get a comprehensive overview of Plk1 as a novel anticancer drug target. This review will also update readers about the progress made in the field of Plk1 inhibitors. TAKE HOME MESSAGE: The current literature about Plk1 inhibitors and knockout studies favor Plk1 inhibition as a potential antitumor therapy.