Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
1.
Angew Chem Int Ed Engl ; 61(2): e202111687, 2022 01 10.
Artículo en Inglés | MEDLINE | ID: mdl-34717043

RESUMEN

Virus-like particles (VLPs) derived from Leviviridae virions contain substantial amounts of cellular and plasmid-derived RNA. This encapsidated polynucleotide serves as a reservoir for the efficient binding of the intercalating dye thiazole orange (TO). Polyethylene glycol (PEG) molecules and oligopeptides of varying length, end-functionalized with TO, were loaded into VLPs up to approximately 50 % of the mass of the capsid protein (hundreds to thousands of cargo molecules per particle, depending on size). The kinetics of TO-PEG binding included a significant entropic cost for the reptation of long chains through the capsid pores. Cargo molecules were released over periods of 20-120 hours following simple reversible first-order kinetics in most cases. These observations define a simple general method for the noncovalent packaging, and subsequent release, of functional molecules inside nucleoprotein nanocages in a manner independent of modifications to the capsid protein.


Asunto(s)
Cápside
2.
J Pharmacol Exp Ther ; 364(2): 246-257, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29263243

RESUMEN

Protease-activated receptor 2 (PAR2) is a cell surface protein linked to G-protein dependent and independent intracellular signaling pathways that produce a wide range of physiological responses, including those related to metabolism, inflammation, pain, and cancer. Certain proteases, peptides, and nonpeptides are known to potently activate PAR2. However, no effective potent PAR2 antagonists have been reported yet despite their anticipated therapeutic potential. This study investigates antagonism of key PAR2-dependent signaling properties and functions by the imidazopyridazine compound I-191 (4-(8-(tert-butyl)-6-(4-fluorophenyl)imidazo[1,2-b]pyridazine-2-carbonyl)-3,3-dimethylpiperazin-2-one) in cancer cells. At nanomolar concentrations, I-191 inhibited PAR2 binding of and activation by structurally distinct PAR2 agonists (trypsin, peptide, nonpeptide) in a concentration-dependent manner in cells of the human colon adenocarcinoma grade II cell line (HT29). I-191 potently attenuated multiple PAR2-mediated intracellular signaling pathways leading to Ca2+ release, extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation, Ras homologue gene family, member A (RhoA) activation, and inhibition of forskolin-induced cAMP accumulation. The mechanism of action of I-191 was investigated using binding and calcium mobilization studies in HT29 cells where I-191 was shown to be noncompetitive and a negative allosteric modulator of the agonist 2f-LIGRL-NH2 The compound alone did not activate these PAR2-mediated pathways, even at high micromolar concentrations, indicating no bias in these signaling properties. I-191 also potently inhibited PAR2-mediated downstream functional responses, including expression and secretion of inflammatory cytokines and cell apoptosis and migration, in human colon adenocarcinoma grade II cell line (HT29) and human breast adenocarcinoma cells (MDA-MB-231). These findings indicate that I-191 is a potent PAR2 antagonist that inhibits multiple PAR2-induced signaling pathways and functional responses. I-191 may be a valuable tool for characterizing PAR2 functions in cancer and in other cellular, physiological, and disease settings.


Asunto(s)
Piperazinas/farmacología , Piridazinas/farmacología , Receptor PAR-2/antagonistas & inhibidores , Transducción de Señal/efectos de los fármacos , Calcio/metabolismo , Caspasas/metabolismo , Movimiento Celular/efectos de los fármacos , Citocinas/biosíntesis , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Células HT29 , Humanos , Piperazinas/química , Proteolisis/efectos de los fármacos , Piridazinas/química , Receptor PAR-2/metabolismo
3.
Bioorg Med Chem Lett ; 26(3): 986-991, 2016 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-26725028

RESUMEN

Activation of protease activated receptor 2 (PAR2) has been implicated in inflammatory and metabolic disorders and its inhibition may yield novel therapeutics. Here, we report a series of PAR2 antagonists based on C-terminal capping of 5-isoxazolyl-L-cyclohexylalanine-L-isoleucine, with benzylamine analogues being effective new PAR2 antagonists. 5-Isoxazolyl-L-cyclohexylalanine-L-isoleucine-2-methoxybenzylamine (10) inhibited PAR2-, but not PAR1-, induced release of Ca(2+) (IC50 0.5 µM) in human colon cells, IL-6 and TNFα secretion (IC50 1-5 µM) from human kidney cells, and was anti-inflammatory in acute rat paw inflammation (ED50 5 mg/kg sc). These findings show that new benzylamide antagonists of PAR2 have anti-inflammatory activity.


Asunto(s)
Antiinflamatorios/química , Receptor PAR-2/antagonistas & inhibidores , Animales , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Calcio/metabolismo , Línea Celular , Edema/inducido químicamente , Edema/tratamiento farmacológico , Edema/patología , Células HT29 , Humanos , Interleucina-6/metabolismo , Isoleucina/química , Túbulos Renales/citología , Túbulos Renales/efectos de los fármacos , Túbulos Renales/metabolismo , Fenilalanina/análogos & derivados , Fenilalanina/química , Ratas , Receptor PAR-2/agonistas , Receptor PAR-2/metabolismo , Relación Estructura-Actividad , Factor de Necrosis Tumoral alfa/metabolismo
4.
Bioorg Med Chem Lett ; 25(23): 5604-8, 2015 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-26522948

RESUMEN

Potent ligands for the human complement C3a receptor (C3aR) were developed from the almost inactive tripeptide Leu-Ala-Arg corresponding to the three C-terminal residues of the endogenous peptide agonist C3a. The analogous Leu-Ser-Arg was modified by condensing the serine side chain with the leucine carbonyl with elimination of water to form leucine-oxazole-arginine. Subsequent elaboration with a variety of N-terminal amide capping groups produced agonists as potent as human C3a itself in stimulating Ca(2+) release from human macrophages. Structure-activity relationships are discussed.


Asunto(s)
Aminoácidos/síntesis química , Oxazoles/síntesis química , Receptores de Complemento/agonistas , Aminoácidos/química , Aminoácidos/farmacología , Arginina/análogos & derivados , Arginina/química , Arginina/farmacología , Compuestos de Bencidrilo/química , Compuestos de Bencidrilo/farmacología , Dipéptidos/química , Dipéptidos/farmacología , Relación Dosis-Respuesta a Droga , Humanos , Ligandos , Macrófagos/efectos de los fármacos , Estructura Molecular , Oxazoles/química , Oxazoles/farmacología , Relación Estructura-Actividad
5.
J Chem Inf Model ; 55(10): 2079-84, 2015 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-26445028

RESUMEN

Virtual screening of a drug database identified Carvedilol, Loratadine, Nefazodone and Astemizole as PAR2 antagonists, after ligand docking and molecular dynamics simulations using a PAR2 homology model and a putative binding mode of a known PAR2 ligand. The drugs demonstrated competitive binding and antagonism of calcium mobilization and ERK1/2 phosphorylation in CHO-hPAR2 transfected cells, while inhibiting IL-6 secretion in PAR2 expressing MDA-MB-231 breast cancer cells. This research highlights opportunities for GPCR hit-finding from FDA-approved drugs.


Asunto(s)
Descubrimiento de Drogas , Reposicionamiento de Medicamentos , Receptor PAR-2/antagonistas & inhibidores , Unión Competitiva , Humanos , Modelos Biológicos , Simulación del Acoplamiento Molecular , Estructura Molecular
6.
J Chem Inf Model ; 55(6): 1181-91, 2015 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-26000704

RESUMEN

Protease activated receptor 2 (PAR2) is an unusual G-protein coupled receptor (GPCR) involved in inflammation and metabolism. It is activated through cleavage of its N-terminus by proteases. The new N-terminus functions as a tethered ligand that folds back and intramolecularly activates PAR2, initiating multiple downstream signaling pathways. The only compounds reported to date to inhibit PAR2 activation are of moderate potency. Three structural models for PAR2 have been constructed based on sequence homology with known crystal structures for bovine rhodopsin, human ORL-1 (also called nociceptin/orphanin FQ receptor), and human PAR1. The three PAR2 model structures were compared and used to predict potential interactions with ligands. Virtual screening for ligands using the Chembridge database, and either ORL-1 or PAR1 derived PAR2 models led to identification of eight new small molecule PAR2 antagonists (IC50 10-100 µM). Notably, the most potent compound 1 (IC50 11 µM) was derived from the less homologous template protein, human ORL-1. The results suggest that virtual screening against multiple homology models of the same GPCR can produce structurally diverse antagonists and that this may be desirable even when some models have less sequence homology with the target protein.


Asunto(s)
Descubrimiento de Drogas/métodos , Simulación del Acoplamiento Molecular , Receptor PAR-2/antagonistas & inhibidores , Receptor PAR-2/química , Homología de Secuencia de Aminoácido , Animales , Sitios de Unión , Bovinos , Membrana Celular/metabolismo , Bases de Datos de Proteínas , Evaluación Preclínica de Medicamentos , Células HT29 , Humanos , Ligandos , Estructura Terciaria de Proteína , Receptor PAR-2/metabolismo
7.
J Am Chem Soc ; 136(34): 11914-7, 2014 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-25102224

RESUMEN

Heterocycles adjacent to amides can have important influences on molecular conformation due to stereoelectronic effects exerted by the heteroatom. This was shown for imidazole- and thiazole-amides by comparing low energy conformations (ab initio MP2 and DFT calculations), charge distribution, dipole moments, and known crystal structures which support a general principle. Switching a heteroatom from nitrogen to sulfur altered the amide conformation, producing different three-dimensional electrostatic surfaces. Differences were attributed to different dipole and orbital alignments and spectacularly translated into opposing agonist vs antagonist functions in modulating a G-protein coupled receptor for inflammatory protein complement C3a on human macrophages. Influences of the heteroatom were confirmed by locking the amide conformation using fused bicyclic rings. These findings show that stereoelectronic effects of heterocycles modulate molecular conformation and can impart strikingly different biological properties.


Asunto(s)
Amidas/química , Compuestos Heterocíclicos/química , Amidas/farmacología , Calcio/metabolismo , Células Cultivadas , Electroquímica , Compuestos Heterocíclicos/farmacología , Humanos , Imidazoles/química , Imidazoles/farmacología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Modelos Moleculares , Conformación Molecular , Estereoisomerismo , Tiazoles/química , Tiazoles/farmacología
8.
FASEB J ; 27(12): 4757-67, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23964081

RESUMEN

Excessive uptake of fatty acids and glucose by adipose tissue triggers adipocyte dysfunction and infiltration of immune cells. Altered metabolic homeostasis in adipose tissue promotes insulin resistance, type 2 diabetes, hypertension, and cardiovascular disease. Inflammatory and metabolic processes are mediated by certain proteolytic enzymes that share a common cellular target, protease-activated receptor 2 (PAR2). This study showed that human and rat obesity correlated in vivo with increased expression of PAR2 in adipose tissue, primarily in stromal vascular cells (SVCs) including macrophages. PAR2 was expressed more than other PARs on human macrophages and was increased by dietary fatty acids (palmitic, stearic, and myristic). A novel PAR2 antagonist, GB88 (5-isoxazoyl-Cha-Ile-spiroindene-1,4-piperidine), given orally at 10 mg/kg/d (wk 8-16) reduced body weight by ∼10% in obese rats fed a high-carbohydrate high-fat (HCHF) diet for 16 wk, and strongly attenuated adiposity, adipose tissue inflammation, infiltrated macrophages and mast cells, insulin resistance, and cardiac fibrosis and remodeling; while reversing liver and pancreatic dysfunction and normalizing secretion of PAR2-directed glucose-stimulated insulin secretion in MIN6 ß cells. In summary, PAR2 is a new biomarker for obesity, and its expression is stimulated by dietary fatty acids; PAR2 is a substantial contributor to inflammatory and metabolic dysfunction; and a PAR2 antagonist inhibits diet-induced obesity and inflammatory, metabolic, and cardiovascular dysfunction.


Asunto(s)
Tejido Adiposo/metabolismo , Obesidad/metabolismo , Receptor PAR-2/metabolismo , Transcripción Genética , Tejido Adiposo/patología , Animales , Línea Celular , Dieta Alta en Grasa/efectos adversos , Ácidos Grasos/farmacología , Humanos , Inflamación/tratamiento farmacológico , Inflamación/etiología , Inflamación/metabolismo , Macrófagos/metabolismo , Masculino , Mastocitos/metabolismo , Obesidad/tratamiento farmacológico , Obesidad/etiología , Oligopéptidos/farmacología , Oligopéptidos/uso terapéutico , Ratas , Ratas Wistar , Receptor PAR-2/antagonistas & inhibidores , Receptor PAR-2/genética , Células del Estroma/metabolismo
9.
Org Lett ; 23(9): 3751-3754, 2021 05 07.
Artículo en Inglés | MEDLINE | ID: mdl-33851842

RESUMEN

Oxanorbornadienes (ONDs) undergo facile Michael addition with thiols and then fragment by a retro-Diels-Alder (rDA) reaction, a unique two-step sequence among electrophilic cleavable linkages. The rDA reaction rate was explored as a function of the furan structure, with substituents at the 2- and 5-positions found to be the most influential and the fragmentation rate to be inversely correlated with electron-withdrawing ability. Density functional theory calculations provided an excellent correlation with the experimentally measured OND rDA rates.


Asunto(s)
Furanos/química , Compuestos de Sulfhidrilo/química , Reacción de Cicloadición , Electrones , Estructura Molecular
10.
Curr Biol ; 31(6): 1326-1336.e5, 2021 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-33581074

RESUMEN

Epithelia must eliminate apoptotic cells to preserve tissue barriers and prevent inflammation.1 Several different mechanisms exist for apoptotic clearance, including efferocytosis2,3 and apical extrusion.4,5 We found that extrusion was the first-line response to apoptosis in cultured monolayers and in zebrafish epidermis. During extrusion, the apoptotic cell elicited active lamellipodial protrusions and assembly of a contractile extrusion ring in its neighbors. Depleting E-cadherin compromised both the contractile ring and extrusion, implying that a cadherin-dependent pathway allows apoptotic cells to engage their neighbors for extrusion. We identify RhoA as the cadherin-dependent signal in the neighbor cells and show that it is activated in response to contractile tension from the apoptotic cell. This mechanical stimulus is conveyed by a myosin-VI-dependent mechanotransduction pathway that is necessary both for extrusion and to preserve the epithelial barrier when apoptosis was stimulated. Earlier studies suggested that release of sphingosine-1-phosphate (S1P) from apoptotic cells might define where RhoA was activated. However, we found that, although S1P is necessary for extrusion, its contribution does not require a localized source of S1P in the epithelium. We therefore propose a unified view of how RhoA is stimulated to engage neighbor cells for apoptotic extrusion. Here, tension-sensitive mechanotransduction is the proximate mechanism that activates RhoA specifically in the immediate neighbors of apoptotic cells, but this also must be primed by S1P in the tissue environment. Together, these elements provide a coincidence detection system that confers robustness on the extrusion response.


Asunto(s)
Apoptosis , Células Epiteliales/citología , Mecanotransducción Celular , Pez Cebra , Proteína de Unión al GTP rhoA/fisiología , Animales , Cadherinas/genética , Lisofosfolípidos , Esfingosina/análogos & derivados
11.
Nat Nanotechnol ; 15(8): 724, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32632322

RESUMEN

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

12.
Nat Nanotechnol ; 15(6): 491-499, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32523099

RESUMEN

Therapeutic delivery selectively to lymph nodes has the potential to address a variety of unmet clinical needs. However, owing to the unique structure of the lymphatics and the size-restrictive nature of the lymph node reticular network, delivering cargo to specific cells in the lymph node cortex and paracortex is difficult. Here, we describe a delivery system to overcome lymphatic and intra-lymph node transport barriers by combining nanoparticles that are rapidly conveyed to draining lymph nodes after administration in peripheral tissues with programmable degradable linkers. This platform enables the controlled release of intra-lymph-mobile small-molecular cargo, which can reach vastly more immune cells throughout the lymph node than either the particles or free compounds alone. The release rate can be programmed, allowing access to different lymph node structures and therefore specific lymphocyte subpopulations. We are thus able to alter the subtypes of drugged lymph node cells to improve immunotherapeutic effects.


Asunto(s)
Adyuvantes Inmunológicos/administración & dosificación , Preparaciones de Acción Retardada/metabolismo , Ganglios Linfáticos/metabolismo , Nanopartículas/metabolismo , Oligodesoxirribonucleótidos/administración & dosificación , Adyuvantes Inmunológicos/uso terapéutico , Animales , Línea Celular , Preparaciones de Acción Retardada/química , Sistemas de Liberación de Medicamentos , Femenino , Humanos , Inmunoterapia , Linfoma/terapia , Ratones Endogámicos C57BL , Nanopartículas/química , Nanopartículas/ultraestructura , Oligodesoxirribonucleótidos/uso terapéutico
13.
J Med Chem ; 63(2): 529-541, 2020 01 23.
Artículo en Inglés | MEDLINE | ID: mdl-31910011

RESUMEN

Structure-activity relationships for a series of small-molecule thiophenes resulted in potent and selective antagonism of human Complement C3a receptor. The compounds are about 100-fold more potent than the most reported antagonist SB290157. A new compound JR14a was among the most potent of the new antagonists in vitro, assessed by (a) inhibition of intracellular calcium release (IC50 10 nM) induced in human monocyte-derived macrophages by 100 nM C3a, (b) inhibition of ß-hexosaminidase secretion (IC50 8 nM) from human LAD2 mast cells degranulated by 100 nM C3a, and (c) selectivity for human C3aR over C5aR. JR14a was metabolically stable in rat plasma and in rat liver microsomes and efficacious in rats when given orally to suppress rat paw inflammation, macrophage and mast cell activation, and histopathology induced by intraplantar paw administration of a C3aR agonist. Potent C3aR antagonists are now available for interrogating C3a receptor activation and suppressing C3aR-mediated inflammation in mammalian physiology and disease.


Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Arginina/análogos & derivados , Compuestos de Bencidrilo/farmacología , Complemento C3a , Receptores de Complemento/antagonistas & inhibidores , Tiofenos/farmacología , Animales , Antiinflamatorios no Esteroideos/farmacocinética , Arginina/farmacocinética , Arginina/farmacología , Compuestos de Bencidrilo/farmacocinética , Calcio/metabolismo , Hexosaminidasas/metabolismo , Humanos , Macrófagos/efectos de los fármacos , Mastocitos , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/metabolismo , Ratas , Ratas Wistar , Bibliotecas de Moléculas Pequeñas , Relación Estructura-Actividad , Tiofenos/síntesis química , Tiofenos/farmacocinética
14.
ACS Chem Biol ; 12(5): 1217-1226, 2017 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-28169521

RESUMEN

Protease activated receptor 2 (PAR2) is associated with metabolism, obesity, inflammatory, respiratory and gastrointestinal disorders, pain, cancer, and other diseases. The extracellular N-terminus of PAR2 is a common target for multiple proteases, which cleave it at different sites to generate different N-termini that activate different PAR2-mediated intracellular signaling pathways. There are no synthetic PAR2 ligands that reproduce the same signaling profiles and potencies as proteases. Structure-activity relationships here for 26 compounds spanned a signaling bias over 3 log units, culminating in three small ligands as biased agonist tools for interrogating PAR2 functions. DF253 (2f-LAAAAI-NH2) triggered PAR2-mediated calcium release (EC50 2 µM) but not ERK1/2 phosphorylation (EC50 > 100 µM) in CHO cells transfected with hPAR2. AY77 (Isox-Cha-Chg-NH2) was a more potent calcium-biased agonist (EC50 40 nM, Ca2+; EC50 2 µM, ERK1/2), while its analogue AY254 (Isox-Cha-Chg-A-R-NH2) was an ERK-biased agonist (EC50 2 nM, ERK1/2; EC50 80 nM, Ca2+). Signaling bias led to different functional responses in human colorectal carcinoma cells (HT29). AY254, but not AY77 or DF253, attenuated cytokine-induced caspase 3/8 activation, promoted scratch-wound healing, and induced IL-8 secretion, all via PAR2-ERK1/2 signaling. Different ligand components were responsible for different PAR2 signaling and functions, clues that can potentially lead to drugs that modulate different pathway-selective cellular and physiological responses.


Asunto(s)
Receptor PAR-2/agonistas , Transducción de Señal/efectos de los fármacos , Animales , Células CHO , Calcio/metabolismo , Cricetulus , Células HT29 , Humanos , Ligandos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Receptor PAR-2/fisiología , Relación Estructura-Actividad , Transfección
15.
Nat Commun ; 8(1): 351, 2017 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-28839129

RESUMEN

Complement C3a is an important protein in innate and adaptive immunity, but its specific roles in vivo remain uncertain because C3a degrades rapidly to form the C3a-desArg protein, which does not bind to the C3a receptor and is indistinguishable from C3a using antibodies. Here we develop the most potent, stable and highly selective small molecule modulators of C3a receptor, using a heterocyclic hinge to switch between agonist and antagonist ligand conformations. This enables characterization of C3 areceptor-selective pro- vs. anti-inflammatory actions in human mast cells and macrophages, and in rats. A C3a receptor-selective agonist induces acute rat paw inflammation by first degranulating mast cells before activating macrophages and neutrophils. An orally administered C3a receptor-selective antagonist inhibits mast cell degranulation, thereby blocking recruitment and activation of macrophages and neutrophils, expression of inflammatory mediators and inflammation in a rat paw edema model. These novel tools reveal the mechanism of C3a-induced inflammation and provide new insights to complement-based medicines.Complement C3a is an important protein in innate and adaptive immunity, but its roles in vivo are unclear. Here the authors develop novel chemical agonists and antagonists for the C3a receptor, and show that they modulate mast cell degranulation and inflammation in a rat paw edema model.


Asunto(s)
Complemento C3a/fisiología , Inmunidad Innata/genética , Receptores de Complemento/química , Animales , Antiasmáticos/farmacología , Degranulación de la Célula/efectos de los fármacos , Células Cultivadas , Complemento C3a/genética , Complemento C3a/metabolismo , Cromolin Sódico/farmacología , Humanos , Ligandos , Macrófagos/inmunología , Masculino , Mastocitos/inmunología , Neutrófilos/inmunología , Conformación Proteica , Ratas , Ratas Wistar , Receptores de Complemento/agonistas , Receptores de Complemento/antagonistas & inhibidores
16.
Expert Opin Ther Pat ; 26(4): 471-83, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26936077

RESUMEN

INTRODUCTION: Protease activated receptor 2 (PAR2) is a self-activated G protein-coupled receptor that has been implicated in several diseases, including inflammatory, gastrointestinal, respiratory, metabolic diseases, cancers and others, making it an important prospective drug target. No known endogenous ligands are available for PAR2, so having potent exogenous agonists and antagonists can be helpful for studying physiological functions of PAR2. AREAS COVERED: This review covers agonist-, antagonist-, antibody- and pepducin-based modulators of PAR2 reported in patent applications between 2010-2015, along with their available structure-activity relationships, biological activities and potential uses for studying PAR2. EXPERT OPINION: In the last six years, substantial efforts were made towards developing PAR2 modulators, but most lack potency or selectivity or have poor pharmacokinetic profiles. Many PAR2 modulators were assessed by measuring Gαq protein-mediated calcium release in cells. This may be insufficient to fully characterize ligand function, since different ligands signal through PAR2 via multiple signaling pathways. It may be feasible to develop biased ligands as drugs that can selectively modulate one or more specific signaling pathways linking PAR2 to a specific diseased state. Accordingly, potent, orally bioavailable, pathway- and receptor-selective PAR2 modulators may be an achievable goal to realizing effective drugs that can treat PAR2-mediated diseases.


Asunto(s)
Diseño de Fármacos , Receptor PAR-2/agonistas , Receptor PAR-2/antagonistas & inhibidores , Animales , Humanos , Ligandos , Terapia Molecular Dirigida , Patentes como Asunto , Receptor PAR-2/metabolismo , Transducción de Señal/efectos de los fármacos , Relación Estructura-Actividad
17.
ACS Med Chem Lett ; 7(1): 105-10, 2016 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-26819675

RESUMEN

Many proteases cut the PAR2 N-terminus resulting in conformational changes that activate cells. Synthetic peptides corresponding to newly exposed N-terminal sequences of PAR2 also activate the receptor at micromolar concentrations. PAR2-selective small molecules reported here induce PAR2-mediated intracellular calcium signaling at nanomolar concentrations (EC50 = 15-100 nM, iCa(2+), CHO-hPAR2 cells). These are the most potent and efficient small molecule ligands to activate PAR2-mediated calcium release and chemotaxis, including for human breast and prostate cancer cells.

18.
Sci Rep ; 6: 24575, 2016 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-27094554

RESUMEN

Drug discovery and translation are normally based on optimizing efficacy by increasing receptor affinity, functional potency, drug-likeness (rule-of-five compliance) and oral bioavailability. Here we demonstrate that residence time of a compound on its receptor has an overriding influence on efficacy, exemplified for antagonists of inflammatory protein complement C5a that activates immune cells and promotes disease. Three equipotent antagonists (3D53, W54011, JJ47) of inflammatory responses to C5a (3 nM) were compared for drug-likeness, receptor affinity and antagonist potency in human macrophages, and anti-inflammatory efficacy in rats. Only the least drug-like antagonist (3D53) maintained potency in cells against higher C5a concentrations and had a much longer duration of action (t1/2 ~ 20 h) than W54011 or JJ47 (t1/2 ~ 1 -3 h) in inhibiting macrophage responses. The unusually long residence time of 3D53 on its receptor was mechanistically probed by molecular dynamics simulations, which revealed long-lasting interactions that trap the antagonist within the receptor. Despite negligible oral bioavailability, 3D53 was much more orally efficacious than W54011 or JJ47 in preventing repeated agonist insults to induce rat paw oedema over 24 h. Thus, residence time on a receptor can trump drug-likeness in determining efficacy, even oral efficacy, of pharmacological agents.


Asunto(s)
Complemento C5a/antagonistas & inhibidores , Complemento C5a/metabolismo , Inmunosupresores/administración & dosificación , Inmunosupresores/farmacocinética , Receptor de Anafilatoxina C5a/metabolismo , Animales , Disponibilidad Biológica , Quimiotaxis/efectos de los fármacos , Quimiotaxis/inmunología , Complemento C5a/inmunología , Modelos Animales de Enfermedad , Edema/tratamiento farmacológico , Edema/inmunología , Edema/metabolismo , Humanos , Inmunosupresores/química , Macrófagos/citología , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Macrófagos/metabolismo , Masculino , Conformación Molecular , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Estructura Molecular , Monocitos/citología , Monocitos/efectos de los fármacos , Monocitos/inmunología , Monocitos/metabolismo , Ratas , Receptor de Anafilatoxina C5a/antagonistas & inhibidores , Receptor de Anafilatoxina C5a/química
19.
ACS Med Chem Lett ; 7(12): 1179-1184, 2016 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-27994760

RESUMEN

PAR2 antagonists have potential for treating inflammatory, respiratory, gastrointestinal, neurological, and metabolic disorders, but few antagonists are known. Derivatives of GB88 (3) suggest that all four of its components bind at distinct PAR2 sites with the isoxazole, cyclohexylalanine, and isoleucine determining affinity and selectivity, while the C-terminal substituent determines agonist/antagonist function. Here we report structurally similar PAR2 ligands with opposing functions (agonist vs antagonist) upon binding to PAR2. A biased ligand AY117 (65) was found to antagonize calcium release induced by PAR2 agonists trypsin and hexapeptide 2f-LIGRLO-NH2 (IC50 2.2 and 0.7 µM, HT29 cells), but it was a selective PAR2 agonist in inhibiting cAMP stimulation and activating ERK1/2 phosphorylation. It showed anti-inflammatory properties both in vitro and in vivo.

20.
J Med Chem ; 57(20): 8459-70, 2014 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-25259874

RESUMEN

The G-protein coupled receptor (C3aR) for human inflammatory protein complement C3a is an important component of immune, inflammatory, and metabolic diseases. A flexible compound (N2-[(2,2-diphenylethoxy)acetyl]-l-arginine, 4), known as a weak C3aR antagonist (IC50 µM), was transformed here into potent agonists (EC50 nM) of human macrophages (Ca(2+) release in HMDM) by incorporating aromatic heterocycles. Antagonists were also identified. A linear correlation between binding affinity for C3aR and calculated hydrogen-bond interaction energy of the heteroatom indicated that its hydrogen-bonding capacity influenced ligand affinity and function mediated by C3aR. Hydrogen-bond accepting heterocycles (e.g., imidazole) conferred the highest affinity and agonist potency (e.g., 21, EC50 24 nM, Ca(2+), HMDM) with comparable efficacy and immunostimulatory activity as that of C3a in activating human macrophages (Ca(2+), IL1ß, TNFα, CCL3). These potent and selective modulators of C3aR, inactivated by a C3aR antagonist, are stable C3a surrogates for interrogating roles for C3aR in physiology and disease.


Asunto(s)
Compuestos Heterocíclicos/química , Receptores de Complemento/agonistas , Receptores de Complemento/metabolismo , Adyuvantes Inmunológicos/química , Adyuvantes Inmunológicos/farmacología , Arginina/análogos & derivados , Arginina/química , Arginina/farmacología , Compuestos de Bencidrilo/química , Compuestos de Bencidrilo/farmacología , Calcio/metabolismo , Células Cultivadas , Técnicas de Química Sintética , Regulación de la Expresión Génica/efectos de los fármacos , Compuestos Heterocíclicos/farmacología , Humanos , Enlace de Hidrógeno , Ligandos , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Receptores de Complemento/antagonistas & inhibidores , Relación Estructura-Actividad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA