RESUMEN
6-Chloro-5-[4-(1-hydroxycyclobutyl)phenyl]-1H-indole-3-carboxylic acid (PF-06409577) is a direct activator of the human ß1-containing adenosine monophosphate-activated protein kinase (ΑMPK) isoforms. The clearance mechanism of PF-06409577 in animals and humans involves uridine diphosphoglucuronosyl transferase (UGT)-mediated glucuronidation to an acyl glucuronide metabolite of PF-06409577 [(2S,3S,4S,5R,6S)-6-((6-chloro-5-(4-(1-hydroxycyclobutyl)phenyl)-1H-indole-3-carbonyl)oxy)-3,4,5-trihydroxytetrahydro-2H-pyran-2-carboxylic acid (M1)], which retains selective activation of human ß1-containing AMPK isoforms. This paper describes a detailed characterization of the human UGT isoform(s) responsible for glucuronidation of PF-06409577 to M1. Studies using a panel of 13 human recombinant UGT (hrUGT) enzymes indicated that PF-06409577 was converted to M1 in a highly selective fashion by UGT1A1, which was further verified in human liver microsomes treated with specific chemical inhibitors, and in different UGT1A1 expressers. Conversion of PF-06409577 to M1 by UGT1A1 occurred in a relatively selective fashion, compared with ß-estradiol (ES), a conventional probe substrate of UGT1A1. The Michaelis-Menten constant (K M) and V max values describing the formation of M1 from PF-06409577 in hrUGT1A1 and microsomal preparations from human intestine, liver, and kidney ranged from 131 to 212 µM (K M) and 107-3834 pmol/min per milligram (V max) in the presence of 2% bovine serum albumin. Relative activity factors (RAF) were determined for UGT1A1 using PF-06409577 and ES to enable estimation of intrinsic clearance from various tissues. RAF values from PF-06409577 and ES were generally comparable with the exception of intestinal microsomes, where ES overestimated the RAF of UGT1A1 due to glucuronidation by intestinal UGT1A8 and UGT1A10. Our results suggest the potential utility of PF-06409477 as a selective probe UGT1A1 substrate for UGT reaction phenotyping and inhibition studies in preclinical discovery/development.
Asunto(s)
Estradiol/metabolismo , Glucurónidos/metabolismo , Glucuronosiltransferasa/metabolismo , Indoles/metabolismo , Microsomas/metabolismo , Femenino , Humanos , Técnicas In Vitro , Inactivación Metabólica , Mucosa Intestinal/metabolismo , Riñón/metabolismo , Cinética , Hígado/metabolismo , Masculino , Isoformas de Proteínas , Especificidad por SustratoRESUMEN
Diabetic nephropathy remains an area of high unmet medical need, with current therapies that slow down, but do not prevent, the progression of disease. A reduced phosphorylation state of adenosine monophosphate-activated protein kinase (AMPK) has been correlated with diminished kidney function in both humans and animal models of renal disease. Here, we describe the identification of novel, potent, small molecule activators of AMPK that selectively activate AMPK heterotrimers containing the ß1 subunit. After confirming that human and rodent kidney predominately express AMPK ß1, we explore the effects of pharmacological activation of AMPK in the ZSF1 rat model of diabetic nephropathy. Chronic administration of these direct activators elevates the phosphorylation of AMPK in the kidney, without impacting blood glucose levels, and reduces the progression of proteinuria to a greater degree than the current standard of care, angiotensin-converting enzyme inhibitor ramipril. Further analyses of urine biomarkers and kidney tissue gene expression reveal AMPK activation leads to the modulation of multiple pathways implicated in kidney injury, including cellular hypertrophy, fibrosis, and oxidative stress. These results support the need for further investigation into the potential beneficial effects of AMPK activation in kidney disease.
Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Aminopiridinas/farmacología , Nefropatías Diabéticas/tratamiento farmacológico , Activadores de Enzimas/farmacología , Indoles/farmacología , Riñón/efectos de los fármacos , Aminopiridinas/uso terapéutico , Animales , Tamaño de la Célula , Nefropatías Diabéticas/metabolismo , Nefropatías Diabéticas/patología , Activación Enzimática , Fibrosis , Humanos , Indoles/uso terapéutico , Isoenzimas/metabolismo , Riñón/metabolismo , Riñón/patología , Pruebas de Función Renal , Macaca fascicularis , Ratones Endogámicos C57BL , Estrés Oxidativo , Fosforilación , Proteinuria/tratamiento farmacológico , Proteinuria/metabolismo , Ratas , Especificidad de la EspecieRESUMEN
Adenosine monophosphate-activated protein kinase (AMPK), a serine/threonine heterotrimeric protein kinase, is a critical regulator of cellular and whole body energy homeostasis. There are twelve known AMPK isoforms that are differentially expressed in tissues and species. Dysregulation of AMPK signaling is associated with a multitude of human pathologies. Hence isoform-selective activators of AMPK are actively being sought for the treatment of cardiovascular and metabolic diseases. The present review summarizes the status of direct AMPK activators from the patent and published literature.
Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Activadores de Enzimas/farmacología , Proteínas Quinasas Activadas por AMP/química , Animales , Activación Enzimática , Humanos , Fosforilación , Conformación ProteicaRESUMEN
The optimization for selectivity and central receptor occupancy for a series of spirocyclic azetidine-piperidine inverse agonists of the ghrelin receptor is described. Decreased mAChR muscarinic M2 binding was achieved by use of a chiral indane in place of a substituted benzylic group. Compounds with desirable balance of human in vitro clearance and ex vivo central receptor occupancy were discovered by incorporation of heterocycles. Specifically, heteroaryl rings with nitrogen(s) vicinal to the indane linkage provided the most attractive overall properties.
Asunto(s)
Sistema Nervioso Central/efectos de los fármacos , Receptores de Ghrelina/antagonistas & inhibidores , Secuencia de Aminoácidos , Animales , Sitios de Unión , Agonismo Inverso de Drogas , Compuestos Heterocíclicos/química , Compuestos Heterocíclicos/farmacología , Humanos , Indanos/química , Indanos/farmacología , Concentración 50 Inhibidora , Isomerismo , Estructura Molecular , Unión Proteica/efectos de los fármacos , Ratas , Relación Estructura-ActividadRESUMEN
New cholecystokinin-1 receptor (CCK1R) agonist 'triggers' were identified using iterative library synthesis. Structural activity relationship studies led to the discovery of compound 10e, a potent CCK1R agonist that demonstrated robust weight loss in a diet-induced obese rat model with very low systemic exposure. Pharmacokinetic data suggest that efficacy is primarily driven through activation of CCK1R's located within the intestinal wall.
Asunto(s)
Amidas/síntesis química , Descubrimiento de Drogas , Piperidinas/síntesis química , Receptor de Colecistoquinina A/agonistas , Amidas/química , Amidas/farmacología , Animales , Células Cultivadas , Modelos Animales de Enfermedad , Humanos , Concentración 50 Inhibidora , Masculino , Ratones , Ratones Obesos , Piperidinas/química , Piperidinas/farmacología , Unión Proteica/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Relación Estructura-Actividad , Pérdida de Peso/efectos de los fármacosRESUMEN
We describe the design, synthesis, and structure-activity relationships of triazolobenzodiazepinone CCK1 receptor agonists. Analogs in this series demonstrate potent agonist activity as measured by in vitro and in vivo assays for CCK1 agonism. Our efforts resulted in the identification of compound 4a which significantly reduced food intake with minimal systemic exposure in rodents.
Asunto(s)
Fármacos Antiobesidad/farmacología , Benzodiazepinas/farmacología , Receptores de Colecistoquinina/agonistas , Animales , Fármacos Antiobesidad/farmacocinética , Benzodiazepinas/química , Benzodiazepinas/farmacocinética , Masculino , Ratas , Ratas Sprague-Dawley , Relación Estructura-ActividadRESUMEN
Sulfonamides, exemplified by 3a, were identified as highly selective EP(2) agonists. Lead optimization led to the identification of CP-533536, 7f, a potent and selective EP(2) agonist. CP-533536 demonstrated the ability to heal fractures when administered locally as a single dose in rat models of fracture healing.
Asunto(s)
Osteogénesis/efectos de los fármacos , Piridinas/química , Receptores de Prostaglandina E/agonistas , Animales , Masculino , Piridinas/administración & dosificación , Piridinas/farmacocinética , Ratas , Ratas Sprague-Dawley , Receptores de Prostaglandina E/metabolismo , Subtipo EP2 de Receptores de Prostaglandina E , Relación Estructura-Actividad , Sulfonamidas/síntesis química , Sulfonamidas/química , Sulfonamidas/farmacologíaRESUMEN
Studies on indole-3-carboxylic acid derivatives as direct activators of human adenosine monophosphate-activated protein kinase (AMPK) α1ß1γ1 isoform have culminated in the identification of PF-06409577 (1), PF-06885249 (2), and PF-06679142 (3) as potential clinical candidates. Compounds 1-3 are primarily cleared in animals and humans via glucuronidation. Herein, we describe the biosynthetic preparation, purification, and structural characterization of the glucuronide conjugates of 1-3. Spectral characterization of the purified glucuronides M1, M2, and M3 indicated that they were acyl glucuronide derivatives. In vitro pharmacological evaluation revealed that all three acyl glucuronides retained selective activation of ß1-containing AMPK isoforms. Inhibition of de novo lipogenesis with representative parent carboxylic acids and their respective acyl glucuronide conjugates in human hepatocytes demonstrated their propensity to activate cellular AMPK. Cocrystallization of the AMPK α1ß1γ1 isoform with 1-3 and M1-M3 provided molecular insights into the structural basis for AMPK activation by the glucuronide conjugates.
Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Indoles/química , Indoles/metabolismo , Lipogénesis/efectos de los fármacos , Proteínas Quinasas Activadas por AMP/química , Animales , Células Cultivadas , Cristalización/métodos , Activación Enzimática/efectos de los fármacos , Glucurónidos/química , Glucurónidos/metabolismo , Glucurónidos/farmacocinética , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Humanos , Indoles/farmacología , Macaca fascicularis , Espectroscopía de Resonancia Magnética , Masculino , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/metabolismo , Ratas Wistar , Uridina Difosfato Ácido Glucurónico/farmacologíaRESUMEN
Dysregulation of hepatic lipid and cholesterol metabolism is a significant contributor to cardiometabolic health, resulting in excessive liver lipid accumulation and ultimately non-alcoholic steatohepatitis (NASH). Therapeutic activators of the AMP-Activated Protein Kinase (AMPK) have been proposed as a treatment for metabolic diseases; we show that the AMPK ß1-biased activator PF-06409577 is capable of lowering hepatic and systemic lipid and cholesterol levels in both rodent and monkey preclinical models. PF-06409577 is able to inhibit de novo lipid and cholesterol synthesis pathways, and causes a reduction in hepatic lipids and mRNA expression of markers of hepatic fibrosis. These effects require AMPK activity in the hepatocytes. Treatment of hyperlipidemic rats or cynomolgus monkeys with PF-06409577 for 6weeks resulted in a reduction in circulating cholesterol. Together these data suggest that activation of AMPK ß1 complexes with PF-06409577 is capable of impacting multiple facets of liver disease and represents a promising strategy for the treatment of NAFLD and NASH in humans.
Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Activadores de Enzimas/farmacología , Hepatocitos/enzimología , Indoles/farmacología , Hígado/enzimología , Enfermedad del Hígado Graso no Alcohólico , Animales , Línea Celular , Haplorrinos , Hepatocitos/patología , Humanos , Hígado/patología , Ratones , Ratones Noqueados , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/enzimología , Enfermedad del Hígado Graso no Alcohólico/patología , RatasRESUMEN
Optimization of the pharmacokinetic (PK) properties of a series of activators of adenosine monophosphate-activated protein kinase (AMPK) is described. Derivatives of the previously described 5-aryl-indole-3-carboxylic acid clinical candidate (1) were examined with the goal of reducing glucuronidation rate and minimizing renal excretion. Compounds 10 (PF-06679142) and 14 (PF-06685249) exhibited robust activation of AMPK in rat kidneys as well as desirable oral absorption, low plasma clearance, and negligible renal clearance in preclinical species. A correlation of in vivo renal clearance in rats with in vitro uptake by human and rat renal organic anion transporters (human OAT/rat Oat) was identified. Variation of polar functional groups was critical to mitigate active renal clearance mediated by the Oat3 transporter. Modification of either the 6-chloroindole core to a 4,6-difluoroindole or the 5-phenyl substituent to a substituted 5-(3-pyridyl) group provided improved metabolic stability while minimizing propensity for active transport by OAT3.
Asunto(s)
Proteínas Quinasas Activadas por AMP/efectos de los fármacos , Activadores de Enzimas/síntesis química , Activadores de Enzimas/farmacología , Indoles/síntesis química , Indoles/farmacología , Animales , Activación Enzimática/efectos de los fármacos , Activadores de Enzimas/farmacocinética , Humanos , Indoles/farmacocinética , Absorción Intestinal , Riñón/efectos de los fármacos , Riñón/enzimología , Masculino , Modelos Moleculares , Transportadores de Anión Orgánico Sodio-Independiente/metabolismo , Ratas , Ratas Wistar , Relación Estructura-ActividadRESUMEN
The AMP-activated protein kinase (AMPK) is a potential therapeutic target for metabolic diseases based on its reported actions in the liver and skeletal muscle. We evaluated two distinct direct activators of AMPK: a non-selective activator of all AMPK complexes, PF-739, and an activator selective for AMPK ß1-containing complexes, PF-249. In cells and animals, both compounds were effective at activating AMPK in hepatocytes, but only PF-739 was capable of activating AMPK in skeletal muscle. In diabetic mice, PF-739, but not PF-249, caused a rapid lowering of plasma glucose levels that was diminished in the absence of skeletal muscle, but not liver, AMPK heterotrimers and was the result of an increase in systemic glucose disposal with no impact on hepatic glucose production. Studies of PF-739 in cynomolgus monkeys confirmed translation of the glucose lowering and established activation of AMPK in skeletal muscle as a potential therapeutic approach to treat diabetic patients.
Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Aminopiridinas/farmacología , Activadores de Enzimas/farmacología , Glucosa/metabolismo , Hipoglucemiantes/farmacología , Indoles/farmacología , Aminopiridinas/uso terapéutico , Animales , Glucemia/metabolismo , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/metabolismo , Activación Enzimática/efectos de los fármacos , Activadores de Enzimas/uso terapéutico , Femenino , Hipoglucemiantes/uso terapéutico , Indoles/uso terapéutico , Hígado/efectos de los fármacos , Hígado/metabolismo , Macaca fascicularis , Masculino , Ratones Endogámicos C57BL , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismoRESUMEN
UNLABELLED: CP432 is a newly discovered, nonprostanoid EP4 receptor selective prostaglandin E2 agonist. CP432 stimulates trabecular and cortical bone formation and restores bone mass and bone strength in aged ovariectomized rats with established osteopenia. INTRODUCTION: The purpose of this study was to determine whether a newly discovered, nonprostanoid EP4 receptor selective prostaglandin E2 (PGE2) agonist, CP432, could produce bone anabolic effects in aged, ovariectomized (OVX) rats with established osteopenia. MATERIALS AND METHODS: CP432 at 0.3, 1, or 3 mg/kg/day was given for 6 weeks by subcutaneous injection to 12-month-old rats that had been OVX for 8.5 months. The effects on bone mass, bone formation, bone resorption, and bone strength were determined. RESULTS: Total femoral BMD increased significantly in OVX rats treated with CP432 at all doses. CP432 completely restored trabecular bone volume of the third lumbar vertebral body accompanied with a dose-dependent decrease in osteoclast number and osteoclast surface and a dose-dependent increase in mineralizing surface, mineral apposition rate, and bone formation rate-tissue reference in OVX rats. CP432 at 1 and 3 mg/kg/day significantly increased total tissue area, cortical bone area, and periosteal and endocortical bone formation in the tibial shafts compared with both sham and OVX controls. CP432 at all doses significantly and dose-dependently increased ultimate strength in the fifth lumber vertebral body compared with both sham and OVX controls. At 1 and 3 mg/kg/day, CP432 significantly increased maximal load in a three-point bending test of femoral shaft compared with both sham and OVX controls. CONCLUSIONS: CP432 completely restored trabecular and cortical bone mass and strength in established osteopenic, aged OVX rats by stimulating bone formation and inhibiting bone resorption on trabecular and cortical surfaces.
Asunto(s)
Envejecimiento/fisiología , Densidad Ósea/efectos de los fármacos , Enfermedades Óseas Metabólicas/tratamiento farmacológico , Dinoprostona/agonistas , Osteogénesis/efectos de los fármacos , Receptores de Prostaglandina E/agonistas , Receptores de Prostaglandina E/metabolismo , Animales , Peso Corporal , Densidad Ósea/fisiología , Modelos Animales de Enfermedad , Femenino , Fémur/anatomía & histología , Vértebras Lumbares/anatomía & histología , Estructura Molecular , Tamaño de los Órganos/efectos de los fármacos , Ovariectomía , Ratas , Ratas Sprague-Dawley , Subtipo EP4 de Receptores de Prostaglandina E , Especificidad por Sustrato , Tibia/anatomía & histologíaRESUMEN
Adenosine monophosphate-activated protein kinase (AMPK) is a protein kinase involved in maintaining energy homeostasis within cells. On the basis of human genetic association data, AMPK activators were pursued for the treatment of diabetic nephropathy. Identification of an indazole amide high throughput screening (HTS) hit followed by truncation to its minimal pharmacophore provided an indazole acid lead compound. Optimization of the core and aryl appendage improved oral absorption and culminated in the identification of indole acid, PF-06409577 (7). Compound 7 was advanced to first-in-human trials for the treatment of diabetic nephropathy.
Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Nefropatías Diabéticas/tratamiento farmacológico , Activadores de Enzimas/química , Indoles/química , Administración Oral , Adsorción , Animales , Cristalografía por Rayos X , Perros , Activadores de Enzimas/síntesis química , Activadores de Enzimas/farmacocinética , Activadores de Enzimas/farmacología , Ensayos Analíticos de Alto Rendimiento , Humanos , Indazoles/síntesis química , Indazoles/química , Indazoles/farmacología , Indoles/síntesis química , Indoles/farmacocinética , Indoles/farmacología , Inyecciones Intravenosas , Macaca fascicularis , Masculino , Modelos Moleculares , Conformación Proteica , RatasRESUMEN
Several polar heteroaromatic acetic acids and their piperidine amides were synthesized and evaluated as ghrelin or type 1a growth hormone secretagogue receptor (GHS-R1a) inverse agonists. Efforts to improve pharmacokinetic and safety profile was achieved by modulating physicochemical properties and, more specifically, emphasizing increased polarity of our chemical series. ortho-Carboxamide containing compounds provided optimal physicochemical, pharmacologic, and safety profile. pH-dependent chemical stability was also assessed with our series.
RESUMEN
UNLABELLED: CP-533,536, a newly discovered, non-prostanoid EP2 receptor-selective PGE2 agonist, stimulates local bone formation and enhances fracture healing in rat models. INTRODUCTION: There is a significant medical need for agents that can stimulate local bone formation and enhance fracture healing. We tested the effects of CP-533,536, a newly discovered, non-prostanoid EP2 receptor-selective prostaglandin E2 (PGE2) agonist, in stimulating local bone formation and enhancing fracture healing in rat models. MATERIALS AND METHODS: In the first model, a single injection of CP-533,536 at doses of 0.3, 1, or 3 mg/kg to the proximal tibial metaphysis of 6-week-old male rats was given on day 1, and the local bone anabolic effect was determined on day 7. We then tested the effects of this compound in inducing bone formation on rat periosteum of the femur. A single dose of 0.3 mg of CP-533,536 incorporated in a poly-(D,L-lactide-co-glycolide) (PLGH) matrix was injected onto the periosteum of the femur in 3-week-old male rats, and local bone formation was determined on day 14. Finally, the ability of CP-533,536 in PLGH matrix in enhancing fracture healing was tested using the rat femoral fracture model. CP-533,536 in PLGH matrix at doses of 0.05, 0.5, or 5 mg was delivered to the local fracture site on the same day of fracture, and its efficacy was evaluated on day 21. RESULTS AND CONCLUSIONS: A single injection of CP-533,536 at doses of 0.3, 1, or 3 mg/kg to the proximal tibial metaphysis dose-dependently stimulated local lamellar bone formation on trabecular, endocortical, and periosteal surfaces, and thus increased bone mineral content and bone strength at the injected site. Similarly, a single injection of 0.3 mg of CP-533,536 incorporated in PLGH matrix onto the periosteum of the femur induced significantly local bone formation. In the rat femoral fracture model, CP-533,536 in PLGH matrix at doses of 0.05, 0.5, and 5 mg dose-dependently increased callus size, density, and strength compared with PLGH matrix alone. These results show that CP-533,536 stimulates new bone formation on trabecular, endocortical, and periosteal surfaces and enhances fracture healing. These data reveal that EP2 receptor-selective agonists provide therapeutic potential for local bone augmentation, bone repair, and bone healing in humans.
Asunto(s)
Huesos/efectos de los fármacos , Dinoprostona/agonistas , Fracturas del Fémur/tratamiento farmacológico , Curación de Fractura/efectos de los fármacos , Piridinas/farmacología , Piridinas/uso terapéutico , Receptores de Prostaglandina E/metabolismo , Animales , Huesos/fisiología , Modelos Animales de Enfermedad , Fluorescencia , Inyecciones , Masculino , Estructura Molecular , Piridinas/administración & dosificación , Ratas , Ratas Sprague-Dawley , Subtipo EP2 de Receptores de Prostaglandina E , Especificidad por SustratoRESUMEN
Ghrelin is an endogenous peptide hormone secreted primarily by the stomach and is involved in a number of physiological processes including growth hormone secretion, food intake, as well as energy and glucose homeostasis. The physiological actions of ghrelin are mediated through the growth hormone secretagogue receptor 1a (ghrelin receptor), a peptidic G-protein-coupled receptor. This target has attracted much interest, as agents that block ghrelin's actions on its receptor are anticipated to be pharmaceutical interventions for a number of diseases. This review provides an overview of ghrelin biology with a focus on metabolic diseases and summarizes recent medicinal chemistry programs aimed at delivering small molecule ghrelin receptor antagonists and inverse agonists to the clinic.
Asunto(s)
Receptores de Ghrelina/antagonistas & inhibidores , Aciltransferasas/genética , Animales , Industria Farmacéutica , Ingestión de Alimentos/efectos de los fármacos , Ghrelina/genética , Ghrelina/farmacología , Glucosa/metabolismo , Homeostasis/efectos de los fármacos , Humanos , Obesidad/tratamiento farmacológico , Páncreas/efectos de los fármacos , Páncreas/fisiología , Ratas , Receptores de Ghrelina/agonistas , Receptores de Ghrelina/genéticaRESUMEN
The identification of potent, highly selective orally bioavailable ghrelin receptor inverse agonists from a spiro-azetidino-piperidine series is described. Examples from this series have promising in vivo pharmacokinetics and increase glucose-stimulated insulin secretion in human whole and dispersed islets. A physicochemistry-based strategy to increase lipophilic efficiency for ghrelin receptor potency and retain low clearance and satisfactory permeability while reducing off-target pharmacology led to the discovery of 16h. Compound 16h has a superior balance of ghrelin receptor pharmacology and off-target selectivity. On the basis of its promising pharmacological and safety profile, 16h was advanced to human clinical trials.
RESUMEN
AMP-activated protein kinase (AMPK) is a principal metabolic regulator affecting growth and response to cellular stress. Comprised of catalytic and regulatory subunits, each present in multiple forms, AMPK is best described as a family of related enzymes. In recent years, AMPK has emerged as a desirable target for modulation of numerous diseases, yet clinical therapies remain elusive. Challenges result, in part, from an incomplete understanding of the structure and function of full-length heterotrimeric complexes. In this work, we provide the full-length structure of the widely expressed α1ß1γ1 isoform of mammalian AMPK, along with detailed kinetic and biophysical characterization. We characterize binding of the broadly studied synthetic activator A769662 and its analogs. Our studies follow on the heels of the recent disclosure of the α2ß1γ1 structure and provide insight into the distinct molecular mechanisms of AMPK regulation by AMP and A769662.
Asunto(s)
Proteínas Quinasas Activadas por AMP/química , Proteínas Quinasas Activadas por AMP/fisiología , Activación Enzimática/fisiología , Modelos Moleculares , Proteínas Quinasas Activadas por AMP/metabolismo , Adenosina Monofosfato/metabolismo , Sitio Alostérico/genética , Compuestos de Bifenilo , Sistemas de Liberación de Medicamentos , Humanos , Cinética , Ligandos , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Fosforilación , Conformación Proteica , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/fisiología , Pironas/metabolismo , Relación Estructura-Actividad , Resonancia por Plasmón de Superficie , Tiofenos/metabolismoRESUMEN
Targeting drugs to the gastrointestinal tract has been and continues to be an active area of research. Gut-targeting is an effective means of increasing the local concentration of active substance at the desired site of action while minimizing concentrations elsewhere in the body that could lead to unwanted side-effects. Several approaches to intestinal targeting exist. Physicochemical property manipulation can drive molecules to large, polar, low absorption space or alternatively to lipophilic, high clearance space in order to minimize systemic exposure. Design of compounds that are substrates for transporters within the gastrointestinal tract, either uptake or efflux, or at the hepato-biliary interface, may help to increase intestinal concentration. Prodrug strategies have been shown to be effective particularly for colon targeting, and several different technology formulation approaches are currently being researched. This review provides examples of various approaches to intestinal targeting, and discusses challenges and areas in need of future scientific advances.
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Sistemas de Liberación de Medicamentos/métodos , Diseño de Fármacos , Tracto Gastrointestinal/metabolismo , Preparaciones Farmacéuticas/química , Preparaciones Farmacéuticas/metabolismo , Humanos , Preparaciones Farmacéuticas/administración & dosificaciónRESUMEN
The tissue distribution of a drug can have significant impact on both its efficacy and safety. As a consequence, selective tissue targeting has become an attractive approach for optimizing the window between efficacy and safety for drug targets that are ubiquitously expressed and important in key physiological processes. Given the liver's key role in metabolic regulation and the fact that it is the principal tissue affected by diseases such as hepatitis B and C viruses as well as hepatocellular carcinoma, designing drugs with hepatoselective distribution profiles is an important strategy in developing safe cardiovascular, metabolic, antiviral and oncology drug candidates. In this paper, we analyze a diverse set of compounds from four different projects within Pfizer that specifically pursued liver targeting strategies. A number of key in vitro and in vivo ADME endpoints were collected including in vivo tissue exposure, oral bioavailability, clearance in preclinical species and in vitro hepatic OATP uptake, in vitro rat liver microsomal stability, permeability, solubility, logD, and others. From this analysis, we determined a set of general structure-liver-selectivity guides for designing orally bioavailable, liver-targeted candidates using liver specific OATP transporters. The guidelines have been formulated using straightforward molecular descriptors and in vitro properties that medicinal chemists routinely optimize. Our analysis emphasizes the need to focus on a chemical space with balanced lipophilicity, high aqueous solubility and low passive permeability in order to achieve the desired hepatoselectivity while maintaining fraction absorbed.