RESUMEN
Endoplasmic reticulum (ER) stress causes neuronal dysfunction followed by cell death and is recognized as a feature of many neurodegenerative diseases. Using a phenotypic screen, we recently identified benzodiazepinone derivatives that reduce ER stress-mediated apoptosis in a rat neuronal progenitor cell line (CSM14.1). Herein we describe how structure-activity relationship (SAR) studies around these screening hits led to compounds that display robust cytoprotective activity against thapsigargin-induced ER stress in SH-SY5Y and H4 human neuronal cell lines. We demonstrate that the most potent of these derivatives, compound 4hh, inhibits the activation of p38 MAP kinase (p38) and c-Jun N-terminal kinase (JNK), protein kinases that are downstream signal effectors of the unfolded protein response (UPR). Compound 4hh specifically protects against thapsigargin-induced cell death and displays no protection against other insults known to induce cellular stress or activate p38. However, compound 4hh provides moderate inhibition of p38 activity stimulated by compounds that disrupt calcium homeostasis. Our data indicate that probe compound 4hh is a valuable small molecule tool that can be used to investigate the effects of ER stress on human neurons. This approach may provide the basis for the future development of therapeutics for the treatment of neurodegenerative diseases.
Asunto(s)
Benzodiazepinonas/química , Benzodiazepinonas/farmacología , Estrés del Retículo Endoplásmico/efectos de los fármacos , Neuronas/efectos de los fármacos , Animales , Calcio/metabolismo , Muerte Celular/efectos de los fármacos , Línea Celular , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/toxicidad , Homeostasis/efectos de los fármacos , Humanos , Imidazoles/farmacología , Ionomicina/farmacología , Leupeptinas/farmacología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/farmacología , Ratas , Relación Estructura-Actividad , Tapsigargina/química , Tapsigargina/toxicidadRESUMEN
We report the discovery and characterization of a series of benzoisothiazolone inhibitors of PHOSPHO1, a newly identified soluble phosphatase implicated in skeletal mineralization and soft tissue ossification abnormalities. High-throughput screening (HTS) of a small molecule library led to the identification of benzoisothiazolones as potent and selective inhibitors of PHOSPHO1. Critical structural requirements for activity were determined, and the compounds were subsequently derivatized and measured for in vitro activity and ADME parameters including metabolic stability and permeability. On the basis of its overall profile the benzoisothiazolone analogue 2q was selected as MLPCN probe ML086.
Asunto(s)
Benzamidas/farmacología , Benzotiazoles/farmacología , Diseño de Fármacos , Inhibidores Enzimáticos/farmacología , Monoéster Fosfórico Hidrolasas/antagonistas & inhibidores , Bibliotecas de Moléculas Pequeñas/farmacología , Animales , Benzamidas/síntesis química , Benzamidas/química , Benzotiazoles/síntesis química , Benzotiazoles/química , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Hepatocitos/efectos de los fármacos , Ensayos Analíticos de Alto Rendimiento , Humanos , Concentración de Iones de Hidrógeno , Ratones , Estructura Molecular , Monoéster Fosfórico Hidrolasas/metabolismo , Bibliotecas de Moléculas Pequeñas/síntesis química , Bibliotecas de Moléculas Pequeñas/química , Relación Estructura-ActividadRESUMEN
As part of our ongoing small-molecule metabotropic glutamate (mGlu) receptor positive allosteric modulator (PAM) research, we performed structure-activity relationship (SAR) studies around a series of group II mGlu PAMs. Initial analogues exhibited weak activity as mGlu2 receptor PAMs and no activity at mGlu3. Compound optimization led to the identification of potent mGlu2/3 selective PAMs with no in vitro activity at mGlu1,4-8 or 45 other CNS receptors. In vitro pharmacological characterization of representative compound 44 indicated agonist-PAM activity toward mGlu2 and PAM activity at mGlu3. The most potent mGlu2/3 PAMs were characterized in assays predictive of ADME/T and pharmacokinetic (PK) properties, allowing the discovery of systemically active mGlu2/3 PAMs. On the basis of its overall profile, compound 74 was selected for behavioral studies and was shown to dose-dependently decrease cocaine self-administration in rats after intraperitoneal administration. These mGlu2/3 receptor PAMs have significant potential as small molecule tools for investigating group II mGlu pharmacology.
Asunto(s)
Trastornos Relacionados con Cocaína/tratamiento farmacológico , Receptores de Glutamato Metabotrópico/agonistas , Regulación Alostérica , Animales , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Diseño de Fármacos , Células HEK293 , Humanos , Masculino , Ratas , Ratas WistarRESUMEN
We recently reported the systematic ligand-based rational design and synthesis of monovalent Smac mimetics that bind preferentially to the BIR2 domain of the anti-apoptotic protein XIAP. Expanded structure-activity relationship (SAR) studies around these peptidomimetics led to compounds with significantly improved selectivity (>60-fold) for the BIR2 domain versus the BIR3 domain of XIAP. The potent and highly selective IAP antagonist 8q (ML183) sensitized TRAIL-resistant prostate cancer cells to apoptotic cell death, highlighting the merit of this probe compound as a valuable tool to investigate the biology of XIAP.
Asunto(s)
Materiales Biomiméticos/síntesis química , Diseño de Fármacos , Oligopéptidos/síntesis química , Proteína Inhibidora de la Apoptosis Ligada a X/antagonistas & inhibidores , Sitios de Unión , Materiales Biomiméticos/química , Materiales Biomiméticos/toxicidad , Línea Celular Tumoral , Supervivencia Celular , Resistencia a Antineoplásicos/efectos de los fármacos , Humanos , Simulación del Acoplamiento Molecular , Oligopéptidos/química , Oligopéptidos/toxicidad , Unión Proteica , Estructura Terciaria de Proteína , Relación Estructura-Actividad , Ligando Inductor de Apoptosis Relacionado con TNF/farmacología , Proteína Inhibidora de la Apoptosis Ligada a X/metabolismoRESUMEN
A series of novel, potent antagonists of the inhibitor of apoptosis proteins (IAPs) were synthesized in a highly convergent and rapid fashion (≤6 steps) using the Ugi four-component reaction as the key step, thus enabling rapid optimization of binding potency. These IAP antagonists compete with caspases 3, 7, and 9 for inhibition by X chromosome-linked IAP (XIAP) and bind strongly (nanomolar binding constants) to several crucial members of the IAP family of cancer pro-survival proteins to promote apoptosis, with a particularly unique selectivity for melanoma IAP (ML-IAP). Experiments in cell culture revealed powerful cancer cell growth inhibitory activity in multiple (breast, ovarian, and prostate) cell lines with single agent toxicity at low nanomolar levels against SKOV-3 human ovarian carcinoma cells. Administration of the compounds to human foreskin fibroblast cells revealed no general toxicity to normal cells. Furthermore, computational modeling was performed, revealing key contacts between the IAP proteins and antagonists, suggesting a structural basis for the observed potency.