RESUMO
This paper describes the structure-activity-relationships of novel fluoroalkyl substituents at the C2 position of iminothiazine dioxide beta secretase inhibitors. Key discoveries include reduced amidine basicity and its effect on Pgp, cell potency, and efficacy in various preclinical in vivo efficacy animal models. Findings from these structure-activity-relationships are discussed.
Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Óxidos/farmacologia , Tiazinas/farmacologia , Administração Oral , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Ácido Aspártico Endopeptidases/metabolismo , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/química , Células HEK293 , Humanos , Estrutura Molecular , Óxidos/administração & dosagem , Óxidos/química , Ratos , Relação Estrutura-Atividade , Tiazinas/administração & dosagem , Tiazinas/químicaRESUMO
While the peripheral nervous system is able to repair itself following injury and disease, recovery is often slow and incomplete, with no available treatments to enhance the effectiveness of regeneration. Using knock-out and transgenic overexpressor mice, we previously reported that BACE1, an aspartyl protease, as reported by Hemming et al. (PLoS One 4:12, 2009), negatively regulates peripheral nerve regeneration. Here, we investigated whether pharmacological inhibition of BACE may enhance peripheral nerve repair following traumatic nerve injury or neurodegenerative disease. BACE inhibitor-treated mice had increased numbers of regenerating axons and enhanced functional recovery after a sciatic nerve crush while inhibition increased axonal sprouting following a partial nerve injury. In the SOD1G93A ALS mouse model, BACE inhibition increased axonal regeneration with improved muscle re-innervation. CHL1, a BACE1 substrate, was elevated in treated mice and may mediate enhanced regeneration. Our data demonstrates that pharmacological BACE inhibition accelerates peripheral axon regeneration after varied nerve injuries and could be used as a potential therapy.
Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Esclerose Lateral Amiotrófica/enzimologia , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Ácido Aspártico Endopeptidases/metabolismo , Axônios/fisiologia , Regeneração Nervosa/fisiologia , Traumatismos dos Nervos Periféricos/enzimologia , Esclerose Lateral Amiotrófica/tratamento farmacológico , Esclerose Lateral Amiotrófica/genética , Animais , Axônios/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Feminino , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Regeneração Nervosa/efeitos dos fármacos , Traumatismos dos Nervos Periféricos/tratamento farmacológico , Traumatismos dos Nervos Periféricos/genética , Superóxido Dismutase/genéticaRESUMO
Functional magnetic resonance imaging (fMRI) is a valuable tool for studying neural activations in the central nervous system of animals due to its wide spatial coverage and non-invasive nature. However, the advantages of fMRI have not been fully realized in functional studies in mice, especially in the olfactory system, possibly due to the lack of suitable anesthesia protocols with spontaneous breathing. Since mice are widely used in biomedical research, it is desirable to evaluate different anesthesia protocols for olfactory fMRI studies in mice. Dexmedetomidine (DEX) as a sedative/anesthetic has been introduced to fMRI studies in mice, but it has a limited anesthesia duration. To extend the anesthesia duration, DEX has been combined with a low dose of isoflurane (ISO) or ketamine (KET) in previous functional studies in mice. In this report, olfactory fMRI studies were performed under three anesthesia protocols (DEX alone, DEX/ISO, and DEX/KET) in three different groups of mice. Isoamyl-acetate was used as an odorant, and the odorant-induced neural activations were measured by blood oxygenation-level dependent (BOLD) fMRI. BOLD fMRI responses were observed in the olfactory bulb (OB), anterior olfactory nuclei (AON), and piriform cortex (Pir). Interestingly, BOLD fMRI activations were also observed in the prefrontal cortical region (PFC), which are most likely caused by the draining vein effect. The response in the OB showed no adaptation to either repeated odor stimulations or continuous odor exposure, but the response in the Pir showed adaptation during the continuous odor exposure. The data also shows that ISO suppresses the olfactory response in the OB and AON, while KET enhances the olfactory response in the Pir. Thus, DEX/KET should be an attractive anesthesia for olfactory fMRI in mice.
Assuntos
Dexmedetomidina/farmacologia , Isoflurano/farmacologia , Ketamina/farmacologia , Bulbo Olfatório/efeitos dos fármacos , Percepção Olfatória/efeitos dos fármacos , Anestésicos/farmacologia , Animais , Hipnóticos e Sedativos/farmacologia , Imageamento por Ressonância Magnética/métodos , Camundongos , Modelos AnimaisRESUMO
The design and synthesis of a new series of tetrahydrobenzisoxazoles as modulators of γ-secretase activity and their structure-activity relationship (SAR) will be detailed. Several compounds are active γ-secretase modulators (GSMs) with good to excellent selectivity for the reduction of Aß42 in the cellular assay. Compound 14a was tested in vivo in a nontransgenic rat model and was found to significantly reduce Aß42 in the CNS compartment compared to vehicle-treated animals (up to 58% reduction of cerebrospinal fluid Aß42 as measured 3 h after an acute oral dosing at 30 mg/kg).
RESUMO
Verubecestat is a potent BACE1 enzyme inhibitor currently being investigated in Phase III trials for the treatment of mild-to-moderate and prodromal Alzheimer's disease. Multiple anti-amyloid immunotherapies have been dose-limited by adverse amyloid related imaging abnormalities such as vasogenic edema (ARIA-E) and microhemorrhage (ARIA-H) observed in human trials and mice. Verubecestat was tested in a 12-week nonclinical study for the potential to exacerbate microhemorrhage (ARIA-H) profiles in 18-22-month-old post-plaque Tg2576-AßPPswe mice. Animals were treated with verubecestat or controls including the anti-Aß antibody analog of bapineuzumab (3D6) as a positive control for ARIA induction. ARIA-H was measured using in-life longitudinal T2*-MRI and Prussian blue histochemistry at study end. Verubecestat reduced plasma and cerebrospinal fluid Aß40 and Aß42 byâ>90% and 62% to 68%, respectively. The ARIA-H profile of verubecestat-treated mice was not significantly different than controls. Anti-Aß treatment significantly increased ARIA-H detected by Prussian blue staining; however, anti-Aß antibody treatment did not impact plaque status. Verubecestat treatment significantly suppressed the accumulation of total levels of brain Aß40 and Aß42 and Thioflavin S positive plaque load. Stereological analysis of cortex and hippocampus plaque load similarly revealed significantly reduced area of Aß immunoreactivity and reduced plaque number in verubecestat-treated animals compared to controls. The absence of elevated ARIA events in verubecestat-treated mice was associated with a significant reduction in the level of accumulated CNS amyloid pathology and brain Aß peptides; effects consistent with the desired therapeutic mechanism of verubecestat in AD patients. These data will be compared with longitudinal MRI profiles from ongoing clinical trials.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/metabolismo , Antipsicóticos/uso terapêutico , Óxidos S-Cíclicos/uso terapêutico , Placa Amiloide/patologia , Tiadiazinas/uso terapêutico , Doença de Alzheimer/complicações , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/genética , Precursor de Proteína beta-Amiloide/genética , Animais , Anticorpos Monoclonais Humanizados/uso terapêutico , Colágeno Tipo IV/metabolismo , Óxidos S-Cíclicos/sangue , Óxidos S-Cíclicos/líquido cefalorraquidiano , Modelos Animais de Doenças , Humanos , Hemorragias Intracranianas/tratamento farmacológico , Hemorragias Intracranianas/etiologia , Estudos Longitudinais , Imageamento por Ressonância Magnética , Camundongos , Camundongos Transgênicos , Mutação/genética , Placa Amiloide/tratamento farmacológico , Presenilina-1/genética , Tiadiazinas/sangue , Tiadiazinas/líquido cefalorraquidianoRESUMO
Leucine-rich repeat kinase 2 (LRRK2) is a large, multidomain protein which contains a kinase domain and GTPase domain among other regions. Individuals possessing gain of function mutations in the kinase domain such as the most prevalent G2019S mutation have been associated with an increased risk for the development of Parkinson's disease (PD). Given this genetic validation for inhibition of LRRK2 kinase activity as a potential means of affecting disease progression, our team set out to develop LRRK2 inhibitors to test this hypothesis. A high throughput screen of our compound collection afforded a number of promising indazole leads which were truncated in order to identify a minimum pharmacophore. Further optimization of these indazoles led to the development of MLi-2 (1): a potent, highly selective, orally available, brain-penetrant inhibitor of LRRK2.
Assuntos
Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Indazóis/química , Indazóis/farmacologia , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/antagonistas & inibidores , Animais , Encéfalo/metabolismo , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/farmacocinética , Humanos , Indazóis/administração & dosagem , Indazóis/farmacocinética , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/metabolismo , Masculino , Simulação de Acoplamento Molecular , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/enzimologia , Ratos , Ratos WistarRESUMO
Verubecestat 3 (MK-8931), a diaryl amide-substituted 3-imino-1,2,4-thiadiazinane 1,1-dioxide derivative, is a high-affinity ß-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitor currently undergoing Phase 3 clinical evaluation for the treatment of mild to moderate and prodromal Alzheimer's disease. Although not selective over the closely related aspartyl protease BACE2, verubecestat has high selectivity for BACE1 over other key aspartyl proteases, notably cathepsin D, and profoundly lowers CSF and brain Aß levels in rats and nonhuman primates and CSF Aß levels in humans. In this annotation, we describe the discovery of 3, including design, validation, and selected SAR around the novel iminothiadiazinane dioxide core as well as aspects of its preclinical and Phase 1 clinical characterization.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Precursor de Proteína beta-Amiloide/antagonistas & inibidores , Óxidos S-Cíclicos/farmacologia , Descoberta de Drogas , Tiadiazinas/farmacologia , Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Óxidos S-Cíclicos/síntese química , Óxidos S-Cíclicos/química , Cães , Relação Dose-Resposta a Droga , Humanos , Macaca fascicularis , Modelos Moleculares , Estrutura Molecular , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Tiadiazinas/síntese química , Tiadiazinas/químicaRESUMO
In this paper we describe our strategy to improve the aqueous solubility of SCH 900229, a potent PS1-selective γ-secretase inhibitor for the treatment of Alzheimer's disease. Incorporation of ionizable amino groups into the side chain terminal generates water soluble ß-aminosulfone analogues of SCH 900229 that maintain robust in vitro potency and in vivo efficacy.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Benzopiranos/química , Benzopiranos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Sulfonas/química , Sulfonas/farmacologia , Doença de Alzheimer/enzimologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Benzopiranos/farmacocinética , Cães , Desenho de Fármacos , Inibidores Enzimáticos/farmacocinética , Haplorrinos , Humanos , Ratos , Solubilidade , Sulfonas/farmacocinética , Água/químicaRESUMO
ß-Amyloid (Aß) peptides are thought to be critically involved in the etiology of Alzheimer's disease (AD). The aspartyl protease ß-site amyloid precursor protein cleaving enzyme 1 (BACE1) is required for the production of Aß, and BACE1 inhibition is thus an attractive target for the treatment of AD. We show that verubecestat (MK-8931) is a potent, selective, structurally unique BACE1 inhibitor that reduced plasma, cerebrospinal fluid (CSF), and brain concentrations of Aß40, Aß42, and sAPPß (a direct product of BACE1 enzymatic activity) after acute and chronic administration to rats and monkeys. Chronic treatment of rats and monkeys with verubecestat achieved exposures >40-fold higher than those being tested in clinical trials in AD patients yet did not elicit many of the adverse effects previously attributed to BACE inhibition, such as reduced nerve myelination, neurodegeneration, altered glucose homeostasis, or hepatotoxicity. Fur hypopigmentation was observed in rabbits and mice but not in monkeys. Single and multiple doses were generally well tolerated and produced reductions in Aß40, Aß42, and sAPPß in the CSF of both healthy human subjects and AD patients. The human data were fit to an amyloid pathway model that provided insight into the Aß pools affected by BACE1 inhibition and guided the choice of doses for subsequent clinical trials.
Assuntos
Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/química , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Sistema Nervoso Central/metabolismo , Óxidos S-Cíclicos/farmacologia , Tiadiazinas/farmacologia , Administração Oral , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Ácido Aspártico Endopeptidases/metabolismo , Encéfalo/metabolismo , Domínio Catalítico , Cristalografia por Raios X , Desenho de Fármacos , Feminino , Glucose/metabolismo , Macaca fascicularis , Espectroscopia de Ressonância Magnética , Camundongos , Bainha de Mielina/química , Peptídeos/química , Coelhos , RatosRESUMO
We describe successful efforts to optimize the in vivo profile and address off-target liabilities of a series of BACE1 inhibitors represented by 6 that embodies the recently validated fused pyrrolidine iminopyrimidinone scaffold. Employing structure-based design, truncation of the cyanophenyl group of 6 that binds in the S3 pocket of BACE1 followed by modification of the thienyl group in S1 was pursued. Optimization of the pyrimidine substituent that binds in the S2'-S2â³ pocket of BACE1 remediated time-dependent CYP3A4 inhibition of earlier analogues in this series and imparted high BACE1 affinity. These efforts resulted in the discovery of difluorophenyl analogue 9 (MBi-4), which robustly lowered CSF and cortex Aß40 in both rats and cynomolgus monkeys following a single oral dose. Compound 9 represents a unique molecular shape among BACE inhibitors reported to potently lower central Aß in nonrodent preclinical species.
Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Desenho de Fármacos , Compostos Heterocíclicos/química , Iminas/química , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Animais , Córtex Cerebral/metabolismo , Inibidores Enzimáticos/farmacologia , Macaca fascicularis , Estrutura Molecular , Ratos , Relação Estrutura-AtividadeRESUMO
Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are the most common genetic cause of familial and sporadic Parkinson's disease (PD). That the most prevalent mutation, G2019S, leads to increased kinase activity has led to a concerted effort to identify LRRK2 kinase inhibitors as a potential disease-modifying therapy for PD. An internal medicinal chemistry effort identified several potent and highly selective compounds with favorable drug-like properties. Here, we characterize the pharmacological properties of cis-2,6-dimethyl-4-(6-(5-(1-methylcyclopropoxy)-1H-indazol-3-yl)pyrimidin-4-yl)morpholine (MLi-2), a structurally novel, highly potent, and selective LRRK2 kinase inhibitor with central nervous system activity. MLi-2 exhibits exceptional potency in a purified LRRK2 kinase assay in vitro (IC50 = 0.76 nM), a cellular assay monitoring dephosphorylation of LRRK2 pSer935 LRRK2 (IC50 = 1.4 nM), and a radioligand competition binding assay (IC50 = 3.4 nM). MLi-2 has greater than 295-fold selectivity for over 300 kinases in addition to a diverse panel of receptors and ion channels. Acute oral and subchronic dosing in MLi-2 mice resulted in dose-dependent central and peripheral target inhibition over a 24-hour period as measured by dephosphorylation of pSer935 LRRK2. Treatment of MitoPark mice with MLi-2 was well tolerated over a 15-week period at brain and plasma exposures >100× the in vivo plasma IC50 for LRRK2 kinase inhibition as measured by pSer935 dephosphorylation. Morphologic changes in the lung, consistent with enlarged type II pneumocytes, were observed in MLi-2-treated MitoPark mice. These data demonstrate the suitability of MLi-2 as a compound to explore LRRK2 biology in cellular and animal models.
Assuntos
Antiparkinsonianos/efeitos adversos , Antiparkinsonianos/uso terapêutico , Indazóis/farmacologia , Inibidores de Proteínas Quinases/efeitos adversos , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Pirimidinas/farmacologia , Células Epiteliais Alveolares/efeitos dos fármacos , Células Epiteliais Alveolares/patologia , Animais , Comportamento Animal/efeitos dos fármacos , Ligação Competitiva , Encéfalo/metabolismo , Química Encefálica/efeitos dos fármacos , Linhagem Celular , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Relação Dose-Resposta a Droga , Humanos , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina , Pulmão/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mutação/genética , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/patologia , Doença de Parkinson/psicologia , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismoRESUMO
RATIONALE: Psychoses are debilitating side effects associated with current dopaminergic treatments for Parkinson's disease (PD). Prepulse inhibition (PPI), in which a non-startling stimulus reduces startle response to a subsequent startle-eliciting stimulus, is important in filtering out extraneous sensory stimuli. PPI deficits induced by dopamine agonists can model symptoms of psychosis. Adenosine A(2A) receptor antagonists, being developed as novel PD treatments, indirectly modulate dopamine signaling in the basal ganglia and may have an improved psychosis profile which could be detected using the PPI model. OBJECTIVES: The aims of this study is to characterize PPI in MitoPark mice, which exhibit progressive loss of dopamine signaling and develop a Parkinson-like motor phenotype, and assess standard and novel PD treatment effects on PPI in MitoPark mice, which more closely mimic the basal ganglia dopamine status of PD patients. RESULTS: MitoPark mice displayed enhanced PPI as dopamine tone decreased with age, consistent with studies in intact mice that show enhanced PPI in response to dopamine antagonists. Paradoxically, older MitoParks were more sensitive to PPI disruption when challenged with dopamine agonists such as apomorphine or pramipexole. Alternatively, SCH 412348, an adenosine A(2A) antagonist, did not disrupt PPI in MitoPark mice at doses that normalized hypoactivity. CONCLUSION: Use of MitoPark mice in the PPI assay to assess the potential for PD treatment to produce psychoses likely represents a more disease-relevant model. SCH 412348 does not differentially disrupt PPI as do dopamine agonists, perhaps indicative of an improved psychosis profile of adenosine A(2A) antagonists, even in PD patients with decreased dopamine tone in the basal ganglia.
Assuntos
Antagonistas do Receptor A2 de Adenosina/farmacologia , Modelos Animais de Doenças , Doença de Parkinson/fisiopatologia , Inibição Pré-Pulso/efeitos dos fármacos , Inibição Pré-Pulso/fisiologia , Pirimidinas/farmacologia , Triazóis/farmacologia , Envelhecimento/fisiologia , Animais , Apomorfina/farmacologia , Benzotiazóis/farmacologia , Agonistas de Dopamina/farmacologia , Masculino , Camundongos , Camundongos Transgênicos , Atividade Motora/efeitos dos fármacos , PramipexolRESUMO
Substantial evidence implicates ß-amyloid (Aß) peptides in the etiology of Alzheimer's disease (AD). Aß is produced by the proteolytic cleavage of the amyloid precursor protein by ß- and γ-secretase suggesting that γ-secretase inhibition may provide therapeutic benefit for AD. Although many γ-secretase inhibitors have been shown to be potent at lowering Aß, some have also been shown to have side effects following repeated administration. All of these side effects can be attributed to altered Notch signaling, another γ-secretase substrate. Here we describe the in vivo characterization of the novel γ-secretase inhibitor SCH 697466 in rodents. Although SCH 697466 was effective at lowering Aß, Notch-related side effects in the intestine and thymus were observed following subchronic administration at doses that provided sustained and complete lowering of Aß. However, additional studies revealed that both partial but sustained lowering of Aßand complete but less sustained lowering of Aß were successful approaches for managing Notch-related side effects. Further, changes in several Notch-related biomarkers paralleled the side effect observations. Taken together, these studies demonstrated that, by carefully varying the extent and duration of Aß lowering by γ-secretase inhibitors, it is possible to obtain robust and sustained lowering of Aß without evidence of Notch-related side effects.
RESUMO
An investigation is detailed of the structure activity relationships (SAR) of two sulfone side chains of compound (-)-1a (SCH 900229), a potent, PS1-selective γ-secretase inhibitor and clinical candidate for the treatment of Alzheimer's disease. Specifically, 4-CF(3) and 4-Br substituted arylsulfone analogs, (-)-1b and (-)-1c, are equipotent to compound (-)-1a. On the right hand side chain, linker size and terminal substituents of the pendant sulfone group are also investigated.
Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Benzopiranos/síntese química , Benzopiranos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Sulfonas/síntese química , Sulfonas/farmacologia , Benzopiranos/química , Ciclização , Ativação Enzimática/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Piranos/síntese química , Piranos/química , Piranos/farmacologia , Relação Estrutura-Atividade , Sulfonas/químicaRESUMO
From an initial lead 1, a structure-based design approach led to identification of a novel, high-affinity iminohydantoin BACE1 inhibitor that lowers CNS-derived Aß following oral administration to rats. Herein we report SAR development in the S3 and F' subsites of BACE1 for this series, the synthetic approaches employed in this effort, and in vivo data for the optimized compound.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/antagonistas & inibidores , Anticonvulsivantes/síntese química , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Inibidores Enzimáticos/síntese química , Hidantoínas/síntese química , Administração Oral , Doença de Alzheimer/sangue , Doença de Alzheimer/líquido cefalorraquidiano , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/sangue , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Animais , Anticonvulsivantes/farmacologia , Ácido Aspártico Endopeptidases/metabolismo , Sítios de Ligação , Simulação por Computador , Cristalografia por Raios X , Modelos Animais de Doenças , Desenho de Fármacos , Inibidores Enzimáticos/farmacologia , Humanos , Hidantoínas/farmacologia , Modelos Moleculares , Ligação Proteica , Ratos , Ratos Sprague-DawleyRESUMO
An exploration of the SAR of the side chain of a novel tricyclic series of γ-secretase inhibitors led to the identification of compound (-)-16 (SCH 900229), which is a potent and PS1 selective inhibitor of γ-secretase (Aß40 IC50 = 1.3 nM). Compound (-)-16 demonstrated excellent lowering of Aß after oral administration in preclinical animal models and was advanced to human clinical trials for further development as a therapeutic agent for the treatment of Alzheimer's disease.
RESUMO
Inhibition of BACE1 to prevent brain Aß peptide formation is a potential disease-modifying approach to the treatment of Alzheimer's disease. Despite over a decade of drug discovery efforts, the identification of brain-penetrant BACE1 inhibitors that substantially lower CNS Aß levels following systemic administration remains challenging. In this report we describe structure-based optimization of a series of brain-penetrant BACE1 inhibitors derived from an iminopyrimidinone scaffold. Application of structure-based design in tandem with control of physicochemical properties culminated in the discovery of compound 16, which potently reduced cortex and CSF Aß40 levels when administered orally to rats.
RESUMO
The endogenous opioid-like peptide, nociceptin, produces anxiolytic-like effects that are mediated via the nociceptin (NOP) receptor. Similarly, synthetic, non-peptide NOP agonists produce robust anxiolytic-like effects although these effects are limited by marked side effects. In the present studies, the effects of a novel NOP receptor agonist, SCH 655842, were examined in rodent models sensitive to anxiolytic drugs and tests measuring potential adverse affects. Oral administration of SCH 655842 produced robust, anxiolytic-like effects in three species, i.e., rat, guinea pig, and mouse. Specifically, SCH 655842 was effective in rat conditioned lick suppression (3-10 mg/kg) and fear-potentiated startle (3-10 mg/kg) tests, a guinea pig pup vocalization test (1-3 mg/kg), as well as in mouse Geller-Seifter (30 mg/kg) and marble burying (30 mg/kg) tests. The anxiolytic-like effect of SCH 655842 in the conditioned lick suppression test was attenuated by the NOP antagonist, J-113397. In mice, SCH 655842 reduced locomotor activity and body temperature at doses similar to the anxiolytic-like dose and these effects were absent in NOP receptor knockout mice. In rats, SCH 655842 did not produce adverse behavioral effects up to doses of 70-100 mg/kg. Pharmacokinetic studies in the rat confirmed dose-related increases in plasma and brain levels of SCH 655842 across a wide oral dose range. Taken together, SCH 655842 may represent a NOP receptor agonist with improved tolerability compared to other members of this class although further studies are necessary to establish whether this extends to higher species.
Assuntos
Ansiolíticos/efeitos adversos , Ansiolíticos/farmacologia , Compostos Azabicíclicos/efeitos adversos , Compostos Azabicíclicos/farmacologia , Receptores Opioides/agonistas , Animais , Ansiolíticos/sangue , Ansiolíticos/farmacocinética , Compostos Azabicíclicos/sangue , Compostos Azabicíclicos/farmacocinética , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Temperatura Corporal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Condicionamento Psicológico/efeitos dos fármacos , Condicionamento Psicológico/fisiologia , Relação Dose-Resposta a Droga , Medo/efeitos dos fármacos , Medo/fisiologia , Feminino , Técnicas de Inativação de Genes , Cobaias , Masculino , Camundongos , Atividade Motora/efeitos dos fármacos , Ratos , Receptores Opioides/deficiência , Receptores Opioides/genética , Teste de Desempenho do Rota-Rod , Especificidade da Espécie , Vocalização Animal/efeitos dos fármacos , Receptor de NociceptinaRESUMO
Metabotropic glutamate receptor 1 (mGluR1) antagonists interfere with learning and memory; however, their role in motor function is not well elucidated despite their abundance in brain areas implicated in the control of movement. Here, the effects of mGluR1 antagonism on movement, coordination, and motor learning were investigated. JNJ16259685, a selective mGluR1 antagonist (negative allosteric modulator), was tested in assays of motor skill, and motor learning in rats and mice. JNJ16259685 produced very minimal effects on locomotor activity and posture up to a dose of 30 mg/kg. Motor skill was unaffected for well-learned tasks (up to 30 mg/kg) in rats, but impaired in mice. Both rats and mice rats were profoundly impaired (0.3 mg/kg) in the acquisition of a novel motor skill (rotarod). These results implicate the mGluR1 receptor in the acquisition of novel motor skills. JNJ16259685 dramatically reduced rearing behavior, exploration of a novel environment and lever pressing for a food reward (rat: 0.3 mg/kg; mouse: 1 mg/kg). JNJ16259685 (30 mg/kg) had no effect on reflexive startle responses to loud auditory stimuli or foot shock in mice. Previous groups have proposed that mGluR1 antagonists induce a general reduction in motivation. The effects seen here to reduce exploration and reward are consistent with that hypothesis. Pharmacological inhibition of the mGluR1 receptor has a modest effect on motor function but blocks motor learning and may reduce motivation to perform simple behaviors.
Assuntos
Atividade Motora/efeitos dos fármacos , Desempenho Psicomotor/efeitos dos fármacos , Quinolinas/farmacologia , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Animais , Antagonistas de Aminoácidos Excitatórios/farmacologia , Aprendizagem/efeitos dos fármacos , Aprendizagem/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Animais , Atividade Motora/fisiologia , Desempenho Psicomotor/fisiologia , Ratos , Ratos Long-Evans , Reflexo de Sobressalto/efeitos dos fármacos , Reflexo de Sobressalto/fisiologiaRESUMO
A new class of 2,6-disubstituted morpholine N-arylsulfonamide gamma-secretase inhibitors was designed based on the introduction of a morpholine core in lieu or piperidine in our lead series. This resulted in compounds with improved CYP 3A4 profiles. Several analogs that were active at lowering Abeta levels in Tg CRND8 mice upon oral administration were identified.