RESUMO
BACKGROUND: Transthyretin amyloid (ATTR) cardiomyopathy is a progressive and fatal disease caused by misfolded transthyretin. Despite advances in slowing disease progression, there is no available treatment that depletes ATTR from the heart for the amelioration of cardiac dysfunction. NI006 is a recombinant human anti-ATTR antibody that was developed for the removal of ATTR by phagocytic immune cells. METHODS: In this phase 1, double-blind trial, we randomly assigned (in a 2:1 ratio) 40 patients with wild-type or variant ATTR cardiomyopathy and chronic heart failure to receive intravenous infusions of either NI006 or placebo every 4 weeks for 4 months. Patients were sequentially enrolled in six cohorts that received ascending doses (ranging from 0.3 to 60 mg per kilogram of body weight). After four infusions, patients were enrolled in an open-label extension phase in which they received eight infusions of NI006 with stepwise increases in the dose. The safety and pharmacokinetic profiles of NI006 were assessed, and cardiac imaging studies were performed. RESULTS: The use of NI006 was associated with no apparent drug-related serious adverse events. The pharmacokinetic profile of NI006 was consistent with that of an IgG antibody, and no antidrug antibodies were detected. At doses of at least 10 mg per kilogram, cardiac tracer uptake on scintigraphy and extracellular volume on cardiac magnetic resonance imaging, both of which are imaging-based surrogate markers of cardiac amyloid load, appeared to be reduced over a period of 12 months. The median N-terminal pro-B-type natriuretic peptide and troponin T levels also seemed to be reduced. CONCLUSIONS: In this phase 1 trial of the recombinant human antibody NI006 for the treatment of patients with ATTR cardiomyopathy and heart failure, the use of NI006 was associated with no apparent drug-related serious adverse events. (Funded by Neurimmune; NI006-101 ClinicalTrials.gov number, NCT04360434.).
Assuntos
Neuropatias Amiloides Familiares , Anticorpos , Cardiomiopatias , Insuficiência Cardíaca , Proteínas Recombinantes , Humanos , Neuropatias Amiloides Familiares/diagnóstico por imagem , Neuropatias Amiloides Familiares/tratamento farmacológico , Neuropatias Amiloides Familiares/complicações , Anticorpos/administração & dosagem , Anticorpos/efeitos adversos , Anticorpos/farmacologia , Anticorpos/uso terapêutico , Cardiomiopatias/diagnóstico por imagem , Cardiomiopatias/tratamento farmacológico , Cardiomiopatias/etiologia , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/etiologia , Imageamento por Ressonância Magnética , Pré-Albumina , Método Duplo-Cego , Doença Crônica , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/farmacocinética , Proteínas Recombinantes/uso terapêutico , Infusões IntravenosasRESUMO
Fragile X-associated tremor/ataxia syndrome (FXTAS) is an inherited neurodegenerative disorder manifesting in carriers of 55 to 200 CGG repeats in the 5' untranslated region (UTR) of the fragile X mental retardation gene (FMR1). FXTAS is characterized by enhanced FMR1 transcription and the accumulation of CGG repeat-containing FMR1 messenger RNA in nuclear foci, while the FMRP protein expression levels remain normal or moderately low. The neuropathological hallmark in FXTAS is the presence of intranuclear, ubiquitin-positive inclusions that also contain FMR1 transcript. Yet, the complete protein complement of FXTAS inclusions and the molecular events that trigger neuronal death in FXTAS remain unclear. In this review, we present the two most accepted toxicity mechanisms described so far, namely RNA gain-of-function and protein gain-of-function by means of repeat-associated non-AUG translation, and discuss current experimental and computational strategies to better understand FXTAS pathogenesis. Finally, we review the current perspectives for drug development with disease-modifying potential for FXTAS.
Assuntos
Ataxia/tratamento farmacológico , Ataxia/metabolismo , Síndrome do Cromossomo X Frágil/tratamento farmacológico , Síndrome do Cromossomo X Frágil/metabolismo , Tremor/tratamento farmacológico , Tremor/metabolismo , Animais , Ataxia/genética , Descoberta de Drogas , Síndrome do Cromossomo X Frágil/genética , Humanos , Tremor/genéticaRESUMO
The metabotropic glutamate receptor 5 (mGlu5) is a glutamate-activated class C G protein-coupled receptor widely expressed in the central nervous system and clinically investigated as a drug target for a range of indications, including depression, Parkinson's disease, and fragile X syndrome. Here, we present the novel potent, selective, and orally bioavailable mGlu5 negative allosteric modulator with inverse agonist properties 2-chloro-4-((2,5-dimethyl-1-(4-(trifluoromethoxy)phenyl)-1H-imidazol-4-yl)ethynyl)pyridine (CTEP). CTEP binds mGlu5 with low nanomolar affinity and shows >1000-fold selectivity when tested against 103 targets, including all known mGlu receptors. CTEP penetrates the brain with a brain/plasma ratio of 2.6 and displaces the tracer [(3)H]3-(6-methyl-pyridin-2-ylethynyl)-cyclohex-2-enone-O-methyl-oxime (ABP688) in vivo in mice from brain regions expressing mGlu5 with an average ED(50) equivalent to a drug concentration of 77.5 ng/g in brain tissue. This novel mGlu5 inhibitor is active in the stress-induced hyperthermia procedure in mice and the Vogel conflict drinking test in rats with minimal effective doses of 0.1 and 0.3 mg/kg, respectively, reflecting a 30- to 100-fold higher in vivo potency compared with 2-methyl-6-(phenylethynyl)pyridine (MPEP) and fenobam. CTEP is the first reported mGlu5 inhibitor with both long half-life of approximately 18 h and high oral bioavailability allowing chronic treatment with continuous receptor blockade with one dose every 48 h in adult and newborn animals. By enabling long-term treatment through a wide age range, CTEP allows the exploration of the full therapeutic potential of mGlu5 inhibitors for indications requiring chronic receptor inhibition.
Assuntos
Comportamento Animal/efeitos dos fármacos , Encéfalo/metabolismo , Febre/tratamento farmacológico , Imidazóis/farmacologia , Imidazóis/farmacocinética , Piridinas/farmacologia , Piridinas/farmacocinética , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Administração Oral , Regulação Alostérica/efeitos dos fármacos , Animais , Ansiolíticos/farmacologia , Disponibilidade Biológica , Barreira Hematoencefálica/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Cálcio/metabolismo , AMP Cíclico/metabolismo , Avaliação Pré-Clínica de Medicamentos , Células HEK293 , Humanos , Imidazóis/administração & dosagem , Imidazóis/metabolismo , Fosfatos de Inositol/metabolismo , Masculino , Camundongos , Terapia de Alvo Molecular , Plasmídeos , Piridinas/administração & dosagem , Piridinas/metabolismo , Ensaio Radioligante , Ratos , Ratos Sprague-Dawley , Receptor de Glutamato Metabotrópico 5 , Receptores de Glutamato Metabotrópico/agonistasRESUMO
Transthyretin amyloid (ATTR) cardiomyopathy is a debilitating disease leading to heart failure and death. It is characterized by the deposition of extracellular ATTR fibrils in the myocardium. Reducing myocardial ATTR load is a therapeutic goal anticipated to translate into restored cardiac function and improved patient survival. For this purpose, we developed the selective anti-ATTR antibody NI301A, a recombinant human monoclonal immunoglobulin G1. NI301A was cloned following comprehensive analyses of memory B cell repertoires derived from healthy elderly subjects. NI301A binds selectively with high affinity to the disease-associated ATTR aggregates of either wild-type or variant ATTR related to sporadic or hereditary disease, respectively. It does not bind physiological transthyretin. NI301A removes ATTR deposits ex vivo from patient-derived myocardium by macrophages, as well as in vivo from mice grafted with patient-derived ATTR fibrils in a dose- and time-dependent fashion. The biological activity of ATTR removal involves antibody-mediated activation of phagocytic immune cells including macrophages. These data support the evaluation of safety and tolerability of NI301A in an ongoing phase 1 clinical trial in patients with ATTR cardiomyopathy.
Assuntos
Neuropatias Amiloides Familiares/tratamento farmacológico , Anticorpos Monoclonais/farmacologia , Cardiomiopatias/tratamento farmacológico , Macrófagos/imunologia , Pré-Albumina/antagonistas & inibidores , Idoso de 80 Anos ou mais , Neuropatias Amiloides Familiares/genética , Neuropatias Amiloides Familiares/patologia , Animais , Anticorpos Monoclonais/uso terapêutico , Cardiomiopatias/patologia , Ensaios Clínicos Fase I como Assunto , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos , Mutação , Miocárdio/patologia , Fagocitose/efeitos dos fármacos , Fagocitose/imunologia , Pré-Albumina/genética , Pré-Albumina/metabolismo , Agregados Proteicos/efeitos dos fármacos , Agregados Proteicos/imunologia , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Transplante HeterólogoRESUMO
BACKGROUND: Fragile X syndrome (FXS) is the most common genetic cause for intellectual disability. Fmr1 knockout (KO) mice are an established model of FXS. Chronic pharmacological inhibition of metabotropic glutamate receptor 5 (mGlu5) in these mice corrects multiple molecular, physiological, and behavioral phenotypes related to patients' symptoms. To better understand the pathophysiology of FXS and the effect of treatment, brain activity was analyzed using functional magnetic resonance imaging in relation to learning and memory performance. METHODS: Wild-type (WT) and Fmr1 KO animals receiving chronic treatment with the mGlu5 inhibitor CTEP or vehicle were evaluated consecutively for 1) learning and memory performance in the inhibitory avoidance and extinction test, and 2) for the levels of brain activity using continuous arterial spin labeling based functional magnetic resonance imaging. Neural activity patterns were correlated with cognitive performance using a multivariate regression analysis. Furthermore, mGlu5 receptor expression in brains of untreated mice was analyzed by autoradiography and saturation analysis using [(3)H]-ABP688. RESULTS: Chronic CTEP treatment corrected the learning deficit observed in Fmr1 KO mice in the inhibitory avoidance and extinction test and prevented memory extinction in WT and Fmr1 KO animals. Chronic CTEP treatment normalized perfusion in the amygdala and the lateral hypothalamus in Fmr1 KO mice and furthermore decreased perfusion in the hippocampus and increased perfusion in primary sensorimotor cortical areas. No significant differences in mGlu5 receptor expression levels between Fmr1 WT and KO mice were detected. CONCLUSIONS: Chronic mGlu5 inhibition corrected the learning deficits and partially normalized the altered brain activity pattern in Fmr1 KO mice.
Assuntos
Encéfalo/efeitos dos fármacos , Cognição/efeitos dos fármacos , Antagonistas de Aminoácidos Excitatórios/uso terapêutico , Síndrome do Cromossomo X Frágil/tratamento farmacológico , Receptor de Glutamato Metabotrópico 5/antagonistas & inibidores , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Encéfalo/irrigação sanguínea , Modelos Animais de Doenças , Eletrochoque/efeitos adversos , Antagonistas de Aminoácidos Excitatórios/farmacocinética , Extinção Psicológica/efeitos dos fármacos , Proteína do X Frágil da Deficiência Intelectual/genética , Proteína do X Frágil da Deficiência Intelectual/metabolismo , Síndrome do Cromossomo X Frágil/genética , Síndrome do Cromossomo X Frágil/patologia , Imidazóis/uso terapêutico , Camundongos , Camundongos Knockout , Oximas/farmacocinética , Oxigênio/sangue , Piridinas/farmacocinética , Piridinas/uso terapêutico , Receptor de Glutamato Metabotrópico 5/metabolismo , Trítio/farmacocinéticaRESUMO
The rising rates of autism spectrum disorder (ASD) and the lack of effective medications to treat its core symptoms have led to an increased sense of urgency to identify therapies for this group of neurodevelopmental conditions. Developing drugs for ASD, however, has been challenging because of a limited understanding of its pathophysiology, difficulties in modelling the disease in vitro and in vivo, the heterogeneity of symptoms, and the dearth of prior experience in clinical development. In the past few years these challenges have been mitigated by considerable advances in our understanding of forms of ASD caused by single-gene alterations, such as fragile X syndrome and tuberous sclerosis. In these cases we have gained insights into the pathophysiological mechanisms underlying these conditions. In addition, they have aided in the development of animal models and compounds with the potential for disease modification in clinical development. Moreover, genetic studies are illuminating the molecular pathophysiology of ASD, and new tools such as induced pluripotent stem cells offer novel possibilities for drug screening and disease diagnostics. Finally, large-scale collaborations between academia and industry are starting to address some of the key barriers to developing drugs for ASD. Here, we propose a conceptual framework for drug discovery in ASD encompassing target identification, drug profiling and considerations for clinical trials in this novel area.
Assuntos
Transtornos Globais do Desenvolvimento Infantil/tratamento farmacológico , Desenho de Fármacos , Descoberta de Drogas , Animais , Criança , Transtornos Globais do Desenvolvimento Infantil/genética , Transtornos Globais do Desenvolvimento Infantil/fisiopatologia , Ensaios Clínicos como Assunto , Comportamento Cooperativo , Modelos Animais de Doenças , Indústria Farmacêutica/métodos , Indústria Farmacêutica/organização & administração , Humanos , Terapia de Alvo MolecularRESUMO
Fragile X syndrome (FXS) is the most common form of inherited intellectual disability. Previous studies have implicated mGlu5 in the pathogenesis of the disease, but a crucial unanswered question is whether pharmacological mGlu5 inhibition is able to reverse an already established FXS phenotype in mammals. Here we have used the novel, potent, and selective mGlu5 inhibitor CTEP to address this issue in the Fmr1 knockout mouse. Acute CTEP treatment corrects elevated hippocampal long-term depression, protein synthesis, and audiogenic seizures. Chronic treatment that inhibits mGlu5 within a receptor occupancy range of 81% ± 4% rescues cognitive deficits, auditory hypersensitivity, aberrant dendritic spine density, overactive ERK and mTOR signaling, and partially corrects macroorchidism. This study shows that a comprehensive phenotype correction in FXS is possible with pharmacological intervention starting in young adulthood, after development of the phenotype. It is of great interest how these findings may translate into ongoing clinical research testing mGlu5 inhibitors in FXS patients.
Assuntos
Antagonistas de Aminoácidos Excitatórios/uso terapêutico , Síndrome do Cromossomo X Frágil/tratamento farmacológico , Imidazóis/uso terapêutico , Piridinas/uso terapêutico , Receptores de Glutamato Metabotrópico/efeitos dos fármacos , Fatores Etários , Animais , Modelos Animais de Doenças , Esquema de Medicação , Proteína do X Frágil da Deficiência Intelectual/genética , Síndrome do Cromossomo X Frágil/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Masculino , Camundongos , Camundongos Knockout , Fenótipo , Receptor de Glutamato Metabotrópico 5 , Receptores de Glutamato Metabotrópico/metabolismoRESUMO
BACKGROUND: Traumatic experiences in early life are risk factors for the development of behavioral and emotional disorders. Such disorders can persist through adulthood and have often been reported to be transmitted across generations. METHODS: To investigate the transgenerational effect of early stress, mice were exposed to chronic and unpredictable maternal separation from postnatal day 1 to 14. RESULTS: We show that chronic and unpredictable maternal separation induces depressive-like behaviors and alters the behavioral response to aversive environments in the separated animals when adult. Most of the behavioral alterations are further expressed by the offspring of males subjected to maternal separation, despite the fact that these males are reared normally. Chronic and unpredictable maternal separation also alters the profile of DNA methylation in the promoter of several candidate genes in the germline of the separated males. Comparable changes in DNA methylation are also present in the brain of the offspring and are associated with altered gene expression. CONCLUSIONS: These findings highlight the negative impact of early stress on behavioral responses across generations and on the regulation of DNA methylation in the germline.
Assuntos
Comportamento Animal/fisiologia , Metilação de DNA , Epigênese Genética , Privação Materna , Estresse Psicológico/genética , Fatores Etários , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Metilação de DNA/fisiologia , Feminino , Expressão Gênica , Humanos , Masculino , Transtornos Mentais/etiologia , Camundongos , Modelos Animais , Fatores Sexuais , Estresse Psicológico/complicações , Estresse Psicológico/fisiopatologiaRESUMO
The molecular underpinnings of exploration and its link to learning and memory remain poorly understood. Here we show that inducible, modest overexpression of neuronal calcium sensor 1 (Ncs1) selectively in the adult murine dentate gyrus (DG) promotes a specific form of exploratory behavior. The mice also display a selective facilitation of long-term potentiation (LTP) in the medial perforant path and a selective enhancement in rapid-acquisition spatial memory, phenotypes that are reversed by direct application of a cell-permeant peptide (DNIP) designed to interfere with NCS-1 binding to the dopamine type-2 receptor (D2R). Moreover, the DNIP and the D2R-selective antagonist L-741,626 attenuated exploratory behavior, DG LTP, and spatial memory in control mice. These data demonstrate a role for NCS-1 and D2R in DG plasticity and provide insight for understanding how the DG contributes to the origin of exploration and spatial memory acquisition.
Assuntos
Giro Denteado/fisiologia , Comportamento Exploratório/fisiologia , Potenciação de Longa Duração/fisiologia , Memória/fisiologia , Proteínas Sensoras de Cálcio Neuronal/metabolismo , Neuropeptídeos/metabolismo , Percepção Espacial/fisiologia , Animais , Membrana Celular/metabolismo , Giro Denteado/efeitos dos fármacos , Antagonistas de Dopamina/farmacologia , Antagonistas dos Receptores de Dopamina D2 , Comportamento Exploratório/efeitos dos fármacos , Técnicas In Vitro , Indóis/farmacologia , Aprendizagem/efeitos dos fármacos , Aprendizagem/fisiologia , Potenciação de Longa Duração/efeitos dos fármacos , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Memória/efeitos dos fármacos , Camundongos , Camundongos Transgênicos , Modelos Neurológicos , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Testes Neuropsicológicos , Piperidinas/farmacologia , Ratos , Receptores de Dopamina D2/metabolismo , Reconhecimento Psicológico/efeitos dos fármacos , Reconhecimento Psicológico/fisiologia , Percepção Espacial/efeitos dos fármacos , Fatores de TempoRESUMO
To achieve inducible and reversible gene expression in the adult mouse brain, we exploited an improved version of the tetracycline-controlled transactivator-based system (rtTA2(S)-M2, rtTA2 hereafter) and combined it with the forebrain-specific CaMKIIalpha promoter. Several independent lines of transgenic mice carrying the CaMKIIalpha promoter-rtTA2 gene were generated and examined for anatomical profile, doxycycline (dox)-dependence, time course, and reversibility of gene expression using several lacZ reporter lines. In two independent rtTA2-expressing lines, dox-treatment in the diet induced lacZ reporter expression in neurons of several forebrain structures including cortex, striatum, hippocampus, amygdala, and olfactory bulb. Gene expression was dose-dependent and was fully reversible. Further, a similar pattern of expression was obtained in three independent reporter lines, indicating the consistency of gene expression. Transgene expression could also be activated in the developing brain (P0) by dox-treatment of gestating females. These new rtTA2-expressing mice allowing inducible and reversible gene expression in the adult or developing forebrain represent useful models for future genetic studies of brain functions.
Assuntos
Encéfalo/metabolismo , Doxiciclina/farmacologia , Neurônios/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Repressoras/genética , Transativadores/genética , Animais , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina , Proteínas Quinases Dependentes de Cálcio-Calmodulina/genética , Feminino , Regulação da Expressão Gênica , Genes Reporter , Vetores Genéticos , Óperon Lac , Camundongos , Camundongos Transgênicos , Gravidez , Regiões Promotoras Genéticas , Prosencéfalo/metabolismoRESUMO
Repetition in learning is a prerequisite for the formation of accurate and long-lasting memory. Practice is most effective when widely distributed over time, rather than when closely spaced or massed. But even after efficient learning, most memories dissipate with time unless frequently used. The molecular mechanisms of these time-dependent constraints on learning and memory are unknown. Here we show that protein phosphatase 1 (PP1) determines the efficacy of learning and memory by limiting acquisition and favouring memory decline. When PP1 is genetically inhibited during learning, short intervals between training episodes are sufficient for optimal performance. The enhanced learning correlates with increased phosphorylation of cyclic AMP-dependent response element binding (CREB) protein, of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and of the GluR1 subunit of the AMPA receptor; it also correlates with CREB-dependent gene expression that, in control mice, occurs only with widely distributed training. Inhibition of PP1 prolongs memory when induced after learning, suggesting that PP1 also promotes forgetting. This property may account for ageing-related cognitive decay, as old mutant animals had preserved memory. Our findings emphasize the physiological importance of PP1 as a suppressor of learning and memory, and as a potential mediator of cognitive decline during ageing.