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1.
J Clin Psychiatry ; 85(1)2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38127305

RESUMO

Patients with amyotrophic lateral sclerosis (ALS) are impacted both physically and psychiatrically during their illness. Emotional distress (ie, anxiety, depression, stress) is common in patients diagnosed with ALS, as prognosis is poor and there are very few effective treatments. The progression of symptoms is unpredictable, and all cases are terminal. Neuropsychiatric symptoms are also increasingly recognized as part of ALS symptomatology. There are currently no empirically supported interventions or best practices for adjustment to ALS. This case presents both the psychological and pharmacologic aspects of caring for a patient with ALS. Psychotherapy utilized a cognitive behavioral therapy-informed approach, and pharmacotherapy was tailored to the specific needs of the patient. We explore how these approaches impacted our patient, as well as how ALS-specific challenges presented throughout the course of treatment.


Assuntos
Esclerose Lateral Amiotrófica , Terapia Cognitivo-Comportamental , Angústia Psicológica , Idoso , Humanos , Masculino , Esclerose Lateral Amiotrófica/complicações , Esclerose Lateral Amiotrófica/diagnóstico , Esclerose Lateral Amiotrófica/terapia , Psicoterapia
2.
Am J Psychiatry ; 179(2): 122-131, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34933568

RESUMO

Objective: The purpose of this study was to examine the effects of REL-1017 (esmethadone), a novel N-methyl-d-aspartate receptor (NMDAR) channel blocker, in patients with major depressive disorder who failed to benefit from one to three standard antidepressant treatments in their current major depressive episode. Methods: A 7-day phase 2 multicenter randomized double-blind placebo-controlled trial, comprising three arms, was conducted to assess the safety, tolerability, pharmacokinetics, and efficacy of two dosages of REL-1017 (25 mg or 50 mg orally once a day). Patients were randomly assigned in a 1:1:1 ratio to placebo (N=22), REL-1017 25 mg/day (N=19), or REL-1017 50 mg/day (N=21). Safety scales included the 4-item Positive Symptom Rating Scale for psychotomimetic symptoms, the Clinician-Administered Dissociative States Scale for dissociative symptoms, the Clinical Opiate Withdrawal Scale for withdrawal signs and symptoms, and the Columbia-Suicide Severity Rating Scale for suicidality. The primary efficacy endpoint was the Montgomery-Åsberg Depression Scale (MADRS) score. All 62 randomly assigned patients were included in the full analysis set population analysis. Results: Patients experienced mild or moderate transient adverse events and no evidence of dissociative or psychotomimetic effects, opioid effects, or withdrawal signs and symptoms. The improvement in MADRS score shown on day 4 in both of the REL-1017 dosage groups was sustained through day 7 (last dose) and day 14 (7 days after the last dose), with effect sizes from 0.7 to 1.0. Conclusions: This trial showed favorable safety, tolerability, and pharmacokinetic profiles and suggests that REL-1017 may have rapid and sustained antidepressant effects compared with placebo in patients with inadequate responses to antidepressant treatments. These results will need confirmation in larger and longer trials.


Assuntos
Transtorno Depressivo Maior , Antidepressivos/efeitos adversos , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/tratamento farmacológico , Método Duplo-Cego , Humanos , Ideação Suicida , Resultado do Tratamento
3.
Int J Psychiatry Med ; 56(6): 459-469, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33297806

RESUMO

We present the case of a 61-year-old retired catholic priest, who was adopted at a very young age, with psychiatric history of anxiety and depression presenting for evaluation of at least 4 year memory loss and word finding difficulties. Over the preceding couple of years his cognitive functions had rapidly declined. As a result, he became dependent on his elderly parents for most of his instrumental activities of daily living including administration of medication, financial management, and driving. He continues to be independent in his personal care. His presentation offered diagnostic challenges due to the interplay of anxiety and cognitive disorders involving both memory and language domains. In addition, he resisted to repeat formal neuropsychological evaluation. At the bedside, his poor effort on testing was often blamed on his severe anxiety confounding the clinical picture. Lack of knowledge of his family history and his childhood development, and unclear premorbid functioning complicated the diagnostic formulation. A differential diagnosis ranging from possible functional cognitive disorder to neurodevelopmental disorder and neurodegenerative disorders will be discussed.


Assuntos
Atividades Cotidianas , Transtornos Cognitivos , Idoso , Transtornos de Ansiedade/diagnóstico , Criança , Transtornos Cognitivos/diagnóstico , Diagnóstico Diferencial , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos
4.
Exp Clin Psychopharmacol ; 28(2): 196-201, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31368772

RESUMO

d-Methadone (dextromethadone) is a noncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonist that binds to the dizocilpine (MK-801)-binding site of the receptor with an affinity comparable with that of well-established NMDAR antagonists. Considering the similar NMDAR activity of ketamine and d-methadone and the rapid and robust antidepressant effects of ketamine, we compared these 2 drugs in the forced swim test in Sprague-Dawley rats, which has been shown to be predictive of antidepressant activity for drugs with different mechanisms of action including ketamine. This study evaluated the antidepressant-like effect of d-methadone (10, 20, and 40 mg/kg) in the forced swim test 24 hr following a single-dose administration. At all doses, d-methadone significantly (p < .05) decreased immobility of rats compared with vehicle, suggesting antidepressant-like activity. In addition, the effect of d-methadone (20 and 40 mg/kg) on immobility was greater than the effect seen with ketamine (10 mg/kg). Importantly, there were no changes in locomotor activity of rats that could have confounded the immobility effects at all doses (10, 20, and 40 mg/kg) of d-methadone. This is the first demonstration that the NMDAR antagonist, d-methadone, exerts antidepressant-like activity in a preclinical animal model and that its efficacy is similar to or even stronger than that of ketamine, an antidepressant that demonstrates a rapid onset activity and robust efficacy in patients with treatment-resistant depression. d-Methadone is currently being evaluated in a Phase 2a clinical study for patients with treatment-resistant depression and could potentially represent a new effective antidepressant in the growing class of NMDAR antagonists. (PsycInfo Database Record (c) 2020 APA, all rights reserved).


Assuntos
Antidepressivos/farmacologia , Depressão/tratamento farmacológico , Metadona/uso terapêutico , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Animais , Ketamina/farmacologia , Masculino , Ratos , Ratos Sprague-Dawley , Natação
5.
Neuropsychopharmacology ; 44(13): 2230-2238, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31454827

RESUMO

Currently available antidepressants have a delayed onset and limited efficacy, highlighting the need for new, rapid and more efficacious agents. Ketamine, an NMDA receptor antagonist, has emerged as a new rapid-acting antidepressant, effective even in treatment resistant patients. However, ketamine induces undesired psychotomimetic and dissociative side effects that limit its clinical use. The d-stereoisomer of methadone (dextromethadone; REL-1017) is a noncompetitive NMDA receptor antagonist with an apparently favorable safety and tolerability profile. The current study examined the rapid and sustained antidepressant actions of d-methadone in several behavioral paradigms, as well as on mTORC1 signaling and synaptic changes in the medial prefrontal cortex (mPFC). A single dose of d-methadone promoted rapid and sustained antidepressant responses in the novelty-suppressed feeding test (NSFT), a measure of anxiety, and in the female urine sniffing test (FUST), a measure of motivation and reward. D-methadone also produced a rapid reversal of the sucrose preference deficit, a measure of anhedonia, in rats exposed to chronic unpredictable stress. D-methadone increased phospho-p70S6 kinase, a downstream target of mTORC1 in the mPFC, and intra-mPFC infusion of the selective mTORC1 inhibitor rapamycin blocked the antidepressant actions of d-methadone in the FUST and NSFT. D-methadone administration also increased levels of the synaptic proteins, PSD95, GluA1, and Synapsin 1 and enhanced synaptic function in the mPFC. Studies in primary cortical cultures show that d-methadone also increases BDNF release, as well as phospho-p70S6 kinase. These findings indicate that d-methadone induces rapid antidepressant actions through mTORC1-mediated synaptic plasticity in the mPFC similar to ketamine.


Assuntos
Antidepressivos/administração & dosagem , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Metadona/administração & dosagem , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Animais , Espinhas Dendríticas/efeitos dos fármacos , Espinhas Dendríticas/fisiologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Ketamina/administração & dosagem , Masculino , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos
6.
J Clin Psychopharmacol ; 39(3): 226-237, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30939592

RESUMO

PURPOSE/BACKGROUND: N-methyl-D-aspartate (NMDA) receptor (NMDAR) antagonists are potential agents for the treatment of several central nervous system disorders including major depressive disorder. Racemic methadone, L-methadone, and D-methadone all bind the NMDAR with an affinity similar to that of established NMDAR antagonists, whereas only L-methadone and racemic methadone bind to opioid receptors with high affinity. Therefore, D-methadone is expected to have no clinically significant opioid effects at therapeutic doses mediated by its NMDAR antagonism. METHODS: We conducted 2 phase 1, double-blind, randomized, placebo-controlled, single- and multiple-ascending-dose studies to investigate the safety and tolerability of oral D-methadone and to characterize its pharmacokinetic profile in healthy opioid-naive volunteers. RESULTS: D-Methadone exhibits linear pharmacokinetics with dose proportionality for most single-dose and multiple-dose parameters. Single doses up to 150 mg and daily doses up to 75 mg for 10 days were well tolerated with mostly mild treatment-emergent adverse events and no severe or serious adverse events. Dose-related somnolence and nausea occurred and were mostly present at the higher dose level. There was no evidence of respiratory depression, dissociative and psychotomimetic effects, or withdrawal signs and symptoms upon abrupt discontinuation. An overall dose-response effect was observed, with higher doses resulting in larger QTcF (QT interval corrected using Fridericia formula) changes from baseline, but none of the changes were considered clinically significant by the investigators. Mild, dose-dependent pupillary constriction of brief duration occurred particularly at the 60-mg dose or above in the single-ascending-dose study and at the dose of 75 mg in the multiple-ascending-dose study. No detectable conversion of D-methadone to L-methadone occurred in vivo. CONCLUSIONS: These results support the safety and continued clinical development of D-methadone as an NMDAR antagonist for the treatment of depression and other central nervous system disorders.


Assuntos
Analgésicos não Narcóticos/administração & dosagem , Metadona/administração & dosagem , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Adulto , Analgésicos não Narcóticos/efeitos adversos , Analgésicos não Narcóticos/farmacocinética , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Masculino , Metadona/efeitos adversos , Metadona/farmacocinética , Pessoa de Meia-Idade , Adulto Jovem
8.
Neuropharmacology ; 117: 171-181, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28122201

RESUMO

Phosphodiesterase 10A (PDE10A) is an enzyme highly enriched in the striatal medium spiny neurons. It is involved in the regulation of cytoplasmic levels of cAMP and cGMP and signaling within the basal ganglia. This study with PDE10A radioligand [18F]MNI-659 was designed to measure the enzyme occupancy of PF-02545920 in 8 healthy male volunteers (48 ± 4 years) after a single oral dose (10 mg or 20 mg) and to evaluate safety and tolerability. Arterial blood sampling was performed to obtain a metabolite-corrected plasma input function for the quantification of [18F]MNI-659 binding to PDE10A. The occupancy of PF-02545920 was calculated with two different methods: In Method 1, [18F]MNI-659 enzyme occupancy was calculated from the estimates of binding potential, using the cerebellum as a reference region; in Method 2, occupancy was estimated from the slope of the revised Lassen's plot. Serum concentrations of PF-02545920 were measured to determine the relationship between concentration and occupancy. Based on Method 1, striatal PDE10A occupancy increased with increasing PF-02545920 dose: 14-27% at 10 mg dose (N = 4) and 45-63% at 20 mg dose (N = 3). Comparable occupancies were observed using Lassen's plot Method 2: 10 mg: 14-37%; 20 mg: 46-55%. The relationship between exposure and occupancy was best described using an Emax model. The serum concentration associated with 50% occupancy was estimated to be 93.2 ng/mL. Single oral doses of 10 mg or 20 mg of PF-02545920 were safe and well tolerated in healthy male volunteers [NCT# 01918202].


Assuntos
Diester Fosfórico Hidrolases/metabolismo , Pirazóis/farmacologia , Quinolinas/farmacologia , Adulto , Corpo Estriado/metabolismo , Radioisótopos de Flúor/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Ftalimidas/sangue , Ftalimidas/metabolismo , Tomografia por Emissão de Pósitrons , Pirazóis/efeitos adversos , Pirazóis/farmacocinética , Quinazolinonas/sangue , Quinazolinonas/metabolismo , Quinolinas/efeitos adversos , Quinolinas/farmacocinética , Ensaio Radioligante/métodos
9.
Alzheimers Dement ; 12(5): 623-30, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27017906

RESUMO

Given the complex neuropathology Alzheimer's disease (AD), combination therapy may be necessary for effective treatment. However, scientific, pragmatic, regulatory, and business challenges need to be addressed before combination therapy for AD can become a reality. Leaders from academia and industry, along with a former member of the Food and Drug Administration and the Alzheimer's Association, have explored these challenges and here propose a strategy to facilitate proof-of-concept combination therapy trials in the near future. First, a more integrated understanding of the complex pathophysiology and progression of AD is needed to identify the appropriate pathways and the disease stage to target. Once drug candidates are identified, novel clinical trial designs and selection of appropriate outcome assessments will be needed to enable definition and evaluation of the appropriate dose and dosing regimen and determination of efficacy. Success in addressing this urgent problem will only be achieved through collaboration among multiple stakeholders.


Assuntos
Doença de Alzheimer/fisiopatologia , Avaliação de Medicamentos , Quimioterapia Combinada , Doença de Alzheimer/tratamento farmacológico , Secretases da Proteína Precursora do Amiloide/administração & dosagem , Humanos
10.
J Psychiatr Res ; 70: 98-105, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26424428

RESUMO

We examined efficacy and safety of one specific cranial electrical stimulator (CES) device at a fixed setting in subjects with treatment-resistant major depressive disorder (MDD). Thirty subjects (57% female, mean age 48.1 ± 12.3 years) with MDD and inadequate response to standard antidepressants were randomized to 3 weeks of treatment with CES (15/500/15,000 Hz, symmetrical rectangular biphasic current of 1-4 mAmp, 40 V) or sham CES (device off) for 20 min, 5 days per week. The primary outcome measure was improvement in the 17-item Hamilton Depression Rating Scale (HAM-D-17). Adverse effects (AEs) were assessed using the Patient Related Inventory of Side Effects (PRISE). Completion rates were 88% for CES, 100% for sham. Both treatment groups demonstrated improvement of about 3-5 points in HAM-D-17 scores (p < 0.05 for both), and no significant differences were observed between groups. Remission rates were 12% for CES, and 15% for sham, a nonsignificant difference. CES was deemed safe, with good tolerability; poor concentration and malaise were the only distressing AEs that differed significantly between CES and sham (p = 0.019 and p = 0.043, respectively). Limitations include a small sample and lack of an active comparator therapy. Although both treatment groups improved significantly, this CES at the setting chosen did not separate from sham in this sample. Thus we cannot rule out that the benefit from this setting used in this particular form of CES was due to placebo effects. Since this form of CES has other settings, future studies should test these settings and compare it against other CES devices. Clinicaltrials.gov ID: NCT01325532.


Assuntos
Antidepressivos/uso terapêutico , Transtorno Depressivo Maior/terapia , Transtorno Depressivo Resistente a Tratamento/terapia , Terapia por Estimulação Elétrica/métodos , Terapia Combinada/efeitos adversos , Terapia Combinada/métodos , Método Duplo-Cego , Terapia por Estimulação Elétrica/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Escalas de Graduação Psiquiátrica , Resultado do Tratamento
11.
Ann Clin Psychiatry ; 25(1): 3-10, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23376864

RESUMO

BACKGROUND: Antidepressant-induced sexual dysfunction affects approximately 50% of patients taking antidepressants. Previous research has explored sildenafil's effectiveness in treating various forms of erectile dysfunction, but there is no research supporting sildenafil's use for improving the quality of life for patients with sexual dysfunction linked to antidepressant use. The authors of this article aimed to assess the improvements in quality of life in patients taking sildenafil to treat antidepressant-induced sexual dysfunction. METHODS: One hundred and two out of 2,239 male and female patients in the follow-up phase of the Sequenced Treatment Alternatives to Relieve Depression antidepressant trials who complained of sexual dysfunction were given sildenafil, 50 to 100 mg, as needed. After 12 months, we measured patients' change in libido, sexual drive, family relationships, overall well-being, satisfaction with treatment, and overall contentment with items on the 17-item Hamilton Depression Rating Scale, Quality of Life Enjoyment and Satisfaction Questionnaire, 30-item Inventory of Depressive Symptoms, and 12-item Short Form Health Survey. RESULTS: There was a significant association between sildenafil use and improvement in libido and sexual drive by month 6. There was no significant improvement in the quality-of-life scores we examined, but treatment satisfaction and overall contentment increased over time. CONCLUSIONS: Despite no direct association with sildenafil use and quality-of-life scores, sildenafil may be a beneficial treatment for antidepressant-induced sexual dysfunction. A double-blind, placebo-controlled study of sildenafil in antidepressant-induced sexual dysfunction is needed to further explore its potential benefits.


Assuntos
Antidepressivos/efeitos adversos , Transtorno Depressivo Maior/tratamento farmacológico , Libido/efeitos dos fármacos , Piperazinas/administração & dosagem , Qualidade de Vida , Comportamento Sexual/efeitos dos fármacos , Disfunções Sexuais Fisiológicas , Sulfonas/administração & dosagem , Adulto , Antidepressivos/administração & dosagem , Antidepressivos/classificação , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Preferência do Paciente , Inibidores da Fosfodiesterase 5/administração & dosagem , Purinas/administração & dosagem , Comportamento Sexual/psicologia , Disfunções Sexuais Fisiológicas/induzido quimicamente , Disfunções Sexuais Fisiológicas/tratamento farmacológico , Disfunções Sexuais Fisiológicas/psicologia , Citrato de Sildenafila , Inquéritos e Questionários , Resultado do Tratamento
12.
J Clin Psychiatry ; 73(12): 1541-7, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23290327

RESUMO

OBJECTIVE: To study ziprasidone monotherapy for major depressive disorder, defined according to the DSM-IV. METHOD: One hundred twenty outpatients were enrolled between June 2008 and September 2010 in a 12-week study that was divided into two 6-week periods according to the sequential parallel comparison design. Patients were randomized in a 2:3:3 fashion to receive ziprasidone for 12 weeks, placebo for 6 weeks followed by ziprasidone for 6 weeks, or placebo for 12 weeks. The main outcome measure was the 17-item Hamilton Depression Rating Scale (HDRS-17), with the Quick Inventory of Depressive Symptomatology, Self-Rated (QIDS-SR), and Clinical Global Impressions-Severity of Illness scale (CGI-S) serving as the study secondary measures. RESULTS: One hundred twenty patients (53 women [44.1%]) were randomized to treatment. The mean (SD) age of these patients was 43.7 (11.0) years. Mean (SD) baseline HDRS-17, CGI-S, and QIDS-SR scores were 19.9 (5.0), 4.3 (0.6), and 15.6 (3.0), respectively. There was no statistically significant difference in reduction of depressive symptoms, response rates, or remission rates between ziprasidone- or placebo-treated patients. This was true for both the study primary as well as secondary outcome scales. CONCLUSIONS: In conclusion, treatment with ziprasidone monotherapy was not associated with any statistically significant advantage in efficacy over placebo. Although studies involving larger sample size would be required to have adequate statistical power to detect treatment differences smaller than 2.5 points on the HDRS-17, such differences would be of questionable clinical relevance. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00555997.


Assuntos
Antipsicóticos/uso terapêutico , Transtorno Depressivo Maior/tratamento farmacológico , Piperazinas/uso terapêutico , Tiazóis/uso terapêutico , Adulto , Antipsicóticos/efeitos adversos , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/psicologia , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inventário de Personalidade/estatística & dados numéricos , Piperazinas/efeitos adversos , Psicometria , Tiazóis/efeitos adversos
13.
Neuromolecular Med ; 12(1): 27-43, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20069392

RESUMO

The hallmark clinical symptom of early Alzheimer's disease (AD) is episodic memory impairment. Recent functional imaging studies suggest that memory function is subserved by a set of distributed networks, which include both the medial temporal lobe (MTL) system and the set of cortical regions collectively referred to as the default network. Specific regions of the default network, in particular, the posteromedial cortices, including the precuneus and posterior cingulate, are selectively vulnerable to early amyloid deposition in AD. These regions are also thought to play a key role in both memory encoding and retrieval, and are strongly functionally connected to the MTL. Multiple functional magnetic resonance imaging (fMRI) studies during memory tasks have revealed alterations in these networks in patients with clinical AD. Similar functional abnormalities have been detected in subjects at-risk for AD, including those with genetic risk and older individuals with mild cognitive impairment. Recently, we and other groups have found evidence of functional alterations in these memory networks even among cognitively intact older individuals with occult amyloid pathology, detected by PET amyloid imaging. Taken together, these findings suggest that the pathophysiological process of AD exerts specific deleterious effects on these distributed memory circuits, even prior to clinical manifestations of significant memory impairment. Interestingly, some of the functional alterations seen in prodromal AD subjects have taken the form of increases in activity relative to baseline, rather than a loss of activity. It remains unclear whether these increases in fMRI activity may be compensatory to maintain memory performance in the setting of early AD pathology or instead, represent evidence of excitotoxicity and impending neuronal failure. Recent studies have also revealed disruption of the intrinsic connectivity of these networks observable even during the resting state in early AD and asymptomatic individuals with high amyloid burden. Research is ongoing to determine if these early network alterations will serve as sensitive predictors of clinical decline, and eventually, as markers of pharmacological response to potential disease-modifying treatments for AD.


Assuntos
Doença de Alzheimer/fisiopatologia , Transtornos da Memória/fisiopatologia , Memória/fisiologia , Rede Nervosa/fisiopatologia , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Animais , Transtornos Cognitivos/patologia , Transtornos Cognitivos/fisiopatologia , Modelos Animais de Doenças , Predisposição Genética para Doença , Humanos , Imageamento por Ressonância Magnética , Transtornos da Memória/patologia , Rede Nervosa/fisiologia , Testes Neuropsicológicos
14.
Mol Cell Neurosci ; 33(3): 274-82, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16962789

RESUMO

Elevated levels of amyloid-beta peptide (Abeta) are found in Down's syndrome patients and alter synaptic function during the early stages of Alzheimer's disease. Dendritic spines, sites of most excitatory synaptic contacts, are considered to be an important locus for encoding synaptic plasticity. We used time-lapse two-photon imaging of hippocampal pyramidal neurons in organotypic slices to study the effects of Abeta on the development of dendritic spines. We report that exposure of hippocampal neurons to sub-lethal levels of Abeta decreased spine density, increased spine length and subdued spine motility. The effect of Abeta on spine density was reversible. Moreover, Abeta's effect on dendritic spine density was blocked by rolipram, a phosphodiesterase type IV inhibitor, suggesting the involvement of a cAMP dependent pathway. These findings raise the possibility that Abeta-induced spine alterations could underlie the cognitive defects in Alzheimer's disease and Down syndrome.


Assuntos
Peptídeos beta-Amiloides/efeitos adversos , Movimento Celular/efeitos dos fármacos , Espinhas Dendríticas/efeitos dos fármacos , Hipocampo/citologia , Fragmentos de Peptídeos/efeitos adversos , Células Piramidais/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Western Blotting/métodos , Sobrevivência Celular/efeitos dos fármacos , AMP Cíclico/fisiologia , Espinhas Dendríticas/ultraestrutura , Diagnóstico por Imagem/métodos , Imunofluorescência/métodos , Proteínas de Fluorescência Verde/metabolismo , Técnicas In Vitro , Camundongos , Microscopia Eletrônica de Varredura/métodos , Inibidores de Fosfodiesterase/farmacologia , Células Piramidais/citologia , Rolipram/farmacologia , Estatísticas não Paramétricas , Fatores de Tempo , Transfecção/métodos
15.
Cell ; 126(4): 775-88, 2006 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-16923396

RESUMO

The neuronal ubiquitin/proteasomal pathway has been implicated in the pathogenesis of Alzheimer's disease (AD). We now show that a component of the pathway, ubiquitin C-terminal hydrolase L1 (Uch-L1), is required for normal synaptic and cognitive function. Transduction of Uch-L1 protein fused to the transduction domain of HIV-transactivator protein (TAT) restores normal enzymatic activity and synaptic function both in hippocampal slices treated with oligomeric Abeta and in the APP/PS1 mouse model of AD. Moreover, intraperitoneal injections with the fusion protein improve the retention of contextual learning in APP/PS1 mice over time. The beneficial effect of the Uch-L1 fusion protein is associated with restoration of normal levels of the PKA-regulatory subunit IIalpha, PKA activity, and CREB phosphorylation.


Assuntos
Doença de Alzheimer/fisiopatologia , Precursor de Proteína beta-Amiloide/metabolismo , Memória/fisiologia , Proteínas Recombinantes de Fusão/metabolismo , Transmissão Sináptica/fisiologia , Ubiquitina Tiolesterase/metabolismo , Doença de Alzheimer/enzimologia , Precursor de Proteína beta-Amiloide/genética , Animais , Aprendizagem da Esquiva , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Modelos Animais de Doenças , Potenciais Pós-Sinápticos Excitadores/fisiologia , Medo , Produtos do Gene tat/genética , Produtos do Gene tat/metabolismo , Hipocampo/citologia , Hipocampo/metabolismo , Humanos , Técnicas In Vitro , Potenciação de Longa Duração/fisiologia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Presenilina-1 , Proteínas Recombinantes de Fusão/genética , Ubiquitina Tiolesterase/genética
16.
J Clin Invest ; 114(11): 1624-34, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15578094

RESUMO

Evidence suggests that Alzheimer disease (AD) begins as a disorder of synaptic function, caused in part by increased levels of amyloid beta-peptide 1-42 (Abeta42). Both synaptic and cognitive deficits are reproduced in mice double transgenic for amyloid precursor protein (AA substitution K670N,M671L) and presenilin-1 (AA substitution M146V). Here we demonstrate that brief treatment with the phosphodiesterase 4 inhibitor rolipram ameliorates deficits in both long-term potentiation (LTP) and contextual learning in the double-transgenic mice. Most importantly, this beneficial effect can be extended beyond the duration of the administration. One course of long-term systemic treatment with rolipram improves LTP and basal synaptic transmission as well as working, reference, and associative memory deficits for at least 2 months after the end of the treatment. This protective effect is possibly due to stabilization of synaptic circuitry via alterations in gene expression by activation of the cAMP-dependent protein kinase (PKA)/cAMP regulatory element-binding protein (CREB) signaling pathway that make the synapses more resistant to the insult inflicted by Abeta. Thus, agents that enhance the cAMP/PKA/CREB pathway have potential for the treatment of AD and other diseases associated with elevated Abeta42 levels.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Cognição/efeitos dos fármacos , Inibidores de Fosfodiesterase , Rolipram , Transmissão Sináptica/efeitos dos fármacos , Doença de Alzheimer/fisiopatologia , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Cognição/fisiologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Modelos Animais de Doenças , Hipocampo/citologia , Hipocampo/metabolismo , Humanos , Técnicas In Vitro , Aprendizagem/efeitos dos fármacos , Aprendizagem/fisiologia , Potenciação de Longa Duração/efeitos dos fármacos , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Transgênicos , Inibidores de Fosfodiesterase/farmacologia , Inibidores de Fosfodiesterase/uso terapêutico , Presenilina-1 , Rolipram/farmacologia , Rolipram/uso terapêutico , Transmissão Sináptica/fisiologia
17.
J Neurocytol ; 33(3): 377-87, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15475691

RESUMO

Synaptic damage and loss are factors that affect the degree of dementia experienced in Alzheimer disease (AD) patients. Multicolor DiOlistic labeling of the hippocampus has been undertaken which allows the full dendritic arbor of targeted neurons to be imaged. Using this labeling technique the neuronal morphology of two transgenic mouse lines (J20 and APP/PS1) expressing mutant forms of the Amyloid Precursor Protein (APP), at various ages, have been visualized and compared to Wild Type (WT) littermate controls. Swollen bulbous dystrophic neurites with loss of spines were apparent in the transgenic animals. Upon quantification, statistically significant reductions in the number of spines and total dendrite area was observed in both transgenic mouse lines at 11 months of age. Similar morphological abnormalities were seen in human AD hippocampal tissue both qualitatively and quantitatively. Immunohistochemistry and DiOlistic labeling was combined so that Abeta plaques were imaged in relation to the dendritic trees. No preferential localization of these abnormal dystrophic neurites was seen in regions with plaques. DiI labeled reative astrocytes were often apparent in close proximity to A beta plaques.


Assuntos
Doença de Alzheimer/patologia , Precursor de Proteína beta-Amiloide/genética , Dendritos/patologia , Espinhas Dendríticas/patologia , Hipocampo/patologia , Envelhecimento/metabolismo , Envelhecimento/patologia , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Animais , Astrócitos/metabolismo , Astrócitos/patologia , Biolística , Carbocianinas , Dendritos/metabolismo , Espinhas Dendríticas/metabolismo , Modelos Animais de Doenças , Hipocampo/metabolismo , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Transgênicos , Mutação/genética , Placa Amiloide/genética , Placa Amiloide/metabolismo , Placa Amiloide/patologia , Células Piramidais/metabolismo , Células Piramidais/patologia , Coloração e Rotulagem/métodos
18.
J Neurosci ; 22(24): 10690-8, 2002 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-12486162

RESUMO

6-hydroxydopamine, 1-methyl-4-phenyl-pyridinium (MPP+), and rotenone cause the death of dopaminergic neurons in vitro and in vivo and are widely used to model Parkinson's disease. To identify regulated genes in such models, we performed serial analysis of gene expression on neuronal PC12 cells exposed to 6-hydroxydopamine. This revealed a striking increase in transcripts associated with the unfolded protein response. Immunoblotting confirmed phosphorylation of the key endoplasmic reticulum stress kinases IRE1alpha and PERK (PKR-like ER kinase) and induction of their downstream targets. There was a similar response to MPP+ and rotenone, but not to other apoptotic initiators. As evidence that endoplasmic reticulum stress contributes to neuronal death, sympathetic neurons from PERK null mice in which the capacity to respond to endoplasmic reticulum stress is compromised were more sensitive to 6-hydroxydopamine. Our findings, coupled with evidence from familial forms of Parkinson's disease, raise the possibility of widespread involvement of endoplasmic reticulum stress and the unfolded protein response in the pathophysiology of this disease.


Assuntos
Retículo Endoplasmático/fisiologia , Neurônios/metabolismo , Simpatolíticos/farmacologia , 1-Metil-4-fenilpiridínio/farmacologia , Animais , Apoptose , Células Cultivadas , Relação Dose-Resposta a Droga , Retículo Endoplasmático/efeitos dos fármacos , Gânglios Simpáticos/efeitos dos fármacos , Gânglios Simpáticos/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Camundongos , Camundongos Knockout , Neurônios/efeitos dos fármacos , Oxidopamina/farmacologia , Células PC12 , Doença de Parkinson/genética , Doença de Parkinson/metabolismo , Dobramento de Proteína , RNA Mensageiro/biossíntese , Ratos , Rotenona/farmacologia , Transcrição Gênica , eIF-2 Quinase/genética
19.
Proc Natl Acad Sci U S A ; 99(20): 13217-21, 2002 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-12244210

RESUMO

Changes in hippocampal function seem critical for cognitive impairment in Alzheimer's disease (AD). Although there is eventual loss of synapses in both AD and animal models of AD, deficits in spatial memory and inhibition of long-term potentiation (LTP) precede morphological alterations in the models, suggesting earlier biochemical changes in the disease. In the studies reported here we demonstrate that amyloid beta-peptide (Abeta) treatment of cultured hippocampal neurons leads to the inactivation of protein kinase A (PKA) and persistence of its regulatory subunit PKAIIalpha. Consistent with this, CREB phosphorylation in response to glutamate is decreased, and the decrease is reversed by rolipram, a phosphodiesterase inhibitor that raises cAMP and leads to the dissociation of the PKA catalytic and regulatory subunits. It is likely that a similar mechanism underlies Alphabeta inhibition of LTP, because rolipram and forskolin, agents that enhance the cAMP-signaling pathway, can reverse this inhibition. This reversal is blocked by H89, an inhibitor of PKA. These observations suggest that Alphabeta acts directly on the pathways involved in the formation of late LTP and agents that enhance the cAMP/PKA/CREB-signaling pathway have potential for the treatment of AD.


Assuntos
Peptídeos beta-Amiloides/farmacologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , AMP Cíclico/metabolismo , Animais , Western Blotting , Células Cultivadas , Eletrofisiologia , Hipocampo/citologia , Potenciação de Longa Duração , Modelos Biológicos , Neurônios/metabolismo , Fosforilação , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Fatores de Tempo
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