RESUMO
AIMS: Buprenorphine is effective at reducing relapse to opioid misuse, morbidity and mortality in opioid-dependent patients. Urine drug screening (UDS) to assess adherence is used routinely in opioid agonist treatment (OAT). The primary aim of this study was to determine factors which may be associated with a negative qualitative urine drug screen for buprenorphine in OAT patients. METHODS: This prospective pilot study was conducted at a tertiary addiction medicine centre. Twenty participants on stable treatment underwent supervised administration of sublingual buprenorphine. Matched urine and blood samples were collected prior to and 2, 4 and 6 hours after buprenorphine administration. Qualitative urine drug screen results were obtained using gas chromatography-mass spectrometry (GC-MS), while quantitative blood and urine results were obtained using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). RESULTS: Qualitative urine assay yielded a negative result for buprenorphine in 57% of tested samples. The median concentration of urinary buprenorphine was 167 mcg/L (range: 2-1730 mcg/L). Thirty percent of all blood samples did not detect buprenorphine (range 0-18 mcg/L). Positive qualitative urine drug screen results were associated with higher urine (343 mcg/L compared with 75 mcg/L; P < .05) and blood (4 mcg/L compared with 2 mcg/L; P < .05) buprenorphine concentrations. Median urine concentrations of buprenorphine were highest at 2 hours and were higher in participants receiving CYP3A4 inhibitors. CONCLUSION: Interpretation of qualitative urine drug screens to assess adherence in OAT is complex. Poor adherence with treatment cannot be assumed in patients returning a negative qualitative GC-MS urine drug screen.
Assuntos
Buprenorfina , Humanos , Buprenorfina/uso terapêutico , Analgésicos Opioides , Projetos Piloto , Cromatografia Líquida/métodos , Estudos Prospectivos , Espectrometria de Massas em Tandem , Adesão à MedicaçãoRESUMO
RATIONALE: Cardiovascular disease is now recognized as the number one cause of death in the world, and the size of the population at risk continues to increase rapidly. The dysregulation of the endocannabinoid (eCB) system plays a central role in a wide variety of conditions including cardiovascular disorders. Cannabinoid receptors, their endogenous ligands, as well as enzymes conferring their synthesis and degradation, exhibit overlapping distributions in the cardiovascular system. Furthermore, the pharmacological manipulation of the eCB system has effects on blood pressure, cardiac contractility, and endothelial vasomotor control. Growing evidence from animal studies supports the significance of the eCB system in cardiovascular disorders. OBJECTIVE: To summarize the literature surrounding the eCB system in cardiovascular function and disease and the new compounds that may potentially extend the range of available interventions. RESULTS: Drugs targeting CB1R, CB2R, TRPV1 and PPARs are proven effective in animal models mimicking cardiovascular disorders such as hypertension, atherosclerosis and myocardial infarction. Despite the setback of two clinical trials that exhibited unexpected harmful side-effects, preclinical studies are accelerating the development of more selective drugs with promising results devoid of adverse effects. CONCLUSION: Over the last years, increasing evidence from basic and clinical research supports the role of the eCB system in cardiovascular function. Whereas new discoveries are paving the way for the identification of novel drugs and therapeutic targets, the close cooperation of researchers, clinicians and pharmaceutical companies is needed to achieve successful outcomes.
Assuntos
Doenças Cardiovasculares/fisiopatologia , Fenômenos Fisiológicos Cardiovasculares , Endocanabinoides/fisiologia , Animais , HumanosRESUMO
OBJECTIVE: There have been no well-controlled and well-powered comparative trials of topiramate with other pharmacotherapies for alcohol use disorder (AUD), such as naltrexone. Moreover, the literature is mixed on the effects of two polymorphisms-rs2832407 (in GRIK1) and rs1799971 (in OPRM1)-on response to topiramate and naltrexone, respectively. The authors sought to examine the comparative effectiveness of topiramate and naltrexone in improving outcomes in AUD and to examine the role of the rs2832407 and rs1799971 polymorphisms, respectively, on response to these medications. METHODS: In a 12-week, double-blind, placebo-controlled, randomized, multisite, genotype-stratified (rs2832407 and rs1799971) clinical trial comparing topiramate and naltrexone in treating AUD, 147 patients with AUD were randomly assigned to treatment with topiramate or naltrexone, stratified by genotype (rs2832407*CC and *AC/AA genotypes and rs1799971*AA and *AG/GG genotypes). The predefined primary outcome was number of heavy drinking days per week. Predefined secondary outcomes included standard drinks per drinking day per week, body mass index (BMI), craving, markers of liver injury, mood, and adverse events. RESULTS: For the number of heavy drinking days per week, there was a near-significant time-by-treatment interaction. For the number of standard drinks per drinking day per week, there was a significant time-by-treatment interaction, which favored topiramate. There were significant time-by-treatment effects, with greater reductions observed with topiramate than naltrexone for BMI, craving, and gamma-glutamyltransferase level. Withdrawal due to side effects occurred in 8% and 5% of the topiramate and naltrexone groups, respectively. Neither polymorphism showed an effect on treatment response. CONCLUSIONS: Topiramate is at least as effective and safe as the first-line medication, naltrexone, in reducing heavy alcohol consumption, and superior in reducing some clinical outcomes. Neither rs2832407 nor rs1799971 had effects on topiramate and naltrexone treatments, respectively.
Assuntos
Alcoolismo , Genótipo , Naltrexona , Receptores de Ácido Caínico , Topiramato , Humanos , Topiramato/uso terapêutico , Naltrexona/uso terapêutico , Método Duplo-Cego , Masculino , Feminino , Alcoolismo/tratamento farmacológico , Alcoolismo/genética , Adulto , Pessoa de Meia-Idade , Receptores de Ácido Caínico/genética , Receptores Opioides mu/genética , Resultado do Tratamento , Antagonistas de Entorpecentes/uso terapêutico , Polimorfismo de Nucleotídeo Único , Fissura/efeitos dos fármacos , Frutose/análogos & derivados , Frutose/uso terapêuticoRESUMO
The A(2A)R has become a therapeutic target in Parkinson disease due to its functional role in the striatum, capable of modulating dopaminergic neurotransmission in the basal ganglia. No conclusive evidence, however, has been provided to demonstrate the existence of A(2A)Rs in the output nuclei of the basal ganglia: the internal segment of the globus pallidus (GPi) and substantia nigra pars reticulata (SNr). Using immunohistochemistry and in situ hybridization techniques we have confirmed the presence of A(2A)Rs in both the striatum (medium spiny and cholinergic neurons) and the external segment of the globus pallidus (GPe), in the monkey. The antibody routinely used to label A(2A)Rs failed to detect A(2A)R-positive neurons in the GPi and SNr, however, in situ hybridization showed that A(2A)R mRNA transcripts were indeed present in both these nuclei. Surprisingly, by labeling pallidothalamic and nigrothalamic projection neurons originating in the GPi and SNr with the neuronal retrograde tracer cholera toxin subunit B (CTB), the receptor protein was unmasked and detectable using the antibody. This unmasking of the protein was specific to CTB and not an artifact of the tracer. We have shown unequivocally that the A(2A)R is present in the output nuclei of the primate basal ganglia, however, to be able to detect the receptor immunohistochemically, unmasking the protein with CTB was necessary. The presence of A(2A)Rs in the GPi and SNr suggests that these output nuclei could be targeted therapeutically in Parkinson disease to restore abnormal activity in the basal ganglia.
Assuntos
Toxina da Cólera/metabolismo , Corpo Estriado/citologia , Globo Pálido/citologia , Neurônios/metabolismo , Receptores A2 de Adenosina/metabolismo , Animais , Biotina/análogos & derivados , Biotina/metabolismo , Colina O-Acetiltransferase/metabolismo , Corpo Estriado/metabolismo , Dextranos/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Globo Pálido/metabolismo , Macaca fascicularis , Masculino , Vias Neurais/fisiologia , RNA Mensageiro/metabolismo , Receptores A2 de Adenosina/genéticaRESUMO
Phenotypic variation in amyotrophic lateral sclerosis (ALS) is common, and one atypical form is the flail arm variant (FAV). Some classic ALS patients carry TARDBP mutations, and so we sought to establish whether TARDBP mutations are also present in the FAV of ALS. Mutation analysis of TARDBP, the gene encoding TDP-43, was performed in cohorts of classic and FAV ALS patients. An analysis of mutation effects was performed in patient fibroblasts. Results showed that a novel heterozygous in-frame insertion/deletion (indel), c.1158_1159delAT; c.1158_1159insCACCAACC, was identified in a highly conserved region encoding the glycine-rich area of TDP-43 in a patient with FAV. This indel was confirmed in the proband's mother, an obligate carrier, and was absent from 480 ethnically-matched control individuals. Transcription of the mutant allele was confirmed. Under induced stress, indel-mutant fibroblasts showed a loss of normal nuclear TDP-43 immunoreactivity and formation of cytoplasmic inclusions of TDP-43, consistent with features seen in affected neurons. In conclusion, TARDBP missense mutations have previously been reported in classic ALS and frontotemporal lobar degeneration. The identification of a TARDBP indel mutation in a patient with FAV extends the spectrum of mutations and further supports the role of TDP-43 in a range of neurodegenerative phenotypes.
Assuntos
Esclerose Lateral Amiotrófica/genética , Proteínas de Ligação a DNA/genética , Degeneração Lobar Frontotemporal/genética , Mutação INDEL/genética , Mutação de Sentido Incorreto/genética , Idoso , Idoso de 80 Anos ou mais , Sequência de Aminoácidos , Análise Mutacional de DNA , Proteínas de Ligação a DNA/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , LinhagemRESUMO
INTRODUCTION: Most analyses of blood DNA in sporadic neuromuscular disorders have been inconclusive. This may be because some genetic variants occur only in brain tissue. We therefore looked for copy number variants (CNVs) in both blood and brain in patients with sporadic amyotrophic lateral sclerosis (SALS). METHODS: Genome-wide CNVs were compared in blood and brain from 32 SALS patients and from 26 normal (control) brains, using Affymetrix 6.0 arrays. RESULTS: There were 410 CNVs present in brain but not blood (somatic CNVs) in 94% of the patients (median 8 CNVs per patient). Twenty-four of the somatic CNVs were rare, were not found in control brains, and overlapped with genes. CONCLUSIONS: Brain-specific CNVs may be common and appear to be present in a proportion of patients with SALS. The more detailed copy number analysis that is becoming available with massively parallel sequencing may uncover brain-specific CNVs that underlie some cases of SALS.
Assuntos
Esclerose Lateral Amiotrófica , Sangue/metabolismo , Encéfalo/metabolismo , Variações do Número de Cópias de DNA/genética , Predisposição Genética para Doença , Idoso , Idoso de 80 Anos ou mais , Esclerose Lateral Amiotrófica/sangue , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Feminino , Perfilação da Expressão Gênica , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos/métodosRESUMO
Somatic mutations have been suggested as a cause of sporadic amyotrophic lateral sclerosis (SALS). These mutations can be difficult to detect since they may involve only a small percentage of cells within the tissue, so we devised a method to detect low mutation levels in brain DNA. Different proportions of a known SOD1 mutation were prepared to determine the sensitivity of DHPLC. The fraction containing the mutant signal was collected and re-amplified ('enriched') to increase sensitivity and to dideoxy sequence the mutation. The combined technique was used to screen all exons and the promoter of SOD1 in 23 SALS brains. DHPLC could detect a known SOD1 mutation in 5% of a sample of brain tissue. Using our enrichment technique doubled the height of the mutant sequencing signal, which allowed identification of an unknown mutation in 10% of brain tissue. No SOD1 mutations were found in the SALS brains using this technique. In conclusion, combining DHPLC and sequencing doubles the sensitivity of sequencing alone and can detect low levels of known and unknown mutations in brain DNA. No SALS SOD1 somatic mutations were detected, but DHPLC would be useful in looking for somatic mutations in other SALS candidate genes.
Assuntos
Esclerose Lateral Amiotrófica/genética , Encéfalo/fisiologia , Cromatografia Líquida de Alta Pressão/métodos , Análise Mutacional de DNA/métodos , Desnaturação de Ácido Nucleico , Idoso , Cromatografia Líquida de Alta Pressão/normas , Análise Mutacional de DNA/normas , Feminino , Testes Genéticos/métodos , Testes Genéticos/normas , Análise Heteroduplex , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Superóxido Dismutase/genética , Superóxido Dismutase-1RESUMO
Mutations in the superoxide dismutase 1 gene (SOD1) are associated with familial ALS but the role of SOD1 in sporadic ALS (SALS) is unclear. We therefore sequenced the entire SOD1 gene in 23 patients with SALS. DNA was extracted from frozen pre-frontal cerebral cortex and from blood. The 5 exons, 4 introns and 1 kb upstream and downstream of SOD1 were sequenced. Novel genetic variants were found in 30% (7 of 23) brains and known variants in 91% (21 of 23) brains from patients with SALS. Two novel variants found in SALS patients and not controls were located in the SOD1 promoter and intron 1, with the promoter variant having potential functional implications. A previously described silent variant in exon 5 in one SALS patient appears to abolish an exonic splicing enhancer. All changes found in brain DNA were also found in blood DNA. In conclusion, sequencing the entire SOD1 gene revealed 3 variants in SALS patients that were not detected in controls. Although no unequivocal mutations were found, some of these variants have potential consequences for SALS pathogenesis.
Assuntos
Esclerose Lateral Amiotrófica/genética , Variação Genética , Superóxido Dismutase/genética , Idoso , Esclerose Lateral Amiotrófica/patologia , Éxons/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Córtex Pré-Frontal/metabolismo , Regiões Promotoras Genéticas/genética , Análise de Sequência de DNA/métodos , Superóxido Dismutase/sangue , Superóxido Dismutase/metabolismo , Superóxido Dismutase-1RESUMO
We have explored the survival of dopaminergic cells of the substantia nigra pars compacta (SNc) in 6 hydroxydopamine (6OHDA)-lesioned rats with prior cortical removal. There were approximately 35% more dopaminergic cells in the ventral sector of SNc (vSNc) of 6OHDA-lesioned rats that had prior cortical removal compared to those that did not. By contrast, there were no differences in dopaminergic cell number between these experimental groups in the ventral tegmental area (VTA) and the dorsal sector of SNc (dSNc). Hence, prior cortical removal in 6OHDA-lesioned rats neuroprotected vSNc--but not VTA or dSNc--dopaminergic cells from death.
Assuntos
Adrenérgicos/toxicidade , Estado de Descerebração , Dopamina/metabolismo , Neurônios/fisiologia , Oxidopamina/toxicidade , Substância Negra/lesões , Animais , Contagem de Células , Morte Celular/fisiologia , Masculino , Ratos , Ratos Sprague-Dawley , Substância Negra/patologia , Tirosina 3-Mono-Oxigenase/metabolismo , Área Tegmentar Ventral/efeitos dos fármacos , Área Tegmentar Ventral/patologiaRESUMO
BACKGROUND AND AIMS: Baclofen has been shown to reduce alcohol consumption in alcohol-dependent individuals, but there is marked heterogeneity in response. An association between GABBR1 rs29220 and alcohol dependence has been demonstrated previously. The present study evaluated whether the response to baclofen is moderated by a single nucleotide polymorphism (rs29220) in the GABAB receptor subunit 1 gene (GABBR1). DESIGN: Double-blind, placebo-controlled study. SETTING: Australia. PARTICIPANTS: Seventy-two alcohol-dependent men and women receiving 12 weeks of 30 mg/day of baclofen, 75 mg baclofen or placebo. MEASUREMENTS: Primary outcomes included time to lapse (any drinking) and relapse (> 5 drinks per day in men and > 4 in women). We also examined alcohol consumption at follow-up (drinks per drinking day, number of heavy drinking days and percentage days abstinent). FINDINGS: We observed significant medication × genotype interaction effect for time to relapse (P = 0.049) and a near-significant interaction effect for time to lapse (P = 0.055). For the CC genotype group, the relapse hazard ratio for baclofen versus placebo was 0.32 [95% confidence interval (CI) = 0.14-0.75] and for the G- group it was 1.07 (95% CI = 0.43-2.63). There was also a significant medication × genotype interaction for follow-up alcohol consumption (drinks per drinking day, heavy drinking days and days abstinent) (P = 0.02). Covarying for baseline levels of craving, aspartate aminotransferase and abstinence before enrolment reduced the medication × genotype effect for time to lapse and relapse but not for alcohol consumption at follow-up. CONCLUSIONS: The GABBR1 rs29220 polymorphism may influence treatment response and possibly predict adverse effects to baclofen in the treatment of alcohol dependence.
Assuntos
Alcoolismo/tratamento farmacológico , Baclofeno/uso terapêutico , Agonistas dos Receptores de GABA-B/uso terapêutico , Receptores de GABA-B/genética , Adulto , Consumo de Bebidas Alcoólicas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variantes Farmacogenômicos , Polimorfismo de Nucleotídeo Único , Modelos de Riscos Proporcionais , Ensaios Clínicos Controlados Aleatórios como Assunto , Recidiva , Resultado do TratamentoRESUMO
BACKGROUND: Current treatments for alcohol use disorders have limited efficacy and there is a high degree of variability in treatment response. In a randomised, placebo-controlled clinical trial, there was a large effect size for topiramate in people homozygous for the GRIK1 rs2832407*C allele. The primary aim of the TOP study is to examine prospectively the therapeutic and cost-effectiveness of topiramate versus an active control (naltrexone) in improving treatment outcomes for alcohol dependence. Participants will be stratified on rs2832407 to compare C-allele homozygotes with A-allele carriers to examine the moderating effect of rs2832407 on drinking outcomes. An exploratory aim is to examine the moderating effects of rs1799971, a polymorphism in OPRM1, on the response to naltrexone by comparing Asn40 homozygotes with Asp40 carriers. METHODS/DESIGN: This double-blind trial will randomise 180 alcohol-dependent participants to a 12-week regime of either topiramate (titrating the dose up to 200 mg/day) or naltrexone (50 mg/day). Participants will be stratified on the two polymorphisms before randomisation. All participants will receive medical management. The primary drinking outcome will be the number of heavy drinking days per week and secondary drinking outcomes will include the time to relapse, the time to lapse and the percentage of abstinent days. Other secondary outcomes will include body mass index, tobacco use, anxiety symptoms and depressive symptoms. DISCUSSION: If successful, the TOP study will improve management strategies for alcohol dependence by providing support for the use of genetic biomarkers to inform medication selection. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03479086 . Registered on 27 March 2018.
Assuntos
Consumo de Bebidas Alcoólicas/prevenção & controle , Alcoolismo/tratamento farmacológico , Antagonistas de Aminoácidos Excitatórios/uso terapêutico , Naltrexona/uso terapêutico , Antagonistas de Entorpecentes/uso terapêutico , Topiramato/uso terapêutico , Adolescente , Adulto , Idoso , Abstinência de Álcool , Consumo de Bebidas Alcoólicas/genética , Consumo de Bebidas Alcoólicas/psicologia , Alcoolismo/diagnóstico , Alcoolismo/genética , Alcoolismo/psicologia , Protocolos Clínicos , Método Duplo-Cego , Antagonistas de Aminoácidos Excitatórios/efeitos adversos , Feminino , Frequência do Gene , Homozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Naltrexona/efeitos adversos , Antagonistas de Entorpecentes/efeitos adversos , New South Wales , Variantes Farmacogenômicos , Estudos Prospectivos , Receptores de Ácido Caínico/genética , Receptores Opioides mu/genética , Recidiva , Projetos de Pesquisa , Fatores de Tempo , Topiramato/efeitos adversos , Resultado do Tratamento , Adulto JovemRESUMO
Although type 1 cannabinoid receptors (CB1Rs) are expressed abundantly throughout the brain, the presence of type 2 cannabinoid receptors (CB2Rs) in neurons is still somewhat controversial. Taking advantage of newly designed CB1R and CB2R mRNA riboprobes, we demonstrate by PCR and in situ hybridization that transcripts for both cannabinoid receptors are present within labeled pallidothalamic-projecting neurons of control and MPTP-treated macaques, whereas the expression is markedly reduced in dyskinetic animals. Moreover, an in situ proximity ligation assay was used to qualitatively assess the presence of CB1Rs and CB2Rs, as well as CB1R-CB2R heteromers within basal ganglia output neurons in all animal groups (control, parkinsonian and dyskinetic macaques). A marked reduction in the number of CB1Rs, CB2Rs and CB1R-CB2R heteromers was found in dyskinetic animals, mimicking the observed reduction in CB1R and CB2R mRNA expression levels. The fact that chronic levodopa treatment disrupted CB1R-CB2R heteromeric complexes should be taken into consideration when designing new drugs acting on cannabinoid receptor heteromers.
Assuntos
Gânglios da Base/metabolismo , Neurônios/metabolismo , Transtornos Parkinsonianos , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/metabolismo , Animais , Canabinoides/metabolismo , Levodopa/metabolismo , Macaca , MasculinoRESUMO
The molecular basis of priming for L-DOPA-induced dyskinesias in Parkinson's disease (PD), which depends on the indirect pathway of motor control, is not known. In rodents, the indirect pathway contains striatopallidal GABAergic neurons that express heterotrimers composed of A(2A) adenosine, CB(1) cannabinoid and D(2) dopamine receptors that regulate dopaminergic neurotransmission. The present study was designed to investigate the expression of these heteromers in the striatum of a primate model of Parkinson's disease and to determine whether their expression and pharmacological properties are altered upon L-DOPA treatment. By using the recently developed in situ proximity ligation assay and by identification of a biochemical fingerprint, we discovered a regional distribution of A(2A)/CB(1) /D(2) receptor heteromers that predicts differential D(2)-mediated neurotransmission in the caudate-putamen of Macaca fascicularis. Whereas heteromers were abundant in the caudate nucleus of both naïve and MPTP-treated monkeys, L-DOPA treatment blunted the biochemical fingerprint and led to weak heteromer expression. These findings constitute the first evidence of altered receptor heteromer expression in pathological conditions and suggest that drugs targeting A(2A)-CB(1) -D(2) receptor heteromers may be successful to either normalize basal ganglia output or prevent L-DOPA-induced side effects.
Assuntos
Antiparkinsonianos/farmacologia , Núcleo Caudado/efeitos dos fármacos , Levodopa/farmacologia , Receptor A2A de Adenosina/metabolismo , Receptor CB1 de Canabinoide/metabolismo , Receptores de Dopamina D2/metabolismo , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Agonistas do Receptor A2 de Adenosina/farmacologia , Antagonistas do Receptor A2 de Adenosina/farmacologia , Animais , Núcleo Caudado/metabolismo , Dopamina/farmacologia , Antagonistas de Dopamina/farmacologia , Antagonistas dos Receptores de Dopamina D2 , Macaca fascicularis , Masculino , Transtornos Parkinsonianos/tratamento farmacológico , Transtornos Parkinsonianos/metabolismo , Putamen/efeitos dos fármacos , Putamen/metabolismo , Receptor CB1 de Canabinoide/agonistasRESUMO
The "basal ganglia" refers to a group of subcortical nuclei responsible primarily for motor control, as well as other roles such as motor learning, executive functions and behaviors, and emotions. Proposed more than two decades ago, the classical basal ganglia model shows how information flows through the basal ganglia back to the cortex through two pathways with opposing effects for the proper execution of movement. Although much of the model has remained, the model has been modified and amplified with the emergence of new data. Furthermore, parallel circuits subserve the other functions of the basal ganglia engaging associative and limbic territories. Disruption of the basal ganglia network forms the basis for several movement disorders. This article provides a comprehensive account of basal ganglia functional anatomy and chemistry and the major pathophysiological changes underlying disorders of movement. We try to answer three key questions related to the basal ganglia, as follows: What are the basal ganglia? What are they made of? How do they work? Some insight on the canonical basal ganglia model is provided, together with a selection of paradoxes and some views over the horizon in the field.
Assuntos
Gânglios da Base/anatomia & histologia , Gânglios da Base/fisiologia , Córtex Cerebral/anatomia & histologia , Emoções/fisiologia , Função Executiva/fisiologia , Humanos , Corpos de Lewy/fisiologia , Vias Neurais/anatomia & histologia , Vias Neurais/fisiologia , Neurônios Aferentes/fisiologia , Neurônios Eferentes/fisiologia , Desempenho Psicomotor/fisiologia , Tálamo/anatomia & histologia , Tálamo/fisiologiaRESUMO
Sporadic Parkinson's disease (PD) is thought to have a major genetic component, but the variants involved remain mostly unknown. One possible reason for the difficulty in finding mutations underlying PD is that rare predominantly brain-situated somatic mutations underlie the disease; these mutations would be missed by analysing blood DNA only. To test the feasibility of looking for somatic mutations in PD brain tissue, we compared copy number variants (CNVs) between 8 PD and 26 control brains using Affymetrix 6.0 arrays. The median number of CNVs per brain, and the overall proportion of amplifications and deletions, were similar in PD and control brains. In 7 of the 8 PD brains, however, a total of 45 CNVs were found that were not present in control brains. Twelve of these CNVs overlapped with one or more genes, some of which are involved in pathways suspected in the pathogenesis of PD, or are rare. This study shows that PD brain CNVs can be detected, and raises the possibility that brain-situated mutations could underlie some cases of PD. A method of undertaking a definitive study of brain somatic mutations in PD, using massively parallel sequencing and multiple tissues, is suggested.
Assuntos
Encéfalo/patologia , Variações do Número de Cópias de DNA , Mutação , Doença de Parkinson/genética , Doença de Parkinson/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Análise Mutacional de DNA , Feminino , Estudos de Associação Genética , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The tegmental pedunculopontine nucleus (PPN) is a basal ganglia-related structure that has recently gained renewed interest as a potential surgical target for the treatment of several aspects of Parkinson's disease. However, the underlying anatomical substrates sustaining the choice of the PPN nucleus as a surgical candidate remain poorly understood. Here, we characterized the chemical phenotypes of different subtypes of PPN efferent neurons innervating the rat parafascicular (PF) nucleus. Emphasis was placed on elucidating the impact of unilateral nigrostriatal denervation on the expression patterns of the mRNA coding the vesicular glutamate transporter type 2 (vGlut2 mRNA). We found a bilateral projection from the PPN nucleus to the PF nucleus arising from cholinergic and glutamatergic efferent neurons, with a small fraction of projection neurons co-expressing both cholinergic and glutamatergic markers. Furthermore, the unilateral nigrostriatal depletion induced a bilateral twofold increase in the expression levels of vGlut2 mRNA within the PPN nucleus. Our results support the view that heterogeneous chemical profiles account for PPN efferent neurons innervating thalamic targets. Moreover, a bilateral enhancement of glutamatergic transmission arising from the PPN nucleus occurs following unilateral dopaminergic denervation, therefore sustaining the well-known hyperactivity of the PF nucleus in parkinsonian-like conditions. In conclusion, our data suggest that the ascending projections from the PPN that reach basal ganglia-related targets could play an important role in the pathophysiology of Parkinson's disease.
Assuntos
Núcleos Intralaminares do Tálamo/citologia , Neurônios Eferentes/metabolismo , Transtornos Parkinsonianos/fisiopatologia , Núcleo Tegmental Pedunculopontino/citologia , RNA Mensageiro/metabolismo , Proteína Vesicular 2 de Transporte de Glutamato/metabolismo , Animais , Neurônios Colinérgicos/metabolismo , Primers do DNA/genética , Ácido Glutâmico/metabolismo , Técnicas Histológicas , Técnicas Imunoenzimáticas , Hibridização in Situ Fluorescente , Microdissecção , Reação em Cadeia da Polimerase , Ratos , EstilbamidinasRESUMO
GABAergic neurons within the internal division of the globus pallidus (GPi) are the main source of basal ganglia output reaching the thalamic ventral nuclei in monkeys. Following dopaminergic denervation, pallidothalamic-projecting neurons are known to be hyperactive, whereas a reduction in GPi activity is typically observed in lesioned animals showing levodopa-induced dyskinesia. Besides the mRNAs coding for GABAergic markers (GAD65 and GAD67), we show that all GPi neurons innervating thalamic targets also express transcripts for the isoforms 1 and 2 of the vesicular glutamate transporter (vGlut1 and vGlut2 mRNA). Indeed, dual immunofluorescent detection of GAD67 and vGlut1/2 confirmed the data gathered from in situ hybridization experiments, therefore demonstrating that the detected mRNAs are translated into the related proteins. Furthermore, the dopaminergic lesion resulted in an up-regulation of expression levels for both GAD65 and GAD67 mRNA within identified pallidothalamic-projecting neurons. This was coupled with a down-regulation of GAD65/67 mRNA expression levels in GPi neurons innervating thalamic targets in monkeys showing levodopa-induced dyskinesia. By contrast, the patterns of gene expression for both vGlut1 and vGlut2 mRNAs remained unchanged across GPi projection neurons in control, MPTP-treated and dyskinetic monkeys. In summary, both GABAergic and glutamatergic markers were co-expressed by GPi efferent neurons in primates. Although the status of the dopaminergic system directly modulates the expression levels of GAD65/67 mRNA, the observed expression of vGlut1/2 mRNA is not regulated by either dopaminergic removal or by continuous stimulation with dopaminergic agonists.
Assuntos
Dopamina/deficiência , Discinesia Induzida por Medicamentos/metabolismo , Neurônios GABAérgicos/metabolismo , Globo Pálido/citologia , Neurônios Eferentes/metabolismo , Transtornos Parkinsonianos/tratamento farmacológico , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Animais , Colorimetria , Primers do DNA/genética , Imunofluorescência , Globo Pálido/fisiologia , Glutamato Descarboxilase/metabolismo , Imuno-Histoquímica , Hibridização In Situ , Hibridização in Situ Fluorescente , Levodopa/toxicidade , Macaca fascicularis , Masculino , Transtornos Parkinsonianos/induzido quimicamente , Reação em Cadeia da Polimerase , Estatísticas não Paramétricas , Tálamo/fisiologia , Proteína Vesicular 1 de Transporte de Glutamato/metabolismoAssuntos
Plexo Corióideo/patologia , Granulomatose com Poliangiite/patologia , Inflamação/patologia , Idoso , Plexo Corióideo/efeitos dos fármacos , Granulomatose com Poliangiite/tratamento farmacológico , Humanos , Imunossupressores/farmacologia , Imunossupressores/uso terapêutico , Inflamação/tratamento farmacológico , Masculino , Resultado do TratamentoRESUMO
All patients with sporadic amyotrophic lateral sclerosis (SALS) have TDP-43 inclusions in their motor neurons, suggesting this protein plays a major role in the disease. Coding mutations in the gene for TDP-43, TARDBP, have been found in only a few patients with SALS. However, the non-coding regulatory regions of TARDBP have not yet been examined in SALS. We therefore sequenced both coding and non-coding regions of TARDBP in 46 tissue-banked SALS brains (brain DNA was used to detect somatic mutations). Non-coding variants (in the promoter or intron 1) were detected in 16 patients (35%) and coding variants in 4 (9%). Two known promoter variants were found more frequently in SALS patients than in controls. Two other variants, found in one patient each but not in controls, have potential regulatory functions. In addition, a novel exon 2 change with predicted functional effects was found in one patient. In summary, variants in the promoter and other non-coding regions of TARDBP may disturb the regulation of this gene in some patients with SALS.