RESUMO
Parkinson's disease is associated with the loss of dopaminergic neurons in the substantia nigra and decreased striatal dopamine levels. We now report that caffeic acid phenethyl ester (CAPE), an active component of propolis, attenuated dopaminergic neurodegeneration and dopamine loss in the MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) mouse model of Parkinson's disease. The neuroprotective effect of CAPE was associated with marked reductions in inducible nitric oxide synthase (iNOS) and caspase 1 expression. Additionally, CAPE inhibited MPP+-induced neurotoxicity in vitro and directly inhibited MPP+-induced release of cytochrome c and apoptosis inducing factor (AIF) from mitochondria. Thus, CAPE may have beneficial effects in slowing or preventing the progression of Parkinson's disease and other neurodegenerative disorders.
Assuntos
Encéfalo/efeitos dos fármacos , Ácidos Cafeicos/farmacologia , Intoxicação por MPTP/patologia , Degeneração Neural/prevenção & controle , Fármacos Neuroprotetores/farmacologia , Álcool Feniletílico/análogos & derivados , Animais , Western Blotting , Encéfalo/metabolismo , Encéfalo/patologia , Imuno-Histoquímica , Intoxicação por MPTP/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Degeneração Neural/metabolismo , Degeneração Neural/patologia , Álcool Feniletílico/farmacologiaRESUMO
Caffeic acid phenethyl ester (CAPE) is an active component of propolis obtained from honeybee hives and is found to have the following properties: anti-mitogenic, anti-carcinogenic, anti-inflammatory, immunomodulatory, and antioxidant. Recent reports suggest that CAPE also has a neuronal protective property against ischemic injury. Since excitotoxicity may play an important role in ischemia, in this study, we investigated whether CAPE could directly protect neurons against excitotoxic insult. We treated cultured rat cerebellar granule neurons (CGNs) with excitotoxic concentrations of glutamate in the presence or absence of CAPE and found that CAPE markedly protected neurons against glutamate-induced neuronal death in a concentration-dependent fashion. Glutamate-induced CGNs death is associated with time-dependent activation of caspase-3 and phosphorylation of p38, both events of which can be blocked by CAPE. Treating CGNs with specific inhibitors of these two enzymes together exerts a synergistic neuroprotective effect, similar to the neuroprotective effect of CAPE exposure. These results suggest that CAPE is able to block glutamate-induced excitotoxicity by inhibiting phosphorylation of p38 and caspase-3 activation. This finding may further help understanding of the mechanism of glutamate-induced neuronal death and CAPE-induced neuroprotection against excitotoxicity.
Assuntos
Ácidos Cafeicos/farmacologia , Cerebelo/citologia , Ácido Glutâmico/toxicidade , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Neurotoxinas/toxicidade , Álcool Feniletílico/análogos & derivados , Animais , Animais Recém-Nascidos , Caspase 3/metabolismo , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Citocromos c/metabolismo , Relação Dose-Resposta a Droga , Interações Medicamentosas , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Mitocôndrias/efeitos dos fármacos , Técnicas de Patch-Clamp , Álcool Feniletílico/farmacologia , Fosforilação/efeitos dos fármacos , Ratos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
BACKGROUND: The economic burden of stroke is considerable. While studies on the costs of acute stroke treatment have been undertaken in Germany, thorough analysis of direct and indirect long-term costs is lacking. PATIENTS AND METHODS: A hospital-based cohort of 151 consecutive patients with stroke or transient ischemic attacks (TIA) was followed up (medical examination and interview) at the end of the 4th year following the cerebrovascular event. Costs were calculated using a bottom-up approach and classified into direct medical and nonmedical costs, indirect costs, and patients' costs. RESULTS: Non-stroke-related costs (mean +/- standard deviation 4,610+/-9,310 Euros/person) were separated from total costs. Total stroke-related costs of the 4th year after stroke/TIA amounted to 7,670+/-10,250 Euros per person. The cost components were as follows: direct costs 56% (4,320+/-5,740 Euros), indirect costs 31% (2,350+/-2,710 Euros), and patients' payments 13% (1,000+/-4,100 Euros). The annual nationwide costs for the 4th year following stroke or TIA amounted to approximately 3 billion Euros. CONCLUSION: The considerable size of long-term costs after stroke/TIA is mainly due to direct costs and poses an economic challenge to the German health care system. Patients contribute in a relevant way by their own payments.
Assuntos
Custos de Cuidados de Saúde/estatística & dados numéricos , Ataque Isquêmico Transitório/economia , Ataque Isquêmico Transitório/epidemiologia , Acidente Vascular Cerebral/economia , Acidente Vascular Cerebral/epidemiologia , Idoso , Feminino , Alemanha/epidemiologia , Humanos , Estudos Longitudinais , Masculino , PrevalênciaRESUMO
OBJECTIVE: To prospectively assess the health-related quality of life (HrQoL) in Parkinson's disease (PD) during 12 months. METHODS: HrQoL was assessed in 145 PD patients using the PD-specific PDQ-39, PDQL and the generic EQ-5D. In addition, clinical rating-scales were used. RESULTS: All scales showed a pronounced effect of PD. In comparison to an age-matched population the EQ-5D was considerably affected. In comparison to baseline, however, there was no significant change in the generic scale but a significant change in the sum-score of disease-specific HrQoL-scales. CONCLUSIONS: Only disease-specific scales were sensitive to change. Further studies are necessary to evaluate the time-dependent change in HrQoL.
Assuntos
Nível de Saúde , Doença de Parkinson/fisiopatologia , Doença de Parkinson/psicologia , Qualidade de Vida , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Psicometria , Índice de Gravidade de Doença , Perfil de Impacto da DoençaRESUMO
Treatment standards or guidelines have been developed for most features of Parkinson's disease (PD). However, data on the actual treatment that is put into practice are scarce. In 2000, a nationwide survey on the topic of sudden onset of sleep (SOS) in PD was initiated among the members of the German patient support group (deutsche Parkinson-Vereinigung, dPV). A part of this mailed questionnaire survey covering the antiparkinsonian and concomitant medication of the participants is presented here. This study analyses data sets from more than 6,500 PD patients. The mean dopaminergic dose was equivalent to 599 +/- 387 mg levodopa/die. The most frequently administered drugs were levodopa (94.2 %), dopamine agonists (DA) (71.7 %), amantadine (40.1 %), selegiline (27.6 %), entacapone (20.4 %), budipine (12.3 %), and anticholinergics (11.8 %). Costs of pharmacotherapy were estimated to be approximately
Assuntos
Antiparkinsonianos/uso terapêutico , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/epidemiologia , Fatores Etários , Idoso , Antiparkinsonianos/classificação , Antiparkinsonianos/economia , Relação Dose-Resposta a Droga , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Exame Neurológico , Razão de Chances , Doença de Parkinson/economia , Estudos Retrospectivos , Fatores Sexuais , Inquéritos e QuestionáriosRESUMO
Aminoglycosides are commonly used antibiotics that often induce ototoxicity leading to permanent hair cell loss and hearing impairment. We hereby examined whether minocycline protects hair cells from gentamicin-induced hair cell damage. Two millimolar gentamicin significantly induced outer hair cell damage and the addition of minocycline to gentamicin-treated explants significantly increased hair cell survival in a dose-dependent manner. Additionally, we demonstrated that gentamicin induced p38 MAPK phosphorylation, cytochrome c release, and caspase 3 activation in these cells and these remarkable changes were blocked by minocycline treatments. Furthermore, we showed that the inhibitor of p38 MAPK or the inhibitor of caspase 3 only partially blocked gentamicin-induced hair cell damage, and the pretreatment of explants with the inhibitor of p38 MAPK and the inhibitor of caspase 3 together exerted a synergic protective effect against gentamicin-induced hair cell damage. Our results suggest that minocycline blocks gentamicin-induced hair cell loss possibly by inhibition of three mechanisms: p38 MAPK phosphorylation, cytochrome c release, and caspase 3 activation. This finding may explain why minocycline has protective activity in a variety of apoptotic models. Therapeutic intervention by using minocycline or related drugs may be a novel means for preventing inner ear injury following the use of aminoglycoside.
Assuntos
Inibidores de Caspase , Cóclea/efeitos dos fármacos , Gentamicinas/toxicidade , Minociclina/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Caspase 3 , Caspases/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Cóclea/enzimologia , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/fisiologia , Inibidores Enzimáticos/farmacologia , Gentamicinas/antagonistas & inibidores , Células Ciliadas Auditivas/efeitos dos fármacos , Células Ciliadas Auditivas/enzimologia , Fosforilação/efeitos dos fármacos , Ratos , Ratos Sprague-DawleyRESUMO
OBJECTIVE: Active or passive immunisation can mitigate plaque pathology in murine models of Alzheimer's disease (AD). Recently, it has been shown that antibodies against beta-amyloid (Abeta) are present in human immunoglobulin preparations (IVIgG), which specifically recognise and inhibit the neurotoxic effects of Abeta. This study reports the results from a pilot study using IVIgG in patients with AD. METHODS: Five patients with AD were enrolled and received monthly IVIgG over a 6 month period. Efficacy assessment included total Abeta/Abeta(1-42) measured in the CSF/serum as well as effects on cognition (ADAS-cog; CERAD) at baseline and at 6 months following IVIgG. RESULTS: Following IVIgG, total Abeta levels in the CSF decreased by 30.1% (17.3-43.5%) compared to baseline (p<0.05). Total Abeta increased in the serum by 233% (p<0.05). No significant change was found in Abeta(1-42) levels in the CSF/serum. Using ADAS-cog, an improvement of 3.7+/-2.9 points was detected. Scores in the MMSE were essentially unchanged (improved in four patients, stable in one patient) following IVIgG compared to baseline. CONCLUSION: Although the sample size of this pilot study is too small to draw a clear conclusion, the results of this pilot study provide evidence for a more detailed investigation of IVIgG for the treatment of AD.
Assuntos
Doença de Alzheimer/imunologia , Doença de Alzheimer/terapia , Peptídeos beta-Amiloides/imunologia , Imunoglobulinas Intravenosas/imunologia , Imunoglobulinas Intravenosas/uso terapêutico , Peptídeos beta-Amiloides/farmacologia , Formação de Anticorpos , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/terapia , Feminino , Humanos , Masculino , Entrevista Psiquiátrica Padronizada , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
BACKGROUND: Stroke care has a high impact on health costs. Therefore, the costs and reimbursements of integrated stroke care were calculated in a German neurological university hospital. PATIENTS AND METHODS: Patient cohorts of 2002 and 2003 were considered. All patients were included who presented with ischemic stroke, intracerebral hemorrhage, or transient ischemic attacks. G-DRG reimbursements were calculated by using the 3M grouper versions 2.2.0 for 2003 and 3.1 for 2004. RESULTS: There were no significant differences between the two patient cohorts. Compared to the former reimbursement system based on fixed daily charges, a base rate of EUR 3,204 was required for a neutral budget in 2002. The actual base rate was EUR 3,169. Assuming this base rate, an average reimbursement of EUR 4,201 (grouper 2.2.0) and of EUR 3,657 (grouper 3.1) was achieved per patient in 2002. An average reimbursement of EUR 4,107 (grouper 2.2.0) and of EUR 3,351 (grouper 3.1) was achieved per patient in 2003. CONCLUSION: The development of reimbursements by the G-DRGs shows a clear downward trend and shows that the high resource use in stroke unit care is inadequately reflected by the G-DRGs.
Assuntos
Custos e Análise de Custo/métodos , Grupos Diagnósticos Relacionados/economia , Custos de Cuidados de Saúde/estatística & dados numéricos , Recursos em Saúde/economia , Reembolso de Seguro de Saúde/economia , Acidente Vascular Cerebral/economia , Acidente Vascular Cerebral/terapia , Idoso , Estudos de Coortes , Grupos Diagnósticos Relacionados/estatística & dados numéricos , Grupos Diagnósticos Relacionados/tendências , Feminino , Alemanha/epidemiologia , Custos de Cuidados de Saúde/tendências , Recursos em Saúde/estatística & dados numéricos , Recursos em Saúde/tendências , Humanos , Reembolso de Seguro de Saúde/estatística & dados numéricos , Reembolso de Seguro de Saúde/tendências , Masculino , Estudos Retrospectivos , Acidente Vascular Cerebral/classificação , Acidente Vascular Cerebral/epidemiologiaRESUMO
OBJECTIVE: To assess the effects on motor functioning, health status and direct medical costs of high-frequency stimulation of the subthalamic nucleus (DBS-STN) in patients with idiopathic Parkinson's disease (PD). In addition, the cost-effectiveness of DBS-STN vs. drug treatment was investigated. METHODS: 16 consecutive patients with PD from two centers (Düsseldorf/Cologne; Kiel) treated by DBS-STN were prospectively evaluated. Clinical evaluations were done at baseline and 1, 3, 6, 12 months following surgery by means of the Unified Parkinson's disease Rating Scale (UPDRS). Health status of PD patients was assessed using the Sickness Impact Profile (SIP) at baseline and 6 months following surgery. Relevant economic data were taken from the medical records and costs (1999) were derived from different German medical economic resources. Costs were determined from the perspective of the health care provider. RESULTS: Following DBS-STN UPDRS scores (subscores and sum score) as well as health status improved considerably in PD patients. The overall SIP score and the physical dimension score (p < 0.009) were significantly different (p < 0.01) six month after surgery compared with baseline values. Mean costs of DM 40,020 (US dollars 20,810, EURO 20,410, GB pounds 12,810) per patient were spent during the 12 month observation period for in-patient and out-patient care. These expenses included already the costs for the electronic device for bilateral stimulation. Following DBS-STN medication was considerably reduced. Mean daily drug costs at baseline were DM 46.7+/-21.8 (US dollars 24, EURO 24, GB pounds 15) and DM 18.3+/-17.7 (US dollars 10, EURO 9, GB pounds 6) at 12 months following DBS-STN. Accounting for the decreased drug consumption, total annual costs amounted to DM 31,400 (US dollars 16,330, EURO 16,010, GB pounds 10,050). Further, we estimated the incremental cost effectiveness as DBS-STN had higher costs but was more effective than baseline treatment. The incremental total cost-effectiveness ratio for DBS-STN was DM 1.800 (US dollars 940, EURO 920, GB pounds 580) for one point decrease of the UPDRS. CONCLUSION: DBS-STN is an effective treatment that considerably alleviates the severity of signs and symptoms and improves the health status of patients with PD. Compared with drug treatment, however, the expenditures associated with DBS-STN are increased when only direct medical costs are considered in a one year horizon. However, on a long-term basis costs will decrease considerably because of the reduction of the drug expenditure and improved functioning in all activities of daily living. To adequately evaluate the cost-effectiveness of DBS-STN compared with standard drug regimen for PD it is necessary to include direct, indirect and intangible costs on a long-term basis and under standardized circumstances.
Assuntos
Antiparkinsonianos/economia , Atenção à Saúde/estatística & dados numéricos , Terapia por Estimulação Elétrica/estatística & dados numéricos , Custos de Cuidados de Saúde/estatística & dados numéricos , Nível de Saúde , Doença de Parkinson/cirurgia , Núcleo Subtalâmico/cirurgia , Idoso , Antiparkinsonianos/administração & dosagem , Antiparkinsonianos/efeitos adversos , Análise Custo-Benefício/estatística & dados numéricos , Custos de Medicamentos/estatística & dados numéricos , Terapia por Estimulação Elétrica/economia , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/fisiopatologia , Núcleo Subtalâmico/fisiologiaAssuntos
Doença de Alzheimer/genética , Cistatinas/genética , Inibidores de Cisteína Proteinase/metabolismo , Polimorfismo Genético/genética , Regiões Promotoras Genéticas/genética , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Cistatina C , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de RiscoRESUMO
Idiopathic Parkinson's disease (PD) is a common chronic progressive neuro-degenerative disorder associated with the progressive loss of dopaminergic neurons in the substantia nigra. The natural course of the disease may lead to severe disability despite a variety of pharmacological and surgical treatment options. Levodopa is still the most effective symptomatic treatment for PD; however, long term use can cause a number of adverse effects including motor complications, nausea and vomiting, postural hypotension and changes in mental status. The onset of motor complications marks a crucial point in the management of PD. They may present as changes between akinetic and mobile phases (motor fluctuations) or as abnormal involuntary movements (dyskinesias). After levodopa treatment for 3 to 5 years, motor complications occur in approximately 50% of patients, and after 10 years in >80% of patients. Treatment options have recently expanded as new drugs have been licensed and surgical procedures refined. Patients with motor complications present a demanding task in disease management, and often multiple drugs and high dosages are necessary to achieve only suboptimal control, resulting in increased healthcare utilisation. Costs increase considerably in patients with motor fluctuations and dyskinesias compared with patients without these symptoms. In a French study, 6-month direct medical costs per patient increased from 1648 euros (EUR) to EUR3028 in patients without and with motor fluctuations, respectively. In a recent French study a significant difference in monthly direct medical costs was found in patients with and without dyskinesias (EUR560 vs 170). Unfortunately, no data are available on the effect of motor complications on indirect costs. Several studies have shown that health-related quality of life (HR-QOL) is reduced when motor fluctuations occur. This may also be true of dyskinesias, but because of the limited number of studies a definite conclusion is not yet possible. Recently, surgical treatment options have been used to deal with advanced PD and late stage complications. Although their effect on motor complications and HR-QOL is well documented, they result in increased costs (total medical cost: EUR28920) compared with drug treatment alone and are increasingly restricted by healthcare providers. The purpose of this article is to review the available data from pharmacotherapeutic. surgical and economic studies on HR-QOL and healthcare expenditure in patients with PD, with a major focus on the impact of motor fluctuations and dyskinesias.
Assuntos
Discinesias/economia , Discinesias/psicologia , Transtornos dos Movimentos/economia , Transtornos dos Movimentos/psicologia , Doença de Parkinson/economia , Doença de Parkinson/psicologia , Qualidade da Assistência à Saúde/economia , Qualidade de Vida , Idoso , Antiparkinsonianos/economia , Antiparkinsonianos/uso terapêutico , Humanos , Procedimentos Neurocirúrgicos/economia , Doença de Parkinson/terapiaRESUMO
Parkinson's disease is a chronic neurodegenerative disorder characterized by the loss of dopamine neurons in the substantia nigra, decreased striatal dopamine levels, and consequent extrapyramidal motor dysfunction. We now report that minocycline, a semisynthetic tetracycline, recently shown to have neuroprotective effects in animal models of stroke/ischemic injury and Huntington's disease, prevents nigrostriatal dopaminergic neurodegeneration in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson's disease. Minocycline treatment also blocked dopamine depletion in the striatum as well as in the nucleus accumbens after MPTP administration. The neuroprotective effect of minocycline is associated with marked reductions in inducible NO synthase (iNOS) and caspase 1 expression. In vitro studies using primary cultures of mesencephalic and cerebellar granule neurons (CGN) and/or glia demonstrate that minocycline inhibits both 1-methyl-4-phenylpyridinium (MPP(+))-mediated iNOS expression and NO-induced neurotoxicity, but MPP(+)-induced neurotoxicity is inhibited only in the presence of glia. Further, minocycline also inhibits NO-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK) in CGN and the p38 MAPK inhibitor, SB203580, blocks NO toxicity of CGN. Our results suggest that minocycline blocks MPTP neurotoxicity in vivo by indirectly inhibiting MPTP/MPP(+)-induced glial iNOS expression and/or directly inhibiting NO-induced neurotoxicity, most likely by inhibiting the phosphorylation of p38 MAPK. Thus, NO appears to play an important role in MPTP neurotoxicity. Neuroprotective tetracyclines may be effective in preventing or slowing the progression of Parkinson's and other neurodegenerative diseases.
Assuntos
Intoxicação por MPTP/tratamento farmacológico , Intoxicação por MPTP/prevenção & controle , Minociclina/farmacologia , Degeneração Neural/prevenção & controle , Fármacos Neuroprotetores/farmacologia , Transtornos Parkinsonianos/tratamento farmacológico , Transtornos Parkinsonianos/prevenção & controle , Animais , Caspase 1/metabolismo , Células Cultivadas , Dopamina/metabolismo , Humanos , Imidazóis/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Monoaminoxidase/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico Sintase Tipo II , Transtornos Parkinsonianos/induzido quimicamente , Fosforilação , Piridinas/farmacologia , Córtex Visual/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por MitógenoRESUMO
BACKGROUND: Retrospective epidemiologic studies suggest that individuals exposed to anti-inflammatory agents such as nonsteroidal anti-inflammatory drugs have a lower probability of developing AD as well as an older age at onset for the illness. Neuroinflammation may play an important role in the pathogenesis of AD. Interleukin 1 (IL-1), a potent proinflammatory cytokine, is colocalized immunohistochemically to neuritic plaques, a requisite neuropathologic feature for AD. A polymorphism in the 5'-flanking regulatory region at -889 of the IL-1 alpha gene (a C-to-T transition designated as IL-1A[-889] allele 2) may cause an overexpression of IL-1 alpha, a finding shown to be associated with inflammatory diseases. The IL-1A(-889) allele 2 polymorphism may be associated with AD pathogenesis. METHODS: A total of 259 patients with AD and 192 nondemented control subjects were included from two different centers (Indianapolis, IN, and Munich, Germany). Genotyping for APOE alleles and IL-1A(-889) allele 2 was performed by PCR-based amplification followed by restrictive endonuclease digestion. Statistical analyses were conducted by center-, gender group-, and age group-stratified Mantel-Haenszel odds ratios, CI, and p values. RESULTS: The allele frequency of IL-1A(-889) allele 2 was 46% in clinically diagnosed patients with probable AD versus 34% in control subjects from the combined centers. CONCLUSION: The authors found an increased risk for AD with an estimated Mantel-Haenszel odds ratio of 1.68 (95% CI 1.1 to 2.6; p = 0.022) for heterozygous carriers and 7.2 (95% CI 2.0 to 24.5; p = 0.003) for individuals homozygous for IL-1A(-889) allele 2. They found no evidence for an interaction between the IL-1A and the apoE epsilon 4 polymorphisms (carriers and homozygotes), age, or gender with regard to conferred risk. The data strongly support an association between the IL-1A(-889) allele 2, especially in homozygotes, and later-onset AD.
Assuntos
Doença de Alzheimer/genética , Interleucina-1/genética , Polimorfismo Genético/genética , Idoso , Idoso de 80 Anos ou mais , Alelos , Doença de Alzheimer/imunologia , Apolipoproteína E4 , Apolipoproteínas E/genética , Estudos de Casos e Controles , Estudos de Coortes , Análise Mutacional de DNA , Feminino , Frequência do Gene , Triagem de Portadores Genéticos , Genótipo , Heterozigoto , Homozigoto , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Medição de RiscoRESUMO
BACKGROUND: alpha2 Macroglobulin is a panproteinase inhibitor that is found immunohistochemically in neuritic plaques, a requisite neuropathologic feature of AD. Recently, a pentanucleotide deletion near the 5' end of the "bait region" of the alpha2 macroglobulin (A2M) gene was reported to be associated with AD in a large cohort of sibpairs, in which the mutation conferred a similar odds ratio with AD as the APOE-epsilon4 allele for carriers of at least one copy of the A2M gene (Mantel-Haenszel odds ratio, 3.56). METHODS: We studied three independent association samples of AD patients (n = 309) with an age range of 50 to 94 years and representative controls (n = 281) to characterize the allele frequency of the pentanucleotide deletion in this cohort. We detected the mutation near the 5' splice site of exon 18 using standard PCR and restriction fragment length polymorphism methods. The results were adjusted for age, gender, education, and APOE polymorphism. RESULTS: We found that the A2M gene polymorphism conferred an increased risk for AD, with an estimated Mantel-Haenszel ratio of 1.5 (95% CI 1.1 to 2.2; p = 0.025). There was no age- or gender-dependent increase in A2M gene allele frequencies in AD patients compared with controls. The combined sample showed the expected association between AD and APOE-epsilon 4. In one of our three samples there was an interaction between the A2M and APOE-epsilon4 genes, but the other two samples showed no interaction between the two risk factors. CONCLUSIONS: Our data support an association between the A2M gene and AD. This association is less pronounced, however, in our cohort than in the previously reported sample of sibpairs.
Assuntos
Doença de Alzheimer/epidemiologia , Doença de Alzheimer/genética , alfa-Macroglobulinas/genética , Idoso , Idoso de 80 Anos ou mais , Apolipoproteínas E/genética , Éxons , Feminino , Deleção de Genes , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Polimorfismo Genético , Fatores de RiscoRESUMO
We quantified the amount of amyloid beta-peptide (Abeta) immunoreactivity as well as amyloid deposits in a large cohort of transgenic mice overexpressing the V717F human amyloid precursor protein (APP(V717F+/-) TG mice) with no, one, or two mouse apolipoprotein E (Apoe) alleles at various ages. Remarkably, no amyloid deposits were found in any brain region of APP(V717F+/-) Apoe(-/-) TG mice as old as 22 mo of age, whereas age-matched APP(V717F +/-) Apoe(+/-) and Apoe(+/+) TG mice display abundant amyloid deposition. The amount of Abeta immunoreactivity in the hippocampus was also markedly reduced in an Apoe gene dose-dependent manner (Apoe(+/+) > Apoe(+/-) >> Apoe(-/-)), and no Abeta immunoreactivity was detected in the cerebral cortex of APP(V717F+/-) Apoe(-/-) TG mice at any of the time points examined. The absence of apolipoprotein E protein (apoE) dramatically reduced the amount of both Abeta(1-40) and Abeta(1-42) immunoreactive deposits as well as the resulting astrogliosis and microgliosis normally observed in APP(V717F) TG mice. ApoE immunoreactivity was detected in a subset of Abeta immunoreactive deposits and in virtually all thioflavine-S-fluorescent amyloid deposits. Because the absence of apoE alters neither the transcription or translation of the APP(V717F) transgene nor its processing to Abeta peptide(s), we postulate that apoE promotes both the deposition and fibrillization of Abeta, ultimately affecting clearance of protease-resistant Abeta/apoE aggregates. ApoE appears to play an essential role in amyloid deposition in brain, one of the neuropathological hallmarks of Alzheimer's disease.
Assuntos
Doença de Alzheimer/patologia , Precursor de Proteína beta-Amiloide/genética , Amiloide/metabolismo , Apolipoproteínas E/genética , Encéfalo/patologia , Doença de Alzheimer/genética , Amiloide/isolamento & purificação , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Apolipoproteínas E/isolamento & purificação , Apolipoproteínas E/metabolismo , Córtex Cerebral/patologia , Modelos Animais de Doenças , Gliose , Heterozigoto , Hipocampo/patologia , Homozigoto , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Neuroglia/metabolismoRESUMO
In recent years inflammatory mechanisms have become increasingly appreciated as important steps in the Alzheimer's pathogenic pathway. There is accumulating evidence that amyloid beta-peptide (A beta), the peptide product of the cleavage of amyloid precursor protein, may promote or exacerbate local inflammation by stimulating glial cells to release immune mediators. In addition, clinical studies using nonsteroidal antiinflammatory drugs have found a reduced risk for Alzheimer's disease with their use. Here we show that the neurotoxic A beta, a major plaque component, and lipopolysaccharides (LPS), an immune reaction-triggering portion of bacterial membranes, are both potent activators of the nuclear transcription factor NF-kappaB in primary rat astroglial cells. The activation was found to be concentration- and time-dependent and could be attenuated in the presence of NF-kappaB decoy nucleotides. The pretreatment by either 17beta-estradiol (1-10 microg) or sodium salicylate (3-30 mM) reduced the A beta (LPS)-induced activation of NF-kappaB by 48 (50%) and 60% (50%) of activated levels, respectively. In addition, 17beta-estradiol (10 microM) and sodium salicylate (10 mM) were able to attenuate the increase in interleukin-1beta levels following exposure to 25 microM A beta. Our data suggest that the aberrant gene expression is at least in part due to A beta-induced activation of NF-kappaB, a potent immediate-early transcriptional regulator of numerous proinflammatory genes; this event takes place in astroglial cells. The results of our experiments provide a further understanding of the effects of estrogen and aspirin on astroglial cells exposed to A beta and LPS.
Assuntos
Peptídeos beta-Amiloides/farmacologia , Astrócitos/metabolismo , Estradiol/farmacologia , Lipopolissacarídeos/farmacologia , NF-kappa B/metabolismo , Fragmentos de Peptídeos/farmacologia , Salicilato de Sódio/farmacologia , Animais , Astrócitos/citologia , Astrócitos/efeitos dos fármacos , Células Cultivadas , Córtex Cerebral/citologia , Feto , Regulação da Expressão Gênica/efeitos dos fármacos , Interleucina-1/genética , Cinética , NF-kappa B/genética , Oligodesoxirribonucleotídeos Antissenso/farmacologia , Ratos , Tionucleotídeos/farmacologiaRESUMO
Neurotoxicity induced by 6-hydroxydopamine (6-OHDA) is believed to be due, in part, to the production of reactive oxygen species (ROS) and/or an inhibition of mitochondrial function. However, little is known about the ensuing intracellular events which ultimately result in cell death. Here we show that exposure to relatively low concentrations of 6-OHDA induces apoptosis of cerebellar granule neurons (CGN). 6-OHDA-induced apoptosis of CGN is associated with activation of a caspase-3-like protease. Western blots of cytosolic extracts from 6-OHDA-treated CGN reveal a translocation of cytochrome c from mitochondria to the cytosol, which precedes activation of the protease detected by Ac-DEVD-pNA. DNA laddering can be blocked by caspase inhibitors zVAD-FMK and Ac-DEVD-CHO, however cell death can only be attenuated for a short time period in the presence of these inhibitors. Our data suggest that 6-OHDA-induced apoptosis of CGN involves activation of a caspase-3-like protease. In contrast to the neurotoxicity induced by MPP+, however, the peptide inhibitors zVAD-FMK and Ac-DEVD-CHO can only attenuate early neuronal death induced by 6-OHDA. At later time points, neuronal death lacking DNA laddering occurs even in the presence of the peptide inhibitor zVAD-FMK or Ac-DEVD-CHO.
Assuntos
Apoptose/fisiologia , Caspases/análise , Neurônios/citologia , Neurônios/enzimologia , 1-Metil-4-fenilpiridínio/farmacologia , Clorometilcetonas de Aminoácidos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Caspase 3 , Células Cultivadas , Cerebelo/citologia , Inibidores de Cisteína Proteinase/farmacologia , Grupo dos Citocromos c/análise , Grupo dos Citocromos c/metabolismo , Fragmentação do DNA , Dopaminérgicos/farmacologia , Mitocôndrias/enzimologia , Neurônios/efeitos dos fármacos , Oligopeptídeos/farmacologia , Oxidopamina , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/metabolismo , Ratos , Ratos Sprague-Dawley , SimpatolíticosRESUMO
Multiple aspartate-specific cysteine proteases have been identified and specific members of this family have been implicated in the apoptotic death of many mammalian cell types. Caspase-3-like proteases seem to play a pivotal role in neuronal apoptosis since mice with germline inactivation of the caspase-3 gene manifest profound alterations in neurogenesis. Moreover, inhibitors of caspase-3-related proteases have been shown to inhibit neuronal apoptosis. Here we extend recent work from our laboratory on the mechanisms mediating the neurotoxic actions of 1-methyl-4-phenylpyridinium using ventral mesencephalon cultures containing dopamine neurons. We demonstrate that low concentrations of 1-methyl-4-phenylpyridinium induce apoptosis in dopamine neurons by morphological and biochemical criteria. Moreover, pretreatment of ventral mesencephalon cultures with the tetrapeptide inhibitors of the caspase-3-like proteases zVAD-FMK or Ac-DEVD-CHO specifically inhibit death of dopamine neurons induced by low concentrations of 1-methyl-4-phenylpyridinium, whereas the caspase-1-like inhibitor Ac-YVAD-CHO was without effect. Our data indicate that exposure of cultured ventral mesencephalon dopamine neurons to low concentrations of 1-methyl-4-phenylpyridinium results in apoptotic death and that caspase-3-like proteases may mediate the neurotoxic apoptotic actions of 1-methyl-4-phenylpyridinium.