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1.
J Psychiatr Res ; 168: 133-139, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37907036

RESUMO

BACKGROUND: Multiple system atrophy (MSA) is a neurodegenerative disorder characterized by autonomic failure and motor dysfunction in parkinsonism and/or cerebellar ataxia. Patients with MSA usually present with depression and anxiety symptoms. This observational study of patients with MSA-cerebellar subtype (MSA-C) with subthreshold depression/anxiety symptoms aimed to compare the efficacy of escitalopram oxalate (an antidepressant drug) and tandospirone citrate (an anxiolytic drug). METHODS: Fifty-six MSA-C patients were included, with 28 patients in each treatment group. One group received escitalopram oxalate 10 mg/day and the other group received tandospirone citrate 30 mg/day. The patients were evaluated at baseline and after 4 weeks. Several psychiatric and neurological tests were performed, including the Hamilton Anxiety Rating Scale (HAMA), Hamilton Depression Rating Scale (HAMD), Scale for the Assessment and Rating of Ataxia (SARA), and the Scale for Outcomes in Parkinson's Disease for Autonomic Symptoms (SCOPA-AUT). Furthermore, post-void residual urine volume (PVR) and blood pressure were measured. RESULTS: There was a more substantial reduction in the HAMA/HAMD, scores of stance, finger tracking, and finger nose test in the SARA, and PVR in the tandospirone group. There was a more substantial reduction in scores of dysuria, light-headed when standing up, syncope and hyperhidrosis in the SCOPA-AUT in the escitalopram group (p's < 0.05). CONCLUSIONS: Tandospirone citrate was more effective in improving depression/anxiety and some cerebellar ataxia symptoms, whereas escitalopram was more effective in improving some autonomic symptoms in MSA-C patients over a short-term period in an open-label observational study without a control group. Further research is needed to evaluate the long-term effects of tandospirone and escitalopram in MSA-C in long-term placebo controlled trials.


Assuntos
Ansiolíticos , Ataxia Cerebelar , Atrofia de Múltiplos Sistemas , Humanos , Ataxia Cerebelar/tratamento farmacológico , Citratos , Escitalopram , Atrofia de Múltiplos Sistemas/complicações , Atrofia de Múltiplos Sistemas/tratamento farmacológico , Atrofia de Múltiplos Sistemas/diagnóstico
2.
Phenomics ; 3(4): 333-349, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37589021

RESUMO

Years of intensive research has brought us extensive knowledge on the genetic and molecular factors involved in Alzheimer's disease (AD). In addition to the mutations in the three main causative genes of familial AD (FAD) including presenilins and amyloid precursor protein genes, studies have identified several genes as the most plausible genes for the onset and progression of FAD, such as triggering receptor expressed on myeloid cells 2, sortilin-related receptor 1, and adenosine triphosphate-binding cassette transporter subfamily A member 7. The apolipoprotein E ε4 allele is reported to be the strongest genetic risk factor for sporadic AD (SAD), and it also plays an important role in FAD. Here, we reviewed recent developments in genetic and molecular studies that contributed to the understanding of the genetic phenotypes of FAD and compared them with SAD. We further reviewed the advancements in AD gene therapy and discussed the future perspectives based on the genetic phenotypes.

3.
Lancet Reg Health West Pac ; 38: 100836, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37457901

RESUMO

Post-COVID cognitive dysfunction (PCCD) is a condition in which patients with a history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, usually three months from the onset, exhibit subsequent cognitive impairment in various cognitive domains, and cannot be explained by an alternative diagnosis. While our knowledge of the risk factors and management strategy of PCCD is still incomplete, it is necessary to integrate current epidemiology, diagnosis and treatment evidence, and form consensus criteria to better understand this disease to improve disease management. Identifying the risk factors and vulnerable population of PCCD and providing reliable strategies for effective prevention and management is urgently needed. In this paper, we reviewed epidemiology, diagnostic markers, risk factors and available treatments on the disease, formed research recommendation framework for vulnerable population, under the background of post-COVID period.

4.
Sci China Life Sci ; 66(12): 2711-2754, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37480469

RESUMO

Transgenic models are useful tools for studying the pathogenesis of and drug development for Alzheimer's Disease (AD). AD models are constructed usually using overexpression or knock-in of multiple pathogenic gene mutations from familial AD. Each transgenic model has its unique behavioral and pathological features. This review summarizes the research progress of transgenic mouse models, and their progress in the unique mechanism of amyloid-ß oligomers, including the first transgenic mouse model built in China based on a single gene mutation (PSEN1 V97L) found in Chinese familial AD. We further summarized the preclinical findings of drugs using the models, and their future application in exploring the upstream mechanisms and multitarget drug development in AD.


Assuntos
Doença de Alzheimer , Camundongos , Animais , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Camundongos Transgênicos , Precursor de Proteína beta-Amiloide/genética , Modelos Animais de Doenças , Pensamento , Peptídeos beta-Amiloides/genética
5.
Alzheimers Res Ther ; 15(1): 40, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36850008

RESUMO

BACKGROUND: Neuropsychology and imaging changes have been reported in the preclinical stage of familial Alzheimer's disease (FAD). This study investigated the effects of APOEε4 and known pathogenic gene mutation on different cognitive domains and circuit imaging markers in preclinical FAD. METHODS: One hundred thirty-nine asymptomatic subjects in FAD families, including 26 APOEε4 carriers, 17 APP and 20 PS1 mutation carriers, and 76 control subjects, went through a series of neuropsychological tests and MRI scanning. Test scores and imaging measures including volumes, diffusion indices, and functional connectivity (FC) of frontostriatal and hippocampus to posterior cingulate cortex pathways were compared between groups and analyzed for correlation. RESULTS: Compared with controls, the APOEε4 group showed increased hippocampal volume and decreased FC of fronto-caudate pathway. The APP group showed increased recall scores in auditory verbal learning test, decreased fiber number, and increased radial diffusivity and FC of frontostriatal pathway. All three genetic groups showed decreased fractional anisotropy of hippocampus to posterior cingulate cortex pathway. These neuropsychological and imaging measures were able to discriminate genetic groups from controls, with areas under the curve from 0.733 to 0.837. Circuit imaging measures are differentially associated with scores in various cognitive scales in control and genetic groups. CONCLUSIONS: There are neuropsychological and imaging changes in the preclinical stage of FAD, some of which are shared by APOEε4 and known pathogenic gene mutation, while some are unique to different genetic groups. These findings are helpful for the early identification of Alzheimer's disease and for developing generalized and individualized prevention and intervention strategies.


Assuntos
Doença de Alzheimer , Humanos , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/genética , Cognição , Anisotropia , Giro do Cíngulo , Mutação/genética
6.
CNS Neurosci Ther ; 29(7): 1805-1816, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36852442

RESUMO

AIMS: This study investigated the relationship between plasma Wnt2b levels and Alzheimer's disease (AD), and explored the effect of Wnt2b on mitochondrial dysfunction in AD. METHODS: Healthy and AD subjects, AD transgenic mice, and in vitro models were used to investigate the roles of Wnt2b in abnormalities in canonical Wnt signaling and mitochondria in AD. RT-qPCR, immunoblotting, and immunofluorescence analysis were performed to assay canonical Wnt signaling. Mitochondrial structure was analyzed by electron microscopy. Flow cytometry was used to examine the intracellular calcium and neuronal apoptosis. RESULTS: Plasma Wnt2b levels were lower in AD patients and positively correlated with cognitive performance. Similarly, Wnt2b was reduced in the hippocampus of AD mice and in vitro models. Next, Wnt2b overexpression and recombinant Wnt2b were used to endogenously and exogenously upregulate Wnt2b levels. Upregulation of Wnt2b could effectively prevent downregulation of canonical Wnt signaling, mitochondrial dysfunction in in vitro AD models. Subsequently, intracellular calcium overload and neuronal damage were ameliorated. CONCLUSIONS: Our study highlights that Wnt2b decline is associated with cognitive impairment in AD, and upregulation of Wnt2b can exert neuroprotective effects in AD, particularly in ameliorating mitochondrial dysfunction.


Assuntos
Doença de Alzheimer , Mitocôndrias , Fármacos Neuroprotetores , Animais , Camundongos , Peptídeos beta-Amiloides/metabolismo , Cálcio , Modelos Animais de Doenças , Camundongos Transgênicos , Mitocôndrias/metabolismo , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Regulação para Cima , Humanos
7.
J Alzheimers Dis ; 90(2): 681-691, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36155508

RESUMO

BACKGROUND: Although elevated levels of homocysteine (Hcy) are associated with cognitive impairment and dementia, the relevance of Hcy, vitamin B12, and folate levels to subtypes of dementia are still unknown. OBJECTIVE: To investigate the changes of Hcy, vitamin B12, and folate levels in mild cognitive impairment (MCI) and subtypes of dementia including Alzheimer's disease (AD), vascular dementia (VaD), frontotemporal dementia (FTD), and Lewy body dementia (LBD), and their relationships with cognitive function and magnetic resonance imaging (MRI) markers. METHODS: We measured serum levels of Hcy, vitamin B12, and folate in 257 subjects. Each subject underwent cognitive function assessment and brain MRI test. The Fazekas and temporal lobe atrophy (MTA) visual rating scales were used to assess the degree of white matter hyperintensities and MTA, respectively. RESULTS: Serum levels of Hcy was higher and vitamin B12 was lower in AD, VaD, FTD, and LBD groups than cognitively normal controls. No significant differences of folate levels were found among 6 groups. Hcy levels were positively correlated with MTA total score in AD (r = 0.448, p < 0.001). Vitamin B12 levels were positively correlated with MoCA in VaD (r = 0.497), and negatively correlated with MTA total score in AD (r = - 0.325) (ps < 0.05). Hyperhomocysteinemia may increase the risk of AD (OR = 2.744), VaD (OR = 3.600), and FTD (OR = 3.244) in the adjusted model (ps < 0.05). CONCLUSION: Hcy and vitamin B12 levels are associated with MTA in AD. Vitamin B12 levels are associated with general cognition in VaD. Hyperhomocysteinemia is a risk factor for not only AD and VaD but also FTD.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Demência Vascular , Demência Frontotemporal , Hiper-Homocisteinemia , Humanos , Doença de Alzheimer/complicações , Ácido Fólico , Demência Frontotemporal/complicações , Homocisteína , Vitamina B 12
8.
Mol Neurobiol ; 59(6): 3370-3381, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35305243

RESUMO

Alzheimer's disease (AD) is the most common form of neurodegenerative disease and most anti-AD drugs have failed in clinical trials; hence, it is urgent to find potentially effective drugs against AD. DL-3-n-butylphthalide (NBP) is a compound extracted from celery seed and is a multiple-target drug. Several studies have demonstrated the neuroprotective effects of NBP on cognitive impairment, but the mechanisms of NBP remains relatively unexplored. In this study, we found that NBP could alleviated the increase of intracellular Ca2+ and reversed down-regulation of Ca2+/calmodulin-dependent protein kinase alpha (CaMKIIα) signaling and rescued neuronal apoptosis in SH-SY5Y cells treated by Aß oligomers. However, these neuroprotective effects of NBP on neuronal damage and CaMKIIα signaling were abolished when CaMKIIα expression was knocked down or its activity was inhibited. Thus, our findings suggested that CaMKIIα signaling was required for the neuroprotective effects of NBP in AD and provided an improved basis for elucidating the mechanism and treatment of NBP in AD.


Assuntos
Doença de Alzheimer , Benzofuranos , Doenças Neurodegenerativas , Fármacos Neuroprotetores , Doença de Alzheimer/metabolismo , Benzofuranos/farmacologia , Benzofuranos/uso terapêutico , Humanos , Doenças Neurodegenerativas/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico
9.
BMC Neurol ; 22(1): 40, 2022 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-35086492

RESUMO

BACKGROUND: Progressive multifocal leukoencephalopathy (PML) is a rare demyelinating lytic brain infection caused by the John Cunningham virus (JCV). JCV manifests primarily in patients with innate immunodeficiency or taking immunomodulatory medications. In this case study, we report a PML patient with comorbid mediastinal teratoma and mild lymphopenia. CASE PRESENTATION: A 73-year-old female presented with a 3-month history of progressive hemiplegia, hemianopsia, and cognitive impairment. She was diagnosed as PML by cerebrospinal fluid metagenomics sequencing and brain biopsy. Extensive immunological tests did not reveal an apparent immunodeficiency, but further work-up revealed that the PML was most likely the first presentation of mediastinal teratoma and the mild lymphopenia. Mirtazapine and immunoglobulin were started, the patient's condition was relatively stable and approved to be discharged from hospital. But unfortunately, she died of the lung infection 10 months after first presentation. CONCLUSIONS: This case confirms that mediastinal teratoma may induce the lymphopenia and trigger PML, delayed or incorrect diagnosis may worsen the course of the disease and result in poor prognosis.


Assuntos
Vírus JC , Leucoencefalopatia Multifocal Progressiva , Teratoma , Idoso , Encéfalo , Feminino , Humanos , Leucoencefalopatia Multifocal Progressiva/complicações , Leucoencefalopatia Multifocal Progressiva/diagnóstico , Mirtazapina , Teratoma/complicações
10.
Alzheimers Res Ther ; 13(1): 107, 2021 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-34044860

RESUMO

BACKGROUND: Accelerated long-term forgetting has been identified in preclinical Alzheimer's disease (AD) and is attributed to a selective impairment of memory consolidation in which the hippocampus plays a key role. As blood may contain multiple senescence-related factors that involved in neurogenesis and synaptic plasticity in the hippocampus, we tested whether there is an association between blood-borne factors and accelerated long-term forgetting in asymptomatic individuals from families with autosomal dominant AD (ADAD). METHODS: We analyzed data of 39 asymptomatic participants (n = 18 ADAD mutation carriers, n = 21 non-carriers) from the Chinese Familial Alzheimer's Disease Network (CFAN) study. Long-term forgetting rates were calculated based on recall or recognition of two materials (word list and complex figure) at three delays comprising immediate, 30 min, and 7 days. Peripheral blood concentrations of candidate pro-aging factors (CC chemokine ligand 11 [CCL11] and monocyte chemotactic protein 1 [MCP1]) and rejuvenation factors (growth differentiation factor 11 [GDF11], thrombospondin-4 [THBS4], and secreted protein acidic and rich in cysteine like 1 [SPARCL1]) were evaluated in all participants. RESULTS: Despite normal performance on standard 30-min delayed testing, mutation carriers exhibited accelerated forgetting of verbal and visual material over 7 days in comparison with matched non-carriers. In the whole sample, lower plasma THBS4 was associated with accelerated long-term forgetting in list recall (ß = -0.46, p = 0.002), figure recall (ß = -0.44, p = 0.004), and list recognition (ß = -0.37, p = 0.010). Additionally, higher plasma GDF11 and CCL11 were both associated with accelerated long-term forgetting (GDF11 versus figure recall: ß = 0.39, p = 0.007; CCL11 versus list recognition: ß = 0.44, p = 0.002). CONCLUSIONS: Accelerated long-term forgetting is a cognitive feature of presymptomatic AD. Senescence-related blood-borne factors, especially THBS4, GDF11, and CCL11, may be promising biomarkers for the prediction of accelerated long-term forgetting.


Assuntos
Doença de Alzheimer , Doença de Alzheimer/genética , Proteínas Morfogenéticas Ósseas , Proteínas de Ligação ao Cálcio , Proteínas da Matriz Extracelular , Fatores de Diferenciação de Crescimento , Humanos , Transtornos da Memória/genética , Rememoração Mental , Testes Neuropsicológicos , Osteonectina , Reconhecimento Psicológico
11.
J Alzheimers Dis ; 81(2): 583-595, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33814442

RESUMO

BACKGROUND: Gut microbiota can influence human brain function and behavior. Recent studies showed that gut microbiota might play an important role in the pathogenesis of Alzheimer's disease (AD). OBJECTIVE: To investigate the composition of gut microbiota in AD patients and their association with cognitive function and neuropsychiatric symptoms (NPS). METHODS: The fecal samples from 60 AD patients (30 with NPS and 30 without NPS) and 32 healthy control subjects (HC) were collected and analyzed by 16S ribosomal RNA sequencing. The functional variations of gut microbiota were predicted using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States. The correlation between different bacterial taxa and cognitive (Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR)), and NPS measures were analyzed. RESULTS: The fecal microbial composition of AD patients was quite distinct from HC. Bifidobacterium, Sphingomonas, Lactobacillus, and Blautia were enriched, while Odoribacter, Anaerobacterium, and Papillibacter were reduced. AD patients with NPS showed decreased Chitinophagaceae, Taibaiella, and Anaerobacterium compared with those without NPS. Functional pathways were different between AD and HC, and between AD patients with and without NPS. Correlation analysis showed that Sphingomonas correlated negatively with MMSE; Anaerobacterium and Papillibacter correlated positively with MMSE and negatively with CDR. Cytophagia, Rhodospirillaceae, and Cellvibrio correlated positively with NPS, while Chitinophagaceae, Taibaiella, and Anaerobacterium correlated negatively with NPS. CONCLUSION: AD patients have gut microbiota alterations related to cognition, and differential taxa between AD patients with and without NPS associated differently with NPS domains, which helps further understand the pathogenesis of AD and explore potential therapeutic targets.


Assuntos
Doença de Alzheimer/microbiologia , Cognição/fisiologia , Fezes/microbiologia , Microbioma Gastrointestinal/genética , RNA Ribossômico 16S/genética , Doença de Alzheimer/genética , Humanos , Testes Neuropsicológicos , Filogenia
12.
J Alzheimers Dis ; 81(1): 19-32, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33749646

RESUMO

Alzheimer's disease (AD) research is entering a unique moment in which enormous information about the molecular basis of this disease is being translated into therapeutics. However, almost all drug candidates have failed in clinical trials over the past 30 years. These many trial failures have highlighted a need for the incorporation of biomarkers in clinical trials to help improve the trial design. Fluid biomarkers measured in cerebrospinal fluid and circulating blood, which can reflect the pathophysiological process in the brain, are becoming increasingly important in AD clinical trials. In this review, we first succinctly outline a panel of fluid biomarkers for neuropathological changes in AD. Then, we provide a comprehensive overview of current and future application of fluid biomarkers in clinical trials for AD. We also summarize the many challenges that have been encountered in efforts to integrate fluid biomarkers in clinical trials, and the barriers that have begun to be overcome. Ongoing research efforts in the field of fluid biomarkers will be critical to make significant progress in ultimately unveiling disease-modifying therapies in AD.


Assuntos
Doença de Alzheimer/diagnóstico , Doença de Alzheimer/sangue , Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/sangue , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Encéfalo/patologia , Humanos , Fosforilação , Proteínas tau/sangue , Proteínas tau/líquido cefalorraquidiano
13.
J Alzheimers Dis ; 78(1): 127-137, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32925042

RESUMO

BACKGROUND: Depression is one of the most common behavioral and psychological symptoms in people with Alzheimer's disease (AD). To date, however, the molecular mechanisms underlying the clinical association between depression and AD remained elusive. OBJECTIVE: Here, we study the relationship between memory impairment and depressive-like behavior in AD animal model, and investigate the potential mechanisms. METHODS: Male SD rats were administered amyloid-ß oligomers (AßOs) by intracerebroventricular injection, and then the depressive-like behavior, neuroinflammation, oxidative stress, and the serotonergic system were measured in the brain. Sulforaphane (SF), a compound with dual capacities of anti-inflammation and anti-oxidative stress, was injected intraperitoneally to evaluate the therapeutic effect. RESULTS: The results showed that AßOs induced both memory impairment and depressive-like behavior in rats, through the mechanisms of inducing neuroinflammation and oxidative stress, and impairing the serotonergic axis. SF could reduce both inflammatory factors and oxidative stress parameters to protect the serotonergic system and alleviate memory impairment and depressive-like behavior in rats. CONCLUSION: These results provided insights into the biological mechanisms underlying the clinical link between depressive disorder and AD, and offered new drug options for the treatment of depressive symptoms in dementia.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Depressão/tratamento farmacológico , Isotiocianatos/uso terapêutico , Sulfóxidos/uso terapêutico , Doença de Alzheimer/complicações , Animais , Antioxidantes/uso terapêutico , Encéfalo/metabolismo , Modelos Animais de Doenças , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
14.
J Alzheimers Dis ; 73(4): 1435-1444, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31929167

RESUMO

BACKGROUND: The default mode network (DMN) could be divided into subsystems, the functional connectivity of which are different across the Alzheimer's disease (AD) spectrum. However, the functional connectivity patterns within the subsystems are unknown in presymptomatic autosomal dominant AD (ADAD). OBJECTIVE: To investigate functional connectivity patterns within the subsystems of the DMN in presymptomatic subjects carrying PSEN1, PSEN2, or APP gene mutations. METHODS: Twenty-six presymptomatic mutation carriers (PMC) and twenty-nine cognitively normal non-carriers as normal controls (NC) from the same families underwent resting state functional MRI and structural MRI. Seed-based analyses were done to obtain functional connectivity of posterior and anterior DMN. For the regions that showed significant connectivity difference between PMC and NC, volumes were extracted and compared between the two groups. Connectivity measures were then correlated with cognitive tests scores. RESULTS: The posterior DMN showed connectivity decrease in the PMC group as compared with the NC group, which was primarily the connectivity of left precuneus with right precuneus and superior frontal gyrus; the anterior DMN showed significant connectivity decrease in the PMC group, which was the connectivity of medial frontal gyrus with middle frontal gyrus. In the brain regions showing connectivity changes in the PMC group, there was no group difference in volume. A positive correlation was observed between the precuneus connectivity value and Mini-Mental State Examination total score. CONCLUSION: Functional connectivity within both posterior and anterior DMN were disrupted in the presymptomatic stage of ADAD. Connectivity disruption within the posterior DMN may be useful for early identification of general cognitive decline and a potential imaging biomarker for early diagnosis.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/genética , Rede Nervosa/diagnóstico por imagem , Adulto , Doença de Alzheimer/psicologia , Precursor de Proteína beta-Amiloide/genética , Mapeamento Encefálico , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/psicologia , Feminino , Heterozigoto , Humanos , Imageamento por Ressonância Magnética , Masculino , Testes de Estado Mental e Demência , Pessoa de Meia-Idade , Mutação/genética , Rede Nervosa/fisiopatologia , Presenilina-1/genética , Presenilina-2/genética , Sintomas Prodrômicos
15.
Alzheimers Res Ther ; 12(1): 14, 2020 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-31937364

RESUMO

BACKGROUND: Although structural and functional changes of the striatum and hippocampus are present in familial Alzheimer's disease, little is known about the effects of specific gene mutation or disease progression on their related neural circuits. This study was to evaluate the effects of known pathogenic gene mutation and disease progression on the striatum- and hippocampus-related neural circuits, including frontostriatal and hippocampus-posterior cingulate cortex (PCC) pathways. METHODS: A total of 102 healthy mutation non-carriers, 40 presymptomatic mutation carriers (PMC), and 30 symptomatic mutation carriers (SMC) of amyloid precursor protein (APP), presenilin 1 (PS1), or presenilin 2 gene, with T1 structural MRI, diffusion tensor imaging, and resting-state functional MRI were included. Representative neural circuits and their key nodes were obtained, including bilateral caudate-rostral middle frontal gyrus (rMFG), putamen-rMFG, and hippocampus-PCC. Volumes, diffusion indices, and functional connectivity of circuits were compared between groups and correlated with neuropsychological and clinical measures. RESULTS: In PMC, APP gene mutation carriers showed impaired diffusion indices of caudate-rMFG and putamen-rMFG circuits; PS1 gene mutation carriers showed increased fiber numbers of putamen-rMFG circuit. SMC showed increased diffusivity of the left hippocampus-PCC circuit and volume reduction of all regions as compared with PMC. Imaging measures especially axial diffusivity of the representative circuits were correlated with neuropsychological measures. CONCLUSIONS: APP and PS1 gene mutations affect frontostriatal circuits in a different manner in familial Alzheimer's disease; disease progression primarily affects the structure of hippocampus-PCC circuit. The structural connectivity of both frontostriatal and hippocampus-PCC circuits is associated with general cognitive function. Such findings may provide further information about the imaging biomarkers for early identification and prognosis of familial Alzheimer's disease, and pave the way for early diagnosis, gene- or circuit-targeted treatment, and even prevention.


Assuntos
Doença de Alzheimer/genética , Doença de Alzheimer/fisiopatologia , Precursor de Proteína beta-Amiloide/genética , Encéfalo/fisiopatologia , Presenilina-1/genética , Presenilina-2/genética , Adulto , Progressão da Doença , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Mutação , Vias Neurais/fisiopatologia
16.
Neurobiol Aging ; 85: 155.e1-155.e4, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31235344

RESUMO

Presenilin 1 (PSEN1), presenilin 2 (PSEN2), and amyloid precursor protein (APP) genes account for the majority of autosomal dominant Alzheimer's disease (AD), with PSEN1 being the most common. We screened these genes for mutations in a Chinese proband from an autosomal dominant early-onset AD pedigree. Early-onset AD is defined as the age at onset of AD < 65 years. A heterozygous variant (c.332G > T) of PSEN1, which results in a missense mutation (p.Gly111Val), was identified. Three prediction programs suggested this mutation was disease causing. When PSEN1 Gly111Val was overexpressed in HEK293/APPswe cells, the ratio of Aß42/Aß40 was significantly increased compared with that of wild-type PSEN1. Our results suggest that this novel PSEN1 Gly111Val mutation may play a pathogenic role in AD.


Assuntos
Doença de Alzheimer/genética , Povo Asiático/genética , Mutação de Sentido Incorreto , Linhagem , Presenilina-1/genética , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Células HEK293 , Humanos , Fragmentos de Peptídeos/metabolismo
17.
Lancet Neurol ; 19(1): 81-92, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31494009

RESUMO

China has the largest population of patients with dementia in the world, imposing a heavy burden on the public and health care systems. More than 100 epidemiological studies on dementia have been done in China, but the estimates of the prevalence and incidence remain inconsistent because of the use of different sampling methods. Despite improved access to health services, inadequate diagnosis and management for dementia is still common, particularly in rural areas. The Chinese Government issued a new policy to increase care facilities for citizens older than 65 years, but most patients with dementia still receive care at home. Western medicines for dementia symptoms are widely used in China, but many patients choose Chinese medicines even though they have little evidence supporting efficacy. The number of clinical trials of Chinese and western medicines has substantially increased as a result of progress in research on new antidementia drugs but international multicentre studies are few in number. Efforts are needed to establish a national system of dementia care enhance training in dementia for health professionals, and develop global collaborations to prevent and cure this disease.


Assuntos
Demência/epidemiologia , Demência/terapia , China/epidemiologia , Demência/diagnóstico , Humanos
18.
EBioMedicine ; 42: 174-187, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30926423

RESUMO

BACKGROUND: Soluble amyloid-ß oligomer (AßO) induced deleterious cascades have recently been considered to be the initiating pathologic agents of Alzheimer's disease (AD). However, little is known about the neurotoxicity and production of different AßOs. Understanding the production and spread of toxic AßOs within the brain is important to improving understanding of AD pathogenesis and treatment. METHODS: Here, PS1V97L transgenic mice, a useful tool for studying the role of AßOs in AD, were used to identify the specific AßO assembly that contributes to neuronal injury and cognitive deficits. Then, we investigated the production and spread of toxic Aß assemblies in astrocyte and neuron cultures, and further tested the results following intracerebroventricular injection of AßOs in animal model. FINDINGS: The results showed that cognitive deficits were mainly caused by the accumulation of nonameric and dodecameric Aß assemblies in the brains. In addition, we found that the toxic AßOs were duplicated in a time-dependent manner when BACE1 and apolipoprotein E were overexpressed, which were responsible for producing redundant Aß and forming nonameric and dodecameric assemblies in astrocytes, but not in neurons. INTERPRETATION: Our results suggest that astrocytes may play a central role in the progression of AD by duplicating and spreading toxic AßOs, thus triggering neuronal injury. FUND: This study was supported by the Key Project of the National Natural Science Foundation of China; the National Key Scientific Instrument and Equipment Development Project; Beijing Scholars Program, and Beijing Brain Initiative from Beijing Municipal Science & Technology Commission.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Astrócitos/metabolismo , Neurônios/metabolismo , Agregados Proteicos , Agregação Patológica de Proteínas/metabolismo , Peptídeos beta-Amiloides/química , Animais , Apolipoproteínas E/metabolismo , Astrócitos/patologia , Sobrevivência Celular , Células Cultivadas , Disfunção Cognitiva/genética , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/psicologia , Modelos Animais de Doenças , Imunofluorescência , Humanos , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Neurônios/patologia , Ligação Proteica , Ratos
19.
PLoS One ; 12(1): e0167242, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28107346

RESUMO

BACKGROUND: This study was to examine the insular cortical functional connectivity in drug naïve patients with first episode schizophrenia and to explore the relationship between the connectivity and the severity of clinical symptoms. METHODS: Thirty-seven drug naïve patients with schizophrenia and 25 healthy controls were enrolled in this study. A seed-based approach was used to analyze the resting-state functional imaging data. Insular cortical connectivity maps were bilaterally extracted for group comparison and validated by voxel-based morphometry (VBM) analysis. Clinical symptoms were measured using the Positive and Negative Syndrome Scale (PANSS). RESULTS: There were significant reductions in the right insular cortical connectivity with the Heschl's gyrus, anterior cingulate cortex (ACC), and caudate (p's<0.001) in the patient group compared with the healthy control (HC) group. Reduced right insular cortical connectivity with the Heschl's gyrus was further confirmed in the VBM analysis (FDR corrected p<0.05). Within the patient group, there was a significant positive relationship between the right insula-Heschl's connectivity and PANSS general psychopathology scores (r = 0.384, p = 0.019). CONCLUSION: Reduced insula-Heschl's functional connectivity is present in drug naïve patients with first episode schizophrenia, which might be related to the manifestation of clinical symptoms.


Assuntos
Mapeamento Encefálico , Córtex Cerebral/fisiopatologia , Esquizofrenia/fisiopatologia , Adolescente , Adulto , Estudos de Casos e Controles , Córtex Cerebral/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Esquizofrenia/diagnóstico por imagem , Índice de Gravidade de Doença , Adulto Jovem
20.
Behav Brain Res ; 289: 78-83, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-25920682

RESUMO

Growing evidence suggests abnormalities in brain morphology including hippocampal structure in patients with methamphetamine (MA) dependence. This study was performed to examine hippocampal volume in abstinent MA users, and to further explore its relationship with cognitive function. 30 abstinent MA users (20 males and 10 females) with average 5.52 months of duration of abstinence and 29 healthy controls (19 males and 10 females) age 18-45 years old were recruited for clinical assessment and imaging scan. FreeSurfer was used to segment the hippocampus bilaterally, and hippocampal volumes were extracted for group and gender comparisons. Cognitive function was measured using the CogState Battery Chinese language version (CSB-C). Analysis of covariance (ANCOVA) controlling for education showed a significant group by gender interaction for the right hippocampal relative volume adjusted for total brain size (p = 0.020); there was a significant difference between male controls and female controls (p < 0.001), but such a difference did not exist between male patients and female patients (p = 0.203). No significant correlations were found between hippocampal volume and cognitive measures. There seems to be a gender difference in how MA affects hippocampal volume in abstinent MA users. Hippocampus might be an important treatment target for cognitive improvement and functional recovery in this patient population, especially in females.


Assuntos
Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Metanfetamina/efeitos adversos , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Adulto Jovem
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