American journal of neurodegenerative disease最新文献

The pathological foundation of human prion diseases is a result of the conversion of the physiological form of prion protein (PrP(c)) to the pathological protease resistance form PrP(res). Most patients with prion disease have unknown reasons for this conversion and the subsequent development of a devastating neurodegenerative disorder. The conversion of PrP(c) to PrP(res), with resultant propagation and accumulation results in neuronal death and amyloidogenesis. However, with increasing understanding of neurodegenerative processes it appears that protein-misfolding and subsequent propagation of these rouge proteins, is a generic phenomenon shared with diseases caused by tau, α-synucleins and β-amyloid proteins. Consequently, effective anti-prion agents may have wider implications. A number of therapeutic approaches include polyanionic, polycyclic drugs such as pentosan polysulfate (PPS), which prevent the conversion of PrP(c) to PrP(res) and might also sequester and down-regulate PrP(res). Polyanionic compounds might also help to clear PrP(res). Treatments aimed at the laminin receptor, which is an important accessory molecule in the conversion of PrP(c) to PrP(res) - neuroprotection, immunotherapy, siRNA and antisense approaches have provided some experimental promise.

The subventricular zone retains its neurogenic capacity throughout life and, as such, is often considered a potential source for endogenous repair in neurodegenerative disorders. Because dopamine is believed to stimulate adult neurogenesis, we looked for possible variations in the dopaminergic innervation of the subventricular zone between cases of Huntington's chorea and Parkinson's diseases. Antibodies against tyrosine hydroxylase (TH) and proliferating cell nuclear antigen (PCNA) were used as specific markers of dopaminergic axons and cell proliferating activity, respectively. The immunohistochemical approach was applied to postmortem tissue from 2 Parkinson's disease cases, 4 Huntington's disease cases, along with age-matched controls. The immunostaining was revealed with either diaminobenzidine or fluorescent-conjugated secondary antibodies. Optical density measurements were made along the entire dorso-ventral extent of the caudate nucleus. An intense TH+ zone was detected along the ventricular border of the caudate nucleus in Huntington's disease cases, but not in patients with Parkinson's disease or age-matched controls. This thin (287±38 μm) paraventricular zone was composed of numerous small and densely packed dopamine axon varicosities and overlapped the deep layers of the subventricular zone. Its immunoreactivity was 47±8% more intense than that of adjacent striatal areas. The dopamine innervation of the subventricular zone is strikingly massive in Huntington's chorea compared to Parkinson's disease, a finding that concurs with the marked increase in neurogenesis noted in the subventricular zone of Huntington's disease patients. This finding suggests that dopamine plays a crucial role in mechanisms designed to compensate for the massive striatal neuronal losses that occur in Huntington's disease.

Alzheimer's disease (AD) is the most common type of dementia, and represents a vast worldwide socio-economic burden, and in the absence of a current cure, effective therapeutic strategies are still needed. Cholinergic and cerebral blood flow deficits, excessive levels of oxidative stress, neuroinflammation and glutamate excitatory mechanisms are all believed to contribute to the development and progression of the disease. Scoparia dulcis, Catharanthus roseus, Sesamum indicum, Erythrina senegalensis and Vigna unguiculata represent five plants that have been used as traditional medicines for the treatment of AD in certain cultures. Review of the scientific literature was conducted to explore the properties of these plants that might be beneficial and explain what would be perceived by many to be largely anecdotal evidence of their benefit. All plants were found to possess varying levels of anti-oxidant capability. Scoparia dulcis was also found to potentiate nerve growth factor-like effects upon cell lines. Catharanthus roseus appears to inhibit acetylcholinesterase with relatively high potency, while Sesamum indicum demonstrated the strongest antioxidant ability. Comparisons with currently used plant derived therapeutics illustrate how these plants may be likely to have some therapeutic benefits in AD. The evidence presented also highlights how appropriate dietary supplementation with some of these plants in various cultural settings might have effects analogous or complementary to the so-called protective Mediterranean diet. However, prior to embarking on making any formal recommendations to this end, further rigorous evaluation is needed to better elucidate the breadth and potential toxicological aspects of medicinal properties harboured by these plants. This would be vital to ensuring a more informed and safe delivery of preparations of these plants if they were to be considered as a form of dietary supplementation and where appropriate, how these might interact with more formally established therapies in relation to AD.

The rising prevalence of Alzheimer's disease (AD) is rapidly becoming one of the largest health and economic challenges in the world. There is a growing need for the development and implementation of reliable biomarkers for AD that can be used to assist in diagnosis, inform disease progression, and monitor therapeutic efficacy. Preclinical models permit the evaluation of candidate biomarkers and assessment of pipeline agents before clinical trials are initiated and provide a translational opportunity to advance biomarker discovery. Fast and inexpensive data can be obtained from examination of peripheral markers, though they currently lack the sensitivity and consistency of imaging techniques such as MRI or PET. Plasma and cerebrospinal fluid (CSF) biomarkers in animal models can assist in development and implementation of similar approaches in clinical populations. These biomarkers may also be invaluable in decisions to advance a treatment to human testing. Longitudinal studies in AD models can determine initial presentation and progression of biomarkers that may also be used to evaluate disease-modifying efficacy of drugs. The refinement of biomarker approaches in preclinical systems will not only aid in drug development, but may facilitate diagnosis and disease monitoring in AD patients.

Background: Amyotrophic lateral sclerosis is a slowly progressive fetal neurodegenerative disease in which clinical phenotype and nutritional status are considered prognostic factors. Advanced age has also been reported to carry a poor prognosis in amyotrophic lateral sclerosis. The elderly population is expected to increase in Japan, as well as in other countries in the near future. Whether late-onset amyotrophic lateral sclerosis affects the average lifespan or survival of patients and the nutritional status was related to survival remains an open question.

Methods: We studied the survival of elderly 34 patients with clinically definite amyotrophic lateral sclerosis aged ≥ 70 years and investigated serum triglycerides, cholesterol, LDL/HDL ratio, and glucose. Serum uric acid was examined.

Results: The average age at respiratory disorders or death as a whole was 77.5 ± 4.3 years. Survival did not differ significantly between different clinical phenotypes or between patients with and those without riluzole usage. Survival differed significantly between patients with and those without other complications. No biochemical parameter is correlated with outcome in this series, including elevated triglyceride or cholesterol levels and an increased LDL/HDL ratio. The survival correlated with the serum uric acid level (r = 0.407, p = 0.017).

Conclusions: The onset of amyotrophic lateral sclerosis at ≥ 70 years of age might not be the key determinant of survival in patients with amyotrophic lateral sclerosis.

Patients with sporadic amyotrophic lateral sclerosis (sALS) show inflammation in the spinal cord and peripheral blood. The inflammation is driven by stimulation of macrophages by aggregated superoxide dismutase 1 (SOD1) through caspase1, interleukin 1 (IL1), IL6 and chemokine signaling. Inflammatory gene activation is inhibited in vitro by tocilizumab, a humanized antibody to IL6 receptor (IL6R). Tocilizumab inhibits global interleukin-6 (IL6) signaling, a key mechanism in chronic rheumatoid disorders. Here we studied in vivo baseline inflammatory gene transcription in peripheral blood mononuclear cells (PBMCs) of 10 sALS patients, and the effects of tocilizumab (Actemra(R)) infusions. At baseline, one half of ALS subjects had strong inflammatory activation (Group 1) (8 genes up regulated >4-fold, P<0.05 vs. controls) and the other half (Group 2) had weak activation. All patients showed greater than four-fold up regulation of MMP1, CCL7, CCL13 and CCL24. Tocilizumab infusions in the Group 1 patients resulted in down regulation of inflammatory genes (in particular IL1β), whereas in the Group 2 patients in up regulation of inflammatory genes. Post-infusion serum and CSF concentrations of tocilizumab inhibited caspase1 activation in vitro. Three of 5 patients receiving tocilizumab infusions showed time-limited attenuation of clinical progression. In conclusion, inflammation of sALS patients at baseline is up- or down-regulated in comparison to controls, but is partially normalized by tocilizumab infusions.

The autosomal dominant cerebellar ataxias, also known as spinocerebellar ataxias (SCA), are characterized by cerebellar degeneration and by their afferent and efferent connections. Currently, at least 31 types of SCA are described, among which a subset, comprising types 1, 2, 3, 6, 7, 17 of the disease, is distinguished due to sharing the same form of mutation involving the repetition of the series of CAG triplets, known as polyglutamine diseases (SCApolyQ). Through a systematic literature review using the Pubmed, PsycoINFO, LILACS and SciELO databases and the keywords Spinocerebellar Ataxia in association with the words neuropsychiatric, psychological, cognitive impairment(s) and psychiatric comorbidities this study aimed to identify the possible associations between SCApolyQ and neuropsychological and psychiatric symptoms/disorders. A greater presence of symptoms of depression and anxiety was evidenced, as well as the existence of cognitive impairments in the patients with SCApolyQ when compared with the general population, with important differences in the profile of these impairments among the types of SCA. It was observed that the findings, in general, indicated greater impairment in the executive functions, verbal fluency and verbal memory and that there was a higher concentration of studies for SCA2 and SCA3. However, there is a need for a greater number of studies using a more homogeneous methodology, which perform direct comparisons between the types of ataxias and that explore some of the still little evaluated neuropsychological functions and the different psychiatric disorders in their amplitude.

Immune reactions inside the central nervous system are finely regulated, thanks to the presence of several checkpoints that have the fundamental purpose to preserve this fragile tissue form harmful events. The current knowledge on the role of neuroinflammation and neuro-immune interactions in the fields of multiple sclerosis, Alzheimer's disease and Parkinson's disease is reviewed. Moreover, a focus on the potential role of both active and passive immunotherapy is provided. Finally, we propose a common perspective, which implies that, under pathological conditions, inflammation may exert both detrimental and protective functions, depending on local factors and the timing of immune activation and shutting-off systems.

Alzheimer's disease (AD) is the most common form of dementia. Several hypotheses have been put forward to explain the basis of disease onset and progression. Unfortunately, none of these seems to clarify the complexity of the pathogenesis. In fact, diverse and independent pathogenetic pathways can be disrupted at the same time, and each contributes to disease etiology. In recent years, researchers have begun studying biometals more deeply. A number of studies have shown that metal dyshomeostasis may enhance AD onset and progression. Specifically, different authors have hypothesized that alterations in metal metabolism are associated with an increased in metal-related oxidative stress and beta-amyloid oligomer formation and precipitation. Studies conducted in vivo, in vitro, in living patients and in silico studies have demonstrated that local and systemic defects in copper metabolism are characteristic signs of AD. This strongly supports the hypothesis that copper pathways may be disrupted by the disease. More specifically, a copper phenotype can be proposed for AD, based on defects found in genes involved in copper metabolism. In this review, we describe copper dyshomeostasis in AD patients and attempt to explain the basis of the AD copper phenotype. Dissecting copper pathways, we highlight mechanisms which may be at the basis of the disease. We also discuss various associated translation outcomes.

We have previously reported that increased numbers of Alz-50-reactive (apoptotic) neurons occurred in young DS subjects compared to controls, but increased in density with increasing age, and in advance of identifiable senile plaques (SP) in DS. The purpose of the study was to determine if there are further differences in Alzheimer's disease (AD)-like neuropathology with increasing age among individuals with Down's syndrome (DS) compared to cognitively normal age-matched controls. The two populations compared were age-matched normal controls (N = 14) between 11 months and 61 years of age and individuals with DS (N = 8) between 1 and 54 years of age. There were 7 cognitively intact DS and 10 control subjects under 35 years of age. The single demented 54 year old DS subject was compared to 4 non-demented controls between 48 and 61 years of age. 50 μm Vibratome sections of formalin fixed hippocampal formations were immunohistochemically stained for amyloid-β (6E10), APP (22C11) and phosphorylated tau (AT8) using standard methods. AT8 immunoreactive features were found only in the oldest DS subject. In contrast, the number and intensity of amyloid-β-immunoreactive neurons were maximal in the youngest DS subjects (1-24 years), reduced in the young adults (25-35 years) synchronous with the appearance of only diffuse-form SP, and were further reduced in the 54 year-old DS subject exhibiting abundant multiform SP. Distribution of APP immunoreactivity (22C11) was distinct from amyloid-β (6E10) in appearance and by location and age in both DS and normal controls. The data indicates that the earliest observable neuropathologic feature in DS may be neuronal accumulation of amyloid-β. Such accumulation of amyloid-β occurs decades in advance of deposition as SP, which in turn occurs decades before cognitive decline.