Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10636 (tau protein)
 5,110 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Alzheimer's disease, the most frequent cause of dementia, is characterized by the formation in the brain of neurofibrillary tangles and senile plaques. Neurofibrillary tangles are composed of bundles of paired helical filaments containing the microtubule-associated protein tau. In autopsy-derived brain samples from patients with Alzheimer's disease, tau is hyperphosphorylated and constitutes a promising disease marker. Senile plaques contain a small amyloid peptide derived from the amyloid precursor protein. Mutations of the amyloid precursor protein gene have been identified in rare cases of familial Alzheimer's disease, suggesting a causal role for amyloid peptide deposition in the disease. However, Alzheimer's disease has been demonstrated to be characterized by an important genetic heterogeneity. The identification of pathogenic DNA mutations, different from those of the amyloid precursor protein gene, will reveal whether the corresponding genes are involved in either an increased production of the amyloid peptide or a decrease of its removal, or in the fibrillogenic properties of the peptide, which seem to be related to its toxicity. Several mammalian cells are able to produce the amyloid peptide from its precursor. Understanding the cellular mechanisms that determine how cleavages occur in cells could help to identify new strategies for modulating amyloid peptide production. In attempts to produce animal models of Alzheimer's disease, investigators have used transgenic strategies. To date, these efforts have not been very successful. However, the expression in transgenic mice of both mutated amyloid peptide precursor and amyloid associated proteins should prove useful for examining the importance of putative etiological factors, and for testing novel therapies including anti-amyloidogenic strategies.
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PMID:The amyloid peptide and its precursor in Alzheimer's disease. 884 71

Alzheimer's disease (AD) is the most common form of dementia, and is characterized by a degeneration of neurones and their synapses, and a higher number of senile plaques (SP) and neurofibrillary tangles (NFT) compared with that found in non-demented individuals of the same age. NFT are composed of a hyperphosphorylated and ubiquitinated form of tau protein. Previous studies have found that in the cerebrospinal fluid (CSF) both tau and ubiquitin are increased in AD. We examined CSF-tau and CSF-ubiquitin in a population based sample of 85-year-olds, 26 demented (11 with probable Alzheimer's disease (AD), 13 with probable vascular dementia (VAD) and 2 with mixed (AD/VAD) type of dementia) and 35 non-demented individuals. CSF-tau was significantly higher both in the probable AD group (254 +/- 113 pg/mL; P < 0.01), and in the probable VAD group (247 +/- 75 pg/mL; P < 0.005), than in the non-demented group (171 +/- 78 pg/mL), but did not significantly differ between the probable AD and probable VAD groups. In contrast, CSF-ubiquitin did not significantly differ between the probable AD (100 +/- 24 ng/mL), probable VAD (102 +/- 16 ng/mL), and non-demented (97 +/- 27 ng/mL) groups. CSF-tau increased with increasing severity of dementia (P < 0.001), though no such relation was found for CSF-ubiquitin. Neither CSF-tau nor CSF-ubiquitin differed between patients with or without the apolipoprotein E E4 isoform. Higher CSF-tau and CSF-ubiquitin levels were also associated with increasing degree of cortical and central brain atrophy as measured by computerized tomography. The relationships between CSF-tau and severity of dementia and to brain atrophy suggest that CSF-tau may be used as a measure of neuronal/axonal degeneration in patients with dementia. We have previously shown a marked increase in both CSF-tau and CSF-ubiquitin in younger patients with AD and VAD. The less pronounced increase in CSF-tau and the lack of difference in CSF-ubiquitin in older patients suggest that the severity of the degenerative process is less in older than in younger demented patients.
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PMID:A population-based study of tau protein and ubiquitin in cerebrospinal fluid in 85-year-olds: relation to severity of dementia and cerebral atrophy, but not to the apolipoprotein E4 allele. 884 37

In Alzheimer disease (AD) the microtubule-associated protein tau is redistributed exponentially into paired helical filaments (PHFs) forming neurofibrillary tangles, which correlate with pyramidal cell destruction and dementia. Amorphous neuronal deposits and PHFs in AD are characterized by aggregation through the repeat domain and C-terminal truncation at Glu-391 by endogenous proteases. We show that a similar proteolytically stable complex can be generated in vitro following the self-aggregation of tau protein through a high-affinity binding site in the repeat domain. Once started, tau capture can be propagated by seeding the further accumulation of truncated tau in the presence of proteases. We have identified a nonneuroleptic phenothiazine previously used in man (methylene blue, MB), which reverses the proteolytic stability of protease-resistant PHFs by blocking the tau-tau binding interaction through the repeat domain. Although MB is inhibitory at a higher concentration than may be achieved clinically, the tau-tau binding assay was used to identify desmethyl derivatives of MB that have Ki values in the nanomolar range. Neuroleptic phenothiazines are inactive. Tau aggregation inhibitors do not affect the tau-tubulin interaction, which also occurs through the repeat domain. Our findings demonstrate that biologically selective pharmaceutical agents could be developed to facilitate the proteolytic degradation of tau aggregates and prevent the further propagation of tau capture in AD.
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PMID:Selective inhibition of Alzheimer disease-like tau aggregation by phenothiazines. 885 35

It is unknown whether aging and Alzheimer's disease (AD) are on the same continuum, or whether they are qualitatively distinct. Tau protein has been identified as a major constituent of paired helical filaments (PHFs) and AD is characterised by a major redistribution of the normal tau protein pool into PHFs. Little is known about the changes in tau protein distribution that occur in the course of normal aging. We have examined PHF-bound and normal tau fractions in frontal, temporal, parietal and occipital neocortex, cerebellum, hippocampus and entorhinal cortex in 15 cognitively unimpaired individuals aged 19-88 years at death. Insoluble tau protein in the PHF fraction did not increase with aging in any brain region, despite the appearance of neurofibrillary pathology at low density in the more elderly cases. By contrast, normal tau protein decreased with aging (r = 0.32, p < 0.001), with an average loss of 14% of soluble tau per decade after the age of 20 years. This was unrelated either to neurofibrillary or beta-amyloid pathology. Frontal grey matter and hippocampus were most vulnerable to age-related tau loss, decreasing by as much as 90% in the older subgroup. These findings contrast with those we have previously reported in AD, where the redistribution of tau protein into the PHF-bound fraction was highly correlated with the extent of neurofibrillary pathology, and suggest that the mechanisms of tau loss in aging and AD are distinct. Age-related tau loss may underlie the neuropsychological impairments seen in the non-demented elderly.
Dementia
PMID:Alterations in tau protein metabolism during normal aging. 886 83

A variety of measures of neuropathology in Alzheimer's disease (AD) correlate with dementia severity. However, the role of beta-amyloid protein and abnormally phosphorylated tau protein in the decline of specific cognitive abilities is unknown. "Constructional praxis' (e.g., copying, constructing) is believed to require integrity of the parietal-occipital lobes. Unlike most other cognitive tasks, some AD patients are able to perform some constructional tasks even late in the disease course. Thus, it may be an ideal task to evaluate the relationship between various measures of AD neuropathology and cognitive performance. Fixed brain tissue was obtained from 16 AD patients who were cognitively assessed shortly before death. Parietal, frontal, entorhinal, and occipital cortices were examined by immunocytochemistry for beta-amyloid protein and abnormally phosphorylated tau protein at both early and later stages of neuropil thread and tangle formation. Constructional praxis in AD was strongly related to early-stage tau hyperphosphorylation in occipital cortex. Praxis ability was specific in that it was not significantly related to pathology in other areas and non-constructive tasks were not associated with occipital cortex pathology. In contrast, global dementia severity was related to beta-amyloid deposition in entorhinal, parietal, and frontal regions. These findings suggest that occipital cortex is critical for some constructional praxis tasks and that some regionally localizable tasks may be good indices of underlying pathology in corresponding brain regions.
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PMID:Constructional apraxia in Alzheimer's disease correlates with neuritic neuropathology in occipital cortex. 900 34

CSF levels of tau protein are increased in many patients with Alzheimer's disease (AD). Studies disagree on whether the increase is found in moderate or severe AD to a greater extent than in mild AD, and in two reports there was an inverse correlation between tau levels and cognitive scores. To readdress this question, we measured CSF tau in a group of mildly impaired patients with AD (Mini-Mental State Examination [MMSE] scores > or =20/30) and compared their tau levels with those in age-comparable normal and neurologic controls. We found that the mean level of CSF tau was significantly increased in the AD group compared with the controls, and 29 of 36 patients with AD had levels that exceeded a cutoff determined in a previous study. CSF tau levels did not correlate with MMSE scores. These findings and those of previous studies show that elevated CSF tau levels are found in most patients with AD, occur early in the course of dementia, and may be useful in supporting the diagnosis of AD.
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PMID:Assessment of CSF levels of tau protein in mildly demented patients with Alzheimer's disease. 940 91

This report concerns an investigation on ubiquitin immunoreactivity in the neuronal perikarya of hippocampal granular cells in Guamanian amyotrophic lateral sclerosis (G-ALS) and Guamanian parkinsonism-dementia complex (G-PDC). Specimens from two non-Guamanian cases of ALS with dementia (ALS-D) were included for comparison. Histologically normal hippocampi from five adults served as controls. Antibodies to ubiquitin and tau protein were used throughout. Most Guamanian patients examined had granular cells with perikaryal ubiquitin immunoreactivity in the dentate gyrus, but in comparison to ALS-D, the frequency of ubiquitin-positive neurons was significantly lower. Tau-positive granular cells were detected in most Guamanian patients, but not in ALS-D. There was a relationship between the numbers of ubiquitin-positive and tau-positive neurons in the dentate granular cell layer of G-ALS and G-PDC patients. This was verified on sections double immunostained for tau protein and ubiquitin. The present findings suggest that the ubiquitin-positive materials observed in the perikarya of the dentate granular cells of patients with G-ALS or with G-PDC seem to be Alzheimer's neurofibrillary tangles rather than the typical ubiquitin-positive intracytoplasmic neuronal inclusions, characteristics of ALS-D. Our data would indicate that different mechanisms are involved in the geneses of cortical neuronal degeneration and decline in cognitive function in ALS-D, G-ALS and G-PDC.
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PMID:Comparative study of ubiquitin immunoreactivity of hippocampal granular cells in amyotrophic lateral sclerosis with dementia, Guamanian amyotrophic lateral sclerosis and Guamanian parkinsonism-dementia complex. 908 58

Neurofibrillary lesions made of hyperphosphorylated microtubule-associated protein tau constitute not only one of the defining neuropathological features of Alzheimer disease but also are present in a number of other neurodegenerative diseases with dementia. Here we describe a novel autosomal dominant disease named familial "multiple system tauopathy with presenile dementia," which is characterized by abundant fibrillary deposits of tau protein in both neurons and glial cells. There are no detectable deposits of beta-amyloid. The tau deposits are in the form of twisted filaments that differ in diameter and periodicity from the paired helical filaments of Alzheimer disease. They are stained by both phosphorylation-independent and -dependent anti-tau antibodies. Moreover, tau immunoreactivity coexists with heparan sulfate in affected nerve and glial cells. Tau protein extracted from filaments of familial multiple system tauopathy with presenile dementia shows a minor 72-kDa band and two major bands of 64 and 68 kDa that contain mainly hyperphosphorylated four-repeat tau isoforms of 383 and 412 amino acids.
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PMID:Familial multiple system tauopathy with presenile dementia: a disease with abundant neuronal and glial tau filaments. 910 14

Argyrophilic grains (ArG) and coiled bodies of argyrophilic grain disease (AgD) and the neurofibrillary lesions of Alzheimer's disease (AD) share similar antigenic determinants, among them hyperphosphorylated microtubule-associated protein tau. Nothing is known about the mechanisms underlying tau hyperphosphorylation in AgD, the hyperphosphorylated sites or the intracellular distribution of abnormally phosphorylated tau. We have analysed brain tissue sections from 41 subjects with AgD with a panel of phosphorylation-dependent (AT270, AT8, Tau-1, AT180, 12E8, PHF-1 and AT100) and phosphorylation-independent anti-tau antibodies (N-tau 5, 304, 189 and 134). All antibodies labelled ArG, coiled bodies and neurofibrillary lesions, with the exception of antibody 12E8, which stained a subset of neurofibrillary tangles, but no ArG or coiled bodies. Most pyramidal neurons in areas rich in ArG showed diffuse granular tau labelling in cell bodies and dendrites. Only very few tau-positive cells also contained neurofibrillary tangles. Phosphorylation-dependent anti-tau antibodies also stained a felt-like network of Gallyas-negative filiform neurites in layer CA1 of the hippocampus and in layer pre-B of the transentorhinal cortex. These results demonstrate a widespread hyperphosphorylation of tau protein in the somatodendritic domain of neurons in AgD, in addition to silver grains in the neuropil. Unlike in AD, tau hyperphosphorylation in the somatodendritic domain in AgD does not appear to be followed by neurofibrillary tangle formation, even in the presence of widespread ArG in the neuropil. Furthermore, our data suggest that no strict correlation exists between the presence or density of ArG in the limbic area and the occurrence of dementia.
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PMID:Argyrophilic grain disease: widespread hyperphosphorylation of tau protein in limbic neurons. 914 86

Apolipoprotein E (apoE) levels were compared in cerebrospinal fluid (CSF) taken on two occasions, with an average 15 months follow up, from groups of patients with Alzheimer's disease (AD: n = 18), mild cognitive impairment (MCI; n = 9) and other dementia disorders (ODD; n = 9). In these groups, CSF apoE levels were between 2-3-fold higher than values for a group of 27 healthy age-matched controls. CSF apoE levels in the AD group were significantly increased at follow up, compared to levels obtained on the first sampling occasion. For the same cases it had been shown previously that CSF tau protein levels were increased at follow up [Blomberg, M., Jensen, M., Basun, H., Lannfelt, L. and Wahlund, L-O., Neurosci. Lett., 214 (1996) 163-166]. The AD, but not MCI, ODD or control groups, also showed statistically significant correlations between CSF apoE and tau protein levels at both the first (r = 0.585, P < 0.01) and follow up (r = 0.695, P > 0.001 ) samplings. It is concluded that CSF measures of both apoE and tau may reflect an intimate relationship between these two proteins in AD and could prove useful in monitoring the progression of this condition.
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PMID:Cerebrospinal fluid apolipoprotein E (apoE) levels in Alzheimer's disease patients are increased at follow up and show a correlation with levels of tau protein. 922 97


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