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

As in Alzheimer-disease (AD) brain, vacuolated muscle fibers of inclusion-body myositis (IBM) contain abnormally accumulated beta-amyloid precursor protein (beta APP), including its beta-amyloid protein epitope, and increased beta APP-751 mRNA. Other similarities between IBM muscle and AD brain phenotypes include paired helical filaments, hyperphosphorylated tau protein, apolipoprotein E, and mitochondrial abnormalities, including decreased cytochrome-c oxidase (COX) activity. The pathogenesis of these abnormalities in IBM muscle and AD brain is not known. We now report that direct transfer of the beta APP gene, using adenovirus vector, into cultured normal human muscle fibers causes structural abnormalities of mitochondria and decreased COX activity. In this adenovirus-mediated beta APP gene transfer, we demonstrated that beta APP overproduction can induce mitochondrial abnormalities. The data suggest that excessive beta APP may be responsible for mitochondrial and COX abnormalities in IBM muscle and perhaps AD brain.
 ...
PMID:Transfer of beta-amyloid precursor protein gene using adenovirus vector causes mitochondrial abnormalities in cultured normal human muscle. 857 61

Transgenic mice carrying heterologous genes directed by a 670-bp segment of the regulatory sequence from the human transferrin (TF) gene demonstrated high expression in brain. Mice carrying the chimeric 0.67kbTF-CAT gene expressed TF-CAT in neurons and glial cells of the nucleus basalis, the cerebrum, corpus callosum, cerebellum, and hippocampus. In brains from two independent TF-CAT transgenic founder lines, copy number of TF-CAT mRNA exceeded the number of mRNA transcripts encoding either mouse endogenous transferrin or mouse endogenous amyloid precursor protein. In two transgenic founder lines, the chloramphenicol acetyltransferase (CAT) protein synthesized from the TF-CAT mRNA was estimated to be 0.10-0.15% of the total soluble proteins of the brain. High expression observed in brain indicates that the 0.67kbTF promoter is a promising director of brain expression of heterologous genes. Therefore, the promoter has been used to express the three common human apolipoprotein E (apoE) alleles in transgenic mouse brains. The apoE alleles have been implicated in the expression of Alzheimer disease, and the human apoE isoforms are reported to interact with different affinities to the brain beta-amyloid and tau protein in vitro. Results of this study demonstrate high expression and production of human apoE proteins in transgenic mouse brains. The model may be used to characterize the interaction of human apoE isoforms with other brain proteins and provide information helpful in designing therapeutic strategies for Alzheimer disease.
 ...
PMID:Discovery of a brain promoter from the human transferrin gene and its utilization for development of transgenic mice that express human apolipoprotein E alleles. 861 55

The most promising discovery in the study of Alzheimer's disease (AD) markers is undoubtedly the implication of apolipoprotein E (apoE). The gene of this apoliprotein is located on chromosome 19 and is characterized by three common alleles epsilon 2, epsilon 3 and epsilon 4 giving raise to 6 genotypes and 6 protein phenotypes. ApoE is well known for its role in cholesterol transport. Different studies have been performed, giving major arguments in favor of an important role of apoE in the pathophysiology of AD. These include the discovery of the relationship between the epsilon 4 allele and AD, the ability of this protein to form complexes with beta amyloid protein (A beta) in seniles plates, its presence in neurofibrillary tangles and in vessels of AD patients. Another important finding is the differential interaction between the different isoforms of apoE and tau protein. Some of the hypotheses implicate the role of different apoE isoforms on the growth and extension of neurones, perhaps by a receptor mediated pathway. It has been suggested that apoE acts as a pathological chaperone protein, or alternatively that it protects neurons by regulation of the cell membrane and modifying calcium homeostasis. It is clear that apoE genotype determination alone cannot be used for diagnosis of AD. The presence of epsilon 4 allele is only one of several risk factors for the development of the disease. Other factors may also be implicated and are the subject of ongoing research.
 ...
PMID:[Alzheimer disease: hypotheses implicating apolipoproteins E]. 869 53

Significant developments in our understanding of the pathophysiology of Alzheimer's disease have been obtained in the recent years. Diagnostic criteria, based on clinical data, have been proposed and have been validated by clinico-pathological correlations. Some neuroimaging techniques and laboratory tests (e.g. dosage in the cerebrospinal fluid) are promising diagnostic avenues. Genetic mutations associated with familial cases of the disease have been identified and the involved genes localized on chromosome 1, 14 or 21. The apolipoprotein E genotype has been discovered to affect the risk of developing the disease, i.e. homozygotes for the apolipoprotein E4 allele are much more prone to develop Alzheimer's disease The definitive diagnosis of the disease still relies on the demonstration of characteristic neuropathological lesions, i.e. neurofibrillary tangles and senile plaques, whose numbers are correlated with the severity of the dementia. Other lesions include neuronal and synaptic loss, amyloid angiopathy, and severe decrease in the level of cortical acetylcholine. Neurofibrillary tangles have been found to be composed of the microtubule-associated protein tau, in highly phosphorylated state. The accumulation of these phosphorylated tau proteins is thought to be associated to disturbances of intracellular transport of molecules and organelles in affected neurones, leading to cell dysfunction and death. An inbalance in the activities of selected protein kinases and phosphatases is also thought to generate these highly phosphorylated tau species. The major component of senile plaques is the A4/beta amyloid peptide, generated by proteolysis of the amyloid peptide precursor, a transmembrane protein. When aggregated into amyloid fibrils, the A4/beta amyloid peptide is thought to be neurotoxic. An abnormal metabolism of the amyloid peptide precursor is often considered as a central physiopathological mechanism of the disease. Although many pharmacological treatments of the disease have been investigated, they have not yet led to sustained and major clinical improvements.
 ...
PMID:The neurobiology of Alzheimer's disease. 869 72

An interaction between the apolipoprotein E (apoE) type 3 and the microtubule-associated protein tau has been demonstrated in vitro and suggested to modulate tau phosphorylation and/or formation of paired helical filaments. To evaluate in vivo the potential interaction between tau and apoE, we have investigated the expression and phosphorylation status of tau in the brain of apoE-deficient mice, using a panel of antibodies reacting with tau in a phosphorylation-dependent manner. The pattern and intensity of immunohistochemical labelling and the pattern of tau immunoreactivity on Western blots were similar in control and apoE-deficient mice. These results suggest that a lack of expression of apoE does not interfere with the expression, distribution and phosphorylation status of tau proteins.
 ...
PMID:Phosphorylation of tau protein is not affected in mice lacking apolipoprotein E. 874 58

Using a specific enzyme linked immunosorbent assay (ELISA) method, total apolipoprotein E immunoreactivity (tApoE-IR) was measured in premortem lumbar CSF and serum of patients with "probable" Alzheimer's disease and in postmortem ventricular CSF of patients with Alzheimer's disease confirmed by necropsy. Concentrations were compared with those from patients with other neurological diseases and controls. The mean serum:lumbar CSF ratio of ApoE-IR was 15.9 suggesting that the main portion of lumbar ApoE-IR is synthesised intrathecally. No significant differences in ApoE-IR between patients with Alzheimer's disease and the other groups were detected in either CSF compartment. In lumbar CSF, there was no correlation between ApoE-IR of patients with Alzheimer's disease and their mini mental state scores. These results suggest that the diagnostic value of ApoE-IR measurements in CSF of patients with Alzheimer's disease as a single determination is less than that of other markers, in particular tau protein. On the other hand, ApoE determinations could be useful as part of a neurochemical profile of Alzheimer's disease.
 ...
PMID:Intra vitam lumbar cerebrospinal fluid and serum and postmortem ventricular immunoreactive apolipoprotein E in patients with Alzheimer's disease. 877 18

Information on the molecular biology of Alzheimer's disease (AD) pointing to new methods of diagnosis and drug therapies is explored. AD is the most common cause of dementia in the elderly and is characterized by senile plaques and neurofibrillary tangles in the brain and loss of cholinergic neurons in the basal forebrain. The disease has a strong genetic component. A definitive diagnosis can be made only by neuropathologic examination at autopsy or biopsy; however, the accuracy of diagnosis based on standard neuropsychological testing and inclusion criteria has improved considerably. Senile plaques consist of a central core of amyloid fibrils surrounded by dystrophic axons. The main component of senile plaque amyloid is a 39-to 42-amino-acid segment referred to as beta-amyloid, which is derived from amyloid precursor protein (APP). APP exists as multiple isoforms encoded by a single gene on chromosome 21. Factors that may influence APP metabolism include activation of phospholipase C, phosphorylation, and the cholinergic system. The microtubule-associated protein tau may contribute to the neurofibrillary tangles of AD. In AD all six adult isoforms of tau can become maximally phosphorylated and can, rather than binding to microtubules, bind to each other, destabilizing the neuronal cytoskeleton. One of the most important discoveries in AD research was the linking of apolipoprotein E phenotype to familial late-onset AD. Acetylcholinesterase inhibitors appear to improve cognitive function but may be limited in utility by adverse effects. Nicotinic agonists are also being investigated as symptomatic therapies. Other possible strategies include nerve growth factor, agents that potentiate the action of endogenous glutamate, antioxidants, nonsteroidal anti-inflammatory drugs, and estrogens. Research into the molecular biology of Alzheimer's disease has begun to point to possible causes of and treatments for this condition.
 ...
PMID:Molecular basis of Alzheimer's disease. 880 75

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.
 ...
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

The concentration of tau protein is elevated in the cerebrospinal fluid (CSF) in Alzheimer's disease (AD), suggesting that CSF tau may be a useful biochemical diagnostic marker for this disorder. We investigated CSF tau concentrations on two occasions in AD (n = 18), mild cognitive impairment (MCI, n = 9) and other dementing disease (OD, n = 9) by ELISA (Innotest hTau Antigen, Innogenetics, Belgium). Tau levels were statistically significant higher in the AD group than in MCI and OD groups on both occasions. Twelve of the AD patients showed increasing values of tau at follow-up and six demonstrated diminished values. All AD patients with increasing tau were carriers of one or two epsilon 4 alleles of the apolipoprotein E (APOE, gene. Of those AD cases with decreasing tau levels only three individuals had the epsilon 4 allele, a difference that was statistically significant (P < 0.05). These findings suggest that there may be apolipoprotein E (apoE) isoform-specific differences of tau regulation in AD.
 ...
PMID:Increasing cerebrospinal fluid tau levels in a subgroup of Alzheimer patients with apolipoprotein E allele epsilon 4 during 14 months follow-up. 887 9

Levels of the microtubule-associated protein tau in cerebrospinal fluid (CSF-tau) were measured in samples from 87 patients with Alzheimer's disease (AD), 114 patients with non-AD neurological diseases, and 22 normal control subjects, by sandwich enzyme-linked immunosorbent assay. The CSF-tau level was significantly higher in patients with AD than in patients with non-AD neurological diseases and in controls. High CSF-tau levels were found irrespective of age at onset, apolipoprotein E genotype, clinical stage, and ethnic group. Western blots of AD CSF proteins revealed two to three immunoreactive bands with apparent molecular mass between 50 and 65 kDa, which is consistent with phosphorylated CSF-tau. These results suggest that CSF-tau reflects progressive accumulation of tau due to the progressive death of neurons in the AD brain. Assay of CSF-tau may prove to be a reliable diagnostic test for AD.
 ...
PMID:[Tau protein in cerebrospinal fluid--a potential marker of Alzheimer's disease]. 894 Aug 64


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>