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John Q. Trojanowski

Bio: John Q. Trojanowski is an academic researcher from University of Pennsylvania. The author has contributed to research in topics: Alzheimer's disease & Dementia. The author has an hindex of 226, co-authored 1467 publications receiving 213948 citations. Previous affiliations of John Q. Trojanowski include Vanderbilt University & University of California, San Francisco.


Papers
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Journal ArticleDOI
TL;DR: There was a significant increase of both metabolites in CSF from AD and MCI, which correlated with lipid peroxidation and tau protein levels, suggesting that the activation of this enzyme occurs early in the course of AD, before the onset of overt dementia, thereby implicating 12/15LOX‐mediated lipidperoxidation in the pathogenesis of AD.
Abstract: The 12/15 lipoxygenase (12/15LOX) enzyme is increased in pathologically affected frontal and temporal regions of Alzheimer's disease (AD) brains compared with controls. Herein, we measured 12(S)-HETE and 15(S)-HETE levels, products of 12/15LOX, in cerebrospinal fluid (CSF) of normal individuals, subjects with mild cognitive impairment (MCI) and AD. Compared with controls, there was a significant increase of both metabolites in CSF from AD and MCI, which correlated with lipid peroxidation and tau protein levels. These results suggest that the activation of this enzyme occurs early in the course of AD, before the onset of overt dementia, thereby implicating 12/15LOX-mediated lipid peroxidation in the pathogenesis of AD.

114 citations

Journal ArticleDOI
TL;DR: A transgenic mouse model of tau pathology in astrocytes is generated by expressing the human tau protein under the control of the glial fibrillary acidic protein (GFAP) promoter and it is demonstrated that compromised motor function and deficits in neuromuscular strength are observed that correlates with reduced expression of glutamate transporter-1 and occurs concurrent with tau inclusion pathology.
Abstract: Filamentous tau inclusions in neurons and glia are neuropathological hallmarks of tauopathies. The discovery of microtubule-associated protein tau gene mutations that are pathogenic for a heterogenous group of neurodegenerative disorders, called frontotemporal dementia and parkinsonism linked to chromosome-17 (FTDP-17), directly implicate tau abnormalities in the onset/progression of disease. Although the role of tau pathology in neurons in disease pathogenesis is well accepted, the contribution of glial pathology is essentially unknown. We recently generated a transgenic (Tg) mouse model of tau pathology in astrocytes by expressing the human tau protein under the control of the glial fibrillary acidic protein (GFAP) promoter. Both wild-type and FTDP-17 mutant GFAP/tau Tg animals manifest an age-dependent accumulation of tau inclusions in astrocytes that resembles the pathology observed in human tauopathies. We further demonstrate that both strains of Tg mice manifest compromised motor function that correlates with altered expression of the glial glutamate-aspartate transporter and occurs before the development of tau pathology. Subsequently, the Tg mice manifest additional deficits in neuromuscular strength that correlates with reduced expression of glutamate transporter-1 (GLT-1) and occurs concurrent with tau inclusion pathology. Reduced GLT-1 expression was associated with a progressive decrease in sodium-dependent glutamate transport capacity. Reductions in GLT-1 expression were also observed in corticobasal degeneration, a tauopathy with prominent pathology in astrocytes. Less robust changes were observed in Alzheimer's disease in which neuronal tau pathology predominates. Thus, these Tg mice recapitulate features of astrocytic pathology observed in tauopathies and implicate a role for altered astrocyte function in the pathogenesis of these disorders.

114 citations

Journal ArticleDOI
TL;DR: The results of CK BB expression analysis demonstrate that the loss of the isoenzyme in different neurodegenerative diseases is likely the consequence of its posttranslational modification, possibly oxidative damage.
Abstract: The presence of the biomarkers of oxidative damage, protein carbonyl formation and the inactivation of oxidatively sensitive brain creatine kinase (CK BB, cytosolic isoform), were studied in frontal lobe autopsy specimens obtained from patients with different age-related neurodegenerative diseases: Alzheimer's disease (AD), Pick's disease (PkD), diffuse Lewy body disease (DLBD), Parkinson's disease (PD), and age-matched control subjects. The CK activity was significantly reduced in the frontal lobe of AD, PkD and DLBD subjects, and CK BB-specific mRNA was significantly reduced in AD and DLBD. Protein carbonyl content was significantly increased in AD, PkD and DLBD. The results of this study confirm that the presence of biomarkers of oxidative damage is related to the presence of histopathological markers of neurodegeneration. Our data suggest that oxidative damage contributes to the development of the symptoms of frontal dysfunction in AD, PkD and DLBD. The development of frontal dysfunction in idiopathic PD might be secondary to oxidative damage and neuronal loss primarily located in the nigrostriatal system. The results of CK BB expression analysis demonstrate that the loss of the isoenzyme in different neurodegenerative diseases is likely the consequence of its posttranslational modification, possibly oxidative damage. Changes in CK BB expression may be an early indicator of oxidative stress in neurons.

114 citations

Journal ArticleDOI
TL;DR: It is concluded that grafted NT2N cells could serve as a suitable platform for the delivery of exogenous proteins into the CNS for gene therapy of human nervous system diseases.

113 citations

Journal ArticleDOI
22 Jan 2020-Neuron
TL;DR: These findings suggest a "feed-forward" mechanism whereby Aβ plaques enhance endogenous α-syn seeding and spreading over time post-injection with mpffs, and hyperphosphorylated tau (p-tau) was induced in α- syn mpff-injected 5xFAD mice.

113 citations


Cited by
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28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
TL;DR: The workgroup sought to ensure that the revised criteria would be flexible enough to be used by both general healthcare providers without access to neuropsychological testing, advanced imaging, and cerebrospinal fluid measures, and specialized investigators involved in research or in clinical trial studies who would have these tools available.
Abstract: The National Institute on Aging and the Alzheimer's Association charged a workgroup with the task of revising the 1984 criteria for Alzheimer's disease (AD) dementia. The workgroup sought to ensure that the revised criteria would be flexible enough to be used by both general healthcare providers without access to neuropsychological testing, advanced imaging, and cerebrospinal fluid measures, and specialized investigators involved in research or in clinical trial studies who would have these tools available. We present criteria for all-cause dementia and for AD dementia. We retained the general framework of probable AD dementia from the 1984 criteria. On the basis of the past 27 years of experience, we made several changes in the clinical criteria for the diagnosis. We also retained the term possible AD dementia, but redefined it in a manner more focused than before. Biomarker evidence was also integrated into the diagnostic formulations for probable and possible AD dementia for use in research settings. The core clinical criteria for AD dementia will continue to be the cornerstone of the diagnosis in clinical practice, but biomarker evidence is expected to enhance the pathophysiological specificity of the diagnosis of AD dementia. Much work lies ahead for validating the biomarker diagnosis of AD dementia.

13,710 citations

Journal ArticleDOI
19 Jul 2002-Science
TL;DR: It has been more than 10 years since it was first proposed that the neurodegeneration in Alzheimer's disease (AD) may be caused by deposition of amyloid β-peptide in plaques in brain tissue and the rest of the disease process is proposed to result from an imbalance between Aβ production and Aβ clearance.
Abstract: It has been more than 10 years since it was first proposed that the neurodegeneration in Alzheimer9s disease (AD) may be caused by deposition of amyloid β-peptide (Aβ) in plaques in brain tissue. According to the amyloid hypothesis, accumulation of Aβ in the brain is the primary influence driving AD pathogenesis. The rest of the disease process, including formation of neurofibrillary tangles containing tau protein, is proposed to result from an imbalance between Aβ production and Aβ clearance.

12,652 citations

Journal ArticleDOI
TL;DR: There is growing evidence that aging involves, in addition, progressive changes in free radical-mediated regulatory processes that result in altered gene expression.
Abstract: At high concentrations, free radicals and radical-derived, nonradical reactive species are hazardous for living organisms and damage all major cellular constituents. At moderate concentrations, how...

9,131 citations