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.

Longitudinal analyses of cerebrospinal fluid α-Synuclein in prodromal and early Parkinson's disease.

Abstract: Author(s): Mollenhauer, Brit; Caspell-Garcia, Chelsea J; Coffey, Christopher S; Taylor, Peggy; Singleton, Andy; Shaw, Leslie M; Trojanowski, John Q; Frasier, Mark; Simuni, Tanya; Iranzo, Alex; Oertel, Wolfgang; Siderowf, Andrew; Weintraub, Daniel; Seibyl, John; Toga, Arthur W; Tanner, Caroline M; Kieburtz, Karl; Chahine, Lana M; Marek, Kenneth; Galasko, Douglas; PPMI study | Abstract: BackgroundAggregation of α-synuclein is central to the pathophysiology of PD. Biomarkers related to α-synuclein may be informative for PD diagnosis/progression.ObjectivesTo analyze α-synuclein in CSF in drug-naive PD, healthy controls, and prodromal PD in the Parkinson's Progression Markers Initiative.MethodsOver up to 36-month follow-up, CSF total α-synuclein and its association with MDS-UPDRS motor scores, cognitive assessments, and dopamine transporter imaging were assessed.ResultsThe inception cohort included PD (n = 376; age [mean {standard deviation} years]: 61.7 [9.62]), healthy controls (n = 173; age, 60.9 [11.3]), hyposmics (n = 16; age, 68.3 [6.15]), and idiopathic rapid eye movement sleep behavior disorder (n = 32; age, 69.3 [4.83]). Baseline CSF α-synuclein was lower in manifest and prodromal PD versus healthy controls. Longitudinal α-synuclein decreased significantly in PD at 24 and 36 months, did not change in prodromal PD over 12 months, and trended toward an increase in healthy controls. The decrease in PD was not shown when CSF samples with high hemoglobin concentration were removed from the analysis. CSF α-synuclein changes did not correlate with longitudinal MDS-UPDRS motor scores or dopamine transporter scan.ConclusionsCSF α-synuclein decreases early in the disease, preceding motor PD. CSF α-synuclein does not correlate with progression and therefore does not reflect ongoing dopaminergic neurodegeneration. Decreased CSF α-synuclein may be an indirect index of changes in the balance between α-synuclein secretion, solubility, or aggregation in the brain, reflecting its overall turnover. Additional biomarkers more directly related to α-synuclein pathophysiology and disease progression and other markers to be identified by, for example, proteomics and metabolomics are needed. © 2019 International Parkinson and Movement Disorder Society.

Alzheimer’s disease tau is a prominent pathology in LRRK2 Parkinson’s disease

Abstract: Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common cause of familial Parkinson’s disease (PD). While the clinical presentation of LRRK2 mutation carriers is similar to that of idiopathic PD (iPD) patients, the neuropathology of LRRK2 PD is less clearly defined. Lewy bodies (LBs) composed of α-synuclein are a major feature of iPD, but are not present in all LRRK2 PD cases. There is some evidence that tau may act as a neuropathological substrate in LB-negative LRRK2 PD, but this has not been examined systematically. In the current study, we examined α-synuclein, tau, and amyloid β (Aβ) pathologies in 12 LRRK2 mutation carriers. We find that α-synuclein pathology is present in 63.6% of LRRK2 mutation carriers, but tau pathology can be found in 100% of carriers and is abundant in 91% of carriers. We further use an antibody which selectively binds Alzheimer’s disease (AD)-type tau and use quantitative analysis of tau pathology to demonstrate that AD tau is the prominent type of tau present in LRRK2 mutation carriers. Abundant Aβ pathology can also be found in LRRK2 mutation carriers and is consistent with comorbid AD pathology. Finally, we assessed the association of neuropathology with clinical features in LRRK2 mutation carriers and idiopathic individuals and find that LRRK2 PD shares clinical and pathological features of idiopathic PD. The prevalence of AD-type tau pathology in LRRK2 PD is an important consideration for understanding PD pathogenesis and refining clinical trial inclusion and progression criterion.

Severe subcortical TDP-43 pathology in sporadic frontotemporal lobar degeneration with motor neuron disease.

Abstract: Recently, TDP-43, a 43 kDa nuclear TAR DNA-binding protein, was identified as the major disease protein in frontotemporal lobar degeneration with ubiquitinated inclusions (FTLD-U), FTLD-U with motor neuron disease (FTLD–MND), and amyotrophic lateral sclerosis. To date, TDP-43 pathology in sporadic FTLD–MND has been reported only in select central nervous system areas. However, this distribution of lesions is insufficient to explain all clinical signs of FTLD–MND and the extent of TDP-43 pathology, throughout the brain, remains unknown. Therefore, as a pilot study, we performed an immunohistochemical whole brain scan of two cases diagnosed clinically as FTLD–MND and two control subjects. We found evidence of both neuronal and glial TDP-43 pathology in multiple brain areas including the nigro-striatal system, neo- and allocortical brain areas, with varying frequency, morphology, and degree, and nowhere in control tissue. The finding of a distinct cytopathological profile consisting of a cell nucleus devoid of endogenous TDP-43 staining coupled with diffuse/granular cytoplasmic staining (“pre-inclusion”) was prominent in a couple of brain areas. These pre-inclusions were not or only weakly ubiquitin-immunoreactive. While the findings of severe involvement of extracortical or extrapyramidal areas are strongly suggestive for FTLD–MND being a TDP-43 multisystem proteinopathy rather than a disease predominantly affecting the cortex and spinal cord, more detailed clinicopathological studies of larger cohorts are needed to fully elucidate the distribution and severity of pathological TDP-43 in this disease.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

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。

The diagnosis of dementia due to Alzheimer’s disease: Recommendations from the National Institute on Aging-Alzheimer’s Association workgroups on diagnostic guidelines for Alzheimer's disease

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.

The Amyloid Hypothesis of Alzheimer's Disease: Progress and Problems on the Road to Therapeutics

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.

Free Radicals in the Physiological Control of Cell Function

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...