Naturally occurring fragments of the abundant semen proteins prostatic acid phosphatase (PAP) and semenogelins form amyloid fibrils in vitro. These fibrils boost HIV infection and may play a key role in the spread of the AIDS pandemic. However, the presence of amyloid fibrils in semen remained to be demonstrated. Here, we use state of the art confocal and electron microscopy techniques for direct imaging of amyloid fibrils in human ejaculates. We detect amyloid aggregates in all semen samples and find that they partially consist of PAP fragments, interact with HIV particles and increase viral infectivity. Our results establish semen as a body fluid that naturally contains amyloid fibrils that are exploited by HIV to promote its sexual transmission.
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http://dx.doi.org/10.1038/ncomms4508 | DOI Listing |
Background: The autophagy lysosomal pathway (ALP) and the ubiquitin-proteasome system (UPS) are key proteostasis mechanisms in cells, which are dysfunctional in AD and linked to protein aggregation and neuronal death. Autophagy is over activated in Alzheimer's disease brain whereas UPS is severely impaired. Activating autophagy has received most attention, however recent evidence suggests that UPS can clear aggregate proteins and a potential therapeutic target for AD and protein misfolding diseases.
View Article and Find Full Text PDFBackground: Availability of amyloid modifying therapies will dramatically increase the need for disclosure of Alzheimer's disease (AD) related genetic and/or biomarker test results. The 21st Century Cares Act requires the immediate return of most medical test results, including AD biomarkers. A shortage of genetic counselors and dementia specialists already exists, thus driving the need for scalable methods to responsibly communicate test results.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
University of Kentucky Sanders-Brown Center on Aging, Lexington, KY, USA.
Background: The presence of multiple comorbid pathologic features in late-onset dementia has been well documented across cohort studies that incorporate autopsy evaluation. It is likely that such mixed pathology potentially confounds the results of interventional trials that are designed to target a solitary pathophysiologic mechanism in Alzheimer's disease and related dementias (ADRD).
Method: The UK ADRC autopsy database was screened for participants who had previously engaged in therapeutic interventional trials for Alzheimer's disease, vascular cognitive impairment, dementia, and/or ADRD prevention trials from 2005 to the present.
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View Article and Find Full Text PDFBackground: Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by the formation of amyloid-beta (Aβ) plaques and neurofibrillary tangles (NFTs) composed of tau aggregates. Research in animal models has generated hypotheses on the underlying mechanisms of the interaction between Aβ and tau pathology. In support of this interaction, results from clinical trials have shown that treatment with anti-Aβ monoclonal antibodies (mAbs) affects tau pathology.
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