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- Kaczmarczyk, Lech, et al.
(författare)
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Distinct translatome changes in specific neural populations precede electroencephalographic changes in prion-infected mice
- 2022
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Ingår i: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 18:8
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Tidskriftsartikel (refereegranskat)abstract
- Selective vulnerability is an enigmatic feature of neurodegenerative diseases (NDs), whereby a widely expressed protein causes lesions in specific cell types and brain regions. Using the RiboTag method in mice, translational responses of five neural subtypes to acquired prion disease (PrD) were measured. Pre-onset and disease onset timepoints were chosen based on longitudinal electroencephalography (EEG) that revealed a gradual increase in theta power between 10- and 18-weeks after prion injection, resembling a clinical feature of human PrD. At disease onset, marked by significantly increased theta power and histopathological lesions, mice had pronounced translatome changes in all five cell types despite appearing normal. Remarkably, at a pre-onset stage, prior to EEG and neuropathological changes, we found that 1) translatomes of astrocytes indicated reduced synthesis of ribosomal and mitochondrial components, 2) glutamatergic neurons showed increased expression of cytoskeletal genes, and 3) GABAergic neurons revealed reduced expression of circadian rhythm genes. These data demonstrate that early translatome responses to neurodegeneration emerge prior to conventional markers of disease and are cell type-specific. Therapeutic strategies may need to target multiple pathways in specific populations of cells, early in disease.
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| 2. |
- Wagner, Jessica, et al.
(författare)
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Medin co-aggregates with vascular amyloid-beta in Alzheimers disease
- 2022
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Ingår i: Nature. - : Nature Portfolio. - 0028-0836 .- 1476-4687. ; 612, s. 123-131
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Tidskriftsartikel (refereegranskat)abstract
- Aggregates of medin amyloid (a fragment of the protein MFG-E8, also known as lactadherin) are found in the vasculature of almost all humans over 50 years of age(1,)(2), making it the most common amyloid currently known. We recently reported that medin also aggregates in blood vessels of ageing wild-type mice, causing cerebrovascular dysfunction(3). Here we demonstrate in amyloid-beta precursor protein (APP) transgenic mice and in patients with Alzheimers disease that medin co-localizes with vascular amyloid-beta deposits, and that in mice, medin deficiency reduces vascular amyloid-beta deposition by half. Moreover, in both the mouse and human brain, MFG-E8 is highly enriched in the vasculature and both MFG-E8 and medin levels increase with the severity of vascular amyloid-beta burden. Additionally, analysing data from 566 individuals in the ROSMAP cohort, we find that patients with Alzheimers disease have higher MFGE8 expression levels, which are attributable to vascular cells and are associated with increased measures of cognitive decline, independent of plaque and tau pathology. Mechanistically, we demonstrate that medin interacts directly with amyloid-beta to promote its aggregation, as medin forms heterologous fibrils with amyloid-beta, affects amyloid-beta fibril structure, and cross-seeds amyloid-beta aggregation both in vitro and in vivo. Thus, medin could be a therapeutic target for prevention of vascular damage and cognitive decline resulting from amyloid-beta deposition in the blood vessels of the brain.
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