| 1. |
- Aguilar-Calvo, Patricia, et al.
(författare)
-
Neuronal Ndst1 depletion accelerates prion protein clearance and slows neurodegeneration in prion infection
- 2023
-
Ingår i: PLoS Pathogens. - : PUBLIC LIBRARY SCIENCE. - 1553-7366 .- 1553-7374. ; 19:9
-
Tidskriftsartikel (refereegranskat)abstract
- Select prion diseases are characterized by widespread cerebral plaque-like deposits of amyloid fibrils enriched in heparan sulfate (HS), a major extracellular matrix component. HS facilitates fibril formation in vitro, yet how HS impacts fibrillar plaque growth within the brain is unclear. Here we found that prion-bound HS chains are highly sulfated, and that the sulfation is essential for accelerating prion conversion in vitro. Using conditional knockout mice to deplete the HS sulfation enzyme, Ndst1 (N-deacetylase / N-sulfotransferase), from neurons or astrocytes, we then investigated how reducing HS sulfation impacts survival and prion aggregate distribution during a prion infection. Neuronal Ndst1-depleted mice survived longer and showed fewer and smaller parenchymal plaques, shorter fibrils, and increased vascular amyloid, consistent with enhanced aggregate transit toward perivascular drainage channels. The prolonged survival was strain-dependent, only affecting mice infected with extracellular, plaque-forming, but not membrane bound, prions. Live PET imaging revealed rapid clearance of recombinant prion protein monomers into the CSF of mice expressing unsulfated HS, further suggesting that HS sulfate groups hinder transit of extracellular prion protein monomers. Our results directly show how a host cofactor slows the spread of prion protein through the extracellular space and identify an enzyme to target to facilitate aggregate clearance. Prions cause a rapidly progressive neurologic disease and death with no curative treatment available. Prion aggregates accumulate exponentially in the brain of affected individuals triggering neuronal loss and neuroinflammation, yet the molecules that facilitate prion protein aggregation are largely unknown. We have found that prions in the brain preferentially bind to a highly sulfated endogenous polysaccharide, known as heparan sulfate (HS). Here we use genetically modified mice that express poorly sulfated, neuron-derived HS, and infect mice with different prions strains. We find that mice infected with a plaque-forming prion strain show a prolonged survival and fewer plaques compared to controls. We also found that recombinant prion protein was efficiently transported within the interstitial fluid of mice having poorly sulfated HS, suggesting more efficient clearance from the brain. Our study provides insight into how HS retains prion aggregates in the brain to accelerate disease and indicates a specific HS biosynthetic enzyme to target to enhance protein clearance.
|
|
| 2. |
- Aguilar-Calvo, Patricia, et al.
(författare)
-
Shortening heparan sulfate chains prolongs survival and reduces parenchymal plaques in prion disease caused by mobile, ADAM10-cleaved prions
- 2020
-
Ingår i: Acta Neuropathologica. - : SPRINGER. - 0001-6322 .- 1432-0533. ; 139:3, s. 527-546
-
Tidskriftsartikel (refereegranskat)abstract
- Cofactors are essential for driving recombinant prion protein into pathogenic conformers. Polyanions promote prion aggregation in vitro, yet the cofactors that modulate prion assembly in vivo remain largely unknown. Here we report that the endogenous glycosaminoglycan, heparan sulfate (HS), impacts prion propagation kinetics and deposition sites in the brain. Exostosin-1 haploinsufficient (Ext1(+/-)) mice, which produce short HS chains, show a prolonged survival and a redistribution of plaques from the parenchyma to vessels when infected with fibrillar prions, and a modest delay when infected with subfibrillar prions. Notably, the fibrillar, plaque-forming prions are composed of ADAM10-cleaved prion protein lacking a glycosylphosphatidylinositol anchor, indicating that these prions are mobile and assemble extracellularly. By analyzing the prion-bound HS using liquid chromatography-mass spectrometry (LC-MS), we identified the disaccharide signature of HS differentially bound to fibrillar compared to subfibrillar prions, and found approximately 20-fold more HS bound to the fibrils. Finally, LC-MS of prion-bound HS from human patients with familial and sporadic prion disease also showed distinct HS signatures and higher HS levels associated with fibrillar prions. This study provides the first in vivo evidence of an endogenous cofactor that accelerates prion disease progression and enhances parenchymal deposition of ADAM10-cleaved, mobile prions.
|
|
| 3. |
- Sevillano, Alejandro M., et al.
(författare)
-
Prion protein glycans reduce intracerebral fibril formation and spongiosis in prion disease
- 2020
-
Ingår i: Journal of Clinical Investigation. - : AMER SOC CLINICAL INVESTIGATION INC. - 0021-9738 .- 1558-8238. ; 130:3, s. 1350-1362
-
Tidskriftsartikel (refereegranskat)abstract
- Posttranslational modifications (PTMs) are common among proteins that aggregate in neurodegenerative disease, yet how PTMs impact the aggregate conformation and disease progression remains unclear. By engineering knockin mice expressing prion protein (PrP) lacking 2 N-linked glycans (Prnp(1)(80Q)(/196Q)), we provide evidence that glycans reduce spongiform degeneration and hinder plaque formation in prion disease.Prnp(1)(80Q)(/196Q )mice challenged with 2 subfibrillar, non-plaque-forming prion strains instead developed plaques highly enriched in ADAM10-cleaved PrP and heparan sulfate (HS). Intriguingly, a third strain composed of intact, glycophosphatidylinositol-anchored (GPI-anchored) PrP was relatively unchanged, forming diffuse, HS-deficient deposits in both the Prnp(1)(80Q/196Q) and WT mice, underscoring the pivotal role of the GPI-anchor in driving the aggregate conformation and disease phenotype. Finally, knockin mice expressing triglycosylated PrP (Prnp(187N)) challenged with a plaque-forming prion strain showed a phenotype reversal, with a striking disease acceleration and switch from plaques to predominantly diffuse, subfibrillar deposits. Our findings suggest that the dominance of subfibrillar aggregates in prion disease is due to the replication of GPI-anchored prions, with fibrillar plaques forming from poorly glycosylated, GPI-anchorless prions that interact with extracellular HS. These studies provide insight into how PTMs impact PrP interactions with polyanionic cofactors, and highlight PTMs as a major force driving the prion disease phenotype.
|
|
