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Prion protein interaction with soil humic substances: environmental implications.

Giachin G, Narkiewicz J, Scaini D, Ngoc AT, Margon A, Sequi P, Leita L, Legname G - PLoS ONE (2014)

Bottom Line: After shedding from diseased animals, prions persist in soil, withstanding biotic and abiotic degradation.As soil is a complex, multi-component system of both mineral and organic components, it is important to understand which soil compounds may interact with prions and thus contribute to disease transmission.Here we show that HS act as potent anti-prion agents in prion infected neuronal cells and in the amyloid seeding assays: HS adsorb both recPrP and prions, thus sequestering them from the prion replication process.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy.

ABSTRACT
Transmissible spongiform encephalopathies (TSE) are fatal neurodegenerative disorders caused by prions. Animal TSE include scrapie in sheep and goats, and chronic wasting disease (CWD) in cervids. Effective management of scrapie in many parts of the world, and of CWD in North American deer population is complicated by the persistence of prions in the environment. After shedding from diseased animals, prions persist in soil, withstanding biotic and abiotic degradation. As soil is a complex, multi-component system of both mineral and organic components, it is important to understand which soil compounds may interact with prions and thus contribute to disease transmission. Several studies have investigated the role of different soil minerals in prion adsorption and infectivity; we focused our attention on the interaction of soil organic components, the humic substances (HS), with recombinant prion protein (recPrP) material. We evaluated the kinetics of recPrP adsorption, providing a structural and biochemical characterization of chemical adducts using different experimental approaches. Here we show that HS act as potent anti-prion agents in prion infected neuronal cells and in the amyloid seeding assays: HS adsorb both recPrP and prions, thus sequestering them from the prion replication process. We interpreted our findings as highly relevant from an environmental point of view, as the adsorption of prions in HS may affect their availability and consequently hinder the environmental transmission of prion diseases in ruminants.

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Related in: MedlinePlus

AFM characterization of HS and MoPrP-HS complexes.Surface morphology of HS alone (HA and FA in panels A and E, respectively) and HS complexes with 25 µg/mL of MoPrP (in panels B and F corresponding to MoPrP-HA and MoPrP-FA complexes, respectively) and with 60 µg/mL of MoPrP (in panels C and G with HA and FA, respectively). Panels D and H show high magnification images of the samples presented in panels C and G.
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pone-0100016-g004: AFM characterization of HS and MoPrP-HS complexes.Surface morphology of HS alone (HA and FA in panels A and E, respectively) and HS complexes with 25 µg/mL of MoPrP (in panels B and F corresponding to MoPrP-HA and MoPrP-FA complexes, respectively) and with 60 µg/mL of MoPrP (in panels C and G with HA and FA, respectively). Panels D and H show high magnification images of the samples presented in panels C and G.

Mentions: Next, we investigated by AFM the surface regions that appeared devoid of the large FA branched chains or HA aggregates observed by optical microscopy. HA showed aggregated structures connected by gel-like filaments (Figure 4A) while FA samples revealed the presence of globular clusters, which appeared as gel-like clumps (Figure 4E). These morphologies were presumably induced by strong water-HS interaction due to HS surface charges.


Prion protein interaction with soil humic substances: environmental implications.

Giachin G, Narkiewicz J, Scaini D, Ngoc AT, Margon A, Sequi P, Leita L, Legname G - PLoS ONE (2014)

AFM characterization of HS and MoPrP-HS complexes.Surface morphology of HS alone (HA and FA in panels A and E, respectively) and HS complexes with 25 µg/mL of MoPrP (in panels B and F corresponding to MoPrP-HA and MoPrP-FA complexes, respectively) and with 60 µg/mL of MoPrP (in panels C and G with HA and FA, respectively). Panels D and H show high magnification images of the samples presented in panels C and G.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4061048&req=5

pone-0100016-g004: AFM characterization of HS and MoPrP-HS complexes.Surface morphology of HS alone (HA and FA in panels A and E, respectively) and HS complexes with 25 µg/mL of MoPrP (in panels B and F corresponding to MoPrP-HA and MoPrP-FA complexes, respectively) and with 60 µg/mL of MoPrP (in panels C and G with HA and FA, respectively). Panels D and H show high magnification images of the samples presented in panels C and G.
Mentions: Next, we investigated by AFM the surface regions that appeared devoid of the large FA branched chains or HA aggregates observed by optical microscopy. HA showed aggregated structures connected by gel-like filaments (Figure 4A) while FA samples revealed the presence of globular clusters, which appeared as gel-like clumps (Figure 4E). These morphologies were presumably induced by strong water-HS interaction due to HS surface charges.

Bottom Line: After shedding from diseased animals, prions persist in soil, withstanding biotic and abiotic degradation.As soil is a complex, multi-component system of both mineral and organic components, it is important to understand which soil compounds may interact with prions and thus contribute to disease transmission.Here we show that HS act as potent anti-prion agents in prion infected neuronal cells and in the amyloid seeding assays: HS adsorb both recPrP and prions, thus sequestering them from the prion replication process.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy.

ABSTRACT
Transmissible spongiform encephalopathies (TSE) are fatal neurodegenerative disorders caused by prions. Animal TSE include scrapie in sheep and goats, and chronic wasting disease (CWD) in cervids. Effective management of scrapie in many parts of the world, and of CWD in North American deer population is complicated by the persistence of prions in the environment. After shedding from diseased animals, prions persist in soil, withstanding biotic and abiotic degradation. As soil is a complex, multi-component system of both mineral and organic components, it is important to understand which soil compounds may interact with prions and thus contribute to disease transmission. Several studies have investigated the role of different soil minerals in prion adsorption and infectivity; we focused our attention on the interaction of soil organic components, the humic substances (HS), with recombinant prion protein (recPrP) material. We evaluated the kinetics of recPrP adsorption, providing a structural and biochemical characterization of chemical adducts using different experimental approaches. Here we show that HS act as potent anti-prion agents in prion infected neuronal cells and in the amyloid seeding assays: HS adsorb both recPrP and prions, thus sequestering them from the prion replication process. We interpreted our findings as highly relevant from an environmental point of view, as the adsorption of prions in HS may affect their availability and consequently hinder the environmental transmission of prion diseases in ruminants.

Show MeSH
Related in: MedlinePlus