Publications by authors named "Michelle Smidak"

Inherited prion diseases are caused by autosomal dominant coding mutations in the human prion protein (PrP) gene (PRNP) and account for about 15% of human prion disease cases worldwide. The proposed mechanism is that the mutation predisposes to conformational change in the expressed protein, leading to the generation of disease-related multichain PrP assemblies that propagate by seeded protein misfolding. Despite considerable experimental support for this hypothesis, to-date spontaneous formation of disease-relevant, transmissible PrP assemblies in transgenic models expressing only mutant human PrP has not been demonstrated.

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Article Synopsis
  • Inherited prion disease (IPD) results from mutations in the prion protein gene and showcases significant clinical variability, particularly with the P102L mutation linked to Gerstmann-Sträussler-Scheinker (GSS) disease.
  • The study investigates the unique transmission properties of prions derived from human GSS P102L and classical CJD in transgenic mice, revealing that these strains exhibit distinct characteristics.
  • Results indicate that GSS-102L prions do not transmit disease to wild type mouse PrP, suggesting the need for future research to prioritize mutant human PrP expression to better model human IPDs.
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Mammalian prions, transmissible agents causing lethal neurodegenerative diseases, are composed of assemblies of misfolded cellular prion protein (PrP). A novel PrP variant, G127V, was under positive evolutionary selection during the epidemic of kuru--an acquired prion disease epidemic of the Fore population in Papua New Guinea--and appeared to provide strong protection against disease in the heterozygous state. Here we have investigated the protective role of this variant and its interaction with the common, worldwide M129V PrP polymorphism.

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Prions are infectious agents causing fatal neurodegenerative diseases of humans and animals. In humans, these have sporadic, acquired and inherited aetiologies. The inherited prion diseases are caused by one of over 30 coding mutations in the human prion protein (PrP) gene (PRNP) and many of these generate infectious prions as evidenced by their experimental transmissibility by inoculation to laboratory animals.

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Article Synopsis
  • Mutations in the CHMP2B gene lead to frontotemporal lobar degeneration by truncating the CHMP2B protein, causing neurodegeneration in mice.
  • Transgenic mice with the truncated CHMP2B show reduced survival, gliosis, and accumulation of specific protein aggregates similar to those found in affected human patients.
  • The study indicates that CHMP2B mutations trigger degenerative changes through a gain of function process, providing a valuable mouse model for understanding this type of dementia.
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Approximately 15 % of human prion disease is associated with autosomal-dominant pathogenic mutations in the prion protein (PrP) gene. Previous attempts to model these diseases in mice have expressed human PrP mutations in murine PrP, but this may have different structural consequences. Here, we describe transgenic mice expressing human PrP with P102L or E200K mutations and methionine (M) at the polymorphic residue 129.

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