Browsing by Author "Gambetti, Pierluigi"

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    Bank Vole Prion Protein As an Apparently Universal Substrate for RT-QuIC-Based Detection and Discrimination of Prion Strains
    (Public Library of Science, 2015-06) Orrú, Christina D.; Groveman, Bradley R.; Raymond, Lynne D.; Hughson, Andrew G.; Nonno, Romolo; Zou, Wenquan; Ghetti, Bernardino; Gambetti, Pierluigi; Caughey, Byron; Department of Pathology and Laboratory Medicine, IU School of Medicine
    Prions propagate as multiple strains in a wide variety of mammalian species. The detection of all such strains by a single ultrasensitive assay such as Real Time Quaking-induced Conversion (RT-QuIC) would facilitate prion disease diagnosis, surveillance and research. Previous studies have shown that bank voles, and transgenic mice expressing bank vole prion protein, are susceptible to most, if not all, types of prions. Here we show that bacterially expressed recombinant bank vole prion protein (residues 23-230) is an effective substrate for the sensitive RT-QuIC detection of all of the different prion types that we have tested so far--a total of 28 from humans, cattle, sheep, cervids and rodents, including several that have previously been undetectable by RT-QuIC or Protein Misfolding Cyclic Amplification. Furthermore, comparison of the relative abilities of different prions to seed positive RT-QuIC reactions with bank vole and not other recombinant prion proteins allowed discrimination of prion strains such as classical and atypical L-type bovine spongiform encephalopathy, classical and atypical Nor98 scrapie in sheep, and sporadic and variant Creutzfeldt-Jakob disease in humans. Comparison of protease-resistant RT-QuIC conversion products also aided strain discrimination and suggested the existence of several distinct classes of prion templates among the many strains tested.
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    Clinicopathological Correlates in a PRNP P102L Mutation Carrier with Rapidly Progressing Parkinsonism-dystonia
    (Wiley, 2016-07) Umeh, Chizoba C.; Kalakoti, Piyush; Greenberg, Michael K.; Notari, Silvio; Cohen, Yvonne; Gambetti, Pierluigi; Oblak, Adrian L.; Ghetti, Bernardino; Mari, Zoltan; Pathology and Laboratory Medicine, School of Medicine
    Parkinsonism-dystonia is rare in carriers of PRNP P102L mutation. Severity and distribution of prion protein (PrP) deposition may influence the clinical presentation. We present such clinic-pathological correlation in a 56-year-old male with a PRNP P102L mutation associated with a phenotype characterized by rapidly progressing parkinsonism-dystonia. The patient was studied clinically (videotaped exams, brain MRIs); molecular genetically (gene sequence analysis); and neuropathologically (histology, immunohistochemistry) during his 7-month disease course. The patient had parkinsonism, apraxia, aphasia, and dystonia, which progressed rapidly. Molecular genetic analysis revealed PRNP P102L mutation carrier status. Brain MRIs revealed progressive global volume loss and T2/FLAIR hyperintensity in neocortex and basal ganglia. Postmortem examination showed neuronal loss, gliosis, spongiform changes, and PrP deposition in the striatum. PrP immunohistochemistry revealed widespread severe PrP deposition in the thalamus and cerebellar cortex. Based on the neuropathological and molecular-genetic analysis, the rapidly progressing parkinsonism-dystonia correlated with nigrostriatal, thalamic, and cerebellar pathology.
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    Efficient transmission of human prion diseases to a glycan-free prion protein-expressing host
    (Oxford University Press, 2024) Cracco, Laura; Cali, Ignazio; Cohen, Mark L.; Aslam, Rabail; Notari, Silvio; Kong, Qingzhong; Newell, Kathy L.; Ghetti, Bernardino; Appleby, Brian S.; Gambetti, Pierluigi; Pathology and Laboratory Medicine, School of Medicine
    It is increasingly evident that the association of glycans with the prion protein (PrP), a major post-translational modification, significantly impacts the pathogenesis of prion diseases. A recent bioassay study has provided evidence that the presence of PrP glycans decreases spongiform degeneration and disease-related PrP (PrPD) deposition in a murine model. We challenged (PRNPN181Q/197Q) transgenic (Tg) mice expressing glycan-free human PrP (TgGlyc-), with isolates from sporadic Creutzfeldt-Jakob disease subtype MM2 (sCJDMM2), sporadic fatal insomnia and familial fatal insomnia, three human prion diseases that are distinct but share histotypic and PrPD features. TgGlyc- mice accurately replicated the basic histotypic features associated with the three diseases but the transmission was characterized by high attack rates, shortened incubation periods and a greatly increased severity of the histopathology, including the presence of up to 40 times higher quantities of PrPD that formed prominent deposits. Although the engineered protease-resistant PrPD shared at least some features of the secondary structure and the presence of the anchorless PrPD variant with the wild-type PrPD, it exhibited different density gradient profiles of the PrPD aggregates and a higher stability index. The severity of the histopathological features including PrP deposition appeared to be related to the incubation period duration. These findings are clearly consistent with the protective role of the PrP glycans but also emphasize the complexity of the conformational changes that impact PrPD following glycan knockout. Future studies will determine whether these features apply broadly to other human prion diseases or are PrPD-type dependent.
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    Gerstmann-Sträussler-Scheinker disease revisited: accumulation of covalently-linked multimers of internal prion protein fragments
    (Biomed Central, 2019-05-29) Cracco, Laura; Xiao, Xiangzhu; Nemani, Satish K.; Lavrich, Jody; Cali, Ignazio; Ghetti, Bernardino; Notari, Silvio; Surewicz, Witold K.; Gambetti, Pierluigi; Pathology and Laboratory Medicine, School of Medicine
    Despite their phenotypic heterogeneity, most human prion diseases belong to two broadly defined groups: Creutzfeldt-Jakob disease (CJD) and Gerstmann-Sträussler-Scheinker disease (GSS). While the structural characteristics of the disease-related proteinase K-resistant prion protein (resPrPD) associated with the CJD group are fairly well established, many features of GSS-associated resPrPD are unclear. Electrophoretic profiles of resPrPD associated with GSS variants typically show 6-8 kDa bands corresponding to the internal PrP fragments as well as a variable number of higher molecular weight bands, the molecular nature of which has not been investigated. Here we have performed systematic studies of purified resPrPD species extracted from GSS cases with the A117V (GSSA117V) and F198S (GSSF198S) PrP gene mutations. The combined analysis based on epitope mapping, deglycosylation treatment and direct amino acid sequencing by mass spectrometry provided a conclusive evidence that high molecular weight resPrPD species seen in electrophoretic profiles represent covalently-linked multimers of the internal ~ 7 and ~ 8 kDa fragments. This finding reveals a mechanism of resPrPD aggregate formation that has not been previously established in prion diseases.
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    Gerstmann-Sträussler-Scheinker disease subtypes efficiently transmit in bank voles as genuine prion diseases.
    (NPG, 2016) Pirisinu, Laura; Di Bari, Michele A.; D’Agostino, Claudia; Marcon, Stefano; Riccardi, Geraldina; Poleggi, Anna; Cohen, Mark L.; Appleby, Brian S.; Gambetti, Pierluigi; Ghetti, Bernardino; Agrimi, Umberto; Nonno, Romolo; Department of Pathology & Laboratory Medicine, IU School of Medicine
    Gerstmann-Sträussler-Scheinker disease (GSS) is an inherited neurodegenerative disorder associated with mutations in the prion protein gene and accumulation of misfolded PrP with protease-resistant fragments (PrPres) of 6–8 kDa.
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    Phenotypic diversity of genetic Creutzfeldt-Jakob disease: a histo-molecular-based classification
    (Springer, 2021) Baiardi, Simone; Rossi, Marcello; Mammana, Angela; Appleby, Brian S.; Barria, Marcelo A.; Calì, Ignazio; Gambetti, Pierluigi; Gelpi, Ellen; Giese, Armin; Ghetti, Bernardino; Herms, Jochen; Ladogana, Anna; Mikol, Jacqueline; Pal, Suvankar; Ritchie, Diane L.; Ruf, Viktoria; Windl, Otto; Capellari, Sabina; Parchi, Piero; Pathology and Laboratory Medicine, School of Medicine
    The current classification of sporadic Creutzfeldt-Jakob disease (sCJD) includes six major clinicopathological subtypes defined by the physicochemical properties of the protease-resistant core of the pathologic prion protein (PrPSc), defining two major PrPSc types (i.e., 1 and 2), and the methionine (M)/valine (V) polymorphic codon 129 of the prion protein gene (PRNP). How these sCJD subtypes relate to the well-documented phenotypic heterogeneity of genetic CJD (gCJD) is not fully understood. We analyzed molecular and phenotypic features in 208 individuals affected by gCJD, carrying 17 different mutations, and compared them with those of a large series of sCJD cases. We identified six major groups of gCJD based on the combination PrPSc type and codon 129 genotype on PRNP mutated allele, each showing distinctive histopathological characteristics, irrespectively of the PRNP associated mutation. Five gCJD groups, named M1, M2C, M2T, V1, and V2, largely reproduced those previously described in sCJD subtypes. The sixth group shared phenotypic traits with the V2 group and was only detected in patients carrying the E200K-129M haplotype in association with a PrPSc type of intermediate size ("i") between type 1 and type 2. Additional mutation-specific effects involved the pattern of PrP deposition (e.g., a "thickened" synaptic pattern in E200K carriers, cerebellar "stripe-like linear granular deposits" in those with insertion mutations, and intraneuronal globular dots in E200K-V2 or -M"i"). A few isolated cases linked to rare PRNP haplotypes (e.g., T183A-129M), showed atypical phenotypic features, which prevented their classification into the six major groups. The phenotypic variability of gCJD is mostly consistent with that previously found in sCJD. As in sCJD, the codon 129 genotype and physicochemical properties of PrPSc significantly correlated with the phenotypic variability of gCJD. The most common mutations linked to CJD appear to have a variable and overall less significant effect on the disease phenotype, but they significantly influence disease susceptibility often in a strain-specific manner. The criteria currently used for sCJD subtypes can be expanded and adapted to gCJD to provide an updated classification of the disease with a molecular basis.