Browsing by Author "Kretzschmar, Hans"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    C9orf72 Intermediate Repeats are Associated with Corticobasal Degeneration, Increased C9orf72 Expression and Disruption of Autophagy
    (Springer, 2019-11) Cali, Christopher P.; Patino, Maribel; Tai, Yee Kit; Ho, Wan Yun; McLean, Catriona A.; Morris, Christopher M.; Seeley, William W.; Miller, Bruce L.; Gaig, Carles; Vonsattel, Jean Paul G.; White, Charles L.; Roeber, Sigrun; Kretzschmar, Hans; Troncoso, Juan C.; Troakes, Claire; Gearing, Marla; Ghetti, Bernardino; Van Deerlin, Vivianna M.; Lee, Virginia M.-Y.; Trojanowski, John Q.; Mok, Kin Y.; Ling, Helen; Dickson, Dennis W.; Schellenberg, Gerard D.; Ling, Shuo-Chien; Lee, Edward B.; Pathology and Laboratory Medicine, School of Medicine
    Microsatellite repeat expansion disease loci can exhibit pleiotropic clinical and biological effects depending on repeat length. Large expansions in C9orf72 (100s-1000s of units) are the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal degeneration (FTD). However, whether intermediate expansions also contribute to neurodegenerative disease is not well understood. Several studies have identified intermediate repeats in Parkinson’s disease patients, but the association was not found in autopsy confirmed cases. We hypothesized that intermediate C9orf72 repeats are a genetic risk factor for corticobasal degeneration (CBD), a neurodegenerative disease that can be clinically similar to Parkinson’s but has distinct tau protein pathology. Indeed, intermediate C9orf72 repeats were significantly enriched in autopsy-proven CBD (n=354 cases, odds ratio=3.59, p-value=0.00024). While large C9orf72 repeat expansions are known to decrease C9orf72 expression, intermediate C9orf72 repeats result in increased C9orf72 expression in human brain tissue and CRISPR/cas9 knockin iPSC derived neural progenitor cells. In contrast to cases of FTD/ALS with large C9orf72 expansions, CBD with intermediate C9orf72 repeats was not associated with pathologic RNA foci or dipeptide repeat protein aggregates. Knock-in cells with intermediate repeats exhibit numerous changes in gene expression pathways relating to vesicle trafficking and autophagy. Additionally, overexpression of C9orf72 without the repeat expansion leads to defects in autophagy under nutrient starvation conditions. These results raise the possibility that therapeutic strategies to reduce C9orf72 expression may be beneficial for the treatment of CBD.
  • Thumbnail Image
    Item
    Incidence and spectrum of sporadic Creutzfeldt–Jakob disease variants with mixed phenotype and co-occurrence of PrPSc types: an updated classification
    (Springer, 2009-11-01) Parchi, Piero; Strammiello, Rosaria; Notari, Silvio; Giese, Armin; Langeveld, Jan P. M.; Ladogana, Anna; Zerr, Inga; Roncaroli, Federico; Cras, Patrich; Ghetti, Bernardino; Pocchiari, Maurizio; Kretzschmar, Hans; Capellari, Sabina; Pathology and Laboratory Medicine, IU School of Medicine
    Six subtypes of sporadic Creutzfeldt–Jakob disease with distinctive clinico-pathological features have been identified largely based on two types of the abnormal prion protein, PrPSc, and the methionine (M)/valine (V) polymorphic codon 129 of the prion protein. The existence of affected subjects showing mixed phenotypic features and concurrent PrPSc types has been reported but with inconsistencies among studies in both results and their interpretation. The issue currently complicates diagnosis and classification of cases and also has implications for disease pathogenesis. To explore the issue in depth, we carried out a systematic regional study in a large series of 225 cases. PrPSc types 1 and 2 concurrence was detected in 35% of cases and was higher in MM than in MV or VV subjects. The deposition of either type 1 or 2, when concurrent, was not random and always characterized by the coexistence of phenotypic features previously described in the pure subtypes. PrPSc type 1 accumulation and related pathology predominated in MM and MV cases, while the type 2 phenotype prevailed in VVs. Neuropathological examination best identified the mixed types 1 and 2 features in MMs and most MVs, and also uniquely revealed the co-occurrence of pathological variants sharing PrPSc type 2. In contrast, molecular typing best detected the concurrent PrPSc types in VV subjects and MV cases with kuru plaques. The present data provide an updated disease classification and are of importance for future epidemiologic and transmission studies aimed to identify etiology and extent of strain variation in sporadic Creutzfeldt–Jakob disease.