-
Chae Kim,
Tracy Haldiman,
Krystyna Surewicz,
Yvonne Cohen,
Wei Chen,
Janis Blevins,
Man-Sun Sy, Mark Cohen,
Qingzhong Kong,
Glenn C Telling,
Witold K Surewicz,
Jiri G Safar
[show abstract]
[hide abstract]
ABSTRACT: The mammalian prions replicate by converting cellular prion protein (PrP(C)) into pathogenic conformational isoform (PrP(Sc)). Variations in prions, which cause different disease phenotypes, are referred to as strains. The mechanism of high-fidelity replication of prion strains in the absence of nucleic acid remains unsolved. We investigated the impact of different conformational characteristics of PrP(Sc) on conversion of PrP(C) in vitro using PrP(Sc) seeds from the most frequent human prion disease worldwide, the Creutzfeldt-Jakob disease (sCJD). The conversion potency of a broad spectrum of distinct sCJD prions was governed by the level, conformation, and stability of small oligomers of the protease-sensitive (s) PrP(Sc). The smallest most potent prions present in sCJD brains were composed only of∼20 monomers of PrP(Sc). The tight correlation between conversion potency of small oligomers of human sPrP(Sc) observed in vitro and duration of the disease suggests that sPrP(Sc) conformers are an important determinant of prion strain characteristics that control the progression rate of the disease.
PLoS Pathogens 08/2012; 8(8):e1002835. · 9.13 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To compare the respective efficiency of CSF tau (quantitative) and CSF 14-3-3 protein (qualitative) in the diagnosis of prion disease.
We made measurements on 420 live subjects, who subsequently underwent a postmortem neuropathology examination, including protein chemistry, immunohistochemistry, and histology. We performed tau by ELISA. We detected 14-3-3 protein by Western blot. Both assays were optimized for maximum efficiency (accuracy).
We found tau and 14-3-3 proteins to be closely correlated, but tau had a significantly better ability to predict disease status than 14-3-3 protein. Also, tau distinguished disease status at least as well as when both assays' results are combined in a variety of ways. Importantly, the area under the receiver operating characteristic curve for tau (0.82) was significantly larger than that for 14-3-3 protein (0.68) (p < 0.001). Diagnostic test statistics are provided for the study subjects with 58.3% prevalence, and for a more typical, nonselected, 7.5% prevalence as received by our center.
In this study, tau is superior to 14-3-3 protein as a marker in the diagnosis of Creutzfeldt-Jakob disease, and is as efficient singly compared to a variety of combinations with 14-3-3 protein. This is the first study of this magnitude to examine prion disease diagnostic tests in a carefully characterized patient population with detailed statistical evaluation.
Neurology 07/2012; 79(6):547-52. · 8.31 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The origin, range, and structure of prions causing the most common human prion disease, sporadic Creutzfeldt-Jakob disease (sCJD), are largely unknown. To investigate the molecular mechanism responsible for the broad phenotypic variability of sCJD, we analyzed the conformational characteristics of protease-sensitive and protease-resistant fractions of the pathogenic prion protein (PrP(Sc)) using novel conformational methods derived from a conformation-dependent immunoassay (CDI). In 46 brains of patients homozygous for polymorphisms in the PRNP gene and exhibiting either Type 1 or Type 2 western blot pattern of the PrP(Sc), we identified an extensive array of PrP(Sc) structures that differ in protease sensitivity, display of critical domains, and conformational stability. Surprisingly, in sCJD cases homozygous for methionine or valine at codon 129 of the PRNP gene, the concentration and stability of protease-sensitive conformers of PrP(Sc) correlated with progression rate of the disease. These data indicate that sCJD brains exhibit a wide spectrum of PrP(Sc) structural states, and accordingly argue for a broad spectrum of prion strains coding for different phenotypes. The link between disease duration, levels, and stability of protease-sensitive conformers of PrP(Sc) suggests that these conformers play an important role in the pathogenesis of sCJD.
PLoS Pathogens 09/2011; 7(9):e1002242. · 9.13 Impact Factor
-
Wen-Quan Zou,
Gianfranco Puoti,
Xiangzhu Xiao,
Jue Yuan,
Liuting Qing,
Ignazio Cali,
Miyuki Shimoji,
Jan P M Langeveld,
Rudy Castellani,
Silvio Notari, [......],
Sabina Capellari,
Giorgio Giaccone,
Ermias D Belay,
Lawrence B Schonberger, Mark Cohen,
George Perry,
Qingzhong Kong,
Piero Parchi,
Fabrizio Tagliavini,
Pierluigi Gambetti
[show abstract]
[hide abstract]
ABSTRACT: The objective of the study is to report 2 new genotypic forms of protease-sensitive prionopathy (PSPr), a novel prion disease described in 2008, in 11 subjects all homozygous for valine at codon 129 of the prion protein (PrP) gene (129VV). The 2 new PSPr forms affect individuals who are either homozygous for methionine (129MM) or heterozygous for methionine/valine (129MV).
Fifteen affected subjects with 129MM, 129MV, and 129VV underwent comparative evaluation at the National Prion Disease Pathology Surveillance Center for clinical, histopathologic, immunohistochemical, genotypical, and PrP characteristics.
Disease duration (between 22 and 45 months) was significantly different in the 129VV and 129MV subjects. Most other phenotypic features along with the PrP electrophoretic profile were similar but distinguishable in the 3 129 genotypes. A major difference laid in the sensitivity to protease digestion of the disease-associated PrP, which was high in 129VV but much lower, or altogether lacking, in 129MV and 129MM. This difference prompted the substitution of the original designation with "variably protease-sensitive prionopathy" (VPSPr). None of the subjects had mutations in the PrP gene coding region.
Because all 3 129 genotypes are involved, and are associated with distinguishable phenotypes, VPSPr becomes the second sporadic prion protein disease with this feature after Creutzfeldt-Jakob disease, originally reported in 1920. However, the characteristics of the abnormal prion protein suggest that VPSPr is different from typical prion diseases, and perhaps more akin to subtypes of Gerstmann-Sträussler-Scheinker disease.
Annals of Neurology 08/2010; 68(2):162-72. · 11.09 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Sushi domain-containing protein 4 (SUSD4) was a hypothetical cell surface protein whose tissue distribution and function were completely unknown. However, recent microarray-based studies have identified deletions of SUSD4 gene in patients with autism or Fryns syndrome, both of which are genetic diseases with severe abnormal neurological development and/or functions. In this article, we described the cloning, expression, refolding, tissue distribution, and functional analysis of this novel protein. Using polyclonal antibodies generated by immunizing chickens with the recombinant SUSD4, we found that SUSD4 is detectable in murine brains, eyes, spinal cords, and testis but not other tissues. In brains, SUSD4 is highly expressed in the white matter on oligodendrocytes/axons, and in eyes, it is exclusively expressed on the photoreceptor outer segments. In in vitro complement assays, SUSD4 augments the alternative but not the classical pathway of complement activation at the C3 convertase step. In in vivo studies, knocking down SUSD4 expression in zebrafish markedly increases ratios of mortality and developmental abnormality. These results provide the first insight into the important physiological roles of SUSD4 and could help to better understand the pathogenesis of autism and Fryns syndrome.
American Journal Of Pathology 03/2010; 176(5):2378-84. · 4.89 Impact Factor
-
Pierluigi Gambetti,
Zhiqian Dong,
Jue Yuan,
Xiangzhu Xiao,
Mengjie Zheng,
Amer Alshekhlee,
Rudy Castellani, Mark Cohen,
Marcelo A Barria,
D Gonzalez-Romero, [......],
Carrie Harris,
James R Burke,
Thomas Montine,
Thomas Wisniewski,
Dennis W Dickson,
Claudio Soto,
Christine M Hulette,
James A Mastrianni,
Qingzhong Kong,
Wen-Quan Zou
[show abstract]
[hide abstract]
ABSTRACT: To report a novel prion disease characterized by distinct histopathological and immunostaining features, and associated with an abnormal isoform of the prion protein (PrP) that, contrary to the common prion diseases, is predominantly sensitive to protease digestion.
Eleven subjects were investigated at the National Prion Disease Pathology Surveillance Center for clinical, histopathological, immunohistochemical, genotypical, and PrP characteristics.
Patients presented with behavioral and psychiatric manifestations on average at 62 years, whereas mean disease duration was 20 months. The type of spongiform degeneration, the PrP immunostaining pattern, and the presence of microplaques distinguished these cases from those with known prion diseases. Typical protease-resistant PrP was undetectable in the cerebral neocortex with standard diagnostic procedures. After enrichment, abnormal PrP was detected at concentrations 16 times lower than common prion diseases; it included nearly 4 times less protease-resistant PrP, which formed a distinct electrophoretic profile. The subjects examined comprised about 3% of sporadic cases evaluated by the National Prion Disease Pathology Surveillance Center. Although several subjects had family histories of dementia, no mutations were found in the PrP gene open reading frame.
The distinct histopathological, PrP immunohistochemical, and physicochemical features, together with the homogeneous genotype, indicate that this is a previously unidentified type of disease involving the PrP, which we designated "protease-sensitive prionopathy" (or PSPr). Protease-sensitive prionopathy is not rare among prion diseases, and it may be even more prevalent than our data indicate because protease-sensitive prionopathy cases are likely also to be classified within the group of non-Alzheimer's dementias.
Annals of Neurology 07/2008; 63(6):697-708. · 11.09 Impact Factor
-
Shenghai Huang,
Jingjing Liang,
Mengjie Zheng,
Xinyi Li,
Meiling Wang,
Ping Wang,
Difernando Vanegas,
Di Wu,
Bikram Chakraborty,
Arthur P Hays,
Ken Chen,
Shu G Chen,
Stephanie Booth, Mark Cohen,
Pierluigi Gambetti,
Qingzhong Kong
[show abstract]
[hide abstract]
ABSTRACT: The prion protein (PrP) level in muscle has been reported to be elevated in patients with inclusion-body myositis, polymyositis, dermatomyositis, and neurogenic muscle atrophy, but it is not clear whether the elevated PrP accumulation in the muscles is sufficient to cause muscle diseases. We have generated transgenic mice with muscle-specific expression of PrP under extremely tight regulation by doxycycline, and we have demonstrated that doxycycline-induced overexpression of PrP strictly limited to muscles leads to a myopathy characterized by increased variation of myofiber size, centrally located nuclei, and endomysial fibrosis, in the absence of intracytoplasmic inclusions, rimmed vacuoles, or any evidence of a neurogenic disorder. The PrP-induced myopathy correlates with accumulation of an N-terminal truncated PrP fragment in the muscle, and the muscular PrP displayed consistent mild resistance to protease digestion. Our findings indicate that overexpression of wild-type PrP in skeletal muscles is sufficient to cause a primary myopathy with no signs of peripheral neuropathy, possibly due to accumulation of a cytotoxic truncated form of PrP and/or PrP aggregation.
Proceedings of the National Academy of Sciences 05/2007; 104(16):6800-5. · 9.68 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We are creating an interactive, simulated "Cancer Genetics Tower" for the self-paced learning of Clinical Cancer Genetics by medical students (go to: http://casemed.case.edu/cancergenetics). The environment uses gaming theory to engage the students into achieving specific learning objectives. The first few levels contain virtual laboratories where students achieve the basic underpinnings of Cancer Genetics. The next levels apply these principles to clinical practice. A virtual attending physician and four virtual patients, available for questioning through virtual video conferencing, enrich each floor. The pinnacle clinical simulation challenges the learner to integrate all information and demonstrate mastery, thus "winning" the game. A pilot test of the program by 17 medical students yielded very favorable feedback; the students found the Tower a "great way to teach", it held their attention, and it made learning fun. A majority of the students preferred the Tower over other resources to learn Cancer Genetics.
Studies in health technology and informatics 02/2007; 125:355-60.
-
[show abstract]
[hide abstract]
ABSTRACT: The flat interface nerve electrode (FINE) is designed to reshape peripheral nerves into favorable geometries for selective stimulation. Compared to cylindrical geometries, the ovoid geometries created by the FINE allow more space for contact placement. Furthermore, the amount of electrically excitable tissue between stimulating contacts and target axons is reduced. In this study, the nerve response to the presence of the FINE is examined histologically. Three different FINEs were designed to reshape peripheral nerves to different opening heights designated as 'wide' (1.3 mm), 'medium' (0.5 mm) and 'narrow' (0.1 mm) cuffs. Twelve adult cats were implanted with one cuff each (four in total of each design) on their right sciatic nerves. At least 3 months later, the animals were sacrificed and their sciatic nerves were harvested for histological evaluation. Cross-sectional areas and eccentricities (defined as the major axis divided by the minor axis of the closest fit ellipse to a region) of the nerves were measured to assess the degree of reshaping. The wide and medium cuff designs significantly reshaped the nerves compared to control nerves, though there was no significant difference in eccentricity between nerves implanted with wide and medium cuffs. There was extensive deposition of connective tissue in the epineurium of all nerves implanted with cuffs. No significant difference in fiber counts was measured in any of the groups studied. Only nerves implanted with narrow cuffs showed evidence of axonal injury and/or demyelination. These results, coupled with stimulation selectivity measurements made on the same animals, suggest that safe, selective electrodes can be designed with ovoid geometries. Moderate reshaping caused no damage, while extreme reshaping generated mild-to-moderate nerve damage. It might be possible, however, to redesign the cuffs to slowly reshape the nerves.
Journal of Neural Engineering 07/2006; 3(2):102-13. · 3.84 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We have developed anin vitromodel in which isolated senile plaque (SP) cores are presented to rat microglial cells in culture. Microglia rapidly phagocytosed, broke apart, and cleared SP cores. However, when cocultured with astrocytes, microglial phagocytosis was markedly suppressed, allowing the SPs to persist. Suppression of phagocytosis by astrocytes appears to be a general phenomena since microglia in the presence of astrocytes showed reduced capacity to phagocytose latex beads as well. The astrocyte effect on microglia is related in part to a diffusible factor(s) since astrocyte- but not fibroblast-conditioned media also reduced phagocytosis. These results suggest that while microglia have the capacity to phagocytose and remove SPs, astrocytes which lie in close association to microglia may help prevent the efficient clearance of SP material allowing them to persist in Alzheimer's disease.
Experimental Neurology 02/1998; · 4.70 Impact Factor
