Bovine spongiform encephalopathy associated insertion/deletion polymorphisms of the prion protein gene in the four beef cattle breeds from North China
Xiang-Yuan Zhu,a Fu-Ying Feng,a Su-Yuan Xue,b Ting Hou,a Hui-Rong Liua
aDepartment of Biochemistry and Molecular Biology, College of Life Sciences, Inner Mongolia Agricultural University, Hohhot, China.
bInner Mongolia Academy of Agricultural Sciences, Hohhot, China.
Corresponding author: Hui-Rong Liu (e-mail: email@example.com).
Paper handled by associate editor J. Bell
Published on the web 19 September 2011.
Two insertion/deletion (indel) polymorphisms of the prion protein gene (PRNP), a 23-bp indel in the putative promoter region and a 12-bp indel within intron I, are associated with the susceptibility to bovine spongiform encephalopathy (BSE) in cattle. In the present study, the polymorphism frequencies of the two indels in four main beef cattle breeds (Hereford, Simmental, Black Angus, and Mongolian) from North China were studied. The results showed that the frequencies of deletion genotypes and alleles of 23- and 12-bp indels were lower, whereas the frequencies of insertion genotypes and alleles of the two indels were higher in Mongolian cattle than in the other three cattle breeds. In Mongolian cattle, the 23-bp insertion / 12-bp insertion was the major haplotype, whereas in Hereford, Simmental, and Black Angus cattle, the 23-bp deletion / 12-bp deletion was the major haplotype. These results demonstrated that Mongolian cattle could be more resistant to BSE, compared with the other three cattle breeds, because of its relatively low frequencies of deletion genotypes and alleles of 23- and 12-bp indel polymorphisms. Thus, this race could be important for selective breeding to improve resistance against BSE in this area.
Keywords: prion protein gene, insertion/deletion polymorphism, bovine spongiform encephalopathy, cattle, North China
An autopsied case of V180I Creutzfeldt-Jakob disease presenting with panencephalopathic-type pathology and a characteristic prion protein type
Yasushi Iwasaki1,*, Keiko Mori1, Masumi Ito1, Masamitsu Nagaoka2, Toshiaki Ieda3, Tetsuyuki Kitamoto4, Mari Yoshida5, Yoshio Hashizume5Article first published online: 27 JAN 2011 DOI: 10.1111/j.1440-1789.2010.01192.x © 2011 Japanese Society of Neuropathology
Keywords: akinetic mutism state; Creutzfeldt-Jakob disease; panencephalopathic-type; prion protein type; V180I
A 73-year-old Japanese woman showed slowly progressive aphasia, apraxia and dementia. She had no family history of prion disease or dementia. One year later she showed parkinsonism and corticobasal degeneration was initially suspected. On MRI, the left temporal neocortex seemed swollen on T2-weighted images in the initial stage, and a later high-signal intensity region was observed in the cerebral cortex in diffusion-weighted images. The patient developed myoclonus and an akinetic mutism state 15 months and 22 months after onset, respectively. Consecutive electroencephalography revealed no periodic sharp-wave complexes. Prion protein (PrP) gene analysis revealed a valine to isoleucine point mutation at codon 180, and methionine homozygosity at codon 129. This patient's clinical symptoms and disease course were atypical for Creutzfeldt–Jakob disease (CJD), and a stable state with nasal tube-feeding lasted several years. She died of respiratory failure at the age of 81, 102 months after the onset. Autopsy revealed widespread spongiform degeneration with weak synaptic-type PrP deposition, confirming the diagnosis of genetic CJD. Neurons in the cerebral cortex were relatively preserved in number and hypertrophic astrocytosis was generally moderate for such long-term disease, but cerebral white matter showed diffuse severe myelin pallor with tissue rarefaction suggestive of panencephalopatic-type pathology. The cerebellar cortex was relatively well preserved with observation of mild spongiform change in the molecular layer, moderate neuron loss in the Purkinje neuron layer, and scattered small plaque-like PrP deposition. Western blot analysis of protease-resistant PrP showed a characteristic pattern without a diglycoform band. V180I CJD is an interesting form of genetic CJD with regards to the clinicopathologic, molecular and genetic findings.
Oral.34: Variably Protease-Sensitive Prionopathy: Transmissibility and PMCA Studies
Pierluigi Gambetti,1,† Wenquan Zou,1 Juan Maria Torres,2 Claudio Soto,3 Silvio Notari,2 Juan Carlos Espinosa2 and Xiangzhu Xiao1
1 Case Western Reserve University; Cleveland, OH USA; 2 Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria; Madrid, Spain; 3 Mitchell Center for Alzheimer Disease and Related Brain Disorders, University of Texas; Houston, TX USA†Presenting author; Email: firstname.lastname@example.org
Variably protease-sensitive prionopathy (VPSPr) is an atypical, apparently sporadic prion disease affects all three genotypes—VV, MV and MM—at codon 129 of the prion protein (PrP) gene. A distinctive and common feature of VPSPr three genotypes is the presence of abnormal PrP forming a ladder-like electrophoretic pattern with variable sensitivity to protease digestion according to the 129 genotype. These atypical features have raised the issue of VPSPr transmissibility to animals and its propensity of being replicated in vitro.
We now report the initial results of an extensive study on the capacity of the VPSPr-associated abnormal PrP to propagate by bioassay and by protein misfolding cyclic amplification (PMCA). Inoculation of brain homogenates from cases of VPSPr-129VV to transgenic (Tg) mice expressing human PrP-129V at 6X normal revealed no clinical phenotype during the normal life span of the inoculated mice. Peculiar PrP plaques with a distinctive topography were present in approximately 30% of the mice with minimal or no spongiform degeneration (SD). Abnormal PrP from several of the plaque-bearing mice displayed a ladder-like electrophoretic profile similar to that of VPSPr. In contrast, Tg mice inoculated with brain homogenate from sporadic CJD-129VV associated with scrapie PrP type 2 became symptomatic and died approximately 220 days post inoculation. They showed widespread SD with only occasional, differently distributed plaques and a typical 3-band or PrP27-30 electrophoretic profile of the protease resistant PrP. Sham- or not inoculated mice revealed no pathology and no ladder or PrP27-30 profiles. The ladder-like electrophoretic profile was also obtained from VPSPr-129VV under modified PMCA conditions. Second passage experiments are underway.
These results support the notion that VPSPr is a prion condition different from classical prion diseases and more like other conformational neurodegenerative diseases such as Alzheimer disease and tauopathies.
Supported by NIH NS062787, AG-08012, AG-14359, CDC UR8/CCU515004 and the Britton Fund.
Bio.183: Association Between a Familial and a Newly-Identified Prion Disease
Xiangzhu Xiao,1 Jue Yuan,1 Ignazio Cali,1 Xiaochen Zhou,1 Jeanne Grosclaude,2 Hubert Laude,2 Robert B. Petersen,1 Pierluigi Gambetti1 and Wenquan Zou1,†
1Case Western Reserve University; Cleveland, OH USA; 2Virologie Immunologie Moléculaires; Jouy-en-Josas, France†Presenting author; Email: email@example.com
Variably protease-sensitive prionopathy (VPSPr) is a newly-identified sporadic prion disease characterized not only by an atypical clinical phenotype and neuropathology, but also by the deposition in the brain of a peculiar prion (PrPSc). The molecular mechanism underlying the formation of the peculiar PrPSc remains unknown. A naturally-occurring pathogenic mutation, valine (V) to isoleucine (I), at PrP residue 180 is linked to familial Creutzfeldt-Jakob disease (fCJDV180I). Here we report that the prions formed in VPSPr and fCJDV180I exhibit striking similarities in glycosylation, enzymatic fragmentation, and immunoreactivity even though they are associated with either wild-type PrP (PrPWt) or mutated PrP, respectively. First, we demonstrate that lack of the proteinase K (PK)-resistant diglycosylated PrP species (PrPDigly) observed in both fCJDV180I and VPSPr results from loss of glycosylation at the first N-linked glycosylation site. Second, although lack of PrPDigly has also been reported in fCJD linked to the PrP Thr183Ala mutation (fCJDT183A, which abolishes the first glycosylation site) and an atypical CJD case, so far fCJDV180I is the only one that is of the peculiar PrPSc with the five-step ladder-like electrophoretic profile (LLEP), a pathognomonic molecular hallmark of VPSPr. Third, PrP with LLEP from the two diseases is preferentially detected by the anti-PrP antibody 1E4, but not by 3F4 although these PrP fragments contain both epitopes. Fourth, unlike fCJDT183A, both VPSPr and fCJDV180I show lack of PrPDigly only in PK-treated but not in untreated PrP. Finally, PrPDigly was detected in PrPWt and PrPV180I, but not in PrPT183A, in cell models. Our study suggests that fCJDV180I shares similar pathogenetic mechanism(s) with VPSPr and that cells and animals expressing human PrPV180I can be used as models for investigating the molecular mechanism underlying the formation of the peculiar PrPSc.
Supported by the National Institutes of Health (NIH) NS062787, NIH AG-08012, AG-14359, the CJD Foundation, Alliance BioSecure, the University Center on Aging and Health with the support of the McGregor Foundation and the President’s Discretionary Fund (CWRU) as well as CDC Contract UR8/CCU515004.
Bio.135: Characterization of the Agent Strain in Sporadic Creutzfeldt-Jakob Disease by Transmission to Wild-Type Mice
Diane L. Ritchie,1,† Aileen Boyle,2 Irene McConnell,2 Mark W. Head,1 James W. Ironside1 and Moira E. Bruce2
1National CJD Surveillance Unit; Edinburgh, UK; 2Neuropathogenesis Division, The Roslin Institute and Royal (Dick) School of Veterinary Studies, The Roslin Institute, Roslin Biocentre; Roslin, UK†Presenting author; Email: firstname.lastname@example.org
Transmissible spongiform encephalopathy (TSE) strains are defined by their biological properties on transmission to wild-type (wt) mice, specifically by their characteristic incubation periods and patterns of vacuolar pathology ("lesion profiles") in the brain. While a single TSE strain has been identified in variant Creutzfeldt-Jakob disease (vCJD), the phenotypic heterogeneity observed in sporadic CJD (sCJD) implies the existence of multiple strains of agent. These distinct strains are proposed to be enciphered by the different conformers of abnormal prion protein (PrP), recognized as different protease resistant PrP (PrPres) types by western blotting (type 1 or type 2) and are thought to be substantially influenced by the prion protein gene (PRNP) codon 129 (M/V) polymorphism.
To test the relationship between disease phenotype and agent strain, we investigated the transmission characteristics of the TSE agents present in brain tissue from 27 sCJD cases (comprising all six possible combinations of PRNP codon 129 genotype and PrPres type) in panels of wt mice using the standard strain typing properties of incubation period and lesion profiles, plus a full analysis of PrP present in the mouse brain. The work was extended to include analysis of subsequent mouse-to-mouse passages.
The results demonstrated the existence of at least two strains of agent, one associated with the MM1/MV1 sCJD subgroup and the other associated with the MM2 subgroup. The lack of transmission in mice challenged with tissues from VV1, MV2 and VV2 sCJD subgroups provided evidence of at least one further sCJD strain. Overall, the PrPres type in sCJD was maintained on transmission, which is consistent with the proposition that PrPres type plays a role in enciphering strain-specific information.
This study highlights a complex relationship between disease phenotype, codon 129 PRNP genotype, PrPres type and agent strain in sCJD and confirms that multiple strains of agent are associated with sCJD, some of which successfully propagate in wt mice. The sCJD strains identified here, by their biological properties partially correlates with the current sub-classification system for sCJD, which is based on the clinical and pathological phenotype of the disease.
Bio.144: Analyses of PrPSc Aggregation State and Protease-Resistance in Human Prions
Daniela Saverioni,1,† Silvio Notari,2 Sabina Capellari1 and Piero Parchi1
1Department of Neurological Sciences, University of Bologna; Bologna, Italy; 2Department of Pathology, National Prion Disease Pathology Surveillance Center, Case Western Reserve University; Cleveland, OH USA†Presenting author; Email: email@example.com
Background. Given the complexity and costs of transmission studies, the analyses of PrPSc properties is increasingly used as surrogate marker for strain typing. Early studies showed that PrPSc extracted from distinct disease phenotypes, in both animals and humans, often differ in physicochemical properties, such as fragment size after protease treatment or glycoform ratio. More recently, studies mainly conducted with scrapie strains isolated in mice or hamster have also reported strain-specific PrPSc differences in the degree of protease resistance, aggregation state, or conformational stability.
Objectives. To establish across the phenotypic spectrum of human prion disease: (1) whether and to what extent distinct PrPSc isoforms differ in protease-resistance; (2) whether and to what extent this PrPSc property is related to the aggregation state of the protein and (3) the relative amount of PK-sensitive PrPSc.
Materials and Methods. Frontal cortex PrPSc from the whole spectrum of sCJD subtypes, vCJD and VPsPr (MM and MV codon 129 genotypes) was purified through sample dilution in Sarkosyl and sequential ultracentrifugation in sucrose cushion and pellet resuspensions by sonication. PrPSc aggregates of different size were isolated after ultracentrifugation in sucrose gradient and fraction (12) collection. Whole purified samples and selected fractions of the sucrose gradient preparation were digested using a wide range of PK activities. A curve or "profile" of PrPSc digestion and the corresponding ED50 (PK activity required to decrease PrPSc by 50%) were obtained for each human strain analyzed.
Results. Protease resistance varied significantly among the TSE groups analysed, being highest in vCJD and sCJDVV2 and lowest in sCJDVV1. Fractions 1–4 always contained a fully PK-sensitive form of PrPSc (PrP-sen). However, PrP-sen only accounted for less than 10% of total purified PrPSc in all subtypes analyzed. Overall, the more "sensitive" subtypes contained a larger proportion of "small" PrPSc aggregates 82 Prion Volume 5 Supplement
(fractions 1–6) with respect to the more "resistant" ones. Nevertheless, PK-resistant aggregates of equal size (fractions 6, 9 and 12) extracted from sCJDMM1 and VV2 maintained, at least in part, the different degree of resistance.
Discussion. Our results indicate that: (1) only a limited portion of PrPSc associated to the majority of human prion strains is fully protease sensitive; (2) the analyses of PrP-sen does not differentiate among human prion strains; (3) the PrPSc forms associated to distinct human prion strains show a significant heterogeneity in the degree of protease resistance, which is at least partially explained by their differing aggregation state.
something to ponder i read in an old book (thanks cele!) take these words with how ever many grains of salt you wish.
The familial mutations, Gajdusek proposed, lowered the barrier to such accidental conversion. "Thus," he wrote in 1996, "with these mutations, this ordinarily rare event becomes a ... dominant inherited trait." But Weissmann's qualification still remained to be refuted: the mutations might simply allow easier entry to a lurking virus. ...page 202 Deadly Feast
something to think about for sure.
but i interpret this as (1st not the gold standard, just my opinion;-), as because of certain gene mutations, one or a family, would be more susceptible to the many different strains of TSE, and the many different proven routes and sources, (which will cause different symptoms, different incubation periods from onset of clinical symptoms to death, different parts of the brain infected, etc.). in other words, it's NOT the gene mutation that CAUSES the disease, but the fact that it makes you more SUSCEPTIBLE, to the TSEs from the surrounding environment, and PLUS accumulation, i think this plays a critical role. maybe there is a one dose scenario, but i think there is more of the 'accumulators' that go clinical, than the 'one dose'. and what is the threshold to sub-clinical to clinical ?
anyway, just pondering out loud here.
also, for anyone interested, there are some studies with links to follow here ;
Saturday, June 25, 2011
Transmissibility of BSE-L and Cattle-Adapted TME Prion Strain to Cynomolgus Macaque
"BSE-L in North America may have existed for decades"
Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME.
The rancher was a ''dead stock'' feeder using mostly (>95%) downer or dead dairy cattle...
Sunday, June 26, 2011
Risk Analysis of Low-Dose Prion Exposures in Cynomolgus Macaque
Thursday, June 23, 2011
Experimental H-type bovine spongiform encephalopathy characterized by plaques and glial- and stellate-type prion protein deposits
Thursday, July 21, 2011
A Second Case of Gerstmann-Sträussler-Scheinker Disease Linked to the G131V Mutation in the Prion Protein Gene in a Dutch Patient Journal of Neuropathology & Experimental Neurology:
August 2011 - Volume 70 - Issue 8 - pp 698-702
Saturday, August 14, 2010
BSE Case Associated with Prion Protein Gene Mutation (g-h-BSEalabama) and VPSPr PRIONPATHY
(see mad cow feed in COMMERCE IN ALABAMA...TSS)
Wednesday, June 15, 2011
Galveston, Texas - Isle port moves through thousands of heifers headed to Russia, none from Texas, Alabama, or Washington, due to BSE risk factor
Saturday, March 5, 2011
MAD COW ATYPICAL CJD PRION TSE CASES WITH CLASSIFICATIONS PENDING ON THE RISE IN NORTH AMERICA
Thursday, August 4, 2011
Terry Singeltary Sr. on the Creutzfeldt-Jakob Disease Public Health Crisis, Date aired: 27 Jun 2011