Society for Neuroscience LA meeting: 10 Nov 98
Portugal meeting: 18 Nov 98
Washington DC meeting: 7-8 Dec 98
Taos NM 3-8 and 9-14th March 1999.
CJD Voice hosts meeting 13-15 June 1999
Thermodynamic stability of human prion P102L, D178N, E200K
Molecular classification of prion diseases without proteinase K
Presence of PrPc on epithelial cells of skin and mucous membranes
Titles of talks, slides, posters, speakers, and webmaster opinion as to substance
Molecular Biology of Prions Causing Neurodegeneration -- A Scientific Odyssey from Heresy to Orthodoxy S. B. Prusiner - Univ. Of California, San Francisco[Might just as well read the very long review article in the 10 Nov 98 PNAS. Won't be any research news reported.]
Slide 103.7: An Abnormal Isoform Of The Mutant Prion Protein In GSS Q217R Is Bound To The Chaperone Bip. Jin, T.; Zanusso, G.; Jing, Y.; Petersen, R.B.; Gambetti, P.; Singh, N.[Chaperone Bip, an endoplasmic reticulum lumen chaperone, has not been heard from before. The chaperone BiP/GRP78 binds to amyloid precursor protein and decreases Abeta40 and Abeta42 secretion. Proparathyroid hormone-related protein is associated with the chaperone protein BiP and undergoes proteasome-mediated degradation. Enhanced binding to the molecular chaperone BiP slows thyroglobulin export from the endoplasmic reticulum.
Poster 578.9: Early Induction Of Protein Nexin-i In Scrapie. Cavallaro, S.; Gibbs, C.J.; Pergami, P.[This sounds like another situation where proteins are identified that increase during the course of disease. These could be quite periferal to the main course of events and aren't necessarily therapeutic targets. Nexin-i has not been heard from before either; probalby a typo for nexin-1, a thrombin-inhibiting neurotrophic serpin protease located on human chromosome 2q33-q35.]
Slide 206.7: GSS Disease With Prnp A117V Mutation: Studies Of A New Family. Ghetti, B.; Young, K.; Piccardo, P.; Dlouhy, S.R.; Pahwa, R.; Lyons, K.E.; Koller, W.C.; Ma, M.J.; Decarli, C.; Rosenberg, R.N.[This is one of the most interesting point mutations because it is in the key cross-beta fibril region. The region has trouble passing through the ER after the valine substitution. A new pedigree is interesting because of possible new degrees of phenotypic variability, perhaps in conjunction with codon 129.]
Poster 578.3: An Insert Mutation In The Prp Gene In A French GSS Family With Psychiatric Features. El Hachimi, K.H.; Laplanche, J.L.; DestŠe, A.; Foncin, J.-f.[One supposes that this means extra copies of octapeptide repeats. It is not clear whether this is a new type. Psychiatric features suggests low copy number or early symptoms of onset, perhaps only 1-2 extra repeats as more cause severe disease.]
Poster 578.2: Physicochemical Properties Of Prion Protein In GSS Q212P. Piccardo, P.; Young, K.; William, A.; Kish, S.J.; Ang, L.C.; Bugiani, O.; Tagliavini, F.; Dlouhy, S.R.; Ghetti, B.[This is a new allele described recently in J Neuropathol Exp Neurol 1998 Oct;57(10):979-88 and so is of considerable interest.]
Poster 578.5: Purification Using Preparative Gel Electrophoresis And N-terminal Sequencing Of Prion Protein From Human Brains Affected With Prion Diseases. Zou, W.Q.; Parchi, P.; Gambetti, P.; Chen, S.G.[Hopefully they have determined what exactly is in prion fibrils. Probably ragged N-terminals will be found within each case and different N-terminals patterns in different cases. A common mistake is to think that different strains have the same covalent structure just because the whole gene did -- this study may show one way in which they don't. It is harder to get at C-terminals though mass spec now enables this. A very recent article on endogenous prion peptidases: Am J Pathol 1998 Nov;153(5):1561-72 ]
Poster 578.1: A Clinical Syndrome Similar To Familial Alzheimer's Disease Caused By A T183A Mutation Of The Prion Protein. Nitsch, R.M.; Mann, U.; Finckh, U.; Windl, O.; Becker, V.; MÐller-thomsen, T.; Growdon, J.H.; Naber, D.; Kretzschmar, H.A.; Gal, A.[This mutation knocks out the first glycosylation site. Another cross-over result making one wonder what the real incidence of CJD is, though T183A is rare as far as anyone knows]
Slide 301.7: Unexpected Spectrum And High Detection Rate Of Disease-causing Mutations In Patients With A Clinical Diagnosis Of Early Onset Familial Alzheimer Disease. Finckh, U.; Mann, U.; MÐller-thomsen, T.; Eggers, C.; Naber, D.; Nitsch, R.M.; Gal, A.[Not sure why meeting search engine returned this -- presumbably some mutations were in the prion gene. Nitsch is on the T183A paper as well. This would be more mis-diagnosis of Alzheimer but would not affect CJD statistics because FAD is quite rare.]
Poster 578.7: Yeast Prion Sup35p Forms Aggregates In Mammalian Cells. Kim, Y.G.; Lee, H.S.; Kwon, N.S.; Baek, K.J.; Yun, H.-y[Evidently some vector allowed the yeast protein to be made in mammalian cells and possibly a homologue of chaperone 104 allowed yeast fibril to form. Sup35 is a closer analogue of poly-glutamine repeat disorders than of prion disease.]
Slide 787.10: Scrapie Infected Mice And Prp Knockout Mice Share Abnormal Localization And Activity Of Neuronal Nitric Oxide Synthase. Keshet, G.I.; Ovadia, H.; Abramsky, O.; Gabizon, R.[Interesting. Nitric oxide, peroxynitrite, and superoxide anion may have involvement with normal prion function.]
Slide 206.11: Mitochondrial Dysfunction Induced By Oxidative Stress In The Brains Of Hamsters Infected With 263k Scrapie Agent. Kim, Y.S.; Choi, S.I.; Ju, W.K.; Choi, E.K.; Kim, J.; Lea, H.Z.; Carp, R.I.; Wisniewski, H.M.[This sounds like superoxide radical and is reminiscent of ALS.]
Slide 203.7: Prp And A-beta Share A Common Mechanism Of Metal-dependent Reactive Oxygen Species Production. Bush, A.I.; Tanzi, R.E.; Multhaup, G.; Hartshorn, M.; Saunders, A.J.; Atwood, C.S.; Huang, X.[Both proteins bind copper. Such proteins can generate superoxide radicals as a side-product or after partial denaturation. Neither has copper in the amyloid portion of its protein.]
Poster 573.2: Amyloidogenic Fragments Of The Human Prion And Beta-amyloid Proteins Activate A Neurotoxic Signaling Response In A Monocytic Cell Line. Combs, C.K.; Cannady, S.B.; Johnson, D.E.; Lehman, T.M.; Landreth, G.E[This could have to do with pathways leading to neuronal cell death but it does not sound like an early-on event.]
Poster 578.6: Ultrastructural Localization Of Cellular Prion Protein At The Neuromuscular Junction. Gohel, C.; Grigoriev, V.; Escaig-hay, F.; Lasmezas, C.I.; Deslys, J.-p.; Langeveld, J.; Akaaboune, M.; Hanta¦, D.; Fournier, J.-g.[There has been earlier work on this location, eg Neuroscience Letters 159:111-114 1993. It does not bode well for meat-eaters because all beef has neuromuscular junctions. It does support the idea of a neural function for prion protein even when it is found outside the brain, though more work is needed on placenta, the second highest tissue.]
Slide 206.10: Prion Protein Modulates Ca2+-activated K+-currents In Cerebellar Purkinje Cells. Herms, J.W.; Tings, T.; Dunker, S.; Kretzschmar, H.A.J Neurosci Res 1998 Nov 1;54(3):341-52 has an article titled 'Prion protein fragment 106-126 induces apoptotic cell death and impairment of L-type voltage-sensitive calcium channel activity in the GH3 cell line.
Poster 578.8: Impairment Of Calcium Homeostasis Is Responsible For The Prion Protein Fragment 106-126-dependent Cell Death. Florio, T.; Thellung, S.; Amico, C.; Robello, M.; Salmona, M.; Bugiani, O.; Tagliavini, F.; Forloni, G.; Schettini, G.
Poster 578.4: Intrinsic Properties Of Ca1 Pyramidal Cells From Mice Homozygous Or Heterozygous For Prp Null Alleles. Li, Y.-g.; Collinge, J.; Jefferys, J.G.R.
Poster 573.12: Alzheimer's Beta-amyloid Protein Prion Protein Fragment, And Islet Amyloid Peptide Cause The Increase Of Intracellular Calcium In Neuronal Cells. Kawahara, M.; Kuroda, Y.
Poster 578.10: Abnormalities Of Plasma Membrane Structure And Function In Scrapie-infected Syrian Hamsters. Bouzamondo, E.; Spilman, P.; Dearmond, S.; Ralston, H.J.[Numerous earlier studies on this. No evidence so far that it is a primary change. Usually involves lipid rafts.]
Poster 578.11: F-18 Pet In Sporadic Creutzfeldt-jakob Disease. Kim, S.E.; Na, D.L.; Choi, J.Y.; Kim, B.-t.[Sounds like an effort to bring in tomography as a tool for diagnosis of sporadic CJD. Not suitable for mass screening, but non-invasive. So far these approaches and nmr have not lead to decisive methods.]
Poster 775.12: Abnormal Periodic Acid-schiff-positive Substance In The Islets Of Langerhans, Pituitaries And Adrenal Glands Of 139H-infected Hamsters. Ye, X.; Scallet, A.; Carp, R.I.[Hard to say what PAS+ would mean per se. Presumbably they looked at it with the usual bank of IHC antibodies.]
November 18th, 1998. Hotel Ritz, Lisbon, Portugal Contact: Cambridge Healthtech Inst. 1037 Chestnut St, Newton Upper Falls, MA 02464, USA Web Tel: 617-630-1300.
Speakers:
Moira Bruce. Evidence that nvCJD and BSE are caused by the same TSE strain.
Rob Will. nvCJD
Michael Klein. Involvement of B-cells in neuroinvasive scrapie
Cornelia van Duijn. Case controlstudy of risk factors of CJD in europe.
Bruo Oesch. Immunological diagnostics of prion diseases.
Martin Wisher. Experience in the validation of purification processes for TSE removal and inactivation.
Andrew Baily. Strategies for validation of biophamaceutical processes for the removal of TSEs.
Ian MacGregor. Time resolved fluorimetry for cellular prion protein in human blood and its components
Jean-Jaques Morgenthaler. Partitioning of the TSE agent during ethanol fractionation of plasma
Sakae Sitoh. TSE removal by filtration.
Terence Snape. TSEs and their mpact on the plasma fractionation industry
December 7-8th 1998. at the Westin City Center Hotel, Washington DC meeting Organised by NMHCC. Contact Elizabeth Lamb, conference producer on 207-492-1861 or fax 207-493-4573
Speakers:
Bruce Chesebro: Multiple roles of PrP in the pathogenesis of TSE
Maura Ricketts: Report on the Ottawa meeting: CJD recalls, withdrawals and recipient notification policy
Hellman K, and William Hueston: JIFSAN wordshop on TSE risks in source materials, processing, end-product use.
David Asher: Updates on recent FDA biological and device regulations and courses of action relevant to TSEs
Rob Rohwer: Titre; distribution and transfusibility of blood borne infectivity in rodent TSE models
Dealler S.: Looking for drugs that may inactivate TSE
Bucher William: Minimizing the risk of TSE in production of monoclonal antibodies
Jeri Ann Boose: Validation of biopharmaceutical purification processes fo the clearance of TSE agents
Alan Moore: TSE clearance utilizing scrapie as surrogate for BSE and CJD
Andrew Bailey: Strategies for validation of biopharmaceutical processes for removal of TSEs
Bruno Oesch: Validation and application of Prionics western blot test for diagnostis of BSE
John Honstead: Keeping biologicals source animals TSE-free through proactive regulation.
Marshall Franklin: Definitions in the collection of biological materials: fact, fallacy and feasibility.
Paul Haffenden: Controlled, isolated herd, donor bovine serum in cell cultured therapeutic products.
Kelly Lechtenburg: Source animal verification: methods and application of quality assurance.
Keystone Symposia. Organizers: Bruce Yanker and Dennis Selkoe.
9th-14th March 1999. Keystone Symposia to be held at Sagebrush Inn, Taos, New Mexico. Organizers: W. Ian Lipkin, Opendra Narayan, William Hickey and Maggie So. TSE session is on Sat Mar 13 8-11am
Multiple roles of PrP in Pathogenesis of Scrapie. Bruce Chesebro
Mechanisms of cell death in TSE diseases Hanz Kretzchmar
Prions and the immune system Adriano Aguzzi
Robin 10 Nov 98 web siteInternet meeting on CJD for people that may have been affected:
"Our conference will be held on the Campus of Indiana University in Bloomington Indiana on June 13th through the 15th, 1999. It is open to anyone who has been affected by CJD. Either by blood recall notices, human growth hormone treatments or the disease itself. So far the people who have been interested to speak are Steven Dealler...Claudio Soto.....Howard Lyman.....Michael Hansen.....Tom Pringle.
I am still sending out invites too. Most people have to wait till it gets closer to the time to see what they will be doing. Hopefully everyone will be able to make it....it would be very interesting then."
Indiana University Bloomington, IN check-in....Sunday, June 13, 1999 check- out....Tuesday, June 15, 1999
JBC Vol. 273,#47 November 20, pp. 31048‚31052, 1998 Wieslaw Swietnicki, Robert B. Petersen, Pierluigi Gambetti, and Witold K. SurewiczHereditary forms of human prion disease are linked to specific mutations in the PRNP gene. It has been postulated that these mutations may facilitate the pathogenic process by reducing the stability of the prion protein (PrP). To test this hypothesis, we characterized the recombinant variants of human PrP(90-231) containing point mutations corresponding to Gerstmann-Straussler-Scheinker disease (P102L), Creutzfeld-Jakob disease (E200K), and fatal familial insomnia (M129/D178N).
The first two of these mutants could be recovered form from the periplasmic space of E. coli in a soluble form, whereas the D178N variant aggregated into inclusion bodies.
The secondary structure of the two soluble variants was essentially identical to that of the wild-type protein. The thermodynamic stability of these mutants was assessed by unfolding in guanidine hydrochloride and thermal denaturation. The stability properties of the P102L variant were indistinguishable from those of wild-type PrP, whereas the E200K mutation resulted in a very small destabilization of the protein. These data, together with the predictive analysis of other familial mutations, indicate that some hereditary forms of prion disease cannot be rationalized using the concept of mutation-induced thermodynamic destabilization of the cellular prion protein.
Comment based on full text (webmaster):
The results on P102L, D178N, E200K are thoroughly incompatible with simple-minded scenarios that would attribute mutational effects to protein folding destablization.. The known 22 point mutations are generally mild, while many others that would potentially be far more destabilizing thermodynamically are not detected. That is, D178Y or D178V are also just single base transitions but they would be much more destabalizing under most circumstances. And why these sites and not others? -- any buried tryptophan to arginine would supply a thermodynamic wallop.
Mutations must be autosomal dominant, autosomal recessives are too rare to show up. This may amount to a very subtle requirement that balances conflicting needs. If the protein is too far off, it may just be rapidly degraded. This paper indirectly provides support for misfolding and mis-topology at the ER as the primary event getting the protein off on a bad track. Chaperone Bip, an endoplasmic reticulum lumen chaperone, may play a role here.
While not practicable at this time, it would be infinitely preferable on thermodynamic studies to use intact holo-protein with a full set of post-translational modifications and prosthetic groups. Grown in E. coli, the arginine and two glycosyl modifications are missing along with copper and GPI. That's too much.
Am J Pathol 1998 Nov;153(5):1561-72 Jimenez-Huete A, Lievens PM, Vidal R, Piccardo P, Ghetti B, Tagliavini F, Frangione B, Prelli F
We have investigated the proteolytic cleavage of the cellular (PrPC) and pathological (PrPSc) isoforms of the human prion protein (PrP) in normal and prion-affected brains and in tonsils and platelets from neurologically intact individuals. The various PrP species were resolved after deglycosylation according to their electrophoretic mobility, immunoreactivity, Sarkosyl solubility, and, as a novel approach, resistance to endogenous proteases.
First, our data show that PrPC proteolysis in brain originates amino-truncated peptides of 21 to 22 and 18 (C1) kd that are similar in different regions and are not modified by the PrP codon 129 genotype, a polymorphism that affects the expression of prion disorders.
Second, this proteolytic cleavage of PrPC in brain is blocked by inhibitors of metalloproteases.
Third, differences in PrPC proteolysis, and probably in Asn glycosylation and glycosylphosphatidylinositol anchor composition, exist between neural and non-neural tissues.
Fourth, protease-resistant PrPSc cores in sporadic CJD) and GSS F198S disease brains all have an intact C1 cleavage site (Met111-His112), which precludes disruption of a domain associated with toxicity and fibrillogenesis.
Fifth, the profile of endogenous proteolytic PrPSc peptides is characteristic of each disorder studied, thus permitting the molecular classification of these prion diseases without the use of proteinase K and even a recognition of PrPSc heterogeneity within type 2 CJD patients having different codon 129 genotype and neuropathological phenotype. This does not exclude the role of additional factors in phenotypic expression; in particular, differences in glycosylation that may be especially relevant in the new variant CJD.
Proteolytic processing of PrP may play an important role in the neurotropism and phenotypic expression of prion diseases, but it does not appear to participate in disease susceptibility.
Comment (webmaster):
The abstract needs clarification. C1r and C1s form a tetrameric serine protease at the beginning of the complement cascade; complement activation by beta-amyloid may be a contributing pathway to Alzheimer neuropathology. Platelets contain C1 serine protease inhibitor in secretory granules which normally regulates complement. The N-terminal CUB domain and the EGF-like domain of C1r are responsible for the calcium dependent C1r-C1s interaction. The substrate specificity of the serine-protease is determined by five repeats at the N-terminal noncatalytic domain. Glial cells in rats express a serine protease homologous to complement C1s precursor. Its expression profile is correlated with glial fibrillary acidic protein and S100B. Hereditary deficiency of C1-esterase inhibitor function is called hereditary angioedema (HAE)
Pammer J, Weninger W, Tschachler E Am J Pathol 1998 Nov;153(5):1353-8Prion diseases are transmissible spongiform encephalopathies of humans and animals characterized by the accumulation of a proteinase-resistant isoform of the cellular prion-related protein (PrPc) within the central nervous system. In the present report we demonstrate for the first time the presence of PrPc on squamous epithelia of normal and diseased human skin and show that inflammatory cytokines regulate PrPc expression in cultured human keratinocytes (KCs). By immunohistochemistry, only little expression of PrPc, which was mainly confined to KCs, was detected in normal skin.
In contrast, in inflammatory skin diseases including psoriasis and contact dermatitis, PrPc was strongly present on both KCs and infiltrating mononuclear cells. Strong PrPc expression was also observed in squamous cell carcinomas and viral warts whereas basal cell carcinomas were mostly negative.
In mucous membranes of the upper digestive tract and the genital region, distinct PrPc expression by basal squamous epithelial cells was a constant feature. In tissue culture, primary KCs constitutively expressed PrPc mRNA and protein. Exposure of these cells to transforming growth factor (TGF)-alpha or interferon (IFN)-gamma led to an increase of PrPc protein expression.
The presence of PrPc on epithelial cells of skin and mucous membranes suggests that these cells represent possible first targets for peripheral infection with prions.
Race R, Jenny A, Sutton D J Infect Dis 1998 Oct;178(4):949-53Probable transmission of bovine spongiform encephalopathy to humans has focused intense interest on all of the transmissible spongiform encephalopathies (TSEs) and how they spread. In all TSEs, an abnormal disease-associated, proteinase K-resistant protein referred to as PrP-res or PrPsc accumulates in brain. In some species, PrP-res accumulates in other tissues as well. Sheep placenta, brain, spleen, and lymph node were analyzed in detail for PrP-res and infectivity. Both were detected in all brain and spleen samples and in placenta and lymph nodes of 80% of the scrapie-infected sheep. A perfect correlation was observed between infectivity and PrP-res detection.
These results substantiate the probability that placenta plays an important role in natural transmission of scrapie, suggest that analysis of placenta for PrP-res could be the basis for an antemortem test for sheep scrapie, and show that PrP-res, scrapie infectivity, and scrapie disease are closely associated.