Misfolding and aggregation of prion protein (PrP) causes neurodegenerative diseases like Creutzfeldt-Jakob disease (CJD) and scrapie. Besides the consensus that spontaneous conversion of normal cellular PrPC into misfolded and aggregating PrPSc is the central event in prion disease, an alternative hypothesis suggests the generation of pathological PrPSc by rare translational frameshifting events in the octa-repeat domain of the PrP mRNA. Ribosomal frameshifting most commonly relies on a slippery site and an adjacent stable RNA structure to stall translating ribosome. Hence, it is crucial to unravel the secondary structure of the octa-repeat domain of PrP mRNA. Each of the five octa-repeats contains a motif (GGCGGUGGUGGCUGGG) which alone in vitro forms a G-quadruplex. Since the propensity of mRNA to form secondary structure depends on the sequence context, we set to determine the structure of the complete octa-repeat region. We assessed the structure of full-length octa-repeat domain of PrP mRNA using dynamic light scattering (DLS), small angle X-ray scattering (SAXS), circular dichroism (CD) spectroscopy and selective 2'-hydroxyl acylation analysis by primer extension (SHAPE). Our data show that the PrP octa-repeat mRNA forms stable A-helical hairpins with no evidence of G-quadruplex structure even in the presence of G-quadruplex stabilizing agents.

• MeSH
• cirkulární dichroismus MeSH
• difrakce rentgenového záření MeSH
• dynamický rozptyl světla MeSH
• G-kvadruplexy MeSH
• HeLa buňky MeSH
• lidé MeSH
• maloúhlový rozptyl MeSH
• messenger RNA chemie   MeSH
• mutace * MeSH
• obrácené repetice MeSH
• prionová bílkovina chemie   genetika   MeSH
• sekvence aminokyselin MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Alzheimer's disease (AD) and sporadic Creutzfeldt-Jakob disease (sCJD) are both characterized by extracellular pathologically conformed aggregates of amyloid proteins-amyloid β-protein (Aβ) and prion protein (PrPSc), respectively. To investigate the potential morphological colocalization of Aβ and PrPSc aggregates, we examined the hippocampal regions (archicortex and neocortex) of 20 subjects with confirmed comorbid AD and sCJD using neurohistopathological analyses, immunohistochemical methods, and confocal fluorescent microscopy. Our data showed that extracellular Aβ and PrPSc aggregates tended to be, in most cases, located separately, and "compound" plaques were relatively rare. We observed PrPSc plaque-like structures in the periphery of the non-compact parts of Aβ plaques, as well as in tau protein-positive dystrophic structures. The AD ABC score according to the NIA-Alzheimer's association guidelines, and prion protein subtype with codon 129 methionine-valine (M/V) polymorphisms in sCJD, while representing key characteristics of these diseases, did not correlate with the morphology of the Aβ/PrPSc co-aggregates. However, our data showed that PrPSc aggregation could dominate during co-aggregation with non-compact Aβ in the periphery of Aβ plaques.

• MeSH
• Alzheimerova nemoc patologie   MeSH
• amyloidní beta-protein genetika   metabolismus   MeSH
• amyloidní plaky patologie   MeSH
• Creutzfeldtova-Jakobova nemoc patologie   MeSH
• extracelulární prostor chemie   MeSH
• jednonukleotidový polymorfismus genetika   MeSH
• kodon genetika   MeSH
• komorbidita MeSH
• lidé středního věku MeSH
• lidé MeSH
• mozek patologie   MeSH
• neurony patologie   MeSH
• pilotní projekty MeSH
• proteinové agregáty * MeSH
• proteiny tau metabolismus   MeSH
• PrPSc proteiny genetika   metabolismus   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Dva nedávno publikované případy pravděpodobného přenosu variantní Creutzfeldt-Jakobovy choroby krevní transfuzí v Anglii razantně upozornily na nezbytnost vývoje preklinického diagnostického testu pro prionové choroby. Jediným známým, skutečně specifickým znakem prionových chorob je přítomnost patologické izofoty prionového proteinu, PrPsc. Detekce PrPsc je komplikována jeho antigenní podobností s běžně se vyskytujícím normálním buněčným prionovým proteinem, PrPc. Existuje řada komerčních testů umožňujících post-mortem diagnostiku „nemoci šílených krav“ detekcí PrPsc v mozkovém homogenitu, avšak není dostupný žádný test, který by umožňoval preklinickou diagnostiku prionových chorob analýzou periferní tkáně. V průběhu posledních pěti let byl učiněn velký pokrok ve zvýšení citlivosti a specificity současných metod detekce PrPsc. Navíc byly popsány nové možnosti jeho detekce a nové analytické molekuly, včetně PrPsc specifických protilátek a syntetických ligandů. Je pravděpodobné, že správná kombinace existujících nástrojů a technologií by mohla vést k vytvoření dlouho očekávaného krevního testu pro detekci prionových chorob.

Two recently reported cases of variant Creutzfeldt-Jakob disease transmission by blood transfusion in England emphasize the pressing need for preclinical diagnostic test for prion diseases. The abnormal isoform of prion protein, PrPsc, is currently the only specific marker of prion diseases, but its detection poses significant laboratory challenge due to its antigenic similarity to the normal cellular prion protein, PrPc. Number of rapid commercial tests for PrPsc detection in brain samples is available for post-mortem diagnosis of bovine spongiform encephalopathy and scrapie, but at present no test utilizing peripheral tissue is available for preclinical diagnosis of animal and human prion diseases. Remarkable progress has been done in improving of sensitivity and specificity of current tests of PrPsc detection. In addition new detection strategies and analytical molecules, including PrPsc specific antibodies and synthetic ligands, have been described. Very likely the right combination of existing tools and technologies may result in the development of longawaited blood screening test for prion diseases.

• MeSH
• Creutzfeldtova-Jakobova nemoc diagnóza   epidemiologie   MeSH
• diagnostické techniky neurologické klasifikace   využití   MeSH
• encefalopatie bovinní spongioformní diagnóza   epidemiologie   MeSH
• Evropská unie MeSH
• finanční podpora výzkumu jako téma MeSH
• hematologické testy škodlivé účinky   trendy   využití   MeSH
• krevní transfuze MeSH
• lidé MeSH
• potransfuzní reakce MeSH
• priony chemie   krev   MeSH
• transplantace škodlivé účinky   MeSH
• Check Tag
• lidé MeSH

Intra-thymic T cell development is coordinated by the regulatory actions of SATB1 genome organizer. In this report, we show that SATB1 is involved in the regulation of transcription and splicing, both of which displayed deregulation in Satb1 knockout murine thymocytes. More importantly, we characterized a novel SATB1 protein isoform and described its distinct biophysical behavior, implicating potential functional differences compared to the commonly studied isoform. SATB1 utilized its prion-like domains to transition through liquid-like states to aggregated structures. This behavior was dependent on protein concentration as well as phosphorylation and interaction with nuclear RNA. Notably, the long SATB1 isoform was more prone to aggregate following phase separation. Thus, the tight regulation of SATB1 isoforms expression levels alongside with protein post-translational modifications, are imperative for SATB1's mode of action in T cell development. Our data indicate that deregulation of these processes may also be linked to disorders such as cancer.

• Publikační typ
• časopisecké články MeSH

Neurodegenerative diseases are characterized by the deposition of specific protein aggregates, both intracellularly and/or extracellularly, depending on the type of disease. The extracellular occurrence of tridimensional structures formed by amyloidogenic proteins defines Alzheimer's disease, in which plaques are composed of amyloid β-protein, while in prionoses, the same term "amyloid" refers to the amyloid prion protein. In this review, we focused on providing a detailed didactic description and differentiation of diffuse, neuritic, and burnt-out plaques found in Alzheimer's disease and kuru-like, florid, multicentric, and neuritic plaques in human transmissible spongiform encephalopathies, followed by a systematic classification of the morphological similarities and differences between the extracellular amyloid deposits in these disorders. Both conditions are accompanied by the extracellular deposits that share certain signs, including neuritic degeneration, suggesting a particular role for amyloid protein toxicity.

• MeSH
• Alzheimerova nemoc metabolismus   MeSH
• amyloid metabolismus   MeSH
• amyloidní beta-protein metabolismus   MeSH
• amyloidní plaky metabolismus   MeSH
• amyloidogenní proteiny metabolismus   MeSH
• amyloidóza metabolismus   MeSH
• Creutzfeldtova-Jakobova nemoc metabolismus   MeSH
• lidé MeSH
• mozek metabolismus   patologie   MeSH
• neurity metabolismus   patologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

BACKGROUND: Recent transmissions of variant Creutzfeldt-Jakob disease by blood transfusion emphasize the need for the development of prion screening tests. The detection of prions in blood is complicated by the presence of poorly characterized cellular prion protein (PrP(C) ) in both plasma and blood cells. According to published studies, most of PrP(C) in blood cells resides in platelets (PLTs) and white blood cells. STUDY DESIGN AND METHODS: To clarify conflicting reports about the quantity of PrP(C) associated with human red blood cells (RBCs), quantitative flow cytometry, Western blot (WB), and enzyme-linked immunosorbent assay (ELISA) were used to measure protein levels in healthy donors. RESULTS: RBCs expressed 290 ± 140 molecules of PrP(C) per cell, assuming equimolar binding of monoclonal antibody (MoAb) 6H4 to PrP(C). Binding of alternate PrP(C) MoAbs, FH11 and 3F4, was substantially lower. WB estimated the level of PrP(C) per cell on RBCs to be just four times lower than in PLTs. A similar level of PrP(C) was detected using ELISA. The weak binding of commonly used MoAb 3F4 was not caused by PrP(C) conformation, truncation, or glycosylation, suggesting a covalent modification, likely glycation, of the 3F4 epitope. CONCLUSIONS: Taken together, human RBCs express low but significant amounts of PrP(C) /cell, which makes them, due to high RBC numbers, major contributors to the pool of cell-associated PrP(C) in blood. Previous reports utilizing MoAb 3F4 may have underestimated the amount of PrP(C) in RBCs. Likewise, screening tests for the presence of the abnormal prion protein in blood may be difficult if the abnormal protein is modified similar to RBC PrP(C).

• MeSH
• Creutzfeldtova-Jakobova nemoc metabolismus   prevence a kontrola   přenos   MeSH
• ELISA MeSH
• epitopy imunologie   MeSH
• erytrocytární membrána metabolismus   MeSH
• erytrocyty metabolismus   MeSH
• glykosylace MeSH
• krevní transfuze MeSH
• lidé MeSH
• monoklonální protilátky imunologie   MeSH
• plošný screening metody   MeSH
• potransfuzní reakce MeSH
• PrPC proteiny imunologie   metabolismus   MeSH
• průtoková cytometrie MeSH
• western blotting MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In this study we attempted to characterize cellular prion-like protein (PrPC) properties and its possible interactions with metal ions. In the first part of this study we described the structure of prion-like protein, its biochemical properties and its role in human or animal organism. In the next and the most important part we summarized accessible information about the metals and heavy metals which can bind prion-like protein. Especially the heavy metals could have really important role in the process of protein misfolding, but this role is still unknown. In the last section we focused on transmissible spongiform encephalopathies, their incubation period and clinical signs.

• MeSH
• kadmium MeSH
• kovy MeSH
• lidé MeSH
• měď MeSH
• prionové nemoci * MeSH
• priony * MeSH
• PrPC proteiny metabolismus   MeSH
• PrPSc proteiny metabolismus   patogenita   MeSH
• těžké kovy * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH
• přehledy MeSH

Creutzfeldtova-Jakobova choroba (CJch) patrí medzi prionové ochorenia, smrteľné neurodegeneratívne ochorenia, postihujúce tak ľudí, ako aj zvieratá. Sú charakterizované konverziou bunkového prionového proteínu PrPC na abnormálnu, nerozpustnú a čiastočne proteázo-rezistentnú izoformu nazývanú scrapie priónový proteín (PrPSC). Gén pre syntézu celulárneho PrP človeka (PRNP) je lokalizovaný na krátkom ramienku chromozómu 20. Rozlišujeme niekoľko foriem CJch, najčastejšou formou CJch je sporadická Creutzfeldtova-Jakobova choroba (sCJch), ktorá sa vyskytuje asi u 85 % pacientov, zriedkavejšie sa vyskytuje genetická forma (gCJch), ktorá vzniká na základe rôznych typov mutácií (bodové mutácie, inzercie, delécie), pri výskyte u viac ako dvoch členov rodiny sa označuje ako familiárna forma (fCJch). Iatrogénna (iCJch), v súčasnosti označovaná ako náhodne prenesená (accidentally transmitted), vznikla prenosom z človeka na človeka kontaminovanými transplantátmi alebo nástrojmi. Nový variant (vCJch) bol prvýkrát popísaný vo Veľkej Británii v roku 1996 a vznikol s vysokou pravdepodobnosťou prenosom z hovädzieho dobytka pri „chorobe šialených kráv“ – bovinnej spongiformnej encefalopatii (BSE).

Creutzfeldt-Jacob disease (CJD) is a prion disease. Prion diseases are fatal neurodegenerative conditions affecting humans and a wide variety of animals. In prion diseases, normal, cellular protein (PrPC) is converted into insoluble, protease-resistant scrapie prion protein (PrPSC). PrP is encoded by the prion protein gene (PRNP) localised on the short arm of chromosome 20. There are several forms of CJD, sporadic CJD (sCJD), seen in about 85% of patients, being the most common one. Some cases are genetic (gCJD) that occur as a consequence of va­rious mutations (including point mutations, insertions and deletions); when the mutation is present in more than two members of a family, the disease is called familial (fCJD). Remaining two forms, i.e. iatrogenic CJD (iCJD) and variant CJD (vCJD), are acquired. iCJD (now called accidentally transmitted) is acquired through contaminated transplants and instruments. vCJD is a novel form of human prion disease first reported in the United Kingdom in 1996. It is likely that bovine prions from „mad cows“, affected with bovine spongiform encefalopathy (BSE), were passed to humans through consumption of beef products from affected animals.

• Klíčová slova
• prionový protein, magnetická rezonance, elektro­encefalografie, protein 14-3-3,
• MeSH
• ataxie MeSH
• biopsie metody   normy   MeSH
• Creutzfeldtova-Jakobova nemoc * diagnóza   genetika   klasifikace   patofyziologie   patologie   MeSH
• demence MeSH
• diferenciální diagnóza MeSH
• elektroencefalografie MeSH
• genetické testování etika   MeSH
• haplotypy MeSH
• histologické techniky MeSH
• kognitivní poruchy MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• mozek radiografie   MeSH
• mutace genetika   MeSH
• neurologické manifestace MeSH
• odběr biologického vzorku metody   normy   MeSH
• priony genetika   MeSH
• proteiny 14-3-3 MeSH
• Check Tag
• lidé MeSH

• MeSH
• DNA genetika   MeSH
• genetické jevy MeSH
• genom MeSH
• geny fyziologie   MeSH
• proteiny genetika   MeSH
• RNA genetika   MeSH
• Publikační typ
• monografie MeSH

• Konspekt
• Obecná genetika. Obecná cytogenetika. Evoluce
• NLK Obory
• genetika, lékařská genetika

Prions are suspected as causative agents of several neuropathogenic diseases, even though the mode of their action is still not clear. A combination of chemical and recombinant syntheses can provide suitable probes for explanation of prions role in pathogenesis of neurodegenerative diseases. However, the prions contain several difficult sequences for synthesis by Fmoc/tBu approach. For that reason, the peptide thioesters as the key building blocks for chemical syntheses of proteins by native chemical ligation were employed. A scan of the mouse prion domain 93-231 was carried out in order to discover availability of derived thioesters as the suitable building blocks for a total chemical synthesis of the prion protein based probes. The synthesis on 2-chlorotritylchloride resin was utilized and after a deprotection of the samples for analysis, the peptide segments were purified and characterized. If the problems were detected during the synthesis, the segment was re-synthesized either using the special pseudoproline dipeptides or by splitting its molecule to two or three smaller segments, which were prepared easier. The protected segments, prepared correctly without any deletion and in sufficient amounts, were coupled either with EtSH after DIC/DMAP activation or with p-Ac-NH-Ph-SH using PyBOP activation to yield corresponding thioesters. In some special cases, the other techniques of thioester formation, like sulfonamide-safety catch and/or trimethylaluminium approach were utilized.

• MeSH
• estery chemická syntéza   chemie   MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• myši MeSH
• peptidové fragmenty chemická syntéza   chemie   MeSH
• priony chemická syntéza   chemie   MeSH
• proteolýza MeSH
• sekvence aminokyselin MeSH
• sulfidy chemická syntéza   chemie   MeSH
• techniky syntézy na pevné fázi MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH