Úloha buněčného prionového proteinu v erytroidní diferenciaci

3 Abstrakt Buněčný prionový protein (PrPC ) je evolučně konzervovaný protein, exprimovaný na povrchu buněk různého původu. Přestože PrPC hraje zásadní roli v patogenezi neurodegenerativních chorob, jeho fyziologická funkce zůstává neznáma. Prionové choroby jsou charakteristické dlouhou dobou latence, během které nejsou diagnostikovatelné žádnou konvenční metodou. Krev by mohla být ideálním materiálem pro vývoj takových testů, bohužel vlastnosti PrPC na krevních buňkách a jeho funkce není dosud spolehlivě vysvětlena. Naše práce ukázala, že jednotlivé lidské červené krvinky exprimují pouze malé množství PrPC , ale vzhledem k počtu erytrocytů v krvi představuje tento protein většinu PrPC vázaného na krevní buňky. Na základě našich dat usuzujeme, že PrPC na povrchu erytrocytů je unikátně modifikován. Podobná modifikace by v případě patologického PrP mohla znesnadňovat diagnostiku prionových chorob z krve. Je prokázáno, že v průběhu prionových onemocnění dochází k deregulaci transkripce erytroidních genů a že PrP-/- myši mají oslabenou odpověď vůči experimentálně navozené anémii. Pro objasnění úlohy PrPC v erytropoéze jsme proto sledovali jeho expresi u myších erytroidních prekursorů in vitro i in vivo. Prokázali jsme, že v průběhu diferenciace buněk dochází k regulaci povrchové exprese PrPC na erytroidních...4 Abstract The cellular prion protein (PrPC ) is evolutionary conserved protein expressed in cells of various origins. Although PrPC plays a basic role in the pathogenesis of the fatal neurodegenerative prion disorders, its physiological role remains enigmatic. Prion diseases are characteristic by long latency period during which they are not identifiable by any conventional methods. Although the blood is an ideal material for developing of screening tests, little is known about traits of PrPC and its role in blood cells. We showed that human erythrocytes express low amounts of PrPC per cell, but due to the high numbers of erythrocytes, they are major contributors to the pool of blood cell-associated PrPC . Based on our biochemical characterization we propose that PrPC on human erythrocytes is uniquely modified. Such a modification in abnormal prion protein may complicate screening tests for prion diseases in blood. It was reported that prion diseases deregulate the transcription of erythroid genes, and PrP-/- mice demonstrate a defective response to experimental anemia. To investigate the role of the PrPC in erythropoiesis, we studied the protein's expression on mouse erythroid precursors in vivo and in vitro. We showed that surface expression of PrPC on erythroid precursors in bone marrow and spleen...Ústav imunologie a mikrobiologie 1. LF UK a VFNInstitute of Immunology and Microbiology First Faculty of Medicine and General University HospitalFirst Faculty of Medicine1. lékařská fakult

The invasion history, distribution and colour pattern forms of the harlequin ladybird beetle Harmonia axyridis (Pall.) (Coleoptera, Coccinellidae) in Slovakia, Central Europe

The harlequin ladybird beetle Harmonia axyridis (Coleoptera, Coccinellidae) has invaded and established in Slovakia. Following unintentional introduction in 2008, the spread of the alien coccinellid was very fast. By the end of 2009, it was recorded across the whole country, and by the end of 2012 it was widely distributed and common in various habitats, particularly gardens, orchards and urban areas, where it was most frequent on trees. The rate of eastward spread was approximately 200 km year-1, similar to the overall rate of spread in Europe. Between 2008 and 2012, the coccinellid was recorded in a total of 153 localities, in altitudes ranging from 98 to 1, 250 m. Most records of this species were made in lowlands, hilly areas and valleys separating mountain ridges. However, it was only rarely documented in areas above 700 m a.s.l. The non-melanic colour form (f. succinea) was dominant along a longitudinal transect including eight urban areas across Slovakia, with the frequency of melanic forms (f. spectabilis and f. conspicua together) between 6.3 and 19.2% and a median equal to 10.5%. The invasion history and distribution of H. axyridis in Slovakia are discussed with regard to the time sequence of records, rate of spread, altitudinal distribution, anthropogenic dispersal, effective recording, proportion of melanic forms and other relevant aspects associated with the spread of this successful invader

Overwintering of ladybirds (Coleoptera: Coccinellidae) on Scots pine in Central Europe

We surveyed ladybirds (Coleoptera: Coccinellidae) in 10 stands of Scots pine (Pinus sylvestris), all monoculture stands 5-100 years old, in western Slovakia, Central Europe, over two successive periods, October 2013 - March 2014 and October 2014 - March 2015. The winter in each period was exceptionally mild. Ladybirds were collected from the lower branches of pine trees using beating trays and were present in 61% of the 1040 samples (one sample containing ladybirds from 20 branches, 1 m long each). In total 3965 individuals of 20 species were recorded. Non-conifer dwelling species associated with broadleaved trees or herbaceous plants prevailed (45% of species), followed by conifer specialists (40%) and generalists (15%). Although 13 species were found at least in one winter month, December, January or February, only four of them, Exochomus quadripustulatus, Coccinella septempunctata, Harmonia axyridis and Hippodamia variegata, were recorded continually during both winters. The number of species, the abundance of all ladybirds and the abundance of dominant species (E. quadripustulatus, C. septempunctata and H. axyridis) decreased from late autumn towards winter and remained lowest during this most adverse time of the year for ladybirds. Overwintering species assemblages of ladybirds changed over time and varied with age of pine stand. Our results suggest that Scots pine in Central Europe supports species rich assemblages of ladybirds from late autumn to early spring and, being widely distributed, it could be suited to winter surveying of ladybirds at large spatial scales to reveal behavioural and ecological responses of species to changing weather or different climates

Ten years of invasion: Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) in Britain

1. Harmonia axyridis was first recorded in Britain in 2004. Two subsequent earlier records were received from 2003. 2. The UK Ladybird Survey, a citizen science initiative involving online recording, was launched in 2005 to encourage people across Britain to track the spread of H. axyridis. Tens of thousands of people have provided records of H. axyridis and other species of ladybirds, creating an invaluable dataset for large-scale and long-term research. Declines in the distribution of seven (of eight assessed) native species of ladybird have been demonstrated, and correlated with the arrival of H. axyridis, using the records collated through the UK Ladybird Survey. 3. Experimental research and field surveys have also contributed to our understanding of the ecology of H. axyridis and particularly the process of invasion. Harmonia axyridis arrived in Britain through dispersal and introduction events from regions in which it was deliberately released as a biological control agent. The rapid spread of this species has been attributed to its high natural dispersal capability by means of both flight and anthropogenic transport. A number of factors have contributed to the successful establishment and indeed dominance of this polymorphic species within aphidophagous guilds, including high reproductive capacity, intra-guild predation, eurytopic nature, high resistance to natural enemies within the invaded range, and potentially phenotypic plasticity. 4. The global invasion by H. axyridis and subsequent research on this species has contributed to the general understanding of biological invasions

Prion protein-specific antibodies that detect multiple TSE agents with high sensitivity

This paper describes the generation, characterisation and potential applications of a panel of novel anti-prion protein monoclonal antibodies (mAbs). The mAbs were generated by immunising PRNP null mice, using a variety of regimes, with a truncated form of recombinant ovine prion protein spanning residues 94–233. Epitopes of specific antibodies were mapped using solid-phase Pepscan analysis and clustered to four distinct regions within the PrP molecule. We have demonstrated the utility of these antibodies by use of Western blotting and immunohistochemistry in tissues from a range of different species affected by transmissible spongiform encephalopathy (TSE). In comparative tests against extensively-used and widely-published, commercially available antibodies, similar or improved results can be obtained using these new mAbs, specifically in terms of sensitivity of detection. Since many of these antibodies recognise native PrPC, they could also be applied to a broad range of immunoassays such as flow cytometry, DELFIA analysis or immunoprecipitation. We are using these reagents to increase our understanding of TSE pathogenesis and for use in potential diagnostic screening assays

The Role of Cellular Prion Protein in Erythroid Differentiation

4 Abstract The cellular prion protein (PrPC ) is evolutionary conserved protein expressed in cells of various origins. Although PrPC plays a basic role in the pathogenesis of the fatal neurodegenerative prion disorders, its physiological role remains enigmatic. Prion diseases are characteristic by long latency period during which they are not identifiable by any conventional methods. Although the blood is an ideal material for developing of screening tests, little is known about traits of PrPC and its role in blood cells. We showed that human erythrocytes express low amounts of PrPC per cell, but due to the high numbers of erythrocytes, they are major contributors to the pool of blood cell-associated PrPC . Based on our biochemical characterization we propose that PrPC on human erythrocytes is uniquely modified. Such a modification in abnormal prion protein may complicate screening tests for prion diseases in blood. It was reported that prion diseases deregulate the transcription of erythroid genes, and PrP-/- mice demonstrate a defective response to experimental anemia. To investigate the role of the PrPC in erythropoiesis, we studied the protein's expression on mouse erythroid precursors in vivo and in vitro. We showed that surface expression of PrPC on erythroid precursors in bone marrow and spleen..

The Role of Cellular Prion Protein in Erythroid Differentiation

4 Abstract The cellular prion protein (PrPC ) is evolutionary conserved protein expressed in cells of various origins. Although PrPC plays a basic role in the pathogenesis of the fatal neurodegenerative prion disorders, its physiological role remains enigmatic. Prion diseases are characteristic by long latency period during which they are not identifiable by any conventional methods. Although the blood is an ideal material for developing of screening tests, little is known about traits of PrPC and its role in blood cells. We showed that human erythrocytes express low amounts of PrPC per cell, but due to the high numbers of erythrocytes, they are major contributors to the pool of blood cell-associated PrPC . Based on our biochemical characterization we propose that PrPC on human erythrocytes is uniquely modified. Such a modification in abnormal prion protein may complicate screening tests for prion diseases in blood. It was reported that prion diseases deregulate the transcription of erythroid genes, and PrP-/- mice demonstrate a defective response to experimental anemia. To investigate the role of the PrPC in erythropoiesis, we studied the protein's expression on mouse erythroid precursors in vivo and in vitro. We showed that surface expression of PrPC on erythroid precursors in bone marrow and spleen..

Распространение и биономика Udea alpinalis (Lepidoptera, Pyralidae) в Западных Карпатах (Словакия)

В работе суммированы все известные и новые места находок Udea alpinalis (Denis et Schiffermuller, 1775) в Словакии. Кроме того, на основании наших данных обсуждается распространение, гипсометрические требования и вариабельность дизайна передних крыльев.Here we summarize all known and new localities with occurrence of Udea alpinalis (Denis et Schiffermüller, 1775) in Slovakia. Furthermore, based on our data we discuss distribution, hypsometric claims and variability of forewings design

Tagging and Capturing of Lentiviral Vectors Using Short RNAs

Lentiviral (LV) vectors have emerged as powerful tools for transgene delivery ex vivo but in vivo gene therapy applications involving LV vectors have faced a number of challenges, including the low efficiency of transgene delivery, a lack of tissue specificity, immunogenicity to both the product encoded by the transgene and the vector, and the inactivation of the vector by the human complement cascade. To mitigate these issues, several engineering approaches, involving the covalent modification of vector particles or the incorporation of specific protein domains into the vector’s envelope, have been tested. Short synthetic oligonucleotides, including aptamers bound to the surface of LV vectors, may provide a novel means with which to retarget LV vectors to specific cells and to shield these vectors from neutralization by sera. The purpose of this study was to develop strategies to tether nucleic acid sequences, including short RNA sequences, to LV vector particles in a specific and tight fashion. To bind short RNA sequences to LV vector particles, a bacteriophage lambda N protein-derived RNA binding domain (λN), fused to the measles virus hemagglutinin protein, was used. The λN protein bound RNA sequences bearing a boxB RNA hairpin. To test this approach, we used an RNA aptamer specific to the human epidermal growth factor receptor (EGFR), which was bound to LV vector particles via an RNA scaffold containing a boxB RNA motif. The results obtained confirmed that the EGFR-specific RNA aptamer bound to cells expressing EGFR and that the boxB containing the RNA scaffold was bound specifically to the λN RNA binding domain attached to the vector. These results show that LV vectors can be equipped with nucleic acid sequences to develop improved LV vectors for in vivo applications