Search the repository

A+ | A- | | SLO | ENG

Abstract: The cancer stem cell model suggests that glioblastomas contain a subpopulation of stem-like tumor cells that reproduce themselves to sustain tumor growth. Targeting these cells thus represents a novel treatment strategy and therefore more specific markers that characterize glioblastoma stem cells need to be identified. In the present study, we performed transcriptomic analysis of glioblastoma tissues compared to normal brain tissues revealing sensible up-regulation of CD9 gene. CD9 encodes the transmembrane protein tetraspanin which is involved in tumor cell invasion, apoptosis and resistance to chemotherapy. Using the public REMBRANDT database for brain tumors, we confirmed the prognostic value of CD9, whereby a more than two fold up-regulation correlates with shorter patient survival. We validated CD9 gene and protein expression showing selective up-regulation in glioblastoma stem cells isolated from primary biopsies and in primary organotypic glioblastoma spheroids as well as in U87-MG and U373 glioblastoma cell lines. In contrast, no or low CD9 gene expression was observed in normal human astrocytes, normal brain tissue and neural stem cells. CD9 silencing in three CD133+ glioblastoma cell lines (NCH644, NCH421k and NCH660h) led to decreased cell proliferation, survival, invasion, and self-renewal ability, and altered expression of the stem-cell markers CD133, nestin and SOX2. Moreover, CD9-silenced glioblastoma stem cells showed altered activation patterns of the Akt, MapK and Stat3 signaling transducers. Orthotopic xenotransplantation of CD9-silenced glioblastoma stem cells into nude rats promoted prolonged survival. Therefore, CD9 should be further evaluated as a target for glioblastoma treatment.
Keywords: biomarker, CD9, glioblastoma stem cells, neural stem cells, tetraspanin
Published in DiRROS: 26.07.2024; Views: 285; Downloads: 187
Full text (6,28 MB)
This document has many files! More...

Abstract: In 2015, 170 bird species were recorded during bird ringing activities in Slovenia. We ringed 73,371 birds belonging to 162 species, there were 132 foreign recoveries of birds ringed in Slovenia, 120 recoveries of birds ringed abroad and found in Slovenia, as well as 1964 local recoveries. The most frequently ringed species were Blackcap Sylvia atricapilla and Great Tit Parus major. In ringed nestlings, Great Tits and Tree Sparrows Passer montanus predominated. In 2015, the first preliminary ringing of Scops Owls Otus scops during migration took place, resulting in the highest number of Scops Owls ringed so far. Concerning recoveries of birds ringed in Slovenia and later recorded abroad and birds ringed abroad and later recorded in Slovenia, the commonest were Mute Swans Cygnus olor and Black-headed Gulls Chroicocephalus ridibundus. The longest-distance recovery concerned a Reed Bunting Emberiza schoeniculus found in Sweden (2,144 km away). Among the interesting finds were also the first finds of ringed Pygmy Cormorants Microcarbo pygmeus so far from breeding sites in Hungary. Among rare species, Yellow-browed Warbler Phylloscopus inornatus, Spanish Sparrow Passer hispaniolensis and a pair of Parrot Crossbills Loxia pytyopsittacus were caught and ringed, the latter for the very first time in Slovenia after more than 100 years. An overview of records of the Parrot Crossbill is given herein, as well as analysis of irruptive years of the Red Crossbills Loxia curvirostra between 1980 and 2015, when the probability of boreal Crossbill species occurrence is the highest. According to the ringers’ data, the irruptive years of Red Crossbills in Slovenia were 1984, 1985, 2007, 2008, 2010, 2011 and 2012. The article points to the probability that Parrot Crossbills have been overlooked in the past, since larger specimens of Crossbills were ringed mostly in irruptive years, but no specific bill measurements important for distinguishing between Parrot and Red Crossbill had been taken.
Keywords: obročkanje, najdbe, Slovenija, 2015, veliki krivokljun
Published in DiRROS: 26.07.2024; Views: 320; Downloads: 136
Full text (629,08 KB)
This document has many files! More...

Abstract: Background Omics approaches have significantly increased our understanding of biological systems. However, they have had limited success in explaining the dramatically increased productivity of commercially important natural products by industrial high-producing strains, such as the erythromycin-producing actinomycete Saccharopolyspora erythraea. Further yield increase is of great importance but requires a better understanding of the underlying physiological processes. Results To reveal the mechanisms related to erythromycin yield increase, we have undertaken an integrated study of the genomic, transcriptomic, and proteomic differences between the wild type strain NRRL2338 (WT) and the industrial high-producing strain ABE1441 (HP) of S. erythraea at multiple time points of a simulated industrial bioprocess. 165 observed mutations lead to differences in gene expression profiles and protein abundance between the two strains, which were most prominent in the initial stages of erythromycin production. Enzymes involved in erythromycin biosynthesis, metabolism of branched chain amino acids and proteolysis were most strongly upregulated in the HP strain. Interestingly, genes related to TCA cycle and DNA-repair were downregulated. Additionally, comprehensive data analysis uncovered significant correlations in expression profiles of the erythromycin-biosynthetic genes, other biosynthetic gene clusters and previously unidentified putative regulatory genes. Based on this information, we demonstrated that overexpression of several genes involved in amino acid metabolism can contribute to increased yield of erythromycin, confirming the validity of our systems biology approach. Conclusions Our comprehensive omics approach, carried out in industrially relevant conditions, enabled the identification of key pathways affecting erythromycin yield and suggests strategies for rapid increase in the production of secondary metabolites in industrial environment.
Keywords: aktinomicete, Saccharopolyspora erythraea, sekundarni metaboliti, antibiotiki, eritromicin, biosinteza, metabolno inženirstvo, proteomika
Published in DiRROS: 25.07.2024; Views: 342; Downloads: 204
Full text (3,06 MB)
This document has many files! More...

Abstract: The protection, preservation and restoration of aquatic ecosystems and their functions are of global importance. For European states it became legally binding mainly through the EU-Water Framework Directive (WFD). In order to assess the ecological status of a given water body, aquatic biodiversity data are obtained and compared to a reference water body. The quantified mismatch obtained determines the extent of potential management actions. The current approach to biodiversity assessment is based on morpho-taxonomy. This approach has many drawbacks such as being time consuming, limited in temporal and spatial resolution, and error-prone due to the varying individual taxonomic expertise of the analysts. Novel genomic tools can overcome many of the aforementioned problems and could complement or even replace traditional bioassessment. Yet, a plethora of approaches are independently developed in different institutions, thereby hampering any concerted routine application. The goal of this Action is to nucleate a group of researchers across disciplines with the task to identify gold-standard genomic tools and novel eco-genomic indices for routine application in biodiversity assessments of European fresh- and marine water bodies. Furthermore, DNAqua-Net will provide a platform for training of the next generation of European researchers preparing them for the new technologies. Jointly with water managers, politicians, and other stakeholders, the group will develop a conceptual framework for the standard application of eco-genomic tools as part of legally binding assessments.
Keywords: aquatic ecosystems, biodiversity, monitoring, genomic tools
Published in DiRROS: 25.07.2024; Views: 284; Downloads: 132
Full text (361,20 KB)
This document has many files! More...

Abstract: Currently, around 50% of the world's population lives in towns and cities within 100 km of the coast. Monitoring of viruses that are frequently present in contaminated coastal environments, such as rotavirus (RoV) and norovirus (NoV), which are also the major cause of human viral gastroenteritis, is essential to ensure the safe use of these water bodies. Since exposure to as few as 10–100 particles of RoV or NoV may induce gastrointestinal disease, there is a need to develop a rapid and sensitive diagnostic method for their detection in coastal water samples. In this study, we evaluate the application of methacrylate monolithic chromatographic columns, commercially available as convective interaction media (CIM®), to concentrate pathogenic enteric viruses from saline water samples prior to virus quantification by one-step reverse transcription quantitative PCR (RT-qPCR). Using RoV and NoV as model enteric viruses, we present our results on the most effective viral concentration conditions from saline water matrices using butyl (C4) hydrophobic interaction monolithic support (CIM® C4). C4 monolithic columns exhibit a good capacity to bind both RoV and NoV and both viruses can be eluted in a single step. Our protocol using a 1 ml C4 column enables processing of 400 ml saline water samples in less than 60 min and increases the sensitivity of RoV and NoV detection by approximately 50-fold and 10-fold respectively. The protocol was also scaled up using larger capacity 8 ml C4 columns to process 4000 ml of seawater samples with concentration factors of 300-fold for RoV and 40-fold for NoV, without any significant increase in processing time. Furthermore, C4 monolithic columns were adapted for field use in an on-site application of RoV concentration from seawater samples with performance equivalent to that of the reference laboratory setup. Overall, the results from successful deployment of CIM C4 columns for concentration of rotavirus and norovirus in seawater samples reiterate the utility of monolithic supports as efficient, scalable and modular preparative tools for processing environmental water samples to enhance viral detection using molecular methods.
Keywords: rotavirus, norovirus, seawater, fecal contamination, qPCR, sewage
Published in DiRROS: 25.07.2024; Views: 320; Downloads: 164
Full text (911,64 KB)
This document has many files! More...