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Published in DiRROS: 05.08.2024; Views: 300; Downloads: 209
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Abstract: Introduction. CD133 is a marker for a population of glioblastoma (GBM) and normal neural stem cells (NNSC). We aimed to reveal whether the migratory potential and differentiation of these stem cells is associated with CD133 expression and with cathepsin proteases (Cats). Materials and methods. The invasiveness of normal NNSC, GBM/CD133+ cell lines and GBM spheroids was evaluated in 3D collagen, as well as of U87-MG and normal astrocytes (NHA) grown in monolayers in 2D Matrigel. Expression of Cats B, L and S was measured at mRNA and activity levels and their relation to invasiveness, to CD133 mRNA in 26 gliomas, and to the survival of these patients. Results. The average yield of CD133+ cells from GBM samples was 9.6%. Survival of patients with higher CD133 mRNA expression was significantly shorter (p< 0.005). Invasion, associated with proteolytic degradation of matrix, was higher in normal stem cells and GBM spheroids and cells than in isolated GBM CD133+ cells. In glioma samples, there was no correlation between CD133 mRNA expression and Cat mRNAs, but there was an inverse correlation with Cat activities. Conclusions. The study confirms CD133 as a prognostic marker for the survival of GBM patients. We demonstrated that NNSC have higher invasion potential and invade the collagen matrix in a mode different from that of GBM, initiating stem cell spheres. This result could have implications for the design of new therapeutics, including protease inhibitors that specifically target invasive tumour stem cells. Increased activity of cathepsins in CD133- cells suggests their role in the invasive behaviour of GBM.
Published in DiRROS: 05.08.2024; Views: 252; Downloads: 135
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Abstract: Abscission occurs specifically in the abscission zone (AZ) tissue as a natural stage of plant development. Previously, we observed delay of tomato (Solanum lycopersicum) leaf abscission when the LX ribonuclease (LX) was inhibited. The known association between LX expression and programmed cell death (PCD) suggested involvement of PCD in abscission. In this study, hallmarks of PCD were identified in the tomato leaf and flower AZs during the late stage of abscission. These included loss of cell viability, altered nuclear morphology, DNA fragmentation, elevated levels of reactive oxygen species and enzymatic activities, and expression of PCD-associated genes. Overexpression of antiapoptotic proteins resulted in retarded abscission, indicating PCD requirement. PCD, LX, and nuclease gene expression were visualized primarily in the AZ distal tissue, demonstrating an asymmetry between the two AZ sides. Asymmetric expression was observed for genes associated with cell wall hydrolysis, leading to AZ, or associated with ethylene biosynthesis, which induces abscission. These results suggest that different abscission-related processes occur asymmetrically between the AZ proximal and distal sides. Taken together, our findings identify PCD as a key mechanism that occurs asymmetrically during normal progression of abscission and suggest an important role for LX in this PCD process.
Keywords: plant cell, cell death, abscission
Published in DiRROS: 05.08.2024; Views: 298; Downloads: 190
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Abstract: Background. The blackspotted smooth-hound, Mustelus punctulatus Risso, 1826, has been regularly caught in the northern Adriatic Sea, although a decreasing trend in its catches was observed off the coast of Slovenia within the last decade The knowledge of feeding behaviour of elasmobranch fish species, through understanding of the local food web structure, contributes to better and more efficient fish stock assessment and ecosystem modelling. This study is a first step in determining the prey consumption by the blackspotted smooth-hound in the area. Materials and methods. A total of 151 blackspotted smooth-hounds caught by commercial fishermen in the Gulf of Trieste from 4 June 2002 to 4 June 2003 were examined in this study. The stomach contents were removed, sorted and identified to the lowest possible taxon using identification keys. Preys were counted and weighed. Frequency of occurrence (F%), relative abundance (N%), the percentage by weight (W%), the Index of Relative Importance (IRI), and its standardized value (%IRI) were calculated following standard procedures. For comparing the diet between four different size classes we calculate average prey weight, dietary diversity, average meal, and trophic level for each size class. Results. A total 130 fish stomachs contained prey items. Crustaceans were the most important prey items (IRI% = 56.14), whereas cephalopods were the second mostly preyed animals (IRI% = 20.2). Teleost fish and bivalves were also found in the stomachs. The most important prey species was Solecurtus strigillatus. Larger sharks consumed larger preys. Male and female sharks consumed similar food. Juvenile individuals consumed predominantly crustaceans, while cephalopods were more important in the diet of adult individuals. The calculated trophic index (TROPH) of M. punctulatus from northern Adriatic Sea was 3.7, showing that it is a highly carnivorous species. Conclusion. This study is a first step in determining prey consumption by Mustelus punctulatus which is, despite the fact that is still common in the area, a rather poorly known species. For elucidating the role of benthic sharks in the study area the further step would be to study the diet of a closely related common smooth-hound M. mustelus.
Keywords: fishes, ichthyology, Adriatic sea, Triakidae, Mustelus punctulatus, trophic level, northern Adriatic, elasmobranchii, diversity, Mustelus, Mediterranean, feeding, Adriatic Sea
Published in DiRROS: 05.08.2024; Views: 312; Downloads: 211
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Abstract: Human activities have caused an enormous rise of the CO2 concentration in the Earth’s atmosphere over the past 200 years. In order to alleviate this problem, the threats to and the concerns of the international community need to be converted into economic opportunities for national economies, which shall develop and utilize technological opportunities rather than simply accepting international obligations to reduce CO2 emissions. In the article we analyze technological possibilities in the Slovenian context as possible opportunities for promoting sustainable development based on regional, renewable resources. Beginning with an analysis of the amine process for CO2 concentration and its possibilities, we continue with CO2 chemistry examples, like the precipitation of calcium carbonate from Ca++ sources like lime or fly ash. Through the concept of product engineering we emphasize the need for a stepwise realization from the laboratory to a pilot plant and then to the industrial scale. The growth of biomass through forestry or algae production can provide an additional CO2 sink. However, for an efficient technical solution and implementation a close working relationship between biologists and engineers is required.
Keywords: CO2 minimization, technological opportunities, amine concentration, CO2 chemistry, forestry, algae production, fly ash CO2 absorption
Published in DiRROS: 05.08.2024; Views: 272; Downloads: 199
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