Andreja Nataša Kopitar

University of Ljubljana

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Alojz Ihan

University of Ljubljana

Miha Skvarč

University of Ljubljana

Bojan Tepeš

Rogaška Medical Centre

M. Kolbezen

Ljubljana University Medical Centre

Janko Kos

University of Ljubljana

Larisa Janžič

University of Ljubljana

Petra Schollmayer

Ljubljana University Medical Centre

Marko Hawlina

Ljubljana University Medical Centre

Branko Zorn

Ljubljana University Medical Centre

Zala Lužnik

Ljubljana University Medical Centre

Cooperative Institutions

Cornell University

226

University of Córdoba

222

University of Ljubljana

126

Ljubljana University Medical Centre

107

Inserm

Centro Medicina della Riproduzione

Institute of Oncology Ljubljana

University Medical Center

Universidad de Las Palmas de Gran Canaria

Erasmus MC

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Semen quality at cryobanking before oncologic treatment

Yasuyo Matsumoto Lévai Írisz Sakae Goto Hidehisa HASHIMOTO S. Kokeguchi

Source

Cite

Citations (0)

Comparison of Lymphocyte Populations in Patients With Dobrava or Puumala orthohantavirus Infection

Frontiers in Cellular and Infection Microbiology (2020)

Katarina Resman Rus Andreja Nataša Kopitar Miša Korva Alojz Ihan Miroslav Petrovec

Hemorrhagic fever with renal syndrome (HFRS), caused by Dobrava (DOBV) and Puumala (PUUV) orthohantaviruses, is an endemic disease in Slovenia. DOBV is mainly responsible for a more severe disease, whereas PUUV usually causes a milder form. Therefore, the aim of our study was to determine whether any differences in lymphocyte population between these two viruses exist. Mononuclear cells from peripheral blood (PBMCs) were isolated from DOBV or PUUV infected patients and different lymphocyte subpopulations were analyzed with flow cytometry. Decreased concentrations of lymphocyte subpopulation were observed in DOBV and in PUUV infected patients compared with a healthy control, which was especially evident in DOBV infected patients. The lower values of T cells are likely due to the extravasation of the activated cells from the circulation to the infected tissue. Higher percentage of NK cells were detected in DOBV infected patients in comparison to PUUV infected patients, which could be associated with a more severe HFRS caused by DOBV. PUUV infected patients had a significantly higher concentration of activated T cell subsets, expressing markers CD25, CD69 and HLA-DR in comparison to DOBV infected patients. Higher activation of T cell subsets in PUUV infected patients could be a contributor to a milder HFRS. Further studies are necessary to elucidate the relation between the protective and the harmful role of activated lymphocytes subsets in HFRS pathogenesis.

Puumala virus

10.3389/fcimb.2020.566149

Cite

Citations (9)

Cathepsin X inhibitor decrease the production of cytokines and monocyte microparticles on THP-1 macrophage-like cells stimulated with Helicobacter pylori

Frontiers in Immunology (2013)

Andreja Nataša Kopitar Janko Kos Samo Jeverica Alojz Ihan

Event Abstract Back to Event Cathepsin X inhibitor decrease the production of cytokines and monocyte microparticles on THP-1 macrophage-like cells stimulated with Helicobacter pylori Andreja Natasa Kopitar1*, Janko Kos2, Samo Jeverica1 and Alojz Ihan1 1 University of Ljubljana, Medical Faculty Ljubljana, Institute of Microbiology and Immunology, Immunology, Slovenia 2 University of Ljubljana, Faculty of Pharmacy, Pharmaceutical Biology, Slovenia INTRODUCTON> The infection with Helicobacter pylori (H. pylori) induces higher levels of cathepsin X in macrophages of the gastric mucosa. Cathepsin X has been predominantly localized on monocytes, macrophages and dendritic cells. Active cathepsin X has been shown to regulate β-2 integrin-dependent adhesion and phagocytosis, which is crucial for effective antigen presentation and initiation of T cell dependent immune response. In our opinion inhibition of cathepsin X blocks this process, because the membrane in the case of inhibition becomes more rigid and internalization is delayed or even impossible. Microparticles have been considered as cellular debris for a long time. However recent findings associate them with cellular stimulation, activation, and degeneration/apoptosis. HYPOTHESIS> Our hypothesis suggests that cathepsin X inhibitor could suppress fluidity of plasmatic membrane and microvesiculation of antigen presenting cells. This process could result in the insufficient immune response to the infection with H. pylori. METHODES>Macrophages like cells were differentiated from THP-1 cell line treated with PHA for 24h. The cells were than stimulated with H. pylori strains, isolated from 20 dyspeptic patients. For negative control we used THP-1 cells co-cultivated with medium alone or we added an inhibitor of cathepsin X. The in vitro secretion of IL-1b, IL-6, IL-8, IL-10, IL-12, TNF and concentration of microparticles were measured with flow cytometry. RESULTATES> Higher concentration of microparticles were observed in the cases of THP-1 macrophage like cells, which were treated with H. pylori alone than in the cases of the untreated cells (p<0.01). The amount of microparticles was still significantly higher in the cases of THP-1 cells stimulated with H. pylori in combination with cathepsin X inhibitor as in the cases of un-stimulated THP-1 cells. Cathepsin X inhibitor decreased the amount of microparticles compared to THP-1 cells stimulated with H. pylori alone (p<0.01). The H. pylori stimulation alone as well as the stimulation in combination of cathepsin X inhibitor increased the production of IL-8, IL-6, IL-10, TNF, IL-12 compared to the negative control. However, we observed lower production of IL-1β and IL-6 by the THP-1 cells stimulated with H. pylori in combination with cathepsin X inhibitor (p<0.01). Figure 1 Figure 2 References 1.Kos J, Jevnikar Z, Obermajer N. The role of cathepsin X in cell signaling. Cell adhesion & migration 2009,3:164-166. 2.Kopitar AN, Stegel V, Tepes B, Gubina M, Novakovic S, Ihan A. Specific T cell responses to Helicobacter pylori predict successful eradication therapy. The Journal of infection 2007,54:257-261. 3.Wang JG, Williams JC, Davis BK, Jacobson K, Doerschuk CM, Ting JP, Mackman N. Monocytic microparticles activate endothelial cells in an IL-1β-dependent manner. Blood. 2011 Aug 25;118(8):2366-74. 4.Obermajer N, Magister S, Kopitar AN, Tepes B, Ihan A, Kos J. Cathepsin X prevents an effective immune response against Helicobacter pylori infection. European journal of cell biology 2009,88:461-471. 5.Bernimoulin M, Waters EK, Foy M, Steele BM, Sullivan M, Falet H, Walsh MT, Barteneva N, Geng JG, Hartwig JH, Maguire PB, Wagner DD. Differential stimulation of monocytic cells results in distinct populations of microparticles. J Thromb Haemost. 2009 Jun; 7(6):1019-28. Keywords: H. pylori, Cathepsin X, microparticles, THP-1 macrophages, IL-6, IL-1beta Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Innate immunity Citation: Kopitar A, Kos J, Jeverica S and Ihan A (2013). Cathepsin X inhibitor decrease the production of cytokines and monocyte microparticles on THP-1 macrophage-like cells stimulated with Helicobacter pylori. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.01049 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 Jun 2013; Published Online: 22 Aug 2013. * Correspondence: Dr. Andreja Natasa Kopitar, University of Ljubljana, Medical Faculty Ljubljana, Institute of Microbiology and Immunology, Immunology, Ljubljana, SI-1000, Slovenia, andreja-natasa.kopitar@mf.uni-lj.si Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Andreja Natasa Kopitar Janko Kos Samo Jeverica Alojz Ihan Google Andreja Natasa Kopitar Janko Kos Samo Jeverica Alojz Ihan Google Scholar Andreja Natasa Kopitar Janko Kos Samo Jeverica Alojz Ihan PubMed Andreja Natasa Kopitar Janko Kos Samo Jeverica Alojz Ihan Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

THP1 cell line

Monocyte

10.3389/conf.fimmu.2013.02.01049

Cite

Citations (0)

Transcriptomic Analysis and Meta-Analysis of Human Granulosa and Cumulus Cells

PLoS ONE (2015)

Tanja Burnik Papler Eda Vrtačnik Bokal Aleš Maver Andreja Nataša Kopitar Luca Lovrečić

Specific gene expression in oocytes and its surrounding cumulus (CC) and granulosa (GC) cells is needed for successful folliculogenesis and oocyte maturation. The aim of the present study was to compare genome-wide gene expression and biological functions of human GC and CC. Individual GC and CC were derived from 37 women undergoing IVF procedures. Gene expression analysis was performed using microarrays, followed by a meta-analysis. Results were validated using quantitative real-time PCR. There were 6029 differentially expressed genes (q < 10−4); of which 650 genes had a log2 FC ≥ 2. After the meta-analysis there were 3156 genes differentially expressed. Among these there were genes that have previously not been reported in human somatic follicular cells, like prokineticin 2 (PROK2), higher expressed in GC, and pregnancy up-regulated nonubiquitous CaM kinase (PNCK), higher expressed in CC. Pathways like inflammatory response and angiogenesis were enriched in GC, whereas in CC, cell differentiation and multicellular organismal development were among enriched pathways. In conclusion, transcriptomes of GC and CC as well as biological functions, are distinctive for each cell subpopulation. By describing novel genes like PROK2 and PNCK, expressed in GC and CC, we upgraded the existing data on human follicular biology.

Granulosa cell

10.1371/journal.pone.0136473

Cite

Citations (31)

Low CD8 T cells in neonates and infants prior to surgery, and health‐care‐associated infections: Prospective observational study

Pediatrics International (2013)

Štefan Grosek Ziva Petrin Andreja Nataša Kopitar Jan Grosek J Erzen

Abstract Background Major surgery suppresses the cell‐mediated immune response in children and adults. Data on preoperative and postoperative T ‐cell counts in pediatric surgical patients and their relationship to health‐care‐associated infection ( HAI ) are not yet known. Methods A prospective observational study was carried out in a level III multidisciplinary neonatal and pediatric intensive care unit. Before and after, and in the first 3 days after surgery, lymphocyte subsets in peripheral blood were measured in 28 neonates and infants on flow cytometry. HAI were classified according to CDC / NHSN criteria. Results Six out of 28 neonates and infants (21.4%) developed HAI (group I ‐ HAI ), while 22 out of 28 (78.6%) remained infection free (group II ‐non‐ HAI ). In group I with HAI , the preoperative median cytotoxic T ‐lymphocyte ( CD8‐T ‐cell) level was found to be below normal, and remained very low throughout the study period. In addition, the median and interquartile CD8 T ‐cell range (358 cells/μ L ; 304–424 cells/μ L ) were twice as low compared to group II without HAI (822 cells/μ L ; 522–933 cells/μ L ; P = 0.013). No differences were found between the two groups with regard to patient demographics and clinical data. Conclusion Neonates and infants who underwent a major surgical procedure and who had a very low preoperative CD8 T ‐cell level, developed HAI postoperatively.

Interquartile range

Demographics

10.1111/ped.12142

Cite

Citations (1)

Correlation Between Filtering Bleb Morphology, Expression of Inflammatory Marker HLA-DR by Ocular Surface, and Outcome of Trabeculectomy

Journal of Glaucoma (2011)

Barbara Cvenkel Andreja Nataša Kopitar Alojz Ihan

To correlate clinical bleb characteristics and the expression of human leukocyte antigen (HLA)-DR by conjunctiva with the outcome of trabeculectomy.In this cross-sectional study, bleb morphology was assessed at slit lamp using the Moorfields Bleb Grading System in 85 eyes of 85 patients. Conjunctival specimens were collected from superior conjunctiva by impression cytology and analyzed for the expression of HLA-DR on epithelial and antigen-presenting cells. The success of trabeculectomy was defined as intraocular pressure <21 mm Hg without antiglaucoma drops. Differences in bleb characteristics and expression of HLA-DR between eyes with surgical success and failure were examined.Fifty-eight of 85 eyes with successful trabeculectomy had significantly greater central and maximal area of the bleb (P<0.001) with decreased vascularity of the central (P=0.02) and peripheral part of the bleb (P=0.03). The expression of HLA-DR on conjunctival epithelial cells and antigen-presenting cells was not different between the eyes with successful and failed trabeculectomy and also not between the eyes with and without topical glaucoma medication or topical corticosteroid eye drops.Successful trabeculectomy was associated with greater area and decreased vascularity of the bleb but not with diminished expression of inflammatory marker by ocular surface. Presence of subclinical inflammation in eyes without eye drops may result from the transcellular aqueous pathway towards the ocular surface, especially in functioning blebs with adjunctive mitomycin C.

Bleb (medicine)

Vascularity

10.1097/ijg.0b013e3182254051

Cite

Citations (14)

Sperm DNA fragmentation and mitochondrial membrane potential combined are better for predicting natural conception than standard sperm parameters

Fertility and Sterility (2015)

Slađana Malić Vončina Barbara Golob Alojz Ihan Andreja Nataša Kopitar M. Kolbezen

Semen Analysis

10.1016/j.fertnstert.2015.11.037

Cite

Citations (57)

Mononuclear Aluminum–Fluoride Ions, AlFx(+/−)—Study of Plausible Frameworks of Complexes with Biomolecules and Their In Vitro Toxicity

Molecules (2025)

A. S. Pavlovic Larisa Janžič Lucija Levstek Andreja Nataša Kopitar Kathleen F. Edwards

The importance of fluorine and aluminum in all aspects of daily life has led to an enormous increase in human exposure to these elements in their various forms. It is therefore important to understand the routes of exposure and to investigate and understand the potential toxicity. Of particular concern are aluminum–fluoride complexes (AlFx), which are able to mimic the natural isostructural phosphate group and influence the activity of numerous essential phosphoryl transferases. Our review of salts of ionic AlFx species, which plausibly form the framework of complexes with biomolecules, revealed that the octahedral configuration of aluminum in the active site of the enzyme is preferred over the trigonal-bipyramidal structure. The effects of varying concentrations of fluoride, aluminum and AlFx—from micromolar to millimolar levels—on the viability and apoptosis rate of THP-1 monocytes were investigated using phosphate buffer solution as a culture media to simulate physiological conditions. Our results suggest that aluminum can reduce the direct toxicity of fluoride through the formation of AlFx. In view of the results found, further in vitro studies are required to clarify the toxicity mechanisms of these species.

Isostructural

Biomolecule

10.3390/molecules30020389

Cite

Citations (0)

Neural differentiation of canine mesenchymal stem cells/multipotent mesenchymal stromal cells

BMC Veterinary Research (2020)

Sonja Prpar Mihevc Vesna Kokondoska Grgich Andreja Nataša Kopitar Luka Mohorič Gregor Majdič

Abstract Background The ability of adipose tissue-derived multipotent mesenchymal stromal cells/mesenchymal stem cells (ASCs) to differentiate in neural lineages promises progress in the field of regenerative medicine, especially for replacing neuronal tissue damaged by different neurological disorders. Reprogramming of ASCs can be induced by the growth medium with neurogenic inductors and specific growth factors. We investigated the neural differentiation potential of canine ASCs using several growth media (KEM, NIMa, NIMb, NIMc) containing various combinations of neurogenic inductors: B27 supplement, valproic acid, forskolin, N2-supplement, and retinoic acid. Cells were first preconditioned in the pre-differentiation neural induction medium (mitogenically stimulated; STIM1), followed by the induction of neuronal differentiation. Results After 3, 6, and 9 days of neural induction, elongated neural-like cells with bipolar elongations were observed, and some oval cells with light nuclei appeared. The expression of neuronal markers tubulin beta III (TUBB3), neurofilament H (NF-H), microtubule-associated protein-2 (MAP2), and glial fibrillary acidic protein (GFAP) was observed using immunocytochemistry, which confirmed the differentiation into neurons and glial cells. Flow cytometry analysis showed high GFAP expression (between 70 and 90% of all cells) after cells had been growing three days in the neural induction medium a (NIMa). Around 25% of all cells also expressed adult neuronal markers NF-H and MAP2. After nine days of ASCs differentiation, the expression of all neural markers was reduced. There were no differences between the neural differentiation of ASCs isolated from female or male dogs. Conclusions The differentiation repertoire of canine ASCs extends beyond mesodermal lineages. Using a defined neural induction medium, the canine ASCs differentiated into neural lineages and expressed markers of neuronal and glial cells, and also displayed the typical neuronal morphology. Differentiated ASCs can thus be a source of neural cellular lineages for the regenerative therapy of nerve damage and could be useful in the future for therapy or the modelling of neurodegenerative diseases.

Neurosphere

Neural Development

Multipotent Stem Cell

Neurofilament

10.1186/s12917-020-02493-2

Cite

Citations (16)

Multi locus sequence typing (MLST) used as a tool to confirm the ability of susceptible Helicobacter pylori strains to gain resistance to clarithromycin during eradication therapy.

PubMed (2014)

Miha Skvarč Romina Kofol Samo Jeverica Andreja Nataša Kopitar Bojan Tepeš

Primary resistance of H. pylori to clarithromycin is the most common reason for eradication failure, followed by mixed susceptible/ resistant H. pylori strain infection. To distinguish between mixed infections and H. pylori switch to resistance phenotype during eradication therapy, we proceeded with multi locus sequence typing (MLST) of H. pylori strains isolated from gastric biopsy samples of patients before and after eradication therapy.We collected H. pylori isolates from gastric biopsies from 133 patients who were never treated for H. pylori. Five patients had eradication failure with the first isolate susceptible and second isolate resistant to clarithromycin. To analyse genotypes of first and second H. pylori isolates, we compared H. pylori strain sequences of 7 housekeeping genes with MLST.Five patients had clarithromycin-sensitive H. pylori before eradication therapy and gained H. pylori-resistant to clarithromycin after eradication therapy. The sensitive and resistant colonies of each of the H. pylori populations, taken from patients before/after antibiotic therapy, had identical sequence types (ST) obtained with MLST.The factors favouring H. pylori survival and switch to antibiotic-resistance during eradication therapy probably enable milder environmental conditions for H. pylori persistence during therapy. One of such factor is the ineffective destruction of mucosa-adhered H. pylori by immune cells during therapy which may be due to locally induced immune deficit by H. pylori molecules like strain specific H. pylori lipopolysaccharides.

Multilocus sequence typing

Housekeeping gene

Source

Cite

Citations (1)