Zoology and Animal physiology (ZFZd)
Activation of endogenous mechanisms leading to neuroprotection after stroke
Stroke represents a serious socio-economic problem with limited treatment options. Recently, the phenomenon of ischemic tolerance, i.e. endogenous stimulation of the mechanisms with the ability to induce neuroprotection, has become an attractive solution for the prevention and treatment of such conditions.
1) Study of mechanisms of ischemic tolerance 2) Defining the role of peripheral blood cells in inducing ischemic tolerance 3) Testing of in vivo and ex vivo conditioning methods 4) Testing of conditioning methods in animal models of ischemic-reperfusion injury of nerve tissue
(1) Bonova, P., Jachova, J., Nemethova, M., Macakova, L., Bona, M., Gottlieb, M., 2020. Rapid remote conditioning mediates modulation of blood cell paracrine activity and leads to the production of a secretome with neuroprotective features. Journal of neurochemistry 154, 99-111. (2) Bonova, P., Koncekova, J., Nemethova, M., Petrova, K., Bona, M., Gottlieb, M., 2022. Identification of Proteins Responsible for the Neuroprotective Effect of the Secretome Derived from Blood Cells of Remote Ischaemic Conditioned Rats. Biomolecules 12. (3) Bonova, P., Nemethova, M., Matiasova, M., Bona, M., Gottlieb, M., 2016. Blood cells serve as a source of factor-inducing rapid ischemic tolerance in brain. The European journal of neuroscience 44, 2958-2965. (4) Hossmann, K.A., 2012. The two pathophysiologies of focal brain ischemia: implications for translational stroke research. Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism 32, 1310-1316.
RNDr. Petra Bonová, PhD.
Zoology and Animal physiology (ZFZd)
The role of the gut microbiome in the pathogenesis and treatment of intestinal and extraintestinal diseases: a mechanistic analysis using a multi-omics approach
In recent years, the study of the human microbiome has focused primarily on the gut, whose microbial composition affects the development and proper functioning of the immune system. Disruption of the gut microbiota - dysbiosis - is associated with the development of various diseases, such as inflammatory bowel diseases (ulcerative colitis) or some metabolic diseases. Studies indicating the connection between the intestinal microbiota and the gut-brain axis are also interesting. The gut brain axis could be involved in the development of the central nervous system, as well as in the development of some behavioural disorders (autism spectrum disorder; ASD). Therefore, microbial therapeutic approaches (faecal microbial therapy, probiotics, synbiotics) have a high potential. Due to the complexity of these diseases, it is necessary to use the latest high-throughput molecular methods (NGS DNA sequencing, RNA-seq) in addition to standard analyses when researching the mechanism of their origin and progression. The aim of the thesis will be to analyse the influence of the gut microbiome and metabolome on the progression and treatment of ulcerative colitis and autism spectrum disorders using an animal gnotobiotic model.
The main aim of the thesis will be to analyse the influence of the gut microbiome and metabolome on the progression and treatment of ulcerative colitis and autism spectrum disorders (ASD) using an animal gnotobiotic model. Under the main goal, we intend to establish the following partial objectives: 1. Study the effect of transplantation of the human microbiota on the course of ulcerative colitis using pseudo germ-free BALB/c mice model 2. To determine the influence of gut microbiota on behaviour related to ASD symptomatology by means of faecal microbiota transplantation (FMT) from children with ASD to pseudo germ-free (PGF) mice model. 3. To reveal the potential of using probiotics (Lactobacillus reuteri CCM 8617, Lactobacillus plantarum CCM 7512) and prebiotics (linseed) to correct ASD symptoms.
1. Taniya MA, Chung HJ, Al Mamun A, Alam S, Aziz MA, Emon NU, Islam MM, Hong SS, Podder BR, Ara Mimi A, Aktar Suchi S, Xiao J. Role of Gut Microbiome in Autism Spectrum Disorder and Its The-rapeutic Regulation. Front Cell Infect Microbiol. 2022 Jul 22;12:915701. doi: 10.3389/fcimb.2022.915701. PMID: 35937689; PMCID: PMC9355470. 2. Anshula Mehra, Geetakshi Arora, Gaurav Sahni, Manmohit Kaur, Hasandeep Singh, Balbir Singh, Sarabjit Kaur, Gut microbiota and Autism Spectrum Disorder: From pathogenesis to potential therapeutic perspectives, Journal of Traditional and Complementary Medicine, Volume 13, Issue 2, 2023, Pages 135-149,ISSN 2225-4110, https://doi.org/10.1016/j.jtcme.2022.03.001 3. Morton, J.T., Jin, DM., Mills, R.H. et al. Multi-level analysis of the gut–brain axis shows autism spectrum disorder-associated molecular and microbial profiles. Nat Neurosci 26, 1208–1217 (2023). https://doi.org/10.1038/s41593-023-01361-0 4. Ni, J., Wu, G., Albenberg, L. et al. Gut microbiota and IBD: causation or correlation?. Nat Rev Gastroenterol Hepatol 14, 573–584 (2017). https://doi.org/10.1038/nrgastro.2017.88 5. Akira Andoh, Atsushi Nishida; Alteration of the Gut Microbiome in Inflammatory Bowel Disea-se. Digestion 3 January 2023; 104 (1): 16–23. https://doi.org/10.1159/000525925
RNDr. Vlasta Demečková, PhD., univerzitná docentka
Molecular Cytology and Genetics (MCGd)
Assessment of the employment of paraarterial spaces of glymphatic system as the alternative administration route for pharmacotherapy of CNS
The glymphatic system is a recently discovered system represented by paravascular spaces in the central nervous system (CNS), which promotes efficient elimination of soluble proteins and metabolites from the nervous tissue to the cerebrospinal fluid (CSF). Understanding of organization and physiology of the glymphatic system could have an impact on the development in the field of pharmacotherapy of the CNS pathologies. PhD study should focus on the study of the glymphatic system and its utilization for the administration of the therapeutics in the treatment of CNS diseases. The first aim is to analyze the components of the glymphatic system during the ontogenesis, focusing on characterization of attributes, which are important for maintenance of homeostasis and for its potential utilization in the pharmacotherapy. The second aim is to investigate, whether the glymphatic system could be utilized for the intracisternal application of therapeutics loaded into the biodegradable nanoparticles based on silicon dioxide, which could overcome restrictions related to the application of drugs via hematoencephalic barrier, or conventional administration of drugs via intracisternal or intrathecal route.
1. Analysis of components of glymphatic system in the telencephalon and spinal cord: paravascular space (Virchow-Robin paraarterial space, paravenous space), cells (astrocytes, microglia, ependymal cells) and CSF during ontogenesis of rats 2. Analysis of the perspective utilization of intracisternal application of therapeutics loaded in silica based biodegradable nanoparticles in the treatment of CNS diseases 3. Study of the impact of administration of biodegradable silica based nanoparticles on the functions of the nervous and glymphatic systems
scientific studies published in scholar journals
doc. RNDr. Juraj Ševc, PhD.
Molecular Cytology and Genetics (MCGdAj)
Assessment of the employment of paraarterial spaces of glymphatic system as the alternative administration route for pharmacotherapy of CNS
The glymphatic system is a recently discovered system represented by paravascular spaces in the central nervous system (CNS), which promotes efficient elimination of soluble proteins and metabolites from the nervous tissue to the cerebrospinal fluid (CSF). Understanding of organization and physiology of the glymphatic system could have an impact on the development in the field of pharmacotherapy of the CNS pathologies. PhD study should focus on the study of the glymphatic system and its utilization for the administration of the therapeutics in the treatment of CNS diseases. The first aim is to analyze the components of the glymphatic system during the ontogenesis, focusing on characterization of attributes, which are important for maintenance of homeostasis and for its potential utilization in the pharmacotherapy. The second aim is to investigate, whether the glymphatic system could be utilized for the intracisternal application of therapeutics loaded into the biodegradable nanoparticles based on silicon dioxide, which could overcome restrictions related to the application of drugs via hematoencephalic barrier, or conventional administration of drugs via intracisternal or intrathecal route.
1. Analysis of components of glymphatic system in the telencephalon and spinal cord: paravascular space (Virchow-Robin paraarterial space, paravenous space), cells (astrocytes, microglia, ependymal cells) and CSF during ontogenesis of rats 2. Analysis of the perspective utilization of intracisternal application of therapeutics loaded in silica based biodegradable nanoparticles in the treatment of CNS diseases 3. Study of the impact of administration of biodegradable silica based nanoparticles on the functions of the nervous and glymphatic systems
scientific studies published in scholar journals
doc. RNDr. Juraj Ševc, PhD.
Molecular Cytology and Genetics (MCGdAj)
Bacterial „dark matter“ in white sulfur mats
Bacterial "dark matter" refers to the unidentified and uncharacterized microbial species that inhabit various environments, including white sulfur mats. These mats are unique ecosystems found in sulfur springs, where bacterial communities thrive in an environment rich in sulfur compounds. The mats are formed by the metabolic activities of chemolithoautotrophic bacteria which obtain energy by hydrogen sulfide oxidation. Within these mats (especially cold-water), there exists a vast diversity of bacteria that have not been fully studied or characterized and our preliminary data indicate that nearly 50% of bacterial population in white sulfur mats are formed by completely unknown bacterial taxa. These bacteria are collectively referred to as "dark matter" due to our limited understanding of their ecological roles and metabolic capabilities. Many of these bacteria belong to novel lineages and possess unique genetic adaptations, suggesting their involvement in complex ecological processes within the mats. However, understanding their specific functions and interactions with other organisms remains a challenge. The aim of the project is to characterize bacterial diversity in cold-water sulfur springs in Slovakia using combination of cultivation and non-cultivation (metagenomic) approaches. The identification of bacterial "dark matter" in white sulfur mats has significant implications for our understanding of microbial ecology and evolution. By characterizing these elusive bacteria, we gain insights into their contributions to sulfur cycling, carbon fixation, and other biogeochemical processes within these mats but understanding the microbial diversity within white sulfur mats may have implications for understanding of microbial life on Earth and beyond, new metabolic pathways, adaptations, and ecological strategies that could have consequences for biotechnology, environmental science, and astrobiology as well.
The goal of the project is to know the biodiversity of non-cultivable bacteria in the white coatings of sulfur bacteria of sulfur springs in Slovakia and to analyze their metabolic potential based on the reconstruction of their genomes from metagenomic data
Pokorna, D., Zabranska, J. Sulfur-oxidizing bacteria in environmental technology, Biotechnology Advance 33(6), Part 2, 2015.ISSN 0734-9750 Zhang L, Chen F, Zeng Z, et al.. Advances in Metagenomics and Its Application in Environmental Microorganisms. Front Microbiol. 2021 Dec 17;12:766364.
doc. RNDr. Peter Pristaš, CSc.
Zoology and Animal physiology (ZFZd)
Beneficial effect of polyunsaturated fatty acids on preimplantation embryo development
Large numbers of people are affected by infertility in their lifetime, according to a new report published by WHO. Around 17.5% of the adult population – roughly 1 in 6 worldwide – experience infertility. Furthermore, in recent decades, many studies have reported a worrisome decrease in the reproductive performance of farm animals. Embryo losses in the early stages of development represent a difficult problem for farmers, as the fundamental element of meat and dairy production is the successful reproduction of animals. However, by managing nutrition during the periconceptional period the incidence of losses can be decreased considerably. Dietary lipid supplementation can be a good strategy to reduce the extent of reproductive failure. Research has shown that polyunsaturated fatty acids (PUFAs) are extremely important and almost essential during pregnancy, especially in the last trimester. These acids are crucial for the proper development of the fetus's brain and eyes. Some of them not only pass through the placenta into the body of the growing fetus, but after birth continue into the body of the newborn through breast milk. Their presence is essential for the further development of the individual. The main aim of the study will be to evaluate the effect of diet supplementation with PUFAs, on the ability to conceive and to reduce early embryo loss in animal model - mouse females. The complementary set of relevant and up-to-date physiological, morphological, biochemical and molecular biology methods will be used in our experiments. Furthemore, acquired knowledge would result in targeted use in livestock production, veterinary practice as well as human reproductive medicine.
1. To evaluate the effect of diet supplementation by PUFAs on reproductive parameters of female mice. 2. To evaluate the mechanisms underlying impact of PUFAs on ovulation and early embryonic development in mouse. 3. To evaluate the protective potential of diet supplementation by PUFAs in reproductive disorders.
Burkuš, J. et al. (2015) The Journal of reproduction and development. doi: 10.1262/jrd.2015-012 Čikoš, Š. et al. (2019) Biology of Reproduction, 100(2), pp. 351–364. doi: 10.1093/biolre/ioy196. Diskin, M. G. et al. (2016) Reproduction, Fertility and Development, 28(2), p. 83. doi: 10.1071/RD15366. Geisert, R. D. and Schmitt, R. A. M. (2002) Journal of Animal Science, 80(E-suppl_1), pp. E54–E65. doi: 10.2527/ANIMALSCI2002.0021881200800ES10009X. Leroy, J. L. M. R. et al. (2013) Anim. Reprod., 10, n.3, pp.258-267. https:/ Šefčíková, Z. et al. (2018) Toxicology, 410, pp. 214–221. doi: 10.1016/j.tox.2018.08.008. Šefčíková, Z. et al. (2021) Reproductive Toxicology, 105, pp. 62–71. doi: 10.1016/j.reprotox.2021.08.006. Vlčková, R. et al. (2018) Animal reprod. science, 193, pp. 171–181. doi: 10.1016/J.ANIREPROSCI.2018.04.066. Vlčková, R., Sopková, D., et al. (2022) Life, 12(8). doi: 10.3390/life12081152. Vlčková, R., Andrejčáková, Z., et al. (2022) General physiology and biophysics, 41(3), pp. 205–219. doi: 10.4149/GPB_2022003.
MVDr. Dušan Fabian, DrSc.
RNDr. Janka Babeľová, PhD.
Molecular Cytology and Genetics (MCGdAj)
Biodiversity and biotechnology use of hypersaline environment microbiota
Biodiversity plays a crucial role in maintaining the balance and sustainability of ecosystems and provides numerous invaluable benefits to human society. One fascinating area of study within biodiversity is the exploration of microbial life in hypersaline environments which re characterized by high salt concentrations, such as salt mines, salt springs etc. Despite their extreme conditions, these environments harbor unique and diverse microbial communities which have adapted to survive and thrive in high salt concentrations. Their remarkable ability to tolerate salt has already led to the discovery of several biotechnological applications. The aim of project is the cultivation-based study of bacterial diversity in hypersaline environment in Slovakia, phylogenetic and phylogenomics characterization of obtained isolates and an analysis of biotechnological potential (production of extremozymes, such as amylases, proteases, and lipases, that can function in high salt concentrations, production of bioplastics). In addition to their biotechnological applications, studying hypersaline environments and the microbiota found within them provides valuable insights into the fundamental principles of life evolution, resilience and diversity on Earth.
The aim of the project is a biodiversity analysis of hypersaline environment microbiota in Slovakia and an analysis of biotechnology potential of hypersaline environment microbiota
Gerday, C., & Glansdorff, N. (2007). Physiology and biochemistry of extremophiles. ASM press. Papke, RT, Oren A (Eds) Halophiles: Genetics and Genomes. Caister Academic Press 2014, 216 p., ISBN: 978-1-908230-65-2. Fred A Rainey: Extremophiles. Methods in Microbiology, Vol . 35. Elsevier Ltd. 2006, ISBN: 9780125215367, 838 pp.
doc. RNDr. Peter Pristaš, CSc.
Molecular Cytology and Genetics (MCGd)
Biodiversity and biotechnology use of hypersaline environment microbiota
Biodiversity plays a crucial role in maintaining the balance and sustainability of ecosystems and provides numerous invaluable benefits to human society. One fascinating area of study within biodiversity is the exploration of microbial life in hypersaline environments which re characterized by high salt concentrations, such as salt mines, salt springs etc. Despite their extreme conditions, these environments harbor unique and diverse microbial communities which have adapted to survive and thrive in high salt concentrations. Their remarkable ability to tolerate salt has already led to the discovery of several biotechnological applications. The aim of project is the cultivation-based study of bacterial diversity in hypersaline environment in Slovakia, phylogenetic and phylogenomics characterization of obtained isolates and an analysis of biotechnological potential (production of extremozymes, such as amylases, proteases, and lipases, that can function in high salt concentrations, production of bioplastics). In addition to their biotechnological applications, studying hypersaline environments and the microbiota found within them provides valuable insights into the fundamental principles of life evolution, resilience and diversity on Earth.
The aim of the project is a biodiversity analysis of hypersaline environment microbiota in Slovakia and an analysis of biotechnology potential of hypersaline environment microbiota
Gerday, C., & Glansdorff, N. (2007). Physiology and biochemistry of extremophiles. ASM press. Papke, RT, Oren A (Eds) Halophiles: Genetics and Genomes. Caister Academic Press 2014, 216 p., ISBN: 978-1-908230-65-2. Fred A Rainey: Extremophiles. Methods in Microbiology, Vol . 35. Elsevier Ltd. 2006, ISBN: 9780125215367, 838 pp.
doc. RNDr. Peter Pristaš, CSc.
Zoology and Animal physiology (ZFZd)
Diversity, ecology and evolution of cave-dwelling beetles (Coleoptera: Carabidae) in Georgia
Altogether 17 species of beetles of the family Carabidae are known from Georgian caves up to date, involving six genera of endemic troglobiotic species. Generally, diversity of the cave fauna in Georgia is underestimated, considering that only 12% of ca. 1500 karstic caves have been studied biologically. Therefore, many invertebrates are yet to be discovered, Coleoptera including. In addition, there is still a lack of DNA data for revealing phylogeny of lineages and the evolution of the cave beetles in Georgian caves. Detailed studies on the ecology of the cave-adapted animals are missing as well. One of the goals of the thesis is to reveal the potential impact of cave management and tourist activities on invertebrate communities of show caves with special reference to Coleoptera.
1. To assess diversity of Georgian cave-adapted beetles (Carabidae: Trechini) using integrative taxonomy approach (combination of morphological and molecular traits); 2. To reveal the phylogeny and phylogeography of the Georgian cave beetles based on analysis of mitochondrial (16S, COI) and nuclear (28S) genes; 3. To evaluate the potential impact of anthropogenic activities in show caves on the invertebrate communities.
Beebee, T,, Rowe, G., 2008: An introduction to molecular ecology. Oxford University Press Culver, D.C., Pipan, T., 2009: The biology of caves and other subterranean habitats. Oxford University Press, 256 pp. Moldovan, O.T., Kováč, Ľ., Halse, S., 2018. Cave Ecology. Ecological Studies. Springer, 235, 545 pp. Lomolino, M.V., Riddle, B.R., Whittaker, R.J., 2017: Biogeography: biological diversity across space and time. 5th edition, Sinauer Associates Hopkin, S. P., 1997: Biology of the springtails (Insecta: Collembola). Oxford University Press White, W.B., Culver, D.C., Pipan, T., 2019: Encyclopedia of caves. 3rd edition. Academic Press, 1250 pp.
prof. RNDr. Ľubomír Kováč, CSc.
Dr. Arnaud Faille, Ph.D.
Molecular Cytology and Genetics (MCGdAj)
Exploitation of nanostructures in the modulation of hydrophobic character and therapeutic potential of selected natural secondary metabolites
In recent years, remarkable progress has been made towards the application of nanoparticles (NPs) as a new approach in the treatment of cancer. NPs-based drug delivery systems offer many advantages over conventional forms, including increased efficacy and reduced systemic toxicity. Among the most significant advantages of NPs are increased solubility in water, increased bioavailability and half-life in plasma, as well as simple surface modification using targeted ligands. It is estimated that more than half of the common chemotherapy drugs are natural compounds or their synthetic derivatives. A promising natural compound with antitumor activity is hyperforin, a phloroglucinol produced by some plants of the genus Hypericum, especially St. John's wort (Hypericum perforatum L.). However, hyperforin is a lipophilic compound with poor solubility and stability in aqueous solutions. Hypericin is another secondary metabolite synthesized mainly by plants of the genus Hypericum. In addition to its activity in dark conditions, hypericin is primarily known for its excellent photosensitizing properties useful in photodynamic therapy (PDT) and diagnostics (PDD). However, even such a promising treatment approach as hypericin-mediated PDT has its drawbacks. They are related to the hydrophobic nature of hypericin, which limits the use of its full therapeutic potential. The aim of the dissertation thesis will be to determine the stability of NPs, tolerability of NPs by healthy cells and the success of conjugation of NPs with plant metabolites, by assessment of their intracellular accumulation and analyzing the potential antitumor effect using human colon tumor cell lines and microtumors formed on the chorioallantoic membrane of avian Japanese quail embryos.
The aim of the dissertation thesis will be to determine the stability of NPs, tolerability of NPs by healthy cells and the success of conjugation of NPs with plant metabolites, by assessment of their intracellular accumulation and analyzing the potential antitumor effect using human colon tumor cell lines and microtumors formed on the chorioallantoic membrane of avian Japanese quail embryos.
1. Sharma K. S., Chiang Y. L., Hamblin R. M. Photodynamic therapy with fullerenes in vivo: reality or a dream? Nanomedicine (Lond.), 2011, 6, p. 1813-1825. 2. Huang Y-Y., Sharma K. S., Dai T., Chung H., Yaroslavsky A., Garcia-Diaz M., Chang J., Chiang Y. L., Hamblin R. M. Can nanotechnology potentiate photodynamic therapy? Nanotechnology Reviews, 2012, 1, p. 111-146. 3. Gurunathan S., Kang M-H., Qasim M., Kim J-H. Nanoparticle-Mediated Combination Therapy: Two-in-One Approach for Cancer. International Journal of Molecular Sciences, 2018, 19, 3264, p. 1-37. 4. Šemeláková M., Mikeš J., Jendželovský R., Fedoročko P. The pro-apoptotic and anti-invasive effects of hypericin-mediated photodynamic therapy are enhanced by hyperforin or aristoforin in HT-29 colon adenocarcinoma cells. Journal of Photochemistry and Photobiology B: Biology, 2012, 117, p. 115-125. 5. Jendželovská Z., Jendželovský R., Kuchárová B., Fedoročko P. Hypericin in the light and in the dark: two sides of the same coin. Frontiers in Plant Science, 2016, 7, p. 1-20. 6. Jendželovský R., Jendželovská Z., Kuchárová B., Fedoročko P. Breast cancer resistance protein is the enemy of hypericin accumulation and toxicity of hypericin-mediated photodynamic therapy. Biomedicine and Pharmacotherapy, 2019, 109, p. 2173-2181. 7. Majerník M., Jendželovský R., Babinčák M., Košuth J., Ševc J., Gombalová T. Z., Jendželovská Z., Buríková M., Fedoročko P. Novel insights into the effect of hyperforin and photodynamic therapy with hypericin on chosen angiogenic factors in colorectal micro-tumors created on chorioallantoic membrane. International Journal of Molecular Sciences, 2019, 20, 3004, p. 1-24. 8. Majerník M., Jendželovský R., Vargová J., Jendželovská Z., Fedoročko P. Multifunctional Nanoplatforms as a Novel Effective Approach in Photodynamic Therapy and Chemotherapy, to Overcome Multidrug Resistance in Cancer. Pharmaceutics, 2022, 14, 1075.
doc. RNDr. Rastislav Jendželovský, PhD.
Molecular Cytology and Genetics (MCGdAj)
Horizontal gene transfer and their role in adaptation of bacteria to extreme environments
In the process of evolution, bacteria have been able to adapt to a wide range of environmental conditions and are often the only forms of life surviving in extreme conditions. To survive in extreme environments, bacteria have developed several molecular adaptations and encode genes and gene clusters allowing them to thrive in these conditions. At least some of these genes are encoded by mobile gene elements ensuring their spread in bacterial populations. The aim of the project is to analyze the mobilome of extreme environments and selected species of extremophilic bacteria using a combination of genomic and metagenomic approaches. The genomes of selected mobile gene elements (with a focus on plasmids and bacteriophages) will be analyzed in silico and in vivo in order to determine the role of horizontal gene transfer in the adaptation of bacteria to extreme environments.
Analysis of the mobilome of extreme environments and selected species of extremophilic bacteria using a combination of genomic and metagenomic approaches in order to determine the role of horizontal gene transfer in the adaptation of bacteria to life in extreme environments.
Gerday, C., & Glansdorff, N. (2007). Physiology and biochemistry of extremophiles. ASM press. Papke, RT, Oren A (Eds) Halophiles: Genetics and Genomes. Caister Academic Press 2014, 216 p., ISBN: 978-1-908230-65-2. Fred A Rainey: Extremophiles. Methods in Microbiology, Vol . 35. Elsevier Ltd. 2006, ISBN: 9780125215367, 838 pp.
doc. RNDr. Peter Pristaš, CSc.
Molecular Cytology and Genetics (MCGd)
Horizontal gene transfer and their role in adaptation of bacteria to extreme environments
In the process of evolution, bacteria have been able to adapt to a wide range of environmental conditions and are often the only forms of life surviving in extreme conditions. To survive in extreme environments, bacteria have developed several molecular adaptations and encode genes and gene clusters allowing them to thrive in these conditions. At least some of these genes are encoded by mobile gene elements ensuring their spread in bacterial populations. The aim of the project is to analyze the mobilome of extreme environments and selected species of extremophilic bacteria using a combination of genomic and metagenomic approaches. The genomes of selected mobile gene elements (with a focus on plasmids and bacteriophages) will be analyzed in silico and in vivo in order to determine the role of horizontal gene transfer in the adaptation of bacteria to extreme environments.
Analysis of the mobilome of extreme environments and selected species of extremophilic bacteria using a combination of genomic and metagenomic approaches in order to determine the role of horizontal gene transfer in the adaptation of bacteria to life in extreme environments.
doc. RNDr. Peter Pristaš, CSc.
Plant physiology (FRd)
Characterization of chemical and biological properties of selected secondary metabolites from the lichen Ophioparma ventosa.
Natural products have deserved a great amount of attention in last decades thanks to their potential for biological activities. Lichens as the origin of many bioactive compounds are no exception and their significance in folk medicine is undeniable. Nowadays, the trend is shifting from folk medicine where extracts were used towards the search for the active components and their modes of action. Lichens are favorable organisms in a concern to the secondary metabolites’ isolation. They are known for their high content. Some metabolites can be effortlessly recrystallized from crude extract with considerable yield, others require the use of more sophisticated chromatographic methods. Depsides and depsidones are two major groups present almost exclusively in liches and their biological potential is being explored with much preliminary success. Deepening the knowledge on the effects of these substances on human cells is a necessary step towards possible applications in pharmaceutical industries. The lichen Ophioparma ventosa is a cosmopolitan species of lichen, which contains the majority of secondary metabolites such as usnic acid, thamnol divaricate or haemoventosin. This species was selected due to known interesting chemical content and the availability of great biomass. The biological effects of usnic acid are well-researched, but only isolated screenings are known about the other substances. The mechanism of action of these substances is still enigmatic.
The aim of the dissertation will be the development of procedures for the isolation of key secondary metabolites from the lichen Ophioparma ventosa. Another goal will be stability tests of isolated substances, as well as physico-chemical properties. After the successful phytochemical analysis, the biological properties of secondary metabolites will be tested on cell lines in vitro.
scientific articles in the Web of Science and Scopus databases
doc. RNDr. Michal Goga, PhD.
RNDr. Martin Kello, PhD.
Plant physiology (FRd)
Lichen and mosses chemical commnication
Mosses and lichens are often sharing their microhabitats suffering the same environmental changes i.e both biotic and abiotic interactions. Here, we want to focus on relationship among selected moss and lichen species, and find out how they communicate chemically. The interaction types are many folded but we would like to explain how moss react to the presence of certain lichens including developmental, biochemical, physiological and chemical parameters changes. Also the allelopathy effects of lichens on moss spore germination will be studied. The expected results are made on hypothesis that counterparts will probably have specific interactions, both positive and negative. Overlapping of the similar interaction will then be analyzed to specify mechanism included in pairwise relationships, and the compounds included in fine chemical communications among tested moss and lichen species.
The aim of the dissertation is the study of interactions between lichens and mosses at the level of chemical communication. Another goal of this work is to deepen the knowledge and insights in the field of allelopathy among these strong groups of cryptogams. The study of adaptation and reaction mechanisms at the chemical level will also be the subject of study in this topic.
scientific articles from web of science and scopus databases.
prof. Marko Sabovljević, Dr. rer. nat.
doc. RNDr. Michal Goga, PhD.
Molecular Cytology and Genetics (MCGd)
Identification of signaling mechanisms responsible for the induction of angiogenic stimulation following the application of hyperforin
Understanding the properties of tumor cells, or specifically, understanding the characteristics of specific populations of tumor cells, is essential for choosing appropriate anticancer therapy. One of such essential factors is the observation that the concentration of protons in non-tumor cells is slightly higher in the cytosol (pH ~ 7.2) than in the extracellular space (pH ~ 7.4). In contrast, the intracellular space of tumor cells is more alkaline (pH ~ 7.4), and the extracellular space is significantly more acidic (pH ~ 6.8). Alkalinization of the cytosol supports cell division, protects against apoptosis, and contributes to the induction of tumor neo-vascularization through the expression of growth factors such as vascular endothelial growth factor (VEGF). Naturally occurring substances capable of influencing cell pH are referred to as protonophores. One significant protonophore is hyperforin. Research results so far indicate its significant proapoptotic properties for a wide range of tumor cells. However, our recent findings alert to the possibility that hyperforin may induce angiogenic stimulation in a subpopulation of cells experiencing its effects. The goal of the dissertation will be to elucidate the mechanism of induction of angiogenic stimulation by hyperforin. Furthermore, it is known that the same signaling pathways that induce angiogenic stimulation may also be involved in the pathological regulation of pH in tumors, thereby increasing their malignant characteristics. Based on this, it can be assumed that hyperforin is potentially involved in the induction and increased expression of ion channels and carboxylic anhydrases.
The goal of the dissertation will be to elucidate the mechanism of induction of angiogenic stimulation by hyperforin. Furthermore, it is known that the same signaling pathways that induce angiogenic stimulation may also be involved in the pathological regulation of pH in tumors, thereby increasing their malignant characteristics. Based on this, it can be assumed that hyperforin is potentially involved in the induction and increased expression of ion channels and carboxylic anhydrases.
prof. RNDr. Peter Fedoročko, CSc.
Zoology and Animal physiology (ZFZd)
Mechanisms of endogenous repair following traumatic spinal cord injury
Several experimental techniques that have led to improvements in neurological function after spinal cord injury (SCI) have not been translated into the clinic. Therefore, a better understanding of the molecular and cellular mechanisms that enhance functional regeneration following SCI may facilitate the translation of successful experimental findings into the clinic. The work will focus on the supporting cells that increase the Neuron/ Glia 2(NG2) proteoglycan expression after the SCI. When, where, and which NG2-expressing cell types respond to spinal cord injury and how these cells may be affected by local neuroregenerative successful (but invasive) approach will be compared with systemic cell-selective therapy. The response of NG2+ cell types to different treatments will be assessed by cell-specific and functional techniques.
To uncover the mechanisms that block or promote the functional tissue repair after the SCI. 2) To demonstrate whether a less invasive but cell-selective treatment can replace the experimentally successful local technique.
Kucharova K, Stallcup WB. 2017. Distinct NG2 proteoglycan-dependent roles of resident microglia and bone marrow-derived macrophages during myelin damage and repair. PLoS One 12(11): e0187530. doi: 10.1371/journal.pone.0187530. eCollection, PMID: 29095924 Kucharova K, Stallcup WB. 2015. NG2-proteoglycan-dependent contributions of oligodendrocyte progenitors and myeloid cells to myelin damage and repair. J Neuroinflammation 12:161. doi: 10.1186/s12974-015-0385-6. PMID: 26338007 Bradbury EJ and Burnsid ER. 2019. Moving beyond the glial scar for spinal cord repair. Nature communications 10:3879 Alizadeh A, Dyck SM, and Karimi-Abdolrezaee S. 2019. Traumatic Spinal Cord Injury: An Overview of Pathophysiology Models and Acute Injury Mechanisms. Front Neurol. 10: 282. PMCID: PMC6439316, PMID: 30967837 Hu X, Xu W, Ren Y, Wang Z,He X, Huang R, Ma B, Zhao J, Zhu R, Cheng L. 2023. Spinal cord injury: molecular mechanisms and therapeutic interventions. Signal Transduct Target Ther. 26;8(1):245. doi: 10.1038/s41392-023-01477-6. PMID: 37357239
MUDr. Karolína Kuchárová, PhD.
Plant physiology (FRd)
Mesozoic palynomorphs in the context of the evolution of Laurasia biota.
The Cretaceous was a critical period in the history of Earth's biogeography. Until the Cretaceous, the world's landmasses were gathered together as a single supercontinent, Pangea, but this landmass began to break up, which was the first step towards the arrangement of the continents in the modern world. Continental fragmentation was crucial in the evolution of life, as flora and fauna evolved to become endemic, unique to their own continent. Changing environment and climate caused key diversifications of various modern groups of organisms. Based on the study of Mesozoic palynomorphs obtained from paleo-samples from Central Asia, the dissertation aims to characterize the biodiversity of the vegetation cover of the localities where dinosaurs and other reptiles, as well as mammals and birds, appeared at that time. Based on the analysis of the composition of the Mesozoic vegetation, it will contribute to the ecophysiological characteristics of the environment, which influenced the evolution and trophic relations within the biota of Laurasia. The main content of the work will be the isolation and subsequent identification of palynomorphs from the sediments of Central Asia and their characterization as part of a more broadly conceived project dedicated to understanding the evolution of biota and climate of that period.
1. Biodiversity characterization of selected samples of Mesozoic flora of Laurasia. 2. Based on the analysis of the composition of the Mesozoic vegetation, contribute to the ecophysiological characteristics of the environment, which influenced the evolution and trophic relations within the biota of Laurasia.
1. Taylor E., Taylor T., Krings M.: Paleobotany. The Biology and Evolution of Fossil Plants. 2nd Ed., 1252 pp. - Academic Press, 2008. 2. Traverse A.: Paleopalynology: Second Edition (Topics in Geobiology, 28) 2nd Ed. - Springer, 2007. 3. Current articles on the topic in journals registered in WOS and SCOPUS.
prof. RNDr. Pavol Mártonfi, PhD.
RNDr. Lenka Mártonfiová, PhD.
doc. RNDr. Martin Kundrát, PhD.
Zoology and Animal physiology (ZFZd)
Molecular-biological analysis of the mechanism of ischemic tolerance in atenuation the consequences of stroke by conditioning
Understanding the mechanisms of neuroprotectivity activation after ischemic brain damage at the molecular level is necessary to understand this process. It is known that peripheral blood reflects changes in gene and protein expression in the brain very sensitively and specifically.
1) To identify potential markers (genes, proteins) of ischemic tolerance activation. 2) To classify and specify genes and proteins in their signalling pathways and creating a reaction map of molecular cascades specific for the mechanism of ischemic tolerance in human blood samples and in a rat model.
Yunoki, Masatoshi, et al. "Ischemic tolerance of the brain and spinal cord: a review." Neurologia medico-chirurgica 57.11 (2017): 590-600. Zhao, Wenbo, et al. "Remote ischemic conditioning: challenges and opportunities." Stroke 54.8 (2023): 2204-2207. Furman, Marek, et al. "Quantitative analysis of selected genetic markers of induced brain stroke ischemic tolerance detected in human blood." Brain Research 1821 (2023): 148590. Bonova, Petra, et al. "Blood cells serve as a source of factor‐inducing rapid ischemic tolerance in brain." European Journal of Neuroscience 44.11 (2016): 2958-2965. Furman, Marek, et al. "Modifications of gene expression detected in peripheral blood after brain ischemia treated with remote postconditioning." Molecular Biology Reports (2022): 1-9.
RNDr. Rastislav Mucha, PhD.
Plant physiology (FRd); Plant physiology (FRd)
Genome multiplication in plant morphogenesis and associated dynamics of cellular and histological changes.
Genome multiplication, or endopolyploidization, is the repeated doubling of the entire nuclear genome of a cell or only part of it and is one of the mechanisms of the ploidy level change at the cellular level. It leads to the formation of polyploid cells and occurs during morphogenesis, i.e. differentiation of various organs of plants. The level of endopolyploidy is the result of the interaction of several factors such as the systematic position of the plant species, the ploidy level, the genome size and the developmental stage of plants, the type of tissues and organs, and environmental conditions. An increased endopolyploidy level is typical for cells of physiologically active tissues (e.g. leaf mesophyll, endosperm, cotyledons, tapetum) as well as for cells whose differentiation requires cell growth acceleration (e.g. trichomes, vascular tissue cells, pericarp cells). Endopolyploidy is phylogenetically determined and is also common in economically important angiosperm families such as Fabaceae, Brassicaceae, Solanaceae or Orchidaceae. Previous knowledge about changes in endopolyploidy in plant cells and associated variability in cell and organ growth is rather limited, obtained mostly by investigation of the model species Arabidopsis thaliana. The enormous taxonomic and morphological diversity of angiosperms represents an unexplored source of suitable models for the study of morphogenesis and associated endopolyploidy-induced changes at the cell and tissue level. The study of new model plants and objects (cells, tissues and organs) different from A. thaliana will bring new knowledge and a better understanding of the role of endopolyploidy in plant morphogenesis. The PhD student will have at his disposal a wide variety of research objects, the morphogenesis of which has not yet been studied with respect to the variable level of endopolyploidy. The aim of the dissertation thesis will be to characterize the level of endopolyploidy and morphological changes at the level of cells and tissues during morphogenesis of i) stress-induced pathologically modified plant organs, ii) variable morphotypes of normally developing organs in selected model species of polysomatic angiosperms (e.g. genera Brassica, Solanum and others.). During the study, the PhD student will learn several research techniques, e.g. flow cytometry, DIC and fluorescence microscopy, histochemical methods or biological 3D confocal imaging techniques. The student has the opportunity to undertake an internship abroad, during which he will be able to use advanced imaging techniques in his research.
The aim of the dissertation thesis will be to characterize the level of endopolyploidy and morphological changes at the level of cells and tissues during morphogenesis of i) stress-induced pathologically modified plant organs, ii) variable morphotypes of normally developing organs in selected model species of polysomatic angiosperms.
Harline K & Roeder AHK. 2023. An optimized pipeline for live imaging whole Arabidopsis leaves at cellular resolution. Plant Methods. 19. Maluszynska J, Kolano B, Sas-Nowosielska H. 2013. Endopolyploidy in plants. In: Leitch IJ, Greilhuber J, Wendel J, eds. Plant genome diversity vol. 2: physical structure, behaviour and evolution of plant genomes. Wien, Austria: Springer-Verlag, 101. Moreno S, Canales J, Hong L, Robinsin D, Roeder AHK, Gutiérrez RA. 2020. Nitrate defines shoot size through compensatory roles for endoreplication and cell division in Arabidopsis thaliana. Current Biology 30:1988–2000. Pacey EK, Maherali H, Husband BC. 2022. Polyploidy increases storage but decreases structural stability in Arabidopsis thaliana. Current Biology 32:4057–4063.e3. Robinson DO, Coate JE, Singh A, Hong LL, Bush M, Doyle JJ, Roeder AHK. 2018. Ploidy and size at multiple scales in the Arabidopsis sepal. The Plant Cell 30:2308–2329. Van de Peer Y, Ashman TL, Soltis PS, Soltis DE. 2021. Polyploidy: an evolutionary and ecological force in stressful times. The Plant Cell 33:11–26.
Mgr. Vladislav Kolarčik, PhD., univerzitný docent
Molecular Cytology and Genetics (MCGdAj)
Occurrence, regulation, selection, and crosstalk of endophytes in Hypericum spp. for in-situ anthraquinone biosynthesis.
Hypericum perforatum and related species are a reservoir of pharmacologically important secondary metabolites, including the well-known anthraquinone hypericin, possessing antineoplastic, photodynamic, antiviral and antibacterial properties. Endophytic microorganisms that colonize the internal tissues of plants frequently contribute to host metabolic function and protect plants against pests and diseases. However, the precise role of endophytes, and the molecular and chemical basis of endophytic interactions in Hypericum plants are not well understood. By employing Hypericum spp. as a model system, the aim of this work is to study in-situ endophytic colonization for impact on plant-microbe signaling pathways, phytohormones, microRNA interactions, and communication strategies such as quorum sensing for colony formation as well as endophyte trafficking in various tissues and essential organs, e.g., the dark glands. Notably, the impact of endophytes on the in-situ tissue/organ-specific biosynthesis of anthraquinones such as hypericin as chemical defense lines for protecting the host and endophytes themselves against invading phytopathogens will be determined. Both wild plants (greenhouse) and sterile plants (lab grown), as well as seeds obtained from mother plants during seeding stage, through the germination of the seeds, and finally up to the establishment of seedlings or daughter plants will be evaluated. Taken together, plant-endophyte interaction through the germination and development of Hypericum plants will be studied holistically at the genomic, transcriptomic, and metabolomic levels to understand of the role of endophytes in anthraquinone biosynthesis in Hypericum plants.
the aim of this work is to study in-situ endophytic colonization for impact on plant-microbe signaling pathways, phytohormones, microRNA interactions, and communication strategies such as quorum sensing for colony formation as well as endophyte trafficking in various tissues and essential organs.
Scientific periodicals.
Doc. dr hab. Souvik Kusari, PhD., univerzitný profesor
prof. RNDr. Eva Čellárová, DrSc.
Zoology and Animal physiology (ZFZd)
Impact of parasitic infection on physiological status of reptiles
Free-living reptiles are often infested with various species of parasites and subsequently infected with vector-borne pathogens, but the effect of this infection on the physiological parameters and health status of the host has not yet been sufficiently investigated. Current studies focus mostly on the monitoring of parasite diversity and abundance. Despite massive parasitemia, the clinical manifestation in reptiles is often inapparent, many individuals do not even show behavioral changes, but the presence of the parasite should induce the metabolic response of the host organism. The analysis of hematological and biochemical parameters will bring new knowledge about the functioning of individual organ systems in the conditions of an infected organism and will contribute to clarifying the parasite-pathogen-host interaction in the process of evolution in selected species of animals.
- determination of parasites and pathogens in wild reptiles - analysis of hematological and biochemical variables in selected wild reptile species and their comparison at the level of infected and non-infected individuals - monitoring of the basic behavioral manifestations of reptiles with confirmed deviations of he-matological and biochemical variables
Sykes, J. M., & Klaphake, E. (2008). Reptile Hematology. Veterinary Clinics of North America: Exotic Animal Practice, 11(3), 481–500. doi:10.1016/j.cvex.2008.03.005 Jacobson, Elliott R., ed. Infectious diseases and pathology of reptiles: color atlas and text. CRC Press, 2007. Chaleow Salakij, Jarernsak Salakij, Piyawan Suthunmapinunta, and Lawan Chanhome. 2002. “Hematology, Morphology and Ultrastructure of Blood Cells and Blood Parasites from Puff-Faced Watersnakes (Homalopsis Buccata)”. Agriculture and Natural Resources 36 (1). Bangkok, Thailand:35-43. Stacy, N. I., Alleman, A. R., & Sayler, K. A. (2011). Diagnostic Hematology of Reptiles. Clinics in Laboratory Medicine, 31(1), 87–108. doi:10.1016/j.cll.2010.10.006 Jacobson, Elliott R., ed. Infectious diseases and pathology of reptiles: color atlas and text. CRC Press, 2007.
doc. RNDr. Monika Kassayová, CSc.
RNDr. Viktória Majláthová, PhD., univerzitná docentka
Molecular Cytology and Genetics (MCGdAj)
Plant oktaketidsynthases
Oktaketidsynthases (OKSs) are the key enzymes of anthranoides biosynthesis. According to up to date knowledge, the first steps of hypericin biosynthesis include the formation of oktaketide by OKS; the expression of HpPKS2 in Hypericum spp. secretory structures, in which hypericins accumulate, was confirmed by in situ hybridization. Even though the OKS genes isolated from several plant genera were cloned and functionally characterized, the formation of linear oktaketides or non-functional aromatic polyketides was observed in most of the tested heterologous systems. Based on previous Arabidopsis thaliana study concerning the OKSs we assume that the use of plant model suitable for HpPKS2 validation would be valuable to elucidate the first steps of hypericin biosynthesis in Hypericum spp.
The aim of this thesis is the validation system preparation and experimental proof of heterologous expression of oktaketidsynthases (OKSs) involved in hypericins biosynthesis.
Relevant scientific literature, publications available from world databases (WOS, SCOPUS, ...)
doc. RNDr. Katarína Bruňáková, PhD.
RNDr. Jana Henzelyová, PhD.
Molecular Cytology and Genetics (MCGd)
Plant oktaketidsynthases
Oktaketidsynthases (OKSs) are the key enzymes of anthranoides biosynthesis. According to up to date knowledge, the first steps of hypericin biosynthesis include the formation of oktaketide by OKS; the expression of HpPKS2 in Hypericum spp. secretory structures, in which hypericins accumulate, was confirmed by in situ hybridization. Even though the OKS genes isolated from several plant genera were cloned and functionally characterized, the formation of linear oktaketides or non-functional aromatic polyketides was observed in most of the tested heterologous systems. Based on previous Arabidopsis thaliana study concerning the OKSs we assume that the use of plant model suitable for HpPKS2 validation would be valuable to elucidate the first steps of hypericin biosynthesis in Hypericum spp.
The aim of this thesis is the validation system preparation and experimental proof of heterologous expression of oktaketidsynthases (OKSs) involved in hypericins biosynthesis.
Relevant scientific literature, publications available from world databases (WOS, SCOPUS, ...)
doc. RNDr. Katarína Bruňáková, PhD.
RNDr. Jana Henzelyová, PhD.
Zoology and Animal physiology (ZFZd)
Collembolan communities (Hexapoda, Collembola) of the cave entrances and eco-physiological traits of selected species in surface subterranean environments
Natural microclimatic gradients, characterized by temperature and vegetation inversion, harbour high diversity of soil Collembola with the species differing in breadth of temperature tolerance. Cave entrances represent environmentally stable and heterogenous habitats characteristic with more or less pronounced environmental gradients, depending on their topology and morphology. Such habitats may serve as important microrefugia for endemic and relict species. Diversity and distributional patterns of collembolan communities in relation to environmental variables will be studied along entrances of caves in a broader geographic scale covering the Western Carpathian Mts and the Balkan Mts. Furthermore, the study will be focused on seasonal and acclimation effects on thermal tolerances of selected relict taxa inhabiting surface-subterranean interface at the cave entrances using modern morphological and ecophysiological methods.
1. To analyse patterns of diversity, community composition and ecology of Collembola occupying cave entrances in the Western Carpathians and Balkan Mts. 2. To assess season and acclimation effect on thermal tolerances (form of phenotypic plasticity) of selected springtails in the surface-subterranean interface.
Denlinger, D. L. and R. E. Lee. 2010. Low Temperature Biology of Insects. Cambridge: Cambridge University Press. 390 pp. Kováč, Ľ., Elhottová, D., Mock, A., Nováková, A., Krištůfek, V., Chroňáková, A., Lukešová, A., Mulec, J., Košel, V., Papáč, V., Ľuptáčik, P., Uhrin, M., Višňovská, Z., Hudec, I., Gaál, Ľ., Bella, P., 2014.The cave biota of Slovakia. Speleologia Slovaca 5. State Nature Conservancy SR, Slovak Caves Administration, Liptovský Mikuláš, 192 pp. Margesin R, Schinner F 1999. Cold-Adapted Organisms—Ecology, Physiology, Enzymology and Molecular Biology. Springer-Verlag, Berlin, 416 pp. Moldovan, O.T., Kováč, Ľ., Halse, S., 2018. Cave Ecology. Ecological Studies. Springer, 235, 545 pp. Wallwork, J.A. 1970. Ecology of Soil Animals. McGraw-Hill, England, 283 pp.
prof. RNDr. Ľubomír Kováč, CSc.
RNDr. Natália Raschmanová, PhD.
Plant physiology (FRd)
Stres metabilites in Lotus sp. and thier relevance in stress-response.
In stress conditions, production of secondary metabolites ignificantly contribute to stres-defense of plants. Moreover, that compounds have often antibacterial or other biological effects, which can be interesting from a pharmaceutical or medical point of view. The work would be focused on the research of biosynthesis and accumulation of flavonoids and isoflavonoids under stress conditions in the model species Lotus japonicus, in forage-varieties of L. corniculatus, or in other species of this genera. Compounds will be analyzed by chromatographic methods and identified by LC-MS. Their biosynthesis will be evaluated at the level of gene expression of involved biosynthetic enzymes or transcription factors. The Lotus species accumulate the isoflavan vestitol to a considerable extent, and its importance in plants as a defence metabolite. Alternatively, other important isoflavonoids may be also focused. In stress conditions, production of secondary metabolites ignificantly contribute to stres-defense of plants. Moreover, that compounds have often antibacterial or other biological effects, which can be interesting from a pharmaceutical or medical point of view. The work would be focused on the research of biosynthesis and accumulation of flavonoids and isoflavonoids under stress conditions in the model species Lotus japonicus, in forage-varieties of L. corniculatus, or in other species of this genera. Compounds will be analyzed by chromatographic methods and identified by LC-MS. Their biosynthesis will be evaluated at the level of gene expression of involved biosynthetic enzymes or transcription factors. The Lotus species accumulate the isoflavan vestitol to a considerable extent, and its importance in plants as a defence metabolite. Alternatively, other important isoflavonoids may be also focused.
The aim of the work is the evaluation of the biosynthesis and accumulation of flavonoids and isoflavonoids under stress conditions in the model species Lotus japonicus incl. Its mutant lines. The results will be compared in the forage-varieties of L. corniculatus, or in other species under the different external factors. Substances will be analysed by chromatographic methods and identified by LC-MS. The biosynthesis of these substances will also be monitored at the level of gene expression for biosynthetic enzymes or transcription factors. Tracking the accumulation of vestitol, clarifying its functions in plant defence. Other important isoflavonoids may be also focused.
doc. RNDr. Peter Paľove-Balang, PhD.
Molecular Cytology and Genetics (MCGdAj)
Targeted genome editing and epigenetic engineering of hypericin biosynthesis in Hypericum spp.-associated endophytic fungi for biotechnological production
Anthraquinones including hypericin, and its putative intermediates emodin, emodin anthrone, skyrin, and others are not only found in Hypericum perforatum (St. John’s wort) and related species, but also widespread in plant-associated fungal endophytes. Biosynthetic core genes and genes coding for regulatory elements are clustered in the fungal genomes. Despite its pharmacological importance, the complete biosynthetic pathway of hypericin and genes coding key enzymes remain largely unknown. Moreover, the genetic and epigenetic regulation of the precursors, reactive intermediates and the produced anthraquinone are not known either in plants or fungi. The aim of this work is to activate the hypericin biosynthetic gene clusters (BCGs) in Hypericum plant-associated selected endophytic fungi, or enhance expression of BCGs that remain silent or are minimally expressed under in vitro culture conditions. Targeted genome editing of endophytes using the short palindromic repeat (CRISPR)/CRISPR-associated protein (Cas9) system and virus-induced gene silencing (VIGS) methods, as well as an epigenetic engineering approach employing specific small-molecule chemical epigenetic modulators to modulate the endophytic fungal epigenome will be employed to activate target and non-target BCGs belonging to the biosynthetic pathway of hypericin and other relevant anthraquinones. Taken together, selected endophytes themselves will be explored as viable “induced” microbial resources for the sustained, high-yield production of hypericin and related anthraquinones.
The aim of this work is to activate the hypericin biosynthetic gene clusters (BCGs) in Hypericum plant-associated selected endophytic fungi, or enhance expression of BCGs that remain silent or are minimally expressed under in vitro culture conditions. Targeted genome editing of endophytes using the short palindromic repeat (CRISPR)/CRISPR-associated protein (Cas9) system and virus-induced gene silencing (VIGS) methods, as well as an epigenetic engineering approach employing specific small-molecule chemical epigenetic modulators to modulate the endophytic fungal epigenome will be employed to activate target and non-target BCGs belonging to the biosynthetic pathway of hypericin and other relevant anthraquinones.
Scientific papers.
Doc. dr hab. Souvik Kusari, PhD., univerzitný profesor
prof. RNDr. Eva Čellárová, DrSc.
Molecular Cytology and Genetics (MCGd)
Bacterial „dark matter“ in white sulfur mats
Bacterial "dark matter" refers to the unidentified and uncharacterized microbial species that inhabit various environments, including white sulfur mats. These mats are unique ecosystems found in sulfur springs, where bacterial communities thrive in an environment rich in sulfur compounds. The mats are formed by the metabolic activities of chemolithoautotrophic bacteria which obtain energy by hydrogen sulfide oxidation. Within these mats (especially cold-water), there exists a vast diversity of bacteria that have not been fully studied or characterized and our preliminary data indicate that nearly 50% of bacterial population in white sulfur mats are formed by completely unknown bacterial taxa. These bacteria are collectively referred to as "dark matter" due to our limited understanding of their ecological roles and metabolic capabilities. Many of these bacteria belong to novel lineages and possess unique genetic adaptations, suggesting their involvement in complex ecological processes within the mats. However, understanding their specific functions and interactions with other organisms remains a challenge. The aim of the project is to characterize bacterial diversity in cold-water sulfur springs in Slovakia using combination of cultivation and non-cultivation (metagenomic) approaches. The identification of bacterial "dark matter" in white sulfur mats has significant implications for our understanding of microbial ecology and evolution. By characterizing these elusive bacteria, we gain insights into their contributions to sulfur cycling, carbon fixation, and other biogeochemical processes within these mats but understanding the microbial diversity within white sulfur mats may have implications for understanding of microbial life on Earth and beyond, new metabolic pathways, adaptations, and ecological strategies that could have consequences for biotechnology, environmental science, and astrobiology as well.
The goal of the project is to know the biodiversity of non-cultivable bacteria in the white coatings of sulfur bacteria of sulfur springs in Slovakia and to analyze their metabolic potential based on the reconstruction of their genomes from metagenomic data
doc. RNDr. Peter Pristaš, CSc.
Zoology and Animal physiology (ZFZd)
The effect of electrical stimulation on axonal regeneration after peripheral nerve injury
After nerve injury, electrical stimulation accelerates the growth of axons, increases their number and improves reinnervation of end organs. However, the effectiveness of stimulation in the most severe form of nerve injury, in which there is extensive segmental loss of nerve tissue, is not known. In our experiments, we will study the effect of electrical stimulation on models of long segmental lesions of the peripheral nerve in the rat.
1) Introduce a methodology for the preparation of acellular rat peripheral nerve grafts. 2) Using a ventral caudal nerve model of segmental injury, evaluate the effects of electrical stimulation on axon regeneration in long acellular nerve grafts.
[1] D. Pan, S.E. Mackinnon, M.D. Wood, Advances in the repair of segmental nerve injuries and trends in reconstruction, Muscle Nerve, 61 (2020) 726-739. [2] T. Kornfeld, P.M. Vogt, C. Radtke, Nerve grafting for peripheral nerve injuries with extended defect sizes, Wien Med Wochenschr, 169 (2019) 240-251. [3] L. Juckett, T.M. Saffari, B. Ormseth, J.L. Senger, A.M. Moore, The Effect of Electrical Stimulation on Nerve Regeneration Following Peripheral Nerve Injury, Biomolecules, 12 (2022). [4] J. Roh, L. Schellhardt, G.C. Keane, D.A. Hunter, A.M. Moore, A.K. Snyder-Warwick, S.E. Mackinnon, M.D. Wood, Short-Duration, Pulsatile, Electrical Stimulation Therapy Accelerates Axon Regeneration and Recovery following Tibial Nerve Injury and Repair in Rats, Plast Reconstr Surg, 149 (2022) 681e-690e. [5] T. Gordon, N. Amirjani, D.C. Edwards, K.M. Chan, Brief post-surgical electrical stimulation accelerates axon regeneration and muscle reinnervation without affecting the functional measures in carpal tunnel syndrome patients, Exp Neurol, 223 (2010) 192-202. [6] J.N. Wong, J.L. Olson, M.J. Morhart, K.M. Chan, Electrical stimulation enhances sensory recovery: a randomized controlled trial, Ann Neurol, 77 (2015) 996-1006. [7] T.W. Hudson, S. Zawko, C. Deister, S. Lundy, C.Y. Hu, K. Lee, C.E. Schmidt, Optimized acellular nerve graft is immunologically tolerated and supports regeneration, Tissue Eng, 10 (2004) 1641-1651.
MVDr. Ivo Vanický, CSc.
Molecular Cytology and Genetics (MCGd)
Exploitation of nanostructures in the modulation of hydrophobic character and therapeutic potential of selected natural secondary metabolites
In recent years, remarkable progress has been made towards the application of nanoparticles (NPs) as a new approach in the treatment of cancer. NPs-based drug delivery systems offer many advantages over conventional forms, including increased efficacy and reduced systemic toxicity. Among the most significant advantages of NPs are increased solubility in water, increased bioavailability and half-life in plasma, as well as simple surface modification using targeted ligands. It is estimated that more than half of the common chemotherapy drugs are natural compounds or their synthetic derivatives. A promising natural compound with antitumor activity is hyperforin, a phloroglucinol produced by some plants of the genus Hypericum, especially St. John's wort (Hypericum perforatum L.). However, hyperforin is a lipophilic compound with poor solubility and stability in aqueous solutions. Hypericin is another secondary metabolite synthesized mainly by plants of the genus Hypericum. In addition to its activity in dark conditions, hypericin is primarily known for its excellent photosensitizing properties useful in photodynamic therapy (PDT) and diagnostics (PDD). However, even such a promising treatment approach as hypericin-mediated PDT has its drawbacks. They are related to the hydrophobic nature of hypericin, which limits the use of its full therapeutic potential. The aim of the dissertation thesis will be to determine the stability of NPs, tolerability of NPs by healthy cells and the success of conjugation of NPs with plant metabolites, by assessment of their intracellular accumulation and analyzing the potential antitumor effect using human colon tumor cell lines and microtumors formed on the chorioallantoic membrane of avian Japanese quail embryos.
The aim of the dissertation thesis will be to determine the stability of NPs, tolerability of NPs by healthy cells and the success of conjugation of NPs with plant metabolites, by assessment of their intracellular accumulation and analyzing the potential antitumor effect using human colon tumor cell lines and microtumors formed on the chorioallantoic membrane of avian Japanese quail embryos.
doc. RNDr. Rastislav Jendželovský, PhD.