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11.
Effect of the oral intake of astaxanthin on semen parameters in patients with oligo-astheno-teratozoospermia : a randomized double-blind placebo-controlled trial
Senka Imamović-Kumalić, Irma Virant-Klun, Eda Vrtačnik-Bokal, Bojana Pinter, 2021, original scientific article

Abstract: Background Higher concentrations of seminal reactive oxygen species may be related to male infertility. Astaxanthin with high antioxidant activity can have an impact on the prevention and treatment of various health conditions, including cancer. However, efficacy studies on astaxanthin in patients with oligospermia with/without astheno- or teratozoospermia (O+-A+-T) have not yet been reported. Our aim was to evaluate the effect of the oral intake of astaxanthin on semen parameters. Patients and methods In a randomized double-blind trial, 80 men with O+-A+-T were allocated to intervention with 16 mg astaxanthin orally daily or placebo. At baseline and after three months basic semen parameters, sperm deoxyribonucleic acid (DNA) fragmentation and mitochondrial membrane potential (MMP) of spermatozoa and serum follicle-stimulating hormone (FSH) value were measured. Results Analysis of the results of 72 patients completing the study (37 in the study group, 35 in the placebo group) did not show any statistically significant change, in the astaxanthin group no improvements in the total number of spermatozoa, concentration of spermatozoa, total motility of spermatozoa, morphology of spermatozoa, DNA fragmentation and mitochondrial membrane potential of spermatozoa or serum FSH were determined. In the placebo group, statistically significant changes in the total number and concentration of spermatozoa were determined. Conclusions The oral intake of astaxanthin did not affect any semen parameters in patients with O+-A+-T.
Keywords: DNA fragmentation, antioxidant, cancer
Published in DiRROS: 17.07.2024; Views: 88; Downloads: 59
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12.
Direct regulation of shikimate, early phenylpropanoid, and stilbenoid pathways by subgroup 2 R2R3-MYBs in grapevine
Luis Orduña, Miaomiao Li, David Navarro-Payá, Chen Zhang, A. Santiago, Pablo Romero, Živa Ramšak, Gabriele Magon, Janine Höll, Patrick Merz, Kristina Gruden, Alessandro Vannozzi, Dario Cantu, Jochen Bogs, Darren C. J. Wong, Shao-shan Carol Huang, José Tomás Matus, 2022, original scientific article

Abstract: The stilbenoid pathway is responsible for the production of resveratrol in grapevine (Vitis vinifera L.). A few transcription factors (TFs) have been identified as regulators of this pathway but the extent of this control has not been deeply studied. Here we show how DNA affinity purification sequencing (DAP-Seq) allows for the genome-wide TF-binding site interrogation in grape. We obtained 5190 and 4443 binding events assigned to 4041 and 3626 genes for MYB14 and MYB15, respectively (approximately 40% of peaks located within −10 kb of transcription start sites). DAP-Seq of MYB14/MYB15 was combined with aggregate gene co-expression networks (GCNs) built from more than 1400 transcriptomic datasets from leaves, fruits, and flowers to narrow down bound genes to a set of high confidence targets. The analysis of MYB14, MYB15, and MYB13, a third uncharacterized member of Subgroup 2 (S2), showed that in addition to the few previously known stilbene synthase (STS) targets, these regulators bind to 30 of 47 STS family genes. Moreover, all three MYBs bind to several PAL, C4H, and 4CL genes, in addition to shikimate pathway genes, the WRKY03 stilbenoid co-regulator and resveratrol-modifying gene candidates among which ROMT2-3 were validated enzymatically. A high proportion of DAP-Seq bound genes were induced in the activated transcriptomes of transient MYB15-overexpressing grapevine leaves, validating our methodological approach for delimiting TF targets. Overall, Subgroup 2 R2R3-MYBs appear to play a key role in binding and directly regulating several primary and secondary metabolic steps leading to an increased flux towards stilbenoid production. The integration of DAP-Seq and reciprocal GCNs offers a rapid framework for gene function characterization using genome-wide approaches in the context of non-model plant species and stands up as a valid first approach for identifying gene regulatory networks of specialized metabolism.
Keywords: secondary metabolism, regulatory networks, transcription factors, transcriptional regulation, DNA affinity purification sequencing
Published in DiRROS: 16.07.2024; Views: 97; Downloads: 95
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13.
HepG2 spheroids as a biosensor-like cell-based system for (geno)toxicity assessment
Martina Štampar, Sonja Žabkar, Metka Filipič, Bojana Žegura, 2022, original scientific article

Abstract: 3D spheroids developed from HepG2 cells were used as a biosensor-like system for the detection of (geno)toxic effects induced by chemicals. Benzo(a)pyrene (B(a)P) and amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) with well-known mechanisms of action were used for system validation. HepG2 spheroids grown for 3 days were exposed to BaP and PhIP for 24 and 72 h. The growth and viability of spheroids were monitored by planimetry and Live/Dead staining of cells. Multi-parametric flow cytometric analysis was applied for simultaneous detection of specific end-effects including cell cycle analysis (Hoechst staining), cell proliferation (KI67 marker), and DNA double-strand breaks (ℽH2AX) induced by genotoxic compounds. Depending on the exposure concentration/time, BaP reduced spheroid growth, affected cell proliferation by arresting cells in S and G2 phase and induced DNA double-strand breaks (DSB). Simultaneous staining of ℽH2AX formation and cell cycle analysis revealed that after BaP (10 μM; 24 h) exposure 60% of cells in G0/G1 phase had DNA DSB, while after 72 h only 20% of cells contained DSB indicating efficient repair of DNA lesions. PhIP did not influence the spheroid size whereas accumulation of cells in the G2 phase occurred after both treatment times. The evaluation of DNA damage revealed that at 200 μM PhIP 50% of cells in G0/G1 phase had DNA DSB, which after 72-h exposure dropped to 40%, showing lower repair capacity of PhIP-induced DSB compared to BaP-induced. The developed approach using simultaneous detection of several parameters provides mechanistic data and thus contributes to more reliable genotoxicity assessment of chemicals as a high-content screening tool.
Keywords: in vitro 3D cell model, HepG2, flow cytometry, cell cycle, proliferation, DNA strand, breaks
Published in DiRROS: 16.07.2024; Views: 108; Downloads: 84
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14.
Pulsed low dose-rate irradiation response in isogenic HNSCC cell lines with different radiosensitivity
Vesna Todorović, Ajda Prevc, Martina Nikšić Žakelj, Monika Savarin, Simon Buček, Blaž Grošelj, Primož Strojan, Maja Čemažar, Gregor Serša, 2020, original scientific article

Abstract: . Management of locoregionally recurrent head and neck squamous cell carcinomas (HNSCC) is challenging due to potential radioresistance. Pulsed low-dose rate (PLDR) irradiation exploits phenomena of increased radiosensitivity, low-dose hyperradiosensitivity (LDHRS), and inverse dose-rate effect. The purpose of this study was to evaluate LDHRS and the effect of PLDR irradiation in isogenic HNSCC cells with different radiosensitivity. Materials and methods. Cell survival after different irradiation regimens in isogenic parental FaDu and radioresistant FaDu-RR cells was determined by clonogenic assay; post irradiation cell cycle distribution was studied by flow cytometry; the expression of DNA damage signalling genes was assesed by reverse transcription-quantitative PCR. Results. Radioresistant Fadu-RR cells displayed LDHRS and were more sensitive to PLDR irradiation than parental FaDu cells. In both cell lines, cell cycle was arrested in G2/M phase 5 hours after irradiation. It was restored 24 hours after irradiation in parental, but not in the radioresistant cells, which were arrested in G1-phase. DNA damage signalling genes were under-expressed in radioresistant compared to parental cells. Irradiation increased DNA damage signalling gene expression in radioresistant cells, while in parental cells only few genes were under-expressed. Conclusions. We demonstrated LDHRS in isogenic radioresistant cells, but not in the parental cells. Survival of LDHRSpositive radioresistant cells after PLDR was significantly reduced. This reduction in cell survival is associated with variations in DNA damage signalling gene expression observed in response to PLDR most likely through different regulation of cell cycle checkpoints.
Keywords: DNA damage, isogenic cell lines, low dose irradiation, pulsed low dose-rate irradiation, radiosensitivity
Published in DiRROS: 12.07.2024; Views: 112; Downloads: 36
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15.
Evaluation of DNA extraction methods for reliable quantification of Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa
Alexandra Bogožalec Košir, Dane Lužnik, Viktorija Tomič, Mojca Milavec, 2023, original scientific article

Abstract: Detection and quantification of DNA biomarkers relies heavily on the yield and quality of DNA obtained by extraction from different matrices. Although a large number of studies have compared the yields of different extraction methods, the repeatability and intermediate precision of these methods have been largely overlooked. In the present study, five extraction methods were evaluated, using digital PCR, to determine their efficiency in extracting DNA from three different Gram-negative bacteria in sputum samples. The performance of two automated methods (GXT NA and QuickPick genomic DNA extraction kit, using Arrow and KingFisher Duo automated systems, respectively), two manual kit-based methods (QIAamp DNA mini kit; DNeasy UltraClean microbial kit), and one manual non-kit method (CTAB), was assessed. While GXT NA extraction kit and the CTAB method have the highest DNA yield, they did not meet the strict criteria for repeatability, intermediate precision, and measurement uncertainty for all three studied bacteria. However, due to limited clinical samples, a compromise is necessary, and the GXT NA extraction kit was found to be the method of choice. The study also showed that dPCR allowed for accurate determination of extraction method repeatability, which can help standardize molecular diagnostic approaches. Additionally, the determination of absolute copy numbers facilitated the calculation of measurement uncertainty, which was found to be influenced by the DNA extraction method used.
Keywords: nucleic acid, dPCR, DNA extraction methods, Gram-negative bacteria
Published in DiRROS: 12.07.2024; Views: 112; Downloads: 132
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Verifikacijsko poročilo LVG POS 025
Zina Devetak, 2024, expertise, arbitration decision

Keywords: varstvo gozdov, morfološke analize, Bretziella fagacearum, hrastova uvelost, diagnostični protokol, molekularna analiza, ekstrakcija DNA, PCR v realnem času, verifikacija
Published in DiRROS: 21.06.2024; Views: 168; Downloads: 0
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Nature-inspired substituted 3-(imidazol-2-yl) morpholines targeting human topoisomerase IIα : dynophore-derived discovery
Barbara Herlah, Matej Janežič, Iza Ogris, Simona Golič Grdadolnik, Katja Kološa, Sonja Žabkar, Bojana Žegura, Andrej Perdih, 2024, original scientific article

Abstract: The molecular nanomachine, human DNA topoisomerase IIα, plays a crucial role in replication, transcription, and recombination by catalyzing topological changes in the DNA, rendering it an optimal target for cancer chemotherapy. Current clinical topoisomerase II poisons often cause secondary tumors as side effects due to the accumulation of double-strand breaks in the DNA, spurring the development of catalytic inhibitors. Here, we used a dynamic pharmacophore approach to develop catalytic inhibitors targeting the ATP binding site of human DNA topoisomerase IIα. Our screening of a library of nature-inspired compounds led to the discovery of a class of 3-(imidazol-2-yl) morpholines as potent catalytic inhibitors that bind to the ATPase domain. Further experimental and computational studies identified hit compound 17, which exhibited selectivity against the human DNA topoisomerase IIα versus human protein kinases, cytotoxicity against several human cancer cells, and did not induce DNA double-strand breaks, making it distinct from clinical topoisomerase II poisons. This study integrates an innovative natural product-inspired chemistry and successful implementation of a molecular design strategy that incorporates a dynamic component of ligand-target molecular recognition, with comprehensive experimental characterization leading to hit compounds with potential impact on the development of more efficient chemotherapies.
Keywords: topoisomerase II, catalytic inhibitors, chemotherapy, DNA damage, cancer
Published in DiRROS: 03.06.2024; Views: 331; Downloads: 211
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