The glycoprotein clusterin (CLU) is involved in cell proliferation and DNA damage repair and is highly expressed in tumor cells. Here, we aimed to investigate the effects of CLU dysregulation on two human astrocytic cell lines: CCF-STTG1 astrocytoma cells and SV-40 immortalized normal human astrocytes. We observed that suppression of CLU expression by RNA interference inhibited cell proliferation, triggered the DNA damage response, and resulted in cellular senescence in both cell types tested. To further investigate the underlying mechanism behind these changes, we measured reactive oxygen species, assessed mitochondrial function, and determined selected markers of the senescence-associated secretory phenotype. Our results suggest that CLU deficiency triggers oxidative stress-mediated cellular senescence associated with pronounced alterations in mitochondrial membrane potential, mitochondrial mass, and expression levels of OXPHOS complex I, II, III and IV, indicating mitochondrial dysfunction. This report shows the important role of CLU in cell cycle maintenance in astrocytes. Based on these data, targeting CLU may serve as a potential therapeutic approach valuable for treating gliomas.
- MeSH
- astrocyty * metabolismus patologie MeSH
- klusterin * metabolismus genetika MeSH
- lidé MeSH
- membránový potenciál mitochondrií * fyziologie MeSH
- mitochondrie * metabolismus MeSH
- nádorové buněčné linie MeSH
- oxidační stres fyziologie MeSH
- oxidativní fosforylace MeSH
- poškození DNA MeSH
- proliferace buněk * MeSH
- reaktivní formy kyslíku metabolismus MeSH
- stárnutí buněk * fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Mitochondria are vital organelles with their own DNA (mtDNA). mtDNA is circular and composed of heavy and light chains that are structurally more accessible than nuclear DNA (nDNA). While nDNA is typically diploid, the number of mtDNA copies per cell is higher and varies considerably during development and between tissues. Compared with nDNA, mtDNA is more prone to damage that is positively linked to many diseases, including cancer. Similar to nDNA, mtDNA undergoes repair processes, although these mechanisms are less well understood. In this review, we discuss the various forms of mtDNA damage and repair and their association with cancer initiation and progression. We also propose horizontal mitochondrial transfer as a novel mechanism for replacing damaged mtDNA.
- MeSH
- lidé MeSH
- mitochondriální DNA * genetika MeSH
- mitochondrie * genetika metabolismus MeSH
- nádory * genetika patologie MeSH
- oprava DNA * MeSH
- poškození DNA * genetika MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Phase separation forms membraneless compartments, including heterochromatin "domains" and repair foci. Pericentromeric heterochromatin mostly comprises repeated sequences prone to aberrant recombination. In Drosophila cells, "safe" homologous recombination (HR) repair of these sequences requires their relocalization to the nuclear periphery before Rad51 recruitment and strand invasion. How this mobilization initiates is unknown, and the contribution of phase separation is unclear. Here, we show that Nup98 nucleoporin is recruited to repair sites before relocalization by Sec13 or Nup88, and downstream of the Smc5/6 complex and heterochromatin protein 1 (HP1). Remarkably, Nup98 condensates are immiscible with HP1 condensates, and they are required and sufficient to mobilize repair sites and exclude Rad51, thus preventing aberrant recombination while promoting HR repair. Disrupting this pathway results in heterochromatin repair defects and widespread chromosome rearrangements, revealing an "off-pore" role for nucleoporins and phase separation in nuclear dynamics and genome integrity in a multicellular eukaryote.
- MeSH
- chromozomální proteiny, nehistonové metabolismus genetika MeSH
- Drosophila melanogaster * genetika metabolismus MeSH
- dvouřetězcové zlomy DNA MeSH
- heterochromatin * genetika metabolismus MeSH
- homolog proteinu s chromoboxem 5 MeSH
- komplex proteinů jaderného póru * metabolismus genetika MeSH
- proteiny buněčného cyklu metabolismus genetika MeSH
- proteiny Drosophily * metabolismus genetika MeSH
- rekombinační oprava DNA * MeSH
- rekombinasa Rad51 * metabolismus genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The use of microfluidic sperm sorting (MFSS) systems in infertility treatment is increasing due to their practicality and ease of use. While often presented as highly effective, their efficacy in patients with varying sperm analysis results remains uncertain. In this study, we evaluated the effectiveness of MFSS compared with the swim-up (SU) technique in terms of oxygen radical levels and spermiogram parameters. Samples from each patient were processed using both methods, followed by assessments of sperm concentration, motility, morphology, DNA integrity, acrosomal status, and mitochondrial membrane potential. Participants were selected based on sperm analysis and categorized as normozoospermic (n = 40) or non-normozoospermic (n = 28). An analysis of separation techniques revealed no significant differences, except for a lower percentage of DNA-fragmented sperm in the MFSS group compared with SU within the non-normozoospermic cohort (SU: 10.0% vs. MFSS: 5.69%, p = 0.027). No differences were observed between SU and MFSS in normozoospermic men. The MFSS method is a simple technique, frequently used in laboratories, that yields good results but does not offer a substantial advantage over SU. The primary benefit of MFSS appears to be a significant reduction in the proportion of sperm with DNA fragmentation compared with SU in patients with abnormal sperm analysis results.
- MeSH
- analýza spermatu metody MeSH
- dospělí MeSH
- fragmentace DNA MeSH
- intracytoplazmatické injekce spermie * metody MeSH
- lidé MeSH
- membránový potenciál mitochondrií MeSH
- mikrofluidika * metody MeSH
- motilita spermií * MeSH
- mužská infertilita terapie MeSH
- separace buněk * metody MeSH
- spermie * cytologie metabolismus MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
Mužská neplodnost je komplexní stav s mnoha etiologickými faktory, včetně hormonálních, anatomických, genetických a vlivů životního stylu. Přestože se mužský faktor podílí až na 40 % případů neplodnosti, přesná příčina zůstává často neznámá (tzv. idiopatická neplodnost). Současné diagnostické metody zahrnují detailní klinické vyšetření, analýzu ejakulátu, hormonální profil, genetické testování a zobrazovací techniky. Výrazný pokrok byl zaznamenán v oblasti testování fragmentace DNA spermií a měření oxidačního stresu, jež poskytují širší pohled na kvalitu spermií. Terapeutické postupy se liší podle příčiny neplodnosti – od farmakologické léčby a chirurgických intervencí až po asistovanou reprodukci. Rychle se rozvíjející výzkum v oblasti regenerativní a genové terapie slibuje nové možnosti léčby. Nedílnou součástí prevence i léčby je rovněž zdravý životní styl a management rizikových faktorů.
Male infertility is a multifactorial condition influenced by hormonal, anatomical, genetic, and lifestyle factors. Although the male factor contributes to up to 40% of infertility cases, the exact etiology often remains unknown (so-called idiopathic infertility). Current diagnostic approaches include detailed clinical evaluation, semen analysis, hormonal assessment, genetic testing, and imaging techniques. Significant progress has been achieved in sperm DNA fragmentation testing and oxidative stress evaluation, offering a broader insight into sperm quality. Treatment strategies vary depending on the underlying cause, ranging from pharmacological therapy and surgical interventions to assisted reproductive technologies. Rapid advances in regenerative medicine and gene therapy show promise for novel therapeutic options. A healthy lifestyle and risk factor management are integral to both prevention and treatment.
Across the tree of life, DNA damage response (DDR) proteins play a pivotal, yet dichotomous role in organismal development and evolution. Here, we present a comprehensive analysis of 432 DDR proteins encoded by 68 genomes, including that of Nucleospora cyclopteri, an intranuclear microsporidia sequenced in this study. We compared the DDR proteins encoded by these genomes to those of humans to uncover the DNA repair-ome across phylogenetically distant eukaryotes. We also performed further analyses to understand if organismal complexity and lifestyle play a role in the evolution of DDR protein length and conserved domain architecture. We observed that the genomes of extreme parasites such as Paramicrocytos, Giardia, Spironucleus, and certain microsporidian lineages encode the smallest eukaryotic repertoire of DDR proteins and that pathways involved in modulation of nucleotide pools and nucleotide excision repair are the most preserved DDR pathways in the eukaryotic genomes analysed here. We found that DDR and DNA repair proteins are consistently longer than housekeeping and metabolic proteins. This is likely due to the higher number of physical protein-protein interactions which DDR proteins are involved. We find that although DNA repair proteins are generally longer than housekeeping proteins, their functional domains occupy a relatively smaller footprint. Notably, this pattern holds true across diverse organisms and shows no dependence on either lifestyle or mitochondrial status. Finally, we observed that unicellular organisms harbour proteins that are tenfold longer than their human homologues, with the extra amino acids forming interdomain regions with a clearly novel albeit undetermined function.
- MeSH
- Eukaryota * genetika MeSH
- fylogeneze MeSH
- lidé MeSH
- Microsporidia genetika MeSH
- molekulární evoluce * MeSH
- oprava DNA * MeSH
- poškození DNA * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Pancreatic cancer (PC) is becoming one of the most serious health problems at present, but its causes and risk factors are still unclear. One of the drivers in pancreatic carcinogenesis is altered genomic (DNA) integrity with subsequent genomic instability in cancer cells. The latter comprises a) DNA damage response and DNA repair mechanisms, b) DNA replication and mitosis, c) epigenetic regulation, and d) telomere maintenance. In our review we addressed the above aspects in relation to the most abundant and severe form of PC, pancreatic ductal adenocarcinoma (PDAC). In summary, the interactions between the DNA damage response, telomere homeostasis and mitotic regulation are not comprehensively understood at present, including the epigenetic factors entering the trait of genomic stability maintenance. In addition, the complexity of telomere homeostasis in relation to PDAC risk, prognosis and prediction also warrants further investigations.
- MeSH
- duktální karcinom slinivky břišní * genetika patologie MeSH
- epigeneze genetická MeSH
- homeostáza telomer * genetika MeSH
- lidé MeSH
- nádory slinivky břišní * genetika patologie MeSH
- nestabilita genomu * MeSH
- oprava DNA MeSH
- poškození DNA * MeSH
- telomery * genetika MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Many photosensitive substances suitable for photodynamic therapy (PDT) have limited applications due to their insufficient solubility in polar solvents. Our research overcomes this challenge by means of nanotechnology in order to transform hydrophobic compounds into stable aqueous solutions, enabling them to use their full potential and unique properties in cancer therapy. In this study, the novel nano-composite cGQDs-PEG-curcumin was developed to overcome the insolubility of curcumin in water and its extraordinary efficacy in PDT was evaluated. Complex characterization was performed using high-resolution transmission electron microscopy (HR-TEM), FTIR, and UV-Vis spectroscopy. Further analysis involved fluorescence lifetime imaging (FLIM), and its cellular localization was mapped with confocal microscopy. In order to evaluate PDT effectiveness, cells treated with cGQDs-PEG-curcumin were irradiated with 5 J/cm2 of 414 nm light. After irradiation, cell viability assay, scanning electron microscopy (SEM), reactive oxygen species (ROS) detection, comet assay, and γH2AX-based DNA double-strand breaks (DSBs) detection were assessed and revealed a remarkable ability of the nano-composite to induce DNA damage after irradiation without ROS production. Our findings highlight the potential of cGQDs-PEG-curcumin as a cutting-edge PDT agent, capable of disrupting cell membrane and nucleolar integrity and impairing ribosomal synthesis, which is crucial for proliferating tumour cells.
- MeSH
- buněčné jadérko * účinky léků metabolismus MeSH
- dvouřetězcové zlomy DNA účinky léků MeSH
- fotochemoterapie * metody MeSH
- fotosenzibilizující látky * farmakologie MeSH
- grafit * chemie farmakologie MeSH
- kurkumin * farmakologie chemie MeSH
- kvantové tečky * chemie MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nádory * farmakoterapie MeSH
- polyethylenglykoly * chemie farmakologie MeSH
- poškození DNA * účinky léků MeSH
- reaktivní formy kyslíku metabolismus MeSH
- viabilita buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Previous research indicated that the cytotoxic activity of the antitumor platinum(II) complex [Pt(1S,2S-diaminocyclohexane)(5,6-dimethyl-1,10-phenanthroline)]2+ (56MESS) was not primarily attributed to DNA binding, despite the complex being confirmed to localize also in the nucleus. In this study, we have demonstrated that the antiproliferative activity of 56MESS indeed involves DNA binding. Furthermore, in addition to binding duplex DNA, the complex also interacts with non-canonical secondary DNA structures, such as G-quadruplexes (G4s) and i-Motifs (iMs). This interaction leads to the suppression of G-regulated oncogene expression and disrupts key enzymatic processes associated with DNA, potentially contributing to DNA damage and the biological activity of 56MESS. These findings build upon previously published results, revealing that the anticancer activity of 56MESS is significantly more multifaceted than previously understood, involving multiple distinct mechanisms.
- MeSH
- DNA metabolismus chemie MeSH
- down regulace * účinky léků MeSH
- G-kvadruplexy * účinky léků MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- organoplatinové sloučeniny * farmakologie chemie MeSH
- poškození DNA * účinky léků MeSH
- proliferace buněk účinky léků MeSH
- protinádorové látky * farmakologie chemie MeSH
- protoonkogenní proteiny c-myc * genetika metabolismus MeSH
- protoonkogenní proteiny p21(ras) * genetika metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Nucleotide excision repair (NER) is crucial for repairing bulky lesions and crosslinks in DNA caused by exogenous and endogenous genotoxins. The number of studies that have considered DNA repair as a biomarker is limited, and therefore one of the primary objectives of the European COST Action hCOMET (CA15132) was to assemble and analyse a pooled database of studies with data on NER activity. The database comprised 738 individuals, gathered from 5 laboratories that ran population studies using the comet-based in vitro DNA repair assay. NER activity data in peripheral blood mononuclear cells were normalized and correlated with various host-related factors, including sex, age, body mass index (BMI), and smoking habits. This multifaceted analysis uncovered significantly higher NER activity in female participants compared to males (1.08 ± 0.74 vs. 0.92 ± 0.71; P = .002). Higher NER activity was seen in older subjects (>30 years), and the effect of age was most pronounced in the oldest females, particularly those over 70 years (P = .001). Females with a normal BMI (<25 kg/m2) exhibited the highest levels of NER, whereas the lowest NER was observed in overweight males (BMI ≥ 25 kg/m2). No independent effect of smoking was found. After stratification by sex and BMI, higher NER was observed in smoking males (P = .017). The biological implication of higher or lower repair capacity remains unclear; the inclusion of DNA repair as a biomarker in molecular epidemiological trials should elucidate the link between health and disease status.
- MeSH
- dospělí MeSH
- excizní oprava MeSH
- index tělesné hmotnosti MeSH
- kometový test MeSH
- kouření MeSH
- leukocyty mononukleární metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- oprava DNA * MeSH
- poškození DNA MeSH
- senioři MeSH
- sexuální faktory MeSH
- věkové faktory MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
