cell reprogramming
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Objev indukované pluripotence v roce 2006 umožnil revoluční způsob získávaní autologních terapeuticky aplikovatelných buněk, a mož‐ nost modelovat jakékoliv onemocnění v in vitro podmínkách. Možnost vrátit libovolnou, finálně diferencovanou buňku „v čase“ zpátky do stádia pluripotence je zajímavé i pro oblast onkologického výzkumu. Tato technologie umožnila studium procesů spojených s roz‐ vojem nádorového fenotypu buňky a taky s přechodem nádorové buňky do stádia s nižší mírou diferenciace. Reprogramování buněk do indukovaných pluripotentních kmenových buněk také pomáhá mnohem lépe studovat raritní populaci buněk, přítomných v nádo‐ rech – tzv. nádorové kmenové buňky. Indukovaná pluripotence některých typů nádorových buněk, spojená s jejich následnou řízenou diferenciací by se zároveň mohla stát jednou z možných terapeutických aplikací v onkologii.
Discovery of technology of induced pluripotency that allows the generation of autologous therapeutically applicable cells and generati‐ on of in vitro cell models for diseases with limited (or highly invasive) access to tested cells has also opened new horizons in the field of oncology research. The unique ability to reprogram the cancer cell into pluripotency with subsequent directed differentiation into cell with no malignant phenotype should be considered as a challenge in the field of new oncotherapy development. Although still conside‐ red to be realistic only on the level of experimental approach, the recent progress in the field of induced pluripotency gives the hope that dedifferentiation‐based therapies connected with the erase of malignant phenotype of original cancer cell will be more realistic in near future. By then, the most important role of induced pluripotency in oncology remains in the field of regenerative therapy as a source of autologous cells for regeneration of tissues or organs damaged by tumor growth or aggressive therapy
Aim: Human induced pluripotent stem cells (iPSCs) are inefficiently derived from somatic cells by overexpression of defined transcription factors. Overexpression of H2A histone variant macroH2A1.1, but not macroH2A1.2, leads to increased iPSC reprogramming by unclear mechanisms. Materials & methods: Cleavage under targets and tagmentation (CUT&Tag) allows robust epigenomic profiling of a low cell number. We performed an integrative CUT&Tag-RNA-Seq analysis of macroH2A1-dependent orchestration of iPSCs reprogramming using human endothelial cells. Results: We demonstrate wider genome occupancy, predicted transcription factors binding, and gene expression regulated by macroH2A1.1 during reprogramming, compared to macroH2A1.2. MacroH2A1.1, previously associated with neurodegenerative pathologies, specifically activated ectoderm/neural processes. Conclusion: CUT&Tag and RNA-Seq data integration is a powerful tool to investigate the epigenetic mechanisms occurring during cell reprogramming.
- MeSH
- endoteliální buňky metabolismus MeSH
- histony * metabolismus MeSH
- indukované pluripotentní kmenové buňky * metabolismus MeSH
- lidé MeSH
- přeprogramování buněk genetika MeSH
- sekvenování transkriptomu MeSH
- transkripční faktory genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Human induced pluripotent stem cells (hiPSCs) play roles in both disease modelling and regenerative medicine. It is critical that the genomic integrity of the cells remains intact and that the DNA repair systems are fully functional. In this article, we focused on the detection of DNA double-strand breaks (DSBs) by phosphorylated histone H2AX (known as γH2AX) and p53-binding protein 1 (53BP1) in three distinct lines of hiPSCs, their source cells, and one line of human embryonic stem cells (hESCs). METHODS: We measured spontaneously occurring DSBs throughout the process of fibroblast reprogramming and during long-term in vitro culturing. To assess the variations in the functionality of the DNA repair system among the samples, the number of DSBs induced by γ-irradiation and the decrease over time was analysed. The foci number was detected by fluorescence microscopy separately for the G1 and S/G2 cell cycle phases. RESULTS: We demonstrated that fibroblasts contained a low number of non-replication-related DSBs, while this number increased after reprogramming into hiPSCs and then decreased again after long-term in vitro passaging. The artificial induction of DSBs revealed that the repair mechanisms function well in the source cells and hiPSCs at low passages, but fail to recognize a substantial proportion of DSBs at high passages. CONCLUSIONS: Our observations suggest that cellular reprogramming increases the DSB number but that the repair mechanism functions well. However, after prolonged in vitro culturing of hiPSCs, the repair capacity decreases.
- MeSH
- 53BP1 genetika metabolismus MeSH
- buněčné linie MeSH
- DNA genetika metabolismus MeSH
- dvouřetězcové zlomy DNA * účinky záření MeSH
- exprese genu MeSH
- fibroblasty cytologie metabolismus účinky záření MeSH
- fosforylace účinky záření MeSH
- histony genetika metabolismus MeSH
- indukované pluripotentní kmenové buňky cytologie metabolismus účinky záření MeSH
- kontrolní body fáze G1 buněčného cyklu genetika MeSH
- kontrolní body fáze G2 buněčného cyklu genetika MeSH
- lidé MeSH
- lidské embryonální kmenové buňky cytologie metabolismus účinky záření MeSH
- oprava DNA genetika MeSH
- přeprogramování buněk MeSH
- stárnutí buněk genetika účinky záření MeSH
- záření gama MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Differentiated nuclei can be reprogrammed/remodelled to totipotency after their transfer to enucleated metaphase II (MII) oocytes. The process of reprogramming/remodelling is, however, only partially characterized. It has been shown that the oocyte nucleus (germinal vesicle - GV) components are essential for a successful remodelling of the transferred nucleus by providing the materials for pseudo-nucleus formation. However, the nucleus is a complex structure and exactly what nuclear components are required for a successful nucleus remodelling and reprogramming is unknown. Till date, the only nuclear sub-structure experimentally demonstrated to be essential is the oocyte nucleolus (nucleolus-like body, NLB). In this study, we investigated what other GV components might be necessary for the formation of normal-sized pseudo-pronuclei (PNs). Our results showed that the removal of the GV nuclear envelope with attached chromatin and chromatin-bound factors does not substantially influence the size of the remodelled nuclei in reconstructed cells and that their nuclear envelopes seem to have normal parameters. Rather than the insoluble nuclear lamina, the GV content, which is dissolved in the cytoplasm with the onset of oocyte maturation, influences the characteristics and size of transferred nuclei.
- MeSH
- buněčné jadérko metabolismus MeSH
- buněčné jádro metabolismus MeSH
- chromatin metabolismus MeSH
- cytoplazma metabolismus MeSH
- jaderná lamina metabolismus MeSH
- jaderný obal metabolismus MeSH
- messenger RNA metabolismus MeSH
- myši MeSH
- oocyty cytologie metabolismus MeSH
- oogeneze MeSH
- ovariální folikul metabolismus MeSH
- přeprogramování buněk * MeSH
- techniky jaderného přenosu * MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The aim of this study was to extensively characterise natal dental pulp stem cells (nDPSC) and assess their efficiency to generate human induced pluripotent stem cells (hiPSC). A number of distinguishing features prompted us to choose nDPSC over normal adult DPSC, in that they differed in cell surface marker expression and initial doubling time. In addition, nDPSC expressed 17 out of 52 pluripotency genes we analysed, and the level of expression was comparable to human embryonic stem cells (hESC). Ours is the first group to report comprehensive characterization of nDPSC followed by directed reprogramming to a pluripotent stem cell state. nDPSC yielded hiPSC colonies upon transduction with Sendai virus expressing the pluripotency transcription factors POU5F1, SOX2, c-MYC and KLF4. nDPSC had higher reprogramming efficiency compared to human fibroblasts. nDPSC derived hiPSCs closely resembled hESC in terms of their morphology, expression of pluripotency markers and gene expression profiles. Furthermore, nDPSC derived hiPSCs differentiated into the three germ layers when cultured as embryoid bodies (EB) and by directed differentiation. Based on our findings, nDPSC present a unique marker expression profile compared with adult DPSC and possess higher reprogramming efficiency as compared with dermal fibroblasts thus proving to be more amenable for reprogramming.
- MeSH
- biologické markery MeSH
- buněčná diferenciace genetika MeSH
- embryoidní tělíska cytologie MeSH
- fibroblasty cytologie metabolismus MeSH
- indukované pluripotentní kmenové buňky cytologie metabolismus MeSH
- karyotyp MeSH
- kmenové buňky cytologie metabolismus MeSH
- kultivované buňky MeSH
- lidé MeSH
- předmléčné zuby cytologie MeSH
- přeprogramování buněk * MeSH
- transkriptom MeSH
- vývojová regulace genové exprese MeSH
- zubní dřeň cytologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Oct4-mediated reprogramming has recently become a novel tool for the generation of various cell types from differentiated somatic cells. Although molecular mechanisms underlying this process are unknown, it is well documented that cells over-expressing Oct4 undergo transition from differentiated state into plastic state. This transition is associated with the acquisition of stem cells properties leading to epigenetically "open" state that is permissive to cell fate switch upon external stimuli. In order to contribute to our understanding of molecular mechanisms driving this process, we characterised human fibroblasts over-expressing Oct4 and performed comprehensive small-RNAseq analysis. Our analyses revealed new interesting aspects of Oct4-mediated cell plasticity induction. Cells over-expressing Oct4 lose their cell identity demonstrated by down-regulation of fibroblast-specific genes and up-regulation of epithelial genes. Interestingly, this process is associated with microRNA expression profile that is similar to microRNA profiles typically found in pluripotent stem cells. We also provide extensive network of microRNA families and clusters allowing us to precisely determine the miRNAome associated with the acquisition of Oct4-induced transient plastic state. Our data expands current knowledge of microRNA and their implications in cell fate alterations and contributing to understanding molecular mechanisms underlying it.
- MeSH
- buněčné linie MeSH
- embryo savčí * MeSH
- fibroblasty cytologie metabolismus MeSH
- lidé MeSH
- mikro RNA * biosyntéza genetika MeSH
- oktamerní transkripční faktor 3 * biosyntéza genetika MeSH
- regulace genové exprese * MeSH
- techniky buněčného přeprogramování * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Prostate cancer (PCa) and Type 2 diabetes (T2D) often co-occur, yet their relationship remains elusive. While some studies suggest that T2D lowers PCa risk, others report conflicting data. This study investigates the effects of peroxisome proliferator-activated receptor (PPAR) agonists Bezafibrate, Tesaglitazar, and Pioglitazone on PCa tumorigenesis. Analysis of patient datasets revealed that high PPARG expression correlates with advanced PCa and poor survival. The PPARγ agonists Pioglitazone and Tesaglitazar notably reduced cell proliferation and PPARγ protein levels in primary and metastatic PCa-derived cells. Proteomic analysis identified intrinsic differences in mTORC1 and mitochondrial fatty acid oxidation (FAO) pathways between primary and metastatic PCa cells, which were further disrupted by Tesaglitazar and Pioglitazone. Moreover, metabolomics, Seahorse Assay-based metabolic profiling, and radiotracer uptake assays revealed that Pioglitazone shifted primary PCa cells' metabolism towards glycolysis and increased FAO in metastatic cells, reducing mitochondrial ATP production. Furthermore, Pioglitazone suppressed cell migration in primary and metastatic PCa cells and induced the epithelial marker E-Cadherin in primary PCa cells. In vivo, Pioglitazone reduced tumor growth in a metastatic PC3 xenograft model, increased phosho AMPKα and decreased phospho mTOR levels. In addition, diabetic PCa patients treated with PPAR agonists post-radical prostatectomy implied no biochemical recurrence over five to ten years compared to non-diabetic PCa patients. Our findings suggest that Pioglitazone reduces PCa cell proliferation and induces metabolic and epithelial changes, highlighting the potential of repurposing metabolic drugs for PCa therapy.
- MeSH
- hypoglykemika * farmakologie MeSH
- lidé MeSH
- metabolické přeprogramování MeSH
- mitochondrie metabolismus účinky léků MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nádory prostaty * metabolismus farmakoterapie patologie MeSH
- pioglitazon * farmakologie MeSH
- pohyb buněk účinky léků MeSH
- PPAR gama * agonisté metabolismus MeSH
- proliferace buněk účinky léků MeSH
- xenogenní modely - testy protinádorové aktivity MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
sv.
- MeSH
- genetické techniky * MeSH
- kmenové buňky MeSH
- Publikační typ
- periodika MeSH
- Konspekt
- Patologie. Klinická medicína
- NLK Obory
- genetika, lékařská genetika
It is now more than nine years since Dolly, the world's first somatic cell cloned mammal was born, and the success of somatic cell nuclear transfer (SCNT) is still disappointingly low. Only about 3-5% of reconstructed embryos develop to term, and it is also evident that even if some clones are born, they are not necessarily fully developed and healthy. Embryonic and neonatal abnormalities of cloned offspring are probably a result of incorrect or incomplete reprogramming of the transferred donor cell nuclei. Such an incomplete reprogramming reflects the extremely low efficiency of SCNT. The key role in the process of reprogramming has been attributed to the enucleated oocyte-cytoplast into which the somatic cell nucleus is transferred. In our chapter, we will discuss the methodological approaches used for the preparation of cytoplasts and their possible reprogramming activities.
- MeSH
- buněčná diferenciace genetika MeSH
- buněčné jádro genetika MeSH
- cytoplazmatické struktury metabolismus MeSH
- embryonální vývoj genetika MeSH
- financování organizované MeSH
- histony genetika MeSH
- klonování organismů metody trendy MeSH
- lidé MeSH
- oocyty metabolismus MeSH
- restrukturace chromatinu genetika MeSH
- techniky jaderného přenosu normy trendy MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
Reprogramming to pluripotency is associated with DNA damage and requires the functions of the BRCA1 tumor suppressor. Here, we leverage separation-of-function mutations in BRCA1/2 as well as the physical and/or genetic interactions between BRCA1 and its associated repair proteins to ascertain the relevance of homology-directed repair (HDR), stalled fork protection (SFP), and replication gap suppression (RGS) in somatic cell reprogramming. Surprisingly, loss of SFP and RGS is inconsequential for the transition to pluripotency. In contrast, cells deficient in HDR, but proficient in SFP and RGS, reprogram with reduced efficiency. Conversely, the restoration of HDR function through inactivation of 53bp1 rescues reprogramming in Brca1-deficient cells, and 53bp1 loss leads to elevated HDR and enhanced reprogramming in mouse and human cells. These results demonstrate that somatic cell reprogramming is especially dependent on repair of replication-associated double-strand breaks (DSBs) by the HDR activity of BRCA1 and BRCA2 and can be improved in the absence of 53BP1.
- MeSH
- 53BP1 * metabolismus genetika MeSH
- dvouřetězcové zlomy DNA * MeSH
- lidé MeSH
- myši MeSH
- oprava DNA * MeSH
- přeprogramování buněk * MeSH
- protein BRCA1 * metabolismus genetika MeSH
- rekombinační oprava DNA MeSH
- replikace DNA MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH