Embryonic stem cells (ESCs) maintain their pluripotency through high expression of pluripotency-related genes. Here, we show that differing levels of Oct4, Nanog, and c-myc proteins among the individual cells of mouse ESC (mESC) colonies and fluctuations in these levels do not disturb mESC pluripotency. Cells with strong expression of Oct4 had low levels of Nanog and c-myc proteins and vice versa. In addition, cells with high levels of Nanog tended to occupy interior regions of mESC colonies. In contrast, peripherally positioned cells within colonies had dense H3K27-trimethylation, especially at the nuclear periphery. We also observed distinct levels of endogenous and exogenous Oct4 in particular cell cycle phases. The highest levels of Oct4 occurred in G2 phase, which correlated with the pKi-67 nuclear pattern. Moreover, the Oct4 protein resided on mitotic chromosomes. We suggest that there must be an endogenous mechanism that prevents the induction of spontaneous differentiation, despite fluctuations in protein levels within an mESC colony. Based on the results presented here, it is likely that cells within a colony support each other in the maintenance of pluripotency.

• MeSH
• antigen Ki-67 metabolismus   MeSH
• buněčná diferenciace MeSH
• buněčné jádro genetika   metabolismus   MeSH
• embryonální kmenové buňky cytologie   metabolismus   MeSH
• epigeneze genetická MeSH
• FRAP MeSH
• G2 fáze MeSH
• histony metabolismus   MeSH
• homeodoménové proteiny genetika   metabolismus   MeSH
• konfokální mikroskopie MeSH
• kultivované buňky MeSH
• lysin metabolismus   MeSH
• metylace MeSH
• myši MeSH
• nika kmenových buněk MeSH
• oktamerní transkripční faktor 3 genetika   metabolismus   MeSH
• pluripotentní kmenové buňky cytologie   metabolismus   MeSH
• protoonkogenní proteiny c-myc genetika   metabolismus   MeSH
• western blotting MeSH
• zelené fluorescenční proteiny genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Embryonic stem cells and induced pluripotent stem cells provided us with fascinating new knowledge in recent years. Mechanistic insight into intricate regulatory circuitry governing pluripotency stemness and disclosing parallels between pluripotency stemness and cancer instigated numerous studies focusing on roles of pluripotency transcription factors, including Oct4, Sox2, Klf4, Nanog, Sall4 and Tfcp2L1, in cancer. Although generally well substantiated as tumour-promoting factors, oncogenic roles of pluripotency transcription factors and their clinical impacts are revealing themselves as increasingly complex. In certain tumours, both Oct4 and Sox2 behave as genuine oncogenes, and reporter genes driven by composite regulatory elements jointly recognized by both the factors can identify stem-like cells in a proportion of tumours. On the other hand, cancer stem cells seem to be biologically very heterogeneous both among different tumour types and among and even within individual tumours. Pluripotency transcription factors are certainly implicated in cancer stemness, but do not seem to encompass its entire spectrum. Certain cancer stem cells maintain their stemness by biological mechanisms completely different from pluripotency stemness, sometimes even by engaging signalling pathways that promote differentiation of pluripotent stem cells. Moreover, while these signalling pathways may well be antithetical to stemness in pluripotent stem cells, they may cooperate with pluripotency factors in cancer stem cells - a paradigmatic example is provided by the MAPK-AP-1 pathway. Unexpectedly, forced expression of pluripotency transcription factors in cancer cells frequently results in loss of their tumour-initiating ability, their phenotypic reversion and partial epigenetic normalization. Besides the very different signalling contexts operating in pluripotent and cancer stem cells, respectively, the pronounced dose dependency of reprogramming pluripotency factors may also contribute to the frequent loss of tumorigenicity observed in induced pluripotent cancer cells. Finally, contradictory cell-autonomous and non-cell-autonomous effects of various signalling molecules operate during pluripotency (cancer) reprogramming. The effects of pluripotency transcription factors in cancer are thus best explained within the concept of cancer stem cell heterogeneity.

• MeSH
• buněčná diferenciace genetika   MeSH
• embryonální kmenové buňky MeSH
• indukované pluripotentní kmenové buňky * metabolismus   MeSH
• lidé MeSH
• nádory * genetika   metabolismus   MeSH
• oktamerní transkripční faktor 3 genetika   metabolismus   MeSH
• pluripotentní kmenové buňky * MeSH
• přeprogramování buněk genetika   MeSH
• transkripční faktory genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The differentiation of embryonic stem cells is associated with extensive changes in gene expression. It is not yet clear whether these changes are the result of binary switch-like mechanisms or that of continuous and progressive variation. Here, I have used immunostaining and single molecule RNA fluorescence in situ hybridization (FISH) to assess changes in the expression of the well-known pluripotency-associated gene Pou5f1 (also known as Oct4) and early differentiation markers Sox1 and T-brachyury in single cells during the early steps of differentiation of mouse embryonic stem cells. I found extensive overlap between the expression of Pou5f1/Sox1 or Pou5f1/T-brachyury shortly after the initiation of differentiation towards either the neuronal or the mesendodermal lineage, but no evidence of correlation between their respective expression levels. Quantitative analysis of transcriptional output at the sites of nascent transcription revealed that Pou5f1 and Sox1 were transcribed in pulses and that embryonic stem cell differentiation was accompanied by changes in pulsing frequencies. The progressive induction of Sox1 was further associated with an increase in the average size of individual transcriptional bursts. Surprisingly, single cells that actively and simultaneously transcribe both the pluripotency- and the lineage-associated genes could easily be found in the differentiating population. The results presented here show for the first time that lineage priming can occur in cells that are actively transcribing a pluripotent marker. Furthermore, they suggest that this process is associated with changes in transcriptional dynamics.

• MeSH
• analýza jednotlivých buněk * MeSH
• buněčná diferenciace genetika   MeSH
• buněčný rodokmen genetika   MeSH
• embryonální kmenové buňky cytologie   metabolismus   MeSH
• fetální proteiny biosyntéza   genetika   MeSH
• hybridizace in situ fluorescenční MeSH
• myši MeSH
• oktamerní transkripční faktor 3 biosyntéza   genetika   MeSH
• pluripotentní kmenové buňky cytologie   metabolismus   MeSH
• proteiny T-boxu biosyntéza   genetika   MeSH
• transkripční faktory SOXB1 biosyntéza   genetika   MeSH
• vývojová regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The possibility of replacing the originally discovered and widely used DNA reprogramming transcription factors is stimulating enormous effort to identify more effective compounds that would not alter the genetic information. Here, we describe the generation of induced pluripotent stem cells (iPSc) from head-derived primary culture of mouse embryonic cells using small chemical inhibitors of the MEK and TGF-beta pathways without delivery of exogenous transcription factors. These iPSc express standard pluripotency markers and retain their potential to differentiate into cells of all germ layers. Our data indicate that head-derived embryonic neural cells might have the reprogramming potential while neither the same primary cells cultivated over five passages in vitro nor a cell population derived from adult brain possesses this capacity. Our results reveal the potential for small molecules to functionally replace routinely used transcription factors and lift the veil on molecular regulation controlling pluripotency. The conditions described here could provide a platform upon which other genome non integrative and safer reprogramming processes could be developed. This work also shows novel potential for developing embryonic neural cells.

• MeSH
• diferenciační antigeny biosyntéza   MeSH
• indukované pluripotentní kmenové buňky cytologie   metabolismus   MeSH
• MAP kinasový signální systém * MeSH
• myši MeSH
• přeprogramování buněk * MeSH
• transformující růstový faktor beta metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Heterogeneous expression of the transcription factor NANOG has been linked to the existence of various functional states in pluripotent stem cells. This heterogeneity seems to arise from fluctuations of Nanog expression in individual cells, but a thorough characterization of these fluctuations and their impact on the pluripotent state is still lacking. Here, we have used a novel fluorescent reporter to investigate the temporal dynamics of NANOG expression in mouse embryonic stem cells (mESCs), and to dissect the lineage potential of mESCs at different NANOG states. Our results show that stochastic NANOG fluctuations are widespread in mESCs, with essentially all expressing cells showing fluctuations in NANOG levels, even when cultured in ground-state conditions (2i media). We further show that fluctuations have similar kinetics when mESCs are cultured in standard conditions (serum plus leukemia inhibitory factor) or ground-state conditions, implying that NANOG fluctuations are inherent to the pluripotent state. We have then compared the developmental potential of low-NANOG and high-NANOG mESCs, grown in different conditions, and confirm that mESCs are more susceptible to enter differentiation at the low-NANOG state. Further analysis by gene expression profiling reveals that low-NANOG cells have marked expression of lineage-affiliated genes, with variable profiles according to the signalling environment. By contrast, high-NANOG cells show a more stable expression profile in different environments, with minimal expression of lineage markers. Altogether, our data support a model in which stochastic NANOG fluctuations provide opportunities for mESCs to explore multiple lineage options, modulating their probability to change functional state.

• MeSH
• analýza hlavních komponent MeSH
• buněčné klony MeSH
• buněčné linie MeSH
• buněčný rodokmen genetika   MeSH
• časosběrné zobrazování MeSH
• embryonální kmenové buňky cytologie   metabolismus   MeSH
• genetická transkripce MeSH
• homeodoménové proteiny genetika   metabolismus   MeSH
• kinetika MeSH
• messenger RNA genetika   metabolismus   MeSH
• myši MeSH
• pluripotentní kmenové buňky cytologie   metabolismus   MeSH
• proliferace buněk MeSH
• průtoková cytometrie MeSH
• stanovení celkové genové exprese MeSH
• stochastické procesy MeSH
• vývojová regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Induced pluripotent stem (iPS) cells are derived from differentiated cells by different reprogramming techniques, by introducing specific transcription factors responsible for pluripotency. Induced pluripotent stem cells can serve as an excellent source for differentiated neural stem/progenitor cells (NSCs/NPs). Several methods and protocols are utilized to create a robust number of NSCs/NPs without jeopardizing the safety issues required for in vivo applications. A variety of disease-specific iPS cells have been used to study nervous system diseases. In this chapter, we will focus on some of the derivation and differentiation approaches and the application of iPS-NPs in the treatment of spinal cord injury and stroke.

• MeSH
• buněčná diferenciace * MeSH
• cévní mozková příhoda patologie   terapie   MeSH
• indukované pluripotentní kmenové buňky cytologie   MeSH
• lidé MeSH
• modely neurologické * MeSH
• nervové kmenové buňky cytologie   MeSH
• poranění míchy patologie   terapie   MeSH
• přeprogramování buněk MeSH
• transkripční faktory metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

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

Development of neural tube has been extensively modeled in vitro using human pluripotent stem cells (hPSCs) that are able to form radially organized cellular structures called neural rosettes. While a great amount of research has been done using neural rosettes, studies have only inadequately addressed how rosettes are formed and what the molecular mechanisms and pathways involved in their formation are. Here we address this question by detailed analysis of the expression of pluripotency and differentiation-associated proteins during the early onset of differentiation of hPSCs towards neural rosettes. Additionally, we show that the BMP signaling is likely contributing to the formation of the complex cluster of neural rosettes and its inhibition leads to the altered expression of PAX6, SOX2 and SOX1 proteins and the rosette morphology. Finally, we provide evidence that the mechanism of neural rosettes formation in vitro is reminiscent of the process of secondary neurulation rather than that of primary neurulation in vivo. Since secondary neurulation is a largely unexplored process, its understanding will ultimately assist the development of methods to prevent caudal neural tube defects in humans.

• MeSH
• buněčná diferenciace * MeSH
• COUP transkripční faktor II genetika   metabolismus   MeSH
• faktory domény POU genetika   metabolismus   MeSH
• homeodoménové proteiny genetika   metabolismus   MeSH
• kultivované buňky MeSH
• lidé MeSH
• nervové kmenové buňky cytologie   metabolismus   MeSH
• neurální trubice cytologie   embryologie   metabolismus   MeSH
• neurulace * MeSH
• pluripotentní kmenové buňky cytologie   metabolismus   MeSH
• transkripční faktor PAX6 genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Duchenne muscular dystrophy (DMD) affects 1:3500-5000 newborn boys and manifests with progressive skeletal muscle wasting, respiratory failure and eventual heart failure. Symptoms show different onset from patients' childhood to the second decade of age. We reprogrammed fibroblasts from two independent DMD patients with a complete loss of dystrophin expression, carrying deletions of exons 45-50 and 48-50. The resulting hiPSCs show expression of pluripotency markers (NANOG, OCT4, SSEA4), differentiation capacity into all three germ layers, normal karyotype, genetic identity to the originating parental fibroblasts and the patient-specific dystrophin mutation.

• MeSH
• buněčná diferenciace MeSH
• buněčné linie cytologie   metabolismus   MeSH
• dítě MeSH
• Duchennova muskulární dystrofie genetika   metabolismus   patofyziologie   MeSH
• dystrofin genetika   metabolismus   MeSH
• exony MeSH
• indukované pluripotentní kmenové buňky cytologie   metabolismus   MeSH
• lidé MeSH
• mladiství MeSH
• oktamerní transkripční faktor 3 genetika   metabolismus   MeSH
• sekvenční delece MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Nitro-oleic acid (NO2-OA), pluripotent cell-signaling mediator, was recently described as a modulator of the signal transducer and activator of transcription 3 (STAT3) activity. In our study, we discovered new aspects of NO2-OA involvement in the regulation of stem cell pluripotency and differentiation. Murine embryonic stem cells (mESC) or mESC-derived embryoid bodies (EBs) were exposed to NO2-OA or oleic acid (OA) for selected time periods. Our results showed that NO2-OA but not OA caused the loss of pluripotency of mESC cultivated in leukemia inhibitory factor (LIF) rich medium via the decrease of pluripotency markers (NANOG, sex-determining region Y-box 1 transcription factor (SOX2), and octamer-binding transcription factor 4 (OCT4)). The effects of NO2-OA on mESC correlated with reduced phosphorylation of STAT3. Subsequent differentiation led to an increase of the ectodermal marker orthodenticle homolog 2 (Otx2). Similarly, treatment of mESC-derived EBs by NO2-OA resulted in the up-regulation of both neural markers Nestin and β-Tubulin class III (Tubb3). Interestingly, the expression of cardiac-specific genes and beating of EBs were significantly decreased. In conclusion, NO2-OA is able to modulate pluripotency of mESC via the regulation of STAT3 phosphorylation. Further, it attenuates cardiac differentiation on the one hand, and on the other hand, it directs mESC into neural fate.

• MeSH
• biologické markery metabolismus   MeSH
• buněčná diferenciace * účinky léků   MeSH
• dusíkaté sloučeniny farmakologie   MeSH
• embryoidní tělíska účinky léků   metabolismus   MeSH
• kardiomyocyty účinky léků   metabolismus   MeSH
• kyseliny olejové farmakologie   MeSH
• myší embryonální kmenové buňky cytologie   účinky léků   metabolismus   MeSH
• myši MeSH
• neurony cytologie   účinky léků   metabolismus   MeSH
• organogeneze účinky léků   MeSH
• pluripotentní kmenové buňky účinky léků   metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• transkripční faktor STAT3 metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH