Dual specificity phosphatase 7 (DUSP7) is a protein belonging to a broad group of phosphatases that can dephosphorylate phosphoserine/phosphothreonine as well as phosphotyrosine residues within the same substrate. DUSP7 has been linked to the negative regulation of mitogen activated protein kinases (MAPK), and in particular to the regulation of extracellular signal-regulated kinases 1 and 2 (ERK1/2). MAPKs play an important role in embryonic development, where their duration, magnitude, and spatiotemporal activity must be strictly controlled by other proteins, among others by DUSPs. In this study, we focused on the effect of DUSP7 depletion on the in vitro differentiation of mouse embryonic stem (ES) cells. We showed that even though DUSP7 knock-out ES cells do retain some of their basic characteristics, when it comes to differentiation, they preferentially differentiate towards neural cells, while the formation of early cardiac mesoderm is repressed. Therefore, our data indicate that DUSP7 is necessary for the correct formation of neuroectoderm and cardiac mesoderm during the in vitro differentiation of ES cells.

• MeSH
• fosfatasa 1 s dvojí specificitou metabolismus   MeSH
• fosfatasy s dvojí specifitou genetika   metabolismus   MeSH
• fosfoserin MeSH
• fosfothreonin MeSH
• fosfotyrosin MeSH
• mezoderm metabolismus   MeSH
• mitogenem aktivované proteinkinasy metabolismus   MeSH
• myší embryonální kmenové buňky * metabolismus   MeSH
• myši MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• Dusp7 protein, mouse MeSH Prohlížeč
• fosfatasa 1 s dvojí specificitou MeSH
• fosfatasy s dvojí specifitou MeSH
• fosfoserin MeSH
• fosfothreonin MeSH
• fosfotyrosin MeSH
• mitogenem aktivované proteinkinasy 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.

• Klíčová slova
• STAT3, cardiomyogenesis, mouse embryonic stem cells, neurogenesis, nitro-oleic acid, pluripotency,
• 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
• Názvy látek
• biologické markery MeSH
• CXA-10 MeSH Prohlížeč
• dusíkaté sloučeniny MeSH
• kyseliny olejové MeSH
• transkripční faktor STAT3 MeSH

The active role of biomaterials in the regeneration of tissues and their ability to modulate the behavior of stem cells in terms of their differentiation is highly advantageous. Here, polypyrrole, as a representantive of electro-conducting materials, is found to modulate the behavior of embryonic stem cells. Concretely, the aqueous extracts of polypyrrole induce neurogenesis within embryonic bodies formed from embryonic stem cells. This finding ledto an effort to determine the physiological cascade which is responsible for this effect. The polypyrrole modulates signaling pathways of Akt and ERK kinase through their phosphorylation. These effects are related to the presence of low-molecular-weight compounds present in aqueous polypyrrole extracts, determined by mass spectroscopy. The results show that consequences related to the modulation of stem cell differentiation must also be taken into account when polypyrrole is considered as a biomaterial.

• Klíčová slova
• biocompatibility, conducting polymer, neurogenesis, polypyrrole, stem cells,
• MeSH
• buněčná diferenciace účinky léků   genetika   MeSH
• buněčné linie MeSH
• embryoidní tělíska cytologie   účinky léků   MeSH
• exprese genu účinky léků   MeSH
• molekulární struktura MeSH
• myší embryonální kmenové buňky cytologie   účinky léků   metabolismus   MeSH
• myši MeSH
• nervové kmenové buňky cytologie   účinky léků   metabolismus   MeSH
• neurogeneze účinky léků   genetika   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• polymery chemie   farmakologie   MeSH
• pyrroly chemie   farmakologie   MeSH
• transkripční faktor PAX6 genetika   MeSH
• transkripční faktory bHLH genetika   MeSH
• transkripční faktory SOXB1 genetika   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• Ascl1 protein, mouse MeSH Prohlížeč
• polymery MeSH
• polypyrrole MeSH Prohlížeč
• pyrroly MeSH
• transkripční faktor PAX6 MeSH
• transkripční faktory bHLH MeSH
• transkripční faktory SOXB1 MeSH

12-O-Tetradecanoylphorbol-13-acetate (TPA) is the most widely used diacylglycerol (DAG) mimetic agent and inducer of protein kinase C (PKC)-mediated cellular response in biomedical studies. TPA has been proposed as a pluripotent cell differentiation factor, but results obtained have been inconsistent. In the present study we show that TPA can be applied as a cardiomyogenesis-promoting factor for the differentiation of mouse embryonic stem (mES) cells in vitro. The mechanism of TPA action is mediated by the induction of extracellular signal-regulated kinase (ERK) activity and the subsequent phosphorylation of GATA4 transcription factor. Interestingly, general mitogens (FGF, EGF, VEGF and serum) or canonical WNT signalling did not mimic the effect of TPA. Moreover, on the basis of our results, we postulate that a TPA-sensitive population of cardiac progenitor cells exists at a certain time point (after days 6-8 of the differentiation protocol) and that the proposed treatment can be used to increase the multiplication of ES cell-derived cardiomyocytes.

• MeSH
• buněčná diferenciace účinky léků   MeSH
• embryonální kmenové buňky cytologie   účinky léků   metabolismus   MeSH
• extracelulárním signálem regulované MAP kinasy metabolismus   MeSH
• fosforylace MeSH
• kardiomyocyty cytologie   metabolismus   MeSH
• myši MeSH
• proteinkinasa C metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• tetradekanoylforbolacetát farmakologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• extracelulárním signálem regulované MAP kinasy MeSH
• proteinkinasa C MeSH
• tetradekanoylforbolacetát MeSH

Mild hypoxia (5% O2) as well as FGFR1-induced activation of phosphatidylinositol-4,5-bisphosphate 3-kinase/protein kinase B (PI3K/AKT) and MAPK signaling pathways markedly support pluripotency in human pluripotent stem cells (hPSCs). This study demonstrates that the pluripotency-promoting PI3K/AKT signaling pathway is surprisingly attenuated in mild hypoxia compared to the 21% O2 environment. Hypoxia is known to be associated with lower levels of reactive oxygen species (ROS), which are recognized as intracellular second messengers capable of upregulating the PI3K/AKT signaling pathway. Our data denote that ROS downregulation results in pluripotency upregulation and PI3K/AKT attenuation in a hypoxia-inducible factor 1 (HIF-1)-dependent manner in hPSCs. Using specific MAPK inhibitors, we show that the MAPK pathway also downregulates ROS and therefore attenuates the PI3K/AKT signaling-this represents a novel interaction between these signaling pathways. This inhibition of ROS initiated by MEK1/2-ERK1/2 may serve as a negative feedback loop from the MAPK pathway toward FGFR1 and PI3K/AKT activation. We further describe the molecular mechanism resulting in PI3K/AKT upregulation in hPSCs-ROS inhibit the PI3K's primary antagonist PTEN and upregulate FGFR1 phosphorylation. These novel regulatory circuits utilizing ROS as second messengers may contribute to the development of enhanced cultivation and differentiation protocols for hPSCs. Since the PI3K/AKT pathway often undergoes an oncogenic transformation, our data could also provide new insights into the regulation of cancer stem cell signaling.

• Klíčová slova
• HIF-1, MAPK, PI3K/AKT, hPSCs, hypoxia, reactive oxygen species,
• Publikační typ
• časopisecké články MeSH

The activation of p38alpha kinase mediates cell response to various extracellular factors including many interleukins and growth factors important for haematopoiesis. The role of p38alpha kinase was previously analysed in particular haematopoietic cells. In this study and for the first time, the role of p38alpha kinase in haematopoiesis was studied using a model of continuous haematopoietic development in pluripotent embryonic stem cells in vitro. The expression of transcripts associated with haematopoiesis and the potential for the formation of specific haematopoietic cell colonies were compared between wild-type and mutant p38alpha gene-depleted cells. The absence of p38alpha kinase led to the inhibition of hemangioblast formation during the first step of haematopoiesis. Later, during differentiation, due to the lack of p38alpha kinase, erythrocyte maturation was impaired. Mutant p38α-/- cells also exhibited decreased potential with respect to the expansion of granulocyte colony-forming units. This effect was reversed in the absence of erythropoietin as shown by colony-forming unit assay in media for colony-forming unit granulocytes/macrophages. p38alpha kinase thus plays an important role in the differentiation of common myeloid precursor cells into granulocyte lineages.

• Publikační typ
• časopisecké články MeSH