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Transient Downregulation of Nanog and Oct4 Induced by DETA/NO Exposure in Mouse Embryonic Stem Cells Leads to Mesodermal/Endodermal Lineage Differentiation.

Mora-Castilla S, Tejedo JR, Tapia-Limonchi R, Díaz I, Hitos AB, Cahuana GM, Hmadcha A, Martín F, Soria B, Bedoya FJ - Stem Cells Int (2014)

Bottom Line: Simultaneously, mRNA of mesodermal markers Flk1 and Mef2c are also regulated by the treatment.Acetylated histone H3 occupancy at the promoter of Nanog is involved in the process of reexpression.Furthermore, Nanog binding to the promoter of Brachyury leads to repression of this gene, thus disrupting mesendoderm transition.

View Article: PubMed Central - PubMed

Affiliation: Andalusian Center for Molecular Biology and Regenerative Medicine (CABIMER), University Pablo de Olavide, Biomedical Research Network (CIBER) of Diabetes and Related Metabolic Diseases, Red-Tercel, Avenida Américo Vespucio S/N, 41092 Seville, Spain ; Sanford Consortium for Regenerative Medicine, University of California San Diego, 2880 Torrey Pines Scenic Drive, La Jolla, CA 92037, USA.

ABSTRACT
The function of pluripotency genes in differentiation is a matter of investigation. We report here that Nanog and Oct4 are reexpressed in two mouse embryonic stem cell (mESC) lines following exposure to the differentiating agent DETA/NO. Both cell lines express a battery of both endoderm and mesoderm markers following induction of differentiation with DETA/NO-based protocols. Confocal analysis of cells undergoing directed differentiation shows that the majority of cells expressing Nanog express also endoderm genes such as Gata4 and FoxA2 (75.4% and 96.2%, resp.). Simultaneously, mRNA of mesodermal markers Flk1 and Mef2c are also regulated by the treatment. Acetylated histone H3 occupancy at the promoter of Nanog is involved in the process of reexpression. Furthermore, Nanog binding to the promoter of Brachyury leads to repression of this gene, thus disrupting mesendoderm transition.

No MeSH data available.


Related in: MedlinePlus

Model for stem cell differentiation. During ES cell differentiation, Nanog and Oct4 expression is downregulated and nascent epigenetic modifications occur. At this point, nitric oxide can participate in transient downregulation of pluripotency network and also in chromatin remodelling events. Nevertheless, Nanog can be reexpressed in transient differentiated precursors. By this, fluctuating levels of Nanog and Oct4 constitute an “opportunity” for commitment through specific lineage differentiation. Nitric oxide participates in this perturbation, but further intrinsic or environmental stimuli are needed for correct commitment decision.
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fig5: Model for stem cell differentiation. During ES cell differentiation, Nanog and Oct4 expression is downregulated and nascent epigenetic modifications occur. At this point, nitric oxide can participate in transient downregulation of pluripotency network and also in chromatin remodelling events. Nevertheless, Nanog can be reexpressed in transient differentiated precursors. By this, fluctuating levels of Nanog and Oct4 constitute an “opportunity” for commitment through specific lineage differentiation. Nitric oxide participates in this perturbation, but further intrinsic or environmental stimuli are needed for correct commitment decision.

Mentions: All in all, the data reported here indicate that pluripotency factors play additional roles other than controlling the machinery of pluripotency. In fact, Oct4 has a dual role working with Sox2 to maintain pluripotency and with Sox17 to promote endodermal lineage differentiation [30]. In our case, environmental perturbations caused by high levels of NO provoke Nanog and Oct4 downregulation and epigenetic chromatin modifications, constituting an opportunity for subsequent differentiation (see Figure 5). Heterogeneous reexpression of Nanog or Oct4, however, is not a barrier for DE differentiation, but an inherent property of mESC. This mechanism might be an evolutionary selected strategy to respond and adapt to the markedly changing external environment and for the generation of new progenitors during differentiation. In fact, during the implantation of the blastocyst, inducible NO synthase (iNOS) levels increase markedly in the uterine tissue of rodents [33]. This phenomenon correlates with the transient decrease in Nanog in newly implanted blastocysts [4, 34]. Subsequently, Nanog is reexpressed in epiblast cells [35], simulating the schemes described in this work. Thus, one would expect the relevance of NO signalling as a new biological system regulating the pluripotency in embryonic cells, setting the stage for the development of new strategies for regenerative medicine.


Transient Downregulation of Nanog and Oct4 Induced by DETA/NO Exposure in Mouse Embryonic Stem Cells Leads to Mesodermal/Endodermal Lineage Differentiation.

Mora-Castilla S, Tejedo JR, Tapia-Limonchi R, Díaz I, Hitos AB, Cahuana GM, Hmadcha A, Martín F, Soria B, Bedoya FJ - Stem Cells Int (2014)

Model for stem cell differentiation. During ES cell differentiation, Nanog and Oct4 expression is downregulated and nascent epigenetic modifications occur. At this point, nitric oxide can participate in transient downregulation of pluripotency network and also in chromatin remodelling events. Nevertheless, Nanog can be reexpressed in transient differentiated precursors. By this, fluctuating levels of Nanog and Oct4 constitute an “opportunity” for commitment through specific lineage differentiation. Nitric oxide participates in this perturbation, but further intrinsic or environmental stimuli are needed for correct commitment decision.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4269087&req=5

fig5: Model for stem cell differentiation. During ES cell differentiation, Nanog and Oct4 expression is downregulated and nascent epigenetic modifications occur. At this point, nitric oxide can participate in transient downregulation of pluripotency network and also in chromatin remodelling events. Nevertheless, Nanog can be reexpressed in transient differentiated precursors. By this, fluctuating levels of Nanog and Oct4 constitute an “opportunity” for commitment through specific lineage differentiation. Nitric oxide participates in this perturbation, but further intrinsic or environmental stimuli are needed for correct commitment decision.
Mentions: All in all, the data reported here indicate that pluripotency factors play additional roles other than controlling the machinery of pluripotency. In fact, Oct4 has a dual role working with Sox2 to maintain pluripotency and with Sox17 to promote endodermal lineage differentiation [30]. In our case, environmental perturbations caused by high levels of NO provoke Nanog and Oct4 downregulation and epigenetic chromatin modifications, constituting an opportunity for subsequent differentiation (see Figure 5). Heterogeneous reexpression of Nanog or Oct4, however, is not a barrier for DE differentiation, but an inherent property of mESC. This mechanism might be an evolutionary selected strategy to respond and adapt to the markedly changing external environment and for the generation of new progenitors during differentiation. In fact, during the implantation of the blastocyst, inducible NO synthase (iNOS) levels increase markedly in the uterine tissue of rodents [33]. This phenomenon correlates with the transient decrease in Nanog in newly implanted blastocysts [4, 34]. Subsequently, Nanog is reexpressed in epiblast cells [35], simulating the schemes described in this work. Thus, one would expect the relevance of NO signalling as a new biological system regulating the pluripotency in embryonic cells, setting the stage for the development of new strategies for regenerative medicine.

Bottom Line: Simultaneously, mRNA of mesodermal markers Flk1 and Mef2c are also regulated by the treatment.Acetylated histone H3 occupancy at the promoter of Nanog is involved in the process of reexpression.Furthermore, Nanog binding to the promoter of Brachyury leads to repression of this gene, thus disrupting mesendoderm transition.

View Article: PubMed Central - PubMed

Affiliation: Andalusian Center for Molecular Biology and Regenerative Medicine (CABIMER), University Pablo de Olavide, Biomedical Research Network (CIBER) of Diabetes and Related Metabolic Diseases, Red-Tercel, Avenida Américo Vespucio S/N, 41092 Seville, Spain ; Sanford Consortium for Regenerative Medicine, University of California San Diego, 2880 Torrey Pines Scenic Drive, La Jolla, CA 92037, USA.

ABSTRACT
The function of pluripotency genes in differentiation is a matter of investigation. We report here that Nanog and Oct4 are reexpressed in two mouse embryonic stem cell (mESC) lines following exposure to the differentiating agent DETA/NO. Both cell lines express a battery of both endoderm and mesoderm markers following induction of differentiation with DETA/NO-based protocols. Confocal analysis of cells undergoing directed differentiation shows that the majority of cells expressing Nanog express also endoderm genes such as Gata4 and FoxA2 (75.4% and 96.2%, resp.). Simultaneously, mRNA of mesodermal markers Flk1 and Mef2c are also regulated by the treatment. Acetylated histone H3 occupancy at the promoter of Nanog is involved in the process of reexpression. Furthermore, Nanog binding to the promoter of Brachyury leads to repression of this gene, thus disrupting mesendoderm transition.

No MeSH data available.


Related in: MedlinePlus