209 Rho signaling-directed regulation of YAP/TAZ in parthenogenetic stem cells

2020 ◽  
Vol 32 (2) ◽  
pp. 233
Author(s):  
G. Pennarossa ◽  
S. Arcuri ◽  
F. Gandolfi ◽  
T. Brevini
Keyword(s):  
Stem Cells ◽  
Molecular Mechanisms ◽  
Rho Gtpase ◽  
Hippo Pathway ◽  
Genetic Material ◽  
Embryonic Stem ◽  
Cell Types ◽  
Embryonic Cell ◽  
And Migration ◽  
The Hippo Pathway

Mammalian oocyte maturation is characterised by asymmetric meiotic division that is regulated by specific cytoskeleton organisation. Similarly, during early embryonic divisions, one of the most important steps is the establishment of polarity that allows cells to adopt distinct developmental fates. All of these events are driven by dynamic changes in actin filaments. It has been demonstrated recently that the Rho signalling pathway plays a key role in the organisation and rearrangement of actin-containing structures, regulating cell polarity and migration. In addition, beside its effect on cell cytoskeleton, Rho directly interacts with the Hippo pathway, influencing both embryonic cell proliferation and differentiation. Because both Rho and Hippo are expressed by the oocyte and maternally inherited (Zhang et al. 2014 Cell Cycle 13, 3390-3403, https://doi.org/10.4161/15384101.2014.952967; Menchero et al. 2017 Dev. Dyn. 246, 245-261, https://doi.org/10.1002/dvdy.24471), we investigated their regulation in parthenogenetic embryonic stem cells (ParthESC) that possess exclusively maternal genetic material, and compared the results with biparental ESCs. Previous results obtained by whole-transcriptome analysis revealed the presence of several differentially expressed genes involved in the Rho pathway and showed no differences for most of the Hippo signalling genes. To better elucidate the molecular mechanisms involved, in the present study, we dissected the expression pattern of the Rho and Hippo regulatory genes in human biparental ESCs and ParthESC. Experiments were performed on 4 biparental ESC and 4 ParthESC lines using cells between passages 5 to 25. The results showed significantly increased transcription of the Rho GTPase family genes (RHOA, RHOB, and RHOC) in ParthESC compared with biparental ESCs. Consistent with this, 12 of 17 Rho activators were significantly upregulated, whereas 8 of 11 Rho inhibitors were significantly decreased in ParthESC. Furthermore, monoparental cells displayed significantly higher expression levels of YAP and TAZ, whereas the upstream genes involved in the Hippo pathway (LATS1/2, MOB1, MST1/2, NF2) were comparable in the two cell types. Interestingly, a significantly higher total YAP protein content was detected in ParthESC, whereas the quantity of the phosphorylated form was comparable in the two cell types. This accounts for the observed upregulation of Rho genes, which stimulate the assembly of contractile actin stress fibres, inhibiting LATS1/2 phosphorylation and preventing subsequent phosphorylation of YAP/TAZ (Yu and Guan 2013 Genes Dev. 27, 355-371; https://doi.org/10.1101/gad.210773.112). Altogether, our results suggest that the Rho pathway may regulate YAP/TAZ behaviour via a LATS/MST/NF2-independent process in ParthESC, similarly to a previous report in oocytes (Posfai and Rossant 2016 Cell Res. 26, 393-394; https://doi.org/10.1038/cr.2016). Although further clarifications are needed, we hypothesise that the regulatory mechanisms detected in ParthESC may be related to their strictly maternal origin, with a possible impact on their plasticity and potency. This study was supported by Carraresi Foundation. Authors are members of the COST Actions CA16119.

scholarly journals MicroRNAs and Stem-like Properties: The Complex Regulation Underlying Stemness Maintenance and Cancer Development

Biomolecules ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1074
Author(s):  
Giuseppina Divisato ◽  
Silvia Piscitelli ◽  
Mariantonietta Elia ◽  
Emanuela Cascone ◽  
Silvia Parisi
Keyword(s):  
Stem Cells ◽  
Molecular Mechanisms ◽  
Epithelial Mesenchymal Transition ◽  
Embryonic Stem ◽  
Cell Types ◽  
Cancer Development ◽  
Special Focus ◽  
Self Renewal ◽  
Mesenchymal Transition ◽  
Different Cell Types

Embryonic stem cells (ESCs) have the extraordinary properties to indefinitely proliferate and self-renew in culture to produce different cell progeny through differentiation. This latter process recapitulates embryonic development and requires rounds of the epithelial–mesenchymal transition (EMT). EMT is characterized by the loss of the epithelial features and the acquisition of the typical phenotype of the mesenchymal cells. In pathological conditions, EMT can confer stemness or stem-like phenotypes, playing a role in the tumorigenic process. Cancer stem cells (CSCs) represent a subpopulation, found in the tumor tissues, with stem-like properties such as uncontrolled proliferation, self-renewal, and ability to differentiate into different cell types. ESCs and CSCs share numerous features (pluripotency, self-renewal, expression of stemness genes, and acquisition of epithelial–mesenchymal features), and most of them are under the control of microRNAs (miRNAs). These small molecules have relevant roles during both embryogenesis and cancer development. The aim of this review was to recapitulate molecular mechanisms shared by ESCs and CSCs, with a special focus on the recently identified classes of microRNAs (noncanonical miRNAs, mirtrons, isomiRs, and competitive endogenous miRNAs) and their complex functions during embryogenesis and cancer development.

Investigation of the Stem Cells Used in Modeling Human Placental Trophoblast

2021 ◽  
Author(s):  
Lulu Ji ◽  
Lin Wang
Keyword(s):  
Stem Cells ◽  
Molecular Mechanisms ◽  
Embryonic Stem ◽  
Cell Lineage ◽  
Cell Types ◽  
Model Systems ◽  
Alternative Methods ◽  
Laboratory Animals ◽  
Placental Development ◽  
Induced Pluripotent

Human placenta is vital for fetal development, and act as an interface between the fetus and the expecting mother. Abnormal placentati on underpins various pregnancy complications such as miscarriage, pre-eclampsia and intrauterine growth restriction. Despite the important role of placenta, the molecular mechanisms governing placental formation and trophoblast cell lineage specification is poorly understand. It is mostly due to the lack of appropriate model system. The great various in placental types across mammals make it limit for the use of laboratory animals in studying human placental development. However, over the past few years, alternative methods have been employed, including human embryonic stem cells, induced pluripotent stem cells, human trophoblast stem cell, and 3-dimensional organoids. Herein, we summarize the present knowledge about human development, differentiated cell types in the trophoblast epithelium and current human placental trophoblast model systems.

scholarly journals Loss of Mob1a/b impairs the differentiation of mouse embryonic stem cells into the three germ layer lineages

2019 ◽  
Vol 51 (11) ◽  
pp. 1-12 ◽  
Author(s):  
June Sung Bae ◽  
Sun Mi Kim ◽  
Yoon Jeon ◽  
Juyeon Sim ◽  
Ji Yun Jang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Hippo Pathway ◽  
Critical Role ◽  
Embryonic Stem ◽  
Mouse Escs ◽  
Germ Layers ◽  
Stem Cell Maintenance ◽  
The Hippo Pathway ◽  
Cell Maintenance

AbstractThe Hippo pathway plays a crucial role in cell proliferation and apoptosis and can regulate stem cell maintenance and embryonic development. MOB kinase activators 1A and 1B (Mob1a/b) are key components of the Hippo pathway, whose homozygous deletion in mice causes early embryonic lethality at the preimplantation stage. To investigate the role of Mob1a/b in stem cell maintenance and differentiation, an embryonic stem cell (ESC) clone in which Mob1a/b could be conditionally depleted was generated and characterized. Although Mob1a/b depletion did not affect the stemness or proliferation of mouse ESCs, this depletion caused defects in differentiation into the three germ layers. Yap knockdown rescued the in vitro and in vivo defects in differentiation caused by Mob1a/b depletion, suggesting that differentiation defects caused by Mob1a/b depletion were Yap-dependent. In teratoma experiments, Yap knockdown in Mob1a/b-depleted ESCs partially restored defects in differentiation, indicating that hyperactivation of Taz, another effector of the Hippo pathway, inhibited differentiation into the three germ layers. Taken together, these results suggest that Mob1a/b or Hippo signaling plays a critical role in the differentiation of mouse ESCs into the three germ layers, which is dependent on Yap. These close relationship of the Hippo pathway with the differentiation of stem cells supports its potential as a therapeutic target in regenerative medicine.

Stem cells and lineage development in the mammalian blastocyst

2007 ◽  
Vol 19 (1) ◽  
pp. 111 ◽  
Author(s):  
Janet Rossant
Keyword(s):  
Stem Cells ◽  
Cell Fate ◽  
Es Cells ◽  
Mammalian Species ◽  
Embryonic Stem ◽  
Cell Types ◽  
Mouse Cell ◽  
Embryonic Cell ◽  
Primitive Endoderm ◽  
Key Factors

The mammalian blastocyst is the source of the most pluripotent stem cells known: embryonic stem (ES) cells. However, ES cells are not totipotent; in mouse chimeras, they do not contribute to extra-embryonic cell types of the trophectoderm (TE) and primitive endoderm (PrE) lineages. Understanding the genetic pathways that control pluripotency v. extra-embryonic lineage restriction is key to understanding not only normal embryonic development, but also how to reprogramme adult cells to pluripotency. The trophectoderm and primitive endoderm lineages also provide the first signals that drive patterned differentiation of the pluripotent epiblast cells of the embryo. My laboratory has produced permanent mouse cell lines from both the TE and the PrE, termed trophoblast stem (TS) and eXtra-embryonic ENdoderm (XEN) cells. We have used these cells to explore the genetic and molecular hierarchy of lineage restriction and identify the key factors that distinguish the ES cell v. the TS or XEN cell fate. The major molecular pathways of lineage commitment defined in mouse embryos and stem cells are probably conserved across mammalian species, but more comparative studies of lineage development in embryos of non-rodent mammals will likely yield interesting differences in terms of timing and details.

scholarly journals SIRT1 Inhibition Affects Angiogenic Properties of Human MSCs

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Botti Chiara ◽  
Caiafa Ilaria ◽  
Coppola Antonietta ◽  
Cuomo Francesca ◽  
Miceli Marco ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Molecular Mechanisms ◽  
Human Mesenchymal Stem Cells ◽  
Cell Types ◽  
Therapeutic Angiogenesis ◽  
Induced Response ◽  
Human Mscs ◽  
Hypoxic Conditions ◽  
And Migration

Human mesenchymal stem cells (hMSCs) are attractive for clinical and experimental purposes due to their capability of self-renewal and of differentiating into several cell types. Autologous hMSCs transplantation has been proven to induce therapeutic angiogenesis in ischemic disorders. However, the molecular mechanisms underlying these effects remain unclear. A recent report has connected MSCs multipotency to sirtuin families, showing that SIRT1 can regulate MSCs function. Furthermore, SIRT1 is a critical modulator of endothelial angiogenic functions. Here, we described the generation of an immortalized human mesenchymal bone marrow-derived cell line and we investigated the angiogenic phenotype of our cellular model by inhibiting SIRT1 by both the genetic and pharmacological level. We first assessed the expression of SIRT1 in hMSCs under basal and hypoxic conditions at both RNA and protein level. Inhibition of SIRT1 by sirtinol, a cell-permeable inhibitor, or by specific sh-RNA resulted in an increase of premature-senescence phenotype, a reduction of proliferation rate with increased apoptosis. Furthermore, we observed a consistent reduction of tubule-like formation and migration and we found that SIRT1 inhibition reduced the hypoxia induced accumulation of HIF-1α protein and its transcriptional activity in hMSCs. Our findings identify SIRT1 as regulator of hypoxia-induced response in hMSCs and may contribute to the development of new therapeutic strategies to improve regenerative properties of mesenchymal stem cells in ischemic disorders through SIRT1 modulation.

A New Mechanism of Communication between Stem Cells Involving Vertical Transfer of mRNA by Its Intracellular Delivery within Membrane-Derived Microvesicles.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 460-460
Author(s):  
Janina Ratajczak ◽  
Kasia Miekus ◽  
Magda Kucia ◽  
Petr Dvorak ◽  
Mariusz Ratajczak
Keyword(s):  
Stem Cells ◽  
Culture Media ◽  
Es Cells ◽  
Embryonic Stem ◽  
Cell Types ◽  
Embryonic Cell ◽  
Target Cells ◽  
Similar Data ◽  
Hematopoietic Stem ◽  
Vertical Transfer

Abstract Membrane-derived microvesicles (MV) are spherical membrane fragments that are released from eukaryoctic cells upon their activation. We reported that MV transfer cell membrane-derived receptors between cells and/or directly stimulate target cells by the ligands expressed on their surface (Blood2001:98;3143; AIDS2003:17;33). Recently we observed that embryonic stem cells (ES) shed MV into culture media and that co-culture of ES with hematopoietic stem cells enhances the latter’s expansion. Similarly, co-culture of ES with somatic cells induces their dedifferentiation. Although the mechanisms responsible for these phenomena are not clear, we hypothesized that ES-derived MV (ESMV) could play an important role. To address this we isolated ESMV from murine (ES-D3) and two human (CCTL-12 and CCTL-14) embryonic cell lines and focused on molecules that may be responsible for epigenetic changes of cells co-cultured with ESMV. We found that ESMV as compared to the ES cells from which they originated are highly enriched in mRNA. This increase in mRNA content suggested a segregation mechanism that enriches ESMV in cytoplasmatic mRNA during their shedding from ES. Using real-time RT-PCR we found that ES-MV are highly enriched (x 103−107) in mRNA for early transcription factors that regulate self-renewal of stem cells (e.g., Oct-4, Gata-4, Rex-1 and Nanog). Intrigued by these observations we hypothesized that ESMV could penetrate the cells and deliver ES-derived mRNA and that this could be a novel mechanism for reprogramming target cells. Supporting our hypothesis we found (i) by confocal microscopy that ESMV do indeed penetrate the cells (e.g., BM-derived CD34+ cells or ES themselves), and (ii) by Western blot analysis that mRNA delivered to the target cells by ESMV is not trapped in the endosomal compartment but is delivered to the cytoplasm and actively transcribed into appropriate proteins (e.g., Oct-4). Based on these data we postulate that MV may transfer mRNA between the stem cells and play a role in vertical transfer of genetic information. Our recent similar data on MV derived from other cell types (normal and malignant) lend further support to this novel hypothesis and mechanism of cell to cell signaling/communication.

scholarly journals State of the Art in Stem Cell Research: Human Embryonic Stem Cells, Induced Pluripotent Stem Cells, and Transdifferentiation

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Giuseppe Maria de Peppo ◽  
Darja Marolt
Keyword(s):  
Stem Cells ◽  
Pluripotent Stem Cells ◽  
Biomedical Applications ◽  
Molecular Mechanisms ◽  
Embryonic Stem ◽  
Cell Types ◽  
New Developments ◽  
Invaluable Tool ◽  
Induced Pluripotent ◽  
Near Future

Stem cells divide by asymmetric division and display different degrees of potency, or ability to differentiate into various specialized cell types. Owing to their unique regenerative capacity, stem cells have generated great enthusiasm worldwide and represent an invaluable tool with unprecedented potential for biomedical research and therapeutic applications. Stem cells play a central role in the understanding of molecular mechanisms regulating tissue development and regeneration in normal and pathological conditions and open large possibilities for the discovery of innovative pharmaceuticals to treat the most devastating diseases of our time. Not least, their intrinsic characteristics allow the engineering of functional tissues for replacement therapies that promise to revolutionize the medical practice in the near future. In this paper, the authors present the characteristics of pluripotent stem cells and new developments of transdifferentiation technologies and explore some of the biomedical applications that this emerging technology is expected to empower.

Role of Rho GTPases in stem cell regulation

2021 ◽  
Author(s):  
Zheng Zhang ◽  
Ming Liu ◽  
Yi Zheng
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cancer Stem Cells ◽  
Rho Gtpases ◽  
Rho Gtpase ◽  
Embryonic Stem ◽  
Cell Types ◽  
Tissue Homeostasis ◽  
Cell Manipulation ◽  
Stem Cell Regulation

The future of regenerative medicine relies on our understanding of stem cells which are essential for tissue/organ generation and regeneration to maintain and/or restore tissue homeostasis. Rho family GTPases are known regulators of a wide variety of cellular processes related to cytoskeletal dynamics, polarity and gene transcription. In the last decade, major new advances have been made in understanding the regulatory role and mechanism of Rho GTPases in self-renewal, differentiation, migration, and lineage specification in tissue-specific signaling mechanisms in various stem cell types to regulate embryonic development, adult tissue homeostasis, and tissue regeneration upon stress or damage. Importantly, implication of Rho GTPases and their upstream regulators or downstream effectors in the transformation, migration, invasion and tumorigenesis of diverse cancer stem cells highlights the potential of Rho GTPase targeting in cancer therapy. In this review, we discuss recent evidence of Rho GTPase signaling in the regulation of embryonic stem cells, multiple somatic stem cells, and cancer stem cells. We propose promising areas where Rho GTPase pathways may serve as useful targets for stem cell manipulation and related future therapies.

scholarly journals Stem cell differentiation is a stochastic process with memory

2017 ◽  
Author(s):  
Patrick S. Stumpf ◽  
Rosanna C. G. Smith ◽  
Michael Lenz ◽  
Andreas Schuppert ◽  
Franz-Josef Müller ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stochastic Process ◽  
Statistical Mechanics ◽  
Molecular Mechanisms ◽  
Embryonic Stem ◽  
Stem Cell Differentiation ◽  
Cell Types ◽  
Hematopoietic Stem ◽  
Pluripotent State

AbstractPluripotent stem cells are able to self-renew indefinitely in culture and differentiate into all somatic cell types in vivo. While much is known about the molecular basis of pluripotency, the molecular mechanisms of lineage commitment are complex and only partially understood. Here, using a combination of single cell profiling and mathematical modeling, we examine the differentiation dynamics of individual mouse embryonic stem cells (ESCs) as they progress from the ground state of pluripotency along the neuronal lineage. In accordance with previous reports we find that cells do not transit directly from the pluripotent state to the neuronal state, but rather first stochastically permeate an intermediate primed pluripotent state, similar to that found in the maturing epiblast in development. However, analysis of rate at which individual cells enter and exit this intermediate metastable state using a hidden Markov model reveals that the observed ESC and epiblast-like ‘macrostates’ conceal a chain of unobserved cellular ‘microstates’, which individual cells transit through stochastically in sequence. These hidden microstates ensure that individual cells spend well-defined periods of time in each functional macrostate and encode a simple form of epigenetic ‘memory’ that allows individual cells to record their position on the differentiation trajectory. To examine the generality of this model we also consider the differentiation of mouse hematopoietic stem cells along the myeloid lineage and observe remarkably similar dynamics, suggesting a general underlying process. Based upon these results we suggest a statistical mechanics view of cellular identities that distinguishes between functionally-distinct macrostates and the many functionally-similar molecular microstates associated with each macrostate. Taken together these results indicate that differentiation is a discrete stochastic process amenable to analysis using the tools of statistical mechanics.

scholarly journals Multiple Roles for Cholinergic Signaling from the Perspective of Stem Cell Function

2021 ◽  
Vol 22 (2) ◽  
pp. 666
Author(s):  
Toshio Takahashi
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Function ◽  
Cell Activity ◽  
Embryonic Stem ◽  
Cholinergic Neurons ◽  
Cell Types ◽  
Proliferative Potential ◽  
True Nature ◽  
Cholinergic Signaling

Stem cells have extensive proliferative potential and the ability to differentiate into one or more mature cell types. The mechanisms by which stem cells accomplish self-renewal provide fundamental insight into the origin and design of multicellular organisms. These pathways allow the repair of damage and extend organismal life beyond that of component cells, and they probably preceded the evolution of complex metazoans. Understanding the true nature of stem cells can only come from discovering how they are regulated. The concept that stem cells are controlled by particular microenvironments, also known as niches, has been widely accepted. Technical advances now allow characterization of the zones that maintain and control stem cell activity in several organs, including the brain, skin, and gut. Cholinergic neurons release acetylcholine (ACh) that mediates chemical transmission via ACh receptors such as nicotinic and muscarinic receptors. Although the cholinergic system is composed of organized nerve cells, the system is also involved in mammalian non-neuronal cells, including stem cells, embryonic stem cells, epithelial cells, and endothelial cells. Thus, cholinergic signaling plays a pivotal role in controlling their behaviors. Studies regarding this signal are beginning to unify our understanding of stem cell regulation at the cellular and molecular levels, and they are expected to advance efforts to control stem cells therapeutically. The present article reviews recent findings about cholinergic signaling that is essential to control stem cell function in a cholinergic niche.

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