scholarly journals Apoptotic Find-me Signals are an Essential Driver of Stem Cell Conversion To The Cardiac Lineage

2021 ◽  
Author(s):  
Loic Fort ◽  
Vivian Gama ◽  
Ian G Macara

Pluripotent stem cells can be driven by manipulation of Wnt signaling through a series of states similar to those that occur during early embryonic development, transitioning from an epithelial phenotype into the cardiogenic mesoderm lineage and ultimately into functional cardiomyocytes. Strikingly, we observed that induced pluripotent stem cells (iPSCs) and embryonic stem cells (ESCs) undergo widespread apoptosis upon 49 hrs of Wnt activation, followed by a synchronous epithelial-mesenchymal transition (EMT). The EMT requires induction of transcription factors SNAI1/SNAI2 downstream of MESP1 expression, and double knock-out of SNAI1/2, or loss of MESP1 in iPSCs blocks EMT and prevents cardiac differentiation. Remarkably, blockade of early apoptosis chemically or by ablation of pro-apoptotic genes also completely prevents the EMT, suppressing even the earliest events in mesoderm conversion, including EOMES, TBX6, and MESP1 induction. Conditioned medium from WNT-activated WT iPSCs overcomes the block to EMT by cells incapable of apoptosis (Apop-), suggesting the involvement of soluble factors from apoptotic cells in mesoderm conversion. Treatment with a purinergic P2Y receptor inhibitor or addition of apyrase demonstrated a requirement for nucleotide triphosphate signaling. ATP was sufficient to induce a partial EMT in Apop- cells treated with WNT activator. We conclude that nucleotides, in addition to acting as chemo-attractants for clearance of apoptotic cells can, unexpectedly, function as essential paracrine signals in mesoderm specification.

2014 ◽  
Vol 26 (1) ◽  
pp. 208
Author(s):  
Y.-S. Kim ◽  
B.-R. Yi ◽  
S.-H. Hyun ◽  
C.-K. Lee ◽  
K.-C. Choi

In transgenic pig production for generating animal models of human diseases, apoptosis of an early implantation embryo disturbs the transgenic pig production. Porcine embryonic stem cells (pESC) and porcine induced pluripotent stem cells (piPSC) have an advantage for the generation of transgenic pigs; however, porcine stem cells have not yet been established. In addition, epithelial–mesenchymal transition (EMT) may play a critical role in embryo development and apoptosis. Thus, in this study we generated pESC and pIPSC and further examined the changes in EMT and apoptotic markers. We cultured pESC and piPSC in pESC media containing basic fibroblast growth factor (bFGF), doxicyclin, and leukemia inhibitory factor (LIF), and performed RT-PCR and alkaline phosphatase (AP) test to measure pluripotency markers. The RT-PCR results show that OCT-4, NANOG, and SOX2 were expressed in these stem cells, characteristic of stem cells. AP-positive cells were observed in pESCs and piPSC. In addition, we performed immunocytochemistry (ICC) to examine the expression of surface markers, such as SSEA-1 and SSEA-4. We found that pESC and piPSC expressed these markers, indicating that they have a stem cell property similar to rodent and human stem cells. Second, we treated pESC and piPSC with transforming growth factor beta (TGF-β) to examine the relationship between EMT and apoptotic markers, and confirmed a significant variation of EMT and apoptotic markers, i.e. bcl-2, bax, E-cadherin, and vimentin, by Western blot analysis. In a future study, we will examine the effect(s) of various endocrine hormones secreted by the ovary, such as E2 or P4, on the expressions of EMT and apoptotic markers in pESC and piPSC. Consequently, this study will contribute to elucidate underlying mechanism(s) of EMT and apoptosis by endocrine factors to prevent early apoptosis of pig embryos in these porcine stem cells. This work was supported by a grant from the Next-Generation BioGreen 21 Program (No. PJ009599), Rural Development Administration, Republic of Korea.


2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Aniela Skrzypczyk ◽  
Stephanie Kehr ◽  
Ilona Krystel ◽  
Stephan H. Bernhart ◽  
Shibashish Giri ◽  
...  

Recent advances in the stem cell field allow to obtain many human tissues in vitro. However, hepatic differentiation of induced pluripotent stem cells (iPSCs) still remains challenging. Hepatocyte-like cells (HLCs) obtained after differentiation resemble more fetal liver hepatocytes. MicroRNAs (miRNA) play an important role in the differentiation process. Here, we analysed noncoding RNA profiles from the last stages of differentiation and compare them to hepatocytes. Our results show that HLCs maintain an epithelial character and express miRNA which can block hepatocyte maturation by inhibiting the epithelial-mesenchymal transition (EMT). Additionally, we identified differentially expressed small nucleolar RNAs (snoRNAs) and discovered novel noncoding RNA (ncRNA) genes.


2020 ◽  
Vol 15 (4) ◽  
pp. 301-307 ◽  
Author(s):  
Gaifang Wang ◽  
Maryam Farzaneh

Primary Ovarian Insufficiency (POI) is one of the main diseases causing female infertility that occurs in about 1% of women between 30-40 years of age. There are few effective methods for the treatment of women with POI. In the past few years, stem cell-based therapy as one of the most highly investigated new therapies has emerged as a promising strategy for the treatment of POI. Human pluripotent stem cells (hPSCs) can self-renew indefinitely and differentiate into any type of cell. Human Embryonic Stem Cells (hESCs) as a type of pluripotent stem cells are the most powerful candidate for the treatment of POI. Human-induced Pluripotent Stem Cells (hiPSCs) are derived from adult somatic cells by the treatment with exogenous defined factors to create an embryonic-like pluripotent state. Both hiPSCs and hESCs can proliferate and give rise to ectodermal, mesodermal, endodermal, and germ cell lineages. After ovarian stimulation, the number of available oocytes is limited and the yield of total oocytes with high quality is low. Therefore, a robust and reproducible in-vitro culture system that supports the differentiation of human oocytes from PSCs is necessary. Very few studies have focused on the derivation of oocyte-like cells from hiPSCs and the details of hPSCs differentiation into oocytes have not been fully investigated. Therefore, in this review, we focus on the differentiation potential of hPSCs into human oocyte-like cells.


2009 ◽  
Vol 1 (1) ◽  
pp. 76-82 ◽  
Author(s):  
Mark Denham ◽  
Jessie Leung ◽  
Cheryl Tay ◽  
Raymond C.B. Wong ◽  
Peter Donovan ◽  
...  

Biomolecules ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1074
Author(s):  
Giuseppina Divisato ◽  
Silvia Piscitelli ◽  
Mariantonietta Elia ◽  
Emanuela Cascone ◽  
Silvia Parisi

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.


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