Epithelial–mesenchymal transition process in human embryonic stem cells cultured in feeder-free conditions

Epithelial to mesenchymal transition (EMT) is a critical cellular process that has been well characterized during embryonic development and cancer metastasis and it also is implicated in several physiological and pathological events including embryonic stem cell differentiation. During early stages of differentiation, human embryonic stem cells pass through EMT where deeper morphological, molecular and biochemical changes occur. Though initially considered as a decision between two states, EMT process is now regarded as a fluid transition where cells exist on a spectrum of intermediate states. In this work, using a CRISPR interference system in human embryonic stem cells, we describe a molecular characterization of the effects of downregulation of E-cadherin, one of the main initiation events of EMT, as a unique start signal. Our results suggest that the decrease and delocalization of E-cadherin causes an incomplete EMT where cells retain their undifferentiated state while expressing several characteristics of a mesenchymal-like pheno-type. Namely, we found that E-cadherin downregulation induces SNAI1 and SNAI2 upregulation, promotes MALAT1 and LINC-ROR downregulation, modulates the expression of tight junction occludin 1 and gap junction connexin 43, increases human embryonic stem cells migratory capacity and delocalize b-catenin. Altogether, we believe our results provide a useful tool to model the molecular events of an unstable intermediate state and further identify multiple layers of molecular changes that occur during partial EMT.

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323 ESTROGEN-INDUCED EPITHELIAL-MESENCHYMAL TRANSITION AND EXPRESSION OF PROAPOPTOTIC MARKERS IN PORCINE STEM CELLS

Reproduction Fertility and Development ◽

10.1071/rdv27n1ab323 ◽

2015 ◽

Vol 27 (1) ◽

pp. 250

Author(s):

Y.-S. Kim ◽

S.-H. Hyun ◽

C.-K. Lee ◽

K.-C. Choi

Keyword(s):

Stem Cells ◽

Embryonic Stem Cells ◽

Epithelial Mesenchymal Transition ◽

Steroid Hormone ◽

Embryonic Stem ◽

Transgenic Pig ◽

Rt Pcr ◽

Mesenchymal Transition ◽

Apoptotic Markers ◽

E Cadherin

In transgenic pig production for generating animal models of human diseases, apoptosis of early implantation embryo disturbs the transgenic pig production. In general, epithelial-mesenchymal transition (EMT) is considered important in embryo development and apoptosis. In addition, it was reported that 17β-oestradiol (E2), among hormones that participate in early implantation of embryo, could induce EMT and neural differentiation in mouse embryonic stem cells. Therefore, in this study, we examined the effects of the steroid hormone, E2, in the changes of EMT and apoptotic markers in porcine embryonic stem cells (pESC) and porcine induced pluripotent stem cells (piPSC). During the study, we cultured pESC and piPSC in pESC media containing basic fibroblast growth factor (b-FGF) and leukemia inhibitory factor (LIF) and performed RT-PCR and an alkaline phophatase (AP) test to measure pluripotent and undifferentiation markers of these porcine stem cells. The RT-PCR results showed that OCT4, NANOG, and SOX2 were expressed in these pESC and piPSC, indicating their pluripotency as stem cells. Also, these porcine stem cells showed positive AP activity, demonstrating undifferentiation. Additionally, we treated pESC and piPSC with E2 to examine effects of steroid hormone on the changes of EMT and apoptotic markers (i.e. bcl-2, bax, E-cad, and vimentin). The E2 treatment increased the expression of vimentin and bcl-2, while decreased the expression of E-cadherin and bax. By using immunocytochemistry (ICC), we examined the protein expression of EMT markers, which are vimentin and E-cadherin at the translational level, and found that expression of vimentin protein was increased while E-cadherin protein level was reduced at periphery of the colonies in pESC and piPSC. In conclusion, these results indicate that E2 can promote EMT process and reverse apoptosis in these pESC and iPSC. In a future study, we will further examine the effects of progesterone on the expressions of EMT and apoptotic markers in pESC and piPSC. Consequently, this study will contribute to elucidate the underlying mechanisms of EMT and apoptosis controlled by steroid hormones in porcine stem cells.

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64 EPITHELIAL MESENCHYMAL TRANSITION AND DIFFERENTIATION OF STEROIDOGENIC FACTOR 1 MOUSE EMBRYONIC STEM CELLS INTO THE STEROIDOGENIC CELLS

Reproduction Fertility and Development ◽

10.1071/rdv28n2ab64 ◽

2016 ◽

Vol 28 (2) ◽

pp. 162

Author(s):

H. Y. Kang ◽

Y.-K. Choi ◽

J.-U. Hwang ◽

E.-B. Jeung

Keyword(s):

Stem Cells ◽

Embryonic Stem Cells ◽

Epithelial Mesenchymal Transition ◽

Embryonic Stem ◽

Primitive Streak ◽

Mouse Embryonic Stem Cells ◽

Mrna Levels ◽

Forkhead Transcription Factor ◽

Steroidogenic Factor 1 ◽

Mesenchymal Transition

Steroidogenic factor 1 (SF-1) is essential for the development and function of steroidogenic tissues. Stable incorporation of SF-1 into embryonic stem cells has been reported to prime the cells for steroidogenesis. In this study, we transfected mouse embryonic stem cells (mESCs) with the mouse SF1 gene (SF1-mESCs) by using the nucleofector (Lonza), and selected SF1-mESCs by G418 250 μg mL–1. The selected cells were differentiated into granulosa-like cells through hanging-drops for 3 days, suspension culture for 1 day, then attachment onto 6-well plates. Expression of steroidogenesis-related genes and gonadal lineage-markers was analysed by real-time PCR. To test the phenotype for granulosa-like cells, transcripts of specific forkhead transcription factor (Foxl2) and follicle stimulating hormone receptor (Fshr) were measured. Also, expression of EMT-related genes, such as E-Cadherin (Cdh1), N-Cadherin (Cdh2), Snai1, Snai2 (Slug), Twist, and Vimentin, was monitored. SF1-mESCs were differentiated into the primitive streak‐mesendoderm and the steroidogenic enzymes such as 3β-hydroxysteroid dehydrogenase (Hsd3b1), cytochrome P450-containing enzyme (Cyp)-11a1, and Cyp19a1 were time-dependently changed. Next, the mRNA levels of Foxl2 and Fshr representing granulosa-like cell were increased during differentiation of SF1-mESCs. Especially, the level of oestradiol and Cdh2 was increased at a specific differentiation time. We induced differentiation of mESCs into the functional granulosa-like cells through transfection of the mouse SF1 gene. These cells will be useful for further study and potential application of these cells in steroidogenesis. This research was supported by a grant (15182MFDS460) from the Ministry of Food and Drug Safety in 2015.

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