Talk:Developmental Mechanism - Epithelial Mesenchymal Transition
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Cite this page: Hill, M.A. (2021, January 26) Embryology Developmental Mechanism - Epithelial Mesenchymal Transition. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Talk:Developmental_Mechanism_-_Epithelial_Mesenchymal_Transition
Zhang Z, Wu W, Fang X, Lu M, Wu H, Gao C & Xia Z. (2020). Sox9 promotes renal tubular epithelial‑mesenchymal transition and extracellular matrix aggregation via the PI3K/AKT signaling pathway. Mol Med Rep , , . PMID: 32901875 DOI.
Sox9 promotes renal tubular epithelial‑mesenchymal transition and extracellular matrix aggregation via the PI3K/AKT signaling pathway
Sox9 is important for multiple aspects of development, such as testis, pancreas and heart development. Previous studies have reported that Sox9 induced epithelial‑mesenchymal transition (EMT) and extracellular matrix (ECM) production in organ fibrosis and associated diseases, such as vascular calcification. However, to the best of our knowledge, the role and underlying mechanism of action of Sox9 in renal fibrogenesis remains unknown. The results of the present study revealed that Sox9 expression levels were upregulated in the tubular epithelial cells of a rat model of obstructive nephropathy. Furthermore, the overexpression of Sox9 in NRK‑52E cells was discovered to promote renal tubular EMT and ECM aggregation, and these fibrogenic actions were potentiated by TGF‑β1. Notably, RNA‑sequencing analysis indicated the possible regulatory role of the PI3K/AKT signaling pathway in Sox9‑mediated renal tubular EMT and ECM aggregation. It was further demonstrated that the expression levels of phosphorylated AKT were upregulated in NRK‑52E cells overexpressing Sox9, while the PI3K inhibitors, LY29002 and wortmannin, inhibited the renal tubular EMT and ECM aggregation induced by the overexpression of Sox9 in NEK‑52E cells. In conclusion, the findings of the present study suggested that Sox9 may serve a profibrotic role in the development of renal tubular EMT and ECM aggregation via the PI3K/AKT signaling pathway. Therefore, Sox9 may be considered as a promising target for treating renal fibrosis.
Evidence from a Mouse Model That Epithelial Cell Migration and Mesenchymal-Epithelial Transition Contribute to Rapid Restoration of Uterine Tissue Integrity during Menstruation
PLoS One. 2014 Jan 22;9(1):e86378. doi: 10.1371/journal.pone.0086378. eCollection 2014.
Cousins FL, Murray A, Esnal A, Gibson DA, Critchley HO, Saunders PT. Author information
BACKGROUND: In women dynamic changes in uterine tissue architecture occur during each menstrual cycle. Menses, characterised by the shedding of the upper functional layer of the endometrium, is the culmination of a cascade of irreversible changes in tissue function including stromal decidualisation, inflammation and production of degradative enzymes. The molecular mechanisms that contribute to the rapid restoration of tissue homeostasis at time of menses are poorly understood. METHODOLOGY: A modified mouse model of menses was developed to focus on the events occurring within the uterine lining during endometrial shedding/repair. Decidualisation, vaginal bleeding, tissue architecture and cell proliferation were evaluated at 4, 8, 12, and 24 hours after progesterone (P4) withdrawal; mice received a single injection of bromodeoxyuridine (BrdU) 90 mins before culling. Expression of genes implicated in the regulation of mesenchymal to epithelial transition (MET) was determined using a RT2 PCR profiler array, qRTPCR and bioinformatic analysis. PRINCIPAL FINDINGS: Mice exhibited vaginal bleeding between 4 and 12 hours after P4 withdrawal, concomitant with detachment of the decidualised cell mass from the basal portion of the endometrial lining. Immunostaining for BrdU and pan cytokeratin revealed evidence of epithelial cell proliferation and migration. Cells that appeared to be in transition from a mesenchymal to an epithelial cell identity were identified within the stromal compartment. Analysis of mRNAs encoding genes expressed exclusively in the epithelial or stromal compartments, or implicated in MET, revealed dynamic changes in expression, consistent with a role for reprogramming of mesenchymal cells so that they could contribute to re-epithelialisation. CONCLUSIONS/SIGNIFICANCE: These studies have provided novel insights into the cellular processes that contribute to re-epithelialisation post-menses implicating both epithelial cell migration and mesenchymal cell differentiation in restoration of an intact epithelial cell layer. These insights may inform development of new therapies to induce rapid healing in the endometrium and other tissues and offer hope to women who suffer from heavy menstrual bleeding. PMID 24466063
Endocardial and epicardial epithelial to mesenchymal transitions in heart development and disease
Circ Res. 2012 Jun 8;110(12):1628-45. doi: 10.1161/CIRCRESAHA.111.259960.
von Gise A, Pu WT. Source Department of Cardiology, Children's Hospital Boston, 300 Longwood Ave, Boston, MA 02115, USA.
Abstract Epithelial to mesenchymal transition (EMT) converts epithelial cells to mobile and developmentally plastic mesenchymal cells. All cells in the heart arise from one or more EMTs. Endocardial and epicardial EMTs produce most of the noncardiomyocyte lineages of the mature heart. Endocardial EMT generates valve progenitor cells and is necessary for formation of the cardiac valves and for complete cardiac septation. Epicardial EMT is required for myocardial growth and coronary vessel formation, and it generates cardiac fibroblasts, vascular smooth muscle cells, a subset of coronary endothelial cells, and possibly a subset of cardiomyocytes. Emerging studies suggest that these developmental mechanisms are redeployed in adult heart valve disease, in cardiac fibrosis, and in myocardial responses to ischemic injury. Redirection and amplification of disease-related EMTs offer potential new therapeutic strategies and approaches for treatment of heart disease. Here, we review the role and molecular regulation of endocardial and epicardial EMT in fetal heart development, and we summarize key literature implicating reactivation of endocardial and epicardial EMT in adult heart disease.
Mesenchymal-to-Epithelial Transition Contributes to Endometrial Regeneration Following Natural and Artificial Decidualization
Stem Cells Dev. 2012 Dec 6. [Epub ahead of print]
Patterson AL, Zhang L, Arango NA, Teixeira J, Pru JK. Source Washington State University, Department of Animal Sciences, Center for Reproductive Biology,, Pullman, Washington, United States; firstname.lastname@example.org. Abstract Despite being a histologically dynamic organ, mechanisms coordinating uterine regeneration during the menstrual/estrous cycle and following parturition are poorly understood. In the current study, we hypothesized that endometrial epithelial tissue regeneration is accomplished, in part, by mesenchymal-to-epithelial transition (MET). To test this hypothesis, fate mapping studies were completed using a double transgenic (Tg) reporter strain, Amhr2-Cre; Rosa26-Stopfl/fl-EYFP (i.e., flox-stop EYFP reporter). EYFP expression was observed in Müllerian duct mesenchyme-derived stroma and myometrium, but not epithelia in young and peripubertal double Tg female mice. However, mosaic EYFP expression was observed in epithelia of double Tg mice following parturition. To ensure the observed epithelial EYFP expression was not due to leaky Amhr2 promoter activity, resulting in aberrant Cre expression, transgenic mice expressing LacZ under the control of the Amhr2 promoter (Amhr2-LacZ) were used to monitor β-galactosidase (β-Gal) activity within the uterus. β-Gal activity was not detected in luminal or glandular epithelia regardless of age, reproductive status or degree of damage incurred within the uterus. Lastly, a unique population of transitional cells was identified that express both the epithelial cell marker, pan-cytokeratin, and the stromal cell marker, vimentin. These cells localized predominantly to the regeneration zone in the mesometrial region of the endometrium. These findings suggest a previously unappreciated role for MET in endometrial regeneration and have important implications for proliferative diseases of the endometrium such as endometriosis.
p53 coordinates cranial neural crest cell growth and epithelial-mesenchymal transition/delamination processes
Development. 2011 May;138(9):1827-38. Epub 2011 Mar 29.
Rinon A, Molchadsky A, Nathan E, Yovel G, Rotter V, Sarig R, Tzahor E. Source Department of Biological Regulation, Weizmann Institute of Science, Rehovot 76100, Israel.
Neural crest development involves epithelial-mesenchymal transition (EMT), during which epithelial cells are converted into individual migratory cells. Notably, the same signaling pathways regulate EMT function during both development and tumor metastasis. p53 plays multiple roles in the prevention of tumor development; however, its precise roles during embryogenesis are less clear. We have investigated the role of p53 in early cranial neural crest (CNC) development in chick and mouse embryos. In the mouse, p53 knockout embryos displayed broad craniofacial defects in skeletal, neuronal and muscle tissues. In the chick, p53 is expressed in CNC progenitors and its expression decreases with their delamination from the neural tube. Stabilization of p53 protein using a pharmacological inhibitor of its negative regulator, MDM2, resulted in reduced SNAIL2 (SLUG) and ETS1 expression, fewer migrating CNC cells and in craniofacial defects. By contrast, electroporation of a dominant-negative p53 construct increased PAX7(+) SOX9(+) CNC progenitors and EMT/delamination of CNC from the neural tube, although the migration of these cells to the periphery was impaired. Investigating the underlying molecular mechanisms revealed that p53 coordinates CNC cell growth and EMT/delamination processes by affecting cell cycle gene expression and proliferation at discrete developmental stages; disruption of these processes can lead to craniofacial defects.
Evidence for partial epithelial-to-mesenchymal transition (pEMT) and recruitment of motile blastoderm edge cells during avian epiboly
Dev Dyn. 2011 Jun;240(6):1502-11. doi: 10.1002/dvdy.22607. Epub 2011 Mar 15.
Futterman MA, García AJ, Zamir EA. Source Woodruff School of Mechanical Engineering, Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Embryonic epiboly has become an important developmental model for studying the mechanisms underlying collective movements of epithelial cells. In the last couple of decades, most studies of epiboly have utilized Xenopus or zebrafish as genetically tractable model organisms, while the avian epiboly model has received virtually no attention. Here, we re-visit epiboly in quail embryos and characterize several molecular markers of epithelial-to-mesenchymal transition (EMT) in the inner zone of the extraembryonic Area Opaca and at the blastoderm edge. Our results show that the intermediate filament vimentin, a widely-used marker for the mesenchymal phenotype, is strongly expressed in the edge cells compared to the cells in the inner zone. Laminin, an extracellular matrix protein that is a major structural and adhesive component of the epiblast basement membrane and the inner zone of the Area Opaca, is notably absent from the blastoderm edge. While these expression profiles are consistent with a mesenchymal phenotype, several other epithelial markers, including cytokeratin, β-catenin, and E-cadherin, are present in the blastoderm edge cells. Moreover, the results of a BrDU proliferation assay strongly suggest that expansion of the edge cell population is primarily due to recruitment of cells from the inner zone, as opposed to proliferation. Taken together, our data show that the edge cells of the avian blastoderm have characteristics of both epithelial and mesenchymal cells, and that the avian epiboly model, which has been dormant for so many years, may yet again prove to be helpful as a unique developmental model for studying partial EMT in the context of collective epithelial cell migration.
Copyright © 2011 Wiley-Liss, Inc.
Establishment of Hertwig's epithelial root sheath cell line from cells involved in epithelial-mesenchymal transition
Biochem Biophys Res Commun. 2011 Jan 7;404(1):308-12. Epub 2010 Dec 3.
Akimoto T, Fujiwara N, Kagiya T, Otsu K, Ishizeki K, Harada H. Source Division of Periodontology, Department of Conservative Dentistry and Rehabilitation, School of Dentistry, Iwate Medical University, Morioka, Iwate, Japan.
The epithelial-mesenchymal transition (EMT) is an important event in the developmental process of various organs. In periodontal development during root formation of a tooth, this EMT has been a subject of controversy. Hertwig's epithelial root sheath (HERS), consisting of two epithelial layers, plays a role of inducing odontogenesis during root development and thereafter becomes fragmented. Some researchers have maintained that in the process of this fragmentation, some HERS cells change from epithelial to mesenchymal cells. Here, we established a HERS cell line (HERS01a) and examined its gene and protein expression. Immunohistochemical staining and real-time PCR analysis showed that HERS01a cells expressed vimentin and N-cadherin as mesenchymal markers as well as cytokeratin14, E-cadherin, and p63 as epithelial stem cell markers. In the presence of TGF-β, HERS01a cells also expressed many more mesenchymal markers, as well as snail1 and 2 as EMT markers. Taken together, our data show that HERS01a displayed unique features associated with EMT in the root formation process, and will thus be useful for analyzing the biological characteristics of HERS and the molecular mechanism underlying the EMT.
Copyright © 2010 Elsevier Inc. All rights reserved.
The existence of multipotent stem cells with epithelial-mesenchymal transition features in the human liver bud
Int J Biochem Cell Biol. 2010 Dec;42(12):2047-55. Epub 2010 Sep 25.
Su J, You P, Li WL, Tao XR, Zhu HY, Yao YC, Yu HY, Han QW, Yu B, Liu FX, Xu J, Lau JT, Hu YP. Source Department of Cell Biology, Second Military Medical University, Xiangyin Rd. 800, Shanghai 200433, PR China.
During early stage of embryonic development, the liver bud, arising from the foregut endoderm, is the beginning for the formation of future liver three-dimensional structure. While the gene expression profiles associated with this developmental stage have been well explored, the detailed cellular events are not as clear. Epithelial-mesenchymal transition (EMT) was thought to be essential for cell migration in the early vertebrate embryo but seldom demonstrated in human liver development. In this study, we tried to identify the cell populations with both stem cell and EMT features in the human liver bud. Our in situ studies show that the phenotype of EMT occurs at initiation of human liver development, accompanied by up-regulation of EMT associated genes. A human liver bud derived stem cell line (hLBSC) was established, which expressed not only genes specific to both mesenchymal cells and hepatic cells, but also octamer-binding protein 4 (OCT4) and nanog. Placed in appropriate media, hLBSC differentiated into hepatocytes, adipocytes, osteoblast-like cells and neuron-like cells in vitro. When transplanted into severe combined immunodeficiency mice pre-treated by carbon tetrachloride, hLBSC engrafted into the liver parenchyma and proliferated. These data suggests that there are cell populations with stem cell and EMT-like properties in the human liver bud, which may play an important role in the beginning of the spatial structure construction of the liver.
Copyright © 2010 Elsevier Ltd. All rights reserved.