Epidermal cell lineage

1998 ◽  
Vol 76 (6) ◽  
pp. 889-898 ◽  
Author(s):  
Kursad Turksen ◽  
Tammy-Claire Troy

The epidermis is a stratified squamous epithelium, which is under a constant state of proliferation, commitment, differentiation, and elimination so that the functional integrity of the tissue is maintained. The intact epidermis has the ability to respond to diverse environmental stimuli by continuous turnover to maintain its normal homeostasis throughout an organism's life. This is achieved by a tightly regulated balance between stem cell self-renewal and the generation of a population of cells that undergo a limited number of more rapid (amplifying) transit divisions before giving rise to nonproliferative, terminally differentiating cells. This process makes it an excellent model system to study lineage, commitment, and differentiation, although neither the identity of epidermal stem cells nor the precise steps and regulators that lead to mature epidermal cells have yet been determined. Furthermore, the identities of genes that initiate epidermal progenitor commitment to the epidermal lineage, from putative epidermal stem cells, are unknown. This is mainly due to the lack of an in vitro model system, as well as the lack of specific reagents, to study the early events in epidermal lineage. Our recent development of a differentiating embryonic stem cell model for epidermal lineage now offers the opportunity to analyze the factors that regulate epidermal lineage. These studies will provide new insight into epidermal lineage and lead to a better understanding of various hyperproliferative skin diseases such as psoriasis and cancer.Key words: epidermis, lineage differentiation, embryonic stem cells.

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Ling Leng ◽  
Jie Ma ◽  
Luye Lv ◽  
Wenjuan Wang ◽  
Dunqin Gao ◽  
...  

Abstract Millions suffer from skin diseases. Functional interfollicular epidermal stem cells are needed in skin therapy or drug screening in vitro. We obtained functional interfollicular epidermal stem cells with intact stemness and cell junctions by treating them with Wnt3a. Moreover, epidermal stem cell-derived extracellular vesicles were useful in epidermal cell growth. Finally, functional epidermal 3D organoids with polarity were cultured using Wnt3a and the supernatant derived from interfollicular epidermal stem cells and fresh medium in a 1:1 ratio. These results provide novel directions for the improvement of skin organoids and their potential in clinical application.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Kirsty ML Mackinlay ◽  
Bailey AT Weatherbee ◽  
Viviane Souza Rosa ◽  
Charlotte E Handford ◽  
George Hudson ◽  
...  

Human embryogenesis entails complex signalling interactions between embryonic and extra-embryonic cells. However, how extra-embryonic cells direct morphogenesis within the human embryo remains largely unknown due to a lack of relevant stem cell models. Here, we have established conditions to differentiate human pluripotent stem cells (hPSCs) into yolk sac-like cells (YSLCs) that resemble the post-implantation human hypoblast molecularly and functionally. YSLCs induce the expression of pluripotency and anterior ectoderm markers in human embryonic stem cells (hESCs) at the expense of mesoderm and endoderm markers. This activity is mediated by the release of BMP and WNT signalling pathway inhibitors, and, therefore, resembles the functioning of the anterior visceral endoderm signalling centre of the mouse embryo, which establishes the anterior-posterior axis. Our results implicate the yolk sac in epiblast cell fate specification in the human embryo and propose YSLCs as a tool for studying post-implantation human embryo development in vitro.


2017 ◽  
Vol 37 (2) ◽  
Author(s):  
Guoyi Dong ◽  
Zhouchun Shang ◽  
Longqi Liu ◽  
Chuanyu Liu ◽  
Yuping Ge ◽  
...  

Spermatogenic lineage has been directly generated in spermatogonial stem cell (SSC) conditions from human pluripotent stem cells (PSCs). However, it remains unknown whether mouse embryonic stem cells (ESCs) can directly differentiate into advanced male germ cell lineage in the same conditions. Here, we showed rather low efficiency of germ-like cell generation from mouse ESCs in SSC conditions. Interestingly, addition of retinoic acid (RA) into SSC conditions enabled efficient differentiation of mouse ESCs into germ-like cells, as shown by the activation of spermatogenesis-associated genes such as Mvh, Dazl, Prdm14, Stella, Scp1, Scp3, Stra8 and Rec8. In contrast, for cells cultured in control medium, the activation of the above genes barely occurred. In addition, RA with SSC conditions yielded colonies of Acrosin-expressing cells and the positive ratio reached a peak at day 6. Our work thus establishes a simple and cost-efficient approach for male germ like cell differentiation from mouse PSCs and may propose a useful strategy for studying spermatogenesis in vitro.


Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 453
Author(s):  
Susana M. Chuva de Sousa Lopes ◽  
Marta S. Alexdottir ◽  
Gudrun Valdimarsdottir

Emerging data suggest that a trophoblast stem cell (TSC) population exists in the early human placenta. However, in vitro stem cell culture models are still in development and it remains under debate how well they reflect primary trophoblast (TB) cells. The absence of robust protocols to generate TSCs from humans has resulted in limited knowledge of the molecular mechanisms that regulate human placental development and TB lineage specification when compared to other human embryonic stem cells (hESCs). As placentation in mouse and human differ considerably, it is only with the development of human-based disease models using TSCs that we will be able to understand the various diseases caused by abnormal placentation in humans, such as preeclampsia. In this review, we summarize the knowledge on normal human placental development, the placental disease preeclampsia, and current stem cell model systems used to mimic TB differentiation. A special focus is given to the transforming growth factor-beta (TGFβ) family as it has been shown that the TGFβ family has an important role in human placental development and disease.


1996 ◽  
Vol 91 (2) ◽  
pp. 141-146 ◽  
Author(s):  
P. H. Jones

1. The keratinocytes in human epidermis are constantly turned over and replaced by a population of stem cells located in the basal epidermal layer. Until recently there were no markers allowing the isolation of viable epidermal stem cells. However, it has now been shown that epidermal stem cells can be isolated both in vitro and direct from the epidermis as they express high levels of functional β1 integrin family receptors for extracellular matrix proteins. 2. The evidence for integrins as stem cell markers and the insights that have been gained into stem cell behaviour are reviewed.


Zygote ◽  
2021 ◽  
pp. 1-6
Author(s):  
Gerelchimeg Bou ◽  
Shimeng Guo ◽  
Jia Guo ◽  
Zhuang Chai ◽  
Jianchao Zhao ◽  
...  

Summary The efficiency of establishing pig pluripotent embryonic stem cell clones from blastocysts is still low. The transcription factor Nanog plays an important role in maintaining the pluripotency of mouse and human embryonic stem cells. Adequate activation of Nanog has been reported to increase the efficiency of establishing mouse embryonic stem cells from 3.5 day embryos. In mouse, Nanog starts to be strongly expressed as early as the morula stage, whereas in porcine NANOG starts to be strongly expressed by the late blastocyst stage. Therefore, here we investigated both the effect of expressing NANOG on porcine embryos early from the morula stage and the efficiency of porcine pluripotent embryonic stem cell clone formation. Compared with intact porcine embryos, NANOG overexpression induced a lower blastocyst rate, and did not show any advantages for embryo development and pluripotent embryonic stem cell line formation. These results indicated that, although NANOG is important pluripotent factor, NANOG overexpression is unnecessary for the initial formation of porcine pluripotent embryonic stem cell clones in vitro.


2020 ◽  
pp. 019262332091824
Author(s):  
Richard Haworth ◽  
Michaela Sharpe

In 2011, Goldring and colleagues published a review article describing the potential safety issues of novel stem cell-derived treatments. Immunogenicity and immunotoxicity of the administered cell product were considered risks in the light of clinical experience of transplantation. The relative immunogenicity of mesenchymal stem cells, embryonic stem cells (ESCs), and induced pluripotent stem cells (iPSCs) was being addressed through in vitro and in vivo models. But the question arose as to whether the implanted cells needed to be identical to the recipient in every respect, including epigenetically, to evade immune recognition? If so, this set a high bar which may preclude use of many cells derived from iPSCs which have vestiges of a fetal phenotype and epigenetic memory of their cell of origin. However, for autologous iPSCs, the immunogenicity reduces once the surface antigen expression profile becomes close to that of the parent somatic cells. Therefore, a cell product containing incompletely differentiated cells could be more immunogenic. The properties of the administered cells, the immune privilege of the administration site, and the host immune status influence graft success or failure. In addition, the various approaches available to characterize potential immunogenicity of a cell therapy will be discussed.


2010 ◽  
Vol 22 (1) ◽  
pp. 354
Author(s):  
T. S. Rascado ◽  
J. F. Lima-Neto ◽  
S. E. R. S. Lorena ◽  
B. W. Minto ◽  
F. C. Landim-Alvarenga

The domestic cat can be used as a biological model for humans because of similarities in some disease and genetically transmitted conditions. Embryonic stem cells might complete nuclear reprogramming more efficiently than somatic cells and, therefore, are potentially useful for increasing interspecific cloning success. The objective of this study was to establish an effective culture system for inner cell mass (ICM)-derived cells in the domestic cat, testing the ability of the ICM to attach to the culture dish and to form embryonic stem cell colonies in the presence of fetal calf serum (FCS) and Knockout serum (KS). Moreover, knowing that the transcription factor Oct-4 is important for the maintenance of pluripotency in human and murine embryonic stem cells, the expression of this factor was evaluated in in vitro-produced blastocyst and in the attached ICM. Domestic cat oocytes were matured, fertilized, and cultured in vitro until the blastocyst stage. The ICM was mechanically isolated (n = 60) using a scalpel blade and transferred to a monolayer of chemically inactivated cat fibroblasts with 10 μg mL-1 mitomicin C. The base culture media (BM) was DMEM/F12 supplemented with nonessential amino acids, glutamine, leukemia inhibitory factor, fibroblast growth factor-2, 2-mercaptoethanol, and antibiotics. Three groups were tested: G1 = BM with 20% FCS (20); G2 = BM with 20% KS (20); G3 = BM with 15% FSC and 5% KS (20). Culture was performed in a 5% CO2 in air incubator at 38.5°C. No statistical difference was observed among groups in relation to ICM attachment (chi-square, P > 0.05). Ninety percent of the ICM presented good adhesion after 3 days of culture and started to grow in all media tested. However, until now, no good colonies were formed. Fifteen blastocysts and 10 attached ICM were fixed in 3% paraformaldehyde and permeabilized in 0.2% triton X-100 in PBS. Subsequently, to block nonspecific binding of the primary antibody, the preadsorption for 2 h at room temperature with OCT4 blocking peptide (sc-8628P, Santa Cruz Biotechnology, Santa Cruz, CA, USA) was used. Samples were incubated with Oct4 antibody (N-19 : sc 8628, Santa Cruz Biotechnology) and with the appropriate secondary antibody (A21431, Invitrogen) and examined by fluorescence microscopy. Oct4 protein was detected both in the ICM and trophoderm cells, and it was distributed in cytoplasm and nuclei. These embryos were also stained with Hoechst 33342. Although further standardization of the culture media is needed, it seems that the KS can be replaced by FCS in cat embryonic stem cell culture. Furthermore, the immunostain of the trophoderm with Oct-4 indicates a difference in the expression of this factor when compared with its expression on human and murine blastocysts. This could be related to in vitro production, or Oct 4 is not a good pluripotency marker for cat embryos and cat embryonic stem cell, consequently. This fact has been noted in goat, bovine, and porcine embryos. Acknowledgment is given to FAPESP.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
XiaoLin Sun ◽  
HongXiao Li ◽  
Ye Zhu ◽  
Pei Xu ◽  
QiSheng Zuo ◽  
...  

The use of stem cells in generating cell-based pacemaker therapies for bradyarrhythmia is currently being considered. Due to the propensity of stem cells to form tumors, as well as ethical issues surrounding their use, the seed cells used in cardiac biological pacemakers have limitations. Very small embryonic-like stem cells (VSELs) are a unique and rare adult stem cell population, which have the same structural, genetic, biochemical, and functional characteristics as embryonic stem cells without the ethical controversy. In this study, we investigated the ability of rat bone marrow- (BM-) derived VSELs to differentiate in vitro into cardiomyocytes by 5-Azacytidine (5-AzaC) treatment. The morphology of VSELs treated with 10 μM 5-AzaC increased in volume and gradually changed to cardiomyocyte-like morphology without massive cell death. Additionally, mRNA expression of the cardiomyocyte markers cardiac troponin-T (cTnT) and α-sarcomeric actin (α-actin) was significantly upregulated after 5-AzaC treatment. Conversely, stem cell markers such as Nanog, Oct-4, and Sox2 were continuously downregulated posttreatment. On day 14 post-5-AzaC treatment, the positive expression rates of cTnT and α-actin were 18.41±1.51% and 19.43±0.51%, respectively. Taken together, our results showed that rat BM-VSELs have the ability to differentiate into cardiomyocytes in vitro. These findings suggest that VSELs would be useful as seed cells in exploring the mechanism of biological pacemaker activity.


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