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Hair follicle stem cells (HFSCs) are among the most widely available resources and most frequently approved model systems used for studying adult stem cells. HFSCs are particularly useful because of their self-renewal and differentiation properties. Additionally, the cyclic growth of hair follicles is driven by HFSCs. There are high expectations for the use of HFSCs as favourable systems for studying the molecular mechanisms that contribute to HFSC identification and can be applied to hair loss therapy, such as the activation or regeneration of hair follicles, and to the generation of hair using a tissue-engineering strategy. A variety of molecules are involved in the networks that critically regulate the fate of HFSCs, such as factors in hair follicle growth and development (in the Wnt pathway, Sonic hedgehog pathway, Notch pathway, and BMP pathway), and that suppress apoptotic cues (the apoptosis pathway). Here, we review the life cycle, biomarkers and functions of HFSCs, concluding with a summary of the signalling pathways involved in HFSC fate for promoting better understanding of the pathophysiological changes in the HFSC niche. Importantly, we highlight the potential mechanisms underlying the therapeutic targets involved in pathways associated with the treatment of hair loss and other disorders of skin and hair, including alopecia, skin cancer, skin inflammation, and skin wound healing. [ABSTRACT FROM AUTHOR]

Background: The biological role of miR-203 and the underlying mechanisms on the proliferation of epidermal stem cells (ESCs) have not yet been reported during the progression of chronic wound healing in diabetes mellitus. Our previous studies have observed that the expression of miR-203 showed a marked upregulation and ESC proliferation capacity was impaired in diabetes mellitus skin wounds in rats. Methods: Wound models were established in normal rats and rats with type 2 diabetes. Expression level of miR-203 and the alteration of ESCs' number and function were detected. ESCs were isolated from the back skin of fetal rats to assess the effects of glucose in vitro. An antagomir to miR-203 was used to assess its effect on ESCs. Using microarray analysis, we further identified potential target genes and signaling pathways of miR-203. Results: We found that high glucose significantly upregulated the expression of miR-203 and subsequently reduced the number of ESCs and impaired their proliferation capacity. Meanwhile, over-expression of miR-203 reduced the ESCs' numbers and impaired the proliferation capacity via downregulation of the Notch and Wnt signaling pathways. Conversely, inhibition of miR-203 enhanced the proliferation capacity. Additionally, silencing miR-203 in skin of rats with type 2 diabetes accelerated wound healing and improved healing quality via the upregulation of the Notch and Wnt signaling pathways. Finally, over-expression of miR-203 downregulated genes ROCK2, MAPK8, MAPK9, and PRKCA. Conclusion: Our findings demonstrated that induced expression of miR-203 by high glucose in type 2 diabetic rats decreased the number of ESCs and impaired ESC proliferation capacity via downregulating genes related to Notch and Wnt signaling pathways, resulting in a delayed wound healing. [ABSTRACT FROM AUTHOR]

The epidermis, which is the outermost layer of mammalian skin, provides an essential barrier that is essential for maintenance of life. The epidermis is a stratified epithelium, which is maintained by the proliferation of epidermal stem cells (EPSCs) at the basal layer of the epidermis. As a unique cell population characterized by self-renewal and differentiation capabilities, EPSCs ensure the maintenance of adult skin homeostasis and participate in repair of the epidermis after injury. Recently, the utilization of EPSCs for wound healing and tissue regeneration has been attracting increased attention from researchers. In addition, the advances in tissue engineering have increased the interest in applying EPSCs in tissue-engineered scaffolds to further reconstitute injured tissues. In this review, we introduce research developments related to EPSCs, including methods recently used in the culture and enrichment of EPSCs, as well as advanced tools to study EPSCs. The function and mechanism of the EPSC-dermal units in the development and homeostasis of the skin are also summarized. Finally, the potential applications of EPSCs in skin tissue engineering are discussed. [ABSTRACT FROM AUTHOR]

Background/Aims: Little is known how miR-203 is involved in epidermal stem cells (ESCs) differentiation and scar formation. Methods: We first used luciferase assay to determine the interaction of miR-203 with the 3'-UTR in regulation of Hes1 expression. We then used flow cytometry to analyze the effects of miR-203 expression on the differentiation of ESCs to MFB by determination of CK15 ratio and α-SMA. To confirm the results of flow cytometry analysis, we used Western blot to examine the expression of α-SMA, Collagen I (Col I), and Collagen III (Col III), as well as the expression of Notch1, Jagged1, and Hes1 in ESCs after the treatment of pre-miR-203 or anti-miR-203. Finally, we examined the effects local anti-miR-203 treatment on would closure and scar formation using a mouse skin wound model. Results: Pre-miR-203 treatment increased ESCs differentiation to MFB cells, as indicated by decreased CK15 ratio and increased MFB biomarkers. This phenomenon was reversed by overexpression of Hes1 in ESCs. In addition, skin incision increased expression of miR-203 in wound tissue. Local treatment of anti-miR-203 could accelerate wound closure and reduce scar formation in vivo, which was associated with increased re-epithelialization, skin attachment regeneration, and collagen reassignment. Finally, we confirmed that anti-miR-203 treatment could inhibit ESCs differentiation in vivo via increasing Hesl expression. Conclusion: Taken together, our results suggested that overexpression of miR-203 in ESCs after skin wound may be a critical mechanism underlying the scar formation. [ABSTRACT FROM AUTHOR]

Correction to: Stem Cell Res Ther (2020) 11:303 https://doi.org/10.1186/s13287-020-01796-3 The authors wish to note the following in this correction article: Figure 1 in the original article [[1]] was based on Fig. References 1 Yang R, Yang S, Zhao J, Hu X, Chen X, Wang J. Progress in studies of epidermal stem cells and their application in skin tissue engineering. [Extracted from the article]

An amendment to this paper has been published and can be accessed via the original article. [ABSTRACT FROM AUTHOR]

The skin has important barrier, sensory, and immune functions, contributing to the health and integrity of the organism. Extensive skin injuries that threaten the entire organism require immediate and effective treatment. Wound healing is a natural response, but in severe conditions, such as burns and diabetes, this process is insufficient to achieve effective treatment. Epidermal stem cells (EPSCs) are a multipotent cell type and are committed to the formation and differentiation of the functional epidermis. As the contributions of EPSCs in wound healing and tissue regeneration have been increasingly attracting the attention of researchers, a rising number of therapies based on EPSCs are currently under development. In this paper, we review the characteristics of EPSCs and the mechanisms underlying their functions during wound healing. Applications of EPSCs are also discussed to determine the potential and feasibility of using EPSCs clinically in wound healing. [ABSTRACT FROM AUTHOR]