Research

Jump to: Review

9356 KiB

Open AccessArticle

Cell Density-Dependent Upregulation of PDCD4 in Keratinocytes and Its Implications for Epidermal Homeostasis and Repair

by Tao Wang, Shuang Long, Na Zhao, Yu Wang, Huiqin Sun, Zhongmin Zou, Junping Wang, Xinze Ran and Yongping Su

Int. J. Mol. Sci. 2016, 17(1), 8; https://doi.org/10.3390/ijms17010008 - 23 Dec 2015

Cited by 33 | Viewed by 5536

Abstract

Programmed cell death 4 (PDCD4) is one multi-functional tumor suppressor inhibiting neoplastic transformation and tumor invasion. The role of PDCD4 in tumorigenesis has attracted more attention and has been systematically elucidated in cutaneous tumors. However, the normal biological function of PDCD4 in skin [...] Read more.

Programmed cell death 4 (PDCD4) is one multi-functional tumor suppressor inhibiting neoplastic transformation and tumor invasion. The role of PDCD4 in tumorigenesis has attracted more attention and has been systematically elucidated in cutaneous tumors. However, the normal biological function of PDCD4 in skin is still unclear. In this study, for the first time, we find that tumor suppressor PDCD4 is uniquely induced in a cell density-dependent manner in keratinocytes. To determine the potential role of PDCD4 in keratinocyte cell biology, we show that knockdown of PDCD4 by siRNAs can promote cell proliferation in lower cell density and partially impair contact inhibition in confluent HaCaT cells, indicating that PDCD4 serves as an important regulator of keratinocytes proliferation and contact inhibition in vitro. Further, knockdown of PDCD4 can induce upregulation of cyclin D1, one key regulator of the cell cycle. Furthermore, the expression patterns of PDCD4 in normal skin, different hair cycles and the process of wound healing are described in detail in vivo, which suggest a steady-state regulatory role of PDCD4 in epidermal homeostasis and wound healing. These findings provide a novel molecular mechanism for keratinocytes’ biology and indicate that PDCD4 plays a role in epidermal homeostasis. Full article

(This article belongs to the Special Issue Molecular Research of Epidermal Stem Cells 2015)

► Show Figures

Graphical abstract

2129 KiB

Open AccessArticle

Spatiotemporal Expression of p63 in Mouse Epidermal Commitment

by Qian Zhao, Shuang Liu, Huishan Zhang, Na Li, Xinyue Wang, Yujing Cao, Lina Ning, Enkui Duan and Guoliang Xia

Int. J. Mol. Sci. 2015, 16(12), 29542-29553; https://doi.org/10.3390/ijms161226185 - 10 Dec 2015

Cited by 3 | Viewed by 6289

Abstract

The embryonic surface ectoderm is a simple flat epithelium consisting of cells that express the cytokeratins K8/K18. Before stratification, K5/K14 expression substitutes K8/K18 expression, marking the event called epidermal commitment. Previous studies show that the transcription factor p63 plays an essential role in [...] Read more.

The embryonic surface ectoderm is a simple flat epithelium consisting of cells that express the cytokeratins K8/K18. Before stratification, K5/K14 expression substitutes K8/K18 expression, marking the event called epidermal commitment. Previous studies show that the transcription factor p63 plays an essential role in epidermal commitment. However, detailed expression information of p63 during early epidermal development in mice is still unclear. We systematically studied the expression pattern of p63 in mouse epidermal commitment, together with K8 and K5. We show that p63 expression could be detected as early as E8.5 in mouse embryos preceding epidermal commitment. p63 expression first appears near the newly formed somites and the posterior part of the embryo, further expanding to the whole embryonic surface with particular enrichment in the first branchial arches and the limb buds. ΔNp63 is the major class of isoforms expressed in this period. Relative expression intensity of p63 depends on the embryonic position. In summary, there is a sequential and regular expression pattern of K8, p63 and K5 in mouse epidermal commitment. Our study not only contributes to understanding the early events during epidermal development but also provides a basal tool to study the function of p63 in mammals. Full article

(This article belongs to the Special Issue Molecular Research of Epidermal Stem Cells 2015)

► Show Figures

Figure 1

4300 KiB

Open AccessArticle

Notch Cooperates with Survivin to Maintain Stemness and to Stimulate Proliferation in Human Keratinocytes during Ageing

by Elisabetta Palazzo, Paolo Morandi, Roberta Lotti, Annalisa Saltari, Francesca Truzzi, Sylvianne Schnebert, Marc Dumas, Alessandra Marconi and Carlo Pincelli

Int. J. Mol. Sci. 2015, 16(11), 26291-26302; https://doi.org/10.3390/ijms161125948 - 03 Nov 2015

Cited by 17 | Viewed by 9786

Abstract

The Notch signaling pathway orchestrates cell fate by either inducing cell differentiation or maintaining cells in an undifferentiated state. This study aims to evaluate Notch expression and function in normal human keratinocytes. Notch1 is expressed in all epidermal layers, though to a different [...] Read more.

The Notch signaling pathway orchestrates cell fate by either inducing cell differentiation or maintaining cells in an undifferentiated state. This study aims to evaluate Notch expression and function in normal human keratinocytes. Notch1 is expressed in all epidermal layers, though to a different degree of intensity, with a dramatic decrease during ageing. Notch1 intracellular domain (N1ICD) levels are decreased during transit from keratinocyte stem cells (KSC) to transit amplifying (TA) cells, mimicking survivin expression in samples from donors of all ages. Calcium markedly reduces N1ICD levels in keratinocytes. N1ICD overexpression induces the up-regulation of survivin and the down-regulation of keratin 10 and involucrin, while increasing the S phase of the cell cycle. On the other hand, Notch1 inhibition (DAPT) dose-dependently decreases survivin, stimulates differentiation, and reduces keratinocyte proliferation in samples from donors of all ages. Silencing Notch downgrades survivin and increases keratin 10. In addition, Notch1 inhibition decreases survivin levels and proliferation both in KSC and TA cells. Finally, while survivin overexpression decreases keratinocyte differentiation and increases N1ICD expression both in KSC and TA cells, silencing survivin results in N1ICD down-regulation and an increase in differentiation markers. These results suggest that the Notch1/survivin crosstalk contributes to the maintenance of stemness in human keratinocytes. Full article

(This article belongs to the Special Issue Molecular Research of Epidermal Stem Cells 2015)

► Show Figures

Graphical abstract

5186 KiB

Open AccessArticle

Ovine Hair Follicle Stem Cells Derived from Single Vibrissae Reconstitute Haired Skin

by Huishan Zhang, Shoubing Zhang, Huashan Zhao, Jingqiao Qiao, Shuang Liu, Zhili Deng, Xiaohua Lei, Lina Ning, Yujing Cao, Yong Zhao and Enkui Duan

Int. J. Mol. Sci. 2015, 16(8), 17779-17797; https://doi.org/10.3390/ijms160817779 - 03 Aug 2015

Cited by 13 | Viewed by 7488

Abstract

Hair follicle stem cells (HFSCs) possess fascinating self-renewal capacity and multipotency, which play important roles in mammalian hair growth and skin wound repair. Although HFSCs from other mammalian species have been obtained, the characteristics of ovine HFSCs, as well as the methods to [...] Read more.

Hair follicle stem cells (HFSCs) possess fascinating self-renewal capacity and multipotency, which play important roles in mammalian hair growth and skin wound repair. Although HFSCs from other mammalian species have been obtained, the characteristics of ovine HFSCs, as well as the methods to isolate them have not been well addressed. Here, we report an efficient strategy to obtain multipotent ovine HFSCs. Through microdissection and organ culture, we obtained keratinocytes that grew from the bulge area of vibrissa hair follicles, and even abundant keratinocytes were harvested from a single hair follicle. These bulge-derived keratinocytes are highly positive for Krt15, Krt14, Tp63, Krt19 and Itga6; in addition to their strong proliferation abilities in vitro, these keratinocytes formed new epidermis, hair follicles and sebaceous glands in skin reconstitution experiments, showing that these are HFSCs from the bulge outer root sheath. Taken together, we developed an efficient in vitro system to enrich ovine HFSCs, providing enough HFSCs for the investigations about the ovine hair cycle, aiming to promote wool production in the future. Full article

(This article belongs to the Special Issue Molecular Research of Epidermal Stem Cells 2015)

► Show Figures

Graphical abstract

Review

Jump to: Research

4570 KiB

Open AccessReview

Lingual Epithelial Stem Cells and Organoid Culture of Them

by Hiroko Hisha, Toshihiro Tanaka and Hiroo Ueno

Int. J. Mol. Sci. 2016, 17(2), 168; https://doi.org/10.3390/ijms17020168 - 28 Jan 2016

Cited by 11 | Viewed by 9907

Abstract

As tongue cancer is one of the major malignant cancers in the world, understanding the mechanism of maintenance of lingual epithelial tissue, which is known to be the origin of tongue cancer, is unquestionably important. However, the actual stem cells that are responsible [...] Read more.

As tongue cancer is one of the major malignant cancers in the world, understanding the mechanism of maintenance of lingual epithelial tissue, which is known to be the origin of tongue cancer, is unquestionably important. However, the actual stem cells that are responsible for the long-term maintenance of the lingual epithelium have not been identified. Moreover, a simple and convenient culture method for lingual epithelial stem cells has not yet been established. Recently, we have shown that Bmi1-positive cells, residing at the second or third layer of the epithelial cell layer at the base of the interpapillary pit (IPP), were slow-cycling and could supply keratinized epithelial cells for over one year, indicating that Bmi1-positive cells are long-term lingual epithelial stem cells. In addition, we have developed a novel lingual epithelium organoid culture system using a three-dimensional matrix and growth factors. Here, we discuss current progress in the identification of lingual stem cells and future applications of the lingual culture system for studying the regulatory mechanisms of the lingual epithelium and for regenerative medicine. Full article

(This article belongs to the Special Issue Molecular Research of Epidermal Stem Cells 2015)

► Show Figures

Graphical abstract

861 KiB

Open AccessReview

Understanding Melanocyte Stem Cells for Disease Modeling and Regenerative Medicine Applications

by Amber N. Mull, Ashwini Zolekar and Yu-Chieh Wang

Int. J. Mol. Sci. 2015, 16(12), 30458-30469; https://doi.org/10.3390/ijms161226207 - 21 Dec 2015

Cited by 28 | Viewed by 12760

Abstract

Melanocytes in the skin play an indispensable role in the pigmentation of skin and its appendages. It is well known that the embryonic origin of melanocytes is neural crest cells. In adult skin, functional melanocytes are continuously repopulated by the differentiation of melanocyte [...] Read more.

Melanocytes in the skin play an indispensable role in the pigmentation of skin and its appendages. It is well known that the embryonic origin of melanocytes is neural crest cells. In adult skin, functional melanocytes are continuously repopulated by the differentiation of melanocyte stem cells (McSCs) residing in the epidermis of the skin. Many preceding studies have led to significant discoveries regarding the cellular and molecular characteristics of this unique stem cell population. The alteration of McSCs has been also implicated in several skin abnormalities and disease conditions. To date, our knowledge of McSCs largely comes from studying the stem cell niche of mouse hair follicles. Suggested by several anatomical differences between mouse and human skin, there could be distinct features associated with mouse and human McSCs as well as their niches in the skin. Recent advances in human pluripotent stem cell (hPSC) research have provided us with useful tools to potentially acquire a substantial amount of human McSCs and functional melanocytes for research and regenerative medicine applications. This review highlights recent studies and progress involved in understanding the development of cutaneous melanocytes and the regulation of McSCs. Full article

(This article belongs to the Special Issue Molecular Research of Epidermal Stem Cells 2015)

► Show Figures

Graphical abstract

571 KiB

Open AccessReview

Dermal Contributions to Human Interfollicular Epidermal Architecture and Self-Renewal

by Kynan T. Lawlor and Pritinder Kaur

Int. J. Mol. Sci. 2015, 16(12), 28098-28107; https://doi.org/10.3390/ijms161226078 - 25 Nov 2015

Cited by 46 | Viewed by 9372

Abstract

The human interfollicular epidermis is renewed throughout life by populations of proliferating basal keratinocytes. Though interfollicular keratinocyte stem cells have been identified, it is not known how self-renewal in this compartment is spatially organized. At the epidermal-dermal junction, keratinocytes sit atop a heterogeneous [...] Read more.

The human interfollicular epidermis is renewed throughout life by populations of proliferating basal keratinocytes. Though interfollicular keratinocyte stem cells have been identified, it is not known how self-renewal in this compartment is spatially organized. At the epidermal-dermal junction, keratinocytes sit atop a heterogeneous mix of dermal cells that may regulate keratinocyte self-renewal by influencing local tissue architecture and signalling microenvironments. Focusing on the rete ridges and complementary dermal papillae in human skin, we review the identity and organisation of abundant dermal cells types and present evidence for interactions between the dermal microenvironment and the interfollicular keratinocytes. Full article

(This article belongs to the Special Issue Molecular Research of Epidermal Stem Cells 2015)

► Show Figures

Graphical abstract

736 KiB

Open AccessReview

Stem Cells in Skin Regeneration, Wound Healing, and Their Clinical Applications

by Nkemcho Ojeh, Irena Pastar, Marjana Tomic-Canic and Olivera Stojadinovic

Int. J. Mol. Sci. 2015, 16(10), 25476-25501; https://doi.org/10.3390/ijms161025476 - 23 Oct 2015

Cited by 218 | Viewed by 17560

Abstract

The skin is the largest organ of the body and has an array of functions. Skin compartments, epidermis, and hair follicles house stem cells that are indispensable for skin homeostasis and regeneration. These stem cells also contribute to wound repair, resulting in restoration [...] Read more.

The skin is the largest organ of the body and has an array of functions. Skin compartments, epidermis, and hair follicles house stem cells that are indispensable for skin homeostasis and regeneration. These stem cells also contribute to wound repair, resulting in restoration of tissue integrity and function of damaged tissue. Unsuccessful wound healing processes often lead to non-healing wounds. Chronic wounds are caused by depletion of stem cells and a variety of other cellular and molecular mechanisms, many of which are still poorly understood. Current chronic wound therapies are limited, so the search to develop better therapeutic strategies is ongoing. Adult stem cells are gaining recognition as potential candidates for numerous skin pathologies. In this review, we will discuss epidermal and other stem cells present in the skin, and highlight some of the therapeutic applications of epidermal stem cells and other adult stem cells as tools for cell/scaffold-based therapies for non-healing wounds and other skin disorders. We will also discuss emerging concepts and offer some perspectives on how skin tissue-engineered products can be optimized to provide efficacious therapy in cutaneous repair and regeneration. Full article

(This article belongs to the Special Issue Molecular Research of Epidermal Stem Cells 2015)

794 KiB

Open AccessReview

Cancer Microenvironment: What Can We Learn from the Stem Cell Niche

by Lukas Lacina, Jan Plzak, Ondrej Kodet, Pavol Szabo, Martin Chovanec, Barbora Dvorankova and Karel Smetana Jr.

Int. J. Mol. Sci. 2015, 16(10), 24094-24110; https://doi.org/10.3390/ijms161024094 - 12 Oct 2015

Cited by 53 | Viewed by 8127

Abstract

Epidermal stem cells (ESCs) are crucial for maintenance and self- renewal of skin epithelium and also for regular hair cycling. Their role in wound healing is also indispensable. ESCs reside in a defined outer root sheath portion of hair follicle—also known as the [...] Read more.

Epidermal stem cells (ESCs) are crucial for maintenance and self- renewal of skin epithelium and also for regular hair cycling. Their role in wound healing is also indispensable. ESCs reside in a defined outer root sheath portion of hair follicle—also known as the bulge region. ECS are also found between basal cells of the interfollicular epidermis or mucous membranes. The non-epithelial elements such as mesenchymal stem cell-like elements of dermis or surrounding adipose tissue can also contribute to this niche formation. Cancer stem cells (CSCs) participate in formation of common epithelial malignant diseases such as basal cell or squamous cell carcinoma. In this review article, we focus on the role of cancer microenvironment with emphasis on the effect of cancer-associated fibroblasts (CAFs). This model reflects various biological aspects of interaction between cancer cell and CAFs with multiple parallels to interaction of normal epidermal stem cells and their niche. The complexity of intercellular interactions within tumor stroma is depicted on example of malignant melanoma, where keratinocytes also contribute the microenvironmental landscape during early phase of tumor progression. Interactions seen in normal bulge region can therefore be an important source of information for proper understanding to melanoma. The therapeutic consequences of targeting of microenvironment in anticancer therapy and for improved wound healing are included to article. Full article

(This article belongs to the Special Issue Molecular Research of Epidermal Stem Cells 2015)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Molecular Research of Epidermal Stem Cells 2015

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Related Special Issues

Published Papers (9 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI