Biological characterization of cultured dermal papilla cells and hair follicle regeneration in vitro and in vivo:

Epidermal ET-1 signal induces activation of resting hair follicles by upregulating the PI3K/AKT pathway in the dermis

The prevalence of alopecia has increased recently. Hair loss is often accompanied by the resting phase of hair follicles (HFs). Dermal papilla (DP) plays a crucial role in HF development, growth, and regeneration. Activating DP can revive resting HFs. Augmenting WNT/β-catenin signaling stimulates HF growth. However, the factors responsible for activating resting HFs effectively are unclear. In this study, we investigated epidermal cytokines that can activate resting HFs effectively. We overexpressed β-catenin in both in vivo and in vitro models to observe its effects on resting HFs. Then, we screened potential epidermal cytokines from GEO DATASETs and assessed their functions using mice models and skin-derived precursors (SKPs). Finally, we explored the molecular mechanism underlying the action of the identified cytokine. The results showed that activation of WNT/β-catenin in the epidermis prompted telogen-anagen transition. Keratinocytes infected with Ctnnb1-overexpressing lentivirus enhanced SKP expansion. Subsequently, we identified endothelin 1 (ET-1) expressed higher in hair-growing epidermis and induced the proliferation of DP cells and activates telogen-phase HFs in vivo. Moreover, ET-1 promotes the proliferation and stemness of SKPs. Western blot analysis and in vivo experiments revealed that ET-1 induces the transition from telogen-to-anagen phase by upregulating the PI3K/AKT pathway. These findings highlight the potential of ET-1 as a promising cytokine for HF activation and the treatment of hair loss.

Hypoxia enhances the hair growth-promoting effects of embryonic stem cell-derived mesenchymal stem cells via NADPH oxidase 4

Human embryonic stem cell (hES)-derived mesenchymal stem cells (-MSCs) are an unlimited source of MSCs. The hair growth-promoting effects of diverse MSCs have been reported, but not that of hES-MSCs. In the present study, we investigated the hair growth-promoting effects of hES-MSCs and their underlying mechanisms. hES-MSCs or conditioned medium of hES-MSCs exhibited hair-growth effects, which increased the length of mouse vibrissae and human hair follicles. hES-MSCs accelerated the telogen-to-anagen transition in C3H mice and were more effective than adipose-derived stem cells. We further examined whether hypoxia could enhance the hair-growth promoting effects of hES-MSCs. The injection of hES-MSCs or conditioned medium (Hyp-CM) cultured under hypoxia (2% O₂) enhanced the telogen-to-anagen transition in C3H mice. Additionally, Hyp-CM increased the length of mouse vibrissae, human hair follicles, and the proliferation of human dermal papilla and outer root sheath cells. Moreover, fibroblast growth factor 7, interleukin 12B, and teratocarcinoma-derived growth factor 1 were upregulated under hypoxia, and the co-treatment with these three proteins increased the hair length and induced telogen-to-anagen transition. Hypoxia increased reactive oxygen species (ROS) production, and ROS scavenging attenuated the secretion of growth factors. NADPH oxidase 4 was primarily expressed in hES-MSCs and generated ROS under hypoxia. Collectively, our results suggest that hES-MSCs exhibit hair-growth effects, which is enhanced by hypoxia.

Cell Proteomic Footprinting: Advances in the Quality of Cellular and Cell-Derived Cancer Vaccines

In omics sciences, many compounds are measured simultaneously in a sample in a single run. Such analytical performance opens up prospects for improving cellular cancer vaccines and other cell-based immunotherapeutics. This article provides an overview of proteomics technology, known as cell proteomic footprinting. The molecular phenotype of cells is highly variable, and their antigenic profile is affected by many factors, including cell isolation from the tissue, cell cultivation conditions, and storage procedures. This makes the therapeutic properties of cells, including those used in vaccines, unpredictable. Cell proteomic footprinting makes it possible to obtain controlled cell products. Namely, this technology facilitates the cell authentication and quality control of cells regarding their molecular phenotype, which is directly connected with the antigenic properties of cell products. Protocols for cell proteomic footprinting with their crucial moments, footprint processing, and recommendations for the implementation of this technology are described in this paper. The provided footprints in this paper and program source code for their processing contribute to the fast implementation of this technology in the development and manufacturing of cell-based immunotherapeutics.

Extremely Low-Frequency Electromagnetic Fields Increase Cytokines in Human Hair Follicles through Wnt/β-Catenin Signaling

Hair loss is a chronic disorder that affects many people; however, a complete treatment has not yet been developed. Therefore, new therapeutic agents for preventing hair loss must be developed, and electromagnetic field (EMF) therapy has been proven to be a promising medical treatment in various fields, including hair loss treatment. This study evaluated the effect of extremely low-frequency electromagnetic field (ELF-EMF) intensity and exposure time by analyzing the expression of cytokines and anagen-related molecules, which influence hair activation and growth, in hair bulb spheroid (HBS) and hair follicle (HF) organ cultures. ELF-EMFs did not induce toxicity in the HBSs, as verified via the lactate dehydrogenase (LDH) assay. Moreover, an ELF-EMF intensity of 5–20 G promoted the expression of ALP, versican, β-catenin, and several cytokines (VEGF, PDGF, FGF-10, and ET-1) in HBSs. Immunohistochemical staining showed that ELF-EMF at an intensity of 5–20 G upregulated ALP and β-catenin and decreased TUNEL staining in HBS. Moreover, HFs exposed to ELF-EMF for 60 min exhibited an increase in hair length and a 1.5-fold increase in IL-4, ICAM-1, ALP, and versican mRNA expression compared to the control. Immunohistochemical staining indicated that 60 min of ELF-EMF can increase the expression of ALP and β-catenin and decreases TUNEL staining in organ cultures. Collectively, our results demonstrated that ELF-EMF exposure at a 10 G intensity for 60 min promoted hair shaft growth in HFs due to the effect of cytokines and adhesion molecules via the Wnt/β-catenin pathway. Therefore, ELF-EMF is a promising treatment for hair loss.

miR-140-5p in Small Extracellular Vesicles From Human Papilla Cells Stimulates Hair Growth by Promoting Proliferation of Outer Root Sheath and Hair Matrix Cells

The application of dermal papilla cells to hair follicle (HF) regeneration has attracted a great deal of attention. However, cultured dermal papilla cells (DPCs) tend to lose their capacity to induce hair growth during passage, restricting their usefulness. Accumulating evidence indicates that DPCs regulate HF growth mainly through their unique paracrine properties, raising the possibility of therapies based on extracellular vesicles (EVs). In this study, we explored the effects of EVs from high- and low-passage human scalp follicle dermal papilla cells (DP-EVs) on activation of hair growth, and investigated the underlying mechanism. DP-EVs were isolated by ultracentrifugation and cultured with human scalp follicles, hair matrix cells (MxCs), and outer root sheath cells (ORSCs), and we found low-passage DP-EVs accelerated HF elongation and cell proliferation activation. High-throughput miRNA sequencing and bioinformatics analysis identified 100 miRNAs that were differentially expressed between low- (P3) and high- (P8) passage DP-EVs. GO and KEGG pathway analysis of 1803 overlapping target genes revealed significant enrichment in the BMP/TGF-β signaling pathways. BMP2 was identified as a hub of the overlapping genes. miR-140-5p, which was highly enriched in low-passage DP-EVs, was identified as a potential regulator of BMP2. Direct repression of BMP2 by miR-140-5p was confirmed by dual-luciferase reporter assay. Moreover, overexpression and inhibition of miR-140-5p in DP-EVs suppressed and increased expression of BMP signaling components, respectively, indicating that this miRNA plays a critical role in hair growth and cell proliferation. DP-EVs transport miR-140-5p from DPCs to epithelial cells, where it downregulates BMP2. Therefore, DPC-derived vesicular miR-140-5p represents a therapeutic target for alopecia.

SANTAVACTM: Summary of Research and Development

SANTAVAC is an antigen composition developed via proteomics and cell culture technology that is intended for the development of cancer vaccines against various solid tumors. Its mechanism of action is based on the heterogeneity of endothelial cells, the polypeptides of which are similar to the surface antigens of tumor-vessel cells, allowing targeted destruction by vaccination. While research and development work with SANTAVAC is ongoing, the existing data provide strong evidence that allogeneic SANTAVAC is an ideal candidate for the development of cancer vaccines with significant efficacy and safety. The SANTAVAC compositions described here demonstrated the ability to inhibit the growth of tumor vessel-specific endothelial cells up to 60 fold, with minimal effect on normal vasculature. Innovation, background, description of product development, and summary of nonclinical studies with SANTAVAC to date are presented in this review.

Synergistic effect of rice bran extract and extremely low-frequency electromagnetic fields on dermal papilla/melanocytes in melanogenesis

Melanocytes in hair are located around dermal papilla cells at the tip of the hair follicle. In this study, we examined the melanogenesis of a three-dimensional (3D) hair dermal papilla model treated with natural extracts and electromagnetic fields (EMFs). The 3D model involved dermal papilla-like tissue (DPLT), an aggregation of a mixture of dermal papilla cells, and melanocytes in microwells. Rice bran extract (RBE), an EMF, and RBE/EMF were applied to different DPLT groups. The LDH assay indicated no cell stress in all experimental groups, and detection of tyrosinase activity demonstrated high activity in the RBE/EMF group. Western blot analysis of the RBE, EMF, and RBE/EMF groups revealed increased MITF, TRP-1, and tyrosinase expression. In addition, the mRNA expression of ET-1, laminin, bFGF, β-catenin, MITF, and tyrosinase was increased in the RBE/EMF group, as demonstrated by RT-qPCR analysis. HMB45 and Fontana-Masson immunostaining showed that the RBE/EMF group had the highest melanin content. Therefore, RBE and EMF may be used as a material and therapy, respectively, for the treatment of vitiligo and white hair, through activation of melanogenesis in melanocytes. Bioelectromagnetics. 39:595-603, 2018. © 2018 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc..

Regulation of hair follicle development by exosomes derived from dermal papilla cells

BACKGROUND

Dermal papilla cells (DPCs) play a critical role in the regulation of hair follicle (HF) growth, formation, and cycling. DPCs are thought to regulate HF growth through a paracrine mechanism, in which exosomes may play a critical role.

METHODS

DPC-Exos were cutaneously injected into HFs at different HF cycle stages and the effects were evaluated by histological and immunohistochemical analyses. The effects of DPC-Exos on proliferation, migration, and cell cycle status of outer root sheath cells (ORSCs) were evaluated. After treatment of DPC-Exos, changes in mRNA and protein levels of β-catenin and Sonic hedgehog (Shh) in ORSCs were detected.

RESULTS

DPC-Exos were approximately 105 nm in diameter and expressed tumor susceptibility gene 101, cluster of differentiation (CD)9, and CD63. Injection of DPC-Exos accelerated the onset of HF anagen and delayed catagen in mice. Immunohistochemical analyses revealed that β-catenin and Shh levels were upregulated in the skin. In vitro, DPC-Exo treatment enhanced ORSC proliferation and migration, and stimulated the expression of β-catenin and Shh.

CONCLUSION

DPC-Exos contribute to the regulation of HF growth and development, and provide a potential avenue for the treatment of hair loss.

A Novel Secretory Vesicle from Deer Antlerogenic Mesenchymal Stem Cell-Conditioned Media (DaMSC-CM) Promotes Tissue Regeneration

Multipotent stem cells have the capacity to generate terminally differentiated cell types of each lineage; thus, they have great therapeutic potential for a wide variety of diseases. The most widely available stem cells are derived from human tissues, and their use for therapeutic application is limited by their high cost and low productivity. Herein, we report that conditioned media of mesenchymal stem cells (MSCs) isolated from deer antlers enhanced tissue regeneration through paracrine action via a combination of secreted growth factors and cytokines. Notably, DaMSC-conditioned media (DaMSC-CM) enhanced hair regeneration by activating the Wnt signaling pathway. In addition, DaMSC-CM had regenerative potential in damaged skin tissue through induction of skin regeneration-related genes. Remarkably, we identified round vesicles derived from DaMSC-CM, with an average diameter of ~120 nm that were associated with hair follicle formation, suggesting that secretory vesicles may act as paracrine mediators for modulation of local cellular responses. In addition, these secretory vesicles could regulate the expression of Wnt-3a, Wnt-10b, and lymphoid enhancer-binding factor-1 (LEF-1), which are related to tissue renewal. Thus, our findings demonstrate that the use of DaMSC-CM as a unique natural model for rapid and complete tissue regeneration has possible application for therapeutic development.

Hair growth-promoting effect of Geranium sibiricum extract in human dermal papilla cells and C57BL/6 mice

Background

Geranium sibiricum L. has been used as a medicinal plant to treat diarrhea, bacterial infection, and cancer in Bulgaria, Peru, and Korea. However, its hair growth-promoting effect was not investigated so far. This study examined the effects of Geranium sibiricum L. extract (GSE) on hair growth, using in vitro and in vivo models.

Methods

Antioxidant, proliferation and migration assay of GSE was performed with human dermal papilla cells (hDPCs). Hair-growth promoting effect was measured in animal model. Relative expression of interleukin-1, vascular endothelial growth factor, hepatocyte growth factor, and transforming growth factor beta 1 was determined by real time RT-PCR. Expression of Ki-67 and stem cell factor were analyzed by immunohistochemistry.

Results

GSE treatment proliferated and migrated human dermal papilla cells (hDPCs) more than treatment of 10 μM minoxidil. GSE significantly stimulated the expression of Ki-67 protein and the mRNA levels of hepatocyte growth factor and vascular endothelial growth factor in hDPCs. Topical application of 1,000 ppm GSE for 3 weeks promoted more significant hair growth on shaved C57BL/6 mice than did 5% minoxidil. The histological morphology of hair follicles demonstrated an active anagen phase with the induction of stem cell factor. GSE treatment significantly reduced the number of mast cells and the expression of transforming growth factor beta 1 in mouse skin tissues.

Conclusions

These results demonstrated that GSE promotes hair growth in vitro and in vivo by regulating growth factors and the cellular response.

hMSCs possess the potential to differentiate into DP cells in vivo and in vitro

DP (dermal papilla) is a mesenchyme-derived structure situated at the base of the HF (hair follicle) that plays an important role in embryonic hair morphogenesis and maintenance of the hair growth cycle. hMSCs (human mesenchymal stem cells) have gained widespread attention in the field of tissue engineering, but not much is known about the differentiation of hMSCs into DP cells. hMSCs involved in HF formation were examined in our previous study. Here, we have explored the differentiation potential of hMSCs into DP cells by co-culturing hMSCs with DP cells, which proved to be the case. During the differentiation process, the expression of versican, CD133, SCF (stem cell factor), ET-1 (endothelin-1) and bFGF (basic fibroblast growth factor) increased. Compared with hMSCs alone, the aggregate number clearly increased when co-cultured with DP cells. The expression in vivo of HLA-I (human leucocyte antigen class I) was confined to DP of the newly formed HF. The data suggest that hMSCs possess the potential to differentiate into DP cells in vivo and in vitro.

VEGF induces proliferation of human hair follicle dermal papilla cells through VEGFR-2-mediated activation of ERK

Vascular endothelial growth factor (VEGF) is one of the strongest regulators of physiological and pathological angiogenesis. VEGF receptor 2 (VEGFR-2), the primary receptor for VEGF, is thought to mediate major functional effects of VEGF. Previously, we have localized both VEGF and VEGFR-2 in human hair follicles. In this study, we further defined the expression and roles of VEGFR-2 on human hair follicle dermal papilla (DP) cells. The expression of VEGFR-2 on DP cells was examined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis separately, and localization of VEGFR-2 was defined by immunofluorescence. The effect of VEGF on DP cells was analyzed by MTT assays and specific inhibitors. Finally, the role of VEGF involved in the signaling pathways was investigated by Western blot. RT-PCR and Western blot analysis demonstrated the expression of VEGFR-2 on DP cells. Immunostaining for VEGFR-2 showed strong signal on cultured human DP cells in vitro. Exogenous VEGF(165) stimulated proliferation of DP cells in a dose-dependent manner. Furthermore, this stimulation was blocked by a VEGFR-2 neutralizing antibody (MAB3571) and an ERK inhibitor (PD98059). VEGF(165)-induced phosphorylation of ERK1/2 was abolished by MAB3571 and PD98059, while the phosphorylation of p38, JNK and AKT were not changed by VEGF(165). Taken together, VEGFR-2 is expressed on primary human hair follicle DP cells and VEGF induces proliferation of DP cells through VEGFR-2/ERK pathway, but not p38, JNK or AKT signaling.

Hormones and the pilosebaceous unit

Hormones can exert their actions through endocrine, paracrine, juxtacrine, autocrine and intracrine pathways. The skin, especially the pilosebaceous unit, can be regarded as an endocrine organ meanwhile a target of hormones, because it synthesizes miscellaneous hormones and expresses diverse hormone receptors. Over the past decade, steroid hormones, phospholipid hormones, retinoids and nuclear receptor ligands as well as the so-called stress hormones have been demonstrated to play pivotal roles in controlling the development of pilosebaceous units, lipogenesis of sebaceous glands and hair cycling. Among them, androgen is most extensively studied and of highest clinical significance. Androgen-mediated dermatoses such as acne, androgenetic alopecia and seborrhea are among the most common skin disorders, with most patients exhibiting normal circulating androgen levels. The "cutaneous hyperandrogenism" is caused by in stiu overexpression of the androgenic enzymes and hyperresponsiveness of androgen receptors. Regulation of cutaneous steroidogenesis is analogous to that in gonads and adrenals. More work is needed to explain the regional difference within and between the androgn-mediated dermatoses. The pilosebaceous unit can act as an ideal model for studies in dermato-endocrinology.

Identification of transcriptional targets of Wnt/beta-catenin signaling in dermal papilla cells of human scalp hair follicles: EP2 is a novel transcriptional target of Wnt3a

BACKGROUND

Recent studies showed that Wnt signaling through the beta-catenin pathway (canonical Wnt signaling) act on mouse dermal papilla cells (DPCs) enabling hair follicles to keep growing.

OBJECTIVE

To investigate whether human DPCs respond to canonical Wnt signaling and, if so, to identify target genes of Wnt/beta-catenin pathway.

METHODS

Cultured human DPCs were transiently transfected with the beta-catenin responsive TCF reporter plasmid (pTopflash) and corresponding negative control reporter (pFopflash) to assess the activity of beta-catenin signaling by Wnt3a (one of the canonical Wnts). Immunofluorescence staining was also performed to localize beta-catenin in the presence or absence of Wnt3a. Microarray was carried out using Affymetrix gene chips. RT-PCR analysis and immunoblot were employed to verify microarray data. Cyclic AMP (cAMP) levels were measured using EIA assay after Wnt3a and PGE2 treatment in DPCs.

RESULTS

Wnt3a significantly stimulated the transcriptional activity of pTopflash but not pFopflash. In line with this, we identified a number of genes that are regulated by Wnt3a. Some of the differently expressed genes including EP2 were confirmed by RT-PCR analysis. Immunoblot further confirmed that EP2 protein is indeed increased by Wnt3a. DPCs pretreated with Wnt3a showed higher responsiveness to PGE2 as measured by cAMP levels.

CONCLUSIONS

Elucidation of the role of Wnt3a-regulated genes identified in this study including EP2 would help our understanding of hair-induction and maintenance of anagen phase.

Hair follicle neogenesis induced by cultured human scalp dermal papilla cells

AIM

To develop a method by which human hair follicle dermal papilla (DP) cells can be expanded in vitro while preserving their hair-inductive potential for use in follicular cell implantation, a cellular therapy for the treatment of hair loss.

MATERIALS & METHODS

DP cells were isolated from scalp hair follicles in biopsies from human donors. DP cell cultures were established under conditions that preserved their hair-inductive potential and allowed for significant expansion. The hair-inductive potential of cells cultured for approximately 36 doublings was tested in an in vivo flap-graft model. In some experiments, DiI was used to label cells prior to grafting.

RESULTS

Under the culture conditions developed, cultures established from numerous donors reproducibly resulted in an expansion that averaged approximately five population doublings per passage. Furthermore, the cells consistently induced hair formation in an in vivo graft assay. Grafted DP cells appeared in DP structures of newly formed hairs, as well as in the dermal sheath and in the dermis surrounding follicles. Induced hair follicles persisted and regrew after being plucked 11 months after grafting.

CONCLUSION

A process for the propagation of human DP cells has been developed that provides significant expansion of cells and maintenance of their hair-inductive capability, overcoming a major technical obstacle in the development of follicular cell implantation as a treatment for hair loss.

The mesenchymal component of hair follicle neogenesis: background, methods and molecular characterization

Hair follicle morphogenesis and regeneration occur by an extensive and collaborative crosstalk between epithelial and mesenchymal skin components. A series of pioneering studies, which revealed an indispensable role of follicular dermal papilla and dermal sheath cells in this crosstalk, has led workers in the field to study in detail the anatomical distribution, functional properties, and molecular signature of the trichogenic dermal cells. The purpose of this paper was to provide a practical summary of the development and recent advances in the study of trichogenic dermal cells. Following a short review of the relevant literature, the methods for isolating and culturing these cells are summarized. Next, the bioassays, both in vivo and in vitro, that enable the evaluation of trichogenic properties of tested dermal cells are described in detail. A list of trichogenic molecular markers identified by those assays is also provided. Finally, this methods review is completed by defining some of the major questions needing resolution.

Cell proteomic footprint

The authentication of mammalian cell cultures and their subpopulations is of great demand in biotechnology and cell therapy. However, current techniques are either not efficient or can be very complex and expensive. Here we report a simple and straightforward approach for authentication of biological cells and their subpopulations with high speed, high throughput, low sample cost, and high sensitivity. We discovered that cell cultures treated with protease under soft, 'non-killing' conditions release fragments of cell surface proteins, whose composition is a strong characteristic of the cells. Mass spectrometric analysis of the released fragments allows a direct comparison of the produced mass spectrum with the mass spectrum of known cells. As an example, we applied this technique to verify subpopulations of human fibroblasts with different origins and which exhibit different medical characteristics.

A graft model for hair development

Follicular cell implantation (FCI) is an experimental cell therapy for the treatment of hair loss that uses cultured hair follicle cells to induce new hair formation. This treatment is based on the demonstration that adult dermal papilla cells (DPC) retain the hair inductive capacity they acquired during hair morphogenesis in the embryo. For FCI, hair inductive cells are isolated from scalp biopsies and then propagated in culture in order to provide enough cells to generate many new follicles from a few donor follicles. Following expansion in culture, the cells are implanted into the scalp where they induce the formation of new follicles. Because the process relies on the ability to retain the potential for hair induction during the expansion of DPC in culture, we sought a consistent, reliable and easily performed in vivo assay in which to test hair induction. In this study, we describe a simple graft model that supports hair morphogenesis. The assay combines dermal cells with embryonic mouse epidermis that provides the keratinocyte component of induced follicles. The grafts are placed under a protective skin flap in the host athymic mouse where the cells will form a skin graft with hair if the dermal cells are hair inductive DPC. Using the assay, freshly isolated and cultured mouse embryo dermal cells as well as cultured dermal papilla cells from other species all induced hair formation. The induced hairs were aesthetically indistinguishable from those of the epidermal donor in length, thickness, and pigmentation, and they were histologically normal.

Expression of cell cycle regulatory proteins in epithelial components of dental follicles

Dental follicle is a component of tooth germs, which remain adjacent to the crown of unerupted or impacted teeth. Under the influence of pathologic changes, however, dental follicles that possess reduced epithelium can proliferate into stratified squamous epithelium as far as originate dental cysts. In order to clarify the role of apoptosis and cellular proliferation herein, expression of p53 and PCNA was examined in epithelial components of dental follicles associated with impacted third molars by means of immunohistochemistry. A total of 40 cases was included in this study being 22 cases with reduced epithelium and 18 cases with stratified epithelium. Expression of p53 expression was weak or not detected in dental follicles with reduced and stratified squamous epithelium. By contrast, PCNA positive cells were evidenced in basal and supra basal layers of the stratified squamous epithelium and in reduced epithelium of dental follicles, but without any significant statistically differences between them (P > 0.05). In conclusion, these data suggest that dental follicles possess proliferative activity as depicted by PCNA-positive nuclei in some epithelial cells. However, the biological behavior of dental follicles during the late stage of dental eruptive process may not be associated with deregulation of death and/or cell proliferation.