Establishment and functional characterization of immortalized rabbit dermal papilla cell lines

Hair follicle (HF) undergo periodic growth and development in mammals, which regulated by dermal papilla cells (DPCs) are reported to play an important role in HF morphogenesis and development. However, primary DPCs have low proliferative activity, age quickly, and fresh cell isolation is both time-consuming and laborious. In this study, we introduced the SV40 large T antigen (SV40T) into dissociated early passage rabbit vibrissae DPCs with lentiviral vectors and established seven immortalized DPC lines (R-1, R-2, R-3, R-4, R-5, R-6 and R-7). These cell lines displayed early passage morphology and high alkaline phosphatase activity. RT-PCR and immunofluorescence staining showed that all the immortalized cell lines expressed the DPC markers (α-SMA, IGF1, ALPL, FGF2, BMP2 and TGFβ2), but α-SMA was only expressed well in R-3, R-4, and R-7. Furthermore, it was found that R-7 was the only line to survive beyond 50 passages. Compared to melanoma cells, R-7 did not undergo malignant transformation. Karyotyping and cell growth viability analysis illustrated that the R-7 cell line preserved the basic characteristics of primary DPCs. The R-7 DPCs established have potential application for future hair research. The study provides the theoretical basis in the cell research of HF growth and development.

Effective and economical cell therapy for hair regeneration

We reviewed and summarized the latest reports on the characteristics of stem cells and follicular cells that are under development for hair loss treatment. Compared with conventional medicine, cell therapy could be effective in the long term with a single treatment while having mild adverse effects. Adipose-derived stem cells (ASCs) have the advantages of easy access and large isolation amount compared with dermal papilla cells (DPCs) and dermal sheath cup cells (DSCs), and promote hair growth through the paracrine effect. ASCs have a poor potential in hair neogenesis, therefore, methods to enhance trichogenecity of ASCs should be developed. DSCs can be isolated from the peribulbar dermal sheath cup, while having immune tolerance, and hair inductivity. Therefore, DSCs were first developed and finished the phase II clinical trial; however, the hair growth was not satisfactory. Considering that a single injection of DSCs is effective for at least 9 months in the clinical setting, they can be an alternative therapy for hair regeneration. Though DPCs are not yet studied in clinical trials, we should pay attention to DPCs, as hair loss is associated with gradual reduction of DPCs and DP cell numbers fluctuate over the hair cycle. DPCs could make new hair follicles with epidermal cells, and have an immunomodulatory function to enable allogeneic transplantation. In addition, we can expand large quantities of DPCs with hair inductivity using spheroid culture, hypoxia condition, and growth factor supplement. 'Off-the-shelf' DPC therapy could be effective and economical, and therefore promising for hair regeneration.

3D bioprinting of a gelatin-alginate hydrogel for tissue-engineered hair follicle regeneration

Hair follicle (HF) regeneration remains challenging, principally due to the absence of a platform that can successfully generate the microenvironmental cues of hair neogenesis. Here, we demonstrate a 3D bioprinting technique based on a gelatin/alginate hydrogel (GAH) to construct a multilayer composite scaffold simulating the HF microenvironment in vivo. Fibroblasts (FBs), human umbilical vein endothelial cells (HUVECs), dermal papilla cells (DPCs), and epidermal cells (EPCs) were encapsulated in GAH (prepared from a mixture of gelatin and alginate) and respectively 3D-bioprinted into the different layers of a composite scaffold. The bioprinted scaffold with epidermis- and dermis-like structure was subsequently transplanted into full-thickness wounds in nude mice. The multilayer scaffold demonstrated suitable cytocompatibility and increased the proliferation ability of DPCs (1.2-fold; P < 0.05). It also facilitated the formation of self-aggregating DPC spheroids and restored DPC genes associated with hair induction (ALP, β-catenin, and α-SMA). The dermal and epidermal cells self-assembled successfully into immature HFs in vitro. HFs were regenerated in the appropriate orientation in vivo, which can mainly be attributed to the hierarchical grid structure of the scaffold and the dot bioprinting of DPCs. Our 3D printed scaffolds provide a suitable microenvironment for DPCs to regenerate entire HFs and could make a significant contribution in the medical management of hair loss. This method may also have broader applications in skin tissue (and appendage) engineering. STATEMENT OF SIGNIFICANCE: Hair loss remains a challenging clinical problem that influences quality of life. Three-dimensional (3D) bioprinting has become a useful tool for the fabrication of tissue constructs for transplantation and other biomedical applications. In this study, we used a 3D bioprinting technique based on a gelatin/alginate hydrogel to construct a multi-layer composite scaffold with cuticular and corium layers to simulate the microenvironment of dermal papilla cells (DPCs) in the human body. This new approach permits the controllable formation of self-aggregating spheroids of DPCs in a physiologically relevant extracellular matrix and the initiation of epidermal-mesenchymal interactions, which results in HF formation in vivo. The ability to regenerate entire HFs should have a significant impact on the medical management of hair loss.

Electrical stimulation to human dermal papilla cells for hair regenerative medicine

Hair follicle dermal papilla cells (DPCs) are specialized mesenchymal cells that play pivotal roles in hair formation, growth, and cycles, and they are considered as a cell source in hair regenerative medicine. Rodent dermal papilla cells have been shown to induce de novo hair follicle generation in the skin of recipients following transplantation, suggesting that dermal papilla cells can reprogram epidermal microenvironments. However, human DPCs (hDPCs) lose their ability to generate de novo hair follicles under conventional culture methods. We investigated the effects of electrical stimulation (ES) on hDPCs to restore the depressed trichogenic activity. We demonstrated that ES with a polypyrrole (PPy)-modified electrode upregulated trichogenic gene expression in hDPCs in vitro, and the activated cells when transplanted into mice generated double the number of hairs compared to that without the ES. Using specific inhibitors, we revealed that the mechanisms behind the electrical activation are associated with voltage-gated ion channels. Further, ES can be adapted for hDPCs from a patient with androgenic alopecia. Thus, this approach is potentially beneficial in preparing hDPCs for hair regenerative medicine.

Pyridoxine regulates hair follicle development via the PI3K/Akt, Wnt and Notch signalling pathways in rex rabbits

This study was conducted to evaluate the effect of pyridoxine on the development of hair follicles in Rex rabbits and the underlying molecular mechanism. Two hundred 3-month-old Rex rabbits were randomly divided into 5 groups and fed diets supplemented with 0, 5, 10, 20, or 40 mg/kg pyridoxine. The hair follicle density on the dorsal skin and the gene and protein expression levels of components of the phosphoinositide 3-kinase (PI3K)/protein kinase B (PKB or Akt), Wnt, Notch and bone morphogenetic protein (BMP) signalling pathways were measured. In addition, free hair follicles were isolated from Rex rabbits and cultured with pyridoxine in vitro to measure hair shaft growth. Furthermore, dermal papilla cells (DPC) were isolated from the skin of Rex rabbits and cultured with pyridoxine in vitro to measure the gene and protein expression levels of components of the PI3K/Akt, Wnt, Notch and BMP signalling pathways. The results showed that the addition of dietary pyridoxine significantly increased the total follicle density, secondary follicle density, and secondary-to-primary ratio (S/P, P < 0.05), that the growth ratio of hair stems was promoted by pyridoxine in basic culture medium, and that the growth length of tentacle hair follicles cultured in the pyridoxine group was longer than that in the control group (P < 0.05). In addition, pyridoxine changed the DPC cycle progression and promoted cell proliferation, and appropriate concentrations of pyridoxine (10 and 20 μmol/L) significantly inhibited cell apoptosis (P < 0.05). Pyridoxine significantly affected the gene expression of components of the PI3K/Akt, Wnt and Notch signalling pathways in the skin and DPC of Rex rabbits (P < 0.05), increased the levels of phosphorylated catenin beta 1 (CTNNB1) and Akt, and decreased the level of phosphorylated glycogen synthase kinase 3 beta (GSK-3β) (P < 0.05). Therefore, the molecular mechanism by which pyridoxine promotes hair follicle density in Rex rabbits probably occurs through activation of the PI3K/Akt, Wnt and Notch signalling pathways, prolonging hair follicle growth and delaying the onset of telogen.

A three-dimensional bioprinting technique, based on a gelatin/alginate hydrogel, for the tissue engineering of hair follicle reconstruction

Hair loss remains a challenging clinical problem that influences the quality of life. Three-dimensional (3D) bioprinting has become a valuable tool for fabricating tissue constructs for transplantation and other biomedical applications. Although some simple organs, such as skin and cartilage, have been successfully simulated, it remains challenging to make hair follicles (HFs), which are highly complex organs. The tissue engineering of human HFs has been a long-standing challenge, and progress with this has lagged behind that with other lab-grown tissues. This is principally due to a lack of availability of a platform that can successfully recapitulate the microenvironmental cues required to maintain the requisite cellular interactions for hair neogenesis. In this study, we used a 3D bioprinting technique based on a gelatin/alginate hydrogel to construct a multilayer composite scaffold with cuticular and corium layers to simulate the microenvironment of dermal papilla cells (DPCs) in the human body. This new approach permits the controllable formation of self-aggregating spheroids of DPCs in a physiologically relevant extracellular matrix and the initiation of epidermal-mesenchymal interactions, which results in HF formation in vivo. In conclusion, our 3D-bioprinted multilayer composite scaffold prepared using a gelatin/alginate hydrogel provides a suitable 3D microenvironment for DPCs to induce HF formation. The ability to regenerate entire HFs should have a significant impact on the medical management of hair loss. This method may also have critical applications for skin tissue engineering, with its appendages, for other purposes.

The effect of hypoxia on the proliferation capacity of dermal papilla cell by regulating lactate dehydrogenase

Hypoxia is of great significance for stem cells to maintain the proliferation and differentiation capacity. As a specialized mesenchymal component of the hair follicle (HF), the dermal papilla cell (DPC) not only regulates HF cycle, but also plays a pivotal role in differentiating hair follicle stem cell(HFSC) into HF. However, whether hypoxia could affect DPCs on proliferation or metabolism remains unclear. In our study, DPCs were cultured in normoxia (20%O₂) or hypoxia (5%O₂). Cell viability assays were performed, and lactate dehydrogenase (LDH) activity and lactate level in DPCs were detected. After that, LDH was overexpressed or knocked down in DPCs; then, the expression of protein markers (ALP, Ki‐67) was assessed by Western blotting, and cell proliferation was also detected after overexpression or knockdown of LDH. Hypoxia did show positive effect on proliferation of DPCs. The LDH activity of DPCs cultured under hypoxic condition was significantly higher than that of cultured under normoxic condition. Overexpression of LDH significantly up‐regulates the expression of ALP and Ki‐67 compared with knockdown and negative control. Cell proliferation was also promoted in DPCs with elevated LDH. Our findings showed that the proliferation activity of DPCs could be stimulated under hypoxia. Meanwhile, LDH plays an important role in maintaining the activity of DPCs in hypoxic condition.

Pantothenic acid promotes dermal papilla cell proliferation in hair follicles of American minks via inhibitor of DNA Binding 3/Notch signaling pathway

AIMS

Pantothenic acid (PA) has been applied to treat alopecia, but the underlying mechanism is still unclear. Our study aims to explore the underlying mechanism of PA in regulating hair follicle (HF) growth.

MAIN METHODS

Mink HFs and dermal papilla (DP) cells were isolated and cultured in vitro. HFs and DP cells were treated with 0, 10, 20, 40 μg/ml PA. The effect of PA on HF growth, DP cell proliferation, cell cycle distribution, cell migration, and insulin-like growth factor-1 (IGF-1) and vascular endothelial growth factor (VEGF) expressions in DP cells was measured. Moreover, the effect of PA on inhibitor of DNA binding 3 (ID3)/Notch signaling pathway was analyzed. Subsequently, ID3 was silenced to validate whether ID3/Notch signaling pathway was involved in regulating DP cell proliferation by PA.

KEY FINDINGS

Both 20 μg/ml and 40 μg/ml PA promoted HF growth, G1/S transition of DP cells and IGF-1 and VEGF expressions in DP cells, while only 20 μg/ml PA promoted cell viability and the migration of DP cells. Thus 20 μg/ml PA was chosen for the following experiments. PA treatment was found to up-regulate ID3 expression but down-regulate Notch receptor 1 (Notch1) and Notch signaling targets expressions. Furthermore, ID3 knockdown reversed PA-induced cell proliferation and inhibition of Notch1 and Notch signaling targets expressions, indicating that PA-induced DP cell proliferation and inhibition of Notch signaling were mediated via up-regulation of ID3.

SIGNIFICANCE

This study provides an underlying mechanism related to the effect of PA on stimulating DP cell proliferation.

The functions of ocu-miR-205 in regulating hair follicle development in Rex rabbits

BACKGROUND

Hair follicles are an appendage of the vertebrate epithelium in the skin that arise from the embryonic ectoderm and regenerate cyclically during adulthood. Dermal papilla cells (DPCs) are the key dermal component of the hair follicle that directly regulate hair follicle development, growth and regeneration. According to recent studies, miRNAs play an important role in regulating hair follicle morphogenesis and the proliferation, differentiation and apoptosis of hair follicle stem cells.

RESULTS

The miRNA expression profile of the DPCs from Rex rabbits with different hair densities revealed 240 differentially expressed miRNAs (|log2(HD/LD)| > 1.00 and Q-value≤0.001). Among them, ocu-miR-205-5p was expressed at higher levels in DPCs from rabbits with low hair densities (LD) than in rabbits with high hair densities (HD), and it was expressed at high levels in the skin tissue from Rex rabbits (P < 0.05). Notably, ocu-miR-205 increased cell proliferation and the cell apoptosis rate, altered the progression of the cell cycle (P < 0.05), and modulated the expression of genes involved in the PI3K/Akt, Wnt, Notch and BMP signalling pathways in DPCs and skin tissue from Rex rabbits. It also inhibited the phosphorylation of the CTNNB1 and GSK-3β proteins, decreased the level of the noggin (NOG) protein, and increased the level of phosphorylated Akt (P < 0.05). A significant change in the primary follicle density was not observed (P > 0.05), but the secondary follicle density and total follicle density (P < 0.05) were altered upon interference with ocu-miR-205-5p expression, and the secondary/primary ratio (S/P) in the ocu-miR-205-5p interfered expression group increased 14 days after the injection (P < 0.05).

CONCLUSIONS

In the present study, ocu-miR-205 promoted the apoptosis of DPCs, altered the expression of genes and proteins involved in the PI3K/Akt, Wnt, Notch and BMP signalling pathways in DPCs and skin from Rex rabbits, promoted the transition of hair follicles from the growth phase to the regression and resting phase, and altered the hair density of Rex rabbits.

Isolation, culture and growth characteristics of dermal papilla cells from Rex rabbits

Dermal papilla cells (DPCs) is the key dermal component of the hair follicle that directly regulates hair follicle development, growth and regeneration. Successfully isolated and cultured DPCs of Rex rabbit could provide a good model for the study of hair follicle development mechanism in vitro. Skin samples were collected from 30-day old Rex rabbits and separated by combination of Dispase II and Collagenase D, separation, culture, and purification of DPCs. The morphology of DPCs in vitro was observed and the growth curve was drawn, the number of DPCs presented progressive increase in a logarithmic model between the 4^th day and the 7^th day. The results of immune chemical and immune fluorescence shown that α smooth muscle actin (α-SMA) and versican were positive in cells. Growth character of the passages 3 (P3), P6, P9 and P12 DPCs were observed using MTT at 24 h, 48 h, 72 h, 96 h, 120 h and 144 h. The cell density of P12 was lower than P3 (P < 0.05); the flow cytometric analysis showed that DPCs at resting state/first gap (G0/G1) stage of P3 was higher than P12 (P < 0.05), and second gap/mitosis (G2/M) stage of P3 was lower than P12 (P < 0.05). However, the DPCs of P12 present triangular or short fusiform, retaining their unique aggregative growth characteristics. This results shown that the DPCs properties of P12 from Rex rabbits, still fit functional research in vitro. In conclusion, we successfully established the culturing condition of DPCs from Rex rabbits, and provide a material for studying the molecular mechanism of hair follicle development.

Preliminary study on microR-148a and microR-10a in dermal papilla cells of Hu sheep

Background

Hu sheep, a unique Chinese breed with high reproductive performance, are also well known for their rare white lambskin in China. The quality of lambskin is affected by hair follicles, and dermal papilla cells are an important component of hair follicles that plays a key role in hair follicle growth and development. This study helps elucidate the effect of miR-148a and miR-10a on hair follicle growth and development.

Results

Based on the results of gene chip and high-throughput sequencing, bone morphogenetic protein 7 (BMP7) was used as a research object. Bioinformatics analysis and the dual-luciferase reporter system indicated that, along with Western blot and quantitative real-time polymerase chain reaction (qRT-PCR) that miR-148a and miR-10a target relationships with BMP7. BMP7 was the target gene both for miR-148a and miR-10a by the dual-luciferase reporter system and Western blot. Hu sheep dermal papilla cells were successfully isolated and purified, and after transfecting miR-148a/miR-10a mimics and inhibitors into dermal papilla cells, a Cell Counting Kit-8 (CCK-8) was used to determine that miR-148a/miR-10a inhibited the proliferation of Hu sheep dermal papilla cells. In addition, after the overexpression of miR-148a, the expression levels of Smad3 (P < 0.05), Smad6 (P < 0.05), Smad4 (P < 0.01), and Smad5 (P < 0.01) were significantly higher than those of the control groups. After the inhibition of miR-148a, the expression levels of Smad3 (P < 0.05), Smad4 (P < 0.05), and TGF-β (P < 0.01) were significantly lower than those of the control groups. After the overexpression of miR-10a, the expression levels of Smad1 (P < 0.01), Smad2 (P < 0.05), Smad4 (P < 0.01), Smad5 (P < 0.01), and TGF-β (P < 0.05) were significantly lower than those of the control groups. After the inhibition of miR-10a, the expression levels of Smad1 (P < 0.01) and Smad2 (P < 0.05) were significantly lower than those of the control groups.

Conclusions

These results revealed the target relationship between miR-148a, miR-10a and BMP7, and the effect of miR-148a and miR-10a on the proliferation of dermal papilla cells. They will provide the basis for a follow-up study on how miR-148a, and miR-10a mediate BMP7 regulation of hair follicle growth and development.

In vivo and in vitro evaluation of hair growth potential of Cacumen Platycladi, and GC-MS analysis of the active constituents of volatile oil

ETHNOPHARMACOLOGICAL RELEVANCE

Cacumen Platycladi (CP) is the leaves of Platycladus orientalis which has been traditionally used to resist alopecia and promote hair growth. However, no study has been reported on the effects of CP on proliferation of dermal papilla cells (DPCs). And there is also no complete and systematic research on hair re-growth efficacies of CP.

AIM OF THE STUDY

To evaluate the hair-growth activity of their extracts on the proliferation of DPCs and the promotion of hair reproduction in C57BL/6 mice.

MATERIALS AND METHODS

For the DPCs, different extract fractions of CP were investigated. The hair growth effect of CP volatile oil on C57BL/6 mice was evaluated for 28 days. Meanwhile, the chemical constituents of the volatile oil from Cacumen Platycladi were isolated and identified by GC-MS.

RESULTS

The study showed that the extracts of CP could promote the proliferation of DPCs, and the activity of volatile oil was the best. CP volatile oil (100 μg/mL) resulted in stronger proliferation of DPCs by 239.8% compared with control (100%) and minoxidil (130.3%) during the 48 h incubation. And no obvious cytotoxic activity was observed when volatile oil was dosed up to 500 μg/mL. At different growth stages, mice treated with 0.2 g/kg CP volatile oil required shorter time than 2% minoxidil. Hair length for 0.2 g/kg CP volatile oil treated group was longer than those of minoxidil and control. Further histological observation indicated that CP volatile oil could prolonged the anagen phase of hair follicles. Moreover, thirty four components, with contents of 81.9% of the total volatile oils, were separaed and identified.

CONCLUSION

The CP volatile oil may have the potential therapeutic agent for the treatment of alopecia.

Preparation of hair beads and hair follicle germs for regenerative medicine

Hair regenerative medicine is a promising approach for hair loss, during which autologous follicular stem cells are transplanted into regions of hair loss to regenerate hairs. Because cells transplanted as a single cell suspension scarcely generate hairs, the engineering of three-dimensional (3D) tissues before transplantation has been explored to improve this process. Here, we propose an approach to fabricate collagen-enriched cell aggregates, named hair beads (HBs), through the spontaneous constriction of cell-encapsulated collagen drops. Mouse embryonic mesenchymal cells or human dermal papilla cells were encapsulated in 2-μl collagen microgels, which were concentrated >10-fold in volume during 3 days of culture. Interestingly, HB constriction was attributed to attraction forces driven by myosin II and involved the upregulation of follicular genes. Single HBs with epithelial cells seeded in U-shaped microwells formed dumbbell-like structures comprising respective aggregates (named bead-based hair follicle germs, bbHFGs), during 3 days of culture. bbHFGs efficiently generated hair follicles upon intracutaneous transplantation into the backs of nude mice. Using an automated spotter, this approach was scalable to prepare a large number of bbHFGs, which is important for clinical applications. Therefore, this could represent a robust and practical approach for the preparation of germ-like tissues for hair regenerative medicine.

Synthesized Ceramide Induces Growth of Dermal Papilla Cells with Potential Contribution to Hair Growth

Background

The ceramide is known to play an important role in the formation of intracellular lipids, and play a crucial role as a barrier for skin and hair cuticle. Recent study has revealed that ceramide has potential effect on hair growth in a mouse model. However, the role of ceramide in human dermal papilla cells (hDPCs) known to play an important role in hair growth is not well understood yet.

Objective

The goal of this study was to investigate the effect of synthetic ceramides (oleyl and stearyl ceramides) on hair growth using hDPCs.

Methods

hDPCs were treated with synthesized ceramides. hDPCs viability was evaluated by MTT assay. The expression of hair growth related factors were investigated by western blot, real-time polymerase chain reaction and growth factor array. The expression of β-catenin was confirmed by immunofluorescence.

Results

Treatment with ceramides increased the expression of proteins affecting cell proliferation such as Bcl-2, BAX, phosphorylated-ERK and Cyclin D1. Also, ceramides treatment were increased the expression of several growth factors, including epidermal growth factor family, and promote the expression of Wnt/β-catenin and BMP2/4 signaling.

Conclusion

Our data suggest that synthetic ceramides stimulates hair growth by induction proliferation of hDPCs via modulation of Wnt/β-catenin and BMP2/4 signaling.

Human umbilical cord blood mesenchymal stem cells engineered to overexpress growth factors accelerate outcomes in hair growth

Human umbilical cord blood mesenchymal stem cells (hUCB-MSCs) are used in tissue repair and regeneration; however, the mechanisms involved are not well understood. We investigated the hair growth-promoting effects of hUCB-MSCs treatment to determine whether hUCB-MSCs enhance the promotion of hair growth. Furthermore, we attempted to identify the factors responsible for hair growth. The effects of hUCB-MSCs on hair growth were investigated in vivo, and hUCB-MSCs advanced anagen onset and hair follicle neogeneration. We found that hUCB-MSCs co-culture increased the viability and up-regulated hair induction-related proteins of human dermal papilla cells (hDPCs) in vitro. A growth factor antibody array revealed that secretory factors from hUCB-MSCs are related to hair growth. Insulin-like growth factor binding protein-1 (IGFBP-1) and vascular endothelial growth factor (VEGF) were increased in co-culture medium. Finally, we found that IGFBP-1, through the co-localization of an IGF-1 and IGFBP-1, had positive effects on cell viability; VEGF secretion; expression of alkaline phosphatase (ALP), CD133, and β-catenin; and formation of hDPCs 3D spheroids. Taken together, these data suggest that hUCB-MSCs promote hair growth via a paracrine mechanism.

Generation of trichogenic adipose-derived stem cells by expression of three factors

BACKGROUND

Previous studies demonstrated that adipose-derived stem cells (ASCs) can promote hair growth, but unmet needs exist for enhancing ASC hair inductivity.

OBJECTIVE

Therefore, we introduced three trichogenic factors platelet-derived growth factor-A, SOX2, and β-catenin to ASCs (tfASCs) and evaluated whether tfASCs have similar characteristics as dermal papilla (DP) cells.

METHOD

Global gene expression was examined using NGS analysis. Telogen-to-anagen induction, vibrissae hair follicle organ culture and patch assay were used.

RESULTS

tfASC cell size is smaller than that of ASCs, and they exhibit short doubling time. tfASCs also resist aging and can be expanded until passage 12. Cell proportion in S and G₂/M increases in tfASCs, and tfASCs express high mRNA levels of cell cycle related genes. The mRNA expression of DP markers was notably higher in tfASCs. Moreover, NGS analysis revealed that the global gene expression of tfASCs is similar to that of DP cells. The injection of tfASCs accelerated the telogen-to-anagen transition and conditioned medium of tfASCs increased the anagen phase of vibrissal hair follicles. Finally, we found that the injection of 3D-cultured tfASCs at p 9 generated new hair follicles in nude mice.

CONCLUSION

Collectively, these results indicate that 1) tfASCs have similar characteristics as DP cells, 2) tfASCs have enhanced hair-regenerative potential compared with ASCs, and 3) tfASCs even at late passage can make new hair follicles in a hair reconstitution assay. Because DP cells are difficult to isolate/expand and ASCs have low hair inductivity, tfASCs and tfASC-CM are clinically good candidates for hair regeneration.

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.

Establishment of dermal sheath cell line from Cashmere goat and characterizing cytokeratin 13 as its novel biomarker

OBJECTIVE

To establish a dermal sheath cell line, a dermal papilla cell line and a outer root sheath cell line from Cashmere goat and clarify the similarities and differences among them.

RESULTS

We established a dermal sheath cell line, a dermal papilla cell line and a outer root sheath cell line from the pelage skin hair follicles of Cashmere goat. The growth rate of dermal sheath cells was intermediate between that of dermal papilla cells and outer root sheath cells. Immunofluorescence experiments and reverse transcription-polymerase chain reaction analysis showed that at both the transcriptional and translational levels, the dermal sheath cells were alpha-smooth muscle actin (α-SMA)⁺/cytokeratin 13⁺, while the dermal papilla cells were α-SMA⁺/cytokeratin 13^- and the outer root sheath cells were α-SMA^-/cytokeratin 13⁺. Patterns of cytokeratin 13 expression could distinguish the dermal sheath cells from the dermal papilla cells.

CONCLUSIONS

These results suggest that cytokeratin 13 could serve as a novel biomarker for dermal sheath cells of Cashmere goat, and should prove useful for researchers investigating dermal stem cells or interaction of different types of cells during hair cycle.

Promotion of hair growth by newly synthesized ceramide mimetic compound

Based on the crucial roles of ceramides in skin barrier function, use of ceramides or their structural mimetic compounds, pseudoceramides, as cosmetic ingredients are getting more popular. While currently used pseudoceramides are intended to substitute the structural roles of ceramides in stratum corneum, development of bioactive pseudoceramides has been repeatedly reported. In this study, based on the potential involvement of sphingolipids in hair cycle regulation, we investigated the effects of newly synthesized pseudoceramide, bis-oleamido isopropyl alcohol (BOI), on hair growth using cultured human hair follicles and animal models. BOI treatment promoted hair growth in cultured human hair follicles ex vivo and induced earlier conversion of telogen into anagen. Although we did not find a significant enhancement of growth factor expression and follicular cell proliferation, BOI treatment resulted in an increased sphinganine and sphingosine contents as well as increased ceramides contents in cultured dermal papilla (DP) cells. Taken together, our data strongly suggest that biologically active pseudoceramide promotes hair growth by stimulating do novo synthesis of sphingolipids in DP cells.

Glycyrrhizic acid attenuates stem cell-like phenotypes of human dermal papilla cells

BACKGROUND

Although the growth of unwanted hair or hirsutism is a harmless condition, many people find it bothersome and embarrassing. Maintaining stem cell features of dermal papilla cells is a critical biological process that keeps the high rate of hair growth. Glycyrrhizic acid has been reported to impair hair growth in some studies; however, its underlying mechanism has not yet been investigated.

PURPOSE

This study aimed to explore the effect and underlying mechanism of glycyrrhizic acid on stemness of human dermal papilla cells.

STUDY DESIGN/METHODS

The stem cell molecular markers, epithelial to mesenchymal markers and Wnt/β-catenin-associated proteins of human dermal papilla cell line and primary human dermal papilla cells were analysed by western blot analysis and immunocytochemistry.

RESULTS

The present study demonstrated that glycyrrhizic acid significantly depressed the stemness of dermal papilla cells in dose- and time-dependent manners. Clonogenicity and stem cell markers in the glycyrrhizic acid-treated cells were found to gradually decrease in the culture in a time-dependent manner. Our results demonstrated that glycyrrhizic acid exerted the stem cell suppressing effects through the interruption of ATP-dependent tyrosine kinase/glycogen synthase kinase3β-dependent mechanism which in turn down-regulated the β-catenin signalling pathway, coupled with decreased its down-stream epithelial-mesenchymal transition and self-renewal transcription factors, namely, Oct-4, Nanog, Sox2, ZEB1 and Snail. The effect of glycyrrhizic acid on the reduction of stem cell features was also observed in the primary dermal papilla cells directly obtained from human hair follicles.

CONCLUSION

These results revealed a novel molecular mechanism of glycyrrhizic acid in regulation of dermal papilla cells and provided the evidence supporting the use of this compound in suppressing the growth of unwanted hair.

Herbal Extracts Induce Dermal Papilla Cell Proliferation of Human Hair Follicles

BACKGROUND

The number of people suffering from balding or hair thinning is increasing, despite the advances in various medical therapies. Therefore, it is highly important to develop new therapies to inhibit balding and increase hair proliferation.

OBJECTIVE

We investigated the effects of herbal extracts commonly used for improving balding in traditional medicine to identify potential agents for hair proliferation.

METHODS

The expression levels of 5α-reductase isoforms (type I and II) were analyzed using quantitative real-time reverse transcription polymerase chain reaction in the human follicular dermal papilla cells (DPCs). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylteterazolium bromide and bromodeoxyuridine tests were used to evaluate the cell proliferation effect of herbal extracts in DPCs. The expression levels of extracellular signal-regulated kinase (ERK), Akt, cyclin D1, cyclin-dependent kinase 4 (Cdk4), B-cell lymphoma (Bcl-2) and Bcl-2-associated X protein (Bax) were measured using western blot analysis.

RESULTS

The 5α-reductase isoform mRNAs and proteins were detected in the cultured DPCs, and the expression level of 5α-R2 in DPCs in the presence of the herbal extracts was gradually decreased. Herbal extracts were found to significantly increase the proliferation of human DPCs at concentrations ranging from 1.5% to 4.5%. These results show that the herbal extracts tested affected the protein expressions of ERK, Akt, cyclin D1, Cdk4, Bcl-2, and Bax in DPCs.

CONCLUSION

These results suggest that herbal extracts exert positive effects on hair proliferation via ERK, Akt, cyclin D1, and Cdk4 signaling in DPCs; they also suggest that herbal extracts could be a great alternative therapy for increasing hair proliferation.

Fibroblast growth factor 5-short (FGF5s) inhibits the activity of FGF5 in primary and secondary hair follicle dermal papilla cells of cashmere goats

To determine the relationship between fibroblast growth factor 5 (FGF5) and FGF5-short (FGF5s) in dermal papilla cells of cashmere goat primary and secondary hair follicles. We isolated dermal papilla cells from primary hair follicle (PHF) and secondary hair follicle (SHF) of cashmere goat, and found that the FGF5 receptor, fibroblast growth factor receptor 1 (FGFR1), was expressed in these two types of dermal papilla cells. Moreover, adenovirus-mediated overexpression of FGF5 could upregulate the mRNA expression of insulin-like growth factor-1 (IGF-1), versican and noggin that were important for follicle growth maintenance, whereas downregulate the expression of anagen chalone bone morphogenetic protein 4 (BMP4) in dermal papilla cells. However, these alterations were partly reversed by FGF5s overexpression. In conclusion, our results demonstrated that FGF5s acted as an inhibitor of FGF5 in the regulation of anagen-catagen transition of cashmere goat dermal papilla cells.

Hair growth promoting potential of phospholipids purified from porcine lung tissues

BP201, porcine lung tissue-derived phospholipids, consists of phosphatidylcholine as a major phospholipid species. BP201 promoted hair growth after application onto the shaved backs of BALB/c and C3H mice. Its effect was enhanced when applied together with minoxidil (MNX) in C3H mice. When the tissue specimens prepared from the shaved skins of BP201-treated and control mice were microscopically examined, the total numbers of hair follicles in both anagen and telogen phases of BP201-treated mice were significantly higher than those of control mice. The numbers of hair follicles in the anagen phase of BP201-treated mice were also higher than those of control mice. In combination with MNX, BP201 further increased the total number of hair follicles, but did not alter the percentage of hair follicles in the anagenic phase. BP201 also increased the proliferation of human hair follicle dermal papilla cells. Collectively, BP201 possesses hair growth promoting potential, which would suggest its use singly or in combination for hair growth products.

Hair-Loss Preventing Effect of Grateloupia elliptica

This study was conducted to evaluate the effect of Grateloupia elliptica, a seaweed native to Jeju Island, Korea, on the prevention of hair loss. When immortalized rat vibrissa dermal papilla cells were treated with extract of G. elliptica, the proliferation of dermal papilla cells significantly increased. In addition, the G. elliptica extract significantly inhibited the activity of 5α-reductase, which converts testosterone to dihydrotestosterone (DHT), a main cause of androgenetic alopecia. On the other hand, the G. elliptica extract promoted PGE2 production in HaCaT cells in a dose-dependent manner. The G. elliptica extract exhibited particularly high inhibitory effect on LPS-stimulated IL-12, IL-6, and TNF-α production in lipopolysaccharide (LPS)-stimulated bone marrow-derived dendritic cells. The G. elliptica extract also showed inhibitory activity against Pityrosporum ovale, a main cause of dandruff. These results suggest that G. elliptica extract has the potential to treat alopecia via the proliferation of dermal papilla, 5α-reductase inhibition, increase of PGE2 production, decrease of LPS-stimulated pro-inflammatory cytokines and inhibitory activity against Pityrosporum ovale.