Catagen Phase Research Articles

HNG, A Humanin Analogue, Promotes Hair Growth by Inhibiting Anagen-to-Catagen Transition.

The hair follicle goes through repetitive cycles including anagen, catagen, and telogen. The interaction of dermal papilla cells (DPCs) and keratinocytes regulates the hair cycle and hair growth. Humanin was discovered in the surviving brain cells of patients with Alzheimer’s disease. HNG, a humanin analogue, activates cell growth, proliferation, and cell cycle progression, and it protects cells from apoptosis. This study was performed to investigate the promoting effect and action mechanisms of HNG on hair growth. HNG significantly increased DPC proliferation. HNG significantly increased hair shaft elongation in vibrissa hair follicle organ culture. In vivo experiment showed that HNG prolonged anagen duration and inhibited hair follicle cell apoptosis, indicating that HNG inhibited the transition from the anagen to catagen phase mice. Furthermore, HNG activated extracellular signal-regulated kinase (Erk)1/2, Akt, and signal transducer and activator of transcription (Stat3) within minutes and up-regulated vascular endothelial growth factor (VEGF) levels on DPCs. This means that HNG could induce the anagen phase longer by up-regulating VEGF, which is a Stat3 target gene and one of the anagen maintenance factors. HNG stimulated the anagen phase longer with VEGF up-regulation, and it prevented apoptosis by activating Erk1/2, Akt, and Stat3 signaling.

The effects of α-MSH on epidermal γδ T cell activation and function

Abstract The hair follicle is a site of immune privilege that, when disrupted, results in the autoimmune disorder alopecia areata. Although there are a variety of cell types that reside near the hair follicle and may be involved in the initiation of alopecia areata, few studies have focused on γδ T cells. γδ T cells are resident in epithelial tissues where they normally play roles in inflammation and wound healing. Alpha-melanocyte-stimulating(α-MSH) is an immunoregulator locally produced within the hair follicle. α-MSH ensures the immune system is suppressed during anagen phase (growth phase) and restored during catagen phase (resting phase). The effects of α-MSH on epidermal γδ T cells via MC1R, one of five melanocortin receptors, is unknown. We therefore purified primary epidermal γδ T cells to investigate the immunomodulatory effects of α-MSH. Flow cytometry and the Luminex platform were used to compare changes in MC1R expression levels and cytokine production in response to α-MSH. Here we show that resting epidermal γδ T cells express MC1R, and TCR stimulation increases MC1R expression. Upregulation of MC1R expression is augmented further by stimulation with α-MSH. Epidermal γδ T cells significantly upregulate immunostimulatory cytokines when stimulated with anti-CD3, but cytokine production did not significantly change with the addition of α-MSH. Additional findings suggest that α-MSH instead plays a role in MC1R regulated pathways such as DNA repair and cell survival. This study begins to delineate the mechanisms by which α-MSH impacts γδ T cell function and leads to the disruption of immune privilege that occurs in alopecia areata.

CRISPR/Cas9-mediated Disruption of Fibroblast Growth Factor 5 in Rabbits Results in a Systemic Long Hair Phenotype by Prolonging Anagen.

Hair growth and morphology are generally regulated by the hair cycle in mammals. Fibroblast Growth Factor 5 (FGF5), which is a hair cycle regulator, has a role in regulating the hair cycle during the transition from the anagen phase to the catagen phase, and a hereditary long hair phenotype has been widely reported when FGF5 is mutated in humans and other species. However, there has been no such report in rabbits. Thus, the first exon of rabbit FGF5 was disrupted by the CRISPR/Cas9 system, and the phenotype of FGF5-/- rabbits was characterized while using hematoxylin and eosin (H&E) staining, immunohistochemistry, quantitative PCR, scanning electron microscopy, and western blotting. The results showed a significant and systemic long hair phenotype in the FGF5-/- rabbits, which indicated that FGF5 is a negative regulator of hair growth. In addition, a decreased diameter of the fiber and a higher area proportion of hair follicle clusters were determined in FGF5-/- rabbits as compared with the WT rabbits. Further investigation verified that prolonging the anagen phase in rabbits, with decreased BMP2/4 pathway signaling and increased VERSICAN pathway signaling, caused the systemic long hair phenotype. Taken together, these results indicate a systemic long hair phenotype by prolonging anagen in FGF5-/- rabbits, which could be widely used for Fur production and an ideal model for studying the mechanism of long hair in the future.

Ectodysplasin-A2 induces apoptosis in cultured human hair follicle cells and promotes regression of hair follicles in mice

Ectodysplasin is a ligand of the TNF family that plays a key role in ectodermal differentiation. EDA-A1 and EDA-A2 are two isoforms of ectodysplasin that differ only by the insertion of two amino acids and bind to two different receptors, ectodysplasin A receptor (EDAR) and ectodysplasin A2 receptor (EDA2R), respectively. Mutations of EDA-A1 and its receptor EDAR have been associated with hypohidrotic ecodermal dysplasia (HED). However, the role of EDA-A2 and the expression pattern of EDA2R in human hair follicles and in the mouse hair growth cycle have not been reported. In this study, we first investigated the expression of EDA2R in human hair follicles and in cultured follicular cells. EDA2R was strongly expressed in outer root sheath (ORS) cells and weakly expressed in dermal papilla (DP) cells. EDA-A2 induced the apoptosis of both ORS cells and DP cells via the activation of cleaved caspase-3. In addition, EDA2R was highly expressed in the late anagen phase compared with other phases in the hair growth cycle. Moreover, EDA-A2 induced apoptosis in cultured human hair follicle cells and in the mouse hair growth cycle, causing the premature onset of the catagen phase. Collectively, our results suggest that EDA-A2/EDA2R signaling could inhibit hair growth, and an inhibitor of EDA-A2/EDA2R signaling may be a promising agent for the treatment and prevention of hair loss.

An important role of cutaneous lymphatic vessels in coordinating and promoting anagen hair follicle growth.

The lymphatic vascular system plays important roles in the control of tissue fluid homeostasis and immune responses. While VEGF-A-induced angiogenesis promotes hair follicle (HF) growth, the potential role of lymphatic vessels (LVs) in HF cycling has remained unknown. In this study, we found that LVs are localized in close proximity to the HF bulge area throughout the postnatal and depilation-induced hair cycle in mice and that a network of LVs directly connects the individual HFs. Increased LV density in the skin of K14-VEGF-C transgenic mice was associated with prolongation of anagen HF growth. Conversely, HF entry into the catagen phase was accelerated in K14-sVEGFR3 transgenic mice that lack cutaneous LVs. Importantly, repeated intradermal injections of VEGF-C promoted hair growth in mice. Conditioned media from lymphatic endothelial cells promoted human dermal papilla cell (DPC) growth and expression of IGF-1 and alkaline phosphatase, both activators of DPCs. Our results reveal an unexpected role of LVs in coordinating and promoting HF growth and identify potential new therapeutic strategies for hair loss-associated conditions.

Nerve growth factor regulates the proliferation of cashmere goat outer root sheath cells through the activation of cAMP-binding protein

The quality and yield of cashmere are closely related to the growth and development of the secondary hair follicles of cashmere goats. Outer root sheath cell (ORSC) proliferation is considered particularly important for the growth and development of hair follicles; however, the factors affecting this are unclear. We previously showed that the expression of nerve growth factor (NGF) in secondary follicle ORSCs was significantly higher in the anagen phase than in the catagen phase, suggesting that NGF promotes ORSC proliferation. To investigate whether ORSCs secrete NGF, and to investigate its role in ORSCs from goat secondary hair follicles, we used enzyme linked immunosorbent assay (ELISA) to show that NGF levels in cultured ORSC medium decreased significantly with the passage of time (P < 0.05). Immunofluorescence analysis detected the transcription factor cAMP-binding protein (CREB) in ORSCs, with a stronger signal intensity observed in the nucleus than in the cytoplasm. An alkaline phosphatase reporter system assay showed that the exogenous addition of 20 ng/mL or 100 ng/mL recombinant NGF protein significantly enhanced the activity of CREB in ORSCs, while treatment with K252α, which inhibits tropomyosin receptor kinase A (TrkA), revealed that NGF enhanced intracellular CREB activity in an NGF/TrkA-dependent manner. Real-time quantitative PCR investigated the expression of proliferating cell nuclear antigen (PCNA) mRNA after treatment with NGF or the CREB inhibitor ICG-001. The NGF/TrkA/CREB system was found to play an important role in maintaining and promoting the expression of PCNA, which will provide a theoretical basis for marker-assisted breeding of cashmere goats.

MiR-218-5p regulates skin and hair follicle development through Wnt/β-catenin signaling pathway by targeting SFRP2.

The hair follicle is a complex biological system involved in a dynamic process governed by gene regulation. MicroRNAs play a critical role in the regulation of gene expression. We demonstrated that the expression of miR-218-5p and SFRP2 showed the opposite relationship in catagen and telogen phases and that miR-218-5p promoted the growth of hair shafts. The luciferase reporter assays confirmed that SFRP2 is the direct target of miR-218-5p. The expression of miR-218-5p may decrease the expression of SFRP2, which activates the Wnt signaling pathway, including the regulation of downstream genes and β-catenin/T-cell-specific factor transcriptional activity. Moreover, miR-218-5p enhanced apoptosis, but inhibition of miR-218-5p decreased apoptosis and inhibited RAB-9 cell proliferation. In this study, we show that miR-218-5p positively regulates the Wnt signaling pathway by targeting SFRP2 and acts as a dynamic governor during skin and hair follicle development.

TGF-β and HSP70 profiles during transformation of yak hair follicles from the anagen to catagen stage.

Transforming growth factor-β (TGF-β) and heat shock protein 70 (HSP70) are important for the hair follicle (HF) cycle, but it is unclear whether they participate in HF regression in yak skin. In this study, we investigated the role of TGF-β, TGF-βRII, and HSP70 in the transition from anagen to catagen of HFs. The results showed that TGF-β2 transcription was significantly higher than that of TGF-β1 and TGF-β3 in the same periods. Meanwhile, the expressions of TGF-β2, TGF-βRII, and caspase-3 were higher in the catagen phase than that in mid-anagen, and some TGF-βRII-positive HF cells were terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL)-positive. Moreover, the HSP70 protein levels in mid-anagen were higher than those in late-anagen and catagen. These results suggested that TGF-β2 plays a major role in catagen induction in yak HFs, which might be achieved via TGF-βRII-mediated apoptosis in HF epithelial cells. In contrast, HSP70 might protect epithelial cells from apoptosis and ultimately inhibit HF regression. In conclusion, TGF-β2 has positive effects, whereas HSP70 has negative effects, on catagen induction.

Transcriptomic analysis reveals critical genes for the hair follicle of Inner Mongolia cashmere goat from catagen to telogen.

There are two main types of hair follicle in Inner Mongolia Cashmere goats, the primary hair follicle (PHF) producing hair fibers and the secondary hair follicle (SHF) producing cashmere fibers. Of both fibers from cashmere-bearing goats in Aerbasi, Inner Mongolia, the timing of cyclical phases for the cashmere have been well clarified but hair fibers have been less noticeable. Herein, we evaluated transcriptome of PHF and SHF from the same three goats in Aerbasi at the catagen- and telogen phase of cashmere growth. We totally found 1977 DEGs between PHFs at the telogen and catagen phases of SHF, 1199 DEGs between telogen- and catagen SHF, 2629 DEGs between PHF at the catagen phase of SHF and catagen SHF, and 755 DEGs between PHF at the telogen phase of SHF and telogen SHF. By analyzing gene functions based on GO and KEGG database, we found that the DEGs have functions in muscle contraction and muscle filament sliding between catagen- and telogen SHF, indicating that arrector pilli muscles might play a role on the transition from catagen to telogen. Moreover, considering that the enriched GO and KEGG categories of the DEGs between PHF and SHF, we suggested that part of PHF might rest in their own anagen phase when SHF are at catagen, but PHF might enter into the telogen phase at SHF’s telogen. Finally, we highly recommended the several potential genes acting as the regulators of the transition between growth phases including IL17RB and eight members of ZNF. These results provide insight into molecular mechanisms on the transition of SHF from catagen to telogen together with PHF’s growth situation at SHF’s catagen and telogen in Inner Mongolia Cashmere goats.

Decorin promotes proliferation and migration of ORS keratinocytes and maintains hair anagen in mice.

DECORIN is a prototypical member of the small leucine-rich proteoglycan (SLRP) family that plays important roles in numerous biological processes and cellular biological pathways. We previously showed that Decorin expression was highly enhanced in mouse dorsal hair follicles (HFs) during the anagen phase and was reduced during the catagen and telogen phases, suggesting that Decorin might modulate follicular cycling and morphogenesis. In this study, to further clarify the effects of DECORIN on hair cells and the cycling transition, an in vitro overexpression strategy and Decorin-null (Dcn-/- ) mice were used to investigate the effects of DECORIN on outer root sheath (ORS) keratinocytes. DECORIN overexpression significantly enhanced proliferation and migration in ORS keratinocytes in vitro. Moreover, DECORIN overexpression upregulated the mRNA and protein expression levels of WNT10b, β-CATENIN and LEF1. The DECORIN overexpression-induced increase in the proliferation and migration of ORS keratinocytes was partially inhibited by a Wnt/β-catenin inhibitor. Furthermore, Dcn-/- mice had a shortened anagen phase and lower levels of β-catenin expression than were observed in wild-type mice in imaging and histological analyses. Taken together, these findings suggest that DECORIN promotes the proliferation and migration of ORS keratinocytes in vitro and maintains hair anagen in mice.

Hair-Growth Potential of Ginseng and Its Major Metabolites: A Review on Its Molecular Mechanisms.

The functional aspect of scalp hair is not only to protect from solar radiation and heat/cold exposure but also to contribute to one’s appearance and personality. Progressive hair loss has a cosmetic and social impact. Hair undergoes three stages of hair cycle: the anagen, catagen, and telogen phases. Through cyclical loss and new-hair growth, the number of hairs remains relatively constant. A variety of factors, such as hormones, nutritional status, and exposure to radiations, environmental toxicants, and medications, may affect hair growth. Androgens are the most important of these factors that cause androgenic alopecia. Other forms of hair loss include immunogenic hair loss, that is, alopecia areata. Although a number of therapies, such as finasteride and minoxidil, are approved medications, and a few others (e.g., tofacitinib) are in progress, a wide variety of structurally diverse classes of phytochemicals, including those present in ginseng, have demonstrated hair growth-promoting effects in a large number of preclinical studies. The purpose of this review is to focus on the potential of ginseng and its metabolites on the prevention of hair loss and its underlying mechanisms.

1365 Interest of Biotrinine®, a mix of Nasturtium officinale and Tropaeolum majus extracts, for chronic hair loss treatment

The hair follicle (HF) undergoes cycles of growth (anagen), regression (catagen) and resting (telogen) phases. Chronic hair loss is caused by the shortening of the active growing phase (anagen) and the extension of the quiescence phase (telogen) of the HF, which occurs mainly under the control of androgens that activate the expression of hair growth cycles inhibitors in dermal papilla cells. This imbalance leads first to the miniaturization of HFs, then to the loose of their ability to generate new hair shafts. The aim of this study was to evaluate the effect of Biotrinine® dry extract on signals and molecular markers of human dermal papilla cells (HDPCs) that regulate anagen phases onset, HF growth maintenance and the transition of anagen to catagen phase. Potential synergistic activities with adenosine triphosphate (ATP) were also investigated. Wnt/b-catenin pathway activation was measured using a gene reporter assay strategy (transfection of HDPCs with a lentivirus expressing luciferase gene under the control of TCF/LEF promoter). Keratinocyte Growth Factor (KGF), Hepatocyte Growth Factor (HGF) and Dickkopf-related protein 1 (DKK1) protein expression levels were measured in HDPCs culture supernatants using ELISA and Luminex technology. Aromatase expression in HDPCs was analysed at mRNA level (Q-PCR analysis) and proteic level (western blot analysis) following respectively 24 and 48 hours of incubation with Biotrinine® dry extract. We found that Biotrinine® dry extract activated Wnt/b-catenin pathway (+38%), enhanced KGF and HGF secretion when tested in association with ATP with synergistic activities (respectively +72% and +133%), and inhibited DKK1 production and release (-65%). Aromatase expression was also induced by Biotrinine® dry extract (+48%). The results of this study indicate that Biotrinine® is a good candidate for chronic hair loss treatment and could be associated with ATP to potentiate their respective effects.

Gene Expression and Localization of LAMTOR3 in the Skin Cells of Liaoning Cashmere Goats

ABSTRACTLiaoning cashmere goats are the most precious genetic resources in China. The function of LAMTOR3 [late endosomal/lysosomal adaptor, mitogen-activated protein kinase (MAPK), and mammalian target of rapamycin activator 3/MAPK scaffold protein 1] gene is expressed in the skin of Liaoning cashmere goats. In situ hybridization (ISH) found that LAMTOR3 is expressed in the inner root sheath (IRS) of hair follicles. During the anagen or catagen phase, the expression of LAMTOR3 is higher in secondary hair follicles than in primary hair follicles. Expression of LAMTOR3 in skin cells treated with melatonin or insulin-like growth factor-1 (IGF-1) is lower than in untreated cells. In addition, the simultaneous treatment of fibroblast growth factor 5 and melatonin decrease the expression of LAMTOR3 in skin cells. The simultaneous treatment with melatonin and 10−5 g/L IGF-1 or 10−4 g/L IGF-1 increases the expression of LAMTOR3 gene in skin cells. If Noggin expression is decreased, then LAMTOR3 expression is increased. This hypothesis suggested that LAMTOR3 influences the character of cashmere fiber, and it may regulate the development of hair follicle and cashmere growth by inducing the MAPK signaling pathway.

Cashmere growth control in Liaoning cashmere goat by ovarian carcinoma immunoreactive antigen-like protein 2 and decorin genes.

ObjectiveThe study investigated the biological functions and mechanisms for controlling cashmere growth of Liaoning cashmere goat by ovarian carcinoma immunoreactive antigen-like protein 2 (OCIAD2) and decorin (DCN) genes.MethodscDNA library of Liaoning cashmere goat was constructed in early stages. OCIAD2 and DCN genes related to cashmere growth were identified by homology analysis comparison. The expression location of OCIAD2 and DCN genes in primary and secondary hair follicles (SF) was performed using in situ hybridization. The expression of OCIAD2 and DCN genes in primary and SF was performed using real-time polymerase chain reaction (PCR).ResultsIn situ hybridization revealed that OCIAD2 and DCN were expressed in the inner root sheath of Liaoning cashmere goat hair follicles. Real-time quantitative PCR showed that these genes were highly expressed in SF during anagen, while these genes were highly expressed in primary hair follicle in catagen phase. Melatonin (MT) inhibited the expression of OCIAD2 and promoted the expression of DCN. Insulin-like growth factors-1 (IGF-1) inhibited the expression of OCIAD2 and DCN, while fibroblast growth factors 5 (FGF5) promoted the expression of these genes. MT and IGF-1 promoted OCIAD2 synergistically, while MT and FGF5 inhibited the genes simultaneously. MT+IGF-1/MT+FGF5 inhibited DCN gene. RNAi technology showed that OCIAD2 expression was promoted, while that of DCN was inhibited.ConclusionActivation of bone morphogenetic protein (BMP) signaling pathway up-regulated OCIAD2 expression and stimulated SF to control cell proliferation. DCN gene affected hair follicle morphogenesis and periodic changes by promoting transforming growth factor-β (TGF-β) and BMP signaling pathways. OCIAD2 and DCN genes have opposite effects on TGF-β signaling pathway and inhibit each other to affect the hair growth.

In vitro effect of diammonium glycyrrhizinate on the growth of human hair follicles and Wnt/β-catenin signaling pathway

Objective To evaluate the effect of diammonium glycyrrhizinate extracted from the Chinese traditional medicine licorice root on the growth of human hair follicles cultured in vitro, and to detect the expression of wnt/β-catenin signaling pathway-related molecules. Methods Isolated hair follicles were cultured with diammonium glycyrrhizinate at different concentrations of 0.1, 0.01, 0.001 and 0.000 1 μmol/L for 10 days, and the hair follicles cultured in Williams′ E medium without diammonium glycyrrhizinate served as a control group. The length of hair follicles was measured under a microscope every day, the morphologic changes of hair follicles were observed, and photos were taken. Immunofluorescence assay was performed to assess the proliferation of hair matrix cells, as well as to determine the expression of β-catenin, glycogen synthase kinase 3β (GSK3β) , phosphorylated GSK3β (p-GSK3β) and lymphoid enhancer factor-1 (Lef1) in the Wnt/β-catenin signaling pathway. Statistical analysis was carried out by repeated-measures analysis of variance and one-way analysis of variance. Results As repeated-measures analysis of variance showed, only 0.01 μmol/L diammonium glycyrrhetate showed significantly promotive effect on the growth of hair follicles compared with the medium alone (P 0.05) . Least significant difference (LSD) -t test revealed that the expre-ssion of β-catenin, p-GSK3β and Lef1 in the hair matrix cells was significantly higher in the 0.1-, 0.01-, 0.001-μmol/L diammonium glycyrrhizinate groups than in the control group (all P 0.05) . Conclusion Diammonium glycyrrhetate at the concentration of 0.01 μmol/L shows markedly promotive effect on the in vitro growth of hair follicles, and can increase the proliferative activity of hair matrix cells and delay the transition to the catagen phase, which may be associated with the activation of Wnt/β-catenin signaling pathway. Key words: Hair follicle; Organ culture techniques; Wnt signaling pathway; Fluoroimmunoassay; Diammonium glycyrrhizinate

Hair growth promotion effect of cedrol cream and its dermatopharmacokinetics.

Topical use of cedrol ethanol has been reported to have a beneficial effect on hair loss. However, the use of cedrol has been limited by application-related issues, such as poor water solubility and volatile features. Therefore, the present study developed a cream formulation of cedrol and evaluated various physicochemical parameters of the prepared cream. The optimized cedrol cream was selected after orthogonal tests and determined further. The dermatopharmacokinetics were studied to investigate the absorption difference between cedrol cream and cedrol ethanol after dermal application, and the concentrations of cedrol in skin were analysed by the gas chromatography-mass spectrometry (GC-MS) method. By comparison, the area under the curve (AUC0–24 h) of cedrol cream was almost three times higher than that of cedrol ethanol. Moreover, this study was undertaken to evaluate the hair growth promoting efficacy of cedrol cream in C57BL/6 mice and Wistar rats. Macroscopic assessment and alopecia score showed that C57BL/6 mice treated with cedrol cream showed a faster production of pigmentation and a higher score at different growth stages than other groups. The hair length of the cedrol cream-treated group was much longer than those of the cedrol ethanol and minoxidil groups. Histological analyses indicated that in the cedrol ethanol group, most follicles of the C57BL/6 mice were in the catagen phase, whereas nearly 83% of hair follicles in the cedrol cream group remained in the anagen phase. Taken together, our data strongly suggest that the cream formulation of cedrol has a stronger hair growth promotion effect, gave no irritation and was safe for topical administration.

A lncRNA-H19 transcript from secondary hair follicle of Liaoning cashmere goat: Identification, regulatory network and expression regulated potentially by its promoter methylation

The H19 transcript (imprinted maternally expressed transcript) is well-known as long noncoding RNA (lncRNA), and it is thought to be associated with the inductive capacity of dermal papilla cells for hair-follicle reconstruction. In this study, we isolated and characterized a lncRNA-H19 transcript from the secondary hair follicle of Liaoning cashmere goat. Also, we investigated its transcriptional pattern and methylation status of H19 gene in secondary hair follicle of this breed during different stages of hair follicle cycle. Nucleotide composition analysis indicated that guanine (G) and cytosine (C) are the dominant nucleotides in the lncRNA-H19 transcript of Liaoning cashmere goat with the highest frequency distribution (11.25%) of GG nucleotide pair. The regulatory network showed that lncRNA-H19 transcript appears to have remarkably diverse regulatory relationships with its related miRNAs and the potential target genes. In secondary hair follicle, the relative expression of lncRNA-H19 transcript at the anagen phase is significantly higher than that at both telogen and catagen phases suggesting that lncRNA-H19 transcript might play essential roles in the formation and growth of cashmere fiber of goat. Methylation analysis indicated that the methylation of the promoter region of H19 gene most likely participates in its transcriptional suppression in secondary hair follicle of Liaoning cashmere goat.

Anti-CXCL4 monoclonal antibody accelerates telogen to anagen transition and attenuates apoptosis of the hair follicle in mice.

Although hair loss or alopecia is a common disease, its exact mechanisms are not yet well understood. The present study investigated the hypothesis that the homeostatic regulation of genes during hair regeneration may participate in hair loss, based on the cyclicity of hair growth. A cluster of such genes was identified by an expression gene-array from the dorsal skin in a depilated mouse model, and CXCL4 was identified as a significantly regulated gene during the hair regeneration process. To elucidate the function of CXCL4 in hair growth, CXCL4 activity was blocked by the administration of an anti-CXCL4 monoclonal antibody (mAb). Histomorphometric analysis indicated that anti-CXCL4 mAb induced an earlier anagen phase and delayed hair follicle regression, in contrast with that in the control group. Moreover, CXCL4 mAb upregulated the transcription levels of several hair growth-related genes, including Lef1, Wnt10b, Bmp4 and Bmp2. In addition, CXCL4 mAb increased the levels of the proliferation-related protein PCNA and Bcl-2 during the anagen phase, while it reduced the expression of pro-apoptotic protein Bax and cleaved caspase-3 during the catagen phase. These findings reveal that CXCL4 plays an important role in hair growth, and that blockade of CXCL4 activity promotes hair growth.

Effect of plum-blossom needle tapping with different stimulation intensities on hair regrowth in hair removal mice

To determine the role of intensity of plum-blossom needle tapping in treating alopecia areata. The BALB/c mice were randomized into a normal group, a control group, a roller-needle (RN) group, a mild plum-blossom needle (MP) group, and a heavy plum-blossom needle (HP) group. An area of hair was removed by external application of 8% sodium sulfide on BALB/c mice. The hair regrowth, hair follicle changes, and local inflammatory factor changes after cutaneous acupuncture were observed. After treated with sodium sulfide, the hair was completely removed, the local hair follicles reached the catagen phase, and the expressions of interleukin (IL)-1α, IL-1β, IL-2, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and IL-17 were increased. Mice intervened by RN achieved the same hair growth rating as the controls but with thicker hair shafts; mice in the MP group had incomplete and uneven hair growth but thicker hair shafts; mice in the HP group didn’t show hair growth. Pathological analysis revealed significant inflammatory infiltration into the local follicle bulbs and increased catagen-phase follicles in the control group, while RN and MP groups showed significantly increased anagen-phase follicles, coarser individual hairs, and obvious hair shafts. Meanwhile, most of the hair follicles in the HP group were in telogen phase and showed obvious surrounding inflammatory infiltration. RN, MP, and HP significantly down-regulated the increased IL-2, IL-1α, IL-1β, TNF-α, and IFN-γ levels (P 0.05). Cutaneous acupuncture with heavy stimulation intensity can inhibit hair growth in hair removal mice, while RN, with the lightest stimulation intensity, is unlikely to affect hair growth but may make hair shafts thicker and follicles larger.

883 Hair follicle bulb developed as 3D scaffold free microtissue

The hair follicle is a self-renewing “mini-organ” which undergoes to continuous cycles of growth and regression. As reported in the study of Higgins et al. (2013, PNAS), dermal papilla cells deeply modify their gene expression profile when cultured as monolayer, but the transcriptional pattern can be partially restored when they are cultured as 3D spheroids. The hanging drop technology was applied to develop a DPF-ORSK co-culture in order to create a scaffold free “proto-follicle”. A multi-parametric approach was adopted in order to characterise the model and to have a comprehensive view of its evolution during culture time. Viability by quantitative measure of cellular ATP and H&E staining coupled with immunohistochemistry and immunofluorescence on selected biomarkers served to monitor the presence and maintenance of type-specific features of the two cell populations (ck6, collagen IV, versican). To verify the feature of 3D proto-hair model compared to 2D culture, the expression of key genes by qRT-PCR (Taqman technology) during the time course were evaluated in comparison with HHDPC in 2D. Genes were selected according to their relevance for Anagen phase: Ki67, HGF, IGF-I, CK6, CK14, CK17 and Catagen Phase: Apoptosis by TUNEL and Annexin V, TNFa, TGFb2. Two aspects of hair follicle physiology have been considered: a) metabolic activity and growth by quantifying genes that promotes the active phases of hair growth as BMP2 and FGF7 b) hair follicle structure evaluating the interaction between the mesenchymal cells of the dermal papilla and the epithelial cells of the outer root sheath LAMC3. The results of gene expression has shown a time dependent development of the fully developed hair papilla model suggesting a anagen-like phase between 3 and 6 days cultivation in the plate and a catagen-like phase after 7 days and up to 14 in a co-culture model where the 2 cellular compartments appear well differentiated.