Growth Of Dermal Papilla Cells Research Articles

Hypoxia Treatment of Adipose Mesenchymal Stem Cells Promotes the Growth of Dermal Papilla Cells via HIF-1α and ERK1/2 Signaling Pathways.

Dermal papilla cells (DPCs) cultured in vitro induce hair follicle formation. Using a hypoxic microenvironment to culture adipose mesenchymal stem cells (ADSCs) can promote hair follicle growth. However, the exact molecular mechanisms underlying this process remain unclear. In this study, ADSCs and DPCs from Arbas Cashmere goats were used. A hypoxic microenvironment promoted the proliferation of ADSCs and increased the pluripotency of ADSCs. The growth factors vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and platelet-derived growth factor (PDGF) were upregulated in ADSCs in the hypoxia-conditioned medium (Hypo-cm). Hypo-cm also enhanced the ability of DPCs to induce hair follicle formation. Inhibitors of the ERK1/2 signaling pathway caused the expressions of growth factors that increased in hypoxic microenvironments to decrease; moreover, hypoxia-inducible factor-1α (HIF-1α) increased the expression levels of VEGF, bFGF, and PDGF and inhibited the expression of bone morphogenic protein 7 (BMP7). In conclusion, these findings improve the theoretical basis for the development of gene therapy drugs for the treatment of alopecia areata and hair thinning.

Maintaining Inducibility of Dermal Follicle Cells on Silk Fibroin/Sodium Alginate Scaffold for Enhanced Hair Follicle Regeneration.

Simple SummaryPatients with severe skin damage need to transplant artificial skin substitutes to achieve repair, and often the repaired part cannot achieve the regeneration of accessory organs such as hair follicles. It is very important to study artificial skin substitutes that can promote the regeneration of hair follicles. Dermal papilla cells in hair follicles can express a variety of growth factors, which play an important role in the growth of hair follicles. Dermal papilla cells were used as seed cells and cultured with a biomimetic silk fibroin/sodium alginate scaffold similar to the extracellular matrix around the dermal papilla to explore cell-compatibility on the scaffold. Our research found that a silk fibroin/sodium alginate scaffold is a good biomimetic of the extracellular matrix structure, and that the dermal papilla cells could maintain normal morphology and aggregate growth characteristics on the scaffold. We then proved through animal experiments that this scaffold can promote skin repair and induce hair follicle regeneration.The extracellular matrix (ECM) is important for maintaining cell phenotype and promoting cell proliferation and differentiation. In order to better solve the problem of skin appendage regeneration, a combination of mechanical/enzymatic digestion methods was used to self-extract dermal papilla cells (DPCs), which were seeded on silk fibroin/sodium alginate scaffolds as seed cells to evaluate the possibility of skin regeneration/regeneration of accessory organs. Scanning electron microscopy (SEM) graphs showed that the interconnected pores inside the scaffold had a pore diameter in the range of 153–311 μm and a porosity of 41–82%. Immunofluorescence (IF) staining and cell morphological staining proved that the extracted cells were DPCs. The results of a Cell Counting Kit-8 (CCK-8) and Calcein-AM/PI live-dead cell staining showed that the DPCs grew well in the composite scaffold extract. Normal cell morphology and characteristics of aggregation growth were maintained during the 3-day culture, which showed that the silk fibroin/sodium alginate (SF/SA) composite scaffold had good cell-compatibility. Hematoxylin-eosin (H&E) staining of tissue sections further proved that the cells adhered closely and aggregated to the pore wall of the scaffold, and retained the ability to induce differentiation of hair follicles. All these results indicate that, compared with a pure scaffold, the composite scaffold promotes the adhesion and growth of DPCs. We transplanted the SF/SA scaffolds into the back wounds of SD rats, and evaluated the damage model constructed in vivo. The results showed that the scaffold inoculated with DPCs could accelerate the repair of the skin and promote the regeneration of the hair follicle structure.

CRISPR/Cas9-mediated VDR knockout plays an essential role in the growth of dermal papilla cells through enhanced relative genes.

BackgroundHair follicles in cashmere goats are divided into primary and secondary hair follicles (HFs). HF development, which determines the morphological structure, is regulated by a large number of vital genes; however, the key functional genes and their interaction networks are still unclear. Although the vitamin D receptor (VDR) is related to cashmere goat HF formation, its precise effects are largely unknown. In the present study, we verified the functions of key genes identified in previous studies using hair dermal papilla (DP) cells as an experimental model. Furthermore, we used CRISPR/Cas9 technology to modify the VDR in DP cells to dissect the molecular mechanism underlying HF formation in cashmere goats.ResultsThe VDR expression levels in nine tissues of Shaanbei white cashmere goats differed significantly between embryonic day 60 (E60) and embryonic day 120 (E120). At E120, VDR expression was highest in the skin. At the newborn and E120 stages, the VDR protein was highly expressed in the root sheath and hair ball region of Shaanbei cashmere goats. We cloned the complete CDS of VDR in the Shaanbei white cashmere goat and constructed a VDR-deficient DP cell model by CRISPR/Cas9. Heterozygous and homozygous mutant DP cells were produced. The growth rate of mutant DP cells was significantly lower than that of wild-type DP cells (P < 0.05) and VDR mRNA levels in DP cells decreased significantly after VDR knockdown (P < 0.05). Further, the expression levels of VGF, Noggin, Lef1, and β-catenin were significantly downregulated (P < 0.05).ConclusionsOur results indicated that VDR has a vital role in DP cells, and that its effects are mediated by Wnt and BMP4 signaling.

Effect of levocetirizine hydrochloride on the growth of human dermal papilla cells: a preliminary study

Objective To preliminarily evaluate the effect of levocetirizine hydrochloride at different concentrations on the growth of in vitro cultured human dermal papilla cells, and to explore its mechanism. Methods Human dermal papilla cells were divided into several groups to be cultured with Dulbecco′s modified eagle medium (DMEM) containing 0 (control group) , 1, 10, 100, 1 000, 10 000 μg/L levocetirizine hydrochloride respectively for 48 hours. Immunofluorescence staining was performed to observe the growth of the dermal papilla cells, and methyl thiazolyl tetrazolium (MTT) assay to evaluate the proliferative activity of the dermal papilla cells. Real-time fluorescence-based quantitative PCR was conducted to measure the mRNA expression of cyclooxygenase 2 (COX-2) , prostaglandin D2 synthase (PTGDS) , prostaglandin E2 (PGE2) , prostaglandin F2alpha (PGF2α) , G protein-coupled receptor 44 (GPR44) , protein kinase B (AKT) and glycogen synthase kinase 3β (GSK3β) , and Western blot analysis to determine the protein expression of PTGDS. After 24-hour culture with DMEM containing levocetirizine hydrochloride at different concentrations, enzyme-linked immunosorbent assay (ELISA) was performed to detect the levels of prostaglandin D2 (PGD2) and PGD2R receptor in the culture supernatant of the human dermal papilla cells. Statistical analysis was carried out with SPSS17.0 software using one-way analysis of variance for the comparison of the above indices among the groups, and least significant difference (LSD) -t test for multiple comparisons. Results Immunofluorescence staining showed that human dermal papilla cells grew well and reached over 90% confluence in the 100 μg/L levocetirizine hydrochloride group. MTT assay revealed that there were significant differences in the proliferation rate among all the groups (F=42.22, P 0.05) . The 100 μg/L levocetirizine hydrochloride group showed significantly decreased mRNA expression of COX-2, PTGDS and GPR44 (0.84 ± 0.08, 0.81 ± 0.10 and 0.85 ± 0.09 respectively) compared with the control group (t=1.97, 2.17 and 2.66 respectively, all P < 0.05) , but significantly increased mRNA expression of PGF2α and AKT (1.96 ± 0.25 and 1.74 ± 0.32 respectively) compared with the control group (t=3.66, 7.32 respectively, both P < 0.05) . Moreover, the protein expression of PTGDS, PGD2 and PGD2R significantly differed among these groups (all P < 0.05) , and was significantly lower in the 100 μg/L levocetirizine hydrochloride group than in the control group (P < 0.05) . Conclusion Levocetirizine hydrochloride can promote the in vitro growth of human dermal papilla cells, likely by inhibiting the PGD2-GPR44 pathway and activating the AKT signal pathway. Key words: Cetirizine; Prostaglandins; Alopecia; Receptors, G-protein-coupled; Dermal papilla cells

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

BackgroundThe 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.ObjectiveThe goal of this study was to investigate the effect of synthetic ceramides (oleyl and stearyl ceramides) on hair growth using hDPCs.MethodshDPCs 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.ResultsTreatment 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.ConclusionOur data suggest that synthetic ceramides stimulates hair growth by induction proliferation of hDPCs via modulation of Wnt/β-catenin and BMP2/4 signaling.

Dermoscopic pre- and posttreatment evaluation in patients with androgenetic alopecia on platelet-rich plasma-A prospective study.

Platelet-rich plasma is rich in growth factors that promote differentiation and growth of dermal papilla cells by various signaling pathways. Dermoscopy is handy, bedside tool that helps to improve diagnostic accuracy in various hair disorders. To evaluate and study the role of dermoscopy in patients with androgenetic alopecia (AGA) pre- and posttreatment with platelet-rich plasma (PRP). It is a prospective comparative study. Twenty male patients with AGA, aged 18-45years with modified Norwood-Hamilton classification grade II-VI were included in this study. Patients were given platelet-rich plasma injections every 3week for a period of 3months. Dermoscopy was performed with 10 x magnifications in polarized mode at baseline and at 3months from the baseline and photographs were taken. Patients were evaluated based on following dermoscopic findings (a) hair count, (b) hair density, (c) hair diameter diversity, perifollicular pigmentation, yellow dots, multi-hair follicular units, honeycomb pigment pattern and white dots, (d) patient's hair growth assessment score. Posttherapy, patients showed significant improvement in hair count (27.4%), hair diversity (84.2%), increase in number of thick, terminals hairs, reduction in yellow dots (60%), perifollicular pigmentation (92.3%) was appreciated. Hair pull test negative after treatment in 10 patients (50%). Patient's hair growth assessment score showed 50%-75% improvement in 7 (35%) patients. Dermoscopy helps to easily evaluate and compare the therapeutic response pre- and posttreatment which can be easily documented and visualized at every visit.

Role of Annexin A2 isoform 2 on the aggregative growth of dermal papillae cells.

The dermal papilla is a major component of hair, which signals the follicular epithelial cells to prolong the hair growth process. Human Annexin A2 was preliminarily identified by two-dimensional gel electrophoresis (2-DE), MALDI-TOF-MS and database searching. The aim of the present study was to explore the role of Annexin A2 in the aggregative growth of dermal papillae cells (DPC). Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were adopted to detect the expression of Annexin A2. And siRNA technique was used to suppress the expression of Annexin A2. Construction of over-expression vector was used to up-regulate the expression of Annexin A2. Cell Counting Kit 8 (CCK-8) and proliferating cell nuclear antigen (PCNA) were taken to detect the proliferation of DPC. The expression of Annexin A2 mRNA was up-regulated in passage 3 DPC compared with passage 10 DPC by RT-PCR. In line with the results at the mRNA level, Western blot analysis revealed that Annexin A2 isoform 2 was up-regulated significantly in passage 3 DPC compared with passage 10 DPC. The Annexin A2 isoform 2 siRNA was synthesized and transfected into passage 3 DPC. RT-PCR data showed the mRNA expression of Annexin A2 isoform 2 was suppressed in passage 3 DPC. Western blot results showed the expression level of Annexin A2 isoform 2 and PCNA were suppressed in passage 3 DPC. CCK-8 results showed that the proliferation of passage 3 DPC was suppressed (P < 0.05). Recombinant plasmid PLJM-Annexin A2 isoform 2-expression vector were constructed and were transfected into passage 10 DPC. RT-PCR data showed the mRNA expression of Annexin A2 isoform 2 was up-regulated in passage 10 DPC. Western blot results showed the expression level of annexin A2 isoform 2 and PCNA were up-regulated in passage 10 DPC. CCK-8 assay showed the proliferation of DPC was stimulated compared with control group (*P < 0.05). Our study proved that Annexin A2 isoform 2 may participate in regulating the proliferation of DPC and may be related to aggregative growth of dermal papilla cells. Therefore, our study suggests that Annexin A2 may be linked to hair follicle growth cycle.

Knockout of p16INK4a promotes aggregative growth of dermal papilla cells.

Dermal papilla cells (DPCs) are located in the hair follicles and play an important role in hair growth. These cells have the ability to induce hair follicle formation when they display aggregative behavior. DPCs derived from the androgenetic alopecia (AGA) area undergo premature senescence in vitro, associated with p16INK4a expression. The aim of the current study was to investigate the expression of p16INK4a in aggregative and non-aggregative DPCs and the effect of p16INK4a down-regulation in these cells by adenovirus-mediated RNA interference (RNAi). DPCs were isolated and cultured from healthy human scalp. p16INK4a gene and protein were detected in aggregative and non-aggregative cells. Expression of p16INK4a in DPCs was silenced by infection with rAd5-CDKN1A-1p2shRNA. Cell fate was monitored after infection. The growth of cells was measured by MTT assay. Cell cycle was evaluated by flow cytometry (FCM). DPCs were isolated by digestion and showed aggregative behavior for six passages. The expression of p16INK4a showed a clear upward trend in non-aggregative cells when compared with aggregative group. p16INK4a expression was silenced by rAd5-CDKN1A-1p2shRNA (p<0.05). The p16INK4a-silenced cells grew more rapidly and exhibited a trend towards aggregative growth. There was an increase in the proportion of cells in G1 phase, while those in S phase were reduced after p16INK4a gene silencing (p<0.05). Our results suggest that p16INK4a plays an important role in the premature senescence and aggregative behavior of DPCs. These observations can lead to novel therapeutic strategies for treatment of AGA.

Expression characteristics of annexin A2 in dermal papilla cells with aggregative behavior

Objective To analyze the expression characteristics of annexin A2 in dermal papilla cells (DPCs) with aggregative behavior. Methods Reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot were performed to measure the mRNA and protein expressions of annexin A2 respectively in DPCs with or without aggregative behavior. Results The mRNA expression level of annexin A2 was significantly higher in DPCs with aggregative behavior than in those without aggregative behavior (0.50 ± 0.15 vs. 0.35 ± 0.19, t= 8.26, P< 0.05). Western blot showed that annexin A2 had two isoforms, including one isoform with a relative molecular mass of 40 000 and the other one with a relative molecular mass of 36 000. The annexin A2 isoform with a relative molecular mass of 40 000 was highly expressed in both DPCs with aggregative behavior and those without aggregative behavior, while the other isoform was only expressed in DPCs with aggregative behavior. Conclusion Annexin A2 may be closely related to the aggregative growth of DPCs. Key words: Hair follicle; Annexin A2; Cell growth processes; Reverse transcriptase polymerase chain reaction; Blotting, Western; Dermal papilla cells

Ascorbigen Induces Dermal Papilla Cell Proliferation in Vitro, but Fails to Modulate Chemotherapy‐Induced Alopecia in Vivo

Ascorbigen (ABG) is the predominant indole-derived compound from Brassica vegetables. In this study, we attempted to evaluate the effects of ABG on hair growth. To this end, we examined the proliferation of isolated human dermal papilla (DP) cells and keratinocytes after incubation in various concentrations (0-1.25 mM) of ABG. Furthermore, hair shaft regrowth was monitored in a mouse model of chemotherapy-induced alopecia (CIA), and hematoxylin and eosin staining was performed for histological analyses. We found that 1.25 mM ABG induced a 1.2-fold increase in the growth of DP cells, but not keratinocytes. However, ABG did not exert significant protective effects against CIA in the mouse model. These findings suggest that ABG may not be able to counteract CIA and that further investigation of the therapeutic potential of ABG in disease models is required.

Effect of PRP on the proliferation of dermal papilla cells and hair follicle regeneration in mice

To investigate the effects of platelet-rich plasma (PRP) on the proliferation of dermal papilla cells (DPCs) and hair follicle regeneration. PRP was prepared using the double-spin method and applied to DPCs. The proliferative effect of activated PRP on DPCs was measured using MTT assay. To understand the influence of activated PRP on the hair-inductive capacity of DPCs, freshly isolated epidermal cells and DPCs of passage 4 were resuspended, mixed with various concentrations of a PRP (0%, 5% or 10%) and were then transferred to a grafting chamber, which was implanted onto the dorsal skin of nude mice. The chambers were removed 1 week after grafting and HF formation was monitored for 4 weeks; the graft site was harvested and processed for histological examination. Activated PRP increased the proliferation benefited the aggregative growth of DPCs. There are significant difference in the yield of hair follicles compared with 10% PRP (344 +/- 27) with 0% PRP (288 +/- 35) in the area of reconstituted skin (P < 0.05). The areas treated with PRP demonstrated an increase in hair follicles density of 19.4%. Ten percent PRP (18 +/- 1) d also can significantly shorten the time of hair formation, compared with 0% PRP (20 +/- 1) d (P < 0.05). There is a considerable effect of PRP on the time of hair formation and the yield of hair follicles reconstitution.

Clonal Growth of Dermal Papilla Cells in Hydrogels Reveals Intrinsic Differences between Sox2-Positive and -Negative Cells In Vitro and In Vivo

In neonatal mouse skin, two types of dermal papilla (DP) are distinguished by Sox2 expression: CD133+Sox2+ DP are associated with guard/awl/auchene hairs, whereas CD133+Sox2− DP are associated with zigzag (ZZ) hairs. We describe a three-dimensional hydrogel culture system that supports clonal growth of CD133+Sox2+, CD133+Sox2−, and CD133−Sox2− (non-DP) neonatal dermal cells. All three cell populations formed spheres that expressed the DP markers alkaline phosphatase, α8 integrin, and CD133. Nevertheless, spheres formed by CD133− cells did not efficiently support hair follicle formation in skin reconstitution assays. In the presence of freshly isolated P2 dermal cells, CD133+Sox2+ and CD133+Sox2− spheres contributed to the DP of both AA and ZZ hairs. Hair type did not correlate with sphere size. Sox2 expression was maintained in culture, but not induced significantly in Sox2− cells in vitro or in vivo, suggesting that Sox2+ cells are a distinct cellular lineage. Although Sox2+ cells were least efficient at forming spheres, they had the greatest ability to contribute to DP and non-DP dermis in reconstituted skin. As the culture system supports clonal growth of DP cells and maintenance of distinct DP cell types, it will be useful for further analysis of intrinsic and extrinsic signals controlling DP function.

Versican targeting by RNA interference suppresses aggregative growth of dermal papilla cells

Dermal papilla cells (DPCs) are specialized fibroblasts found in the hair follicle papilla, which are associated with the development and cycle regulation of hair follicles (HFs). DPCs exhibit a multilayer aggregative growth character, which is closely related to induction of HF formation. Versican, a large chondroitin sulphate proteoglycan and one of the major components of the extracellular matrix, is involved in the formation of HF. To confirm the relationship between versican and the aggregative growth of DPCs, we first induced and established an aggregative cell model in DPCs in vitro, with cells taken to passage 8. Simultaneously, aggregative passage 2 DPCs and nonaggregative passage 8 DPCs were selected as parallel controls. RNA interference (RNAi) targeted to versican was used in passage 2 DPCs using a lentiviral vector. Reverse transcriptase (RT)-PCR and western blotting were used to assay the expression of versican in DPCs. RNAi targeted to versican efficiently suppressed the aggregative growth of passage 2 DPCs, and the inhibitory effect was significant 3 days after RNAi treatment. The mRNA and protein levels of versican were also downregulated in passage 2 DPCs, and were lower than levels in nonaggregative passage 8 DPCs. Notably, the aggregative growth of nonaggregative passage 8 DPCs was restored after induction in a 1 : 1 v/v mixture of fresh DMEM and medium recycled from a previous passage. Versican is a key gene for the aggregative growth of DPCs, and might be significant in the regeneration of HF.

Effect of Wnt-3a signaling on aggregative growth of dermal papilla cells:a pilot study

Objective To investigate the influence of Wnt-3a signaling on aggregative growth of dermal papilla cells.Methods Recombinant adenovirus pAdEasy-1/Wnt-3a was constructed at first,and used to transfect cultured dermal papilla cells(DPCs).Then,the growth pattem of DPCs was observed by inverse microscopy;laser confocal microscopy and Western blot were utilized to detect the expressions of Wnt-3a,β-catenin and versican in low-passage DPCs,high-passage DPCs and transfected high-passage DPCs.Results The over-expression of Wnt-3a protein could effectively induce the aggregative growth of DPCs.Laser confocal microscopy showed that the fluorescence intensity of β-catenin and versican increased from 34.16±9.62 and 18.81±9.59 in high-passage DPCs to 87.35±17.28 and 92.18±18.39 in transfected high-passage DPCs(t=11.98,17.88,both P＜0.0 1),respectively.Also,Western blot proved a significant increase of expression intensity of β-catenin(15.27±2.17 vs 60.09±7.24,t=10.10,P＜0.01)and versican(19.32±2.46 vs 58.46±2.78,t=20.63,P＜0.01)in transfected high-passage DPCs compared with untransfected high-passage DPCS.ConclusionsWnt-3a signaling plays an important role in modulating aggregative growth of DPCs,which is mainly through the classical pathway with β-catenin as the key protein.As an important downstream gene of Wnt signaling,vesican is an indispensable part for the modulation of aggregative growth of DPCs. Key words: Wnt proteins; Hair follicles; Aggregative growth; Beta-catenin; Versicans

The hair growth promoting effect of Sophora flavescens extract and its molecular regulation

In search of natural extracts for hair growth, we found that the extract of dried root of Sophora flavescens has outstanding hair growth promoting effect. After topical application of Sophora flavescens extract onto the back of C57BL/6 mice, the earlier conversion of telogen-to-anagen was induced. The growth of dermal papilla cells cultured in vitro, however, was not affected by Sophora flavescens extract treatment. RT-PCR analysis showed that Sophora flavescens extract induced mRNA levels of growth factors such as IGF-1 and KGF in dermal papilla cells, suggesting that the effects of Sophora flavescens extract on hair growth may be mediated through the regulation of growth factors in dermal papilla cells. In addition, the Sophora flavescens extract revealed to possess potent inhibitory effect on the type II 5α-reductase activity. Taken together, these results suggest that Sophora flavescens extract has hair growth promoting potential and can be used for hair growing products.

A comparison of the culture and growth of dermal papilla cells from hair follicles from non-balding and balding (androgenetic alopecia) scalp

A comparison of the culture and growth of dermal papilla cells from hair follicles from non-balding and balding (androgenetic alopecia) scalp

A comparison of the culture and growth of dermal papilla cells from hair follicles from non-balding and balding (androgenetic alopecia) scalp

Male pattern baldness is a common, androgen-dependent skin problem in adult men which is not well understood, although androgens are believed to act on the hair follicle via the mesenchyme-derived dermal papilla situated in the middle of the hair follicle bulb. Since dermal papilla cells retain specific characteristics in culture, such as hair-growth promoting ability and appropriate features of the mechanism of androgen action, dermal papilla cells from follicles undergoing androgen-stimulated miniaturization may provide a useful in vitro model system. Therefore, dermal papilla cells have been derived from intermediate follicles from balding and nearly clinically normal sites of men with androgenetic alopecia. Balding dermal papillae were much smaller than non-balding ones and grew much less well under normal growth conditions. Supplementing the medium with human serum, rather than fetal calf serum, increased both the yield of established cultures and the number and health of the dermal papilla cells produced. Non-balding cells also grew faster in human serum. Balding cells retained the normal fibroblastic shape and aggregative behaviour of dermal papilla cells, but always grew less well than non-balding cells. Nearly clinically normal dermal papillae were similar, or slightly smaller, in size to non-balding ones, but their growth resembled balding cells. Since balding dermal papilla cells can be cultured, though with much greater difficulty than nonbalding ones, and exhibit differing growth characteristics to non-balding cells, they merit further investigation which may increase our understanding of, and ability to control, androgenetic alopecia.

Sex hormones and antiandrogens influence in vitro growth of dermal papilla cells and outer root sheath keratinocytes of human hair follicles

Anagen hair bulb papillae, interfollicular dermal fibroblasts, and interfollicular keratinocytes isolated from fronto-parietal scalp biopsies as well as outer root sheath keratinocytes from plucked anagen hairs were separately grown in subculture for 14 d. The effect of different concentrations (2.4 nM-17.3 μM) of testosterone, dihydrotestosterone, and the antiandrogens cyproterone acetate or 17α-propylmesterolone on growth behavior of the mesenchymal and epithelial cell types of the hair follicle were comparatively studied by means of growth curves, cell doubling times, and 3H-thymidine incorporation. For control, all cell lines were subcultured in hormone-free medium.Testosterone and dihydrotestosterone (345 nM) significantly reduced proliferation of papilla cells compared with dermal fibroblasts (p < 0.01) and outer root sheath keratinocytes compared with interfollicular keratinocytes (p < 0.01), as well as compared with cells cultured in control medium. Low concentrations of 17β-estradiol were ineffective, whereas doses of 180 nM 17β-estradiol increased the growth velocities of all cell types, especially of papilla cells, compared with dermal fibroblasts. Low doses of either cyproterone acetate (24 nM) or 17α-propylmesterolone (29 nM) induced a growth enhancement, especially of papilla cells and outer root sheath keratinocytes, whereas high doses of cyproterone (1.20 μM) and 17α-propylmesterolone (1.45 μM) had opposite effects. These changes were significant between papilla cells and dermal fibroblasts as well as between outer root sheath keratinocytes and interfollicular keratinocytes. Applying increasing doses of androgens to cyproterone acetate (24 nM)- or 17α-propylmesterolone (29 nM)-containing media neutralized the growth-stimulating effect of antiandrogens, particularly in papilla cells and outer root sheath keratinocytes. However, minor differences between testosterone and dihydrotestosterone effects on cell growth were found.The data clearly demonstrate that the changes of in vitro growth of hair follicle cells depend on the concentrations of androgens and antiandrogens, as higher doses of both antiandrogens tested retarded the cell proliferation similar to testosterone or dihydrotestosterone. The papilla cells and outer root sheath keratinocytes reacted more sensitively to the hormones tested, thereby confirming the concept of a distinct androgen sensitivity of these specialized hair follicle cells.

Sex hormones and antiandrogens influence in vitro growth of dermal papilla cells and outer root sheath keratinocytes of human hair follicles.

Anagen hair bulb papillae, interfollicular dermal fibroblasts, and interfollicular keratinocytes isolated from fronto-parietal scalp biopsies as well as outer root sheath keratinocytes from plucked anagen hairs were separately grown in subculture for 14 d. The effect of different concentrations (2.4 nM-17.3 microM) of testosterone, dihydrotestosterone, and the antiandrogens cyproterone acetate or 17 alpha-propylmesterolone on growth behavior of the mesenchymal and epithelial cell types of the hair follicle were comparatively studied by means of growth curves, cell doubling times, and 3H-thymidine incorporation. For control, all cell lines were subcultured in hormone-free medium. Testosterone and dihydrotestosterone (345 nM) significantly reduced proliferation of papilla cells compared with dermal fibroblasts (p < 0.01) and outer root sheath keratinocytes compared with interfollicular keratinocytes (p < 0.01), as well as compared with cells cultured in control medium. Low concentrations of 17 beta-estradiol were ineffective, whereas doses of 180 nM 17 beta-estradiol increased the growth velocities of all cell types, especially of papilla cells, compared with dermal fibroblasts. Low doses of either cyproterone acetate (24 nM) or 17 alpha-propylmesterolone (29 nM) induced a growth enhancement, especially of papilla cells and outer root sheath keratinocytes, whereas high doses of cyproterone (1.20 microM) and 17 alpha-propylmesterolone (1.45 microM) had opposite effects. These changes were significant between papilla cells and dermal fibroblasts as well as between outer root sheath keratinocytes and interfollicular keratinocytes. Applying increasing doses of androgens to cyproterone acetate (24 nM)- or 17 alpha-propylmesterolone (29 nM)-containing media neutralized the growth-stimulating effect of antiandrogens, particularly in papilla cells and outer root sheath keratinocytes. However, minor differences between testosterone and dihydrotestosterone effects on cell growth were found. The data clearly demonstrate that the changes of in vitro growth of hair follicle cells depend on the concentrations of androgens and antiandrogens, as higher doses of both antiandrogens tested retarded the cell proliferation similar to testosterone or dihydrotestosterone. The papilla cells and outer root sheath keratinocytes reacted more sensitively to the hormones tested, thereby confirming the concept of a distinct androgen sensitivity of these specialized hair follicle cells.