Dihydrotestosterone-induced hair regrowth inhibition by activating androgen receptor in C57BL6 mice simulates androgenetic alopecia

Design, proof-of-concept of single robotic hair transplant mechanisms for both harvest and implant of hair grafts

The design and development of a prototype for a singular robotic hair transplant system capable of harvesting and implanting hair grafts were executed in this study. To establish a proof-of-concept for hair transplant procedures involving harvesting and implantation, a test system using a spherical phantom of the scalp was selected. The developed prototype of the robotic hair transplant system demonstrates the potential to reduce the duration that grafts remain without a blood supply, thereby minimizing hair graft damage. Additionally, the overall operation time for follicular unit extraction is comparatively shorter than that of conventional systems. Results from the robot vision tests indicate an 89.6% accuracy for hair graft detection with a 4 mm hair length phantom and 97.4% for a 2 mm hair length phantom. In the robot position control test, the root mean square error was found to be 1.268°, with a standard error of the mean of 0.203°. These outcomes suggest that the proposed system performs effectively under the conditions of a spherical phantom with a 2 mm hair length and a 5 mm distance between harvests.

Improvement of androgenic alopecia by extracellular vesicles secreted from hyaluronic acid-stimulated induced mesenchymal stem cells

BACKGROUND

Androgenetic alopecia (AGA) is a common form of hair loss. Androgens, such as testosterone and dihydrotestosterone, are the main causes of AGA. Extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) can reduce AGA. However, preparing therapeutic doses of MSCs for clinical use is challenging. Induced pluripotent stem cell-derived MSCs (iMSCs) are homogenous and easily expandable, enabling scalable production of EVs. Hyaluronic acid (HA) can exert various functions including free radical scavenging, immune regulation, and cell migration. Herein, we examined whether hyaluronic acid (HA) stimulation of iMSCs could produce EVs with enhanced therapeutic outcomes for AGA.

METHODS

EVs were collected from iMSCs primed with HA (HA-iMSC-EVs) or without HA (iMSC-EVs). The characteristics of EVs were examined using dynamic light scattering, cryo-transmission electron microscopy, immunoblotting, flow cytometry, and proteomic analysis. In vitro, we compared the potential of EVs in stimulating the survival of hair follicle dermal papilla cells undergoing testosterone-mediated AGA. Additionally, the expression of androgen receptor (AR) and relevant growth factors as well as key proteins of Wnt/β-catenin signaling pathway (β-catenin and phosphorylated GSK3β) was analyzed. Subsequently, AGA was induced in male C57/BL6 mice by testosterone administration, followed by repeated injections of iMSC-EVs, HA-iMSC-EVs, finasteride, or vehicle. Several parameters including hair growth, anagen phase ratio, reactivation of Wnt/β-catenin pathway, and AR expression was examined using qPCR, immunoblotting, and immunofluorescence analysis.

RESULTS

Both types of EVs showed typical characteristics for EVs, such as size distribution, markers, and surface protein expression. In hair follicle dermal papilla cells, the mRNA levels of AR, TGF-β, and IL-6 increased by testosterone was blocked by HA-iMSC-EVs, which also contributed to the augmented expression of trophic genes related to hair regrowth. However, no notable changes were observed in the iMSC-EVs. Re-activation of Wnt/β-catenin was observed in HA-iMSC-EVs but not in iMSC-EVs, as shown by β-catenin stabilization and an increase in phosphorylated GSK3β. Restoration of hair growth was more significant in HA-iMSC-EVs than in iMSC-EVs, and was comparable to that in mice treated with finasteride. Consistently, the decreased anagen ratio induced by testosterone was reversed by HA-iMSC-EVs, but not by iMSC-EVs. An increased expression of hair follicular β-catenin protein, as well as the reduction of AR was observed in the skin tissue of AGA mice receiving HA-iMSC-EVs, but not in those treated with iMSC-EVs.

CONCLUSIONS

Our results suggest that HA-iMSC-EVs have potential to improve AGA by regulating growth factors/cytokines and stimulating AR-related Wnt/β-catenin signaling.

Effects of Camellia oleifera seed shell polyphenols and 1,3,6-tri-O-galloylglucose on androgenic alopecia via inhibiting 5a-reductase and regulating Wnt/β-catenin pathway

Androgenetic alopecia (AGA) is the leading cause of hair loss in adults. Its pathogenesis remains unclear, but studies have shown that the androgen-mediated 5α-reductase-AR receptor pathway and the Wnt/β-catenin signaling pathway play significant roles. Camellia oleifera is an oil plant, and its fruits have been documented in folklore as having a hair cleansing effect and preventing hair loss. In this study, we used UPLC-Q-TOF-MS/MS to identify the structure of the substances contained in the polyphenols of Camellia oleifera seed shell. These polyphenols are mainly used for shampooing and anti-hair loss purposes. Next, we used molecular docking technology to dock 41 polyphenols and steroidal 5 alpha reductase 2 (SRD5A2). We found that the docking scores and docking sites of 1,3,6-tri-O-galloylglucose (TGG) and finasteride were similar. We constructed a mouse model of DHT-induced AGA to evaluate the effects of Camellia oleifera seed shell polyphenols (CSSP) and TGG in vivo. Treatment with CSSP and TGG alleviated alopecia symptoms and reduced DHT levels. Additionally, CSSP and TGG were able to reduce androgen levels by inhibiting the SRD5A2-AR receptor signaling pathway. Furthermore, by regulating the secretion of growth factors and activating the Wnt/β-catenin signaling pathway, CSSP and TGG were able to extend the duration of hair growth. In conclusion, our study showed that CSSP and TGG can improve AGA in C57BL/6 J mice and reduce the effect of androgen on hair follicle through the two signaling pathways mentioned above. This provides new insights into the material basis and mechanism of the treatment of AGA by CSSP.

Hair Growth Promoting Effects of Solubilized Sturgeon Oil and Its Correlation with the Gut Microbiome

Androgenetic alopecia is a common disease that occurs in both men and women. Several approved medications have been used to treat this condition, but they are associated with certain side effects. Therefore, use of extracts derived from natural products, such as Siberian sturgeon (Acipenser baerii), and the regulation of the gut microbiota have become important topics of research. Sturgeon is known for its high nutritional value and anti-inflammatory properties; however, its effects on androgenetic alopecia and gut microbiota remain uncharacterized. Here, we aimed to investigate whether solubilized sturgeon oil (SSO) promotes hair growth and regulates the gut microbiome. C57BL/6 mice were divided into four groups. Three groups received topical applications of distilled water, SSO, or minoxidil, and one group was orally administered SSO. Each treatment was administered over 4 weeks. Histopathological analysis revealed a significant increase in follicle number (p < 0.001) and follicle diameter (p < 0.05). Immunohistochemical analysis revealed upregulation of β-catenin and ERK-1, markers involved in hair growth-promoting pathways. Furthermore, microbiome analysis revealed that the reduced gut microbiota was negatively correlated with these markers. Our findings indicate that oral administration of SSO promotes hair growth and regulates the abundance of hair growth-promoting gut microbiota.

Rational Design of Human Hair Keratin-Driven Proteins for Hair Growth Promotion

Keratins, the most abundant proteins in human hair, are excellent hair nutrients for growth. However, the complex components of keratin extract hinder their mechanism investigation, and the pure recombinant keratin with poor solubility limited its hair growth promotion efficiency. Here, the water-soluble recombinant keratins (RKs) of K31 and K81 are rationally designed through QTY Code methodology, which are then used to fabricate the microneedles to study the effect of keratin on hair growth. Interestingly, it is discovered that more than 40% of the hair follicles (HFs) in the RK81QTY group entered the anagen on day 12 and the diameter of new hair is 15.10 ± 2.45 µm, which significantly promoted growth and development of HFs and improved new hair quality compared to RK31QTY. Water-soluble RKs significantly enhanced HFs activity and de novo regeneration of robust hairs compared to extract and minoxidil by upregulating the PI3K/AKT/Nf-κB signaling axis. These findings highlight the potential of designing solubilized recombinant keratins with distinct properties to improve therapeutical effects and open new avenues to designing keratin-based proteins.

Optimized Depilation Method and Comparative Analysis of Hair Growth Cycle in Mouse Strains

In mice, hair growth follows a mosaic or wavy patterning. Therefore, synchronization of the hair growth cycle is required to adequately evaluate any trichogenic interventions pre-clinically. Depilation is the established method for synchronizing the growth phase of mouse hair follicles. When attempting to reproduce procedures reported in the literature, C57BL/6J mice developed severe wounds. This led us not only to optimize the procedure, but also to test the procedure in other strains, namely Sv129 and the F1 generation from C57BL/6J crossed with Sv129 (B6129F1 mixed background), for which the hair growth cycle has not been ascertained yet. Here, we describe an optimized depilation procedure, using cold wax and an extra step to protect the animal skin that minimizes injury, improving experimental conditions and animal welfare in all strains. Moreover, our results show that, although hair cycle kinetics are similar in all the analyzed strains, Sv129 and B6129F1 skins are morphologically different from C57BL/6J skin, presenting an increased number and size of hair follicles in anagen, consistent to the higher hair density observed macroscopically. Altogether, the results disclose an optimized mouse depilation method that excludes the detrimental and confounding effects of skin injury in hair growth studies and reveals the hair cycle features of other mouse strains, supporting their use in hair growth pre-clinical studies.

Pilose antler extracts promotes hair growth in androgenetic alopecia mice by activating hair follicle stem cells via the AKT and Wnt pathways

Background: Angrogenetic alopecia (AGA) is one of the most prevalent hair loss disorders worldwide. The hair follicle stem cell (HFSC) is closely related to the formation of hair follicle (HF) structure and HF self-renewal. The activation of HFSC in AGA is critical for hair growth. Pilose antler has been reported to have hair growth-promoting activity, but the mechanism of action on AGA and HFSC has not been reported. Methods: We previously extracted an active component from the pilose antler known as PAEs. In this study, we conducted experiments using AGA mice and HFSC. The effects of PAEs on hair growth in AGA mice were firstly detected, and then the mechanisms of PAEs for AGA were predicted by integrating network pharmacology and de novo transcriptomics data of pilose antler. Finally, biological experiments were used to validate the molecular mechanism of PAEs in treating AGA both in vivo and in vitro. Results: It was found that PAEs promoted hair regrowth by accelerating the activation of anagen, delaying the anagen-catagen transition. It also alleviated the morphological changes, such as hair shortening, thinning, miniaturization, and HF number reduction, and regulated the hair regeneration process of four subtypes of hair. We further found that PAEs could promote the proliferation of HFSC, outer root sheath (ORS) cells, and hair bulb cells in AGA mice. We then integrated network pharmacology and pilose antler transcriptomics data to predict that the mechanism of PAEs treatment in AGA mice is closely related to the PI3K-AKT/Wnt-β-Catenin pathways. Subsequently, it was also verified that PAEs could activate both pathways in the skin of AGA mice. In addition, we found that PAEs perhaps increased the number of blood vessels around dermal papilla (DP) in experiments in vivo. Meanwhile, the PAEs stimulated the HFSC proliferation in vitro and activated the AKT and Wnt pathways. However, the proliferative activity of HFSC was inhibited after blocking the Wnt pathway and AKT activity. Conclusion: This study suggests that the hair growth-promoting effect of PAEs in AGA mice may be closely related to the stimulation of the AKT and Wnt pathways, which in turn activates the proliferation of HFSC.

High molecular weight hyaluronic acid-liposome delivery system for efficient transdermal treatment of acute and chronic skin photodamage

Photodamage is one of the most common causes of skin injury. High molecular weight hyaluronic acid (HHA) has shown immense potential in the treatment of skin photodamage by virtue of its anti-inflammatory, reparative, and antioxidative properties. However, due to its large molecular structure of HHA, HHA solution could only form a protective film on the skin surface in conventional application, failing to effectively penetrate the skin, which necessitates the development of new delivery strategies. Liposomes, with a structure similar to biological membranes, have garnered extensive attention as transdermal drug delivery carriers because of their advantages in permeability, dermal compatibility, and biosafety. Herein, we have developed a HHA-liposome transdermal system (HHL) by embedding HHA into the liposome structure using reverse evaporation, high-speed homogenization, and micro-jet techniques. The effective penetration and long-term residence of HHA in skin tissue were multidimensionally verified, and the kinetics of HHA in the skin were extensively studied. Moreover, it was demonstrated that HHL significantly strengthened the activity of human keratinocytes and effectively inhibits photo-induced cellular aging in vitro. Furthermore, a murine model of acute skin injury induced by laser ablation was established, where the transdermal system showed significant anti-inflammatory and immunosuppressive properties, promoting skin proliferation and scar repair, thereby demonstrating immense potential in accelerating skin wound healing. Meanwhile, HHL significantly ameliorated skin barrier dysfunction caused by simulated sunlight exposure, inhibited skin erythema, inflammatory responses, and oxidative stress, and promoted collagen expression in a chronic photodamage skin model. Therefore, this transdermal delivery system with biocompatibility represents a promising new strategy for the non-invasive application of HHA in skin photodamage, revealing the significant potential for clinical translation and broad application prospects. STATEMENT OF SIGNIFICANCE: The transdermal system utilizing hyaluronic acid-based liposomes enhances skin permeability and retains high molecular weight hyaluronic acid (HHL). In vitro experiments with human keratinocytes demonstrate significant skin repair effects of HHL and its effective inhibition of cellular aging. In an acute photodamage model, HHL exhibits stronger anti-inflammatory and immunosuppressive properties, promoting skin proliferation and scar repair. In a chronic photodamage model, HHL significantly improves skin barrier dysfunction, reduces oxidative stress induced by simulated sunlight, and enhances collagen expression.

Comprehensive transcriptome profiling between balding and non-balding scalp of female pattern hair loss in Asian

While many gene expression studies have focused on male pattern baldness (MPB), few studies have investigated the genetic differences between bald and non-bald hair follicles in female pattern hair loss (FPHL). This study aimed to identify molecular biomarkers associated with FPHL through genetic analysis of paired bald and non-bald hair follicles from 18 FPHL patients, using next-generation sequencing (NGS) techniques. RNA transcriptome analysis was performed to identify differentially expressed genes (DEGs) between bald and non-bald hair follicles in FPHL. The DEGs were validated using real-time PCR, and protein expression was confirmed through immunohistochemistry and western blot analysis. Our findings suggest that HOXB13, SFRP2, PTGDS, CXCR3, SFRP4, SOD3, and DCN are significantly upregulated in bald hair follicles compared to non-bald hair follicles in FPHL. SFRP2 and PTGDS were found to be consistently highly expressed in bald hair follicles in all 18 samples. Additionally, elevated protein levels of SFRP2 and PTGDS were confirmed through western blot and immunohistochemical analysis. Our study identified SFRP2 and PTGDS as potential biomarkers for FPHL and suggests that they may play a role in inducing hair loss in this condition. These findings provide a foundation for further research on the pathogenesis of FPHL and potential therapeutic targets.

Stimulation of hair regrowth in an animal model of androgenic alopecia using 2-deoxy-D-ribose

Androgenic alopecia (AGA) affects both men and women worldwide. New blood vessel formation can restore blood supply and stimulate the hair regrowth cycle. Recently, our group reported that 2-deoxy-D-ribose (2dDR) is 80%-90% as effective as VEGF in the stimulation of neovascularization in in vitro models and in a chick bioassay. In this study, we aimed to assess the effect of 2dDR on hair growth. We prepared an alginate gel containing 2dDR, polypropylene glycol, and phenoxyethanol. AGA was developed in C57BL6 mice by intraperitoneally injecting testosterone (TE). A dihydrotestosterone (DHT)-treated group was used as a negative control, a minoxidil group was used as a positive control, and we included groups treated with 2dDR gel and a combination of 2dDR and minoxidil. Each treatment was applied for 20 days. Both groups treated with 2dDR gel and minoxidil stimulated the morphogenesis of hair follicles. H&E-stained skin sections of C57BL/6 mice demonstrated an increase in length, diameter, hair follicle density, anagen/telogen ratio, diameter of hair follicles, area of the hair bulb covered in melanin, and an increase in the number of blood vessels. Masson's trichrome staining showed an increase in the area of the hair bulb covered in melanin. The effects of the FDA-approved drug (minoxidil) on hair growth were similar to those of 2dDR (80%-90%). No significant benefit were observed by applying a combination of minoxidil with 2dDR. We conclude that 2dDR gel has potential for the treatment of androgenic alopecia and possibly other alopecia conditions where stimulation of hair regrowth is desirable, such as after chemotherapy. The mechanism of activity of 2dDR remains to be established.

Spanlastic-laden nanogel as a plausible platform for dermal delivery of bimatoprost with superior cutaneous deposition and hair regrowth efficiency in androgenic alopecia

Bimatoprost (BIM) is a prostaglandin F2α analogs originally approved for the treatment of glaucoma and ocular hypertension. Recent studies have highlighted its potential to boost hair growth. The objective of this investigation is to challenge the potential of spanlastics (SLs) as a surfactant-based vesicular system for promoting the cutaneous delivery of BIM for the management of alopecia. BIM-loaded spanlastics (BIM-SLs), composed of Span as the main vesicle component and Tween as the edge activator, were fabricated by ethanol injection method. The formulated BIM-SLs were optimized by 23 full factorial design. The optimized formula (F1) was characterized for entrapment efficiency, surface charge, vesicle size, and drug release after 12 h (Q12h). The optimized formula (F1) exhibited high drug entrapment efficiency (83.1 ± 2.1%), appropriate zeta potential (-19.9 ± 2.1 mV), Q12h of 71.3 ± 5.3%, and a vesicle size of 364.2 ± 15.8 nm, which favored their cutaneous accumulation. In addition, ex-vivo skin deposition studies revealed that entrapping BIM within spanlastic-based nanogel (BIM-SLG) augmented the dermal deposition of BIM, compared to naïve BIM gel. Furthermore, in vivo studies verified the efficacy of spanlastic vesicles to boost the cutaneous accumulation of BIM compared to naive BIM gel; the AUC0-12h of BIM-SLG was 888.05 ± 72.31 μg/mL.h, which was twice as high as that of naïve BIM gel (AUC0-12h 382.86 ± 41.12 μg/mL.h). Intriguingly, BIM-SLG outperforms both naïve BIM gel and commercial minoxidil formulations in stimulating hair regrowth in an androgenetic alopecia mouse model. Collectively, spanlastic vesicles might be a potential platform for promoting the dermal delivery of BIM in managing alopecia.

Discovery of a novel and highly selective JAK3 inhibitor as a potent hair growth promoter

JAK-STAT signalling pathway inhibitors have emerged as promising therapeutic agents for the treatment of hair loss. Among different JAK isoforms, JAK3 has become an ideal target for drug discovery because it only regulates a narrow spectrum of γc cytokines. Here, we report the discovery of MJ04, a novel and highly selective 3-pyrimidinylazaindole based JAK3 inhibitor, as a potential hair growth promoter with an IC50 of 2.03 nM. During in vivo efficacy assays, topical application of MJ04 on DHT-challenged AGA and athymic nude mice resulted in early onset of hair regrowth. Furthermore, MJ04 significantly promoted the growth of human hair follicles under ex-vivo conditions. MJ04 exhibited a reasonably good pharmacokinetic profile and demonstrated a favourable safety profile under in vivo and in vitro conditions. Taken together, we report MJ04 as a highly potent and selective JAK3 inhibitor that exhibits overall properties suitable for topical drug development and advancement to human clinical trials.

Synergistic therapeutic effect of ginsenoside Rg3 modified minoxidil transfersomes (MXD-Rg3@TFs) on androgenic alopecia in C57BL/6 mice

Inflammation in hair follicles will reduce the effectiveness of minoxidil (MXD) in the treatment of androgen alopecia (AGA) caused by elevated androgen levels. To target multiple physiological and pathological processes in AGA, a novel natural bioactive compound modified transfersomes (MXD-Rg3@TFs) was prepared to replace cholesterol that may disrupt hair growth, with ginsenosides Rg3 (Rg3) that have anti-inflammatory effects on AGA. The effects of MXD, Rg3 and their combination on AGA were evaluated using dihydrotestosterone (DHT) induced human dermal papilla cells (DPCs), and the results showed that the combination of MXD and Rg3 can significantly promote the proliferation, reduce the level of intracellular ROS and inflammatory factors, and inhibit the aging of DHT induced DPCs. Compared with cholesterol membrane transfersomes (MXD-Ch@TFs), MXD-Rg3@TFs has similar deformability, smaller particle size and better stability. MXD-Rg3@TFs has also significant advantages in shortening telogen phase and prolonging the growth period of hair follicles in C57BL/6 mice than MXD-Ch@TFs and commercial MXD tincture. The prominent ability of MXD-Rg3@TFs to inhibit the conversion of testosterone to DHT and reduce the level of inflammatory factors suggested that Rg3 and MXD in MXD-Rg3@TFs have synergistic effect on AGA therapy. MXD-Ch@TFs with no irritation to C57BL/6 mice skin is expected to reduce the dose of MXD and shorten the treatment time, which would undoubtedly provide a promising therapeutic option for treatment of AGA.

Botulinum Toxin Type A Alleviates Androgenetic Alopecia by Inhibiting Apoptosis of Dermal Papilla Cells via Targeting circ_0135062/miR-506-3p/Bax Axis

Botulinum toxin type A (BTXA) has the potential to treat androgenetic alopecia (AGA); however, its impact on the apoptosis of dermal papillary cells (DPCs) is not yet fully understood. Noncoding RNAs play a crucial role in AGA. In this study, we investigated the potential mechanism by which BTXA alleviates apoptosis induced by dihydrotestosterone (DHT) in DPCs. We assessed the mRNA levels of circ_0135062, miR-506-3p, and Bax using qRT-PCR. Binding interactions were analyzed using RNA pulldown and dual-luciferase assays. Cell viability was determined using a cell counting kit-8 assay, and cell apoptosis was assessed using flow cytometry, TUNEL assays, and western blotting. Our findings revealed that BTXA inhibited the apoptosis of DPCs treated with DHT. Moreover, circ_0135062 overexpression counteracted the protective effect of BTXA on DHT-treated DPCs. MiR-506-3p was found to interact with Bax and inhibit apoptosis in DPCs by suppressing Bax expression in response to DHT-induced damage. Furthermore, circ_0135062 acted as a sponge for miR-506-3p, thereby inhibiting the targeting of Bax expression by miR-506-3p. In conclusion, BTXA exhibited an antiapoptotic effect on DHT-induced DPC injury via the circ_0135062/miR-506-3p/Bax axis.Level of Evidence II This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Exosomal microRNA-Based therapies for skin diseases

Based on engineered cell/exosome technology and various skin-related animal models, exosomal microRNA (miRNA)-based therapies derived from natural exosomes have shown good therapeutic effects on nine skin diseases, including full-thickness skin defects, diabetic ulcers, skin burns, hypertrophic scars, psoriasis, systemic sclerosis, atopic dermatitis, skin aging, and hair loss. Comparative experimental research showed that the therapeutic effect of miRNA-overexpressing exosomes was better than that of their natural exosomes. Using a dual-luciferase reporter assay, the targets of all therapeutic miRNAs in skin cells have been screened and confirmed. For these nine types of skin diseases, a total of 11 animal models and 21 exosomal miRNA-based therapies have been developed. This review provides a detailed description of the animal models, miRNA therapies, disease evaluation indicators, and treatment results of exosomal miRNA therapies, with the aim of providing a reference and guidance for future clinical trials. There is currently no literature on the merits or drawbacks of miRNA therapies compared with standard treatments.

Serum lipidomic changes and sex differences in androgenetic alopecia

Background

Androgenetic alopecia (AGA) is the most common form of hair loss. Studies have suggested a potential link to metabolic disorders, but with conflicting results. To elucidate the lipidomics profile and sex-specific variations in AGA, while exploring correlation between AGA and metabolic syndrome (MetS).

Methods

The AGA patients (n = 83) and healthy controls (n = 84) were collected in the study. The lipid profiles were analyzed using ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Serum levels of important factors associated with AGA, namely dihydrotestosterone (DHT), prostaglandin D2 (PGD2) and transforming growth factor-β1 (TGF-β1) were quantified using ELISA.

Results

Compared with controls, AGA patients had a higher probability of MetS (26.51% vs 11.9%, P < 0.05). Fifty-one differentially expressed lipids were identified in AGA. The kind of triglyceride (TG) were significantly increased, while phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylinositol (PI), and phosphatidylserine (PS) exhibited remarkable decrease. PC (16:2/21:6), PC (34:4p), PE (41:7), PE (44:12), PG (40:9), PI (32:2) and TG (15:0/18:1/18:1) were identified as potential biomarkers of AGA with the highest specificity. The levels of DHT, PGD2 and TGF-β1 were significantly elevated in AGA. All seven lipids showed significant correlations with DHT, PC (34:4p) and TG (15:0/18:1/18:1) were significantly associated with PGD2, TGF-β1 displayed exclusively correlation with TG (15:0/18:1/18:1) (all P < 0.05). Furthermore, these lipids were also significantly linked to systolic blood pressure and BMI, while some of them also showed significant associations with total cholesterol and HDL-C. In subgroups, forty-two differentially expressed lipids were identified in male AGA vs male control and eighty-one in female AGA vs female control. PC (16:2/21:6) was the only specific lipids common to both sexes.

Conclusions

Aberrant lipid metabolism was observed in AGA, with distinct lipidomic profiles between male and female AGA. The potential biomarkers were closely related to DHT, PGD2, TGF-β1 and MetS-related indicators. It provides the foundation for revealing the mechanisms of AGA.

IGFBP-rP1 is a potential therapeutic target in androgenic alopecia

The available interventions for androgenic alopecia (AGA), the most common type of hair loss worldwide, remain limited. The insulin growth factor (IGF) system may play an important role in the pathogenesis of AGA. However, the exact role of IGF binding protein-related protein 1 (IGFBP-rP1) in hair growth and AGA has not been reported. In this study, we first found periodic variation in IGFBP-rP1 during the hair cycle transition in murine hair follicles (HFs). We further demonstrated that IGFBP-rP1 levels were lower in the serum and scalp HFs of individuals with AGA than in those of healthy controls. Subsequently, we verified that IGFBP-rP1 had no cytotoxicity to human outer root sheath cells (HORSCs) and that IGFBP-rP1 reversed the inhibitory effects of DHT on the migration of HORSCs in vitro. Finally, a DHT-induced AGA mouse model was created. The results revealed that the expression of IGFBP-rP1 in murine HFs was downregulated after DHT treatment and that subcutaneous injection of IGFBP-rP1 delayed catagen occurrence and prolonged the anagen phase of HFs in mice with DHT-induced AGA. The present work shows that IGFBP-rP1 is involved in hair cycle transition and exhibits great therapeutic potential for AGA.

CXCL12 Neutralizing Antibody Promotes Hair Growth in Androgenic Alopecia and Alopecia Areata

We had previously investigated the expression and functional role of C-X-C Motif Chemokine Ligand 12 (CXCL12) during the hair cycle progression. CXCL12 was highly expressed in stromal cells such as dermal fibroblasts (DFs) and inhibition of CXCL12 increased hair growth. Therefore, we further investigated whether a CXCL12 neutralizing antibody (αCXCL12) is effective for androgenic alopecia (AGA) and alopecia areata (AA) and studied the underlying molecular mechanism for treating these diseases. In the AGA model, CXCL12 is highly expressed in DFs. Subcutaneous (s.c.) injection of αCXCL12 significantly induced hair growth in AGA mice, and treatment with αCXCL12 attenuated the androgen-induced hair damage in hair organ culture. Androgens increased the secretion of CXCL12 from DFs through the androgen receptor (AR). Secreted CXCL12 from DFs increased the expression of the AR and C-X-C Motif Chemokine Receptor 4 (CXCR4) in dermal papilla cells (DPCs), which induced hair loss in AGA. Likewise, CXCL12 expression is increased in AA mice, while s.c. injection of αCXCL12 significantly inhibited hair loss in AA mice and reduced the number of CD8+, MHC-I+, and MHC-II+ cells in the skin. In addition, injection of αCXCL12 also prevented the onset of AA and reduced the number of CD8+ cells. Interferon-γ (IFNγ) treatment increased the secretion of CXCL12 from DFs through the signal transducer and activator of transcription 3 (STAT3) pathway, and αCXCL12 treatment protected the hair follicle from IFNγ in hair organ culture. Collectively, these results indicate that CXCL12 is involved in the progression of AGA and AA and antibody therapy for CXCL12 is promising for hair loss treatment.

Cyanidin-3-O-glucoside and its derivative vitisin A alleviate androgenetic alopecia by exerting anti-androgen effect and inhibiting dermal papilla cell apoptosis

Androgenetic alopecia (AGA), one of the most common forms of hair loss, lacks satisfactory treatment methods in modern society. This study employed an experimental design combining in vitro and in vivo approaches to explore the effects of Cyanidin-3-O-glucoside (C3G) and Carboxypyranocyanidin-3-O-glucoside (Vitisin A) on AGA. In human dermal papilla cells (HDPCs), both anthocyanins demonstrated inhibitory effects on androgen receptors, significantly reduced dihydrotestosterone (DHT) induced apoptosis of HDPCs, and regulated the secretion of Fibroblast growth factor 7 and Transforming growth factor beta 1. In vitro transdermal experiment revealed that both C3G and Vitisin A could penetrate mice skin, aided by the application of cream. Furthermore, in vivo experiments with mice indicated that application of C3G or Vitisin A cream effectively improved hair follicles miniaturization, regression, and apoptosis caused by DHT. The repression of Wnt10b and β-catenin expression induced by DHT was prevented by C3G and Vitisin A in both cell and mouse model. Consequently, these findings suggest that C3G and Vitisin A could be considered as alternative methods for alleviating AGA.

Active pharmaceutical ingredient-ionic liquids assisted follicular co-delivery of ferulic acid and finasteride for enhancing targeted anti-alopecia

Androgenetic alopecia (AGA) is the primary hair loss with impairing patients' quality of life. Finasteride (FIN) is an SRD5A2 inhibitor for AGA treatment, but oral FIN causes systemic adverse effects. Topical FIN delivery is anticipated to overcome this problem. Ferulic acid (FA) is a natural phenolic acid with vascular remodeling and anti-inflammatory effects. Herein, an active pharmaceutical ingredient ionic liquid (API IL) based on choline and FA (CF-IL) is for the first time constructed to load FIN for fabricating FIN CF-IL. CF-IL aims to act as carriers and cargos and enhance hair follicle (HF) co-delivery of FA and FIN for synergistic anti-alopecia. Thermal and spectroscopic analysis combined with quantum chemistry calculations and molecular dynamics confirm the formation of CF-IL. The CF-IL simultaneously increases the solubility of FA (∼648-fold) and FIN (∼686-fold), enhances the permeation and retention of FIN and FA through the follicular pathway, and promotes cellular uptake. FIN CFIL regulates the abnormal mRNA expressions in dihydrotestosterone-irritated hDPCs, and promotes hair regrowth in AGA mice in a combined manner with FIN and FA. These findings suggest that FA-based API IL is a promising approach for percutaneously co-delivering FA and FIN to HF, providing an enhanced targeting treatment for AGA.

The In Vivo and In Vitro Effects of Terminalia bellirica (Gaertn.) Roxb. Fruit Extract on Testosterone-Induced Hair Loss

Due to the continuous increase in patients with androgenetic alopecia (AGA) and psychological disorders such as depression and anxiety, the demand for hair loss treatment and effective hair growth materials has increased. Terminalia bellirica (Gaertn.) Roxb. (TBE) reportedly exerts anti-inflammatory, hepatoprotective, and antidiabetic effects, among others, but its effects on testosterone (TS)-inhibited hair growth remains unclear. In this study, we evaluated the effects of TBE on TS-induced hair growth regression in human follicle dermal papilla cells (HFDPCs) and C57BL/6 mice. Oral administration of TBE increased TS-induced hair growth retardation. Interestingly, effects were greater when compared with finasteride, a commercial hair loss treatment product. Histological analyses revealed that oral TBE administration increased hair follicles in the dorsal skin of C57BL/6 mice. Additionally, western blotting and immunofluorescence showed that oral TBE administration recovered the TS-induced inhibition of cyclin D1, proliferating cell nuclear antigen (PCNA), and Ki67 expression in vivo. Using in vitro proliferation assays, TBE promoted HFDPC growth, which was suppressed by TS treatment. Thus, TBE may be a promising nutraceutical for hair health as it promoted hair growth in AGA-like in vitro and in vivo models.

Trichoscopic evaluation of dental pulp stem cell conditioned media for androgenic alopecia

BACKGROUND

Conditioned media (CM) derived from mesenchymal stem cells (MSC) is known to induce hair regrowth in androgenic alopecia.

OBJECTIVES

The objectives of the study were to assess the efficacy and safety of one type of MSC-CM, the CM derived from dental pulp stem cells obtained from human exfoliated deciduous teeth (SHED-CM) and to compare the efficacy of SHED-CM with and without dihydrotestosterone synthesis inhibitor (DHT-inhibitor).

METHODS

Eighty-eight male androgenic alopecia subjects with Hamilton-Norwood Classification (H-N C) I-VII were evaluated by trichoscopy to explore which trichoscopic factors statistically correlated with H-N C. After being screened, 33 subjects received six SHED-CM treatments at 1-month intervals. Clinical severity was assessed through global and trichoscopic images from baseline to 9th month.

RESULTS

SHED-CM was effective for 75% of subjects regardless of disease severity, concomitant DHT-inhibitor use, and age. Adverse effects including pain and small hemorrhages were transient and mild. We also found that clinical hair status evaluated by absolute values of three quantitative trichoscopic factors (maximum hair diameter, vellus hair rate, and multi-hair follicular unit rate) showed a good correlation with H-N C stages, and what is more-a scoring system of these three factors can be a possible predictor of SHED-CM efficacy.

CONCLUSIONS

We have shown that SHED-CM provides global and trichoscopic image improvement for androgenic alopecia, regardless of concomitant DHT-inhibitor use.

Non-invasive assessment of hair regeneration in androgenetic alopecia mice in vivo using two-photon and second harmonic generation imaging

The identification of crucial targets for hair regrowth in androgenetic alopecia (AGA) involves determining important characteristics and different stages during the process of hair follicle regeneration. Traditional methods for assessing key features and different stages of hair follicle primarily involve taking skin tissue samples and determining them through various staining or other methods. However, non-invasive assessment methods have been long sought. Therefore, in this study, endogenous fluorescence signals from skin keratin and second harmonic signals from skin collagen fibers were utilized as probes, two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) imaging techniques were employed to non-invasively assess hair shafts and collagen fibers in AGA mice in vivo. The TPEF imaging technique revealed that the alternation of new and old hair shafts and the different stages of the growth period in AGA mice were delayed. In addition, SHG imaging found testosterone reduced hair follicle area and miniaturized hair follicles. The non-invasive TPEF and SHG imaging techniques provided important methodologies for determining significant characteristics and different stages of the growth cycle in AGA mice, which will facilitate future non-invasive assessments on human scalps in vivo and reduce the use of animal testing.

Vellus-to-terminal Hair Follicle Reconversion Occurs in Male Pattern Balding and is Promoted by Minoxidil and Platelet-rich Plasma: In Vivo Evidence from a New Humanized Mouse Model of Androgenetic Alopecia

Abstract is missing (Short communication)

Fabrication of carboxymethyl cellulose/hyaluronic acid/polyvinylpyrrolidone composite pastes incorporation of minoxidil-loaded ferulic acid-derived lignin nanoparticles and valproic acid for treatment of androgenetic alopecia

Androgenetic alopecia (AGA) is a transracial and cross-gender disease worldwide with a higher prevalence among young individuals. Traditional oral or subcutaneous injections are often used to treat AGA, however, they may cause severe side-effects and therefore effective treatments for AGA are currently lacking. In this work, to treat AGA, we developed a composite paste system based on minoxidil (MXD)-loaded nanoparticles and valproic acid (VPA) with the assistance of roller-microneedles (roller-MNs). The matrix of composite paste systems is carboxymethyl cellulose (CMC), hyaluronic acid (HA) and polyvinylpyrrolidone (PVP). The roller-MNs can create microchannels in the skin to enhance drug transdermal efficiency. With the combined effects of the stimulation hair follicle (HF) regrowth by upregulating Wnt/beta-catenin of VPA and the mechanical microchannels induced by roller-MNs, the as-prepared composite paste systems successfully boost perifollicular vascularization, and activate hair follicle stem cells, thereby inducing notably faster hair regeneration at a lower administration frequency on AGA mouse model compared with minoxidil. This approach offers several benefits, including the avoidance of efficacy loss due to the liver's first-pass effect associated with oral drug, reduction in the risk of infection from subcutaneous injection, and significant decrease in the side effects of lower-dose MXD.

Whole-Genome Resequencing Reveals Selection Signal Related to Sheep Wool Fineness

Wool fineness affects the quality of wool, and some studies have identified about forty candidate genes that affect sheep wool fineness, but these genes often reveal only a certain proportion of the variation in wool thickness. We further explore additional genes associated with the fineness of sheep wool. Whole-genome resequencing of eight sheep breeds was performed to reveal selection signals associated with wool fineness, including four coarse wool and four fine/semi-fine wool sheep breeds. Multiple methods to reveal selection signals (Fst and θπ Ratio and XP-EHH) were applied for sheep wool fineness traits. In total, 269 and 319 genes were annotated in the fine wool (F vs. C) group and the coarse wool (C vs. F) group, such as LGR4, PIK3CA, and SEMA3C and NFIB, OPHN1, and THADA. In F vs. C, 269 genes were enriched in 15 significant GO Terms (p < 0.05) and 38 significant KEGG Pathways (p < 0.05), such as protein localization to plasma membrane (GO: 0072659) and Inositol phosphate metabolism (oas 00562). In C vs. F, 319 genes were enriched in 21 GO Terms (p < 0.05) and 16 KEGG Pathways (p < 0.05), such as negative regulation of focal adhesion assembly (GO: 0051895) and Axon guidance (oas 04360). Our study has uncovered genomic information pertaining to significant traits in sheep and has identified valuable candidate genes. This will pave the way for subsequent investigations into related traits.

DKK1-targeting cholesterol-modified siRNA implication in hair growth regulation

Despite advancements in medical research, androgenetic alopecia (AGA) remains a humankind problem that still needs to be overcome. To date, clinical practice lacks an ideal treatment for AGA. The Wnt/β-catenin signaling pathway is evidenced to play a key role in hair regrowth, hence, modulating this signaling pathway for AGA therapy appears to be rational. One of the major inhibitors of the canonical Wnt/β-catenin signaling pathway is dickkopf-related protein 1 (DKK1). In this report, we have selected a small interfering RNA (siRNA) targeting DKK1 in vitro via qPCR and then tested its efficacy in vivo on the depilated dorsal skin of the mice. The changes in hair growth in different groups were observed over time. Moreover, the visual observation of the hair growth and hematoxylin and eosin (HE) staining showed that DKK1-targeting siRNA reveals non-inferior results compared with the mice treated with the Food and Drug Administration (FDA)-approved, commercially available minoxidil (5%) topical solution that was used as a positive control. Both- positive control and DKK1-targeting siRNA groups demonstrated significantly superior results compared with the control group that received negative control siRNA. Consequently, siRNAs targeting DKK1 may promote hair growth regulation in the AGA population via potentially activating the Wnt/β-catenin signaling pathway.

Effect of cyclosporine A - Tempol topical gel for the treatment of alopecia and anti-inflammatory disorders

Over the years, extensive research has been carried out to develop new chemical entities for hair loss treatment. Despite these efforts, the newly developed topical and oral treatments have not proven to be curative. Hair loss can result from underlying mechanisms, such as inflammation and apoptosis around hair follicles. We have developed a nanoemulsion based on Pemulen gel for topical application, tentatively addressing both mechanisms. The novel formulation contains two well-known molecules: Cyclosporin A (CsA), an immunosuppressant calcineurin inhibitor, and Tempol, a potent antioxidant. The in vitro permeation study on human skin revealed that the CsA-Tempol gel formulation effectively delivered CsA into the skin's inner target layer, the dermis. The effects of the CsA-Tempol gel on hair regrowth were further demonstrated in the in vivo well-established androgenetic model induced in female C57BL/6 mice. The beneficial outcome was statistically confirmed by quantitative analysis of hair regrowth, weasured by color density. The results were further supported by histology analysis. Our findings revealed a topical synergy effect, resulting in lower therapeutic concentrations of both actives unlikely to cause systemic side effects. Overall, our research suggests that the CsA-Tempol gel is a highly promising platform for treating alopecia.

Cell Therapy for Androgenetic Alopecia: Elixir or Trick?

Androgenetic alopecia is the most common cause of hair loss aggravated by increased life pressure, tension, and anxiety. Although androgenetic alopecia (AGA) does not significantly effect physical health, it can have serious negative impact on the mental health and quality of life of the patient. Currently, the effect of medical treatment for AGA is not idealistic, stem cell-based regenerative medicine has shown potential for hair regrowth and follicle repair, but the long-term effect and mechanism of stem cell therapy is not quite explicit. In this review, we summarize the methods, efficacy, mechanism, and clinical progress of stem cell therapies for AGA by now, hope it will present a more comprehensive view in this topic.

Medicinal and edible plant Allium macrostemon Bunge for the treatment of testosterone-induced androgenetic alopecia in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Allium macrostemon Bunge (AMB), a widely distributed wild garlic plant, possesses a variety of health-promoting properties. Androgenetic alopecia (AGA) is a common disorder that affects quality of life.

AIM OF THE STUDY

We sought to investigate whether AMB stimulates hair regrowth in AGA mouse model, and clarify the underlying molecular mechanisms.

MATERIALS AND METHODS

The chemical constituents of AMB water extract were identified by ultra-high performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q/TOF-MS) analysis. Cell viability assay and Ki-67 immunostaining were undertaken to evaluate the impacts of AMB on human hair dermal papilla cell (HDPC) proliferation. Wound-healing assay was undertaken to assess cell migration. Flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay were performed to examine cell apoptosis. Western blotting, real-time reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and immunostaining assays were undertaken to determine the impacts of AMB on Wnt/β-catenin signaling and growth factors expression in HDPC cells. AGA mouse model was induced by testosterone treatment. The effects of AMB on hair regeneration in AGA mice were demonstrated by hair growth measuring and histological scoring. The levels of β-catenin, p-GSK-3β, and Cyclin D1 in dorsal skin were measured.

RESULTS

AMB promoted proliferation and migration, as well as the expression of growth factors in cultured HDPC cells. Meanwhile, AMB restrained apoptosis of HDPC cells by increasing the ratio of anti-apoptotic Bcl-2/pro-apoptotic Bax. Besides, AMB activated Wnt/β-catenin signaling and thereby enhancing growth factors expression as well as proliferation of HDPC cells, which was abolished by Wnt signaling inhibitor ICG-001. In addition, an increase of hair shaft elongation was observed in mice suffering from testosterone-induced AGA upon the treatment of AMB extract (1% and 3%). Consistent with the in vitro assays, AMB upregulated the Wnt/β-catenin signaling molecules in dorsal skin of AGA mice.

CONCLUSION

This study demonstrated that AMB promoted HDPC cell proliferation and stimulated hair regrowth in AGA mice. Wnt/β-catenin signaling activation, which induced production of growth factors in hair follicles and, eventually, contributed to the influence of AMB on the hair regrowth. Our findings may contribute to effective utilization of AMB in alopecia treatment.

Effects of Allium hookeri Extracts on Hair-Inductive and Anti-Oxidative Properties in Human Dermal Papilla Cells

Oxidative stress and cellular senescence in dermal papilla cells (DPCs) are major etiological factors causing hair loss. In this study, the effect of the Allium hookeri extract (AHE) on hair-inductive and anti-oxidative properties was investigated in human DPCs. As a result, it was found that a non-cytotoxic concentration of the extracts increased the viability and size of the human DPC spheroid, which was associated with the increased expression of hair-growth-related genes in cells. To determine whether or not these effects could be attributed to intracellular anti-oxidative effects, liquid chromatography-mass spectrometry alongside various biochemical analyses are conducted herein. An ingredient called alliin was identified as one of the main components. Furthermore, AHE treatment induced a significant decrease in H₂O₂-mediated cytotoxicities, cell death, and cellular senescence in human DPCs. Upon analyzing these results with a molecular mechanism approach, it was shown that AHE treatment increased β-Catenin and NRF2 translocation into the nucleus while inhibiting the translocation of NF-κB (p50) through p38 and PKA-mediated phosphorylations of GSK3β, an upstream regulator of those proteins. These results overall indicate the possibility that AHE can regulate GSK3β-mediated β-Catenin, NRF2, and NF-κB signaling to enhance hair-inductive properties and ultimately protect against oxidative stress-induced cellular damage in human DPCs.

Enhanced Skin Permeation and Controlled Release of β-Sitosterol Using Cubosomes Encrusted with Dissolving Microneedles for the Management of Alopecia

The use of synthetic medication for treating alopecia is restricted because of systemic exposure and related negative effects. Beta-sitosterol (β-ST), a natural chemical, has lately been studied for its potential to promote hair development. The cubosomes with dissolving microneedles (CUBs-MN_D) created in this study may be a useful starting point for the creation of a sophisticated dermal delivery system for β-ST. Cubosomes (CUBs) were prepared by the emulsification method, using glyceryl monooleate (GMO) as a lipid polymer. CUBs were loaded with dissolving microneedles (MN_D) fabricated with HA and a PVP-K90 matrix. An ex vivo skin permeation study and an in vivo hair growth efficacy test of β-ST were performed with both CUB and CUB-MN_D. The average particle size of the CUBs was determined to be 173.67 ± 0.52 nm, with a low polydispersity index (0.3) and a high zeta potential value that prevents the aggregate formation of dispersed particles. When compared to CUBs alone, CUBs-MN_D displayed higher permeating levels of β-ST at all-time points. In the animals from the CUB-MN_D group, significant hair development was observed. According to the results of the current investigation, CUBs that integrate dissolving microneedles of β-ST are superior in terms of transdermal skin penetration and activity for the treatment of alopecia.

Adipose Mesenchymal Stromal Cell-Derived Exosomes Carrying MiR-122-5p Antagonize the Inhibitory Effect of Dihydrotestosterone on Hair Follicles by Targeting the TGF-β1/SMAD3 Signaling Pathway

Androgenic alopecia (AGA) is the most common type of hair loss, where local high concentrations of dihydrotestosterone (DHT) in the scalp cause progressive shrinkage of the hair follicles, eventually contributing to hair loss. Due to the limitations of existing methods to treat AGA, the use of multi-origin mesenchymal stromal cell-derived exosomes has been proposed. However, the functions and mechanisms of action of exosomes secreted by adipose mesenchymal stromal cells (ADSCs-Exos) in AGA are still unclear. Using Cell Counting Kit-8 (CCK8) analysis, immunofluorescence staining, scratch assays, and Western blotting, it was found that ADSC-Exos contributed to the proliferation, migration, and differentiation of dermal papilla cells (DPCs) and up-regulated the expression of cyclin, β-catenin, versican, and BMP2. ADSC-Exos also mitigated the inhibitory effects of DHT on DPCs and down-regulated transforming growth factor-beta1 (TGF-β1) and its downstream genes. Moreover, high-throughput miRNA sequencing and bioinformatics analysis identified 225 genes that were co-expressed in ADSC-Exos; of these, miR-122-5p was highly enriched and was found by luciferase assays to target SMAD3. ADSC-Exos carrying miR-122-5p antagonized DHT inhibition of hair follicles, up-regulated the expression of β-catenin and versican in vivo and in vitro, restored hair bulb size and dermal thickness, and promoted the normal growth of hair follicles. So, ADSC-Exos enhanced the regeneration of hair follicles in AGA through the action of miR-122-5p and the inhibition of the TGF-β/SMAD3 axis. These results suggest a novel treatment option for the treatment of AGA.

CXXC5 Mediates DHT-Induced Androgenetic Alopecia via PGD2

The number of people suffering from hair loss is increasing, and hair loss occurs not only in older men but also in women and young people. Prostaglandin D₂ (PGD₂) is a well-known alopecia inducer. However, the mechanism by which PGD₂ induces alopecia is poorly understood. In this study, we characterized CXXC5, a negative regulator of the Wnt/β-catenin pathway, as a mediator for hair loss by PGD₂. The hair loss by PGD₂ was restored by Cxxc5 knock-out or treatment of protein transduction domain-Dishevelled binding motif (PTD-DBM), a peptide activating the Wnt/β-catenin pathway via interference with the Dishevelled (Dvl) binding function of CXXC5. In addition, suppression of neogenic hair growth by PGD₂ was also overcome by PTD-DBM treatment or Cxxc5 knock-out as shown by the wound-induced hair neogenesis (WIHN) model. Moreover, we found that CXXC5 also mediates DHT-induced hair loss via PGD₂. DHT-induced hair loss was alleviated by inhibition of both GSK-3β and CXXC5 functions. Overall, CXXC5 mediates the hair loss by the DHT-PGD₂ axis through suppression of Wnt/β-catenin signaling.

CircAGK regulates high dihydrotestosterone-induced apoptosis in DPCs through the miR-3180-5p/BAX axis

The incidence of androgen alopecia (AGA), also known as seborrheic alopecia, has surged in recent years, and onset is occurring at younger ages. Dermal papilla cells (DPCs) are key to maintaining hair cycling, and apoptosis-driven processes in DPCs are closely related to hair follicle regeneration. Circular RNAs (circRNAs) are widely present in the human body and are closely related to the occurrence and development of many diseases. Currently, the biological functions of circRNAs in AGA are largely unknown. Whole-transcriptome sequencing was used to screen differential circRNA expression profiles between AGA patients and non-AGA patients. We found that hsa_circ_0002980 (circAGK) was significantly highly expressed in the AGA group. CircAGK promoted DPC apoptosis in the presence of high dihydrotestosterone (DHT) (15 nmol/L). By regulating the miR-3180-5p/BAX axis, circAGK promotes DPC apoptosis in a high DHT environment in vitro and inhibits hair growth in AGA mice in vivo, indicating that circAGK is a potential target for the clinical treatment of AGA.

Integrative and Mechanistic Approach to the Hair Growth Cycle and Hair Loss

The hair cycle is composed of four primary phases: anagen, catagen, telogen, and exogen. Anagen is a highly mitotic phase characterized by the production of a hair shaft from the hair follicle, whereas catagen and telogen describe regression and the resting phase of the follicle, respectively, ultimately resulting in hair shedding. While 9% of hair follicles reside in telogen at any time, a variety of factors promote anagen to telogen transition, including inflammation, hormones, stress, nutritional deficiency, poor sleep quality, and cellular division inhibiting medication. Conversely, increased blood flow, direct stimulation of the hair follicle, and growth factors promote telogen to anagen transition and subsequent hair growth. This review seeks to comprehensively describe the hair cycle, anagen and telogen balance, factors that promote anagen to telogen transition and vice versa, and the clinical utility of a variety of lab testing and evaluations. Ultimately, a variety of factors impact the hair cycle, necessitating a holistic approach to hair loss.

PROTAC Degraders of Androgen Receptor-Integrated Dissolving Microneedles for Androgenetic Alopecia and Recrudescence Treatment via Single Topical Administration

Androgenetic alopecia (AGA) is a transracial and cross-gender disease worldwide with a youth-oriented tendency, but it lacks effective treatment. The binding of androgen receptor (AR) and androgen plays an essential role in the occurrence and progression of AGA. Herein, novel proteolysis targeting chimera degrader of AR (AR-PROTAC) is synthesized and integrated with dissolving microneedles (PROTAC-MNs) to achieve AR destruction in hair follicles for AGA treatment. The PROTAC-MNs possess adequate mechanical capabilities for precise AR-PROTAC delivery into the hair follicle-residing regions for AR degradation. After applying only once topically, the PROTAC-MNs achieve an accelerated onset of hair regeneration as compared to the daily application of the first-line topical drug minoxidil. Intriguingly, PROTAC-MNs via single administration still realize superior hair regeneration in AGA recrudescence, which is the major drawback of minoxidil in clinical practice. With the degradation of AR, the PROTAC-MNs successfully regulate the signaling cascade related to hair growth and activate hair follicle stem cells. Furthermore, the PROTAC-MNs do not cause systemic toxicity or androgen deficiency-related chaos in vivo. Collectively, these AR-degrading dissolving microneedles with long-lasting efficacy, one-step administration, and high biocompatibility provide a great therapeutic potential for AGA treatment.

Male sex hormones, aging, and inflammation

Adequate levels of androgens (eugonadism), and specifically testosterone, are vital compounds for male quality of life, longevity, and positive health outcomes. Testosterone exerts its effects by binding to the androgen receptor, which is expressed in numerous tissues throughout the body. Significant research has been conducted on the impact of this steroid hormone on skeletal, muscle and adipose tissues and on the cardiovascular, immune, and nervous systems. Testosterone levels have also been studied in relation to the impact of diseases, aging, nutrition and the environment on its circulating levels. Conversely, the impact of testosterone on health has also been evaluated with respect to its cardiac and vascular protective effects, body composition, autoimmunity and all-cause mortality. The male aging process results in decreasing testosterone levels over time. The exact mechanisms and impact of these changes in testosterone levels with age on health- and life-span are still not completely clear. Further research is needed to determine the optimal testosterone and androgen levels to protect from chronic age-related conditions such as frailty and osteoporosis.

Guava (Psidium guajava L.) Leaf Extract as Bioactive Substances for Anti-Androgen and Antioxidant Activities

Leaves of guava (Psidium guajava L.) have been used in Thai folk medicine without any supporting evidence as a traditional herbal remedy for hair loss. Androgenetic alopecia (AGA) is chronic hair loss caused by effects of androgens in those with a genetic predisposition, resulting in hair follicle miniaturization. Our objectives were to provide the mechanistic assessment of guava leaf extract on gene expressions related to the androgen pathway in well-known in vitro models, hair follicle dermal papilla cells (HFDPC), and human prostate cancer cells (DU-145), and to determine its bioactive constituents and antioxidant activities. LC-MS analysis demonstrated that the main components of the ethanolic extract of guava leaves are phenolic substances, specifically catechin, gallic acid, and quercetin, which contribute to its scavenging and metal chelating abilities. The guava leaf extract substantially downregulated SRD5A1, SRD5A2, and SRD5A3 genes in the DU-145 model, suggesting that the extract could minimize hair loss by inhibiting the synthesis of a potent androgen (dihydrotestosterone). SRD5A suppression by gallic acid and quercetin was verified. Our study reveals new perspectives on guava leaf extract's anti-androgen properties. This extract could be developed as alternative products or therapeutic adjuvants for the treatment of AGA and other androgen-related disorders.

Development and Skin Penetration Pathway Evaluation Using Confocal Laser Scanning Microscopy of Microemulsions for Dermal Delivery Enhancement of Finasteride

This study aimed to develop microemulsions using poloxamer 124 as a surfactant to improve the skin penetration of finasteride and to investigate the skin penetration pathways of these microemulsions by colocalization techniques using confocal laser scanning microscopy (CLSM). The prepared finasteride-loaded microemulsions had average particle sizes ranging from 80.09 to 136.97 nm with particle size distributions within acceptable ranges and exhibited negative surface charges. The obtained microemulsions could significantly increase the skin penetration of finasteride compared to a finasteride solution. According to the skin penetration pathway evaluation conducted with CLSM, the microemulsions were hair follicle-targeted formulations due to penetration via the transfollicular pathway as a major skin penetration pathway. Additionally, this study found that the microemulsions also penetrated via the intercluster pathway more than via the intercellular pathway and transcellular pathway. The intercluster pathway, intercellular pathway, and transcellular pathway were considered only minor pathways.

A combination therapy for androgenic alopecia based on quercetin and zinc/copper dual-doped mesoporous silica nanocomposite microneedle patch

A nanocomposite microneedle (ZCQ/MN) patch containing copper/zinc dual-doped mesoporous silica nanoparticles loaded with quercetin (ZCQ) was developed as a combination therapy for androgenic alopecia (AGA). The degradable microneedle gradually dissolves after penetration into the skin and releases the ZCQ nanoparticles. ZCQ nanoparticles release quercetin (Qu), copper (Cu²⁺) and zinc ions (Zn²⁺) subcutaneously to synergistically promote hair follicle regeneration. The mechanism of promoting hair follicle regeneration mainly includes the regulation of the main pathophysiological phenomena of AGA such as inhibition of dihydrotestosterone, inhibition of inflammation, promotion of angiogenesis and activation of hair follicle stem cells by the combination of Cu²⁺ and Zn²⁺ ions and Qu. This study demonstrates that the systematic intervention targeting different pathophysiological links of AGA by the combination of organic drug and bioactive metal ions is an effective treatment strategy for hair loss, which provides a theoretical basis for development of biomaterial based anti-hair loss therapy.

Scalable and high-throughput production of an injectable platelet-rich plasma (PRP)/cell-laden microcarrier/hydrogel composite system for hair follicle tissue engineering

BACKGROUND

Tissue engineering of hair follicles (HFs) has enormous potential for hair loss treatment. However, certain challenges remain, including weakening of the dermal papilla cell (DPC) viability, proliferation, and HF inducibility, as well as the associated inefficient and tedious preparation process required to generate extracellular matrix (ECM)-mimicking substrates for biomolecules or cells. Herein, we utilized gelatin methacryloyl (GelMA) and chitosan hydrogels to prepare scalable, monodispersed, and diameter-controllable interpenetrating network GelMA/chitosan-microcarriers (IGMs) loaded with platelet-rich plasma (PRP) and seeded with DPCs, on a high-throughput microfluidic chip.

RESULTS

The ECM-mimicking hydrogels used for IGMs exhibited surface nano-topography and high porosity. Mass production of IGMs with distinct and precise diameters was achieved by adjusting the oil and aqueous phase flow rate ratio. Moreover, IGMs exhibited appropriate swelling and sustained growth factor release to facilitate a relatively long hair growth phase. DPCs seeded on PRP-loaded IGMs exhibited good viability (> 90%), adhesion, spreading, and proliferative properties (1.2-fold greater than control group). Importantly, PRP-loaded IGMs presented a higher hair inducibility of DPCs in vitro compared to the control and IGMs group (p < 0.05). Furthermore, DPC/PRP-laden IGMs were effectively mixed with epidermal cell (EPC)-laden GelMA to form a PRP-loaded DPC/EPC co-cultured hydrogel system (DECHS), which was subcutaneously injected into the hypodermis of nude mice. The PRP-loaded DECHS generated significantly more HFs (~ 35 per site) and novel vessels (~ 12 per site) than the other groups (p < 0.05 for each).

CONCLUSION

Taken together, these results illustrate that, based on high-throughput microfluidics, we obtained scalable and controllable production of ECM-mimicking IGMs and DECHS, which simulate an effective micro- and macro-environment to promote DPC bioactivity and hair regeneration, thus representing a potential new strategy for HF tissue engineering.

Bioengineered polyester nanoparticles for the synergistic treatment of androgenic alopecia via the suppression of 5α-reductase and knockdown of androgen receptor

Androgenic alopecia (AGA) is a common disease that negatively affects patients’ physical and mental health. AGA can be treated with drugs that improve the perifollicular microenvironment, such as 5α-reductase inhibitors (e.g., dutasteride [DUT]), androgen receptor blockers, and minoxidil. However, the efficacy of these treatments is limited. Therefore, this study aimed to show that nanoparticles are effective as stable carriers with high curative benefits and little adverse effects. The in vitro study showed that PLGA-DUT/siAR@DPCM NPs could deliver both DUT and siAR to dermal papilla cells. They could successfully suppress 5α-reductase and knock down androgen receptor, respectively, and thereby promote cell proliferation. In the in vivo study, PLGA-DUT/siAR@DPCM NPs showed a significant therapeutic effect in an AGA mouse model. They successfully penetrated the stratum corneum and showed a clear targeting effect on hair follicles and surrounding tissues. PLGA-DUT/siAR@DPCM NPs could enable the targeted delivery of DUT and siAR through percutaneous penetration, enhancing phagocytosis and decreasing adverse effects. Thus, they have great potential in the clinical treatment of AGA.

Gender-Difference in Hair Length as Revealed by Crispr-Based Production of Long-Haired Mice with Dysfunctional FGF5 Mutations

Fibroblast growth factor 5 (FGF5) is an important molecule required for the transition from anagen to catagen phase of the mammalian hair cycle. We previously reported that Syrian hamsters harboring a 1-bp deletion in the Fgf5 gene exhibit excessive hair growth in males. Herein, we generated Fgf5 mutant mice using genome editing via oviductal nucleic acid delivery (GONAD)/improved GONAD (i-GONAD), an in vivo genome editing system used to target early embryos present in the oviductal lumen, to study gender differences in hair length in mutant mice. The two lines (Fgf5go-malc), one with a 2-bp deletion (c.552_553del) and the other with a 1-bp insertion (c.552_553insA) in exon 3 of Fgf5, were successfully established. Each mutation was predicted to disrupt a part of the FGF domain through frameshift mutation (p.Glu184ValfsX128 or p.Glu184ArgfsX128). Fgf5go-malc1 mice had heterogeneously distributed longer hairs than wild-type mice (C57BL/6J). Notably, this change was more evident in males than in females (p < 0.0001). Immunohistochemical analysis revealed the presence of FGF5 protein in the dermal papilla and outer root sheath of the hair follicles from C57BL/6J and Fgf5go-malc1 mice. Histological analysis revealed that the prolonged anagen phase might be the cause of accelerated hair growth in Fgf5go-malc1 mice.

The Emergent Power of Human Cellular vs Mouse Models in Translational Hair Research

Different animal models have been used for hair research and regeneration studies based on the similarities between animal and human skins. Primary knowledge on hair follicle (HF) biology has arisen from research using mouse models baring spontaneous or genetically engineered mutations. These studies have been crucial for the discovery of genes underlying human hair cycle control and hair loss disorders. Yet, researchers have become increasingly aware that there are distinct architectural and cellular features between the mouse and human HFs, which might limit the translation of findings in the mouse models. Thus, it is enticing to reason that the spotlight on mouse models and the unwillingness to adapt to the human archetype have been hampering the emergence of the long-awaited human hair loss cure. Here, we provide an overview of the major limitations of the mainstream mouse models for human hair loss research, and we underpin a future course of action using human cell bioengineered models and the emergent artificial intelligence.

Glycyrrhizin micellar nanocarriers for topical delivery of baicalin to the hair follicles: A targeted approach tailored for alopecia treatment

Alopecia affected approximately 16.6% of all people in China, however, treatment options remain limited due to the side effects. Plant bioactive compound baicalin (BC) possesses hair growth-promotion activity, but poor water solubility and unsuitable log P value restrict its topical application, and natural Glycyrrhizin (GL) can exactly overcome these drawbacks. Here, BC was encapsulated in GL to form GL-BC micelles for alopecia treatment. Simultaneously, tween 80 (TW) as carriers was incorporated in the GL-BC to form GL-TW-BC micelles. The topical penetration, penetration pathways, cellular uptake and the underlying mechanisms behind the hair loss reconstruction of the GL micelles were investigated. We found the optimal GL-BC and GL-TW-BC formulations significantly improved the penetration and accumulation of BC in the porcine skin predominantly through the hair follicles pathways without causing skin irritation, which resulted in a targeted treatment. The proliferation of human dermal papilla cells (hDPCs) and effective cellular uptake was also enhanced. Moreover, the activation of the Wnt/β-catenin pathway, up-expression of vascular endothelial growth factor (VEGF), α-melanocyte-stimulating hormone (α-MSH) and interleukin-10 (IL-10) were the mechanisms of micelles for the hair recovery. Interestingly, GL and BC exhibited a synergistic treatment of alopecia. Collectively, GL-BC and GL-TW-BC can be used as promising approaches for the treatment of alopecia.

Evaluation of the efficacy and toxicity of oral and topical pumpkin oil on the hair growth of mice

This study aimed to evaluate the efficacy and safety of a topical and oral administration of pumpkin seed oil (PSO) on the hair growth of BALB/c male mice. The animals had their dorsal area shaved (2 ×2 cm) and they were divided into 6 experimental groups. They received orally saline (OS), finasteride (F), or PSO (OP) for 14 days; or topically saline (TS), minoxidil (M), or PSO (TP) for 7 days. The euthanasia of all of the mice occurred on the 22nd day, and the histological slides from the skin area were analyzed. Lipoperoxidation in the liver was assessed through the TBARS method and was also evaluated by the antioxidant enzymes (SOD and CAT). The comet assay and the micronucleus tests were performed for genotoxic/mutagenic safety analyses. A significant increase in the number of hair follicles in the TP group was seen (8.8 ± 0.8) but it was disorganized, with loose dermal collagen. Finasteride presented a significant increase in the levels of the TBARS, SOD, and CAT in the liver, and M increased the DNA damage in the blood and the liver tissues. PSO did not induce any significant changes. In addition, PSO did not induce genotoxic or mutagenic effects. In conclusion, the oral PSO for 14 days acted in the proliferation of the hair follicles, without toxicity signals in the liver. DATA AVAILABILITY: The authors confirm that all of the relevant data is included in the article and/or in the supplementary information file.

Isolation and HPLC Quantitative Determination of 5α-Reductase Inhibitors from Tectona grandis L.f. Leaf Extract

Steroid 5α-reductase plays a crucial role in catalyzing the conversion of testosterone to dihydrotestosterone, which is involved in many androgen-dependent disorders. Leaf-hexane extract from Tectona grandis L.f. has shown promise as a 5α-reductase inhibitor. The objectives of this current study were to isolate and identify 5α-reductase inhibitors from T. grandis leaves and to use them as the bioactive markers for standardization of the extract. Three terpenoid compounds, (+)-eperua-8,13-dien-15-oic acid (1), (+)-eperua-7,13-dien-15-oic acid (2), and lupeol (3), were isolated and evaluated for 5α-reductase inhibitory activity. Compounds 1 and 2 exhibited potent 5α-reductase inhibitory activity, while 3 showed weak inhibitory activity. An HPLC method for the quantitative determination of the two potent inhibitors (1 and 2), applicable for quality control of T. grandis leaf extracts, was also developed. The ethanolic extract showed a significantly higher content of 1 and 2 than found in the hexane extract, suggesting that ethanol is a preferable extraction solvent. This study is the first reported isolation of 5α-reductase inhibitors (1 and 2) from T. grandis leaves. The extraction and quality control methods that are safe and useful for further development of T. grandis leaf extract as an active ingredient for hair loss treatment products are also reported.

Preparation of topical bimatoprost with enhanced skin infiltration and in vivo hair regrowth efficacy in androgenic alopecia

To prepare a topical formulation of bimatoprost (BIM) with high skin permeability, we designed a solvent mixture system composed of ethanol, diethylene glycol monoethyl ether, cyclomethicone, and butylated hydroxyanisole, serving as a volatile solvent, nonvolatile co-solvent, spreading agent, and antioxidant, respectively. The ideal topical BIM formulation (BIM–TF#5) exhibited 4.60-fold higher human skin flux and a 529% increase in dermal drug deposition compared to BIM in ethanol. In addition, compared to the other formulations, BIM–TF#5 maximally activated human dermal papilla cell proliferation at a concentration of 5 μM BIM, equivalent to 10 μM minoxidil. Moreover, BIM–TF#5 (0.3% [w/w] BIM) significantly promoted hair regrowth in the androgenic alopecia mouse model and increased the area covered by hair at 10 days by 585% compared to the vehicle-treated mice, indicating that entire telogen area transitioned into the anagen phase. Furthermore, at day 14, the hair weight of mice treated with BIM–TF#5 (5% [w/w] BIM) was 8.45- and 1.30-fold greater than in the 5% (w/w) BIM in ethanol and 5% (w/v) minoxidil treated groups, respectively. In the histological examination, the number and diameter of hair follicles in the deep subcutis were significantly increased in the BIM–TF#5 (0.3 or 5% [w/w] BIM)-treated mice compared to the mice treated with vehicle or 5% (w/w) BIM in ethanol. Thus, our findings suggest that BIM–TF#5 is an effective formulation to treat scalp alopecia, as part of a novel therapeutic approach involving direct prostamide F2α receptor-mediated stimulation of dermal papilla cells within hair follicles.

Androgen receptor-mediated paracrine signaling induces regression of blood vessels in the dermal papilla in androgenetic alopecia

Androgenetic alopecia (AGA), also known as male pattern baldness, is associated with androgen and androgen receptor (AR) signaling; however, the pathogenesis of AGA remains largely unknown. Here, we demonstrate that nuclear localization of androgen receptor is elevated in the dermal papilla (DP) of balding scalp from patients with AGA. Transcriptome analysis identifies microvascular abnormalities in the DP of balding scalp compared to non-balding scalp of AGA patients. We provide further evidence that blood vessels regress in the DP of balding scalp at the early stage of hair follicle miniaturization in AGA development. Consistently, we find that microvascular vessels accumulate around the dermal papilla upon anagen initiation, and angiogenesis is required for hair regeneration in mice. Mechanistically, we show that AR-mediated paracrine signaling, mainly TGF-β signaling, from DP cells induces apoptosis of microvascular endothelial cells in the DP of balding scalp of AGA. These findings define a role of AR-mediated regression of blood vessels in DP in AGA and support the notion that early anti-AR treatment is better than late treatment.