Control of hair growth and follicle size by VEGF-mediated angiogenesis

Hydrogel forming microneedles loaded with VEGF and Ritlecitinib/polyhydroxyalkanoates nanoparticles for mini-invasive androgenetic alopecia treatment

Androgenetic alopecia (AGA), the most prevalent clinical hair loss, lacks safe and effective treatments due to downregulated angiogenic genes and insufficient vascularization in the perifollicular microenvironment of the bald scalp in AGA patients. In this study, a hyaluronic acid (HA) based hydrogel-formed microneedle (MN) was designed, referred to as V-R-MNs, which was simultaneously loaded with vascular endothelial growth factor (VEGF) and the novel hair loss drug Ritlecitinib, the latter is encapsulated in slowly biodegradable polyhydroxyalkanoates (PHAs) nanoparticles (R-PHA NPs) for minimally invasive AGA treatment. The integration of HA based hydrogel alongside PHA nanoparticles significantly bolstered the mechanical characteristics of microneedles and enhanced skin penetration efficiency. Due to the biosafety, mechanical strength, and controlled degradation properties of HA hydrogel formed microneedles, V-R-MNs can effectively penetrate the skin's stratum corneum, facilitating the direct delivery of VEGF and Ritlecitinib in a minimally invasive, painless and long-term sustained release manner. V-R-MNs not only promoted angiogenesis and improve the immune microenvironment around the hair follicle to promote the proliferation and development of hair follicle cells, but also the application of MNs to the skin to produce certain mechanical stimulation could also promote angiogenesis. In comparison to the clinical drug minoxidil for AGA treatment, the hair regeneration effect of V-R-MN in AGA model mice is characterized by a rapid onset of the anagen phase, improved hair quality, and greater coverage. This introduces a new, clinically safer, and more efficient strategy for AGA treatment, and serving as a reference for the treatment of other related diseases.

Protective Action of Curcumin and Alpha-lipoic Acid, Against Experimental Ultraviolet-A/B Induced Dermal-injury in Rats

The objective of this study was to examine the therapeutic efficacy of curcumin (CUR) and α-lipoic acid (ALA) in mitigating UV-A and UV-B-induced damage (UVAB) in rat dorsal skin. This was achieved through the utilisation of immunohistochemical (TUNEL), biochemical and stereological techniques. The rats in the UVAB, UVAB + CUR, and UVAB + ALA groups were subjected to UVAB irradiation for a period of two hours per day over the course of one month. The UVAB + CUR and UVAB + ALA groups were administered 100 mg/kg/day of curcumin and 100 mg/kg/day of α-lipoic acid via gavage 30 min prior to UVAB irradiation. The CUR group was administered 100 mg/kg/day of curcumin via gavage, while the ALA group received the same dose of α-lipoic acid. A significant change in the volume ratio of the dorsal skin epidermis and dermis was observed in the stereological findings of the rats in the UVAB group. These changes exhibited a favourable progression as a consequence of the CUR and ALA applications. In the UVAB group, TOS and OSI were significantly elevated as a consequence of the rise in oxidative stress. Conversely, the treatment groups demonstrated a notable reduction in TOS and OSI levels. The study also revealed a substantial increase in the number of apoptotic cells within the UVAB group. However, the treatment groups exhibited a significant decline in apoptotic cells. In conclusion, the findings suggest that CUR and ALA possess a protective effect against UVAB-induced skin damage.

Progress of clinical research on fractional laser treatment of androgenetic alopecia: A review article

BACKGROUND

Androgenetic alopecia (AGA) is a prevalent form of hair loss that affects both men and women, severely impacting patients' quality of life. Traditional treatments include oral medications, topical medications, and hair transplantation, but these methods have certain side effects and limitations. How to safely effectively and maximally promote hair growth has been a key issue in the treatment of AGA. In recent years, fractionated laser therapy, as a noninvasive method, has gradually gained attention due to its minimally invasive and highly effective nature.

AIMS

In this paper, we summarized the studies related to fractional laser treatment of AGA in the past 15 years, and discussed its therapeutic mechanism, clinical effect, future development direction, and advantages and disadvantages compared with traditional treatment methods in the treatment of AGA.

METHODS

An extensive literature search was conducted using PubMed, Google, Google Scholar, Embase, and Scopus. All available articles studying fractional laser treatment of AGA were compiled in March 2024. Titles and abstracts were then screened for relevance and thoroughly examined for patient clinical outcomes. Prospective clinical trials, retrospective chart reviews, case series, and individual case reports were included in the literature review.

CONCLUSIONS

Fractional laser treatment of AGA showed remarkable efficacy and high safety. Compared with traditional treatments, fractional laser has the advantages of minimally invasive, quick recovery, fewer side effects, and a wide range of population applicability, providing an effective treatment option for AGA patients. Further large-scale clinical studies will help optimize the laser parameters and treatment settings to improve the therapeutic effect.

Is autologous platelet-rich plasma capable of increasing hair density in patients with androgenic alopecia? A systematic review and meta-analysis of randomized clinical trials⋆

FUNDAMENTALS

Platelet-rich plasma (PRP) has been progressively more used in androgenetic alopecia (AGA).

OBJECTIVES

The authors aimed to evaluate PRP efficacy compared to placebo in AGA.

METHODS

A comprehensive search was conducted across seven databases, until 01/04/2023. Randomized clinical trials focusing on AGA and PRP use to increase hair density were included. Patients aged between 15 and 63 years, diagnosed with AGA characterized by Norwood I‒VII and Ludwig I‒III scales, were included. Studies with a sample size <10, lacking PRP processing method, focusing on complementary therapies or other alopecias, were excluded. The authors conducted subgroup analysis for activator, spin method, study design, risk of bias, and gender. Meta-regression was conducted for activator, spin method, design, and gender. The authors used GRADEpro to assess evidence certainty and the RoB-2 tool for risk of bias. Asymmetry was measured through a Funnel plot followed by Egger's test. The protocol was registered at PROSPERO (CRD42023407334).

RESULTS

The authors screened 555 registers and included fourteen studies involving 431 patients for qualitative synthesis, with 13 studies included in the meta-analysis. Meta-analysis demonstrated a mean difference of 27.55 hairs/cm2 and 95% CI (14.04; 41.06), I2 = 95.99%, p < 0.05. Hair diameter meta-analysis presented a mean difference of 2.02 μm, 95% CI (-0.85 μm; 4.88 μm), and I2 = 77.11% (p = 0.02). That is, low quality evidence.

LIMITATIONS OF THE STUDY

Studies were highly heterogeneous, of low quality, and presented evident publication bias.

CONCLUSIONS

Highly heterogeneous studies with publication bias suggest PRP effectively increases hair density in AGA, so further high-quality randomized clinical trials are recommended to strengthen the evidence.

Combining multiomics to analyze the molecular mechanism of hair follicle cycle change in cashmere goats from Inner Mongolia

Sheep body size can directly reflect the growth rates and fattening rates of sheep and is also an important index for measuring the growth performance of meat sheep.Inner Mongolia Cashmere Goat is a local excellent breed of cashmere and meat dual-purpose, which is a typical heterogeneous indumentum. The hair follicles cycle through periods of vigorous growth (anagen), a regression caused by apoptosis (catagen), and relative rest (telogen). At present, it is not clear which genes affect the cycle transformation of hair follicles and unclear how proteins impact the creation and expansion of hair follicles.we using multi-omics joint analysis methodologies to investigated the possible pathways of transformation and apoptosis in goat hair follicles. The results showed that 917,1,187, and 716 proteins were specifically expressed in anagen, catagen andtelogen. The result of gene ontology (GO) annotation showed that differentially expressed proteins (DEPs) are in different growth cycle periods, and enriched GO items are mostly related to the transformation of cells and proteins. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment result indicated that the apoptosis process has a great impact on hair follicle's growth cycle. The results of the protein interaction network of differential proteins showed that the ribosomal protein family (RPL4, RPL8, RPS16, RPS18, RPS2, RPS27A, RPS3) was the core protein in the network. The results of combined transcriptome and proteomics analysis showed that there were 16,34, and 26 overlapped DEGs and DEPs in the comparison of anagen VS catagen, catagen VS telogen and anagen VS telogen, of which API5 plays an important role in regulating protein and gene expression levels. We focused on API5 and Ribosomal protein and found that API5 affected the apoptosis process of hair follicles, and ribosomal protein was highly expressed in the resting stage of hair follicles. They are both useful as molecular marker candidate genes to study hair follicle growth and apoptosis,and they both have an essential function in the cycle transition process of hair follicles. The results of this study may provide a theoretical basis for further research on the growth and development of hair follicles in Inner Mongolian Cashmere goats.

Identification of an osteopontin-derived peptide that binds neuropilin-1 and activates vascular repair responses and angiogenesis

The osteopontin-derived peptide FOL-005 stimulates hair growth. Using ligand-receptor glyco-capture technology we identified neuropilin-1 (NRP-1), a known co-receptor for vascular endothelial growth factor (VEGF) receptors, as the most probable receptor for FOL-005 and the more stable analogue FOL-026. X-ray diffraction and microscale thermophoresis analysis revealed that FOL-026 shares binding site with VEGF in the NRP-1 b1-subdomain. Stimulation of human umbilical vein endothelial cells with FOL-026 resulted in phosphorylation of VEGFR-2, ERK1/2 and AKT, increased cell growth and migration, stimulation of endothelial tube formation and inhibition of apoptosis in vitro. FOL-026 also promoted angiogenesis in vivo as assessed by subcutaneous Matrigel plug and hind limb ischemia models. NRP-1 knock-down or treatment of NRP-1 antagonist EG00229 blocked the stimulatory effects of FOL-026 on endothelial cells. Exposure of human coronary artery smooth muscle cells to FOL-026 stimulated cell growth, migration, inhibited apoptosis, and induced VEGF gene expression and VEGFR-2/AKT phosphorylation by an NRP-1-dependent mechanism. RNA sequencing showed that FOL-026 activated pathways involved in tissue repair. These findings identify NRP-1 as the receptor for FOL-026 and show that its biological effects mimic that of growth factors binding to the VEGF receptor family. They also suggest that FOL-026 may have therapeutical potential in conditions that require vascular repair and/or enhanced angiogenesis.

AP collagen peptides (APCPs) promote hair growth by activating the GSK-3β/β-catenin pathway and improve hair condition

AP collagen peptides (APCPs) are enzymatically decomposed collagen peptides that contain tri-peptides such as glycine-proline-hydroxyproline. We found that APCPs increased the proliferation of both human dermal papilla cells (hDPCs) and human outer root sheath cells (hORSCs). APCPs also stimulated the secretion of several growth factors, including IGFBP-6, PDGF-AB, PIGF and VEGF in hDPCs. Moreover, APCPs enhanced the phosphorylation of Akt(Ser473), GSK-3β(Ser9) and β-catenin(Ser675), indicating the activation of the GSK-3β/β-catenin signalling pathway. Ex vivo culture of human hair follicles (hHFs) tissue and in vivo patch assay revealed that APCPs promoted the elongation of hHFs and the induction of new hair shafts. In a mouse model, APCPs significantly promoted the transition from telogen to anagen phase and prolonged anagen phase, resulting in increased hair growth. APCPs also improved the thickness, amino acid content (cystine and methionine) and roughness of mouse hair. Taken together, these findings demonstrate that APCPs accelerate hair growth and contribute to overall hair health. Therefore, APCPs have the potential to be utilized as a food supplement and ingredient for preventing hair loss and maintaining hair health.

Topical Minoxidil Rejuvenates Hair Follicles from Men with Androgenetic Alopecia in Vivo

Abstract is missing (Short communication)

Biotransformation of Cacumen platycladi Extract by Lactiplantibacillus plantarum CCFM1348 Promotes Hair Growth in Mice

Cacumen platycladi (CP) is a frequently used traditional Chinese medicine to treat hair loss. In this study, CP fermented by Lactiplantibacillus plantarum CCFM1348 increased the proliferation of human dermal papilla cells. In an in vivo assay, compared to nonfermented CP, postbiotics (fermented CP) and synbiotics (live bacteria with nonfermented CP) promoted hair growth in mice. The Wnt/β-catenin signaling pathway plays crucial roles in the development of hair follicles, including growth cycle restart and maintenance. Both postbiotics and synbiotics upregulated β-catenin, a major factor of the Wnt/β-catenin signaling pathway. Postbiotics and synbiotics also increased the vascular endothelial growth factor expression and decreased the BAX/Bcl2 ratio in the dorsal skin of mice. These results suggest that fermented CP by L. plantarum CCFM1348 may promote hair growth through regulating the Wnt/β-catenin signaling pathway, promoting the expression of growth factors and reducing apoptosis.

The Effects of Negative Pressure Therapy on Hair Growth of Mouse Models

Negative pressure therapy (NPT) has been shown to facilitate wound healing and promote hair growth in a porcine model. However, there is a paucity of research on the impact of negative pressure on hair growth in murine models. Despite the ability of nude mice to develop hair follicles, the hair they produce is often flawed towing to genetically induced keratin disorders, rendering them a pertinent animal model for assessing hair regeneration. Therefore, this study aims to investigate the effects of negative pressure on hair follicle growth in a nude mouse model. To achieve this, a customized external tissue expansion device was developed to apply negative pressure to the dorsum of nude mice. The mice were subjected to several treatment courses consisting of 15 and 30 min of continuous negative pressure at 10 mmHg, which were repeated 5 and 10 times every other day until sacrifice. Dorsal skin samples were subsequently extracted from the suction and nonsuction areas. The sections were stained with various antibodies to assess the expression of SOX-9, LHX-2, Keratin-15, β-catenin, CD31, and vascular endothelial growth factor-A, and a TUNEL assay was used to analyze cell apoptosis. The results showed that the number of hair follicles and angiogenesis were significantly higher in the suction area than in the nonsuction area in all groups. Moreover, mice that received NPT for 15 min for 10 times had a higher hair follicle density than the other three groups. Immunofluorescence staining for LHX-2 and Keratin 15 further validated the results of these findings. In conclusion, this study demonstrated that negative pressure effectively promotes hair follicle growth and angiogenesis in nude mice through SOX-9- and LHX-2-mediated follicular regeneration and β-catenin-mediated hair follicle morphogenesis.

Optimization of hair follicle spheroids for hair-on-a-chip

Currently, most models for hair follicle research have the limitation of not replicating some key features of the hair follicle microenvironment. To complement this, we transfected various factors for hair growth into dermal papilla cells (DPCs) by electroporation and cultured the spheroids with keratinocytes (KCs). We optimized the cell number and culture period for applying spheroids to hair-on-a-chip. Furthermore, we investigated the expression of hair growth factors in spheroids depending on the presence or absence of human umbilical vein endothelial cells (HUVECs) and transfection. In spheroids in which DPCs, KCs, and HUVECs were co-cultured for 21 days, the expression of lymphoid enhancer factor 1 (LEF1), T-cell factor 1 (TCF1), and keratin 25 (K25) in the center of the spheroid, the expression of keratin 17 (K17) on the outer surface of the spheroid, and the shape of hair extending outward from the spheroid surface were observed. From these results, it is expected that a hair-on-a-chip experiment in which short-term cultured TKH spheroids are injected into the dermis and co-cultured with KC will enable the production of full-thickness skin equivalents containing hair in vitro without transplantation into animals.

Keratin Microspheres as Promising Tool for Targeting Follicular Growth

Skin is the body barrier that constrains the infiltration of particles and exogenous aggression, in which the hair follicle plays an important role. Recent studies have shown that small particles can penetrate the skin barrier and reach the hair follicle, making them a potential avenue for delivering hair growth-related substances. Interestingly, keratin-based microspheres are widely used as drug delivery carriers in various fields. In this current study, we pursue the effect of newly synthesized 3D spherical keratin particles on inducing hair growth in C57BL/6 male mice and in human hair follicle dermal papilla cells. The microspheres were created from partially sulfonated, water-soluble keratin. The keratin microspheres swelled in water to form spherical gels, which were used for further experiments. Following topical application for a period of 20 days, we observed a regrowth of hair in the previously depleted area on the dorsal part of the mice in the keratin microsphere group. This observation was accompanied by the regulation of hair-growth-related pathways as well as changes in markers associated with epidermal cells, keratin, and collagen. Interestingly, microsphere keratin treatment enhanced the cell proliferation and the expression of hair growth markers in dermal papilla cells. Based on our data, we propose that 3D spherical keratin has the potential to specifically target hair follicle growth and can be employed as a carrier for promoting hair growth-related agents.

Intraoperative bioprinting of human adipose-derived stem cells and extra-cellular matrix induces hair follicle-like downgrowths and adipose tissue formation during full-thickness craniomaxillofacial skin reconstruction

Craniomaxillofacial (CMF) reconstruction is a challenging clinical dilemma. It often necessitates skin replacement in the form of autologous graft or flap surgery, which differ from one another based on hypodermal/dermal content. Unfortunately, both approaches are plagued by scarring, poor cosmesis, inadequate restoration of native anatomy and hair, alopecia, donor site morbidity, and potential for failure. Therefore, new reconstructive approaches are warranted, and tissue engineered skin represents an exciting alternative. In this study, we demonstrated the reconstruction of CMF full-thickness skin defects using intraoperative bioprinting (IOB), which enabled the repair of defects via direct bioprinting of multiple layers of skin on immunodeficient rats in a surgical setting. Using a newly formulated patient-sourced allogenic bioink consisting of both human adipose-derived extracellular matrix (adECM) and stem cells (ADSCs), skin loss was reconstructed by precise deposition of the hypodermal and dermal components under three different sets of animal studies. adECM, even at a very low concentration such as 2 % or less, has shown to be bioprintable via droplet-based bioprinting and exhibited de novo adipogenic capabilities both in vitro and in vivo. Our findings demonstrate that the combinatorial delivery of adECM and ADSCs facilitated the reconstruction of three full-thickness skin defects, accomplishing near-complete wound closure within two weeks. More importantly, both hypodermal adipogenesis and downgrowth of hair follicle-like structures were achieved in this two-week time frame. Our approach illustrates the translational potential of using human-derived materials and IOB technologies for full-thickness skin loss.

Dermal papilla cells cultured as spheres improve angiogenesis

Tissue-engineered skin represents a helpful strategy for the treatment of deep skin injuries. Nevertheless, these skin substitutes must promote and encourage proper vascularization for a successful graft take. Previous work showed that dermal papilla cells (DPC) favour an earlier neovascularization process of grafted skin substitute contributing to the rapid maturation of the neovascular network, reducing inflammation and favouring extracellular matrix remodelling in nude mice. Based on these results, we studied the influence of DPC and its culture conditions on the different stages of angiogenesis in in vitro models. Here, we showed that DPC cultured as spheres favour the expression of angiogenic factors such as VEGF, FGF2 and angiogenin compared to their monolayer culture. To study the effects of DPC on the different stages of angiogenesis, an in vitro model has been adapted. DPC cultured as spheres significantly enhanced HUVEC migration and tubule formation, indicating the importance of employing physiological culture systems that provide a closer representation of cell behaviour and interactions occurring in vivo. Overall, these results allow us to speculate that the use of DPC spheres in skin substitutes could promote its grafting, vascularization and vascular network maturation through the secretion of angiogenic factors. This approach has great potential to improve clinical outcomes in regenerative medicine and skin wound repair.

Human Hair Graying Revisited: Principles, Misconceptions, and Key Research Frontiers

Hair graying holds psychosocial importance and serves as an excellent model for studying human pigmentation and aging in an accessible miniorgan. Current evidence suggests that graying results from an interindividually varying mixture of cumulative oxidative and DNA damage, excessive mTORC1 activity, melanocyte senescence, and inadequate production of pigmentation-promoting factors in the hair matrix. Various regulators modulate this process, including genetic factors (DNA repair defects and IRF4 sequence variation, peripheral clock genes, P-cadherin signaling, neuromediators, HGF, KIT ligand secretion, and autophagic flux. This leads to reduced MITF- and tyrosinase-controlled melanogenesis, defective melanosome transfer to precortical matrix keratinocytes, and eventual depletion of hair follicle (HF) pigmentary unit (HFPU) melanocytes and their local progenitors. Graying becomes irreversible only when bulge melanocyte stem cells are also depleted, occurring later in this process. Distinct pigmentary microenvironments are created as the HF cycles: early anagen is the most conducive phase for melanocytic reintegration and activation, and only during anagen can the phenotype of hair graying and repigmentation manifest, whereas the HFPU disassembles during catagen. The temporary reversibility of graying is highlighted by several drugs and hormones that induce repigmentation, indicating potential target pathways. We advise caution in directly applying mouse model concepts, define major open questions, and discuss future human antigraying strategies.

Evaluation of efficacy of Silybum marianum flower extract on the mitigating hair loss in vitro and in vivo

BACKGROUND

Natural components that can exert a wide range of anti-hair loss activity with fewer side effects are in high demand. The objective of this study was to investigate the anti-hair loss potential of Silybum marianum flower extract (SMFE) in vitro and in vivo.

METHODS

The effect of SMFE on dermal papilla cells was evaluated by measuring cell proliferation and VEGF production in hair follicle dermal papilla cells (HFDPCs). In addition, to confirm the effect of SMFE on dermal papilla senescence, SA-β-gal staining and senescence associated secretory phenotype (SASP) production such as IL-6 was observed in both replicative and hydrogen peroxide (H2 O2 )-induced senescence models. In a clinical study, hair growth was determined by reconstitution analysis after shaving the hair of the clinical subject's scalp and hair area.

RESULTS

SMFE increased the proliferation and VEGF production of HFDPCs. It also suppressed cellular senescence of HFDPCs and IL-6 production in replicative senescence and oxidative stress-induced senescence models. The hair density and total hair count at 16 and 24 weeks after using hair shampoo containing SMFE were significantly increased compared with those of the placebo group.

CONCLUSION

SMFE has the potential to be used as a natural ingredient for alleviating hair loss.

Advances in the Application of Microneedles in the Treatment of Local Organ Diseases

In recent years, microneedles (MNs) have attracted a lot of attention due to their microscale sizes and high surface area (500-1000 µm in length), allowing pain-free and efficient drug delivery through the skin. In addition to the great success of MNs based transdermal drug delivery, especially for skin diseases, increasing studies have indicated the expansion of MNs to diverse nontransdermal applications, including the delivery of therapeutics for hair loss, ocular diseases, and oral mucosal. Here, the current treatment of hair loss, eye diseases, and oral disease is discussed and an overview of recent advances in the application of MNs is provided for these three noncutaneous localized organ diseases. Particular emphasis is laid on the future trend of MNs technology development and future challenges of expanding the generalizability of MNs.

Low Molecular Weight Collagen Peptide (LMWCP) Promotes Hair Growth by Activating the Wnt/GSK-3β/β-Catenin Signaling Pathway

Low molecular weight collagen peptide (LMWCP) is a collagen hydrolysate derived from fish. We investigated the effects of LMWCP on hair growth using human dermal papilla cells (hDPCs), human hair follicles (hHFs), patch assay, and telogenic C57BL/6 mice, while also examining the underlying mechanisms of its action. LMWCP promoted proliferation and mitochondrial potential, and the secretion of hair growth-related factors, such as EGF, HB-EGF, FGF-4, and FGF-6 in hDPCs. Patch assay showed that LMWCP increased the neogeneration of new HFs in a dose-dependent manner. This result correlated with an increase in the expression of dermal papilla (DP) signature genes such as, ALPL, SHH, FGF7, and BMP-2. LMWCP upregulated phosphorylation of glycogen synthase kinase-3β (GSK-3β) and β-catenin, and nuclear translocation of β-catenin, and it increased the expression of Wnt3a, LEF1, VEGF, ALP, and β-catenin. LMWCP promoted the growth of hHFs and increased the expression of β-catenin and VEGF. Oral administration of LMWCP to mice significantly stimulated hair growth. The expression of Wnt3a, β-catenin, PCNA, Cyclin D1, and VEGF was also elevated in the back skin of the mice. Furthermore, LMWCP increased the expression of cytokeratin and Keratin Type I and II. Collectively, these findings demonstrate that LMWCP has the potential to increase hair growth via activating the Wnt/β-catenin signaling pathway.

The effect of oxygen supply using perfluorocarbon-based nanoemulsions on human hair growth

Hair dermal papilla cells (hDPCs) play a crucial role in hair growth and regeneration, and their function is influenced by nutrient and oxygen supply. A microenvironment with significantly low oxygen (O2) levels, known as anoxic conditions (<0.2%) due to oxygen deficiency, hinders hDPC promotion and retards hair regrowth. Here, a nanoemulsion (NE) based on perfluorooctyl bromide (PFOB), a member of the perfluorocarbon family, is presented to provide a sustainable O2 supply and maintain physical stability in vitro. The PFOB-NE has been shown to continuously release oxygen for 36 h, increasing and maintaining the O2 concentration in the anoxic microenvironment of up to 0.8%. This sustainable O2 supply using PFOB-NE has promoted hDPC growth and also induced a complex cascade of effects. These effects encompass regulation via inhibiting lactate accumulation caused via oxygen deficiency, increasing lactate dehydrogenase activity, and promoting the expression of genes, such as the hypoxia-inducible factor 1 family and NADPH oxidase 4 under anoxic conditions. Sustained O2 supply is shown to enhance human hair organ elongation approximately four times compared to the control under anoxic conditions. In conclusion, the perfluorocarbon-based NE containing oxygen proves to be an important strategic tool for improving hair growth and alleviating hair loss.

The effect of an oral product containing Amla fruit (Phyllanthus emblica L.) on female androgenetic alopecia: A randomized controlled trial

ETHNOPHARMACOLOGICAL RELEVANCE

Amla (Phyllanthus emblica) fruit has been emphasized as a hair tonic in Traditional Persian Medicine (TPM) and recommended for hair loss orally and topically.

AIM OF THE STUDY

This study aimed to investigate the effect of an oral product containing Amla fruit on Female Androgenetic Alopecia (FAGA).

MATERIALS AND METHODS

This study was a triple-blind, randomized, controlled clinical trial. Sixty women with FAGA were randomly assigned into two groups of thirty. The intervention group received ten cc Amla syrup thrice a day for 12 weeks. The second group received a placebo with the same dose and duration. Hair growth parameters were analyzed using TrichoScan before and after 12 weeks of intervention. Physician and patient satisfaction were assessed using the CGI-I and PGI-I questionnaires, respectively.

RESULTS

Twenty-seven participants in the intervention group and 25 in the placebo group completed the trial. Based on our findings, the anagen-to-telogen ratio increased significantly in the intervention group compared with the group who received placebo (F = 10.4, P = 0.002). Physician and patient satisfaction increased in the amla group compared with placebo at 12th weeks of intervention (P<0.001), (P<0.001). The formula had no remarkable side effects. Only one case of mild constipation was reported in one of the participants after one month of consuming Amla syrup.

CONCLUSION

The results of this study demonstrated that Amla syrup could help treat androgenic hair loss in women and increase the anagen phase. Further studies are needed to evaluate this potential treatment for FAGA.

Minoxidil delivered via a stem cell membrane delivery controlled release system promotes hair growth in C57BL/6J mice

Objective: Umbilical cord-derived mesenchymal stem cell membrane-loaded minoxidil (MXD) nanoparticles (STCM-MXD-NPs) were prepared to investigate their effects on hair growth in C57BL/6J mice. Methods: STCM-MXD-NPs were obtained by freeze-thawing and differential centrifugation, and their effects on hair growth were evaluated using C57BL/6J mice. The mRNA and protein expression levels of vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF-1) were detected by real-time polymerase chain reaction and enzyme-linked immunosorbent assays, respectively. Protein expression levels of marker of proliferation Ki-67 (MKI67) and β-catenin (CTNNB) in skin tissue were detected by immunohistochemistry. Results: STCM-MXD-NPs improved MXD solubility. They released the drug slowly, increasing its transdermal properties, accumulation in the skin, and content in the hair bulb tissues with a better efficacy than that of ordinary MXD. Moreover, STCM-MXD-NPs significantly upregulated the mRNA and protein levels of VEGF and IGF-1 and promoted the protein expression of MKI67 and CTNNB in mouse skin tissues, promoting mouse hair growth. Conclusion: Stem cell membrane-loaded MXD nanoparticles with slow-release properties increased MXD accumulation in the skin by improving its transdermal properties, increasing VEGF, IGF-1, MKI67, and CTNNB expression levels and promoting hair growth in C57BL/6J mice.

Chemical Constituents of Halophyte Suaeda glauca and Their Therapeutic Potential for Hair Loss

Suaeda glauca, a halophyte in the Amaranthaceae family, exhibits remarkable resilience to high salt and alkali stresses despite the absence of salt glands or vesicles in its leaves. While there is growing pharmacological interest in S. glauca, research on its secondary metabolites remains limited. In this study, chemical constituents of the aerial parts of S. glauca were identified using 1D- and 2D-NMR experiments, and its biological activity concerning hair loss was newly reported. Eight compounds, including alkaloids (1~3), flavonoids (4~6), and phenolics (7 and 8), were isolated. The compounds, except the flavonoids, were isolated for the first time from S. glauca. In the HPLC chromatogram, quercetin-3-O-β-d-glucoside, kaempferol-3-O-β-d-glucoside, and kaempferol were identified as major constituents in the extract of S. glauca. Additionally, the therapeutic potential of the extract of S. glauca and the isolated compounds 1~8 on the expressions of VEGF and IGF-1, as well as the regulation of Wnt/β-catenin signaling, were evaluated in human follicle dermal papilla cells (HFDPCs) and human umbilical vein endothelial cells (HUVECs). Among the eight compounds, compound 4 was the most potent in terms of increasing the expression of VEGF and IGF-1 and the regulation of Wnt/β-catenin. These findings suggest that S. glauca extract and its compounds are potential new candidates for preventing or treating hair loss.

Duo-role Platelet-rich Plasma: temperature-induced fibrin gel and growth factors' reservoir for microneedles to promote hair regrowth

INTRODUCTION

Alopecia concerns more than half our adult population. Platelet-rich plasma (PRP) has been applied in skin rejuvenation and hair loss treatment. However, the pain and bleeding during injection and the troublesome for fresh preparation of each action limit PRP's in-depth applying dedication to clinics.

OBJECTIVES

We report a temperature-sensitive PRP induced fibrin gel included in a detachable transdermal microneedle (MN) for hair growth.

RESULTS

PRP gel interpenetrated with the photocrosslinkable gelatin methacryloyl (GelMA) to realize sustained release of growth factors (GFs) and led to 14% growth in mechanical strength of a single microneedle whose strength reached 1.21 N which is sufficient to penetrate the stratum corneum. PRP-MNs' release of VEGF, PDGF, and TGF-β were characterized and quantitatively around the hair follicles (HFs) for 4-6 days consecutively. PRP-MNs promoted hair regrowth in mice models. From transcriptome sequencing, PRP-MNs induced hair regrowth through angiogenesis and proliferation. The mechanical and TGF-β sensitive gene Ankrd1 was significantly upregulated by PRP-MNs treatment.

CONCLUSION

PRP-MNs show convenient, minimally invasive, painless, inexpensive manufacture, storable and sustained effects in boosting hair regeneration.

Oral Administration of Lactilactobacillus curvatus LB-P9 Promotes Hair Regeneration in Mice

This study was designed to examine the effect of Lactilactobacillus curvatus LB-P9 on hair regeneration. The treatment of LB-P9 conditioned medium increased the proliferation of both hair follicle dermal papilla cells and hair germinal matrix cells (hGMCs). Moreover, the expression levels of hair growth factors such as vascular endothelial growth factor (VEGF) and fibroblast growth factor 7 were significantly elevated in hGMCs co-cultured with LB-P9. After time-synchronized depilation, mice were orally administered with either 4×107 colony forming unit (CFU) of LB-P9 (low dose) or 4×108 CFU of LB-P9 (high dose), once daily for 4 weeks. Compared with the vehicle (phosphate-buffered saline)-administrated group, the LB-P9-treated groups exhibited accelerated hair regrowth rate and enhanced hair thickness in a dose-dependent manner. Supporting this observation, both hair follicle numbers and the dermal thickness in skin tissues of the LB-P9-treated groups were increased, compared to those of the vehicle-treated group. These results might be explained by the increased level of β-catenin and number of hair follicle stem cells (CD34+CD49f+ cells) in the skin tissues of mice administered with LB-P9, compared to the vehicle-treated mice. Also, increased serum levels of hair growth factors such as VEGF and insulin-like growth factor-1, and superoxide dismutase were found in the LB-P9-treated groups, compared to those of the vehicle-treated group. Taken together, these results might demonstrate that the oral administration of LB-P9 promotes hair regeneration by the enhancement of dermal papilla proliferation through the stimulation of hair growth factor production.

An Overview of Growth Factors as the Potential Link between Psoriasis and Metabolic Syndrome

Psoriasis is a chronic, complex, and immunologically mediated systemic disease that not only affects the skin, but also the joints and nails. It may coexist with various other disorders, such as depression, psoriatic arthritis, cardiovascular diseases, diabetes mellitus, and metabolic syndrome. In particular, the potential link between psoriasis and metabolic syndrome is an issue worthy of attention. The dysregulation of growth factors could potentially contribute to the disturbances of keratinocyte proliferation, inflammation, and itch severity. However, the pathophysiology of psoriasis and its comorbidities, such as metabolic syndrome, remains incompletely elucidated. Growth factors and their abnormal metabolism may be a potential link connecting these conditions. Overall, the objective of this review is to analyze the role of growth factor disturbances in both psoriasis and metabolic syndrome.

Salmon nasal cartilage proteoglycan stimulates hair growth

Hair loss is a commonly encountered problem. In this study, hair growth was enhanced by daily oral ingestion of salmon nasal cartilage proteoglycan (PG) in mice. Proteoglycan stimulated vesicular endothelial growth factor production in human follicle dermal papilla cells through insulin growth factor-1 receptor signaling, suggesting the possibility of hair loss improvement by PG ingestion.

mRNA Levels of Aromatase, 5α-Reductase Isozymes, and Prostate Cancer-Related Genes in Plucked Hair from Young Men with Androgenic Alopecia

Androgenic alopecia (AGA) is the most prevalent type of progressive hair loss and has psychological repercussions. Nevertheless, the effectiveness of current pharmacological treatments remains limited, in part because the molecular basis of the disease has not been fully elucidated. Our group previously highlighted the important roles of aromatase and 5α-reductase (5α-R) in alopecia in young women with female pattern hair loss. Additionally, an association has been proposed between AGA and prostate cancer (PCa), suggesting that genes implicated in PCa would also be involved in AGA. A low-invasive, sensitive, and precise method was used to determine mRNA levels of aromatase, 5α-R isozymes, and 84 PCa-related genes in samples of plucked hair from young men with AGA and controls. Samples were obtained with a trichogram from the vertex scalp, and mRNA levels were quantified using real-time RT-PCR. The men with AGA had significantly higher 5α-R2 mRNA levels in comparison to controls; interestingly, some of them also showed markedly elevated mRNA levels of 5α-R1 or 5α-R3 or of both, which may explain the varied response to 5α-R inhibitor treatments. The men with AGA also showed significant changes versus controls in 6 out of the 84 genes implicated in PCa. This study contributes greater knowledge of the molecular bases of AGA, facilitating early selection of the most appropriate pharmacological therapy and opening the way to novel treatments.

Soy protein/β-chitin sponge-like scaffolds laden with human mesenchymal stromal cells from hair follicle or adipose tissue promote diabetic chronic wound healing

Chronic wounds are a worldwide problem that affect >40 million people every year. The constant inflammatory status accompanied by prolonged bacterial infections reduce patient's quality of life and life expectancy drastically. An important cell type involved in the wound healing process are mesenchymal stromal cells (MSCs) due to their long-term demonstrated immunomodulatory and pro-regenerative capacity. Thus, in this work, we leveraged and compared the therapeutic properties of MSCs derived from both adipose tissue and hair follicle, which we combined with sponge-like scaffolds (SLS) made of valorized soy protein and β-chitin. In this regard, the combination of these cells with biomaterials permitted us to obtain a multifunctional therapy that allowed high cell retention and growing rates while maintaining adequate cell-viability for several days. Furthermore, this combined therapy demonstrated to increase fibroblasts and keratinocytes migration, promote human umbilical vein endothelial cells angiogenesis and protect fibroblasts from highly proteolytic environments. Finally, this combined therapy demonstrated to be highly effective in reducing wound healing time in vivo with only one treatment change during all the experimental procedure, also promoting a more functional and native-like healed skin.

Isolation, characterization and differentiation of dermal papilla cells from Small-tail Han sheep

Dermal papilla cells (DPCs) are the key dermal component of the hair follicle that directly regulates hair follicle development, growth and regeneration. Successfully isolated and cultured DPCs from Small-tail Han sheep could provide a good model for the study of hair follicle development mechanism in vitro. DPCs were isolated using enzyme digestion and dissecting microscope from Small-tail Han sheep. Adherent cells were identified by cell characteristics, particular gene expression, differentiation capability to adipocyte and osteoblast using specific differentiation mediums. Additionally, flow cytometry was used to detect the cell cycle of DPCs. Cells originating from the dermal papilla showed the morphological appearance of mesenchymal cells (fibroblast-like cells). Purified DPCs were positive for α-SMA (α smooth muscle actin) and vimentin; in addition to their strong proliferation abilities in vitro, these DPCs can be differentiated into adipocyte and osteoblasts lineage under appropriate culture condition. DPCs were successfully isolated and subcultured from Small-tail Han sheep, which exhibited progenitor cell features and multiple differentiation potency. It provides a material for studying the molecular mechanism of hair follicle development and hair cycle, which will promote wool production in the future.

Repurposing DPP4 Inhibition to Improve Hair Follicle Activation and Regeneration

Skin injury and several diseases elicit fibrosis and induce hair follicle (HF) growth arrest and loss. The resulting alopecia and disfiguration represent a severe burden for patients, both physically and psychologically. Reduction of profibrotic factors such as dipeptidyl peptidase 4 (DPP4) might be a strategy to tackle this issue. We show DPP4 overrepresentation in settings with HF growth arrest (telogen), HF loss, and nonregenerative wound areas in mouse skin and human scalp. Topical DPP4 inhibition with Food and Drug Administration/European Medicines Agency-approved sitagliptin on preclinical models of murine HF activation/regeneration results in accelerated anagen progress, whereas treatment of wounds with sitagliptin results in reduced expression of fibrosis markers, increased induction of anagen around wounds, and HF regeneration in the wound center. These effects are associated with higher expression of Wnt target Lef1, known to be required for HF anagen/HF-activation and regeneration. Sitagliptin treatment decreases profibrotic signaling in the skin, induces a differentiation trajectory of HF cells, and activates Wnt targets related to HF activation/growth but not those supporting fibrosis. Taken together, our study shows a role for DPP4 in HF biology and shows how DPP4 inhibition, currently used as oral medication to treat diabetes, could be repurposed into a topical treatment agent to potentially reverse HF loss in alopecia and after injury.

Effect of topical naringenin and its combination with minoxidil on enhancing hair growth in a mouse model

This study aimed to investigate the efficacy of naringenin (NAR) in reducing hair loss. Twenty-four adult Wistar Albino mice, weighing between 25-35 g and aged 6-7 weeks, were used in this research. The dorsal hair of these mice was meticulously clipped and stained subsequently. The mice were randomly divided into four groups (n=6 for each group): (1) negative control group, treated with absolute ethanol alcohol as the vehicle (2) minoxidil (5%) treated group; (3) 0.5% naringenin treated group, and (4) naringenin plus minoxidil treated group. The treatment groups had significantly higher total antioxidant capacity in tissue levels and increased serum levels of vascular endothelial growth factor compared to the control group. No significant differences were observed in keratinocyte growth factor tissue levels between the treatment and control groups. However, the medication significantly increased hair growth, hair follicle diameter expansion, and hair follicle quantity compared to the control group. The finding suggests that the antioxidant and anti-inflammatory properties of NAR significantly reduced hair loss in adult male mice.

Incorporation of hair follicles in 3D bioprinted models of human skin

Current approaches fail to adequately introduce complex adnexal structures such as hair follicles within tissue engineered models of skin. Here, we report on the use of 3D bioprinting to incorporate these structures in engineered skin tissues. Spheroids, induced by printing dermal papilla cells (DPCs) and human umbilical vein cells (HUVECs), were precisely printed within a pregelled dermal layer containing fibroblasts. The resulting tissue developed hair follicle-like structures upon maturation, supported by migration of keratinocytes and melanocytes, and their morphology and composition grossly mimicked that of the native skin tissue. Reconstructed skin models with increased complexity that better mimic native adnexal structures can have a substantial impact on regenerative medicine as grafts and efficacy models to test the safety of chemical compounds.

Intraoperative Bioprinting of Human Adipose-derived Stem cells and Extra-cellular Matrix Induces Hair Follicle-Like Downgrowths and Adipose Tissue Formation during Full-thickness Craniomaxillofacial Skin Reconstruction

Craniomaxillofacial (CMF) reconstruction is a challenging clinical dilemma. It often necessitates skin replacement in the form of autologous graft or flap surgery, which differ from one another based on hypodermal/dermal content. Unfortunately, both approaches are plagued by scarring, poor cosmesis, inadequate restoration of native anatomy and hair, alopecia, donor site morbidity, and potential for failure. Therefore, new reconstructive approaches are warranted, and tissue engineered skin represents an exciting alternative. In this study, we demonstrated the reconstruction of CMF full-thickness skin defects using intraoperative bioprinting (IOB), which enabled the repair of defects via direct bioprinting of multiple layers of skin on immunodeficient rats in a surgical setting. Using a newly formulated patient-sourced allogenic bioink consisting of both human adipose-derived extracellular matrix (adECM) and stem cells (ADSCs), skin loss was reconstructed by precise deposition of the hypodermal and dermal components under three different sets of animal studies. adECM, even at a very low concentration such as 2% or less, has shown to be bioprintable via droplet-based bioprinting and exhibited de novo adipogenic capabilities both in vitro and in vivo . Our findings demonstrate that the combinatorial delivery of adECM and ADSCs facilitated the reconstruction of three full-thickness skin defects, accomplishing near-complete wound closure within two weeks. More importantly, both hypodermal adipogenesis and downgrowth of hair follicle-like structures were achieved in this two-week time frame. Our approach illustrates the translational potential of using human-derived materials and IOB technologies for full-thickness skin loss.

Feasibility of adipose-derived therapies for hair regeneration: Insights based on signaling interplay and clinical overview

Dermal white adipose tissue (dWAT) is a dynamic component of the skin and closely interacts with the hair follicle. Interestingly, dWAT envelops the hair follicle during anagen and undergoes fluctuations in volume throughout the hair cycle. dWAT-derived extracellular vesicles can significantly regulate the hair cycle, and this provides a theoretical basis for utilizing adipose tissue as a feasible clinical strategy to treat hair loss. However, the amount and depth of the available literature are far from enough to fully elucidate the prominent role of dWAT in modulating the hair growth cycle. This review starts by investigating the hair cycle-coupled dWAT remodeling and the reciprocal signaling interplay underneath. Then, it summarizes the current literature and assesses the advantages and limitations of clinical research utilizing adipose-derived therapies for hair regeneration.

The co-expression pattern of VEGFR-2 with indicators related to proliferation, apoptosis, and differentiation of anagen hair follicles

An increasing number of studies show that vascular endothelial growth factor is an important regulator of hair growth, and involves in processes of hair follicle development by vascularization. Recently, VEGF receptor-2 (VEGFR-2) has been detected in epithelial cells of hair follicles, indicating that it may have a direct role in the biological activity of hair follicles. To explore how VEGFR-2 regulates hair follicle development, we investigated the co-expression pattern of VEGFR-2 with β-catenin, Bax, Bcl-2, involucrin, AE13 (hair cortex cytokeratin), keratin 16, keratin 14, and Laminin 5 by immunofluorescence double staining in anagen hair follicles of normal human scalp skin. The results of double staining immunofluorescence showed a strong overlapping and similar expression pattern for VEGFR-2 with β-catenin and Bcl-2, and revealing associated expression pattern with involucrin, AE13, keratin 14, keratin 16, and Laminin 5. These results elucidated that VEGFR-2 activation may participate in hair follicle differentiation, proliferation, and apoptosis in vivo.

Alk1 acts in non-endothelial VE-cadherin+ perineurial cells to maintain nerve branching during hair homeostasis

Vascular endothelial (VE)-cadherin is a well-recognized endothelial cell marker. One of its interacting partners, the TGF-β receptor Alk1, is essential in endothelial cells for adult skin vasculature remodeling during hair homeostasis. Using single-cell transcriptomics, lineage tracing and gene targeting in mice, we characterize the cellular and molecular dynamics of skin VE-cadherin+ cells during hair homeostasis. We describe dynamic changes of VE-cadherin+ endothelial cells specific to blood and lymphatic vessels and uncover an atypical VE-cadherin+ cell population. The latter is not a predicted adult endovascular progenitor, but rather a non-endothelial mesenchymal perineurial cell type, which forms nerve encapsulating tubular structures that undergo remodeling during hair homeostasis. Alk1 acts in the VE-cadherin+ perineurial cells to maintain proper homeostatic nerve branching by enforcing basement membrane and extracellular matrix molecular signatures. Our work implicates the VE-cadherin/Alk1 duo, classically known as endothelial-vascular specific, in perineurial-nerve homeostasis. This has broad implications in vascular and nerve disease.

COX2-ATP Synthase Regulates Spine Follicle Size in Hedgehogs

Skin evolves essential appendages with adaptive patterns that synergistically insulate the body from environmental insults. How similar appendages in different animals generate diversely-sized appendages remain elusive. Here we used hedgehog spine follicles and mouse hair follicles as models to investigate how similar follicles form in different sizes postnatally. Histology and immunostaining show that the spine follicles have a significantly greater size than the hair follicles. By RNA-sequencing analysis, we found that ATP synthases are highly expressed in hedgehog skin compared to mouse skin. Inhibition of ATP synthase resulted in smaller spine follicle formation during regeneration. We also identified that the mitochondrial gene COX2 functions upstream of ATP synthase that influences energy metabolism and cell proliferation to control the size of the spine follicles. Our study identified molecules that function differently in forming diversely-sized skin appendages across different animals, allowing them to adapt to the living environment and benefit from self-protection.

Ischemic alopecia as a complication from therapeutic embolization of the middle meningeal artery

Selective endovascular embolization using microspheres is a widely used, relatively low-risk procedure to control intracranial bleeding. Side effects such as cranial nerve palsies and stroke have been reported in the literature. Skin necrosis and alopecia are exceedingly rare complications of endovascular embolization with a reported incidence of less than 1%. We report a case of a 55-year-old female who developed alopecia following a therapeutic embolization of the middle meningeal artery using microspheres. The clinical-histopathologic diagnosis and relevant literature are reviewed.

Dissolving microneedles for alopecia treatment

Alopecia is a treatable benign disease, however, approximately 15-30% of women and 50% of men suffer from alopecia, which greatly affects patient's self-esteem and quality of life. Currently, commercial products for alopecia treatment include topical minoxidil solution, oral finasteride tablets and oral baricitinib tablets. However, the barrier of stratum corneum, systemic adverse effects and poor cure rate limit the application of commercial products. Therefore, researchers investigated the mechanism of alopecia, and developed new drugs that could target lactate dehydrogenase-related pathways, remove excessive reactive oxygen in hair follicles, and reduce the escape of hair follicle stem cells, thus injecting new strength into the treatment of alopecia. Moreover, starting from improving drug stratum corneum penetration and reducing side effects, researchers have developed hair loss treatment strategies based on dissolved microneedles (MNs), such as drug powders/microparticles, nanoparticles, biomimetic cell membranes, phototherapy and magnetically responsive soluble microneedles, which show exciting alopecia treatment effects. However, there are still some challenges in the practical application of the current alopecia treatment strategy with soluble microneedles, and further studies are needed to accelerate its clinical translation.

3D multicellular micropatterning biomaterials for hair regeneration and vascularization

Hair loss caused by the abnormal functions of hair follicles in skin can seriously impact the quality of an individual's life. The development of sophisticated skin tissue-engineered constructs is required to enable the function recovery of hair follicles. However, effective hair regrowth in skin substitutes still remains a great challenge. In this study, a 3D multicellular micropattern was successfully fabricated by arranging the hair follicle-related cells orderly distributed in the interval of vascular-cell networks via bioprinting technology. By combining the stable biomimetic micropattern structure and the bio-inducing substrate incorporated with magnesium silicate (MS) nanomaterials, the 3D multicellular micropattern possessed significant follicular potential and angiogenic capacity in vitro. Furthermore, the 3D multicellular micropattern with MS incorporation contributed to efficient hair regrowth during skin tissue regeneration in both immunodeficient mice and androgenetic alopecia (AGA) mice models. Thus, this study proposes a novel 3D micropatterned multicellular system assembling a biomimetic micro-structure and modulating the cell-cell interaction for hair regeneration during skin reconstruction.

Cell-free fat extract restores hair loss: a novel therapeutic strategy for androgenetic alopecia

BACKGROUND

Androgenetic alopecia (AGA) is one of the most common hair loss diseases worldwide. However, current treatments including medicine, surgery, and stem cells are limited for various reasons. Cell-free fat extract (CEFFE), contains various cell factors, may have potential abilities in treating AGA. This study aims to evaluate the safety, effectiveness and the underlying mechanism of CEFFE in treating AGA.

METHODS

Sex hormone evaluation, immunogenicity assay and genotoxicity assay were conducted for CEFFE. In vivo study, male C57BL/6 mice were injected subcutaneously with dihydrotestosterone (DHT) and were treated with different concentration of CEFFE for 18 days (five groups and n = 12 in each group: Control, Model, CEFFELow, CEFFEMiddle, CEFFEHigh). Anagen entry rate and hair coverage percentage were analyzed through continuously taken gross photographs. The angiogenesis and proliferation of hair follicle cells were evaluated by hematoxylin-eosin, anti-CD31, and anti-Ki67 staining. In vitro study, dermal papilla cells (DPCs) were incubated with different concentrations of CEFFE, DHT, or CEFFE + DHT, followed by CCK-8 assay and flow cytometry to evaluate cell proliferation cycle and apoptosis. The intracellular DHT level were assessed by enzyme-linked immunosorbent assay. The expression of 5α-reductase type II, 3α-hydroxysteroid dehydrogenase and androgen receptor were assessed through reverse transcription-quantitative polymerase chain reaction (RT-qPCR) or/and western blot.

RESULTS

In CEFFE-treated mice, an increase in the anagen entry rate and hair coverage percentage was observed. The number of CD31-positive capillaries and Ki67-positive cells were increased, suggesting that CEFFE promoted the proliferation of DPCs, modulated the cell cycle arrest, inhibited apoptosis caused by DHT, reduced the intracellular concentration of DHT in DPCs, and downregulated the expression of AR.

CONCLUSIONS

CEFFE is a novel and effective treatment option for AGA through producing an increased hair follicle density and hair growth rate. The proposed mechanisms are through the DHT/AR pathway regulation and regional angiogenesis ability.

BFNB Enhances Hair Growth in C57BL/6 Mice through the Induction of EGF and FGF7 Factors and the PI3K-AKT-β-Catenin Pathway

The objective of this study was to investigate the potential effects of a formulation derived from the bioactive fraction of nanostructured Bacopa procumbens (BFNB) on the promotion of hair growth in C57BL/6 mice. The characterization of the follicular phases and histomorphological analysis showed that the topical application of the formulation for 15 days significantly increased pigmentation and hair growth on the dorsum and head of the mice. Additionally, an acceleration of the follicular cycle phases was observed, along with an increase in the number of follicles, hair length, and diameter, compared to mice treated with minoxidil. In silico analysis and molecular characterization demonstrated that BFNB enhances the expression of epidermal growth factor (EGF) and fibroblast growth factor 7 (FGF7), activating the PI3K-AKT-β-catenin signaling pathway, as well as the expression of PCNA, KI-67, Cyclin D1, and Cyclin E, regulating the cell cycle and cell proliferation, crucial events for hair regeneration. Our results strongly suggest the utility of BFNB as a therapeutic alternative to stimulate hair growth and promote hair health.

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.

Urotensin II promotes the proliferation and secretion of vascular endothelial growth factor in rat dermal papilla cells by activating the Wnt-β-catenin signaling pathway

Introduction. Urotensin II (U II) is a kind of active peptide with a variety of biological effects, such as promoting cell proliferation and endocrine effects. The aim of this study is to investigate the effect of urotensin II on the proliferation and secretion of vascular endothelial growth factor (VEGF) in cultured rat dermal papilla cells (DPCs), and to explore its molecular mechanism. Materials and Methods. We used the DPCs isolated from the thoracic aortas of Wistar-Kyoto rats to run the CCK8 and ELISA assay, RC-PCR and Western blotting techniques to identify the effect of Urotensin II on the proliferation and secretion of VEGF in DPCs, data were analyzed by one-way ANOVA or t-test. Results. U II can increase the mRNA expression of proliferation markers Ki67 and PCNA. In addition, the Wnt/β-catenin pathway was activated by U II, but Wnt inhibitor DKK1 reversed the effect of U II. Conclusions. U II promoted the proliferation and secretion of VEGF in rat DPCs through activation of the Wnt-β-catenin signaling pathway.

Single-cell profiling reveals a potent role of quercetin in promoting hair regeneration

Hair loss affects millions of people at some time in their life, and safe and efficient treatments for hair loss are a significant unmet medical need. We report that topical delivery of quercetin (Que) stimulates resting hair follicles to grow with rapid follicular keratinocyte proliferation and replenishes perifollicular microvasculature in mice. We construct dynamic single-cell transcriptome landscape over the course of hair regrowth and find that Que treatment stimulates the differentiation trajectory in the hair follicles and induces an angiogenic signature in dermal endothelial cells by activating HIF-1α in endothelial cells. Skin administration of a HIF-1α agonist partially recapitulates the pro-angiogenesis and hair-growing effects of Que. Together, these findings provide a molecular understanding for the efficacy of Que in hair regrowth, which underscores the translational potential of targeting the hair follicle niche as a strategy for regenerative medicine, and suggest a route of pharmacological intervention that may promote hair regrowth.

Blood endothelial ALK1-BMP4 signaling axis regulates adult hair follicle stem cell activation

Blood vessels can play dual roles in tissue growth by transporting gases and nutrients and by regulating tissue stem cell activity via signaling. Correlative evidence implicates skin endothelial cells (ECs) as signaling niches of hair follicle stem cells (HFSCs), but functional demonstration from gene depletion of signaling molecules in ECs is missing to date. Here, we show that depletion of the vasculature-factor Alk1 increases BMP4 secretion from ECs, which delays HFSC activation. Furthermore, while previous evidence suggests a lymphatic vessel role in adult HFSC activation possibly through tissue drainage, a blood vessel role has not yet been addressed. Genetic perturbation of the ALK1-BMP4 axis in all ECs or the lymphatic ECs specifically unveils inhibition of HFSC activation by blood vessels. Our work suggests a broader relevance of blood vessels, adding adult HFSCs to the EC functional repertoire as signaling niches for the adult stem cells.

Single-cell transcriptomics of adult skin VE-cadherin expressing lineages during hair cycle

Adult skin homeostasis involves global reorganization of dermal lineages at different stages of the mouse hair growth cycle. Vascular endothelial cadherin (VE-cadherin encoded by Cdh5 ) expressing cells from blood and lymphatic vasculature structures are known to remodel during the adult hair cycle. Here we employ single-cell RNA-sequencing (scRNA-seq) 10x-genomics analysis of FACS-sorted VE-cadherin expressing cells marked via Cdh5-CreER genetic labeling at resting (telogen) and growth (anagen) stage of hair cycle. Our comparative analysis between the two stages uncovers a persistent Ki67 ⁺ proliferative EC population and documents changes in EC population distribution and gene expression. Global gene expression changes in all the analyzed populations revealed bioenergetic metabolic changes that may drive vascular remodeling during HF growth phase, alongside a few highly restricted cluster-specific gene expression differences. This study uncovers active cellular and molecular dynamics of adult skin endothelial lineages during hair cycle that may have broad implications in adult tissue regeneration and for understanding vascular disease.

γ-Aminobutyric acid promotes the inhibition of hair growth induced by chronic restraint stress

Stress plays a critical role in hair loss, although the underlying mechanisms are largely unknown. γ-aminobutyric acid (GABA) has been reported to be associated with stress; however, whether it affects stress-induced hair growth inhibition is unclear. This study aimed to investigate the potential roles and mechanisms of action of GABA in chronic restraint stress (CRS)-induced hair growth inhibition. We performed RNA-seq analysis and found that differentially expressed genes (DEGs) associated with neuroactive ligand-receptor interaction, including genes related to GABA receptors, significantly changed after mice were treated with CRS. Targeted metabolomics analysis and enzyme-linked immunosorbent assay (ELISA) also showed that GABA levels in back skin tissues and serum significantly elevated in the CRS group. Notably, CRS-induced hair growth inhibition got aggravated by GABA and alleviated through GABA_A antagonists, such as picrotoxin and ginkgolide A. RNA sequencing analysis revealed that DEGs related to the cell cycle, DNA replication, purine metabolism, and pyrimidine metabolism pathways were significantly downregulated in dermal papilla (DP) cells after GABA treatment. Moreover, ginkgolide A, a GABA_A antagonist extracted from the leaves of Ginkgo biloba, promoted the cell cycle of DP cells. Therefore, the present study demonstrated that the increase in GABA could promote CRS-induced hair growth inhibition by downregulating the cell cycle of DP cells and suggested that ginkgolide A may be a promising therapeutic drug for hair loss.

Effects of Cudrania tricuspidata and Sargassum fusiforme extracts on hair growth in C57BL/6 mice

BACKGROUND

Cudrania tricuspidata is a perennial plant, and Sargassum fusiforme is a brown seaweed with numerous potential benefits, including anticancer, anti-inflammatory, and antioxidant activities. However, the efficacies of C. tricuspidata and S. fusiforme on hair growth have not yet been elucidated. Therefore, the present study examined the effects of C. tricuspidata and S. fusiforme extracts on hair growth in C57BL/6 mice.

RESULTS

ImageJ demonstrated that drinking and skin application of C. tricuspidata and/or S. fusiforme extracts significantly increased the hair growth rate in the dorsal skin of C57BL/6 mice compared to the control group. Histological analysis confirmed that drinking and skin application of C. tricuspidata and/or S. fusiforme extracts for 21 days significantly increased the length of hair follicles on the dorsal skin of treated C57BL/6 mice compared to that in the control mice. RNA sequencing analysis revealed that hair growth cycle-related factors (anagen factors) such as Catenin Beta 1 (Ctnnb1) and platelet-derived growth factor (Pdgf) were upregulated (> twofold) only by C. tricuspidate extracts, whereas vascular endothelial growth factor (Vegf) and Wnts were upregulated by both C. tricuspidata or S. fusiforme applications in treated mice (compared to the control mice). In addition, oncostatin M (Osm, a catagen-telogen factor) was downregulated (< 0.5 fold) by C. tricuspidata when administered via both skin and drinking mode in treated mice compared to that in control mice.

CONCLUSIONS

Our results suggest that C. tricuspidata and/or S. fusiforme extracts show potential hair growth efficacy by upregulating anagen factor genes, including β-catenin, Pdgf, Vegf, and Wnts, and downregulating catagen-telogen factor genes, including Osm, in C57BL/6 mice. The findings suggest that C. tricuspidata and/or S. fusiforme extracts are potential drug candidates to treat alopecia.