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.

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.

The Flavonol Quercitrin Hinders GSK3 Activity and Potentiates the Wnt/β-Catenin Signaling Pathway

The Wnt/β-catenin signaling pathway dictates cell proliferation and differentiation during embryonic development and tissue homeostasis. Its deregulation is associated with many pathological conditions, including neurodegenerative disease, frequently downregulated. The lack of efficient treatment for these diseases, including Alzheimer’s disease (AD), makes Wnt signaling an attractive target for therapies. Interestingly, novel Wnt signaling activating compounds are less frequently described than inhibitors, turning the quest for novel positive modulators even more appealing. In that sense, natural compounds are an outstanding source of potential drug leads. Here, we combine different experimental models, cell-based approaches, neuronal culture assays, and rodent behavior tests with Xenopus laevis phenotypic analysis to characterize quercitrin, a natural compound, as a novel Wnt signaling potentiator. We find that quercitrin potentiates the signaling in a concentration-dependent manner and increases the occurrence of the Xenopus secondary axis phenotype mediated by Xwnt8 injection. Using a GSK3 biosensor, we describe that quercitrin impairs GSK3 activity and increases phosphorylated GSK3β S9 levels. Treatment with XAV939, an inhibitor downstream of GSK3, impairs the quercitrin-mediated effect. Next, we show that quercitrin potentiates the Wnt3a-synaptogenic effect in hippocampal neurons in culture, which is blocked by XAV939. Quercitrin treatment also rescues the hippocampal synapse loss induced by intracerebroventricular injection of amyloid-β oligomers (AβO) in mice. Finally, quercitrin rescues AβO-mediated memory impairment, which is prevented by XAV939. Thus, our study uncovers a novel function for quercitrin as a Wnt/β-catenin signaling potentiator, describes its mechanism of action, and opens new avenues for AD treatments.

Lagerstroemia indica extract regulates human hair dermal papilla cell growth and degeneration via modulation of β-catenin, Stat6 and TGF-β signaling pathway

BACKGROUND

Lagerstroemia indica (L. indica) is reported to have diverse biological activities including anti-inflammatory, anti-cancer, neuro-regulatory, antidiabetic and antioxidant activity.

AIMS

The purpose of the present study is to examine the potential of hair growth promotion and/or hair loss prevention by L. indica extract.

PATIENTS/METHODS

The effects of L. indica on hair growth have been studied in human hair follicle dermal papillary (hHFDP) cells and follicular organ culture ex vivo by cell proliferation assay, PCR, western blot analysis and reporter gene activity assay. Moreover, a clinical trial was conducted in healthy volunteers.

RESULTS

L. indica significantly promoted the proliferation of hHFDP cells, which was associated with increased expression of TCF/LEF, VEGF and Gli1 mRNA, and inhibition of STAT6 and Smad2 mRNA. Treatment with L. indica also increased the TCF/LEF reporter gene activity but downregulated the SBE- and STAT6-luciferase activities. The expression of total β-catenin, CDK4 and CDK2 were elevated, while that of STAT6 and SMAD2/3 was suppressed upon treatment with L. indica. In human hair follicles organ culture, L. indica significantly inhibited hair follicular degeneration. The clinical trial showed a statistically significant rise in total hair count in test group (n=24) after 24 weeks of applying the hair tonic enriched with L. indica (141.46 ± 21.27 number/cm² , p < 0.05).

CONCLUSION

We suggest that L. indica extract prevents hair loss as well as stimulate hair growth by regulating the Wnt-β-catenin, JAK3-STAT6 and TGF-β1-Smad signaling pathways, and may be further developed as a novel functional cosmetic for preventing hair loss.

A Highly Selective GSK-3β Inhibitor CHIR99021 Promotes Osteogenesis by Activating Canonical and Autophagy-Mediated Wnt Signaling

The discovery and application of small molecules is one of the practical strategies of safe osteogenic drugs. The small molecule CHIR99021 (C91) is a highly specific, safe, and most effective GSK-3β Inhibitor. This study found that it efficiently activates the canonical Wnt signaling of bone marrow stromal cell ST2 and promotes osteoblast differentiation and mineralization. C91 increases the production and biochemical activity of osteoblast marker alkaline phosphatase, the expression of osteoblast marker genes Alpl, Bglap, Runx2, and Sp7, and the formation of bone nodules. Triptonide is a transcription inhibitor of Wnt target gene, which diminishes C91-induced osteoblast differentiation in a dose-dependent manner. Meanwhile, C91 also induces autophagy through autophagosome formation and conversion of autophagy biomarker LC-3I into LC-3II. Autophagy inhibitor 3MA partially reduces C91-induced osteoblast differentiation and mineralization; autophagy inducer Rapamycin increases the expression of β-catenin to promote osteogenic differentiation, but cannot alleviate the inhibition of Triptonide on C91-induced osteogenic differentiation, indicating the crosstalk of canonical Wnt signaling and autophagy regulates C91-induced osteoblast differentiation. Furthermore, in order to simulate the in vivo detection of C91 in osteogenesis process, we made a C91 slow-release hydrogel with our newly established polycaprolactone and cell-integrated 3D printing system (PCCI3D module). The sustained release C91 promotes the differentiation and mineralization of ST2 cells. C91 can also enhance the proliferative activity of ST2 cells. The release rate of C91 from hydrogel gradually decreases within 7 days. During this period, the C91 is released by 83.0% and the cell viability maintained at 96.4%. Therefore, the small molecule Wnt agonist C91 promotes osteogenesis through caonical and autophagy-mediated Wnt signaling pathway with an option for translational application.

Perspectives on miRNAs Targeting DKK1 for Developing Hair Regeneration Therapy

Androgenetic alopecia (AGA) remains an unsolved problem for the well-being of humankind, although multiple important involvements in hair growth have been discovered. Up until now, there is no ideal therapy in clinical practice in terms of efficacy and safety. Ultimately, there is a strong need for developing a feasible remedy for preventing and treating AGA. The Wnt/β-catenin signaling pathway is critical in hair restoration. Thus, AGA treatment via modulating this pathway is rational, although challenging. Dickkopf-related protein 1 (DKK1) is distinctly identified as an inhibitor of canonical Wnt/β-catenin signaling. Thus, in order to stimulate the Wnt/β-catenin signaling pathway, inhibition of DKK1 is greatly demanding. Studying DKK1-targeting microRNAs (miRNAs) involved in the Wnt/β-catenin signaling pathway may lay the groundwork for the promotion of hair growth. Bearing in mind that DKK1 inhibition in the balding scalp of AGA certainly makes sense, this review sheds light on the perspectives of miRNA-mediated hair growth for treating AGA via regulating DKK1 and, eventually, modulating Wnt/β-catenin signaling. Consequently, certain miRNAs regulating the Wnt/β-catenin signaling pathway via DKK1 inhibition might represent attractive candidates for further studies focusing on promoting hair growth and AGA therapy.

DNA methylation and histone acetylation are involved in Wnt10b expression during the secondary hair follicle cycle in Angora rabbits

Secondary hair follicles (SHFs) in the Angora rabbit exhibit classic cyclic hair development, but the multiple molecular signals involved in hair cycling are yet to be explored in detail. In the present study, we investigated the expression pattern, methylation and histone H3 acetylation status of Wnt10b, as a molecular signal participating in hair cycling, during the SHF cycle in the Angora rabbit. Expression of Wnt10b at the anagen phase was significantly higher than that at both the telogen and catagen phases, suggesting that Wnt10b might serve as a critical activator during cyclic transition of SHFs. Methylation frequency of the fifth CpG site (CpG5-175 bp) in CpG islands at the anagen phase was lower than that at both the catagen and telogen phases. The methylation status of the CpG5 site was negatively correlated with Wnt10b expression. This indicated that the methylation of CpG5 might participate in Wnt10b transcriptional suppression in SHFs. Furthermore, histone H3 acetylation status in the regions-256~-11 bp and 98 ~ 361 bp were significantly lower at both the catagen and telogen phases than at the anagen phase. The histone H3 acetylation level was significantly positively correlated with Wnt10b expression. This confirmed that histone acetylation was likely involved in upregulating Wnt10b transcription in SHFs. Additionally, potential binding to the transcription factors ZF57 and HDBP was predicted within the CpG5 site. In conclusion, our findings reveal the epigenetic mechanism of Wnt10b transcription and provide a new insight into epigenetic regulation during the SHF cycle in the Angora rabbit.

Vanillic Acid Stimulates Anagen Signaling via the PI3K/Akt/ β-Catenin Pathway in Dermal Papilla Cells

The hair cycle (anagen, catagen, and telogen) is regulated by the interaction between mesenchymal cells and epithelial cells in the hair follicles. The proliferation of dermal papilla cells (DPCs), mesenchymal-derived fibroblasts, has emerged as a target for the regulation of the hair cycle. Here, we show that vanillic acid, a phenolic acid from wheat bran, promotes the proliferation of DPCs via a PI3K/Akt/Wnt/β-catenin dependent mechanism. Vanillic acid promoted the proliferation of DPCs, accompanied by increased levels of cell-cycle proteins cyclin D1, CDK6, and Cdc2 p34. Vanillic acid also increased the levels of phospho(ser473)-Akt, phospho(ser780)-pRB, and phospho(thr37/46)-4EBP1 in a time-dependent manner. Wortmannin, an inhibitor of the PI3K/Akt pathway, attenuated the vanillic acid-mediated proliferation of DPCs. Vanillic acid-induced progression of the cell-cycle was also suppressed by wortmannin. Moreover, vanillic acid increased the levels of Wnt/β-catenin proteins, such as phospho(ser9)-glycogen synthase kinase-3β, phospho(ser552)-β-catenin, and phospho(ser675)-β-catenin. We found that vanillic acid increased the levels of cyclin D1 and Cox-2, which are target genes of β-catenin, and these changes were inhibited by wortmannin. To investigate whether vanillic acid affects the downregulation of β-catenin by dihydrotestosterone (DHT), implicated in the development of androgenetic alopecia, DPCs were stimulated with DHT in the presence and absence of vanillic acid for 24 h. Western blotting and confocal microscopy analyses showed that the decreased level of β-catenin after the incubation with DHT was reversed by vanillic acid. These results suggest that vanillic acid could stimulate anagen and alleviate hair loss by activating the PI3K/Akt and Wnt/β-catenin pathways in DPCs.

Loss-of-function variants in C3ORF52 result in localized autosomal recessive hypotrichosis

PURPOSE

Localized autosomal recessive hypotrichosis (LAH) has been associated with pathogenic variants in DSG4, encoding a desmosomal protein as well as in LIPH and LPAR6, encoding respectively lipase H, which catalyzes the formation of 2-acyl-lysophosphatidic acid (LPA), and lysophosphatidic acid receptor 6, a receptor for LPA. LPA promotes hair growth and differentiation. In this study we aimed at delineating the genetic basis of LAH in patients without pathogenic variants in these three genes.

METHODS

Variant analysis was conducted using exome and direct sequencing. We then performed quantitative reverse transcription polymerase chain reaction (RT-qPCR), immunofluorescence staining, immunoblotting, enzymatic, and coimmunoprecipitation assays to evaluate the consequences of potential etiologic variants.

RESULTS

We identified homozygous variants in C3ORF52 in four individuals with LAH. C3ORF52 was found to be coexpressed with lipase H in the inner root sheath of the hair follicle and the two proteins were found to directly interact. The LAH-causing variants were associated with decreased C3ORF52 expression and resulted in markedly reduced lipase H-mediated LPA biosynthesis.

CONCLUSION

LAH can be caused by abnormal function of at least three proteins which are necessary for proper LPA biosynthesis.

Androgenetic alopecia: combing the hair follicle signaling pathways for new therapeutic targets and more effective treatment options

Introduction: In the past 30 years, only two drugs have received FDA approval for the treatment of androgenetic alopecia reflecting a lack of success in unraveling novel targets for pharmacological intervention. However, as our knowledge of hair biology improves, new signaling pathways and organogenesis processes are being uncovered which have the potential to yield more effective therapeutic modalities. Areas covered: This review focuses on potential targets for drug development to treat hair loss. The physiological processes underlying the promise of regenerative medicine to recreate new functional hair follicles in bald scalp are also examined. Expert opinion: The discovery of promising new targets may soon enable treatment options that modulate the hair cycle to preserve or extend the growth phase of the hair follicle. These new targets could also be leveraged to stimulate progenitor cells and morphogenic pathways to reactivate miniaturized follicles in bald scalp or to harness the potential of wound healing and embryogenic development as an emerging paradigm to generate new hair follicles in barren skin.

Effects of Wnt10b on dermal papilla cells via the canonical Wnt/β-catenin signalling pathway in the Angora rabbit

Wnt10b is a member of Wnt family that plays a variety of roles in biological functions, including those in the development of hair follicles. To investigate the effect of Wnt10b on hair growth in the Angora rabbit and to determine the underlying molecular mechanism, we cultured dermal papilla (DP) cells with exogenous Wnt10b in vitro. We observed the expressions of downstream critical gene β-catenin and lymphoid enhancer-binding factor 1 (LEF1) in Wnt/β-catenin pathway. The levels of β-catenin mRNA and protein were higher in the Wnt10b group of DP cells than in the Control group, and the mRNA level of LEF1 in the Wnt10b group was higher than in the Control group. Moreover, translocation of β-catenin from cytoplasm to nucleus was activated in the Wnt10b group. Furthermore, the mRNA levels of the hair follicle-regulatory genes, insulin-like growth factor-1 (IGF-1) and alkaline phosphatase (ALP), and the protein activity of ALP was also upregulated in the Wnt10b group compared to their corresponding levels in the Control group. These data suggest that Wnt10b could activate the canonical Wnt/β-catenin signalling pathway to induce DP cells in the Angora rabbit. In addition, the proliferation of DP cells was significantly promoted when cultured with Wnt10b for 48 and 72 hr, suggesting that Wnt10b plays a pivotal role in the proliferation and maintenance of DP cells in vitro. In conclusion, this study demonstrates that Wnt10b may promote hair follicle growth in Angora rabbit through the canonical Wnt/β-catenin signalling pathway that promotes the proliferation of DP cells.

Activating Wnt/β-catenin signaling pathway for disease therapy: Challenges and opportunities

Wnt/β-catenin signaling pathway is essential for embryo development and adult tissue homeostasis and regeneration, abnormal regulation of the pathway is tightly associated with many disease types, suggesting that Wnt/β-catenin signaling pathway is an attractive target for disease therapy. While the Wnt inhibitors have been extensively reviewed, small molecules activating Wnt/β-catenin signaling were rarely addressed. In this article, we firstly reviewed the diseases that were associated with disruption of Wnt/β-catenin signaling pathway, including hair loss, pigmentary disorders, wound healing, bone diseases, neurodegenerative diseases and chronic obstructive pulmonary diseases, etc. We also comprehensively summarized small molecules that activated Wnt/β-catenin signaling pathway in various models in vitro and in vivo. To evaluate the therapeutic potential of Wnt activation, we focused on the discovery strategies, phenotypic characterization, and target identification of the Wnt activators. Finally, we proposed the challenges and opportunities in development of Wnt activators for pharmacological agents in term of targeting safety and selectivity.

Promotion of anagen, increased hair density and reduction of hair fall in a clinical setting following identification of FGF5-inhibiting compounds via a novel 2-stage process

Background

There are very few effective, scientifically validated treatments with known mechanisms of action for treatment of hair loss in both men and women. Fibroblast growth factor 5 (FGF5) is an important factor in the irreversible transition from anagen to catagen, and inhibition of FGF5 prolongs anagen phase and reduces hair loss.

Objective

We aimed to screen botanically derived molecules for FGF5 inhibitory activity in vitro and assess efficacy in a clinical setting.

Methods

We screened for FGF5 inhibitory efficacy via a novel 2-step in vitro pipeline consisting of an engineered FGF5 responsive cell line, followed by an activated dermal papillae (DP) cell method. Efficacy in a clinical setting was assessed in a randomized, single-blind, placebo-controlled trial against early- to mid-stage pattern hair loss in men and women.

Results

We observed FGF5 inhibitory activity for a number of compounds from the monoterpenoid family, many showing greater inhibitory efficacy than our previously reported crude plant extracts. Evaluation of a lead candidate in a clinical study over 112 days showed a significant improvement in anagen:telogen (AT) ratio (p = 0.002), reduced hair fall (p = 0.007) and improved visual grading (p = 0.004). Scientifically matched photography on a subgroup of randomly chosen participants highlighted significant improvement in hair density, with increases evident in all tested participants compared to baseline.

Conclusion

Isolates from the monoterpenoid family displayed efficacy in FGF5 inhibition in vitro. A topical formulation containing a leading isolate significantly improved AT ratio, reduced hair fall and increased apparent hair density in the tested population of men and women.

New Treatments for Hair Loss

The treatment of hair loss is an important part of clinical dermatology given the prevalence of the problem and great impact on patients' quality of life. Many new treatments have been introduced in recent years. This review summarizes the main ones in 4 groups: a) For androgenetic alopecia, we discuss new excipients for oral minoxidil, dutasteride, and finasteride as well as new forms of topical application; prostaglandin agonists and antagonists; low-level laser therapy; and regenerative medicine with Wnt signaling activators and stem cell therapy. b) For alopecia areata, Janus kinase inhibitors are reviewed. c) For frontal fibrosing alopecia, we discuss the use of antiandrogens and, for some patients, pioglitazone. d) Finally, we mention new robotic devices for hair transplant procedures and techniques for optimal follicular unit extraction.