Analysis of the microRNA expression profile of normal human dermal papilla cells treated with 5α-dihydrotestosterone

Transient stimulation of TRPMLs enhance the functionality of hDPCs and facilitate hair growth in mice

Autophagy is essential for eliminating aging and organelle damage that maintaining cellular homeostasis. However, the dysfunction of autophagy has been proven in hair loss such as AGA. Despite the crucial role of TRPML channels in regulating autophagy, their specific function in hair growth remains unclarified. To investigate the biological functions and associated molecular mechanisms of TRPMLs in hair growth, Animal experiments were conducted to confirm the function of TRLMLs activation in promoting hair growth. Subsequently, we analyzed molecular mechanisms in human dermal papilla cells (hDPCs) activated by TRPMLs through transcriptome sequencing analysis. MLSA1(a TRPML agonist) promoted hair regeneration and accelerated hair cycle transition in mice. The activation of TRPMLs upregulated calcium signaling inducing hDPCs to secrete hair growth promoting factors and decrease hair growth inhibiting factors. In addition, activation of TRPMLs triggered autophagy and reduced the generation of ROS, thereby delaying the senescence of hDPCs. All these findings suggested that TRPMLs activation could promote hair growth by regulating hDPCs secretion of hair growth-related factors. Moreover, it may play a prominent role in preventing hDPCs from ROS damage induced by H2O2 or DHT. Targeting TRPMLs may represent a promising therapeutic strategy for treating hair loss.

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

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

Utilising SNP Association Analysis as a Prospective Approach for Personalising Androgenetic Alopecia Treatment

INTRODUCTION

Androgenetic alopecia (AGA) is a prevalent, multifactorial form of hair loss involving complex aetiological factors, such as altered androgen regulation and energy metabolism. Existing treatments offer limited success, thus highlighting the need for advanced, personalised therapeutic strategies. This study focuses on correlating the genetic mechanisms of AGA with molecular targets involved in the response to current treatment modalities.

METHODS

An anonymised database including 26,607 patients was subjected to analysis. The dataset included information on patients' genotypes in 26 single nucleotide polymorphisms (SNPs), specifically, and diagnosed AGA grades, representing a broad range of ethnic backgrounds.

RESULTS

In our sample, 64.6% of males and 35.4% of females were diagnosed with female pattern hair loss. This distribution aligns well with prior studies, thus validating the representativeness of our dataset. AGA grading was classified using the Hamilton-Norwood and Ludwig scales, although no association was found to the grade of the disease. SNP association analysis revealed eight SNPs, namely rs13283456 (PTGES2), rs523349 (SRD5A2), rs1800012 (COL1A1), rs4343 (ACE), rs10782665 (PTGFR), rs533116 (PTGDR2), rs12724719 (CRABP2) and rs545659 (PTGDR2), to be statistically significant with a p-value below 0.05.

CONCLUSIONS

The study establishes a preliminary association between eight specific SNPs and AGA. These genetic markers offer insights into the variability of therapeutic responses, thus underlining the importance of personalised treatment approaches. Our findings show the potential for more targeted research to understand these SNPs' and further roles in AGA pathophysiology and in modulating treatment response.

MiR-200c-3p as a novel genetic marker and therapeutic tool for alopecia areata

BACKGROUND

MicroRNAs (miRNAs) are small RNA molecules that regulate gene expression in diverse biological processes. They hold promise as therapeutic candidates for targeting human disease pathways, although our understanding of their gene regulatory mechanism remains incomplete. Alopecia areata (AA) is a prevalent inflammatory ailment distinguished by the infiltration of T cells targeting the anagen-stage hair follicles. The scarcity of effective remedies for AA may stem from limited understanding regarding its precise cellular mechanism.

AIM

To investigate and examine the importance and role of the miR-200c-3p as a genetic indicator for AA, and its possible impact on disease progression.

SUBJECTS AND METHODS

Case-control study included 65 patients with AA and 65 matched healthy controls. A real-time PCR technique was used to measure the expression of miR-200c-3p for both groups. Bioinformatic tools were used for prediction with genes and gene-gene interaction, and protein-protein interaction.

RESULTS

The expression levels of miR-200c-3p were significantly higher in AA patients than in healthy controls. We predicted that miR-200c-3p plays a markable role in the development of AA by its effect on the EGFR tyrosine kinase inhibitor resistance pathway.

CONCLUSION

We were able to identify the influence of miR-200c-3p on both PLCG1 and RPS6KP1 genes which in turn regulate the EGFR tyrosine kinases resistance pathway that displayed the most substantial increase in activity. Our outcomes shed light on the era of the potential theranostic role of this innovative miRNA in AA.

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.

Transcriptomic Analysis Reveals Candidate Ligand-Receptor Pairs and Signaling Networks Mediating Intercellular Communication between Hair Matrix Cells and Dermal Papilla Cells from Cashmere Goats

Hair fiber growth is determined by the spatiotemporally controlled proliferation, differentiation, and apoptosis of hair matrix cells (HMCs) inside the hair follicle (HF); however, dermal papilla cells (DPCs), the cell population surrounded by HMCs, manipulate the above processes via intercellular crosstalk with HMCs. Therefore, exploring how the mutual commutations between the cells are molecularly achieved is vital to understanding the mechanisms underlying hair growth. Here, based on our previous successes in cultivating HMCs and DPCs from cashmere goats, we combined a series of techniques, including in vitro cell coculture, transcriptome sequencing, and bioinformatic analysis, to uncover ligand-receptor pairs and signaling networks mediating intercellular crosstalk. Firstly, we found that direct cellular interaction significantly alters cell cycle distribution patterns and changes the gene expression profiles of both cells at the global level. Next, we constructed the networks of ligand-receptor pairs mediating intercellular autocrine or paracrine crosstalk between the cells. A few pairs, such as LEP-LEPR, IL6-EGFR, RSPO1-LRP6, and ADM-CALCRL, are found to have known or potential roles in hair growth by acting as bridges linking cells. Further, we inferred the signaling axis connecting the cells from transcriptomic data with the advantage of CCCExplorer. Certain pathways, including INHBA-ACVR2A/ACVR2B-ACVR1/ACVR1B-SMAD3, were predicted as the axis mediating the promotive effect of INHBA on hair growth via paracrine crosstalk between DPCs and HMCs. Finally, we verified that LEP-LEPR and IL1A-IL1R1 are pivotal ligand-receptor pairs involved in autocrine and paracrine communication of DPCs and HMCs to DPCs, respectively. Our study provides a comprehensive landscape of intercellular crosstalk between key cell types inside HF at the molecular level, which is helpful for an in-depth understanding of the mechanisms related to hair growth.

Assessment of the anti-hair loss potential of Camellia japonica fruit shell extract in vitro

OBJECTIVE

Hair loss is caused by various factors. Impacts of these factors are often overlapped and intensified. Currently, mitigation of hair loss is being studied by proliferating dermal papilla cells (DPCs) and inhibiting deleterious factors such as dihydrotestosterone (DHT) and oxidative stress on hair growth. Camellia japonica (C. japonica) fruit shell is a discarded part. Its biological activity remains to be elucidated. In this study, we investigated the capacity of C. japonica fruit shell extract (CJFSE) for hair loss mitigation.

METHODS

MTT assay, spheroid culture and quantitative RT-PCR were performed to observe the proliferative effect of CJFSE on hair follicle dermal papilla cells (HFDPCs). Effects of CJFSE on DHT-induced hair loss were confirmed by Dkk-1 ELISA, β-galactosidase (β-gal) and 5α-reductase activity assay. In addition, effects of CJFSE on oxidative stress were confirmed through DPPH and ROS production assays.

RESULTS

CJFSE increased the proliferation and spheroid size of HFDPCs. Expression levels of VEGF-A, Wnt-1, c-Myc and Cyclin D1 were upregulated by CJFSE. CJFSE also suppressed 5α-reductase activity and DHT-induced decrease in cell proliferation, Dkk-1 secretion and β-gal activity. Moreover, CJFSE showed DPPH scavenging activity and ameliorated hydrogen peroxide-induced ROS production and β-gal activity. Finally, gallic acid and protocatechuic acid were observed in CJFSE through HPLC analysis.

CONCLUSION

CJFSE has the potential to alleviate hair loss by promoting hair cell growth and suppressing effects of DHT and oxidative stress on hair.

Integral characterization of normal and alopecic hair at different degeneration stages by in-situ visible and chemical imaging

Direct exploration to differences between normal hair (NH) and alopecic hair (AH) at different degeneration stages is still lacking. To reveal compositional and structural variation of AH with reference to NH internally and externally, infrared spectroscopic imaging combined with scanning electron microscopy was applied to investigate integral changes of hair chemical profiles and surface texture structures, and infrared macro-fingerprinting analysis revealed detailed chemical compositions of NH and AH. Results showed that AH had excessive irregular laminated structures compared to NH, leading to a lower weight bearing capacity. Spatial distributions of lipids, phosphates, lipoproteins and phospholipids in hair transverse sections showed that their infrared absorptions were intensified and gradually centralized to medulla with average variable-areas increasing upto 2.3 folds (lipoproteins area changed from 13% in NH to 30% in AH)as the alopecia progressed. Extracted pixel spectra from the chemical images showed different fingerprint characteristics in 1075-1120 cm^-1. Specifically, compared to NH, AH showed red shift of phosphate peaks, indicating the occurrence of phosphates transformation. In this study, in-situ visible and infrared chemical imaging directly revealed more irregular laminated scalps with decreasing weight bearing capacity and increasing distributive areas expanding to medulla of key components (phosphates, phospholipids, etc.) that were relevant to alopecia development from NH to AH, and offered a fast, eco-friendly and effective method for hair research.

Progressive expression of PPARGC1α is associated with hair miniaturization in androgenetic alopecia

Current opinion views androgens as the pathogenic driver in the miniaturization of hair follicles of androgenetic alopecia by interfering with the dermal papilla. This cannot be the sole cause and therefore it is important for therapeutic and diagnostic purposes to identify additional pathways. Comparative full transcriptome profile analysis of the hair bulb region of normal and miniaturized hair follicles from vertex and occipital region in males with and without androgenetic alopecia revealed that next to the androgen receptor as well the retinoid receptor and particularly the PPAR pathway is involved in progressive hair miniaturization. We demonstrate the concurrent up-regulation of PPARGC1a in the epithelial compartment and androgen receptor in the dermal papilla of miniaturized hair. Dynamic Ppargc1a expression in the mouse hair cycle suggests a possible role in regulating hair growth and differentiation. This is supported by reduced proliferation of human dermal papilla and predominantly epithelial keratinocytes after incubation with AICAR, the agonist for AMPK signaling which activates PPARGC1a and serves as co-activator of PPARγ. In addition, miRNA profiling shows enrichment of miRNA-targeted genes in retinoid receptors and PPARGC1α/PPARγ signaling, and antigen presentation pathways.

Review of Hair Follicle Dermal Papilla cells as in vitro screening model for hair growth

Hair disorders such as hair loss (alopecia) and androgen dependent, excessive hair growth (hirsutism, hypertrichosis) may impact the social and psychological well-being of an individual. Recent advances in understanding the biology of hair have accelerated the research and development of novel therapeutic and cosmetic hair growth agents. Preclinical models aid in dermocosmetic efficacy testing and claim substantiation of hair growth modulators. The in vitro models to investigate hair growth utilize the hair follicle Dermal Papilla cells (DPCs), specialized mesenchymal cells located at the base of hair follicle that play essential roles in hair follicular morphogenesis and postnatal hair growth cycles. In this review, we have compiled and discussed the extensively reported literature citing DPCs as in vitro model to study hair growth promoting and inhibitory effects. A variety of agents such as herbal and natural extracts, growth factors and cytokines, platelet-rich plasma, placental extract, stem cells and conditioned medium, peptides, hormones, lipid-nanocarrier, light, electrical and electromagnetic field stimulation, androgens and their analogs, stress-serum and chemotherapeutic agents etc. have been examined for their hair growth modulating effects in DPCs. Effects on DPCs' activity were determined from untreated (basal) or stress induced levels. Cell proliferation, apoptosis and secretion of growth factors were included as primary end-point markers. Effects on a wide range of biomolecules and mechanistic pathways that play key role in the biology of hair growth were also investigated. This consolidated and comprehensive review summarizes the up-to-date information and understanding regarding DPCs based screening models for hair growth and may be helpful for researchers to select the appropriate assay system and biomarkers. This review highlights the pivotal role of DPCs in the forefront of hair research as screening platforms by providing insights into mechanistic action at cellular level, which may further direct the development of novel hair growth modulators.

Intracrine androgen biosynthesis, metabolism and action revisited

Androgens play an important role in metabolic homeostasis and reproductive health in both men and women. Androgen signalling is dependent on androgen receptor activation, mostly by testosterone and 5α-dihydrotestosterone. However, the intracellular or intracrine activation of C₁₉ androgen precursors to active androgens in peripheral target tissues of androgen action is of equal importance. Intracrine androgen synthesis is often not reflected by circulating androgens but rather by androgen metabolites and conjugates. In this review we provide an overview of human C₁₉ steroid biosynthesis including the production of 11-oxygenated androgens, their transport in circulation and uptake into peripheral tissues. We conceptualise the mechanisms of intracrinology and review the intracrine pathways of activation and inactivation in selected human tissues. The contribution of liver and kidney as organs driving androgen inactivation and renal excretion are also highlighted. Finally, the importance of quantifying androgen metabolites and conjugates to assess intracrine androgen production is discussed.

A review of the role of estrogen in dermal aging and facial attractiveness in women

Estrogens are known to have protective and favorable influences on skin health; conversely, androgens oppose the actions of estrogens. Estrogen's chemical messages are transmitted via the classical nuclear hormone estrogen receptors (ER) alpha and beta and the rapid-acting G-coupled membrane estrogen receptor. Androgens [both testosterone and 5α-dihydrotestosterone (5α-DHT)] bind the same androgen receptor. Estrogen levels peak in the mid- to late 20s in women and then decline by 50% by 50 years of age and dramatically decrease further after menopause. The loss of estrogens with aging contributes to diminished dermal health, whereas estrogen hormone therapy [eg, oral conjugated equine estrogens (CEE)] restores skin health. Several reports suggest positive correlations between the levels of circulating estrogens and: (1) perceived age, (2) attractiveness, (3) enhanced skin health, and (4) facial coloration in women. Based upon a psychological dermato-endocrine perspective, the positive correspondence of high estrogens levels with perceived age and facial attractiveness in women especially with aging demonstrates the importance of hormonal influences on observed dermal health and youthful appearance.

Prostaglandin D2-Mediated DP2 and AKT Signal Regulate the Activation of Androgen Receptors in Human Dermal Papilla Cells

Prostaglandin D2 (PGD2) and prostaglandin D2 receptor 2 (DP2) is known to be an important factor in androgenetic alopecia (AGA). However, the effect of PGD2 in human dermal papilla cells (hDPCs) is not fully understood. The function of PGD2-induced expression of the androgen receptor (AR), DP2, and AKT (protein kinase B) signal were examined by using real time-PCR (qRT-PCR), western blot analysis, immunocytochemistry (ICC), and siRNA transfection system. PGD2 stimulated AR expression and AKT signaling through DP2. PGD2 stimulated AR related factors (transforming growth factor beta 1 (TGFβ1), Creb, lymphoid enhancer binding factor 1 (LEF1), and insulin-like growth factor 1, (IGF-1)) and AKT signaling (GSK3β and Creb) on the AR expression in hDPCs. However, these factors were down-regulated by DP2 antagonist (TM30089) and AKT inhibitor (LY294002) as well as DP2 knockdown in hDPCs decreased AR expression and AKT signaling. Finally, we confirmed that PGD2 stimulates the expression of AR related target genes, and that AKT and its downstream substrates are involved in AR expression on hDPCs. Taken together, our data suggest that PGD2 promotes AR and AKT signal via DP2 in hDPCs, thus, PGD2 and DP2 signal plays a critical role in AR expression. These findings support the additional explanation for the development of AGA involving PGD2-DP2 in hDPCs.

Resveratrol, 4' Acetoxy Resveratrol, R-equol, Racemic Equol or S-equol as Cosmeceuticals to Improve Dermal Health

Phytochemicals are botanical compounds used in dermatology applications as cosmeceuticals to improve skin health. Resveratrol and equol are two of the best-known polyphenolic or phytoestrogens having similar chemical structures and some overlapping biological functions to 17β-estradiol. Human skin gene expression was reviewed for 28 different biomarkers when resveratrol, 4′ acetoxy resveratrol (4AR), R-equol, racemic equol or S-equol were tested. Sirtuin 1 activator (SIRT 1) was stimulated by resveratrol and 4AR only. Resveratrol, R-equol and racemic equol were effective on the aging biomarkers proliferating cell nuclear factor (PCNA), nerve growth factor (NGF), 5α-reductase and the calcium binding proteins S100 A8 and A9. Racemic equol and 4AR displayed among the highest levels for the collagens, elastin and tissue inhibitor of the matrix metalloproteinase 1 (TIMP 1). S-equol displayed the lowest level of effectiveness compared to the other compounds. The 4AR analog was more effective compared to resveratrol by 1.6-fold. R-equol and racemic equol were almost equal in potency displaying greater inhibition vs. resveratrol or its 4′ analog for the matrix metalloproteinases (MMPs), but among the inflammatory biomarkers, resveratrol, 4AR, R-equol and racemic equol displayed high inhibition. Thus, these cosmeceuticals display promise to improve dermal health; however, further study is warranted to understand how phytochemicals protect/enhance the skin.

Pretreatment of Ferulic Acid Protects Human Dermal Fibroblasts against Ultraviolet A Irradiation

Background

Approximately 90%~99% of ultraviolet A (UVA) ray reaches the Earth's surface. The deeply penetrating UVA rays induce the formation of reactive oxygen species (ROS), which results in oxidative stress such as photoproducts, senescence, and cell death. Thus, UVA is considered a primary factor that promotes skin aging.

Objective

Researchers investigated whether pretreatment with ferulic acid protects human dermal fibroblasts (HDFs) against UVA-induced cell damages.

Methods

HDF proliferation was analyzed using the water-soluble tetrazolium salt assay. Cell cycle distribution and intracellular ROS levels were assessed by flow cytometric analysis. Senescence was evaluated using a senescence-associated β-galactosidase assay, while Gadd45α promoter activity was analyzed through a luciferase assay. The expression levels of superoxide dismutase 1 (SOD1), catalase (CAT), xeroderma pigmentosum complementation group A and C, matrix metalloproteinase 1 and 3, as well as p21 and p16 were measured using quantitative real-time polymerase chain reaction.

Results

Inhibition of proliferation and cell cycle arrest were detected in cells that were irradiated with UVA only. Pretreatment with ferulic acid significantly increased the proliferation and cell cycle progression in HDFs. Moreover, ferulic acid pretreatment produced antioxidant effects such as reduced DCF intensity, and affected SOD1 and CAT mRNA expression. These effects were also demonstrated in the analysis of cell senescence, promoter activity, expression of senescent markers, and DNA repair.

Conclusion

These results demonstrate that ferulic acid exerts protective effects on UVA-induced cell damages via anti-oxidant and stress-inducible cellular mechanisms in HDFs.

Human Hair Reconstruction: Close, But Yet So Far

Billions of dollars are annually invested in pharmaceutical industry and cosmetic sector with intent to develop new drugs and treatment strategies for alopecia. Because the hair looks an important characteristic of humans-an effective appendage in perception, expression of beauty, and preservation of self-esteem-the global market for hair loss treatment products is exponentially increasing. However, current methods to treat hair loss endure yet multiple challenges, such as unfavorable outcomes, nonpermanent and patient-dependent results, as well as unpredictable impacts, which limit their application. Over recent years, remarkable advances in the fields of regenerative medicine and hair tissue engineering have raised new hopes for introducing novel cell-based approaches to treat hair loss. Through cell-based approaches, it is possible to produce hair-like structures in the laboratory setting or manipulate cells in their native niche (in vivo lineage reprogramming) to reconstruct the hair follicle. However, challenging issues still exist with the functionality of cultured human hair cells, the proper selection of nonhair cell sources in cases of shortage of donor hair, and the development of defined culture conditions. Moreover, in the case of in vivo lineage reprogramming, selecting appropriate induction factors and their efficient delivery to guide resident cells into a hair fate-with the aim of reconstructing functional hair-still needs further explorations. In this study, we highlight recent advances and current challenges in hair loss treatment using cell-based approaches and provide novel insights for crucial steps, which must be taken into account to develop reproducible, safe, and efficient cell-based treatment.

Skin aging and oxidative stress: Equol's anti-aging effects via biochemical and molecular mechanisms

Oxygen in biology is essential for life. It comes at a cost during normal cellular function, where reactive oxygen species (ROS) are generated by oxidative metabolism. Human skin exposed to solar ultra-violet radiation (UVR) dramatically increases ROS production/oxidative stress. It is important to understand the characteristics of human skin and how chronological (intrinsic) aging and photo-aging (extrinsic aging) occur via the impact of ROS production by cascade signaling pathways. The goal is to oppose or neutralize ROS insults to maintain good dermal health. Botanicals, as active ingredients, represent one of the largest categories used in dermatology and cosmeceuticals to combat skin aging. An emerging botanical is equol, a polyphenolic/isoflavonoid molecule found in plants and food products and via gastrointestinal metabolism from precursor compounds. Introductory sections cover oxygen, free radicals (ROS), oxidative stress, antioxidants, human skin aging, cellular/molecular ROS events in skin, steroid enzymes/receptors/hormonal actions and genetic factors in aging skin. The main focus of this review covers the characteristics of equol (phytoestrogenic, antioxidant and enhancement of extracellular matrix properties) to reduce skin aging along with its anti-aging skin influences via reducing oxidative stress cascade events by a variety of biochemical/molecular actions and mechanisms to enhance human dermal health.

Skin steroidogenesis in health and disease

The skin is an important extra-gonadal steroidogenic organ, capable of metabolizing various hormones from their precursors, as well as of synthesizing de novo a broad palette of sex steroids and glucocorticoids from cholesterol. In this manuscript, we review the major steroidogenic properties of human skin and we suggest steroidogenesis' impairment as a cardinal factor for various pathological conditions such as acne, rosacea, atopic dermatitis, and androgenic alopecia.

Epigallocatechin Gallate-Mediated Alteration of the MicroRNA Expression Profile in 5α-Dihydrotestosterone-Treated Human Dermal Papilla Cells

BACKGROUND

Dihydrotestosterone (DHT) induces androgenic alopecia by shortening the hair follicle growth phase, resulting in hair loss. We previously demonstrated how changes in the microRNA (miRNA) expression profile influenced DHT-mediated cell death, cell cycle arrest, cell viability, the generation of reactive oxygen species (ROS), and senescence. Protective effects against DHT have not, however, been elucidated at the genome level.

OBJECTIVE

We showed that epigallocatechin gallate (EGCG), a major component of green tea, protects DHT-induced cell death by regulating the cellular miRNA expression profile.

METHODS

We used a miRNA microarray to identify miRNA expression levels in human dermal papilla cells (DPCs). We investigated whether the miRNA expression influenced the protective effects of EGCG against DHT-induced cell death, growth arrest, intracellular ROS levels, and senescence.

RESULTS

EGCG protected against the effects of DHT by altering the miRNA expression profile in human DPCs. In addition, EGCG attenuated DHT-mediated cell death and growth arrest and decreased intracellular ROS levels and senescence. A bioinformatics analysis elucidated the relationship between the altered miRNA expression and EGCG-mediated protective effects against DHT.

CONCLUSION

Overall, our results suggest that EGCG ameliorates the negative effects of DHT by altering the miRNA expression profile in human DPCs.