Effects of photobiomodulation at various irradiances on normal and dihydrotestosterone-treated human hair dermal papilla cells in vitro

Androgenetic alopecia (AGA) is the most common type of hair loss caused by dihydrotestosterone (DHT) binding to androgen receptors in dermal papilla cells (DPCs). Photobiomodulation (PBM) is a promising treatment for AGA but suffers from inconsistent outcomes and inconsistent effective light parameters. This study investigated the impact of red light at various irradiances on normal and DHT-treated DPCs. Our results suggested that red light at 8 mW/cm2 was most effective in promoting DPCs growth. Furthermore, a range of irradiances from 2 to 64 mW/cm2 modulated key signaling pathways, including Wnt, FGF, and TGF, in normal and DHT-treated DPCs. Interestingly, 8 mW/cm2 had a greater impact on these pathways in DHT-treated DPCs and altered the Shh pathway, suggesting that the effect of PBM varies with the cellular environment. This study highlights specific factors that influence PBM effectiveness and provides insight into the need for personalized PBM treatment approaches.

Clinical Patterns of Hair Loss in Men: Is Dihydrotestosterone the Only Culprit?

A number of pathways and factors including oxidative stress, inflammation, prostaglandins, vasculogenesis, Wnt/β-catenin, and transforming growth factor-β have been shown to be important in male androgenetic alopecia. There is limited but increasing evidence of the potential usefulness of antioxidants, anti-inflammatory agents, prostaglandins, and growth factors for treating of androgenetic alopecia. Lifestyle factors and comorbidities including cardiovascular risk factors have been shown to be associated with male androgenetic alopecia. Further study of these pathways, factors, and comorbidities is needed to better understand the pathophysiology, find potentially useful therapeutic targets, and ensure a comprehensive approach to the management of androgenetic alopecia in men.

Dickkopf-1 Expression in Androgenetic Alopecia and Alopecia Areata in Male Patients

BACKGROUND

Androgenetic alopecia (AGA) results from shortening of the anagen phase of the hair cycle and, subsequently, miniaturization of hair follicles. Alopecia areata (AA) is a disease of autoimmunity where T cells attack anagen hair follicles and shows multifactorial etiology. Dickkopf-1 (DKK-1) is a gene that is responsible for transformation of anagen to catagen, which suggests that it is involved in development of both diseases.

OBJECTIVES

To evaluate the tissue levels of dickkopf-1 in male patients with AGA and AA in comparison with controls, in an attempt to know its role in the pathogenesis of both disorders.

METHODS

DKK-1 immunohistochemical expression was evaluated in lesional scalp biopsies taken from 20 male patients with AGA evaluated clinically by the modified Norwood-Hamilton score, 20 male patients with AA evaluated clinically by SALT score, and 20 healthy controls within the same age and sex of the studied patients.

RESULTS

A highly significant difference in DKK-1 expression between patients with AGA and healthy controls was found (P2 < 0.001). There were also significant differences in DKK-1 expression between patients with AA and healthy controls (P3 = 0.013), and between both patient groups (P1 = 0.002).

CONCLUSIONS

Both AGA and AA showed significant increase in DKK-1 immunohistochemical expression. This may enhance the idea of its possible role in the pathogenesis of AGA and AA, and being a new target for treatment of these hair disorders.

Proprietary Herbal Extract Downregulates the Gene Expression of IL-1α in HaCaT Cells: Possible Implications Against Nonscarring Alopecia

Background

Currently while, topical minoxidil and oral finasteride are the only medications approved in androgenetic alopecia (AGA), the cause oriented treatment and immunsupressive treatment are being performed in telogen effluvium (TE) and alopecia areata (AA) respectively. Considering the inflammatory factors in the pathogenesis of these three nonscarring alopecia forms, we have formulated a mixture for topical usage composed of six different herbal extracts (HE) which have already known antiinflammatory and antioxidant features.

Materials and Methods

In addition to performing the phytochemical analysis of HE, we detected the gene expression level of IL-1α, the crucial hair loss mediator, for the putative efficacy in nonscarring alopecia. Cell proliferation assay was performed by XTT reagent. After determination of non-cytotoxic concentration, HaCaT cells were treated with HE. RNA isolations were carried out from both non-treated and treated cell groups by using TRI-reagent. Gene expressions of IL-1α and as control GAPDH were determined by RT-qPCR analysis.

Results

Results were represented as “IL-1α/GAPDH Fold Change”. HE solution caused statistically significant downregulation of IL-1α gene expressions (p<0.0001), compared to untreated control cells. HE treatment ended up with 0.1900 fold change for IL-1α.

Conclusion

IL-1α is a direct growth inhibitory agent in hair follicles and an important actor in the pathogenesis of AGA , TE, and AA. Considering together the vitamins, flavonoids, and trace elements identified in the phytochemical analyses and downregulation of IL-1α in HaCaT cells, our HE may be an auxiliary agent in the therapy of these three nonscarring alopecia forms.

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.

A specific combination of zeaxanthin, spermidine and rutin prevents apoptosis in human dermal papilla cells

Hair follicle (HF) regression is characterized by the activation of apoptosis in HF cells. Dermal papilla cells play a leading role in the regulation of HF development and cycling. Human follicular dermal papilla cells (HFDPC) were used to investigate the protective activities of rutin, sperimidine and zeaxanthine. HFDP cell incubation with staurosporine caused apoptosis, which was completely inhibited by exposure to rutin (2.2 μM), spermidine (1 μM) and zeaxanthin (80 μM). These agents were much less effective when applied as single compounds. Moreover, treatment preserved the expression of anti-apoptotic molecules such as Bcl-2, MAP-kinases and their phosphorylated forms. In conclusion, the investigated agents may represent an effective treatment for the prevention of apoptosis, one of the leading events involved in hair bulb regression.