What’s new in hair — May 2017 | Dr. Yuval Ramot
Genes Dev. 2017 May 2. doi: 10.1101/gad.298703.117. [Epub ahead of print]
In recent years, we have learnt a lot on the factors that regulate the stem cells of the hair follicle that reside in the bulge, the stem cell niche. Nevertheless, the mechanisms that control hair pigmentation and the interaction between the melanocytes and the progenitor cells were still obscure. Many of the most important findings in science are found by accident, and this was also true for this study. Liao et al. describe how they have deleted Scf in neurofibroma neoplastic cells by using the Schwann cell lineage Krox20Cre mouse. To their surprise, they found that these mice developed premature hair greying, and quickly lost all hair pigmentation. This has led to a series of experiments to uncover the reason for hair depigmentation in these mice. Liao et al. have found that the transcription factor KROX20 is a marker for a sublineage of hair follicle epithelial cells toward the differentiation of hair shaft during the morphogenesis of the hair follicle. These cells serve as a source for the growth factor SCF, stem cell factor, that maintains the pool of mature melanocytes in the hair matrix that result in hair pigmentation. Deletion of the Krox20 lineage cells resulted in complete loss of hair, further demonstrating the importance of these cells for hair growth and normal function. Further research is needed to find if these results could be translated to therapeutic options for reversing hair whitening.
Exp Dermatol. 2017 May 8. doi: 10.1111/exd.13380. [Epub ahead of print]
There is evidence that psychological stress can lead to hair loss and vitiligo, and therefore it is possible that hair follicle melanogenesis is also dependent on stress and stress factors. In this study, Liao et al. used two mice models to test the assumption that stress plays a role in hair follicle melanogenesis. These models included the chronic restraint stress (CRS) and the chronic unpredicted mice stress (CUMS). Both stress models caused depigmentation of the hair follicle, associated with a decrease in the expression of melanogenic enzymes. Furthermore, keratinocyte proliferation was decreased and apoptosis was increased in both models. These effects were accompanied by decreased serum and skin levels of 5-HT levels, which has been shown to induce melanogensis in vitro. This study offers an experimental explanation for the suggested link between psychological stress and hair follicle depigmentation, which should be further confirmed in future studies.
SOCS3 treatment prevents the development of alopecia areata by inhibiting CD8+ T cell-mediated autoimmune destruction
Oncotarget. 2017 May 16;8(20):33432-33443. doi: 10.18632/oncotarget.16504
The immune system, and specifically T cells, play a crucial role in the development of alopecia areata. Cytokines mediate a large part of this immune process, and therefore it was speculated that suppressors of cytokine signalling (SOCS) might change the disease process. On this basis, Gao et al. examined whether SOCS3 can prevent the formation of autoimmune alopecia. Using the grafted C3H/HeJ mouse model they showed that treatment with recombinant SOCS3 decreased the incidence of alopecia areata, accompanied by a reduction in CD44high CD62Llow effector memory CD8+ T cells. Furthermore, SOCS3 prevented the development of alopecia areata by inhibiting CD8+ T cell-mediated autoimmune destruction and by inhibition of IFN-γ signalling. A hint to the relevance of this protein also to humans with alopecia areata was provided by the authors by showing that SOCS3 levels were decreased in lesional skin from humans with alopecia areata. These data suggest that SOCS3 might be a target for future treatments for alopecia areata.
Low level light-minoxidil 5% combination versus either therapeutic modality alone in management of female patterned hair loss: A randomized controlled study
Lasers Surg Med. 2017 May 10. doi: 10.1002/lsm.22684. [Epub ahead of print]
Minoxidil and low-level laser therapy (LLLT) are the only FDA-approved treatment modalities for female pattern hair loss (FPHL), and their effectiveness has been documented in several studies. However, a direct comparison between these two treatment options and the combination of both treatments were not tested previously. In this study, Esmat et al conducted a randomized controlled study in 45 patients with FPHL, and found that the patients in the combination group achieved better improvement in Ludwig scale and in patient satisfaction. Dermoscopic and ultrasound bio-microscopic evaluations also demonstrated that both treatments, either alone or in combination, have beneficial effects on hair growth parameters. The authors conclude that LLLT and minoxidil show comparable results in terms of hair growth, and that their combination can achieve better results than each treatment separately. It should be taken into consideration, though, that due to inherent study limitations, patients were not blinded to treatment, and that 5% minoxidil twice daily was used, rather the 2% concentration that is approved for use in women. Furthermore, the number of patients that were recruited to this study was rather small, and therefore a larger study is needed to confirm these results.
Efficacy of Topical Latanoprost Versus Minoxidil and Betamethasone Valerate on The Treatment of Alopecia Areata
J Dermatolog Treat. 2017 May 18:1-31. doi: 10.1080/09546634.2017.1330527. [Epub ahead of print]
Topical treatment is often used for localized alopecia areata (AA), but there is lack of evidence on the efficacy of such treatment. In this study, El-Ashmawy et al. conducted a single-blind randomized controlled study to test the efficacy of latanoprost, minoxidil, betamethasone and a combination of latanoprost with betamethasone in 100 patients with AA. The patients were treated for 20 weeks, and were followed-up for additional 12 weeks without treatment. All treatments were found to be significantly effective and safe for the treatment of patchy AA. Of special interest is the finding that the addition of latanoprost to betamethasone valerate significantly improved its efficacy, suggesting that this could be a promising adjunct for the treatment of localized AA. Nevertheless, more studies should be conducted to confirm these results, and to determine the best concentration for the treatment of AA.
Importance of Group Therapeutic Support for Family Members of Children with Alopecia Areata: A Cross-Sectional Survey Study
Pediatr Dermatol. 2017 May 16. doi: 10.1111/pde.13176. [Epub ahead of print]
The psychological effects of alopecia areata (AA) on the patients are well-documented, and can lead to a significant reduction in the quality of life of the patients. The alopecia areata bowling social (AABS) is an event organized by the Minnesota branch of the National Alopecia Areata Foundation to connect children with AA and their families. In this study, Aschenbeck et al. used this event to collect information from the parents of children with AA, and showed that socializing with other AA patients and their families was an important factor for the people attending this event (100% of the people that responded to the questionnaires). This study shows the importance of conducting social events for AA patients and their families, and the necessity of making support groups available for the patients.