Alopecia Areata Susceptibility in Rodent Models

With our current view of alopecia areata as an autoimmune disease, it is probable that disease development in an individual is dependent on multiple genetic and environmental factors interacting in a complex system. Rodent models afford the opportunity to investigate alopecia areata development and to define the significance of the different factors involved. Recently, rodent model characterization has been conducted using flow cytometry, microarray analysis, and functional studies. From these a pattern of events in alopecia areata development has emerged. Although the preliminary activation events for the onset of alopecia areata remain unknown, the response of the immune system is characterized by antigen presentation and costimulation of lymphocytes in the lymph nodes and skin, a deficiency of CD4+/CD25+ regulatory cells, and an action of activated lymphocytes on hair follicles via Fas/FasL signaling and cytokines. Thus, onset of disease may require appropriate (or inappropriate) expression of stimulatory antigens within the hair follicle, the breakdown of the putative hair follicle immune privilege, the presentation of antigens to the immune system, a failure of immune system regulation, and the ability of the activated immune system to disrupt anagen-stage hair follicles. Once the sequence of events is initiated, it may become a self-perpetuating cycle, with epitope spreading leading to a wider range of targets in chronic alopecia areata. Rodent model studies have provided significant insight into alopecia areata, but much more remains to be explained about the mechanisms of disease development

Alopecia Areata: Treatment of Today and Tomorrow

It is the aim of this article to review and appraise available data on treatments for alopecia areata (AA) according to the demands of evidence based medicine. Studies evaluating the efficacy of a treatment for AA should include appropriate controls, use cosmetically acceptable hair regrowth as a parameter for treatment success, include patients with AA totalis, universalis or extensive patchy AA, and exclude patients suffering from AA for less than 3 months. Moreover, the treatment must be safe over a prolonged period of time. Among the various therapeutic approaches presently available for AA, only treatment with contact sensitizers such as diphenylcyclopropenone or squaric acid dibutylester has been shown to be effective in studies that fulfill these criteria.Improved future treatments may be immunosup-pressive or immunomodulatory targeting of the autoimmune pathogenesis of AA, or they may otherwise protect hair follicles from the injurious effects of inflammation. Such possible future therapeutic approaches include the incorporation of immunomodulatory agents into liposomes as an improved vehicle; inhibition of apoptosis mediated by the Fas-FasL system; inhibition of the lymphocyte homing receptor CD44v10; induction of tolerance

Cultured Peribulbar Dermal Sheath Cells Can Induce Hair Follicle Development and Contribute to the Dermal Sheath and Dermal Papilla

Green fluorescent protein (GFP)-expressing wild-type, and nontransgenic mouse vibrissa follicle cells were cultured and implanted to mouse ears and footpads. Dermal papiller (DP)-derived cells and cells from the peribulbar dermal sheath “cup” (DSC) induced new hair follicles in both implanted ears and footpads, while nonbulbar dermal sheath cells did not. Confocal microscopy revealed that GFP-expressing DP and DSC cells induced hair growth associated with the formation of DP exclusively comprised of fluorescent cells. In mouse ears, but not footpads, fluorescent DP and DSC cells could also be identified in DP along with nonfluorescent cells. DSC cells were characterized in vivo and in vitro by low alkaline phosphatase activity in contrast to high alkaline phosphatase in DP cells. The results indicate transplanted DP and DSC cells were equally capable of DP formation and hair follicle induction. This suggests the DP and peribulbar DSC may be functionally similar. In addition to observing papillae exclusively composed of GFP-expressing cells, DP and DSC cells may also have combined with resident cells to form papillae composed of implanted GFP-expressing cells and host-derived non-GFP-expressing cells. Alkaline phosphatase expression may be utilized as a simple marker to identify hair follicle mesenchyme derived cells with hair follicle inductive abilities

Sequential cyclic changes of hair roots revealed by dermoscopy demonstrate a progressive mechanism of diffuse alopecia areata over time.

YesBACKGROUND: Diffuse alopecia areata (DAA) often leads to a complete hair shedding within a few months. OBJECTIVE: To explore features and mechanisms underlying DAA. MATERIALS AND METHODS: Scalp and hair root dermoscopy were conducted on 23 DAA patients throughout the disease process, 20 patchy Alopecia areata patients, 23 acute telogen effluvium (ATE) patients and 10 normal controls. Histopathology was also evaluated. RESULTS: We found almost all hair roots were anagen in early stage DAA in 18 patients (18/23, 78.3%) within the first 4-8 weeks after hair loss onset. Anagen effluvium (~4 weeks) was followed by catagen (~4 weeks) and then telogen/exogen (~8 weeks) effluvium with overlap. Hair root and proximal hair shaft depigmentation was more prominent in later DAA disease stages. Black dots, exclamation mark hairs and inconsistent thickness of hair shafts were found more often in early than later DAA (Ps < 0.01). Early DAA histopathology revealed more prominent inflammation and hair follicle regression than that observed in the later stages. Patchy alopecia areata patients showed mixed anagen, catagen and telogen hair roots while ATE patients showed increased exogen and mildly decreased hair root pigmentation. CONCLUSION: Sequential cyclic staging of shed hairs in DAA indicates the insult may be hair-cycle specific. We suggest that DAA is initially an anagen effluvium disease involving an intense inflammatory insult, later progressing to a brief catagen effluvium, and then to telogen effluvium with premature exogen, in later stages of DAA.This study was supported by the following grants to Xingqi Zhang: National Natural Science Foundation of China (81573066); Natural Science Foundation of Guangdong Province (2014A030313098)

Alopecia areata is associated with increased expression of heart disease biomarker cardiac troponin I

YesThe development of androgenetic alopecia is associated with a risk of developing cardiovascular diseases, but the association of alopecia areata with cardiovascular diseases in humans is largely unexplored. We measured the plasma level of two common cardiovascular disease markers, cardiac troponin I and Creactive protein, in alopecia areata and androgenetic alopecia-affected subjects. Also, we investigated the possible presence of pro-apoptotic factors in the plasma of hair loss subjects. The mean plasma cardiac troponin I level was highest in alopecia areata subjects, moderately higher in androgenetic alopecia subjects, and lowest in subjects without hair loss (p < 0.05). Alopecia areata subjects not receiving treatments had highest levels of cardiac troponin I (p < 0.05). Alopecia areata plasma samples with high cardiac troponin I levels also induced significantly higher rates of cardiomyocyte apoptosis in cell culture assays. The results suggest the potential for increased heart remodelling. Close monitoring of cardiovascular health in alopecia areata subjects, as well as subsets of androgenetic alopecia patients, may be appropriate.Canadian Institutes of Health Research (CIHR; MOP-82927). EW is the recipient of a Banting Postdoctoral Fellowship (SAC-92845)

Autologous cell therapy for aged human skin: A randomized, placebo-controlled, phase-I study

YesIntroduction: Skin ageing involves senescent fibroblast accumulation, disturbance in extracellular matrix (ECM) homeostasis, and decreased collagen synthesis. Objective: to assess a cell therapy product for aged skin (RCS-01; verum) consisting of ~25 × 106 cultured, autologous cells derived from anagen hair follicle non-bulbar dermal sheath (NBDS). Methods: For each subject in the verum group, 4 areas of buttock skin were injected intradermally 1 or 3 times at monthly intervals with RCS-01, cryomedium, or needle penetration without injection; in the placebo group RCS-01 was replaced by cryomedium. The primary endpoint was assessment of local adverse event profiles. As secondary endpoints, expression of genes related to ECM homeostasis was assessed in biopsies from randomly selected volunteers in the RCS-01 group taken 4 weeks after the last injection. ­Results: Injections were well tolerated with no severe adverse events reported 1 year after the first injection. When compared with placebo-treated skin, a single treatment with RCS-01 resulted in a significant upregulation of TGFβ1, CTGF, COL1A1, COL1A2, COL3A1, and lumican mRNA expression. Limitations: The cohort size was insufficient for dose ­ranging evaluation and subgroup analyses of efficacy. Conclusions: RCS-01 therapy is well tolerated and associated with a gene expression response consistent with an improvement of ECM homeostasis.Replicel Life Sciences Inc, Vancouver, Canada

Growth factor concentrations in platelet-rich plasma for androgenetic alopecia: an intra-subject, randomized, blinded, placebo-controlled, pilot study

YesBackground: Platelet rich plasma (PRP), processed from autologous peripheral blood, is used to treat androgenetic alopecia (AGA). Objective: To determine the efficacy of PRP for hair growth promotion in AGA patients in a randomized, blinded, placebo controlled, pilot clinical trial (NCT02074943). Methods: The efficacy of an 8 week, 5 session, PRP treatment course was determined by measuring hair density and hair caliber changes in 10 AGA affected patients. For each PRP sample, the concentrations of selected growth factors were determined using a multiplex assay system. The clinical results were then correlated to the growth factor concentrations in PRP. Results: At 16 weeks, 8 weeks after the last PRP injection, treated areas exhibited increased mean hair density (+12.76%) over baseline compared to placebo (+0.99%). Mean hair caliber decreased in both treated and placebo regions (-16.22% and -19.46% respectively). Serial analysis of PRP significant variability in concentrations between patients. Overall, there was a positive correlation between GDNF concentration and hair density (p= 0.004). Trends, though not statistically significant, were also observed for FGF2 and VEGF. Limitations: Small sample size and lack of comparative cohorts receiving protocol variations limit confidence in the study data. Conclusions: This small pilot clinical trial suggests PRP treatment may be beneficial for AGA. However, the variable hair growth responses between patients indicate there is a significant opportunity to improve PRP therapy protocols for hair growth promotion. The variability in growth factor concentration in PRP suggests standardization of growth factors post-processing might improve hair growth responses.RepliCel Life Sciences Inc. (Canada

Hair Follicle Mesenchyme-Associated PD-L1 Regulates T-Cell Activation Induced Apoptosis: A Potential Mechanism of Immune Privilege

The immune privilege (IP) of hair follicles (HFs) has been well established in previous studies. However, whether cultured HF cells still exhibit IP properties, the individual factors involved in this process, and the detailed mechanisms that drive and maintain IP, are largely unidentified. We found preferential expression of IP-associated genes in cultured HF dermal papilla and dermal sheath cup cells (DSCCs) compared with non-follicular fibroblasts (FBs) at passage 4, suggesting a potential for functional IP. Notably, programmed cell death 1 ligand 1 (PD-L1) was significantly upregulated in DSCCs and dermal papilla cells relative to FBs. IFNγ secretion from peripheral blood mononuclear cells (PBMCs) co-cultured with histoincompatible DSCCs was significantly lower than with FB and higher percentages of early apoptotic, Annexin V+ cells were observed in PBMC co-cultured with DSCCs. Knockdown of PD-L1 translation by silencing interfering RNA in DSCCs enabled increased IFNγ secretion by PBMCs, whereas transfection of pCMV6-XL4/hPD-L1 in FB significantly reduced IFNγ secretion and increased apoptosis in co-cultured PBMCs. We also found that apoptosis in allogeneic T cells induced by DSCCs was largely dependent on the mitochondrial pathway. Our study suggests IP properties are exhibited in cultured DSCCs in part through expression of negative co-signaling molecule PD-L1

Serum level of IL-4 predicts response to topical immunotherapy with diphenylcyclopropenone in alopecia areata.

YesBackground: This study investigated predictors of response to topical diphenylyclopropenone (DPCP) immunotherapy in patients with alopecia areata (AA). Objective: To identify predictors of response, or resistance, to treatment for AA through clinical observations and serum tests. Methods: Eighty four AA patients were treated with DPCP. Serum cytokine levels were measured in 33 AA patients pre- and post-treatment, and in 18 healthy controls, using ELISA assays. Results: Of patients, 56.1% responded to DPCP with satisfactory hair regrowth; the response rate was negatively correlated with hair loss extent. Before DPCP treatment, higher serum IFN-γ and IL-12 cytokine levels were observed in AA patients compared to healthy controls. Non-responders to DPCP had significantly elevated serum IL-4 pre-treatment (3.07 fold higher) and lower IL-12 levels compared with responders. After DPCP treatment, non-responders had persistently high IL-4, increased IL-12, negligible decrease in IFN-γ and decreased IL-10. Post-treatment DPCP responders exhibited significantly decreased IFN-γ and IL-12, and increased IL-4 and IL-10. Development of adverse side-effects was significantly associated with higher pre-treatment serum IgE levels. Limitations: A small number of subjects were evaluated. Conclusions: Potentially, elevated pre-treatment serum levels of IL-4 and IL-12 can be used as unfavorable and favorable predictors of DPCP therapeutic effect, respectively. In addition, pre-treatment elevated serum total IgE may predict increased risk for severe adverse side-effects to DPCP application. Whether serum cytokine expression levels can be used as predictors of response to other forms of treatment is unknown, but it may warrant investigation in the development of personalized treatments for AA.This work is supported by the National Natural Science Foundation of China (81573066) and Natural Science Foundation of Guangdong Province (2014A030313098) to Xingqi Zhang