Restoration of hair growth in mice with an alopecia areata-like disease using topical anthralin

An Updated Review on Current Treatment of Alopecia Areata and Newer Therapeutic Options

Alopecia areata (AA) is a dermatological disease that causes nonscarring hair loss. It can occur at any age and has an unpredictable and variable evolution in individuals. The aim of this review is to provide an update on the novel therapies currently being used, as well as upcoming therapeutic options in the treatment of AA.

Topical diphenylcyclopropenone plus topical 0.5% anthralin versus topical diphenylcyclopropenone alone for the treatment of chronic extensive alopecia areata: A split-scalp, double-blind, controlled study

Background:

The combination of diphenylcyclopropenone (DCP) and anthralin may demonstrate synergistic effects in the treatment of chronic extensive alopecia areata (AA).

Objective:

The objective of the study was to compare the efficacy of the combination therapy of topical DCP and topical 0.5% anthralin versus topical DCP alone for the treatment of chronic extensive AA.

Materials and Methods:

Ten patients were included in the study. Of these, 1, 2, and 7 patients were diagnosed with alopecia totalis, severe AA (>50% hair loss), and alopecia universalis, respectively. For each patient, one side of the scalp was treated with a DCP solution and 0.5% anthralin for 6 months, while the other side was treated with DCP and a cream base for the same duration. The clinical responses were assessed at baseline and then monthly until the end of the 6-month study period using the Severity of Alopecia Tool score. The side effects were evaluated at each follow-up visit.

Results:

The difference in the efficacies of the combination treatment and DCP alone was not statistically significant (P = 0.59). Regarding the side effects, DCP plus 0.5% anthralin caused significantly more excessive dermatitis than DCP alone (7 patients vs. 2 patients; P = 0.02). Eight patients reported temporary hyperpigmentation at the combination-treatment site, whereas no hyperpigmentation was reported at the DCP-alone site of any patient (P < 0.001).

Conclusions:

The combination of DCP and 0.5% anthralin was not superior to DCP alone for the treatment of chronic extensive AA. An increase in side effects – excessive dermatitis and hyperpigmentation – was observed in the combination-treatment group.

Nonsurgical Induction of Alopecia Areata in C3H/HeJ Mice via Adoptive Transfer of Cultured Lymphoid Cells

Surgical induction of alopecia areata (AA) via full-thickness grafting of spontaneous AA-affected C3H/HeJ mouse skin to naïve recipients has been a primary method of transferring the AA disease model phenotype. However, this method is associated with the need to perform an invasive procedure that could negatively impact animal wellbeing. Therefore, a rodent model that rapidly develops AA at a predictable rate and without the need to perform invasive surgical procedures on the mice is essential for studying the pathogenesis of AA. Here we describe a cell injection technique using cultured skin-draining lymph node cells (LNCs) injected intradermally into naïve recipients to induce rapid AA development. The cultured LNCs can reach ~ten fold expansion after 6 days with specific cytokine stimulation. The LNCs derived from a single AA affected mouse donor can induce AA development in more than 80 naïve mice within 2-18 weeks. For comparative control studies, mice receiving cultured LNCs from normal donors remain normally haired. The method enables the production of large numbers of AA mice for use in research and treatment development studies while avoiding the use of surgical procedures. We anticipate that the protocol can also be adapted for use in other mouse autoimmune disease models.

New and Emerging Therapies for Alopecia Areata

Alopecia areata (AA) is an autoimmune condition that affects up to 2% of the general population. Currently available treatment options for AA are of limited efficacy and can be associated with adverse effects. The advancement in understanding of the genetic and molecular mechanisms of AA has led to the development of novel treatment options, with the Janus kinase (JAK) inhibitor class of drugs at the forefront of ongoing clinical trials. Platelet-rich plasma, fecal transplants, and cytokine-targeted therapy with ustekinumab and dupilumab have also been shown to regrow hair in patients with AA in individual case reports or small studies. Several other novel therapies have preliminary data or are being tested in clinical trials.

Childhood Alopecia Areata: An Overview of Treatment and Recent Patents

BACKGROUND

Alopecia Areata (AA) is a systemic autoimmune condition that usually starts in childhood.

OBJECTIVE

This article aims to review genetics, therapy, prognosis, and recent patents for AA.

METHODS

We used clinical queries and keywords "alopecia areata" AND "childhood" as a search engine. Patents were searched using the key term "alopecia areata" in Patents.google.com and freepatentsonline. com.

RESULTS

Due to an immune-mediated damage to the hair follicles, hair is lost from the scalp and other areas of the body temporarily or even permanently. Children with AA are generally healthy. Evidence of genetic association and increased predisposition for AA was found by studying families with affected members. Pathophysiologically, T- lymphocytes attack hair follicles and cause inflammation and destruction of the hair follicles and hair loss. In mild cases, there would be well-demarcated round patchy scalp hair loss. The pathognomonic "exclamation mark hairs" may be seen at the lesion periphery. In more severe cases, the hair loss may affect the whole scalp and even the whole body. The clinical course is also variable, which may range from transient episodes of recurrent patchy hair loss to an indolent gradually deteriorating severe hair loss. The treatment of AA depends on factors including patients' age, the extent of the hair loss, duration of disease, psychological impact, availability and side effect profile of the treatments. For localized patchy alopecia, topical application of corticosteroids and/or intralesional corticosteroids are the treatment of choice. Other topical treatments include minoxidil, anthralin, coal tar and immunotherapy. In severe resistant cases, systemic immunosuppressants may be considered. Although herbal medicine, acupuncture, complementary and alternative medicine may be tried on children in some Asian communities, the evidence to support these practices is lacking. To date, only a few recent patents exist in topical treatments, including Il-31, laser and herbal medications. Clinical efficacy is pending for these treatment modalities.

CONCLUSION

None of the established therapeutic options are curative. However, newer treatment modalities, including excimer laser, interleukin-31 antibodies and biologics, are evolving so that there may be significant advances in treatment in the near future. AA can be psychosocially devastating. It is important to assess the quality of life, degree of anxiety, social phobia and mood of the patients and their families. Psychological support is imperative for those who are adversely affected psychosocially.

Recalcitrant alopecia areata responsive to leflunomide and anthralin-Potentially undiscovered JAK/STAT inhibitors?

Several treatment modalities are available for the management of alopecia areata (AA); however, no therapy is universally effective and treatment can be frustrating in severe cases, with low response and high recurrence rates. Recent studies show that the JAK/STAT pathway plays a central role in the pathogenesis of this disease by determining the crosstalk between the infiltrating CD8+ T cells and the hair follicles, suggesting a role of JAK inhibitors in the treatment of AA. However, reports on the off-label use of these more expensive targeted agents have shown variable results. We present a case of a child with recalcitrant ophiasis-pattern AA who had failed steroid therapy and was treated successfully with leflunomide and anthralin, possibly by the synergistic effect on the JAK/STAT pathway inhibition, and we propose this combination could be a cost-effective therapeutic option for recalcitrant AA.

Treating Alopecia Areata: Current Practices Versus New Directions

Alopecia areata (AA) is non-scarring hair loss resulting from an autoimmune disorder. Severity varies from patchy hair loss that often spontaneously resolves to severe and chronic cases that can progress to total loss of scalp and body hair. Many treatments are available; however, the efficacy of these treatments has not been confirmed, especially in severe cases, and relapse rates are high. First-line treatment often includes corticosteroids such as intralesional or topical steroids for mild cases and systemic steroids or topical immunotherapy with diphenylcyclopropenone or squaric acid dibutylester in severe cases. Minoxidil and bimatoprost may also be recommended, usually in combination with another treatment. Ongoing research and new insights into mechanisms have led to proposals of innovative therapies. New directions include biologics targeting immune response as well as lasers and autologous platelet-rich plasma therapy. Preliminary data are encouraging, and it is hoped this research will translate into new options for the treatment of AA in the near future.

Mechanism of action of herbs and their active constituents used in hair loss treatment

This article discusses the mechanisms via topically applied products containing herbs and their active constituents affect the hair growth process. It was reported that the mechanisms involving (1) insulin-like growth factor-I (IGF-I), (2) vascular endothelial growth factor (VEGF), (3) epidermal growth factor (EGF), (4) fibroblast growth factor 2 (FGF-2), (5) endothelial nitric oxide synthase (eNOS), (6) Wnt/β-catenin signalling pathway, (7) prostaglandin E (PGE), (8) prostaglandin F (PGF) stimulate hair growth, whereas the mechanisms engaging (1) 5α-reductase and dihydrotestosterone (DHT), (2) transforming growth factor beta (TGF-β), (3) fibroblast growth factor 5 (FGF-5), (4) prostaglandin D₂ (PGD₂) inhibit hair growth. The knowledge summarized in the paper may be an inspiration to create new preparations for the treatment of hair loss.

Endogenous retinoids in the pathogenesis of alopecia areata

Alopecia areata (AA) is an autoimmune disease that attacks anagen hair follicles. Gene array in graft-induced C3H/HeJ mice revealed that genes involved in retinoic acid (RA) synthesis were increased, whereas RA degradation genes were decreased in AA compared with sham controls. This was confirmed by immunohistochemistry in biopsies from patients with AA and both mouse and rat AA models. RA levels were also increased in C3H/HeJ mice with AA. C3H/HeJ mice were fed a purified diet containing one of the four levels of dietary vitamin A or an unpurified diet 2 weeks before grafting and disease progression followed. High vitamin A accelerated AA, whereas mice that were not fed vitamin A had more severe disease by the end of the study. More hair follicles were in anagen in mice fed high vitamin A. Both the number and localization of granzyme B-positive cells were altered by vitamin A. IFNγ was also the lowest and IL13 highest in mice fed high vitamin A. Other cytokines were reduced and chemokines increased as the disease progressed, but no additional effects of vitamin A were seen. Combined, these results suggest that vitamin A regulates both the hair cycle and immune response to alter the progression of AA.

Alopecia areata update: part II. Treatment

Various therapeutic agents have been described for the treatment of alopecia areata (AA), but none are curative or preventive. The aim of AA treatment is to suppress the activity of the disease. The high rate of spontaneous remission and the paucity of randomized, double-blind, placebo-controlled studies make the evidence-based assessment of these therapies difficult. The second part of this two-part series on AA discusses treatment options in detail and suggests treatment plans according to specific disease presentation. It also reviews recently reported experimental treatment options and potential directions for future disease management.

LEARNING OBJECTIVES

After completing this learning activity, participants should be able to compare the efficacy and safety of various treatment options, formulate a treatment plan tailored to individual patients, and recognize recently described treatments and potential therapeutic approaches.

The C3H/HeJ mouse and DEBR rat models for alopecia areata: review of preclinical drug screening approaches and results

The C3H/HeJ inbred mouse strain and the Dundee Experimental Bald Rat (DEBR) strain spontaneously develop adult onset alopecia areata (AA), a cell-mediated disease directed against actively growing hair follicles. The low frequency of AA and the inability to predict the stage of AA as it evolves in the naturally occuring C3H/HeJ model of AA can be converted into a highly predictable system by grafting full thickness skin from AA-affected mice to normal haired mice of the same strain. The rat DEBR model develops spontaneous AA at a higher frequency than in the mouse model but they are more expensive to use in drug studies owing to their larger size. Regardless of the shortcomings of either model, these rodent models can be used succesfully to screen novel or approved drugs for efficacy to treat human AA. As the pathogenesis of AA follows the canonical lymphocytic co-stimulatory cascade in the mouse AA model, it can be used to screen compounds potentially useful to treat a variety of cell-mediated diseases. Efficacy of various agents can easily be screened by simply observing the presence, rate, and cosmetic acceptability of hair regrowth. More sophisticated assays can refine how the drugs induce hair regrowth and evaluate the underlying pathogenesis of AA. Some drugs commonly used to treat human AA patients work equally as well in both rodent models validating their usefulness as models for drug efficacy and safety for humanAA.

Controlled delivery of T-box21 small interfering RNA ameliorates autoimmune alopecia (Alopecia Areata) in a C3H/HeJ mouse model

Autoimmune alopecia (alopecia areata) is considered to be triggered by a collapse of immune privilege in hair follicles. Here we confirmed that infiltrating CD4 T lymphocytes around hair follicles of patients with alopecia areata were primarily CCR5-positive with few CCR4-positive cells, suggesting a dominant role of Th1 cells in the alopecic lesion. Given this finding, we sought to elucidate the effect of cytokine therapy in C3H/HeJ mice, a mouse model of alopecia areata, by applying recombinant interleukin-4 and neutralizing anti-interferon-gamma antibody. We found that local injections of both interleukin-4 and neutralizing anti-interferon-gamma antibody effectively treated alopecia in C3H/HeJ mice. Results from immunohistochemistry and semiquantitative reverse transcription-polymerase chain reaction demonstrated that intralesional injection of interleukin-4 suppressed CD8 T cell infiltrates around the hair follicles and repressed enhanced interferon-gamma mRNA expression in the affected alopecic skin. Furthermore, Th1 transcription factor T-box21 small interfering RNAs conjugated to cationized gelatin showed mitigating effects on alopecia in C3H/HeJ mice, resulting in the restoration of hair shaft elongation. Taken together, the use of gelatin-small interfering RNA conjugates promises to be a novel, efficient, and safe tool as an alternative gene therapy for the treatment of various human diseases. To our knowledge, this is the first report of effective controlled delivery of small interfering RNA using biodegradable cationized gelatin microspheres in an animal model of disease.

Lymphocytes, neuropeptides, and genes involved in alopecia areata

Many lessons in autoimmunity - particularly relating to the role of immune privilege and the interplay between genetics and neuroimmunology - can be learned from the study of alopecia areata, the most common cause of inflammation-induced hair loss. Alopecia areata is now understood to represent an organ-restricted, T cell-mediated autoimmune disease of hair follicles. Disease induction is associated with collapse of hair follicle immune privilege in both humans and in animal models. Here, the role of HLA associations, other immunogenetic factors, and neuroendocrine parameters in alopecia areata pathogenesis are reviewed. This instructive and clinically significant model disease deserves more widespread interest in the immunology community.

What Can We Learn from Animal Models of Alopecia areata?

Alopecia areata (AA) is a hair loss disease marked by a focal inflammatory infiltrate of dystrophic anagen stage hair follicles by CD4+ and CD8+ lymphocytes. Although AA is thought to be an autoimmune disorder, definitive proof is lacking. Moreover, characterization of the primary pathogenic mechanisms by which hair loss is induced in AA is limited. In this context, animal models may provide a vital contribution to understanding AA. Recent research using animal models of AA has focused on providing evidence in support of a lymphocyte-mediated pathogenic mechanism consistent with AA as an autoimmune disease. In the future, research with both humans and animal models shall likely concentrate on identifying the primary antigenic epitopes involved in AA and the genetics of AA susceptibility. With a comprehensive understanding of the key elements in AA pathogenesis, new avenues for therapeutic research and intervention will be defined.

Reversal of a full-length mutant huntingtin neuronal cell phenotype by chemical inhibitors of polyglutamine-mediated aggregation

BACKGROUND

Huntington's disease (HD) is an inherited neurodegenerative disorder triggered by an expanded polyglutamine tract in huntingtin that is thought to confer a new conformational property on this large protein. The propensity of small amino-terminal fragments with mutant, but not wild-type, glutamine tracts to self-aggregate is consistent with an altered conformation but such fragments occur relatively late in the disease process in human patients and mouse models expressing full-length mutant protein. This suggests that the altered conformational property may act within the full-length mutant huntingtin to initially trigger pathogenesis. Indeed, genotype-phenotype studies in HD have defined genetic criteria for the disease initiating mechanism, and these are all fulfilled by phenotypes associated with expression of full-length mutant huntingtin, but not amino-terminal fragment, in mouse models. As the in vitro aggregation of amino-terminal mutant huntingtin fragment offers a ready assay to identify small compounds that interfere with the conformation of the polyglutamine tract, we have identified a number of aggregation inhibitors, and tested whether these are also capable of reversing a phenotype caused by endogenous expression of mutant huntingtin in a striatal cell line from the HdhQ111/Q111 knock-in mouse.

RESULTS

We screened the NINDS Custom Collection of 1,040 FDA approved drugs and bioactive compounds for their ability to prevent in vitro aggregation of Q58-htn 1-171 amino terminal fragment. Ten compounds were identified that inhibited aggregation with IC50 < 15 microM, including gossypol, gambogic acid, juglone, celastrol, sanguinarine and anthralin. Of these, both juglone and celastrol were effective in reversing the abnormal cellular localization of full-length mutant huntingtin observed in mutant HdhQ111/Q111 striatal cells.

CONCLUSIONS

At least some compounds identified as aggregation inhibitors also prevent a neuronal cellular phenotype caused by full-length mutant huntingtin, suggesting that in vitro fragment aggregation can act as a proxy for monitoring the disease-producing conformational property in HD. Thus, identification and testing of compounds that alter in vitro aggregation is a viable approach for defining potential therapeutic compounds that may act on the deleterious conformational property of full-length mutant huntingtin.