SOCS3 treatment prevents the development of alopecia areata by inhibiting CD8+ T cell-mediated autoimmune destruction

Amygdalin ameliorates alopecia areata on C3H/HeJ mice by inhibiting inflammation through JAK2/STAT3 pathway

BACKGROUND

Evidence has demonstrated that Chinese medicine formula Xuefu Zhuyu decoction can markedly promote the formation of new hair in patients and mice with alopecia areata (AA). Amygdalin is one of the active components of Xuefu Zhuyu decoction, but its therapeutic effects and the underlying mechanisms on AA remains largely unrevealed.

PURPOSE

Therefore, this study aims to investigate the therapeutic effects and to probe its molecular mechanisms of inflammation and immune regulation on AA model of C3H/HeJ mice.

STUDY DESIGN

The C3H/HeJ female mice were divided into control, AA, rusolitinib (60 mg/kg), and amygdalin groups (60, 90, and 120 mg/kg, 0.2 ml/10 g, i.g.).

METHODS

The optical microscope was used to observe the feature of the local skin, and the number of lanugo and terminal hair. H&E staining was performed to determine the degree of pathological damage to the skin. ELISA was performed to detect levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) in mice serum. Flow cytometry was carried out to analyze the CD4+CD25+FOXP3+, CD4+ and CD8+ of skin tissue. And the levels of CD4+ and CD8+, p-JAK/JAK2, p-STAT3/STAT, and SOCS3 were detected by immunohistochemistry. Western blot and qRT-PCR were employed to examine the expression levels of IL-6, TNF-α, IFN-γ, JAK2, p-JAK, STAT, p-STAT3 and SOCS3 proteins and genes in skin tissues.

RESULTS

Compared with AA group, amygdalin immensely increased the number of vellus hairs and decreased the number of terminal hairs determined by skin microscopy and H&E staining. ELISA, Western blot and qRT-PCR data showed that the levels of IL-6, TNF-α and IFN-γ in serum and skin tissues of AA mice were significantly increased, while amygdalin administration dramatically restrained the contents of the three pro-inflammatory factors. Flow cytometry and immunohistochemistry hinted that amygdalin observably enhanced the number of CD4+CD25+FOXP3+ and CD4+ cells, while inhibited the number of CD8+ positive cells in mice with AA. Moreover, amygdalin signally reduced JAK2/STAT3 pathway-related protein and gene levels in AA mice.

CONCLUSION

Amygdalin could inhibit inflammatory response and improve immune function in the treatment of AA. The underlying molecular mechanism may be related to inhibition of JAK2/STAT3 pathway.

Translational impact of omics studies in alopecia areata: recent advances and future perspectives

INTRODUCTION

Alopecia areata (AA) is a non-scarring, hair loss disorder and a common autoimmune-mediated disease with an estimated lifetime risk of about 2%. To date, the treatment of AA is mainly based on suppression or stimulation of the immune response. Genomics and transcriptomics studies generated important insights into the underlying pathophysiology, enabled discovery of molecular disease signatures, which were used in some of the recent clinical trials to monitor drug response and substantiated the consideration of new therapeutic modalities for the treatment of AA such as abatacept, dupilumab, ustekinumab and Janus Kinase (JAK) inhibitors.

AREAS COVERED

In this review, genomics and transcriptomics studies in AA are discussed in detail with particular emphasis on their past and prospective translational impacts. Microbiome studies are also briefly introduced.

EXPERT OPINION

The generation of large datasets using the new high-throughput technologies has revolutionized medical research and AA has also benefited from the wave of omics studies. However, the limitations associated with JAK inhibitors and clinical heterogeneity in AA patients underscore the necessity for continuing omics research in AA for discovery of novel therapeutic modalities and development of clinical tools for precision medicine.

Diagnostic implications of MicroRNAs; 155, 146 a, and 203 lesional expression in alopecia areata: A preliminary case-controlled study

BACKGROUND

Alopecia areata (AA) is an immune mediated disorder that attacks hair follicles with unknown pathophysiology. MicroRNAs (miRNAs) are small noncoding RNA molecules, and their aberrant expression or function has been involved in different autoimmune conditions.

OBJECTIVES

We aimed at exploring the association between some miRNAs lesional expression and AA pathogenesis by measurement of miRNAs-155, 146a, and 203 expression levels in the lesional skin from patchy AA patients and to evaluate their relation with the studied parameters.

SUBJECTS AND METHODS

Skin expression levels of miRNAs-155, 146a, and 203 were evaluated in 50 patients with patchy AA and 25 healthy controls using reverse transcriptase-quantitative PCR (RT-qPCR). The activity and severity of alopecia were assessed according to AA Investigational Assessment Guidelines criteria.

RESULTS

Studied patients showed significant up-regulation of miRNAs-203, 146a, and 155 lesional tissue expression levels when compared to control group (p < 0.05 each). Only miRNA-146a skin expression level was significantly higher in patients with multiple lesions (p < 0.001). However, patients with active AA had significantly higher tissue expression levels of the investigated miRNAs than those with inactive disease (P 0.001, 0.009, and 0.001, respectively).

CONCLUSIONS

Investigated miRNAs seem to be role players in AA pathogenesis and may be considered potential indicators of disease activity. However, more research is needed to clarify their accurate role and clinical importance.

Induction of alopecia areata in C3H/HeJ mice using cryopreserved lymphocytes

BACKGROUND

Alopecia areata (AA) is an autoimmune disease resulting in non-scarring hair loss. Animal models are useful means to identify candidates for therapeutic agents. The C3H/HeJ mouse AA model induced via transferring cultured lymphoid cells isolated from AA-affected mice is widely used for AA research. However, this conventional method requires the continuous breeding of AA mice.

OBJECTIVE

We aimed to establish a new method to generate AA model using the transfer of cryopreserved cells, which allows the rapid induction of a large number of AA mice when needed.

METHODS

We cryopreserved lymph node cells soon after isolation from AA-affected mice and injected thawed-cultured cells into recipient mice. H&E staining, immunohistochemical staining, quantitative real-time PCR and ELISA were conducted to identify pathological characteristics. Flow cytometry was performed to reveal the profile of transferred cells.

RESULTS

More than 90 % of recipient mice developed AA-like hair loss and showed inflammatory cell infiltration around anagen hair follicles, markedly increased mRNA expressions of interferon-γ, CXCL11, and granzyme B, and elevated interferon-α protein levels in the skin compared with naïve mice. Higher percentages of effector memory T cells and dendritic cells in transferred cells resulted in a higher incidence of AA.

CONCLUSION

This is the first report to establish a method for generating AA mice using cryopreserved lymphocytes. These AA mice have similar pathological characteristics to AA mice generated with the conventional method and AA patients. This convenient and reproducible method is expected to be valuable for AA study.

Frontiers in alopecia areata pathobiology research

This current review explores selected and as yet insufficiently investigated frontiers in current alopecia areata (AA) pathobiology research, with an emphasis on potential "new" players in AA pathobiology that deserve more systematic exploration and therapeutic targeting. Indeed, new evidence suggests that CD8⁺ T cells, which have long been thought to be the central players in AA pathobiology, are not the only drivers of disease. Instead, subsets of natural killer (NK) and so-called "unconventional" T cells (invariant NK T cells, γδ T cells, classic NK cells, and type 1 innate lymphoid cells), all of which can produce large amounts of IFN-γ, might also drive AA pathobiology independent of classical, autoantigen-dependent CD8⁺ T-cell functions. Another important new frontier is the role of regulatory lymphocyte subsets, such as regulatory T cells, γδ regulatory T cells, NKT10 cells, and perifollicular mast cells, in maintaining physiologic hair follicle immune privilege (IP); the extent to which these functions are defective in patients with AA; and how this IP-protective role could be restored therapeutically in patients with established AA. Broadening our AA research horizon along the lines suggested above promises not only to open the door to innovative and even more effective immunotherapy strategies for AA but will also likely be relevant for other autoimmune disorders in which pathobiology, ectopic MHC class I expression, and IP collapse play an important role.

Morpho-regulation in diverse chicken feather formation: Integrating branching modules and sex hormone-dependent morpho-regulatory modules

Many animals can change the size, shape, texture and color of their regenerated coats in response to different ages, sexes, or seasonal environmental changes. Here, we propose that the feather core branching morphogenesis module can be regulated by sex hormones or other environmental factors to change feather forms, textures or colors, thus generating a large spectrum of complexity for adaptation. We use sexual dimorphisms of the chicken to explore the role of hormones. A long-standing question is whether the sex-dependent feather morphologies are autonomously controlled by the male or female cell types, or extrinsically controlled and reversible. We have recently identified core feather branching molecular modules which control the anterior-posterior (bone morphogenetic orotein [BMP], Wnt gradient), medio-lateral (Retinoic signaling, Gremlin), and proximo-distal (Sprouty, BMP) patterning of feathers. We hypothesize that morpho-regulation, through quantitative modulation of existing parameters, can act on core branching modules to topologically tune the dimension of each parameter during morphogenesis and regeneration. Here, we explore the involvement of hormones in generating sexual dimorphisms using exogenously delivered hormones. Our strategy is to mimic male androgen levels by applying exogenous dihydrotestosterone and aromatase inhibitors to adult females and to mimic female estradiol levels by injecting exogenous estradiol to adult males. We also examine differentially expressed genes in the feathers of wildtype male and female chickens to identify potential downstream modifiers of feather morphogenesis. The data show male and female feather morphology and their color patterns can be modified extrinsically through molting and resetting the stem cell niche during regeneration.

Alopecia areata: a review of disease pathogenesis

BACKGROUND

Alopecia areata is a disorder that results in nonscarring hair loss. The psychological impact can be significant, leading to feelings of depression and social isolation. Objectives In this article, we seek to review the pathophysiological mechanisms proposed in recent years in a narrative fashion.

METHODS

We searched MEDLINE and Scopus for articles related to alopecia areata, with a particular emphasis on its pathogenesis.

RESULTS

The main theory of alopecia areata pathogenesis is that it is an autoimmune phenomenon resulting from a disruption in hair follicle immune privilege. What causes this breakdown is an issue of debate. Some believe that a stressed hair follicle environment triggers antigen presentation, while others blame a dysregulation in the central immune system entangling the follicles. Evidence for the latter theory is provided by animal studies, as well investigations around the AIRE gene. Different immune-cell lines including plasmacytoid dendritic cells, natural killer cells and T cells, along with key molecules such as interferon-γ, interleukin-15, MICA and NKG2D, have been identified as contributing to the autoimmune process.

CONCLUSIONS

Alopecia areata remains incurable, although it has been studied for years. Available treatment options at best are beneficial for milder cases, and the rate of relapse is high. Understanding the exact mechanisms of hair loss in alopecia areata is therefore of utmost importance to help identify potential therapeutic targets.

Tetrahydroxystilbene Glucoside Effectively Prevents Apoptosis Induced Hair Loss

The effect of Polygonum multiflorum against hair loss has been widely recognized. 2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-glucoside (TSG) is the main component of Polygonum multiflorum; however, its role in hair regeneration has not been established. To evaluate the hair growth-promoting activity of TSG, depilated C57BL/6J mice were topically treated with normal saline, TSG, Pifithrin-α, Minoxidil for 2 weeks. In this study, we identified that p53, Caspase-3, Active Caspase-3, and Caspase-9 were obviously upregulated in the skin of human and mice with hair loss by western blot analysis. Depilated mice treated with TSG showed markedly hair regrowth. TUNEL⁺ cells were also reduced in mice with TSG. These changes were accompanied with inhibition of Fas, p53, Bax, Active Caspase-3, and Procaspase-9 activities. These results demonstrated that TSG exerts great hair regrowth effect on hair loss, which was probably mediated by inhibition of p53, Fas, and Bax induced apoptosis.

Hair Follicle Immune Privilege Revisited: The Key to Alopecia Areata Management

The collapse of the immune privilege (IP) of the anagen hair bulb is now accepted as a key element in AA pathogenesis, and hair bulb IP restoration lies at the core of AA therapy. Here, we briefly review the essentials of hair bulb IP and recent progress in understanding its complexity. We discuss open questions and why the systematic dissection of hair bulb IP and its pharmacological manipulation (including the clinical testing of FK506 and α-melanocyte-stimulating hormone analogs) promise to extend the range of future therapeutic options in AA and other IP collapse-related autoimmune diseases.

Induction of SOCS3 by liver X receptor suppresses the proliferation of hepatocellular carcinoma cells

Liver X receptor (LXR), a member of nuclear receptor superfamily, is involved in the regulation of glucose, lipid and cholesterol metabolism. Recently, it has been reported that LXR suppress different kinds of cancers including hepatocellular carcinoma (HCC). However, the corresponding mechanism is still not well elucidated. In the present study, we found that activation of LXR downregulated cyclin D1 while upregulated p21 and p27 by elevating the level of suppressor of cytokine signaling 3 (SOCS3), leading to the cell cycle arrest at G1/S phase and growth inhibition of HCC cells. Moreover, we demonstrated that LXRα (not LXRβ) mediated the induction of SOCS3 in HCC cells. Subsequently, we showed that LXR activation enhanced the mRNA stability of SOCS3, but had no significant influence on the transcriptional activity of SOCS3 gene promoter. The experiments in nude mice revealed that LXR agonist inhibited the growth of xenograft tumors and enhanced SOCS3 expression in vivo. These results indicate that “LXRα-SOCS3-cyclin D1/p21/p27” is a novel pathway by which LXR exerts its anti-HCC effects, suggesting that the pathway may be a new potential therapeutic target for HCC treatment.