Genome-Wide MicroRNA Analysis Implicates miR-30b/d in the Etiology of Alopecia Areata

MiR-200c-3p as a novel genetic marker and therapeutic tool for alopecia areata

BACKGROUND

MicroRNAs (miRNAs) are small RNA molecules that regulate gene expression in diverse biological processes. They hold promise as therapeutic candidates for targeting human disease pathways, although our understanding of their gene regulatory mechanism remains incomplete. Alopecia areata (AA) is a prevalent inflammatory ailment distinguished by the infiltration of T cells targeting the anagen-stage hair follicles. The scarcity of effective remedies for AA may stem from limited understanding regarding its precise cellular mechanism.

AIM

To investigate and examine the importance and role of the miR-200c-3p as a genetic indicator for AA, and its possible impact on disease progression.

SUBJECTS AND METHODS

Case-control study included 65 patients with AA and 65 matched healthy controls. A real-time PCR technique was used to measure the expression of miR-200c-3p for both groups. Bioinformatic tools were used for prediction with genes and gene-gene interaction, and protein-protein interaction.

RESULTS

The expression levels of miR-200c-3p were significantly higher in AA patients than in healthy controls. We predicted that miR-200c-3p plays a markable role in the development of AA by its effect on the EGFR tyrosine kinase inhibitor resistance pathway.

CONCLUSION

We were able to identify the influence of miR-200c-3p on both PLCG1 and RPS6KP1 genes which in turn regulate the EGFR tyrosine kinases resistance pathway that displayed the most substantial increase in activity. Our outcomes shed light on the era of the potential theranostic role of this innovative miRNA in AA.

The crosstalk between PTEN-induced kinase 1-mediated mitophagy and the inflammasome in the pathogenesis of alopecia areata

Alopecia areata (AA) is a T-cell-mediated autoimmune disease that causes chronic, relapsing hair loss; however, its precise pathogenesis remains to be elucidated. Recent studies have provided compelling evidence of crosstalk between inflammasomes and mitophagy-a process that contributes to the removal of damaged mitochondria. Our previous studies showed that the NLR family pyrin domain containing 3 (NLRP3) inflammasome is important for eliciting and progressing inflammation in AA. In this study, we detected mitochondrial DNA damage in AA-affected scalp tissues and IFNγ and poly(I:C) treated outer root sheath (ORS) cells. In addition, IFNγ and poly(I:C) treatment increased mitochondrial reactive oxygen species (ROS) levels in ORS cells. Moreover, we showed that mitophagy induction alleviates IFNγ and poly(I:C)-induced NLRP3 inflammasome activation in ORS cells. Lastly, PTEN-induced kinase 1 (PINK1) knockdown increased NLRP3 inflammasome activation, indicating that PINK1-mediated mitophagy plays a critical role in NLRP3 inflammasome activation in ORS cells. This study supports previous studies showing that oxidative stress disrupts immune privilege status and promotes autoimmunity in AA. The results emphasize the significance of crosstalk between mitophagy and inflammasomes in the pathogenesis of AA. Finally, mitophagy factors regulating mitochondrial dysfunction and inhibiting inflammasome activation could be novel therapeutic targets for AA.

mTOR signaling in hair follicle and hair diseases: recent progress

Mammalian target of rapamycin (mTOR) signaling pathway is a major regulator of cell proliferation and metabolism, playing significant roles in proliferation, apoptosis, inflammation, and illness. More and more evidences showed that the mTOR signaling pathway affects hair follicle circulation and maintains the stability of hair follicle stem cells. mTOR signaling may be a critical cog in Vitamin D receptor (VDR) deficiency-mediated hair follicle damage and degeneration and related alopecia disorders. This review examines the function of mTOR signaling in hair follicles and hair diseases, and talks about the underlying molecular mechanisms that mTOR signaling regulates.

Clinical and Genetic Aspects of Alopecia Areata: A Cutting Edge Review

Alopecia areata (AA) is a chronic, non-scarring, immune-mediated skin disease that affects approximately 0.5-2% of the global population. The etiology of AA is complex and involves genetic and environmental factors, with significant advancements in genetic research occurring in recent years. In addition to well-known genes such as PTPN22, CTLA4, and IL2, which have been widely supported as being associated with AA, an increasing number of specific gene-related loci have been discovered through advances in genetic research. For instance, gene analysis of microRNAs can reveal the critical role of miRNAs in regulating gene expression, aiding in the understanding of cellular and organismal functional regulatory mechanisms. Furthermore, numerous studies have confirmed the existence of correlations between AA and other immune-related diseases. Examples include hyperthyroidism and rheumatoid arthritis. By understanding the interrelationships between AA and other immune diseases, we can further comprehend potential shared genetic foundations or pathogenic mechanisms among different diseases. Genetic research plays a crucial role in unraveling the pathogenesis of AA, as the identification of genetic variations associated with AA can assist in formulating more effective and targeted treatment strategies.

Female Pattern Hair Loss: An Overview with Focus on the Genetics

Pattern hair loss can occur in both men and women, and the underlying molecular mechanisms have been continuously studied in recent years. Male androgenetic alopecia (M-AGA), also termed male pattern hair loss, is the most common type of hair loss in men. M-AGA is considered an androgen-dependent trait with a background of genetic predisposition. The interplay between genetic and non-genetic factors leads to the phenotype of follicular miniaturization. Although this similar pattern of phenotypic miniaturization can also be found in female pattern hair loss (FPHL), the corresponding genetic factors in M-AGA do not account for the phenotype in FPHL, indicating that there are different genes contributing to FPHL. Therefore, the role of genetic factors in FPHL is still uncertain. Understanding the genetic mechanism that causes FPHL is crucial for the future development of personalized treatment strategies. This review aims to highlight the differences in the ethnic prevalence and genetic background of FPHL, as well as the current genetic research progress in nutrition, Wnt signaling, and sex hormones related to FPHL.

Novel potential therapeutic targets of alopecia areata

Alopecia areata (AA) is a non-scarring hair loss disorder caused by autoimmunity. The immune collapse of the hair follicle, where interferon-gamma (IFN-γ) and CD8+ T cells accumulate, is a key factor in AA. However, the exact functional mechanism remains unclear. Therefore, AA treatment has poor efficacy maintenance and high relapse rate after drug withdrawal. Recent studies show that immune-related cells and molecules affect AA. These cells communicate through autocrine and paracrine signals. Various cytokines, chemokines and growth factors mediate this crosstalk. In addition, adipose-derived stem cells (ADSCs), gut microbiota, hair follicle melanocytes, non-coding RNAs and specific regulatory factors have crucial roles in intercellular communication without a clear cause, suggesting potential new targets for AA therapy. This review discusses the latest research on the possible pathogenesis and therapeutic targets of AA.

Hair Follicle-Related MicroRNA-34a Serum Expression and rs2666433A/G Variant in Patients with Alopecia: A Cross-Sectional Analysis

Alopecia areata (AA) is a type of immune-mediated alopecia. Recent studies have suggested microRNAs’ (miRNAs) implication in several cellular processes, including epidermal and hair follicle biology. Single nucleotide polymorphisms (SNPs) can modify gene expression levels, which may induce an autoimmune response. This case−control study included 480 participants (240 for each case/control group). MicroRNA-34a gene (MIR-34A) rs2666433A/G variant was genotyped using real-time allelic discrimination polymerase chain reaction (PCR). Additionally, circulatory miR-34a levels were quantified by quantitative reverse transcription PCR (qRT-PCR). On comparing between alopecia and non-alopecia cohorts, a higher frequency of A variant was noted among patients when compared to controls—A allele: 28 versus 18% (p < 0.001); A/A genotype: 9 versus 2%; A/G genotype: 39 versus 32% (p < 0.001). A/A and A/G carriers were more likely to develop alopecia under heterozygote comparison (OR = 1.83, 95% CI = 1.14−2.93), homozygote comparison (OR = 4.19, 95% CI = 1.33−13.1), dominant (OR = 2.0, 95% CI = 1.27−3.15), recessive (OR = 3.36, 95% CI = 1.08−10.48), over-dominant (OR = 1.65, 95% CI = 1.04−32.63), and log additive (OR = 1.91, 95% CI = 1.3−2.82) models. Serum miR-34a expression levels were upregulated in alopecia patients with a median and quartile fold change of 27.3 (1.42−2430). Significantly higher levels were more pronounced in A/A genotype patients (p < 0.01). Patients carrying the heterozygote genotype (rs2666433 * A/G) were two times more likely to develop more severe disease grades. Stratified analysis by sex revealed the same results. A high expression level was associated with concomitant autoimmune comorbidities (p = 0.001), in particular SLE (p = 0.007) and vitiligo (p = 0.049). In conclusion, the MIR34A rs2666433 (A/G) variant is associated with AA risk and severity in the studied population. Furthermore, high miR-34a circulatory levels could play a role in disease pathogenesis.

The Roles of Non-coding RNA in the Development and Regeneration of Hair Follicles: Current Status and Further Perspectives

Alopecia is a common problem that affects almost every age group and is considered to be an issue for cosmetic or psychiatric reasons. The loss of hair follicles (HFs) and hair caused by alopecia impairs self-esteem, thermoregulation, tactile sensation and protection from ultraviolet light. One strategy to solve this problem is HF regeneration. Many signalling pathways and molecules participate in the morphology and regeneration of HF, such as Wnt/β-catenin, Sonic hedgehog, bone morphogenetic protein and Notch. Non-coding RNAs (ncRNAs), especially microRNAs and long ncRNAs, have significant modulatory roles in HF development and regeneration via regulation of these signalling pathways. This review provides a comprehensive overview of the status and future prospects of ncRNAs in HF regeneration and could prompt novel ncRNA-based therapeutic strategies.

Alopecia Areata: an Update on Etiopathogenesis, Diagnosis, and Management

Alopecia areata (AA) is a common chronic tissue-specific autoimmune disease, resulting in hair loss, that affects up to 2% of the general population. The exact pathobiology of AA has still remained elusive, while the common theory is the collapse of the immune privilege of the hair follicle caused by immunological mechanism. Multiple genetic and environment factors contribute to the pathogenesis of AA. There are several clinical treatments for AA, varying from one or multiple well-defined patches to more diffuse or total hair loss of the scalp (alopecia totalis) or hair loss of the entire body (alopecia universalis). The available treatments for AA, such as corticosteroids and other immunomodulators, minoxidil, and contact immunotherapy, are of limited efficacy with a high risk of adverse effects and high recurrence rates, especially for patients with severe AA. Recent insights into the pathogenesis of AA have led to the development of new treatment strategies, such as Janus kinase (JAK) inhibitors, biologics, and several small molecular agents. In addition, modern therapies for AA, including antihistamines, platelet-rich plasma (PRP) injection, and other novel therapies have been well explored. In this review, we discussed the recent advances in the pathogenesis, diagnosis, and treatment of AA.

Chi-miR-370-3p regulates hair follicle morphogenesis of Inner Mongolian cashmere goats

MicroRNAs (miRNAs), a class of 22 nucleotide (nt) noncoding RNAs, negatively regulate mRNA posttranscriptional modification in various biological processes. Morphogenesis of skin hair follicles in cashmere goats is a dynamic process involving many key signaling molecules, but the associated cellular biological mechanisms induced by these key signaling molecules have not been reported. In this study, differential expression, bioinformatics, and Gene Ontology/Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed on miRNA expression profiles of Inner Mongolian cashmere goats at 45, 55, and 65 days during the fetal period, and chi-miR-370-3p was identified and investigated further. Real-time fluorescence quantification (qRT-PCR), dual luciferase reporting, and Western blotting results showed that transforming growth factor beta receptor 2 (TGF-βR2) and fibroblast growth factor receptor 2 (FGFR2) were the target genes of chi-miR-370-3p. Chi-miR-370-3p also regulated the expression of TGF-βR2 and FGFR2 at mRNA and protein levels in epithelial cells and dermal fibroblasts. DNA staining, Cell Counting Kit-8, and fluorescein-labelled Annexin V results showed that chi-miR-370-3p inhibited the proliferation of epithelial cells and fibroblasts but had no effect on apoptosis. Cell scratch test results showed that chi-miR-370-3p promoted the migration of epithelial cells and fibroblasts. Chi-miR-370-3p inhibits the proliferation of epithelial cells and fibroblasts by targeting TGF-βR2 and FGFR2, thereby improving cell migration ability and ultimately regulating the fate of epithelial cells and dermal fibroblasts to develop the placode and dermal condensate, inducing hair follicle morphogenesis.

Current insight into the functions of microRNAs in common human hair loss disorders: a mini review

Alopecia areata (AA) and Androgenic alopecia (AGA) are the most common multifactorial hair loss disorders that have a serious psychological impact on the affected individuals, while frontal fibrosing alopecia (FFA) is comparatively less common. However, due to the unknown etiology and the effect of many adverse factors, the prognosis of these conditions is challenging to predict. Moreover, no approved therapy has been available to date to prevent or treat these disorders. MicroRNAs (miRNAs) are a group of evolutionary conserved small non-coding RNA molecules with significant roles in the posttranscriptional gene regulation either through mRNA degradation or translational repression. A number of biological processes are controlled by these molecules, including cell growth and differentiation, proliferation, inflammation, immune responses, and apoptosis. Recently, a handful of studies have demonstrated the impact of miRNAs on common hair loss-related disorders; however, the exhaustive molecular mechanisms are still unclear. In this review, we discussed the functional implications of miRNAs in common hair loss-related disorders and addressed their efficacy to be used for theranostic purposes shortly.

The Roles of Tenascins in Cardiovascular, Inflammatory, and Heritable Connective Tissue Diseases

Tenascins are a family of multifunctional extracellular matrix (ECM) glycoproteins with time- and tissue specific expression patterns during development, tissue homeostasis, and diseases. There are four family members (tenascin-C, -R, -X, -W) in vertebrates. Among them, tenascin-X (TNX) and tenascin-C (TNC) play important roles in human pathologies. TNX is expressed widely in loose connective tissues. TNX contributes to the stability and maintenance of the collagen network, and its absence causes classical-like Ehlers-Danlos syndrome (clEDS), a heritable connective tissue disorder. In contrast, TNC is specifically and transiently expressed upon pathological conditions such as inflammation, fibrosis, and cancer. There is growing evidence that TNC is involved in inflammatory processes with proinflammatory or anti-inflammatory activity in a context-dependent manner. In this review, we summarize the roles of these two tenascins, TNX and TNC, in cardiovascular and inflammatory diseases and in clEDS, and we discuss the functional consequences of the expression of these tenascins for tissue homeostasis.

A "hair-raising" history of alopecia areata

A 3500-year-old papyrus from ancient Egypt provides a list of treatments for many diseases including "bite hair loss," most likely alopecia areata (AA). The treatment of AA remained largely unchanged for over 1500 years. In 30 CE, Celsus described AA presenting as scalp alopecia in spots or the "windings of a snake" and suggested treatment with caustic compounds and scarification. The first "modern" description of AA came in 1813, though treatment still largely employed caustic agents. From the mid-19th century onwards, various hypotheses of AA development were put forward including infectious microbes (1843), nerve defects (1858), physical trauma and psychological stress (1881), focal inflammation (1891), diseased teeth (1902), toxins (1912) and endocrine disorders (1913). The 1950s brought new treatment developments with the first use of corticosteroid compounds (1952), and the first suggestion that AA was an autoimmune disease (1958). Research progressively shifted towards identifying hair follicle-specific autoantibodies (1995). The potential role of lymphocytes in AA was made implicit with immunohistological studies (1980s). However, studies confirming their functional role were not published until the development of rodent models (1990s). Genetic studies, particularly genome-wide association studies, have now come to the forefront and open up a new era of AA investigation (2000s). Today, AA research is actively focused on genetics, the microbiome, dietary modulators, the role of atopy, immune cell types in AA pathogenesis, primary antigenic targets, mechanisms by which immune cells influence hair growth, and of course the development of new treatments based on these discoveries.

Emerging Topical and Systemic JAK Inhibitors in Dermatology

Accumulating data on cellular and molecular pathways help to develop novel therapeutic strategies in skin inflammation and autoimmunity. Examples are psoriasis and atopic dermatitis, two clinically and immunologically well-defined disorders. Here, the elucidation of key pathogenic factors such as IL-17A/IL-23 on the one hand and IL-4/IL-13 on the other hand profoundly changed our therapeutic practice. The knowledge on intracellular pathways and governing factors is shifting our attention to new druggable molecules. Multiple cytokine receptors signal through Janus kinases (JAKs) and associated signal transducer and activators of transcription (STATs). Inhibition of JAKs can simultaneously block the function of multiple cytokines. Therefore, JAK inhibitors (JAKi) are emerging as a new class of drugs, which in dermatology can either be used systemically as oral drugs or locally in topical formulations. Inhibition of JAKs has been shown to be effective in various skin disorders. The first oral JAKi have been recently approved for the treatment of rheumatoid arthritis and psoriatic arthritis. Currently, multiple inhibitors of the JAK/STAT pathway are being investigated for skin diseases like alopecia areata, atopic dermatitis, dermatomyositis, graft-versus-host-disease, hidradenitis suppurativa, lichen planus, lupus erythematosus, psoriasis, and vitiligo. Here, we aim to discuss the immunological basis and current stage of development of JAKi in dermatology.

Italian Guidelines in diagnosis and treatment of alopecia areata

Alopecia areata (AA) is an organ-specific autoimmune disorder that targets anagen phase hair follicles. The course is unpredictable and current available treatments have variable efficacy. Nowadays, there is relatively little evidence on treatment of AA from well-designed clinical trials. Moreover, none of the treatments or devices commonly used to treat AA are specifically approved by the Food and Drug Administration. The Italian Study Group for Cutaneous Annexial Disease of the Italian Society of dermatology proposes these Italian guidelines for diagnosis and treatment of Alopecia Areata deeming useful for the daily management of the disease. This article summarizes evidence-based treatment associated with expert-based recommendations.