Mechanism of desuccinylation of G6PD mediated by SIRT7 to promote vitiligo disease progression.

BACKGROUND: Sirtuin 7 (SIRT7) is pivotal in diverse diseases progression. Importantly, SIRT7 is associated with melanin production. However, whether SIRT7 regulates vitiligo is unclear. Therefore, we aimed to investigate the effects of SIRT7 on pigmentation and the modification of glucose 6-phosphate dehydrogenase (G6PD). METHODS: After knockdown SIRT7 and G6PD, pigmentation of melanocytes was evaluated using commercial kits, immunofluorescence, and Western blot analysis. The succinylation of G6PD mediated by SIRT7 was analyzed using co-immunoprecipitation, immunofluorescence, Western blot analysis, and cycloheximide-chase experiment. RESULTS: We found that SIRT7 was highly expressed in vitiligo skin lesions. Knockdown of SIRT7 increased tyrosinase activity, melanin content, and the levels of α-melanocyte-stimulating hormone, MITF, TYR, TRP1, and TRP2. Additionally, SIRT7 directly interacted with G6PD. Silenced SIRT7 promoted the succinylation of G6PD and enhanced its protein stability. G6PD knockdown reversed the effect of reduced SIRT7 expression on melanin production. CONCLSUION: Silencing of SIRT7 promotes pigmentation of melanocytes by succinylating G6PD, suggesting that SIRT7-mediated G6PD desuccinylation may promote vitiligo progression.

Polyphenols targeting multiple molecular targets and pathways for the treatment of vitiligo.

Vitiligo, a pigmentary autoimmune disorder, is marked by the selective loss of melanocytes in the skin, leading to the appearance of depigmented patches. The principal pathological mechanism is the melanocyte destruction mediated by CD8+ T cells, modulated by oxidative stress and immune dysregulation. Vitiligo affects both physical health and psychological well-being, diminishing the quality of life. Polyphenols, naturally occurring compounds with diverse pharmacological properties, including antioxidant and anti-inflammatory activities, have demonstrated efficacy in managing various dermatological conditions through multiple pathways. This review provides a comprehensive analysis of vitiligo and the therapeutic potential of natural polyphenolic compounds. We examine the roles of various polyphenols in vitiligo management through antioxidant and immunomodulatory effects, melanogenesis promotion, and apoptosis reduction. The review underscores the need for further investigation into the precise molecular mechanisms of these compounds in vitiligo treatment and the exploration of their combination with current therapies to augment therapeutic outcomes.

Antibody immune responses and causal relationships in four immune skin diseases: Evidence from Mendelian randomization and Bayesian Weighting (Antibody Responses in Skin Diseases: MR & Bayesian).

BACKGROUND: Recent studies increasingly suggest that microbial infections and the immune responses they elicit play significant roles in the pathogenesis of chronic inflammatory skin diseases. This study uses Mendelian randomization (MR) and Bayesian weighted Mendelian randomization (BWMR) to explore the causal relationships between immune antibody responses and four common skin diseases: psoriasis, atopic dermatitis (AD), rosacea, and vitiligo. METHODS: We utilized summary statistics from genome-wide association studies (GWAS) for antibody responses to 13 infectious pathogens and four skin diseases. Single nucleotide polymorphisms (SNPs) were selected as instrumental variables (IVs) to assess causal relationships using multiple MR methods, including inverse variance weighted (IVW), MR Egger, and weighted median. BWMR was also employed to confirm findings and address potential pleiotropy. RESULTS: The IVW analysis identified significant associations between specific antibody responses and the skin diseases studied. Key findings include protective associations of anti-Epstein-Barr virus (EBV) IgG seropositivity and Helicobacter pylori UREA antibody levels with psoriasis and AD. anti-chlamydia trachomatis IgG seropositivity, anti-polyomavirus 2 IgG seropositivity, and varicella zoster virus glycoprotein E and I antibody levels were negatively associated with rosacea, while EBV Elevated levels of the early antigen (EA-D) antibody levels and HHV-6 IE1B antibody levels were positively associated with rosacea. H. pylori Catalase antibody levels were protectively associated with vitiligo, whereas anti-herpes simplex virus 2 (HSV-2) IgG seropositivity was positively associated with vitiligo. The BWMR analysis confirmed these associations. CONCLUSION: This study underscores the significant role of H. pylori and other pathogens in these skin diseases, suggesting both protective and exacerbating effects depending on the specific condition. Understanding these pathogen-immune interactions can lead to the development of more effective, personalized treatments and preventative strategies, ultimately improving patient outcomes and quality of life.

Co-regulatory mechanisms and potential markers of oxidative stress-related genes in vitiligo and alopecia areata.

BACKGROUND: The specific role of oxidative stress (OS) in vitiligo and alopecia areata (AA) remains unclear. The aim of this study was to analyze and identify the key markers of OS in vitiligo and AA by bioinformatics. METHODS: We obtained vitiligo and AA datasets from gene expression omnibus (GEO) database. The difference-expressed genes of vitiligo and AA were identified by differential analysis, and the functions of difference-expressed genes were identified by gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA) enrichment analysis. Subsequently, Veen package was used to obtain the intersection genes of OS-related genes with vitiligo and AA. Finally, we used CIBERSORT to assess the infiltration of immune cells in vitiligo and AA. RESULTS: Through enrichment analysis, we found that vitiligo and AA were mainly enriched in cell cycle and cell adhesion molecular channels. We identified KLB and EIF3C as key genes in OS regulation of vitiligo and AA, and found that KLB and EIF3C participate in disease progression by regulating T cells and neutrophils. CONCLUSIONS: According to our findings, KLB and EIF3C play a crucial role in the progression and development of vitiligo and AA, which have been identified as biomarkers and target for early diagnosis of patients.

Evaluation of diagnostic accuracy of dermoscopy in some common hypopigmented skin diseases.

BACKGROUND: Diagnosis of cutaneous hypopigmentation can sometimes be challenging. Dermoscopy may play a role in identifying hypo or-depigmented dermatoses. The aim was to investigate which dermoscopic criteria represent potent indicators for the diagnosis of vitiligo, nevus depigmentosus, pityriasis alba, hypopigmented pityriasis versicolor, idiopathic guttate hypomelanosis, hypopigmented mycosis fungoides (MF), lichen sclerosus et atrophicus and ash leaf hypopigmented macules of tuberous sclerosis, and evaluate their diagnostic accuracy. 168 individuals diagnosed with one of these hypopigmented disorders were evaluated for the presence or absence of predetermined dermoscopic criteria. Evaluation of dermatoscopic characteristics in each condition and analysis for sensitivity and specificity of dermatoscopic diagnosis in these hypopigmented lesions was performed. The starburst pattern, micro-koebnerization, and trichrome pattern were unique to vitiligo diagnosis. Vitiligo had higher comet-tail appearance, perifollicular pigmentation, and perilesional hyperpigmentation than other hypopigmented illnesses. Other hypopigmented lesions had greater incidence of amoeboid pattern, faint or diminished pigment network, islands of pigmentation, ill-defined boundaries, pseudopods, and widespread scaling than vitiligo. Finally, perifollicular scaling, comedo-like openings, blue-gray specks, and fibrotic regions excluded vitiligo. Dermoscopy can help identify common hypopigmented skin lesions and reduce the need for skin biopsy. Nevus depigmentosus, pityriasis alba and idiopathic guttate hypomelanosis were the top three hypopigmented dermatoses that could be diagnosed by dermoscopy with 100% sensitivity. Vitiligo was in the second rank (94.7%), followed by lichen sclerosis et atrophicus (93.3%) then hypopigmented MF at 81.2% sensitivity. Dermoscopy sensitivity was lowest in pityriasis versicolor and ash leaf macules of tuberous sclerosis (52.6% and 46.7%, respectively).

Case report: Psoriasiform eczema with immune-mediated comorbidities treated with upadacitinib.

Immune-mediated comorbidities in patients with psoriasiform eczema are common. It can be challenging to manage multiple immune-mediated diseases, especially considering that biologic treatments are prone to causing paradoxical effects. The aim of this retrospective observational case series was to describe the course of both psoriasiform eczema and immune-mediated comorbidities in five patients treated with upadacitinib for psoriasiform dermatitis. Five patients, all male, were included. All the patients suffered from psoriasiform eczema. Moreover, two of the patients suffered from alopecia areata, two from vitiligo, one from ulcerative colitis and one from hidradenitis suppurativa. In all cases, the treatment with upadacitinib was rapidly effective on the eczema. The effectiveness on alopecia areata was good in both cases, while the results on vitiligo were only partial. The only case of ulcerative colitis achieved complete remission, while the case of hidradenitis suppurativa experience partial improvement. In conclusion, upadacitinib was effective in treating not only psoriasiform eczema, but also several immune mediated comorbidities. Additional studies are necessary to determine the efficacy of upadacitinib in alopecia areata, vitiligo and hidradenitis suppurativa.

Impact on quality of life, health care access, and health care utilization of individuals with vitiligo: an analysis of the All of Us research program.

Vitiligo is an autoimmune skin depigmenting disorder that can negatively impact quality of life. A new FDA approved treatment for vitiligo offers considerable promise, and to maximize benefits strategies to implementation should consider disease burden, healthcare access, and healthcare utilization of individuals with vitiligo. Using the All of Us Research Program's large data set, including survey responses, we investigated these outcomes among participants with and without vitiligo. Our analysis used quality of life, delayed care due to an obstacle, and seeing a doctor in the past year as dichotomized proxies for disease burden, healthcare access, and healthcare utilization. The results show that people with vitiligo are more likely to report worse quality of life but ostensibly greater healthcare access and utilization compared to people without vitiligo. However, these relationships are not significant when adjusted for demographics, socioeconomic characteristics, and comorbidities of vitiligo. Prior research has shown non-Caucasian individuals have worse health outcomes in general, and worse quality of life within the vitiligo population. Our data demonstrated consistent findings; moreover, we found that non-Caucasian individuals with vitiligo had inferior healthcare access and lower health care utilization than Caucasian individuals. Implementation of new treatments for vitiligo should prioritize disadvantaged individuals to improve health equity.

Changes in epidermal thickness and their correlation with clinical characteristics in patients with vitiligo.

Vitiligo is an autoimmune disorder characterized by epidermal melanocyte damage, with the typical clinical manifestation of white patches of skin. Keratinocytes, which work in concert with melanocytes to maintain the structural and functional integrity of the skin, are implicated in the progression of vitiligo. Recent studies have reported abnormal keratinocyte proliferation and epidermal thickening in some patients with vitiligo; however, the relationship between these changes and the clinical characteristics of vitiligo remains unclear. We assessed the changes in epidermal thickness in patients with vitiligo and their correlation with clinical characteristics. Compared to the non-lesional skins, the stratum corneum, viable epidermis, and full epidermis in the lesional skins were all significantly thicker. The thickness of the stratum corneum in the head, neck, and trunk was greatly lower than that in the extremities. The thickness of the stratum corneum in the sun-exposed area was higher than that in the sun-protected area, whereas the thickness of the viable epidermis decreased. In conclusion, our study found that the epidermis in the lesional skins of patients with vitiligo was significantly thickened, especially in the sun-exposed areas and extremities.

A meta-analysis of therapeutic trials of topical ruxolitinib cream for the treatment of vitiligo: therapeutic efficacy, safety, and implications for therapeutic practice.

Vitiligo, an autoimmune condition characterized by depigmented skin patches due to the loss of functional melanocytes, has been linked to dysregulation in the JAK-STAT signaling pathway, particularly in IFN-g signaling. The use of JAK inhibitors, such as ruxolitinib cream, a JAK1 and JAK2 inhibitor, presents a promising approach for vitiligo treatment. This study aims to systematically assess the effectiveness and safety of ruxolitinib cream in patients with vitiligo. We conducted a systematic review and meta-analysis following PRISMA guidelines to evaluate the efficacy and safety of ruxolitinib cream for the treatment of vitiligo. A comprehensive search of PubMed, Google Scholar, and Cochrane Library databases for randomized controlled trials (RCTs). Data selection, screening, extraction, and risk of bias assessment were meticulously performed. Statistical analysis was conducted using Review Manager Software, version 5.4, with significant heterogeneity addressed through appropriate methods. Our meta-analysis included 3 studies with 830 vitiligo patients. Significant improvements were observed in F-VASI, T-VASI, F-BSA, and T-BSA scores, with greater efficacy at 24 weeks compared to 12 weeks [MD -24.17, 95% CI (-31.78 to -16.56), P < 0.00001], [MD -14.12, 95% CI (-20.54 to -7.70); P < 0.0000], [MD -16.25, 95% CI (-22.20 to -10.31), P < 0.00001], [MD -9.19, 95% CI (-13.47 to -4.92); P < 0.00001]. Ruxolitinib showed increased risk ratios for F-VASI75, F-VASI90, and F-VASI50, indicating better outcomes with longer treatment durations [MD 2.9, 95% CI 1.88-4.49; P < 0.00001], [MD 4.66, 95% CI 2.09-10.39; P = 0.0002], [MD 2.53, 95% CI 1.84-3.46; P < 0.00001]. No significant differences were found in mild and moderate adverse events, while severe cases favored ruxolitinib. Placebo had a significant advantage in any adverse events, with no significant difference in drug-related adverse events. Serious adverse events did not significantly differ between groups. The findings strongly support the efficacy of ruxolitinib therapy in improving various parameters over time for treating vitiligo. However, thorough consideration of its safety profile, particularly concerning adverse events and potential side effects, is warranted. Further studies with larger sample sizes are needed to confirm these conclusions.

The relationship between psoriasis and vitiligo: From a comprehensive study.

BACKGROUND: Both psoriasis and vitiligo are autoimmune skin diseases. Previous observational studies have indicated a relationship between the two conditions, and simultaneous onset of both diseases poses increased health risks to patients. However, limited research has explored the causal relationship between psoriasis and vitiligo. OBJECTIVES: To investigate whether a causal association exists between psoriasis and vitiligo. METHODS: A case of Chinese patients diagnosed with psoriasis and vitiligo has been reported. Transcriptome sequencing was performed on normal, psoriasis, vitiligo, and co-morbid skin tissues of the patients, and single-cell transcriptome sequencing was conducted on the co-morbid skin tissues. A comprehensive Mendelian randomization analysis of Genome-wide association studies (GWAS) was performed on a cohort of 261 018 European individuals with psoriasis from the IEU Open GWAS Project and vitiligo from the National Institutes of Health (NIH) Database of Genotypes and Phenotypes. RESULTS: Case report and transcriptome results showed that skin tissue with vitiligo combined with psoriasis exhibited both vitiligo and psoriasis. Single-cell transcriptome sequencing results showed that in comparison to normal skin and psoriatic skin, the proportions of CD8+ T cells, natural killer cells, naive T cells, T helper cells 17, regulatory T cells, conventional type 1 dendritic cells, Conventional type 2 dendritic cells, and plasmacytoid dendritic cells were all increased in skin tissue with vitiligo combined with psoriasis. Mendelian randomization analysis included 4510 patients with psoriasis and 4680 patients with vitiligo. The results showed no causal relationship between vitiligo and psoriasis in the forward direction (p = 0.192; odds ratio [OR], 1.059; 95% confidence interval [CI], 0.971-1.155) or in the reverse direction (p = 0.459; OR, 0.927; 95% CI, 0.757-1.134). CONCLUSIONS: This study suggests that the association between psoriasis and vitiligo may be closely related to immunity, however, Mendelian randomization studies do not support a causal relationship. These findings hold significant implications for clinicians aiming to enhance their understanding and treatment approaches for psoriasis and vitiligo.

Ritlecitinib, a JAK3/TEC family kinase inhibitor, stabilizes active lesions and repigments stable lesions in vitiligo.

The efficacy of ritlecitinib, an oral JAK3/TEC family kinase inhibitor, on active and stable lesions was evaluated in patients with active non-segmental vitiligo in a phase 2b trial (NCT03715829). Patients were randomized to placebo or daily ritlecitinib 50 mg (with or without 4-week 100-mg or 200-mg loading dose), 30 mg, or 10 mg for 24 weeks. Active lesions showed greater baseline expression of inflammatory/immune markers IFNG and CCL5, levels of CD103, and T-cell infiltrates than stable lesions. Patients with more active than stable vitiligo lesions showed higher baseline serum levels of CXCL9 and PD-L1, while patients with more stable than active lesions showed higher baseline serum levels of HO-1. At Week 24, ritlecitinib 50 mg significantly stabilized mean percent change from baseline in depigmentation extent in both active lesions and stable lesions vs. placebo-response, with stable lesions showing greater repigmentation. After 24 weeks of treatment, ritlecitinib 50 mg increased expression of melanocyte markers in stable lesions, while Th1/Th2-related and co-stimulatory molecules decreased significantly in both stable and active lesions. Serum from patients with more active than stable lesions showed decreased levels of ICOS and NK cell activation markers. These data, confirmed at transcription/protein levels, indicate that stable lesion repigmentation occurs early with ritlecitinib, while active lesions require stabilization of inflammation first. ClinicalTrials.gov: NCT03715829.

Exosome-derived microRNAs: emerging players in vitiligo.

Exosome-derived microRNAs (miRNAs) are biomacromolecules and nanoscale extracellular vesicles originating from intracellular compartments that are secreted by most cells into the extracellular space. This review examines the formation and function of exosomal miRNAs in biological information transfer, explores the pathogenesis of vitiligo, and highlights the relationship between exosomal miRNAs and vitiligo. The aim is to deepen the understanding of how exosomal miRNAs influence immune imbalance, oxidative stress damage, melanocyte-keratinocyte interactions, and melanogenesis disorders in the development of vitiligo. This enhanced understanding may contribute to the development of potential diagnostic and therapeutic options for vitiligo.

Estimation of genetic variation in vitiligo associated genes: Population genomics perspective.

BACKGROUND: Vitiligo is an auto-immune progressive depigmentation disorder of the skin due to loss of melanocytes. Genetic risk is one of the important factors for development of vitiligo. Preponderance of vitiligo in certain ethnicities is known which can be analysed by understanding the distribution of allele frequencies across normal populations. Earlier GWAS identified 108 risk alleles for vitiligo in Europeans and East Asians. In this study, 64 of these risk alleles were used for analysing their enrichment and depletion across populations (1000 Genomes Project and IndiGen) with reference to 1000 Genomes dataset. Genetic risk scores were calculated and Fisher's exact test was performed to understand statistical significance of their variation in each population with respect to 1000 Genomes dataset as reference. In addition to SNPs reported in GWAS, significant variation in allele frequencies of 1079 vitiligo-related genes were also analysed. Two-tailed Chi-square test and Bonferroni's multiple adjustment values along with fixation index (≥ 0.5) and minimum allele frequency (≥ 0.05) were calculated and used to prioritise the variants based on pairwise comparison across populations. RESULTS: Risk alleles rs1043101 and rs10768122 belong to 3 prime UTR of glutamate receptor gene SLC1A2 are found to be highly enriched in the South Asian population when compared with the 'global normal' population. Intron variant rs4766578 (ATXN2) was found to be deleted in SAS, EAS and AFR and enriched in EUR and AMR1. This risk allele is found to be under positive selection in SAS, AMR1 and EUR. From the ancillary vitiligo gene list, nonsynonymous variant rs16891982 was found to be enriched in the European and the Admixed American populations and depleted in all others. rs2279238 and rs11039155 belonging to the LXR-α gene involved in regulation of metalloproteinase 2 and 9 (melanocyte precursors) were found to be associated with vitiligo in the North Indian population (in earlier study). CONCLUSION: The differential enrichment/depletion profile of the risk alleles provides insight into the underlying inter-population variations. This would provide clues towards prioritisation of SNPs associated with vitiligo thereby elucidating its preponderance in different ethnic groups.

Real-world evidence for vitiligo using an electronic medical records database in Spain: the REVEAL-ES study.

The European prevalence of vitiligo diagnosis is 0.2%-0.8%, with country-specific and methodological differences. Although vitiligo profoundly impacts quality of life, limited studies have evaluated disease burden and treatment patterns. This real-world study describes the prevalence, incidence, characteristics, and treatment patterns of vitiligo among patients in Spain during 2015-2021. This retrospective observational study using the IQVIA Electronic Medical Records database in Spain included patients with vitiligo (International Classification of Diseases, Ninth Revision codes 709.01/374.53). Incident and prevalent cohorts comprised registered patients with vitiligo diagnoses during and before 2015-2021, respectively. Patient characteristics and treatment data were extracted. Vitiligo incidence was 0.016 (95% CI: 0.014-0.018) per 100 person-years, and prevalence was 0.19% (95% CI: 0.18%-0.19%) in 2021. Females were more affected than males (0.16% vs 0.13%, respectively). Among 1,400 incident patients, mean (SD) age was 40.7 (19.7) years; most were female (53.9%). The most common comorbidities after vitiligo diagnosis were eczema (20.8%), hypercholesterolaemia/hypertriglyceridaemia (17.9%), anxiety (10.9%), thyroid disorders (9.1%), and diabetes (6.4%). In 2021, 78.6% of prevalent patients did not receive vitiligo-related treatments. The most prescribed vitiligo-related treatments were topical calcineurin inhibitors (13.9%) and topical corticosteroids (13.0%); 11.9% had a record of psychiatric medications. This study confirms the association between vitiligo and comorbidities (e.g., eczema, thyroid disorders) and high disease burden. The prevalence in Spain in 2021 (0.19%) was within the lower band of European estimates based on surveys/medical screenings. Most patients are not receiving vitiligo-related treatment and could benefit from new, effective treatments.

Molecular and therapeutic landscape of ferroptosis in skin diseases.

ABSTRACT: Regulated cell death (RCD) is a critical physiological process essential in maintaining skin homeostasis. Among the various forms of RCD, ferroptosis stands out due to its distinct features of iron accumulation, lipid peroxidation, and involvement of various inhibitory antioxidant systems. In recent years, an expanding body of research has solidly linked ferroptosis to the emergence of skin disorders. Therefore, understanding the mechanisms underlying ferroptosis in skin diseases is crucial for advancing therapy and prevention strategies. This review commences with a succinct elucidation of the mechanisms that underpin ferroptosis, embarks on a thorough exploration of ferroptosis's role across a spectrum of skin conditions, encompassing melanoma, psoriasis, systemic lupus erythematosus (SLE), vitiligo, and dermatological ailments precipitated by ultraviolet (UV) exposure, and scrutinizes the potential therapeutic benefits of pharmacological interventions aimed at modulating ferroptosis for the amelioration of skin diseases.

Establishment of a promising vitiligo mouse model for pathogenesis and treatment studies.

AIMS: Vitiligo is a chronic dermatological condition characterized by the progressive loss of melanocytes, for which traditional therapy has shown limited efficacy. This study aimed to establish a vitiligo model with easy operability, high repeatability, and stable depigmentation to provide a foundation for studying the pathogenesis and developing novel therapies for vitiligo. METHODS: (1) Establishing vitiligo model: Firstly, deliver B16F10 cells to the back skin of C57BL/6 J via intradermal injection (day 0), and the CD4 depletion antibody was injected intraperitoneally on day 4 and 10. Secondly, the melanoma was surgically removed on day 12. Thirdly, CD8 antibody was administered intraperitoneally every fourth day till day 30. (2) Identification of vitiligo model: H&E staining, immunohistochemistry, and immunofluorescence were used to detect the melanocytes. The melanin was detected by transmission electron microscopy (TEM), Lillie ferrous sulfate staining and L-DOPA staining. RESULTS: (1) The back skin and hair began to appear white on day 30. Melanin loss reached peak on day 60; (2) Hematoxylin and eosin (H&E) staining, immunohistochemistry and immunofluorescence results showed melanocytes were reduced. L-DOPA staining, Lillie ferrous sulfate staining and TEM results showed that melanin decreased in the epidermis. CONCLUSION: We successfully establishment a vitiligo mouse model which can be more capable to simulate the pathogenesis of human vitiligo and provide an important basis for the study of pathogenesis and therapy of vitiligo.