Association between miR-202, miR-211, and miR-1238 gene polymorphisms and risk of vitiligo.

Vitiligo, as a common pigment defect in the skin, hair, and mucous membranes, results from the destruction of melanocytes. Recent investigations have shown that miRNA dysregulation contributes in the pathogenesis of vitiligo. Therefore, in this research, our aim is to explore the relationship between miR-202 rs12355840, miR-211 rs8039189, and miR-1238 rs12973308 polymorphisms and susceptibility to vitiligo. A total number of 136 vitiligo patients and 129 healthy individuals as a control group were included in this research. The salting out approach was implemented to extraction genomic DNA. The genetic polymorphisms of miR-202 rs12355840, miR-211 rs8039189, and miR-1238 rs12973308 were determined using PCR-RFLP approach. The findings revealed that miR-202 rs12355840 polymorphism under codominant (CT and TT genotypes), dominant, recessive, overdominant, and also allelic models is correlated with increased risk of vitiligo. In addition, codominant, dominant, overdominant, as well as allelic models of miR-211 rs8039189 polymorphism decrease risk of vitiligo. No significant relationship was observed between the miR-1238 rs12973308 polymorphism and susceptibility to vitiligo. The miR-211 rs8039189 polymorphism may serve a protective effect on vitiligo development and miR-202 rs12355840 polymorphism may act as a risk factor for vitiligo susceptibility.

Association of SOD1 gene variants (50 bp Ins/Del, rs4817415, rs2070424, rs1041740, rs17880135) with plasma protein levels in vitiligo patients and their analysis in silico.

OBJECTIVE: Vitiligo is a common systemic, idiopathic autoimmune disease. The aim of this study was to analyze the frequency of variants of the superoxide dismutase 1 (SOD1) gene (50 bp Ins/Del, rs4817415, rs2070424, rs1041740, rs17880135) and circulating plasma protein levels through in-silico analysis. PATIENTS AND METHODS: Blood samples were collected from adult patients of both sexes with a clinical diagnosis of vitiligo. ELISA tests for SOD and analysis of gene variants by qPCR were compared to a disease-free reference group. RESULTS: The population analyzed was young people between 29 and 37 years old, with a higher percentage of women. The population was found in the Hardy-Weinberg equilibrium (HWE). The 50 bp Ins/Del, rs4817415, and rs2070424 variants showed no significant difference between groups (p > 0.05). Although, in the dominant model, the CT and CTTT genotypes of the rs1041740 and rs17880135 variants showed an association with susceptibility to vitiligo compared to the control. Plasma SOD levels showed significant differences between the groups, and when stratified according to the genotypes of each variant, there was a significant difference, except with the rs17880135 variant. The haplotypes InsCGTC and InsAGCC are shown to be risk factors for susceptibility to vitiligo. The in-silico analysis demonstrated that the rs4817415, rs2070424, rs1041740, and rs17880135 variants of the SOD1 gene participate in the modification of selected regulatory elements for differentiating the protein, transcription factors, and long non-coding RNA. CONCLUSIONS: Information regarding the pathogenesis of vitiligo helps recognize risk factors and identify the relationship of diagnostic markers of cell damage inherent to the disease. This will help improve aspects of prevention and the choice of treatment alternatives appropriate to each case.

Transcriptional variations at perilesional site in vitiligo patients: probably a fight for cell-survival.

Exploration of gene expression variations is a potential source to unravel biological pathways involved in pathological changes in body and understand the mechanism underneath. Vitiligo patients were explored for gene expression changes transcriptionally at perilesional site in comparison to normal site of same patients for melanogenesis pathway (TYR, DCT & TYRP1) cell adhesion (MMPs & TIMP1), cell survival (BCL2 & BAX1) as well as proliferation, migration & development (SOX9, SOX10 & MITF) regulatory system, using skin biopsy samples. Results were also compared with changes in gene expression for melanocytes under stress after hydrogen peroxide treatment in-vitro. Gene amplification was carried out via real time PCR. We found increased expression of proliferation, migration & development regulatory genes as well as melanogenesis pathway genes at perilesional site of patients. In-vitro study also supports induced MITF expression and disturbed melanogenesis in melanocytes under stress. Expression level ratio of cell survival regulatory genes' (BCL2/BAX1) as well as cell adhesion regulatory genes (MMPs/TIMP1) was observed upregulated at patient's perilesional site however downregulated in hydrogen peroxide treated melanocytes in-vitro. Observed upregulated gene expression at perilesional site of patients may be via positive feedback loop in response to stress to increase cell tolerance power to survive against adverse conditions. Gene expression analysis suggests better cell survival and proliferation potential at perilesional site in vitiligo patients. It seems in-vivo conditions/growth factors supports cells to fight for survival to accommodate stressed conditions.

Identification of Coding Variants in 10q22.1 Associated with Vitiligo in the Chinese Han Population.

Objective: This study aims to identify causal variants associated with vitiligo in an expanded region of 10q22.1. Materials and Methods: We conducted a fine-scale deep analysis of the expanded 10q22.1 region using in a large genome-wide association studies dataset consisting of 1117 cases and 1701 controls through imputation. We selected five nominal coding single nucleotide polymorphisms (SNPs) located in SLC29A3 and CDH23 and genotyped them in an independent cohort of 2479 cases and 2451 controls in a Chinese Han population cohort using the Sequenom MassArray iPLEX1 system. Results: A missense SNP in SLC29A3, rs2252996, showed strong evidence of association with vitiligo (p = 1.34 × 10-8, odds ratio [OR] = 0.82). Three synonymous SNPs (rs1084004 in SLC29A3; rs12218559 and rs10999978 in CDH23) provided suggestive evidence of association for vitiligo (p = 1.69 × 10-6, OR = 0.84; p = 9.47 × 10-5, OR = 1.18; p = 6.90 × 10-4, OR = 1.16, respectively). Stepwise conditional analyses identified two significant independent disease-associated signals from the four SNPs (both p < 0.05; both D' = 0.03; and r2 = 0.00). Conclusion: The study identifies four genetic coding variants in SLC29A3 and CDH23 on 10q22.1 that may contribute to vitiligo susceptibility with one missense variant affecting disease subphenotypes. The presence of multiple genetic variants underscores their significant role in the genetic pathogenesis of the disease.

Identification and validation of RNA-binding protein SLC3A2 regulates melanocyte ferroptosis in vitiligo by integrated analysis of single-cell and bulk RNA-sequencing.

BACKGROUND: The pathogenesis of vitiligo remains unclear. The genes encoding vitiligo-related RNA-binding proteins (RBPs) and their underlying pathogenic mechanism have not been determined. RESULTS: Single-cell transcriptome sequencing (scRNA-seq) data from the CNCB database was obtained to identify distinct cell types and subpopulations and the relative proportion changes in vitiligo and healthy samples. We identified 14 different cell types and 28 cell subpopulations. The proportion of each cell subpopulation significantly differed between the patients with vitiligo and healthy groups. Using RBP genes for unsupervised clustering, we obtained the specific RBP genes of different cell types in vitiligo and healthy groups. The RBP gene expression was highly heterogeneous; there were significant differences in some cell types, such as keratinocytes, Langerhans, and melanocytes, while there were no significant differences in other cells, such as T cells and fibroblasts, in the two groups. The melanocyte-specific RBP genes were enriched in the apoptosis and immune-related pathways in the patients with vitiligo. Combined with the bulk RNA-seq data of melanocytes, key RBP genes related to melanocytes were identified, including eight upregulated RBP genes (CDKN2A, HLA-A, RPL12, RPL29, RPL31, RPS19, RPS21, and RPS28) and one downregulated RBP gene (SLC3A2). Cell experiments were conducted to explore the role of the key RBP gene SLC3A2 in vitiligo. Cell experiments confirmed that melanocyte proliferation decreased, whereas apoptosis increased, after SLC3A2 knockdown. SLC3A2 knockdown in melanocytes also decreased the SOD activity and melanin content; increased the Fe2+, ROS, and MDA content; significantly increased the expression levels of TYR and COX2; and decreased the expression levels of glutathione and GPX4. CONCLUSION: We identified the RBP genes of different cell subsets in patients with vitiligo and confirmed that downregulating SLC3A2 can promote ferroptosis in melanocytes. These findings provide new insights into the pathogenesis of vitiligo.

Identification of a novel TSC1 gene variant in a patient with atypical vitiligo-like skin lesions: Unveiling the hidden tuberous sclerosis complex.

BACKGROUND: Tuberous sclerosis complex (TSC), an autosomal-dominant disorder, is characterized by hamartomas affecting multiple organ systems. The underlying etiology of TSC is the pathogenic variations of the TSC1 or TSC2 genes. The phenotype variability of TSC could lead to missed diagnosis; therefore, the latest molecular diagnostic criteria for identifying a heterozygous pathogenic variant in either the TSC1 or TSC2 gene filled this gap. Furthermore, the pathogenicity of numerous variants remains unverified, potentially leading to misinterpretations of their functional consequences. METHODS: In this study, a single patient presenting with atypical vitiligo-like skin lesions suspected to have TSC was enrolled. Targeted next-generation sequencing and Sanger sequencing were employed to identify a pathogenic variant. Additionally, a minigene splicing assay was conducted to assess the impact of TSC1 c.1030-2A>T, located in intron 10, on RNA splicing. RESULTS: A novel TSC1: c.1030-2A>T heterozygosis variant was identified in intron 10. In vitro minigene assay revealed that the c.1030-2A>T variant caused exon 11 skipping, resulting in a frameshift in the absence of 112 base pairs of mature messenger RNA and premature termination after 174 base pairs (p.Ala344Glnfs*59). CONCLUSION: The detection of this novel pathogenic TSC1 variant in the patient with atypical vitiligo-like skin lesions enrolled in our study ultimately resulted in the diagnosis of TSC. As a result, our study contributes to expanding the mutational spectrum of the TSC1 gene and refining the genotype-phenotype map of TSC.

Exosomes containing miR-1469 regulate natural killer cells by targeting CD122 in non-segmental vitiligo.

BACKGROUND: Plasma exosomal microRNAs (miRNAs) have been used as potential biomarkers for various diseases and have been investigated for their possible involvement in the pathogenesis of vitiligo. However, the miRNA expression profile of plasma exosomes in patients with non-segmental vitiligo (NSV) has not been determined yet. OBJECTIVE: To screen differentially expressed microRNAs in plasma exosomes derived from patients with NSV and explore their roles in the pathogenesis of NSV. METHODS: High-throughput sequencing was performed to determine the expression profiles of exosomal miRNAs in NSV. The effect of upregulated miR-1469 in NSV circulating exosomes on natural killer (NK) cells was further investigated using various molecular biological techniques. RESULTS: MiR-1469 was identified as a candidate biomarker whose expression was significantly increased in circulating exosomes of NSV patients. Circulating exosomes were internalized by NK cells and increased NK cell proliferation viability and IFN-γ secretion capacity delivering miR-1469. Further studies revealed that the upregulation of CD122, the predicted target of miR-1469, could partially reverse the effect of miR-1469 on natural killer cells. CONCLUSION: Alterations in plasma exosomal cargo occur in NSV and appear to contribute to NK cell dysfunction. Exosomal miR-1469 may be a biomarker of disease activity and could be used as a therapeutic drug target against innate immunity in NSV patients. The present study provides new insights into the role of exosomal miRNAs in NSV and suggests a novel miR-1469-CD122-IFN-γ pathway of NK cell underlying pathogenesis of NSV.

Circadian clock gene expression and polymorphism in non-segmental vitiligo.

BACKGROUND: Vitiligo is an acquired and progressive mucocutaneous disease with the damage of functioning epidermal melanocytes. Metabolic syndrome is associated with inflammatory skin diseases incorporating vitiligo. The circadian dysfunction triggers the pathogenesis of metabolic diseases, so our study aimed to determine the relationship between aryl hydrocarbon receptor nuclear translocator-like gene, a ligand-activated transcription factor and sensor of environmental chemicals, expression and polymorphism with non-segmental vitiligo, as well as its effect on lipid profile. METHODS: This case-control study was handled on 50 non-segmental vitiligo patients (generalized (12) and localized type (focal; 24 and acrofacial; 14)) and 50 matched controls. Each subject was proposed for full history taking, clinical examinations, serum lipid profile, and measurement of BMAL1 gene expression in the blood, and BMAL1 rs2279287 polymorphism of DNA extract from whole blood by real time-PCR. RESULTS: We identified that total cholesterol, triglyceride, and low-density lipoprotein were significantly higher, but high-density lipoprotein was significantly lower in non-segmental vitiligo patients than in the control group. A significant increase in circadian gene expression in non-segmental vitiligo patients was observed, with more detection of the BMAL1 T/C genotype (92%) than the T/T genotype. There was a significant positive relationship between the level of the circadian gene and the vitiligo patient's age, age of onset, and VIDA Score. The level of the circadian gene at Cutoff  ≥ 1.16 can predict the prognosis of vitiligo with a sensitivity of 78%, specificity of 84%, and accuracy of 81%. CONCLUSION: The circadian gene has an active role in the progress of non-segmental vitiligo and targeting this gene could have a significant impact on its management.

Genome-wide DNA methylation of lesional and peri-lesional skin in vitiligo: a comparative and integrated analysis of multi-omics in Chinese population.

Several studies have emphasized the role of DNA methylation in vitiligo. However, its profile in human skin of individuals with vitiligo remains unknown. Here, we aimed to study the DNA methylation profile of vitiligo using pairwise comparisons of lesions, peri-lesions, and healthy skin. We investigated DNA methylation levels in six lesional skin, six peri-lesional skin, and eight healthy skin samples using an Illumina 850 K methylation chip. We then integrated DNA methylation data with transcriptome data to identify differentially methylated and expressed genes (DMEGs) and analyzed their functional enrichment. Subsequently, we compared the methylation and transcriptome characteristics of all skin samples, and the related genes were further studied using scRNA-seq data. Finally, validation was performed using an external dataset. We observed more DNA hypomethylated sites in patients with vitiligo. Further integrated analysis identified 264 DMEGs that were mainly functionally enriched in cell division, pigmentation, circadian rhythm, fatty acid metabolism, peroxidase activity, synapse regulation, and extracellular matrix. In addition, in the peri-lesional skin, we found that methylation levels of 102 DMEGs differed prior to changes in their transcription levels and identified 16 key pre-DMEGs (ANLN, CDCA3, CENPA, DEPDC1, ECT2, DEPDC1B, HMMR, KIF18A, KIF18B, TTK, KIF23, DCT, EDNRB, MITF, OCA2, and TYRP1). Single-cell RNA analysis showed that these genes were associated with cycling keratinocytes and melanocytes. Further analysis of cellular communication indicated the involvement of the extracellular matrix. The expression of related genes was verified using an external dataset. To the best of our knowledge, this is the first study to report a comprehensive DNA methylation profile of clinical vitiligo and peri-lesional skin. These findings would contribute to future research on the pathogenesis of vitiligo and potential therapeutic strategies.

Exploring genetic associations between vitiligo and mental disorders using Mendelian randomization.

Although a large number of existing studies have confirmed that people with vitiligo are prone to mental disorders, these observational studies may be subject to confounding factors and reverse causality, so the true causal relationship is inconclusive. We conducted a bidirectional Mendelian randomization (MR) analysis to assess the causality between vitiligo and mental disorders, namely depression, anxiety, insomnia, schizophrenia, bipolar disorder, obsessive-compulsive disorder (OCD) and attention-deficit hyperactivity disorder (ADHD). Summary statistics from large available genome-wide association study (GWAS) datasets for generalized vitiligo (n = 44 266), depression (n = 173 005), anxiety (n = 17 310), insomnia (n = 386 988), schizophrenia (n = 130 644), bipolar disorder (n = 413 466), OCD (n = 9725) and ADHD (n = 225 534) were utilized. Inverse-variance weighted (IVW), MR-Egger and weighted median were employed to estimate causal effects. Sensitivity analysis and MR Pleiotropy Residual Sum and Outliers (MR PRESSO) were conducted to assess heterogeneity and pleiotropy, ensuring the robustness of the results. Additionally, we corrected for estimating bias that might be brought on by sample overlap using MRlap. In our findings, none of the rigorous bidirectional MR analyses uncovered a significant causal association. Even after applying the MRlap correction, the effect sizes remained statistically nonsignificant, thereby reinforcing the conclusions drawn via IVW. In summary, our genetic-level investigation did not reveal a causal link between generalized vitiligo and mental disorders.

ViCEKb: Vitiligo-linked Chemical Exposome Knowledgebase.

Vitiligo is a complex disease wherein the environmental factors, in conjunction with the underlying genetic predispositions, trigger the autoimmune destruction of melanocytes, ultimately leading to depigmented patches on the skin. While genetic factors have been extensively studied, the knowledge on environmental triggers remains sparse and less understood. To address this knowledge gap, we present the first comprehensive knowledgebase of vitiligo-triggering chemicals namely, Vitiligo-linked Chemical Exposome Knowledgebase (ViCEKb). ViCEKb involves an extensive and systematic manual effort in curation of published literature and subsequent compilation of 113 unique chemical triggers of vitiligo. ViCEKb standardizes various chemical information, and categorizes the chemicals based on their evidences and sources of exposure. Importantly, ViCEKb contains a wide range of metrics necessary for different toxicological evaluations. Notably, we observed that ViCEKb chemicals are present in a variety of consumer products. For instance, Propyl gallate is present as a fragrance substance in various household products, and Flutamide is used in medication to treat prostate cancer. These two chemicals have the highest level of evidence in ViCEKb, but are not regulated for their skin sensitizing effects. Furthermore, an extensive cheminformatics-based investigation revealed that ViCEKb chemical space is structurally diverse and comprises unique chemical scaffolds in comparison with skin specific regulatory lists. For example, Neomycin and 2,3,5-Triglycidyl-4-aminophenol have unique chemical scaffolds and the highest level of evidence in ViCEKb, but are not regulated for their skin sensitizing effects. Finally, a transcriptomics-based analysis of ViCEKb chemical perturbations in skin cell samples highlighted the commonality in their linked biological processes. Overall, we present the first comprehensive effort in compilation and exploration of various chemical triggers of vitiligo. We believe such a resource will enable in deciphering the complex etiology of vitiligo and aid in the characterization of human chemical exposome. ViCEKb is freely available for academic research at: https://cb.imsc.res.in/vicekb.

Decreased ZMIZ1 suppresses melanogenesis in vitiligo by regulating mTOR/AKT/GSK-3ß-mediated glucose uptake.

The loss of epidermal melanocytes is a distinguishing feature of vitiligo (VIT), a prevalent and long-lasting skin ailment. While various hypotheses exist to explain the cause of VIT, the precise mechanisms leading to this disease remain unclear. Zinc finger MIZ-type containing 1 (ZMIZ1) has a strong link with the development and occurrence of VIT. However, the exact role of ZMIZ1 and its underlying mechanisms in VIT are not well understood. Our study aims to illustrate that targeting ZMIZ1 is an effective therapeutic and prophylactic strategy for treating VIT. We obtained the RNA expression profile of VIT samples using RNA-seq and determined the locations and expression of ZMIZ1 in these samples via immunochemistry. Glucose uptake was analyzed through immunofluorescence and glucose uptake assay. We evaluated mRNA levels using qPCR and used plasmids transfection to knock down ZMIZ1 in PIG1 and PIG3V cell lines. The activation of the mTOR/AKT/GSK-3ß signalling pathway was assessed using Western blotting analysis. We found that ZMIZ1 expression was decreased in VIT samples. Decreased ZMIZ1 expression inhibits the proliferation, migration, and invasion of melanocytes in vitro. Moreover, we revealed that decreased ZMIZ1 could also inhibit the glucose uptake of melanocytes in vitro. Decreased ZMIZ1 expression inhibits the activation of the mTOR/AKT/GSK-3ß pathway and the expression of melanin synthesis-related proteins in melanocytes. Finally, we demonstrated that decreased ZMIZ1 may inhibit the cell viability of melanocytes and the synthesis of melanin by mTOR/AKT/GSK-3ß-mediated oxidative stress in vitro. In conclusion, our study suggests that decreased ZMIZ1 suppresses melanogenesis in vitiligo by regulating the mTOR/AKT/GSK-3ß-mediated glucose uptake in vitro, making ZMIZ1 an attractive therapeutic target for the treatment of VIT.

The Role of Regulatory Cell Death in Vitiligo.

Vitiligo is one of the common chronic autoimmune skin diseases in clinic, which is characterized by localized or generalized depigmentation and seriously affects the physical and mental health of patients. At present, the pathogenesis of vitiligo is not clear; mainly, heredity, autoimmunity, oxidative stress, melanocyte (MC) self-destruction, and the destruction, death, or dysfunction of MCs caused by various reasons are always the core of vitiligo. Regulatory cell death (RCD) is an active and orderly death mode of cells regulated by genes, which widely exists in various life activities, plays a pivotal role in maintaining the homeostasis of the organism, and is closely related to the occurrence and development of many diseases. With the deepening of the research and understanding of RCD, people gradually found that there are many different forms of RCD in the lesions and perilesional skin of vitiligo patients, such as apoptosis, autophagy, pyroptosis, ferroptosis, and so on. Different cell death modes have different mechanisms in vitiligo, and different RCDs can interact and regulate each other. In this article, the mechanism related to RCD in the pathogenesis of vitiligo is reviewed, which provides new ideas for exploring the pathogenesis and targeted treatment of vitiligo.

Rational design of a JAK1-selective siRNA inhibitor for the modulation of autoimmunity in the skin.

Inhibition of Janus kinase (JAK) family enzymes is a popular strategy for treating inflammatory and autoimmune skin diseases. In the clinic, small molecule JAK inhibitors show distinct efficacy and safety profiles, likely reflecting variable selectivity for JAK subtypes. Absolute JAK subtype selectivity has not yet been achieved. Here, we rationally design small interfering RNAs (siRNAs) that offer sequence-specific gene silencing of JAK1, narrowing the spectrum of action on JAK-dependent cytokine signaling to maintain efficacy and improve safety. Our fully chemically modified siRNA supports efficient silencing of JAK1 expression in human skin explant and modulation of JAK1-dependent inflammatory signaling. A single injection into mouse skin enables five weeks of duration of effect. In a mouse model of vitiligo, local administration of the JAK1 siRNA significantly reduces skin infiltration of autoreactive CD8+ T cells and prevents epidermal depigmentation. This work establishes a path toward siRNA treatments as a new class of therapeutic modality for inflammatory and autoimmune skin diseases.

Increased Expression of Long Noncoding RNA LOC100506314 in T cells from Patients with Nonsegmental Vitiligo and Its Contribution to Vitiligo Pathogenesis.

This study aimed to identify the abnormal expression of long noncoding RNAs (lncRNAs) in T cells from patients with vitiligo and to investigate their functional roles in the immune system. Using microarray analysis, the expression levels of RNA transcripts in T cells from patients with vitiligo and controls were compared. We identified several genes and validated their expression levels in T cells from 41 vitiligo patients and 41 controls. The biological functions of the lncRNAs were studied in a transfection study using an RNA pull-down assay, followed by proteomic analysis and western blotting. The expression levels of 134 genes were significantly increased, and those of 142 genes were significantly decreased in T cells from vitiligo patients. After validation, six genes had increased expression, and three genes had decreased expression in T cells from patients with vitiligo. T-cell expression of LOC100506314 was increased in vitiligo, especially CD4+, but not CD8+ T cells. The expression levels of LOC100506314 in CD4+ T cells was positively and significantly associated with the severity of vitiligo. LOC100506314 was bound to the signal transducer and activator of transcription 3 (STAT3) and macrophage migration inhibitory factor (MIF). Enhanced expression of LOC100506314 inhibited the phosphorylation of STAT3, protein kinase B (AKT), and extracellular signal-regulated protein kinases (ERK), as well as the levels of nuclear protein of p65 and the expression of IL-6 and IL-17 in Jurkat cells and T cells from patients with vitiligo. In conclusion, this study showed that the expression of LOC100506314 was elevated in CD4+ T cells from patients with vitiligo and associated the severity of vitiligo. LOC100506314 interacted with STAT3 and MIF and inhibited IL-6 and IL-17 expression by suppressing the STAT3, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), AKT, and ERK pathways. Enhanced expression of LOC100506314 in T cells may be a potential treatment strategy for vitiligo.

Metagenomic sequencing reveals altered gut microbial compositions and gene functions in patients with non-segmental vitiligo.

BACKGROUND: Vitiligo has been correlated with an abnormal gut microbiota. We aimed to systematically identify characteristics of the gut microbial compositions, genetic functions, and potential metabolic features in patients with non-segmental vitiligo. METHODS: Twenty-five patients with non-segmental vitiligo and 25 matched healthy controls (HCs) were enrolled. Metagenomic sequencing and bioinformatic analysis were performed to determine the gut microbiota profiles. Differences in gut microbiota diversity and composition between patients with vitiligo and HCs were analyzed. Gene functions and gut metabolic modules were predicted with the Kyoto Encyclopedia of Gene and Genomes (KEGG) and MetaCyc databases. RESULTS: Compared with HCs, alpha diversity of intestinal microbiome in vitiligo patients was significantly reduced. At the species level, the relative abundance of Staphylococcus thermophiles was decreased, and that of Bacteroides fragilis was increased in patients with vitiligo compared with those of the HCs. Linear discriminant analysis (LDA) effect size (LEfSe) analysis revealed representative microbial markers of Lachnospiraceae_bacterium_BX3, Massilioclostridium_coli, TM7_phylum_sp_oral_taxon_348 and Bacteroides_fragilis for patients with vitiligo. KEGG gene function analysis showed that the NOD-like receptor signaling pathway was significantly enriched in patients with vitiligo. Gut metabolic modules (GMMs) analysis showed that cysteine degradation was significantly down-regulated, and galactose degradation was up-regulated in patients with vitiligo. A panel of 28 microbial features was constructed to distinguish patients with vitiligo from HCs. CONCLUSIONS: The gut microbial profiles and genetic functions of patients with vitiligo were distinct from those of the HCs. The identified gut microbial markers may potentially be used for earlier diagnosis and treatment targets.

Oxidative Stress and Potential Antioxidant Therapies in Vitiligo: A Narrative Review.

Vitiligo is a chronic skin disorder characterised by the loss of melanocytes and subsequent skin depigmentation. Although many theories have been proposed in the literature, none alone explains the pathogenesis of vitiligo. Oxidative stress has been identified as a potential factor in the pathogenesis of vitiligo. A growing body of evidence suggests that antioxidant therapies may offer a promising approach to managing this condition. This review summarises the potential mechanisms of oxidative stress and the types of melanocyte death in vitiligo. We also provide a brief overview of the most commonly studied antioxidants. Melanocytes in vitiligo are thought to be damaged by an accumulation of reactive oxygen species to destroy the structural and functional integrity of their DNA, lipids, and proteins. Various causes, including exogenous and endogenous stress factors, an imbalance between prooxidants and antioxidants, disruption of antioxidant pathways, and gene polymorphisms, lead to the overproduction of reactive oxygen species. Although necroptosis, pyroptosis, ferroptosis, and oxeiptosis are newer types of cell death that may contribute to the pathophysiology of vitiligo, apoptosis remains the most studied cell death mechanism in vitiligo. According to studies, vitamin E helps to treat lipid peroxidation of the skin caused by psoralen ultra-violet A treatment. In addition, Polypodium leucotomos increased the efficacy of psoralen ultra-violet A or narrow-band ultraviolet B therapy. Our review provides valuable insights into the potential role of oxidative stress in pathogenesis and antioxidant-based supporting therapies in treating vitiligo, offering a promising avenue for further research and the development of effective treatment strategies.

Genetic association of nuclear factor of activated T cells' 3'UTR and structural polymorphisms with susceptibility to generalized vitiligo in Gujarat population.

Generalized vitiligo (GV) is an autoimmune skin depigmenting disease characterized by loss of functional melanocytes. Nuclear factor of activated T cells (NFATs) play a key role in regulatory T cells' (Tregs) activation and function. Our previous studies have highlighted the role of reduced NFATs expression and activity in impaired Tregs suppressive capacity, leading to GV pathogenesis. 3'UTR region and structural single nucleotide polymorphisms(SNPs) could lead to reduced NFAT expression and activity. Therefore, we studied the association of NFATs 3'UTR [NFATC2 rs4811198 (T > G) & NFATC4 rs11848279 (A > G)] and structural [NFATC1 rs754093 (T > G) & NFATC2 rs12479626 (T > C)] SNPs in 427 GV patients and 415 controls from Gujarat population by Polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). Additionally, we carried out genotype-phenotype correlation and in silico analysis to assess the effect of NFATs SNPs on NFATs expression and structure. NFATC2 rs4811198 (T > G) 3' UTR & NFATC2 rs12479626 (T > C) structural SNPs were significantly associated with GV (p < 0.0001). Interestingly, for NFATC2 rs4811198 (T > G) SNP, there was a significant difference in the TT vs GG genotypes' frequencies (p = 0.0034; Table 2), and for NFATC2 rs12479626 (T > C) SNP there was a significant difference between TT vs TC and CC genotypes' frequencies (p < 0.0001 & p = 0.0002) between GV patients and controls. Furthermore, Odds ratio suggested that the susceptible alleles for NFATC2 rs4811198 (T > G) & NFATC2 rs12479626 (T > C) SNPs increased the risk of GV by 1.38 & 3.04 fold. However, the NFAT 3' UTR [NFATC2 rs4811198 (T > G)] and structural [NFATC1 rs754093 (T > G)] SNPs were not significantly associated with GV. Interestingly, the genotype-phenotype correlation suggested that the susceptible 'G' allele of NFATC2 rs4811198 (T > G) & NFATC4 rs11848279 (A > G) 3' UTR SNPs lead to reduced NFATC2 and NFATC4 expression (p < 0.0001). Furthermore, in silico analysis suggested that hsa-miR-3183 & hsa-miR-6720-3p miRNAs specifically bound to 'G' allele of NFATC2 rs4811198 SNP and has-miR-4652-3p miRNA specifically bound to 'G' allele of NFATC4 rs11848279 SNP. Overall, our study suggests that NFATC2 rs4811198 (T > G) 3' UTR & NFATC2 rs12479626 (T > C) structural SNPs may be associated with GV susceptibility in Gujarat population. Moreover, the susceptible alleles for the 3' UTR SNPs could lead to reduced NFATs levels, which may further possibly, affect the Treg suppressive function leading to GV.

Analysis of CD8+ TCRß Chain repertoire in peripheral blood of vitiligo via high-throughput sequencing.

Vitiligo is an autoimmune depigmentation dermatosis induced by melanocyte destruction, and CD8+ T cells play a pivotal role in melanocyte destruction. However, an accurate profile of the CD8+ T cell receptor (TCR) repertoire in vitiligo patients has not been reported, and the clonotype features of the involved CD8+ T cells remain largely unknown. This study aimed to assess the TCRß chain repertoire diversity and composition of blood in nine nonsegmental vitiligo patients via high-throughput sequencing. Vitiligo patients manifested a low TCRß repertoire diversity with highly expanded clones. Differential usage of TRBV, the TRBJ gene, and the TRBV/TRBJ combination were compared between patients with vitiligo and healthy controls. A set of TRBV/TRBJ combinations could differentiate patients with vitiligo from healthy controls (area under the curve = 0.9383, 95% CI: 0.8167-1.00). Our study revealed distinct TCRß repertoires of CD8+ T cells in patients with vitiligo and will help explore novel immune biomarkers and potential therapeutic targets for vitiligo.

Mitophagy and immune infiltration in vitiligo: evidence from bioinformatics analysis.

Background: Vitiligo is an acquired, autoimmune, depigmented skin disease with unclear pathogenesis. Mitochondrial dysfunction contributes significantly to vitiligo, and mitophagy is vital for removing damaged mitochondria. Herein, using bioinformatic analysis, we sought to determine the possible role of mitophagy-associated genes in vitiligo and immune infiltration. Methods: Microarrays GSE53146 and GSE75819 were used to identify differentially expressed genes (DEGs) in vitiligo. By crossing vitiligo DEGs with mitophagy-related genes, the mitophagy-related DEGs were identified. Functional enrichment and protein-protein intersection (PPI) analyses were conducted. Then, the hub genes were identified using two machine algorithms, and receiver operating characteristic (ROC) curves were generated. Next, the immune infiltration and its connection with hub genes in vitiligo were investigated. Finally, the Regnetwork database and NetworkAnalyst were used to predict the upstream transcriptional factors (TFs), microRNAs (miRNAs), and the protein-compound network. Results: A total of 24 mitophagy-related genes were screened. Then, five mitophagy hub genes (GABARAPL2, SP1, USP8, RELA, and TBC1D17) were identified using two machine learning algorithms, and these genes showed high diagnostic specificity for vitiligo. The PPI network showed that hub genes interacted with each other. The mRNA expression levels of five hub genes were validated in vitiligo lesions by qRT-PCR and were compatible with the bioinformatic results. Compared with controls, the abundance of activated CD4+ T cells, CD8+ T cells, immature dendritic cells and B cells, myeloid-derived suppressor cells (MDSCs), gamma delta T cells, mast cells, regulatory T cells (Tregs), and T helper 2 (Th2) cells was higher. However, the abundance of CD56 bright natural killer (NK) cells, monocytes, and NK cells was lower. Correlation analysis revealed a link between hub genes and immune infiltration. Meanwhile, we predicted the upstream TFs and miRNAs and the target compounds of hub genes. Conclusion: Five hub mitophagy-related genes were identified and correlated with immune infiltration in vitiligo. These findings suggested that mitophagy may promote the development of vitiligo by activating immune infiltration. Our study might enhance our comprehension of the pathogenic mechanism of vitiligo and offer a treatment option for vitiligo.