An in-depth analysis identifies two new independent signals in 11q23.3 associated with vitiligo in the Chinese Han population

MicroRNAs: Emerging players in the pathogenesis of vitiligo

Vitiligo is an autoimmune skin disease characterized by presence of pale patchy areas of depigmentation. MicroRNAs (miRNAs) are important regulators of gene expression and play significant roles in diverse biological and pathological processes. Accumulating evidence has shown that miRNAs were differentially expressed in skin lesions and peripheral blood mononuclear cells of patients with vitiligo. In particular, miRNAs are significantly correlated with the development and progression of vitiligo. The abundance of some miRNAs in serum was also correlated with the vitiligo lesion severity, indicating that miRNAs might serve as prognostic biomarkers. Importantly, the direct involvement of miRNAs in the pathogenesis of vitiligo has been demonstrated. For example, increased expression of miR-25 contributes to vitiligo through promoting the dysfunction and oxidative stress-induced destruction of melanocytes. However, there are limited studies on the function and mechanism of deregulated miRNAs in vitiligo. Further studies are required to establish clinical applications of miRNAs for vitiligo. More in-depth investigations of miRNAs are needed for the understanding of the pathogenesis of vitiligo and the development of novel therapeutic targets. This present review summarizes the current literature on the deregulation and pathogenic roles of miRNAs in vitiligo. We also highlight the potential clinical applications of miRNAs in patients with vitiligo.

A Common Variant at 11q23.3 Is Associated with Susceptibility to Atopic Dermatitis in the Han Chinese Population

Background: Genome-wide association studies (GWASs) have identified many genetic variants that are risk factors for numerous immune-mediated diseases. In particular, different immune-mediated diseases have been found to share the same susceptibility loci. Therefore, exploring the genetic overlap between atopic dermatitis (AD) and other immune-mediated diseases in more detail may help identify additional shared susceptibility loci among common immune-mediated diseases. Recent evidence suggests that the 11q23.3 locus is a susceptibility locus shared among multiple immune-mediated diseases. Objective: This study was designed to investigated whether SNPs at the chromosome 11q23.3 locus are associated with AD in the Han Chinese population. Methods: In total, 16 SNPs within the 11q23.3 locus were genotyped using TaqMan assays for 1,012 AD cases and 1,362 controls. From these SNPs, we selected rs638893 with an association values of p < 5 × 10^-2 for AD for further analysis in an independent replication study using the Sequenom MassARRAY system to genotype an additional (consisting of 1,288 cases and 1,380 controls). The combined analyses were performed in two stages using a meta-analytical method. Results: We identified a common variant at 11q23.3 (rs638893), that was significantly associated (p = 1.58 × 10^-3, OR = 1.22) with AD. The genotype-based association analysis revealed that the recessive model provided the best fit for rs638893. Conclusion: Our study identified a variant on chromosome 11q23.3 that likely confers susceptibility to AD, thereby advancing our understanding of the genetic basis of this disease.

Validation of Susceptibility Loci for Vitiligo Identified by GWAS in the Chinese Han Population

Forty-nine susceptible loci have been reported to be significantly associated with vitiligo by genome-wide association studies (GWASs) in European-derived whites. To date, some of these reported susceptibility loci have not yet been validated in the Chinese Han population. The purpose of this study was to examine whether the 16 reported susceptible loci in European-derived whites were associated with vitiligo in the Chinese Han population. Imputation was performed using our previous GWAS dataset by IMPUTE v2.2.2. The 16 imputed top single-nucleotide polymorphisms (SNPs) with suggestive signals, together with the reported SNPs, were genotyped in a total of 2581 patients and 2579 controls by the Sequenom MassARRAY system. PLINK 2.0 software was used to perform association analysis. The dbSNP database, HaploReg, and eQTL data were adopted to annotate the biological function of the SNPs. Finally, four SNPs from three loci were significantly associated with vitiligo, including rs3747517 (P = 1.29 × 10^–3, OR = 0.87) in 2q24.2, rs4807000 (P = 7.78 × 10^–24, OR = 0.66) and rs6510827 (P = 3.65 × 10^–5, OR = 1.19) in 19p13.3, and rs4822024 (P = 6.37 × 10^–10, OR = 0.67) in 22q13.2. According to the dbSNP database, rs3747517 is a missense variant of IFIH1, rs4807000 and rs6510827 are located in TICAM1, and rs4822024 is located 6 kb upstream of TEF. Further bioinformatics analysis by HaploReg and eQTL found that rs4807000, rs6510827, and rs4822024 are involved in regulating gene expression. Our study revealed the strong association of 2q24.2 (rs3747517), 19p13.3 (rs4807000, rs6510827), and 22q13.2 (rs4822024) with the risk of vitiligo in the Chinese Han population, which implicates common factors for vitiligo across different ethnicities, and helps expand the understanding of the genetic basis of this disease.

Association Study Reveals One Susceptibility Locus with Vitiligo in the Chinese Han Population

Objective: The purpose of this study was to investigate associations between the 14 reported loci (from a meta-analysis of genome-wide association studies [GWAS] in the Caucasian population) and vitiligo in the Chinese Han population. Materials and Methods: In this study 14 single nucleotide polymorphisms (SNPs) at 14 different genetic loci were evaluated for their association with viteligo in a Chinese Han cohort, including 1472 cases and 1472 controls of by using the Sequenom MassArray iPLEX1 system. A Bonferroni adjustment was used for multiple comparisons and p_Bonferroni <0.0056 was considered statistically significant. Results: The T allele of the locus within the FBXO45-NRROS gene (3q29) was significantly associated with vitiligo (odds ratio = 1.22, 95% confidence interval: 1.10-1.36, p = 0.0001). Association at the genotype level was strong (p = 0.0007). The other SNPs were not associated with vitiligo (p_Bonferroni >0.0056). Conclusion: A SNP at the rs6583331 locus 3q29 is associated with the susceptibility of vitiligo in the Chinese Han population, which suggests that there is a common genetic factor predisposing to the development of vitiligo in the Chinese and Caucasian populations.

CXCL13 and Its Receptor CXCR5 in Cancer: Inflammation, Immune Response, and Beyond

It is well-established that the chemokine C-X-C motif ligand 13 (CXCL13) and its receptor, the G-protein coupled receptor (GPCR) CXCR5, play fundamental roles in inflammatory, infectious and immune responses. Originally identified as a B-cell chemoattractant, CXCL13 exerts important functions in lymphoid neogenesis, and has been widely implicated in the pathogenesis of a number of autoimmune diseases and inflammatory conditions, as well as in lymphoproliferative disorders. Current evidence also indicates that the CXCL13:CXCR5 axis orchestrates cell-cell interactions that regulate lymphocyte infiltration within the tumor microenvironment, thereby determining responsiveness to cytotoxic and immune-targeted therapies. In this review, we provide a comprehensive perspective of the involvement of CXCL13 and its receptor in cancer progression. Studies in recent years postulated novel roles for this chemokine in controlling the cancer cell phenotype, and suggest important functions in the growth and metastatic dissemination of solid tumors. Carcinogens have been found to induce CXCL13 production, and production of this chemokine within the tumor milieu has been shown to impact the proliferation, migration, and invasive properties of cancer cells. Thus, the complex networks of cellular interactions involving tumoral CXCL13 and CXCR5 integrate to promote cancer cell autonomous and non-autonomous responses, highlighting the relevance of autocrine and paracrine interactions in dictating the cancer phenotype. Dissecting the molecular and signaling events regulated by CXCL13 and how this chemokine dynamically controls the interaction between the cancer cell and the tumor microenvironment is key to identify novel effectors and therapeutic targets for cancer treatment.

Imbalance of peripheral follicular helper T lymphocyte subsets in active vitiligo

Vitiligo is an autoimmune disease characterized by the presence of several autoantibodies, some of which are directed against melanocyte components and have been shown to be associated with the progression of the disease. However, the mechanism involved in the production of autoantibodies remains unclear. Follicular helper CD4⁺ T cells (TFH) are specialized in B-cell activation and antibody production, especially the TFH cell subsets type 2 and type 17. To date, TFH cell subsets have not been studied in human vitiligo. This study in 44 vitiligo patients and 19 healthy controls showed an increase in circulating TFH cells associated with disease clinical progression. A more precise analysis of TFH cell phenotype demonstrated that vitiligo is characterized by populations of peripheral TFH cells responsible for helping B-cell function, such as TFH type 2 and type 17 which produce Th2- and TH17-related cytokines, respectively. These findings suggest a new mechanism involving TFH cell subsets in the pathogenesis of human vitiligo and leading to the production of autoantibodies and disease.