Molecular Pathogenesis of Vitiligo: Emerging Roles of Epigenetic Regulation.

Vitiligo is a chronic acquired depigmenting disorder characterized by progressive loss of functional melanocytes and is commonly associated with other autoimmune diseases. Although genome-wide association studies have identified multiple susceptibility loci, incomplete concordance among monozygotic twins and variable onset indicate strong contributions from environmental triggers and gene-environment interactions. A convergent pathogenic sequence is emerging: oxidative stress and defective cytoprotective responses render melanocytes vulnerable, promote release of danger signals, and activate innate immune pathways, followed by adaptive cytotoxic immunity dominated by autoreactive CD8+ T cells. Keratinocyte,fibroblasts immune crosstalk driven by IFN-γ and downstream JAK-STAT signaling induces CXCL9/CXCL10, recruiting CXCR3+ T cells and sustaining an amplification loop; CXCL10-CXCR3B signaling may also directly enhance melanocyte apoptosis. Tissue-resident memory T cells further maintain local immune surveillance and contribute to relapse after therapy. Epigenetic regulation provides a mechanistic bridge that translates transient stress into durable transcriptional states in both cutaneous cells and immune compartments. We review evidence for altered DNA methylation at melanocyte differentiation and survival genes (e.g., TYR, MITF) and immune regulatory loci (e.g., NLRP1, PTPN22), as well as contributions from histone modifications and non-coding RNAs that shape cytokine production and checkpoint pathways. Finally, we discuss translational opportunities, including topical JAK inhibition, epigenetic biomarkers for prognosis and treatment response, and emerging strategies for targeted epigenetic modulation. Integrated epigenomic approaches have the potential to advance the development of next-generation therapies.