Hyperglycemia aggravates vitiligo through succinate/SUCNR1-mediated T cell activation.

Vitiligo is an autoimmune skin disease characterized by depigmentation, mainly due to CD8+ T cell-mediated destruction of melanocytes. Hyperglycemia exacerbates autoimmune responses and is associated with vitiligo; however, the underlying immunometabolic mechanisms are poorly understood. Here, we demonstrated the correlation between hyperglycemia and vitiligo in a case-control study and demonstrated that hyperglycemia aggravated vitiligo based on a mouse model. Targeted metabolomics identified succinate as the potential metabolite mediating hyperglycemia-aggravated vitiligo. Mechanistically, succinate promotes the activation of CD8+ T cells through succinate receptor 1 (SUCNR1) and promotes keratinocytes to secrete CXCL9 and CXCL10 by enhancing the stability and nuclear translocation of hypoxia-inducible factor-1α, facilitating the skin-homing of CD8+ T cells. Thus, hyperglycemia aggravates vitiligo through succinate/SUCNR1 axis-regulated CD8+ T cell hyperactivation. Our study provides insights into the long-observed yet previously unclear mechanism by which hyperglycemia accelerates vitiligo progression and highlights SUCNR1 as a potential therapeutic target.