Glucose transporter-1 (GLUT-1) upregulation in vitiligo: A possible link to skin depigmentation

Background: Vitiligo is a prevalent autoimmune skin disorder characterized by progressive depigmented patches of the skin and/or mucosa. Lately, extensive research has been investigating molecular pathogenesis underlying vitiligo, epidermal-immune cell crosstalk, structural aberrations in cellular skin components and immune cell metabolism derangements. Glucose transporter-1 (GLUT-1) has recently proved to be increased in proinflammatory conditions and autoimmune diseases. GLUT-1 expression is upregulated in rheumatoid arthritis, systemic lupus erythematosus, psoriasis and chronic spongiotic dermatitis. Objective: To investigate GLUT-1 expression in vitiligo. Subjects and methods: The study included 30 vitiligo patients "vitiligo vulgaris" and 30 healthy individuals. Biopsies of the patients' lesional vitiligo skin and the control group's normal skin were obtained. They were all tested for GLUT-1 mRNA expression using real-time polymerase chain reaction (RT-PCR) and GLUT-1 antibody expression using immunohistochemistry (IHC). Hematoxylin and eosin (H&E) staining for the specimens was additionally done for histopathological assessment. Results: GLUT-1 expression was upregulated in lesional skin of vitiligo patients compared to normal control skin (P-value < 0.001). Also, lesional specimens from stable disease showed more GLUT-1 expression than active disease but without a significant difference (P-value = 0.283). There was no significant correlation between the proposed vitiligo histological scoring system and vitiligo signs of the disease activity score. Conclusion: GLUT-1 could play a crucial role in vitiligo disease onset, persistence and progression, through keratinocyte-melanocyte-fibroblast-immune cell crosstalk, being the initially deranged metabolic pathway for all these cells giving an insight into vitiligo metabolomics.