生化学と分析生化学

概要

Interleukin 1-α: A Modulator of Melanocyte Homeostasis in Vitiligo

Mala Singh, Mohmmad Shoab Mansuri, Mansi A Parasrampuria and Rasheedunnisa Begum

Background: Vitiligo is a hypomelanotic autoimmune skin disorder arising from a breakdown in immunological self-tolerance, which leads to aberrant immune responses against melanocytes leading to selective destruction of melanocytes. High levels of Interleukin 1(IL1) have been reported in various autoimmune disorders including vitiligo. The aim of present study was to explore the effect of IL1-α on melanocyte biology by monitoring the melanocyte viability, IL1R1 membrane expression, melanogenesis (TYR, TYRP1 and MITF-M) and other immuno modulatory molecules (IL1A, IL1B, IL1RN,IL1R1 IL8, TNFA, IL6, and ICAM1) upon exogenous stimulation of IL1- α on primary cultured normal human melanocytes (NHM).

Materials and methods: Melanocytes were isolated from normal c skin biopsies and cultured in vitro. The NHMs were treated with IL1-α (0-100 ng/ml) and cell viability was monitored by MTT assay, IL1R1 membrane expression was monitored using flow cytometry and relative gene expression was performed using semi-quantitative RT-PCR.

Results: The dose dependent effect of IL1-α on melanocytes showed ~12% melanocyte death and ~22% increase in IL1R1 membrane expression upon 100 ng/ml IL1-α treatment for 48 hrs. Further, IL1RN, IL1A, IL1B, IL6, TNFA, ICAM1 showed significantly increased expression (p<0.05) and MITF-M showed significantly decreased expression (p<0.05) upon IL1-α (10 and 100 ng/ml, 48 hrs) stimulation on NHM; while TYR, TYRP1, IL8 and IL1R1 showed no difference.

Conclusion: Overall, the present study suggests the crucial role of IL1-α in melanocyte destruction in vitiligo by regulating MITF-M and other immunomodulatory molecules.