Vitiligo-inducing phenols activate the unfolded protein response in melanocytes resulting in upregulation of IL6 and IL8.
Vitiligo is characterized by depigmented skin patches caused by loss of epidermal melanocytes. Oxidative stress may have a role in vitiligo onset, while autoimmunity contributes to disease progression. In this study, we sought to identify mechanisms that link disease triggers and spreading of lesions. A hallmark of melanocytes at the periphery of vitiligo lesions is dilation of the endoplasmic reticulum (ER). We hypothesized that oxidative stress results in redox disruptions that extend to the ER, causing accumulation of misfolded peptides, which activates the unfolded protein response (UPR). We used 4-tertiary butyl phenol and monobenzyl ether of hydroquinone, known triggers of vitiligo. We show that expression of key UPR components, including the transcription factor X-box-binding protein 1 (XBP1), is increased following exposure of melanocytes to phenols. XBP1 activation increases production of immune mediators IL6 and IL8. Co-treatment with XBP1 inhibitors reduced IL6 and IL8 production induced by phenols, while overexpression of XBP1 alone increased their expression. Thus, melanocytes themselves produce cytokines associated with activation of an immune response following exposure to chemical triggers of vitiligo. These results expand our understanding of the mechanisms underlying melanocyte loss in vitiligo and pathways linking environmental stressors and autoimmunity.
The Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, New York, USA.
Siavash
S
Toosi
Seth J
SJ
Orlow
Prashiela
P
Manga
D015551:Autoimmunity / Q000502:physiology; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects / Q000276:immunology; D006801:Humans; D006873:Hydroquinones / Q000633:toxicity; D007231:Infant, Newborn; D015850:Interleukin-6 / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D016209:Interleukin-8 / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D008544:Melanocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D018384:Oxidative Stress / Q000187:drug effects / Q000276:immunology; D010636:Phenols / Q000633:toxicity; D000071701:Regulatory Factor X Transcription Factors; D012867:Skin / Q000166:cytology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D056811:Unfolded Protein Response / Q000276:immunology*; D015854:Up-Regulation / Q000276:immunology; D014820:Vitiligo / Q000276:immunology* / Q000378:metabolism*; D000071717:X-Box Binding Protein 1
C508606:CXCL8 protein, human; D004268:DNA-Binding Proteins; D006873:Hydroquinones; C508600:IL6 protein, human; D015850:Interleukin-6; D016209:Interleukin-8; D010636:Phenols; D000071701:Regulatory Factor X Transcription Factors; D014157:Transcription Factors; D000071717:X-Box Binding Protein 1; C000605543:XBP1 protein, human; C006429:monobenzone; C006862:butylphen