LL37-DNA Complex Drives Vitiligo Progression Through TLR9-MyD88 Signaling Pathways.

Vitiligo is an autoimmune disorder characterized by chronic depigmentation and milk-white patches on the skin. Skin infiltration by autoreactive CD8+ T cells causes melanocyte destruction in vitiligo. Multiple risk factors, particularly immune-related inflammatory factors, are involved in the disappearance of melanocytes. LL37 is a classic damage-associated molecular pattern molecule that is involved in the development of various autoimmune diseases. An enhanced expression of LL37 in vitiligo is known; however, the exact role of LL37 in melanocyte loss has not yet been elucidated. In the present study, we detected increased LL37 expression in vitiligo serum and lesions. Furthermore, we confirmed that cultured keratinocytes released LL37 after treatment with H2O2. Moreover, the LL37-DNA complex enhanced the secretion of CXCL9, CXCL10, and CXCL16 from keratinocytes via the TLR9-MyD88 signaling pathway and facilitated the migration of CD8+ T cells. Altogether, our study demonstrates that LL37 released from keratinocytes binds to DNA and contributes to melanocyte destruction under oxidative stress-induced autoimmunity in vitiligo.

Damage-associated molecular patterns in vitiligo: igniter fuse from oxidative stress to melanocyte loss.

OBJECTIVES: The pathogenesis of vitiligo remains unclear. In this review, we comprehensively describe the role of damage associated molecular patterns (DAMPs) during vitiligo pathogenesis. METHODS: Published papers on vitiligo, oxidative stress and DAMPs were collected and reviewed via database searching on PubMed, MEDLINE and Embase, etc. RESULTS: Oxidative stress may be an important inducer of vitiligo. At high oxidative stress levels, damage-associated molecular patterns (DAMPs) are released from keratinocytes or melanocytes in the skin and induce downstream immune responses during vitiligo. Treatment regimens targeting DAMPs can effectively improve disease severity. DISCUSSION: DAMPs play key roles in initiating host defenses against danger signals, deteriorating the condition of vitiligo. DAMP levels in serum and skin may be used as biomarkers to indicate vitiligo activity and prognosis. Targeted therapies, incorporating HMGB1, Hsp70, and IL-15 could significantly improve disease etiology. Thus, novel strategies could be identified for vitiligo treatment by targeting DAMPs.

A CASE REPORT of Lichen Nitidus on the Penis: Tiny but Annoying Eruptions.

Most patients are anxious about the skin lesions on the penis. This study reports a case of lichen nitidus on the penis and reviews related literature. A 40-year-old male has presented with small papules with skin color on the penis for one year. The patient was diagnosed with lichen nitidus, and tacrolimus cream and humectant were topically administered after diagnosis. The symptoms were alleviated after treatment. We first report a series of the cases with lichen nitidus on the penis, knowing the clinical and pathological manifestations of this disease can reduce misdiagnosis and unnecessary treatment.