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Correlation between diffuse pigmentation and keratinocyte-derived endothelin-1 in systemic sclerosis
1Department of Dermatology and Physiology, Dokkyo University School of Medicine, Tochigi, Japan.
International Journal of Dermatology
|February 13, 2001
Summary
Systemic sclerosis (SSc) patients, particularly diffuse scleroderma cases, exhibit increased endothelin-1 (ET-1) production by skin keratinocytes. This heightened ET-1 productivity correlates significantly with the severity of skin hyperpigmentation in SSc.
Area of Science:
- Dermatology
- Pathophysiology
- Molecular Biology
Background:
- The mechanism of skin hyperpigmentation in systemic sclerosis (SSc) remains unclear.
- Endothelin-1 (ET-1), produced by keratinocytes, is hypothesized to contribute to SSc hyperpigmentation.
Purpose of the Study:
- To investigate the productivity of ET-1 in epidermal cells of SSc patients using in situ hybridization histochemistry.
- To determine the correlation between ET-1 hyperproductivity in keratinocytes and skin hyperpigmentation in SSc.
Main Methods:
- In situ hybridization histochemistry was performed on SSc (n=9) and normal control (n=4) skin specimens.
- Quantified ET-1 expression (grain counts) in epidermis and microvessels.
- Assessed skin pigmentation using the skin reflectance factor (Y).
Main Results:
- SSc epidermis showed significantly higher ET-1 expression compared to controls (P < 0.01).
- A strong correlation was observed between epidermal ET-1 grain counts and skin reflectance factor in diffuse SSc (dSSc) patients (P = 0.02).
- No correlation was found between serum ET-1 levels and skin pigmentation or epidermal ET-1 frequency.
Conclusions:
- Increased ET-1 production by keratinocytes is evident in SSc patients, especially in dSSc.
- Keratinocyte-derived ET-1 plays a significant role in the pathogenesis of skin hyperpigmentation in SSc.
- The study highlights ET-1 as a key factor in SSc-related skin darkening.