Effects of drugs and anticytokine antibodies on expression of ATP2A2 and ATP2C1 in cultured normal human keratinocytes.

BACKGROUND: Darier's disease (DD) and Hailey-Hailey disease (HHD) are skin disorders arising, respectively, from autosomal dominant mutations in ATP2A2, encoding the sacro/endoplasmic reticulum calcium ATPase, and ATP2C1, encoding the Golgi apparatus calcium ATPase. Exposure to ultraviolet (UV) B irradiation exacerbates the skin lesions, which can be treated with corticosteroids and retinoids.

OBJECTIVES: To investigate the molecular basis for DD and HHD.

METHODS: We used quantitative reverse transcriptase-polymerase chain reactions to examine the effects of UVB irradiation on ATP2A2 and ATP2C1 mRNA levels in cultured normal keratinocytes.

RESULTS: We observed that UVB irradiation reduced ATP2A2 and ATP2C mRNA levels. The addition of retinoids or corticosteroids to the cell culture inhibited the UVB-induced suppression of both ATP2A2 and ATP2C1 mRNA levels, and UVB-induced suppression of ATP2C1 mRNA was also inhibited by the addition of ciclosporin, tacrolimus and vitamin D(3). The addition of anti-interleukin (IL)-6 antibody to the cell culture prevented the UVB-induced suppression of ATP2A2 and ATP2C1 mRNA; in contrast, the addition of anti-IL-8 antibody slightly accelerated the suppression.

CONCLUSIONS: These results suggest that drugs effective for DD and HHD act by modulating ATP2A2 and ATP2C1 mRNA expression, respectively, and that the proinflammatory cytokines IL-6 and IL-8 play important roles in the regulation of ATPA2 and ATP2C1 expression in homeostasis and/or inflammation of the skin.