To determine the involvement of PGs in the pathogenesis of EPF.
We performed immunostaining for PG synthases in EPF skin lesions. We examined the effect of PGD2 on induction of eotaxin, a chemoattractant for eosinophils, in human keratinocytes, fibroblasts, and sebocytes and sought to identify its responsible receptor.
Hematopoietic PGD synthase was detected mainly in infiltrating inflammatory cells in EPF lesions, implying that PGD2 was produced in the lesions. In addition, PGD2 and its immediate metabolite 15-deoxy-¦¤ 12,14-PGJ2 (15d-PGJ2) induced sebocytes to produce eotaxin-3 via peroxisome proliferator-activated receptor gamma. Consistent with the above findings, eotaxin-3 expression was immunohistochemically intensified in sebaceous glands of the EPF lesions.
The PGD2/PGJ2-peroxisome proliferator-activated receptor gamma pathway induces eotaxin production from sebocytes, which may explain the massive eosinophil infiltrates observed around pilosebaceous units in EPF.