Inhibition of skin sclerosis by 15deoxy Δ12,14-prostaglandin J2 and retrovirally transfected prostaglandin D synthase in a mouse model of bleomycin-induced scleroderma

Hematopoietic prostaglandin D synthase (PGDS) is a key enzyme involved in production of the PGD and J series, which have various role in inflammation and immunity. We evaluated the effect of treatment with 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) or the injection of prostaglandin D2 synthase (PGDS) cDNA expressing-retrovirally transfected fibroblasts on bleomycin (BLM)-induced scleroderma-like skin sclerosis. Daily injection of BLM (30 μg) for 4 weeks induced histological evidence of dermal sclerosis in C3H mice. We examined the effect of injection of 15d-PGJ2 (30 ng twice a day) or PGDS expressing-retrovirally transfected fibroblast on BLM-induced dermal sclerosis. Administration of 15d-PGJ2 (a nonenzymatic metabolite of PGD2) injection of PGDS cDNA-expressing fibroblasts significantly reduced dermal sclerosis, the hydroxyproline content, and dermal thickness. Moreover, 15-d PGJ2 down-regulation of the expression of transforming growth factor β1 and connective tissue growth factor which had been induced by BLM. Mast cells were also increased in the skin by BLM injection and there was prominent degranulation of these mast cells along with elevated plasma histamine levels. 15-d PGJ2 and PGDS-expressing cells also suppressed degranulation of cultured mast cells and histamine release by these cells. These results show that 15-d PGJ2 and PGDS-expressing cells can prevent experimental skin sclerosis induced by BLM and raise the possibility of therapeutic approaches targeting of PPARγ for the skin lesion of scleroderma.