The effect of imatinib (Glivec (R)) on scleroderma and normal dermal fibroblasts: A preclinical study

Background: Scleroderma skin overexpresses the platelet-derived growth factor receptor beta-subunit (PDGFR-beta) in dermal vessels and PDGFR-beta messenger RNA in cultured fibroblasts. Moreover, increased levels of PDGF and stimulatory autoantibodies to PDGFR have been identified in the serum of scleroderma patients. Objective: Imatinib being an inhibitor of tyrosine kinase receptors such as PDGFR, its effect on scleroderma fibroblasts was evaluated in vitro as a preclinical therapeutic step. Methods: The effect of imatinib on fibroblasts grown from normal or involved/uninvolved scleroderma skin was studied by Western blot and the methyltetrazolium test. The pattern of distribution of PDGFR-beta in scleroderma versus normal skin was studied by immunohistochemistry. Results: In vitro, imatinib inhibited the proliferation of normal dermal and scleroderma fibroblasts at least partly via the inhibition of the phosphorylation of PDGFR. PDGFR-beta was expressed in the epidermis and ad-nexae in 5 lesional scleroderma biopsies and not in controls. Conclusion: This study suggests that imatinib can serve as therapy to limit dermal fibroblast proliferation in scleroderma. Copyright (c) 2008 S. Karger AG, Basel