Characteristics of Animal Models for Scleroderma

Scleroderma is a fibrotic condition characterized by immunologic abnormalities, vascular injury and increased accumulation of matrix proteins in the affected dermis. Although the etiology of scleroderma is not fully elucidated, numerous studies suggest that extracellular matrix overproduction by activated fibroblasts and myofibroblasts results from a complex interactions among endothelial cells, lymphocytes, macrophages, and fibroblasts, via a number of mediators. Animal models which exhibit all the aspects of human scleroderma are not currently available, however, several spontaneous or experimental animal models, such as tight skin (Tsk) mouse, Tsk2 mouse, bleomycin-induced scleroderma, sclerodermatous graft-versus-host disease (Scl GvHD) model, UCD chicken, and fibrosis model by exogenous injections of TGF-β/CTGF have been investigated. This review describes different animal models for scleroderma, paying the most attention to the recent progress in bleomycin-induced experimental murine scleroderma. Each model exhibits unique characteristics of dermal fibrosis/sclerosis which can be of great help in exploring the pathogenesis as well as therapeutic strategies of scleroderma.