041 Regulatory T cells drive stem cell differentiation during skin barrier repair

Abstract

Autophagy is an essential intracellular self-degradation system to maintain the homeostatic balance between the synthesis, degradation and recycling of cellular proteins and organelles. Recently, it is reported that autophagy is associated with systemic lupus erythematosus, rheumatoid arthritis and idiopathic pulmonary fibrosis. The association with autophagy and scleroderma (SSc) is also suspected, however, the role of autophagy in the pathogenesis of tissue fibrosis is still unclarified, and the association of which phase of scleroderma is largely unknown. Therefore, we investigated the role of autophagy in the pathogenesis of SSc by using skin and lung samples of bleomycin (BLM)-induced SSc murine model and human SSc skin. BLM or phosphate-buffered saline (PBS) was injected into shaved back of C3H/HeJ mice for 2 or 4 weeks. Also, we used skin samples of edematous phase SSc and those of sclerotic phase SSc. We carried out haematoxylin and eosin (HE) stain for evaluation of skin sclerosis and immunofluorescent stain by anti microtubule-associated protein 1 light chain 3 (LC3) antibody, which is the most common autophagy marker. We evaluated the number of LC3positive dots in fibroblasts in the mice samples (skin and lung) and the human skin samples (both edematous and sclerotic phase). There was no clear difference between the number of LC3-positive dots of skin samples from PBS mice and those from BLM mice qualitatively. We are currently investigating the number of LC3-positive dots of mice lung tissues and human skin samples in more numbers.