Characterization of the mechanisms underlying glucocorticoids effects myositis (GC-MYOS) – GC-MYOS

Myositis are autoimmune diseases characterized by inflammation of skeletal muscle causing weakness and increased mortality. Glucocorticoids (GC) improve the disease through currently unknown mechanisms (therapeutic effect) but expose to many adverse events including steroid-induced myopathy (iatrogenic effect). The objective of GC-MYOS is to unravel the mechanisms underlying the therapeutic effects of GC in myositis using innovative approach that combine i) an experimental myositis (EM) that we have recently established ii) cell specific temporally controlled targeted deletion of GC receptor in mice iii) muscle single cells molecular signatures associated with GC response in human myositis samples. The results gained from this project will provide an in depth characterization of the therapeutic mechanisms of GC in myositis (as opposed to their iatrogenic effects) and to approach the mechanism of GC resistance that will pave the way for optimization of myositis care.