Measurement of activation of the endoplasmic reticulum stress response in autoimmune myositis

Evidence suggests that both immune (cell-mediated and humoral) and nonadaptive immune (endoplasmic reticulum (ER) stress and autophagy) mechanisms play a role in muscle fiber damage and dysfunction in idiopathic inflammatory myopathies (IIM). More recently, the ER stress response pathway, the activation of unfolded protein response, and the ER overload response are being studied to understand their contribution in the progression of IIM. A variety of qualitative and quantitative techniques are used to measure the activation of the endoplasmic reticulum stress response in myopathy. Accurately assessing the activation of ER stress response pathway would not only help in the understanding of disease pathogenesis but would also help to assess the response to therapy. Here, we describe common techniques such as western blotting, immunohistochemistry, immunofluorescence, and determination of mRNA levels for the gene of interest to monitor the ER stress in skeletal muscle tissues.