A Preclinical Model of Sepsis-Induced Myopathy with Disuse in Mice.

Sepsis is a major cause of in-hospital deaths. Improvements in treatment result in a greater number of sepsis survivors. Approximately 75% of the survivors develop muscle weakness and atrophy, increasing the incidence of hospital readmissions and mortality. However, the available preclinical models of sepsis do not address skeletal muscle disuse, a key component for the development of sepsis-induced myopathy. Our objective in this protocol is to provide a step-by-step guideline for a mouse model that reproduces the clinical setting experienced by a bedridden septic patient. Male C57Bl/6 mice were used to develop this model. Mice underwent cecal ligation and puncture (CLP) to induce sepsis. Four days post-CLP, mice were subjected to hindlimb suspension (HLS) for seven days. Results were compared with sham-matched surgeries and/or animals with normal ambulation (NA). Muscles were dissected for in vitro muscle mechanics and morphological assessments. The model results in marked muscle atrophy and weakness, a similar phenotype observed in septic patients. The model represents a platform for testing potential therapeutic strategies for the mitigation of sepsis-induced myopathy.