Time-course study of macrophage infiltration and inflammation in cast immobilization-induced atrophied muscle of mice

Atrophy signaling pathway activation, but not macrophage infiltration, was observed during the early phase after cast immobilization. Our findings indicate that macrophage infiltration may contribute very little to the early phase of muscle atrophy after cast immobilization. Muscle Nerve 57: 1006-1013, 2018.

C57BL/6J mice were euthanized after cast immobilization at 1, 3, 7, and 14 days.

Skeletal muscle macrophage numbers were unchanged on days 1 and 3 after immobilization, but were elevated on days 7 (2.7-fold, P < 0.01) and 14 (4.1-fold, P < 0.01). Ubiquitin ligase expression was increased 1 and 3 days after cast immobilization, as was the LC3-II/LC3-I ratio.