Expression of Autophagy-Associated Protein in Rat Muscle Tissues after Antemortem and Postmortem Injury

Objective To study the expression of the three autophagy-associated proteins, BECN1, LC3 and p62, after the injury of the skeletal muscle of rats and to explore its application in differentiation between antemortem and postmortem injury. Methods The 72 healthy Sprague-Dawley rats were randomly divided into the undamaged control group, the antemortem injury group （0.5 h, 1 h, 2 h, 4 h, 8 h, 16 h and 24 h） and postmortem injury group （0.5 h, 1 h, 2 h and 4 h）. A model of the injured right hind limb of rats was constructed. The expressions of the autophagy-associated proteins, BECN1, LC3-2/LC3-1 and p62, in the control group, the antemortem injury group and postmortem injury group were detected by Western blotting method. The data were respectively centralized and standardized and the orthogonal partial least square-discrimination analysis （OPLS-DA） identification model of antemortem and postmortem injury groups was constructed. Results The expression of BECN1, p62 protein and LC3-2/LC3-1 after the injury of the skeletal muscle of the rats showed different degrees of changes, but the differences among the 3 groups had no statistical significance. Antemortem and postmortem injury groups can be distinguished by centralizing and standardizing the expression levels of autophagy protein BECN1 and the ratio of LC3-2/LC3-1. The principal components extracted from OPLS-DA model of antemortem injury and postmortem injury had a relatively good interpretation of the model （R_x²=0.563, R_y²=0.439）, but it were less predictive （Q²=0.366）. Conclusion The expression of BECN1 and the ratio of LC3-2/LC3-1 in injured local tissue of the rat skeletal muscle can be used for the differentiation of antemortem injury group and postmortem injury group.