Serum miR-206 as a biomarker for drug-induced skeletal muscle injury in rats

Creatine kinase (CK) and lactate dehydrogenase (LDH) serve as biomarkers for skeletal muscle injury in preclinical toxicity studies, but have a limitation regarding tissue specificity. Circulating miR-206 was recently reported to be a useful biomarker for skeletal muscle disorders in humans. Here, we sought to determine whether serum miR-206 can be used as a biomarker in preclinical toxicity studies to detect drug-induced skeletal muscle injury with higher sensitivity and specificity than the biomarkers CK, LDH, skeletal troponin I (sTnI), and myosin light chain 3 (Myl3). We established rat models of skeletal muscle injury through treatment with the muscle toxicant 2,3,5,6-tetramethyl-p-phenylenediamine (TMPD) as well as four in-house compounds. We found that serum miR-206 levels significantly increased after treatment with TMPD, and tended to be higher in rats treated with in-house compounds than in control rats. ROC analysis revealed that the specificity of serum miR-206 for detection of skeletal muscle injury was higher compared with those of other markers. Further, serum miR-206 levels were unchanged in rats with isoproterenol-induced cardiotoxicity. These findings demonstrate that serum miR-206 may serve as a highly specific biomarker for preclinical analysis of rats with drug-induced skeletal muscle injuries.