Overexpression of Neural Cell Adhesion Molecule in Regenerative Muscle Fibers in 3-Hydroxy-3-Methylglutaryl Coenzyme: A Reductase Inhibitor-induced Rhabdomyolysis

Skeletal muscle degeneration is a side effect of cholesterol-lowering hydroxymethylglutaryl coenzyme A reductase inhibitors. The expression of the cell-cell adhesion proteins, neural cell adhesion molecule and neural-cadherin was studied in a case of rhabdomyolysis induced by the hydroxymethylglutaryl coenzyme A reductase inhibitor cerivastatin. Neural cell adhesion molecule and N-cadherin participate in the interactions of muscle cells during skeletal myogenesis. In the adult muscle, neural cell adhesion molecule is restricted to neuromuscular sites but is re-expressed in denervated muscle and in rhabdomyolysis. Our results show expression of neural cell adhesion molecule in regenerative skeletal muscle fibers but not in degenerated or unaffected fibers in cerivastatin-induced rhabdomyolysis. In contrast, N-cadherin was not expressed. The presence of apoptotic cells was studied by a fluorescence-based Tdt-mediated dUTP nick-end labeling in the same sections. Apoptosis was detected in degenerative fibers and inflammatory cells but not in regenerative fibers. We hypothesize that the expression of neural cell adhesion molecule in regenerative fibers may have a protective role against apoptosis during rhabdomyolysis. Cerivastatin-induced rhabdomyolysis appears to have common features with rhabdomyolysis of other causes. The immunohistochemical study of neural cell adhesion molecule can serve as an additional tool in the evaluation of muscle regeneration in rhabdomyolysis.