The environmental pollutant cadmium induces homeostasis alteration in muscle cells in vitro

BACKGROUND: Cadmium (Cd) is a heavy metal widely distributed throughout the environment as a result of contamination from a variety of sources. It exerts toxic effects in many tissues but scarce data are present as yet on potential effects on skeletal muscle tissue. AIM: To evaluate the potential alteration induced by Cd in skeletal muscle cells. MATERIALS AND METHODS: C2C12 skeletal muscle cells were treated with Cd at different times of cellular differentiation and gene expression was evaluated. RESULTS: Exposure to Cd decreased significantly p21 mRNA expression and strongly up-regulated cyclin D1 mRNA expression in committed cells and in differentiated myotubes. Moreover, myogenin, fast MyHC-IIb and slow MyHC-I mRNAs expression were also significantly decreased both in committed cells and in myotubes. Moreover, Cd exposure induced a strong increase of Pax3, Pax7 and Myf5 mRNAs expression and stimulated an up-regulation of IL6 and TNF-α proinflammatory cytokines. CONCLUSION: These data lead to hypothesize that environmental Cd exposure might trigger an injury-like event in muscle tissue, possibly by an estrogen receptor-mediated mechanism