[Cigarette smoke extract induces senescence of murine skeletal muscle cells by oxidative stress-induced down-regulation of histone deacetylase 2].

OBJECTIVE

To investigate whether cigarette smoke extract (CSE) induces the senescence of skeletal muscle cells by oxidative stress-induced down-regulation of histone deacetylase 2 (HDAC2).

METHODS

C2C12 myoblasts were induced to differentiate into skeletal muscle cells. H2O2 and N-acetyl cysteine (NAC) were used to investigate the effects of CSE on oxidative stress, cell senescence and the expression of HDAC2 in skeletal muscle cells, and detect the changes of the activities of malondialdehyde (MDA), superoxide dismutase (SOD), reactive oxygen species (ROS) and glutathione peroxidase (GSH-Px). Cell senescence was identified by senescence-associated β-galactosidase staining. The expressions of HDAC2 mRNA and protein were measured by real-time quantitative PCR and Western blotting, respectively.

RESULTS

Compared with the control group, MDA concentration and ROS activity significantly increased, the activities of SOD and GSH-Px significantly decreased, the expression of β-galactosidase was up-regulated, and the expressions of HDAC2 mRNA and protein were down-regulated in the CSE group and the H2O2 group. However, the changes in the CSE group were reversed after the pretreatment of NAC.

CONCLUSION

CSE may lead to the senescence of murine skeletal muscle cells by oxidative stress-induced down-regulation of HDAC2.