Objective: To observe changes of inflammatory mediators, histone deacetylase 2 (HDAC2) and nuclear factor κB (NF-κB) in murine C2C12 skeletal muscle myocytes after exposed to cigarette smoke.
Methods: Murine C2C12 skeletal muscle myocytes were cultured and treated with cigarette smoke extract (CSE). MTT assay was used to detect the effect of CSE on cell proliferation to determine appropriate concentration of CSE. The C2C12 cells cultured for 6-7 days were planted in six-well plates, and divided into control group, (6.25, 12.50, 25.0) mL/L CSE groups. The cells were cultured for 24 hours. The levels of interleukin-8 (IL-8) and tumor necrosis factor-α (TNF-α) in the supernatant were measured by ELISA. The mRNA level of HDAC2 was determined by real-time quantitative PCR. The protein level of HDAC2 was detected by Western blotting. HDAC2/NF-κB compound was determined by the method of co-immunoprecipitation.
Results: MTT assay showed that CSE at the concentration of 50 mL/L inhibited proliferation of C2C12 cells. After 24-hour treatment with CSE, IL-8 and TNF-α releasing from C2C12 cells increased and the level of HDAC2 mRNA and protein were reduced, which were CSE dose-dependent. Co-immunoprecipitation confirmed that HDAC2/NF-κB compound existed in the CSE-exposed C2C12 cells.
Conclusion: CSE can down-regulate the expression of HDAC2 and increase inflammatory cytokines releasing from C2C12 cells.