香烟提取物通过减少HDAC2表达诱导小鼠C2C12成肌细胞衰老

目的:探讨香烟提取物(CSE)能否引起小鼠C2C12成肌细胞衰老,并研究成肌细胞衰老与组蛋白去乙酰化酶2(HDAC2)的关系。方法:培养C2C12细胞株,分化为成熟成肌细胞,观察CSE干预对成肌细胞衰老和HDAC2表达的影响,采用real-time PCR和Western blot方法分别检测HDAC2 mRNA和蛋白的表达;β-半乳糖苷酶染色检测衰老细胞的百分率。结果:MTT法测定最佳CSE浓度与干预时间分别为60 m L/L和24 h。CSE干预后β-半乳糖苷酶染色阳性细胞数增加,同时伴有HDAC2 mRNA和蛋白表达的减少。四溴苯三唑(TBB)在促进HDAC2 mRNA和蛋白表达的同时,β-半乳糖苷酶染色阳性细胞数减少;用HDAC2的特异性阻滞剂丙戊酸抑制HDAC2 mRNA和蛋白的表达时,β-半乳糖苷酶染色阳性细胞数增加。结论:香烟提取物可通过减少小鼠C2C12成肌细胞HDAC2的表达促进细胞老化。

Cigarette smoke extract promotes senescence by reducing expression of HDAC2 in C2C12 myoblasts

AIM: To investigate whether the cigarette smoke extract (CSE) causes senescence of C2C12 myoblasts and the relationship between senescence and histone deacetylase 2(HDAC2).METHODS: Murine C2C12 cells were induced to differentiate into myoblasts. The HDAC2 activator and inhibitor were used to investigate the effects of CSE in the myoblasts on cell senescence and the expression of HDAC2. The expression of HDAC2 at mRNA and protein levels was determined by real-time PCR and Western blot, respectively, and the positive cell rate of β-galactosidase staining for cell senescence was also detected.RESULTS: The optimal concentration of CSE was 60 mL/L and the intervention time was 24 h. After the intervention of CSE, the positive cell rate of β-galactosidase staining was increased, accompanied with the reduction of HDAC2 expression at mRNA and protein levels. The expression of HDAC2 at mRNA and protein levels was increased by 4, 5, 6, 7-tetrabromobenzotriazole (TBB), accompanied with the reduction of positive cell rate of β-galactosidase staining. Furthermore, when HDAC2 expression at mRNA and protein levels was reduced by HDAC2 inhibitor valproic acid, the positive cell rate of β-galactosidase staining was increased.CONCLUSION: CSE promotes the senescence by reducing the expression of HDAC2 in C2C12 myoblasts.