不同应激条件下分化抑制因子Id2在成肌细胞C2C12中的表达与分布

The expression and cellular distribution of Id2 in myoblast C2C12 under different stimuli

目的观察在不同应激条件下成肌细胞C2C12中Id2的表达与细胞分布情况,并探讨其表达与分布变化的机制。方法体外培养C2C12细胞,分别采用不同浓度H2O2氧化应激诱导细胞增殖或凋亡,不同浓度的促炎症信号LPS诱导细胞增殖,以及2%马血清诱导细胞分化。利用RT-PCR比较不同应激条件下Id2 mRNA的表达,同时利用免疫荧光检测Id2蛋白的表达强度和细胞分布。结果25μmol/l和50μmol/l的H_2O_2诱导下,Id2 mRNA表达比对照组分别增高80.5%和55.5%,荧光显著增强,Id2呈现细胞核与细胞质均匀分布。100 ng/ml和500 ng/ml的LPS亦诱导Id2 mRNA表达,较对照组增高21.7%和40.2%,荧光增强,但此时Id2以细胞核分布为主,细胞质少量分布。在2%马血清诱导成肌细胞分化后,Id2 mRNA表达显著降低,荧光显著减弱,并以细胞质分布为主。结论不同应激条件下Id2在成肌细胞中呈现不同的表达和分布,与其对骨骼肌损伤后再生的调控作用密切相关,表明Id2是骨骼肌损伤后再生的重要调控分子。

Objective TO observe the expression and distribution of Id2 after myoblasts were induced to proliferation, apoptosis and differentiation with various stimuli. Methods Cultured C2C12 cells were treated with 25~300 μmol/L different concentration of H2O2, 100 ng/ml or 500 ng/ml of LPS, and 2%horse serum to induce proliferation, apoptosis or differentiation. After treatment,RT-PCR and immunofluorescence were used to detect the expression level and the cellular distribution of Id2 in C2C12 cells.Results After treatment with 25 μmol/l or 50 μmol/l of H2O2, expression of Id2 in C2C12 cells was80.5% and 55.5% higher than control cells, and Id2 were present evenly in the both nucleus and cytoplasm.LPS of 100 ng/ml and 500 ng/ml also induced Id2 expression, 21.7% and 40.2% higher than control cells,but at a weaker level, and the majority of Id2 was in the nucleus of C2C12, with the detectable signals in the cytoplasm. On the contrary, with differentiation of C2C12 cells after treatment with 2% horse serum, Id2 expression decreased and most Id2 migrated into cytoplasm. Conclusion Different expression and distribution of Id2 could be observed after induction of myoblasts to proliferation, apoptosis and differentiation with various stimuli. And the result has demonstrated that Id2 could regulate regeneration of skeletal muscle. Ithas indicated that Id2 is a very impossible regulatory factor of regeneration of skeletal muscle after injury.