不同功率的激光刺激对小鼠C2C12成肌细胞耗氧率水平的影响及机制

目的：探讨不同功率的低强度650 nm激光刺激对C₂C₁₂成肌细胞耗氧率水平和相关蛋白的影响及其机制。方法：以体外培养的C₂C₁₂小鼠成肌细胞作为实验对象，以4×10⁵个/孔接种于牵张6孔板中，采用输出功率5 mW，波长650 nm的二极管激光进行单次刺激，激光照射剂量分别0 J/cm²（0 min）、0.4 J/cm²（12.8 min）、0.8 J/cm²（25.6 min）。实验结束后，采用耗氧率试剂盒（Luxcel Biosciences）检测细胞耗氧率；提取细胞总蛋白，采用Western blot技术检测成肌调节因子（MyoD）、过氧化物酶体增殖活化受体γ共激活因子1α（PGC-1α）、雷帕霉素靶蛋白和磷酸化蛋白（p-mTOR/mTOR）表达。结果：与对照组相比，低剂量组细胞氧化耗氧率结果、MyoD、PGC-1α蛋白表达显著增加（P<0.05），高剂量组MyoD、PGC-1α蛋白表达显著增加（P<0.05），p-mTOR/mTOR蛋白显著降低（P<0.05）。结论：较低剂量（0.4 J/cm²）的650 nm低强度激光增强了细胞氧化功能水平，并对细胞分化相关蛋白有一定影响。其机制可能与适宜的激光刺激影响PGC-1α蛋白的表达，进而影响线粒体氧化呼吸有关。

Effects of laser stimulation with different power on oxygen consumption rate of C2C12 myoblasts in mice

Objective: To investigate the effects of 650 nm laser irradiation on cell oxygen consumption rate in C₂C₁₂ myoblasts following different doses. Methods: C₂C₁₂ cells were irradiated with 650 nm laser(λ=650 nm, p=5 mW) with energy densities of 0, 0.4, and 0.8 J/cm². Cell oxidative function was measured by oxygen consumption rate kit. Protein expression of myogenic determination factor (MyoD), peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), mammalian target of rapamycin (mTOR) and its phosphorylation were detected by Western blot. Results: Compared to the control group, the expression levels of MyoD, PGC-1α protein were increased and cell oxygen consumption rate was promoted in the low dose group(P<0.05). MyoD and PGC-1α protein expressions were also increased(P<0.05), the ratio of mTOR and its phosphorylationwere decreased significantly in the high dose group(P<0.05). Conclusion: 650 nm laser irradiation that dose is 0.4 J/cm² enhances cell oxidative function, it related to that proper dose laser irradiation promoted the expression of PGC-1a protein.