强磁重力环境对MG63成骨样细胞钙离子/钙调蛋白信号的影响

Effects of high magneto-gravitational environment on calcium/calmodulin signal of MG63 osteoblast-like cells

目的:研究强磁重力环境对MG63成骨样细胞钙离子浓度和钙离子下游信号分子表达的影响。方法:利用大梯度强磁场提供μg(12T),1g(16T)和2g(12T)三组不同强磁重力复合环境处理MG63成骨样细胞后,经Fluo-3/AM标记的细胞用激光共聚焦显微镜检测处理0.5 h对细胞胞内游离钙离子浓度([Ca2+]i)的影响;用Western blot检测处理3 h对钙调蛋白(CaM)和肌球蛋白轻链激酶(MLCK)表达以及钙离子/钙调蛋白依赖蛋白激酶Ⅱ(CaMKⅡ)活性的变化。结果:钙离子浓度检测结果表明,与对照组细胞(1 g,地磁)相比,1 g(16 T)组细胞Fluo-3荧光强度增加,结果显示强磁场导致[Ca2+]i增加;与2 g(12 T)组相比,μg(12 T)组细胞Fluo-3荧光强度下降,结果显示模拟失重导致[Ca2+]i降低,抑制钙离子信号。蛋白质表达的检测结果表明,与对照组相比,1 g组细胞CaM和MLCK表达以及CaMKⅡ活性没有明显变化;与2 g(12 T)组相比,μg(12 T)组细胞CaM表达以及CaMK活性下降,结果显示模拟失重抑制CaM/CaMKⅡ信号。结论:强磁场导致MG63成骨样细胞胞内游离钙离子浓度增加,模拟失重抑制成骨样细胞钙离子/钙调蛋白信号。

AIM： To investigate the effects of high magneto-gravitational environment on Ca2＋/calmodulin（CaM） signal of MG63 osteoblast-like cells.METHODS： A special designed large gradient high magnetic field could produce three different high magneto-gravitational environments including μg（12 T）,1 g（16 T） and 2 g（12 T）.The effects of high magneto-gravitational environments on intracellular free Ca2＋ concentration（i） and protein expression including calmodulin（CaM）,myosin light chain kinases（MLCK） and phosphorylated Ca2＋/CaM dependent protein kinase Ⅱ（pCaMKⅡ） were measured by Fluo-3/AM or Western blot,respectively.RESULTS： When compared with control group,an increase of i of MG63 was caused by strong magnetic field;Compared to 2 g,μg decreased i of MG63.The protein expression of CaM and pCaMKⅡof MG63 cells was decreased by simulated weightlessness.CONCLUSION： i of MG63 cells was increased by strong magnetic field;simulated weightlessness inhibited Ca2＋/CaM signaling of MG63 cells.