20W微波照射骨骼肌卫星细胞的增殖与分化:兔骨折内固定模型研究

Effects of low power microwave irradiation(20 W) on the proliferation and differentiation of skeletal muscle satellite cells in a rabbit model of femoral fracture with internal fixation

背景:研究表明,控制微波照射在较低功率时,微波能够促进内固定骨折的愈合,但对骨折周围骨骼肌的作用机制尚不清楚。目的:观察20 W功率微波对内固定骨折骨骼肌卫星细胞增殖能力的影响。方法:取雄性新西兰家兔40只建立骨折+钛合金内固定动物模型,随机分成自然恢复组(n=20)、微波治疗组(n=20),微波治疗组于造模后第4天行20 W功率微波照射治疗,连续照射30 d,自然恢复组不照射。取家兔大腿肌通过分离纯化培养获得骨骼肌卫星细胞,应用免疫组织化学、苏木精-伊红染色法、qR T-PCR技术对骨骼肌卫星细胞的增殖分化能力进行检测。结果与结论:(1)苏木精-伊红染染色光镜下观察显示微波治疗组和自然恢复组肌肉组织形态学无明显的差别;(2)微波治疗组体外培养的卫星细胞MyoG mR NA的表达水平高于自然恢复组(P<0.05);(3)a-sarcometric actin染色阳性细胞数多于自然恢复组(P<0.05),早期增殖能力受到抑制,后期不受影响;(4)结果说明,应用20 W微波能促进植入物周围骨骼肌卫星细胞的分化能力,对其增殖能力的抑制也是可逆的;进一步证实低剂量微波治疗内固定骨折的安全性和有效性。

BACKGROUND：Low power microwave irradiation has been shown to promote the healing of fractures with internal fixation;however, its action mechanisms on the skeletal muscle around the fracture site are unclear. OBJECTIVE：To study the effects of low power microwave irradiation （20 W） on the proliferation ability of skeletal muscle satel ite cel s in a rabbit model of femoral fracture with internal fixation. METHODS：Forty male New Zealand rabbits were used to establish femoral fracture fol owed by internal fixation models, and then were equal y randomized into spontaneous recovery and microwave treatment groups. Low power microwave irradiation （20 W） was given for 30 consecutive days in the microwave treatment group on day 4 after modeling, while no microwave irradiation was given in the spontaneous recovery group. Rabbit thigh muscles adjacent to the implant were obtained to isolate skeletal muscle satel ite cel s. Immunohistochemical staining, hematoxylin-eosin staining and quantitative RT-PCR were used to evaluate the ability of the proliferation and differentiation of skeletal muscle satel ite cel s. RESULTS AND CONCLUSON：Hematoxylin-eosin staining showed that there was no significant difference in the morphology and histology of skeletal muscle tissues between the spontaneous recovery and microwave treatment groups. However, the relative mRNA expression of MyoG in the cultured skeletal muscle satel ite cel s in vitro and the number ofα-sarcometric actin-postive cel s in the microwave treatment group were significantly increased compared with the spontaneous recovery group （P〈0.05）. The proliferative ability of skeletal muscle satel ite cel s was inhibited at the early stage, but not at the later stage. Our results suggest that low power microwave irradiation （20 W） can promote the proliferation and differentiation of skeletal muscle satel ite cel s around the implant in a rabbit model of femoral fracture with internal fixation, and thereby confirm the efficacy and safety of low power microwave irradiation for the internal fixation of fractures.