微波对骨折愈合过程中骨髓间充质干细胞迁移能力的影响

摘要

目的 探讨微波电疗法对骨折愈合过程中骨髓间充质干细胞(BMSC)迁移能力的影响.方法 将30只SD大鼠建骨折模型后随机分成两组(对照组、实验组各15只),实验组微波治疗30 d,对照组不予治疗,采用X线平片观察第10天及第30天两组大鼠骨折愈合的情况;另取3只SD大鼠分离BMSC体外培养,对照组正常培养,实验组进行0.5 W/cm2微波照射60 min,采用划痕实验、transwell小室实验评价两组BMSC的迁移能力;采用Western-blot检测两组BMSC中HIF-1、VEGF、FGF、PDGF、IGF-1的表达.结果 X线平片结果表明照射第10天对照组与实验组射线相对密度分别为(0.81±0.10)和(0.94±0.13),差异有统计学意义(P=0.02),而第30天两组分别为(0.96±0.12)和(0.99±0.09),差异无统计学意义.划痕实验对照组距离基线迁移距离(192±15)μm,实验组迁移距离(430±21) μm,差异具有统计学意义(P=0.01).Transwell小室实验对照组迁移细胞数(68±18)个,实验组迁移细胞数(112±25)个,差异具有统计学意义(P=0.02).Western blot结果表明,与对照组比较,实验组BMSC中HIF-1及VEGF表达显著升高(均P＜0.05),而FGF、PDGF、IGF-1表达两组间差异不显著.结论 微波可能通过促进骨髓间充质干细胞迁移而影响骨折愈合.%Objective The current studied aimed to study the effect of microwave to the migration of BMSC during the healing of fracture.Methods Thirty animals were divided into two groups (15 in each group).For the treatment group,it was provided a 30-day microwave therapy of (0.5 W/cm2,60 min/d),but not for the control group.The effect of microwave therapy on fracture repair in a rat femoral fracture model was evaluated by X-ray on the 10th and 30th day.To identify the influence of microwave on BMSCs migration,the scratch assay and transwell assay were employed in vitro.A preliminary study of factors expression by western blot including HIF-1,VEGF,FGF,PDGF and IGF-1.Results The Radiographic density of the fracture gap were (0.81 ±0.10) for control group and (0.94 ±0.13) for treatment group.Radiographic assessments showed that fracture healing was accelerated especially on the 10th day of the microwave treatment (P =0.02) but not statistically significant at 30th day (0.96 ± 0.12) and (0.99 ± 0.09),P ＞ 0.05).In scratch test,the migration distance of BMSC was (192 ± 15)μm in control group and (430 ± 21)μm in treatment group (P =0.01).In transwell test,the number of transmembrane cells were (68 ± 18) in control group and (112 ± 25) in treatment group (P =0.02).The results of scratch and transwell assay indicated that the BMSCs migration was promoted by microwave.HIF-1 and VEGF protein expression levels increased after microwave exposure (each P ＜ 0.05).But there was no significant difference in the expression of FGF,PDGF and IGF-1 with or without microwave exposure (each P ＞ 0.05).Conclusion Microwave therapy promoting fracture healing by enhancing bmscs migration.