慢病毒介导乳铁转运蛋白对大鼠骨质疏松性骨折愈合的影响

Effect of lentivirus -mediated lactoferrin transporter on osteoporotic fracture healing in rats

目的观察慢病毒介导乳铁转运蛋白(LF)对大鼠骨质疏松性骨折愈合的影响。方法将40只SD大鼠随机分为对照组和观察组,均采用切除卵巢去势法建立骨质疏松模型组,观察组于骨折部位注射过表达LF的慢病毒,对照组于骨折部位注射等体积空载体慢病毒。注射8周后,取两组大鼠骨痂组织,采用Western blot分析两组大鼠LF、骨保护素(OPG)和核因子-κB受体活化因子配体(RANKL)蛋白的表达水平;采用Micro-CT测定两组大鼠骨折区域骨密度(BMD)、骨小梁体积(BV),组织体积(TV)、平均骨小梁厚度(Tb.Th)和平均骨小梁数目(TB.N);采用三点弯曲试验测定骨折部位生物力学参数。结果与对照组LF、OPG和RANKL蛋白表达水平(0.69±0.16、0.30±0.12、0.88±0.20)比较,观察组大鼠骨折部位LF、OPG和RANKL蛋白水平(1.17±0.31、1.25±0.18、1.10±0.15)明显增加,差异有统计学意义(t=2.965、2.183、3.018,P<0.01]。观察组大鼠BMD、BV、TV、Tb.Th和Tb.N均明显高于对照组,差异有统计学意义(t=4.019、3.183、2.195、3.012、3.091,P<0.05)。观察组大鼠骨折部位生物力学参数(最大载荷、弹性载荷、刚度和最大挠度)显著高于对照组,差异有统计学意义(t=3.691、2.985、3.911、2.198,P<0.01)。结论 慢病毒介导LF在骨质疏松性骨折部位表达,可显著促进成骨细胞分化,促进骨生长和骨折愈合,改善骨质量。

ObjectiveTo investigate the effect of lentivirus-mediated lactoferrin transporter (LF) on the healing of osteoporotic fracture in rats.MethodsFifty SD rats were randomly divided into control group and observation group. Ovariectomy was used to establish osteoporosis model group. Lentiviruses overexpressing LF were injected into the fracture site in the observation group, and equal volume empty carrier lentivirus were injected into the fracture site in the control group. Eight weeks after injection, the expression of LF, bone protection element (OPG) and receptor activator of nuclear factor κB ligand (RANKL) proteins was analyzed by Western blotting. Bone mineral density (BMD), trabecular volume (BV), tissue volume (TV), average trabecular thickness (Tb.Th) and average number of trabeculae (TB.N) were measured by micro-CT. Three points bending test was used to determine the biomechanical parameters of the fracture site.Results Compared to the control group (0.69±0.16, 0.30±0.12 and 0.88±0.20), the expression levels of LF, OPG and RANKL proteins in the fracture site of rats in the observation group (1.17±0.31, 1.25±0.18 and 1.10±0.15) were significantly increased (t=2.965, 2.183 and 3.018 respectively, P<0.01). BMD, BV, TV, Tb.Th and Tb.N in the observation group were significantly higher than those in the control group (t=4.019, 3.183, 2.195, 3.012 and 3.091 respectively, P<0.05). The biomechanical parameters (maximum load, elastic load, stiffness and maximum deflection) of fracture site in the observation group were significantly higher than those in the control group (t=3.691, 2.985, 3.911 and 2.198 respectively, P<0.01)].Conclusion Lentiviral-mediated LF expression in osteoporotic fracture can significantly promote osteoblast differentiation, promote bone growth and fracture healing, and improve bone quality.