青少年特发性脊柱侧凸患者低骨量与成骨细胞中BMP-2的关系

The relationship between BMP-2 and the decreased bone mass in adolescent idiopathic scoliosis patients

目的:探讨成骨细胞(osteoblast,OB)中骨形态发生蛋白-2(bone morphogenetic proteins,BMP-2)与青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)患者骨量降低的关系。方法:AIS患者27例,年龄12～18岁,平均14.7岁,Cobb角40°～94°,平均57.1°。8例非脊柱畸形青少年患者作为对照组,年龄12～18岁,平均15.1岁。均采用双能X线吸收测量仪(dual-energy x-ray absorptiometry,DEXA)测量非优势侧股骨近端及腰椎骨密度(bone mineral density,BMD)。将AIS患者按BMD值分为两组,A组14例,为骨量正常患者;B组13例,为骨量减低患者。对照组8例定为C组。3组患者均需取自体髂骨植骨,取髂骨时获取适量髂前上嵴的松质骨,应用植块法培养OB。培养至P2代后行表型鉴定,用RT-PCR和Western blotting法检测AIS组和对照组OB中BMP-2mRNA及蛋白的表达水平。结果:A、B、C三组患者OB中BMP-2的mRNA的表达量分别为0.67±0.22、0.62±0.21、0.51±0.13,三组间比较无显著性差异(P>0.05);BMP-2蛋白表达强度分别为0.63±0.26、0.58±0.20、0.70±0.13,三组间比较亦无显著性差异(P>0.05)。结论:AIS患者OB中BMP-2mRNA及蛋白表达强度无明显改变,AIS骨量降低可能不是由成骨细胞中BMP-2所致。

Objective： To investigate the possible relationship between bone morphogenetic proteins-2（BMP- 2） in osteoblast and the low bone mass of adolescent idiopathic scoliosis （AIS）.Method：This study involved 27 AIS patients with mean age of 14.7 years （range from 12 to 18 years） and mean Cobb angle of 57.1°. （range from 40° to 94°）,and 8 non- AIS patients who underwent spinal surgery as normal group with mean age of 15.1 years （range fiom 12 to 18 years）.BMD of the lumbar spine and proximal femur was measured using dual energy X-ray absorptiometry （DEXA） for these two groups.MS patients were subdivided into two groups according to BMD value.Patients in group A （14 cases） maintained normal bone mineral density （BMD）.Patients in group B（13 cases） sustained osteopenia.Small cancellous bone samples were harvested from the lilac crest during the operation in all patients and the osteoblasts were obtained by explant cuhure method.Osteoblasts from P2 generation were analyzed to confirm the cell phenotype.Expression of mRNA and protein of BMP-2 in IY2 generation osteoblasts from three groups were detected by using RT-PCR and Western blotting.Result：The mRNA expression of BMP-2 in osteoblasts was 0.67±0.22 in group A,0.62±0.21 in group B and 0.51±0.13 in group C respectively.The protein expression of BMP-2 in osteoblasts was 0.63±0.26 in group A,0.58±0.20 in group B and 0.70±0.13 in group C respectively.Both mRNA and protein expression intensity among three groups had no significant differences （P〉0.05）.Conclusion：The expression intensity of BMP-2 of osteoblasts in AIS patients is normal and it may not be related to the low bone mass of AIS.