转录因子Runx2在青少年特发性脊柱侧凸患者成骨细胞中的表达及其意义

Abnormal expression and significance of Runx2 in osteoblasts of adolescent idiopathic scoliosis patients

目的从成骨细胞（0B）水平探讨转录因子Runx2与青少年特发性脊柱侧凸（AIS）患者骨量降低的关系。方法2008年3月至12月行后路手术的AIS患者28例为试验组，男性2例，女性26例；年龄12～18岁，平均14．9岁；Cobb角40°-94°，平均57．3°。试验组根据骨密度（BMD）情况又分为：A组（骨量正常组）15例，B组（骨量减低组）13例。正常对照组（C组）为住院治疗的非脊柱畸形的8例患者，男性6例，女性2例；年龄12—18岁，平均15.3岁。各组均采用双能X线吸收测量仪（DEXA）测量骨密度（BMD），测量部位包括非优势侧股骨近端及腰椎。所有受试者术中取适量髂前上嵴的松质骨，运用植块法培养OB。培养至P2代后行表型鉴定，用RT-PCR和Western blot法检测各组Runx2 mRNA及蛋白的表达水平并进行统计学分析。结果Runx2的mRNA及蛋白水平的表达，B组较A组和c组均降低，差异均有统计学意义（P〈0．05），A组与C组差异无统计学意义（P〉0．05）。结论Runx2在OB水平mRNA及蛋白表达水平的异常可能与AIS骨量降低的分子机制相关。

Objective To investigate the possible relationship between Runx2 and the low bone mass of adolescent idiopathic scoliosis（AIS） patients at the osteoblast level. Methods Twenty eight AIS patients （mean age 14. 9 years, mean Cobb angle 57.3°） in experimental group, including 2 male and 26 female, underwent posterior instrumentation between March and December 2008. They were divided into two groups. Patients in group A maintained normal bone mineral density （BMD）. Patients in group B sustained osteopenia. Normal group, including 8 patients （2 males and 6 females） with a mean age of 15.3 years, were age-matched non-scoliosis adolescents who underwent spinal surgery. BMD of the lumbar spine and proximal femur was measured by using dual energy X-ray absorptiometry in three groups. Small cancellous bone samples were harvested from the iliac crest during the operation. The chipped explants were cultured to obtained the osteoblasts. P2 generation osteoblasts were analyzed to confirm the cell phenotype. Expression of mRNA and protein of Runx2 were detected by using RT-PCR and Western blot in P2 generation osteoblasts from three groups. Results The expression of Runx2 of osteoblasts had decreased obviously in group B compared with group A and group C （ P 〈 0. 05 ）. However, there was no significant difference between group A and group C （P 〉 0.05 ）. Conclusions The abnormal expression of Runx2 of osteoblasts may be responsible for the low bone mass in adolescent idiopathic scoliosis patients.