成都地区骨质疏松症患者骨密度与Ⅰ型胶原α_1链基因Sp1结合位点多态性的相关性研究

Relationship between the polymorphism of Sp1 site of collagen Ⅰ alpha 1 gene and bone mineral density(BMD) in osteoporotic patients in Chengdu region

目的探讨Ⅰ型胶原α1链（COLIA1）基因Sp1结合位点的多态性与成都地区骨质疏松症患者骨密度的相互关系。方法（1）选取四川大学华西医院门诊骨质疏松症患者中合格的自愿受试者237例，应用双能X线吸收法测定其第2-4腰椎（L2-L4）部位的骨密度值；（2）抽取受试者外周静脉血2ml，提取白细胞基因组DNA；（3）采用聚合酶链反应（PCR）扩增目的基因所在的DNA片段（第1112-1328核苷酸之间的片段，扩增产物长度为217 bp）；（4）应用聚合酶链反应—限制性片段长度多态性（PCR-RFLP）方法检测外周血白细胞基因组COLIA1基因Sp1结合位点多态性，扩增产物经限制性内切酶Van91I（pflMI）酶切，琼脂糖凝胶电泳观察，有酶切位点用S基因表示，无酶切位点用S基因表示。结果237例受试对象中，所有标本的扩增片段都能被限制性酶识别并切开，未能观察到Ⅰ型胶原α．链Sp1结合位点G→T突变，COLIA1基因型均为野生纯合子SS型，未发现SS基因型和SS基因型。结论在成都地区部分汉族骨质疏松症患者中，未发现COLIA1基因Sp1结合位点的多态性，其腰椎骨密度可能与Ⅰ型胶原α，链基因Sp1结合位点多态性无关。

Objective To investigate the relationships between COLIA1 gene polymorphisms and bone mineral density（BMD） in voluntary osteoparetic patients in Chengdu region. Methods （1） 237 voluntary osteoparetic outpatients in West China Hospital of Sichuan University were selected and their BMD were measured by dualenergy X-ray absorptiometry （DEXA）at lumbar spine （L2-L4）. （2） 2 ml peripheral blood was drawn-off and genomic DNA was extracted from white blood cells. （3） The specific fragment which includes the objective gene was amplified by Polymerase chain reaction （PCR） ; （4） the genotypes of SP1 binding site in COLIA1 were detected by Polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） method. The PCR product was digested with restriction endonuclease Van91I（pflMI） and the result was observed by agarose gel electrophoresis. The capital letter S represents for the presence of the restriction endonuclease site, while the small letter s for the absence of the restriction endonuclease site. Results All the PCR products were recognized and cut-off by the restriction endonuclease Van91I（pflMI）. The 237 samples showed normal wild type homozygotes SS of COLIA1 gene, neither type Ss nor type ss was found. Conclusions In these voluntary osteoparetic patients in Chengdu,COLIA1 gene polymorphism at Spl blinding cannot be found. There is no certain correlation between lumbar vertebrae BMD and Spl binding site COLIA1 gene polymorphism.