title: [Influence of mutation of -1997G-->T of COL I A1 gene on the biochemical function of osteoblast].
abstract: OBJECTIVE
  To study the influence of mutation of -1997G-->T of COL I A1 gene on the biochemical function of osteoblast, and the pathomechanism of BMD.
  
  
  METHODS
  Spongy bones were obtained to culture osteoblast primarily during total hip or knee replacements. The genotype of osteoblast was identified with PCR-RFLP. The amount of mRNA of COL I A1 and collagen type I were determined by RT-PCR and ELISA. The growth of osteoblast, the activity of bone ALP, and the amount of calcium in cell matrix and calcium nodus were measured.
  
  
  RESULTS
  Three genotypes GG, GT and TT in osteoblast were successfully identified. Compared with GG and GT genotypes, lower expression of mRNA of COL I A1 gene, lesser collagen type I, calcium in cell matrix, and calcium nodus were found in the cells with TT genotype (P < 0.01). No significant differences were found between GG and GT genotype (P > 0.05). There were no significant differences in age, growth of osteoblast, and activity of bone ALP among the three genotypes (P > 0.05).
  
  
  CONCLUSIONS
  Cells with TT genotype have low expression of mRNA of COL I A1 gene and less collagen type I , calcium in cell matrix and calcium nodus. The lower amount of collagen type I synthesized by osteoblast can decrease the matrix outside the bone cells and result in insufficient site for calcium deposition. This may be the cause of lower BMD in patients with TT genotype.
authors.affiliation: Department of Orthopaedics Surgery, West China Hospital, Sichuan University, Chengdu 610041, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Cao
authors.forename: Bin
authors.initials: B
authors.lastname: Shen
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.forename: Qiang
authors.initials: Q
authors.lastname: Huang
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.forename: Zong-ke
authors.initials: ZK
authors.lastname: Zhou
authors.forename: Peng-de
authors.initials: PD
authors.lastname: Kang
authors.forename: Wen-zhen
authors.initials: WZ
authors.lastname: Peng
authors.forename: Qing-jie
authors.initials: QJ
authors.lastname: Xia
authors.forename: Fu-xing
authors.initials: FX
authors.lastname: Pei
mesh_terms: D019644:Arthroplasty, Replacement, Hip; D015519:Bone Density; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D024042:Collagen Type I / Q000235:genetics* / Q000378:metabolism; D000090602:Collagen Type I, alpha 1 Chain; D005260:Female; D006801:Humans; D008875:Middle Aged; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D015663:Osteoporosis, Postmenopausal / Q000235:genetics* / Q000378:metabolism; D017354:Point Mutation; D011110:Polymorphism, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; D012333:RNA, Messenger; D002118:Calcium