mRNA Expressions of Type I collagen, Osteocalcin and Osteoprotegerin in Iliac Cancellous Bone from Girls with Adolescent Idiopathic Scoliosis

In girls with adolescent idiopathic scoliosis (AIS), osteopenia has been widely reported with unclear molecular mechanism. Type I collagen, osteocalcin and osteoprotegerin are important either in bone structure or in bone biology. This study consisted of 43 girls with AIS. All girls aged 12–18yr, with Cobb angle>40°. Small iliac cancellous bone samples were harvested during the operative procedures. After mRNA extraction, reverse transcription-polymerase chain reaction (RT-PCR) was used to assay mRNA expressions of type I collagen, osteocalcin and osteoprotegerin. Osteocalcin and osteoprotegerin mRNA contents were similar in Group A (normal BMD) and Group B (osteopenia), and significant correlations were not found between osteocalcin and osteoprotegerin mRNA contents and BMD values. However, subjects in Group A had slightly but not significantly higher mRNA contents of type I collagen than in Group B. And a weak positive correlation between mRNA contents of type I collagen and BMD values at both sites. Although significant correlations were not found between mRNA contents of type I collagen, osteocalcin and osteoprotegerin and BMD values, the association between mRNA contents of type I collagen and osteopenia in AIS girls should not be excluded.