Expression of Runx2 and type X collagen in human vertebral growth plate of adolescent idiopathic scoliosis

Runx2 and type X collagen play important roles in vertebral growth, which has been involved in the development and progression of adolescent idiopathic scoliosis (AIS). Seventy-two specimens of vertebral growth plates were collected at the end and apex vertebrae of the scoliotic spine from 12 AIS patients. Expression of Runx2 and type X collagen were examined by immunohistochemistry and in situ hybridization. There were significant difference of the total expression of type X collagen, Runx2 protein and Runx2 mRNA between convex side and concave side of the apex vertebral growth plates. The total expression of type X collagen in the concave side of the lower end vertebral growth plates, and that of Runx2 in the concave side in the upper and lower end vertebral growth plate, were higher than those in the same side of apex (P<0.05). The expression of Runx2 per cell in the concave side at the apex was higher than those in the convex side of the apex and in the concave side of the upper and lower end vertebral growth plates (P<0.05). Expression discrepancy of type X collagen and Runx2 between convex and concave sides of the vertebral growth plate implicate a different chondrocytic kinetics, which may be a possible etiological factor or a secondary change in the progression of adolescent idiopathic scoliosis.