Expression of transforming growth factor-beta1 and basic fibroblast growth factor in articular process cartilages of adolescent idiopathic scoliosis

Abstract

To investigate the characteristics of the expression of transforming growth factor-beta(1) (TGF-beta(1)) and basic fibroblast growth factor (bFGF) in the apical articular process cartilages of adolescent idiopathic scoliosis (AIS) patients. The specimens of articular processes of 22 AIS patients and 18 congenital scoliosis (CS) patients were collected during operation. The pathology of the processes was observed with H.E staining. Immunohistochemistry and in situ hybridization were adopted to detect the expression of TGF-beta(1) and bFGF. The differences in the pathological changes, and expression of TGF-beta(1) and bFGF between the apical processes and the end processes, the convex processes and the concave processes, and the AIS processes and CS processes. The images of immunohistochemistry and in situ hybridization were input into the image analysis system and were analyzed semi-quantitatively. The SAS (8.01) software was adopted and (128.1 +/- 50.6 vs 165.4 +/- 59.2, 126.5 +/- 47.0 vs 168.3 +/- 46.8; 76.6 +/- 29.9 vs 96.4 +/- 28.4, 73.7 +/- 31.6 vs 101.8 +/- 39.4; 77.1 +/- 52.2 vs 114.4 +/- 59.4, and 69.5 +/- 40.1 vs 109.8 +/- 51.0 (P < 0.05) was defined as the significant levels. The expression of TGF-beta(1) and the expression of bFGF were not significantly different between the AIS patients and the CS patients. The TGF-beta(1) expression in the concave side of the apical vertebrae of the AIS group was 165.4 +/- 59.2, significantly higher than that in the convex sides (128.1 +/- 50.6, P = 0.03), and the TGF-beta(1) expression in the concave side of the apical vertebrae of the CS group was 168.3 +/- 46.8, significantly higher than that of the convex side (126.5 +/- 47.0, P = 0.02). However, there was no statistically significant differences in the TGF-beta(1) expression between the concave and convex sides of the upper and lower end vertebrae and between the upper and lower end vertebrae. The bFGF expression in the concave side of the apical vertebrae of the AIS group, and the bFGF expression in the concave side of the apical vertebrae of the CS group was 101.8 +/- 39.4, significantly higher than that of the convex side (73.7 +/- 31, P = 0.02). However, there were no statistically significant differences in the bFGF expression between the concave and convex sides of the upper and lower end vertebrae and between the upper and lower end vertebrae. The cartilages of the apical processes show some signs of regression and hypoplasia in AIS patients, especially at the concave side in comparison with the convex side. Increase of TGF-beta(1) and bFGF in the concave sides of apical processes in AIS may be the results of reconstruction of extracellular matrix and the compensation reactions which are caused by abnormal biomechanical forces, especially compressive stresses.