Background: In a previous report, we demonstrated the presence of cells with a neural/glial phenotype on the concave side of the vertebral body growth plate in Idiopathic Scoliosis (IS) and proposed this phenotype alteration as the main etiological factor of IS. In the present study, we utilized the same specimens of vertebral body growth plates removed during surgery for Grade III-IV IS to analyse gene expression. We suggested that phenotype changes observed on the concave side of the vertebral body growth plate can be associated with altered expression of particular genes, which in turn compromise mechanical properties of the concave side. Methods: We used a Real-Time SYBR Green PCR assay to investigate gene expression in vertebral body growth plates removed during surgery for Grade III-IV IS; cartilage tissues from human fetal spine were used as a surrogate control. Special attention was given to genes responsible for growth regulation, chondrocyte differentiation, matrix synthesis, sulfation and transmembrane transport of sulfates. We performed morphological, histochemical, biochemical, and ultrastructural analysis of vertebral body growth plates. Results: Expression of genes that control chondroitin sulfate sulfation and corresponding protein synthesis was significantly lower in scoliotic specimens compared to controls. Biochemical analysis showed 1) a decrease in diffused proteoglycans in the total pool of proteoglycans; 2) a reduced level of their sulfation; 3) a reduction in the amount of chondroitin sulfate coinciding with raising the amount of keratan sulfate; and 4) reduced levels of sulfation on the concave side of the scoliotic deformity. Conclusion: The results suggested that altered expression of genes that control chondroitin sulfate sulfation and corresponding changes in protein synthesis on the concave side of vertebral body growth plates could be causal agents of the scoliotic deformity.

Idiopathic scoliosis is one of the most common disabling pathologies of children and adolescents. Etiology and pathogenesis of idiopathic scoliosis remain unknown. To study the etiology of this disease we identified the cells' phenotypes in the vertebral body growth plates in patients with idiopathic scoliosis. Materials and methods: The cells were isolated from vertebral body growth plates of the convex and concave sides of the deformity harvested intraoperatively in 50 patients with scoliosis. Cells were cultured and identified by methods of common morphology, neuromorphology, electron microscopy, immunohistochemistry and PCR analysis. Results: Cultured cells of convex side of deformation were identified as chondroblasts. Cells isolated from the growth plates of the concave side of the deformation showed numerous features of neuro- and glioblasts. These cells formed synapses, contain neurofilaments, and expressed neural and glial proteins. Conclusion: For the first time we demonstrated the presence of cells with neural/glial phenotype in the concave side of the vertebral body growth plate in scoliotic deformity. We hypothesized that neural and glial cells observed in the growth plates of the vertebral bodies represent derivatives of neural crest cells deposited in somites due to alterations in their migratory pathway during embryogenesis. We also propose that ectopic localization of cells derived from neural crest in the growth plate of the vertebral bodies is the main etiological factor of the scoliotic disease.