| Congenital scoliosis is a common form of spine deformities in clinical. It is believed that the imbalanced spinal longitudinal growth in inherent abnormal vertebrae may result in scoliosis. In patients with congenital scoliosis, spinal longitudinal growth relies in the growth of vertebral growth plate cartilage. Thus the activity of growth of vertebral growth plate cartilage in apex vertebral, which acts as a trigger point in the progression of congenital scoliosis, is directly related to the occurrence and progression of scoliosis. Many important previous studies have confirmed that the vertebral growth plate shares the similar characteristics as the long bone growth plate does, and its growth and differentiation is regulated by a variety of cytokines. Among these factors, SOX9is a transcription factor which is highly homologous with SRY(Y chromosome in sex determination area)-the gender factor of the mammals. SPY, which is expressed in all differentiated chondrocytes except for hypertrophic chondrocytes, runs through the whole progression in the formation of the cartilage. Thus it is considered very important at the initial stages of endochondral bone formation. Vascular endothelial growth factor (VEGF) is an important factor in stimulating the growth of endothelial cells growth and the regeneration of blood vessels. In the process of endochondral bone formation, VEGF act as a basic regulatory substance in cartilage cell death, extracellular matrix remodeling, angiogenesis, and cartilaginous ossification. Therefore, by detecting the expression of VEGF and SOX9in both convex and concave sides of apical vertebral scoliosis, we can find the differences in the ability of cartilaginous ossification on its both sides in order to draw a conclusion on the molecular biology basis concerning the occurrence and progression of congenital scoliosis in children,and lay the foundation for further molecular biology studies.ObjectiveThis study was to determine where and how SOX9and VEGF are expressed on both convex and concave sides of the growth plate cartilage in the children with congenital scoliosis by immunochemistry and mRNA hybridization in situ, so we can have a good idea of the distinction of bioactivity between the growth plate cartilage on both sides, and correlation between SOX9and VEGF expression. Meanwhile the study aims at exploring the molecular on which the onset and progression of congenital scoliosis are based. So it is possible to provide the basis for the prognosis and surgical intervention in congenital scoliosis.MethodsThe20patients, aging from one to five years old with congenital scoliosis admitted in Third Affiliated Hospital of Zhengzhou University from Oct2010to Sep2011were selected, with8males and12females, whose average age was3.2years old(3.2±0.6). Before surgery all patients underwent a detailed physical and neurological examination, including X-ray film, full spine spiral CT+three-dimensional reconstruction and MRI, all of which help us make a definite diagnosis of CS. Permitted by patients’family members, the removed growth plate cartilage on both convex and concave sides were collected. Immunohistochemistry and mRNA hybridization in situ were used to detect the expression of SOX9and VEGF in apex vertebral growth plate cartilage, and on both convex and concave sides of it. At the same time, the respective studies were conducted to explore the correlation among the expression of SOX9, VEGF and VEGFmRNA. The expression of factors on the convex and concave sides were detected by means of paired t-test, and their difference was found statistically significant, as p<0.05. Correlation between SOX9and VEGF using Pearson correlation analysis, marked statistically, p<0.05as the test standard.Results1. According to the morphological observation of growth plate on both sides of the cartilage plate and their HE staining, it showed that the structure of growth plate was similar to the long bone growth plates, which can be divided into three layers: stationary zone, proliferative zone and hypertrophic zone. The thickness of the proliferative zone and hypertrophic zone on convex side of growth plate cartilage are thicker than that on concave side, and the cartilage cells of convex are arranged more closely.2. SOX9was mainly expressed in the stationary layer and proliferative zone, while VEGF in hypertrophic zone with only a small amount in the proliferative zone, but none has been detected in the stationary layer. The amount of SOX9expressed in the convex side of growth plate chondrocytes comes up to154.376±8.055and121.413±6.751on the concave side, and the amount of VEGF expressed in convex and concave were134.989±9.731,108.498±8.737respectively, while the expression of VEGFmRNA on both sides of the growth plate is116.517±7.536and97.077±6.627respectively. The expression of SOX9, VEGF and VEGF mRNA in growth plate on convex and concave sides of the apical vertebra by using paired t-test respectively drew a conclusion that the difference between their expression was statistically significant(p<0.05).3. Pearson correlation analysis was used in detecting the expression of SOX9and the VEGF, it is found that they present positive correlation, r=0.650, and their difference is p<0.05marked statistically significabt. The correlation analysis of the expression of VEGF and VEGFmRNA found r=0.343, p>0.05. Not statistically significant.Conclusion1. The growth plate cartilage of apcial vertebral from congenital scoliosis showing that convex side growth plate has higher biological activity.2. As for congenital scoliosis children, the expression of SOX9, VEGF and VEGFmRNA in convex side of apical vertebral growth plate is more than those on concave side, this expression difference may be the key factor to the occurrence and progress of congenital scoliosis in children.3. The expression amount of SOX9and VEGF in different zone of growth plate possess its own characteristics, and there is a positive linear correlation between the expression of the SOX9and the VEGF. |
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