The Expression Of Protein Relating With Cytoskeleton And Collagen In The Paraspinal Muscles In Idiopathic Scoliosis

IS which is the most common type in scoliosis defines that its cause remainunknowed of structural scoliosis.Although the domestic and foreign scholars have explored cause of IS for manyyears, until now they have not obtained the definite result. From clinical andexperimental study, there are many possible causes of IS at present: Heredity factor,spinal column structure ingredient, skeletal muscle around spinal column, growth andhormone, nervous system, biotic factor.Unbalanced contracture of muscles between two sides in the spinal column isconsidered as the most possible cause of IS. The scientific workers have conducted alot of researches in paraspinal muscle. The abnormal muscle includes the muscle fibershape and type, chemical factor in muscular tissue and so on. But there is dispute thatabnormality of the muscle is involved in the aetiology or progression of IS. As we knew, nerve unit damages and muscle malnutrition might cause thescoliosis. So we thought pathological change in paraspinal muscles might causescoliosis. But abnormality in IS may affect the spinal column activity andpathological changes in paraspinal muscles on two sides. When we explored relationbetween the paraspinal muscle and IS, it is necessary to compare the pathologicalchange of the muscles in IS with that in CS, thus we could extrapolate the mechanismof paraspinal muscle in IS developing.In the present research, we observed the pathological change, expression ofdesmin, vimentin and collagen in paraspinal muscles in IS and compared with CS. Weexplore the relation between these proteins and IS, the mechanism of IS producingand provide new idea and method for research of clinical treatment. Desmin andvimentin respond damage regeneration, and function of the muscle fiber, expressionof collagen,collagenⅠand collagenⅢrespond the muscle function, stages ofpathology in muscle damage and regeneration; Moreover, pathological change andactivity in paraspinal muscles can affect synthesis of desmin vimentin and collagen.The topic is divided into two parts:First: Expressions of desmin and vimentin in the paraspinal muscles ofpatients with idiopathic scoliosis.Second: Expressions of collgen in the paraspinal muscles of patients withidiopathic scoliosis.The objective of the first part investigation: To study the expression of desminand vimentin in the paraspinal muscles at the apex of the curve in the patients with ISand CS, and study which role paraspinal muscles play in the pathogenesis of IS.METHODS: 1,Between July 2005 and November 2006, 12 cases of IS with themean Cobb angle of 73.8°and 5 cases of congenital with the mean Cobb angle of36.6°, were selected from the Department of Spinal and Orthopedic Surgery, Nanfang Hospital of Southern Medical University. Meanwhile, 2 cases of lumbarintervertebral disc herniation and 3 cases of vegetation in thoracolumbar spinal canalwere selected as control group. The patients aged between 10 and 20 years. 2,Biopsywas obtained from the paraspinal muscles of both convex and concave sides at theapex of the curve in patients with IS and CS and from non-diseased region of controlgroup. The informed consent was signed by the patients. 3,The muscle wasimmediately fixed with 4% paraformldehyde for 24 hours, embed in paraffin,incised in to section and stained with hematoxylin and eosin then was observed underlight microscrope. The muscle was also fixed with 2.5% glutaraldehyde and managedfor electron microscropital obserstion. 4,The morphous changes ofparaspinal musclewere observed under light and electron microscopes; the desmin and vimentin of thelight microscope section were given immunohistochemical staining with SP methodand the expressions were examined under light microscope. OD(Optical delnsity) oflight of the expression of desmin was measured with image analysis system.RESULTS: All of the 22 patients were involved in the result analysis. 1,Morphous of paraspinal muscle: The morphometry of paraspinal muscle on the bothsides in patients with IS changed, but that on the concave side was more severe thanthat on the convex. 2,Positive expression of desmin: The expression of desmin in theparaspinal muscle on the convex in patients with IS and CS(0.272 7+0.047 8 and0.276 8+0.037 2) was higher than that in the control group (0.242 9+0.0.027 2, F=6.328, P=0.008); the expression of desmin in paraspinal muscle on the concave sidein scoliosis patients(IS: 0.189 8+0.025 8, CS: 0.186 9±0.030 6,) was lower than thatin the control group (F=62.281, P＜0.001). Expression of desmin of the muscles onthe convex in IS and CS is higher than that on the concave (IS: t=11.719,P＜0.001; CS: t=11.300, P＜0. 001). 3,Positive expression of vimentin: Noexpression of vimentin was detected in the paraspinal muscle of each group. There were no expression of vimentin in any group.CONCLUSION: There is no regenerating paraspinal muscle. The expression ofdesmin in IS is increased on the convex, but decreased on the concave. These changeis secondary to IS.The objective of the second part investigation: To investigate expression ofcollage in the paraspinal muscles at the apex of the curve in IS and their role in IS.METHODS: The study included 12 cases with IS, 5 cases with CS and 5 caseswithout scoliosis as control group. Biopsy was obtained from the paraspinal musclefrom the both right and left side at the apex of the curve in IS and CS and fromnon-diseased region of control group. The sections was stained to show collagenusing Masson trichrome stain and with antibodies against collagenⅠand collagenⅢusing SP method of immunoistochemical stain. Percent of positive area (PPA) ofcollagen in a light microscope was measured using image analysis system. The dataof positive area was analysed with statistics. The expression of collagenⅠandcollagenⅢwas observed under light microscrope.RESULTS: PPA of the expression of collagen of paraspinal muscle on theconvex and concave in IS, the convex and concave in CS and in control group was0.057±0.006 1,0.255±0.03 6,0.055±0.002 2,0.253±0.023 2,0.056±0.004 2. Theexpression of collagen in paraspinal muscle on the concave in IS and CS (H=11.087,P=0.004) was the highest, and no significant difference on the same side in IS or CS(F=0.480, P=0.626). The expression of collagenⅠin paraspinal muscle on the convexin IS and CS and in control group was higher than that on concave(IS: H=10.500,P＜0.001; CS: H=0.000, P=0.008), and no significant difference on the same side inIS or CS (H=2.100, P=0.350). The expression of collagenⅢin muscle could notfind difference in any group(H=0.381, P=0.826; H=2.386, P=0.303; H=47.500,P=0.119; H=10.000, P=0.549). CONCLUSION: The expression of collagen in paraspinal muscle on the concavein IS increases and its change is secondary to IS.