Expression of the Trp2 Allele of COL9A2 Is Associated With Alterations in the Mechanical Properties of Human Intervertebral Discs
- 1 December 2007
- journal article
- research article
- Published by Ovid Technologies (Wolters Kluwer Health) in Spine
- Vol. 32 (25), 2820-2826
- https://doi.org/10.1097/brs.0b013e31815b75c5
Abstract
Biomechanical study into the association between genetic polymorphism in COL9A2 and mechanical properties of human nucleus pulposus. To examine whether there is an association between genetic polymorphism in a structural gene, and alterations in the mechanical properties of the intervertebral discs that may predispose to disc degeneration. Genetic studies have demonstrated that a polymorphism (Trp2 allele) in COL9A2 coding for α2 chain of collagen IX predisposes the individual to disc degeneration. The mechanism of this predisposition is not known. Blood and whole disc samples were retrieved from adolescents and young adults during scoliosis surgery, degenerated discs were retrieved from patients with back pain during anterior spinal fusion. Anulus fibrosus and nucleus pulposus from a set of the scoliosis discs were used to perform immunohistochemistry to demonstrate the presence of collagen IX in the scoliosis discs. For the remaining samples, DNA was extracted from blood to determine the Trp2 status by sequencing. Nondegenerated (Trp2−), nondegenerated (Trp2+), and degenerated (Trp2−) nucleus pulposus samples were tested in confined compression. Swelling pressure and compressive modulus were measured and compared between groups. Positive staining of collagen IX was detected in both anulus fibrosus and nucleus pulposus sections confirming its presence in the scoliosis discs. The mean swelling pressure and compressive modulus values of 6 nondegenerated (Trp2+) samples (swelling pressure = 0.0019 MPa, compressive modulus = 0.97 MPa) were significantly lower (P Conclusion. This is the first study to demonstrate an association between the Trp2 allele and disc mechanics, thus relating genetic variations and debilitating mechanical alterations that may ultimately result in intervertebral disc degeneration.Keywords
This publication has 15 references indexed in Scilit:
- What is Intervertebral Disc Degeneration, and What Causes It?Spine, 2006
- Genetics of disc degenerationEuropean Spine Journal, 2006
- Association of the Taq I Allele in Vitamin D Receptor With Degenerative Disc Disease and Disc Bulge in a Chinese PopulationSpine, 2006
- The TRP2 Allele of COL9A2 is an Age-Dependent Risk Factor for the Development and Severity of Intervertebral Disc DegenerationSpine, 2005
- Lumbar Disc DegenerationSpine, 2004
- Covalent Cross-linking of the NC1 Domain of Collagen Type IX to Collagen Type II in CartilageJournal of Biological Chemistry, 2004
- An Allele of COL9A2 Associated with Intervertebral Disc DiseaseScience, 1999
- Collagen type IX from human cartilage: a structural profile of intermolecular cross-linking sitesBiochemical Journal, 1996
- Development and degeneration of the intervertebral discsMolecular Medicine Today, 1995
- The cartilage end‐plate and intervertebral disc in scoliosis: Calcification and other sequelaeJournal of Orthopaedic Research, 1993