Expression and significance of Wnt-5a gene in a model of intervertebral disc degeneration / 中国组织工程研究

ABSTRACT

BACKGROUND: Important extracellular matrixes are reduced with the prolongation of duration of cyclic pressure in the endplate of the intervertebral disc. Meanwhile, the expression of Wnt-5a gene is significantly decreased. There is an important relationship between Wnt-5a gene and intervertebral disc degeneration (IDD). OBJECTIVE: To investigate the expression of Wnt-5a gene under cyclic pressure in a rabbit model of IDD and to explore its role in IDD progress. METHODS: Lumbar intervertebral discs were removed from the 6-month-old New Zealand white rabbits to prepare IDD models and were then randomly divided into experimental (cyclic pressure ) and control (no intervention) groups. The morphological changes of intervertebral discs were observed by hematoxylin-eosin staining and safranin O-fast green staining. The mRNA expression levels of proteoglycan, collagen type Ⅱ, and Wnt-5a were detected by real-time PCR. The protein expression level of Wnt-5a was detected by western blot assay. RESULTS AND CONCLUSION: The morphology of intervertebral discs cultured for 7 days in the experimental and control groups showed a certain change, but was still intact; expression levels of aggrecan, type Ⅱ collagen, Wnt-5a showed differences from the intervertebral discs cultured for 0 day. On day 14, the damage to the histomorphology was severer in the experimental group than the 0-day control group. The mRNA expression levels of proteoglycan, collagen type Ⅱ, and Wnt-5a were decreased in both groups, especially the experimental group, at 7 and14 days. The mRNA and protein expression levels of Wnt-5a revealed the same change trend with time. To conclude, regulation of Wnt-5a expression may alter the process of endplate cartilage degeneration, and thus providing new ideas for the prevention and treatment of IDD.