Expression Of RhoA Signal Transduction In Rabbit Endplate Cartilage Under The Cyclic Loading

Objective: This study is to establish the rabbit degeneration model induced by cyclic loading and to determine the expression alteration of the RhoA signal transduction in endplate cartilage and its significance.Methods: New Zealand white rabbits at the age of four month old were randomly divided into three groups,including blank control,sham-tension and tension group.These rabbits were used to establish degeneration model induced by body cyclic loading.Morphological changes in the intervertebral disc were observed through H&E staining.Furthermore,Real-time PCR was used to analyze the expression change of COL-2A,AGN,SOX9,and RhoA.The protein expression alteration of RhoA was determined by western blot.Results: The displacement of intervertebral disc fibrous rings and shrinking nucleus pulposus were observed with the increase of cyclic loading time.The expression level of COL-2A,AGN,and SOX9 in endplate cartilage was significantly decreased(p<0.05),while the RhoA expression was increased(p<0.05)under the cyclic loading.Conclusion: By the induction of cyclic loading,the rabbit intervertebral disc began to degenerate with the increasing time of tension application.This process is likely to be mediated by the RhoA signal pathway,while the regulation of RhoA in the intervertebral disc releases or ceases the degeneration of endplate cartilage.This study will provide the new insights into the prevention and treatment of intervertebral disc degeneration.