The Expresssion Of NDRG2 In Degenerated Human Lumbar Nucleus Pulposus Tissues And The Relationship Between NDRG2 And Nucleus Pulposus Cell Senescence

Objective:1. To investigate the expression of NDRG2 in degenerated human lumbar nucleus pulposus tissues,and the relationship between the expression of NDRG2 and the expression of p53. 2. To investigate the relationship between the proportion of senescent nucleus pulposus cells and the expression of NDRG2 in degenerated human lumbar nucleus pulposus tissues.Methods:1. 47 lumbar intervertebral disc samples were recruited, and divided into Ⅰ~Ⅴ groups according to Pfirrmann grade. The expression of NDRG2 of nucleus pulposus cells was determined by immunohistochemistry, real-time PCR(RT-PCR) and Western-Blotting. The m RNA level of P53 was measured by RT-PCR. 2. Senescent nucleus pulposus cells were examined via senescence-associated β-galactosidased(SA-β-gal) assay.Results:1. The upregulated level of NDRG2 was in accord with severity of intervertebral disc degeneration and its expression was positively correlated with the Pfirrmann grade. The m RNA level of P53 was increased in degenerated human lumbar intervertebral disc tissues, and was positively correlated with that of NDRG2. 2. The upregulated percentage of SA-β-gal-positive cells was along with severity of intervertebral disc degeneration and positively correlated with the NDRG2-positive cells.Conclusion:1. The enhanced expression of NDRG2 was involved in the pathological process of lumbar disc degeneration. 2. NDRG2 increased the incidence of intervertebral disc degeneration probably via accelerated nucleus pulposus cell senescence.