Effects of cyclic distraction stress on proliferation of human nucleus pulposus cells

English Keywords:Cyclic distraction stress  Human nucleus pulposus  Proliferation  Cell cycle

English Abstract:

  【Abstract】 Objectives: To investigate the effects of cyclic distraction stress on the proliferation of human nucleus pulposus cells(HNPCs). Methods: HNPCs were cultured in vitro and identified via the toluidine blue, safranin O and immunocytochemical stain of collagenⅡ. P3 HNPCs were inoculated on elasticity polymer. After HNPCs were attached, BioDynamic test instrument was used to exert different distraction strain(0, 5%, 10%, and 15%) on HNPCs for 3 hours; after that, HNPCs were cultured for 24 hours, and the flow cytometry was used to examine the cell cycle and calculate the S phase fraction and proliferative index. Results: The cell adhesion and growth were well under different strain for 3h; S phase fraction in 0, 5%, 10% and 15%strain groups was 1.86±1.22, 2.07±0.09, 7.56±1.40 and 7.55±3.25 respectively. Proliferative index in these groups was 3.47±2.52, 7.88±2.45, 16.05±1.51 and 14.7±0.61 respectively. Compared with 0 strain group, proliferative index in 5% strain group increased significantly(P<0.05). Compared with 0 and 5% strain group, S phase fraction and proliferative index in 10% and 15% strain groups increased significantly(P<0.05); but S phase fraction and proliferative index showed no significant difference between 10% and 15% strain groups(P＞0.05). Conclusions: The proliferation of HNPCs increases under some stress.