We investigated the effect of prolonged rhBMP-2 treatment on telomerase activity, replicative capacity and senescence of nucleus pulposus cells (NPCs) during long term culture. We obtained intervertebral disc (IVD) tissues with grade III degeneration from four patients. NPCs were isolated and passaged serially in three groups: control group, low-dose rhBMP-2 group and high-dose rhBMP-2 group until the cells reached the end of their replicative lifespan. Cumulative population doubling level (CPDL), telomerase activity and senescence markers, senescence-associated β-galactosidase (SA-β-gal), p53, p21, and p16, were assessed. The replicative capacity of NPCs in the high-dose rhBMP-2 group was decreased significantly compared to the control and low-dose rhBMP-2 groups. Mean telomerase activity was significantly greater in the high-dose rhBMP-2 group compared to the control and low-dose rhBMP-2 groups. The percentage of SA-β-gal-positive NPCs increased more rapidly in the high-dose rhBMP-2 group with passaging compared to the control and low-dose rhBMP-2 groups. The expression of p53, p21, and p16 in both low and high dose rhBMP-2 groups increased in all passages compared to the control group. We found that prolonged high-dose rhBMP-2 treatment increased telomerase activity of human NPCs, but decreased replicative capacity and lifespan in long term culture. We also found that excessive growth stimulation by prolonged high-dose rhBMP-2 treatment can promote NPCs senescence and result in growth arrest.

我们研究了长期rhBMP-2处理对髓核细胞（NPCs）端粒酶活性，复制能力和衰老的影响。我们从四名患者中获得了III级变性的椎间盘（IVD）组织。分离NPC并在三组中连续传代：对照组，低剂量rhBMP-2组和高剂量rhBMP-2组，直到细胞达到其复制寿命。评估了累积种群倍增水平（CPDL），端粒酶活性和衰老标记，衰老相关的β-半乳糖苷酶（SA-β-gal），p53，p21和p16。与对照组和低剂量rhBMP-2组相比，高剂量rhBMP-2组中NPC的复制能力显着降低。与对照组和低剂量rhBMP-2组相比，高剂量rhBMP-2组的平均端粒酶活性明显更高。与对照组和低剂量的rhBMP-2组相比，高剂量的rhBMP-2组中通过传代的SA-β-gal阳性NPC的百分比增长更快。与对照组相比，低剂量和高剂量rhBMP-2组中p53，p21和p16的表达在所有传代中均增加。我们发现长时间的大剂量rhBMP-2处理可增加人NPC的端粒酶活性，但在长期培养中可降低复制能力和寿命。我们还发现，长期用大剂量rhBMP-2处理过度刺激生长会促进NPC衰老并导致生长停滞。与对照组和低剂量的rhBMP-2组相比，高剂量的rhBMP-2组中通过传代的SA-β-gal阳性NPC的百分比增长更快。与对照组相比，低剂量和高剂量rhBMP-2组中p53，p21和p16的表达在所有传代中均增加。我们发现长时间的大剂量rhBMP-2处理可增加人NPC的端粒酶活性，但在长期培养中可降低复制能力和寿命。我们还发现，长期用大剂量rhBMP-2处理过度刺激生长会促进NPC衰老并导致生长停滞。与对照组和低剂量的rhBMP-2组相比，高剂量的rhBMP-2组中，随着年龄的增长，SA-β-gal阳性NPC的百分比增加更快。与对照组相比，低剂量和高剂量rhBMP-2组中p53，p21和p16的表达在所有传代中均增加。我们发现长时间的大剂量rhBMP-2处理可增加人NPC的端粒酶活性，但在长期培养中可降低复制能力和寿命。我们还发现，长期用大剂量rhBMP-2处理过度刺激生长会促进NPC衰老并导致生长停滞。我们发现长时间的大剂量rhBMP-2处理可增加人NPC的端粒酶活性，但在长期培养中可降低复制能力和寿命。我们还发现，长期用大剂量rhBMP-2处理过度刺激生长会促进NPC衰老并导致生长停滞。我们发现长时间的大剂量rhBMP-2处理可增加人NPC的端粒酶活性，但在长期培养中可降低复制能力和寿命。我们还发现，长期用大剂量rhBMP-2处理过度刺激生长会促进NPC衰老并导致生长停滞。