Basic Research
The effect of mechanical stretching stress on the proliferation, apoptosis of degenerative disc nucleus pulposus cells and expression of extracellular matrix
Zhang Wen, Xu Hui, Luo Dawei, Feng Hongyong, Ji Changbin, Yang Keshi, Li Bin, Li Kunpeng
Published 2018-10-25
Cite as Chin J Phys Med Rehabil, 2018,40(10): 721-726. DOI: 10.3760/cma.j.issn.0254-1424.2018.10.001
Abstract
ObjectiveTo observe in vitro the effect of mechanical stress at different intensities on the proliferation, apoptosis and extracellular matrix of degenerative human nucleus pulposus cells.
MethodsThe cells were isolated and cultured in vitro, and divided into a control group, a low-intensity group, a medium-intensity group and a high-intensity group. The low-, medium- and high-intensity groups were stretched mechanically by 1000 μ, 2000 μ or 4000 μ respectively for 6 hours using a four-point bending system, while the control group was not stressed. Flow cytometry was used to explore any changes in the cell cycle and the proliferation index (PI). The expression of proliferating cell nuclear antigen (PCNA), B-cell lymphoma-2 (BCL-2)/Bax, collagen II and aggrecan were measured using real-time quantitative polymerase chain reactions.
ResultsThe mechanical stretching significantly influenced proliferation, apoptosis and the extracellular matrices compared with the control group. The PI and PCNA expression increased at first and then decreased gradually with the exercise intensity. Compared with the control group, the mRNA expression level of Bcl-2/Bax increased significantly to 1.53 times that of the control group after 1000 μ stretching, but to only 0.71 times that of the control group at 2000 μ and 0.43 times at 4000 μ. The gene expression of collagen II increased significantly by 1.1 times and that of aggrecan by 1.3 times after 1000 μ stress stimulation compared with the control group (P≤0.05). However, the expression of collagen II and aggrecan was inhibited significantly at 2000 and 4000 μ , with the lowest levels at 4000 μ (P≤0.05).
ConclusionStretching at different intensities has different effects on the proliferation, apoptosis and extracellular matrix of human pulposus cells with degenerate nuclei.
Key words:
Mechanical stress; Stretching; Degenerate nuclei; Pulposus cells; Proliferation; Apoptosis; Extracellular matrices
Contributor Information
Zhang Wen
Department of Ultrasonography, People′s Hospital of Liaocheng, Liaocheng 252000, China
Xu Hui
Luo Dawei
Feng Hongyong
Ji Changbin
Yang Keshi
Li Bin
Li Kunpeng