Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Jan 19;7(1):e1314.
doi: 10.1002/jsp2.1314. eCollection 2024 Mar.

Repetitive strikes loading organ culture model to investigate the biological and biomechanical responses of the intervertebral disc

Jiaxiang Zhou  1 , Jianmin Wang  2 , Jianfeng Li  2 , Zhengya Zhu  2 , Zhongyuan He  2 , Junhong Li  2 , Tao Tang  2 , Hongkun Chen  2 , Yukun Du  1 , Zhen Li  3 , Manman Gao  2   4   5   6 , Zhiyu Zhou  2   4 , Yongming Xi  1
Affiliations

Repetitive strikes loading organ culture model to investigate the biological and biomechanical responses of the intervertebral disc

Jiaxiang Zhou et al. JOR Spine. .

Abstract

Background: Disc degeneration is associated with repetitive violent injuries. This study aims to explore the impact of repetitive strikes loading on the biology and biomechanics of intervertebral discs (IVDs) using an organ culture model.

Methods: IVDs from the bovine tail were isolated and cultured in a bioreactor, with exposure to various loading conditions. The control group was subjected to physiological loading, while the model group was exposed to either one strike loading (compression at 38% of IVD height) or repetitive one strike loading (compression at 38% of IVD height). Disc height and dynamic compressive stiffness were measured after overnight swelling and loading. Furthermore, histological morphology, cell viability, and gene expression were analyzed on Day 32. Glycosaminoglycan (GAG) and nitric oxide (NO) release in conditioned medium were also analyzed.

Results: The repetitive one strike group exhibited early disc degeneration, characterized by decreased dynamic compression stiffness, the presence of annulus fibrosus clefts, and degradation of the extracellular matrix. Additionally, this group demonstrated significantly higher levels of cell death (p < 0.05) and glycosaminoglycan (GAG) release (p < 0.05) compared to the control group. Furthermore, upregulation of MMP1, MMP13, and ADAMTS5 was observed in both nucleus pulposus (NP) and annulus fibrosus (AF) tissues of the repetitive one strike group (p < 0.05). The one strike group exhibited annulus fibrosus clefts but showed no gene expression changes compared to the control group.

Conclusions: This study shows that repetitive violent injuries lead to the degeneration of a healthy bovine IVDs, thereby providing new insights into early-stage disc degeneration.

Keywords: degeneration; intervertebral disc; mechanical load; organ culture; repetitive injury.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Figures

FIGURE 1
FIGURE 1
(A) Disc height change after swelling. (B) Dynamic compressive stiffness of the IVDs measured at different time points. Data were normalized to original height of each disc on Day 0 after dissection, and dynamic compressive stiffness of each disc on Day 1 after free swelling, Mean + SD; n = 3; *p < 0.05. Ten strikes loading group versus physiological loading group.
FIGURE 2
FIGURE 2
Representative LDH/ETH staining images of IVDs collected on Day 32 after physiological loading (A, D, G), on Day 32 after one strike loading (B, E, H), and on Day 32 after ten strikes loading (C, F, I). Cell viability was assessed using LDH/ETH staining (blue and blue/red = alive cell; red only = dead cell). Figures A–C represent NP tissue. Figures D–F represent inner AF (IAF) tissue. Figures G–I represent outer AF (OAF) tissue. Scale bar: 100 μm.
FIGURE 3
FIGURE 3
The numbers of alive cells, dead cells, and cell viability from different groups. A1, B1, C1 represent NP region; A2, B2, C2 represent inner AF (IAF) region; A3, B3, C3 represent outer AF (OAF) region. the data were normalized to Control group (n = 3), Mean + SD, *p < 0.05.
FIGURE 4
FIGURE 4
Representative Safranin O/Fast green staining images of cross histological sections from IVDs on Day 32 after physiological loading (A, D, G), on Day 32 after one strike loading (B, E, H), and on Day 32 after ten strikes loading (C, F, I). Scale bar: 650 μm. (J) Histological scoring values based on Safranin O/Fast green staining, Mean + SD; n = 3; *p < 0.05.
FIGURE 5
FIGURE 5
Gene expression in NP (A) and AF (B) tissue of one strike loading group and ten strikes loading group normalized to physiological loading group on Day 32. n = 3. *p < 0.05 versus physiological loading group; ↑ indicates the gene expression was significantly upregulated in ten strikes loading group compared to physiological loading group, ↓ indicates the gene expression was significantly downregulated in ten strikes loading group compared to physiological loading group.
FIGURE 6
FIGURE 6
Accumulative NO (A) and GAG (B) release in conditioned media of IVDs cultured with physiological loading, one strike loading or ten strikes loading during culture. Mean ± SD; n = 3; *p < 0.05 versus physiological loading group. GAG; glycosaminoglycan; NO, nitric oxide.
See this image and copyright information in PMC

References

    1. Wu A, Dong W, Liu S, et al. The prevalence and years lived with disability caused by low back pain in China, 1990 to 2016: findings from the global burden of disease study 2016. Pain. 2019;160:1237‐1245. - PMC - PubMed
    1. Cieza A, Causey K, Kamenov K, et al. Global estimates of the need for rehabilitation based on the global burden of disease study 2019: a systematic analysis for the global burden of disease study 2019. Lancet (London, England). 2021;396:102672006‐102672017. - PMC - PubMed
    1. Global age‐sex‐specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950–2019: a comprehensive demographic analysis for the global burden of disease study 2019. Lancet (London, England). 2020;396:102581160‐102581203. - PMC - PubMed
    1. Maher C, Ferreira G. Time to reconsider what global burden of disease studies really tell us about low back pain. Ann Rheum Dis. 2022;81:3306‐3308. - PMC - PubMed
    1. Iatridis JC, MacLean JJ, Roughley PJ, Alini M. Effects of mechanical loading on intervertebral disc metabolism in vivo. J Bone Jt Surg Am. 2006;88(Suppl 2):241‐246. - PMC - PubMed