Effect of Static Load on the Nucleus Pulposus of Rabbit Intervertebral Disc Motion Segment in an Organ Culture

A randomized controlled trial: The efficacy and safety of Bushen Huoxue formula in the management of lower back pain from lumbar disc herniation

BACKGROUND

Lower back pain (LBP) arising from lumbar disc herniation (LDH) poses a challenging health issue, often necessitating therapeutic interventions. Bushen Huoxue formula (BSHXF) has proved as a potential treatment option with great clinical effect. However, comprehensive investigations into its efficacy and safety in conjunction with celecoxib for managing LBP from LDH are lacking. The objective of this article is to investigate the efficacy and safety of BSHXF in the management of patients with LBP from LDH.

METHODS

This single center, randomized clinical trial was conducted from March 2023 to September 2023 and all patients suffered from LBP of LDH. Participants were randomly assigned to the BSHXF group (celecoxib and BSHXF) or the control group (celecoxib and placebo). The patients received treatment for 2 weeks. Assessment was conducted before treatment, the last day of the treatment, 4 weeks and 8 weeks after the treatment. Oswestry Disability Index (ODI), Visual Analog Scale (VAS), Roland-Morris Disability Questionnaire (RMDQ), Timed up and go test (TUGT), trunk range of movement (Trunk ROM), Hospital Anxiety and Depression Scale (HADS) were used for the evaluation.

RESULTS

A total of 206 subjects completed treatment, among whom 104 participants were randomized to the BSHXF group and 102 participants were randomized to the control group. There were no significant differences between groups in terms of the observed indicators (P > .05). After treatment, patients in BSHXF group obtained significant lower scores at 2-week, 4-week, 8-week of VAS, ODI, RMDQ, TUGT, Trunk ROM and HADS than the baseline data (P < .05). The ODI score was significantly lower than the control group at 2-week, 4-week, 8-week (2w: 11.30 ± 5.80 vs 14.23 ± 6.33, P < .001; 4w: 10.95 ± 4.93 vs 13.54 ± 6.35, P < .001; 8w: 10.27 ± 5.25 vs 12.84 ± 6.57, P = .002). Similarly, the scores of VAS, RMDQ, TUGT, Trunk ROM scores of the BSHXF group markedly decreased at 2, 4, and 8-week when compared to their control group (P < .05). Furthermore, no significant difference showed up in the score of HADS between the between the BSHXF and the control group after treatment (P > .05).

CONCLUSION

This randomized clinical trial found that BSXHF can help significantly improve the clinical outcomes of celecoxib including pain intensity reduction and lumbar function improvement in LBP patients.

Impact of Running Exercise on Intervertebral Disc: A Systematic Review

CONTEXT

Running is one of the most popular sports worldwide. However, controversies exist regarding how running affects runner's intervertebral discs (IVD).

OBJECTIVE

The purpose of this study was to systematically review studies that evaluated IVD morphology or composition changes in response to running exercise, to determine the impact of running exercise on IVD.

DATA SOURCES

A systematic literature search was performed for 4 major databases: PubMed, Cochrane, Embase, and Web of Science.

STUDY SELECTION

Inclusion criteria were as follows: (1) healthy people without known IVD disease or major complications such as tuberculosis (IVD degeneration or low back pain are considered as minor complications); (2) subjects performed 1-time or regular running exercises; (3) pre and post comparison of runners or comparison between runners and healthy control subjects; (4) direct or indirect IVD morphology or composition measured; (5) IVD assessed before and after either acute or chronic running exercise, or compared cross-sectionally between runners and controls. Exclusion criteria were as follows: (1) reviews, editorials, letters or abstracts only; (2) animal studies; (3) subjects performed exercise other than running.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 3.

DATA EXTRACTION

The extracted data included study design and primary outcomes of the included studies. The Newcastle-Ottawa scale (NOS) was used to evaluate study quality and risk of bias.

RESULTS

A total of 13 studies with 632 participants were included in the final analysis; 4 studies measured IVD changes using stature or spinal height, and the other 9 measured IVD changes using magnetic resonance imaging; 6 studies found that running acutely and negatively impacts IVD; 3 out of 5 cross-sectional studies found that IVD parameters are better for runners than controls; 1 longitudinal study found no significant difference in IVD before and after training for marathon in runners; 1 longitudinal study found no significant difference in changes of IVD between runners and controls after 15 years of follow-up.

CONCLUSION

Negative changes in IVD exist for a short period of time after running, which may be due to the temporary compression pushing water content out of the disc. Cross-sectional studies suggest that long-term running exerts a mild positive effect on IVD; however, this inference has not been confirmed by high-quality longitudinal studies.

Efficacy and Safety of Bushen Huoxue Formula in Patients with Discogenic Low-Back Pain: A Double-Blind, Randomized, Placebo-Controlled Trial

OBJECTIVE

To assess the efficacy and safety of Bushen Huoxue Formula (BSHXF) for the treatment of discogenic low-back pain (DLBP).

METHODS

This was a parallel, double-blind, randomized, clinical trial performed between May 2019 and June 2020. Seventy patients were assigned by computerized random number table to the treatment group (lumbar traction and BSHXF, 35 cases) or the control group (lumbar traction and placebo, 35 cases). The patients received intervention for 3 weeks. Assessment was conducted before treatment and at week 1, 2, 3 during treatment. Primary outcome was the self-reported score of Oswestry Disability Index (ODI). Secondary outcomes included Visual Analog Scale (VAS), clinical efficacy rate by minimal clinically important difference (MCID) as well as lumbar tenderness, muscle tone and lumbar spine mobility. Adverse reactions were recorded. Follow-up was performed at 1 and 3 months after the end of treatment.

RESULTS

In the treatment group, ODI score was significantly decreased compared with baseline (P<0.05) and the control group at 2- and 3- week treatment. Similarly, VAS score decreased compared with the baseline (P<0.05) and was lower than that in the control group at 2- and 3- week treatment (P<0.05). The clinical efficacy rate of the treatment group was higher than that of the control group after treatment [32.35% (11/34) vs. 3.13% (1/32), P<0.05). Moreover, the tenderness, and muscle tone, as well as the back extension and left flexion in lumbar spine mobility in the treatment group at 3-week treatment were significantly improved compared with the control group (P<0.05). Follow-up showed that at 1-month after treatment, the treatment group had better outcomes than the control group with regard to a total score of ODI and VAS scores, as well as clinical efficacy rate (all P<0.05). Moreover, VAS score was still significantly lower than the control group at 3-month follow-up (P<0.05). No adverse reactions were reported during the study.

CONCLUSION

BSXHF combined with lumbar traction can significantly improve the clinical symptoms including pain intensity, functionality, muscle tone, and lumbar spine mobility in DLBP patients. (Registration No. ChiCTR1900027777).

Intervertebral Disc Degeneration Models for Pathophysiology and Regenerative Therapy -Benefits and Limitations

Aim:This review summarized the recent intervertebral disc degeneration (IDD) models and described their advantages and potential disadvantages, aiming to provide an overview for the current condition of IDD model establishment and new ideas for new strategies development of the treatment and prevention of IDD.Methods:The database of PubMed was searched up to May 2021 with the following search terms: nucleus pulposus, annulus fibrosus, cartilage endplate, intervertebral disc(IVD), intervertebral disc degeneration, animal model, organ culture, bioreactor, inflammatory reaction, mechanical stress, pathophysiology, epidemiology. Any IDD model-related articles were collected and summarized.Results:The best IDD model should have the features of repeatability, measurability and controllability. There are a lot of aspects to be considered in the selection of animals. Mice, rats and rabbits are low-cost and easy to access. However, their IVD size and shape are more different from human anatomy than pigs, cattle, sheep and goats. Organ culture models and animal models are two options in model establishment for IDD. The IVD organ culture model can put the studying variables into the controllable system for transitional research. Unlike the animal model, the organ culture model can only be used to evaluate the short-term effects and it is not applicable in simulating the complex process of IDD. Similarly, the animal models induced by different methods also have their advantages and disadvantages. For studying the mechanism of IDD and the corresponding treatment and prevention strategies, the selection of model should be individualized based on the purpose of each study.Conclusions:Various models have different characteristics and scope of application due to their different rationales and methods of construction. Currently, there is no experimental model that can perfectly mimic the degenerative process of human IVD. Personalized selection of appropriate model based on study purpose and experimental designing can enhance the possibility to obtain reliable and real results.

Effects of Axial Compression and Distraction on Vascular Bud and VEGFA Expression in the Vertebral Endplate of an Ex Vivo Rabbit Spinal Motion Segment Culture Model

STUDY DESIGN

An ex vivo study of the rabbit's vertebral endplate.

OBJECTIVE

The aim of this study was to assess the effect of axial compression and distraction on vascular buds and vascular endothelial growth factor (VEGFA) expression of the vertebral endplate (VEP).

SUMMARY OF BACKGROUND DATA

The abnormal load can lead to intervertebral disc degeneration (IDD), whereas axial distraction can delay this process. The effects of different mechanical loads on the intervertebral disc (IVD) have been hypothesized to be related to changes in the vascular buds of the VEP; moreover, the process that might involve the vascular endothelial growth factor (VEGF) within the VEP.

METHODS

Rabbit spinal segments (n = 40) were harvested and randomly classified into four groups: Control group, no stress was applied; Group A, a constant compressive load applied; Group B, compression load removed for a fixed time daily on a continuous basis, and substituted with a distraction load for 30 minutes; and Group C, compression removed for 30 minutes for a fixed period daily on a continuous basis. Tissue specimens were collected before the culture (day 0) and on day 14 post-culture of each group for analysis of IVDs' morphology, and protein and mRNA expression of Aggrecan, COL2al, VEGFA, and vascular endothelial growth factor receptor 2 of the VEPs.

RESULTS

Application of axial distraction and dynamic load compression significantly delayed time- and constant compression-mediated VEP changes and IDD. Moreover, the degree of degeneration was associated with loss of vascular buds, as well as the downregulation of VEGFA and its receptor.

CONCLUSION

The regulation of vascular buds and VEGF expression in the VEP represents one of the mechanisms of axial distraction and dynamic loading.Level of Evidence: N/A.

Constant compression decreases vascular bud and VEGFA expression in a rabbit vertebral endplate ex vivo culture model

SUMMARY OF BACKGROUND DATA

The vascular buds in the vertebral endplate (VEP) are the structural foundation of nutrient exchange in the intervertebral disc (IVD). VEGF is closely related to angiogenesis in the endplate and intervertebral disc degeneration (IDD).

OBJECTIVE

To investigate the effects of static load on vascular buds and VEGF expression in the VEP and to further clarify the relation between IDD and VEGF.

METHODS

IVD motion segments were harvested from rabbit lumbar spines and cultured under no-loading conditions (controls) or in custom-made apparatuses under a constant compressive load (0.5 MPa) for up to 14 days. Tissue integrity and the number of vascular buds were determined, and the concentrations and expression of Aggrecan, COL2a1, and VEGFA in the VEPs were assessed after 3, 7, and 14 days of culturing and then compared with those of fresh tissues.

RESULTS

Under the constant compression, the morphological integrity of the VEPs was gradually disrupted, and immunohistochemistry results showed a significant decrease in the levels of Agg and COL2a1. During the static load, the number of vascular buds in the VEPs was gradually reduced from the early stage of culture, and ELISA showed that the constant compressive load caused a significant decrease in the VEGFA and VEGFR2 protein concentrations, which were consistent with the immunohistochemistry results. Western blot and RT-PCR results also showed that the loading state caused a significant decrease in VEGFA expression compared with that of fresh and control samples.

CONCLUSIONS

Constant compression caused degeneration of the VEP as well as a decreased number of vascular buds, thereby accelerating disc degeneration. VEGFA is involved in this process. We anticipate that regulating the expression of VEGFA may improve the condition of the lesions to the vascular buds in the endplates, thus enhancing the nutritional supply function in IVD and providing new therapeutic targets and strategies for the effective prevention and treatment of IDD.

Long-term load duration induces N-cadherin down-regulation and loss of cell phenotype of nucleus pulposus cells in a disc bioreactor culture

Long-term exposure to a mechanical load causes degenerative changes in the disc nucleus pulposus (NP) tissue. A previous study demonstrated that N-cadherin (N-CDH)-mediated signalling can preserve the NP cell phenotype. However, N-CDH expression and the resulting phenotype alteration in NP cells under mechanical compression remain unclear. The present study investigated the effects of the compressive duration on N-CDH expression and on the phenotype of NP cells in an ex vivo disc organ culture. Porcine discs were organ cultured in a self-developed mechanically active bioreactor for 7 days. The discs were subjected to different dynamic compression durations (1 and 8 h at a magnitude of 0.4 MPa and frequency of 1.0 Hz) once per day. Discs that were not compressed were used as controls. The results showed that long-term compression duration (8 h) significantly down-regulated the expression of N-CDH and NP-specific molecule markers (Brachyury, Laminin, Glypican-3 and Keratin 19), attenuated Alcian Blue staining intensity, decreased glycosaminoglycan (GAG) and hydroxyproline (HYP) contents and decreased matrix macromolecule (aggrecan and collagen II) expression compared with the short-term compression duration (1 h). Taken together, these findings demonstrate that long-term load duration can induce N-CDH down-regulation, loss of normal cell phenotype and result in attenuation of NP-related matrix synthesis in NP cells.