Traditional Chinese exercises on pain and disability in middle-aged and elderly patients with lumbar disc herniation: a systematic review and meta-analysis of randomized controlled trials.

Background: Traditional Chinese exercises (TCEs) have played a significant role in treating various diseases. However, there is limited research assessing the efficacy of TCEs in treating Lumbar disc herniation (LDH). This study aimed to systematically evaluate the effects of four commonly used TCEs (Baduanjin, Yijinjing, Taichi, and Wuqinxi) on pain and disability in elderly patients with LDH. Objectives: To assess the quality of relevant randomized controlled trials (RCTs) to provide evidence support for the treatment of LDH. Methods: RCTs were identified through eight databases. Meta-analysis and trial sequence analysis (TSA) were conducted using RevMan 5.4, Stata 17.0, and TSA 0.9. Results: A total of 22 RCTs, involving 1931 patients, were included in the analysis. TCEs exhibited a superior effectiveness in treating LDH compared to the control group. However, the TSA analysis suggested the possibility of false positives, indicating the need for more high-quality RCT evidence. Nevertheless, TCEs showed reliable results in significantly improving the VAS score and JOA score of LDH patients. Conclusion: Current evidence indicates that the four TCEs have advantages in treating LDH in middle-aged and elderly individuals. However, considering the limitations of this study, we need to exercise caution in drawing conclusions, and further research is required to validate these findings. Systematic Review Registration: http://www.crd.york.ac.uk/PROSPERO, identifier [CRD42023431633].

[Salvianolic acid A contributes to cartilage endplate cell restoration by regulating miR-940 and miR-576-5p].

OBJECTIVE: To investigate whether Salvianolic acid A (SAA) can restore cartilage endplate cell degeneration of intervertebral discs and to identify the mechanism via regulation of micro-RNA. METHODS: Cartilage endplate cells were isolated from lumbar intervertebral disc surgical samples and were treated with serum containing a series of concentrations of SAA (2, 5, and 10 ?M) for 24, 48, and 72 h to identify a proper dose and treatment time of SAA. The effect SAA on interlenkin-1ß (IL-1ß)-induced extracellular matrix degradation of cartilage endplate cells were analyzed by Alcian blue staining and assessment of the expression levels of ADAMTS-5, MMP3 and Col2a1. Further, the potential target miRNAs were preliminarily screened by micro-RNA sequencing combining qRT-PCR and Western blot, and then, the miRNAs mimics and inhibitors were used to verify the regulatory effect of SAA on potential target miRNAs. RESULTS: The 10 µM SAA treatment for 48 h significantly enhanced the viability of cartilage endplate cells, and increased Col2a1 expression and glycosaminoglycan accumulation that were repressed by IL-1ß, and reduced the effect of IL-1ß on ADAMTS-5, and MMP3. Screening analysis based on micro-RNA sequencing and Venny analysis identified the downstream micro-RNAs, including miR-940 and miR-576-5p. Then, the miR-940-mimic or miR-576-5p-mimic were transfected into CEPCs. Compared with the SAA group, the expression of ADAMTS-5 and MMP3 increased significantly and the expression of COL2A1 obviously decreased after overexpression of miR-940 or miR-576-5p in CEPCs. CONCLUSION: Salvianolic acid A attenuated the IL-1ß-induced extracellular matrix degradation of cartilage endplate cells by targeting regulate the miR-940 and the miR-576-5p.

Traditional Chinese Medicine formula Bu-Shen-Huo-Xue-Fang (BSHXF) protects nucleus pulposus cells against the inflammatory and oxidative stress-induced degenerative changes.

Degeneration of the intervertebral disc is primarily caused by the loss of nucleus pulposus cells (NPCs) and extracellular matrix (ECM) (IDD). Bu-Shen-Huo-Xue-Fang (BSHXF), a traditional Chinese medicine decoction, has been used to treat IDD in clinical; nevertheless, the active components and underlying molecular mechanisms remain unknown. BSHXF improved IL-1ß and H2O2 stimulation-induced injuries on NPCs by promoting cell viability, increasing ECM deposition, inhibiting cell senescence, and decreasing the levels of inflammatory factors. The active ingredients in BSHXF were identified by LC-MS/MS analysis; three active ingredients from the principal drugs, Aucubin, Tanshinol, and Tanshinone II A promoted NPC viability; and Aucubin and Tanshinol promoted NPC viability more. Aucubin and Tanshinol, respectively, improved H2O2 stimulation-induced injuries on NPCs by promoting cell viability, increasing ECM deposition, inhibiting cell senescence, and decreasing the levels of inflammatory factors. The activator of NF-κB and Wnt signaling pathways attenuated Aucubin and Tanshinol's protective effects by promoting ECM degradation and NPC senescence. Aucubin, Tanshinol, and Tanshinone II A were identified as the most potent compounds in BSHXF protection against degenerative changes in NPCs. The NF-κB and Wnt signaling pathways might be involved in the protective effects of Aucubin and Tanshinol against H2O2-induced degenerative changes.

From Mechanobiology to Mechanical Repair Strategies: A Bibliometric Analysis of Biomechanical Studies of Intervertebral Discs.

Neck pain and low back pain are major challenges in public health, and intervertebral disc (IVD) biomechanics is an important multidisciplinary field. To date, no bibliometric literature review of the relevant literature has been performed, so we explored the emerging trends, landmark studies, and major contributors to IVD biomechanics research. We searched the Web of Science core collection (1900-2022) using keywords mainly composed of "biomechanics" and "intervertebral disc" to conduct a bibliometric analysis of original papers and their references, focusing on citations, authors, journals, and countries/regions. A co-citation analysis and clustering of the references were also completed. A total of 3189 records met the inclusion criteria. In the co-citation network, cluster #0, labeled as "annulus fibrosus tissue engineering", and cluster #1, labeled as "micromechanical environment", were the biggest clusters. References by MacLean et al and Holzapfel et al were positioned exactly between them and had high betweenness centrality. There existed a research topic evolution between mechanobiology and mechanical repair strategies of IVDs, and the latter had been identified as an emerging trend in IVD biomechanics. Numerous landmark studies had contributed to several fields, including mechanical testing of normal and pathological IVDs, mechanical evaluation of new repair strategies and development of finite element model. Adams MA was the author most cited by IVD biomechanics papers. Spine, the European Spine Journal, and the Journal of Biomechanics were the three journals where the most original articles and their references have been published. The United States has contributed most to the literature (n = 1277 papers); however, the research output of China is increasing. In conclusion, the present study suggests that IVD repair is an emerging trend in IVD biomechanics.

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).

[Research progress in mechanism of Chinese herbal compounds and monomers in delaying lumbar intervertebral disc degeneration].

Traditional Chinese medicine has unique advantages in the treatment of degenerative bone and joint diseases, and its widely used in clinical practice. In recent years, many scholars have conducted a large number of basic studies on the delay of intervertebral disc degeneration by herbal compound and monomeric components from different perspectives. In order to further elucidate its mechanism of action, this paper summarizes the in vivo and in vitro experimental studies conducted at the level of both herbal compound and single components, respectively, in order to provide references for the basic research on the treatment of lumbar intervertebral disc degeneration by Chinese medicine. A summary shows that commonly used herbal compound prescriptions include both classical prescriptions such as Duhuo Jisheng Decoction, as well as clinical experience prescriptions such as Yiqi Huoxue Recipe. Angelicae Sinensis Radix, Chuanxiong Rhizoma, Rehmanniae Radix Praeparata, Achyranthis Bidentatae Radix, and Eucommiae Cortex were used most frequently. Tonic for deficiency and blood stasis activators were used most frequently. The most utilized monomeric components include icariin, ginsenoside Re, salvianolic acid B and aucubin. The main molecular mechanisms by which herbal compound and monomeric components delay of lumbar intervertebral disc degeneration include improving the intervertebral disc microenvironment, promoting the synthesis of aggregated proteoglycans and type Ⅱ collagen in the intervertebral disc, reducing the degradation of the extracellular matrix, and inhibiting apoptosis in the nucleus pulposus cells, etc. The main signaling pathways involved include Wnt/ß-catenin signaling pathway, MAPK-related signaling pathway, mTOR signaling pathway, Fas/FasL signaling pathway, PI3 K/Akt signaling pathway, NF-κB signaling pathway, JAK/STAT signaling pathway, and hedgehog signaling pathway, etc.

Systematic analysis of Long non-coding RNAs reveals diagnostic biomarkers and potential therapeutic drugs for intervertebral disc degeneration.

Long non-coding RNAs (lncRNAs) are related to a variety of human diseases. However, little is known about the role of lncRNA in intervertebral disc degeneration (IDD). LncRNA expression profile of human IDD were downloaded from Gene Expression Omnibus (GEO) database. Potential biomarkers and therapeutic drugs for IDD were analyzed by weighted gene co-expression network analysis (WGCNA), R software package Limma, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). We identified 1455 differentially expressed genes and 423 differentially expressed lncRNAs. Twenty-six co-expression modules were obtained, among them, the tan, brown, and turquoise modules were most closely related to IDD. The turquoise module contained a large number of differential expressed lncRNAs and genes, these genes were mainly enriched in the MAPK signaling pathway, TGF-beta signaling pathway. Furthermore, we obtained 11,857 LmiRM-Degenerated, these lncRNAs and genes showed higher differential expression multiples and higher expression correlation. After constructing a disease-gene interaction network, 25 disease-specific genes and 9 disease-specific lncRNAs were identified. Combined with the drug-target gene interaction network, three drugs, namely, Calcium citrate, Calcium Phosphate, and Calcium phosphate dihydrate, which may have curative effects on IDD, were determined. Finally, a genetic diagnosis model and lncRNA diagnosis model with 100% diagnostic performance in both the training data set and the validation data set were established based on these genes and lncRNA. This study provided new diagnostic features for IDD and could help design personalized treatment of IDD.

Effects of seated lumbar rotation manipulation in treating degenerative lumbar instability: a protocol for a randomized controlled trial.

BACKGROUND: Degenerative lumbar instability (DLI) is a common disease that causes low back pain (LBP) in clinic. It is difficult to completely recover from DLI, and it occurs repeatedly, which seriously affects the quality of life of patients. The epidemiological survey showed that 20-30% of low back pain was related to lumbar instability. Increasing evidence shows that seated lumbar rotation manipulation can effectively improve the clinical symptoms of patients with low back pain. The primary aim of this clinical trial is to observe the intervention effect of seated lumbar rotation manipulation on DLI patients. METHOD/DESIGN: A total of 60 participants with DLI will be recruited and randomly allocated into the seated lumbar rotation manipulation group (the intervention group) or lumbar traction in supine position group (the control group) in this prospective, outcome assessor-blind, two-arm randomized controlled clinical trial. The treatment of the two groups lasted for 3 weeks, and the manipulation of the intervention group would be carried out once every other day, three times a week, a total of 9 times; the control group would be given lumbar traction once a day, five times a week, a total of 15 times. JOA (Japanese Orthopaedic Association) and VAS (Visual Analogue Scales) scores will be recorded as the primary outcomes before the treatment and at the 1st, 3rd, 5th, 8th, 10th, 12th, 15th, 17th, and 19th days after treatment and follow-up visit at the first, third, and sixth months. JOA efficacy evaluation standard will be used to evaluate the overall efficacy as the secondary outcomes. DISCUSSION: The results of this prospective, randomized controlled trial will provide a clinical evidence for the treatment of DLI with seated lumbar rotation manipulation. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2000032017 . Registered on 18 April 2020, Prospective registration.

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.

[Study on mechanism of "Epimedii Folium-Paeoniae Radix Alba" in treatment of lumbar disc herniation based on network pharmacology].

The aim of this paper was to investigate the key targets and mechanism of "Epimedii Folium-Paeoniae Radix Alba" in the treatment of lumbar disc herniation by means of network pharmacology. The currently recognized databases and analysis software at home and abroad were used to construct the network from drugs and diseases. The chemical components of Epimedii Folium and Paeo-niae Radix Alba were collected by using databases such as TCMSP, while their active components were determined and the action targets were predicted according to threshold screening and literature reports. The genes for lumbar disc herniation were collected by using GeneCards, OMIM, and DisGeNET databases. The drug targets were mapped to disease targets, and protein interaction network analysis for key targets, GO function enrichment analysis and KEGG signaling pathway enrichment analysis were performed. Finally, 23 active components of Epimedium Folium and 13 active components of Paeoniae Radix Alba were determined, and a total of 624 drug targets were obtained. After standardization, 214 drug targets were obtained. In addition, 306, 2 and 5 related targets of lumbar disc herniation were collected from GeneCards, OMIM, and DisGeNET database, respectively, and a total of 293 disease targets were obtained after deduplication. After the mapping of drug target and disease target, 44 common targets were obtained. PPI protein interaction network analysis showed that IL-6, TNF, AKT1, MAPK1, and VEGFA may be the core targets for the treatment of lumbar disc herniation. GO enrichment analysis identified 56 items(P<0.05), among which biological processes mainly included immune response, apoptosis, etc.; cell components mainly included extracellular space, extracellular region, etc.; molecular functions mainly included cytokine activity, metallopeptidase activity and so on. Through KEGG pathway enrichment analysis, 91 signaling pathways related to inflammation, metabolism, and senescence were identified, mainly including IL-17 signaling pathway and TNF signaling pathway and so on. "Epimedii Folium-Paeoniae Radix Alba" showed the characteristics of multi-channel and multi-target for the treatment of lumbar disc herniation. This study preliminarily explored the key targets for its role and the biological processes and signaling pathways involved. It was found that it may play a therapeutic role by affecting inflammation and immune regulation, which laid the foundation for further experimental verification.

Manipulation for treatment of degenerative lumbar spondylolisthesis: A protocol of systematic review and meta-analysis.

BACKGROUND: Degenerative lumbar spondylolisthesis (DLS) is one of the common orthopedic diseases which causes low back pain in patients, which seriously affects people's daily life and work. As a method of conservative treatment of this disease, manipulation is widely used in clinical practice. We will summarize the current published evidence of manipulation in the treatment of DLS, and evaluate the effectiveness and safety of manipulation through systematic review and meta-analysis, so as to provide more reliable evidence for future clinical practice. METHODS: We will conduct a comprehensive search of the following 9 databases until January 2019: PubMed, Embase, Cochrane Library, ClinicalTrials.gov, Web of Science, Chinese National Knowledge Infrastructure, Chinese Science and Technique Journals Database, Wan Fang Database, and Chinese Biomedical Database. The 2 researchers will independently search, screen, extract data, and evaluate the quality of the literatures. The primary outcomes include clinical effectiveness, Japanese Orthopaedic Association scores, and the secondary outcomes include visual analog scale scores, symptom scores, and adverse events. Bias risk tools provided by Cochrane Collaboration will be used for literature quality assessment, and RevMan 5.3 software will be used for meta-analysis. RESULTS: The results of this study will systematically evaluate the effectiveness and safety of manipulation intervention for people with DLS, especially in improving lumbar function scores and pain scores. CONCLUSION: The systematic review of this study will summarize the current published evidence of manipulation for the treatment of DLS, which can further guide the promotion and application of it. ETHICS AND DISSEMINATION: This study does not require ethical approval and the results will be published in a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42019139933.

[Effect of serum of Bushen Huoxue prescription on rabbit with intervertebral disc motion segments in vitro culture].

OBJECTIVE: To compare effect of serum of Bushen Huoxue prescription on rabbit with intervertebral disc motion segments in vitro culture. METHODS: Twenty-four New Zealand white rabbits aged from 4 to 6 months and weighted from 2.5 to 3 kg were divided into medicated group and control group, 7 in each group. Rabbits were excuted under condition of asepsis, 28 spinal motion segments were taken out in each group, and segments were loaded in spinal motion segments in vitro and cultured in culture apparatus. Nutrient solution of medicated group contain 10% serum of Bushen Huoxue prescription, and 10% blank serum in control group. Seven discs between two groups were taken out and observed by histomorphology, proteoglycan PAS/AB stining, collagen II immunohistochemical staining, AGG, Col2aI by PCR test before culture and on the 3th, 7th and 14th day after culture. RESULTS: Histomorphology results showed the formation of medicated group was better than that of control group at 1 week after culture. PAB/AB test results showed content of poteoglycan between two groups were decreased. Imunohistochemical results showed content of collagen II in medicated group were obviously increased than that of control group at 3 days, but decreased obviously at 1 week than that of control group. PCR results showed expression of Agg in medicated group was obviously decreased than that of control group, but no statistical significance between two groups on the 7 th and 14 th day. Expression of Col2aI between two groups at 3 days were increased, and medicated group increased obviously more, while there were no significant difference between two groups. CONCLUSIONS: Serum of Bushen Huoxue prescription could delay intervertebral disc degeneration at short time for it is relate with improving circulation, inhibiting inflammatory, regulating extracellular matrix, so the prescription plays an important role in early prevention and treatment for intervertebral disc degeneration.

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

The development of mechanically active culture systems helps in understanding of the role of mechanical stress in intervertebral disc (IVD) degeneration. Motion segment cultures facilitate the application and control of mechanical loads. The purpose of this study was to establish a culturing method for rabbit IVD motion segments to observe the effect of static load on the whole disc organ. Segments were cultured in custom-made apparatuses under a constant, compressive load (3 kg) for 2 weeks. Tissue integrity, matrix synthesis, and matrix gene expression profile were assessed and compared with fresh one. The results showed ex vivo culturing of samples gradually destroyed the morphology. Proteoglycan contents and gene expression were decreased and downregulated obviously. However, immunohistochemical staining intensity and collagen type II gene expression were significantly enhanced and upregulated. In contrast, these trends were reversed under constant compression. These results indicated short-term static load stimulated the synthesis of type II collagen; however, constant compression led to progressive degeneration and specifically to proteoglycan. Through this study a loading and organ-culturing system for ex vivo rabbit IVD motion segments was developed, which can be used to study the effects of mechanical stimulation on the biology of IVDs and the pathomechanics of IVD degeneration.

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

BACKGROUND: The development of mechanically active culture systems helps increase the understanding of the role of mechanical stress in intervertebral disc (IVD) degeneration. Motion segment cultures allow for preservation of the native IVD structure, and adjacent vertebral bodies facilitate the application and control of mechanical loads. The purpose of this study was to establish loading and organ culture methods for rabbit IVD motion segments to study the effect of static load on the whole disc organ. METHODS: IVD motion segments were harvested from rabbit lumbar spines and cultured in no-loading 6-well plates (control conditions) or custom-made apparatuses under a constant, compressive load (3 kg, 0.5 MPa) for up to 14 days. Tissue integrity, matrix synthesis, and the matrix gene expression profile were assessed after 3, 7, and 14 days of culturing and compared with those of fresh tissues. RESULTS: The results showed that ex vivo culturing of motion segments preserved tissue integrity under no-loading conditions for 14 days whereas the static load gradually destroyed the morphology after 3 days. Proteoglycan contents were decreased under both conditions, with a more obvious decrease under static load, and proteoglycan gene expression was also downregulated. However, under static load, immunohistochemical staining intensity and collagen Type II alpha 1 (COL2A1) gene expression were significantly enhanced (61.54 ± 5.91, P = 0.035) and upregulated (1.195 ± 0.040, P = 0.000), respectively, compared with those in the controls (P < 0.05). In contrast, under constant compression, these trends were reversed. Our initial results indicated that short-term static load stimulated the synthesis of collagen Type II alpha 1; however, sustained constant compression led to progressive degeneration and specifically to a decreased proteoglycan content. CONCLUSIONS: A loading and organ culture system for ex vivo rabbit IVD motion segments was developed. Using this system, we were able to study the effects of mechanical stimulation on the biology of IVDs, as well as the pathomechanics of IVD degeneration.

[Changes of nucleus pulposus after in vitro culture of rabbit whole intervertebral disc and spinal motion segment].

OBJECTIVE: To compare the changes of nucleus pulposus after in vitro culture of rabbit whole intervertebral disc and spinal motion segment. METHODS: Twenty-one New Zealand white rabbits which were randomly divided into organ group with 8 rabbits and segment group with 13 rabbits. Fifty intervertebral discs and 50 spinal motion segments were harvested respectively under aseptic conditions from two groups. These specimens were maintained in organ culture with hyperosmotic media (410 mOsm/kg), then 10 discs of the two groups were observed respectively by HE staining, immunohistochemistry of collagen type III, proteoglycan content and cells viability of nucleus pulposus before culture and at 3, 7, 14, 21 days after culture. RESULTS: HE staining showed the intervertebral disc tissue structure remained intact after culture of 21 days organ group and 14 days segment group,but there was severely degenerated of 21 days segment group. The intensity value of type II collagen immunohistochemical staining in the nucleus pulposus were not changed significantly between 21 days organ group and 14 days segment group (P > 0.05), but the staining of segment group at 21 days became shallower, there was significant difference compared with before each time points and organ group at 21 days (P < 0.05). PAS/AB staining of proteoglycan of nucleus pulposus showed that there were not decrease of tinting strength of two groups within 7 days, but the strength weakened slightly of two groups at 14 days, and the tinting strength became weaker at 21 days segment group, the change is more obvious than the organ group. The intensity value of fluorescence staining of nucleus pulposus cells was not changed significantly within 7 days of two groups (P > 0.05), the intensity value decreased slightly at 21 days organ group and 14 days segment group, but there were no significant difference compared with before time points (P > 0.05) however at 21 days segment group the intensity decreased as cells viability of nucleus pulposus decreased,and there was a significant difference compared with before each time points and organ group at 21 days (P < 0.05). CONCLUSION: It is not obviously degenerated of the discs of organ group cultured within 21 days and segment group cultured within 14 days, but there was significant degeneration of the intervertebral disc of segment group after cultured 21 days, so the rabbit spinal motion segment can be used on research about the biomechanics of intervertebral disc as a vitro experimental model within 14 days.