scholarly journals Aberrant spinal mechanical loading stress triggers intervertebral disc degeneration by inducing pyroptosis and nerve ingrowth

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fangda Fu ◽  
Ronghua Bao ◽  
Sai Yao ◽  
Chengcong Zhou ◽  
Huan Luo ◽  
...  

AbstractAberrant mechanical factor is one of the etiologies of the intervertebral disc (IVD) degeneration (IVDD). However, the exact molecular mechanism of spinal mechanical loading stress-induced IVDD has yet to be elucidated due to a lack of an ideal and stable IVDD animal model. The present study aimed to establish a stable IVDD mouse model and evaluated the effect of aberrant spinal mechanical loading on the pathogenesis of IVDD. Eight-week-old male mice were treated with lumbar spine instability (LSI) surgery to induce IVDD. The progression of IVDD was evaluated by μCT and Safranin O/Fast green staining analysis. The metabolism of extracellular matrix, ingrowth of sensory nerves, pyroptosis in IVDs tissues were determined by immunohistological or real-time PCR analysis. The apoptosis of IVD cells was tested by TUNEL assay. IVDD modeling was successfully produced by LSI surgery, with substantial reductions in IVD height, BS/TV, Tb.N. and lower IVD score. LSI administration led to the histologic change of disc degeneration, disruption of the matrix metabolism, promotion of apoptosis of IVD cells and invasion of sensory nerves into annulus fibrosus, as well as induction of pyroptosis. Moreover, LSI surgery activated Wnt signaling in IVD tissues. Mechanical instability caused by LSI surgery accelerates the disc matrix degradation, nerve invasion, pyroptosis, and eventually lead to IVDD, which provided an alternative mouse IVDD model.

2020 ◽  
Author(s):  
Fang-da Fu ◽  
Sai Yao ◽  
Zhi-tao Sun ◽  
Cheng-cong Zhou ◽  
Huan Yu ◽  
...  

Abstract Background Whole body vibration (WBV) is a non-pharmaceutical therapy that has been widely incorporated into clinical practice for musculoskeletal disorders, including low back pain (LBP). Intervertebral disc (IVD) degeneration (IVDD) is clinically associated with LBP and is known as the main cause for LBP. However, cumulative evidence also suggested WBV might have an adverse impact on IVDs. Moreover, previous studies have been focusing on the effects of WBV on healthy mice, rather than those suffering from IVDD. Thus, uncertainties still exist concerning the effects of WBV on IVDs undergoing IVDD. This study was aiming to evaluate the effects of WBV intervention on the development and progression of IVDD mouse model induced by lumbar spine instability (LSI) surgery. Methods LSI surgery, by resecting the lumbar 3 rd -5 th spinous processes along with the supraspinous and interspinous ligaments, was conducted in 10-week-old male mice which then received WBV treatment (1 h per day, 5 days per week, at 3 Hz with peak acceleration at 0.4 g) or sham treatment. The progression of IVDD was evaluated by MRI, μCT and histological analyses after WBV treatment. The matrix metabolism, distribution of sensory nerves, pyroptosis in IVDs tissues were determined by immunohistological analysis or real-time PCR. The apoptosis of IVD cells was detected by TUNEL assay. Results LSI surgery was successful in producing IVDD modeling. WBV caused decreases in IVD height and annulus fibrosus (AF) score, as well as increased numbers of apoptotic cells in IVD tissues. WBV contributed to sensory innervation into AF and upregulation of Adamts5 and MMP3 expression in IVDD mice received LSI surgery. In addition, WBV treatment triggered earlier activation of Wnt/β-catenin signaling in IVDD mice with WBV treatment compared with those without WBV treatment. Unexpectedly, WBV significantly attenuated Caspase-1 and IL-1β expression in AF. Conclusions Collectively, our findings demonstrate that WBV treatment may worsen the development of ongoing IVDD. Decrease of IL-1β expression after WBV intervention may partially account for patient self-reported pain relief after WBV treatment in some previous trials. This study may help us better understand the effects of WBV intervention on patients experiencing LBP resulting from the degeneration of lumbar IVDs.


2009 ◽  
Vol 10 (6) ◽  
pp. 522-530 ◽  
Author(s):  
Huina Zhang ◽  
Frank La Marca ◽  
Scott J. Hollister ◽  
Steven A. Goldstein ◽  
Chia-Ying Lin

Object The goal in this study was to develop a convenient, less-invasive animal model to monitor progression of intervertebral disc (IVD) degeneration for future testing of new treatments for disc degeneration. Methods Level 5/6 and 7/8 IVDs of rat caudal spine were stabbed laterally with 18- or 21-gauge hypodermic needles to a depth of 5 mm from the subcutaneous surface with the aid of fluoroscopy. In vivo MR imaging studies were performed at 4, 8, and 12 weeks postsurgery to monitor progression of IVD degeneration. Histological analysis including H & E and safranin O staining, and immunohistochemical studies of collagen type II and bone morphogenetic protein receptor type II (BMPRII) were assessed at 12 weeks postsurgery. Results The 18- and 21-gauge needle–stabbed discs illustrated decreases in both the T2 density and MR imaging index starting at 4 weeks, with no evidence of spontaneous recovery by 12 weeks. Histological staining demonstrated a decreased nucleus pulposus (NP) area, and the NP–anulus fibrosus border became unclear during the progression of disc degeneration. Similar patterns of degenerative signs were also shown in both safranin O– and collagen type II–stained sections. The BMPRII immunohistochemical analysis of stabbed discs demonstrated an increase in BMPRII expression in the remaining NP cells and became stronger in anulus fibrosus with the severity of disc degeneration. Conclusions After introducing an 18- or 21-gauge needle into the NP area of discs in the rat tail, the stabbed disc showed signs of degeneration in terms of MR imaging and histological outcome measurements. Changes in BMPRII expression in this animal model provide an insight for the effectiveness of delivering BMPs into the region responsible for chondrogenesis for disc repair. This convenient, less-invasive, reproducible, and cost-effective model may be a useful choice for testing novel treatments for disc degeneration.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Chencheng Feng ◽  
Minghui Yang ◽  
Minghong Lan ◽  
Chang Liu ◽  
Yang Zhang ◽  
...  

Excessive reactive oxygen species (ROS) generation in degenerative intervertebral disc (IVD) indicates the contribution of oxidative stress to IVD degeneration (IDD), giving a novel insight into the pathogenesis of IDD. ROS are crucial intermediators in the signaling network of disc cells. They regulate the matrix metabolism, proinflammatory phenotype, apoptosis, autophagy, and senescence of disc cells. Oxidative stress not only reinforces matrix degradation and inflammation, but also promotes the decrease in the number of viable and functional cells in the microenvironment of IVDs. Moreover, ROS modify matrix proteins in IVDs to cause oxidative damage of disc extracellular matrix, impairing the mechanical function of IVDs. Consequently, the progression of IDD is accelerated. Therefore, a therapeutic strategy targeting oxidative stress would provide a novel perspective for IDD treatment. Various antioxidants have been proposed as effective drugs for IDD treatment. Antioxidant supplementation suppresses ROS production in disc cells to promote the matrix synthesis of disc cells and to prevent disc cells from death and senescence in vitro. However, there is not enough in vivo evidence to support the efficiency of antioxidant supplementation to retard the process of IDD. Further investigations based on in vivo and clinical studies will be required to develop effective antioxidative therapies for IDD.


Author(s):  
Kaiwen Liu ◽  
Jianlu Wei ◽  
Guohua Li ◽  
Ronghan Liu ◽  
Dawang Zhao ◽  
...  

Objective: Fexofenadine (FFD) is an antihistamine drug with an anti-inflammatory effect. The intervertebral disc (IVD) degeneration process is involved in inflammation in which tumor necrosis factor-α (TNF-α) plays an important role. This study aims to investigate the role of FFD in the pathological process of IVD degeneration.Methods: Safranin O staining was used for the measurement of cartilageous tissue in the disc. Hematoxylin-Eosin (H&E) staining was used to determine the disc construction. A rat needle puncture model was taken advantage of to examine the role of FFD in disc degeneration in vivo. Western Blotting assay, immunochemistry, and immunoflurence staining were used for the determination of inflammatory molecules. ELISA assay was performed to detect the release of inflammatory cytokines. A real-time PCR assay was analyzed to determine the transcriptional expressions of molecules.Results: Elevated TNF-α resulted in inflammatory disc degeneration, while FFD protected against TNF-α-induced IVD degeneration. Mechanism study found FFD exhibited a disc protective effect through at least two pathways. (a) FFD inhibited TNF-α-mediated extracellular matrix (ECM) degradation and (b) FFD rescued TNF-α induced inflammation in disc degeneration. Furthermore, the present study found that FFD suppressed TNF-α mediated disc degeneration via the cPLA2/NF-κB signaling pathway.Conclusions: FFD provided another alternative for treating disc degeneration through a novel mechanism. Additionally, FFD may also be a potential target for the treatment of other inflammatory-related diseases, including IVD degeneration.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Lin Xiao ◽  
Dongping Gong ◽  
Loufeng Liang ◽  
Anwei Liang ◽  
Huaxin Liang ◽  
...  

Abstract Background Intervertebral disc degeneration (IDD) is a major cause of lower back pain. This study aimed at exploring the effects of histone deacetylase 4 (HDAC4) and its upstream and downstream signaling molecules on IDD development. Methods A murine IDD model was established by inducing a needle puncture injury to the vertebrate, whereupon we isolated and transfected of nucleus pulposus (NP) cells. Disc height index (DHI) of the mice was determined by X-ray tomography, while the pain experienced by the IDD mice was evaluated by mechanical and thermal sensitivity tests. Next, the interaction between GSK3β and HDAC4 as well as that between HDAC4 and KLF5 acetylation was assessed by co-immunoprecipitation, while the promoter region binding was assessed identified by chromatin immunoprecipitation. By staining methods with TUNEL, Safranin O fast green, and hematoxylin and eosin, the NP cell apoptosis, degradation of extracellular matrix, and morphology of intervertebral disc tissues were measured. Furthermore, mRNA and protein expressions of GSK3β, HDAC4, KLF5, and ASK1, as well as the extent of HDAC4 phosphorylation, were determined by RT-qPCR and Western blotting. Results GSK3β was identified to be downregulated in the intervertebral disc tissues obtained from IDD mice, while HDAC4, KLF5, and ASK1 were upregulated. HDAC4 silencing alleviated IDD symptoms. It was also found that GSK3β promoted the phosphorylation of HDAC4 to increase its degradation, while HDAC4 promoted ASK1 expression through upregulating the expression of KLF5. In IDD mice, GSK3β overexpression resulted in increased DHI, inhibition of NP cell apoptosis, alleviation of disc degeneration, and promoted mechanical and thermal pain thresholds. However, HDAC4 overexpression reversed these effects by promoting ASK1 expression. Conclusion Based on the key findings of the current study, we conclude that GSK3β can promote degradation of HDAC4, which lead to an overall downregulation of the downstream KLF5/ASK1 axis, thereby alleviating the development of IDD.


2017 ◽  
Vol 54 (6) ◽  
pp. 945-952 ◽  
Author(s):  
Tove Hansen ◽  
Lucas A. Smolders ◽  
Marianna A. Tryfonidou ◽  
Björn P. Meij ◽  
Johannes C. M. Vernooij ◽  
...  

Since the seminal work by Hans-Jörgen Hansen in 1952, it has been assumed that intervertebral disc (IVD) degeneration in chondrodystrophic (CD) dogs involves chondroid metaplasia of the nucleus pulposus, whereas in nonchondrodystrophic (NCD) dogs, fibrous metaplasia occurs. However, more recent studies suggest that IVD degeneration in NCD and CD dogs is more similar than originally thought. Therefore, the aim of this study was to compare the histopathology of IVD degeneration in CD and NCD dogs. IVDs with various grades of degeneration (Thompson grade I–III, n = 7 per grade) from both CD and NCD dogs were used (14 CD and 18 NCD dogs, 42 IVDs in total). Sections were scored according to a histological scoring scheme for canine IVD degeneration, including evaluation of the presence of fibrocyte-like cells in the nucleus pulposus. In CD dogs, the macroscopically non-degenerated nucleus pulposus contained mainly chondrocyte-like cells, whereas the non-degenerated nucleus pulposus of NCD dogs mainly contained notochordal cells. The histopathological changes in degenerated discs were similar in CD and NCD dogs and resembled chondroid metaplasia. Fibrocytes were not seen in the nucleus pulposus, indicating that fibrous degeneration of the IVD was not present in any of the evaluated grades of degeneration. In conclusion, intervertebral disc degeneration was characterized by chondroid metaplasia of the nucleus pulposus in both NCD and CD dogs. These results revoke the generally accepted concept that NCD and CD dogs suffer from a different type of IVD degeneration, in veterinary literature often referred to as chondroid or fibroid degeneration, and we suggest that chondroid metaplasia should be used to describe the tissue changes in the IVD in both breed types.


Author(s):  
Sheng-Long Ding ◽  
Tai-Wei Zhang ◽  
Qi-Chen Zhang ◽  
Wang Ding ◽  
Ze-Fang Li ◽  
...  

AbstractNight shift workers with disordered rhythmic mechanical loading are more prone to intervertebral disc degeneration (IDD). Our results showed that circadian rhythm (CR) was dampened in degenerated and aged NP cells. Long-term environmental CR disruption promoted IDD in rats. Excessive mechanical strain disrupted the CR and inhibited the expression of core clock proteins. The inhibitory effect of mechanical loading on the expression of extracellular matrix genes could be reversed by BMAL1 overexpression in NP cells. The Rho/ROCK pathway was demonstrated to mediate the effect of mechanical stimulation on CR. Prolonged mechanical loading for 12 months affected intrinsic CR genes and induced IDD in a model of upright posture in a normal environment. Unexpectedly, mechanical loading further accelerated the IDD in an Light-Dark (LD) cycle-disrupted environment. These results indicated that intrinsic CR disruption might be a mechanism involved in overloading-induced IDD and a potential drug target for night shift workers.


2000 ◽  
Vol 122 (3) ◽  
pp. 245-251 ◽  
Author(s):  
Anthony E. Baer ◽  
Lori A. Setton

Cells of the intervertebral disc exhibit spatial variations in phenotype and morphology that may be related to differences in their local mechanical environments. In this study, the stresses, strains, and dilatations in and around cells of the intervertebral disc were studied with an analytical model of the cell as a mechanical inclusion embedded in a transversely isotropic matrix. In response to tensile loading of the matrix, the local mechanical environment of the cell differed among the anatomic regions of the disc and was strongly influenced by changes in both matrix anisotropy and parameters of cell geometry. The results of this study suggest that the local cellular mechanical environment may play a role in determining both cell morphology in situ and the inhomogeneous response to mechanical loading observed in cells of the disc. [S0148-0731(00)00603-8]


Bone Research ◽  
2022 ◽  
Vol 10 (1) ◽  
Author(s):  
Zuqiang Wang ◽  
Hangang Chen ◽  
Qiaoyan Tan ◽  
Junlan Huang ◽  
Siru Zhou ◽  
...  

AbstractThe intervertebral disc (IVD) is the largest avascular tissue. Hypoxia-inducible factors (HIFs) play essential roles in regulating cellular adaptation in the IVD under physiological conditions. Disc degeneration disease (DDD) is one of the leading causes of disability, and current therapies are ineffective. This study sought to explore the role of HIFs in DDD pathogenesis in mice. The findings of this study showed that among HIF family members, Hif1α was significantly upregulated in cartilaginous endplate (EP) and annulus fibrosus (AF) tissues from human DDD patients and two mouse models of DDD compared with controls. Conditional deletion of the E3 ubiquitin ligase Vhl in EP and AF tissues of adult mice resulted in upregulated Hif1α expression and age-dependent IVD degeneration. Aberrant Hif1α activation enhanced glycolytic metabolism and suppressed mitochondrial function. On the other hand, genetic ablation of the Hif1α gene delayed DDD pathogenesis in Vhl-deficient mice. Administration of 2-methoxyestradiol (2ME2), a selective Hif1α inhibitor, attenuated experimental IVD degeneration in mice. The findings of this study show that aberrant Hif1α activation in EP and AF tissues induces pathological changes in DDD, implying that inhibition of aberrant Hif1α activity is a potential therapeutic strategy for DDD.


Author(s):  
Xin Gao ◽  
Weiyong Gu

Abstract Intervertebral disc (IVD) degeneration may cause low back pain which has a tremendous impact on the society and economy in the United States. It is important to quantitatively and qualitatively evaluate its pathophysiology in order to diagnose and treat disc degeneration. Recently, we have developed a multiphasic computational model for investigating cell mediated disc degeneration as well as exploring new strategies for disc therapies. The objective of this study was to verify this new computational model according to the guidelines of ASME V&V40. The model was discretized with finite element method and implemented in COMSOL Multiphysics. Several benchmark problems and method of manufactured solutions (MMS) were used to verify the numerical implementation. For all the benchmark problems tested, the numerical results were in excellent agreement with those analytical solutions or other numerical solutions. In addition, the observed convergence rates of primary unknowns obtained with MMS were in excellent agreement with theoretical convergence rates. This study showed that our model has been verified and found no evidence of coding errors.


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