Intervertebral Disc Degeneration Research Articles

"Elucidating the immunomodulatory role of endocannabinoids in intervertebral disc degeneration".

The endocannabinoid system (ECS) has been well-established to play a crucial role in the regulation of several physiological processes as well as many inflammatory disease conditions. However, its role in intervertebral disc degeneration has been least explored. We aim to investigate the immunomodulatory role of endocannabinoids in regulating IVD health. The study population included 20 healthy volunteers (controls) and 40 patients with disc degeneration (disease group) (20 Modic and 20 Non Modic). 16S metagenome sequencing of the V3-V4 region was performed for the DNA extracted from NP tissue samples of both control and disease groups. Sequencing was carried out using the Novaseq 6000 platform using 250bp paired-end chemistry. A global metabolic profile was obtained using the uHPLC system coupled with Q Exactive Plus Hybrid Quadrupole-Orbitrap mass spectrometer. Our study revealed a higher prevalence of gram-negative bacteria, particularly opportunistic pathogens like Pseudomonas, in diseased discs (71-81%) compared to healthy controls (54%). Further investigation using metabolomics identified significant changes in the lipid profiles of diseased discs. We found that the signalling molecules of the ECS, 2-arachidonylglycerol (2-AG) and N-arachidonoylethanolamine (AEA), were significantly lower in diseased discs compared to controls (Log2FC -2.62 for 2-AG and -3.15 for AEA). Conversely, pro-inflammatory metabolites like LTA4, HPETE, HETE, and Prostaglandin G2 were elevated in diseased discs, with a Log2 fold increase greater than 2.5. The study reveals that the endocannabinoid metabolites (2-AG and AEA) of the ECS could be a significant molecule influencing susceptibility to infection and inflammation within the intervertebral discs, which could be a potential target for improving disc health. Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Melatonin attenuates degenerative disc degression by downregulating DLX5 via the TGF/Smad2/3 pathway in nucleus pulposus cells.

Intervertebral disc degeneration (IVDD) is the leading cause of low back pain, and apoptosis plays a key role in its pathogenesis. Distal-less homeobox 5 (Dlx5) has been reported to induce cell apoptosis. Melatonin, as a powerful antiapoptotic agent, has been widely reported. This study aimed to investigate the role of DLX5 in the pathogenesis of IVDD and the potential therapeutic role of melatonin in targeting DLX5 in IVDD. Western blotting, RT-qPCR, immunohistochemistry, si-DLX5, Ex-DLX5, flow cytometry, and immunofluorescence were used to examine the regulatory effect of DLX5 on apoptosis. Therapeutic efficacy was assessed by the intraperitoneal injection of melatonin into IVDD mice. The expression level of DLX5 is significantly increased in IVDD, and the expression levels were positively correlated with the grade of IVDD. DLX5 was significantly upregulated in TNF-α-induced degenerative NP cells. Degenerative NP cells transfected with si-DLX5 exhibited significantly less apoptosis than control cells. Melatonin significantly alleviated IVDD in surgically induced IVDD model mice. The results revealed that the expression of DLX5 was positively correlated with the severity of IVDD and that melatonin ameliorated DLX5-induced apoptosis and extracellular matrix imbalance by inhibiting the TGF-β/Smad signaling pathway. This study may provide therapeutic strategies to alleviate inflammation-induced apoptosis IVDD-associated inflammation-induced apoptosis. DLX5 plays an important role in IVDD progression by promoting apoptosis, and melatonin represents a promising therapeutic strategy for alleviating IVDD-associated inflammation and apoptosis.

PH-Responsive Modified HAMA Microspheres Regulate the Inflammatory Microenvironment of Intervertebral Discs.

Currently, intervertebral disc (IVD) degeneration is believed to lead to local accumulation of lactic acid in the IVD, a decrease in pH, activation of the inflammatory pathway, and continued destruction of homeostasis of the IVD. To address these issues, the intelligent and accurate release of drugs is particularly important. In this study, acid-sensitive release methacrylated hyaluronic acid (HAMA) microspheres were constructed by using microfluidic technology, which can be used as a targeted drug delivery system for intervertebral disc degeneration (IVDD) through Schiff base chemical bonding on the surface of the microspheres to achieve intelligent drug release. Interleukin-1 receptor antagonist (IL-1 Ra) is a naturally occurring anti-inflammatory antagonist of the interleukin-1 family of pro-inflammatory cytokines. Despite its outstanding broad-spectrum anti-inflammatory effects, IL-1 Ra has a short biological half-life (4-6 h). The slow-release performance of IL-1 Ra can be greatly improved using bovine serum albumin nanoparticles (BNP). In addition, the modified HAMA microspheres exhibited good injectability and porosity, and efficient and uniform loading of nanoparticles was achieved via the Schiff base bond. The inflammatory microenvironment can be significantly reversed by transporting the modified HAMA microspheres-BNPs (Modified MS) to the degenerative nucleus pulposus.

Assessment of the Concentration of Transforming Growth Factor Beta 1–3 in Degenerated Intervertebral Discs of the Lumbosacral Region of the Spine

The purpose of this study was to evaluate the feasibility of using the expression profile of transforming growth factor beta (TGF-β-1-3) to assess the progression of L/S spine degenerative disease. The study group consisted of 113 lumbosacral (L/S) intervertebral disc (IVD) degenerative disease patients from whom IVDs were collected during a microdiscectomy, whereas the control group consisted of 81 participants from whom IVDs were collected during a forensic autopsy or organ harvesting. Hematoxylin and eosin staining was performed to exclude degenerative changes in the IVDs collected from the control group. The molecular analysis consisted of reverse-transcription real-time quantitative polymerase chain reaction (RT-qPCR), an enzyme-linked immunosorbent assay (ELISA), Western blotting, and an immunohistochemical analysis (IHC). In degenerated IVDs, we noted an overexpression of all TGF-β-1-3 mRNA isoforms with the largest changes observed for TGF-β3 isoforms (fold change (FC) = 19.52 ± 2.87) and the smallest for TGF-β2 (FC = 2.26 ± 0.16). Changes in the transcriptional activity of TGF-β-1-3 were statistically significant (p < 0.05). Significantly higher concentrations of TGF-β1 (2797 ± 132 pg/mL vs. 276 ± 19 pg/mL; p < 0.05), TGF-β2 (1918 ± 176 pg/mL vs. 159 ± 17 pg/mL; p < 0.05), and TGF-β3 (2573 ± 102 pg/mL vs. 152 ± 11 pg/mL) were observed in degenerative IVDs compared with the control samples. Determining the concentration profiles of TGF-β1-3 appears to be a promising monitoring tool for the progression of degenerative disease as well as for evaluating its treatment or developing new treatment strategies with molecular targets.

Single-cell sequencing reveals cellular heterogeneity of nucleus pulposus in intervertebral disc degeneration

The nucleus pulposus (NP) plays a vital role in intervertebral disc degeneration (IVDD). Previous studies have revealed cellular heterogeneity in NP tissue during IVDD progression. However, the cellular and molecular alterations of diverse cell clusters during IVDD remain to be fully elucidated. NP tissues were isolated from patients with different grades of IVDD undergoing discectomy, and then subjected to single-cell RNA sequencing (scRNA-seq). Cell subsets were identified based on unbiased clustering of gene expression profiles. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to determine the molecular features of diverse cell clusters. Monocle analysis was used to illustrate the differentiation trajectories of chondrocytes. Additionally, CellPhoneDB analysis revealed potential interactions between chondrocytes and other cells during IVDD. Based on the expression profiles of 47,610 individual cells, eight putative clusters including chondrocytes, endothelial cells, fibroblasts, macrophages, mural cells, osteoclasts, proliferating stromal cells and T cells were identified. The chondrocyte cluster was classified into three subsets, C1-C3, which were associated with stress-resistance, fibrosis and inflammatory responses, respectively. Pseudo-time trajectories suggested that chondrocytes gradually differentiated into fibroblasts during IVDD. Immune cells including cDC2s, macrophages and monocytes were identified. Further analysis showed that chondrocytes might communicate with immune cells via the MIF, TNFSF9, SPP1 and CCL4L2 signaling pathways. In addition, we found that invading endothelial cells might interact with chondrocytes through the COL4A1, CXCL12, VEGFA and SEMA3E signaling pathways. Our results reveal the cellular complexity and phenotypic characteristics of NP tissues at single-cell resolution, which will contribute to the in-depth investigation of preventative and regenerative strategies for IVDD.

S1P regulates intervertebral disc aging by mediating endoplasmic reticulum-mitochondrial calcium ion homeostasis.

As the aging process progresses, age-related intervertebral disc degeneration (IVDD) is becoming an emerging public health issue. Site-1 protease (S1P) has recently been found to be associated with abnormal spinal development in patients with mutations and has multiple biological functions. Here, we discovered a reduction of S1P in degenerated and aging intervertebral discs, primarily regulated by DNA methylation. Furthermore, through drug treatment and siRNA-mediated S1P knockdown, nucleus pulposus cells were more prone to exhibit degenerative and aging phenotypes. Conditional KO of S1P in mice resulted in spinal developmental abnormalities and premature aging. Mechanistically, S1P deficiency impeded COP II-mediated transport vesicle formation, which leads to protein retention in the endoplasmic reticulum (ER) and subsequently ER distension. ER distension increased the contact between the ER and mitochondria, disrupting ER-to-mitochondria calcium flow and resulting in mitochondrial dysfunction and energy metabolism disturbance. Finally, using 2-APB to inhibit calcium ion channels and the senolytic drug dasatinib and quercetin (D + Q) partially rescued the aging and degenerative phenotypes caused by S1P deficiency. In conclusion, our findings suggest that S1P is a critical factor in causing IVDD in the process of aging and highlight the potential of targeting S1P as a therapeutic approach for age-related IVDD.

Effect of chondroitin sulfate and bone marrow-derived mesenchymal stem cells on intervertebral disc degeneration treatment in rabbits

The present study evaluated the influence of bone marrow-derived stem cells (BM-SC) and chondroitin sulfate (CS) on histological changes in intervertebral disc (IVD). A randomized clinical trial was conducted, thirty-six healthy New Zealand rabbits were randomly distributed into four different groups (n=9): con-trol group (A), stem cell group (B), chondroitin sulfate group (C), and associa-tion of stem cells with chondroitin sulfate group (D). All animals underwent the experimental disc degeneration procedure. Group A received two intradiscal applications of DEM (Dulbecco’s modified eagle’s medium), one and two weeks after intervertebral disc degeneration (IVDD), while group B received two intradiscal applications of 1.2 x 106 BM-SC at the same time interval as group A. After IVDD, group C received eight subcutaneous applications of CS at a dose of 5 mg/kg, one application every seven days. In contrast, group D received the association of the techniques used in groups B and C. Sixty days after the end of the interventions, all animals were euthanized, then the crani-ocaudal thickness of the IVD was measured, and IVDD was classified in scores according to the histological grading model. All groups that received CS had thicker IVDs, and all the treated groups presented better scores on several items and a better overall score. It was possible to conclude that in the species studied, the isolated use of CS or BM-SC was statistically significant in improv-ing the histopathological aspects of IVDD, however, the combination of treat-ments did not prove to be more efficient.

Stem Cell Membrane-Camouflaged Biomimetic Nanoparticles Inhibiting Leptin Pathway for Intervertebral Disc Degeneration Therapy.

Leptin, a kind of adipokine, with its receptor in which the long isoform plays a crucial role in signal transduction, has been identified in intervertebral disc (IVD) tissues, especially showing an increased expression in degenerated discs. Initially identified as a metabolic sensor, leptin has recently been found able to regulate inflammation into imbalance, which favors catabolic degradative processes, thus contributing to progressive intervertebral disc degeneration (IDD). Therefore, efficiently inhibiting the leptin pathway may provide a new strategy to treat IDD. In this study, we introduced an innovative drug delivery system (DDS) that employs stem cell membranes (SCM) to encapsulate (Zeolitic imidazolate frameworks-8) ZIF-8 nanoparticles. These nanoparticles are used to transport a plasmid containing shRNA targeting the leptin receptor (LEPR), with the aim of facilitating repair in IDD. The regenerative performances of this DDS in IDD were verified through a combination of the in vitro western blot and immunofluorescence with the in vivo radiologic examination and histological staining. The DDS demonstrated excellent cell adhesion properties and gene transfection efficiency in vitro, along with impressive treatment outcomes in vivo. Both in vitro and in vivo studies revealed that the DDS effectively reduced leptin receptor expression and alleviated the inflammatory environment, thereby promoting regeneration in degenerated IVDs. We propose that the DDS represents a promising novel approach for treating IDD and may also be beneficial for other degenerative diseases linked to leptin pathway dysfunction.

The muscle-intervertebral disc interaction mediated by L-BAIBA modulates extracellular matrix homeostasis and PANoptosis in nucleus pulposus cells.

Upon engaging in physical activity, skeletal muscle synthesizes myokines, which not only facilitate crosstalk with various organs, including the brain, adipose tissue, bone, liver, gut, pancreas, and skin but also promote intramuscular signaling. Crosstalk is vital for maintaining various physiological processes. However, the specific interactions between skeletal muscle and intervertebral discs remain largely unexplored. β-Aminoisobutyric acid (BAIBA), an exercise-induced myokine and a metabolite of branched-chain amino acids in skeletal muscle, has emerged as a key player in this context. Our study demonstrated that exercise significantly elevates BAIBA levels in skeletal muscle, plasma, and nucleus pulposus (NP) tissues. Moreover, exercise enhances extracellular matrix (ECM) synthesis in NP tissues and upregulates L-BAIBA synthase in skeletal muscle. Both in vivo and in vitro evidence revealed that L-BAIBA impedes PANoptosis and ECM degradation in NP cells by activating the AMPK/NF-κB signaling pathway. These findings suggest that exercise, coupled with the resulting increase in L-BAIBA, may serve as an effective intervention to decelerate the progression of intervertebral disc degeneration (IDD). Consequently, L-BAIBA, which originates from skeletal muscle, is a promising new therapeutic approach for IDD.

The Impact of Changes in Paraspinal Muscle Tissue on Lumbar Percutaneous Intradiscal Radiofrequency Therapy

Background/Objectives: This study aimed to assess whether fatty changes in paraspinal muscle tissue negatively affect pain relief and functional outcomes, measured by the Oswestry Disability Index (ODI), in patients undergoing intradiscal bipolar radiofrequency thermocoagulation for lumbar degenerative disc (LDD) disease. Fatty changes in paraspinal muscles, often associated with sarcopenia, are known to negatively influence treatment outcomes. However, there is limited research on how these changes affect pain and functional capacity following intradiscal procedures. Methods: In this study, data from 59 patients treated for LDD were analyzed. Pain severity was measured using the Numerical Rating Scale (NRS), and the ODI was recorded before the procedure and at 1, 3, and 6 months post-procedure. Fatty changes in the paraspinal muscle tissue were evaluated using the Goutallier classification based on pre-procedure T2-weighted MRI scans, while disc degeneration was assessed using the Pfirrmann classification. Results: The results showed significant positive correlations between the Goutallier and Pfirrmann classifications and pain levels at all time points post-procedure (p < 0.05). Notably, the relationship between NRS scores and Goutallier classification was stronger than that with Pfirrmann classification (p < 0.05). ODI scores were also significantly correlated with both Goutallier and Pfirrmann classifications at each time point, with a stronger association observed between ODI and Goutallier classification than with NRS (p < 0.05). Conclusions: These findings suggest that fatty changes in the paraspinal muscle tissue may significantly influence treatment outcomes and should be considered during pre-treatment evaluations. Further research is needed to explore this relationship more comprehensively.

Causal effects of plasma proteome on intervertebral disc degeneration: a comprehensive mendelian randomization study.

Intervertebral disc degeneration (IVDD) considerably impacts global disability and quality of life. Although potential links between plasma proteins and IVDD exist, their causal correlation remains undefined. This study explored the causal links between plasma proteins and IVDD employing genome-wide association study data. For this observational study, summary statistics for plasma proteins were derived from an Icelandic population, paralleled with genome-wide data on IVDD obtained from the FinnGen consortium. Using two-sample Mendelian randomization, we assessed the causal relationship between 4,907 plasma proteins and IVDD. Standard sensitivity analyses encompassing heterogeneity, pleiotropy, and leave-one-out cross-validation tests confirmed the stability and robustness of the findings. Subsequently, through Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, and protein interaction analyses, we delved into the functional interrelation among identified plasma proteins. A causal association with IVDD was identified for 47 plasma proteins; myoneurin, intersectin 1, and eukaryotic translation initiation factor 4 gamma 3 maintained significant correlations post multiple correction tests (P < 1.02 × 10- 5), influencing IVDD development positively. GO/KEGG pathway analyses confirmed that multiple pathways may be involved in IVDD development. The study underscores the causal correlation between plasma protein levels and IVDD risk. These identified proteins could emerge as unique biomarkers for IVDD, contributing to its predictive measures. The findings further our understanding of IVDD pathomechanisms and prospective therapeutic targets.

CILP-2 expression in the intervertebral discs of patients with lumbar radiculopathy

BackgroundIntervertebral disc (IVD) degeneration (IVDD) is one of the main causes of low back pain. One of the most important features of IVDD is the loss of extracellular matrix (ECM) with its structural components. Cartilage intermediate layer proteins (CILPs), minor glycoproteins residing in ECM, have been found to be increased in IVD as degeneration and aging progresses. The aim of the present study was to evaluate the expression of CILP-2 in the IVD of patients with lumbar radiculopathy.MethodsThe IVD samples were collected from 25 patients during spinal surgery (interlaminectomy, herniated disc removal). The control IVD samples were obtained from nine patients who underwent lateral corpectomies in the thoracic region. CILP-2 expression was detected by immunohistochemistry. The patients were divided into two groups – aged under or over 50 years. A standardized clinical examination with assessment of radicular signs and deficits was performed. Subjective disability and pain were assessed using the visual analogue scale and Oswestry Disability Index (ODI). The pre-operative MRI was graded for the degree of IVD degeneration by Pfirrmann grading system. IVD samples obtained during operations were subjected to the standardized histopathological analysis applying modified Boos classification. The data were analysed by t-test, Mann-Whitney U-test, and Spearman correlation test.ResultsBoth histopathology scores and Pfirrmann grades did not differ between patients’ groups. Also, no correlations were found between histopathology and Pfirrmann grades, neither were any differences seen when correlating both grades to ODI, back pain or leg pain scores. CILP-2 staining was noted in all studied samples, notably strong staining was seen around large cell clusters. However, no differences in CILP-2 staining were seen between the age groups of patients. No correlations were found between CILP-2 staining and Pfirrmann grades. Grading of CILP-2 immunostaining in nine control patient samples resulted in significantly lower values. The difference is statistically significant (P = 0.002) compared to CILP-2 staining scores of all 25 patients’ samples.ConclusionIn this study, we detected increased CILP-2 expression in the human IVD as compared to the control group patients. CILP-2 can be a possible IVDD marker; however, as knowledge about the role of CILP-2 is limited, further studies are required.

Comparison of the efficacy of autologous Lp-PRP and Lr-PRP for treating intervertebral disc degeneration: in vitro and in vivo study

BackgroundIntervertebral disc degeneration (IDD) was the most common cause of low back pain. Platelet rich plasma (PRP) has the potential to repair IDD, however, there is still no conclusion on whether Leukocyte-poor platelet rich plasma (Lp-PRP) or Leukocyte-rich platelet rich plasma (Lr-PRP) is better for the treatment of IDD.MethodsFirst, we conducted an in vitro study to compare the effects of autologous Lp-PRP and Lr-PRP on human degenerated nucleus pulposus (NP) cells. Then we verified the in vivo effects of autologous Lp-PRP and Lr-PRP in treating disc degeneration through a rabbit IDD model.ResultsThe in vitro study showed both autologous Lp-PRP and Lr-PRP can promote the cell proliferation, the synthesis of COL II and Aggrecan of human degenerated NP cells, while Lp-PRP are better than Lr-PRP (P<0.05). In addition, only Lp-PRP can inhibit the apoptosis of human degenerated NP cells (P<0.05), whereas Lr-PRP activates the catabolism on the contrary (P<0.05). Further, the in vivo study through the rabbit IDD model verified that autologous Lp-PRP has better effects than autologous Lr-PRP in repairing IDD according to X-ray, MRI, histological, and immunohistochemical assessment (P<0.05, respectively). And the caspase-3 IHC results also showed that only autologous Lp-PRP treatment could inhibit apoptosis of NP cells in the rabbit IDD model (P<0.05).ConclusionCombining in vivo and in vitro studies, the present study confirmed that autologous Lp-PRP has a better effect than autologous Lr-PRP in repairing IDD, which may be due to the inflammatory factors (TNFα, IL-1β, etc.) in Lr-PRP antagonizing part of the repair effects and promoting the catabolism additionally. Therefore, our findings suggest that Lp-PRP may provide better results than Lr-PRP for treating IDD. Further randomized clinical trials will provide evidence to guide practice.

Efficacy of Stand-Alone Anterior Lumbar Interbody Fusion With PEEK Cages, BMP-2, and Allografts for Treating Discogenic Low Back Pain: Assessing Clinical and Radiographic Outcomes.

Chronic low back pain secondary to degenerative disc disease is a significant public health issue worldwide, contributing to substantial health care burdens and patient disability. Anterior lumbar interbody fusion (ALIF) has emerged as a promising surgical solution, offering benefits such as disc height restoration, reduced neural compression, and improved spinal alignment. This study evaluates the efficacy of stand-alone ALIF using polyetheretherketone (PEEK) cages, structural femoral head allografts, and recombinant human bone morphogenetic protein-2 (rhBMP-2) in treating discogenic low back pain caused by degenerative disc disease. This prospective case series study included 1335 patients who underwent stand-alone ALIF by a single surgeon. The surgical construct involved PEEK cages with structural femoral allograft dowels and rhBMP-2, supplemented by anterior fixation. Patient-reported outcome measures, including the visual analog scale for back and leg pain, the Oswestry Disability Index, the Roland-Morris Disability Questionnaire, and patient satisfaction, were monitored over 12 months. The overall fusion rate was 99.6%, with pseudoarthrosis occurring in 0.2% of patients. Lower fusion rates were observed in patients older than 65 years and those using the Brantigan cage. Significant improvements were seen in visual analog scale for back and leg pain, Oswestry Disability Index, and Roland-Morris Disability Questionnaire scores from baseline, with most scores exceeding the substantial clinical benefit thresholds. More than 85% of patients reported "Excellent" or "Good" outcomes. Stand-alone ALIF, augmented with rhBMP-2 and structural femoral head allografts, can enhance mechanical stability, fusion rates, and radiographic assessment. This integrated approach achieves successful spinal fusion and positive clinical outcomes for patients with refractory discogenic low back pain. Stand-alone ALIF with PEEK cages, structural femoral head allografts, and rhBMP-2 demonstrates high fusion rates and significant clinical improvements in patients with discogenic low back pain. This approach enhances spinal stability and promotes biological healing, making it a reliable and effective surgical option.

The proteomic landscape of extracellular vesicles derived from human intervertebral disc cells.

Extracellular vesicles (EVs) function as biomarkers and are crucial in cell communication and regulation, with therapeutic potential for intervertebral disc (IVD)-related low back pain (LBP). EV cargo is often affected by tissue health, which may affect the therapeutic potential. There is currently limited knowledge of how the cargo of IVD cell-derived EVs varies with tissue health and how differences in proteomic profile affect the predicted biological functions. Our study purified EVs from human IVD cell conditioned media by size-exclusion chromatography. Nanoparticle tracking analysis was conducted to measure EV size and concentration. Transmission electron microscopy and Western blot were performed to examine EV structure and markers. Tandem mass tag-mass spectrometry was conducted to determine protein cargo. Most EVs were exosomes and intermediate microvesicles with an increasing amount linked to disease progression. Of the proteins detected, 88.6% were shared across the non-degenerate, mildly-degenerate, and degenerate samples. GO and KEGG analyses revealed that cargo from the mildly-degenerate samples was the most distinct, with the proteins in high abundance strongly associated with extracellular matrix (ECM) organization and structure. Shared proteins, highly expressed in the non-degenerate and degenerate samples, showed strong associations with cell adhesion, ECM-receptor interaction, and vesicle-mediated transport, respectively. Our findings indicate that EVs from IVD cells from tissue with different degrees of degeneration share a majority of the cargo proteins. However, the level of expression differs with degeneration grade. Cargo from the mildly-degenerate samples exhibits the most differences. A better understanding of changes in EV cargo in the degenerative process may provide novel information related to molecular mechanisms underlying IVD degeneration and suggest new potential treatment modalities for IVD-related LBP.

The Role of the Bone Morphogenetic Protein Antagonist Noggin in Nucleus Pulposus Intervertebral Disc Cells.

Low back pain (LBP) is a significant global health issue, contributing to disability and socioeconomic burdens worldwide. The degeneration of the human intervertebral disc (IVD) is a critical factor in the pathogenesis of LBP. Recent studies have emphasized the significance of a specific set of genes and extracellular matrix (ECM) in IVD health. In particular, Noggin has emerged as a critical gene due to its high expression levels in healthy nucleus pulposus cells (NPCs) observed in our previous research. In this study, it was hypothesized that decreased Noggin expression in NPCs is associated with IVD degeneration and contributes to LBP development. A lentivirus-mediated RNAi was applied to knock down Noggin expression in primary NPCs from six human donors. The NPCs after transduction were evaluated through cell viability analysis, XTT assay, and cell apoptosis analyses. After two weeks, a colony formation assay was used to examine the anchor-independent growth ability of transduced cells. At the transcript level, anabolic and catabolic markers were quantified using RT-qPCR. The results demonstrated that lentivirus-mediated downregulation of Noggin significantly inhibited cell proliferation, reduced cell viability, and suppressed colony formation, while inducing apoptosis in human NPCs in vitro. Notably, it disrupted cellular anabolic processes and promoted catabolic activity in human NPCs post-transduction. Our findings indicated that the degeneration of human IVD is possibly related to decreased Noggin expression in NPCs. This research provides valuable insights into the role of Noggin in IVD homeostasis and its implications in LBP treatment.

Unveiling the Gut-Disc Axis: How Microbiome Dysbiosis Accelerates Intervertebral Disc Degeneration.

The gut microbiome (GM), often referred to as the second genome of the human body, plays a crucial role in various metabolic processes and mediates the development of numerous diseases. Intervertebral disc degeneration (IDD) is an age-related degenerative spinal disease characterized by the loss of disc height, hydration, and integrity, leading to pain and reduced mobility. Although the pathogenesis of IDD is not fully understood, recent studies suggest that dysbiosis of the gut microbiome may accelerate the progression of IDD through multiple mechanisms. This article begins by discussing the potential relationship between GM dysbiosis and human diseases, followed by a comprehensive review of the regulatory mechanisms of GM in skeletal diseases within the gut-disc axis framework. Furthermore, it explores three potential pathways through which GM dysbiosis may mediate the development of IDD: immunomodulation, bacterial translocation and colonization, and the decomposition and absorption of intestinal metabolites. These pathways can disrupt disc cell homeostasis and promote degenerative changes. Finally, this paper summarizes for the first time the potential therapeutic approaches for delaying IDD by targeting the gut-disc axis, providing new insights into the pathogenesis and regenerative repair strategies for IDD.

A Novel Multi-Omics approach for Identifying Key Genes in Intervertebral Disc Degeneration

Many different cell types and complex molecular pathways are involved in intervertebral disc degeneration (IDD). We used a multi-omics approach combining single-cell RNA sequencing, differential gene expression analysis, and Mendelian randomization to clarify the underlying genetic architecture of IDD. We identified 1,164 differentially expressed genes (DEGs) across four important cell types associated with IDD using publicly available single-cell datasets. A thorough gene network analysis identified 122 genes that may be connected to programmed cell death, a crucial route in the etiology of IDD. SLC40A1, PTGS2, and GABARAPL1 have been identified as noteworthy regulatory genes that may impede the advancement of IDD. Furthermore, distinct cellular subpopulations and dynamic gene expression patterns were revealed by functional enrichment analysis and pseudo-temporal ordering of chondrocytes. Our results highlight the therapeutic potential of GABARAPL1, PTGS2, and SLC40A1 targeting in the treatment of IDD.

Self-healing hydrogels loaded with Spatholobi Caulis alleviate disc degeneration by promoting autophagy in nucelus pulposus

Intervertebral disc degeneration (IDD) is a common degenerative disease of the spine that has a significant impact on both society and human health. Many studies have confirmed that there is a close relationship between IDD and senescence and apoptosis, and autophagy can combat apoptosis and senescence. Spatholobi caulis (SC) is an herb that contains various active compounds that are effective in tissue repair and regeneration, but it has not been explored in field of IDD. In this study, it was first found that SC can boost autophagy and reduce the apoptosis and senescence of Nucleus pulposus cell (NPCs). However, our animal studies revealed limited absorption of SC. To improve the bioavailability and efficacy of SC, we developed a hydrogel incorporating quaternary ammonium chitosan (QCS) and oxidized starch (OST) as carriers for SC. The QCS-OST/SC hydrogel exhibits excellent compatibility with cells, can be easily injected, and can release SC durably. At the cellular level, the QCS-OST/SC hydrogel enhances cell viability, initiates autophagy and release of the extracellular matrix (ECM), and inhibits cellular senescence and apoptosis. The injection of the QCS-OST/SC hydrogel via microneedles (MNs) into discs had successfully diminished disc degeneration in rats, which shows that this hydrogel has broad potential in the treatment of IDD.

Identification of extracellular matrix proteins in plasma as a potential biomarker for intervertebral disc degeneration.

Recently, there has been significant focus on extracellular matrix proteolysis due to its importance in the pathological progression of intervertebral disc degeneration (IVDD). The present study investigates the circulating levels of extracellular matrix proteins in the plasma of IVDD and determines their potential relevance as biomarkers in disc degeneration. Global proteomic analysis was performed in the plasma samples of 10 healthy volunteers (HV) and 10 diseased subjects (DS) after depletion of highly abundant proteins such as albumin and IgG. We identified 144 and 135 matrix-associated proteins in plasma samples from healthy volunteers (HV) and patients with disc degeneration (DS), respectively. Among these, 49 of the matrix-associated proteins were identical to the proteins found in intervertebral disc (IVD) tissues retrieved from the in-house library. Applying stringent parameters, we selected 28 proteins, with 26 present in DS and 21 in HV. 19 proteins were found common between the groups, two of which-aggrecan (ACAN) and fibulin 1 (FBLN1) - showed statistically significant differences. Specifically, ACAN was up-regulated and FBLN1 was down-regulated in the DS-plasma. In particular, DS-plasma exhibited specific expression of collagen type 2a1 (COL2A1), native to the nucleus pulposus. The distinct presence of collagen type 2a1 and the elevated expression of aggrecan in IVDD plasma may serve as the basis for the development of a potential biomarker for monitoring the progression of disc degeneration.