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Lumbar disc herniation (LDH) is a common degenerative disease of the lumbar spine, which is related to host genetic factors. Our study aimed to explore the association between MIR3142HG polymorphisms and LDH susceptibility. Six SNPs in MIR3142HG from 504 LDH patients and 500 healthy individuals were genotyped by the Agena MassARRAY platform. The relationship between SNPs and LDH susceptibility was evaluated with logistic regression analysis by calculating odds ratios (ORs) and 95% confidence intervals (CIs). The interactions between SNP and SNP were analyzed using the multifactor dimensionality reduction (MDR) method. Our study showed that rs7727115 was related to a decreased susceptibility to LDH. Rs2961920 and rs58747524 were significantly associated with an increased risk of LDH. Stratified analysis showed that rs7727115 reduced the risk of LDH in patients aged > 49 years. Rs17057846, rs2961920, and rs58747524 had a risk-increasing influence on patients aged > 49 years and women. Besides, rs7727115 decreased susceptibility in cases of disc prolapse, while rs2961920 and rs58747524 increased the risk. Rs2431689 increased susceptibility in patients with a single hernia, and rs58747524 correlated with an increased risk in cases of multiple hernias. Moreover, MDR analysis indicated that the combination of rs1582417, rs2431689, rs7727115, rs17057846, rs2961920, and rs58747524 was the best predictive model for LDH. Our study showed that MIR3142HG polymorphisms were significantly associated with LDH risk, which suggests that MIR3142HG polymorphisms play some potential roles in diagnosing LDH., Competing Interests: Declarations. Competing interests: The authors declare no competing interests. Ethics approval and consent to participate: The studies involving human participants were reviewed and approved by the ethics committee of the First Affiliated Hospital of Xi’an Jiaotong University. The participants provided their written informed consent to participate in this study., (© 2024. The Author(s).)

Given that lumbar disc herniation (LDH) is a prevalent spinal condition that causes significant individual suffering and societal costs, the genetic basis of LDH has received relatively little research. Our aim is to increase understanding of the genetic factors influencing LDH. We perform a genome-wide association analysis (GWAS) of LDH in the FinnGen project and in Estonian and UK biobanks, followed by a genome-wide meta-analysis to combine the results. In the meta-analysis, we identify 41 loci that have not been associated with LDH in prior studies on top of the 23 known risk loci. We detect LDH-associated loci in the vicinity of genes related to inflammation, disc-related structures, and synaptic transmission. Overall, our research contributes to a deeper understanding of the genetic factors behind LDH, potentially paving the way for the development of new therapeutics, prevention methods, and treatments for symptomatic LDH in the future., (© 2024. The Author(s).)

Background: Although intervertebral disc degeneration (IVDD) is a critical factor in many spine-related diseases and has an extremely high prevalence in the aging population, the potential pathogenesis remains to be clarified entirely. Immune cells have been found to perform an essential function during the onset and progression of IVDD in recent years. Therefore, we explored the association between immune cell characteristics and IVDD through Mendelian randomization (MR) analysis and further delved into the mediating role of potential metabolites., Methods: Based on the MR analysis, the association of 731 immune cell phenotypes and 1400 metabolites on IVDD were assessed. Single nucleotide polymorphisms were closely associated the expression levels of immune cell characteristics and the concentrations of metabolites and have been used as instrumental variables for deducing them as risk factors or protective factors for IVDD. In addition, mediation analyses have been performed to identify potential metabolite mediators between immune cell characteristics and IVDD., Results: MR analysis identified 27 immune cell phenotypes and 79 metabolites significantly associated with IVDD. In addition, mediation analysis was performed by selecting the immune cell phenotype that most significantly increased the risk of IVDD - CD86 on monocytes. A total of 4 metabolite-mediated mediation relationships were revealed (3 b-hydroxy-5-cholenoic acid, X-22509, N-acetyl-L-glutamine, and N2-acetyl, N6, N6-dimethyllysine)., Conclusions: The findings of this analysis identified underlying association between immune cell phenotypes, metabolite, and IVDD that may serve as predictive and prognostic clinical biomarkers and benefit IVDD pathogenesis research., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Lumbar disc herniation (LDH) is a common clinical spinal disorder, yet its etiology remains unclear. We aimed to explore the role of cuproptosis-related genes (CRGs) and identify potential diagnostic biomarkers. Our analysis involved interrogating the GSE124272 and GSE150408 datasets for differential gene expression profiles associated with CRGs and immune characteristics. Molecular clustering was performed on LDH samples, followed by expression and immune infiltration analyses. Using the WGCNA algorithm, specific genes within CRG clusters were identified. After selecting the most predictive genes from the optimal model, four machine learning models were constructed and validated. This study identified nine CRGs associated with copper-regulated cell death. Two copper-containing molecular clusters linked to death were detected in LDH samples. Elevated expression and immune infiltration levels were found in LDH patients, particularly in CRG cluster C2. Utilizing XGB, five genes were identified for constructing a diagnostic model, achieving an area under the curve values of 0.715. In conclusion, this research provides valuable insights into the association between LDH and copper-regulated cell death, alongside proposing a promising predictive model., (© 2024. The Author(s).)

Background: While intervertebral disc degeneration (IVDD) is crucial in numerous spinally related illnesses and is common among the elderly, the complete understanding of its pathogenic mechanisms is still an area of ongoing study. In recent years, it has revealed that liposomes are crucial in the initiation and progression of IVDD. However, their intrinsic mediators and related mechanisms remain unclear. With the development of genomics, an increasing amount of data points to the contribution of genetics in the etiology of disease. Accordingly, this study explored the causality between liposomes and IVDD by Mendelian randomization (MR) analysis and deeply investigated the intermediary roles of undetected metabolites., Methods: According to MR analysis, 179 liposomes and 1400 metabolites were evaluated for their causal association with IVDD. Single nucleotide polymorphisms (SNPs) are strongly associated with the concentrations of liposomes and metabolites. Consequently, they were employed as instrumental variables (IVs) to deduce if they constituted risk elements or protective elements for IVDD. Furthermore, mediation analysis was conducted to pinpoint possible metabolic mediators that link liposomes to IVDD. The inverse variance weighting (IVW) was the main analytical technique. Various confidence tests in the causality estimates were performed, including consistency, heterogeneity, pleiotropy, and sensitivity analyses. Inverse MR analysis was also utilized to estimate potential reverse causality., Results: MR analysis identified 13 liposomes and 79 metabolites markedly relevant to IVDD. Moreover, the mediation analysis was carried out by choosing the liposome, specifically the triacylglycerol (48:2) levels, which were found to be most notably associated with an increased risk of IVDD. In all, three metabolite-associated mediators were identified (3-methylcytidine levels, inosine 5'-monophosphate (IMP) to phosphate ratio, and adenosine 5'-diphosphate (ADP) to glycine ratio)., Conclusion: The analysis's findings suggested possible causal connections between liposomes, metabolites, and IVDD, which could act as both forecast and prognosis clinical indicators, thereby aiding in the exploration of the pathogenesis behind IVDD., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Chen, Que, Xu, Xiao, Sun, Song, Feng, Lin and Rui.)

Background: There is growing evidence to suggest a potential genetic component underlying the development and progression of lumbar spine diseases. However, the heritability and the concordance rates for the phenotypes requiring surgery for the common spine diseases lumbar spinal stenosis (LSS) and lumbar disc herniation (LDH) are unknown. The aim of this study was to determine the heritability and the concordance rates for LSS and LDH requiring surgery by studying monozygotic (MZ) and dizygotic (DZ) twin pairs., Methods: Patients between 18 and 85 years of age who underwent surgery for LSS or LDH between 1996 and 2022 were identified in the national Swedish spine registry (LSS: 45,110 patients; LDH: 39,272 patients), and matched with the Swedish Twin Registry to identify MZ and DZ twins. Pairwise and probandwise concordance rates, heritability estimates, and MZ/DZ concordance ratios were calculated., Results: We identified 414 twin pairs (92 MZ and 322 DZ pairs) of whom 1 or both twins underwent surgery for LSS. The corresponding number for LDH was 387 twin pairs (118 MZ and 269 DZ pairs). The probandwise concordance rate for LSS requiring surgery was 0.25 (26 of 105) (95% confidence interval [CI], 0.14 to 0.34) for MZ twins and 0.04 (12 of 328) (95% CI, 0.01 to 0.07) for DZ twins. The corresponding values for LDH requiring surgery were 0.03 (4 of 120) (95% CI, 0 to 0.08) and 0.01 (4 of 271) (95% CI, 0 to 0.04), respectively. The probandwise MZ/DZ concordance ratio was 6.8 (95% CI, 2.9 to 21.5) for LSS and 2.3 (95% CI, 0 to 8.9) for LDH. The heritability was significantly higher in LSS compared with LDH (0.64 [95% CI, 0.50 to 0.74] versus 0.19 [95% CI, 0.08 to 0.35])., Conclusions: Our findings suggest that genetic factors may play an important role in the risk of developing LSS requiring surgery, whereas heredity seems to be of less importance in LDH requiring surgery., Level of Evidence: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Disclosure: No external funding was received for this work. The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article ( http://links.lww.com/JBJS/H891 )., (Copyright © 2024 by The Journal of Bone and Joint Surgery, Incorporated.)

Objective: To evaluate the breed-characteristic features of cervical intervertebral disc disease (C-IVDD) and associated vertebral instability in small-breed dogs and to present the concept of intervertebral disc degeneration and associated instability stage, method of diagnosis, treatment and outcomes., Animals: In total, 307 client-owned dogs with C-IVDD treated with spinal cord decompression with or without vertebral stabilization (2000-2021)., Methods: Information on age, sex, affected sites, stabilized sites, diagnostic methods for vertebral instability and outcomes were retrieved. The patient's age, affected sites (cranial vs caudal discs), and frequency of vertebral stabilization were compared in six CD and five NCD breed. Multivariable analyses of the chondrodystrophic (CD) vs non-CD (NCD) groups, and vertebral stabilization (dogs stabilized vs dogs not stabilized) were performed., Results: In total, 222 (72.3%) and 77 (25.1%) were CD and NCD breeds, respectively. Vertebral instabilities were diagnosed based on the survey radiographs with computed tomography/magnetic resonance imaging (n = 2), dynamic myelography (n = 29), intraoperative spinal manipulation (n = 11) or second surgery in dogs with persistent postoperative paraspinal pain (n = 3). Of these dogs, 295 (96.1%) recovered (median follow-up: 8.5 [range, 1-119] months). Significant differences in age, affected sites and frequency of stabilization were noted among the breeds. Older age and frequent vertebral stabilization were the associated factors for the NCD breed dogs. Male dogs, caudal discs affected (C5-T1) and the NCD breed dogs were risk factors for the dogs with vertebral stabilization., Conclusion: Vertebral stabilization is indicated for small-breed dogs with cervical disc-associated vertebral instability., (© 2024 Australian Veterinary Association.)

Percutaneous endoscopic lumbar discectomy (PELD) is one of the main means of minimally invasive spinal surgery, and is an effective means of treating lumbar disc herniation, but its early recurrence is still difficult to predict. With the development of machine learning technology, the auxiliary model based on the prediction of early recurrent lumbar disc herniation (rLDH) and the identification of causative risk factors have become urgent problems in current research. However, the screening ability of current models for key factors affecting the prediction of rLDH, as well as their predictive ability, needs to be improved. Therefore, this paper presents a classification model that utilizes wrapper feature selection, developed through the integration of an enhanced bat algorithm (BDGBA) and support vector machine (SVM). Among them, BDGBA increases the population diversity and improves the population quality by introducing directional mutation strategy and guidance-based strategy, which in turn allows the model to secure better subsets of features. Furthermore, SVM serves as the classifier for the wrapper feature selection method, with its classification prediction results acting as a fitness function for the feature subset. In the proposed prediction method, BDGBA is used as an optimizer for feature subset filtering and as an objective function for feature subset evaluation based on the classification results of the support vector machine, which improves the interpretability and prediction accuracy of the model. In order to verify the performance of the proposed method, this paper proves the performance of the model through global optimization experiments and prediction experiments on real data sets. The accuracy of the proposed rLDH prediction model is 93.49% and sensitivity is 88.33%. The experimental results show that Level of herniated disk, Modic change, Disk height, Disk length, and Disk width are the key factors for predicting rLDH, and the proposed method is an effective auxiliary diagnosis method., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Genetic polymorphism of KIAA1217 has been reported to be associated with lumbar disc herniation (LDH) in different populations such as Japanese population and Finnish population. This study aimed to explore whether the genetic polymorphism of KIAA1217 is functionally associated with LDH in Chinese population., Methods: SNP rs16924573 of KIAA1217 was genotyped in 1272 patients and 1248 healthy controls. The mRNA expression of KIAA1217 in the intervertebral disc was analyzed for 84 patients and 32 controls. The differences of genotype and allele distributions between LDH patients and healthy controls were evaluated using the Chi-square test. One-way ANOVA test was used to compare the relationship between genotypes and tissue expression of KIAA1217., Results: Patients were found to have significantly higher frequency of genotype GG of rs16924573 than the controls (64.2% vs. 52.8%, p<0.001). The frequency of allele G was remarkably higher in the patients than in the controls (79.8% vs. 73.2%, p<0.001), with an OR of 1.45 (95% confidential interval=1.27-1.66). Compared with the controls, LDH patients were observed to have significantly decreased expression of KIAA1217. Patients with genotype GG had remarkably lower mRNA expression of KIAA1217 than those with genotype AG or AA (p=0.01)., Conclusions: SNP rs16924573 of KIAA1217 could be functionally associated with LDH in the Chinese population. More in vivo and vitro experiments need to be carried out to further clarify the regulatory mechanism of functional variants in KIAA1217., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Bone morphogenetic protein 7 (BMP7) can induce skeletal formation, promote the differentiation of chondrocytes and osteoblasts, and ameliorate intervertebral disc degeneration. The study was designed to evaluate the relationship of BMP7 variants to LDH risk in the Chinese Han population. BMP7 variants were genotyped with the Agena MassARRAY system among 690 LDH patients and 690 healthy controls. The odds ratio (OR) and 95% confidence interval (CI) were calculated by logistic regression. Multi-factor dimension reduction (MDR) (version 3.0.2) software was used to evaluate the effect of BMP7 variant-variant interaction on the susceptibility to LDH. Here, the risk-reducing association between rs230189 and LDH occurrence was found ( p  = 0.005, OR = 0.79). Specially, rs230189 was associated with decreased LDH risk in females ( p  = 0.001, OR = 0.60), elder group ( p  = 0.025, OR = 0.76), subjects with BMI < 24 kg/m 2 ( p  = 0.027, OR = 0.48), nonsmokers ( p  = 0.001, OR = 0.66), and nondrinkers ( p  = 0.011, OR = 0.72). Moreover, rs1321862 might be the risk factor for LDH susceptibility among the participants with BMI < 24 kg/m 2 ( p  = 0.024, OR = 1.84). MDR results displayed that rs230189 was the greatest attribution factor on LDH risk in the single-locus model, with an information gain of 0.44%. The present study demonstrated that BMP7 rs230189 g.55771443A>C may play a protective role against LDH risk. Our findings may help to understand the potential mechanism of BMP7 in LDH susceptibility.

Trp3 allele in COL9A3 gene has been widely studied in populations with intervertebral disc disease. We identified a novel pathogenic variant in COL9A3 gene in a pedigree with multiple lumbar disc herniation (LDH). The proband was a 14-year-old boy who developed LDH at the L4/5 and L5/S1 spinal segments. His father, paternal aunt and grandfather were diagnosed with LDH at an age of 35, 30 and 23, respectively. By applying whole exome sequencing, a heterozygous missense variant (c.1150C > T, p.Arg384Trp) in COL9A3 was identified. According to the ACMG guidelines, this variant is predicted to be pathogenic. In addition, prediction tools found COL9A3 protein of this variant a reduced stability, some changed charge properties, and an altered spatial conformation. Findings expanded the mutational spectrum of LDH and contributed to the understanding of COL9A3 in the pathogenesis of LDH., (© 2023. The Author(s).)

Objective: To analyze available literature data on the role of genetic factors in degenerative disc disease., Methodology: We reviewed the PubMed, MEDLINE, Cohrane Library, e-Library databases using the following keywords: degenerative spine lesions, intervertebral disc herniation, pathogenesis, genetic regulation., Results: Searching depth was 2002-2022. We reviewed 84 references. Exclusion criteria: duplicate publications, reviews without detailed description of results, opinions. Finally, we included 43 the most significant studies., Conclusion: There are literature data on proinflammatory cytokines, growth factors and osteodestructive processes in pathogenesis of degenerative disc disease. However, there is only fragmentary information about the role of genetic regulation of these processes. Some factors, such as microRNA, TGF-b, VEGF, MMP are still poorly understood.

Lumbar disc herniation (LDH) is the most common condition associated with low back pain, and it adversely impacts individuals' health. Ferroptosis has recently emerged as a novel factor in the pathogenesis of LDH; however, the specific impacts of ferroptosis on LDH have not been fully elucidated. Ferroptosis-related differentially expressed genes (FRDEGs) were identified from the transcriptomic datasets of LDH. Gene set enrichment analysis (GSEA) was conducted to identify biological mechanism and related pathways. LASSO and SVM-RFE algorithms were applied to detect signature genes. Function of the signature gene was confirmed by RT-qPCR. The CIBERSORT algorithm was used to compare immune infiltration between LDH and normal samples. Correlation analysis between MYB and immune cells was analyzed using the Pearson method. Additionally, we used scRNA-seq to dissect cell clusters and cellular interactions. AUCell scoring was used to analyze the ferroptosis scores of different cell types. We found that MYB, a highly expressed ferroptosis-related gene, was associated with LDH By leveraging bioinformatics analysis. In immune infiltration analysis, the abundance of monocytes and macrophages varied significantly between the LDH group and disc spondylolisthesis (DS) group. MYB was correlated with most immune cells. GSEA revealed MYB was significantly enriched in immune-related pathways. Furthermore, scRNA-seq analysis revealed the presence of eight distinct cell types. AUCell analysis showed that macrophages had a high ferroptosis score. Cell trajectory analysis revealed that chondrocyte 1 was at the beginning of the trajectory, while calcification inhibiting chondrocytes and fibrochondrocytes accumulated along the middle and tail end of the trajectory, respectively. Cell-cell communication analysis identified chondrocyte 1 had an extensive communication network with other clusters and interacted with nucleus pulposus through collagen signaling pathway. Our analysis demonstrated that MYB may be a potential therapeutic target for LDH. This study provides a resource for the orthopedics community that will facilitate additional discoveries directedly toward understanding the pathogenesis process of LDH., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Lumbar disc herniation (LDH) is a complex spinal disease, with multiple genetic polymorphisms being related to its risk. Nevertheless, the role of LINC-PINT polymorphisms in LDH risk has remained unknown. Therefore, this study aimed to investigate the association between LINC-PINT polymorphisms and LDH risk., Methods: DNA was extracted from 504 LDH patients and 500 healthy controls. Three single nucleotide polymorphisms (SNPs) in LINC-PINT were selected and genotyped using Agena MassARRAY. We used logistic regression analysis to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) under multiple genetic models to evaluate the association between LINC-PINT polymorphisms and LDH risk. Haploview 4.2 and SNPStats software were used to evaluate the linkage strength of SNPs and the correlation between haplotypes and LDH risk. The impact of SNP-SNP interactions on LDH risk was analyzed using multi-factor dimensionality reduction (MDR)., Results: Results showed that rs157916 (G vs. A: OR = 1.23, FDR-p = 0.029) and rs7801029 (G vs. C: OR = 1.39, FDR-p = 0.006; GG vs. CC: OR = 2.34, FDR-p = 0.038; recessive: OR = 2.13, FDR-p = 0.045; additive: OR = 1.39, FDR-p = 0.030) were associated with an increased risk of LDH. Furthermore, LINC-PINT rs157916 and rs780129 were found to be significantly associated with LDH risk in males. The "GGG" haplotype was associated with increased LDH risk (OR = 1.41, FDR-p = 0.006). MDR analysis indicated that the interaction between rs7801029 and rs16873842 was associated with an increased risk of LDH (OR = 1.47, p = 0.004). Additionally, there were significant differences in C-reactive protein levels among different genotypes of rs157916 and rs780129 (p < 0.05)., Conclusion: This study suggests that LINC-PINT gene polymorphisms (rs157916 and rs7801029) are considered risk factors for LDH in the Chinese Han population and provide a scientific basis for early screening, prevention, and diagnosis of LDH., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Objective: To observe the effect of acupuncture at "Houxi"(SI3) and "Huantiao"(GB30) on high mobility group box 1(HMGB1) protein and mRNA in spinal nerve trunk(SNT) of rats with lumbar disc herniation(LDH), so as to explore the mechanisms of acupuncture at this paired points on the treatment for LDH., Methods: SD rats were randomly divided into sham operation, model, conventional acupuncture(CA) and paired points(PP) groups (with 8 rats in each group). The LDH model was established by injection of autologous suspension made from rats' own nucleus pulsus into the epidural space. Rats in the CA group received acupuncture treatment at bilateral "Weizhong"(BL40), "Dachangshu"(BL25) and "Shenshu"(BL23), while rats in the PP group received acupuncture at bilateral SI3 and GB30, 30 min each time, once daily for 14 consecutive days. The thermal pain threshold of bilateral hind feet of rats was detected by thermal pain stimulator. The contents of serum IL-1β, IL-6 and IL-8 of rats were detected by ELISA. Western blot and immunofluorescence were used to detect the expression of HMGB1 protein in the lumbar(L)5 SNT of rats. The relative expression of HMGB1 mRNA in L5 SNT was determined by qPCR. HE staining was used to observe the morphological changes of L5 SNT., Results: Compared with the sham operation group, the thermal pain threshold of bilateral hind feet in the model group was decreased ( P <0.05); compared with the model group, the thermal pain threshold of bilateral hind feet in the CA group and the PP group were increased ( P <0.05). The expressions of HMGB1 protein and mRNA in L5 SNT, and the contents of serum IL-1β, IL-6 and IL-8 of rats in the model group were significantly increased( P <0.000 1, P <0.001) in contrast to the sham operation group. The expressions of HMGB1 protein and mRNA in L5 SNT, and the levels of serum IL-1β, IL-6 and IL-8 were significantly decreased ( P <0.01, P <0.000 1, P <0.001, P <0.05) in the CA and PP group, in comparison with those of the model group. Compared with the CA group, the above indexes of rats in the PP group recovered more significantly ( P <0.05, P <0.001, P <0.01, P <0.000 1). The histomorphological results showed scattered and various-sized nerve fibers, vacuolation, a large number of disintegrating myelin sheath and lysed Schwann cells in the model group. Myelin sheaths regeneration, regularly-arranged nerve fibers were seen in the CA group and the PP group, with more obvious histopathological recovery observed in the PP group than the CA group., Conclusion: Acupuncture intervention inhibites the expressions of HMGB1 protein and mRNA in rats with LDH, and further reduces the production of IL-1β, IL-6 and IL-8, which is beneficial to inflammatory response inhibition and pain alleviation. The therapeutic effect of the PP group is more obvious than that of the CA group.

Objective: To observe the effect of acupotomy intervention on the expressions of biglycan(BGN), decorin(DCN) and Caspase-3 in lumbar intervertebral disc of rabbits with lumbar intervertebral disc degeneration (LIDD), so as to explore its possible mechanism in relieving LIDD., Methods: Thirty male Japanese white rabbits were randomly divided into normal, model and acupotomy groups, with 10 rabbits in each group. The LIDD model was established by axial compression method, and magnetic resonance imaging (MRI) was used to judge whether the model was successful or not. After modeling, the acupotomy was applied to lumbar (L)4-L5 spinous process space and bilateral transverse processes for loosening, twice a week for 4 weeks. The structural changes of L4-L5 intervertebral disc were observed by MRI. The morphological changes of lumbar spine were observed by HE staining. The expression of Caspase-3 in nucleus pulposus was observed by immunohistochemistry, and the protein expressions of DCN and BGN in intervertebral disc were detected by Western blot, separatively., Results: After mode-ling, the rabbits showed slow movement, stiff back muscles with cords or nodules, the fibrous ring structure of lumbar intervertebral disc was disordered, the number of nucleus pulposus cells was reduced, and the signal intensity of L4-L5 intervertebral disc was decreased in the model group relevant to the normal group. At the same time, the expression of Caspase-3 in nucleus pulposus was increased significantly ( P <0.05), and the expression levels of DCN and BGN in intervertebral disc were decreased significantly ( P <0.05). After acupotomy treatment, the modeling induced slow movement, stiff back muscles and disordered structure of lumbar intervertebral disc were significantly improved. The number of nucleus pulposus cells was increased, the signal intensity of L4-L5 intervertebral disc was enhanced, the expression of Caspase-3 in nucleus pulposus was decreased significantly ( P <0.05), and the expression levels of DCN and BGN in intervertebral disc were increased significantly ( P <0.05) compared with the model group., Conclusion: Acupotomy intervention can inhibit cell apoptosis, reduce the degradation of extracellular matrix in nucleus pulposus of intervertebral disc, and restore the normal force balance and dynamic balance of lumbar spine, which may be one of its mechanisms underlying improving LIDD.

Purpose: LDH caused by lumbar disc degeneration is associated with genetic factors. However, the role of ADAMTS6 and ADAMTS17 genes in LDH risk is still unknown., Methods: To investigate the interaction between ADAMTS6 and ADAMTS17 variants in the susceptibility of LDH, five SNPs were genotyped in 509 patients and 510 healthy individuals. The experiment used logistic regression to calculate odds ratio (OR) and 95% confidence interval (CI). Multi-factor dimensionality reduction (MDR) was chosen to evaluate impact of interaction of SNP-SNP on susceptibility to LDH., Results: ADAMTS17-rs4533267 is significantly associated with reducing risk of LDH (OR = 0.72, 95% CI = 0.57-0.90, p = 0.005). Stratified analysis indicates that ADAMTS17-rs4533267 is significantly associated with the reducing risk of LDH among participants aged ≤ 48 years old. In addition, we observed that ADAMTS6-rs2307121 was associated with increasing risk of LDH in females. MDR analysis shows that single-locus model composed by ADAMTS17-rs4533267 can be chosen as the best model for predicting susceptibility to LDH (CVC = 10/10, test accuracy = 0.543)., Conclusion: ADAMTS6-rs2307121 and ADAMTS17-rs4533267 are potentially associated with LDH susceptibility. In particular, ADAMTS17-rs4533267 has a strong association with reducing risk of LDH., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: The purpose of this study was to understand potential baseline transcriptional expression differences in paraspinal skeletal muscle from patients with different underlying lumbar pathologies by comparing multifidus gene expression profiles across individuals with either disc herniation, facet arthropathy, or degenerative spondylolisthesis., Methods: Multifidus biopsies were obtained from patients (n = 44) undergoing lumbar surgery for either disc herniation, facet arthropathy, or degenerative spondylolisthesis. Diagnostic categories were based on magnetic resonance images, radiology reports, and intraoperative reports. Gene expression for 42 genes was analysed using qPCR. A one-way analysis of variance was performed for each gene to determine differences in expression across diagnostic groups. Corrections for multiple comparisons across genes (Benjamini-Hochberg) and for between-group post hoc comparisons (Sidak) were applied., Results: Adipogenic gene (ADIPOQ) expression was higher in the disc herniation group when compared to the facet arthropathy group (p = 0.032). Adipogenic gene (PPARD) expression was higher in the degenerative spondylolisthesis group when compared to the disc herniation group (p = 0.013), although absolute gene expression levels for all groups was low. Fibrogenic gene (COL3A1) had significantly higher expression in the disc herniation group and facet arthropathy group when compared to the degenerative spondylolisthesis group (p < 0.001 and p = 0.038, respectively). When adjusted for multiple comparisons, only COL3A1 remained significant (p = 0.012)., Conclusion: Individuals with disc herniation and facet arthropathy demonstrate higher COL3A1 gene expression compared to those with degenerative spondylolisthesis. Future research is required to further understand the biological relevance of these transcriptional differences., (© 2023. The Author(s).)

Objective: To investigate the association between interleukin (IL)-1α (rs1800587), IL-1β (rs1143634) and IL-1 receptor antagonist (RN) variable number tandem repeat polymorphisms, expression levels and lumbar disc disease (LDD)., Methods: All relevant articles were searched from 4 databases including PubMed, Embase, Web of Science and China National Knowledge Infrastructure. Odds ratios (OR) with 95% confidence intervals (CI) were calculated to evaluate the association between IL-1 gene locus polymorphisms (rs1800587 in IL-1α, rs1143634 in IL-1β, variable number tandem repeat in interleukin-1 receptor antagonist) and LDD susceptibility. Statistical analysis was conducted by Review Manager (Revman) 5.31 software (Nordic Cochrane Centre, Cochrane Collaboration, Copenhagen, Denmark). Furthermore, qRT-PCR and immunohistochemistry were performed to evaluate IL-1α, IL-1β and interleukin-1 receptor antagonist expressions in the normal and degenerated disc., Results: A total of 15 case-control studies (1455 cases and 2362 controls) were included in our meta-analysis. The pooled results suggested that IL-1α rs1800587 polymorphism was associated with an increased risk of LDD in overall population (T vs. C, OR = 1.21, 95% CI = 1.04-1.40, P = .01). The subgroup analysis found a significant association between IL-1β rs1143634 polymorphism and LDD in Asian population (T vs. C, OR = 0.61, 95% CI = 0.39-0.96, P = .03). Results of qRT-PCR and immunohistochemistry demonstrated that expressions of IL-1α and IL-1β were significantly increased in the degenerated disc. (all P < .05)., Conclusion: IL-1α rs1800587 and IL-1β rs1143634 polymorphisms were significantly associated with LDD in overall population and in Asian population, respectively. The increased expression levels of IL-1α and IL-1β may be the important risk factors for LDD., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

Lumbar disc herniation (LDH) is a common spinal disease that endangers human health. Genetic factors play a vital role in the progression of LDH. This study aimed to explore the relationship of the MIR31HG polymorphism with LDH risk in the Chinese population. Seven candidate SNPs on MIR31HG in 504 patients with LDH and 503 healthy people were genotyped by Agena MassARRAY platform. Logistic regression was used to calculate the relationship between MIR31HG polymorphism and LDH risk under different genetic models. Multi-factor dimensionality reduction (MDR) analysis was performed to evaluate the SNP-SNP interaction. We found that rs10965059 was significantly associated with a decreased risk of LDH under the dominant (OR = 0.46, 95% CI: 0.34-0.62, P < 0.001), log-additive (OR = 0.59, 95%CI: 0.45-0.76, P < 0.001), and codominant (OR = 0.40, 95%CI: 0.29-0.55, P < 0.001) models in the overall analysis. In the subgroup analyses of age, male, and complications, we found that rs10965059 was associated with a reduced risk of LDH. However, there was no significant correlation between MiR-31HG polymorphisms and risk of LDH in females. In addition, the three SNPs (rs72703442-rs2025327-rs55683539) was mapped to a 26kb LD block with D' >0.96, suggesting a significant linkage disequilibrium presence among each pair SNPs. MDR analysis showed that the best single-locus and multi-locus models for the prediction of LDH risk were rs10965059 and seven-locus models, respectively, and both of them increased LDH risk. Our results shown that in the Chinese Han population, the MIR31HG polymorphism rs10965059 was involved in a risk to symptomatic LDH, which provides a scientific basis for early screening, prevention, diagnosis and treatment of local LDH high-risk populations.

Background: The miR-21 has been implicated in the process of neuroinflammation as well as neuropathic pain., Objectives: To explore the relationship between the plasma and local expression of miR-21 with disease severity of lumbar disc herniation (LDH) patients with sciatic pain., Material and Methods: Ninety-two LDH patients with sciatic pain and 25 scoliosis patients as painless controls were enrolled in the current study. Samples from nucleus pulposus (NP), annulus fibrosus (AF) and soft tissues around nerve root (STANR) were obtained. The plasma and local expressions of miR-21 were detected with quantitative reverse transcription polymerase chain reaction (qRT-PCR). The visual analogue scale (VAS) for lumbar pain and leg pain, and Japanese Orthopedic Association (JOA) score were selected to evaluate the clinical severity. The degree of disc compression on nerve was evaluated using the Pfirrmann grade based on the magnetic resonance imaging (MRI) findings. For the convenience of analysis, LDH patients with sciatic pain were classified into a severe pain (SP) group (VAS ≥ 6) and a mild-moderate pain (MP) group (VAS < 6). Receiver operating characteristic (ROC) curve analysis was performed to detect the potential diagnostic power of miR-21 with regard to the Pfirrmann grade., Results: There were no significant differences in serum miR-21 expressions among SP LDH patients, MP LDH patients and scoliosis painless controls. Local expressions of miR-21 in STANR, AF and NP were all drastically upregulated in the SP group in comparison with the MP group and scoliosis painless group. Local NP and STANR miR-21 expressions were positively associated with the Pfirrmann grade. Local miR-21 expressions in STANR and AF were positively associated with VAS score and negatively related to JOA score. The ROC curve analysis indicated that both STANR and AF miR-21 expressions may serve as significant diagnostic factors for the Pfirrmann grade., Conclusions: Increased local miR-21 expressions are linked with clinical severity of LDH in patients with sciatic pain.

Objective: To explore the mechanisms of dorsal root ganglia and spinal microglia cascade cross in electroacupuncture (EA) analgesia in the treatment of lumbar disc herniation., Methods: A rat model of lumbar disc herniation (LDH) was established, EA was administered at Huantiao (GB30) acupoint 30 min once a day, for 3 d. Before and after modeling, and after EA, mechanical allodynia thresholds were detected. Hyperpolarization-activated cyclic nucleotide-gated 2 (HCN2) in dorsal root ganglia was detected by quantitative polymerase chain reaction (qPCR) and Western blot. C-X3-C motif chemokine ligand 1 (CX3CL1) and activity of microglia in spinal cord was observed separately qPCR and immunofluorescence staining., Results: The mechanical allodynia threshold of the right planta of model rats was significantly reduced ( < 0.01), EA increased the mechanical pain threshold of rats ( < 0.01), and decreased HCN2 mRNA, and protein expression, reduced the expression of CX3CL1 and the activation of microglia. ZD7288 (a blocker of HCN channel) reduced the analgesic effect of EA from 1.83 ± 0.84 to 0.74 ± 0.20 ( < 0.05), and the expression of CX3CL1 in the spinal cord decreased from 0.52 ± 0.11 to 0.15 ± 0.05 ( < 0.01)., Conclusion: EA analgesia on the radicular pain of LDH is definite. EA reduced the expression of HCN2 channel in the dorsal root ganglion, thereby decreasing the noxious stimulation entered to microglia in spinal dorsal horn. Our work supports EA is an effective treatment for radicular pain of LDH.

The current experiment was carried out to explore the effect of the miR-146a-mediated TLR4 signaling pathway on the lumbar disc herniation pains. For this aim, a total of 32 rats were divided randomly into 4 groups - the blank group (Group C), Model group (M), miR-146a overexpression group (agomiR-146a group) and negative control group (NC group), with 8 rats in each group. Rats in Group M were prepared for the construction of lumbar disc herniation models, while those in the agomiR-146a group or NC group, in addition to the model construction, would receive the intrathecal injection of agomiR-146a or agomiRNA-146a NC. Thereafter, a series of tests were performed for rats, including the mechanical pain test and heat pain test to measure the pain threshold, RT-PCR to detect the expression of miR-146a, and the transcription of TLR4, IRAK1, TRAF6, IL-6 and TNF-α, Western blot to determine the expression of IRAK1 and TRAF6 and ELISA to determine the expression of IL-6 and TNF-α. Results showed that as compared to the blank group, rats in Group M were more sensitive to the pains, presenting with declines in the thresholds in the pain, and upregulation in the TRL4 signaling pathway (TLR4, IRAK1 and TRAF6) and pro-inflammatory factors, including IL-6 and TNF-α. In comparison with Group M, intrathecal injection of agomiR-146a relieved the pains, with significant upregulation of miR-146a and downregulation of TLR4, IRAK1, TRAF6, IL-6 and TNF-α. Then upregulation of miR-146a could reduce the activity of the TLR4 signaling pathway and the release of pro-inflammatory factors, which may be a potential strategy for the treatment of lumbar disc herniation.

Background Context: There is apparent causality between chronic infection of the intervertebral disc and its degenerative process. Although disc is considered a sterile tissue, collected samples of uninfected patients sent to culture testing resulted positive., Purpose: The purpose of this study was to analyze the microbiome of the intervertebral disc by using and validating the next-generation sequencing (NGS) molecular test, controlled with tissue culture and clinical presentation of patients., Study Design/setting: Prospective study of consecutive patients in a hospital., Patient Sample: Patients with lumbar disc herniation undergoing open microdiscectomy aging 18 to 65 years., Outcome Measures: NGS, tissue culture METHODS: Subjects undergoing open decompression surgery for lumbar disc herniation were consecutively included and clinically followed for one year. Three samples of the excised herniated disc fragment were sent to tissue culture and another sample of the disc was sent to NGS test for microbiome analysis. Control samples of the ligamentum flavum and deep muscle were collected and sent to culture., Results: A total of 17 patients were included. All patients presented negative cultures of the removed disc samples, as well as negative cultures of muscle and yellow ligament. None of the patients evolved to clinical infection one year after surgery, nor presented significant alteration of laboratory markers. NGS mapped a mean of 14,645 (range 6,540 to 27,176) DNA sequences for each disc sample of each patient. There were a total of 45 different bacteria genera remnants with different amount of DNA sequences detected. There was a mean of 8 (range 3-17) different bacterial elements in each sample of intervertebral disc. Three bacteria were present in all disc samples (Herbaspirillum, Ralstonia, and Burkolderia). Although there were a considerable mean number of bacterial sequences mapped in each disc sample, the amount of sequences related to bacteria was low. Cutibacterium acnes elements was not found in any disc microbiome analysis., Conclusions: NGS has been proven to adequately determine bacterial DNA presence within the intervertebral disc. C. acnes was not isolated in culture neither in microbiome analysis of patients with lumbar disc herniation. We cannot confirm disc sterility since, even if it does not cause infection, there is bacterial or remnant DNA in herniated discs., Competing Interests: Declarations of competing interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Two FGF4 retrogenes ( FGF4L1 on chromosome 18 and FGF4L2 on chromosome 12) have been identified to cause dwarfism across many dog breeds. Some breeds are nearly homozygous for both retrogenes (e.g., Dachshunds) and others are homozygous for just one (e.g., Beagles and Scottish Terriers). Since most breeds do not segregate both of these retrogenes, it is challenging to evaluate their individual effects on long bone length and body size. We identified two dog breeds selected for hunting ability, the Alpine Dachsbracke and the Schweizer Niederlaufhund, that segregate both of these retrogenes. Using individual measurements of height at the shoulder, back length, head width, thorax depth and width, and thoracic limb measurements, we evaluated the combined effects of FGF4 retrogenes within these breeds. We applied multivariable linear regression analysis to determine the effects of retrogene copy numbers on the measurements. Copy numbers of both retrogenes had significant effects reducing height at the shoulders and antebrachial length, with FGF4L1 having a much greater effect than FGF4L2 . FGF4L1 alone influenced the degree of carpal valgus and FGF4L2 alone increased head width. Neither retrogene had an effect on thorax width or depth. Selectively breeding dogs with FGF4L1 and without FGF4L2 would likely lead to a reduction in the FGF4L2 -related risk of intervertebral disc herniation while maintaining the reduction in leg length resulting from FGF4L1.

Back pain is a common and debilitating disorder with largely unknown underlying biology. Here we report a genome-wide association study of back pain using diagnoses assigned in clinical practice; dorsalgia (119,100 cases, 909,847 controls) and intervertebral disc disorder (IDD) (58,854 cases, 922,958 controls). We identify 41 variants at 33 loci. The most significant association (OR IDD  = 0.92, P = 1.6 × 10 -39 ; OR dorsalgia  = 0.92, P = 7.2 × 10 -15 ) is with a 3'UTR variant (rs1871452-T) in CHST3, encoding a sulfotransferase enzyme expressed in intervertebral discs. The largest effects on IDD are conferred by rare (MAF = 0.07 - 0.32%) loss-of-function (LoF) variants in SLC13A1, encoding a sodium-sulfate co-transporter (LoF burden OR = 1.44, P = 3.1 × 10 -11 ); variants that also associate with reduced serum sulfate. Genes implicated by this study are involved in cartilage and bone biology, as well as neurological and inflammatory processes., (© 2022. The Author(s).)

Intervertebral disc disease (IVDD) is a common musculoskeletal disease affecting about 5% of all individuals. It is characterized by lumbar disc herniation, which causes nerve root irritation, either mechanically or via inflammatory mediators, and results in radiating pain, known as sciatica. Numerous studies have been conducted to identify the causes and risk factors for IVDD. Lifting heavy loads, torsional stress, and motor vehicle driving are among the best-identified environmental risk factors. However, it has become evident recently from family and twin studies that genetic factors may also be important in IVDD. This hypothesis was strengthened by the identification of two collagen IX alleles associated with sciatica and lumbar disc herniation. In addition, disc degeneration has been shown to be related to an aggrecan gene polymorphism, a Vitamin D receptor and matrix metalloproteinase-3 gene alleles. This review highlights the genetic role and occupational aspects of IVDD., (© 2021 American Association of Clinical Anatomists.)

Background: Osteochondritis dissecans is a condition wherein there is a subchondral bone lesion that causes pain, inflammation, and cartilage damage. Dominant Familial Osteochondritis Dissecans is a rare and severe form of osteochondritis dissecans (OCD). It is caused by heterozygous pathogenic variants in the gene encoding Aggrecan; ACAN. Aggrecan, a proteoglycan, is an essential component of the articular and growth plate cartilage., Methods: Herein, we report three individuals from one family; the proband who presented with short stature, a lower limb bone exostosis, and bilateral knee and elbow OCD at the age of 13 years old. His twin brother presented with isolated short stature and his father with short stature and lumbar disc herniation., Results: Next-generation sequencing of the ACAN gene in the proband identified a frameshift variant which is also present in the brother and father with short stature. The proband was treated surgically with bilateral elbow microfracture, after the failure of conservative therapy., Conclusion: To the best of our knowledge, this is the first patient with an aggrecanopathy who presents with osteochondritis dissecans due to a frameshift variant. This family presents with variable expressivity which might be attributed to modifier genes., (© 2021 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Background: Intervertebral disc degeneration (IDD) is a common and complex condition. Vascular endothelial growth factor (VEGF) is one of the key regulators of angiogenesis and vascular permeability. Nitric oxide (NO) plays a role in various physiological events. The endothelial nitric oxide synthase (eNOS) that catalyses NO generation are crucial for the regulation of NO level. This study aimed to evaluate the association between VEGF/ eNOS gene variants with IDD., Materials and Methods: Two hundred ninety-one subjects (111 IDD patients and 180 controls) were included in the present case-control study. VEGF -2549 insertion/deletion (I/D) and eNOS VNTR variants were analysed by PCR method. The results of this analysis were evaluated for statistical significance., Results: There were no statistically significant differences in genotype and allele distribution of VEGF -2549 I/D/ eNOS VNTR variants between IDD patients and control subjects. We then evaluated the association between the allele frequencies of these variants and clinical features of IDD. Lumber IDD was more common in patients carrying VEGF I/D variant D allele (p < 0.001). Also, patients with lumbar disc herniation, cervical disc herniation, lumbar stenosis, and lumbar IDD had more 4 b allele (p = 0.005, p < 0.001, p < 0.001, and p = 0.03, respectively)., Conclusions: In conclusion, this study demonstrates first time that some clinical characteristics of IDD have been associated with allele frequencies of VEGF -2549 I/D/ eNOS VNTR variants.

Intervertebral disc (IVD) degeneration and its inflammatory microenvironment ultimately led to discogenic pain, which is thought to originate in the nucleus pulposus (NP). In this study, key genes involved in NP tissue immune infiltration in lumbar disc herniation (LDH) were identified by bioinformatic analysis. Gene expression profiles were downloaded from the Gene Expression Omnibus (GEO) database. The CIBERSORT algorithm was used to analyze the immune infiltration into NP tissue between the LDH and control groups. Hub genes were identified by the WGCNA R package in Bioconductor and single-cell sequencing data was analyzed using R packages. Gene expression levels were evaluated by quantitative real-time polymerase chain reaction. The immune infiltration profiles varied significantly between the LDH and control groups. Compared with control tissue, LDH tissue contained a higher proportion of regulatory T cells and macrophages, which are associated with the macrophage polarization process. The most significant module contained three hub genes and four subclusters of NP cells. Functional analysis of these genes was performed, the hub gene expression pattern was confirmed by PCR, and clinical features of the patients were investigated. Finally, we identified TGF-β and MAPK signaling pathways as crucial in this process and these pathways may provide diagnostic markers for LDH. We hypothesize that the hub genes expressed in the specific NP subclusters, along with the infiltrating macrophages play important roles in the pathogenesis of IVD degeneration and ultimately, disc herniation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Wang, He, Liu, Tai, Wang, Zhang and Quan.)

Background : The objective of this study was to determine the role of single nucleotide polymorphisms (SNPs) in interleukin 1 alpha ( IL-1A ), tumor necrosis factor-alpha ( TNF-A ), and vitamin D receptor ( VDR ) genes on the susceptibility to herniated nucleus pulposus (HNP). Methods : Four databases (PubMed, Embase, Cochrane, and Web of Science) were searched as of April 1 st , 2021. Authors, publication year, targeted genes, genotype and allele frequency in each case and control groups were collected. Newcastle-Ottawa scale was used to evaluate the publication quality. The pooled estimates of association of IL-1A -889C>T (rs1800587), TNF-A -238G>A (rs361525), and VDR TaqI (rs731236) and susceptibility to HNP were assessed using Z test and presented as odd ratio (OR) and 95% confidence intervals (95%CI). Results : We screened 3,067 unique studies for eligibility and three, two and nine studies on IL-1A -889C>T, TNF-A -238G>A, and VDR TaqI were included, respectively, in our meta-analysis. The studies consisting 369 HNP cases and 433 controls for IL-1A -889C>T, 252 cases and 259 controls for TNF-A -238G>A and 1130 cases and 2096 controls for VDR TaqI. Our pooled estimates indicated that there was no significant association of those SNPs with the susceptibility to HNP in any genotype, dominant model, recessive model, or allele comparations. Conclusion : Although individual studies suggested the important role of gene expression dysregulation associated with SNPs in IL-1A , TNF-A , and VDR , our data indicated that IL-1A -889C>T, TNF-A -238G>A, and VDR TaqI had weak association with HNP susceptibility in both genotypes and allele distributions. However, since heterogeneity was identified among studies included in this meta-analysis, further meta-analysis with a larger population and subgroup analysis on specific population are warranted to support this finding., Competing Interests: No competing interests were disclosed., (Copyright: © 2021 Azharuddin A et al.)

Objective: To investigate the expression and clinical significance of receptor interacting protein serine-threonine kinases 1 (RIPK1) in the nucleus pulposus of patients with lumbar disc herniation (LDH)., Methods: Nucleus pulposus tissue specimens of 40 patients with LDH patients underwent surgical treatment from January 2016 to January 2018 as the case group, and nucleus pulposus tissue specimens of 30 patients with lumbar spine fracture underwent surgical treatment at the same time as the control group. The expression of RIPK1 mRNA and protein of receptor interaction were detected by polymerase chain reaction (PCR) and Western blot, respectively. The expression of RIPK1 protein in the nucleus pulposus were detected by immunohistochemical staining. The concentrations of RIPK1 and tumor necrosis factor-α (TNF-α) in nucleus pulposus were detected by ELISA method. The relationship between the concentrations of RIPK1, TNF-α in nucleus pulposus and the Pearce grade of LDH patients was analyzed by one-way ANOVA. The correlation between RIPK1 and TNF-α was analyzed by Pearson., Results: RIPK1 was weakly positively expressed in nucleus pulposus of control group, and RIPK1 protein was positively or strongly positively expressed in case group. The expression of RIPK1 mRNA in nucleus pulposus of case group was higher than that of control group ( P <0.05). The expression of RIPK1 protein in nucleus pulposus of case group was higher than that of control group( P <0.05). The RIPK1 concentration in nucleus pulposus of case group was higher than that of control group ( P =0.012). The concentration of TNF-α in nucleus pulposus of case group was significantly higher than that of control group ( P =0.009). There were significantdifferences in concentrations of RIPK1 and TNF-α in nucleus pulposus of LDH patients with different Pearce classification ( P >0.05). The concentration of RIPK1 and TNF-α in nucleus pulposus increased significantly with the increase of Pearce grade. Pearson correlation analysis showed that there was a significant positive correlation between RIPK1 and TNF-α in nucleus pulposus of LDH patients ( r =0.781, P <0.001)., Conclusion: The expression levels of RIPK1 mRNA and protein in the intervertebral disc tissues of LDH patients are higher than those of normal intervertebral disc tissues, and increased with the increase of Pearce grade, which may be an important factor involved in LDH inflammatory disease.

Background: Lumbar disc herniation (LDH) places a serious burden on the daily lives and socioeconomics of people. Although the pathogenesis of LDH is complex, genetic factors such as single nucleotide polymorphisms (SNPs) may affect the risk of developing LDH. In the present study, we aimed to elucidate the effect of RAB40C SNPs on the risk of LDH in the Chinese Han population., Methods: We investigated 508 LDH cases and 508 healthy controls for this case-control study. Three tag SNPs in RAB40C were selected and genotyped using the Agena MassARRAY platform (Agena Bioscience, San Diego, CA, USA). After adjusting for age and gender, odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression., Results: In the allele model, we found rs62030917 and rs2269556 in RAB40C with a minor G allele significantly increased the risk of LDH (rs62030917: OR = 1.23, 95% CI = 1.00-1.50, p = 0.046; rs2269556: OR = 1.21, 95% CI = 1.02-1.45, p = 0.033). In genetic model analysis, rs2269556 was associated with an increased risk of LDH under both codominant (OR = 1.49, 95% CI = 1.03-2.15, p = 0.035) and log-additive models (OR = 1.21, 95% CI = 1.01-1.45, p = 0.035). rs62030917 of RAB40C was associated with an increased risk of LDH under codominant, recessive and log-additive models (p < 0.05) only among individuals younger than 49 years after stratification by age., Conclusions: For the first time, our results suggest that rs62030917 and rs2269556 in the RAB40C gene influence genetic susceptibility to LDH., (© 2020 John Wiley & Sons, Ltd.)

Degeneration of the cartilage endplate (CEP) induces intervertebral disc degeneration (IVDD). Nucleus pulposus cell (NPC) apoptosis is also an important exacerbating factor in IVDD, but the cascade mechanism in IVDD is not clear. We investigated the apoptosis of NPCs and IVDD when stimulated by normal cartilage endplate stem cell (CESC)-derived exosomes (N-Exos) and degenerated CESC-derived exosomes (D-Exos) in vitro and in vivo. Tert-butyl hydroperoxide (TBHP) was used to induce inflammation of CESCs. The bioinformatics differences between N-Exos and D-Exos were analyzed using mass spectrometry, heat map, and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. NPC apoptosis was examined using TUNEL staining. The involvement of the AKT and autophagy signaling pathways was investigated using the signaling inhibitor LY294002. Magnetic resonance imaging, Western blotting, and immunofluorescence staining were used to evaluate the therapeutic effects of N-Exos in rats with IVDD. TBHP effectively induced inflammation and the degeneration of CEP in rat. N-Exos were more conducive to autophagy activation than D-Exos. The apoptotic rate of NPCs decreased obviously after treatment with N-Exos compared to D-Exos. N-Exos inhibited NPCs apoptosis and attenuated IVDD in rat via activation of the AKT and autophagy pathways. These results are the first findings to confirm that CEP delayed the progression of IVDD via exosomes. The therapeutic effects of N-Exos on NPC apoptosis inhibition and the slowing of IVDD progression were more effective than D-Exos due to activation of the PI3K/AKT/autophagy pathway, which explained the increase in the incidence of IVDD after inflammation of the CEP., (©2021 The Authors. Stem Cells published by Wiley Periodicals LLC on behalf of AlphaMed Press 2020.)

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., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Based on the Thompson classification of intervertebral discs (IVDs), we systematically analyzed gene expression differences between severely degenerated and mildly degenerated IVDs and explored the underlying molecular mechanisms using bioinformatics methods and multichip integration. We used multiomics analysis, includes mRNA microarray and methylation chips, to explore the genetic network and mechanisms of lumbar disc herniation (LDH). Subsequently, the Combat function of the R language SVA package was applied to eliminate heterogeneity between the gene expression data. And the protein-protein interaction (PPI) network, gene ontology (GO), and molecular pathways were used to constructs the mechanisms network. Consequently, we obtained 149 differentially expressed genes. Related molecular pathways are the following: ribosome activity, oxidative phosphorylation, extracellular matrix response. Besides, through PPI network analysis, genes with higher connectivity such as UBA52, RPLP0, RPL3, RPLP2, and RPL27 were also identified, suggesting that they play important regulatory roles in the complex network associated with LDH. Additionally, cg12556991 (RPL27) and cg06852319 (RPLP0) were found to be LDH-related candidate DNA methylation modification sites in the IVDs tissue of LDH patients. In conclusions, ribosome activity, oxidative phosphorylation, and extracellular matrix response may be potential molecular mechanisms underlying LDH, while hub genes involved in UBA52, RPLP0, RPL3, RPLP2, and RPL27, and candidate DNA methylation modification sites of cg12556991and cg06852319 are likely key regulators in the development of LDH., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Endplate degeneration is characterized by an unbalance between the anabolism and catabolism of endplate chondrocyte (CH). Fibroblast growth factor 2 (FGF2) has been shown to promote cartilage repair by increasing articular CH anabolic activity. We aimed to explore the effect of FGF2 on the metabolism of endplate CH to elucidate whether FGF2 could be used as a therapy to delay the endplate degeneration., Methods: We collected the endplate tissue from the patients and tested the collagen II mRNA level as the anabolic marker and the MMP-13 and TIMP-4 expression as the catabolic markers. The FGF2, FGF receptor 1 (FGFR1), and FGFR3 mRNA expression of the endplate tissue were also analyzed. Besides, we treated the CHs with exogenic FGF2 protein, measured the markers mentioned above, the proliferation and the apoptosis of the CHs. To compare the effect of FGF2 on the CHs with or without degeneration, we also induced CHs degeneration by interleukin-1β (IL-1β) stimulation and used the FGF2 protein to treat the degenerative CHs., Results: Severely degenerative endplate had a lower collagen II and TIMP-4 mRNA level, but it expressed a more massive amount of MMP-13, FGF2, and FGFR1. FGF2 supplement upregulated the FGFR1/FGFR3, TIMP-4, collagen II expression, and promoted the CHs proliferation. In the first 24 h of IL-1β treatment, the FGF2 mRNA expression was suppressed, but it significantly increased 48 h later. Meanwhile, the FGFR1 was upregulated, and FGFR3 was inhibited by IL-1β treatment. Interestingly, the FGF2 protein supplement accelerated the degenerative CHs catabolism by decreasing collagen II and TIPM-4 expression but increasing MMP-13. However, the FGF2 could promote the anabolism process in case of the blocking of FGFR1. The FGF2 supplement could also promote the proliferation and inhibited the apoptosis of degenerative CHs, which could be magnified by FGFR1 blocking., Conclusions: The results demonstrate that FGF2 is upregulated in the highly degenerative endplate. The supplement of FGF2 contributes to the anabolism in the early phase of endplate degeneration. In the later stage of endplate degeneration, FGF2 turns to accelerate the catabolism, which can be rejected by the reasonable use of FGFR1 inhibitors., (Copyright © 2020. Published by Elsevier Inc.)

Aim and Background: Lumbar disc degeneration (LDD) is thought to be multifactorial in origin. Very recently the focus has shifted to the involvement of a family of candidate genes in the pathogenesis of LDD. There is particular emphasis on the vitamin D receptor gene (VDR gene). The VDR polymorphisms FOK1, TAQ1, and APO1 have been variably associated with LDD., Objective: To evaluate the association between the FOK1/Taq1 genes and LDD., Materials and Methods: One hundred unrelated healthy (asymptomatic) individuals who presented for routine health checkup and 93 consecutive patients (43 males and 50 females) with no history of low back pain were enrolled in the study after informed consent was obtained. The MRI images of cases and controls were graded and peripheral blood samples were collected from all participants and sent for genetic analysis., Results: Individuals with the dominant genotype for Taq1 had a significantly higher association with LDD than those without it. There was no association between LDD and the Fok1 genotype., Conclusion: Genetic predisposition is an important risk factor for LDD., (© 2020 Wiley Periodicals LLC.)

The aim of this study is to investigate the expression levels of genome-wide association studies (GWAS)-identified variants near Gasdermin-C (GSDMC) and its association with lumbar disc degeneration (LDD) in a Chinese population. In accordance with previously reported findings, our study involved the top 4 variants; rs6651255, rs7833174, rs4130415, and rs7816342. A total of 800 participants, 400 LDD patients and 400 controls were involved in the study. The LDD patients were divided into two mutually exclusive subgroups: subgroup 1: lumbar disc herniation; subgroup 2: lumbar spinal stenosis. Genotyping were performed using TaqMan assay, and Enzyme-Linked Immunosorbent Assay (ELISA) used to measure the plasma GSDMC levels, while quantitative reverse-transcription (qRT)-PCR and immunohistochemistry (IHC) were used to evaluate the GSDMC expression levels. Among the studied variants, there were no statistically significant differences in allelic and genotypic frequencies between LDD patients and their controls (all P > 0.05). However, the subgroup analysis revealed a significant association between rs6651255 and rs7833174 in patients with lumbar spinal stenosis (subgroup 2). Furthermore, the max-statistic test revealed that the inheritance models of two variants of lumbar spinal stenosis were represented by the recessive model. The plasma and mRNA expression levels of GSDMC were significantly higher in patients with lumbar spinal stenosis compared with the control group (P < 0.05). Furthermore, the CC genotypes of rs6651255 and rs7833174 were significantly associated with increased plasma expression levels of GSDMC in patients with lumbar spinal stenosis (P < 0.01). Two GWAS-identified variants (rs6651255 and rs7833174) near GSDMC were associated with a predisposition to lumbar spinal stenosis. GSDMC protein and mRNA expression levels may have prognostic qualities as biomarkers for the existence, occurrence or development of lumbar spinal stenosis.

Lumbar disc herniation (LDH) is a relatively common spinal disease, but its pathogenesis is still unknown. Numerous studies have shown that LDH is closely correlated with inflammation, and it has been found to be related to some single nucleotide polymorphisms (SNPs). Our purpose is to explore the correlation between gene polymorphisms of GSDMC and LDH risk, which is of great significance for the study of the pathogenesis of LDH. DNA was extracted from 508 LDH patients and 508 controls. We select SNPs with minor allele frequency >5% in GSDMC gene from 1,000 genome project (http://www.internationalgenome.org/). Then, genotyping was performed using Agena MassARRAY. We used unconditional logistic regression analysis to calculate odds ratios (ORs) and 95% confidence intervals (CIs). The haplotype construction and analysis in GSDMC were applied to detect the association. We identified that rs77681114 in the GSDMC gene was significantly associated with a decreased risk of LDH in the alleles model (OR = 0.81, 95% CI = 0.66-0.99, p = .049) and the log-additive model (OR = 0.81, 95% CI = 0.65-0.99, p = .049) adjusted by age and gender. The haplotype "AG" constructed by rs77681114 and rs4285452 (OR = 1.24, 95% CI = 1.01-1.53, p = .039) was associated with increased risk of LDH. After age and gender stratification, rs77681114 protected LDH risk at age 49 or older in allelic model (p = .010), co-dominant model (p = .006), dominant model (p = .029), recessive model (p = .011) and log-additive model (p = .005). Rs77681114 had protective effect on female LDH risk in both co-dominant models (p = .033) and recessive models (p = .043). These studies indicated that genetic polymorphisms of GSDMC can relatively reduce the risk of LDH., (© 2020 John Wiley & Sons Ltd.)

Ethnopharmacological Relevance: Yaobitong capsule (YBTC) was a traditional Chinese medicine (TCM) and it had clinically used to treat lumbar disc degeneration (LDH) for a long time. However, the active ingredients of YBTC absorption into the plasma and its pharmacological mechanism of treatment for LDH still remained unclear., Aim of the Study: In this study, our research committed to identify the absorbed active ingredients of YBTC in rat plasma, and it may be a potential mechanism of action on LDH by the biological targets regulating related pathways., Materials and Methods: An ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was established to identify the absorption components and metabolites of YBTC in rat plasma, and the network pharmacology was further investigated to illuminate its potential mechanism of treatment for LDH by the biological targets regulating related pathways., Results: The network analysis found that 56 components were identified as its main active ingredients including ginsenoside Rg1, ginsenoside Rb1, senkyunolide H, and tetrahydropalmatine, etc. Combining with biological process, cellular component and molecular functions of GO, and kyotoencyclopedia of genes and genomes pathway enrichment analysis to perform network topology analysis on core targets. These active ingredients regulated 29 mainly pathways by 87 direct target genes including MAPK, Ras, PI3K-Akt, and NF-kappa B signaling pathway, etc. CONCLUSION: In this study, the absorption active ingredients of YBTC in rat plasma were firstly combined with the network pharmacology investigation to elucidate its biological mechanism of treatment for LDH in vivo. It inhibited excessive inflammatory reactions, thereby reducing the sensitivity of the nerves to reduce pain and relieve LDH, and potential medicine targets could be identified to clarify the molecular mechanism of YBTCs' regulation of LDH., (Copyright © 2020. Published by Elsevier B.V.)

Intervertebral disc (IVD) disease (IDD) is a complex, multifactorial disease. While various aspects of IDD progression have been reported, the underlying molecular pathways and transcriptional networks that govern the maintenance of healthy nucleus pulposus (NP) and annulus fibrosus (AF) have not been fully elucidated. We defined the transcriptome map of healthy human IVD by performing single-cell RNA-sequencing (scRNA-seq) in primary AF and NP cells isolated from non-degenerated lumbar disc. Our systematic and comprehensive analyses revealed distinct genetic architecture of human NP and AF compartments and identified 2,196 differentially expressed genes. Gene enrichment analysis showed that SFRP1, BIRC5, CYTL1, ESM1 and CCNB2 genes were highly expressed in the AF cells; whereas, COL2A1, DSC3, COL9A3, COL11A1, and ANGPTL7 were mostly expressed in the NP cells. Further, functional annotation clustering analysis revealed the enrichment of receptor signaling pathways genes in AF cells, while NP cells showed high expression of genes related to the protein synthesis machinery. Subsequent interaction network analysis revealed a structured network of extracellular matrix genes in NP compartments. Our regulatory network analysis identified FOXM1 and KDM4E as signature transcription factor of AF and NP respectively, which might be involved in the regulation of core genes of AF and NP transcriptome.

Lumbar degenerative disc disease (DDD) is a multifaceted progressive condition and often accompanied by disc herniation (DH) and/or degenerative spondylolisthesis (DS). Given the high prevalence of the disease (up to 20% according to some estimates) and the high costs associated with its care, there is a need to explore novel therapies such as regenerative medicine. Exploring these novel therapies first warrants investigation of molecular pathways underlying these disorders. Here, we show results from next generation RNA sequencing (RNA-seq) on mRNA isolated from 10 human nucleus pulposus (NP) samples of lumbar degenerated discs (DH and DS; n = 5 for each tissue) and other musculoskeletal tissues (Bone, cartilage, growth plate, and muscle; n = 7 for each tissue). Pathway and network analyses based on gene ontology (GO) terms were used to identify the biological functions of differentially expressed mRNAs. A total of 701 genes were found to be significantly upregulated in lumbar NP tissue compared to other musculoskeletal tissues. These differentially expressed mRNAs were primarily involved in DNA damage, immunity and G1/S transition of mitotic cell cycle. Interestingly, DH-specific signaling genes showed major network in chemotactic (e.g., CXCL10, CXCL11, IL1RL2 and IL6) and matrix-degrading pathway (e.g., MMP16, ADAMTSL1, 5, 8, 12, and 15), while DS-specific signaling genes were found to be those involved in cell adhesion (e.g., CDH1, EPHA1 and EFNA2) and inflammatory cytokines (e.g., CD19, CXCL5, CCL24, 25 and XCL2). Our findings provide new leads for therapeutic drug discovery that would permit optimization of medical or pharmacological intervention for cases of lumbar DDD., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Two transcribed retrocopies of the fibroblast growth factor 4 ( FGF4 ) gene have previously been described in the domestic dog. An FGF4 retrocopy on chr18 is associated with disproportionate dwarfism, while an FGF4 retrocopy on chr12 is associated with both disproportionate dwarfism and intervertebral disc disease (IVDD). In this study, whole-genome sequencing data were queried to identify other FGF4 retrocopies that could be contributing to phenotypic diversity in canids. Additionally, dogs with surgically confirmed IVDD were assayed for novel FGF4 retrocopies. Five additional and distinct FGF4 retrocopies were identified in canids including a copy unique to red wolves ( Canis rufus ). The FGF4 retrocopies identified in domestic dogs were identical to domestic dog FGF4 haplotypes, which are distinct from modern wolf FGF4 haplotypes, indicating that these retrotransposition events likely occurred after domestication. The identification of multiple, full length FGF4 retrocopies with open reading frames in canids indicates that gene retrotransposition events occur much more frequently than previously thought and provide a mechanism for continued genetic and phenotypic diversity in canids.

Purpose: Lumbar disc herniation (LDH) is an important cause of back pain and sciatica, but its aetiology is not fully understood. Single-nucleotide polymorphisms (SNPs) in specific collagen genes are known to increase the risk of lumbar disc degeneration. We performed a case-control study among the Chinese Han population to investigate whether genetic variations in collagen genes were associated with the risk of LDH or not., Methods: We genotyped SNPs selected from 1000 Genome Projects using Agena MassARRAY technology. Three hundred and eighty-four LDH cases were compared with 384 controls of similar age, using the odds ratio and 95% confidence interval to calculate the susceptibility in several genetic models., Results: Our results revealed that subjects with the rs6122316-C variant of the COL9A3 gene had a higher likelihood of LDH than subjects with the allele T variant in both the codominant and recessive models. In addition, after gender stratification analysis, we found significant associations between rs16970089 and rs740024 and LDH risk in females. Age stratification analysis illustrated that rs16970089 and rs6122316 were also correlated with LDH risk in people over 50 years. The smoking stratification illustrated that rs2071358 and rs740024 had an increased association with LDH risk in smokers. And after drinking stratification, we also observed the significance between rs740024 and LDH risk., Conclusions: Variants in genes for COL1A1, COL9A3 and COL2A1 significantly influence the risk of LDH. Large and well-designed studies are needed to confirm and explain these conclusions. These slides can be retrieved under Electronic Supplementary Material.

Objective: Lumbar disk herniation (LDH) is a complex condition based on lumbar disk degeneration (LDD). Previous studies have shown that genetic factors are highly associated with the severity and risk for LDH. This case-control study was aimed to evaluate the association between the matrix metalloproteinase (MMP)-3 gene rs591058 C/T polymorphism and LDH risk in a southern Chinese population., Methods: A total of 231 LDH patients and 312 healthy controls were recruited in this study. Genotyping was analyzed using a standard polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP)., Results: It was observed that TT genotype or T allele carriers of the MMP-3 gene rs591058 C/T polymorphism was more likely associated with an increased risk for LDH. Subgroup analyses showed the following characteristics increased the risk for LDH: female sex; cigarette smoking; and alcohol consumption. Furthermore, individuals with high whole body vibration, bending/twisting, and lifting were associated with an increased risk for LDH., Conclusion: Taken together, these data indicated that the MMP-3 gene rs591058 C/T polymorphism was associated with an increased risk for LDH. The MMP-3 gene rs591058 C/T polymorphism might serve as a clinical indicator and marker for LDH risk in the Chinese population., (© 2020 The Authors. Journal of Clinical Laboratory Analysis Published by Wiley Periodicals, Inc.)

Background: Interleukin (IL)-1 is a cytokine superfamily, which involved in the inflammatory process and immune response in human body. IL-1 receptor antagonist (IL1RN) has been found to be associated with risk of lumbar disk herniation (LDH) in Finland samples. However, to date, there was no investigation focus on the polymorphisms of IL1RN in Chinese Han LDH patient., Materials and Methods: We conducted a case-control study based on 498 LDH patients and 463 controls. Five single-nucleotide polymorphisms (SNPs) in IL1RN were genotyped., Results: As a result, we found that the AG and GG genotypes of rs3181052 were associated with decreased risk LDH under the dominant model (OR = 0.74, 95%CI: 0.57-0.96, p = .025). In the stratification analysis, the frequency of the "A" allele of rs17042888 was significantly lower in elder LDH cases than in controls (OR = 0.723, 95%CI: 0.544-0.961, p = .025). In addition, the AG and AA genotypes of rs17042888 were associated with decreased risk of LDH in elder group under the dominant model (OR = 0.69, 95%CI: 0.49-0.98, p = .038). The GG genotype of rs315919 was identified have correlation with decreased risk of LDH in elder group under the recessive model (OR = 0.60, 95%CI: 0.37-0.97, p = .034)., Conclusions: Our data showed that IL1RN may be a susceptibility gene for risk of LDH in Chinese Han population., (© 2020 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Intervertebral disc (IVD) herniation and degeneration is a major source of back pain. In order to regenerate a herniated and degenerated disc, closure of the anulus fibrosus (AF) is of crucial importance. For molecular characterization of AF, genome-wide Affymetrix HG-U133plus2.0 microarrays of native AF and cultured cells were investigated. To evaluate if cells derived from degenerated AF are able to initiate gene expression of a regenerative pattern of extracellular matrix (ECM) molecules, cultivated cells were stimulated with bone morphogenetic protein 2 (BMP2), transforming growth factor β1 (TGFβ1) or tumor necrosis factor-α (TNFα) for 24 h. Comparative microarray analysis of native AF tissues showed 788 genes with a significantly different gene expression with 213 genes more highly expressed in mild and 575 genes in severe degenerated AF tissue. Mild degenerated native AF tissues showed a higher gene expression of common cartilage ECM genes, whereas severe degenerated AF tissues expressed genes known from degenerative processes, including matrix metalloproteinases (MMP) and bone associated genes. During monolayer cultivation, only 164 differentially expressed genes were found. The cells dedifferentiated and altered their gene expression profile. RTD-PCR analyses of BMP2- and TGFβ1-stimulated cells from mild and severe degenerated AF tissue after 24 h showed an increased expression of cartilage associated genes. TNFα stimulation increased MMP1, 3, and 13 expression. Cells derived from mild and severe degenerated tissues could be stimulated to a comparable extent. These results give hope that regeneration of mildly but also strongly degenerated disc tissue is possible.

The cell cycle regulator p16 is known as a biomarker and an effector of aging. However, its function in intervertebral disc degeneration (IVDD) is unclear. In this study, p16 expression levels were found to be positively correlated with the severity of human IVDD. In a mouse tail suspension (TS)-induced IVDD model, lumbar intervertebral disc height index and matrix protein expression levels were reduced significantly were largely rescued by p16 deletion. In TS mouse discs, reactive oxygen species levels, proportions of senescent cells, and the senescence-associated secretory phenotype (SASP) were all increased, cell cycling was delayed, and expression was downregulated for Sirt1, superoxide dismutase 1/2, cyclin-dependent kinases 4/6, phosphorylated retinoblastoma protein, and transcription factor E2F1/2. However, these effects were rescued by p16 deletion. Our results demonstrate that p16 plays an important role in IVDD pathogenesis and that its deletion attenuates IVDD by promoting cell cycle and inhibiting SASP, cell senescence, and oxidative stress., Competing Interests: HC, JL, YL, CM, HL, JQ, JD, ZZ, CX, DM, LW, YR No competing interests declared, (© 2020, Che et al.)