Matrix metalloproteinase-3, vitamin D receptor gene polymorphisms, and occupational risk factors in lumbar disc degeneration

Association of IL‑6 and MMP‑3 gene polymorphisms with adolescent idiopathic scoliosis: A systematic review and meta‑analysis

The pathogenesis of adolescent idiopathic scoliosis (AIS) remains unclear. It has been found that interleukin-6 (IL-6) rs1800795 locus and matrix metalloproteinase-3 (MMP-3) rs3025058 locus gene polymorphisms may be associated with AIS susceptibility, which has been controversial and needs to be further confirmed by updated meta-analysis. The aim of the present study was to investigate the association of MMP-3 rs3025058 and IL-6 rs1800795 single nucleotide polymorphisms (SNPs) with susceptibility to AIS. All relevant articles that met the criteria were retrieved and included, and the publication dates were limited from January 2005 to December 2023. The allele frequencies and different genotype frequencies of IL-6 rs1800795 and MMP-3 rs3025058 loci in each study were extracted and statistically analyzed by ReviewManager 5.4 software, and the odds ratio (OR) and 95% confidence interval (95% CI) of different genetic models were calculated. The results of the meta-analysis showed that there was no significant association between the gene polymorphism of IL-6 rs1800795 locus and the pathogenesis of AIS. The allele 5A and genotype 5A5A of MMP-3 rs3025058 SNP were associated with AIS susceptibility (5A vs. 6A, OR=1.18; 95% CI, 1.04-1.33; 5A5A vs. 6A6A, OR=1.65; 95% CI, 1.23-2.21; and 5A5A vs. 5A6A + 6A6A, OR=1.54; 95% CI, 1.19-1.99). Results of subgroup analysis revealed that the allele 5A and genotype 5A5A of MMP-3 rs3025058 SNP were associated with AIS susceptibility in the Caucasian population, and the susceptibility of AIS was associated with the genotype 5A5A of MMP-3 rs3025058 SNP in an Asian population. There was no significant association between the gene polymorphism of IL-6 rs1800795 locus and the pathogenesis of AIS, while the allele 5A of MMP-3 rs3025058 locus was associated with the susceptibility to AIS, especially in the Caucasian population.

Quantum Molecular Resonance Radiofrequency Disc Decompression and Percutaneous Microdiscectomy for Lumbar Radiculopathy

Within the practice of pain management, one of the most commonly encountered events is low back pain. Lumbar radiculopathy (LR) is a pain syndrome caused by the compression or irritation of the nerve roots in the lower back due to lumbar disc herniation, vertebra degeneration, or foramen narrowing. Symptoms of LR include low back pain that propagates toward the legs, numbness, weakness, and loss of reflexes. The aim of this study is to assess the long-term effectiveness of quantum molecular resonance disc decompression and its combination with a percutaneous microdiscectomy using Grasper© forceps (QMRG) in patients with persistent lumbar radiculopathy (LR) in relation to patient physical stress status. The main outcome measures of this prospective observational study were DN4, NRS, ODI, SF12, PGI, CGI, and MOS Sleep Scale. An improvement 12 months post-intervention was observed in patients without physical stress, presenting better overall results. The mean change was over the minimal clinically important difference in 64.3% of outcome measures studied for the whole sample. QMRG appears to be an effective treatment option for LR, but a reduction in physical stress is needed to ensure long-term effectiveness.

Pathogenesis and therapeutic implications of matrix metalloproteinases in intervertebral disc degeneration: A comprehensive review

Intervertebral disc (IVD) degeneration (IDD) is a common disorder that affects the spine and is a major cause of lower back pain (LBP). The extracellular matrix (ECM) is the structural foundation of the biomechanical properties of IVD, and its degradation is the main pathological characteristic of IDD. Matrix metalloproteinases (MMPs) are a group of endopeptidases that play an important role in the degradation and remodeling of the ECM. Several recent studies have shown that the expression and activity of many MMP subgroups are significantly upregulated in degenerated IVD tissue. This upregulation of MMPs results in an imbalance of ECM anabolism and catabolism, leading to the degradation of the ECM and the development of IDD. Therefore, the regulation of MMP expression is a potential therapeutic target for the treatment of IDD. Recent research has focused on identifying the mechanisms by which MMPs cause ECM degradation and promote IDD, as well as on developing therapies that target MMPs. In summary, MMP dysregulation is a crucial factor in the development of IDD, and a deeper understanding of the mechanisms involved is needed to develop effective biological therapies that target MMPs to treat IDD.

A Case-Control Study of the Fokl Polymorphism of the Vitamin D Receptor Gene in Bulgarians With Lumbar Disc Herniation

BACKGROUND

The present study investigates whether vitamin D receptor (VDR) gene polymorphisms play a role in intervertebral disc degeneration (IDD), a common cause of low back pain (LBP) and reduced quality of life. Specifically, we examined the FokI VDR polymorphism and its potential association with lumbar disc herniation (LDH) in patients from Bulgaria. Previous studies have suggested a link between mutations in the VDR gene and IDD.

METHODS

We investigated whether a potential connection between VDR polymorphisms and LDH was present by comparing the FokI polymorphism of 60 selected patients (25 to 60) with LDH and 60 healthy volunteers within the same age range. We used polymerase chain reaction to assess the phenotype of the examined subjects and statistical tests to evaluate whether the obtained results were statistically significant.

RESULTS

The performed genetic and statistical analyses reviewed significant differences in genotypic frequencies between the patient group and healthy volunteers. The frequency of the F allele is notably higher in patients with LDH (80%) compared to volunteers (52%), while the f allele is more common among patients (86.6%) than volunteers (100%).

CONCLUSION

This study strongly suggests that expression of the F allele of the VDR gene may increase the susceptibility of developing LDH, while having the f allele could potentially have a protective effect. Our results shed light on the underlying complex mechanisms contributing to the development of LDH.

Patient-related risk factors and lifestyle factors for lumbar degenerative disc disease: a systematic review

OBJECTIVE

Back pain is a very widespread disease pattern and is one of the most frequent causes for consultation of a physician in general. In most cases, discogenic changes are the pathomorphological correlate of back pain. Numerous risk factors have been identified for these degenerative changes, but the influence and significance of the risk factors remain unclear, which was the aim of this systematic review.

METHODS

A systematic literature search of the commonly used Pubmed database was performed using specific MESH terms. Further selection of the included studies was performed according to the PRISMA scheme, taking into account scientific merit as well as the relation to the research question.

RESULTS

A total of 111 studies out of 1035 found were finally included in the literature search. 134 risk factors for disc degeneration and disc herniation were identified. These were divided into (1) patient-specific risk factors (n░=░34), (2) radiological risk factors (n░=░31), (3) lifestyle risk factors (n░=░6), (4) workplace-related risk factors (n░=░12), (5) genetic risk factors (n░=░50), and (6) other risk factors (n░=░1). Non-adjustable risk factors were age >50 years (OR 1.7/year), female gender (OR 1.41), family disposition (OR 4.0), comorbidities like atherosclerosis (OR 2.24), arthritic changes in other joints (OR 3.1) and history of injuries of the back (OR 3.1). Adjustable factors were elevated BMI (OR 2.77), comorbidities like hypertension (OR 1.25), dyslipidemia (OR 1.26) and diabetes mellitus (OR 6.8), as well as lifestyle habits like smoking (OR 3.8).

DISCUSSION

In summary, intervertebral disc degenerations and herniations represent multifactorial events whose risk factors can be partly influenced and partly not influenced. This systematic review highlights the current state of knowledge as a basis for creating patient-specific algorithms to calculate risk for the development or progression of degenerative disc changes and disc herniations.

Low back pain and osteoarthritis pain: a perspective of estrogen

Low back pain (LBP) is the world's leading cause of disability and is increasing in prevalence more rapidly than any other pain condition. Intervertebral disc (IVD) degeneration and facet joint osteoarthritis (FJOA) are two common causes of LBP, and both occur more frequently in elderly women than in other populations. Moreover, osteoarthritis (OA) and OA pain, regardless of the joint, are experienced by up to twice as many women as men, and this difference is amplified during menopause. Changes in estrogen may be an important contributor to these pain states. Receptors for estrogen have been found within IVD tissue and nearby joints, highlighting the potential roles of estrogen within and surrounding the IVDs and joints. In addition, estrogen supplementation has been shown to be effective at ameliorating IVD degeneration and OA progression, indicating its potential use as a therapeutic agent for people with LBP and OA pain. This review comprehensively examines the relationship between estrogen and these pain conditions by summarizing recent preclinical and clinical findings. The potential molecular mechanisms by which estrogen may relieve LBP associated with IVD degeneration and FJOA and OA pain are discussed.

Intervertebral disc degeneration-Current therapeutic options and challenges

Degeneration of the intervertebral disc (IVD) is a normal part of aging. Due to the spine's declining function and the development of pain, it may affect one's physical health, mental health, and socioeconomic status. Most of the intervertebral disc degeneration (IVDD) therapies today focus on the symptoms of low back pain rather than the underlying etiology or mechanical function of the disc. The deteriorated disc is typically not restored by conservative or surgical therapies that largely focus on correcting symptoms and structural abnormalities. To enhance the clinical outcome and the quality of life of a patient, several therapeutic modalities have been created. In this review, we discuss genetic and environmental causes of IVDD and describe promising modern endogenous and exogenous therapeutic approaches including their applicability and relevance to the degeneration process.

Vitamin D reduces pain and cartilage destruction in knee osteoarthritis animals through inhibiting the matrix metalloprotease (MMPs) expression

Aim of the study

In this study, we investigated the therapeutic potential of vitamin D (VITD) in OA Wistar rats induced by anterior cruciate ligament transection combined with medial meniscectomy (ACLT + MMx). In ACLT + MMx-induced OA rats, pain severity, cartilage destruction, inflammatory cytokines, and MMPs were all measured.

Materials and methods

ACLT + MMx methods were used to induce OA, and pain behavioral studies such as the weight bearing test and paw withdrawal test were performed while the knee width and body weights were also measured. Furthermore, Hematoxylin and Eosin (H&E) staining was used to determine knee histopathological studies, as well as OARSI scoring, cartilage thickness, cartilage width, and cartilage degradation scores. The enzyme-linked immunosorbent assay (ELISA) studies were used to check the serum levels of VITD, C-telopeptide of Type II collagen (CTX-II), and pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and anti-inflammatory cytokines interleukin-10 (IL-10), and MMPs (MMP-3, MMP-9, and MMP-13). Finally, the reverse transcription polymerase chain reaction (RT-PCR) test was used to determine the levels of MMPs, nuclear factor-kappa B (NF-κB), TNF-α, IL-6, and IL-10 in IL-1β stimulated chondrocytes.

Results

The oral VITD supplement significantly reduced OA pain, inflammation, cartilage destruction, and MMPs levels. Furthermore, serum VITD levels increased while CTX-II levels decreased, indicating that VITD reduced cartilage degradation effectively. Moreover, VITD supplementation reduced the expression of pro-inflammatory TNF-α, IL-1β, and IL-6 cytokines while increasing the expression of anti-inflammatory IL-10. The elevation of MMPs after ACLT + MMx surgery contributed to articular cartilage destruction, which was reduced by VITD supplementation. Finally, VITD supplementation significantly reduces serum levels of MMPs, IL-1β, TNF-α, and IL-6 while increasing IL-10 levels. Then, using the in-vitro cytotoxicity (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) MTT assay, examine the cytotoxicity profile of VITD in rat chondrocytes after stimulated with IL-1β, which shows no toxicity in the dose range of VITD 0-500 IU. Finally, RT-PCR studies in IL-1β stimulated rat chondrocytes revealed that VITD (50, 100, and 500 IU) significantly reduced the mRNA levels of MMPs, NF-κB, TNF-α, and IL-6, while increasing IL-10 levels, indicating that VITD reduced chondrocyte destruction and overcame harsh conditions in a dose-dependent manner.

Conclusion

Overall, the in vivo and in vitro findings show that VITD effectively reduces OA pain, inflammation, and chondrocyte destruction by lowering MMPs levels specifically.

Oestrogen and Vibration Improve Intervertebral Disc Cell Viability and Decrease Catabolism in Bovine Organ Cultures

Postmenopausal women are at an increased risk for intervertebral disc degeneration, possibly due to the decrease in oestrogen levels. Low-magnitude, high-frequency vibration (LMHFV) is applied as a therapeutic approach for postmenopausal osteoporosis; however, less is known regarding possible effects on the intervertebral disc (IVD) and whether these may be oestrogen-dependent. The present study investigated the effect of 17β-oestradiol (E2) and LMHFV in an IVD organ culture model. Bovine IVDs (n = 6 IVDs/group) were treated with either (i) E2, (ii) LMHFV or (iii) the combination of E2 + LMHFV for 2 or 14 days. Minor changes in gene expression, cellularity and matrix metabolism were observed after E2 treatment, except for a significant increase in matrix metalloproteinase (MMP)-3 and interleukin (IL)-6 production. Interestingly, LMHFV alone induced cell loss and increased IL-6 production compared to the control. The combination of E2 + LMHFV induced a protective effect against cell loss and decreased IL-6 production compared to the LMHFV group. This indicates possible benefits of oestrogen therapy for the IVDs of postmenopausal women undergoing LMHFV exercises.

Microgravity and the intervertebral disc: The impact of space conditions on the biomechanics of the spine

The environmental conditions to which astronauts and other military pilots are subjected represent a unique example for understanding and studying the biomechanical events that regulate the functioning of the human body. In particular, microgravity has shown a significant impact on various biological systems, such as the cardiovascular system, immune system, endocrine system, and, last but not least, musculoskeletal system. Among the potential risks of flying, low back pain (LBP) has a high incidence among astronauts and military pilots, and it is often associated with intervertebral disc degeneration events. The mechanisms of degeneration determine the loss of structural and functional integrity and are accompanied by the aberrant production of pro-inflammatory mediators that exacerbate the degenerative environment, contributing to the onset of pain. In the present work, the mechanisms of disc degeneration, the conditions of microgravity, and their association have been discussed in order to identify possible molecular mechanisms underlying disc degeneration and the related clinical manifestations in order to develop a model of prevention to maintain health and performance of air- and space-travelers. The focus on microgravity also allows the development of new proofs of concept with potential therapeutic implications.

Single-Cell RNA Sequencing Reveals the Difference in Human Normal and Degenerative Nucleus Pulposus Tissue Profiles and Cellular Interactions

Background: The nucleus pulposus is a constituent structure of the human intervertebral disc, and its degeneration can cause intervertebral disc degeneration (IDD). However, the cellular and molecular mechanisms involved remain elusive. Methods: Through bioinformatics analysis, the single-cell transcriptome sequencing expression profiles of human normal nucleus pulposus (NNP) cells and human degenerative nucleus pulposus (DNP) cells were compared to clarify the transcriptome differential expression profiles of human NNP and DNP. The single-cell sequencing results of the two samples were analyzed using bioinformatics methods to compare the differences in histiocytosis between human NNP and DNP, map the histiocytes of NNP and DNP, perform cell differentiation trajectories for the cell populations of interest and predict cell function, and explore their heterogeneity by pathway analysis and Gene Ontology analysis. Results: Nine cell types were identified, which were chondrocyte 1, chondrocyte 2, chondrocyte 3, chondrocyte 4, chondrocyte 5, endothelial, macrophage, neutrophil, and T cells. Analysis of the proportion of chondrocytes in different tissues revealed that chondrocyte 1 accounted for a higher proportion of NNP cells and highly expressed COL2A1 compared with DNP cells; chondrocyte 2, chondrocyte 3, chondrocyte 4, and chondrocyte 5 accounted for a higher proportion of DNP cells compared with NNP cells. Among them, chondrocyte 2 was an inhibitory calcified chondrocyte with high expression of MGP, chondrocytes 3 were fibrochondrocytes with high expression of COL1A1, chondrocytes 4 were chondrocytes that highly express pain inflammatory genes such as PTGES, and chondrocytes 5 were calcified chondrocytes with high expression of FN1 (chondrocytes 4 and chondrocytes 5 were found for the first time in a study of single-cell transcriptome sequencing of disc tissue). Cell trajectory analysis revealed that chondrocyte 1 was at the beginning of the trajectory and chondrocyte 3 was at the end of the trajectory, while chondrocyte 5 appeared first in the trajectory relative to chondrocyte 2 and chondrocyte 4. Conclusion: After functional identification of the specifically expressed genes in five chondrocytes, it was found that chondrocyte 1 was a chondrocyte with high expression of COL2A1, COL9A2, COL11A2, and CHRDL2 in a high proportion of NNP cells, and chondrocyte 3 was a fibrochondrocyte with high expression of COL1A1, COL6A3, COL1A2, COL3A1, AQP1, and COL15A1 in an increased proportion during nucleus pulposus cell degeneration. Through cell trajectory analysis, it was found that chondrocytes 5 specifically expressing FN1, SESN2, and GDF15 may be the key cells leading to degeneration of nucleus pulposus cells. Chondrocytes 2 expressing MGP, MT1G, and GPX3 may play a role in reversing calcification and degeneration, and chondrocytes 4 expressing PTGES, TREM1, and TIMP1 may play a role in disc degeneration pain and inflammation.

Association between severe lumbar disc degeneration and self-reported occupational physical loading

Objectives

Occupational physical loading has been reported to be associated with intervertebral disc degeneration. However, previous literature reports inconsistent results for different vertebral levels. The aim of our study was to investigate the association between lumbar disc degeneration (LDD) at different vertebral levels and the self‐reported physical loading of occupation.

Methods

The study population consisted of 1,022 postmenopausal women and was based on the prospective Kuopio Osteoporosis Risk Factor and Prevention (OSTPRE) study cohort. The severity of LDD was graded from T2‐weighted MRI images using the five‐grade Pfirrmann classification. Five intervertebral levels (L1–L2 to L5–S1) were studied (total 5110 discs). The self‐rated occupational physical loading contained four groups: sedentary, light, moderate, and heavy.

Results

The heavy occupational physical loading group had higher odds for severe LDD at the L5–S1 vertebral level (OR 1.86, 95% CI: 1.19–2.92, p = .006) in comparison with the sedentary work group. A clear trend of increasing disc degeneration with heavier occupational loading was also observed at the L5–S1 level. Age, smoking, and higher body mass index (BMI) were associated with more severe LDD. Leisure‐time physical activity at the age of 11–17 years was associated with less severe LDD. Controlling for confounding factors did not alter the results.

Conclusions

There appears to be an association between occupational physical loading and severe disc degeneration at the lower lumbar spine in postmenopausal women. Individuals in occupations with heavy physical loading may have an increased risk for work‐related disability due to more severe disc degeneration.

17β-Estradiol alleviates intervertebral disc degeneration by inhibiting NF-κB signal pathway

AIM

To investigate the effect of 17β-Estradiol (E2) on intervertebral disc degeneration (IVDD) and the related mechanism.

MATERIALS AND METHODS

Immunohistochemistry was used to detect the expression of estrogen receptor β (ERβ) within intervertebral discs of humans and rats. After that, rat IVDD model was established by needle puncture and bilateral ovariectomy. Then, the serum E2 level was detected by enzyme linked immunosorbent assay, and the degree of IVDD was evaluated by X-ray, magnetic resonance imaging, hematoxylin and eosin staining, and Safranin O-Fast Green staining. Finally, we used immunohistochemistry and immunofluorescence staining to determine the effect of E2 on nuclear factor kappa-B (NF-κB) signal pathway both in vivo and in vitro.

KEY FINDINGS

We identified that IVDD was associated with lower levels of ERβ and ERβ levels were inversely correlated with IVDD. The histological staining and radiological results showed that E2 supplement could alleviate IVDD progression. Additionally, immunohistochemistry staining demonstrated that E2 could inhibit nucleus pulposus cell (NPC) apoptosis, matrix metalloproteinases (MMPs) synthesis, and degradation of extracellular matrix (ECM) by inhibiting the activation of NF-κB signal pathway. Furthermore, immunofluorescence staining showed that the above effects of E2 on the NF-κB signal pathway could be blocked by the estrogen receptor antagonist ICI182780 in vitro. Finally, inhibition of NF-κB signal pathway by BAY11-7082 could reduce MMPs synthesis and ECM degradation of NPCs.

SIGNIFICANCE

Collectively, these findings indicated that E2 could effectively ameliorate IVDD by inhibiting NPC apoptosis via inhibition of NF-κB signal pathway.

Association of Single Nucleotide Polymorphism rs2228570 with Lumbar Disc Degeneration: A Case-Control Study and Meta-Analysis

Objective

To examine the association between single nucleotide polymorphisms (SNPs) rs2228570, rs731236, rs7975232, and rs1544410 and lumbar disc degeneration (LDD) predisposition.

Methods

A search strategy was carried out, and the data were extracted after being chosen by the inclusion and exclusion criteria. Pooled odds ratios and 95% confidence intervals were calculated to assess the association between the aforementioned SNPs and LDD under allelic, dominant, recessive, heterozygous, and homozygous genetic models. In addition, a case–control study involving 46 LDD cases and 45 controls was also performed in the analysis to verify the result.

Results

A total of 17 studies were included in this meta-analysis. The pooled results did not show any association between vitamin D receptor (VDR) gene polymorphisms and LDD. But, interestingly, in subgroup analysis, the rs2228570 polymorphism was associated with LDD under the allelic (OR = 0.70, 95% CI = 0.56–0.87, p = 0.002), recessive (OR = 0.60, 95% CI = 0.43–0.84, p = 0.003), and homozygous (OR = 0.47, 95% CI= 0.28–0.79, p = 0.004) genetic models in the Asian population. SNPs rs731236 and rs7975232 still did not show any obvious association. We obtained a similar result from the case–control study: rs2228570 had an obvious relationship with LDD under allelic and homozygous genetic models. At the same time, we found that rs2228570 was also associated with the degree of low back pain (visual analogue scale, VAS score) in LDD population.

Conclusion

SNP rs2228570 was significantly associated with LDD predisposition and the degree of low back pain in the Asian population.

The role of TaqI, ApaI and BsmI polymorphisms of VDR gene in lumbar spine pathologies: systematic review and meta-analysis

PURPOSE

The objective of the present meta-analysis was to evaluate the association between TaqI (rs731236), ApaI (rs7975232) and BsmI (rs1544410) polymorphisms of the VDR gene and lumbar spine pathologies such as lumbar disc herniation and lumbar disc degeneration.

BACKGROUND

VDR gene polymorphisms have been reported to be associated with an increased risk of lumbar spine pathologies.

MATERIALS AND METHODS

A systematic search was performed up to February 2020 using PubMed, EBSCO and Web of Science databases. We used the keywords and combinations "lumbar disc degeneration," "lumbar disc herniation," "lumbar spine pathologies" and "VDR polymorphism." Subsequently, we performed a meta-analysis with the results of the included studies.

RESULTS

We found that the TaqI polymorphism was associated with an increased risk of developing lumbar spine pathologies (recessive model OR 1.25, 95% CI 1.01-1.54) and lumbar disc degeneration (allelic model OR 1.26, 95% CI 1.07-1.48; recessive model OR 1.34, 95% CI 1.06-1.69), but not with lumbar disc herniation. Additionally, ApaI was associated with an increased risk of developing lumbar spine pathologies (heterozygous model OR 1.45, 95% CI 1.06-1.98), but not with lumbar disc herniation or lumbar disc degeneration.

CONCLUSIONS

Our findings indicate that TaqI and ApaI polymorphisms of the VDR gene are important risk factors for developing lumbar spine pathologies. Moreover, the TaqI polymorphism is a risk factor for lumbar disc degeneration.

Vitamin D receptor gene polymorphisms and risk of intervertebral disc degeneration: An updated meta-analysis based on 23 studies

BACKGROUND

Numerous studies have investigated the associations between Vitamin D receptor (VDR) gene polymorphisms and risk of intervertebral disc degeneration but the results remain controversial. This study aimed to drive a more precise estimation of association between VDR gene polymorphisms and risk of intervertebral disc degeneration.

METHODS

PubMed, EMBASE, Cochrane library, Web of Science and China Knowledge Resource Integrated Database for papers on VDR gene polymorphisms and risk of intervertebral disc degeneration were searched. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association in the homozygote model, heterozygote model, dominant model, recessive model and an additive model.

RESULTS

Overall, 23 articles were included in the final meta-analysis. The subgroup analyses by ethnicity showed a significant association of VDR FokI mutation with disc degeneration risk in Caucasians (recessive model, OR with 95%CI 1.301, [1.041, 1.626]; additive model, OR with 95%CI 1.119, [1.006, 1.245]). The results of subgroup analyses by ethnicity showed a significant association of VDR TaqI mutation with disc degeneration risk in Asians but not in Caucasians. There was a significant association between VDR ApaI mutation and risk of disc degeneration and subgroup analyses by ethnicity showed a significant association in Caucasians and in Asians.

CONCLUSIONS

In summary, VDR FokI polymorphisms was associated with disc degeneration risk among Caucasians but not Asians, VDR TaqI polymorphisms was associated with disc degeneration risk among Asians but not Caucasians, while VDR ApaI polymorphism was associated with disc degeneration risk among Asians and Caucasians.

Associations between vitamin D receptor gene polymorphisms and spinal degenerative disease: evidence from a meta-analysis based on 35 case-control studies

OBJECTIVE

Dozens of reports on the associations of vitamin D receptor (VDR) gene polymorphisms and susceptibility to spinal degenerative disease (SDD) were conducted with inconsistent findings. This study aimed to elucidate the associations through a meta-analysis approach.

METHODS

Databases of PubMed, EMBASE, Web of Science, CNKI, and Wanfang were searched until July 10, 2020. Study quality was evaluated by using Newcastle-Ottawa Scale (NOS). Odds ratios (ORs) and 95% confidence intervals (95%CIs) were calculated to evaluate the associations under allelic model (1 vs. 2), homozygous model (11 vs. 22), heterozygous model (12 vs. 22), dominant model (11 + 12 vs. 22), and recessive model (11 vs. 12 + 22).

RESULTS

A total of 5021 cases and 5746 controls from 35 studies were eligible to this meta-analysis. According to NOS, the included studies were in excellent quality. In the overall population, the pooled data indicated that ApaI was associated with a reduced SDD susceptibility (AA vs. Aa + aa, OR = 0.83, 95%CI 0.71 - 0.96, P = 0.010). But the association was not observed in FokI, TaqI, and BsmI polymorphisms. Subgroup analysis suggested that TaqI polymorphism was correlated to an elevated SDD risk in Asians (TT + Tt vs. tt, OR = 2.55, 95%CI 1.90 - 3.44, P < 0.001).

CONCLUSION

The present study indicates that ApaI polymorphism may contribute to a reduced risk to SDD in the overall population, and TaqI polymorphism confers an elevated susceptibility to SDD in Asians. While, BsmI and FokI polymorphisms appear to have no significant association with SDD.

Interactions between the MMP-3 gene rs591058 polymorphism and occupational risk factors contribute to the increased risk for lumbar disk herniation: A case-control study

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.

17β-Estradiol Prevents Extracellular Matrix Degradation by Downregulating MMP3 Expression via PI3K/Akt/FOXO3 Pathway

STUDY DESIGN

In vitro studies of the role of 17β-estradiol (E2) and its possible targets in intervertebral disc degeneration (IDD).

OBJECTIVE

To define the regulatory role of E2 in IDD and the potential mechanisms.

SUMMARY OF BACKGROUND DATA

IDD has intricate etiology that is influenced by multiple risk factors. However, the underlying molecular mechanisms of occurrence and progression of IDD are not well elucidated. The degradation of extracellular matrix (ECM) has been extensively observed in IDD. E2 was found to inhibit ECM degradation in human nuleus pulposus cells (HNPCs), but the molecular mechanism remained to be determined.

METHODS

Western blot and qPCR was performed to quantify the expression of target proteins in HNPCs. Luciferase reporter gene assay was applied to detect the effects of E2 and forkhead box O-3 (FOXO3) on matrix metalloproteinases (MMP)-3 promoter activity. Chromatin immunoprecipitation assay analyzed the binding of FOXO3 to MMP-3 and the effect of E2 on this process.

RESULTS

We identified the upregulation of collagen II and aggrecan by E2 independent of time and concentration. And E2 downregulated MMP-3 expression in human nucleus pulposus cells. The phosphorylation of FOXO3 led to the reduction of MMP-3 promoter activity. Furthermore, 17β-estradiol-induced the activation of PI3K/Akt pathway is required for FOXO3 phosphorylated.

CONCLUSION

E2 prevents the degradation of ECM by upregulating collagen II and aggrecan expression via reducing MMP-3 expression in HNPCs, and PI3K/Akt/FOXO3 pathway is dispensable for MMP-3 downregulated. Therefore, E2 protects against IDD by preventing ECM degradation.

LEVEL OF EVIDENCE

3.

Lumbar Degenerative Disease Part 1: Anatomy and Pathophysiology of Intervertebral Discogenic Pain and Radiofrequency Ablation of Basivertebral and Sinuvertebral Nerve Treatment for Chronic Discogenic Back Pain: A Prospective Case Series and Review of Literature

Degenerative disc disease is a leading cause of chronic back pain in the aging population in the world. Sinuvertebral nerve and basivertebral nerve are postulated to be associated with the pain pathway as a result of neurotization. Our goal is to perform a prospective study using radiofrequency ablation on sinuvertebral nerve and basivertebral nerve; evaluating its short and long term effect on pain score, disability score and patients’ outcome. A review in literature is done on the pathoanatomy, pathophysiology and pain generation pathway in degenerative disc disease and chronic back pain. 30 patients with 38 levels of intervertebral disc presented with discogenic back pain with bulging degenerative intervertebral disc or spinal stenosis underwent Uniportal Full Endoscopic Radiofrequency Ablation application through either Transforaminal or Interlaminar Endoscopic Approaches. Their preoperative characteristics are recorded and prospective data was collected for Visualized Analogue Scale, Oswestry Disability Index and MacNab Criteria for pain were evaluated. There was statistically significant Visual Analogue Scale improvement from preoperative state at post-operative 1wk, 6 months and final follow up were 4.4 ± 1.0, 5.5 ± 1.2 and 5.7 ± 1.3, respectively, p < 0.0001. Oswestery Disability Index improvement from preoperative state at 1week, 6 months and final follow up were 45.8 ± 8.7, 50.4 ± 8.2 and 52.7 ± 10.3, p < 0.0001. MacNab criteria showed excellent outcomes in 17 cases, good outcomes in 11 cases and fair outcomes in 2 cases Sinuvertebral Nerve and Basivertebral Nerve Radiofrequency Ablation is effective in improving the patients’ pain, disability status and patient outcome in our study.

Gene polymorphisms and expression levels of interleukin-6 and interleukin-10 in lumbar disc disease: a meta-analysis and immunohistochemical study

Background

To investigate the association between interleukin-6 (IL-6) (rs1800795, rs1800796, rs1800797, rs13306435, rs2069849) and interleukin-10 (IL-10) (rs1800871, rs1800896) gene polymorphisms, expression levels, and lumbar disc disease (LDD).

Methods

We conducted a literature research on PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure (CNKI) until February 28, 2019. We included all case-control studies about the association between IL-6 and IL-10 gene polymorphisms and LDD. The odds ratio (OR) and 95% confidence interval (CI) were calculated to estimate the strength of association. Statistical analysis was conducted by Review Manager (RevMan) 5.3 software. Furthermore, immunohistochemistry (IHC) and RT-PCR were performed to evaluate IL-6 and IL-10 expressions in the normal and degenerated disc.

Results

A total of 6 studies, involving 1456 cases and 1611 controls, were included in this meta-analysis. G alleles of rs1800795 and rs1800797 in the IL-6 gene were significantly associated with LDD (rs1800795: G vs. C, OR = 1.38, 95% CI = 1.16–1.64, P = 0.0002; rs1800797: G vs. A, OR = 1.35, 95% CI = 1.14–1.61, P = 0.0006). Begg’s funnel plot and Egger’s tests did not show any evidence of publication bias. IL-6 expression and IL-6 mRNA levels were significantly increased in the degenerated disc compared with those in the normal disc (IL-6 immunopositive cells, 73.68 ± 10.99% vs. 37.23 ± 6.42%, P < 0.001).

Conclusions

IL-6 gene polymorphisms (rs1800795 and rs1800797) were significantly associated with susceptibility to LDD. A high expression level of IL-6 may be an important risk factor for LDD.

A population-based study identifies an association of THBS2 with intervertebral disc degeneration

OBJECTIVE

To clarify the genetic mechanisms underlying intervertebral disc degeneration (IDD), we examined the associations between single-nucleotide polymorphisms (SNPs) and indicated as coefficient of interaction term (IDD) in a general population in Japan.

METHODS

This was a cross-sectional study. In 1,605 participants, C2-3 to L5/S1 in the total spine magnetic resonance imaging (MRI) were evaluated using the Pfirrmann's scoring system. Disc scores of 4 and 5 were defined as IDD. Eight SNPs in eight genes associated with IDD were examined at each disc level, considering the non-genetic risk factors of age, sex, and body mass index (BMI).

RESULTS

The highest odds ratio was found for rs9406328 in the THBS2 gene at disc level T12-L1 (OR 1.27, 95%CI 1.05 to 1.53), and this association was strengthened after adjustment for age using logistic regression (OR 1.37, 95%CI 1.12 to 1.67). Among participants aged <50 years and 50-59, the average IDD score in those with 2 risk alleles of rs9406328 was markedly higher than in those with 0 or 1 risk allele, and the difference is much wider than the elderly participants. It indicates the genetic effect of rs9406328 is stronger in the younger age groups. Finally, multiple linear regression analyses of the association between rs9406328 and IDD, adjusted for age, sex, and BMI at each disc level, showed a statistical interaction between age and the number of risk alleles at C7-T1, T3-4 and T4-T5 as well as T12-L1.

CONCLUSION

CONCLUSION: The association between rs9406328 in THBS2 and IDD was replicated. The contributions of genetic and environmental factors to IDD differed by disc level.

Associations Between Intervertebral Disc Degeneration Grading Schemes and Measures of Disc Function

Disc degeneration is a major cause of spinal dysfunction and pain, but grading schemes concentrate on tissue changes rather than altered function. The aim of this study was to compare disc degeneration grading systems with each other, and with biomechanical measures of disc function. Sixty-six motion segments (T8-9 to L5-S1) were dissected from cadavers aged 48-98 years. Disc function was assessed by measuring nucleus pressure (IDP) and maximum stresses in the annulus under 1 kN of compression. Detailed "scores" of disc degeneration were based on independent radiographic, macroscopic, and microscopic evaluations. For each evaluation, scores were used to assign a degeneration "grade" (I-IV), and functional measures were then correlated with degeneration scores and grades. Results showed that all measures were reliable (intraclass correlation coefficients: 0.82-0.99). Macroscopic and microscopic assessments were highly correlated with each other (r: 0.57-0.89, p < 0.001) but only weakly correlated with radiographic features. The overall macroscopic and microscopic scores of degeneration increased significantly with age and at lower spinal levels, although the influence of age was less marked in the case of the microscopic scores. IDP decreased with age and at lower spinal levels, but annulus stresses were more variable. Importantly, IDP and annulus stresses decreased consistently with all measures of disc degeneration, and these associations remained strong after controlling for age, gender, and spinal level. We conclude that radiographic and tissue-based assessments of disc degeneration are consistent with each other, and are more closely related to mechanical (dys)function than to age or spinal level. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1946-1955, 2019.

Low Back Pain, a Comprehensive Review: Pathophysiology, Diagnosis, and Treatment

PURPOSE OF REVIEW

Low back pain encompasses three distinct sources: axial lumbosacral, radicular, and referred pain. Annually, the prevalence of low back pain in the general US adult population is 10-30%, and the lifetime prevalence of US adults is as high as 65-80%.

RECENT FINDINGS

Patient history, physical exam, and diagnostic testing are important components to accurate diagnosis and identification of patient pathophysiology. Etiologies of low back pain include myofascial pain, facet joint pain, sacroiliac joint pain, discogenic pain, spinal stenosis, and failed back surgery. In chronic back pain patients, a multidisciplinary, logical approach to treatment is most effective and can include multimodal medical, psychological, physical, and interventional approaches. Low back pain is a difficult condition to effectively treat and continues to affect millions of Americans every year. In the current investigation, we present a comprehensive review of low back pain and discuss associated pathophysiology, diagnosis, and treatment.

Serum 25-hydroxyvitamin D, serum calcium and vitamin D receptor (VDR) polymorphisms in a selected population with lumbar disc herniation-A case control study

Background

Association of Vitamin D receptor (VDR) polymorphisms with lumbar disc herniation (LDH) have been identified in several ethnic groups globally. Despite abundant sunlight, vitamin D deficiency is reported in many tropical countries. As vitamin D is a key modulator for intestinal calcium absorption, low vitamin D could contribute to low serum calcium leading to abnormalities of skeletal homeostasis. Therefore, present study was aimed to study the association of serum 25-hydroxyvitamin D (25(OH)D), serum calcium and VDR polymorphisms in a selected Sri Lankan population.

Materials & methods

A case control study was conducted in 119 participants (cases = 51: controls = 68). Serum 25(OH)D levels were measured using ELISA. The VDR polymorphisms (Fok I and Taq I) were detected by polymerase chain reaction followed by restriction fragment length polymorphism.

Results

Findings indicated a significantly low (p = 0.000) 25(OH)D levels in cases (18.7±3.7 ng/mL) compared to controls(25.5±9.8 ng/mL) while 25(OH)D in both groups were below the reference range. Mean serum calcium levels in both groups were within normal reference range and was not significantly different among groups. Statistically significant association was not observed between VDR Fok I polymorphisms among cases and controls. Although Fok I polymorphism genotypes were in Hardy-Weinberg equilibrium (HWE), Taq I genotypes in controls violated HWE.

Conclusion

Present study confirms that insufficient serum 25(OH)D levels in cases have major contribution to LDH. VDR Fok I polymorphisms did not have any significant association with LDH in Sri Lankan ethnicity.

Genetic background of degenerative disc disease in the lumbar spine

This is a review paper on the topic of genetic background of degenerative disc diseases in the lumbar spine. Lumbar disc diseases (LDDs), such as lumbar disc degeneration and lumbar disc herniation, are the main cause of low back pain. There are a lot of studies that tried to identify the causes of LDDs. The causes have been categorized into environmental factors and genetic factors. Recent studies revealed that LDDs are mainly caused by genetic factors. Numerous studies have been carried out using the genetic approach for LDDs. The history of these studies is divided into three periods: (1) era of epidemiological research using familial background and twins, (2) era of genomic research using DNA polymorphisms to identify susceptible genes for LDDs, and (3) era of functional research to determine how the genes cause LDDs. This review article was undertaken to present the history of genetic approach to LDDs and to discuss the current issues and future perspectives.

Influence of lifestyle characteristics and VDR polymorphisms as risk factors for intervertebral disc degeneration: a case-control study

BACKGROUND

Intervertebral disc degeneration (DD) is an important cause of low back pain and its precise aetiology is not fully understood, being attributed to cumulative environmental, biomechanical and genetic effects. The vitamin D plays a key role in regulation of calcium homeostasis and bone mineralization, exerting its biological activities by binding to a high-affinity receptor (VDR). Polymorphisms in VDR gene were previously associated with DD process, however with conflicting results. Here, we aimed to investigate the influence of lifestyle characteristics and VDR TaqI, BsmI, ApaI and FokI polymorphisms as risk factors for DD process.

METHODS

Retrospective case-control study involving 231 participants: 119 with confirmed DD and 112 healthy controls. Genotyping of VDR polymorphisms was performed by PCR-RFLP and real-time PCR using TaqMan methodology. All patients answered a questionnaire regarding lifestyle characteristics, such as educational level, pain localization, smoking habits, engagement of physical activity, postural and load weight at work and familial history of disc degeneration. The variables were compared between groups and adjusted by age and gender.

RESULTS

The case group was composed by 52% female and 48% male and the mean age was 40.0 years old, while in the control group 79% was female and 21% male and the mean age was 32.0 years old. Although gender distribution and mean age were different between groups, in the control group all participants were less than 45 years old and there was a prevalence of women in both groups. The factors that could be possibly associated to DD in the Brazilian population studied included smoking habits (26% in cases and 9% in controls, p = 0.003), lack of engagement in physical activity (observed in 77% of cases and 62% of controls, p = 0.018), and loading weight during work routine (58% in cases and 24% in controls, p ≤ 0.001). However, after adjusting by age and gender, only smoking habits remained associated to disc degeneration (p = 0.027). Considering the educational level, 35.2% of cases and 15.6% of controls had only the Elementary School, and 5.5% of DD group and 28.6% of control group had completed College (p = 0.025). In addition, educational level was directly associated to load weight at work (p = 0.012). Regarding VDR polymorphisms, no significant difference in genotype and allele frequencies between groups was observed. The haplotype analysis revealed that the combined wild-type alleles of TaqI, ApaI and FokI polymorphisms-TGT-was observed in a higher frequency in control group (p = 0.039).

CONCLUSION

The findings suggested that smoking habits was a risk factor for disc degeneration in the population studied. Single analysis revealed no significant effects of VDR polymorphisms in disc degeneration process, while the combination of wild-type alleles of TaqI, ApaI and FokI polymorphisms, TGT haplotype, decreased the risk of the disease.

Association between vitamin D receptor gene polymorphisms and intervertebral disc degeneration: A meta-analysis

BACKGROUND

Studies that have investigated the association between vitamin D receptor (VDR) gene polymorphisms and intervertebral disc degeneration (IDD) have yielded inconsistent results.

METHODS

To investigate the association between VDR gene polymorphisms and IDD, a systematic literature search for relevant published studies was performed on PubMed, Embase, Web of Science, Cochrane library, Wan-Fang, and CNKI databases. A random effects model was used for heterogeneous data; while a fixed effect model was used for homogenous data. Odds ratios (OR) and 95% confidence intervals (CI) were calculated to evaluate the strength of the association.

RESULTS

We observed no association between VDR FokI, TaqI-ApaI polymorphisms and IDD. However, on subgroup analysis by ethnicity, VDR FokI mutation was associated with a significantly lower risk for IDD [dominant model: OR = 0.78, 95% CI = 0.65-0.93; heterozygote model: OR = 0.76, 95% CI = 0.63-0.92; allele model: OR = 0.86, 95% CI = 0.75-0.98] among Caucasians.

CONCLUSION

These results suggest that the VDR FokI polymorphism may be associated with IDD among Caucasians. However, the association between VDR TaqI-ApaI polymorphisms and IDD in Asians is still not clear. Further well-designed studies are needed to arrive at a definitive conclusion.

Genes associated with persistent lumbar radicular pain; a systematic review

Background

The aim of the present study was to provide an overview of the literature addressing the role of genetic factors and biomarkers predicting pain recovery in newly diagnosed lumbar radicular pain (LRP) patients.

Methods

The search was performed in Medline OVID, Embase, PsycInfo and Web of Science (2004 to 2015). Only prospective studies of patients with LRP addressing the role of genetic factors (genetic susceptibility) and pain biomarkers (proteins in serum) were included. Two independent reviewers extracted the data and assessed methodological quality.

Results

The search identified 880 citations of which 15 fulfilled the inclusion criteria. Five genetic variants; i.e., OPRM1 rs1799971 G allele, COMT rs4680 G allele, MMP1 rs1799750 2G allele, IL1α rs1800587 T allele, IL1RN rs2234677 A allele, were associated with reduced recovery of LRP. Three biomarkers; i.e., TNFα, IL6 and IFNα, were associated with persistent LRP.

Conclusion

The present results indicate that several genetic factors and biomarkers may predict slow recovery in LRP. Still, there is a need for replication of the findings. A stricter use of nomenclature is also highly necessary.

Trial registration

The review is registered PROSPERO 20^th of November 2015. Registration number is CRD42015029125.

Genetic Alterations in Intervertebral Disc Disease

BACKGROUND

Intervertebral disc degeneration (IVDD) is considered a multifactorial disease that is influenced by both environmental and genetic factors. The last two decades of research strongly demonstrate that genetic factors contribute about 75% of the IVDD etiology. Recent total genome sequencing studies have shed light on the various single-nucleotide polymorphisms (SNPs) that are associated with IVDD.

AIM

This review presents comprehensive and updated information about the diversity of genetic factors in the inflammatory, degradative, homeostatic, and structural systems involved in the IVDD. An organized collection of information is provided regarding genetic polymorphisms that have been identified to influence the risk of developing IVDD. Understanding the proteins and signaling systems involved in IVDD can lead to improved understanding and targeting of therapeutics.

MATERIALS AND METHODS

An electronic literature search was performed using the National Library of Medicine for publications using the keywords genetics of IVDD, lumbar disc degeneration, degenerative disc disease, polymorphisms, SNPs, and disc disease. The articles were then screened based on inclusion criteria that included topics that covered the correlation of SNPs with developing IVDD. Sixty-five articles were identified as containing relevant information. Articles were excluded if they investigated lower back pain or just disc herniation without an analysis of disc degeneration. This study focuses on the chronic degeneration of IVDs.

RESULTS

Various genes were identified to contain SNPs that influenced the risk of developing IVDD. Among these are genes contributing to structural proteins, such as COL1A1, COL9A3, COL9A3, COL11A1, and COL11A2, ACAN, and CHST3. Furthermore, various SNPs found in the vitamin-D receptor gene are also associated with IVDD. SNPs related to inflammatory cytokine imbalance are associated with IVDD, although some effects are limited by sex and certain populations. SNPs in genes that code for extracellular matrix-degrading enzymes, such as MMP-1, MMP-2, MMP-3, MMP-9, MMP-14, ADAMTS-4, and ADAMTS-5 are also associated with IVDD. Apoptosis-mediating genes, such as caspase 9 gene (CASP9), TRAIL, and death receptor 4 (DR4), as well as those for growth factors, such as growth differentiation factor 5 and VEGF, are identified to have polymorphisms that influence the risk of developing IVDD.

CONCLUSION

Within the last 10 years, countless new SNPs have been identified in genes previously unknown to be associated with IVDD. Furthermore, the last decade has also revealed new SNPs identified in genes already known to be involved with increased risk of developing IVDD. Improved understanding of the numerous genetic variants behind various pathophysiological elements of IVDD could help advance personalized care and pharmacotherapeutic strategies for patients suffering from IVDD in the future.

Vitamin D Receptor Gene, Matrix Metalloproteinase 3 Polymorphisms and the Risk of Intervertebral Disc Degeneration Susceptibility: Meta-Analysis

Several studies have evaluated the association between vitamin D receptor, matrix metalloproteinase 3 (MMP-3) polymorphisms and the risk of intervertebral disc degeneration susceptibility. The findings were inconsistent. This meta-analysis aimed to systematically assess the association between vitamin D receptor, MMP-3 polymorphisms and the risk of intervertebral disc degeneration susceptibility. A search of various databases was done covering all papers published until December 31th, 2014. Eight, 4, 3 studies were finally included that addressed the risk of intervertebral disc degeneration susceptibility and vitamin D receptor FokI (rs2228570), ApaI (rs7975232), and MMP-3 (rs731236) polymorphisms, respectively. FokI (f vs. F: summary odds ratio [OR], 1.13; 95% confidence interval [CI], 0.76–1.69; ff vs. FF: OR, 1.02; 95% CI, 0.59–1.77; ff vs. Ff/FF: OR, 1.05; 95% CI, 0.70–1.58), ApaI (a vs. A: OR, 0.73; 95% CI, 0.45–1.19; aa vs. AA: OR, 0.53; 95% CI, 0.22–1.25 p=0.14; aa vs. AA/Aa: OR, 0.69; 95% CI, 0.53–0.89) in the vitamin D receptor gene and MMP3 polymorphisms (5A vs. 6A: OR, 1.92; 95% CI, 0.77–4.80; 5A5A vs. 6A6A: OR, 2.17; 95% CI, 0.75–6.24; 5A5A vs. 5A6A/6A6A: OR, 1.58; 95% CI, 0.72–3.44) were not obviously associated with risk of intervertebral disc degeneration susceptibility. FokI, ApaI polymorphisms in the vitamin D receptor gene and MMP-3 polymorphism are not obvious risk factors for intervertebral disc degeneration susceptibility.

Associations of Caspase-3 gene polymorphism with lumbar disc herniation

To investigate Caspase-3 gene polymorphisms (rs4647693 G/A, rs4647610 A/G, and rs12108497 T/C) and susceptibility to lumbar intervertebral disc herniation (LDH). The genotype frequency distributions of the polymorphisms were detected by polymerase chain reaction-restriction fragment length polymorphism in 107 LDH patients (case group) and 121 healthy individuals (control group). SHEsis software was used to conduct gene linkage disequilibrium and haplotype analysis. Regression analysis was used to analyze possible risk factors for LDH. Statistically significant differences in family history of LDH, amateur sports, leisure activities, bed types, and spine load grade were found between the case and control groups. The distribution of allele and genotype frequencies of rs4647693 G/A, rs4647610 A/G, and rs12108497 T/C polymorphisms of Caspase-3 were significantly different between the case and control groups. Haplotype analysis showed that the G-G-C (rs4647693-rs4647610-rs12108497) haplotype might be a risk factor for LDH, whereas the A-A-T haplotype might be a protective factor (p < 0.05). Binary logistic regression analysis showed that the GA+AA genotype of rs4647693 was negatively associated with the risk of LDH, whereas high spine load grade was positively associated with the risk of LDH. These findings revealed that rs4647693 G/A, rs4647610 A/G, and rs12108497 T/C polymorphisms of Caspase-3 may be associated with susceptibility to LDH and that interaction and modification effects may exist between Caspase-3 polymorphisms.

Vitamin D receptor gene polymorphisms and lumbar disc degeneration: a systematic review and meta-analysis

PURPOSE

To examine the association between Vitamin D receptor (VDR) gene polymorphisms and lumbar disc degeneration (LDD) predisposition.

METHODS

A comprehensive literature search was conducted to identify all the relevant studies. The allele/genotype frequencies were extracted from each study. We calculated the pooled odds ratios (ORs) and 95 % confidence intervals (CI) to assess the strength of the association between the VDR gene polymorphisms and LDD risk. Statistical analysis was performed using RevMan 5.31 software.

RESULTS

A total of 23 case-control studies (1835 cases and 1923 controls) were included in this systematic review. For the TaqI (rs731236), FokI (rs2228570) and ApaI (rs7975232) polymorphisms of VDR gene, nine studies, seven studies, and five studies, were eventually included in the meta-analysis, respectively. There was no evidence that the VDR gene polymorphisms (TaqI, FokI, ApaI) had significant associations with LDD risk.(for TaqI allelic comparison, OR = 1.07, 95 % CI 0.81-1.40, p = 0.64; for FokI allelic comparison, OR = 1.23, 95 % CI 0.83-1.82, p = 0.31; for ApaI allelic comparison, OR = 0.79, 95 % CI 0.55-1.14, p = 0.20). For stratified analyses by ethnicity and study design, no significant associations were found in Caucasian population and Asian population, as well as the population-based studies and hospital-based studies under all genetic models.

CONCLUSIONS

TaqI, FokI, and ApaI polymorphisms of VDR gene were not significantly associated with the predisposition of LDD. Large-scale and well-designed international studies are needed to further analyze this field.

BsmI, ApaI and TaqI Polymorphisms in the Vitamin D Receptor Gene (VDR) and Association with Lumbar Spine Pathologies: An Italian Case-Control Study

Three adjacent single nucleotide polymorphisms of the vitamin D receptor gene (VDR) BsmI (rs1544410), ApaI (rs7975232), and TaqI (rs731236) are commonly studied in several pathologies. We aimed to evaluate the distribution of VDR BsmI, ApaI, and TaqI allele, genotype, and haplotype frequencies in an Italian cohort of 266 patients with lumbar spine disorders assessed by Magnetic Resonance Imaging and 252 asymptomatic controls. The exposure to putative risk factors was evaluated by a questionnaire. Polymorphisms were detected by PCR-RFLP and TaqMan^® SNP Genotyping Assay. The results were statistically adjusted for the identified conventional risk factors. The three SNPs were in linkage disequilibrium. For all cases BbAaTT was a 3-fold risk factor OR = 3.38), whereas bbAATT (OR = 0.22), and bbaaTT (OR = 0.47) genotypes were found to be protective. Specifically, for patients affected by disc herniation only (n = 88) and all lumbar pathologies excluding stenosis and/or spondylolistesis (n = 215) B allele, Bb, Aa, and BbAaTT genotypes were risky, whereas b allele, bb, aa, and bbaaTT genotypes were protective. In patients affected by osteochondrosis with or without disc hernation (n = 50), T allele, Aa, and bbAaTT genotypes were risky, whereas t allele, AA, tt genotypes were protective. In patients affected by stenosis and/or spondylolistesis (n = 51) no significant associations were found. This is the first study showing an association of the three genetic VDR variants BsmI, ApaI, and TaqI and lumbar spine pathologies. Our study contributes to delineate genetic risk factors for specific subgroups of patients with lumbar spine pathologies highlighting the importance of haplotype analysis, and of detailed clinical evaluation of the patients for identification of genetic biomarkers.

Autophagy: A double-edged sword in intervertebral disk degeneration

Autophagy is a homeostatic mechanism through which intracellular damaged organelles and proteins are degraded and recycled in response to increased metabolic demands or stresses. Although primarily cytoprotective, dysfunction of autophagy is often associated with many degenerative diseases, including intervertebral disc (IVD) degeneration (IDD). As a main contributing factor to low back pain, IDD is the pathological basis for various debilitating spinal diseases. Either higher or lower levels of autophagy are observed in degenerative IVD cells. Despite the precise role of autophagy in disc degeneration that is still controversial, with difference from protection to aggravation, targeting autophagy has shown promise for mitigating disc degeneration. In the current review, we summarize the changes of autophagy in degenerative IVD cells and mainly discuss the relationship between autophagy and IDD. With continued efforts, modulation of the autophagic process could be a potential and attractive therapeutic strategy for degenerative disc disease.

Association of collagen I, IX and vitamin D receptor gene polymorphisms with radiological severity of intervertebral disc degeneration in Southern European Ancestor

PURPOSE

Several genomic loci have been previously found to be associated with intervertebral disc degeneration, so far. Data are mostly derived from northern European countries whereas data derived from Southern European Ancestor are limited. This study aimed to evaluate the association between radiological disease severity of lumbar disc degeneration and certain genetic loci in a sample of participants from Southern Europe.

METHODS

Seventy-five patients with mild to severe lumbar disc degeneration and 25 healthy controls were enrolled into the study. In each subject, each lumbar intervertebral disc was separately examined to obtain a total radiological score for disease severity. In addition, single-nucleotide polymorphisms of predefined genetic samples were analyzed in all participants: COL1A1 Sp1, COL9a2 Trp2, COL9a3 Trp3, and VDR TaqI.

RESULTS

Degeneration scores were significantly worse in cases with COL1A1 Sp1, COL9a3 Trp3, and VDR TaqI mutations; however, COL9a2 Trp2 mutation was not associated with a difference in the severity of disc degeneration. In addition, subjects with mutation in more than one gene sample (n = 20) had significantly worse degeneration scores than the remaining study participants (n = 80) (17.70 ± 2.72 vs. 21.81 ± 1.81, p < 0.001).

CONCLUSION

Single-nucleotide polymorphisms occurring in COL1A1, COL9a3 and VDR genes seem to be associated with the development of lumbar disc degeneration in this cohort, possibly with even more pronounced association when multiple mutations are present in the same individual. By further prospective twin studies in associated genes and analyses of their relationship with environmental factors in an internationally sampled large cohort will make a more clear-minded conclusion about their association with disc degeneration, which would yield better appreciation and clinical planning of some predisposed people for these pathologies.

MMPs and ADAMTSs in intervertebral disc degeneration

Intervertebral disc degeneration (IDD) is the most common diagnosis in patients with low back pain, a leading cause of musculoskeletal disability worldwide. The major components of extracellular matrix (ECM) within the discs are type II collagen (Col II) and aggrecan. Excessive destruction of ECM, especially loss of Col II and aggrecan, plays a critical role in promoting the occurrence and development of IDD. Matrix metalloproteinases (MMPs) and a disintegrin and metalloprotease with thrombospondin motifs (ADAMTSs) are primary enzymes that degrade collagens and aggrecan. There is a large and growing body of evidence that many members of MMPs and ADAMTSs are highly expressed in degenerative IVD tissue and cells, and are closely involved in ECM breakdown and the process of disc degeneration. In contrast, targeting these enzymes has shown promise for promoting ECM repair and mitigating disc regeneration. In the current review, after a brief description regarding the biology of MMPs and ADAMTSs, we mainly focus on their expression profiles, roles and therapeutic potential in IDD. A greater understanding of the catabolic pathways involved in IDD will help to develop potential prophylactic or regenerative biological treatment for degenerative disc disease in the future.

Dysregulated COL3A1 and RPL8, RPS16, and RPS23 in Disc Degeneration Revealed by Bioinformatics Methods

STUDY DESIGN

Bioinformatics analysis of published microarray data.

OBJECTIVE

This study aimed to reveal the possible genes and pathways related to the pathogenesis of disc degeneration (DD) by analyzing the microarray data.

SUMMARY OF BACKGROUND DATA

DD is one of the main causes of low back pain, which has become an enormous economic burden for society.

METHODS

Gene expression data of annulus cells and nucleus pulposus cells from patients with DD and controls subjects were downloaded from Gene Expression Omnibus. T test and enrichment analysis were used to identify differentially expressed genes (DEGs) and DEGs-associated functions and pathways in DD, respectively. Protein-protein interaction network and module were constructed to analyze the key nodes associated with this disease.

RESULTS

A total of 326 DEGs and 35 DEGs were obtained from the annulus cells and nucleus pulposus cells, respectively. The DEGs of DD in annulus cells were mainly involved in translation, cell adhesion, cell death regulation, and skeletal system development whereas the DEGs in nucleus pulposus cells were mainly related to the biological processes of vascular system development, skeletal system development, and enzyme-linked receptor protein signaling pathway. COL3A1 was the common DEG in both annulus cells and nucleus pulposus cells. The genes encode ribosomal proteins (RPL8, RPS16, and RPS23) in module were enriched in biological processes of translation, translation elongation, and RNA processing.

CONCLUSION

The results revealed the involvement of COL3A1 in skeletal system process and RPL8, RPS16, and RPS23 in the protein synthesis processes in the progression of DD, suggesting their potential use in the diagnosis and therapy of DD.

LEVEL OF EVIDENCE

N/A.

Association of adiponectin protein and ADIPOQ gene variants with lumbar disc degeneration

Lumbar disc degeneration (LDD) is a widespread public health problem that may lead to disability and loss of productivity. Adiponectin is an adipokine secreted by adipose tissue and has been shown to be involved in cartilage homeostasis. In the present study, the association between the rs266729 (−11377C/G) and rs2241766 (45T/G) single nucleotide polymorphisms (SNPs) in the adiponectin gene (ADIPOQ) and LDD was investigated. In addition, the correlation between the plasma adiponectin level and LDD was examined. A total of 289 subjects, 168 patients with LDD and 122 healthy individuals, were recruited in the study. All subjects were genotyped for rs266729 and rs2241766 SNPs using polymerase chain reaction-restriction fragment length polymorphism. Circulating levels of adiponectin protein were measured using the ELISA technique. A strong association was found between adiponectin level and LDD (P<0.01), where high levels of adiponectin were found in patients compared with healthy controls. The increase in adiponectin level was not affected by gender. However, no significant differences were found in the genotype distribution or allelic frequency of the two examined polymorphisms between patients with LDD and healthy controls (P>0.05). In conclusion, adiponectin appears to be elevated in patients with LDD. The rs266729 and rs2241766 SNPs in the ADIPOQ gene are not associated with LDD.

Analysis of FokI polymorphism of vitamin D receptor gene in intervertebral disc degeneration

AIM

We have hypothesized a possible relationship between disc degeneration (DD) and VDR FokI/T2C polymorphism.

METHODS

A case-control study was performed comprising 121 Brazilian patients with confirmed DD by nuclear magnetic resonance and a control group consisting of 131 healthy patients without a history of disc cysts of the lumbar spine. Detection of VDR FokI/T2C polymorphism was performed using restriction fragment length polymorphism-polymerase chain reaction. The chi-square test was used to compare allele and genotype frequencies between groups, and a p-value of <0.05 was considered statistically significant.

RESULTS

The results disclosed statistical difference between allele distribution among cases and controls (p=0.025, odds ratio=1.58, confidence interval=1.07-2.32) considering VDR FokI/T2C polymorphism.

CONCLUSION

The results showed a positive association between VDR FokI/T2C polymorphism and DD in Brazilian patients tested.