A functional polymorphism in COL11A1, which encodes the alpha 1 chain of type XI collagen, is associated with susceptibility to lumbar disc herniation

A longitudinal population-based study identifies THBS2 as a susceptibility gene for intervertebral disc degeneration

PURPOSE

Intervertebral disc degeneration (IDD) is a common degenerative disease associated with ageing. Additionally, IDD is recognized as one of the leading causes of low back pain and disability in the working-age population and is the first step in the process leading to degenerative spinal changes. However, the genetic factors and regulatory mechanisms of IDD remain unknown. Therefore, we selected eight single nucleotide polymorphisms of genes to reveal the progression of IDD in a 7-year longitudinal study of the general population in Japan.

METHODS

IDD was evaluated in the Wakayama Spine Study (WSS), which is a population-based cohort study. Overall, 574 participants from the general population cohort who underwent whole spine magnetic resonance imaging and provided clinical information were included in this longitudinal survey.

RESULTS

The progression of IDD was affected only by THBS2 at the lumbar region, T12-L1 (p = 0.0044) and L3-4 (p = 0.0045). The significant interaction between THBS2 and age with IDD negatively affected the thoracic spines and passively influenced both the thoracolumbar junction and thoracic spines. The higher progression per year of Pfirrmann's score was rapid in young people with age; however, this decelerated the IDD progression per year in different ages.

CONCLUSION

Our longitudinal study found the genes associated with IDD progression and that genetic factors' impact on IDD differs depending on disc level and age.

Bioenergetic dysfunction in the pathogenesis of intervertebral disc degeneration

Intervertebral disc (IVD) degeneration is a frequent cause of low back pain and is the most common cause of disability. Treatments for symptomatic IVD degeneration, including conservative treatments such as analgesics, physical therapy, anti-inflammatories and surgeries, are aimed at alleviating neurological symptoms. However, there are no effective treatments to prevent or delay IVD degeneration. Previous studies have identified risk factors for IVD degeneration such as aging, inflammation, genetic factors, mechanical overload, nutrient deprivation and smoking, but metabolic dysfunction has not been highlighted. IVDs are the largest avascular structures in the human body and determine the hypoxic and glycolytic features of nucleus pulposus (NP) cells. Accumulating evidence has demonstrated that intracellular metabolic dysfunction is associated with IVD degeneration, but a comprehensive review is lacking. Here, by reviewing the physiological features of IVDs, pathological processes and metabolic changes associated with IVD degeneration and the functions of metabolic genes in IVDs, we highlight that glycolytic pathway and intact mitochondrial function are essential for IVD homeostasis. In degenerated NPs, glycolysis and mitochondrial function are downregulated. Boosting glycolysis such as HIF1α overexpression protects against IVD degeneration. Moreover, the correlations between metabolic diseases such as diabetes, obesity and IVD degeneration and their underlying molecular mechanisms are discussed. Hyperglycemia in diabetic diseases leads to cell senescence, the senescence-associated phenotype (SASP), apoptosis and catabolism of extracellualr matrix in IVDs. Correcting the global metabolic disorders such as insulin or GLP-1 receptor agonist administration is beneficial for diabetes associated IVD degeneration. Overall, we summarized the recent progress of investigations on metabolic contributions to IVD degeneration and provide a new perspective that correcting metabolic dysfunction may be beneficial for treating IVD degeneration.

Genetic polymorphism of KIAA1217 is functionally associated with lumbar disc herniation in the Chinese population

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.

COL11A1 is associated with developmental dysplasia of the hip and secondary osteoarthritis in the HUNT study

Objective

Developmental dysplasia of the hip (DDH) is a congenital condition affecting 2-3% of all infants. DDH increases the risk of osteoarthritis, is the cause of 30 ​% of all total hip arthroplasties (THAs) in adults <40 years of age and can result in loss of life quality. Our aim was to explore the genetic background of DDH in order to improve diagnosis, management and longterm outcome.

Design

We used the large, ongoing, longitudinal Trøndelag Health Study (HUNT) database. Case definition was based on ICD-9/-10 diagnoses of DDH, or osteoarthritis secondary to DDH. Analyses were performed using SAIGE software, with covariates including sex, batch, birth year and principal components. We included only single nucleotide polymorphisms (SNPs) with minor allele frequency (MAF) ≥ 0.01, R2≥ 0.8 and Hardy-Weinberg equilibrium (HWE) P-value ≥ 0.0001. Significance level was set at p ​< ​5 ​× ​10-8. Meta-analysis using data from DDH and primary osteoarthritis genome-wide association studies (GWASs) was done using METAL software. The study was approved by the regional ethical committee.

Results

Analysis included 69,500 individuals, of which 408 cases, and 8,531,386 SNPs. Two SNPs near COL11A1 were significantly associated with DDH; rs713162 (β  ​= ​-0.43, SE ​= ​0.07, p ​= ​8.4 ​× ​10-9) and rs6577334 (β  ​= ​-0.43, SE ​= ​0.08, p ​= ​8.9 ​× ​10-9). COL11A1 has previously been associated with acetabular dysplasia and osteoarthritis. Meta-analysis supported previous GWAS findings of both DDH and primary osteoarthritis.

Conclusions

This large, genome-wide case-control study indicates an association between COL11A1 and DDH and is an important contribution to investigating the etiology of DDH, with further research needed.

Association of genetic variation in COL11A1 with adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) is a common and progressive spinal deformity in children that exhibits striking sexual dimorphism, with girls at more than fivefold greater risk of severe disease compared to boys. Despite its medical impact, the molecular mechanisms that drive AIS are largely unknown. We previously defined a female-specific AIS genetic risk locus in an enhancer near the PAX1 gene. Here, we sought to define the roles of PAX1 and newly identified AIS-associated genes in the developmental mechanism of AIS. In a genetic study of 10,519 individuals with AIS and 93,238 unaffected controls, significant association was identified with a variant in COL11A1 encoding collagen (α1) XI (rs3753841; NM_080629.2_c.4004C>T; p.(Pro1335Leu); p=7.07E-11, OR = 1.118). Using CRISPR mutagenesis we generated Pax1 knockout mice (Pax1-/-). In postnatal spines we found that PAX1 and collagen (α1) XI protein both localize within the intervertebral disc-vertebral junction region encompassing the growth plate, with less collagen (α1) XI detected in Pax1-/- spines compared to wild-type. By genetic targeting we found that wild-type Col11a1 expression in costal chondrocytes suppresses expression of Pax1 and of Mmp3, encoding the matrix metalloproteinase 3 enzyme implicated in matrix remodeling. However, the latter suppression was abrogated in the presence of the AIS-associated COL11A1P1335L mutant. Further, we found that either knockdown of the estrogen receptor gene Esr2 or tamoxifen treatment significantly altered Col11a1 and Mmp3 expression in chondrocytes. We propose a new molecular model of AIS pathogenesis wherein genetic variation and estrogen signaling increase disease susceptibility by altering a PAX1-COL11a1-MMP3 signaling axis in spinal chondrocytes.

Detailed MRI evaluation of the spine: a 2-year follow-up study of young individuals reporting different training doses

OBJECTIVE

To characterize the discs and vertebrae in detail over time in a group of adolescent individuals with varying training doses using magnetic resonance imaging (MRI).

METHOD

Thirty-five students were recruited from regular high schools (n=13) as well as schools with athlete competitive skiing programmes (n = 22). The thoraco-lumbar spine of all individuals was examined at baseline and at 2-year follow-up using the same 1.5T scanner and imaging protocol. The individuals were grouped based on their reported training dose: low-to-normal training dose (≤5 h/week, n = 11, mean age 16.5 ± 0.5 years) and high training dose (>5 h/week, n = 24, mean age 17.2 ± 0.6 years.) RESULTS: At baseline, the signal intensity in the discs and vertebrae were significantly lower in individuals reporting high compared to low-to-normal training dose. The vertebral signal changed significantly over the 2-year period in both groups. However, only individuals reporting low-to-normal training dose displayed an overall disc signal change. Interestingly, the regional analysis displayed at baseline high annular signals in the more training-active individuals followed by a reduction over the two-year period.

CONCLUSION

This study suggests that disc degeneration is manifested earlier in individuals reporting a higher training dose. Over a 2-year period, however, the degeneration process did not accelerate further. Also, a significant difference in the vertebral signal, at baseline and follow-up as well as over time, could be seen between groups of individuals reporting high versus low-to-normal training dose.

Circular circRANGAP1 Contributes to Non-small Cell Lung Cancer Progression by Increasing COL11A1 Expression Through Sponging miR-653-5p

Numerous studies have discovered that hsa_circ_0063526 (also known as circRANGAP1) is an oncogenic circular RNA (circRNA) in some human tumors, including non-small cell lung cancer (NSCLC). However, the concrete molecular mechanism of circRANGAP1 involved in NSCLC is not completely elucidated. CircRANGAP1, microRNA-653-5p (miR-653-5p), and Type XI collagen (COL11A1) contents were determined via real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferative ability, migration, and invasion were measured using 5-ethynyl-2'-deoxyuridine (EdU), colony formation, wound healing, and transwell assays. E-cadherin, N-cadherin, Vimentin, and COL11A1 protein levels were detected via western blot assay. After Starbase software prediction, the binding between miR-653-5p and circRANGAP1 or COL11A1 was verified using a dual-luciferase reporter assay. Besides, the role of circRANGAP1 on tumor cell growth was analyzed using a xenograft tumor model in vivo. Increased circRANGAP1 and COL11A1, and reduced miR-653-5p were found in NSCLC tissues and cell lines. Furthermore, circRANGAP1 absence might hinder NSCLC cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) in vitro. Mechanically, circRANGAP1 functioned as a sponge of miR-653-5p to increase COL11A1 expression. In vivo experiments illustrated that circRANGAP1 knockdown repressed tumor growth. CircRANGAP1 silencing might suppress NSCLC cell malignant biological behaviors, at least in part, through the miR-653-5p/COL11A1 axis. These results provided a promising strategy for treating NSCLC malignancies.

Association of genetic variation in COL11A1 with adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) is a common and progressive spinal deformity in children that exhibits striking sexual dimorphism, with girls at more than five-fold greater risk of severe disease compared to boys. Despite its medical impact, the molecular mechanisms that drive AIS are largely unknown. We previously defined a female-specific AIS genetic risk locus in an enhancer near the PAX1 gene. Here we sought to define the roles of PAX1 and newly-identified AIS-associated genes in the developmental mechanism of AIS. In a genetic study of 10,519 individuals with AIS and 93,238 unaffected controls, significant association was identified with a variant in COL11A1 encoding collagen (α1) XI (rs3753841; NM_080629.2_c.4004C>T; p.(Pro1335Leu); P=7.07e-11, OR=1.118). Using CRISPR mutagenesis we generated Pax1 knockout mice (Pax1-/-). In postnatal spines we found that PAX1 and collagen (α1) XI protein both localize within the intervertebral disc (IVD)-vertebral junction region encompassing the growth plate, with less collagen (α1) XI detected in Pax1-/- spines compared to wildtype. By genetic targeting we found that wildtype Col11a1 expression in costal chondrocytes suppresses expression of Pax1 and of Mmp3, encoding the matrix metalloproteinase 3 enzyme implicated in matrix remodeling. However, this suppression was abrogated in the presence of the AIS-associated COL11A1P1335L mutant. Further, we found that either knockdown of the estrogen receptor gene Esr2, or tamoxifen treatment, significantly altered Col11a1 and Mmp3 expression in chondrocytes. We propose a new molecular model of AIS pathogenesis wherein genetic variation and estrogen signaling increase disease susceptibility by altering a Pax1-Col11a1-Mmp3 signaling axis in spinal chondrocytes.

Understanding Intervertebral Disc Degeneration: Background Factors and the Role of Initial Injury

The etiology of intervertebral disc degeneration (IVDD) is complex and multifactorial, and it is still not fully understood. A better understanding of the pathogenesis of IVDD will help to improve treatment regimens and avoid unnecessary surgical aggression. In order to summarize recent research data on IVDD pathogenesis, including genetic and immune factors, a literature review was conducted. The pathogenesis of IVDD is a complex multifactorial process without an evident starting point. There are extensive data on the role of the different genetic factors affecting the course of the disease, such as mutations in structural proteins and enzymes involved in the immune response. However, these factors alone are not sufficient for the development of the disease. Nevertheless, like mechanical damage, they can also be considered risk factors for IVDD. In conclusion, currently, there is no consensus on a single concept for the pathogenesis of IVDD. We consider the intervertebral disc autoimmune damage hypothesis to be the most promising hypothesis for clinicians, because it can be extrapolated to all populations and does not counteract other factors. The genetic factors currently known do not allow for building effective predictive models; however, they can be used to stratify the risks of individual populations.

An Integrated Review of Carpal Tunnel Syndrome: New Insights to an Old Problem

Carpal tunnel syndrome (CTS) is a common entrapment neuropathy characterized by pain, numbness, and impaired function of the hand due to compression of the median nerve at the level of the wrist. Although CTS can develop from repetitive strain, injury, or medical conditions, there are also congenital and genetic risk factors that can predispose individuals to the condition. With respect to anatomical factors, some individuals are born with a smaller carpal tunnel, which increases their susceptibility to median nerve compression. Variations in specific genes, such as those encoding proteins involved in extracellular matrix remodeling, inflammation, and nerve function, have also been linked to an increased risk for CTS. CTS is associated with a high cost of health care maintenance and loss of work productivity. Therefore, it is vital that primary care physicians fully understand the anatomy, epidemiology, pathophysiology, etiology, and risk factors of CTS, so they can be proactive in prevention, diagnosing, and guiding proper treatment. This integrated review also provides insights into how biological, genetic, environmental, and occupational factors interact with structural elements to determine who is most likely to acquire and suffer from CTS. Keeping health practitioners abreast of all the factors that could impact CTS should go a long way in decreasing the health care and socioeconomic burden of CTS.

A common variant rs2054564 in ADAMST17 is associated with susceptibility to lumbar spondylosis

The molecular pathophysiology underlying lumbar spondylosis development remains unclear. To identify genetic factors associated with lumbar spondylosis, we conducted a genome-wide association study using 83 severe lumbar spondylosis cases and 182 healthy controls and identified 65 candidate disease-associated single nucleotide polymorphisms (SNPs). Replication analysis in 510 case and 911 control subjects from five independent Japanese cohorts identified rs2054564, located in intron 7 of ADAMTS17, as a disease-associated SNP with a genome-wide significance threshold (P = 1.17 × 10-11, odds ratio = 1.92). This association was significant even after adjustment of age, sex, and body mass index (P = 7.52 × 10-11). A replication study in a Korean cohort, including 123 case and 319 control subjects, also verified the significant association of this SNP with severe lumbar spondylosis. Immunohistochemistry revealed that fibrillin-1 (FBN1) and ADAMTS17 were co-expressed in the annulus fibrosus of intervertebral discs (IVDs). ADAMTS17 overexpression in MG63 cells promoted extracellular microfibrils biogenesis, suggesting the potential role of ADAMTS17 in IVD function through interaction with fibrillin fibers. Finally, we provided evidence of FBN1 involvement in IVD function by showing that lumbar IVDs in patients with Marfan syndrome, caused by heterozygous FBN1 gene mutation, were significantly more degenerated. We identified a common SNP variant, located in ADAMTS17, associated with susceptibility to lumbar spondylosis and demonstrated the potential role of the ADAMTS17-fibrillin network in IVDs in lumbar spondylosis development.

The role of ADAMTS6 and ADAMTS17 polymorphisms in susceptibility to lumbar disc herniation in Chinese Han population

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.

Macrophages and Intervertebral Disc Degeneration

The intervertebral disc (IVD) aids in motion and acts to absorb energy transmitted to the spine. With little inherent regenerative capacity, degeneration of the intervertebral disc results in intervertebral disc disease, which contributes to low back pain and significant disability in many individuals. Increasing evidence suggests that IVD degeneration is a disease of the whole joint that is associated with significant inflammation. Moreover, studies show elevated macrophage accumulation within the IVD with increasing levels of disease severity; however, we still need to understand the roles, be they causative or consequential, of macrophages during the degenerative process. In this narrative review, we discuss hallmarks of IVD degeneration, showcase evidence of macrophage involvement during disc degeneration, and explore burgeoning research aimed at understanding the molecular pathways regulating macrophage functions during intervertebral disc degeneration.

The Association of Variants within Types V and XI Collagen Genes with Knee Joint Laxity Measurements

Joint laxity is a multifactorial phenotype with a heritable component. Mutations or common polymorphisms within the α1(V) (COL5A1), α1(XI) (COL11A1) and α2(XI) (COL11A2) collagen genes have been reported or proposed to associate with joint hypermobility, range of motion and/or genu recurvatum. The aim of this study was to investigate whether polymorphisms within these collagen-encoding genes are associated with measurements of knee joint laxity and computed ligament length changes within the non-dominant leg. One hundred and six healthy participants were assessed for genu recurvatum (knee hyperextension), anterior-posterior tibial translation, external-internal tibial rotation and ligament length changes during knee rotation of their non-dominant leg. Participants were genotyped for COL5A1 rs12722 (T/C), COL11A1 rs3753841 (C/T), COL11A1 rs1676486 (T/C) and COL11A2 rs1799907 (A/T). The genotype-genotype combination of any two or more of the four COL5A1 rs12722 CC, COL11A1 rs3753841 CC, COL11A1 rs1676486 TT and COL11A2 rs1799907 AA genotypes was associated with decreased active and passive knee hyperextension. These genotype-genotype combinations, including sex (male), increased age and decreased body mass collectively, also contributed to decreased passive knee hyperextension. These findings suggest that COL5A1, COL11A1 and COL11A2 gene-gene interactions are associated with knee hyperextension measurements of the non-dominant leg of healthy individuals.

Pathophysiology, Diagnosis, Treatment, and Genetics of Carpal Tunnel Syndrome: A Review

Carpal tunnel syndrome (CTS) is a common peripheral canalicular nerve entrapment syndrome in the upper extremities. The compression of or injury to the median nerve at the wrist as it passes through a space-limited osteofibrous carpal canal can cause CTS, resulting in hand pain and impaired function. The present paper reviews the literature on the prevalence, pathology, diagnosis, treatment, and risk factors of CTS in conjunction with the role of genetic factors in CTS etiology. CTS diagnosis is primarily linked with clinical symptoms; still, it is simplified by sophisticated approaches such as magnetic resonance imaging and ultrasonography. CTS symptoms can be ameliorated through conservative and surgical strategies. The exact CTS pathophysiology needs clarification. Genetic predispositions to CTS are augmented by various variants within genes; however, CTS etiology could include risk factors such as wrist movements, injury, and specific conditions (e.g., age, body mass index, sex, and cardiovascular conditions). The high prevalence of CTS diminishes the quality of life of its sufferers and imposes costs on health systems, hence the significance of research and clinical trials to elucidate CTS pathogenesis and develop novel therapeutic targets.

COL11A1 as a potential prognostic target for oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a malignant tumor occurring in the oral cavity. However, the molecular mechanism of OSCC is not clear. Bioinformatics was used to screen and identify role of collagen type X1 alpha 1 (COL11A1) on OSCC. 200 patients with OSCC were recruited. Clinical and follow-up data were recorded and COL11A1 expression levels were tested. Pearson chi-square test and Spearman correlation coefficient were used to analyze relationship between prognosis and related parameters in patients with OSCC. Univariate and multivariate Logistic regression, univariate and multivariate Cox proportional risk regression were used for further analysis, survival curve was drawn. Through bioinformatics analysis, OSCC patients with higher expression of COL11A1 have poor overall survival compare with OSCC patients with lower expression of COL11A1 (hazard ratios [HR] = 1.32, P = .047). Pearson chi-square test showed that age (P = .011), tumor grade (P = .023), COL11A1 (P < .001) was significantly correlated with prognosis of OSCC. Univariate Logistic regression analysis showed age (odds ratio [OR] = 2.102, 95% confidence intervals [95%CI]: 1.180-3.746, P = .012), tumor grade (OR = 1.919, 95%CI: 1.093-3.372, P = .023) and COL11A1 (OR = 12.775, 95%CI: 6.509-25.071, P < .001). Multivariate Logistic regression analysis showed that COL11A1 (OR = 12.066, 95%CI: 6.042-24.096, P < .001) was significantly associated with prognosis of patients with OSCC. Univariate Cox regression analysis showed that age (HR = 1.592, 95%CI: 1.150-2.205, P = .005), tumor grade (HR = 1.460, 95%CI: 1.067-1.999, P = .018) and COL11A1 (HR = 1.848, 95%CI: 1.340-2.548, P < .001) were significantly correlated with survival time of OSCC patients. Multivariate Cox regression analysis showed that tumor grade (HR = 1.466, 95%CI: 1.064-2.020, P = .019) and COL11A1 (HR = 1.645, 95%CI: 1.164-2.325, P = .005) were significantly correlated with survival time of OSCC patients. COL11A1 is significantly correlated with occurrence of OSCC. When COL11A1 is highly expressed, prognosis of patients with OSCC is worse and the survival time is shorter.

In Silico Analysis of Collagens Missense SNPs and Human Abnormalities

Collagens are the most abundant proteins in the extra cellular matrix/ECM of human tissues that are encoded by different genes. There are single nucleotide polymorphisms/SNPs which are considered as the most useful biomarkers for some disease diagnosis or prognosis. The aim of this study is screening and identifying the functional missense SNPs of human ECM-collagens and investigating their correlation with human abnormalities. All of the missense SNPs were retrieved from the NCBI SNP database and screened for a global frequency of more than 0.1. Seventy missense SNPs that met the screening criteria were characterized for functional and stability impact using six and three protein analysis tools, respectively. Next, HOPE and geneMANIA analysis tools were used to show the effect of SNPs on three-dimensional structure (3D) and physical interaction of proteins. Results showed that 13 missense SNPs (rs2070739, rs28381984, rs13424243, rs1800517, rs73868680, rs12488457, rs1353613, rs59021909, rs9830253, rs2228547, rs3753841, rs2855430, and rs970547), which are in nine different collagen genes, affect the structure and function of different collagen proteins. Among these polymorphisms, COL4A3-rs13424243 and COL6A6-rs59021909 were predicted as the most effective ones. On the other hand, designed mutated and native 3D of rs13424243 variant illustrated that it can disturb the protein motifs. Also, geneMANIA predicted that COL4A3 and COL6A6 are interacting with some proteins including: DDR1, COL6A1, COL11A2 and so on. Based on our findings, ECM-collagens functional SNPs are important and may be considered as a risk factor or molecular marker for human disorders in the future studies.

Immuno-Modulatory Effects of Intervertebral Disc Cells

Low back pain is a highly prevalent, chronic, and costly medical condition predominantly triggered by intervertebral disc degeneration (IDD). IDD is often caused by structural and biochemical changes in intervertebral discs (IVD) that prompt a pathologic shift from an anabolic to catabolic state, affecting extracellular matrix (ECM) production, enzyme generation, cytokine and chemokine production, neurotrophic and angiogenic factor production. The IVD is an immune-privileged organ. However, during degeneration immune cells and inflammatory factors can infiltrate through defects in the cartilage endplate and annulus fibrosus fissures, further accelerating the catabolic environment. Remarkably, though, catabolic ECM disruption also occurs in the absence of immune cell infiltration, largely due to native disc cell production of catabolic enzymes and cytokines. An unbalanced metabolism could be induced by many different factors, including a harsh microenvironment, biomechanical cues, genetics, and infection. The complex, multifactorial nature of IDD brings the challenge of identifying key factors which initiate the degenerative cascade, eventually leading to back pain. These factors are often investigated through methods including animal models, 3D cell culture, bioreactors, and computational models. However, the crosstalk between the IVD, immune system, and shifted metabolism is frequently misconstrued, often with the assumption that the presence of cytokines and chemokines is synonymous to inflammation or an immune response, which is not true for the intact disc. Therefore, this review will tackle immunomodulatory and IVD cell roles in IDD, clarifying the differences between cellular involvements and implications for therapeutic development and assessing models used to explore inflammatory or catabolic IVD environments.

Development, Pathogenesis, and Regeneration of the Intervertebral Disc: Current and Future Insights Spanning Traditional to Omics Methods

The intervertebral disc (IVD) is the fibrocartilaginous joint located between each vertebral body that confers flexibility and weight bearing capabilities to the spine. The IVD plays an important role in absorbing shock and stress applied to the spine, which helps to protect not only the vertebral bones, but also the brain and the rest of the central nervous system. Degeneration of the IVD is correlated with back pain, which can be debilitating and severely affects quality of life. Indeed, back pain results in substantial socioeconomic losses and healthcare costs globally each year, with about 85% of the world population experiencing back pain at some point in their lifetimes. Currently, therapeutic strategies for treating IVD degeneration are limited, and as such, there is great interest in advancing treatments for back pain. Ideally, treatments for back pain would restore native structure and thereby function to the degenerated IVD. However, the complex developmental origin and tissue composition of the IVD along with the avascular nature of the mature disc makes regeneration of the IVD a uniquely challenging task. Investigators across the field of IVD research have been working to elucidate the mechanisms behind the formation of this multifaceted structure, which may identify new therapeutic targets and inform development of novel regenerative strategies. This review summarizes current knowledge base on IVD development, degeneration, and regenerative strategies taken from traditional genetic approaches and omics studies and discusses the future landscape of investigations in IVD research and advancement of clinical therapies.

Genetics and Epigenetics of Bone Remodeling and Metabolic Bone Diseases

Bone metabolism consists of a balance between bone formation and bone resorption, which is mediated by osteoblast and osteoclast activity, respectively. In order to ensure bone plasticity, the bone remodeling process needs to function properly. Mesenchymal stem cells differentiate into the osteoblast lineage by activating different signaling pathways, including transforming growth factor β (TGF-β)/bone morphogenic protein (BMP) and the Wingless/Int-1 (Wnt)/β-catenin pathways. Recent data indicate that bone remodeling processes are also epigenetically regulated by DNA methylation, histone post-translational modifications, and non-coding RNA expressions, such as micro-RNAs, long non-coding RNAs, and circular RNAs. Mutations and dysfunctions in pathways regulating the osteoblast differentiation might influence the bone remodeling process, ultimately leading to a large variety of metabolic bone diseases. In this review, we aim to summarize and describe the genetics and epigenetics of the bone remodeling process. Moreover, the current findings behind the genetics of metabolic bone diseases are also reported.

Main and Minor Types of Collagens in the Articular Cartilage: The Role of Collagens in Repair Tissue Evaluation in Chondral Defects

Several collagen subtypes have been identified in hyaline articular cartilage. The main and most abundant collagens are type II, IX and XI collagens. The minor and less abundant collagens are type III, IV, V, VI, X, XII, XIV, XVI, XXII, and XXVII collagens. All these collagens have been found to play a key role in healthy cartilage, regardless of whether they are more or less abundant. Additionally, an exhaustive evaluation of collagen fibrils in a repaired cartilage tissue after a chondral lesion is necessary to determine the quality of the repaired tissue and even whether or not this repaired tissue is considered hyaline cartilage. Therefore, this review aims to describe in depth all the collagen types found in the normal articular cartilage structure, and based on this, establish the parameters that allow one to consider a repaired cartilage tissue as a hyaline cartilage.

COL11A1 promotes esophageal squamous cell carcinoma proliferation and metastasis and is inversely regulated by miR-335-5p

Background

Esophagus squamous cell carcinoma (ESCC) is a sort of cancer that occurs in the esophageal epithelial tissue. This study performed integrated bioinformatics analysis of Gene Expression Omnibus (GEO) datasets GSE32424, GSE29968, and GSE130078. Collagen type XI alpha 1 (COL11A1) was identified as the hub gene in ESCC progression. The involvement of COL11A1 in ESCC development was next determined using in vitro functional tests.

Methods

Hub genes were identified through integrated bioinformatics analysis. The real-time reverse transcription-polymerase chain reaction was implemented for detecting the expression of COL11A1 mRNA in esophageal cancer cells. KYSE-30 cells were transfected using a vector encoding COL11A1. The proliferation of cells was determined using the Cell Counting Kit-8 (CCK-8) assay. Detection of the cell migration and invasion was made through making use of the transwell test. The development of ESCC cells in vivo was evaluated in naked mice. The interplay among COL11A1 and microRNA-335-5p (miR-335-5p) was discovered using a luciferase reporter experiment.

Results

In vitro studies showed the upregulation of COL11A1 in ESCC cell lines obtained from ESCC patients and upregulation of COL11A1 was correlated with poor disease-free survival of ESCC patients, thereby implying an oncogenic involvement of COL11A1 in ESCC. Overexpression of COL11A1 enhanced the proliferation of ESCC cells, invasion, and migration; whereas COL11A1 knockdown impeded the proliferation of ESCC cells, invasion, and migration. Additionally, miRNA pathway analysis in combination with TargetScan’s online prediction and the luciferase reporter assay suggested miR-335-5p targeting and negatively regulating the COL11A1 3' untranslated region (3'UTR) within ESCC cells. MiR-335-5p overexpression diminished the development of ESCC cells. Additionally, co-expression of COL11A1 ameliorated the repressive influence of miR-335-5p overexpression on the growth and metastasis of ESCC cells.

Conclusions

Using comprehensive bioinformatics analysis, the current study identified COL11A1 as an oncogene in ESCC. The mechanistic studies indicated that COL11A1 promoted ESCC cell progression and that miR-335-5p negatively regulated the expression of COL11A1 in ESCC.

Association between polymorphisms of collagen genes and susceptibility to intervertebral disc degeneration: a meta-analysis

Background

Collagens are important structural components of intervertebral disc. A number of studies have been performed for association between polymorphisms of collagen genes and risk of intervertebral disc degeneration (IVDD) but yielded inconsistent results. Here, we performed a meta-analysis to investigate the association of collagen IX alpha 2 (COL9A2) Trp2, collagen IX alpha 3 (COL9A3) Trp3, collagen I alpha 1 (COL1A1) Sp1 and collagen XI alpha 1 (COL11A1) C4603T polymorphisms with susceptibility to IVDD.

Method

Eligible studies were retrieved by searching MEDLINE, EMBASE, Web of Science prior to 31 March, 2021. Odds ratio (OR) and corresponding 95% confidence interval (CI) were calculated for association strength.

Results

A total of 28 eligible studies (31 datasets comprising 5497 cases and 5335 controls) were included. COL9A2 Trp2 carriers had an increased risk of IVDD than non-carriers in overall population (OR = 1.43, 95% CI 0.99–2.06, P = 0.058), which did not reach statistical significance. However, Trp2 carriers had 2.62-fold (95% CI 1.15–6.01, P = 0.022) risk than non-carriers in Caucasians. COL9A3 Trp3 was not associated with IVDD risk (OR = 1.28, 95% CI 0.81–2.02, P = 0.299). T allele and TT genotype of COL1A1 Sp1 (+ 1245G > T) were correlated with increased risk of IVDD. Significant associations were found between COL11A1 C4603T and IVDD risk under allelic (OR = 1.33, 95% CI 1.20–1.48), dominant (OR = 1.45, 95% CI 1.26–1.67), recessive (OR = 1.55, 95% CI 1.21–1.98) and homozygote model (OR = 1.81, 95% CI 1.40–2.34).

Conclusions

COL1A1 Sp1 and COL11A1 C4603T polymorphism are associated with IVDD risk while the predictive roles of collagen IX gene Trp2/3 need verification in more large-scale studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02724-8.

Transcriptional profiling of intervertebral disc in a post-traumatic early degeneration organ culture model

INTRODUCTION

The goal of this study is to characterize transcriptome changes and gene regulation networks in an organ culture system that mimics early post-traumatic intervertebral disc (IVD) degeneration.

METHODS

To mimic a traumatic insult, bovine caudal IVDs underwent one strike loading. The control group was cultured under physiological loading. At 24 hours after one strike or physiological loading, RNA was extracted from nucleus pulposus (NP) and annulus fibrosus (AF) tissue. High throughput next generation RNA sequencing was performed to identify differentially expressed genes (DEGs) between the one strike loading group and the control group. Gene Ontology (GO) functional and Kyoto Encyclopedia of Genes and Genomes analyses were performed to analyze DEGs and pathways. Protein-protein interaction (PPI) network was analyzed with cytoscape software. DEGs were verified using qRT-PCR. Degenerated human IVD tissue was collected for immunofluorescence staining to verify the expression of DEGs in human disc tissue.

RESULTS

One strike loading resulted in significant gene expression changes compared with physiological loading. In total 253 DEGs were found in NP tissue and 208 DEGs in AF tissue. Many of the highly dysregulated genes have known functions in disc degeneration and extracellular matrix (ECM) homeostasis. ACTB, ACTG, PFN1, MYL12B in NP tissue and FGF1, SPP1 in AF tissue were verified by qRT-PCR and immunofluorescence imaging. The identified DEGs were involved in focal adhesion, ECM-receptor interaction, PI3K-AKT, and cytokine-cytokine receptor interaction pathways. Three clusters of PPI networks were identified. GO enrichment revealed that these DEGs were mainly involved in inflammatory response, the ECM and growth factor signaling and protein folding biological process.

CONCLUSION

Our study revealed different DEGs, pathways, biological process and PPI networks involved in post-traumatic IVD degeneration. These findings will advance the understanding of the pathogenesis of IVD degeneration, and help to identify novel biomarkers for the disease diagnosis.

The Role of Polymorphisms in Collagen-Encoding Genes in Intervertebral Disc Degeneration

(1) Background: The purpose of this review is to analyze domestic and foreign studies on the role of collagen-encoding genes polymorphism in the development of intervertebral discs (IVDs) degeneration in humans. (2) Methods: We have carried out a search for full-text articles published in e-Library, PubMed, Oxford Press, Clinical Case, Springer, Elsevier and Google Scholar databases. The search was carried out using keywords and their combinations. The search depth was 5 years (2016–2021). In addition, this review includes articles of historical interest. Despite an extensive search, it is possible that we might have missed some studies published in recent years. (3) Results: According to the data of genome-wide and associative genetic studies, the following candidate genes that play a role in the biology of IVDs and the genetic basis of the processes of collagen degeneration of the annulus fibrosus and nucleus pulposus of IVDs in humans are of the greatest interest to researchers: COL1A1, COL2A1, COL9A2, COL9A3, COL11A1 and COL11A2. In addition, the role of genes COL1A2, COL9A1 and others is being actively studied. (4) Conclusions: In our review, we summarized and systematized the available information on the role of genetic factors in IVD collagen fibers turnover and also focused on the functions of different types of collagen present in the IVD. Understanding the etiology of impaired collagen formation can allow doctors to prescribe pathogenetically-based treatment, achieving the most effective results.

The role of single nucleotide polymorphisms of IL-1A -889C>T (rs1800587), TNF-A -238G>A (rs361525), and VDR TaqI (rs731236) on susceptibility to herniated nucleus pulposus: a systematic review and meta-analysis

Background: The pathogenesis of herniated nucleus pulposus (HNP) is complex and may involve the wide variety of gene polymorphism. However, the reports from the existing studies are inconclusive. 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. Results: We screened 3,067 unique studies for eligibility and three, two and nine case-control 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.

The role of single nucleotide polymorphisms of IL-1A -889C>T (rs1800587), TNF-A -238G>A (rs361525), and VDR TaqI (rs731236) on susceptibility to herniated nucleus pulposus

Background: The pathogenesis of herniated nucleus pulposus (HNP) is complex and may involve the wide variety of gene polymorphism. However, the reports from the existing studies are inconclusive. 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. Results: We screened 3,067 unique studies for eligibility and three, two and nine case-control 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.

The role of single nucleotide polymorphisms of IL-1A -889C>T (rs1800587), TNF-A -238G>A (rs361525), and VDR TaqI (rs731236) on susceptibility to herniated nucleus pulposus

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.

MiR-144-3p inhibits the proliferation, migration and invasion of lung adenocargen cancer cells by targeting COL11A1

This study aimed to investigate the regulatory relationship between miR-144-3p and COL11A1, and to explore its effect on the proliferation, migration and invasion of lung adenocarcinoma (LUAD) cells. A series of methods and experiments were applied. miR-144-3p was downregulated in LUAD tissue and cells, whereas COL11A1 was highly expressed. Overexpressing miR-144-3p inhibited the proliferation, migration and invasion of LUAD cells, which could be reversed by overexpression of COL11A1. Overexpressing miR-144-3p inhibits the proliferation, migration and invasion of LUAD cells by silencing COL11A1.

Risk Factors of Intervertebral Disc Pathology-A Point of View Formerly and Today-A Review

Intervertebral disc pathology is a common disorder that can be caused by genetic, mechanical, and behavioral factors; however, it is possible to slow its progression. Although environmental and behavioral factors were previously considered to be the sole causes of intervertebral disc pathologies such as disc herniation, recent studies have shown that genetic factors also play an important role. This review compares the perception of major risk factors from the last and present centuries. It also examines individual genetic and non-genetic factors acting as risk factors, as well as some approaches for preventing intervertebral disc pathologies, and compares available statistics regarding disc herniation.

Proteomics-based Predictive Model for the Early Detection of Metastasis and Recurrence in Head and Neck Cancer

BACKGROUND/AIM

Head and neck squamous cell carcinoma (HNSCC) presents high morbidity, an overall poor prognosis and survival, and a compromised quality of life of the survivors. Early tumor detection, prediction of its behavior and prognosis as well as the development of novel therapeutic strategies are urgently needed for a more successful HNSCC management.

MATERIALS AND METHODS

In this study, a proteomics analysis of HNSCC tumor and non-tumor samples was performed and a model to predict the risk of recurrence and metastasis development was built.

RESULTS

This predictive model presented good accuracy (>80%) and comprises as variables the tumor staging along with DHB12, HMGB3 and COBA1 proteins. Differences at the intensity levels of these proteins were correlated with the development of metastasis and recurrence as well as with patient's survival.

CONCLUSION

The translation of proteomic predictive models to routine clinical practice may contribute to a more precise and individualized clinical management of the HNSCC patients, reducing recurrences and improving patients' quality of life. The capability of generalization of this proteomic model to predict the recurrence and metastases development should be evaluated and validated in other HNSCC populations.

RAB40C gene polymorphisms rs62030917 and rs2269556 are associated with an increased risk of lumbar disc herniation development in the Chinese Han population

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.

A Meta-analysis Assessing the Association Between COL11A1 and GDF5 Genetic Variants and Intervertebral Disc Degeneration Susceptibility

STUDY DESIGN

Meta-analysis to collect relevant studies to assess the association between COL11A1 and GDF5 genetic variants and susceptibility to IDD.

OBJECTIVE

The aim of this study was to assess whether or not COL11A1 and GDF5 genetic variants were associated with susceptibility to IDD.

SUMMARY OF BACKGROUND DATA

IDD or LDH is a major public health problem. There have been several studies evaluating the relationship between COL11A1 and GDF5 genetic variants with risk of intervertebral disc degeneration (IDD). However, the studies were limited in discrete outcome and sample size, and some of the results were contradictory.

METHODS

We systematically searched the relevant publications in electronic databases. Eligible studies were included based on the defined criteria. The pooled odds ratios (ORs) with its 95% confidence intervals (CIs) were received using STATA 15. Subgroup analysis, sensitivity analysis, publication bias, and the "Trim and fill" method were performed in the meta-analysis.

RESULTS

A total of 3287 IDD cases and 5115 controls were incorporated into the meta-analysis. Our results demonstrated that COL11A1 rs1676486 was significantly associated with increased IDD susceptibility under all genetic models (allele model T vs. C: OR = 1.40, 95% CI 1.23-1.59, P = 0.000; homozygote model TT vs. CC: OR = 1.89, 95%CI 1.40-2.56, P = 0.000; dominant model TT+TC vs. CC: OR = 1.52, 95% CI 1.29-1.80, P = 0.000; recessive model TT vs. TC + CC: OR = 1.58, 95% CI 1.18-2.12, P = 0.002). However, GDF5 rs143383 was not (allele model T vs. C: OR = 1.15, 95% CI 0.91-1.44, P = 0.244; homozygote model TT vs. CC: OR = 1.22, 95% CI 0.75-2.00, P = 0.429; dominant model TT vs. CC+CT: OR = 1.22, 95% CI 0.95-1.57, P = 0.112; recessive model TC + TT vs. CC: OR = 1.12, 95% CI 0.73-1.73, P = 0.594). Subgroup analysis indicated ethnicity was not the source of heterogeneity. Sensitivity analysis, publication bias, and the "Trim and fill" method demonstrated the meta-analysis was of reliability.

CONCLUSION

Our results suggested that COL11A1 rs1676486 was significantly associated with IDD and the T allele was a risky factor. However, GDF5 rs143383 was not.

LEVEL OF EVIDENCE

1.

Association of GSDMC polymorphisms with lumbar disc herniation among Chinese Han population

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.

Genetic polymorphisms of IL1RN were associated with lumbar disk herniation risk in a Chinese Han population

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.

Actions of Prostaglandins on Human Nucleus Pulposus Metabolism Inferred by Cyclooxygenase 2 Inhibition of Cytokine Activated Cells

OBJECTIVE

Low back pain is frequently treated with nonsteroidal anti-inflammatory drugs (NSAIDs), but little is known about intervertebral disc metabolism of the prostaglandins that are diminished by these drugs. Hence, this study aimed at delineating prostaglandin actions in cytokine activated disc cells by comparing the response of nucleus pulposus (NP) cells to the pro-inflammatory cytokine interleukin (IL)-1β with and without cyclooxygenase 2 (COX-2) inhibition.

METHODS

NP cells cultured in alginate beads were activated with IL-1β ± the COX-2 inhibitor Sc-58125. Media harvested from cultured cells were analyzed for prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2α), IL-6, and matrix metalloproteinase (MMP)-3 by enzymelinked immunosorbent assay and nitric oxide by Griess Reaction. Gene expression along with proteoglycan, collagen, and total protein synthesis were also measured.

RESULTS

IL-1β increased culture media PGE2 and PGF2α, but decreased proteoglycan and collagen syntheses as well as mRNA expression of the matrix genes aggrecan, versican, collagen I, and collagen II. COX-2 inhibition partially rescued proteoglycan and collagen syntheses and collagen I mRNA, but decreased collagen II mRNA IL-1β activated NP cells. COX-2 inhibition initially enhanced and subsequently reduced IL-1β induced inducible nitric oxide synthase, without altering medium nitrite. IL-1β induction of MMP-3 mRNA was increased by COX-2 inhibition at 24 and 48 hours.

CONCLUSION

COX-2 inhibition alters the response of NP cells to IL-1β, suggesting IL-1β action on disc cells is mediated at least in part through COX-2 and its prostaglandins. COX-2 inhibition produces minimal effects on several key catabolic mediators, with the exception of MMP-3. Blocking COX-2 might be beneficial for maintaining disc matrix since it provides an overall rescue of IL-1 induced loss of matrix protein synthesis.

Multifactor dimensionality reduction reveals a strong gene-gene interaction between STC1 and COL11A1 genes as a possible risk factor of knee osteoarthritis

Articular cartilage is an avascular tissue with a structure that allows it to support and cushion the overload of the surfaces in contact. It maintains its metabolic functions due to the contribution of different signaling pathways. However, several factors play a role in its deterioration, allowing to the development of osteoarthritis (OA), and one of the major factors is genetic. Our goal was to identify gene-gene interactions (epistasis) between five signaling pathways involved in the articular cartilage metabolism as possible indicators of OA risk. We applied the Multifactor-Dimensionality Reduction (MDR) method to identify and characterize the epistasis between 115 SNPs located in 73 genes related to HIF-1α, Wnt/β-catenin, cartilage extracellular matrix metabolism, oxidative stress, and uric acid transporters. Ninety three patients diagnosed with primary knee OA and 150 healthy controls were included in the study. Genotyping was performed with the OpenArray system, the statistical analysis was carried out with the STATA software v14, and epistasis was analyzed with the MDR software v3.0.2. The MDR analysis revealed that the best interaction model was between polymorphisms rs17786744 of the STC1 gene and rs2615977 of the COL11A1 gene, with an entropy value of 4.44%, CVC 8/10, OR 5.60, 95% CI 3.27-9.59, p < 0.0001. Under this interaction model, we identified high and low risk genotypes involved in OA development. Our results suggest complex interactions between STC1 and COL11A1 genes that might have an impact on genetic susceptibility to develop OA. Further studies are required to confirm it.

Pathomechanism of intervertebral disc degeneration

Intervertebral disc degeneration (IDD) is the main contributor to low back pain, which is a leading cause of disability worldwide. Although substantial progress has been made in elucidating the molecular mechanisms of IDD, fundamental and long-lasting treatments for IDD are still lacking. With increased understanding of the complex pathomechanism of IDD, alternative strategies for treating IDD can be discovered. A brief overview of the prevalence and epidemiologic risk factors of IDD is provided in this review, followed by the descriptions of anatomic, cellular, and molecular structure of the intervertebral disc as well as the molecular pathophysiology of IDD. Finally, the recent findings of intervertebral disc progenitors are reviewed and the future perspectives are discussed.

Blood and urinary collagen markers in osteoarthritis: markers of tissue turnover and disease activity

Introduction: The need for diagnostic markers in osteoarthritis (OA) is acute and immediate, as sensitive and precise tools that monitor disease activity and treatment response are lacking. Collagens - types I, II, and III - are the skeleton of the extracellular matrix of joint tissues. Joint collagens are generally turned over at a low rate, but the balance between formation and degradation is disturbed, leading to the loss of, for example, cartilage.Areas covered: We discuss the markers reflecting collagen turnover and provide examples of how they have been applied in OA research, as well as how we believe these should be used in the future. We have searched PubMed for full-text articles written in English using different combinations of the following terms: OA, biomarker, and collagen. The result is a narrative review that gives examples from the literature.Expert opinion: Collagen markers show promise, as they are direct measures of tissue balance. Until now, collagen markers have mainly been tested in observational cohorts, which may provide insights into the association between the candidate marker and clinical variables; however, these do not advance the development of qualified markers that can be used for drug development or in clinical practice.

Association of Susceptibility Genes for Adolescent Idiopathic Scoliosis and Intervertebral Disc Degeneration With Adult Spinal Deformity

STUDY DESIGN

Genetic case-control study of single nucleotide polymorphisms (SNPs).

OBJECTIVE

To examine the association of previously reported susceptibility genes for adolescent idiopathic scoliosis (AIS) and intervertebral disc (IVD) degeneration with adult spinal deformity (ASD).

SUMMARY OF BACKGROUND DATA

ASD is a spinal deformity that develops and progresses with age. Its etiology is unclear. Several ASD susceptibility genes were recently reported using a candidate gene approach; however, the sample sizes were small and associations with ASD development were not determined.

METHODS

ASD was defined as structural scoliosis with a Cobb angle more than 15° on standing radiographs, taken of patients at age 40 to 75 years in this study. Subjects in whom scoliosis was diagnosed before age 20 were excluded. We recruited 356 Japanese ASD subjects and 3341 healthy controls for case-control association studies of previously reported SNPs. We genotyped four known AIS-associated SNPs (rs11190870 in LBX1, rs6570507 in GPR126, rs10738445 in BNC2, and rs6137473 in PAX1) and three IVD degeneration-associated SNPs (rs1245582 in CHST3, rs2073711 in CILP, and rs1676486 in COL11A1) by the Invader assay.

RESULTS

Among the AIS-associated SNPs, rs11190870 and rs6137473 showed strong and nominal associations with ASD (P = 1.44 × 10, 1.00 × 10, respectively). Of the IVD degeneration-associated SNPs, rs1245582 and rs2073711 showed no association with ASD, while rs1676486 showed a nominal association (P = 1.10 × 10). In a subgroup analysis, rs11190870 was significantly associated with a Cobb angle more than 20° in the minor thoracic curve (P = 1.44 × 10) and with a left convex lumbar curve (P = 6.70 × 10), and nominally associated with an apical vertebra higher than L1 (P = 1.80 × 10).

CONCLUSION

rs11190870 in LBX1, a strong susceptibility SNP for AIS, may also be a susceptibility SNP for ASD. Thus, ASD and AIS may share a common genetic background.

LEVEL OF EVIDENCE

4.

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.

Microarray‑based analysis of COL11A1 and TWIST1 as important differentially‑expressed pathogenic genes between left and right‑sided colon cancer

Colonic cancer has become a main reason of mortality associated with cancer; however, left and right-sided colonic cancer have diverse outcomes in terms of epidemiological, histological, clinical parameters and prognosis. We aimed to examine the discrepancies between these two types of colon cancers to identify potential therapeutic targets. In the present study, three gene expression profiles (GSE44076, GSE31595, GSE26906) from Gene Expression Omnibus (GEO) database were downloaded and further analyzed. A PPI (protein-protein interaction) network of the differentially-expressed genes (DEGs) of GSE44076 between tumor and normal was established with the Search Tool for the Retrieval of Interacting Genes database. Then, the DEGs of these two colon cancers (left, right) samples were identified. Subsequently, the intersection of DEGs of left and right-sided colon cancer samples obtained from three databases, and DEGs of tumor and normal samples were analyzed. Collagen type XI α1 chain (COL11A1), Twist family bHLH transcription factor 1 (TWIST1), insulin-like 5 and chromogranin A were upregulated proteins, while 3β-hydroxysteroid dehydrogenase was downregulated protein in right colon cancer than in left-sided tumor samples. Through further experimental verification, we revealed that COL11A1 and TWIST1 were significantly upregulated at the mRNA and protein levels within right-sided colon cancer compared with in left-sided colon cancer samples (P<0.05), consistent with bioinformatical analysis. Furthermore, a positive correlation between COL11A1 and TWIST1 protein expression was observed (P<0.0276). Collectively, our data showed that COL11A1 and TWIST1 may be potential prognostic indicators and molecular targets for the treatment of right-sided colon cancer.

IL1R1 Polymorphisms are Associated with Lumbar Disc Herniation Risk in the Northwestern Chinese Han Population

Background

The aim of this study was to assess the association of single-nucleotide polymorphisms (SNPs) in IL1R1 with the risk of lumbar disc herniation (LDH) in the Han population in northwest China.

Material/Methods

To estimate the association of IL1R1 polymorphisms with LDH risk, Agena MassARRAY was used to determine the genotypes of 498 LDH patients and 463 controls. The association between IL1R1 variants and LDH risk was examined by logistic regression analysis with adjustments for age and gender. Stratification analysis was observed between gender and age with polymorphisms of IL1R1. Haplotype construction and analysis in IL1R1 were also applied to detect the potential association.

Results

The mutant homozygous genotype in codominant model (AA versus GG, OR=2.37, 95% CI: 1.08–5.21, P=0.001) and in recessive model (AA versus GG/GA, OR=2.82, 95% CI: 1.30–6.12, P=0.005) of rs956730 were associated with an increased LDH risk in males, while rs956730 heterozygous genotype under codominant model (AG versus GG, OR=0.65, 95% CI: 0.46–0.92, P=0.001) was a protective genotype in males. In addition, the recessive model (CT/CC versus TT, OR=3.43, 95% CI: 1.11–10.57, P=0.020) of rs10490571 was associated with an increased LDH risk among people older than 50 years of age.

Conclusions

This study demonstrated that genetic variants in the IL1R1 genes were associated with LDH risk in the Han population of northwestern China.

Type XI collagen-perlecan-HS interactions stabilise the pericellular matrix of annulus fibrosus cells and chondrocytes providing matrix stabilisation and homeostasis

The aim of this study was to ascertain whether, like many cell types in cartilaginous tissues if type XI collagen was a pericellular component of annulus fibrosus (AF) cells and chondrocytes. Fine fibrillar networks were visualised which were perlecan, HS (MAb 10E4) and type XI collagen positive. Heparitinase-III pre-digestion abolished the type XI collagen and 10E4 localisation in these fibrillar assemblies demonstrating a putative HS mediated interaction which localised the type XI collagen. Type XI collagen was confirmed to be present in the Heparitinase III treated AF monolayer media samples by immunoblotting. Heparitinase-III generated ΔHS stub epitopes throughout these fibrillar networks strongly visualised by MAb 3-G-10. Monolayers of murine hip articular chondrocytes from C57BL/6 and Hspg2 exon 3 null mice also displayed pericellular perlecan localisations, however type XI collagen was only evident in the Wild type mice. Perlecan was also immunolocalised in control and murine knee articular cartilage from the two mouse genotypes subjected to a medial meniscal destabilisation procedure which induces OA. This resulted in a severe depletion of perlecan levels particularly in the perlecan exon 3 null mice and was consistent with OA representing a disease of the pericellular matrix. A model was prepared to explain these observations between the NPP type XI collagen domain and HS chains of perlecan domain-I in the pericellular matrix of AF cells which likely contributed to cellular communication, tissue stabilization and the regulation of extracellular matrix homeostasis.

Classifying patients with lumbar disc herniation and exploring the most effective risk factors for this disease

Objectives: To classify patients suffering from low back pain (LBP) into two different groups – patients with lumbar disc herniation (LDH) and patients without this disease based on simple questions and without magnetic resonance imaging (MRI) procedure – and to diagnose the most effective risk factors of LDH.

Methods: Four hundred patients aged over 18 years suffering from LBP for over 6 months were randomized into two groups in this cross-sectional study. The data were gathered at Besat clinic, in Kerman, southeast of Iran. Twelve dichotomous questions from the main LDH risk factors were asked. Three statistical classification methods – K-nearest neighbors (KNN), support vector machine (SVM), and logistic regression (LR) – were performed. LR was used in order to diagnose the most important risk factors of LDH.

Results: SVM method was more efficient among the small sample sizes, while KNN method showed the best classification relative to other methods when the sample size increased. LR model had the least efficiency of all. The drug use increased the chance of LDH more than 7 times (OR=7.249), and the chance of having LDH among people who had associated illness was 4.847 times more compared with people who did not have. Using hookah increased the chance of having LDH more than twice (OR=2.401), and the chance of smokers for LDH was near four times higher than nonsmokers (OR=3.877).

Conclusion: The statistical classification methods had acceptable precisions for diagnosis of LDH patients. It is suggested that neurologists become more familiar with these methods and use them before MRI prescription to decrease the unnecessary burden on health services. Addiction to drugs, cigarettes, and hookah is the main factor in the creation of a lumbar disc herniation.

COL11A1 Polymorphisms Are Associated with Primary Angle-Closure Glaucoma Severity

Purpose

PLEKHA7 and COL11A1 were genotyped for single-nucleotide polymorphisms (SNPs) to investigate the possible association of these two genes with primary angle-closure glaucoma (PACG) and disease severity.

Method

A total of 51 PACG cases and 51 normal controls were recruited. Twelve SNPs in the PLEKHA7 (rs216489, rs1027617, rs366590, rs11024060, rs6486330, rs11024097, and rs11024102) and COL11A1 (rs1676484, rs3753841, rs12138977, rs2126642, and rs2622848) genes were genotyped by direct Sanger sequencing. Distributions of allele frequencies and genotype frequencies in cases and controls, as well as in mild, moderate, and severe subgroups, were compared based on mean defect (MD ≤ 6.00 dB, 6 dB < MD ≤ 12 dB, and MD > 12 dB were considered mild, moderate, and severe, respectively). Independent Student's t-tests and chi-square tests were used to compare characteristics of PACG cases and controls. Chi-square tests were used to compare the distribution of allele frequencies in cases and controls and in MD-based subgroups with various degrees of glaucoma severity. Binary logistic regression was used to compare the distribution of genotype frequencies and calculate odds ratios (OR) with confidence intervals (CI).

Result

Three of the 12 SNPs in COL11A1, rs1676486 (P=0.026, OR = 2.089, 95% CI = 1.092–3.996), rs3753841 (P=0.036, OR = 1.886, 95% CI = 1.038–3.426), and rs12138977 (P=0.024, OR = 2.133, 95% CI = 1.104–4.123) were found to have a significant association with PACG. Furthermore, in the subgroup analysis, rs1676486 (P=0.018, OR = 2.416, 95% CI = 1.284–4.544; P=0.011, OR = 2.119, 95% CI = 1.204–3.729), rs12138977 (P=0.009, OR = 2.158, 95% CI = 1.287–3.618; P=0.006, OR = 1.962, 95% CI = 1.239–3.106), and rs3753841 (P=0.007, OR = 2.550, 95% CI = 1.344–4.839) showed statistically significant differences between moderate/severe groups and controls.

Conclusion

Our data suggested that COL11A1 rs1676484, rs3753841, and rs12138977 polymorphisms may be of value for further study as potential gene-dependent risk factors for developing PACG. Moreover, COL11A1 rs1676484 and rs12138977 polymorphisms might be associated with PACG disease severity.

Annotating Transcriptional Effects of Genetic Variants in Disease-Relevant Tissue: Transcriptome-Wide Allelic Imbalance in Osteoarthritic Cartilage

OBJECTIVE

Multiple single-nucleotide polymorphisms (SNPs) conferring susceptibility to osteoarthritis (OA) mark imbalanced expression of positional genes in articular cartilage, reflected by unequally expressed alleles among heterozygotes (allelic imbalance [AI]). We undertook this study to explore the articular cartilage transcriptome from OA patients for AI events to identify putative disease-driving genetic variation.

METHODS

AI was assessed in 42 preserved and 5 lesioned OA cartilage samples (from the Research Arthritis and Articular Cartilage study) for which RNA sequencing data were available. The count fraction of the alternative alleles among the alternative and reference alleles together (φ) was determined for heterozygous individuals. A meta-analysis was performed to generate a meta-φ and P value for each SNP with a false discovery rate (FDR) correction for multiple comparisons. To further validate AI events, we explored them as a function of multiple additional OA features.

RESULTS

We observed a total of 2,070 SNPs that consistently marked AI of 1,031 unique genes in articular cartilage. Of these genes, 49 were found to be significantly differentially expressed (fold change <0.5 or >2, FDR <0.05) between preserved and paired lesioned cartilage, and 18 had previously been reported to confer susceptibility to OA and/or related phenotypes. Moreover, we identified notable highly significant AI SNPs in the CRLF1, WWP2, and RPS3 genes that were related to multiple OA features.

CONCLUSION

We present a framework and resulting data set for researchers in the OA research field to probe for disease-relevant genetic variation that affects gene expression in pivotal disease-affected tissue. This likely includes putative novel compelling OA risk genes such as CRLF1, WWP2, and RPS3.

Tandem Disc Herniation of the Lumbar and Cervical Spine: Case Series and Review of the Epidemiological, Pathophysiological and Genetic Literature

Introduction

Lumbar disc herniation (LDH) and cervical disc herniation (CDH) represent a relevant public health problem. Patients with symptomatic tandem herniations of the cervical and lumbar spine are rare and not described in the literature. In these patients, certain variables may predispose the development of disc herniation which could increase the understanding of the development of disc herniations. Our aim is to present the first case series of tandem disc herniation, and to elucidate whether tandem herniation is attributable to a certain propensity for disc herniation or not.

Methods 

From a prospective registry, patients with symptomatic tandem disc herniations were included, and the literature was reviewed on the comparative pathophysiology, genetics, and epidemiology of disc herniation and disc degeneration.

Results

Out of 3,156 patients with disc herniations in our registry, 16 presented with symptomatic tandem LDH and CDH that required discectomy. Therefore, we estimate the incidence of tandem disc herniation at 0.51% (95% confidence interval (CI): 0.26% - 0.75%) in the surgical population. The mean number of degenerated lumbar discs was 2.1 ± 1.1. Compared to the 1,241 patients with isolated LDH, no investigated factors were significantly associated with tandem herniations.

Conclusion

From a genetic, pathophysiological, and epidemiological position, disc herniation is not commonly a consequence of disc degeneration. Rather, degeneration and herniation seem to exist as two separate and distinctly different processes. Based on the literature, it is tenable that tandem disc herniation does not deviate from the normal pathophysiology, but rather occurs in the rare case that two individual herniated discs coincide.

Genetic variants in COL11A2 of lumbar disk degeneration among Chinese Han population

BACKGROUND

Lumbar disk disease (LDD) is a common musculoskeletal disorder. Several predisposing genetic and environmental risk factors have been established for symptomatic LDD.

METHODS

We conducted a case-control association study to investigate the role of the COL11A2 gene in LDD. Genotyping of 384 Chinese Han LDD patients and 384 Chinese Han controls was made for six single-nucleotide polymorphisms (SNPs) from COL11A2 by Agena Massarray. We evaluated these SNPs association with LDD using the chi-square test and genetic model analysis.

RESULTS

The strongest associations with LDD were observed for polymorphisms in rs2071025. Carriers of "A" allele had an increased risk of LDD (OR = 1.47, 95% CI = 1.20-1.80, p = 0.0002) as compared with the "G" allele in allele model. We found that rs2071025 were associated with LDD in female and male from the stratification analyses (p < 0.05). Genetic models showed that rs986522(C) significantly increased the risk of LDD in female; however, in males, we did not find significant associations between the rs986522 and LDD risk.

CONCLUSION

This study showed a genetic association with COL11A2 polymorphism in individuals with LDD. These data may provide novel insights into the pathogenesis of LDD, although further studies with larger numbers of participants worldwide are needed for validation of our conclusions.

Twenty-year Longitudinal Follow-up MRI Study of Asymptomatic Volunteers: The Impact of Cervical Alignment on Disk Degeneration

STUDY DESIGN

A 20-year longitudinal study.

OBJECTIVE

To evaluate the long-term effect of sagittal alignment of the cervical spine on intervertebral disk degeneration in healthy asymptomatic subjects.

SUMMARY OF BACKGROUND DATA

This study continues a previous 10-year longitudinal study to determine whether sagittal alignment affects disk degeneration during normal aging.

MATERIALS AND METHODS

We assessed 90 healthy subjects (30 men and 60 women) from among 497 volunteers who underwent magnetic resonance imaging (MRI) and plain radiographs of the cervical spine between 1994 and 1996 (follow-up rate 18.1%). The mean age at the initial study was 35.5±13.4 years (11-65 y). We compared initial MRIs and follow-up MRIs, conducted at an average of 21.6 years after the initial study, for (1) decreased signal intensity of the intervertebral disks, (2) posterior disk protrusion, and (3) disk-space narrowing from C2-3 to C7-T1. Subjects were grouped by age at follow-up (under 40 vs. 40 y and older) and by a lordotic or nonlordotic cervical sagittal alignment at baseline. We assessed neck pain, stiff shoulders, and upper-arm numbness at follow-up, and examined associations between clinical symptoms and MRI parameters.

RESULTS

Progressive changes during the 20-year period included a decrease in disk signal intensity (84.4% of subjects), posterior disk protrusion (86.7%), and disk-space narrowing (17.8%). No significant association was observed between sagittal alignment and decreased disk signal intensity, posterior disk protrusion, or disk-space narrowing. Among subjects over the age of 40, progressive degenerative changes at C7-T1 were significantly more frequent in nonlordotic subjects (90.9%) compared with those with cervical lordosis (54.2%, P=0.032). The prevalence of clinical symptoms was similar in lordotic and nonlordotic subjects at follow-up.

CONCLUSIONS

Nonlordotic cervical alignment was related to the progression of disk degeneration at C7-T1 but not other levels. Cervical alignment did not affect the development of clinical symptoms in healthy subjects.

LEVEL OF EVIDENCE

Level III.