Role of the IL-6 gene in the etiopathogenesis of idiopathic scoliosis

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.

The Role of Muscle Biomarkers in Adolescent Idiopathic Scoliosis

Adolescent idiopathic scoliosis (AIS) is the predominant orthopedic disorder in children, affecting 1-3% of the global population. Research in this field has tried to delineate the genetic factors behind scoliosis and its association with heredity since AIS is considered a polygenic disease and has different genetic and epigenetic factors. The current study conducted a narrative review of the literature, focusing on biomarkers in the pathophysiology of muscle in AIS patients. Articles were collected from Scopus, Pubmed, and Web of Science. The key screening parameters were scoliosis classification, sampling, and the biomarkers evaluated. This review emphasizes potential key mechanisms and molecular regulators in muscle tissue. While there has been limited focus on the proteins contributing to muscle changes in AIS, significant attention has been given to genomic studies of single-nucleotide polymorphisms, particularly in LBX1. Despite these efforts, the exact causes of AIS remain elusive, with several theories suggesting genetic and hormonal factors. This review identified critical protein biomarkers such as Gi-protein alpha subunits, fibrillin-1 and -2, and various differentially expressed proteins, which may be linked to muscle alterations in AIS. This field of research is still limited due to a lack of homogeneity in the distinction of patients by groups and curve severity. Although the pathophysiology of AIS is still unclear, molecular research is important to guide the treatment of AIS before achieving skeletal maturity, thus avoiding serious problems associated with posture changes and low quality of life. In the future, a more comprehensive synergy between orthopedic and molecular research might ameliorate the diagnosis and treatment of AIS patients.

Predictive value of single-nucleotide polymorphisms in curve progression of adolescent idiopathic scoliosis

PURPOSE

Genetic diagnosis is a promising approach because several single-nucleotide polymorphisms (SNPs) associated with adolescent idiopathic scoliosis (AIS) progression have been reported. We review the predictive value of SNPs in curve progression of adolescent idiopathic scoliosis.

METHODS

We reviewed DNA-based prognostic testing to predict curve progression. Then, the multiple polymorphisms in loci related to AIS progression were also reviewed, and we elucidated the predictive value of SNPs from four functional perspectives, including endocrine metabolism, neuromuscular system, cartilage and extracellular matrix, enzymes, and cytokines.

RESULTS

The ScoliScores were less successful predictors than expected, and the weak power of predictive SNPs might account for its failure. Susceptibility loci in ESR1, ESR2, GPER, and IGF1, which related to endocrine metabolism, have been reported to predict AIS progression. Neuromuscular imbalance might be a potential mechanism of scoliosis, and SNPs in LBX1, NTF3, and SOCS3 have been reported to predict the curve progression of AIS. Susceptibility loci in SOX9, MATN1, AJAP1, MMP9, and TIMP2, which are related to cartilage and extracellular matrix, are also potentially related to AIS progression. Enzymes and cytokines play essential roles in regulating bone metabolism and embryonic development. SNPs in BNC2, SLC39A8, TGFB1, IL-6, IL-17RC, and CHD7 were suggested as predictive loci for AIS curve progression.

CONCLUSIONS

Many promising SNPs have been identified to predict the curve progression of AIS. However, conflicting results from replication studies and different ethnic groups hamper their reliability. Convincing SNPs from multiethnic populations and functional verification are needed.

Association of the IL-6 -174G > C (rs1800795) Polymorphism with Adolescent Idiopathic Scoliosis: Evidence from a Case-Control Study and Meta-Analysis

Recent epidemiological studies have identified that the -174G > C (rs1800795) polymorphism in the promoter region of the interleukin-6 ( IL-6 ) gene is associated with the risk of developing adolescent idiopathic scoliosis (AIS), but they presented inconsistent and controversial results. Thus, we performed a case-control study and meta-analysis to derive a more precise estimation of the relationship between the IL-6 -174G > C polymorphism and the risk of developing AIS. A total of 80 patients with AIS and 80 matched healthy control subjects were genotyped using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. In addition, all eligible studies published up to June 2018 were identified through a search in the PubMed, EMBASE, Google Scholar, and China National Knowledge Infrastructure (CNKI) databases. We calculated the odds ratios (ORs) and 95% confidence intervals (95%CIs) to assess the association. A total of 10 eligible studies comprising 1,695 AIS cases and 2,097 healthy controls were included in the meta-analysis. The pooled data suggested a significant association between the IL-6 -174G > C polymorphism and the susceptibility to develop AIS, which was demonstrated under 4 genetic models, that is, the allelic (C versus G; OR = 0.671; 95%CI: 0.457–0.985; p  = 0.042), heterozygous (CG versus GG; OR = 0.734; 95%CI: 0.554–0.973; p  = 0.032), dominant (CC + CG versus GG; OR = 0.660; 95%CI: 0.440–0.990; p  = 0.044) and recessive models (CC versus CG + GG; OR = 0.506; 95%CI: 0.264–0.970; p  = 0.040). The stratification analysis by ethnicity revealed an increased risk of developing AIS in Caucasians, but not in Asians. The present meta-analysis, which is inconsistent with the previous meta-analysis, suggests that the IL-6 -174G > C polymorphism may increase the individual susceptibility to develop AIS, especially in Caucasians, and it could serve as a biomarker to predict the population at high risk of developing AIS.

GENETIC ASPECTS OF IDIOPATHIC ESCOLIOSIS - A LITERATURE REVIEW

ABSTRACT The idiopathic scoliosis (IS) is the most common form of spinal deformity. The pathogenesis of IS is still poorly understood. Several studies show evidence that the genetic component is determinant to the development of IS. In this setting, a crescent focus has been placed on the identification of genes, associated genetic polymorphisms, and multiple susceptibility loci. This review highlights the genes and genetic polymorphisms currently studied, identified as influential in the genesis of IS, such as MMP-3, IL-6, type I collagen, and vitamin D and estrogen receptors. We concluded that IS remains a complex disease with a polygenic background and that genetic polymorphisms are intrinsically related to this condition. Level of evidence III; Narrative Review.

A biallelic mutation in IL6ST encoding the GP130 co-receptor causes immunodeficiency and craniosynostosis

Multiple cytokines, including interleukin 6 (IL-6), IL-11, IL-27, oncostatin M (OSM), and leukemia inhibitory factor (LIF), signal via the common GP130 cytokine receptor subunit. In this study, we describe a patient with a homozygous mutation of IL6ST (encoding GP130 p.N404Y) who presented with recurrent infections, eczema, bronchiectasis, high IgE, eosinophilia, defective B cell memory, and an impaired acute-phase response, as well as skeletal abnormalities including craniosynostosis. The p.N404Y missense substitution is associated with loss of IL-6, IL-11, IL-27, and OSM signaling but a largely intact LIF response. This study identifies a novel immunodeficiency with phenotypic similarities to STAT3 hyper-IgE syndrome caused by loss of function of GP130.

Association of IL-6 and MMP-3 gene polymorphisms with susceptibility to adolescent idiopathic scoliosis: a meta-analysis

Recently, several institutions have investigated the associations of MMP-3-1171 5A/6A and IL-6-174-G/C gene polymorphisms with adolescent idiopathic scoliosis (AIS), while reports from different institutions are not consistent. Therefore, we, comprehensively and systematically performed this meta-analysis to detect whether the two gene polymorphisms are correlated with AIS. From January 1994 to October 2015, all case-control studies focussed on the relationship between the two aforementioned gene polymorphisms and the susceptibility to AIS were retrieved from bibliographic databases. A total of 16 articles were found, of which five consisted of 944 cases and 1177 controls, were finally included after being assessed by two reviewers. We calculated the pooled odds ratio (OR) with 95% confidence interval (95% CI) to assess the associations. The pooled data analyses were based on allele contrast, homozygote, heterozygote, dominant and recessive models. Overall, there was no significant association of IL-6-174-G/C gene polymorphism with AIS risk. Significant association was observed in homozygote model of MMP-3-1171-5A/6A gene polymorphism (5A5A versus 6A6A: OR = 1.69, 95% CI = 1.11-2.58, P = 0.02). When stratified into Caucasian and Asian populations, positive association was found in Caucasian population (5A versus 6A: OR = 1.43, 95% CI = 1.11-1.84, P = 0.006; 5A5A versus 6A6A: OR = 1.90, 95% CI = 1.13-3.19, P = 0.015); however, there was no significant association in Asian population. The present study concluded that 5A5A genotype of MMP-3-1171 5A/6A gene polymorphism was associated with AIS, especially in Caucasian population. However, no significant association was detected between IL-6-174-G/C gene polymorphism and AIS.

Adolescent idiopathic scoliosis: evidence for intrinsic factors driving aetiology and progression

Adolescent idiopathic scoliosis (AIS) is now considered to be a multifactorial heterogeneous disease, with recent genomic studies supporting the role of intrinsic factors in contributing to the onset of disease pathology and curve progression. Understanding the key molecular signalling pathways by which these intrinsic factors mediate AIS pathology may facilitate the development of pharmacological therapeutics and the identification of predictive markers of progression. The heterogenic nature of AIS has implicated multiple tissue types in the disease pathophysiology, including spinal bone, intervertebral disc and paraspinal muscles. In this review, we highlight some of the mechanisms and intrinsic molecular regulators within these different tissue types and review the evidence for their involvement in AIS pathology.

The TGFB1 gene is associated with curve severity but not with the development of adolescent idiopathic scoliosis: a replication study in the Chinese population

Background

The transforming growth factor beta-1 (TGFB1) gene was recently reported to be a new susceptible gene of adolescent idiopathic scoliosis (AIS) in Russian population. This study aimed to replicate the relationship between the TGFB1 gene and the susceptibility of AIS in a Chinese population, and to further describe its association with the curve severity.

Methods

A total of 1251 female AIS patients and 994 age-matched healthy controls were included in this study. The rs1800469 of TGFB1 gene was genotyped for all participants using the PCR-based Invader assay. The differences of genotype and allele distributions between AIS patients and healthy controls were assessed using the Chi-square test. One-way ANOVA test was used to compare the mean Cobb angles among patients with different genotypes.

Results

There was no significant difference in terms of the genotype and the allele frequency between the patients and the controls. The mean Cobb angle was 34.7 ± 11.9° (range 25–61°). Case-only analysis showed that rs1800469 was significantly associated with the curve severity. Patients with genotype TT had remarkably higher curve magnitude (39.1 ± 12.8°) than those with genotype CT (34.8 ± 11.1°) or CC (32.1 ± 10.6°).

Conclusions

The TGFB1 gene may not be a predisposition gene of AIS in the Chinese population. However, it can play a role in the curve progression of AIS. Replication studies in other ethnic groups are warranted to understand the implication of TGFB1 gene in AIS.