Genetic Predictors of Early-Onset Spinal Intervertebral Disc Degeneration: Part One of Two

Intervertebral disc degenerative disease in South Africa: a case-control analysis of selected gene variants

BACKGROUND

Intervertebral disc (IVD) degenerative disease is a multifactorial disease for which genetics plays an integral role. Several genes, and their variants, associated with the development and progression of IVD degenerative disease have been identified. While several studies have investigated these genes in Asian and European populations, no available evidence exists for the South African population. Therefore, this study aimed to investigate these parameters.

METHODS AND RESULTS

Biological samples were collected in the form of buccal swabs from patients and DNA was extracted using a standard salt-lysis protocol. DNA purity and quantity was assessed by spectrophotometry, and subsequent genotyping was performed using the MassARRAY®System IPLEX extension reaction. For associations between variants and the presence of IVD degenerative disease, odds ratios (OR), confidence intervals (CI), chi-squared analysis and logistic regression was calculated. Age and sex were adjusted for, and Bonferroni's correction was applied. This study found statistically significant associations for five of the evaluated single nucleotide polymorphisms (SNPs) with IVD degenerative disease, whereby IL-1α rs1304037 and rs1800587, ADAMTs-5 rs162509, and MMP-3 rs632478 demonstrated increased odds of a positive diagnosis for IVD degenerative disease, while decreased odds of IVD degenerative disease were seen for GDF-5 rs143383.

CONCLUSION

To the best of our knowledge, this study represents the first of its kind to investigate the association of gene variants associated with IVD degenerative disease within the South African population. This study has shown that 5 of these gene variants were significantly associated with the presence of IVD degenerative disease, reflecting their integral roles in development and possible progression of the disease.

Intervertebral disc degeneration-Current therapeutic options and challenges

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

Regulating the fate of stem cells for regenerating the intervertebral disc degeneration

Lower back pain is a leading cause of disability and is one of the reasons for the substantial socioeconomic burden. The etiology of intervertebral disc (IVD) degeneration is complicated, and its mechanism is still not completely understood. Factors such as aging, systemic inflammation, biochemical mediators, toxic environmental factors, physical injuries, and genetic factors are involved in the progression of its pathophysiology. Currently, no therapy for restoring degenerated IVD is available except pain management, reduced physical activities, and surgical intervention. Therefore, it is imperative to establish regenerative medicine-based approaches to heal and repair the injured disc, repopulate the cell types to retain water content, synthesize extracellular matrix, and strengthen the disc to restore normal spine flexion. Cellular therapy has gained attention for IVD management as an alternative therapeutic option. In this review, we present an overview of the anatomical and molecular structure and the surrounding pathophysiology of the IVD. Modern therapeutic approaches, including proteins and growth factors, cellular and gene therapy, and cell fate regulators are reviewed. Similarly, small molecules that modulate the fate of stem cells for their differentiation into chondrocytes and notochordal cell types are highlighted.