Genotype-dependent miR-499/SOX5 axis regulation and its association with chronic low back pain risk and severity

The pathogenesis of chronic low back pain (CLBP) is complex and intricately linked to genetic predisposition. This study aimed to investigate the association between the microRNA-499 (miR-499) rs3746444 genetic polymorphism and CLBP, as well as to elucidate the underlying molecular mechanisms.

A total of 180 patients with CLBP and 180 healthy controls were enrolled in this study. Genotyping of the rs3746444 locus was performed using the TaqMan probe method. The expression of miR-499 and SRY-related HMG-box 5 (SOX5) was quantified by reverse transcription quantitative polymerase chain reaction (RT‑qPCR). RNA immunoprecipitation (RIP) and dual-luciferase reporter gene assays were employed to validate the targeting relationship between miR-499 and SOX5.

Genetic model analysis showed that the TC/CC genotypes and the C allele of miR-499 rs3746444 were associated with increased CLBP risk, with a clear genotype‑dose effect. In CLBP patients, miR-499 was upregulated while SOX5 was downregulated. The two molecules were negatively correlated, and SOX5 was validated as a direct target of miR-499. Genotype stratification revealed that the rs3746444 polymorphism was associated with pathology‑dependent regulation of the miR-499/SOX5 axis: mutant genotypes (TC/CC) correlated with miR-499 upregulation and SOX5 downregulation only in CLBP patients, not in healthy controls. Adjusted multivariate logistic regression identified rs3746444 as an independent CLBP risk factor (TC: OR = 1.636, P = 0.037; CC: OR = 3.457, P = 0.002). Additionally, miR-499 showed good diagnostic performance for CLBP and correlated positively with Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) scores, indicating its potential as a disease activity biomarker.

The miR-499 rs3746444 polymorphism was associated with both the risk of developing CLBP and disease severity, suggesting a potential role for context-dependent regulation of the miR-499/SOX5 axis in CLBP pathogenesis, although this mechanistic interpretation requires further functional validation.