Link Between Chronic Tinnitus and miR-30e, miR-206 , and miR-124 Polymorphisms Modulating the Brain-Derived...

Brain-derived neurotrophic factor (BDNF) plays a crucial role in the initial formation of the central auditory system and the sensory epithelium within the inner ear. Mounting evidence indicates that BDNF administration promotes microRNA (miRNA) production in neurons, despite the typical suppressive effect of miRNAs on BDNF expression. Therefore, miRNAs regulating BDNF expression may impact the auditory system and serve as potential gene polymorphisms affecting human hearing ability. This study aimed to investigate the contribution of miRNA polymorphisms affecting BDNF to tinnitus pathophysiology.

A total of 70 tinnitus patients aged 18-55 years and 70 age-matched healthy controls without tinnitus or systemic illnesses were recruited from an Ear, Nose & Throat clinic. Tinnitus assessment included tympanometric, audiological, and psychoacoustic evaluations. Seven miRNA single-nucleotide polymorphisms (miR-30e rs112439044, rs10489167, miR-206 rs16882131, miR-30a rs1491500379, miR-26b rs565919718, rs188612260, and miR-124 rs5315564) regulating the BDNF gene were analyzed using the Fluidigm platform.

Significant differences in genotype distributions were observed for miR-30e rs112439044, miR-124 rs5315564, and miR-206 rs16882131 between the tinnitus patients and controls (P < .05). Genetic inheritance-model analysis revealed that miR-30e rs112439044 was associated with 0.20- and 0.83-fold risks under dominant and additive models, respectively. The miR-124 rs5315564 showed a 1.65-fold risk in the dominant model, while miR-206 rs16882131 exhibited an 11.1-fold protective effect under the dominant model and an 8.57-fold risk under the additive model.

The findings suggest that polymorphisms in miR-206, miR-30e, and miR-124 may influence the auditory pathway by modulating BDNF gene expression, potentially contributing to the pathophysiology of chronic tinnitus.