A Neuron-Like Cellular Model for Severe Tinnitus Associated with Rare Variations in the ANK2 Gene

Area of Science:

• Neuroscience
• Genetics
• Otolaryngology

Background:

• Tinnitus, the perception of sound without an external source, is linked to auditory pathway and brain region alterations.
• Recent studies implicate ANK2 gene missense variants in severe tinnitus.
• ANK2 (ankyrin-B) regulates axon branching; mutations may cause excessive branching and excitatory synapse formation.

Purpose of the Study:

• To generate a patient-derived induced pluripotent stem cell (iPSC) model of severe tinnitus.
• To differentiate these iPSCs into otic-neural progenitors and inner ear neurons.
• To investigate the cellular and molecular impact of ANK2 gene variants in severe tinnitus.

Main Methods:

• Patient-derived iPSCs were generated through cell reprogramming.
• A two-stage neural differentiation protocol was employed to create otic-neural progenitors and neuron-like cells.
• Quantitative PCR (qPCR) and immunostaining confirmed gene, protein, and cellular marker expression, including ANK2.

Main Results:

• A severe tinnitus cellular model was successfully established.
• Analysis showed higher ANK2 expression in control cell lines compared to the patient-derived line.
• Patient-derived neurons exhibited closely grouped formations with increased projections and dendrites versus controls.

Conclusions:

• The developed cellular model serves as a valuable tool for studying ANK2-associated cellular and molecular changes in severe tinnitus.
• This model shows promise for advancing the development of novel drug and gene-based therapies for severe tinnitus.
• ANK2 gene variants may contribute to tinnitus pathophysiology through altered neuronal structure and connectivity.