Cochlear Explantation Prevents Hair Cell Degeneration in Transmembrane Serine Protease 3 (Tmprss3) Deficient Mice

Background/Objective: Transmembrane serine protease 3 (TMPRSS3) is the most common causative hearing loss gene in adults undergoing cochlear implantation and a significant cause of non-syndromic loss. However, function TMPRSS3 within inner ear unknown. In murine models, Tmprss3Y260X/Y260X mutants (Tmprss3-/-) have normal hair cell development followed by rapid degeneration from postnatal day 12 (P12) to P14. The endocochlear potential vivo rises P7 peak at P12, when mice begin hear, which temporally corresponds HC Tmprss3-/- mice. We tested if death occurs after removal through explantation.Methods: organ Corti explants control (Tmprss3+/-) were cultured 5 mM potassium solution for 7 days vitro (equivalent P14). Whole mounts (P7+7DIV) P14 cochlea immunostained MYO7A (hair marker) DAPI quantification outer (IHC/OHC) counts per 20 μm. Statistical analysis included two tailed t-test with p-value (<0.01, n=6).Results: As expected, there complete cells Compared vivo, OC displayed significantly improved IHC OHC survival (P<0.001). OCH was similar between (P=0.99, n=6)Conclusion: These results suggest that due factors related implicate regulation epithelial tight junctions. Future directions include confirming potassium-mediated crossing Pou3f4del-J mice, decreased without degeneration.