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Abstract Transforming growth factor-β (TGF-β) signaling plays a significant role in multiple biological processes, including inflammation, immunity, and cell death. However, its specific impact on the cochlea remains unclear. In this study, we aimed to investigate the effects of TGF-β signaling suppression on auditory function and cochlear pathology in mice with kanamycin-induced ototoxicity. Kanamycin and furosemide (KM-FS) were systemically administered to 8-week-old C57/BL6 mice, followed by immediate topical application of a TGF-β receptor inhibitor (TGF-βRI) onto the round window membrane. Results showed significant TGF-β receptor upregulation in spiral ganglion neurons (SGNs) after KM-FA ototoxicity, whereas expression levels in the TGF-βRI treated group remained unchanged. Interestingly, despite no significant change in cochlear TGF-β expression after KM-FS ototoxicity, TGF-βRI treatment resulted in a significant decrease in TGF-β signaling. Regarding auditory function, TGF-βRI treatment offered no therapeutic effects on hearing thresholds and hair cell survival following KM-FS ototoxicity. However, SGN loss and macrophage infiltration were significantly increased with TGF-βRI treatment. These results imply that inhibition of TGF-β signaling after KM-FS ototoxicity promotes cochlear inflammation and SGN degeneration.

Abstract Objective Statins have been reported to improve vascular endothelial function and microcirculation, reduce oxidative stress, and exert anti‐inflammatory and protective effects against inner ear damage. Therefore, this study aimed to investigate the effect of statins on hearing prognosis in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). Methods We reviewed the medical records of 149 patients diagnosed with ISSNHL. Clinical characteristics, hearing thresholds, statin medications, and hematological findings were investigated. First, patients with ISSNHL were assigned to the good and poor outcome groups, and factors influencing their prognosis were analyzed. Furthermore, patients with dyslipidemia were investigated to determine whether statins have therapeutic effects on ISSNHL. Results Significant differences in age (p = .011), days from the onset of ISSNHL to the initiation of treatment (p = .04), and hematological total cholesterol (TC; p = .015) between the good and poor outcome groups were observed. Furthermore, when hearing outcomes were investigated in patients with dyslipidemia, TC was significantly lower in the good outcome group (p = .03). Although no significant therapeutic effects of statins were observed in participants with dyslipidemia, patients in the statin‐treated group were significantly older and experienced more diabetic complications than those in the non‐statin‐treated group. Conclusion Although our study showed that dyslipidemia is a poor prognostic factor for ISSNHL, statins had no significant therapeutic effects on hearing recovery in ISSNHL patients with dyslipidemia. The patients that received statin medications were significantly older and experienced more diabetic complications, which may have affected their hearing prognosis. Level of Evidence Level 4.