摘要: Aminoglycoside antibiotics are essential in managing many life-threatening diseases. However, their derivatives, such as neomycin, are associated with severe side effects such as persistent sensorineural hearing loss. Therefore, it is essential to elucidate the molecular and biochemical mechanisms of aminoglycoside-induced ototoxicity and identify targets for alleviating ototoxic injury. Here, we provide a detailed cochlear cell atlas of neomycin-induced acute and chronic ototoxicity-related changes through single-nucleus RNA sequencing profiling. Utilising this cochlear cell atlas, we used the Augur and scDist algorithms to evaluate cell-type-specific susceptibility to neomycin injury. We observed aberrant expression of X-linked inhibitor of apoptosis (Xiap)-associated factor 1 (Xaf1) in neomycin-exposed cochleae using the cochlear cell atlas, and we identified a novel role for Xaf1 in facilitating PANoptosis through overexpression and knockdown assays in vitro. Finally, we assessed the protective role of Xaf1 against neomycin-induced ototoxicity by Xaf1 knockdown in cochlear hair cells using adeno-associated virus-based gene delivery. Mechanistically, Xaf1 orchestrates PANoptosis activation through direct interaction with and transcriptional regulation of ZBP1, establishing its hierarchical position upstream in the signalling cascade. This study presents detailed cochlear cellular maps of neomycin-induced ototoxicity and serves as a valuable resource for identifying transcriptome-wide disease-driving perturbations at the single-cell level. More importantly, we identified Xaf1 as a critical target for modulating the PANoptosis pathway, offering a promising treatment strategy for aminoglycoside-induced ototoxicity.

摘要: Transcriptomics studies have identified integrin receptor beta 2 subunit (ITGB2) as a core gene in osteoarthritis (OA), strongly linked to osteoclast function in the subchondral bone. However, the mechanism through which ITGB2 regulates osteoclast function in OA remains unclear. In this study, we found that ITGB2 was negatively correlated with ITGB1 in the human subchondral bone. Proteomic analysis indicated that integrin binding is crucial in OA subchondral bone, with ITGB2 identified as a significantly upregulated protein in OA. In vitro experiments using immunoprecipitation and bimolecular fluorescence complementation revealed that ITGB2, but not ITGB1, directly interacts with Rac1 during osteoclast differentiation. Activated Rac1 promotes osteoclast differentiation and bone resorption through several mechanisms. ITGB2 knockdown reduced Rac1-GTP levels and increased ITGB1 expression. ITGB2 inhibition reduced actin ring formation and microtubule migration to the cell edge during osteoclast differentiation. Additionally, overexpression of ITGB1 in ITGB2-knockdown cells not only further suppressed ITGB2 expression but also exacerbated the inhibition of osteoclast differentiation. In a DMM mouse model, ITGB2 was associated with osteoclast activity in the subchondral bone. ITGB2 knockdown significantly reduced bone resorption and slowed OA progression by inhibiting osteoclastogenesis. In conclusion, our study identified a novel mechanism for the reciprocal regulation of integrin subunits. Moreover, inhibition of the ITGB2 signalling pathway slows subchondral bone remodelling in osteoarthritis by inhibiting osteoclast differentiation, offering a potential strategy for targeted therapeutic interventions.