■类甲基转移酶3(METTL3),N6-甲基腺苷(m6A)甲基转移酶家族的一个组成部分,在HEI-OC1细胞和耳蜗外植体中表现出显着表达。氨基糖苷类抗生素,以耳毒性潜力而闻名,经常引起毛细胞不可逆的听觉损伤,主要通过氧化应激机制。然而,METTL3在卡那霉素诱导的毛细胞丢失中的具体作用尚不清楚.
■本研究旨在阐明METTL3对卡那霉素诱导的耳毒性的作用机制。
■体内实验表明,卡那霉素给药后,耳蜗外植体中的METTL3表达显着降低,伴随着应激颗粒(SGs)的形成。同样,在HEI-OC1细胞和新生儿耳蜗外植体中,24小时卡那霉素治疗导致METTL3表达降低并诱导SG形成,证实了体内观察。慢病毒介导的转染用于在HEI-OC1细胞中过表达和敲低METTL3。METTL3的敲低导致活性氧(ROS)水平增加和卡那霉素诱导的细胞凋亡,同时减少SG形成。相反,METTL3的过表达减弱了ROS的产生,凋亡率降低,并促进卡那霉素诱导的SG形成。因此,METTL3介导的SG形成为减轻卡那霉素诱导的ROS产生和细胞凋亡率提供了有希望的靶标。
■这一发现表明,METTL3介导的SG形成具有通过减少ROS形成和凋亡率来减轻卡那霉素诱导的耳蜗毛细胞损伤的潜力。
UNASSIGNED: Methyltransferase-like 3 (METTL3), a component of the N6-methyladenosine (m6A) methyltransferase family, exhibits significant expression in HEI-OC1 cells and cochlear explants. Aminoglycoside antibiotics, known for their ototoxic potential, frequently induce irreversible auditory damage in hair cells, predominantly through oxidative stress mechanisms. However, the specific role of METTL3 in kanamycin-induced hair cell loss remains unclear.
UNASSIGNED: This study aims to elucidate the mechanisms by which METTL3 contributes to kanamycin-induced ototoxicity.
UNASSIGNED: In vivo experiments demonstrated a notable reduction in METTL3 expression within cochlear explants following kanamycin administration, concomitant with the formation of stress granules (SGs). Similarly, a 24-hour kanamycin treatment led to decreased METTL3 expression and induced SG formation both in HEI-OC1 cells and neonatal cochlear explants, corroborating the in vivo observations. Lentivirus-mediated transfection was employed to overexpress and knockdown METTL3 in HEI-OC1 cells. Knockdown of METTL3 resulted in increased reactive oxygen species (ROS) levels and apoptosis induced by kanamycin, while concurrently reducing SG formation. Conversely, overexpression of METTL3 attenuated ROS generation, decreased apoptosis rates, and promoted SG formation induced by kanamycin. Therefore, METTL3-mediated SG formation presents a promising target for mitigating kanamycin-induced ROS generation and the rate of apoptosis.
UNASSIGNED: This finding indicates that METTL3-mediated SG formation holds potential in mitigating kanamycin-induced impairments in cochlear hair cells by reducing ROS formation and apoptosis rates.