HOTAIR Promotes Spiral Ganglion Neuron Proliferation via miR-211-5p/EYA3 Regulation.

Abstract

Sensorineural hearing loss (SNHL) seriously affects people's lives, and the degradation of spiral ganglion neurons (SGNs) is the main cause of SNHL. Many studies have revealed that long non-coding RNAs (lncRNAs) are linked to SGNs. However, it is still unclear how lncRNAs affect damage repair in SGNs. Fluorescence in situ hybridization (FISH) and nuclear-cytoplasmic separation (NCS) assays were used to verify the cellular localization of lncRNA-HOTAIR in SGNs. Primary SGNs were dissected from the C57BL/6J male mice. We constructed sh-HOTAIR SGNs to investigate the role of HOTAIR. Target gene levels were analyzed using qRT-PCR and Western blot assays. Additionally, SGN proliferation was assessed using the CCK-8 and flow cytometry assays. Moreover, RIP and dual-luciferase assays were conducted to elucidate the interactions among HOTAIR, miRNA, and mRNA. Our findings illustrated that HOTAIR was primarily expressed in the cytoplasm, and downregulation of HOTAIR increased SGN apoptosis by approximately 30% (P < 0.001). In addition, miR-211-5p was identified as being directly downstream of HOTAIR, which could bind with miR-211-5p to modulate SGNs growt (all P < 0.05). Furthermore, miR-211-5p reduced the proliferation of SGNs (P < 0.001) and increased apoptosis (P < 0.01) by binding to the 3'-UTR of EYA3, whereas overexpression of EYA3 reversed this result (all P < 0.05). Our findings suggest that HOTAIR promotes SGN proliferation by competitively binding to miR-211-5p and regulating EYA3 expression, highlighting its potential as a novel target for sensorineural hearing loss therapies.