bFGF Gene Transfer into Cochlea in Rats for Protection and Treatment in Blast Deafness

CHENG Xiaohua; GUO Wei; ZHAI Suoqiang; DING Jijiang; HUANG Lihui

doi:10.3969/j.issn.1672-2922.2014.03.033

Abstract：Objective To study effects of the transduction efficiency of cationic liposome mediated EGFP-bFGF gene into the cochlea through an intact round window membrane (RWM) in rats with noise-induced hearing loss, and to assess its influence on hearing. Methods Thirty SD adult rats were divided into four groups:(1) noise exposure group:exposure to 155 dB SPL im-pulse noise 20 times only (n=6);(2) EGFP control group:cationic liposome-pEGFP complex administered immediately after im-pulse noise exposure (n=8);(3) bFGF rescue group:cationic liposome-pEGFP-bFGF complex administered immediately after impulse noise (n=8);(4) bFGF protection group:cationic liposome-pEGFP-bFGF complex administered 3 days before impulse noise (n=8). ABR thresholds were measured in all the animals before and after blast on day 1, day 3, day 7 and day 14, respec-tively. On postoperative day 14, all the animals were sacrificed, bilateral cochleae were harvested and surface preparations of basilar membrane were studied. The expression of bFGF in hair cells was detected by immunofluorescent staining. Results At day 1 after blast, the ABR threshold of the bFGF protection group was lower than the noise group and EGFP control group (P<0.05). At day 3, day 7 and day 14 after blast, the ABR threshold of the bFGF protection group and bFGF rescue group showed significant change compared with the two control groups (P<0.05). On postoperative day 14, fluorescent microscopy showed green fluorescence in the cochlea on operated side in the prevention and rescue groups. Conclusion Cationic liposome mediated bFGF gene transferred into the cochlea through the RWM can be expressed, and can partially facilitate recovery of hear-ing loss caused by impulse noise.