FST Attenuates Cochlear Inflammation And Oxidative Stress Via Regulating The IκBα/NF-κB Signaling Pathway

Objective: To investigate the anti-inflammatory and anti-oxidative effects of follistatin on the basilar membrane of cochlea after neomycin injury and its mechanism,so as to seek an innovative therapeutic target for sensorineural deafness.Methods: A neomycin injury model was established in the basement membrane of neonatal mouse cochlea.FST gene was overexpressed in the model group,and the expression of FST was detected by RT-PCR after the three groups of basement membrane tissues were cultured.Immunofluorescence staining was used to observe the effect of up-regulated FST gene on inner ear hair cells,and the changes of the number of inner ear hair cells were counted.The levels of TNF-α IL-1β and IL-6 inflammatory cytokines were detected by ELISA,and the expressions of inflammatory cytokines(TNF-α IL-1β and IL-6)oxidative stress index(i NOS,COX-2)and IκBαP/IκBα/NF-κb p65 protein were detected by Western-blot.Results: The results of RT-PCR showed that FST was expressed in the cochlea basilar membrane tissue.The expression of FST was significantly decreased in the neomycin-damaged model group,and the FST content was partially reversed after overexpression of FST.In addition,the experiment proved that no load of adenovirus had no effect on the results of this experiment,and the same was true in the Western Blot experiment.After neomycin damaged cochlea basement membrane tissue,the results of overexpression of FST showed that the number of hair cells in the middle circle of the basement membrane was statistically significant compared with the number of hair cells in the model group(P < 0.05).There was no significant difference in the number of hair cells in the top and bottom circles compared with that in the model group(P < 0.05).The expression levels of TNF-α,IL-1β,IL-6,i NOS and COX-2 in model group were increased,while the overexpression of FST could significantly reduce the contents of inflammatory indexes and oxidative stress indexes(P < 0.05),and the results were the same in Western blot(P < 0.05).The protein expression levels of IκBα and NF-κb p65 in cytoplasm of model group were decreased,while the protein expression levels of P-IκBα were increased.However,the protein expression levels of IκBα and NF-κb p65 were significantly increased after FST overexpression(P < 0.05),while the protein expression levels of P-IκBα were significantly decreased(P < 0.05).The expression of NF-κb p65 in the nucleus was significantly increased,but it was partially reversed after FST overexpression(P < 0.05).Conclusion: The up-regulation of FST gene can reduce the contents of inflammatory factors and oxidative stress indexes in cochlear basement membrane tissue after neomycin injury,and promote the partial recovery of hair cell number in the middle ring of cochlear basement membrane,thus improving partial hearing of patients.The mechanism may be that FST reduces cochlear inflammation and oxidative stress process by regulating IκBα/NF-κB signaling pathway.