Expression Of Neurod In Spiral Ganglion Cells In Rat After Cisplatin-induced Ototoxicity

Objective To investigate after injury of cisplatin-induced ototoxicity,theeffects of Neurogenic differentiation（NeuroD）in rats spiral ganglion cells(SGCs)expression of the cochlea change,to explore in the spiral ganglion injury repair.Methods Adult SD（Sprague-Dawley）male rats64only,according to randomNumbers randomly divided into four groups, they are: the control group:0.9%by weight with saline5ml/kg intraperitoneal injection per day, for5days, onthe sixth day to death; Drug1day group: according to the weight to cisplatin5mg/kg intraperitoneal injection, the following day to death; Drug3days group:according to the weight to cisplatin5mg/kg intraperitoneal injection per day, forthree days, in the fourth day to death; Drug5days group: according to theweight to cisplatin5mg/kg intraperitoneal injection per day, for5days, on thesixth day to be put to death. Each group of16only, establish cisplatin ear toxicmodel. Through the HE Dyeing, Immunofluorescence stain,Immunohistochemical staining, Western Blot, Real-Time PCR and other means, to test NeuroD protein in cisplatin model and observe NeuroD expressionchanges in the cochlea spiral ganglion cells after injury of different time point.Results We successfully built cisplatin ear ototoxicity in the rat model, withthe drug use the extension of time, the expression of NeuroD in cochlear spiralganglion was dynamic change. The NeuroD mRNA expression in1day and3days group compared with the control group and5days group was a statisticallysignificant difference(P<0.01); Immunohistochemical image optical density testresults show that drugs1day groupand3days group and control group wasstatistically significant (P <0.01), medication for five days with the controlgroup showed no statistically significant (P>0.05); Western Blot results showthat drug1day group and3days compared with a control group are statisticallysignificant(P<0.01), drug5days compared with a control group was notstatistically significant(P>0.05).The research data showed the expression ofNeuroD exhibited in SGCs was dynamic along with the administration lasting．Conclusions The expression of NeuroD increased to increase at first, threedays later peak, five days later down． The expression of NeuroDhave had early treatment enhanced expression of late expression wasdecreased significantly, while hearing loss. It may play an important role in therepair process of cochlear spiral ganglion cells, specially at early stage of thedamage．...