[Protective effect of NT-3 gene mediated by hydroxyapatite nanoparticle on the cochlea of guinea pigs injured by excitotoxicity].
OBJECTIVE
To transfect the recombinant plasmid enhancement type green fluorescent protein C2- neurotrophic factor-3 (pEGFPC2-NT3) into the spinal ganglion cells(SGCs) of guinea pigs' cochlea injured by the excitotoxicity of hydroxyapatite particle (HAT), to inject the recombinant plasmid pEGFPC2-NT3 into the guinea pigs' cochlea, and to observe the expression of pEGFPC2-NT3 and the protective effect of pEGFPC2-NT3 on SGCs of the cochlea in guinea pigs.


METHODS
The recombinant plasmid pEGFPC2-NT3 with gene-green fluorescent protein was established. Kanic acid (KA) was injected into guinea pigs'cochleae and the excitotoxicity model was established. After a week the recombinant plasmid was transferred into SGCs of guinea pigs'cochlea treated with HAT. The following week the expression of NT-3 was examined by the immunohistochemical method, and the morphology of SGNs was observed under the electronic microscope after 4 weeks, in the mean time the changes of auditory brain-stem response (ABR) were examined.


RESULTS
The excitotoxicity models were established successfully. NT-3 expression in the intracytoplasm of SGNs was observed by the immunohistochemical method 1 week after the injection, the morphologic damages of SGNs lessened under the electronic microscope after 4 weeks. ABR was partly restored, compared with ABR after the injury of the excitotoxicity.


CONCLUSIONS
On the 7th day, NT3 gene transferred by HAT through the scala tympani can lessen the excitotoxicity of SGCs after KA was injected into the guinea pigs cochlea.
Jiang
Ming
M
Department of Otorhinolaryngology--Head and Neck Surgery, Third Xiangya Hospital, Central South University, Changsha 410013, China.
Zhang
Yong-Quan
YQ
He
Guang-Xiang
GX
Sun
Hong
H
D000818:Animals; D003051:Cochlea / Q000187:drug effects*; D017886:Durapatite / Q000008:administration & dosage / Q000494:pharmacology*; D016057:Evoked Potentials, Auditory, Brain Stem; D005727:Ganglia, Spinal / Q000187:drug effects / Q000378:metabolism*; D015316:Genetic Therapy; D006168:Guinea Pigs; D007608:Kainic Acid / Q000009:adverse effects; D053761:Nanocomposites; D009498:Neurotoxins / Q000009:adverse effects; D020933:Neurotrophin 3 / Q000235:genetics*; D010957:Plasmids
D009498:Neurotoxins; D020933:Neurotrophin 3; D017886:Durapatite; D007608:Kainic Acid