The phosphatidylinositol-3 kinase （PI3K）/Akt pathway and brain-derived neurotrophic factor （BDNF） are involved in neurological functional recovery following cerebral ischemia. Therefore, we hypothesized that mecha...The phosphatidylinositol-3 kinase （PI3K）/Akt pathway and brain-derived neurotrophic factor （BDNF） are involved in neurological functional recovery following cerebral ischemia. Therefore, we hypothesized that mechanisms of neuroprotection by transplantation of neural stem cells （NSCs） on cerebral ischemia contributed to activation of the PI3K/Akt pathway and enhanced BDNF expression. In the present study, Wortmannin （a specific, covalent inhibitor of PI3K） was administered adjacent to ischemic hippocampus by stereotactic transplantation to further confirm the neuroprotective mechanisms of NSC transplantation following cerebral ischemia. Results showed that focal infarct volume was significantly smaller in the NSCs group, but the neurological behavior score in the NSC group was significantly greater than the middle cerebral artery occlusion model group, Wortmannin treatment group, and NSCs ＋ Wortmannin treatment group. Protein expression of BDNF was significantly greater in the NSC group compared with the Wortmannin treatment group and NSCs ＋ Wortmannin treatment group. These results suggest that the neuroprotective role of NSC transplantation in the cerebral ischemia activated the PI3K/Akt pathway and upregulated BDNF expression in lesioned brains.展开更多
Brain-derived neurotrophic factor(BDNF)has robust effects on synaptogenesis,neuronal differentiation and synaptic transmission and plasticity.The maturation of BDNF is a complex process.Proprotein convertase 1/3(PC1/3...Brain-derived neurotrophic factor(BDNF)has robust effects on synaptogenesis,neuronal differentiation and synaptic transmission and plasticity.The maturation of BDNF is a complex process.Proprotein convertase 1/3(PC1/3)has a key role in the cleavage of protein precursors that are directed to regulated secretory pathways;however,it is not clear whether PC1/3 mediates the change in BDNF levels caused by ischemia.To clarify the role of PC1/3 in BDNF maturation in ischemic cortical neurons,primary cortical neurons from fetal rats were cultured in a humidified environment of 95%N_2 and 5%CO_2 in a glucose-free Dulbecco's modified Eagle's medium at 37℃for3 hours.Enzyme-linked immunosorbent assays and western blotting showed that after oxygen-glucose deprivation,the secreted and intracellular levels of BDNF were significantly reduced and the intracellular level of PC1/3 was decreased.Transient transfection of cortical neurons with a PC1/3 overexpression plasmid followed by oxygen-glucose deprivation resulted in increased PC1/3 levels and increased BDNF levels.When levels of the BDNF precursor protein were reduced,the concentration of BDNF in the culture medium was increased.These results indicate that PC 1/3 cleavage of BDNF is critical for the conversion of pro-BDNF in rat cortical neurons during ischemia.The study was approved by the Animal Ethics Committee of Wuhan University School of Basic Medical Sciences.展开更多
Pitx3 is strongly associated with the phenotype, differentiation, and survival of dopaminergic neurons. The relationship between Pitx3 and glial cell line-derived neurotrophic factor（GDNF） in dopaminergic neurons re...Pitx3 is strongly associated with the phenotype, differentiation, and survival of dopaminergic neurons. The relationship between Pitx3 and glial cell line-derived neurotrophic factor（GDNF） in dopaminergic neurons remains poorly understood. The present investigation sought to construct and screen a lentivirus expression plasmid carrying a rat Pitx3 short hairpin（sh）RNA and to assess the impact of Pitx3 gene knockdown on GDNF transcriptional activity in MES23.5 dopaminergic neurons. Three pairs of interference sequences were designed and separately ligated into GV102 expression vectors. These recombinant plasmids were transfected into MES23.5 cells and western blot assays were performed to detect Pitx3 protein expression. Finally, the most effective Pitx3 sh RNA and a dual-luciferase reporter gene plasmid carrying the GDNF promoter region（GDNF-luciferase） were cotransfected into MES23.5 cells. Sequencing showed that the synthesized sequences were identical to the three Pitx3 interference sequences. Inverted fluorescence microscopy revealed that the lentivirus expression plasmids carrying Pitx3-sh RNA had 40-50% transfection efficiency. Western blot assay confirmed that the corresponding Pitx3 of the third knockdown sequence had the lowest expression level. Dual-luciferase reporter gene results showed that the GDNF transcriptional activity in dopaminergic cells cotransfected with both plasmids was decreased compared with those transfected with GDNF-luciferase alone. Together, the results showed that the designed Pitx3-sh RNA interference sequence decreased Pitx3 protein expression, which decreased GDNF transcriptional activity.展开更多
Neurotrophins play a major role in the regulation of neuronal growth such as neurite sprouting or regeneration in response to nerve injuries. The role of nerve growth factor, neurotrophin-3, and brain-derived neurotro...Neurotrophins play a major role in the regulation of neuronal growth such as neurite sprouting or regeneration in response to nerve injuries. The role of nerve growth factor, neurotrophin-3, and brain-derived neurotrophic factor in maintaining the survival of peripheral neurons remains poorly understood. In regenerative medicine, different modalities have been investigated for the delivery of growth factors to the injured neurons, in search of a suitable system for clinical applications. This study was to investigate the influence of nerve growth factor, neurotrophin-3 and brain-derived neurotrophic factor on the growth of neurites using two in vitro models of dorsal root ganglia explants and dorsal root ganglia-derived primary cell dissociated cultures. Quantitative data showed that the total neurite length and tortuosity were differently influenced by trophic factors. Nerve growth factor and, indirectly, brain-derived neurotrophic factor stimulate the tortuous growth of sensory fibers and the formation of cell clusters. Neurotrophin-3, however, enhances neurite growth in terms of length and linearity allowing for a more organized and directed axonal elongation towards a peripheral target compared to the other growth factors. These findings could be of considerable importance for any clinical application of neurotrophic factors in peripheral nerve regeneration. Ethical approval was obtained from the Regione Piemonte Animal Ethics Committee ASLTO1(file # 864/2016-PR) on September 14, 2016.展开更多
A variety of neurotrophic factors have been shown to repair the damaged peripheral nerve. However, in clinical practice, nerve growth factor, neurotrophin-3 and brain-derived neuro- trophic factor are all peptides or ...A variety of neurotrophic factors have been shown to repair the damaged peripheral nerve. However, in clinical practice, nerve growth factor, neurotrophin-3 and brain-derived neuro- trophic factor are all peptides or proteins that may be rapidly deactivated at the focal injury site; their local effective concentration time following a single medication cannot meet the required time for spinal axons to regenerate and cross the glial scar. In this study, we produced polymer sustained-release microspheres based on the polylactic-co-glycolic acid copolymer; the micro- spheres at 300-pm diameter contained nerve growth factor, neurotrophin-3 and brain-derived neurotrophic factor. Six microspheres were longitudinally implanted into the sciatic nerve at the anastomosis site, serving as the experimental group; while the sciatic nerve in the control group was subjected to the end-to-end anastomosis using 10/0 suture thread. At 6 weeks after implanta- tion, the lower limb activity, weight of triceps surae muscle, sciatic nerve conduction velocity and the maximum amplitude were obviously better in the experimental group than in the control group. Compared with the control group, more regenerating nerve fibers were observed and dis- tributed in a dense and ordered manner with thicker myelin sheaths in the experimental group. More angiogenesis was also visible. Experimental findings indicate that polylactic-co-glycolic acid composite microspheres containing nerve growth factor, neurotrophin-3 and brain-derived neurotrophic factor can promote the restoration of sciatic nerve in rats after injury.展开更多
Decreased expression of brain-derived neurotrophic factor（BDNF） plays an important role in the pathogenesis of Alzheimer＇s disease, and a typical pathological change in Alzheimer＇s disease is neurofibrillary tangl...Decreased expression of brain-derived neurotrophic factor（BDNF） plays an important role in the pathogenesis of Alzheimer＇s disease, and a typical pathological change in Alzheimer＇s disease is neurofibrillary tangles caused by hyperphosphorylation of tau. An in vivo model of Alzheimer＇s disease was developed by injecting okadaic acid（2 μL） and exogenous BDNF（2 μL） into the hippocampi of adult male Wister rats. Spatial learning and memory abilities were assessed using the Morris water maze. The expression levels of protein phosphatase 2 A（PP2 A）, PP2 Ac-Yp307, p-tau（Thr231）, and p-tau（Ser396/404） were detected by western blot assay. The expression levels of BDNF, TrkB, and synaptophysin mRNA were measured by quantitative real-time polymerase chain reaction. Our results indicated that BDNF expression was suppressed in the hippocampus of OA-treated rats, which resulted in learning and memory deficits. Intra-hippocampal injection of BDNF attenuated this OA-induced cognitive impairment. Finally, our findings indicated an involvement of the PI3 K/GSK-3β/AKT pathway in the mechanism of BDNF in regulating cognitive function. These results indicate that BDNF has beneficial effect on Alzheimer＇s disease, and highlight the potential of BDNF as a drug target for treatment of Alzheimer＇s disease.展开更多
Ciliary neurotrophic factor has neuroprotective effects mediated through signal transducer and Janus kinase（JAK） 2/activator of transcription 3（STAT3） and phosphatidylinositol 3-kinase（PI3 K）/Akt signaling pathw...Ciliary neurotrophic factor has neuroprotective effects mediated through signal transducer and Janus kinase（JAK） 2/activator of transcription 3（STAT3） and phosphatidylinositol 3-kinase（PI3 K）/Akt signaling pathways.Whether ciliary neurotrophic factor is neuroprotective for glutamate-induced excitotoxicity of dorsal root ganglion neurons is poorly understood.In the present study,the in vitro neuroprotective effects of ciliary neurotrophic factor against glutamate-induced excitotoxicity were determined in a primary culture of dorsal root ganglion neurons from Wistar rat embryos at embryonic day 15.Whether the JAK2/STAT3 and PI3 K/Akt signaling pathways were related to the protective effects of ciliary neurotrophic factor was also determined.Glutamate exposure inhibited neurite outgrowth,cell viability,and growth-associated protein 43 expression and promoted apoptotic neuronal cell death,all of which were reversed by the administration of exogenous ciliary neurotrophic factor.Additionally,preincubation with either JAK2 inhibitor AG490 or PI3 K inhibitor LY294002 blocked the neuroprotective effect of ciliary neurotrophic factor.These data indicate that the two pathways JAK2/STAT3 and PI3 K/Akt play major roles in mediating the in vitro neuroprotective effects of ciliary neurotrophic factor on dorsal root ganglion neurons with glutamate-induced neurotoxicity.展开更多
The present study utilized beta amyloid （Aβ）-induced cell apoptosis in PC12 cells as a cell model of Alzheimer＇s disease to investigate the interaction between brain-derived neurotrophic factor （BDNF） and the tr...The present study utilized beta amyloid （Aβ）-induced cell apoptosis in PC12 cells as a cell model of Alzheimer＇s disease to investigate the interaction between brain-derived neurotrophic factor （BDNF） and the tropomyosin-related kinase B receptor. Results showed that Aβ（25-35） can reduce survival of PC12 cells and increase cleaved caspase-3 expression in PC12 cells. However, BDNF inhibited Aβ（25-35）-induced cytotoxicity and cleaved casapase-3 expression. Interestingly, pretreatment with the tropomyosin-related kinase receptor inhibitor K252a for 20 minutes prior to BDNF blocked the neuroprotective effect of BDNF on PC12 cells.展开更多
目的:利用羟基磷灰石纳米颗粒(hydroxyapatite nanoparticle,HAT)携带构建的神经营养因子-3(neurotrophic factor-3,NT-3)-绿色荧光蛋白基因(enhancement type Green fluorescent protein C2,pEGFPC2),通过耳蜗灌注方法转染兴奋毒性损...目的:利用羟基磷灰石纳米颗粒(hydroxyapatite nanoparticle,HAT)携带构建的神经营养因子-3(neurotrophic factor-3,NT-3)-绿色荧光蛋白基因(enhancement type Green fluorescent protein C2,pEGFPC2),通过耳蜗灌注方法转染兴奋毒性损伤后的豚鼠耳蜗螺旋神经节细胞(spinal ganglion cells,SGCs),观察pEGFPC2-NT3的表达及其对耳蜗螺旋神经节细胞的保护作用。方法:构建携带绿色荧光蛋白报告基因的重组质粒pEGFPC2-NT3。通过耳蜗灌注海人酸(kainic acid,KA)建立豚鼠耳蜗兴奋性损伤模型,在给KA1周后利用HAT携带重组质粒进行耳蜗灌注以转染耳蜗螺旋神经节细胞,免疫组化法观察转染后1周NT-3的表达及4周后电镜下螺旋神经节细胞形态学变化,同时观察对听觉脑干诱发电位(auditory brain-stem response,ABR)的影响。结果:成功构建豚鼠耳蜗兴奋损伤模型。灌注重组质粒后1周免疫组化法观察到螺旋神经节细胞胞浆内NT-3蛋白表达。4周后电镜下螺旋神经节细胞形态学损害减轻,ABR检测听功能较兴奋毒性损害后有恢复。结论:在豚鼠耳蜗灌注KA造成耳蜗兴奋性损伤后第7天,经耳蜗鼓阶转染羟基磷灰石纳米颗粒介导的NT-3基因仍可减轻KA对耳蜗螺旋神经节细胞的兴奋性毒性损伤。展开更多
文摘The phosphatidylinositol-3 kinase （PI3K）/Akt pathway and brain-derived neurotrophic factor （BDNF） are involved in neurological functional recovery following cerebral ischemia. Therefore, we hypothesized that mechanisms of neuroprotection by transplantation of neural stem cells （NSCs） on cerebral ischemia contributed to activation of the PI3K/Akt pathway and enhanced BDNF expression. In the present study, Wortmannin （a specific, covalent inhibitor of PI3K） was administered adjacent to ischemic hippocampus by stereotactic transplantation to further confirm the neuroprotective mechanisms of NSC transplantation following cerebral ischemia. Results showed that focal infarct volume was significantly smaller in the NSCs group, but the neurological behavior score in the NSC group was significantly greater than the middle cerebral artery occlusion model group, Wortmannin treatment group, and NSCs ＋ Wortmannin treatment group. Protein expression of BDNF was significantly greater in the NSC group compared with the Wortmannin treatment group and NSCs ＋ Wortmannin treatment group. These results suggest that the neuroprotective role of NSC transplantation in the cerebral ischemia activated the PI3K/Akt pathway and upregulated BDNF expression in lesioned brains.
基金supported by the National Nature Science Foundation of China,No.81501053(to YC)
文摘Brain-derived neurotrophic factor(BDNF)has robust effects on synaptogenesis,neuronal differentiation and synaptic transmission and plasticity.The maturation of BDNF is a complex process.Proprotein convertase 1/3(PC1/3)has a key role in the cleavage of protein precursors that are directed to regulated secretory pathways;however,it is not clear whether PC1/3 mediates the change in BDNF levels caused by ischemia.To clarify the role of PC1/3 in BDNF maturation in ischemic cortical neurons,primary cortical neurons from fetal rats were cultured in a humidified environment of 95%N_2 and 5%CO_2 in a glucose-free Dulbecco's modified Eagle's medium at 37℃for3 hours.Enzyme-linked immunosorbent assays and western blotting showed that after oxygen-glucose deprivation,the secreted and intracellular levels of BDNF were significantly reduced and the intracellular level of PC1/3 was decreased.Transient transfection of cortical neurons with a PC1/3 overexpression plasmid followed by oxygen-glucose deprivation resulted in increased PC1/3 levels and increased BDNF levels.When levels of the BDNF precursor protein were reduced,the concentration of BDNF in the culture medium was increased.These results indicate that PC 1/3 cleavage of BDNF is critical for the conversion of pro-BDNF in rat cortical neurons during ischemia.The study was approved by the Animal Ethics Committee of Wuhan University School of Basic Medical Sciences.
基金supported by the National Natural Science Foundation of China,No.81372698
文摘Pitx3 is strongly associated with the phenotype, differentiation, and survival of dopaminergic neurons. The relationship between Pitx3 and glial cell line-derived neurotrophic factor（GDNF） in dopaminergic neurons remains poorly understood. The present investigation sought to construct and screen a lentivirus expression plasmid carrying a rat Pitx3 short hairpin（sh）RNA and to assess the impact of Pitx3 gene knockdown on GDNF transcriptional activity in MES23.5 dopaminergic neurons. Three pairs of interference sequences were designed and separately ligated into GV102 expression vectors. These recombinant plasmids were transfected into MES23.5 cells and western blot assays were performed to detect Pitx3 protein expression. Finally, the most effective Pitx3 sh RNA and a dual-luciferase reporter gene plasmid carrying the GDNF promoter region（GDNF-luciferase） were cotransfected into MES23.5 cells. Sequencing showed that the synthesized sequences were identical to the three Pitx3 interference sequences. Inverted fluorescence microscopy revealed that the lentivirus expression plasmids carrying Pitx3-sh RNA had 40-50% transfection efficiency. Western blot assay confirmed that the corresponding Pitx3 of the third knockdown sequence had the lowest expression level. Dual-luciferase reporter gene results showed that the GDNF transcriptional activity in dopaminergic cells cotransfected with both plasmids was decreased compared with those transfected with GDNF-luciferase alone. Together, the results showed that the designed Pitx3-sh RNA interference sequence decreased Pitx3 protein expression, which decreased GDNF transcriptional activity.
基金supported by the research start-up and the MWU’s intramural grant(to MF)the Italian MURST-MIUR foundation(to SG and IP)
文摘Neurotrophins play a major role in the regulation of neuronal growth such as neurite sprouting or regeneration in response to nerve injuries. The role of nerve growth factor, neurotrophin-3, and brain-derived neurotrophic factor in maintaining the survival of peripheral neurons remains poorly understood. In regenerative medicine, different modalities have been investigated for the delivery of growth factors to the injured neurons, in search of a suitable system for clinical applications. This study was to investigate the influence of nerve growth factor, neurotrophin-3 and brain-derived neurotrophic factor on the growth of neurites using two in vitro models of dorsal root ganglia explants and dorsal root ganglia-derived primary cell dissociated cultures. Quantitative data showed that the total neurite length and tortuosity were differently influenced by trophic factors. Nerve growth factor and, indirectly, brain-derived neurotrophic factor stimulate the tortuous growth of sensory fibers and the formation of cell clusters. Neurotrophin-3, however, enhances neurite growth in terms of length and linearity allowing for a more organized and directed axonal elongation towards a peripheral target compared to the other growth factors. These findings could be of considerable importance for any clinical application of neurotrophic factors in peripheral nerve regeneration. Ethical approval was obtained from the Regione Piemonte Animal Ethics Committee ASLTO1(file # 864/2016-PR) on September 14, 2016.
基金financially supported by a grant from the Natural Science Foundation of Hunan Province of China,No.13JJ6016
文摘A variety of neurotrophic factors have been shown to repair the damaged peripheral nerve. However, in clinical practice, nerve growth factor, neurotrophin-3 and brain-derived neuro- trophic factor are all peptides or proteins that may be rapidly deactivated at the focal injury site; their local effective concentration time following a single medication cannot meet the required time for spinal axons to regenerate and cross the glial scar. In this study, we produced polymer sustained-release microspheres based on the polylactic-co-glycolic acid copolymer; the micro- spheres at 300-pm diameter contained nerve growth factor, neurotrophin-3 and brain-derived neurotrophic factor. Six microspheres were longitudinally implanted into the sciatic nerve at the anastomosis site, serving as the experimental group; while the sciatic nerve in the control group was subjected to the end-to-end anastomosis using 10/0 suture thread. At 6 weeks after implanta- tion, the lower limb activity, weight of triceps surae muscle, sciatic nerve conduction velocity and the maximum amplitude were obviously better in the experimental group than in the control group. Compared with the control group, more regenerating nerve fibers were observed and dis- tributed in a dense and ordered manner with thicker myelin sheaths in the experimental group. More angiogenesis was also visible. Experimental findings indicate that polylactic-co-glycolic acid composite microspheres containing nerve growth factor, neurotrophin-3 and brain-derived neurotrophic factor can promote the restoration of sciatic nerve in rats after injury.
文摘Decreased expression of brain-derived neurotrophic factor（BDNF） plays an important role in the pathogenesis of Alzheimer＇s disease, and a typical pathological change in Alzheimer＇s disease is neurofibrillary tangles caused by hyperphosphorylation of tau. An in vivo model of Alzheimer＇s disease was developed by injecting okadaic acid（2 μL） and exogenous BDNF（2 μL） into the hippocampi of adult male Wister rats. Spatial learning and memory abilities were assessed using the Morris water maze. The expression levels of protein phosphatase 2 A（PP2 A）, PP2 Ac-Yp307, p-tau（Thr231）, and p-tau（Ser396/404） were detected by western blot assay. The expression levels of BDNF, TrkB, and synaptophysin mRNA were measured by quantitative real-time polymerase chain reaction. Our results indicated that BDNF expression was suppressed in the hippocampus of OA-treated rats, which resulted in learning and memory deficits. Intra-hippocampal injection of BDNF attenuated this OA-induced cognitive impairment. Finally, our findings indicated an involvement of the PI3 K/GSK-3β/AKT pathway in the mechanism of BDNF in regulating cognitive function. These results indicate that BDNF has beneficial effect on Alzheimer＇s disease, and highlight the potential of BDNF as a drug target for treatment of Alzheimer＇s disease.
基金supported by the Natural Science Foundation of Shandong Province of China,No.ZR2014HQ065a grant from the Medical Science and Technology Development Project of Shandong Province of China,No.2015WS0445
文摘Ciliary neurotrophic factor has neuroprotective effects mediated through signal transducer and Janus kinase（JAK） 2/activator of transcription 3（STAT3） and phosphatidylinositol 3-kinase（PI3 K）/Akt signaling pathways.Whether ciliary neurotrophic factor is neuroprotective for glutamate-induced excitotoxicity of dorsal root ganglion neurons is poorly understood.In the present study,the in vitro neuroprotective effects of ciliary neurotrophic factor against glutamate-induced excitotoxicity were determined in a primary culture of dorsal root ganglion neurons from Wistar rat embryos at embryonic day 15.Whether the JAK2/STAT3 and PI3 K/Akt signaling pathways were related to the protective effects of ciliary neurotrophic factor was also determined.Glutamate exposure inhibited neurite outgrowth,cell viability,and growth-associated protein 43 expression and promoted apoptotic neuronal cell death,all of which were reversed by the administration of exogenous ciliary neurotrophic factor.Additionally,preincubation with either JAK2 inhibitor AG490 or PI3 K inhibitor LY294002 blocked the neuroprotective effect of ciliary neurotrophic factor.These data indicate that the two pathways JAK2/STAT3 and PI3 K/Akt play major roles in mediating the in vitro neuroprotective effects of ciliary neurotrophic factor on dorsal root ganglion neurons with glutamate-induced neurotoxicity.
文摘The present study utilized beta amyloid （Aβ）-induced cell apoptosis in PC12 cells as a cell model of Alzheimer＇s disease to investigate the interaction between brain-derived neurotrophic factor （BDNF） and the tropomyosin-related kinase B receptor. Results showed that Aβ（25-35） can reduce survival of PC12 cells and increase cleaved caspase-3 expression in PC12 cells. However, BDNF inhibited Aβ（25-35）-induced cytotoxicity and cleaved casapase-3 expression. Interestingly, pretreatment with the tropomyosin-related kinase receptor inhibitor K252a for 20 minutes prior to BDNF blocked the neuroprotective effect of BDNF on PC12 cells.
文摘目的:利用羟基磷灰石纳米颗粒(hydroxyapatite nanoparticle,HAT)携带构建的神经营养因子-3(neurotrophic factor-3,NT-3)-绿色荧光蛋白基因(enhancement type Green fluorescent protein C2,pEGFPC2),通过耳蜗灌注方法转染兴奋毒性损伤后的豚鼠耳蜗螺旋神经节细胞(spinal ganglion cells,SGCs),观察pEGFPC2-NT3的表达及其对耳蜗螺旋神经节细胞的保护作用。方法:构建携带绿色荧光蛋白报告基因的重组质粒pEGFPC2-NT3。通过耳蜗灌注海人酸(kainic acid,KA)建立豚鼠耳蜗兴奋性损伤模型,在给KA1周后利用HAT携带重组质粒进行耳蜗灌注以转染耳蜗螺旋神经节细胞,免疫组化法观察转染后1周NT-3的表达及4周后电镜下螺旋神经节细胞形态学变化,同时观察对听觉脑干诱发电位(auditory brain-stem response,ABR)的影响。结果:成功构建豚鼠耳蜗兴奋损伤模型。灌注重组质粒后1周免疫组化法观察到螺旋神经节细胞胞浆内NT-3蛋白表达。4周后电镜下螺旋神经节细胞形态学损害减轻,ABR检测听功能较兴奋毒性损害后有恢复。结论:在豚鼠耳蜗灌注KA造成耳蜗兴奋性损伤后第7天,经耳蜗鼓阶转染羟基磷灰石纳米颗粒介导的NT-3基因仍可减轻KA对耳蜗螺旋神经节细胞的兴奋性毒性损伤。
