简介：目的检测神经分化因子NeuroD在大鼠耳蜗螺旋神经元顺铂损伤后的表达变化。方法通过免疫组织化学及Real—TimePCR技术，观察耳蜗螺旋神经元损伤1d、3d、5d后NeuroD的表达变化。正常成年SD大鼠32只随机分为对照组（生理盐水5ml／kg，1次／d，腹腔注射，连续5d），用药1d组（顺铂5mg／kg，腹腔注射），用药3d组（顺铂5mg／kg，10Vd，腹腔注射，连续3d），用药5d组（顺铂5mg／kg，1次，d，腹腔注射，连续5d），每组8只，建立顺铂耳毒性模型。采用Real—TimePCR、免疫组织化学染色检测不同时间螺旋神经元NeuroD的mRNA及蛋白表达变化。结果成功建立顺铂耳毒性大鼠模型，随着用药时间的延长，神经分化因子NeuroD在耳蜗螺旋神经元中呈动态变化。NeuroD的mRNA和蛋白表达在用药1d及3d组分别为2．17~0．39、1．15~0．20及7．02~0．69、2．42~0．40，与对照组及用药5d组比较具有统计学意义（P值〈0．01）。结论NeuroD在用药1d后开始增加，3d后达到高峰，5d后下降；在用药早期有一过性表达增强，后期表达下降同时听力损失明显。表明NeuroD可能参与顺铂损伤螺旋神经元后的修复过程。

简介：【目的】神经干细胞（neuralstemcells,NSCs）是一群能自我更新并具有多种分化潜能的细胞,可分化成神经元、少突胶质细胞和星形细胞。NSCs分化受多种转录因子调控网络的影响,本实验旨在研究神经分化因子1（neuronaldifferentiation1,NeuroD1）过表达对NSCs增殖和分化的影响。【方法】分离培养原代大鼠NSCs,免疫荧光染色鉴定NSCs。将携带NeuroD1基因的逆转录病毒转染NSCs,QPCR检测NeuroD1过表达神经干细胞系的构建。QPCR和MTT检测过表达NeuroD1对NSCs增殖和分化的影响;光镜下观察分化细胞形态变化。【结果】第3代NSCs经免疫荧光染色证实所培养细胞为NSCs,可分化为神经元和星形胶质细胞。QPCR结果显示NeuroD1mRNA在NSCs-NeuroD1组表达最高,与其他两组有统计学差异（P〈0.05）。QPCR结果显示MAP2在NSCs-NeuroD1组表达最高,与其他两组有统计学差异（P〈0.05）。MTT结果显示NSCs-NeuroD1组细胞增殖水平最高,与其他两组有统计学差异（P〈0.05）。光镜下可见NSCs-NeuroD1组细胞多分化为神经元细胞。【结论】成功构建NeuroD1过表达神经干细胞系。NeuroD1可促进NSCs增殖和向神经元方向分化。

简介：AbstractObjective:In contrast to the most commonly reported forms of maturity-onset diabetes of the young (MODY), including MODY2, MODY3 and MODY5, MODY6 is a relatively rare subtype. To investigate whether NEUROD1 is responsible for MODY in Chinese individuals, we screened its mutations in MODY pedigrees and explored the potential pathogenic mechanisms.Methods:Polymerase chain reaction direct sequencing was performed to screen NEUROD1 mutations in 32 Chinese MODY probands who were negative for the GCK/MODY2, HNF1A/MODY3 and HNF1B/MODY5 genes in this observational study. In addition, we enrolled 201 unrelated, non-diabetic control subjects of Han Chinese descent. The functional significance of newly identified mutations was analyzed using clinical phenotype, pathophysiology and three-dimensional structure studies. This study was approved by the Institutional Review Board of Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, China (approval No. YS-2017-83) on March 3, 2017.Results:E59Q (c.175 G>C, p.Glu59Gln), a heterozygous missense mutation in the NEUROD1 gene, was identified in one family with MODY. The Glu59 residue in NeuroD1 is highly conserved across mammalian species. Four diabetic patients carrying the mutation (a proband and her son, brother and sister) were lean, with a body mass index of 20.9 (20.3-21.2) kg/m2. Compared with their unaffected relatives (n= 4), E59Q carriers (n= 4) had significantly decreased ratios of fasting and 2-hour insulin to plasma glucose (both fasting plasma insulin/fasting plasma glucose and 2-hour postprandial plasma insulin/2-hour postprandial plasma glucose, P < 0.005). The proband’s father had an E59Q mutation and normal glucose tolerance, which suggested non-penetrance. The E59Q mutation was not detected in other probands or in the 201 control subjects with normal glucose tolerance. Two salt-bridge bonds of Glu59 were disrupted at the Q59 mutation site.Conclusion:The NEUROD1-E59Q mutation changed the molecular conformation of the N-terminal in NeuroD1, which may decrease binding of the E59Q mutant to the insulin promoter and insulin gene transcription activity, therefore causing the MODY6 subtype with defective insulin secretion.