神经轴突再生过程中微小RNA(miRNA)、转录因子和靶基因的网络功能分析（英文）

创新点:本研究比较详细地阐明了与神经轴突再生相关的微小RNA(mi RNA)、转录因子和靶基因的相互作用关系,为神经系统疾病的恢复奠定基础。方法:本研究从基因表达综合数据库中获得与轴突再生相关的转录因子和基因数据,利用文献报道及生物信息学数据库预测的方法筛选与轴突再生相关的基因靶向mi RNA。利用生物信息学方法分析了三者之间的网络作用关系,预测了在相互作用网络中发挥重要作用的节点。最后对目标基因的基因本体(GO)功能进行了富集。结论:通过分析,初步筛选了与神经轴突再生相关的51个mi RNA、27个转录因子和59个靶标基因。进一步分析得到359对前馈环路,在此基础上推测了神经轴突再生过程中发挥重要作用的7个核心基因(Nap1l1、Arhgef12、Sema6d、Akt3、Trim2、Rab11fip2和Rps6ka3),6个miRNA(hsa-miR-204-5p、hsa-miR-124-3p、hsa-miR-26a-5p、hsamiR-16-5p、hsa-miR-17-5p和hsa-miR-15b-5p)和8个转录因子(Smada2、Fli1、Wt1、Sp6、Sp3、Smad4、Smad5和Creb1)。

Protective Effects of Hydroxysafflor Yellow A against Oxidative Damage of β-Mercaptoethanol During Neural Differentiation of Mesenchymal Stem Cells

Objective To study the protective effects of hydroxysafflor yellow A （HSYA） against the oxidative damage caused by β-mercaptoethanol （BME） during neural differentiation of mesenchymal stem cells （MSCs） in vitro. Methods When the confluence reached 50%-60%, 4th passage MSCs were divided into three groups to culture. Gt ： normal group which was cultured using basic medium （DMEM containing 10% FBS all the time）; G2： unprotected group which was continuously cultured using basic medium for 24 h, and then cultured using pre-induction medium （DMEM containing 10% FBS and 1 mmol/L BME）; G3： protected group which was firstly cultured using protective medium （DMEM containing 10% FBS and 160 mg/L HSYA） for 24 h, and then cultured using pre-induction medium for 24 h. After these treatments as above, cell viability, relative levels of SOD/GSH and apoptosis rate were respectively detected. The expression of Bcl and Bax was examined by Western blotting. After HSYA protection and BME pre-induction, neural induction was performed. The expression of NSE and MAP-2 was respectively analyzed on cellular and molecular levels. Results Compared with unprotected group, 160 mg/L HSYA could obviously improve cells viability, maintain high level of SOD and GSH in MSCs, reduce apoptosis rate and improve the ratio of Bcl/Bax. After protection with 160 mg/L HSYA, the survival time of neuron-like cells could be extended. Immunocytochemical staining showed that after 10 h of neural induction, the differentiated neuron-like cells in protected group were still in a good state, and the mRNA levels of NSE and MAP-2 were increased during the induction course checked. Conclusion HSYA could improve the resistance of cells to the oxidative damage caused by BME.

Secondary plasmon resonance in graphene nanostructures

The plasmon characteristics of two graphene nanostructures are studied using time-dependent den- sity functional theory （TDDFT）. The absorption spectrum has two main bands, which result from and σ ＋ π plasmon resonances. At low energies, the Fourier transform of the induced charge density maps exhibits anomalous behavior, with a π phase change in the charge density maps in the plane of the graphene and those in the plane 0.3 A from the graphene. The charge density fluctuations close to the plane of the graphene are much smaller than those above and beneath the graphene plane. However, this phenomenon disappears at higher energies. By analyzing the electronic properties, we may conclude that the restoring force for the plasmon in the plane of the graphene does not result from fixed positive ions, but rather the Coulomb interactions with the plasmonic oscillations away from the plane of the graphene, which extend in the surface-normal direction. The collective oscillation in the graphene plane results in a forced vibration. Accordingly, the low-energy plasmon in the graphene can be split into two components： a normal component, which corresponds to direct feedback of the external perturbation, and a secondary component, which corresponds to feedback of the Coulombic interaction with the normal component.

基于芯片数据的神经分化基因网络互作分析为神经系统疾病的细胞疗法提供基础（英文）

目的:通过筛选差异基因,获得控制骨髓间充质干细胞向神经细胞分化及神经发育的中心基因,为治疗神经系统疾病提供参考。方法:从基因表达综合数据库(Gene Expression Omnibus database)中获得芯片数据,利用生物信息学软件筛选差异基因,并对差异基因进行GO功能富集、蛋白互作网络分析和中心基因分析。结论:通过分析,初步推测Nrcam、Sema3a、Mapk8、Dlg4、Slit1、Creb1、Ntrk2、Cntn2和Pax6等中心基因在调控骨髓间充质干细胞向神经细胞的分化中发挥重要作用;Dcx、Nrcam、Sema3a、Cntn2、Slit1、Ephb1和Pax6等中心基因在神经发育过程中发挥作用;Fgf2、Tgfβ1、Vegfa、Serpine1、Il6和Stat1等中心基因在抑制神经分化过程中发挥作用。