RSK1 promotes mammalian axon regeneration by inducing the synthesis of regeneration-related proteins

In contrast to the adult mammalian central nervous system (CNS), the neurons in the peripheral nervous system (PNS) can regenerate their axons. However, the underlying mechanism dictating the regeneration program after PNS injuries remains poorly understood. Combining chemical inhibitor screening with gain- and loss-of-function analyses, we identified p90 ribosomal S6 kinase 1 (RSK1) as a crucial regulator of axon regeneration in dorsal root ganglion (DRG) neurons after sciatic nerve injury (SNI). Mechanistically, RSK1 was found to preferentially regulate the synthesis of regeneration-related proteins using ribosomal profiling. Interestingly, RSK1 expression was up-regulated in injured DRG neurons, but not retinal ganglion cells (RGCs). Additionally, RSK1 overexpression enhanced phosphatase and tensin homolog (PTEN) deletion-induced axon regeneration in RGCs in the adult CNS. Our findings reveal a critical mechanism in inducing protein synthesis that promotes axon regeneration and further suggest RSK1 as a possible therapeutic target for neuronal injury repair.

This study shows that p90 ribosomal S6 kinase 1 (RSK1) responds differentially to nerve injury in the peripheral and central nervous systems, and identifies it as a crucial regulator of axonal regeneration; mechanistically, RSK1 preferentially induces the synthesis of regeneration-related proteins via the RSK1-eEF2K-eEF2 axis.     

水杨酸对芒果炭疽病的诱导抗性作用

大田试验结果表明,水杨酸叶面喷雾可减轻芒果炭疽病的发生,100—200mgL-1均有极显著的效果,病情指数分别比对照下降了23％－41．1％,以浓度为100mgL-1的效果最好,而在马铃薯培养基（PDA）中平板培养时,100mgL-1水杨酸对芒果炭疽菌菌丝生长和孢子萌发均无抑制作用．因此认为,水杨酸处理芒果后感病指数下降,是由于水杨酸处理提高了芒果幼果的抗病性,即幼果产生了诱导抗性而引起的．     

Insulin-like growth factor binding proteins 7 prevents dental pulp-derived mesenchymal stem cell senescence via metabolic downregulation of p21

Cellular senescence affects the efficacy of mesenchymal stem cells(MSCs)-mediated tissue regeneration. Insulin-like growth factor binding proteins-7(IGFBP7), as a member of the IGF family, is associated with osteogenic differentiation and the senescence of MSCs, but its exact function and mechanism remain unclear. We found IGFBP7 promoted the osteogenic differentiation and prevented the senescence of dental pulp-derived MSCs(DPSCs), as observed in the gain-of-function and lossof-function analyse...     

Proteome analysis of porcine epidemic diarrhea virus (PEDV)‐infected Vero cells

Porcine epidemic diarrhea virus (PEDV) causes an acute, highly contagious, and devastating viral enteric disease with a high mortality rate in suckling pigs. A large‐scale outbreak of PED occurred in China in 2010, with PEDV emerging in the United States in 2013 and spreading rapidly, posing significant economic and public health concerns. In this study, LC–MS/MS coupled to iTRAQ labeling was used to quantitatively identify differentially expressed cellular proteins in PEDV‐infected Vero cells. We identified 49 differentially expressed cellular proteins, of which 8 were upregulated and 41 downregulated. These differentially expressed proteins were involved in apoptosis, signal transduction, and stress responses. Based on these differentially expressed proteins, we propose that PEDV might utilize apoptosis and extracellular signal regulated kinases pathways for maximum viral replication. Our study is the first attempt to analyze the protein profile of PEDV‐infected cells by quantitative proteomics, and we believe our findings provide valuable information with respect to better understanding the host response to PEDV infection.     

Protein Production and Crystallization at SECSG – An Overview

Using a high degree of automation, the Southeast Collaboratory for Structural Genomics (SECSG) has developed high throughput pipelines for protein production, and crystallization using a two-tiered approach. Primary, or tier-1, protein production focuses on producing proteins for members of large Pfam families that lack a representative structure in the Protein Data Bank. Target genomes are Pyrococcus furiosus and Caenorhabditis elegans. Selected human proteins are also under study. Tier-2 protein production, or target rescue, focuses on those tier-1 proteins, which either fail to crystallize or give poorly diffracting crystals. This two tier approach is more efficient since it allows the primary protein production groups to focus on the production of new targets while the tier-2 efforts focus on providing additional sample for further studies and modified protein for structure determination. Both efforts feed the SECSG high throughput crystallization pipeline, which is capable of screening over 40 proteins per week. Details of the various pipelines in use by the SECSG for protein production and crystallization, as well as some examples of target rescue are described.     

MicroRNA-190 alleviates neuronal damage and inhibits neuroinflammation via Nlrp3 in MPTP-induced Parkinson's disease mouse model

Parkinson's disease (PD) is neurodegenerative dyskinesia characterized by loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Although neuroinflammation is one of the pathological features of PD, its mechanism of promoting PD is still not fully understood. Recently, the microRNA (miR) is considered to play a critical regulatory role in inflammatory responses. In this study, we examined the anti-inflammatory activity, antineuronal injury, and the underlying target of miR-190 with MPTP-induced PD mouse model and BV2 cells. The results showed that miR-190 is downregulated in lipopolysaccharide (LPS)-induced BV2 cells; however, when the miR-190 overexpressed, the expression of proinflammatory mediators, such as iNOS, IL-6, TNF-α, and TGF-β1, were inhibited and the anti-inflammatory mediator such IL-10 was increased. In addition, we predicted the potential target of miR-190 to be Nlrp3 and verified by luciferase reporter assay. The results also showed that Nlrp3 was upregulated in LPS-induced BV2 cells, whereas knockdown of Nlrp3 inhibited the LPS-induced inflammatory response in BV2 cells. Furthermore, upregulation of miR-190 or knockdown of Nlrp3 inhibited LPS-induced apoptosis in BV2 cells. However, the apoptosis inhibition effect of miR-190 was abrogated by overexpression of Nlrp3. Finally, upregulation of miR-190 inhibited the activation of microglial cells and inflammation and attenuated the tyrosine hydroxylase loss in SNpc in MPTP-induced PD mice. In conclusion, we demonstrated that miR-190 alleviates neuronal damage and inhibits inflammation via negatively regulating the expression and activation of Nlrp3 in MPTP-induced PD mouse model.     

金粟兰属植物根的组织发育研究

观察金粟兰属7种、4变种植物不定根的组织发育,发现本属大多数植物不定根具有典型的单子叶植物不定根的组织特征,特别是在同一条根中初生木质部的脊数可以随根的发育而增加。双子叶植物和单子叶植物根的组织学系统发育不仅在本属大多数种内不定根的个体发育中得以重演,而且在属内种间得以重演。     

太鼠坐骨神经、胫神经、腓总神经在脊髓胶状质定位投射的定量分析—FRAP 法

本实验按照跨神经节溃变的原理,用抗氟化物酸性磷酸酶(FRAP)法和显微测量,对大鼠坐骨神经,胫神经和腓总神经感觉纤维在脊髓胶状质的定位投射进行了定量分析。大鼠坐骨神经和胫神经向胶状质的纵向投射为 L_(2～3);腓总神经为 L_(2.6)及 S_1的上中部。水平向投射,坐骨神经:L_(2～3)主要为胶状质的最内侧和中间区的部分区域,L_4～S_1,主要为内侧,中间和部分外侧区的全部胶状质,但未见向胶状质最外侧区投射;胫神经:L_2～S_1主要为内侧区,中间及部分外侧区仅部分实验动物有投射;腓总神经:仅向 L_2～S_1的中间和部分外侧区一处投射。     

谷子胚和胚乳的发育

合子的第一次分裂为斜的横分裂,胚发育至棒状原胚后,胚顶端一侧的细胞加速分裂形成一团分生组织细胞,由这团分生组织分化盾片、胚芽鞘、胚芽生长点和胚根。胚体的其它部分参与部分盾片和胚根鞘的构成。胚柄不参与胚的组成,胚无外胚叶,胚胎发育属禾本型。核型胚乳。从胚囊壁产生的自由生长壁把胚乳游离核隔开形成一层胚乳细胞。然后这层细胞平周分裂使胚乳细胞变成二层,以后的胚乳细胞增殖以细胞有丝分裂方式进行。胚乳的最外层