An MRI-Visible Non-Viral Vector Bearing GD2 Single Chain Antibody for Targeted Gene Delivery to Human Bone Marrow Mesenchymal Stem Cells

The neural ganglioside GD2 has recently been reported to be a novel surface marker that is only expressed on human bone marrow mesenchymal stem cells within normal marrow. In this study, an MRI-visible, targeted, non-viral vector for effective gene delivery to human bone marrow mesenchymal stem cells was first synthesized by attaching a targeting ligand, the GD2 single chain antibody (scAb_GD2), to the distal ends of PEG-g-PEI-SPION. The targeted vector was then used to condense plasmid DNA to form nanoparticles showing stable small size, low cytotoxicity, and good biocompatibility. Based on a reporter gene assay, the transfection efficiency of targeting complex reached the highest value at 59.6% ± 4.5% in human bone marrow mesenchymal stem cells, which was higher than those obtained using nontargeting complex and lipofectamine/pDNA (17.7% ± 2.9% and 34.9% ± 3.6%, respectively) (P<0.01). Consequently, compared with the nontargeting group, more in vivo gene expression was observed in the fibrotic rat livers of the targeting group. Furthermore, the targeting capacity of scAb_GD2-PEG-g-PEI-SPION was successfully verified in vitro by confocal laser scanning microscopy, Prussian blue staining, and magnetic resonance imaging. Our results indicate that scAb_GD2-PEG-g-PEI-SPION is a promising MRI-visible non-viral vector for targeted gene delivery to human bone marrow mesenchymal stem cells.     

Pierisformotoxins A – D,Polyesterified Grayanane Diterpenoids from Pieris formosa and Their cAMP‐Decreasing Activities

Four highly acylated diterpenoids, designated as pierisformotoxins A–D ( 1 – 4 , resp.), along with 26 known compounds, were isolated from the flowers of Pieris formosa. Among them, pierisformotoxins A and B ( 1 and 2 , resp.) were new highly acylated grayanane diterpenoids, of which the five‐membered ring A has undergone an oxidative cleavage between C(3) and C(4), followed by lactonization, to give rise to a five‐membered lactone ring between C(3) and C(5), differing from the previously reported grayanane diterpenoids with a 5/7/6/5 ring system. Results of the cAMP‐regulation‐activity assay showed that pierisformotoxin C ( 3 ) at 10 μM (inhibitory ratio (IR): 10.1%) or 2 μM (9.8%), and pierisformotoxin B ( 2 ) at 50 μM (13.9%) significantly decreased the cAMP level in N1E‐115 neuroblastoma cells (p<0.05).     

The First Report on Excellent Cycling Stability and Superior Rate Capability of Na3V2(PO4)3 for Sodium Ion Batteries

Sodium ion batteries are attractive for the rapidly emerging large‐scale energy storage market for intermittent renewable resources. Currently a viable cathode material does not exist for practical non‐aqueous sodium ion battery applications. Here we disclose a high performance, durable electrode material based on the 3D NASICON framework. Porous Na₃V₂(PO₄)₃/C was synthesized using a novel solution‐based approach. This material, as a cathode, is capable of delivering an energy storage capacity of ～400 mWh/g vs. sodium metal. Furthermore, at high current rates (10, 20 and 40 C), it displayed remarkable capacity retention. Equally impressive is the long term cycle life. Nearly 50% of the initial capacity was retained after 30,000 charge/discharge cycles at 40 C (4.7 A/g). Notably, coulombic efficiency was 99.68% (average) over the course of cycling. To the best of our knowledge, the combination of high energy density, high power density and ultra long cycle life demonstrated here has never been reported before for sodium ion batteries. We believe our findings will have profound implications for developing large‐scale energy storage systems for renewable energy sources.     

P16 and P53 Play Distinct Roles in Different Subtypes of Breast Cancer

Breast cancers are heterogeneous and complex diseases, and subtypes of breast cancers may involve unique molecular mechanisms. The p16^INK4a and p53 pathways are two of the major pathways involved in control of the cell cycle. They also play key roles in tumorigenesis. However, whether the roles of these pathways differ in the subtypes of breast cancer is unclear. Therefore, p16 and p53 expression were investigated in different breast cancer subtypes to ascertain their contributions to these cancers. A total of 400 cases of non-invasive ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC), including the major molecular subtypes luminal-A, luminal-B, Her-2, and triple-negative subtypes, and 50 cases of normal controls were compared. Luminal-A cancers expressed the lowest level of p16 among the subtypes in DCIS, and the level of p16 expression was up-regulated in the luminal-A of IDC (P<0.008). Triple-negative breast cancers were characterized by a correlation of p53 overexpression with a high level of p16 expression. Luminal lesion types with high p16 expression in DCIS were found to be more likely to develop into aggressive breast cancers, possibly promoted by p53 dysfunction. Taken together, the present study suggest that p16 expression in luminal-A breast cancers is associated with their progression from DCIS to IDC, and both p53 and p16 expressions are important for the development of triple-negative breast cancers in DCIS and IDC.     

Binding and uptake of single and dual-opsonized targets by macrophages

Our current understanding of phagocytosis is largely derived from studies of individual receptor-ligand interactions and their downstream signaling pathways. Because phagocytes are exposed to a variety of ligands on heterogeneous target particles in vivo, it is important to observe the engagement of multiple receptors simultaneously and the triggered involvement of downstream signaling pathways. Potential crosstalk between the two well-characterized opsonic receptors, FcγR and CR3, was briefly explored in the early 1970s, where macrophages were challenged with dual-opsonized targets. However, subsequent studies on receptor crosstalk were primarily restricted to using single opsonins on different targets, typically at saturating opsonin conditions. Beyond validating these initial explorations on receptor crosstalk, we identify the early signaling mechanisms that underlie the binding and phagocytosis during the simultaneous activation of both opsonic receptors, through the presence of a dual-opsonized target (immunoglobulin G [IgG] and C3bi), compared with single receptor activation. For this purpose, we used signaling protein inhibitor studies as well as live cell brightfield and fluorescent imaging to fully understand the role of tyrosine kinases, F-actin dynamics and internalization kinetics for FcγR and CR3. Importantly, opsonic receptors were studied together and in isolation, in the context of sparsely opsonized targets. We observed enhanced particle binding and a synergistic effect on particle internalization during the simultaneous activation of FcγR and CR3 engaged with sparsely opsonized targets. Inhibition of early signaling and cytoskeletal molecules revealed a differential involvement of Src kinase for FcγR- vs CR3- and dual receptor-mediated phagocytosis. Src activity recruits Syk kinase and we observed intermediate levels of Syk phosphorylation in dual-opsonized particles compared with those opsonized with IgG or C3bi alone. These results likely explain the intermediate levels of F-actin that is recruited to sites of dual-opsonized particle uptake and the notoriously delayed internalization of C3bi-opsonized targets by macrophages.     

Reproductive biology of Oxygymnocypris stewartii in the Yarlung Zangbo River in Tibet, China

We determined the gonadal histology, reproductive characteristics and implications for management of Oxygymnocypris stewartii from individuals collected in the Yarlung Zangbo River. Based on the analyses of gonad development and the size distribution of oocytes, O. stewartii spawns just once each year. Peak spawning occurred between late March and early April, when water temperature exceeded 5°C. The standard lengths and the ages at 50 % maturity for males and females were 273 mm and 357 mm, and 5.1 year and 7.3 years, respectively. The mean fecundity of 34211 and mean relative fecundity of 25.4 eggs per gram of fish body weight suggest that O. stewartii might be especially vulnerable to exploitation.     

Analysis of genetic variability and relationships among Mentha L. using the limonene synthase gene, LS

The genus Mentha comprises a group of aromatic plants with worldwide distribution. Because of frequent interspecific hybridization, the genetic relationships within the genus are not clearly understood. Limonene synthase, which catalyses the first committed step in the essential oil monoterpene biosynthetic pathway, is considered to be a possible rate limiting enzyme. With the homology-based cloning method, primers were designed according to cDNA sequence to amplify full-length DNA sequences in 13 Mentha samples from five species, using Perilla as an outgroup. Analyses of gene structure, length variation, GC-content, Ts/Tv ratio and evolutionary diversity were carried out. Consensus phylogenetic trees were obtained using maximum likelihood, neighbor-joining, and maximum parsimony, respectively, based on the full-length genomic DNA sequences, complete ORF coding sequences and predicted amino acid sequences. The results presented here based on the sequence of MhLS provide the first credibly supported genetic relationships for Mentha, which enables a basis for further mint taxonomy, cultivation and breeding.