The Effect of TCM-Induced HAMP on Key Enzymes in the Hydrolysis of AD Model Cells

Neurochemical Research - Alzheimer’s disease (AD) process is characterized classically by two hallmark pathologies: β-amyloid (Aβ) plaque deposition and neurofibrillary tangles of...     

Developing a Novel Gene-Delivery Vector System Using the Recombinant Fusion Protein of Pseudomonas Exotoxin A and Hyperthermophilic Archaeal Histone HPhA

Non-viral gene delivery system with many advantages has a great potential for the future of gene therapy. One inherent obstacle of such approach is the uptake by endocytosis into vesicular compartments. Receptor-mediated gene delivery method holds promise to overcome this obstacle. In this study, we developed a receptor-mediated gene delivery system based on a combination of the Pseudomonas exotoxin A (PE), which has a receptor binding and membrane translocation domain, and the hyperthermophilic archaeal histone (HPhA), which has the DNA binding ability. First, we constructed and expressed the rPE-HPhA fusion protein. We then examined the cytotoxicity and the DNA binding ability of rPE-HPhA. We further assessed the efficiency of transfection of the pEGF-C1 plasmid DNA to CHO cells by the rPE-HPhA system, in comparison to the cationic liposome method. The results showed that the transfection efficiency of rPE-HPhA was higher than that of cationic liposomes. In addition, the rPE-HPhA gene delivery system is non-specific to DNA sequence, topology or targeted cell type. Thus, the rPE-HPhA system can be used for delivering genes of interest into mammalian cells and has great potential to be applied for gene therapy.     

DIA-Based Proteomics Identifies IDH2 as a Targetable Regulator of Acquired Drug Resistance in Chronic Myeloid Leukemia

Drug resistance is a critical obstacle to effective treatment in patients with chronic myeloid leukemia. To understand the underlying resistance mechanisms in response to imatinib mesylate (IMA) and adriamycin (ADR), the parental K562 cells were treated with low doses of IMA or ADR for 2 months to generate derivative cells with mild, intermediate, and severe resistance to the drugs as defined by their increasing resistance index. PulseDIA-based (DIA [data-independent acquisition]) quantitative proteomics was then employed to reveal the proteome changes in these resistant cells. In total, 7082 proteins from 98,232 peptides were identified and quantified from the dataset using four DIA software tools including OpenSWATH, Spectronaut, DIA-NN, and EncyclopeDIA. Sirtuin signaling pathway was found to be significantly enriched in both ADR-resistant and IMA-resistant K562 cells. In particular, isocitrate dehydrogenase (NADP(+)) 2 was identified as a potential drug target correlated with the drug resistance phenotype, and its inhibition by the antagonist AGI-6780 reversed the acquired resistance in K562 cells to either ADR or IMA. Together, our study has implicated isocitrate dehydrogenase (NADP(+)) 2 as a potential target that can be therapeutically leveraged to alleviate the drug resistance in K562 cells when treated with IMA and ADR.     

Sperm cell surface characteristics of Plumbago zeylanica L. in relation to transport in the embryo sac

Myosin associated with the male germ cells of angiosperms interacts with actin, promoting transport of the non-motile generative and later sperm cells in the pollen tube. Myosin localizing on the sperm cell plasma membrane seems negligible in Plumbago, as reflected by the absence of: (i) anti-myosin labeling using immunoelectron microscopy, (ii) sperm motility on actin matrices, and (iii) electrophoretic movement changes after addition of antibody. Sperm cells injected directly into actively streaming Nitella internodal cells, however, follow actin bundles and their movement is sensitive to ATP and Mg²⁺. This may be based on simple charge binding since negatively charged latex beads also migrate on actin, whereas neutral or positively-charged latex beads do not. Sperm cells are negatively charged according to capillary microelectrophoresis, whereas killed sperm cells, which are positively charged do not migrate. The sperm cell that normally fertilizes the egg has a higher calculated charge (8.277 × 10³ esu/cm²) compared with the sperm cell that fuses with the central cell (6.120 × 10³ esu/cm²). Received: 15 December 1998 / Accepted: 21 January 1999     

Global domination by crazy ants: phylogenomics reveals biogeographical history and invasive species relationships in the genus Nylanderia (Hymenoptera: Formicidae)

Nylanderia (Emery) is one of the world's most diverse ant genera, with 123 described species worldwide and hundreds more undescribed. Fifteen globetrotting or invasive species have widespread distributions and are often encountered outside their native ranges. A molecular approach to understanding the evolutionary history and to revision of Nylanderia taxonomy is needed because historical efforts based on morphology have proven insufficient to define major lineages and delimit species boundaries, especially where adventive species are concerned. To address these problems, we generated the first genus-wide genomic dataset of Nylanderia using ultraconserved elements (UCEs) to resolve the phylogeny of major lineages, determine the age and origin of the genus, and describe global biogeographical patterns. Sampling from seven biogeographical regions revealed a Southeast Asian origin of Nylanderia in the mid-Eocene and four distinct biogeographical clades in the Nearctic, the Neotropics, the Afrotropics/Malagasy region, and Australasia. The Nearctic and Neotropical clades are distantly related, indicating two separate dispersal events to the Americas between the late Oligocene and early Miocene. We also addressed the problem of misidentification that has characterized species-level taxonomy in Nylanderia as a result of limited morphological variation in the worker caste by evaluating the integrity of species boundaries in six of the most widespread Nylanderia species. We sampled across ranges of species in the N. bourbonica complex (N. bourbonica (Forel) + N. vaga (Forel)), the N. fulva complex (N. fulva (Mayr) + N. pubens (Forel)), and the N. guatemalensis complex (N. guatemalensis (Forel) + N. steinheili (Forel)) to clarify their phylogenetic placement. Deep splits within these complexes suggest that some species names – specifically N. bourbonica and N. guatemalensis – each are applied to multiple cryptic species. In exhaustively sampling Nylanderia diversity in the West Indies, a ‘hot spot’ for invasive taxa, we found five adventive species among 22 in the region; many remain morphologically indistinguishable from one another, despite being distantly related. We stress that overcoming the taxonomic impediment through the use of molecular phylogeny and revisionary study is essential for conservation and invasive species management.     

光诱导角膜交联及检测技术的研究进展

由于圆锥角膜疾病导致越来越多的人患有近视,常见的矫正方法有佩戴近视眼镜、隐形眼镜等.随着科技的进步,利用光对近视等眼科疾病进行屈光矫正已经成为当前临床中常用的方法.使用光诱导角膜胶原蛋白发生交联,从而达到治疗圆锥角膜疾病、提高患者视力水平的目的,这是一种新型的光治疗眼睛疾病的方法.同时这种方法由于无侵入性、对操作者能力依赖性小等优势成为新的研究热点.本文阐述光诱导角膜交联的基本原理,并介绍其发展历程,分析现有的各种交联方法和角膜检测技术的原理,并对现有交联方法和检测方法的优缺点进行讨论.最后,本文对光诱导角膜交联和检测技术的最新进展进行系统的论述,并对未来的发展趋势进行展望.     

Synthesis,Biological Evaluation,and Docking Study of Ring-Opening Amide Analogs of Matrine as Antitumor Agents

In this article, we designed and synthesized two series of matrine analogs with ring-opening in the lactam portion of the molecule. Our in vitro cytotoxicity study showed that analog N-(3-bromophenyl)-4-[(1R,3aS,10aR,10bS)-decahydro-1H,4H-pyrido[3,2,1-ij][1,6]naphthyridin-1-yl]butanamide ( B11 ) with a meta-bromide on the phenyl ring displayed the best antiproliferative activity. Moreover, B11 induced cell cycle arrest in G1 phase and cell apoptosis in a dose-dependent manner in A549 cells. Molecular modeling revealed that B11 achieved a higher docking score compared to its precursor tert-butyl (1R,3aS,10aR,10bS)-1-[4-(3-bromoanilino)-4-oxobutyl]octahydro-1H,4H-pyrido[3,2,1-ij][1,6]naphthyridine-2(3H)-carboxylate ( A11 , an analog of B11 with a Boc group) and parent compound matrine, possibly because B11 formed a hydrogen bond with SER91 and a halogen bond with GLN320 on the binding site of annexin A2. Overall, we discovered the potential anticancer lead compound B11 , which can be used for further study both in vitro and in vivo.