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Zhao C.-H.,Liaoning Normal University | Zhao C.-H.,Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery | Xu J.,Liaoning Normal University | Zhang Y.-Q.,CAS Institute of Microbiology | And 3 more authors.
Chemical and Pharmaceutical Bulletin | Year: 2014

A large number of bioactive pentacyclic triterpenoids have been shown to have multiple biological activities. This study was conducted to evaluate the inhibitory activities of 6 newly synthesized and novel pentacyclic triterpenoids against enterovirus 71 (EV71). The parent compound, ursolic acid (UA), showed the greatest inhibitory activity against EV71, while oleanolic acid (OA), asiatic acid (AA), and synthetic derivatives of 18-β-glycyrrhetinic acid (GA) and OA also exhibited inhibitory effects, although to lesser extents. The results suggest these compounds show potential for further optimization as antiviral candidates for treatment of EV71 infections. © 2014 The Pharmaceutical Society of Japan.

Wang J.,Liaoning Normal University | Wang J.,Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery | Zhang Y.,Liaoning Normal University | Zhang Y.,Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery | And 5 more authors.
Shengwu Gongcheng Xuebao/Chinese Journal of Biotechnology | Year: 2011

Arg-Gly-Asp (RGD)-toxin protein Lj-RGD3 of Lampetra japonica shares homologous with a Histidine-rich glycoprotein (HRG), and both RGD-toxin protein and HRG have antiangiogenic activities with different targets. To study the relationship between the function and the structure of Lj-RGD3, we studied the anti-angiogenic characteristics of both Lj-RGD3 and the mutation named Lj-112 of which three RGD motifs of Lj-RGD3 were deleted. We synthesized the gene of Lj-112, constructed it to the plasmid pET23b, and expressed the recombinant proteins in Escherichia coli BL21. Both recombinant proteins with the C-terminal his-tag were 15 kDa soluble proteins. Then we purified rLj-RGD3 and rLj-112 using the His-Bind affinity chromatography. To examine the effect of both proteins on bFGF-induced proliferation of ECV304 cell, we carried out the 3-(4, 5)-dimethylthiahiazo (-z-y1)-3, 5-di-phenytetrazoliumromide (MTT) assays. For cell migration and invasion assays, we used Transwell containing insert filter and Matrigel to imitate the in vivo environment. To examine whether both proteins were capable of interrupting the angiogenesis in vivo, we used the chick chicken embryonic chorioallantoic membrane (CAM) as an angiogenesis model. We used Integrin-linked kinase1 (ILK1) ELISA method to study functionary mechanisms of rLj-RGD3 and rLj-112. Both rLj-RGD3 and rLj-112 inhibited bFGF-induced proliferation of ECV304 cells in a dose-dependent manner with IC50 at 0.889 μmol/L and 0.160 μmol/L, respectively. The results of migration and invasion assays revealed that both rLj-RGD3 and rLj-112 showed significant inhibition on bFGF induced migration and invasion of ECV304; and rLj-112 was more active than rLj-RGD3. The result of CAM angiogenesis assay demonstrated that both proteins inhibited the angiogenesis in chick CAM, and rLj-112 was more active than rLj-RGD3. ELISA assay of ILK1 showed that both rLj-RGD3 and rLj-112 down-regulated ILK1 expression of ECV304 cell. The fact of rLj-112 was more active than rLj-RGD3 on anti-angiogenesis indicate that rLj-112 was likely with histidine-rich glycoprotein (HRG), and the factor of sequence homologous between rLj-RGD3 and HRG cannot enhance antiangiogenic activities of rLj-RGD3, the signal pathway of anti-angiogenesis of rLj-RGD3 and rLj-112 are differently. © 2011 CJB, All rights reserved.

Wang L.,Dalian Medical University | Xu J.,Liaoning Normal University | Zhao C.,Liaoning Normal University | Zhao C.,Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery | And 3 more authors.
Chemical and Pharmaceutical Bulletin | Year: 2013

Asiatic acid (AA) is a pentacyclic triterpene in Centella asiatica known to inhibit proliferation and induce apoptosis in several tumor cell lines. In the current study, we synthesized five AA derivatives and examined their inhibitory activities on growth in non-small cell lung cancer cell lines, A549 and PC9/G. Four derivatives were found to have stronger cell growth inhibitory activity than AA. Among them, compound A-3 showed the most significant antiproliferative effects on tumor. Growth of A549 and PC9/G cells was inhibited by A-3 in a dose- and time-dependent manner. To determine the cellular gene expression changes in A549 and PC9/G cells treated with A-3, Affymetrix GeneChip® Human Genome U133 Plus 2.0 Array were used to screen transcriptome differences. Expression levels of 1121 genes in A549 and 1873 genes in PC9/G were significantly altered upon treatment with 10 μM A-3 after 48 h, with 357 overlapping genes. The signaling pathways molecules involved in the antiproliferative and cell cycle dysregulation effects of A-3 identified using microarray were further validated via Western blot analyses. The results collectively indicate that A-3 induces inhibition of cell proliferation via downregulation of the Ras/Raf/MEK/ERK pathway and cell cycle arrest at G1/S and G2/M. © 2013 The Pharmaceutical Society of Japan.

Li A.,Shanghai JiaoTong University | Zhang Y.,Shanghai JiaoTong University | Wang C.,Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery | Wu G.,Shanghai JiaoTong University | Wang Z.,Yuming High School
World Journal of Microbiology and Biotechnology | Year: 2013

Antimicrobial peptides from a wide range of amphibian species, especially frogs of the genus Rana, have been characterised and are potential therapeutic agents. Here we describe the isolation, purification, and structural and biological characterisation of three novel antimicrobial peptides from the skin secretions of the black spotted frog, Rana nigromaculata, from Northeastern China. The peptides were identified as belonging to two known families: the temporin, which was first identified in R. nigromaculata from China, and the brevinin-2. Temporin-1RNa and temporin-1RNb both containing three positive charges and have a high potency against microorganisms (MIC: 3.13-8.3 μM against Gram-positive bacteria, 12.5-25.0 μM against Gram-negative bacteria, and 6.25-12.5 μM against Candida albicans) and a high haemolytic activity against human erythrocytes (HC50: 100-150 μM). Brevinin-2RNa contains a single intra-disulphide bridge at the C-terminus that is active towards the tested Gram-positive bacteria but is not active against E. coli and P. aeruginosa. The cDNAs encoding three novel peptide precursors were also subsequently cloned from an R. nigromaculata skin cDNA library and sequenced. The precursors contain 58-72 amino acid residues, which include a conserved signal peptide, acidic propeptide, and the mature temporin-1RNa, temporin-1RNb and brevinin-2RNa. The CD spectra of temporin-1RNa and temporin-1RNb in water, 30 mM SDS and 50 % trifluoroethanol (TFE) indicated that both peptides adopted an aperiodic structure in water and an organised structure with an α-helical conformation in TFE and SDS solution. The conformational transition induced by TFE or SDS reflects the potential ability of temporin-1RNa and temporin-1RNb to interact with anionic membranes. © 2013 Springer Science+Business Media Dordrecht.

Shang D.,Liaoning Normal University | Shang D.,Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery | Sun Y.,Liaoning Normal University | Wang C.,Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery | And 3 more authors.
Journal of Applied Microbiology | Year: 2012

Aims: To understand the structure-activity relationship of chensinin-1, a anti-microbial peptide (AMP) with an unusual structure, and to develop novel AMPs as therapeutic agents. Methods and Results: A series of chensinin-1 analogues were designed and synthesized by one to three replacement of glycines with leucines at the hydrophilic face of chensinin-1 or rearrangement of some of the residues in its sequence. Circular dichroism spectroscopy showed that the analogues adopted α-helical-type conformations in 50% trifluoroethanol/water but adopted β-strand-type conformations in 30 mmol l-1 sodium dodecyl sulphate. The anti-microbial activities of the peptides against Gram-positive bacteria increased 5- to 30-fold, and these increases paralleled the increases in the peptides' hydrophobicities. Their haemolytic activities also increased. Amphipathicities had little influence on the bactericidal activity of chensinin-1. All peptides caused leakage of calcein entrapped in negatively charged liposomes although with different efficiencies. The peptides did not induce leakage of calcein from uncharged liposomes. Conclusions: Peptide adopted an aperiodic structure can improve the anti-microbial potency by increasing peptide hydrophobicity. Its target is bacteria plasma membrane. Significance and Impact of the Study: Chensinin-1 can act as a new lead molecule for the study of AMPs with atypical structures. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

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