Screening and Anti-virulent Study of N-Acyl Homoserine Lactones DNA Aptamers against Pseudomonas aeruginosa Quorum Sensing

Zu-Guo Zhao,Yun Mei Yu,Bi Yu Xu,Shuang-Shuang Yan,Jun-Fa Xu,Fang Liu,Guo-Ming Li,Yuan Lin Ding,Shu Qing Wu 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.2

In Pseudomonas aeruginosa, a quorum sensing (QS) system regulates the expression of many virulence factors. N-acyl homoserine lactone (HSL) is the signal molecule of QS system. In order to find a novel HSL binder to interfere with QS signaling and to attenuate P. aeruginosa virulence, an amino lactam surrogate (ALS) of HSL was used as a target to screen HSL aptamers with the technique of systematic evolution of ligands by exponential enrichment (SELEX). Eight HSL aptamers with high affinities for 3O-C12-HSL (20 nM ≤ Kd < 35 nM) or C4-HSL (25 nM < Kd < 50 nM) were finally obtained. In vitro QS-inhibiting study of P. aeruginosa showed that HSL aptamers could inhibit virulence in a dose-dependent manner. ALSap-8 which bound C4-HSL primarily acted on the rhl system and inhibited the secretion of pyocyanin. ALSap-5 which bound 3O-C12-HSL not only showed strong inhibitory activity on biofilm formation as well as secretions of LasA protease and LasB elastase, but also reduced pyocyanin secretion. Since the las system is capable of activating the rhl system mildly, we speculated that ALSap-5 can simultaneously interfere with the las and rhl systems. High-affinity aptamers against HSL in this study are novel QS and virulence-inhibitors, and may have potential as drug candidates for the treatment of P. aeruginosa infection.

Study on molten salt oxidation process of simulated Co doped cation exchange resins

Yun Xue,Yue-Lin Wang,Yu Li,Wen-Da Xu,Fu-Qiu Ma,Yang-Hai Zheng,Qing-Guo Zhang,Zhi Zhang,Mi-lin Zhang,Yong-De Yan 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.126 No.-

Cation exchange resins (CERs) are widely applied to purify waste liquids generated during the operationof nuclear reactors. The radioactive nuclides 60Co and 58Co are important corrosion activation products inreactor cooling water. In this study, the simulated Co doped CERs were oxidized with ternary carbonate. According to the thermogravimetric analysis (TG), the decomposition of Co doped CERs includes threeprocesses: 1. Elimination of the osmotic water; 2. Pyrolysis of sulfonic acid group; 3. Destruction of styrene–divinylbenzene copolymer. The X-Ray Diffraction (XRD) patterns indicate that sulfur mainly exists inthe form of sulfate in waste salt. The Co2+ undergoes the path of CoS2 ? Co3O4 with the increase of temperatureand the transition point is 650 C. Combined with Fourier Transform Infrared Spectrometer (FTIR)spectra and X-ray Photoelectron Spectroscopy (XPS) analysis, sulfonic acid groups begin to decomposeat 350 C. During the molten salt oxidation process, most of the sulfur in sulfonic acid groups is entrappedby carbonate as the form of sulfate, and a little of which remains as sulfone group, sulfoxide group andsulfur bridge in residue. When the resins are oxidized at 800 C, the retention rate of Co2+ is 97.3%, indicatingthat the molten salt oxidation can effectively remain Co2+ and convert it into a more stablesubstance.

OsCML4 improves drought tolerance through scavenging of reactive oxygen species in rice

Xu Ming Yin,Li Fanng Huang,Xin Zhang,Man Ling Wang,Guo Yun Xu,Xin Jie Xia 한국식물학회 2015 Journal of Plant Biology Vol.58 No.1

Calmodulin-like (CML) genes function in regulating plant responses to different abiotic stresses, such as high salt and drought. Using japonica type rice seedlings (‘Nipponbare’), we induced the expression of OsCML4 (Accession No. NM_001057768), which encodes a rice CML protein. Under drought conditions, transgenic plants over-expressing that gene exhibited obviously improved growth performance and higher survival rates than the wild type (WT). Activity by reactive oxygen species (ROS)- scavenging enzymes superoxide dismutase (SOD) and catalase (CAT), as well as proline concentrations, were significantly increased in transgenic plants. Expression by ROS scavenging-related genes APXI and Cat-B and the stress-related gene OsP5CS1 was also enhanced in the transgenics under drought conditions. However, the sensitivity to abscisic acid (ABA) was similar between over-expressing and WT plants. These results suggest that OsCML4 confers drought tolerance partially through ROS-scavenging and also by inducing other stress-related genes in an ABAindependent manner.

An Aqueous Extract of Yunnan Baiyao Inhibits the Quorum-Sensing-Related Virulence of Pseudomonas aeruginosa

Zu-Guo Zhao,Shuang-Shuang Yan,Yun-Mei Yu,Na Mi,La-Xi Zhang,Jun Liu,Xiao-Ling Li,Fang Liu,Jun-Fa Xu,Wei-Qing Yang,Guo-Ming Li 한국미생물학회 2013 The journal of microbiology Vol.51 No.2

Yunnan Baiyao is a famous Chinese medicine that has long been directly applied to wounds to reduce bleeding, pain, and swelling without causing infection. However, little is known about its ability to prevent infection. The present study aimed to assess in vitro the anti-virulence activity of an aqueous extract of Yunnan Baiyao (YBX) using Pseudomonas aeruginosa as a pathogenic model. We found that a sub-MIC (2.5 mg/ml) of YBX can efficiently interfere with the quorum-sensing (QS) signaling circuit. Real-time polymerase chain reaction analysis showed that a sub-MIC of YBX downregulated the transcriptions of lasR, lasI, rhlR, and rhlI,which resulted in global attenuation of QS-regulated virulence activities, such as biofilm formation, and secretion of LasA protease, LasB elastase and pyocyanin. Further, YBX reduced the motility of P. aeruginosa related to QS, and impaired the formation of biofilms. These results suggest that YBX may possess global inhibitory activity against the virulence of P. aeruginosa and that YBX may also exhibit antimicrobial activity in vivo. The present study suggests that Yunnan Baiyao represents a potential source for isolating novel, safe, and efficacious antimicrobial agents.

Proteome analysis of chloroplast proteins in stage albinism Line of winter wheat (triticum aestivum) FA85

( Dain Yun Hou ),( Hong Xu ),( Guang Yuan Du ),( Jun Tang Lim ),( Min Duan ),( Ai Guang Guo ) 생화학분자생물학회 2009 BMB Reports Vol.42 No.7

Synthesis, Characterization, Luminescence and Biological Activity of Two Lanthanide Complexes Involving Mixed Ligands

De-Yun Ma,Hai-Fu Guo,Liang Qin,Jun Xu 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.9

Two new isostructural dinuclear complexes, Ln2(4-cpa)6(bpy)2 (Ln = Eu (1); Tb (2), 4-cpa = 4-chlorophenylacetate, bpy = 2,2'-bipyridine), have been hydrothermally synthesized and characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis (TGA), powder X-ray diffraction and single-crystal X-ray diffraction. The lanthanide ions are bridged by two bidentate and two terdentate carboxylate groups to give centrosymmetric dimers with Ln···Ln separations of 3.967(2) and 3.956(3) Å, respectively. Each metal atom is nine-coordinate and exhibits a distorted tricapped trigonal prismatic geometry. Three-dimensional fluorescence spectra show that both 1 and 2 emit bright red and green luminescence at room temperature, with long lifetimes of up to 0.369 ms (at 614 nm) and 0.432 ms (at 543 nm), respectively. Moreover, poor luminescence efficiency has been noted for complex 2. The 4-Hcpa ligand and complexes 1-2 have been screened for their phytogrowthinhibitory activities against Brassica napus L. and Echinochloa crusgalli L., and the results are compared with the activity of quizalofop-P-ethyl.

Robust H<SUB>∞</SUB> Control for Uncertain Two-Dimensional Discrete Systems Described by the General Model via Output Feedback Controllers

Huiling Xu,Yun Zou,Shengyuan Xu,Lei Guo 대한전기학회 2008 International Journal of Control, Automation, and Vol.6 No.5

This paper considers the problem of robust H∞ control for uncertain 2-D discrete systems in the General Model via output feedback controllers. The parameter uncertainty is assumed to be norm-bounded. The purpose is the design of output feedback controllers such that the closed-loop system is stable while satisfying a prescribed H∞ performance level. In terms of a linear matrix inequality, a sufficient condition for the solvability of the problem is obtained, and an explicit expression of desired output feedback controllers is given. An example is provided to demonstrate the application of the proposed method.

Corrosion inhibition properties of two imidazolium ionic liquids with hydrophilic tetrafluoroborate and hydrophobic hexafluorophosphate anions in acid medium

Yangyang Guo,Bin Xu,Ying Liu,Wenzhong Yang,Xiaoshuang Yin,Yun Chen,Jinxun Le,Zhihao Chen 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.56 No.-

The ionic liquids, 1-vinyl-3-aminopropylimidazolium hexafluorophosphate ([VAIM][PF6]) and 1-vinyl-3-aminopropylimidazolium tetrafluoroborate ([VAIM][BF4]) acted as the corrosion inhibitors. Weight lossmeasurements showed the corrosion inhibition efficiencies of [VAIM][PF6] and [VAIM][BF4] were 90.53%and 54.01% at 45 C, respectively. The ILs were mix-type inhibitors. Raising the temperature can have adecreased inhibition efficiency of [VAIM][BF4], while [VAIM][PF6] presented an opposite trend. Inaddition, [VAIM][PF6] obeyed Langmuir monolayer adsorption isotherm, while [VAIM][BF4] obeyed EIAwadykinetic-thermodynamic adsorption for blocking active sites. Moreover, Molecular DynamicSimulations showed that [VAIM][PF6] owned a higher adsorption energy, which may be responsible forthe more adsorption groups of [VAIM][PF6].

Electroacupuncture-Modulated MiR106b-5p Expression Enhances Autophagy by Targeting Beclin-1 to Promote Motor Function Recovery After Spinal Cord Injury in Rats

Shuhui Guo,Jianmin Chen,Ye Yang,Xiaolu Li,Yun Tang,Yuchang Gui,Jianquan Chen,Jianwen Xu 대한척추신경외과학회 2023 Neurospine Vol.20 No.3

Objective: Electroacupuncture (EA) has a definite effect on the treatment of spinal cord injuries (SCIs), but its underlying molecular mechanism remains unclear. Meanwhile, MiR-106b-5p is an autophagy- and apoptosis-related microribonucleic acid, but whether it regulates the progression of autophagy and apoptosis in SCIs is yet undetermined. As such, this study aimed to elucidate the involvement of miR-106b-5p in the EA treatment of an SCI. Methods: The miR-106b-5p level was detected by quantitative real-time polymerase chain reaction. In vitro, SH-SY5Y cells were transfected with miR-106b-5p mimics or inhibitors to regulate the miR-106b-5p expression, while in vivo, SCI rats were treated with EA for 7 days at the bilateral Zusanli (ST36) and Jiaji (EX-B2) acupoints. The motor function was evaluated using the Basso-Beattie-Bresnahan (BBB) criteria. Further, autophagic vacuoles, pathological damage, and neuronal cell morphology were observed by transmission electron microscopy, as well as by hematoxylin and eosin and Nissl staining, respectively. Results: The miR-106b-5p level, which can interact directly with Beclin-1 by influencing its expression, as well as the expressions of P62, Caspase-3, and Bax, was upregulated after an SCI, but it decreased after EA. Moreover, the ratio of LC3-II to LC3-I was upregulated after EA. EA can enhance autophagy, reduce neuronal apoptosis, and minimize motor dysfunction and histopathological deficits after an SCI. More importantly, however, all the above effects induced by EA can be reversed after an injection of miR-106-5p agomir to produce an overexpression of miR-106b-5p. Conclusion: EA treatment could downregulate miR-106b-5p to alleviate SCI-mediated injuries by promoting autophagy and inhibiting apoptosis.

Neurotrophin-4 induces myelin protein zero expression in cultured Schwann cells via the TrkB/PI3K/Akt/mTORC1 pathway

Wei Guo,Yan Li,Chao Sun,Hui-Quan Duan,Shen Liu,Shi-Qing Feng,Yun-Qiang Xu 한국통합생물학회 2017 Animal cells and systems Vol.21 No.2

Myelin formation during peripheral nervous system development, as well as myelin repair after injury and in disease, requires multiple intrinsic and extrinsic signals. Neurotrophin-4 (NT-4) is a member of the neurotrophin family, which regulates the development of neuronal networks by participating in the growth of neuronal processes, synaptic development and plasticity, neuronal survival, and differentiation. However, the intracellular signaling pathways by which NT-4 participates in myelination by Schwann cells remain elusive. In this study, we examined the effects of NT-4 on the expression of compact myelin proteins in cultured Schwann cells. Using real-time quantitative RT-PCR and western blotting, we found that NT-4 could significantly enhance the expression of myelin protein zero (MPZ) but not the expression of myelin basic protein or peripheral myelin protein 22. Further, knockdown of truncated TrkB with small interfering RNA could eliminate the effect of NT-4 on MPZ expression. Moreover, we demonstrated that the NT-4-enhanced MPZ expression depended on Akt and mTORC1 signaling. Taken together, these results suggest that NT-4 binds TrkB to enhance the expression of MPZ in Schwann cells, probably through the PI3K/Akt/mTORC1 signaling pathway, thus contributing to myelination.