BMB Reports : siRNA-mediated gene silencing of MexB from the MexA-MexB-OprM efflux pump in Pseudomonas aeruginosa

( Feng Yun Gong ),( Ding Yu Zhang ),( Jiang Guo Zhang ),( Li Li Wang ),( Wei Li Zhan ),( Jun Ying Qi ),( Jian Xin Song ) 생화학분자생물학회(구 한국생화학분자생물학회) 2014 BMB Reports Vol.47 No.4

To gain insights into the effect of MexB gene under the short interfering RNA (siRNA), we synthesized 21 bp siRNA duplexes against the MexB gene. RT-PCR was performed to determine whether the siRNA inhibited the expression of MexB mRNA. Changes in antibiotic susceptibility in response to siRNA were measured by the E-test method. The efficacy of siRNAs was determined in a murine model of chronic P. aeruginosa lung infection. MexB-siRNAs inhibited both mRNA expression and the activity of P. aeruginosa in vitro. In vivo, siRNA was effective in reducing the bacterial load in the model of chronic lung infection and the P. aeruginosa-induced pathological changes. MexB-siRNA treatment enhanced the production of inflammatory cytokines in the early infection stage (P < 0.05). Our results suggest that targeting of MexB with siRNA appears to be a novel strategy for treating P. aeruginosa infections. [BMB Reports 2014; 47(4): 203-208]

Human Recombinant Endostatin Combined with Cisplatin Based Doublets in Treating Patients with Advanced NSCLC and Evaluation by CT Perfusion Imaging

Zhang, Feng-Lin,Gao, Er-Yun,Shu, Rong-Bao,Wang, Hui,Zhang, Yan,Sun, Peng,Li, Min,Tang, Wei,Jiang, Bang-Qin,Chen, Shuang-Qi,Cui, Fang-Bo Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.15

Aims: To study the effectiveness of human recombinant endostatin injection (Endostar(R)) combined with cisplatin doublets in treating advanced non-small cell lung cancer (NSCLC), and to evaluate outcome by CT perfusion imaging. Methods: From April 2011 to September 2014, 76 patients with advanced NSCLC who were treated with platinum-based doublets were divided into group A (36 patients) and group B (40 patients). Endostar(R) 15mg/day was administered 4 days before chemotherapy and combined with chemotherapy from day 5 in group A, and combined with chemotherapy from the first day in Group B. Endostar(R) in the two groups was injected intravenously for 14 days. Results: Treatment effectiveness in the two groups differed with statistical significance (p<0.05). Effectiveness evaluated by CT perfusion imaging, BF, BV, MTT and PS also demonstrated significant differences (all p<0.05). Adverse reactions in the two groups did not significantly vary (p> 0.05). Conclusions: The response rate with Endostar(R) administered 4 days before chemotherapy and combined with chemotherapy from day 5 in group A was better than Endostar(R) combined with chemotherapy from the first day, and CT perfusion imaging could be a reasonable method for evaluation of patient outcomes.

Overexpression of NDRG2 Can Inhibit Neuroblastoma Cell Proliferation through Negative Regulation by CYR61

Zhang, Zhi-Guo,Li, Gang,Feng, Da-Yun,Zhang, Jian,Zhang, Jing,Qin, Huai-Zhou,Ma, Lian-Ting,Gao, Guo-Dong,Wu, Lin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

Several recent studies have showed that the n-myc downstream regulated gene 2 (NDRG2) is a new tumor suppressor gene, and that it plays an important role in tumor suppression in several cancers or cancer cell lines. However, few studies focused on its function in neuroblastoma cells. In the present investigation, we demonstrated that NDRG2 overexpression inhibited their proliferation. Using a cDNA microarray, we found that overexpression of NDRG2 inhibited the expression of cysteine-rich protein 61 (CYR61), a proliferation related gene. From our research, CYR61 may partially hinder NDRG2-mediated inhibition of cell proliferation. Overexpression of NDRG2 resulted in accumulation of cells in the G1 phase, which was accompanied by upregulation of p21 and p27 and downregulation of CDK4 and cyclin D1. Taken together, these data indicate that NDRG2 inhibits the proliferation of neuroblastoma cells partially through suppression of CYR61. Our findings offer novel insights into the physiological roles of NDRG2 in neuroblastoma cell proliferation, and NDRG2 may prove to be effective candidate for the treatment of children with neuroblastoma.

Inhibitory Effects of Phenolic Alkaloids of Menispermum Dauricum on Gastric Cancer in Vivo

Zhang, Hong-Feng,Wu, Di,Du, Jian-Kuo,Zhang, Yan,Su, Yun-Ming Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.24

The present study was conducted to investigate effects and mechanisms of action of phenolic alkaloids of Menispermum dauricum (PAMD) on gastric cancer in vivo. In vitro, cell apoptosis of human gastric cancer cell line SGC-7901 was observed using fluorescence staining. In vivo, a mice model was constructed to observe tumor growth with different doses. Cell apoptosis was examined using flow cytometry and K-RAS protein expression using Western blotting. The mRNA expression of P53, BCL-2, BAX, CASPASE-3, K-RAS was examined by real-time PCR. PAMD significantly suppressed tumor growth in the xenograft model of gastric cancer in a dose-dependent manner (p<0.01). Functionally, PAMD promoted cell apoptosis of the SGC-7901 cells and significantly increased the rate of cell apoptosis of gastric tumor cells (p<0.05). Mechanically, PAMD inhibited the expression of oncogenic K-RAS both at the mRNA and protein levels. In addition, PAMD affected the mRNA expression of the cell apoptosis-related genes (P53, BCL-2, BAX, CASPASE-3). PAMD could suppress gastric tumor growth in vivo, possibly through inhibiting oncogenic K-RAS, and induce cell apoptosis possibly by targeting the cell apoptosis-related genes of P53, BCL-2, BAX, CASPASE-3.

Effect of proton irradiation on interfacial and electrical performance of N+Np+ InP/InGaAs hetero-junction

Zhang Chen,Su Yongbo,Mei Bo,Yang Feng,Zhang Jialin,Yun Huanqing,Liu Bo,Sun Yi,Zhang Haiming,Jin Zhi,Zhong Yinghui 한국물리학회 2023 Current Applied Physics Vol.48 No.-

InP-based hetero-junction bipolar transistors (HBTs) are attractive for various millimeter-wave and terahertz electronics due to their ultrahigh frequency performance. Therefore, the study of their irradiation reliability is extremely urgent. In this work, 2 MeV proton irradiation experiment has been carried out on self-fabricated N+Np+ InP/InGaAs hetero-junction. The degradation mechanisms have systematically been studied after exposure to protons of 5 × 1013 H+/cm2. The voltage range of recombination current at low forward bias has been largely expanded from 0-0.2 V to 0–0.6 V. Furthermore, the interface states properties have been characterized by utilizing the frequency-dependent conductance technique, the interface states density (Dit) has increased from approximately 9.02 × 1012 cm-2 eV-1–1.99 × 1013 cm-2 eV-1 to 9.51 × 1012 cm-2 eV-1–2.00 × 1013 cm-2 eV-1 after irradiation. The study would be great significance for understanding the evolution of proton irradiation on relative devices.

A brain somatic RHEB doublet mutation causes focal cortical dysplasia type II

Shanshan Zhao,Zhenghui Li,Muxian Zhang,Lingliang Zhang,Honghua Zheng,Jinhuan Ning,Yanyan Wang,Feng-Peng Wang,Xiaobin Zhang,Hexia Gan,Yuanqing Wang,Xian Zhang,Hong Luo,Guojun Bu,Huaxi Xu,Yi Yao,Yun-wu 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

Focal cortical dysplasia type II (FCDII) is a cerebral cortex malformation characterized by local cortical structure disorganization, neuronal dysmorphology, and refractory epilepsy. Brain somatic mutations in several genes involved in the PI3K/AKT/mTOR pathway are associated with FCDII, but they are only found in a proportion of patients with FCDII. The genetic causes underlying the development FCDII in other patients remain unclear. Here, we carried out whole exome sequencing and targeted sequencing in paired brain–blood DNA from patients with FCDII and identified a brain somatic doublet mutation c.(A104T, C105A) in the Ras homolog, mTORC1 binding (RHEB) gene, which led to the RHEB p.Y35L mutation in one patient with FCDII. This RHEB mutation carrier had a dramatic increase of ribosomal protein S6 phosphorylation, indicating mTOR activation in the region of the brain lesion. The RHEB p.Y35L mutant protein had increased GTPλS-binding activity compared with wild-type RHEB. Overexpression of the RHEB p. Y35L variant in cultured cells also resulted in elevated S6 phosphorylation compared to wild-type RHEB. Importantly, in utero electroporation of the RHEB p.Y35L variant in mice induced S6 phosphorylation, cytomegalic neurons, dysregulated neuron migration, abnormal electroencephalogram, and seizures, all of which are found in patients with FCDII. Rapamycin treatment rescued abnormal electroencephalograms and alleviated seizures in these mice. These results demonstrate that brain somatic mutations in RHEB are also responsible for the pathogenesis of FCDII, indicating that aberrant activation of mTOR signaling is a primary driver and potential drug target for FCDII.

Dietary corn resistant starch regulates intestinal morphology and barrier functions by activating the Notch signaling pathway of broilers

Zhang Yingying,Liu Yingsen,Li Jiaolong,Xing Tong,Jiang Yun,Zhang Lin,Gao Feng 아세아·태평양축산학회 2020 Animal Bioscience Vol.33 No.12

Objective: This study was conducted to investigate the effects of dietary corn resistant starch (RS) on the intestinal morphology and barrier functions of broilers. Methods: A total of 320 one-day-old broilers were randomly allocated to 5 dietary treatments: one normal corn–soybean (NC) diet, one corn–soybean–based diet supplementation with 20% corn starch (CS), and 3 corn–soybean–based diets supplementation with 4%, 8%, and 12% corn resistant starch (RS) (identified as 4% RS, 8% RS, and 12% RS, respectively). Each group had eight replicates with eight broilers per replicate. After 21 days feeding, one bird with a body weight (BW) close to the average BW of their replicate was selected and slaughtered. The samples of duodenum, jejunum, ileum, caecum digesta, and blood were collected. Results: Birds fed 4% RS, 8% RS and 12% RS diets showed lower feed intake, BW gain, jejunal villus height (VH), duodenal crypt depth (CD), jejunal VH/CD ratio, duodenal goblet cell density as well as mucin1 mRNA expressions compared to the NC group, but showed higher concentrations of cecal acetic acid and butyric acid, percentage of jejunal proliferating cell nuclear antigen-positive cells and delta like canonical Notch ligand 4 (Dll4), and hes family bHLH transcription factor 1 mRNA expressions. However, there were no differences on the plasma diamine oxidase activity and D-lactic acid concentration among all groups. Conclusion: These findings suggested that RS could suppress intestinal morphology and barrier functions by activating Notch pathway and inhibiting the development of goblet cells, resulting in decreased mucins and tight junction mRNA expression.

Silver nanoparticles cause complications in pregnant mice

Zhang, Xi-Feng,Park, Jung-Hyun,Choi, Yun-Jung,Kang, Min-Hee,Gurunathan, Sangiliyandi,Kim, Jin-Hoi Dove Medical Press 2015 INTERNATIONAL JOURNAL OF NANOMEDICINE Vol.10 No.-

<P><B>Background</B></P><P>Silver nanoparticles (AgNPs) have attracted much interest and have been used for antibacterial, antifungal, anticancer, and antiangiogenic applications because of their unique properties. The increased usage of AgNPs leads to a potential hazard to human health. However, the potential effects of AgNPs on animal models are not clear. This study was designed to investigate the potential impact of AgNPs on pregnant mice.</P><P><B>Methods</B></P><P>The synthesis of AgNPs was performed using culture extracts of <I>Bacillus cereus</I>. The synthesized AgNPs were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy. AgNPs were administrated into pregnant mice via intravenous infusion at 1.0 mg/kg doses at 6.5 days postcoitum (dpc). At 13.5, 15.5, and 17.5 dpc, the pregnant mice were euthanized, and the embryo and placenta were isolated. The meiotic status of oocytes was evaluated. DNA methylation studies were performed, and aberrant imprinting disrupted fetal, placental, and postnatal development. Quantitative real-time polymerase chain reaction analysis and Western blot were used to analyze various gene expressions.</P><P><B>Results</B></P><P>The synthesized AgNPs were uniformly distributed and were spherical in shape with an average size of 8 nm. AgNPs exposure increased the meiotic progression of female germ cells in the fetal mouse ovaries, and maternal AgNP exposure significantly disrupted imprinted gene expression in 15.5 dpc embryos and placentas, such as <I>Ascl2</I>, <I>Snrpn</I>, <I>Kcnq1ot1</I>, <I>Peg3</I>, <I>Zac1</I>, <I>H19</I>, <I>Igf2r</I>, and <I>Igf2</I>; DNA methylation studies revealed that AgNPs exposure significantly altered the methylation levels of differentially methylated regions of <I>Zac1</I>.</P><P><B>Conclusion</B></P><P>The results from this study indicated that early exposure to AgNPs has the potential to disrupt fetal and postnatal health through epigenetic changes in the embryo and abnormal development of the placenta. These results can contribute to research involved in the safe use of various biomedical applications of AgNPs and improves the understanding of the development of AgNPs in biomedical applications.</P>

Transformerless Three-Level DC-DC Buck Converter with a High Step-Down Conversion Ratio

Yun Zhang,Xing-tao Sun,Yi-feng Wang,Hong-jun Shao 전력전자학회 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.1

For high power high step-down dc-dc conversion applications, conventional three-level dc-dc converters are subject to extreme duty cycles or increased volume and cost due to the use of transformers. In this paper, a transformerless three-level dc-dc buck converter with a high step-down conversion ratio is proposed. The converter comprises two asymmetrical half bridges, which are of the neutral point clamped structures. Therefore, the output pulse voltage of the converter can be obtained in terms of the voltage difference between the two half bridges. In order to realize harmonious switching of the converter, a modulation strategy with capacitor voltages self balance is presented. According to the deduced output dc voltage function, transformerless operation without extreme duty cycles can be implemented. Experimental results from a 1kW prototype verify the validity of the proposed converter. It is suitable for ship electric power distribution systems.

A TWO-PATH MECHANISM CUSTOMER-DRIVEN HOTEL EMPLOYEE SERVICE INNOVATIONS: THE ROLE OF ORGANIZATION OPENNESS

Feng Zeng Xu,Emily Ma,Yun Zhang 글로벌지식마케팅경영학회 2020 Global Marketing Conference Vol.2020 No.11